WorldWideScience

Sample records for combined cycle demonstration

  1. INTEGRATED GASIFICATION COMBINED CYCLE PROJECT 2 MW FUEL CELL DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    FuelCell Energy

    2005-05-16

    With about 50% of power generation in the United States derived from coal and projections indicating that coal will continue to be the primary fuel for power generation in the next two decades, the Department of Energy (DOE) Clean Coal Technology Demonstration Program (CCTDP) has been conducted since 1985 to develop innovative, environmentally friendly processes for the world energy market place. The 2 MW Fuel Cell Demonstration was part of the Kentucky Pioneer Energy (KPE) Integrated Gasification Combined Cycle (IGCC) project selected by DOE under Round Five of the Clean Coal Technology Demonstration Program. The participant in the CCTDP V Project was Kentucky Pioneer Energy for the IGCC plant. FuelCell Energy, Inc. (FCE), under subcontract to KPE, was responsible for the design, construction and operation of the 2 MW fuel cell power plant. Duke Fluor Daniel provided engineering design and procurement support for the balance-of-plant skids. Colt Engineering Corporation provided engineering design, fabrication and procurement of the syngas processing skids. Jacobs Applied Technology provided the fabrication of the fuel cell module vessels. Wabash River Energy Ltd (WREL) provided the test site. The 2 MW fuel cell power plant utilizes FuelCell Energy's Direct Fuel Cell (DFC) technology, which is based on the internally reforming carbonate fuel cell. This plant is capable of operating on coal-derived syngas as well as natural gas. Prior testing (1992) of a subscale 20 kW carbonate fuel cell stack at the Louisiana Gasification Technology Inc. (LGTI) site using the Dow/Destec gasification plant indicated that operation on coal derived gas provided normal performance and stable operation. Duke Fluor Daniel and FuelCell Energy developed a commercial plant design for the 2 MW fuel cell. The plant was designed to be modular, factory assembled and truck shippable to the site. Five balance-of-plant skids incorporating fuel processing, anode gas oxidation, heat recovery

  2. Environmental Assessment for the Warren Station externally fired combined cycle demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    The proposed Penelec project is one of 5 projects for potential funding under the fifth solicitation under the Clean Coal Technology program. In Penelec, two existing boilers would be replaced at Warren Station, PA; the new unit would produce 73 MW(e) in a combined cycle mode (using both gas-fired and steam turbines). The project would fill the need for a full utility-size demonstration of externally fire combined cycle (EFCC) technology as the next step toward commercialization. This environmental assessment was prepared for compliance with NEPA; its purpose is to provide sufficient basis for determining whether to prepare an environmental impact statement or to issue a finding of no significant impact. It is divided into the sections: purpose and need for proposed action; alternatives; brief description of affected environment; environmental consequences, including discussion of commercial operation beyond the demonstration period.

  3. Integrated Gasification Combined Cycle (IGCC) demonstration project, Polk Power Station -- Unit No. 1. Annual report, October 1993--September 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This describes the Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project which will use a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,300 tons per day of coal (dry basis) coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 Btu/scf (LHV). The syngas then flows through a high temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product.

  4. Highlights from a Mach 4 Experimental Demonstration of Inlet Mode Transition for Turbine-Based Combined Cycle Hypersonic Propulsion

    Science.gov (United States)

    Foster, Lancert E.; Saunders, John D., Jr.; Sanders, Bobby W.; Weir, Lois J.

    2012-01-01

    NASA is focused on technologies for combined cycle, air-breathing propulsion systems to enable reusable launch systems for access to space. Turbine Based Combined Cycle (TBCC) propulsion systems offer specific impulse (Isp) improvements over rocket-based propulsion systems in the subsonic takeoff and return mission segments along with improved safety. Among the most critical TBCC enabling technologies are: 1) mode transition from the low speed propulsion system to the high speed propulsion system, 2) high Mach turbine engine development and 3) innovative turbine based combined cycle integration. To address these challenges, NASA initiated an experimental mode transition task including analytical methods to assess the state-of-the-art of propulsion system performance and design codes. One effort has been the Combined-Cycle Engine Large Scale Inlet Mode Transition Experiment (CCE-LIMX) which is a fully integrated TBCC propulsion system with flowpath sizing consistent with previous NASA and DoD proposed Hypersonic experimental flight test plans. This experiment was tested in the NASA GRC 10 by 10-Foot Supersonic Wind Tunnel (SWT) Facility. The goal of this activity is to address key hypersonic combined-cycle engine issues including: (1) dual integrated inlet operability and performance issues-unstart constraints, distortion constraints, bleed requirements, and controls, (2) mode-transition sequence elements caused by switching between the turbine and the ramjet/scramjet flowpaths (imposed variable geometry requirements), and (3) turbine engine transients (and associated time scales) during transition. Testing of the initial inlet and dynamic characterization phases were completed and smooth mode transition was demonstrated. A database focused on a Mach 4 transition speed with limited off-design elements was developed and will serve to guide future TBCC system studies and to validate higher level analyses.

  5. The U.S. Department of Energy`s integrated gasification combined cycle research, development and demonstration program

    Energy Technology Data Exchange (ETDEWEB)

    Brdar, R.D.; Cicero, D.C.

    1996-07-01

    Historically, coal has played a major role as a fuel source for power generation both domestically and abroad. Despite increasingly stringent environmental constraints and affordable natural gas, coal will remain one of the primary fuels for producing electricity. This is due to its abundance throughout the world, low price, ease of transport an export, decreasing capital cost for coal-based systems, and the need to maintain fuel diversity. Recognizing the role coal will continue to play, the US Department of Energy (DOE) is working in partnership with industry to develop ways to use this abundant fuel resource in a manner that is more economical, more efficient and environmentally superior to conventional means to burn coal. The most promising of these technologies is integrated gasification combined cycle (IGCC) systems. Although IGCC systems offer many advantages, there are still several hurdles that must be overcome before the technology achieves widespread commercial acceptance. The major hurdles to commercialization include reducing capital and operating costs, reducing technical risk, demonstrating environmental and technical performance at commercial scale, and demonstrating system reliability and operability. Overcoming these hurdles, as well as continued progress in improving system efficiency, are the goals of the DOE IGCC research, development and demonstrate (RD and D) program. This paper provides an overview of this integrated RD and D program and describes fundamental areas of technology development, key research projects and their related demonstration scale activities.

  6. A rocket-based combined-cycle engine prototype demonstrating comprehensive component compatibility and effective mode transition

    Science.gov (United States)

    Shi, Lei; He, Guoqiang; Liu, Peijin; Qin, Fei; Wei, Xianggeng; Liu, Jie; Wu, Lele

    2016-11-01

    A rocket-based combined cycle (RBCC) engine was designed to demonstrate its broad applicability in the ejector and ramjet modes within the flight range from Mach 0 to Mach 4.5. To validate the design, a prototype was fabricated and tested as a freejet engine operating at flight Mach 3 using hydrocarbon fuel. The proposed design was a single module, heat sink steel alloy model with an interior fuel supply and active control system and a fully integrated flowpath that was comprehensively instrumented with pressure sensors. The mass capture and back pressure resistance of the inlet were numerically investigated and experimentally calibrated. The combustion process and rocket operation during mode transition were investigated by direct-connect tests. Finally, the comprehensive component compatibility and multimodal operational capability of the RBCC engine prototype was validated through freejet tests. This paper describes the design of the RBCC engine prototype, reviews the testing procedures, and discusses the experimental results of these efforts in detail.

  7. Biomass Gasification Combined Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Judith A. Kieffer

    2000-07-01

    Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

  8. H gas turbine combined cycle

    Energy Technology Data Exchange (ETDEWEB)

    Corman, J. [General Electric Co., Schenectady, NY (United States)

    1995-10-01

    A major step has been taken in the development of the Next Power Generation System - {open_quotes}H{close_quotes} Technology Combined Cycle. This new gas turbine combined-cycle system increases thermal performance to the 60% level by increasing gas turbine operating temperature to 1430 C (2600 F) at a pressure ratio of 23 to 1. Although this represents a significant increase in operating temperature for the gas turbine, the potential for single digit NOx levels (based upon 15% O{sub 2}, in the exhaust) has been retained. The combined effect of performance increase and environmental control is achieved by an innovative closed loop steam cooling system which tightly integrates the gas turbine and steam turbine cycles. The {open_quotes}H{close_quotes} Gas Turbine Combined Cycle System meets the goals and objectives of the DOE Advanced Turbine System Program. The development and demonstration of this new system is being carried out as part of the Industrial/Government cooperative agreement under the ATS Program. This program will achieve first commercial operation of this new system before the end of the century.

  9. Integrated coal gasification combined cycle

    Science.gov (United States)

    Richards, P. C.; Wijffels, J.-B.; Zuideveld, P. L.

    Features of the integrated coal gasification combined cycle power plants are described against the backdrop of the development and first commercial application of the shell coal gasification process. Focus is on the efficiency and excellent environmental performance of the integrated coal gasification combined power plants. Current IGCC projects are given together with an outline of some of the options for integrating coal gasification with combined cycles and also other applications of synthesis gas.

  10. Airbreathing combined cycle engine systems

    Science.gov (United States)

    Rohde, John

    1992-01-01

    The Air Force and NASA share a common interest in developing advanced propulsion systems for commercial and military aerospace vehicles which require efficient acceleration and cruise operation in the Mach 4 to 6 flight regime. The principle engine of interest is the turboramjet; however, other combined cycles such as the turboscramjet, air turborocket, supercharged ejector ramjet, ejector ramjet, and air liquefaction based propulsion are also of interest. Over the past months careful planning and program implementation have resulted in a number of development efforts that will lead to a broad technology base for those combined cycle propulsion systems. Individual development programs are underway in thermal management, controls materials, endothermic hydrocarbon fuels, air intake systems, nozzle exhaust systems, gas turbines and ramjet ramburners.

  11. Combined cycles with gas turbine engines

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, Y.S.H.; Akyurt, M. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Mechanical Engineering Dept.)

    1994-03-01

    Simple cycle gas turbine engines suffer from limited efficiencies and consequential dominance of fuel prices on generation costs. Combined cycles, however. exploit the waste heat from exhaust gases to boost power output, resulting in overall efficiencies around 50%, which are significantly above those of steam power plants. This paper reviews various types of combined cycles, including repowering, integrated gasification and other advanced systems. (author)

  12. FUEL CELL/MICRO-TURBINE COMBINED CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Larry J. Chaney; Mike R. Tharp; Tom W. Wolf; Tim A. Fuller; Joe J. Hartvigson

    1999-12-01

    A wide variety of conceptual design studies have been conducted that describe ultra-high efficiency fossil power plant cycles. The most promising of these ultra-high efficiency cycles incorporate high temperature fuel cells with a gas turbine. Combining fuel cells with a gas turbine increases overall cycle efficiency while reducing per kilowatt emissions. This study has demonstrated that the unique approach taken to combining a fuel cell and gas turbine has both technical and economic merit. The approach used in this study eliminates most of the gas turbine integration problems associated with hybrid fuel cell turbine systems. By using a micro-turbine, and a non-pressurized fuel cell the total system size (kW) and complexity has been reduced substantially from those presented in other studies, while maintaining over 70% efficiency. The reduced system size can be particularly attractive in the deregulated electrical generation/distribution environment where the market may not demand multi-megawatt central stations systems. The small size also opens up the niche markets to this high efficiency, low emission electrical generation option.

  13. Gasification combined cycle power generation - process alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Korhonen, M.

    1988-01-01

    Interest in Integrated Gasification Combined Cycle (IGCC) power plants has recently increased also in Finland. The IGCC systems offer the potential of superior efficiency and environmental performance over conventional pulverized coal or peat fired boilers. Potential applications are both large-scale electricity production from coal and medium-scale combined heat and electricity production. In the latter case, the gasification process should also be applicable to peat and wood. Several IGCC processes have been developed in USA and in Europe. These processes differ from each other in many respects. Nearest to commercialization are processes, which employ oxygen gasification and cold gas cleanup. The Cool Water plant, which was brought into operation in 1984 in USA, has demonstrated the feasibility of an IGCC system using Texaco entrained-bed gasifier. Several pressurized fluidized-bed and fixed-bed gasification processes have also reached a pilot or demonstration stage with a wide variety of coals from lignite to hard coal. Pressurized fluidized-bed gasification of peat (Rheinbraun-HTW-process) will also be demonstrated at the peat ammonia plant of Kemira Oy, which will be commissioned in 1988 in Oulu, Finland. Oxygen gasification and cold gas cleanup are, however, economically viable only in large-scale applications. Technology is being developed to simplify the IGCC system, in order to reduce its capital costs and increase its efficiency. Air gasification combined with ho gas cleanup seems to have a great potential of improving the competitiveness of the IGCC system.

  14. LIFE-CYCLE IMPACT ASSESSMENT DEMONSTRATION FOR THE BGU-24

    Science.gov (United States)

    The primary goal of this project was to develop and demonstrate a life-cycle impact assessment (LCIA) approach using existing life-cycle inventory (LCI) data on one of the propellants, energetics, and pyrotechnic (PEP) materials of interest to the U.S. Department of Defense (DoD)...

  15. LIFE-CYCLE IMPACT ASSESSMENT DEMONSTRATION FOR THE GBU-24

    Science.gov (United States)

    The primary goal of this project was to develop and demonstrate a life-cycle impact assessment (LCIA) approach using existing life-cycle inventory (LCI) data on one of the propellants, energetics, and pyro-technic (PEP) materials of interest to the U.S. Department of Defense (DoD...

  16. Thermodynamic Analysis of Combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    A.K.Tiwari,

    2010-04-01

    Full Text Available Air Bottoming Cycle (ABC can replace the heat recovery steam generator and the steam turbine of the conventionalcombined cycle plant. The exhaust energy of the topping gas turbine of existing combine cycle is sent to gas-air heat exchange, which heats the air in the secondary gas turbine cycle. In 1980’s the ABC was proposed as an alternative for the conventional steam bottoming cycle. In spite of the cost of reducing hardware installations it could achieve a thermal efficiency of 80%. The complete thermodynamic analysis of the system has been performed by using specially designed programme, enabling the variation of main independent variables. The result shows the gain in net work output as well as efficiency of combined cycle is 35% to 68%.

  17. A combined cycle engine test facility

    Energy Technology Data Exchange (ETDEWEB)

    Engers, R.; Cresci, D.; Tsai, C. [General Applied Science Laboratories Inc., Ronkonkoma, NY (United States)

    1995-09-01

    Rocket-Based Combined-Cycle (RBCC) engines intended for missiles and/or space launch applications incorporate features of rocket propulsion systems operating in concert with airbreathing engine cycles. Performance evaluation of these types of engines, which are intended to operate from static sea level take-off to supersonic cruise or accerlerate to orbit, requires ground test capabilities which integrate rocket component testing with airbreathing engine testing. A combined cycle engine test facility has been constructed in the General Applied Science Laboratories, Inc. (GASL) Aeropropulsion Test Laboratory to meet this requirement. The facility was designed to support the development of an innovative combined cycle engine concept which features a rocket based ramjet combustor. The test requirements included the ability to conduct tests in which the propulsive force was generated by rocket only, the ramjet only and simultaneous rocket and ramjet power (combined cycle) to evaluate combustor operation over the entire engine cycle. The test facility provides simulation over the flight Mach number range of 0 to 8 and at various trajectories. The capabilities of the combined cycle engine test facility are presented.

  18. Combined rankine and vapor compression cycles

    Science.gov (United States)

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  19. Status of the Combined Cycle Engine Rig

    Science.gov (United States)

    Saunders, Dave; Slater, John; Dippold, Vance

    2009-01-01

    Status for the past year is provided of the turbine-based Combined-Cycle Engine (CCE) Rig for the hypersonic project. As part of the first stage propulsion of a two-stage-to-orbit vehicle concept, this engine rig is designed with a common inlet that supplies flow to a turbine engine and a dual-mode ramjet / scramjet engine in an over/under configuration. At Mach 4 the inlet has variable geometry to switch the airflow from the turbine to the ramjet / scramjet engine. This process is known as inlet mode-transition. In addition to investigating inlet aspects of mode transition, the rig will allow testing of turbine and scramjet systems later in the test series. Fully closing the splitter cowl "cocoons" the turbine engine and increases airflow to the scramjet duct. The CCE Rig will be a testbed to investigate integrated propulsion system and controls technology objectives. Four phases of testing are planned to 1) characterize the dual inlet database, 2) collect inlet dynamics using system identification techniques, 3) implement an inlet control to demonstrate mode-transition scenarios and 4) demonstrate integrated inlet/turbine engine operation through mode-transition. Status of the test planning and preparation activities is summarized with background on the inlet design and small-scale testing, analytical CFD predictions and some details of the large-scale hardware. The final stages of fabrication are underway.

  20. Maximisation of Combined Cycle Power Plant Efficiency

    Directory of Open Access Journals (Sweden)

    Janusz Kotowicz

    2015-12-01

    Full Text Available The paper presents concepts for increasing the efficiency of a modern combined cycle power plant. Improvement of gas turbine performance indicators as well as recovering heat from the air cooling the gas turbine’s flow system enable reaching gross electrical efficiencies of around 65%. Analyses for a wide range of compressor pressure ratios were performed. Operating characteristics were developed for the analysed combined cycle plant, for different types of open air cooling arrangements of the gas turbine’s expander: convective, transpiration and film.

  1. Chasing megawatts in combined cycle plants

    Energy Technology Data Exchange (ETDEWEB)

    Koch, J. [Power Plant Performance Specialist, Lansdowne, PA (United States); DeGeeter, S. [Ocean State Power, Harrisville, RI (United States); Haynes, C.J. [New England Power Co., Somerset, MA (United States)

    1996-05-01

    Combined cycle owners do not have to accept that combined cycle performance must degrade over time. Through low cost testing using existing instrumentation, a method is presented to identify causes for lost generation. A 500 MW combined cycle plant, with two STAG 207EA units, had lost 17 MW since initial operation, and found that: Gas side fouling on A four HRSG`s accounted for 8 MW of the total loss LP steam turbine efficiency was below design on one unit, contributing 3 MW Condenser air removal was poor on both units, a loss of an additional 2 MW Compressor and turbine section efficiency losses on 2 of 4 GT`s cost over 4 MW The test also revealed that the other two GT`s, both cooling towers, and one of the two steam turbines, were performing at or near design. Thus far 3 MW has been recovered, with planning underway for recovery of another 3 MW. The remaining 11 MW, though not immediately recoverable, will be the focus of planning for the next major outage. This simple method can be used at any combined cycle using existing instrumentation, with minimal intrusion on daily operations. The use of redundant measurements and uncertainty analysis assures valid and useful results.

  2. Air bottoming cycle, an alternative to combined cycles. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kaikko, J. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

    2002-02-01

    In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

  3. Air bottoming cycle, an alternative to combined cycles. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kaikko, J. [Royal Inst. of Techn., Stockholm (Sweden). Dept. of Energy Technology

    2001-10-01

    In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

  4. Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

    2010-07-01

    Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

  5. Center for Hypersonic Combined Cycle Flow Physics

    Science.gov (United States)

    2015-03-24

    team of expert experimentalists and numerical and chemical kinetic modelers. Flowfields were examined in the turbine /ramjet dual inlet mode transition...at the University of Virginia for extensive data acquisition using various techniques, including OH PLIF, CARS , TDLAS, TDLAT and SPIV. It was...SUBJECT TERMS Hypersonic combined cycle propulsion, turbine /ram dual-inlet transition, ram/scram dual-mode transition, hypervelocity regime, RANS, Hybrid

  6. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    Energy Technology Data Exchange (ETDEWEB)

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  7. Biomass integrated CFB gasification combined cycle plants

    Energy Technology Data Exchange (ETDEWEB)

    Greil, C.; Hirschfelder, H. (Lurgi Umwelt GmbH, Frankfurt am Main (Germany))

    1998-01-01

    This paper presents an overview on the Lurgi-Circulating Fluidized Bed technology (CFB). CFB units are state of the art and have proven their capability of converting biomass, waste or coal into power and/or steam. CFB reactors are in commercial operation for reduction processes and for combustion and gasification of solid fuels. In this paper reduction processes are not considered. The fact, that world-wide over 80 CFB combustion plants using Lurgi technology are commercially operating proves that this technology is well accepted. Lurgi's CFB gasification technology is at present applied in two industrial plants. It is the key process for the advanced biomass or waste utilisation plants. The paper focuses on CFB fuel gas production for combined cycle plants (IGCC) and for cofiring into existing boiler plants. 5 refs., 4 figs.

  8. Biomass integrated CFB gasification combined cycle plants

    Energy Technology Data Exchange (ETDEWEB)

    Greil, C.; Hirschfelder, H. [Lurgi Umwelt GmbH, Frankfurt am Main (Germany)

    1998-12-31

    This paper presents an overview on the Lurgi-Circulating Fluidized Bed technology (CFB). CFB units are state of the art and have proven their capability of converting biomass, waste or coal into power and/or steam. CFB reactors are in commercial operation for reduction processes and for combustion and gasification of solid fuels. In this paper reduction processes are not considered. The fact, that world-wide over 80 CFB combustion plants using Lurgi technology are commercially operating proves that this technology is well accepted. Lurgi`s CFB gasification technology is at present applied in two industrial plants. It is the key process for the advanced biomass or waste utilisation plants. The paper focuses on CFB fuel gas production for combined cycle plants (IGCC) and for cofiring into existing boiler plants. 5 refs., 4 figs.

  9. Glassy carbon supercapacitor: 100,000 cycles demonstrated

    Energy Technology Data Exchange (ETDEWEB)

    Baertsch, M.; Braun, A.; Schnyder, B.; Koetz, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A 5 V glassy carbon capacitor stack was built consisting of four bipolar and two end-plate electrodes. More than 100,000 charging/discharging cycles were applied to test the stability of the double-layer capacitor. Low and high frequency resistances were measured as a function of the number of cycles. (author) 2 figs., 1 ref.

  10. Combination ultracapacitor-battery performance dependence on drive cycle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John M.; Deshpande, Uday [Maxwell Technologies, Inc., San Diego, CA (United States); Dougherty, Thomas J. [Monolith Engines, Inc., Waukesha, WI (United States); Bohn, Thedore P. [Argonne National Lab. (United States)

    2009-07-01

    Automotive performance and economy assessments are generally made using the UDDS, urban dynamometer drive schedule, to quantify vehicle attributes against a cycle representative of how individuals actually drive. But how does selection of drive cycle influence the sizing and efficiency of the ESS, energy storage system? In this paper three representative driving schedules are used to evaluate the energy storage system current demanded of the ultracapacitors in combination with the lithium-ion battery, but a simpler, more generic electric vehicle drive cycle is used to make the comparisons. The drive cycle current demand is then imposed on the hybridized battery to identify via multi-attribute characterization the trade-offs between ultracapacitor useable energy, voltage window and power electronic converter input current requirement. A value proposition is made that demonstrates that today, using the Maxwell Technologies dry electrode processing technique, Thi{sub c}kFLEX trademark, that energy optimized lithium-ion battery can be realized having substantial cost savings over conventional processing. This cost save in turn becomes the budget for the ultracapacitors and dc-dc converter used to decouple power and energy in the combination energy storage system. Our finding is the Maxwell electrode process enables the cost savings on lithium-ion needed to realize the combined ultracapacitor plus lithium-ion performance goals. (orig.)

  11. An insight on reheat gas turbine for combined cycles

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Marco A.C.; Carneiro, Helder F.F.M.; Barbosa, Joao R. [Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica. Dept. de Energia]. E-mail: marco@asap.iae.cta.br; helder@asap.iae.cta.br; barbosa@mec.ita.cta.br; Travieso, Luis E. [Universidad de la Republica, Montevideo (Uruguay)]. E-mail: travisan@adinet.com.uy; Pilidis, Pericles [Cranfield University, Beds (United Kingdom)]. E-mail: p.pilidis@cranfield.ac.uk

    2000-07-01

    The design point performance of reheat gas turbines for combined cycle is investigated in this work. A comparison of reheat and simple cycle results is used to draw the main conclusions. Some conclusions available in the literature were confirmed; such as the fact that reheat increases the specific power and reduces the efficiency of the gas turbines. The latter is mainly a consequence of the increase of the amount of energy (heat) lost in the exhaust, represented by an increase in turbine exhaust temperature. Thus, the reheat cycle gas turbine can be considered well suitable to combined cycle. In this case the reheat combined cycle efficiency increases, compared to simple cycle, in spite of the reduction in efficiency of the gas turbine reheat cycle, with the advantage of a significant increase in specific power. (author)

  12. Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Combined cycle performance

    DEFF Research Database (Denmark)

    Haglind, Fredrik

    2011-01-01

    -derivative configuration and a single-shaft industrial configuration. The results suggest that by the use of variable geometry gas turbines, the combined cycle part-load performance can be improved. In order to minimise the voyage fuel consumption, a combined cycle featuring two-shaft gas turbines with VAN control...

  13. Construction Cost Analysis : Residential Construction Demonstration Project Cycle II.

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, Cole; Thor, Philip W.

    1990-06-01

    The Residential Construction Demonstration Project (RCDP) is designed to demonstrate new residential building techniques and product innovations which advance the stage-of-the-art in constructing energy-efficient electrically heated residences. A secondary purpose is to obtain documented cost and energy savings data from which to make accurate assessments of the cost-effectiveness of various conservation innovations. The project solicits participation of regional homebuilders by offering them financial incentives for constructing homes to the Model Conservation Standards (MCS) and including at least one innovation.'' The innovations are determined by BPA and the States prior to construction and represent construction techniques or energy saving products that might reduce the cost of building MCS homes, or expand the options available to builders in achieving MCS levels of energy efficiency in homes. Besides covering some of the additional risk for employing the innovation, the incentive payment guarantees that builders will provide certain amounts of information regarding the cost and acceptability of building the homes. In addition, an incentive is paid to homeowners for their participation in data collection efforts following construction. Several one-time'' tests were performed on the houses and homeowners were required to report energy consumption and temperature data on a weekly basis for approximately 18 months. BPA and the States compile the information obtained from the builders and homeowners. Access to this data is provided for the purpose of analyzing the cost and performance of the RCDP homes, as well as understanding the value of the various innovations that are tested. 25 tabs., 4 figs.

  14. [Combined hormonal contraception in cycles artificially extended].

    Science.gov (United States)

    Bustillos-Alamilla, Edgardo; Zepeda-Zaragoza, J; Hernández-Ruiz, M A; Briones-Landa, Carlos Humberto

    2010-01-01

    To compare the bleeding patterns, satisfaction and tolerability of 3 different contraceptive in an extended regimens in the service of Family Planning of the North Central Hospital of PEMEX. Healthy, adult women with desire of contraception for one year (N 120) were randomly assigned to receive oral contraceptive drospirenone/ethinyl E2 (group1), the norelgestromin/ethinyl E2 transdermal patch (group 2) and vaginal ring etonogestrel/ ethinyl E2 (group 3) in an extended regimen (42 consecutive days, 1 hormone-free week). Study assessments were conducted at scheduled visits at the time of initial screening, at baseline after 1, 3, 6, and 12 months. Subjects recorded menstrual associated symptoms bleeding data and completed satisfaction questionnaires. Subjects and investigators provided overall assessments of the regimens. Extended use of 3 different contraceptive resulted in fewer bleeding days in every group (66.6%, 55% and 58.3% P 0.0024), and less mastalgia and menstrual pain. Subjects were highly satisfied with three regimens (93.3%, 96.6% and 91.6% P 0.00421). Although not mayor adverse events were reported with this regimen, there was an increase in spotting days; it decreased with each successive cycle of therapy. Efficacy and safety were similar to those reported for traditional cycle. Extended-contraceptive regimen delays menses and reduces bleeding, a profile that may be preferred by women who seek flexibility with their contraceptive method.

  15. Gas--steam turbine combined cycle power plants

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1978-10-01

    The purpose of this technology evaluation is to provide performance and cost characteristics of the combined gas and steam turbine, cycle system applied to an Integrated Community Energy System (ICES). To date, most of the applications of combined cycles have been for electric power generation only. The basic gas--steam turbine combined cycle consists of: (1) a gas turbine-generator set, (2) a waste-heat recovery boiler in the gas turbine exhaust stream designed to produce steam, and (3) a steam turbine acting as a bottoming cycle. Because modification of the standard steam portion of the combined cycle would be necessary to recover waste heat at a useful temperature (> 212/sup 0/F), some sacrifice in the potential conversion efficiency is necessary at this temperature. The total energy efficiency ((electric power + recovered waste heat) divided by input fuel energy) varies from about 65 to 73% at full load to 34 to 49% at 20% rated electric power output. Two major factors that must be considered when installing a gas--steam turbine combines cycle are: the realiability of the gas turbine portion of the cycle, and the availability of liquid and gas fuels or the feasibility of hooking up with a coal gasification/liquefaction process.

  16. INVESTIGATION OF DIFFERENT MODELS OF COMBINED PARALLEL FLASH BINARY CYCLES

    OpenAIRE

    A. Jafar Yazdi*

    2017-01-01

    The aim of this paper is a comparative study of the different geothermal power plant concepts, based on the energy and exergy analysis. The cycles studied in this paper are the combination of single and double flash power plants with two different ORC cycles as basic Organic Rankine Cycle (ORC), ORC with IHE, regenerative ORC and regenerative ORC with an IHE. The main gain due to using combined flash-binary power plants with various types of ORCs is to achieve optimum and efficient energy uti...

  17. Hybrid Combined Cycles with Biomass and Waste Fired Bottoming Cycle - a Literature Study

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Miroslav P.

    2002-02-01

    Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are very flexible and reliable. Their potential for high electric efficiency in condensing mode, high total efficiency in combined heat and power mode and unrivalled load flexibility is explored in this project. The present report is a literature study that concentrates on certain biomass utilization technologies, in particular the design and performance of hybrid combined cycle power units of various configurations, with gas turbines and internal combustion engines as topping cycles. An overview of published literature and general development trends on the relevant topic is presented. The study is extended to encompass a short overview of biomass utilization as an energy source (focusing on Sweden), history of combined cycles development with reference especially to combined cycles with supplementary firing and coal-fired hybrid combined cycles, repowering of old steam units into hybrid ones and combined cycles for internal combustion engines. The hybrid combined cycle concept for municipal solid waste

  18. Exergy analysis for combined regenerative Brayton and inverse Brayton cycles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zelong; Chen, Lingen; Sun, Fengrui [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

    2012-07-01

    This paper presents the study of exergy analysis of combined regenerative Brayton and inverse Brayton cycles. The analytical formulae of exergy loss and exergy efficiency are derived. The largest exergy loss location is determined. By taking the maximum exergy efficiency as the objective, the choice of bottom cycle pressure ratio is optimized by detailed numerical examples, and the corresponding optimal exergy efficiency is obtained. The influences of various parameters on the exergy efficiency and other performances are analyzed by numerical calculations.

  19. Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part A

    DEFF Research Database (Denmark)

    Meroni, Andrea; La Seta, Angelo; Andreasen, Jesper Graa

    2016-01-01

    Axial-flow turbines represent a well-established technology for a wide variety of power generation systems. Compactness, flexibility, reliability and high efficiency have been key factors for the extensive use of axial turbines in conventional power plants and, in the last decades, in organic...... Rankine cycle power systems. In this two-part paper, an overall cycle model and a model of an axial turbine were combined in order to provide a comprehensive preliminary design of the organic Rankine cycle unit, taking into account both cycle and turbine optimal designs. Part A presents the preliminary...

  20. Theoretical Study on CO2 Transcritical Cycle Combined Ejector Cycle Refrigeration System

    Institute of Scientific and Technical Information of China (English)

    卢苇; 马一太; 李敏霞; 查世彤

    2003-01-01

    Chlorofluorocarbons(CFCs) or hydrochlorofluorocarbons(HCFCs) are as main refrigerants used in traditional refrigeration systems driven by electricity from burning fossil fuels, which is regarded as one of the major reasons for ozone depletion (man-made refrigerants emission) and global warming (CO2 emission). So people pay more and more attention to natural refrigerants and energy saving technologies. An innovative system combining CO2 transcritical cycle with ejector cycle is proposed in this paper. The CO2 compression sub-cycle is powered by electricity with the characteristics of relatively high temperature in the gas cooler (defined as an intercooler by the proposed system). In order to recover the waste heat, an ejector sub-cycle operating with the natural refrigerants (NH3, H2O) is employed. The two sub-cycles are connected by an intercooler. This combined cycle joins the advantages of the two cycles together and eliminates the disadvantages. The influences of the evaporation temperature in CO2 compression sub-cycle, the evaporation temperature in the ejector sub-cycle, the temperature in the intercooler and the condensation temperature in the proposed system performance are discussed theoretically in this study. In addition, some unique features of the system are presented.

  1. Exergy analysis of an integrated solar combined cycle system

    Energy Technology Data Exchange (ETDEWEB)

    Baghernejad, A.; Yaghoubi, M. [Engineering School, Shiraz University, Shiraz (Iran)

    2010-10-15

    Exergetic analysis has become an integral part of thermodynamic assessment of any power generation system. Energy and exergy studies for power plants optimum design and for combined chemical industries received much attention recently. An Integrated Solar Combined Cycle System (ISCCS) is proposed as a means of integrating a parabolic trough solar thermal plant with modern combined cycle power plants. In this study attempt will be made to analyze the Integrated Solar Combined Cycle in Yazd, Iran using design plant data. Energy and exergy analysis for the solar field and combined cycle is carried out to assess the plant performance and pinpoint sites of primary exergy destruction. Exergy destruction throughout the plant is quantified and illustrated using an exergy flow diagram, and compared to the energy flow diagram. The causes of exergy destruction in the plant include: losses in combustor, collector, heat exchangers, and pump and turbines which accounts for 29.62, 8.69, 9.11 and 8% of the total exergy input to the plant, respectively. Exergetic efficiencies of the major plant components are determined in an attempt to assess their individual performances. (author)

  2. A combined gas cooled nuclear reactor and fuel cell cycle

    Science.gov (United States)

    Palmer, David J.

    Rising oil costs, global warming, national security concerns, economic concerns and escalating energy demands are forcing the engineering communities to explore methods to address these concerns. It is the intention of this thesis to offer a proposal for a novel design of a combined cycle, an advanced nuclear helium reactor/solid oxide fuel cell (SOFC) plant that will help to mitigate some of the above concerns. Moreover, the adoption of this proposal may help to reinvigorate the Nuclear Power industry while providing a practical method to foster the development of a hydrogen economy. Specifically, this thesis concentrates on the importance of the U.S. Nuclear Navy adopting this novel design for its nuclear electric vessels of the future with discussion on efficiency and thermodynamic performance characteristics related to the combined cycle. Thus, the goals and objectives are to develop an innovative combined cycle that provides a solution to the stated concerns and show that it provides superior performance. In order to show performance, it is necessary to develop a rigorous thermodynamic model and computer program to analyze the SOFC in relation with the overall cycle. A large increase in efficiency over the conventional pressurized water reactor cycle is realized. Both sides of the cycle achieve higher efficiencies at partial loads which is extremely important as most naval vessels operate at partial loads as well as the fact that traditional gas turbines operating alone have poor performance at reduced speeds. Furthermore, each side of the cycle provides important benefits to the other side. The high temperature exhaust from the overall exothermic reaction of the fuel cell provides heat for the reheater allowing for an overall increase in power on the nuclear side of the cycle. Likewise, the high temperature helium exiting the nuclear reactor provides a controllable method to stabilize the fuel cell at an optimal temperature band even during transients helping

  3. Parametric Investigation and Thermoeconomic Optimization of a Combined Cycle for Recovering the Waste Heat from Nuclear Closed Brayton Cycle

    Directory of Open Access Journals (Sweden)

    Lihuang Luo

    2016-01-01

    Full Text Available A combined cycle that combines AWM cycle with a nuclear closed Brayton cycle is proposed to recover the waste heat rejected from the precooler of a nuclear closed Brayton cycle in this paper. The detailed thermodynamic and economic analyses are carried out for the combined cycle. The effects of several important parameters, such as the absorber pressure, the turbine inlet pressure, the turbine inlet temperature, the ammonia mass fraction, and the ambient temperature, are investigated. The combined cycle performance is also optimized based on a multiobjective function. Compared with the closed Brayton cycle, the optimized power output and overall efficiency of the combined cycle are higher by 2.41% and 2.43%, respectively. The optimized LEC of the combined cycle is 0.73% lower than that of the closed Brayton cycle.

  4. TECHNOECONOMIC APPRAISAL OF INTEGRATED GASIFICATION COMBINED-CYCLE POWER GENERATION

    Science.gov (United States)

    The report is a technoeconomic appraisal of the integrated (coal) gasification combined-cycle (IGCC) system. lthough not yet a proven commercial technology, IGCC is a future competitive technology to current pulverized-coal boilers equipped with SO2 and NOx controls, because of i...

  5. TECHNOECONOMIC APPRAISAL OF INTEGRATED GASIFICATION COMBINED-CYCLE POWER GENERATION

    Science.gov (United States)

    The report is a technoeconomic appraisal of the integrated (coal) gasification combined-cycle (IGCC) system. lthough not yet a proven commercial technology, IGCC is a future competitive technology to current pulverized-coal boilers equipped with SO2 and NOx controls, because of i...

  6. Analysis of Superimposed Elementary Thermodynamic Cycles: from the Brayton-Joule to Advanced Mixed (Auto-Combined Cycles

    Directory of Open Access Journals (Sweden)

    Giovanni Manente

    2009-09-01

    Full Text Available

    The need for efficiency improvement in energy conversion systems leads to a stricter functional integration among system components. This results in structures of increasing complexity, the high performance of which are often difficult to be understood easily. To make the comprehension of these structures easier, a new approach is followed in this paper, consisting in their representation as partial or total superimposition of elementary thermodynamic cycles. Although system performance cannot, in general, be evaluated as the sum of the performance of the separate thermodynamic cycles, this kind of representation and analysis can be of great help in understanding directions of development followed in the literature for the construction of advanced energy systems, and could suggest new potential directions of work. The evolution from the simple Brayton-Joule cycle to the so called “mixed” cycles, in which heat at the turbine discharge is exploited using internal heat sinks only without using a separate bottoming section, is used to demonstrate the potentiality of the approach. Mixed cycles are named here "auto-combined cycles” to highlight the combination of different (gas and steam cycles within the same system components.

    • This paper is an updated version of a paper published in the ECOS'08 proceedings. 

  7. Technical and financial analysis of combined cycle gas turbine

    Directory of Open Access Journals (Sweden)

    Khan Arshad Muhammad

    2013-01-01

    Full Text Available This paper presents technical and financial models which were developed in this study to predict the overall performance of combined cycle gas turbine plant in line with the needs of independent power producers in the liberalized market of power sector. Three similar sizes of combined cycle gas turbine power projects up to 200 Megawatt of independent power producers in Pakistan were selected in-order to develop and drive the basic assumptions for the inputs of the models in view of prevailing Government of Pakistan’s two components of electricity purchasing tariff that is energy purchase price and capacity purchase price at higher voltage grid station terminal from independent power producers. The levelized electricity purchasing tariff over life of plant on gaseous fuel at 60 percent plant load factor was 6.47 cent per kilowatt hour with energy purchase price and capacity purchase prices of 3.54 and 2.93 cents per kilowatt hour respectively. The outcome of technical models of gas turbine, steam turbine and combined cycle gas turbine power were found in close agreement with the projects under consideration and provides opportunity of evaluation of technical and financial aspects of combined cycle power plant in a more simplified manner with relatively accurate results. At 105 Celsius exit temperature of heat recovery steam generator flue gases the net efficiency of combined cycle gas turbine was 48.8 percent whereas at 125 Celsius exit temperature of heat recovery steam generator flue gases it was 48.0 percent. Sensitivity analysis of selected influential components of electricity tariff was also carried out.

  8. Combined HSRL and Optical Autocovarience Wind Lidar (HOAWL) Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Demonstrate 2β + 2α + 2δ High Spectral Resolution Lidar (HSRL) and Doppler wind lidar measurements simultaneously at 355nm and 532nm using a single...

  9. Exergy analysis for combined regenerative Brayton and inverse Brayton cycles

    Directory of Open Access Journals (Sweden)

    Zelong Zhang, Lingen Chen, Fengrui Sun

    2012-01-01

    Full Text Available This paper presents the study of exergy analysis of combined regenerative Brayton and inverse Brayton cycles. The analytical formulae of exergy loss and exergy efficiency are derived. The largest exergy loss location is determined. By taking the maximum exergy efficiency as the objective, the choice of bottom cycle pressure ratio is optimized by detailed numerical examples, and the corresponding optimal exergy efficiency is obtained. The influences of various parameters on the exergy efficiency and other performances are analyzed by numerical calculations.

  10. Combination of IVF and IVM in naturally cycling women

    DEFF Research Database (Denmark)

    Tang-Pedersen, Mikael; Westergaard, Lars Grabow; Erb, Karin;

    2012-01-01

    This study investigated the combination of an unstimulated IVF cycle with in-vitro maturation (IVM) of additional immature cumulus-oocyte-complexes (COC) from the same cycle collected at the same time as the spontaneous preovulatory follicle. This could potentially improve rates of embryo transfer...... and pregnancy/live births compared with conventional unstimulated IVF treatment and at the same time eliminate the risk of ovarian hyperstimulation syndrome. This prospective trial included 77 women with regular menstrual cycles. Age at inclusion was between 20 and 37 years. Results showed a retrieval rate...... between endometrial factors and IVM oocytes together with unknown competence of IVM embryos is suspected. For some time, there has been an increasing interest in mild approaches for fertility treatment, in particular IVF. In-vitro maturation (IVM) of immature eggs outside the ovaries followed by IVF...

  11. Open-Cycle Gas Turbine/Steam Turbine Combined Cycles with synthetic fuels from coal

    Science.gov (United States)

    Shah, R. P.; Corman, J. C.

    1977-01-01

    The Open-Cycle Gas Turbine/Steam Turbine Combined Cycle can be an effective energy conversion system for converting coal to electricity. The intermediate step in this energy conversion process is to convert the coal into a fuel acceptable to a gas turbine. This can be accomplished by producing a synthetic gas or liquid, and by removing, in the fuel conversion step, the elements in the fuel that would be harmful to the environment if combusted. In this paper, two open-cycle gas turbine combined systems are evaluated: one employing an integrated low-Btu gasifier, and one utilizing a semi-clean liquid fuel. A consistent technical/economic information base is developed for these two systems, and is compared with a reference steam plant burning coal directly in a conventional furnace.

  12. Effective Parameters on Performance of Multipressure Combined Cycle Power Plants

    OpenAIRE

    Thamir K. Ibrahim; Rahman, M M

    2014-01-01

    A parametric analysis is performed for numerous configurations of a combined cycle gas turbine (CCGT) power plant, including single-pressure, double-pressure, triple-pressure, triple-pressure with reheat, and supplementary triple-pressure with reheat. The compression ratio of the gas turbine and the steam pressure of the steam turbine are taken as design parameters. The thermodynamic model was developed based on an existing MARAFIQ CCGT power plant and performance model code developed using t...

  13. NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Javad Abbasian

    2001-07-01

    The objective of this program is to develop and evaluate novel sorbents for the Siemens Westinghouse Power Company's (SWPC's) ''Ultra-Clean Gas Cleaning Process'' for reducing to near-zero levels the sulfur- and chlorine-containing gas emissions and fine particulate matter (PM2.5) caused by fuel bound constituents found in carbonaceous materials, which are processed in Integrated Gasification Combined Cycle (IGCC) technologies.

  14. The History and Promise of Combined Cycle Engines for Access to Space Applications

    Science.gov (United States)

    Clark, Casie

    2010-01-01

    For the summer of 2010, I have been working in the Aerodynamics and Propulsion Branch at NASA Dryden Flight Research Center studying combined-cycle engines, a high speed propulsion concept. Combined cycle engines integrate multiple propulsion systems into a single engine capable of running in multiple modes. These different modes allow the engine to be extremely versatile and efficient in varied flight conditions. The two most common types of combined cycle engines are Rocket-Based Combined Cycle (RBCC) and Turbine Based Combined Cycle (TBCC). The RBCC essentially combines a rocket and ramjet engine, while the TBCC integrates a turbojet and ramjet1. These two engines are able to switch between different propulsion modes to achieve maximum performance. Extensive conceptual and ground test studies of RBCC engines have been undertaken; however, an RBCC engine has never, to my knowledge, been demonstrated in flight. RBCC engines are of particular interest because they could potentially power a reusable launch vehicle (RLV) into space. The TBCC has been flight tested and shown to be effective at reaching supersonic speeds, most notably in the SR-71 Blackbird2.

  15. Combined cycle plants: Yesterday, today, and tomorrow (review)

    Science.gov (United States)

    Ol'khovskii, G. G.

    2016-07-01

    Gas turbine plants (GTP) for a long time have been developed by means of increasing the initial gas temperature and improvement of the turbo-machines aerodynamics and the efficiency of the critical components air cooling within the framework of a simple thermodynamic cycle. The application of watercooling systems that were used in experimental turbines and studied approximately 50 years ago revealed the fundamental difficulties that prevented the practical implementation of such systems in the industrial GTPs. The steam cooling researches have developed more substantially. The 300 MW power GTPs with a closedloop steam cooling, connected in parallel with the intermediate steam heating line in the steam cycle of the combined cycle plant (CCP) have been built, tested, and put into operation. The designs and cycle arrangements of such GTPs and entire combined cycle steam plants have become substantially more complicated without significant economic benefits. As a result, the steam cooling of gas turbines has not become widespread. The cycles—complicated by the intermediate air cooling under compression and reheat of the combustion products under expansion and their heat recovery to raise the combustion chamber entry temperature of the air—were used, in particular, in the domestic power GTPs with a moderate (700-800°C) initial gas turbine entry temperature. At the temperatures being reached to date (1300-1450°C), only one company, Alstom, applies in their 240-300 MW GTPs the recycled fuel cycle under expansion of gases in the turbine. Although these GTPs are reliable, there are no significant advantages in terms of their economy. To make a forecast of the further improvement of power GTPs, a brief review and assessment of the water cooling and steam cooling of hot components and complication of the GTP cycle by the recycling of fuel under expansion of gases in the turbine has been made. It is quite likely in the long term to reach the efficiency for the

  16. Overview of the Turbine Based Combined Cycle Discipline

    Science.gov (United States)

    Thomas, Scott R.; Walker, James F.; Pittman, James L.

    2009-01-01

    The NASA Fundamental Aeronautics Hypersonics project is focused on technologies for combined cycle, airbreathing propulsions systems to enable reusable launch systems for access to space. Turbine Based Combined Cycle (TBCC) propulsion systems offer specific impulse (Isp) improvements over rocket-based propulsion systems in the subsonic takeoff and return mission segments and offer improved safety. The potential to realize more aircraft-like operations with expanded launch site capability and reduced system maintenance are additional benefits. The most critical TBCC enabling technologies as identified in the National Aeronautics Institute (NAI) study were: 1) mode transition from the low speed propulsion system to the high speed propulsion system, 2) high Mach turbine engine development, 3) transonic aero-propulsion performance, 4) low-Mach-number dual-mode scramjet operation, 5) innovative 3-D flowpath concepts and 6) innovative turbine based combined cycle integration. To address several of these key TBCC challenges, NASA s Hypersonics project (TBCC Discipline) initiated an experimental mode transition task that includes an analytic research endeavor to assess the state-of-the-art of propulsion system performance and design codes. This initiative includes inlet fluid and turbine performance codes and engineering-level algorithms. This effort has been focused on the Combined Cycle Engine Large-Scale Inlet Mode Transition Experiment (CCE LIMX) which is a fully integrated TBCC propulsion system with flow path sizing consistent with previous NASA and DoD proposed Hypersonic experimental flight test plans. This experiment is being tested in the NASA-GRC 10 x 10 Supersonic Wind Tunnel (SWT) Facility. The goal of this activity is to address key hypersonic combined-cycle-engine issues: (1) dual integrated inlet operability and performance issues unstart constraints, distortion constraints, bleed requirements, controls, and operability margins, (2) mode

  17. ISCC Kuraymat Integrated Solar Combined Cycle Power Plant in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Brakmann, G.

    2006-07-01

    The New and Renewable Energy Authority (NREA) of Egypt intends to implement an Integrated Solar Combined Cycle Power Plant, ISCC Kuraymat, to be located about 95 km south of Cairo, on the eastern side of the river Nile, at a northern latitude of 29{sup o} 16' and an eastern longitude of 31{sup o} 15'. The complete ISCC Project shall be implemented in three (3) contract lots: One (1) Contract Lot for Solar Island as EPC cum OandM contract for engineering, procurement, construction, testing, commissioning and five (5) years operation and maintenance; (Two contracts will be used for this Lot (Solar Island), one for EPC and one for the OandM part of the Lot.) The Solar Island shall consist of a parabolic trough solar field capable to generate about 110 MW (thermal) of solar heat at a temperature of 393{sup o}C, the related IandC and control room and the heat transfer fluid (HTF) system up to the HTF inlet and outlet flanges of the Solar Heat Exchanger(s). The Contractor for Solar Island shall guarantee the supply of solar heat to the Solar Heat Exchanger(s) as a function of normal direct solar irradiation (DNI) and of solar position. One (1) Contract for Combined Cycle Island as EPC contract for engineering, procurement, construction, testing and commissioning and extended two (2) year warranty period. The Combined Cycle Island shall consist of one (1) or two (2) gas turbine(s) with ISO rating of about 80 MWe (total), one (1) or two (2) heat recovery steam generator(s) (HRSG), one (1) steam turbine of about 70 MWe, solar heat exchanger(s) capable to absorb about 110 MW (thermal) of solar heat plus all associated balance of plant equipment. The Contractor(s) for Combined Cycle Island shall guarantee the supply of electricity and the heat rate as a function of ambient temperature and as a function of solar heat supply from the Solar Island. One (1) Contract for Combined Cycle Island as OandM contract for five (5) year operation and maintenance. (Author)

  18. Thermoeconomic Evaluation of Integrated Solar Combined Cycle Systems (ISCCS

    Directory of Open Access Journals (Sweden)

    Javier Rodríguez Martín

    2014-07-01

    Full Text Available Three alternatives for integrating a solar field with the bottoming cycle of a combined cycle plant are modeled: parabolic troughs with oil at intermediate and low cycle pressures and Fresnel linear collectors at low cycle pressure. It is assumed that the plant will always operate at nominal conditions, using post-combustion during the hours of no solar resource. A thermoeconomic study of the operation of the plant throughout a year has been carried out. The energy and exergy efficiencies of the plant working in fuel only and hybrid modes are compared. The energy efficiencies obtained are very similar; slightly better for the fuel only mode. The exergy efficiencies are slightly better for hybrid operation than for fuel-only mode, due to the high exergy destruction associated with post-combustion. The values for solar electric efficiency are in line with those of similar studies. The economic study shows that the Fresnel hybridization alternative offers similar performance to the others at a significantly lower cost.

  19. Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part B

    DEFF Research Database (Denmark)

    La Seta, Angelo; Meroni, Andrea; Andreasen, Jesper Graa

    2016-01-01

    Organic Rankine cycle (ORC) power systems have recently emerged as promising solutions for waste heat recovery in low- and medium-size power plants. Their performance and economic feasibility strongly depend on the expander. The design process and efficiency estimation are particularly challenging...... power output of 8.3% compared to the case when the turbine efficiency is assumed to be 80%. This work also demonstrates that this approach can support the plant designer in the selection of the optimal size of the organic Rankine cycle unit when multiple exhaust gas streams are available....

  20. Novel stable isotope analyses demonstrate significant rates of glucose cycling in mouse pancreatic islets.

    Science.gov (United States)

    Wall, Martha L; Pound, Lynley D; Trenary, Irina; O'Brien, Richard M; Young, Jamey D

    2015-06-01

    A polymorphism located in the G6PC2 gene, which encodes an islet-specific glucose-6-phosphatase catalytic subunit, is the most important common determinant of variations in fasting blood glucose (FBG) levels in humans. Studies of G6pc2 knockout (KO) mice suggest that G6pc2 represents a negative regulator of basal glucose-stimulated insulin secretion (GSIS) that acts by hydrolyzing glucose-6-phosphate (G6P), thereby reducing glycolytic flux. However, this conclusion conflicts with the very low estimates for the rate of glucose cycling in pancreatic islets, as assessed using radioisotopes. We have reassessed the rate of glucose cycling in pancreatic islets using a novel stable isotope method. The data show much higher levels of glucose cycling than previously reported. In 5 mmol/L glucose, islets from C57BL/6J chow-fed mice cycled ∼16% of net glucose uptake. The cycling rate was further increased at 11 mmol/L glucose. Similar cycling rates were observed using islets from high fat-fed mice. Importantly, glucose cycling was abolished in G6pc2 KO mouse islets, confirming that G6pc2 opposes the action of the glucose sensor glucokinase by hydrolyzing G6P. The demonstration of high rates of glucose cycling in pancreatic islets explains why G6pc2 deletion enhances GSIS and why variants in G6PC2 affect FBG in humans. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  1. Cycle Analysis using Exhaust Heat of SOFC and Turbine Combined Cycle by Absorption Chiller

    Science.gov (United States)

    Takezawa, Shinya; Wakahara, Kenji; Araki, Takuto; Onda, Kazuo; Nagata, Susumu

    A power generating efficiency of solid oxide fuel cell (SOFC) and gas turbine combined cycle is fairly high. However, the exhaust gas temperature of the combined cycle is still high, about 300°C. So it should be recovered for energy saving, for example, by absorption chiller. The energy demand for refrigeration cooling is recently increasing year by year in Japan. Then, we propose here a cogeneration system by series connection of SOFC, gas turbine and LiBr absorption chiller to convert the exhaust heat to the cooling heat. As a result of cycle analysis of the combined system with 500kW class SOFC, the bottoming single-effect absorption chiller can produce the refrigerating capacity of about 120kW, and the double-effect absorption chiller can produce a little higher refrigerating capacity of about 130kW without any additional fuel. But the double-effect absorption chiller became more expensive and complex than the single-effect chiller.

  2. Transuranic material recovery in the Integral Fast Reactor fuel cycle demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, R.W.; Goff, K.M.

    1993-01-01

    The Integral Fast Reactor is an innovative liquid metal reactor concept that is being developed by Argonne National Laboratory. It takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel cycle economics, environmental protection, and safeguards. The plans for demonstrating the IFR fuel cycle, including its waste processing options, by processing irradiated fuel from the Experimental Breeder Reactor-II fuel in its associated Fuel Cycle Facility have been developed for the first refining series. This series has been designed to provide the data needed for the further development of the IFR program. An important piece of the data needed is the recovery of TRU material during the reprocessing and waste operations.

  3. Transuranic material recovery in the Integral Fast Reactor fuel cycle demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, R.W.; Goff, K.M.

    1993-03-01

    The Integral Fast Reactor is an innovative liquid metal reactor concept that is being developed by Argonne National Laboratory. It takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel cycle economics, environmental protection, and safeguards. The plans for demonstrating the IFR fuel cycle, including its waste processing options, by processing irradiated fuel from the Experimental Breeder Reactor-II fuel in its associated Fuel Cycle Facility have been developed for the first refining series. This series has been designed to provide the data needed for the further development of the IFR program. An important piece of the data needed is the recovery of TRU material during the reprocessing and waste operations.

  4. Combined glucose ingestion and mouth rinsing improves sprint cycling performance.

    Science.gov (United States)

    Chong, Edwin; Guelfi, Kym J; Fournier, Paul A

    2014-12-01

    This study investigated whether combined ingestion and mouth rinsing with a carbohydrate solution could improve maximal sprint cycling performance. Twelve competitive male cyclists ingested 100 ml of one of the following solutions 20 min before exercise in a randomized double-blinded counterbalanced order (a) 10% glucose solution, (b) 0.05% aspartame solution, (c) 9.0% maltodextrin solution, or (d) water as a control. Fifteen min after ingestion, repeated mouth rinsing was carried out with 11 × 15 ml bolus doses of the same solution at 30-s intervals. Each participant then performed a 45-s maximal sprint effort on a cycle ergometer. Peak power output was significantly higher in response to the glucose trial (1188 ± 166 W) compared with the water (1036 ± 177 W), aspartame (1088 ± 128 W) and maltodextrin (1024 ± 202 W) trials by 14.7 ± 10.6, 9.2 ± 4.6 and 16.0 ± 6.0% respectively (p sprint was significantly higher in the glucose trial compared with maltodextrin (p sprinting did not differ significantly between treatments (p > .05). These findings suggest that combining the ingestion of glucose with glucose mouth rinsing improves maximal sprint performance. This ergogenic effect is unlikely to be related to changes in blood glucose, sweetness, or energy sensing mechanisms in the gastrointestinal tract.

  5. Environmental assessmental, geothermal energy, Heber geothermal binary-cycle demonstration project: Imperial County, California

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    The proposed design, construction, and operation of a commercial-scale (45 MWe net) binary-cycle geothermal demonstration power plant are described using the liquid-dominated geothermal resource at Heber, Imperial County, California. The following are included in the environmental assessment: a description of the affected environment, potential environmental consequences of the proposed action, mitigation measures and monitoring plans, possible future developmental activities at the Heber anomaly, and regulations and permit requirements. (MHR)

  6. Demonstration of active vibration control on a stirling-cycle cryocooler testbed

    Science.gov (United States)

    Johnson, Bruce G.; Flynn, Frederick J.; Gaffney, Monique S.; Johnson, Dean L.; Ross, Ronald G., Jr.

    1992-01-01

    SatCon Technology Corporation has demonstrated excellent vibration reduction performance using active control on the JPL Stirling-cycle cryocooler testbed. The authors address the use of classical narrowband feedback control to meet the cryocooler vibration specifications using one cryocooler in a self-cancellation configuration. Similar vibration reduction performance was obtained using a cryocooler back-to-back configuration by actively controlling a reaction mass actuator that was used to mimic the second cooler.

  7. Gasification combined cycle: Carbon dioxide recovery, transport, and disposal

    Energy Technology Data Exchange (ETDEWEB)

    Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.R.; Berry, G.F.; Livengood, C.D.

    1994-09-01

    The objective of the project is to develop engineering evaluations of technologies for the capture, use, and disposal of carbon dioxide (CO{sub 2}). This project emphasizes CO{sub 2}-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems. Complementary evaluations address CO{sub 2} transportation, CO{sub 2} use, and options for the long-term sequestering of unused CO{sub 2}. Commercially available CO{sub 2}-capture technology is providing a performance and economic baseline against which to compare innovative technologies. The intent is to provide the CO{sub 2} budget, or an {open_quotes}equivalent CO{sub 2}{close_quotes} budget, associated with each of the individual energy-cycle steps, in addition to process design capital and operating costs. The value used for the {open_quotes}equivalent CO{sub 2}{close_quotes} budget is 1 kg of CO{sub 2} per kilowatt-hour (electric). The base case is a 458-MW IGCC system that uses an air-blown Kellogg-Rust-Westinghouse agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal feed, and in-bed sulfur removal. Mining, feed preparation, and conversion result in a net electric power production of 454 MW, with a CO{sub 2} release rate of 0.835 kg/kWhe. Two additional life-cycle energy balances for emerging technologies were considered: (1) high-temperature CO{sub 2} separation with calcium- or magnesium-based sorbents, and (2) ambient-temperature facilitated-transport polymer membranes for acid-gas removal.

  8. Economics and Performance Forecast of Gas Turbine Combined Cycle

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaotao; SUGISHITA Hideaki; NI Weidou; LI Zheng

    2005-01-01

    Forecasts of the economics and performance of gas turbine combined cycle (GTCC) with various types of gas turbines will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.

  9. Combined Cycle Power Generation Employing Pressure Gain Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holley, Adam [United Technologies Corporation, East Hartford, CT (United States). Research Center

    2017-05-15

    The Phase I program assessed the potential benefit of applying pressure gain combustion (PGC) technology to a natural gas combined cycle power plant. A conceptual design of the PGC integrated gas turbine was generated which was simulated in a detailed system modeling tool. The PGC integrated system was 1.93% more efficient, produced 3.09% more power, and reduced COE by 0.58%. Since the PGC system used had the same fuel flow rate as the baseline system, it also reduced CO2 emissions by 3.09%. The PGC system did produce more NOx than standard systems, but even with the performanceand cost penalties associated with the cleanup system it is better in every measure. This technology benefits all of DOE’s stated program goals to improve plant efficiency, reduce CO2 production, and reduce COE.

  10. Combining life cycle costing and life cycle assessment for an analysis of a new residential district energy system design

    OpenAIRE

    Ristimäki, Miro; Säynäjoki, Antti; Heinonen, Jukka; Junnila, Seppo

    2013-01-01

    Due to the growing threat of climate change, we are challenged to find improved assessment practises to recognize solutions for sustainable urban development. The focus of the study is on the life cycle design of a district energy system for a new residential development in Finland. This study analyses LCC (life cycle costs) and carbon emissions (LCA (life cycle assessment)), i.e., the “viability” of different energy systems through a methodological life cycle framework. By combining LCC and ...

  11. Monitoring of the thermoeconomic performance in an actual combined cycle power plant bottoming cycle

    Energy Technology Data Exchange (ETDEWEB)

    Cafaro, S.; Napoli, L.; Traverso, A.; Massardo, A.F. [DIMSET (TPG), University of Genoa, Via Montallegro 1, 16145 Genoa (Italy)

    2010-02-15

    This paper presents a research project carried out by TPG (Thermochemical Power Group) of University of Genoa to develop innovative monitoring and diagnostics procedures and software tools for software-aided maintenance and customer support. This work is concerned with preliminary outcomes regarding the thermoeconomic monitoring of the bottoming cycle of a combined cycle power plant, using real historical data. The software is able to calculate functional exergy flows (y), their related costs (c) (using the plant functional diagram); after that non dimensional parameters for the characteristic exergonomic indexes ({delta}c, {delta}c*, {delta}k*) are determined. Through a plant optimization (not described here) the reference conditions of the plant at each operating condition can be determined. Then, non dimensional indexes related to each thermoeconomic parameter are defined, in order to depict a ''cost degradation'', and thus a significant rise in the production cost of the main products of the bottoming cycle (steam and power). The methodology developed has been successfully applied to historical logged data of an existing 400 MW power plant, showing the capabilities in estimating the ''cost degradation'' of the elements of the BC over the plant life, and trends in the thermoeconomic indexes. (author)

  12. Parametric-Based Thermodynamic Analysis of Organic Rankine Cycle as Bottoming Cycle for Combined-Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    SAMIULLAH QURESHI

    2017-01-01

    Full Text Available In Pakistan, the thermal efficiency of the power plants is low because of a huge share of fuel energy is dumped into the atmosphere as waste heat. The ORC (Organic Rankine Cycle has been revealed as one of the promising technologies to recover waste heat to enhance the thermal efficiency of the power plant. In current work, ORC is proposed as a second bottoming cycle for existing CCPP (Combined Cycle Power Plant. In order to assess the efficiency of the plant, a thermodynamic model is developed in the ESS (Engineering Equation Solver software. The developed model is used for parametric analysis to assess the effects of various operating parameters on the system performance. The analysis of results shows that the integration of ORC system with existing CCPP system enhances the overall power output in the range of 150.5-154.58 MW with 0.24-5% enhancement in the efficiency depending on the operating conditions. During the parametric analysis of ORC, it is observed that inlet pressure of the turbine shows a significant effect on the performance of the system as compared to other operating parameters.

  13. [Demonstration of life cycle with four obligatory hosts of the Hemiurid Trematodes].

    Science.gov (United States)

    Kechemir, N

    1978-01-01

    Research on the transmission of Hemiurid Trematode Halipegus ovocaudatus in experimental and natural conditions demonstrates the following: --the miracidium grows into a sporocyst producing rediae in the Mollusc Planorbis planorbis; -- the cystophorous cercariae become mesocercariae in the hemocoele of Copepodes or finally Ostracodes when swallowed; -- the mesocercariae become matacercariae in the mesenteron of larval Odonates (Zygoptera and Anisoptera) when these larvae swallow the Crustacea; -- the metacercariae become become adults in the Amphibial Rana ridibundal perezi which feeds on dragonflies. The four hosts (Mollusc -- Crustacean -- Odonat -- Amphibian) are obligatory in the life cycle for it is impossible to infect the Insects directly with the cecariae or the frog (tadpoles as well as adults) with the mesocercariae. The different stages of the life cycle of H. oveocaudatus aredescribed and the mode of the transmission is compared with the other species of Halipegus and with the Trematodes in general. The adaptative value of the lengthening of the cycle is discussed from the point of view of the conquest of terrestrial hosts by the Hemiurid Trematodes.

  14. Combined Reverse-Brayton Joule Thompson Hydrogen Liquefaction Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Shimko, Martin A. [Gas Equipment Engineering Corporation, Milford, CT (United States); Dunn, Paul M. [Gas Equipment Engineering Corporation, Milford, CT (United States)

    2011-12-31

    The following is a compilation of Annual Progress Reports submitted to the DOE’s Fuel Cell Technologies Office by Gas Equipment Engineering Corp. for contract DE-FG36-05GO15021. The reports cover the project activities from August 2005 through June 2010. The purpose of this project is to produce a pilot-scale liquefaction plant that demonstrates GEECO’s ability to meet or exceed the efficiency targets set by the DOE. This plant will be used as a model to commercialize this technology for use in the distribution infrastructure of hydrogen fuel. It could also be applied to markets distributing hydrogen for industrial gas applications. Extensive modeling of plant performance will be used in the early part of the project to identify the liquefaction cycle architecture that optimizes the twin goals of increased efficiency and reduced cost. The major challenge of the project is to optimize/balance the performance (efficiency) of the plant against the cost of the plant so that the fully amortized cost of liquefying hydrogen meets the aggressive goals set by DOE. This project will design and build a small-scale pilot plant (several hundred kg/day) that will be both a hardware demonstration and a model for scaling to larger plant sizes (>50,000 kg/day). Though an effort will be made to use commercial or near-commercial components, key components that will need development for either a pilot- or full-scale plant will be identified. Prior to starting pilot plant fabrication, these components will be demonstrated at the appropriate scale to demonstrate sufficient performance for use in the pilot plant and the potential to achieve the performance used in modeling the full-scale plant.

  15. Development of LM10-MIRA LOX/LNG expander cycle demonstrator engine

    Science.gov (United States)

    Rudnykh, Mikhail; Carapellese, Stefano; Liuzzi, Daniele; Arione, Luigi; Caggiano, Giuseppe; Bellomi, Paolo; D'Aversa, Emanuela; Pellegrini, Rocco; Lobov, S. D.; Gurtovoy, A. A.; Rachuk, V. S.

    2016-09-01

    This article contains results of joint works by Konstruktorskoe Buro Khimavtomatiki (KBKhA, Russia) and AVIO Company (Italy) on creation of the LM10-MIRA liquid-propellant rocket demonstrator engine for the third stage of the upgraded "Vega" launcher.Scientific and research activities conducted by KBKhA and AVIO in 2007-2014 in the frame of the LYRA Program, funded by the Italian Space Agency, with ELV as Prime contractor, and under dedicated ASI-Roscosmos inter-agencies agreement, were aimed at development and testing of a 7.5 t thrust expander cycle demonstrator engine propelled by oxygen and liquid natural gas (further referred to as LNG).

  16. Gas fired combined cycle plant in Singapore: energy use, GWP and cost-a life cycle approach

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, R. [School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)]. E-mail: kannan@pmail.ntu.edu.sg; Leong, K.C. [School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)]. E-mail: mkcleong@ntu.edu.sg; Osman, Ramli [School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Ho, H.K. [School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Tso, C.P. [Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450 Melaka (Malaysia)

    2005-08-15

    A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established.

  17. Thermodynamic Modeling for Open Combined Regenerative Brayton and Inverse Brayton Cycles with Regeneration before the Inverse Cycle

    Directory of Open Access Journals (Sweden)

    Lingen Chen

    2012-01-01

    Full Text Available A thermodynamic model of an open combined regenerative Brayton and inverse Brayton cycles with regeneration before the inverse cycle is established in this paper by using thermodynamic optimization theory. The flow processes of the working fluid with the pressure drops and the size constraint of the real power plant are modeled. There are 13 flow resistances encountered by the working fluid stream for the cycle model. Four of these, the friction through the blades and vanes of the compressors and the turbines, are related to the isentropic efficiencies. The remaining nine flow resistances are always present because of the changes in flow cross-section at the compressor inlet of the top cycle, regenerator inlet and outlet, combustion chamber inlet and outlet, turbine outlet of the top cycle, turbine outlet of the bottom cycle, heat exchanger inlet, and compressor inlet of the bottom cycle. These resistances associated with the flow through various cross-sectional areas are derived as functions of the compressor inlet relative pressure drop of the top cycle, and control the air flow rate, the net power output and the thermal efficiency. The analytical formulae about the power output, efficiency and other coefficients are derived with 13 pressure drop losses. It is found that the combined cycle with regenerator can reach higher thermal efficiency but smaller power output than those of the base combined cycle at small compressor inlet relative pressure drop of the top cycle.

  18. Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part B: Application on a Case Study

    Directory of Open Access Journals (Sweden)

    Angelo La Seta

    2016-05-01

    Full Text Available Organic Rankine cycle (ORC power systems have recently emerged as promising solutions for waste heat recovery in low- and medium-size power plants. Their performance and economic feasibility strongly depend on the expander. The design process and efficiency estimation are particularly challenging due to the peculiar physical properties of the working fluid and the gas-dynamic phenomena occurring in the machine. Unlike steam Rankine and Brayton engines, organic Rankine cycle expanders combine small enthalpy drops with large expansion ratios. These features yield turbine designs with few highly-loaded stages in supersonic flow regimes. Part A of this two-part paper has presented the implementation and validation of the simulation tool TURAX, which provides the optimal preliminary design of single-stage axial-flow turbines. The authors have also presented a sensitivity analysis on the decision variables affecting the turbine design. Part B of this two-part paper presents the first application of a design method where the thermodynamic cycle optimization is combined with calculations of the maximum expander performance using the mean-line design tool described in part A. The high computational cost of the turbine optimization is tackled by building a model which gives the optimal preliminary design of an axial-flow turbine as a function of the cycle conditions. This allows for estimating the optimal expander performance for each operating condition of interest. The test case is the preliminary design of an organic Rankine cycle turbogenerator to increase the overall energy efficiency of an offshore platform. For an increase in expander pressure ratio from 10 to 35, the results indicate up to 10% point reduction in expander performance. This corresponds to a relative reduction in net power output of 8.3% compared to the case when the turbine efficiency is assumed to be 80%. This work also demonstrates that this approach can support the plant designer

  19. Life cycle assessment of a biomass gasification combined-cycle power system

    Energy Technology Data Exchange (ETDEWEB)

    Mann, M.K.; Spath, P.L.

    1997-12-01

    The potential environmental benefits from biomass power are numerous. However, biomass power may also have some negative effects on the environment. Although the environmental benefits and drawbacks of biomass power have been debated for some time, the total significance has not been assessed. This study serves to answer some of the questions most often raised in regard to biomass power: What are the net CO{sub 2} emissions? What is the energy balance of the integrated system? Which substances are emitted at the highest rates? What parts of the system are responsible for these emissions? To provide answers to these questions, a life cycle assessment (LCA) of a hypothetical biomass power plant located in the Midwest United States was performed. LCA is an analytical tool for quantifying the emissions, resource consumption, and energy use, collectively known as environmental stressors, that are associated with converting a raw material to a final product. Performed in conjunction with a technoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. This study complements a technoeconomic analysis of the same process, reported in Craig and Mann (1996) and updated here. The process studied is based on the concept of power Generation in a biomass integrated gasification combined cycle (BIGCC) plant. Broadly speaking, the overall system consists of biomass production, its transportation to the power plant, electricity generation, and any upstream processes required for system operation. The biomass is assumed to be supplied to the plant as wood chips from a biomass plantation, which would produce energy crops in a manner similar to the way food and fiber crops are produced today. Transportation of the biomass and other materials is by both rail and truck. The IGCC plant is sized at 113 MW, and integrates an indirectly-heated gasifier with an industrial gas turbine and steam cycle. 63 refs., 34 figs., 32 tabs.

  20. Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    B. Wayne Bequette; Priyadarshi Mahapatra

    2010-08-31

    The primary project objectives were to understand how the process design of an integrated gasification combined cycle (IGCC) power plant affects the dynamic operability and controllability of the process. Steady-state and dynamic simulation models were developed to predict the process behavior during typical transients that occur in plant operation. Advanced control strategies were developed to improve the ability of the process to follow changes in the power load demand, and to improve performance during transitions between power levels. Another objective of the proposed work was to educate graduate and undergraduate students in the application of process systems and control to coal technology. Educational materials were developed for use in engineering courses to further broaden this exposure to many students. ASPENTECH software was used to perform steady-state and dynamic simulations of an IGCC power plant. Linear systems analysis techniques were used to assess the steady-state and dynamic operability of the power plant under various plant operating conditions. Model predictive control (MPC) strategies were developed to improve the dynamic operation of the power plants. MATLAB and SIMULINK software were used for systems analysis and control system design, and the SIMULINK functionality in ASPEN DYNAMICS was used to test the control strategies on the simulated process. Project funds were used to support a Ph.D. student to receive education and training in coal technology and the application of modeling and simulation techniques.

  1. Integrated gasification combined cycle (IGCC) process simulation and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Emun, F.; Gadalla, M.; Majozi, T.; Boer, D. [University of Rovira & Virgili, Tarragona (Spain). Dept. of Chemical Engineering

    2010-03-05

    The integrated gasification combined cycle (IGCC) is an electrical power generation system which offers efficient generation from coal with lower effect on the environment than conventional coal power plants. However, further improvement of its efficiency and thereby lowering emissions are important tasks to achieve a more sustainable energy production. In this paper, a process simulation tool is proposed for simulation of IGCC. This tool is used to improve IGCC's efficiency and the environmental performance through an analysis of the operating conditions, together with process integration studies. Pinch analysis principles and process integration insights are then employed to make topological changes to the flowsheet to improve the energy efficiency and minimize the operation costs. Process data of the Texaco gasifier and the associated plants (coal preparation, air separation unit, gas cleaning, sulfur recovery, gas turbine, steam turbine and the heat recovery steam generator) are considered as a base case, and simulated using Aspen Plus. The results of parameter analysis and heat integration studies indicate that thermal efficiency of 45% can be reached, while a significant decrease in CO{sub 2} and SOx emissions is observed. The CO{sub 2} and SOx emission levels reached are 698 kg/MWh and 0.15 kg/MWh, respectively. Application of pinch analysis determines energy targets, and also identifies potential modifications for further improvement to overall energy efficiency. Benefits of energy integration and steam production possibilities can further be quantified. Overall benefits can be translated to minimum operation costs and atmospheric emissions.

  2. Experimental investigation of an ammonia-based combined power and cooling cycle

    Science.gov (United States)

    Tamm, Gunnar Olavi

    A novel ammonia-water thermodynamic cycle, capable of producing both power and refrigeration, was proposed by D. Yogi Goswami. The binary mixture exhibits variable boiling temperatures during the boiling process, which leads to a good thermal match between the heating fluid and working fluid for efficient heat source utilization. The cycle can be driven by low temperature sources such as solar, geothermal, and waste heat from a conventional power cycle, reducing the reliance on high temperature sources such as fossil fuels. A theoretical simulation of the cycle at heat source temperatures obtainable from low and mid temperature solar collectors showed that the ideal cycle could produce power and refrigeration at a maximum exergy efficiency, defined as the ratio of the net work and refrigeration output to the change in availability of the heat source, of over 60%. The exergy efficiency is a useful measure of the cycle's performance as it compares the effectiveness of different cycles in harnessing the same source. An experimental system was constructed to demonstrate the feasibility of the cycle and to compare the experimental results with the theoretical simulations. In this first phase of experimentation, the turbine expansion was simulated with a throttling valve and a heat exchanger. Results showed that the vapor generation and absorption condensation processes work experimentally. The potential for combined turbine work and refrigeration output was evidenced in operating the system. Analysis of losses led to modifications in the system design, which were implemented to yield improvements in heat exchange, vapor generation, pump performance and overall stability. The research that has been conducted verifies the potential of the power and cooling cycle as an alternative to using conventional fossil fuel technologies. The research that continues is to further demonstrate the concept and direct it towards industry. On the large scale, the cycle can be used for

  3. All-regime combined-cycle plant: Engineering solutions

    Science.gov (United States)

    Berezinets, P. A.; Tumanovskii, G. G.; Tereshina, G. E.; Krylova, I. N.; Markina, V. N.; Migun, E. N.

    2016-12-01

    The development of distributed power generation systems as a supplement to the centralized unified power grid increases the operational stability and efficiency of the entire power generation industry and improves the power supply to consumers. An all-regime cogeneration combined-cycle plant with a power of 20-25 mW (PGU-20/25T) and an electrical efficiency above 50% has been developed at the All-Russia Thermal Engineering Institute (ATEI) as a distributed power generation object. The PGU-20/25T two-circuit cogeneration plant provides a wide electrical and thermal power adjustment range and the absence of the mutual effect of electrical and thermal power output regimes at controlled frequency and power in a unified or isolated grid. The PGU-20/25T combined-cycle plant incorporates a gas-turbine unit (GTU) with a power of 16 MW, a heat recovery boiler (HRB) with two burners (before the boiler and the last heating stage), and a cogeneration steam turbine with a power of 6/9 MW. The PGU-20/25T plant has a maximum electrical power of 22 MW and an efficiency of 50.8% in the heat recovery regime and a maximum thermal power output of 16.3 MW (14 Gcal/h) in the cogeneration regime. The use of burners can increase the electrical power to 25 MW in the steam condensation regime at an efficiency of 49% and the maximum thermal power output to 29.5 MW (25.4 Gcal/h). When the steam turbine is shut down, the thermal power output can grow to 32.6 MW (28 Gcal/h). The innovative equipment, which was specially developed for PGU-20/25T, improves the reliability of this plant and simplifies its operation. Among this equipment are microflame burners in the heat recovery boiler, a vacuum system based on liquid-ring pumps, and a vacuum deaerator. To enable the application of PGU-20/25T in water-stressed regions, an air condenser preventing the heat-transfer tubes from the risk of covering with ice during operation in frost air has been developed. The vacuum system eliminates the need for

  4. Pre-Combustion Carbondioxide Capture in Integrated Gasification Combined Cycles

    Directory of Open Access Journals (Sweden)

    M. Zeki YILMAZOĞLU

    2010-02-01

    Full Text Available Thermal power plants have a significant place big proportion in the production of electric energy. Thermal power plants are the systems which converts heat energy to mechanical energy and also mechanical energy to electrical energy. Heat energy is obtained from combustion process and as a result of this, some harmful emissions, like CO2, which are the reason for global warming, are released to atmosphere. The contribution of carbondioxide to global warming has been exposed by the previous researchs. Due to this fact, clean energy technologies are growing rapidly all around the world. Coal is generally used in power plants and when compared to other fossil energy sources unit electricity production cost is less than others. When reserve rate is taken into account, coal may be converted to energy in a more efficient and cleaner way. The aim for using the clean coal technologies are to eradicate the harmful emissions of coal and to store the carbondioxide, orginated from combustion, in different forms. In line with this aim, carbondioxide may be captured by either pre-combustion, by O2/CO2 recycling combustion systems or by post combustion. The integrated gasification combined cycles (IGCC are available in pre-combustion capture systems, whereas in O2/CO2 recycling combustion systems there are ultrasuper critical boiler technologies and finally flue gas washing systems by amines exists in post combustion systems. In this study, a pre-combustion CO2 capture process via oxygen blown gasifiers is compared with a conventional power plant in terms of CO2 emissions. Captured carbondioxide quantity has been presented as a result of the calculations made throughout the study.

  5. Combined Cycle for Power Generation and Refrigeration Using Low Temperature Heat Sources

    OpenAIRE

    Vijay Chauhan; P. Anil Kishan; Sateesh Gedupudi

    2014-01-01

    A combined refrigeration and power cycle, which uses ammonia-water as the working fluid, is proposed by combining Rankine and vapour absorption cycles with an advantage of varying refrigeration capacity to power output ratio. The study investigates the usage of low temperature heat sources for the cycle operation. Results of parametric analysis are presented, which show the scope for optimization. Results of thermodynamic optimization of the cycle for second law efficiency performed using gen...

  6. LIFE CYCLE DESIGN FRAMEWORK AND DEMONSTRATION PROJECTS - PROFILES OF AT&T AND ALLIED SIGNAL

    Science.gov (United States)

    This document offers guidance and practical experience for integrating environmental considerations into product system development. Life cycle design seeks to minimize the environmental burden associated with a product's life cycle from raw materials acquisition through manufact...

  7. A comparison of advanced heat recovery power cycles in a combined cycle for large ships

    DEFF Research Database (Denmark)

    Larsen, Ulrik; Sigthorsson, Oskar; Haglind, Fredrik

    2014-01-01

    Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus in...

  8. Study on effective parameter of the triple-pressure reheat combined cycle performance

    OpenAIRE

    Ibrahim Thamir K.; Rahman M.M.

    2013-01-01

    The thermodynamic analyses of the triple-pressure reheat combined cycle gas turbines with duct burner are presented and discussed in this paper. The overall performance of a combined cycle gas turbine power plant is influenced by the ambient temperature, compression ratio and turbine inlet temperature. These parameters affect the overall thermal efficiency, power output and the heat-rate. In this study a thermodynamic model was development on an existing actual combined cycle gas turbin...

  9. BrainCycles: Experimental Setup for the Combined Measurement of Cortical and Subcortical Activity in Parkinson's Disease Patients during Cycling

    Science.gov (United States)

    Gratkowski, Maciej; Storzer, Lena; Butz, Markus; Schnitzler, Alfons; Saupe, Dietmar; Dalal, Sarang S.

    2017-01-01

    Recently, it has been demonstrated that bicycling ability remains surprisingly preserved in Parkinson's disease (PD) patients who suffer from freezing of gait. Cycling has been also proposed as a therapeutic means of treating PD symptoms, with some preliminary success. The neural mechanisms behind these phenomena are however not yet understood. One of the reasons is that the investigations of neuronal activity during pedaling have been up to now limited to PET and fMRI studies, which restrict the temporal resolution of analysis, and to scalp EEG focused on cortical activation. However, deeper brain structures like the basal ganglia are also associated with control of voluntary motor movements like cycling and are affected by PD. Deep brain stimulation (DBS) electrodes implanted for therapy in PD patients provide rare and unique access to directly record basal ganglia activity with a very high temporal resolution. In this paper we present an experimental setup allowing combined investigation of basal ganglia local field potentials (LFPs) and scalp EEG underlying bicycling in PD patients. The main part of the setup is a bike simulator consisting of a classic Dutch-style bicycle frame mounted on a commercially available ergometer. The pedal resistance is controllable in real-time by custom software and the pedal position is continuously tracked by custom Arduino-based electronics using optical and magnetic sensors. A portable bioamplifier records the pedal position signal, the angle of the knee, and the foot pressure together with EEG, EMG, and basal ganglia LFPs. A handlebar-mounted display provides additional information for patients riding the bike simulator, including the current and target pedaling rate. In order to demonstrate the utility of the setup, example data from pilot recordings are shown. The presented experimental setup provides means to directly record basal ganglia activity not only during cycling but also during other movement tasks in patients who

  10. Advanced Shock Position Control for Mode Transition in a Turbine Based Combined Cycle Engine Inlet Model

    Science.gov (United States)

    Csank, Jeffrey T.; Stueber, Thomas J.

    2013-01-01

    A dual flow-path inlet system is being tested to evaluate methodologies for a Turbine Based Combined Cycle (TBCC) propulsion system to perform a controlled inlet mode transition. Prior to experimental testing, simulation models are used to test, debug, and validate potential control algorithms. One simulation package being used for testing is the High Mach Transient Engine Cycle Code simulation, known as HiTECC. This paper discusses the closed loop control system, which utilizes a shock location sensor to improve inlet performance and operability. Even though the shock location feedback has a coarse resolution, the feedback allows for a reduction in steady state error and, in some cases, better performance than with previous proposed pressure ratio based methods. This paper demonstrates the design and benefit with the implementation of a proportional-integral controller, an H-Infinity based controller, and a disturbance observer based controller.

  11. Gasification integrated to combined cycles; Gasificacion integrada a ciclos combinados

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez M, Manuel F; Alcaraz C, Agustin M [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    The mineral coal is one of the most abundant fuels in the planet, but it has important amounts of sulfur and ashes that make difficult their use. On the other hand, many countries at the present time prevent to use the fuel oil as combustible with conventional technologies due to the metal and sulfur contents. Finally, in the new schemes of oil refinement it is anticipated to use the coking to take advantage of the barrel bottoms. The remainder product of this process, known as refinery coke, has a low commercial value, a high calorific power and high sulfur content and metals. The gasification has been developed in the last the two decades, in the highly industrialized countries, as an alternative for the efficient and clean generation of electricity from dirty fuels, as well as for obtaining certain fuels in places where access to petroleum is not available, but to the coal. This technology fulfills the strictest regulations of the world in what polluting emissions refers and it is the only solution, next to the fluidized beds, for the problems that present some fuels that are difficult to burn with conventional technologies, as the mineral coal, the petroleum coke and even the liquid remainders of the refinement. With base in the former, it is possible to think about the integration of this technology to a combined cycle plant for the generation of electricity or to a refinery generating steam, electrical energy, hydrogen and other consumables at a competitive cost, in such a way that the problems of handling and storage of the remainders are solved; on the other hand the use of the primary power resources in the country is maximized. [Spanish] El carbon mineral es uno de los combustibles mas abundantes en el planeta, pero posee cantidades importantes de azufre y cenizas que dificultan su utilizacion. Por otra parte, muchos paises en la actualidad impiden utilizar el combustoleo como combustible para tecnologias convencionales debido a los contenidos de azufre y

  12. THERMODYNAMIC ANALYSIS AND SIMULATION OF A NEW COMBINED POWER AND REFRIGERATION CYCLE USING ARTIFICIAL NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Hossein Rezvantalab

    2011-01-01

    Full Text Available In this study, a new combined power and refrigeration cycle is proposed, which combines the Rankine and absorption refrigeration cycles. Using a binary ammonia-water mixture as the working fluid, this combined cycle produces both power and refrigeration output simultaneously by employing only one external heat source. In order to achieve the highest possible exergy efficiency, a secondary turbine is inserted to expand the hot weak solution leaving the boiler. Moreover, an artificial neural network (ANN is used to simulate the thermodynamic properties and the relationship between the input thermodynamic variables on the cycle performance. It is shown that turbine inlet pressure, as well as heat source and refrigeration temperatures have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. In addition, the results of ANN are in excellent agreement with the mathematical simulation and cover a wider range for evaluation of cycle performance.

  13. A Thermodynamic Analysis of Two Competing Mid-Sized Oxyfuel Combustion Combined Cycles

    Directory of Open Access Journals (Sweden)

    Egill Thorbergsson

    2016-01-01

    Full Text Available A comparative analysis of two mid-sized oxyfuel combustion combined cycles is performed. The two cycles are the semiclosed oxyfuel combustion combined cycle (SCOC-CC and the Graz cycle. In addition, a reference cycle was established as the basis for the analysis of the oxyfuel combustion cycles. A parametric study was conducted where the pressure ratio and the turbine entry temperature were varied. The layout and the design of the SCOC-CC are considerably simpler than the Graz cycle while it achieves the same net efficiency as the Graz cycle. The fact that the efficiencies for the two cycles are close to identical differs from previously reported work. Earlier studies have reported around a 3% points advantage in efficiency for the Graz cycle, which is attributed to the use of a second bottoming cycle. This additional feature is omitted to make the two cycles more comparable in terms of complexity. The Graz cycle has substantially lower pressure ratio at the optimum efficiency and has much higher power density for the gas turbine than both the reference cycle and the SCOC-CC.

  14. [Exploration and demonstration study on drug combination from clinical real world].

    Science.gov (United States)

    Xie, Yan-ming; Wang, Lian-xin; Wang, Yong-yan

    2014-09-01

    Drug combination is extensive in the clinical real world,which is an important part and the inherent requirements of the post-marketing evaluation of traditional Chinese medicine (TCM). The key issues and technology include multi-domain and multi-disciplinary such as the rationality, efficacy and safety evaluation of combination drug starting from clinical real world, study on component in vivo and mechanism of combination drug, the risk/benefit assessment and cost-benefit evaluation of combination drug and so on. The topic has been studied as clinical demonstration on combination therapy of variety of diseases such as coronary heart disease, stroke, insomnia, depression, hepatitis, herpes zoster, psoriasis and ectopic pregnancy. Meanwhile, multi-disciplinary dynamic innovation alliance of clinical drug combination has been presented, which can promote the academic development and improving service ability and level of TCM.

  15. Increasing of Manoeuvrability of Cogeneration Combined Cycle Power Plants Owing to the Usage of Electric Boilers

    Directory of Open Access Journals (Sweden)

    S. Kachan

    2013-01-01

    Full Text Available The paper contains the results of efficiency evaluation  of using the electric boilers to improve maneuver capabilities of the cogeneration combined cycle power plants (as an example, 230 MW combined cycle unit of Minsk CHP-3 in comparison with the traditional steam-turbine units of cogeneration power plants.

  16. Experimental demonstration of passive coherent combining of fiber lasers by phase contrast filtering.

    Science.gov (United States)

    Jeux, François; Desfarges-Berthelemot, Agnès; Kermène, Vincent; Barthelemy, Alain

    2012-12-17

    We report experiments on a new laser architecture involving phase contrast filtering to coherently combine an array of fiber lasers. We demonstrate that the new technique yields a more stable phase-locking than standard methods using only amplitude filtering. A spectral analysis of the output beams shows that the new scheme generates more resonant frequencies common to the coupled lasers. This property can enhance the combining efficiency when the number of lasers to be coupled is large.

  17. Combined Rankin and Organic Rankin Cycles with Screw Expenders

    OpenAIRE

    Tang, Yan

    2014-01-01

    Low pressure saturated steam exists in a lot of industries. The recovery of the energy from the low pressure saturated steam can save tremendous power consumption for those industries. Although the Rankin cycle with a steam turbine can be used to generate the power from the low pressure saturated steam, the isotropic efficiency of the steam turbine is low, the reliability is questionable due to the two phase expansion, and the size is typically large due to the low pressure. This paper presen...

  18. Generating power at high efficiency: combined cycle technology for sustainable energy production

    Energy Technology Data Exchange (ETDEWEB)

    Jeffs, E.

    2008-04-15

    The book reviews key developments in combined cycle technology; gives examples of plants around the world; and looks at how combined cycle technology can evolve to meet future energy needs. Contents are: Introduction; Brief history of development; Some early schemes; Gas turbine developments; Steam generator concepts; The single shaft block; Repowering steam turbines; Combined heat and power; Gas turbines and coal; and What does the future hold?

  19. Innovative open air brayton combined cycle systems for the next generation nuclear power plants

    Science.gov (United States)

    Zohuri, Bahman

    The purpose of this research was to model and analyze a nuclear heated multi-turbine power conversion system operating with atmospheric air as the working fluid. The air is heated by a molten salt, or liquid metal, to gas heat exchanger reaching a peak temperature of 660 0C. The effects of adding a recuperator or a bottoming steam cycle have been addressed. The calculated results are intended to identify paths for future work on the next generation nuclear power plant (GEN-IV). This document describes the proposed system in sufficient detail to communicate a good understanding of the overall system, its components, and intended uses. The architecture is described at the conceptual level, and does not replace a detailed design document. The main part of the study focused on a Brayton --- Rankine Combined Cycle system and a Recuperated Brayton Cycle since they offer the highest overall efficiencies. Open Air Brayton power cycles also require low cooling water flows relative to other power cycles. Although the Recuperated Brayton Cycle achieves an overall efficiency slightly less that the Brayton --- Rankine Combined Cycle, it is completely free of a circulating water system and can be used in a desert climate. Detailed results of modeling a combined cycle Brayton-Rankine power conversion system are presented. The Rankine bottoming cycle appears to offer a slight efficiency advantage over the recuperated Brayton cycle. Both offer very significant advantages over current generation Light Water Reactor steam cycles. The combined cycle was optimized as a unit and lower pressure Rankine systems seem to be more efficient. The combined cycle requires a lot less circulating water than current power plants. The open-air Brayton systems appear to be worth investigating, if the higher temperatures predicted for the Next Generation Nuclear Plant do materialize.

  20. Performance Improvement of Combined Cycle Power Plant Based on the Optimization of the Bottom Cycle and Heat Recuperation

    Institute of Scientific and Technical Information of China (English)

    Wenguo XIANG; Yingying CHEN

    2007-01-01

    Many F class gas turbine combined cycle (GTCC) power plants are built in China at present because of less emission and high efficiency. It is of great interest to investigate the efficiency improvement of GTCC plant. A combined cycle with three-pressure reheat heat recovery steam generator (HRSG) is selected for study in this paper.In order to maximize the GTCC efficiency, the optimization of the HRSG operating parameters is performed. The operating parameters are determined by means of a thermodynamic analysis, i.e. the minimization of exergy losses. The influence of HRSG inlet gas temperature on the steam bottoming cycle efficiency is discussed. The result shows that increasing the HRSG inlet temperature has less improvement to steam cycle efficiency when it is over 590℃. Partial gas to gas recuperation in the topping cycle is studied. Joining HRSG optimization with the use of gas to gas heat recuperation, the combined plant efficiency can rise up to 59.05% at base load. In addition,the part load performance of the GTCC power plant gets much better. The efficiency is increased by 2.11% at 75% load and by 4.17% at 50% load.

  1. The Development of Coke Carried—Heat Gasification Coal—Fired Combined Cycle

    Institute of Scientific and Technical Information of China (English)

    LiZhao; XiangdongXu

    1999-01-01

    Carried-Heat Partial Gasification Combined cycle is a novel combined cycle which was proposed by Thermal Engineering Department of Tsinghua University in 1992,The idea of the system comes from the situation that the efficiency of the power plants in china is much lower than that of the advanced countries,but the coal consumption is much higher,which brings about the waste of primary energy resources and the pollution of the environment.With the deep study of the gasification technology,Coke Carried-Heat Gasification Coal-Fired Combined Cycle,as the improved system,came into birth in 1996 based on the partial gasification one,At the end of 1997,a new cycle scheme similar to IGCC was created.This paper focuses on several classes combined cycle put forward by Tsinghua University,depending on the plant configuration and carbon conversion,making the solution a viable and attractive option for efficient coal utilization.

  2. Thermodynamic efficiency analysis and cycle optimization of deeply precooled combined cycle engine in the air-breathing mode

    Science.gov (United States)

    Zhang, Jianqiang; Wang, Zhenguo; Li, Qinglian

    2017-09-01

    The efficiency calculation and cycle optimization were carried out for the Synergistic Air-Breathing Rocket Engine (SABRE) with deeply precooled combined cycle. A component-level model was developed for the engine, and exergy efficiency analysis based on the model was carried out. The methods to improve cycle efficiency have been proposed. The results indicate cycle efficiency of SABRE is between 29.7% and 41.7% along the flight trajectory, and most of the wasted exergy is occupied by the unburned hydrogen in exit gas. Exergy loss exists in each engine component, and the sum losses of main combustion chamber(CC), pre-burner(PB), precooler(PC) and 3# heat exchanger(HX3) are greater than 71.3% of the total loss. Equivalence ratio is the main influencing factor of cycle, and it can be regulated by adjusting parameters of helium loop. Increase the maximum helium outlet temperature of PC by 50 K, the total assumption of hydrogen will be saved by 4.8%, and the cycle efficiency is advanced by 3% averagely in the trajectory. Helium recirculation scheme introduces a helium recirculation loop to increase local helium flow rate of PC. It turns out the total assumption of hydrogen will be saved by 9%, that's about 1740 kg, and the cycle efficiency is advanced by 5.6% averagely.

  3. The application of cycling and cycling combined with feedback in the rehabilitation of stroke patients: a review.

    Science.gov (United States)

    Barbosa, David; Santos, Cristina P; Martins, Maria

    2015-02-01

    Stroke is a leading cause of long-term disabilities, such as hemiparesis, inability to walk without assistance, and dependence of others in the activities of daily living. Motor function rehabilitation after stroke demands for methods oriented to the recovery of the walking capacity. Because of the similarities with walking, cycling leg exercise may present a solution to this problem. The aim of this article is to review the state of the art applications of cycling leg exercise as a (1) motor function rehabilitation method and an (2) aerobic training method for stroke patients as well as the commonly used (3) assessment tools. The cycling characteristics and applications, the applied test protocols as well as the tools used to assess the state and the recovery of patients and types of cycling devices are presented. In addition, the potential benefits of the use of other therapies, like feedback, together with cycling are explored. The application of cycling leg exercise alone and combined with feedback in stroke rehabilitation approaches has shown promising results. Positive effects on motor abilities were found in subacute and chronic patients. However, larger and normalized studies and assessments are needed because there is a high heterogeneity in the patients' characteristics, protocols and metrics. This wil allow the comparison between different studies related with cycling. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  4. NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Dennis A. Horazak; Richard A. Newby; Eugene E. Smeltzer; Rachid B. Slimane; P. Vann Bush; James L. Aderhold Jr; Bruce G. Bryan

    2005-12-01

    Development efforts have been underway for decades to replace dry-gas cleaning technology with humid-gas cleaning technology that would maintain the water vapor content in the raw gas by conducting cleaning at sufficiently high temperature to avoid water vapor condensation and would thus significantly simplify the plant and improve its thermal efficiency. Siemens Power Generation, Inc. conducted a program with the Gas Technology Institute (GTI) to develop a Novel Gas Cleaning process that uses a new type of gas-sorbent contactor, the ''filter-reactor''. The Filter-Reactor Novel Gas Cleaning process described and evaluated here is in its early stages of development and this evaluation is classified as conceptual. The commercial evaluations have been coupled with integrated Process Development Unit testing performed at a GTI coal gasifier test facility to demonstrate, at sub-scale the process performance capabilities. The commercial evaluations and Process Development Unit test results are presented in Volumes 1 and 2 of this report, respectively. Two gas cleaning applications with significantly differing gas cleaning requirements were considered in the evaluation: IGCC power generation, and Methanol Synthesis with electric power co-production. For the IGCC power generation application, two sets of gas cleaning requirements were applied, one representing the most stringent ''current'' gas cleaning requirements, and a second set representing possible, very stringent ''future'' gas cleaning requirements. Current gas cleaning requirements were used for Methanol Synthesis in the evaluation because these cleaning requirements represent the most stringent of cleaning requirements and the most challenging for the Filter-Reactor Novel Gas Cleaning process. The scope of the evaluation for each application was: (1) Select the configuration for the Filter-Reactor Novel Gas Cleaning Process, the arrangement of the

  5. Catalytic combustor for integrated gasification combined cycle power plant

    Science.gov (United States)

    Bachovchin, Dennis M.; Lippert, Thomas E.

    2008-12-16

    A gasification power plant 10 includes a compressor 32 producing a compressed air flow 36, an air separation unit 22 producing a nitrogen flow 44, a gasifier 14 producing a primary fuel flow 28 and a secondary fuel source 60 providing a secondary fuel flow 62 The plant also includes a catalytic combustor 12 combining the nitrogen flow and a combustor portion 38 of the compressed air flow to form a diluted air flow 39 and combining at least one of the primary fuel flow and secondary fuel flow and a mixer portion 78 of the diluted air flow to produce a combustible mixture 80. A catalytic element 64 of the combustor 12 separately receives the combustible mixture and a backside cooling portion 84 of the diluted air flow and allows the mixture and the heated flow to produce a hot combustion gas 46 provided to a turbine 48. When fueled with the secondary fuel flow, nitrogen is not combined with the combustor portion.

  6. Advanced power cycles and configurations for solar towers: Modeling and optimization of the decoupled solar combined cycle concept

    Science.gov (United States)

    García-Barberena, Javier; Olcoz, Asier; Sorbet, Fco. Javier

    2017-06-01

    CSP technologies are essential to allow large shares of renewables into the grid due to their unique ability to cope with the large variability of the energy resource by means of technically and economically feasible thermal energy storage (TES) systems. However, there is still the need and sought to achieve technological breakthroughs towards cost reductions and increased efficiencies. For this, research on advanced power cycles, like the Decoupled Solar Combined Cycle (DSCC) is, are regarded as a key objective. The DSCC concept is, basically, a Combined Brayton-Rankine cycle in which the bottoming cycle is decoupled from the operation of the topping cycle by means of an intermediate storage system. According to this concept, one or several solar towers driving a solar air receiver and a Gas Turbine (Brayton cycle) feed through their exhaust gasses a single storage system and bottoming cycle. This general concept benefits from a large flexibility in its design. On the one hand, different possible schemes related to number and configuration of solar towers, storage systems media and configuration, bottoming cycles, etc. are possible. On the other, within a specific scheme a large number of design parameters can be optimized, including the solar field size, the operating temperatures and pressures of the receiver, the power of the Brayton and Rankine cycles, the storage capacity and others. Heretofore, DSCC plants have been analyzed by means of simple steady-state models with pre-stablished operating parameters in the power cycles. In this work, a detailed transient simulation model for DSCC plants has been developed and is used to analyze different DSCC plant schemes. For each of the analyzed plant schemes, a sensitivity analysis and selection of the main design parameters is carried out. Results show that an increase in annual solar to electric efficiency of 30% (from 12.91 to 16.78) can be achieved by using two bottoming Rankine cycles at two different

  7. Thermodynamic analysis of gas – steam combined cycle with carbon dioxide (CO2 emissions saving

    Directory of Open Access Journals (Sweden)

    Alka Gupta, Om Prakash, S.K. Shukla

    2011-03-01

    Full Text Available In this paper, cogeneration or combined heat and power (CHP cycle has been analyzed in order to improve the efficiency of the gas – steam combined cycle and utilization of waste heat. The efficiency of the combined cycle is improved by decreasing the compressor inlet temperature (CIT and increasing the turbine inlet temperature (TIT. It is observed that the cycle offers the advantage of making efficient use of the energy available in the fuel and in turn, eliminate some portion of pollution associated with the power generation. The study also reveals that if this cycle is being employed for cogeneration, there is a significant saving (11.60% in the amount of Carbon dioxide (CO2 emitted by the coal-fired thermal power plants.

  8. Combinations of solid oxide fuel cell and several enhanced gas turbine cycles

    Science.gov (United States)

    Kuchonthara, Prapan; Bhattacharya, Sankar; Tsutsumi, Atsushi

    Combined power generation systems with combinations of solid oxide fuel cell (SOFC) and various enhanced gas turbine (GT) cycles were evaluated. In the GT part, steam injected gas turbine (STIG) cycle, GT/steam turbine (ST) combined cycle, and humid air turbine (HAT) cycle were considered. Moreover, additional recuperation was considered by means of air preheating (APH) in the STIG cycle. Effects of operating turbine inlet temperature (TIT) and pressure ratio (PR) on overall system performance were assessed. Although the SOFC-HAT system shows the lowest specific work output compared to other systems, its highest thermal efficiency presents a significant advantage. Furthermore, at high TITs and PRs the SOFC-HAT system gives the best performance in terms of both thermal efficiency and specific work. Results indicate that energy recuperative features in the HAT promote the positive effect of increasing TIT by means of enhancing GT efficiency, leading to the improvement in thermal efficiency of the overall system.

  9. HA demonstration in the Atalante facility of the Ganex 2. cycle for the grouped TRU extraction

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M.; Roussel, H.; Chareyre, L.; Baron, P.; Espinoux, D.; Calor, J.N.; Viallesoubranne, C.; Lorrain, B.; Masson, M. [CEA/DEN/MAR/DRCP, Marcoule, BP17171, 30207 Bagnols/Ceze (France)

    2009-06-15

    The GANEX process (Group Actinide Extraction), developed by the CEA for the reprocessing of Generation IV spent nuclear fuel, is composed of two extraction cycles following the dissolution of the spent fuel. Once the uranium is selectively extracted from the dissolution solution, the transuranium elements (Np, Pu, Am, and Cm) are separated from the fission products in a second cycle, prior to their co-conversion step and their homogeneous recycling. The DIAMEX-SANEX process, initially developed for the partitioning of trivalent minor actinides (Am and Cm), was adapted to handle neptunium and plutonium along with americium and curium and selected as the reference route for the GANEX 2. cycle process. In the first step, actinides, lanthanides and other extractable fission products are co-extracted at high acidity by a mixture of a malonamide (DMDOHEMA) and an organophosphorous acid (HDEHP) diluted in HTP. In a second step, molybdenum, ruthenium and technetium are stripped from the solvent, before the selective recovery of all actinides by a mixture of HEDTA and citric acid at pH 3. The last step consists in stripping the remaining cations using specific aqueous complexing agents. Distribution ratios of actinides and major fission products were acquired at each step of the process and showed the possibility to adapt the DIAMEX-SANEX process to the group actinide extraction after adjusting experimental conditions (selection of complexing agents, optimization of reagent concentrations). From these batch experiments and from cold and hot counter-current tests, previously performed when studying minor actinide partitioning, a model was developed to describe the behaviour of the target elements. This model was implemented into our liquid-liquid process simulation code in order to design a flowsheet, which was tested in 48 mixer-settlers (laboratory scale) in the CBP hot cell (Atalante facility) on the high active raffinate issued from the GANEX 1. cycle test. (authors)

  10. Performance Analysis of Solar Combined Ejector-Vapor Compression Cycle Using Environmental Friendly Refrigerants

    Directory of Open Access Journals (Sweden)

    A. B. Kasaeian

    2013-04-01

    Full Text Available In this study, a new model of a solar combined ejector-vapor compression refrigeration system has been considered. The system is equipped with an internal heat exchanger to enhance the performance of the cycle. The effects of working fluid and operating conditions on the system performance including COP, entrainment ratio (ω, compression ratio (rp and exergy efficiency were investigated. Some working fluids suggested are: R114, R141b, R123, R245fa, R600a, R365mfc, R1234ze(e and R1234ze(z. The results show that R114 and R1234ze(e yield the highest COP and exergy efficiency followed by R123, R245fa, R365mfc, R141b, R152a and R600a. It is noticed that the COP value of the new solar ejector-vapor compression refrigeration cycle is higher than that of the conventional ejector cycle with R1234ze(e for all operating conditions. This paper also demonstrates that R1234ze(e will be a suitable refrigerant in the solar combined ejector-vapor compression refrigeration system, due to its environmental friendly properties and better performance. ABSTRAK: Kajian ini menganalisa model baru sistem penyejukan mampatan gabungan ejektor-wap solar.Sistem ini dilengkapi dengan penukar haba dalaman untuk meningkatkan prestasi kitaran.Kesan bendalir bekerja dan keadaan operasi pada prestasi sistem termasuk COP, nisbah pemerangkapan (ω, nisbah mampatan (rp dan kecekapan eksergi telah disiasat.Beberapa bendalir bekerja yang dicadangkan adalah: R114, R141b, R123, R245fa, R600a, R365mfc, R1234ze(e dan R1234ze(z.Hasil kajian menunjukkan R114 dan R1234ze(e menghasilkan COP dan kecekapan eksergi tertinggi diikuti oleh R123, R245fa, R365mfc, R141b, R152a dan R600a.Didapati nilai COP kitaran penyejukan mampatan bagi ejektor-wap solar baru adalah lebih tinggi daripada kitaran ejektor konvensional dengan R1234ze(e bagi semua keadaan operasi.Kertas kerja ini juga menunjukkan bahawa R1234ze(e boleh menjadi penyejuk yang sesuai dalam sistem penyejukan mampatan gabungan ejektor

  11. Experimental demonstration of spatially coherent beam combining using optical parametric amplification.

    Science.gov (United States)

    Kurita, Takashi; Sueda, Keiichi; Tsubakimoto, Koji; Miyanaga, Noriaki

    2010-07-05

    We experimentally demonstrated coherent beam combining using optical parametric amplification with a nonlinear crystal pumped by random-phased multiple-beam array of the second harmonic of a Nd:YAG laser at 10-Hz repetition rate. In the proof-of-principle experiment, the phase jump between two pump beams was precisely controlled by a motorized actuator. For the demonstration of multiple-beam combining a random phase plate was used to create random-phased beamlets as a pump pulse. Far-field patterns of the pump, the signal, and the idler indicated that the spatially coherent signal beams were obtained on both cases. This approach allows scaling of the intensity of optical parametric chirped pulse amplification up to the exa-watt level while maintaining diffraction-limited beam quality.

  12. Advanced power plant concepts based on CFB combustion and combined cycles

    Energy Technology Data Exchange (ETDEWEB)

    Plass, L.; Beisswenger, H.; Anders, R. (Lurgi GmbH, Frankfurt am Main (Germany, F.R.). Coal and Energy Division)

    1990-01-01

    The paper describes several power plants employing circulating fluidized bed (CFB) technology. The Moabit power plant of BEWAG (Berliner Kraft und Licht Aktiengesellschaft) supplies electric power and steam for district heating. The Charbonnages de France group has built a 367 t/h CFB boiler with reheat at the Emile Huchet power station in Carling, Lorraine France. This uses dry fuel but operation with slurry feed is scheduled soon. The 150 MWe CFB boiler operated by Texas New Mexico Power Company is the largest CFB boiler worldwide. Salient features of boiler design for these plants are discussed. All meet requirements for low SO{sub 2} and NO{sub x} and particulate emission but have been developed to the full. Improved efficiency and low emission levels can be met by combined cycle power plants employing coal gasification. Demonstration plants for example using the BGL-fixed bed gasifier are mentioned. 1 ref., 13 figs., 7 tabs.

  13. CPC air-blown integrated gasification combined cycle project. Quarterly report, October--December 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    The overall project cost and schedule. The combustion turbine commercial operation date is scheduled for 7/1/95 with the combined cycle commercial operation date of 7/1/96. A two year demonstration period will commence after IGCC commercial operation. Details of costs on a total project and DOE Envelope basis along with detailed schedule components were covered. Major cost variances to date were discussed. The major variances this year relate to contracts which were anticipated to be finalized mid 1992 but which are not executed. These include GEESI, the ASU and key vessels. Some of these contracts are almost in place and others are scheduled for the first quarter 1993. Numerous project specifications, process flow diagrams, piping and instrument diagrams and other drawings have been reviewed and approved as part of the preliminary engineering process.

  14. Waste-heat boiler application for the Vresova combined cycle plant

    Energy Technology Data Exchange (ETDEWEB)

    Vicek, Z. [Energoprojekt Praha, Prague (Czechoslovakia)

    1995-12-01

    This report describes a project proposal and implementation of two combined-cycle units of the Vresova Fuel Complex (PKV) with 2 x 200 MWe and heat supply. Participation of ENERGOPROJECT Praha a.s., in this project.

  15. Modeling minor actinide multiple recycling in a lead-cooled fast reactor to demonstrate a fuel cycle without long-lived nuclear waste

    Directory of Open Access Journals (Sweden)

    Stanisz Przemysław

    2015-09-01

    Full Text Available The concept of closed nuclear fuel cycle seems to be the most promising options for the efficient usage of the nuclear energy resources. However, it can be implemented only in fast breeder reactors of the IVth generation, which are characterized by the fast neutron spectrum. The lead-cooled fast reactor (LFR was defined and studied on the level of technical design in order to demonstrate its performance and reliability within the European collaboration on ELSY (European Lead-cooled System and LEADER (Lead-cooled European Advanced Demonstration Reactor projects. It has been demonstrated that LFR meets the requirements of the closed nuclear fuel cycle, where plutonium and minor actinides (MA are recycled for reuse, thereby producing no MA waste. In this study, the most promising option was realized when entire Pu + MA material is fully recycled to produce a new batch of fuel without partitioning. This is the concept of a fuel cycle which asymptotically tends to the adiabatic equilibrium, where the concentrations of plutonium and MA at the beginning of the cycle are restored in the subsequent cycle in the combined process of fuel transmutation and cooling, removal of fission products (FPs, and admixture of depleted uranium. In this way, generation of nuclear waste containing radioactive plutonium and MA can be eliminated. The paper shows methodology applied to the LFR equilibrium fuel cycle assessment, which was developed for the Monte Carlo continuous energy burnup (MCB code, equipped with enhanced modules for material processing and fuel handling. The numerical analysis of the reactor core concerns multiple recycling and recovery of long-lived nuclides and their influence on safety parameters. The paper also presents a general concept of the novel IVth generation breeder reactor with equilibrium fuel and its future role in the management of MA.

  16. Thermodynamic analysis of heat recovery steam generator in combined cycle power plant

    Directory of Open Access Journals (Sweden)

    Ravi Kumar Naradasu

    2007-01-01

    Full Text Available Combined cycle power plants play an important role in the present energy sector. The main challenge in designing a combined cycle power plant is proper utilization of gas turbine exhaust heat in the steam cycle in order to achieve optimum steam turbine output. Most of the combined cycle developers focused on the gas turbine output and neglected the role of the heat recovery steam generator which strongly affects the overall performance of the combined cycle power plant. The present paper is aimed at optimal utilization of the flue gas recovery heat with different heat recovery steam generator configurations of single pressure and dual pressure. The combined cycle efficiency with different heat recovery steam generator configurations have been analyzed parametrically by using first law and second law of thermodynamics. It is observed that in the dual cycle high pressure steam turbine pressure must be high and low pressure steam turbine pressure must be low for better heat recovery from heat recovery steam generator.

  17. eWaterCycle: Live Demonstration of an Operational Hyper Resolution Global Hydrological Model

    Science.gov (United States)

    Drost, N.; Sutanudjaja, E.; Hut, R.; van Meersbergen, M.; Donchyts, G.; Bierkens, M. F.; Van De Giesen, N.

    2014-12-01

    The eWaterCycle project works towards running an operational hyper-resolution hydrological global model, assimilating incoming satellite data in real time, and making 14 day predictions of floods and droughts.In our approach, we aim to re-use existing models and techniques as much as possible, and make use of standards and open source software wherever we can. To couple the different parts of our system we use the Basic Model Interface (BMI) as developped in the CSDMS community.Starting point of the eWaterCycle project was the PCR-GLOBWB model built by Utrecht University. The software behind this model has been partially re-engineered in order to enable it to run in a High Performance Computing (HPC) environment, and to be able to interface using BMI, and run on multiple compute nodes in parallel. The final aim is to have a spatial resolution of 1km x 1km, (currently 10 x 10km).For the data assimilation we make heavy use of the OpenDA system. This allows us to make use of different data assimilation techniques without the need to implement these from scratch. We have developped a BMI adaptor for OpenDA, allowing OpenDA to use any BMI compatible model. As a data assimilation technique we currently use an Ensemble Kalman Filter, and are working on a variant of this technique optimized for HPC environments.One of the next steps in the eWaterCycle project is to couple the model with a hydrodynamic model. Our system will start a localized simulation on demand based on triggers in the global model, giving detailed flow and flood forecasting in support of navigation and disaster management.We will show a live demo of our system, including real-time integration of satellite data.

  18. Qualifications of Candle Filters for Combined Cycle Combustion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Tomasz Wiltowski

    2008-08-31

    The direct firing of coal produces particulate matter that has to be removed for environmental and process reasons. In order to increase the current advanced coal combustion processes, under the U.S. Department of Energy's auspices, Siemens Westinghouse Power Corporation (SWPC) has developed ceramic candle filters that can operate at high temperatures. The Coal Research Center of Southern Illinois University (SIUC), in collaboration with SWPC, developed a program for long-term filter testing at the SIUC Steam Plant followed by experiments using a single-filter reactor unit. The objectives of this program funded by the U.S. Department of Energy were to identify and demonstrate the stability of porous candle filter elements for use in high temperature atmospheric fluidized-bed combustion (AFBC) process applications. These verifications were accomplished through extended time slipstream testing of a candle filter array under AFBC conditions using SIUC's existing AFBC boiler. Temperature, mass flow rate, and differential pressure across the filter array were monitored for a duration of 45 days. After test exposure at SIUC, the filter elements were characterized using Scanning Electron Microscopy and BET surface area analyses. In addition, a single-filter reactor was built and utilized to study long term filter operation, the permeability exhibited by a filter element before and after the slipstream test, and the thermal shock resilience of a used filter by observing differential pressure changes upon rapid heating and cooling of the filter. The data acquired during the slipstream test and the post-test evaluations demonstrated the suitability of filter elements in advanced power generation applications.

  19. ENSO and annual cycle interaction: the combination mode representation in CMIP5 models

    Science.gov (United States)

    Ren, Hong-Li; Zuo, Jinqing; Jin, Fei-Fei; Stuecker, Malte F.

    2016-06-01

    Recent research demonstrated the existence of a combination mode (C-mode) originating from the atmospheric nonlinear interaction between the El Niño-Southern Oscillation (ENSO) and the Pacific warm pool annual cycle. In this paper, we show that the majority of coupled climate models in the Coupled Model Intercomparison Project Phase 5 (CMIP5) are able to reproduce the observed spatial pattern of the C-mode in terms of surface wind anomalies reasonably well, and about half of the coupled models are able to reproduce spectral power at the combination tone periodicities of about 10 and/or 15 months. Compared to the CMIP5 historical simulations, the CMIP5 Atmospheric Model Intercomparison Project (AMIP) simulations can generally exhibit a more realistic simulation of the C-mode due to prescribed lower boundary forcing. Overall, the multi-model ensemble average of the CMIP5 models tends to capture the C-mode better than the individual models. Furthermore, the models with better performance in simulating the ENSO mode tend to also exhibit a more realistic C-mode with respect to its spatial pattern and amplitude, in both the CMIP5 historical and AMIP simulations. This study shows that the CMIP5 models are able to simulate the proposed combination mode mechanism to some degree, resulting from their reasonable performance in representing the ENSO mode. It is suggested that the main ENSO periods in the current climate models needs to be further improved for making the C-mode better.

  20. RL-10 Based Combined Cycle For A Small Reusable Single-Stage-To-Orbit Launcher

    Science.gov (United States)

    Balepin, Vladimir; Price, John; Filipenco, Victor

    1999-01-01

    This paper discusses a new application of the combined propulsion known as the KLIN(TM) cycle, consisting of a thermally integrated deeply cooled turbojet (DCTJ) and liquid rocket engine (LRE). If based on the RL10 rocket engine family, the KLIN (TM) cycle makes a small single-stage-to-orbit (SSTO) reusable launcher feasible and economically very attractive. Considered in this paper are the concept and parameters of a small SSTO reusable launch vehicle (RLV) powered by the KLIN (TM) cycle (sSSTO(TM)) launcher. Also discussed are the benefits of the small launcher, the reusability, and the combined cycle application. This paper shows the significant reduction of the gross take off weight (GTOW) and dry weight of the KLIN(TM) cycle-powered launcher compared to an all-rocket launcher.

  1. Technetium chemistry in the fuel cycle: combining basic and applied studies.

    Science.gov (United States)

    Poineau, Frederic; Mausolf, Edward; Jarvinen, Gordon D; Sattelberger, Alfred P; Czerwinski, Kenneth R

    2013-04-01

    Technetium is intimately linked with nuclear reactions. The ultraminute natural levels in the environment are due to the spontaneous fission of uranium isotopes. The discovery of technetium was born from accelerator reactions, and its use and presence in the modern world are directly due to nuclear reactors. While occupying a central location in the periodic table, the chemistry of technetium is poorly explored, especially when compared to its neighboring elements, i.e., molybdenum, ruthenium, and rhenium. This state of affairs, which is tied to the small number of laboratories equipped to work with the long-lived (99)Tc isotope, provides a remarkable opportunity to combine basic studies with applications for the nuclear fuel cycle. An example is given through examination of the technetium halide compounds. Binary metal halides represent some of the most fundamental of inorganic compounds. The synthesis of new technetium halides demonstrates trends with structure, coordination number, and speciation that can be utilized in the nuclear fuel cycle. Examples are provided for technetium-zirconium alloys as waste forms and the formation of reduced technetium species in separations.

  2. Shock Position Control for Mode Transition in a Turbine Based Combined Cycle Engine Inlet Model

    Science.gov (United States)

    Csank, Jeffrey T.; Stueber, Thomas J.

    2013-01-01

    A dual flow-path inlet for a turbine based combined cycle (TBCC) propulsion system is to be tested in order to evaluate methodologies for performing a controlled inlet mode transition. Prior to experimental testing, simulation models are used to test, debug, and validate potential control algorithms which are designed to maintain shock position during inlet disturbances. One simulation package being used for testing is the High Mach Transient Engine Cycle Code simulation, known as HiTECC. This paper discusses the development of a mode transition schedule for the HiTECC simulation that is analogous to the development of inlet performance maps. Inlet performance maps, derived through experimental means, describe the performance and operability of the inlet as the splitter closes, switching power production from the turbine engine to the Dual Mode Scram Jet. With knowledge of the operability and performance tradeoffs, a closed loop system can be designed to optimize the performance of the inlet. This paper demonstrates the design of the closed loop control system and benefit with the implementation of a Proportional-Integral controller, an H-Infinity based controller, and a disturbance observer based controller; all of which avoid inlet unstart during a mode transition with a simulated disturbance that would lead to inlet unstart without closed loop control.

  3. Analyzing the possibility of constructing the air heating system for an integrated solid fuel gasification combined-cycle power plant

    Science.gov (United States)

    Mikula, V. A.; Ryzhkov, A. F.; Val'tsev, N. V.

    2015-11-01

    Combined-cycle power plants operating on solid fuel have presently been implemented only in demonstration projects. One of possible ways for improving such plants consists in making a shift to hybrid process circuits of integrated gasification combined-cycle plants with external firing of solid fuel. A high-temperature air heater serving to heat compressed air is a key element of the hybrid process circuit. The article describes application of a high-temperature recuperative metal air heater in the process circuit of an integrated gasification combined-cycle power plant (IGCC). The available experience with high-temperature air heating is considered, and possible air heater layout arrangements are analyzed along with domestically produced heat-resistant grades of steel suitable for manufacturing such air heater. An alternative (with respect to the traditional one) design is proposed, according to which solid fuel is fired in a noncooled furnace extension, followed by mixing the combustion products with recirculation gases, after which the mixture is fed to a convective air heater. The use of this design makes it possible to achieve considerably smaller capital outlays and operating costs. The data obtained from thermal and aerodynamic calculations of the high-temperature air heater with a thermal capacity of 258 MW for heating air to a temperature of up to 800°C for being used in the hybrid process circuit of a combined-cycle power plant are presented.

  4. COP Prediction of an ejector refrigeration cycle combined with a vapour compression cycle for automotive air conditioning

    Directory of Open Access Journals (Sweden)

    Nat Suvarnakuta

    2014-03-01

    Full Text Available This paper presents the COP prediction of an ejector refrigeration cycle combined with a vapour compression cycle for automotive air conditioning. Using computational fluid dynamics (CFD technique, the performance of an ejector was analyzed in term of the entrainment ratio (Rm and critical back pressure (CBP. The results from this study were compared with a previous study of combined ejector refrigeration system for automotive air conditioning application [1] which the entrainment ratio (Rm were predicted from one-dimensional (1-D equation. The performance of an ejector (Rm and CBP from CFD and onedimensional method were analyzed and used as database for a mathematical modeling. In order to predict the COP of the combined system, a set of mathematical equations was developed using EES. The operating conditions are chosen accordingly as, intercooler temperature between 15 ๐ C and 25 ๐ C, condenser temperature equal to 35 ๐ C and evaporator temperature equal to 5 ๐ C. However, when generator temperatures are 80 ๐ C, 85 ๐ C and 90 ๐ C, the results showed average relative errors of the COP of an ejector refrigeration cycle (COPej, between CFD and 1-D are 44.64%, 50.47% and 59.68% respectively, and between CFD and 1-D NEW are 1.54%, 0.08% and 6.49% respectively.

  5. NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    Dennis A. Horazak; Richard A. Newby; Eugene E. Smeltzer; Rachid B. Slimane; P. Vann Bush; James L. Aderhold Jr; Bruce G. Bryan

    2005-12-01

    Development efforts have been underway for decades to replace dry-gas cleaning technology with humid-gas cleaning technology that would maintain the water vapor content in the raw gas by conducting cleaning at sufficiently high temperature to avoid water vapor condensation and would thus significantly simplify the plant and improve its thermal efficiency. Siemens Power Generation, Inc. conducted a program with the Gas Technology Institute (GTI) to develop a Novel Gas Cleaning process that uses a new type of gas-sorbent contactor, the ''filter-reactor''. The Filter-Reactor Novel Gas Cleaning process described and evaluated here is in its early stages of development and this evaluation is classified as conceptual. The commercial evaluations have been coupled with integrated Process Development Unit testing performed at a GTI coal gasifier test facility to demonstrate, at sub-scale the process performance capabilities. The commercial evaluations and Process Development Unit test results are presented in Volumes 1 and 2 of this report, respectively. Two gas cleaning applications with significantly differing gas cleaning requirements were considered in the evaluation: IGCC power generation, and Methanol Synthesis with electric power co-production. For the IGCC power generation application, two sets of gas cleaning requirements were applied, one representing the most stringent ''current'' gas cleaning requirements, and a second set representing possible, very stringent ''future'' gas cleaning requirements. Current gas cleaning requirements were used for Methanol Synthesis in the evaluation because these cleaning requirements represent the most stringent of cleaning requirements and the most challenging for the Filter-Reactor Novel Gas Cleaning process. The scope of the evaluation for each application was: (1) Select the configuration for the Filter-Reactor Novel Gas Cleaning Process, the arrangement of the

  6. Waveguide Power Combiner Demonstration for Multiple High Power Millimeter Wave TWTAs

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.; Lesny, Gary G.; Glass, Jeffrey L.

    2004-01-01

    NASA is presently developing nuclear reactor technologies, under Project Prometheus, which will provide spacecraft with greatly increased levels of sustained onboard power and thereby dramatically enhance the capability for future deep space exploration. The first mission planned for use of this high power technology is the Jupiter Icy Moons Orbiter (JIMO). In addition to electric propulsion and science, there will also be unprecedented onboard power available for deep space communications. A 32 GHz transmitter with 1 kW of RF output power is being considered to enable the required very high data transmission rates. One approach to achieving the 1 kW RF power, now being investigated at NASA GRC, is the possible power combining of a number of 100-1 50 W TWTs now under development. The work presented here is the results of a proof-of-concept demonstration of the power combining Ka-band waveguide circuit design and test procedure using two Ka- band TWTAs (Varian model VZA6902V3 and Logimetrics model A440/KA-1066), both of which were previously employed in data uplink evaluation terminals at 29.36 GHz for the NASA Advanced Communications Technology Satellite (ACTS) program. The characterization of the individual TWTAs and power combining demonstration were done over a 500 MHz bandwidth from 29.1 to 29.6 GHz to simulate the Deep Space Network (DSN) bandwidth of 3 1.8 to 32.3 GHz. Figures 1-3 show some of the power transfer and gain measurements of the TWTAs using a swept signal generator (Agilent 83640b) for the RF input. The input and output powers were corrected for circuit insertion losses due to the waveguide components. The RF saturated powers of both ACTS TWTAs were on the order of 120 W, which is comparable to the expected output powers of the 32 GHz TWTs. Additional results for the individual TWTAs will be presented (AM/AM, AM/PM conversion and gain compression), some of which were obtained from swept frequency and power measurements using a vector network

  7. Demonstration of sub-luminal propagation of single-cycle terahertz pulses for particle acceleration

    CERN Document Server

    Walsh, D A; Snedden, E W; Cliffe, M J; Graham, D M; Jamison, S P

    2016-01-01

    The sub-luminal phase velocity of electromagnetic waves in free space is generally unobtainable, being closely linked to forbidden faster than light group velocities. The requirement of effective sub-luminal phase-velocity in laser-driven particle acceleration schemes imposes a fundamental limit on the total acceleration achievable in free-space, and necessitates the use of dielectric structures and waveguides for extending the field-particle interaction. Here we demonstrate a new travelling-source and free space propagation approach to overcoming the sub-luminal propagation limits. The approach exploits the relative ease of generating ultrafast optical sources with slow group velocity propagation, and a group-to-phase front conversion through non-linear optical interaction near a material-vacuum boundary. The concept is demonstrated with two terahertz generation processes, non-linear optical rectification and current-surge rectification. The phase velocity is tunable, both above and below vacuum speed of lig...

  8. New and advanced energy conversion technologies. Analysis of cogeneration, combined and integrated cycles

    Energy Technology Data Exchange (ETDEWEB)

    Korobitsyn, M.A.

    1998-04-03

    Advances within power cycles, integration of cycles, and combination of existing technologies are the possible ways to improve performance of small- and medium-scale power technology. Identification and development of new energy conversion technologies and systems for distributed power generation applications are the objectives of the New Energy Conversion Technologies (NECT) programme of the Netherlands Agency for Energy and Environment (Novem). The part of the programme, which is dedicated to the development of new and improved combinations of existing energy conversion technologies, defines the structure of this thesis. At the beginning, the basic thermodynamic cycles and their specific features are described. Because no single cycle can offer high efficiency due to the intrinsic limitations and the impossibility to operate within a broad temperature range, combined and advanced cycles are addressed. Combined cycles do not suffer from the drawbacks of the single cycles, since the heat rejected by the topping cycle is utilized by the bottoming one, and better performance can be obtained. The basic cycles are combined according to their temperature level: high-temperature cycles are good candidates for the topping application, and medium- or low-temperature cycles for bottoming. Of the combined cycles considered, each cycle is outlined and its schematic diagram is given. In addition to the combined cycles, improvements within a particular cycle are discussed. The scope of the NECT programme covers power and heat production, so industrial cogeneration is assessed in various configurations (steam boiler, gas turbine, heat pumps) and operating modes. Subsequently, several technologies, which are selected for further development within the NECT programme, are analyzed in detail. One of the configurations is the Joule/Joule combined cycle, which consists of an existing gas turbine and an air bottoming turbine. The bottoming cycle adds 20-30% to the power output, which

  9. Combined vapor compression/absorption heat pump cycles for engine-driven heat pumps

    Science.gov (United States)

    Radermacher, Reinhard; Herold, Keith E.; Howe, Lawrence A.

    1988-12-01

    The performance of three combined absorption/vapor compression cycles for gas-fired internal combustion engine driven heat pumps was theoretically assessed. Two cycles were selected for the preliminary design of breadboard systems using only off-the-shelf components. The first cycle, based on the working pair ammonia/water, is termed the simple-cycle. The second cycle, based on the working pair lithium-bromide/water, is termed the compressor enhanced double-effect chiller. Both cycles are found to be technically feasible. The coefficient of performance and the capacity are increased by up to 21 percent for cooling in the first case (compressor efficiency of 0.7) and by up to 14 percent in the second (compressor efficiency of 0.5). Both were compared against the engine drive R22 vapor compression heat pump. The performance of actual machinery for both cycles is, in the current design, hampered by the fact that the desired oil-free compressors have poor isentropic efficiencies. Oil lubricated compressors together with very effective oil separators would improve the performance of the combined LiBr/water cycle to 23 percent.

  10. Integrated Gasifier Combined Cycle Plant with Integrated CO2 – H2S Removal: Performance Analysis, Life Cycle Assessment and Exergetic Life Cycle Assessment

    Directory of Open Access Journals (Sweden)

    Lidia Lombardi

    2002-03-01

    Full Text Available

    The aim of this study is to assess the possibility of reducing CO2 emissions from an Integrated Gasifier Combined Cycle plant, accounting for the entire life cycle.

    With respect to the basic scheme of a conventional Integrated Gasification Combined Cycle - which already includes H2S removal - a shift reaction section followed by CO2 chemical absorption have been added, before the syngas combustion, in order to obtain a clean and H2-rich synthesis gas.

    The proposed plant reaches 38.8 % efficiency vs. 46.4 % efficiency of the corresponding IGCC without CO2 removal. The main reason for the efficiency reduction is the complexity due to the addition of shift and CO2 removal sections and, hence, the related losses in the complex heat recovery process.

    From LCA results, a substantial decrease in the carbon dioxide total production, due to the applied removal technology, is highlighted. In fact, the CO2 equivalent production in the life cycle, per energy unit, is one order of magnitude lower with respect to the parent IGCC.

    Moreover, the major contribution to CO2 production comes from operation/maintenance phase; likely, in the case of Exergetic Life Cycle Assessment: the major exergy destruction - in term of MJ of destroyed exergy per functional unit - comes from operation/maintenance, which is two orders of magnitude greater than the contributions of the other phases.

    The whole cycle has been simulated by means of Aspen Plus 10.1-0.

  11. Analysis of a combined power and refrigeration cycle by the exergy method

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, A. [Posgrado en Ingenieria (Energia), sede CIE-UNAM, Privada Xochicalco s/n, col. Centro, 62580, Temixco, Morelos (Mexico)]. E-mail: avs@cie.unam.mx; Best, R. [Centro de Investigacion en Energia, CIE-UNAM, Privada Xochicalco s/n, col. Centro, 62580, Temixco, Morelos (Mexico); Rivero, R. [Instituto Mexicano del Petroleo, Grupo de Exergia, Eje Central Lazaro Cardenas No. 152, 07730, Mexico D.F. (Mexico); Facultad de Ingenieria, UNAM, Ciudad Universitaria, Mexico D.F. (Mexico); Cervantes, J. [Facultad de Ingenieria, UNAM, Ciudad Universitaria, Mexico D.F. (Mexico)

    2006-12-15

    The exergy analysis method was applied in order to evaluate the new combined cycle proposed by Goswami [Solar thermal technology: present status and ideas for the future. Energy Sources 1998;20:137-45], using Hasan-Goswami-Vijayaraghavan parameters. This new combined cycle was proposed to produce both power and cooling simultaneously with only one heat source and using ammonia-water mixture as the working fluid. The simulation of the cycle was carried out in the process simulator ASPEN Plus. The Redlich-Kwong-Soave equation of state was used to calculate the thermodynamic properties. The cycle was simulated as a reversible as well as an irreversible process to clearly show the effect of the irreversibilities in each component of the cycle. At the irreversible process two cases were considered, changing the environmental temperature. However, in order to know the performance of the new cycle at different conditions of operation, the second irreversible case was analyzed varying the rectification temperatures, the isentropic efficiency of the turbine and the return temperature of the chilled water. Exergy effectiveness values of {approx}53% and {approx}51% were obtained for the irreversible cycles; with heat input requirements at temperatures of 125 and 150 deg. C. Solar collectors or waste heat are suggested as heat sources to operate the cy0009c.

  12. Tampa Electric Company`s Polk Power Station Integrated Gasification Combined Cycle Project

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, S.D.; Shafer, J.R.

    1994-12-31

    Tampa Electric Company (TEC) is in the construction phase for the new Polk Power Station, Unit {number_sign}1. This will be the first unit at a new site and will use Integrated Gasification Combined Cycle (IGCC) technology for power generation. The unit will utilize oxygen-blown entrained-flow coal gasification, along with combined cycle technology, to provide nominal net 26OMW of generation. As part of the environmental features of this process, the sulfur species in the coal will be recovered as a commercial grade sulfuric acid by-product. The sulfur will be removed from the synthesis gas utilizing a cold gas clean-up system (CGCU).

  13. Profit rate performance optimization for a generalized irreversible combined refrigeration cycle

    Indian Academy of Sciences (India)

    Kang Ma; Lingen Chen; Fengrui Sun

    2009-10-01

    Finite-time exergoeconomic performance of a Newtonian heat transfer law system generalized irreversible combined refrigeration cycle model with finite-rate heat transfer, heat leakage and internal irreversibility is presented in this paper. The operation of the generalized irreversible combined refrigeration cycle is viewed as a production process with exergy as its output. The performance optimization of the cycle is performed by taking profit as the objective. The optimal profit rate, optimal COP (coefficient of performance), as well as the relation between the optimal profit rate and COP of the cycle are derived. The focus of this paper is to obtain the compromise optimization between economics (profit rate) and the energy utilization factor (COP) for the cycle, by searching the optimum COP at maximum profit rate, which is termed as the finite time exergoeconomic performance bound. Moreover, the effects of various factors, including heat leakage, internal irreversibility and the price ratio, on the profit rate performance of the cycle are analysed by detailed numerical examples.

  14. Glucosinolate biosynthesis: demonstration and characterization of the condensing enzyme of the chain elongation cycle in Eruca sativa.

    Science.gov (United States)

    Falk, Kimberly L; Vogel, Christine; Textor, Susanne; Bartram, Stefan; Hick, Alastair; Pickett, John A; Gershenzon, Jonathan

    2004-04-01

    Glucosinolates are a group of sulfur-rich thioglucoside natural products common in the Brassicaceae and related plant families. The first phase in the formation of many glucosinolates involves the chain extension of the amino acid methionine. Additional methylene groups are inserted into the side chain of methionine by a three-step elongation cycle involving 2-oxo acid intermediates. This investigation demonstrated the first step of this chain elongation cycle in a partially-purified preparation from arugula (Eruca sativa). The 2-oxo acid derived from methionine, 4-methylthio-2-oxobutanoic acid, was shown to condense with acetyl-CoA to form 2-(2'-methylthioethyl)malate. The catalyst, designated as a 2-(omega-methylthioalkyl)malate synthase, belongs to a family of enzymes that mediate the condensation of acyl-CoAs with 2-oxo acids, including citrate synthase of the citric acid cycle, and 2-isopropylmalate synthase of leucine biosynthesis. The 2-(omega-methylthioalkyl)malate synthase studied here shares properties with other enzymes of this class, but appears chromatographically distinct and is found only in extracts of plant species producing glucosinolates from chain-elongated methionine derivatives. Although the principal glucosinolates of arugula are formed from methionine that has undergone two rounds of chain elongation to form dihomomethionine, studies with substrates and substrate analogs of different chain lengths showed that the isolated enzyme is responsible only for the condensation step of the first round of elongation.

  15. Thermoeconomic impact on combined cycle performance of advanced blade cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghigliazza, Francesco; Traverso, Alberto; Massardo, Aristide Fausto [Thermochemical Power Group (TPG), Dipartimento di Macchine, Sistemi Energetici e Trasporti (DIMSET) - University of Genoa (Italy)

    2009-10-15

    In this work the thermoeconomic features of two different combined cycles using air ''open loop'' and steam ''closed loop'' cooled gas turbines are presented and compared in depth. In order to properly estimate both thermodynamic and thermoeconomic performance of the different combined cycles an analytical model of the blade cooling system has been developed in details and outlined in the paper. Internal Thermoeconomic functional analysis is not performed here, as only economic results are shown and discussed. The blade cooling detailed model, originally developed by TPG researchers, has been integrated into the web based modular code WTEMP, already validated for GT based cycles, developed in the last ten years by TPG. It is shown that the closed loop blade cooling configuration has the greatest potential in terms of thermodynamic efficiency and economic competitivity in the mid-term. (author)

  16. A Novel Absorption Cycle for Combined Water Heating, Dehumidification, and Evaporative Cooling

    Energy Technology Data Exchange (ETDEWEB)

    CHUGH, Devesh [University of Florida, Gainesville; Gluesenkamp, Kyle R [ORNL; Abdelaziz, Omar [ORNL; Moghaddam, Saeed [University of Florida, Gainesville

    2014-01-01

    In this study, development of a novel system for combined water heating, dehumidification, and space evaporative cooling is discussed. Ambient water vapor is used as a working fluid in an open system. First, water vapor is absorbed from an air stream into an absorbent solution. The latent heat of absorption is transferred into the process water that cools the absorber. The solution is then regenerated in the desorber, where it is heated by a heating fluid. The water vapor generated in the desorber is condensed and its heat of phase change is transferred to the process water in the condenser. The condensed water can then be used in an evaporative cooling process to cool the dehumidified air exiting the absorber, or it can be drained if primarily dehumidification is desired. Essentially, this open absorption cycle collects space heat and transfers it to process water. This technology is enabled by a membrane-based absorption/desorption process in which the absorbent is constrained by hydrophobic vapor-permeable membranes. Constraining the absorbent film has enabled fabrication of the absorber and desorber in a plate-and-frame configuration. An air stream can flow against the membrane at high speed without entraining the absorbent, which is a challenge in conventional dehumidifiers. Furthermore, the absorption and desorption rates of an absorbent constrained by a membrane are greatly enhanced. Isfahani and Moghaddam (Int. J. Heat Mass Transfer, 2013) demonstrated absorption rates of up to 0.008 kg/m2s in a membrane-based absorber and Isfahani et al. (Int. J. Multiphase Flow, 2013) have reported a desorption rate of 0.01 kg/m2s in a membrane-based desorber. The membrane-based architecture also enables economical small-scale systems, novel cycle configurations, and high efficiencies. The absorber, solution heat exchanger, and desorber are fabricated on a single metal sheet. In addition to the open arrangement and membrane-based architecture, another novel feature of the

  17. COMBINED CYCLE GAS TURBINE FOR THERMAL POWER STATIONS: EXPERIENCE IN DESIGNING AND OPERATION, PROSPECTS IN APPLICATION

    Directory of Open Access Journals (Sweden)

    N. V. Karnitsky

    2014-01-01

    Full Text Available The paper has reviewed main world tendencies in power consumption and power system structure. Main schemes of combined cycle gas turbines have been considered in the paper. The paper contains an operational analysis of CCGT blocks that are operating within the Belarusian energy system. The analysis results have been given in tables showing main operational indices of power blocks

  18. Energetic analysis and optimisation of an integrated coal gasification-combined cycle power plant

    NARCIS (Netherlands)

    Vlaswinkel, E.E.

    1992-01-01

    Methods are presented to analyse and optimise the energetic performance of integrated coal gasification-combined cycle (IGCC) power plants. The methods involve exergy analysis and pinch technology and can be used to identify key process parameters and to generate alternative design options for impro

  19. Post combustion in combined cycle power plants; La post-combustion nei cicli combinati

    Energy Technology Data Exchange (ETDEWEB)

    Gozzi, M. [comp. (Italy)

    2002-02-01

    Post combustion is a valid aid for combined cycle gas turbine, are evaluated environmental impact and effectiveness. [Italian] La combustione addizionale puo' essere un valido ausilio per i cicli combinati con turbina a gas. I limiti di convenienza. La valutazione dell'impatto ambientale.

  20. Design for the 145MW blast furnance gas firing gas turbine combined cycle plant

    Energy Technology Data Exchange (ETDEWEB)

    Takano, H. (Kawasaki Steel Corp., Chiba (Japan). Technical Research Lab.); Kitauchi, Y.; Hiura, H. (Mitsubishi Heavy Industries Ltd., Takasago, Hyogo (Japan). Takasago Works)

    1988-01-01

    A 145 MW blast furnance gas firing gas turbine combined cycle plant was designed and installed in a steel works of Japan as a repowering unit. A 124 MW large scale gas turbine with turbine inlet temperature 1150{sup {degrees}}C (1423 K) was adopted as a core engine for the combined cycle plant. The fuel of this gas turbine is blast furnace gas mixed with coke oven gas which are byproducts in steel works, and the calorific value of the mixed gas to be controlled is about 1000 kcal/Nm{sup 3} (4187 kJ/Nm{sup 3}). A specially designed multi-cannular type combustor was developed to burn such a low BTV fuel. The gas turbine, generator, steam turbine and fuel gas compressor are connected to make a single shaft configuration. As a result of this introducing the gas turbine combined cycle plant, the plant thermal efficiency was achieved above 45% (at NET) and the total electricity generation in the works is increased from 243 MW to 317 MW. This paper describes the design features of this combined cycle plant.

  1. Uncertainty analysis of integrated gasification combined cycle systems based on Frame 7H versus 7F gas turbines.

    Science.gov (United States)

    Zhu, Yunhua; Frey, H Christopher

    2006-12-01

    Integrated gasification combined cycle (IGCC) technology is a promising alternative for clean generation of power and coproduction of chemicals from coal and other feedstocks. Advanced concepts for IGCC systems that incorporate state-of-the-art gas turbine systems, however, are not commercially demonstrated. Therefore, there is uncertainty regarding the future commercial-scale performance, emissions, and cost of such technologies. The Frame 7F gas turbine represents current state-of-practice, whereas the Frame 7H is the most recently introduced advanced commercial gas turbine. The objective of this study was to evaluate the risks and potential payoffs of IGCC technology based on different gas turbine combined cycle designs. Models of entrained-flow gasifier-based IGCC systems with Frame 7F (IGCC-7F) and 7H gas turbine combined cycles (IGCC-7H) were developed in ASPEN Plus. An uncertainty analysis was conducted. Gasifier carbon conversion and project cost uncertainty are identified as the most important uncertain inputs with respect to system performance and cost. The uncertainties in the difference of the efficiencies and costs for the two systems are characterized. Despite uncertainty, the IGCC-7H system is robustly preferred to the IGCC-7F system. Advances in gas turbine design will improve the performance, emissions, and cost of IGCC systems. The implications of this study for decision-making regarding technology selection, research planning, and plant operation are discussed.

  2. Thermodynamic Analyses of Biomass Gasification Integrated Externally Fired, Post-Firing and Dual-Fuel Combined Cycles

    Directory of Open Access Journals (Sweden)

    Saeed Soltani

    2015-01-01

    Full Text Available In the present work, the results are reported of the energy and exergy analyses of three biomass-related processes for electricity generation: the biomass gasification integrated externally fired combined cycle, the biomass gasification integrated dual-fuel combined cycle, and the biomass gasification integrated post-firing combined cycle. The energy efficiency for the biomass gasification integrated post-firing combined cycle is 3% to 6% points higher than for the other cycles. Although the efficiency of the externally fired biomass combined cycle is the lowest, it has an advantage in that it only uses biomass. The energy and exergy efficiencies are maximized for the three configurations at particular values of compressor pressure ratios, and increase with gas turbine inlet temperature. As pressure ratio increases, the mass of air per mass of steam decreases for the biomass gasification integrated post-firing combined cycle, but the pressure ratio has little influence on the ratio of mass of air per mass of steam for the other cycles. The gas turbine exergy efficiency is the highest for the three configurations. The combustion chamber for the dual-fuel cycle exhibits the highest exergy efficiency and that for the post-firing cycle the lowest. Another benefit of the biomass gasification integrated externally fired combined cycle is that it exhibits the highest air preheater and heat recovery steam generator exergy efficiencies.

  3. Energy and Exergy Analyses of a Combined Power Cycle Using the Organic Rankine Cycle and the Cold Energy of Liquefied Natural Gas

    OpenAIRE

    2015-01-01

    In this work, energy and exergy analyses are carried out for a combined cycle consisting of an organic Rankine cycle (ORC) and a liquefied natural gas (LNG) Rankine cycle for the recovery of low-grade heat sources and LNG cold energy. The effects of the turbine inlet pressure and the working fluid on the system performance are theoretically investigated. A modified temperature-enthalpy diagram is proposed, which can be useful to see the characteristics of the combined cycle, as well as the te...

  4. Performance evaluation of combined ejector LiBr/H2O absorption cooling cycle

    Directory of Open Access Journals (Sweden)

    Hasan Sh. Majdi

    2016-03-01

    Full Text Available The objective of this work is to develop a computer simulation program to evaluate the performance of solar-assited combined ejector absorption (single-effect cooling system using LiBr/H2O as a working fluid and operating under steady-state conditions. The ejector possess no moving parts and is simple and reliable, which makes it attractive for combination with single-stage absorption cycle for further improvement to the system's performance. In this research, improvement to the system is achieved by utilizing the potential kinetic energy of the ejector to enhance refrigeration efficiency. The effects of the entrainment ratio of the ejector, operating temperature, on the thermal loads, and system performance have been investigated. The results showed that the evaporator and condenser loads, post-addition of the ejector, is found to be permanently higher than that in the basic cycle, which indicates a significant enhancement of the proposed cycle and the cooling capacity of the system increasing with the increase in evaporator temperature and entrainment ratio. The COP of the modified cycle is improved by up to 60 % compared with that of the basic cycle at the given condition. This process stabilizes the refrigeration system, enhanced its function, and enabled the system to work under higher condenser temperatures.

  5. Comparison of algae cultivation methods for bioenergy production using a combined life cycle assessment and life cycle costing approach.

    Science.gov (United States)

    Resurreccion, Eleazer P; Colosi, Lisa M; White, Mark A; Clarens, Andres F

    2012-12-01

    Algae are an attractive energy source, but important questions still exist about the sustainability of this technology on a large scale. Two particularly important questions concern the method of cultivation and the type of algae to be used. This present study combines elements of life cycle analysis (LCA) and life cycle costing (LCC) to evaluate open pond (OP) systems and horizontal tubular photobioreactors (PBRs) for the cultivation of freshwater (FW) or brackish-to-saline water (BSW) algae. Based on the LCA, OPs have lower energy consumption and greenhouse gas emissions than PBRs; e.g., 32% less energy use for construction and operation. According to the LCC, all four systems are currently financially unattractive investments, though OPs are less so than PBRs. BSW species deliver better energy and GHG performance and higher profitability than FW species in both OPs and PBRs. Sensitivity analyses suggest that improvements in critical cultivation parameters (e.g., CO(2) utilization efficiency or algae lipid content), conversion parameters (e.g., anaerobic digestion efficiency), and market factors (e.g., costs of CO(2) and electricity, or sale prices for algae biodiesel) could alter these results.

  6. Distinct pathways regulated by RET and estrogen receptor in luminal breast cancer demonstrate the biological basis for combination therapy.

    Science.gov (United States)

    Spanheimer, Philip M; Cyr, Anthony R; Gillum, Matthew P; Woodfield, George W; Askeland, Ryan W; Weigel, Ronald J

    2014-04-01

    We investigated directed therapy based on TFAP2C-regulated pathways to inform new therapeutic approaches for treatment of luminal breast cancer. TFAP2C regulates the expression of genes characterizing the luminal phenotype including ESR1 and RET, but pathway cross talk and potential for distinct elements have not been characterized. Activation of extracellular signal-regulated kinases (ERK) and AKT was assessed using phosphorylation-specific Western blot. Cell proliferation was measured with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] after siRNA (small interfering RNA) gene knockdown or drug treatment. Cell cycle, Ki-67, and cleaved caspase 3 were measured by fluorescence-activated cell sorting. Tumorigenesis was assessed in mice xenografts. Knockdown of TFAP2C or RET inhibited GDNF (glial cell line-derived neurotrophic factor)-mediated activation of ERK and AKT in MCF-7 cells. Similarly, sunitinib, a small-molecule inhibitor of RET, blocked GDNF-mediated activation of ERK and AKT. Inhibition of RET either by gene knockdown or by treatment with sunitinib or vandetanib reduced RET-dependent growth of luminal breast cancer cells. Interestingly, knockdown of TFAP2C, which controls both ER (estrogen receptor) and RET, demonstrated a greater effect on cell growth than either RET or ER alone. Parallel experiments using treatment with tamoxifen and sunitinib confirmed the increased effectiveness of dual inhibition of the ER and RET pathways in regulating cell growth. Whereas targeting the ER pathway altered cell proliferation, as measured by Ki-67 and S-phase, anti-RET primarily increased apoptosis, as demonstrated by cleaved caspase 3 and increased TUNEL (terminal deoxyneucleotidyl transferase dUTP nick end labeling) expression in xenografts. ER and RET primarily function through distinct pathways regulating proliferation and cell survival, respectively. The findings inform a therapeutic approach based on combination therapy with antiestrogen and

  7. Performance Characteristics of Hybrid Cycle Combined Absorption Heat Transformer and Absorption Refrigerating Machine

    Science.gov (United States)

    Iyoki, Shigeki; Otsuka, Shin-Ichi; Uemura, Tadashi

    In this paper, four kinds of hybrid cycles which combined the single-stage absorption refrigerating machine and four kinds of absorption heat transformers were proposed. It is possible that each of these hybrid cycles gets high temperature and low temperature from one cycle, simultaneously. As basic cycle of absorption heat transformer, the following were chosen: two kinds of single-stage absorption heat transformer and two kinds of two-stage absorption heat transformer. As a working medium-absorbent system, H2O-LiBr system, H2O-LiBr-LiNO3 system, H2O-LiBr-LiNO3-LiCl system, H2O-LiBr-C2H6O2 system and H2O-LiNO3-LiCl system were adopted. Using these five kinds of working medium-absorbent system, the performance characteristics of four kinds of hybrid cycle were simulated. And the performance characteristics of these cycles were compared.

  8. Possibilities for the further development of combined cycle power station technology. Moeglichkeiten zur Weiterentwicklung der Kombi-Kraftwerkstechnik

    Energy Technology Data Exchange (ETDEWEB)

    Adlhoch, W. (Rheinbraun AG, Koeln (Germany)); Bolt, N. (KEMA, Arnheim (Netherlands))

    1994-07-01

    Power plant technology has to make a contribution towards the reduction of the global damage of the climate due to the greenhouse effect. Ways of reducing CO[sub 2] emissions are found in the first place in better utilization of the primary energy used. Possibilities for further development of combined cycle power plant technology are described with the aid of selected examples. In addition to theoretical considerations, the paper also describes current development projects, which demonstrate the potential of process engineering and component development. (orig.)

  9. Reuse fo a Cold War Surveillance Drone to Flight Test a NASA Rocket Based Combined Cycle Engine

    Science.gov (United States)

    Brown, T. M.; Smith, Norm

    1999-01-01

    Plans for and early feasibility investigations into the modification of a Lockheed D21B drone to flight test the DRACO Rocket Based Combined Cycle (RBCC) engine are discussed. Modifications include the addition of oxidizer tanks, modern avionics systems, actuators, and a vehicle recovery system. Current study results indicate that the D21B is a suitable candidate for this application and will allow demonstrations of all DRACO engine operating modes at Mach numbers between 0.8 and 4.0. Higher Mach numbers may be achieved with more extensive modification. Possible project risks include low speed stability and control, and recovery techniques.

  10. DESIGN OF COMBINED CYCLE GENERATION SYSTEM WITH HIGH TEMPERATURE FUEL CELL AND STEAM TURBINE

    Institute of Scientific and Technical Information of China (English)

    Yu Lijun; Yuan Junqi; Cao Guangyi

    2003-01-01

    For environment protection and high efficiency, development of new concept power plant has been required in China. The fuel cell is expected to be used in a power plant as a centralized power station or distributed power plant. It is a chemical power generation device that converts the energy of a chemical reaction directly into electrical energy and not limited by Carnot cycle efficiency. The molten carbonate fuel cell (MCFC) power plant has several attractive features I.e. High efficiency and lower emission of Nox and Sox. A combined cycle generation system with MCFC and steam turbine is designed. Its net electrical efficiency LHV is about 55%.

  11. Analysis of a Coal Fired Combined Cycle with Carried—Heat Gasification

    Institute of Scientific and Technical Information of China (English)

    XuXiangdong; F.N.Fett; 等

    1994-01-01

    In the research of a more effcient,less costly,more environmentally responsible and less technically difficult method for generating electrical power from coal.the Carried-heat Gasification combined Cycle (CGCC) is introduced by Tsinghua University.The high efficiency cycle includes carried-heat partial gasification,compressed air heating in a fluidized bed immersed air heater followed by a combustor and the heat recovery of gas turbine exhaust used as the combustion air for the differential-velocity atmospheric circulating fluidized bed(DFBC),Superheat steam is raised in the DFBC boiler,The comparison of results identifies the causes of performance difference between eight cases,Features of the cycle ensure a high coal conversion efficiency within current state of the art.

  12. Experimental Demonstration of Photon Efficient Coherent Temporal Combining for Data Rate Scaling

    Science.gov (United States)

    2016-02-15

    combining a common block of data received by parallel receivers (i.e., spatial coherent combining)12. Recent advances by the fiber telecom industry towards...Chan, "Optical Satellite Networks ," J. Lightw. Technol., vol. 21, pp. 2811-2827, 2003. [4] M. Toyoshima, "Trends in satellite communications and the

  13. Effect of Gas/Steam Turbine Inlet Temperatures on Combined Cycle Having Air Transpiration Cooled Gas Turbine

    Science.gov (United States)

    Kumar, S.; Singh, O.

    2012-10-01

    Worldwide efforts are being made for further improving the gas/steam combined cycle performance by having better blade cooling technology in topping cycle and enhanced heat recovery in bottoming cycle. The scope of improvement is possible through turbines having higher turbine inlet temperatures (TITs) of both gas turbine and steam turbine. Literature review shows that a combined cycle with transpiration cooled gas turbine has not been analyzed with varying gas/steam TITs. In view of above the present study has been undertaken for thermodynamic study of gas/steam combined cycle with respect to variation in TIT in both topping and bottoming cycles, for air transpiration cooled gas turbine. The performance of combined cycle with dual pressure heat recovery steam generator has been evaluated for different cycle pressure ratios (CPRs) varying from 11 to 23 and the selection diagrams presented for TIT varying from 1,600 to 1,900 K. Both the cycle efficiency and specific work increase with TIT for each pressure ratio. For each TIT there exists an optimum pressure ratio for cycle efficiency and specific work. For the CPR of 23 the best cycle performance is seen at a TIT of 1,900 K for maximum steam temperature of 570 °C, which gives the cycle efficiency of 60.9 % with net specific work of 909 kJ/kg.

  14. Thermoeconomic Analysis and Optimization of a New Combined Supercritical Carbon Dioxide Recompression Brayton/Kalina Cycle

    Directory of Open Access Journals (Sweden)

    S. Mohammad S. Mahmoudi

    2016-10-01

    Full Text Available A new combined supercritical CO2 recompression Brayton/Kalina cycle (SCRB/KC is proposed. In the proposed system, waste heat from a supercritical CO2 recompression Brayton cycle (SCRBC is recovered by a Kalina cycle (KC to generate additional electrical power. The performances of the two cycles are simulated and compared using mass, energy and exergy balances of the overall systems and their components. Using the SPECO (Specific Exergy Costing approach and employing selected cost balance equations for the components of each system, the total product unit costs of the cycles are obtained. Parametric studies are performed to investigate the effects on the SCRB/KC and SCRBC thermodynamic and thermoeconomic performances of key decision parameters. In addition, considering the exergy efficiency and total product unit cost as criteria, optimization is performed for the SCRBC and SCRB/KC using Engineering Equation Solver software. The results indicate that the maximum exergy efficiency of the SCRB/KC is higher than that of the SCRBC by up to 10%, and that the minimum total product unit cost of the SCRB/KC is lower than that of the SCRBC by up to 4.9%.

  15. HTR-Based Power Plants’ Performance Analysis Applied on Conventional Combined Cycles

    Directory of Open Access Journals (Sweden)

    José Carbia Carril

    2015-01-01

    Full Text Available In high temperature reactors including gas cooled fast reactors and gas turbine modular helium reactors (GT-MHR specifically designed to operate as power plant heat sources, efficiency enhancement at effective cost under safe conditions can be achieved. Mentioned improvements concern the implementation of two cycle structures: (a, a stand alone Brayton operating with helium and a stand alone Rankine cycle (RC with regeneration, operating with carbon dioxide at ultrasupercritical pressure as working fluid (WF, where condensation is carried out at quasicritical conditions, and (b, a combined cycle (CC, in which the topping closed Brayton cycle (CBC operates with helium as WF, while the bottoming RC is operated with one of the following WFs: carbon dioxide, xenon, ethane, ammonia, or water. In both cases, an intermediate heat exchanger (IHE is proposed to provide thermal energy to the closed Brayton or to the Rankine cycles. The results of the case study show that the thermal efficiency, through the use of a CC, is slightly improved (from 45.79% for BC and from 50.17% for RC to 53.63 for the proposed CC with He-H2O operating under safety standards.

  16. Modelling and Stability of a Single-Shaft Combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    Costas Vournas

    2007-06-01

    Full Text Available The subject of this paper is the development of a dynamic model for a single-shaft combined cycle plant and the analysis of its response to electrical load and frequency transients. In particular the stability of the frequency control, as well as the implications of overheat control are investigated. The model is developed in the Simulink environment of Matlab as part of an educational and research simulation package for autonomous and interconnected systems.

  17. Analysis and Optimization of a Compressed Air Energy Storage—Combined Cycle System

    OpenAIRE

    Wenyi Liu; Linzhi Liu; Luyao Zhou; Jian Huang; Yuwen Zhang; Gang Xu; Yongping Yang

    2014-01-01

    Compressed air energy storage (CAES) is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. This study proposes a CAES-CC system, which is based on a conventional CAES combined with a steam turbine cycle by waste heat boiler. Simulation and thermodynamic analysis...

  18. PNEM cuts NO[sub x] with GT10 combined cycle cogen plants

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1994-03-01

    A combined cycle cogeneration plant commissioned by the Dutch utility NV Provincale Noordbrabantse Energie Maatschappij (PNEM) in s'Hertogenbosch in the Netherlands is now in commercial operation. The site is adjacent to the famous Heineken brewery. The ABB GT10 gas turbine to be used with the boiler supplied by Schelde Breda Boilers, will be the first gas turbine in The Netherlands in this power range (24 MW) with combustion chambers of the dry low NO[sub x] type. (author)

  19. Design Rules and Issues with Respect to Rocket Based Combined Cycles

    Science.gov (United States)

    2010-09-01

    Section Analysis As we seek for the accelerator, the inlet design is quite art of compromise. To make benefits due to air- breathing propulsion, the...Design Rules and Issues with Respect to Rocket Based Combined Cycles 3 - 4 RTO-EN-AVT-185 2.1.2 Combustor Section Analysis Embedded rocket chamber...cause thrust augmentation due to the ejector effects, which in turn, can reduce the requirement for the rocket engine output. In the speed regime with

  20. Generating power at high efficiency combined cycle technology for sustainable energy production

    CERN Document Server

    Jeffs, E

    2008-01-01

    Combined cycle technology is used to generate power at one of the highest levels of efficiency of conventional power plants. It does this through primary generation from a gas turbine coupled with secondary generation from a steam turbine powered by primary exhaust heat. Generating power at high efficiency thoroughly charts the development and implementation of this technology in power plants and looks to the future of the technology, noting the advantages of the most important technical features - including gas turbines, steam generator, combined heat and power and integrated gasification com

  1. Analysis of energetic and exergetic efficiency, and environmental benefits of biomass integrated gasification combined cycle technology.

    Science.gov (United States)

    Mínguez, María; Jiménez, Angel; Rodríguez, Javier; González, Celina; López, Ignacio; Nieto, Rafael

    2013-04-01

    The problem of the high carbon dioxide emissions linked to power generation makes necessary active research on the use of biofuels in gas turbine systems as a promising alternative to fossil fuels. Gasification of biomass waste is particularly of interest in obtaining a fuel to be run in gas turbines, as it is an efficient biomass-to-biofuel conversion process, and an integration into a combined cycle power plant leads to a high performance with regard to energetic efficiency. The goal of this study was to carry out an energetic, exergetic and environmental analysis of the behaviour of an integrated gasification combined cycle (IGCC) plant fuelled with different kinds of biomass waste by means of simulations. A preliminary economic study is also included. Although a technological development in gasification technology is necessary, the results of simulations indicate a high technical and environmental interest in the use of biomass integrated gasification combined cycle (BioIGCC) systems for large-scale power generation from biomass waste.

  2. Numerical analysis and field study of time dependent exergy-energy of a gas-steam combined cycle

    Directory of Open Access Journals (Sweden)

    Barari Bamdad

    2012-01-01

    Full Text Available In this study, time dependent exergy analysis of the Fars Combined Power Plant Cycle has been investigated. Exergy analysis has been used for investigating each part of actual combined cycle by considering irreversibility from Apr 2006 to Oct 2010. Performance analysis has been done for each part by evaluating exergy destruction in each month. By using of exergy analysis, aging of each part has been evaluated respect to time duration. In addition, the rate of lost work for each month has been calculated and variation of this parameter has been considered as a function of aging rate. Finally, effects of exergy destruction of each part have been investigated on exergy destruction of whole cycle. Entire analysis has been done for Unit 3 and 4 of gas turbine cycle which combined by Unit B of steam cycle in Fars Combined Power Plant Cycle located in Fars province in Iran.

  3. Optimization of advenced liquid natural gas-fuelled combined cycle machinery systems for a high-speed ferry

    DEFF Research Database (Denmark)

    Tveitaskog, Kari Anne; Haglind, Fredrik

    2012-01-01

    . Furthermore, practical and operational aspects of using these three machinery systems for a high-speed ferry are discussed. Two scenarios are evaluated. The first scenario evaluates the combined cycles with a given power requirement, optimizing the combined cycle while operating the gas turbine at part load...

  4. Evaluation of Coal Gasification/Combined Cycle Power Plant Feasibility at the Sewells Point Naval Complex, Norfolk, Virginia.

    Science.gov (United States)

    1981-07-01

    This study evaluates the feasibility of installing a coal gasification /combined cycle cogeneration plant at Sewells Point Naval Complex, Norfolk...fired cogeneration cycles. The utility interface, site considerations and economic analyses are also presented. The study includes that a coal ... gasification /combined cycle cogeneration plant supplying 50 MW of electric power and 290,000 lb/hr of steam is technically feasible. (Author)

  5. Evaluation of Coal Gasification/Combined Cycle Power Plant Feasibility at the Sewells Point Naval Complex, Norfolk, Virginia. Summary.

    Science.gov (United States)

    1981-07-01

    This study evaluates the feasibility of installing a coal gasification /combined cycle cogeneration plant at Sewells Point Naval Complex, Norfolk...fired cogeneration cycles. The utility interface, site considerations and economic analyses are also presented. The study concludes that a coal ... gasification /combined cycle cogeneration plant supplying 50 MW of electric power and 290,000 lb/hr of steam is technically feasible. (Author)

  6. Demonstration of Single Axis Combined Attitude Control and Energy Storage Using Two Flywheels

    Science.gov (United States)

    Kenny, Barbara H.; Jansen, Ralph; Kascak, Peter; Dever, Timothy; Santiago, Walter

    2004-01-01

    The energy storage and attitude control subsystems of the typical satellite are presently distinct and separate. Energy storage is conventionally provided by batteries, either NiCd or NiH, and active attitude control is accomplished with control moment gyros (CMGs) or reaction wheels. An overall system mass savings can be realized if these two subsystems are combined using multiple flywheels for simultaneous kinetic energy storage and momentum transfer. Several authors have studied the control of the flywheels to accomplish this and have published simulation results showing the feasibility and performance. This paper presents the first experimental results showing combined energy storage and momentum control about a single axis using two flywheels.

  7. Experimental demonstration of multi-aperture digital coherent combining over a 3.2-km free-space link

    Science.gov (United States)

    Geisler, D. J.; Yarnall, T. M.; Schieler, C. M.; Stevens, M. L.; Robinson, B. S.; Hamilton, S. A.

    2017-02-01

    The next generation free-space optical communications infrastructure will need to support a wide variety of space-to-ground links. As a result of the limited size, weight, and power on space-borne assets, the ground terminals need to scale efficiently to large collection areas to support extremely long link distances or high data rates. Recent advances in integrated digital coherent receivers enable the coherent combining (i.e., full-field addition) of signals from several small apertures to synthesize an effective single large aperture. In this work, we experimentally demonstrate the coherent combining of signals received by four independent receive chains after propagation through a 3:2-km atmospheric channel. Measured results show the practicality of coherently combining the four received signals via digital signal processing after transmission through a turbulent atmosphere. In particular, near-lossless combining is demonstrated using the technique of maximal ratio combining.

  8. A proposed scheme for coal fired combined cycle and its concise performance

    Energy Technology Data Exchange (ETDEWEB)

    Cai, R.X.; Gou, C.H. [Chinese Academy of Sciences, Beijing (China)

    2007-06-15

    For IGCC, the primary investment is too high due to the demand of high gasification efficiency. For PFBCC, the thermal efficiency is too low due to the relatively low turbine inlet temperature and the hot working medium of the gas turbine is not easy to clean. A new scheme is proposed for coal fired combined cycle to overcome the main drawbacks of IGCC and PFBCC. The research targets are developing a new cycle construction of coal fired combined cycle to raise the efficiency and reduce the primary investment. Actually, the new scheme is a synthesis of some existing proposals. It adopts partial gasification to reduce the primary investment of the gasification equipment. The un-gasified surplus solid is then fed to a pressurized fluidized bed boiler, but adopting Curtiss Wright type external combustion to lower the ash content in the working medium. The gas fuel from the partial gasifier is combusted in a top combustor to further increase the working medium temperature. An extremely concise performance estimation method for the new scheme and its equations is proposed in order to easily understand the basic physical meaning of the new system. Some typical calculations based on this concise method are given. Then, a more detailed computation is accomplished with Aspen Plus code. The basic feasibility of this scheme is proven to be favorable.

  9. Combined cycle solar central receiver hybrid power system study. Final technical report. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    This study develops the conceptual design for a commercial-scale (nominal 100 MWe) central receiver solar/fossil fuel hybrid power system with combined cycle energy conversion. A near-term, metallic heat pipe receiver and an advanced ceramic tube receiver hybrid system are defined through parametric and market potential analyses. Comparative evaluations of the cost of power generation, the fuel displacement potential, and the technological readiness of these two systems indicate that the near-term hybrid system has better potential for commercialization by 1990. Based on the assessment of the conceptual design, major cost and performance improvements are projected for the near-term system. Constraints preventing wide-spread use were not identified. Energy storage is not required for this system and analyses show no economic advantages with energy storage provisions. It is concluded that the solar hybrid system is a cost effective alternative to conventional gas turbines and combined cycle generating plants, and has potential for intermediate-load market penetration at 15% annual fuel escalation rate. Due to their flexibility, simple solar/nonsolar interfacing, and short startup cycles, these hybrid plants have significant operating advantages. Utility company comments suggest that hybrid power systems will precede stand-alone solar plants.

  10. Numerical Model of a Variable-Combined-Cycle Engine for Dual Subsonic and Supersonic Cruise

    Directory of Open Access Journals (Sweden)

    Victor Fernandez-Villace

    2013-02-01

    Full Text Available Efficient high speed propulsion requires exploiting the cooling capability of the cryogenic fuel in the propulsion cycle. This paper presents the numerical model of a combined cycle engine while in air turbo-rocket configuration. Specific models of the various heat exchanger modules and the turbomachinery elements were developed to represent the physical behavior at off-design operation. The dynamic nature of the model allows the introduction of the engine control logic that limits the operation of certain subcomponents and extends the overall engine operational envelope. The specific impulse and uninstalled thrust are detailed while flying a determined trajectory between Mach 2.5 and 5 for varying throttling levels throughout the operational envelope.

  11. Thermodynamic modelling and optimization of a dual pressure reheat combined power cycle

    Indian Academy of Sciences (India)

    T Srinivas

    2010-10-01

    Heat recovery steam generator (HRSG) plays a key role on performance of combined cycle (CC). In this work, attention was focused on a dual pressure reheat (DPRH) HRSG to maximize the heat recovery and hence performance of CC. Deaerator, an essential open feed water heater in steam bottoming cycle was located to enhance the efficiency and remove the dissolved gasses in feedwater. Each of the heating section in HRSG is solved from the local flue gas condition with an aim of getting minimum possible temperature difference. For high performance, better conditions for compressor, HRSG sections, steam reheater and deaerator are developed. The CC system is optimized at a gas turbine inlet temperature of 1400°C due to the present available technology of modern gas turbine blade cooling systems. The exergetic losses in CC system are compared with each other. The present DPRH HRSG model has been compared and validated with the plant and published data.

  12. KRW oxygen-blown gasification combined cycle: Carbon dioxide recovery, transport, and disposal

    Energy Technology Data Exchange (ETDEWEB)

    Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.R.

    1996-08-01

    This project emphasizes CO{sub 2}-capture technologies combined with integrated gasification combined-cycle (IGCC) power systems. Complementary evaluations address CO{sub 2} transportation, CO{sub 2} use, and options for the long-term sequestration of unused CO{sub 2}. The intent is to provide the CO{sub 2} budget, or an equivalent CO{sub 2} budget, associated with each of the individual energy-cycle steps, in addition to process design capital and operating costs. The base case is a 458-MW (gross generation) IGCC system that uses an oxygen-blown Kellogg-Rust-Westinghouse agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal feed, and low-pressure glycol sulfur removal followed by Claus/SCOT treatment to produce a saleable product. Mining, feed preparation, and conversion result in a net electric power production for the entire energy cycle of 411 MW, with a CO{sub 2} release rate of 0.801 kg/k Whe. For comparison, in two cases, the gasifier output was taken through water-gas shift and then to low-pressure glycol H{sub 2}S recovery, followed by either low-pressure glycol or membrane CO{sub 2} recovery and then by a combustion turbine being fed a high-hydrogen-content fuel. Two additional cases employed chilled methanol for H{sub 2}S recovery and a fuel cell as the topping cycle with no shift stages. From the IGCC plant, a 500-km pipeline took the CO{sub 2} to geological sequestering. In a comparison of air-blown and oxygen-blown CO{sub 2}-release base cases, the cost of electricity for the air-blown IGCC was 56.86 mills/kWh, and the cost of oxygen-blown IGCC was 58.29 mills/kWh.

  13. Computational Analysis for Rocket-Based Combined-Cycle Systems During Rocket-Only Operation

    Science.gov (United States)

    Steffen, C. J., Jr.; Smith, T. D.; Yungster, S.; Keller, D. J.

    2000-01-01

    A series of Reynolds-averaged Navier-Stokes calculations were employed to study the performance of rocket-based combined-cycle systems operating in an all-rocket mode. This parametric series of calculations were executed within a statistical framework, commonly known as design of experiments. The parametric design space included four geometric and two flowfield variables set at three levels each, for a total of 729 possible combinations. A D-optimal design strategy was selected. It required that only 36 separate computational fluid dynamics (CFD) solutions be performed to develop a full response surface model, which quantified the linear, bilinear, and curvilinear effects of the six experimental variables. The axisymmetric, Reynolds-averaged Navier-Stokes simulations were executed with the NPARC v3.0 code. The response used in the statistical analysis was created from Isp efficiency data integrated from the 36 CFD simulations. The influence of turbulence modeling was analyzed by using both one- and two-equation models. Careful attention was also given to quantify the influence of mesh dependence, iterative convergence, and artificial viscosity upon the resulting statistical model. Thirteen statistically significant effects were observed to have an influence on rocket-based combined-cycle nozzle performance. It was apparent that the free-expansion process, directly downstream of the rocket nozzle, can influence the Isp efficiency. Numerical schlieren images and particle traces have been used to further understand the physical phenomena behind several of the statistically significant results.

  14. Study on effective parameter of the triple-pressure reheat combined cycle performance

    Directory of Open Access Journals (Sweden)

    Ibrahim Thamir K.

    2013-01-01

    Full Text Available The thermodynamic analyses of the triple-pressure reheat combined cycle gas turbines with duct burner are presented and discussed in this paper. The overall performance of a combined cycle gas turbine power plant is influenced by the ambient temperature, compression ratio and turbine inlet temperature. These parameters affect the overall thermal efficiency, power output and the heat-rate. In this study a thermodynamic model was development on an existing actual combined cycle gas turbine (CCGT (In this case study, an effort has been made to enhance the performance of the CCGT through a parametric study using a thermodynamic analysis. The effect of ambient temperature and operation parameter, including compression ratio and turbine inlet temperature, on the overall performance of CCGT are investigated. The code of the performance model for CCGT power plant was developed utilizing the THERMOFLEX software. The simulating results show that the total power output and overall efficiency of a CCGT decrease with increase the ambient temperature because increase the consumption power in the air compressor of a GT. The totals power of a CCGT decreases with increase the compression rate, while the overall efficiency of a CCGT increases with increase the compression ratio to 21, after that the overall efficiency will go down. Far there more the turbine inlet temperature increases the both total power and overall efficiency increase, so the turbine inlet temperature has a strong effect on the overall performance of CCGT power plant. Also the simulation model give a good result compared with MARAFIQ CCGT power plant. With these variables, the turbine inlet temperature causes the greatest overall performance variation.

  15. Combined Cycle Fatigue Testing with Ultrasonic Frequency Component of S350 Steel Welded Joint

    Institute of Scientific and Technical Information of China (English)

    柳阳; 王东坡; 邓彩艳; 吴良晨; 尹丹青; 龚宝明

    2014-01-01

    A combined cycle fatigue (CCF) testing system with ultrasonic frequency component was developed to evaluate the CCF properties of S350 steel welded joints in this study. The fatigue testing results indicated that the S-N curves of CCF did not have fatigue limit, which agreed with those of pure high frequency fatigue of welded joints. The S-N curves showed that the CCF strength of welded joints dropped greatly with the increasing interaction between high and low frequency fatigue loading. An approximation design method of CCF was presented using amplitude envelope as the stress range.

  16. Energy impacts of controlling carbon dioxide emissions from an integrated gasification/combined-cycle system

    Energy Technology Data Exchange (ETDEWEB)

    Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.

    1994-08-01

    This paper presents results from a study of the impacts associated with CO{sub 2} recovery in integrated gasification/combined-cycle (IGCC) systems which is being conducted for the Morgantown Energy Technology Center by Argonne National Laboratory. The objective of the study is to compare, on a consistent systems-oriented basis, the energy and economic impacts of adding CO{sub 2} capture and sequestration to an IGCC system. The research reported here has emphasized commercial technologies for capturing CO{sub 2}, but ongoing work is also addressing advanced technologies under development and alternate power-system configurations that may enhance system efficiency.

  17. A dynamic process model of a natural gas combined cycle -- Model development with startup and shutdown simulations

    Energy Technology Data Exchange (ETDEWEB)

    Liese, Eric [U.S. DOE; Zitney, Stephen E. [U.S. DOE

    2013-01-01

    Research in dynamic process simulation for integrated gasification combined cycles (IGCC) with carbon capture has been ongoing at the National Energy Technology Laboratory (NETL), culminating in a full operator training simulator (OTS) and immersive training simulator (ITS) for use in both operator training and research. A derivative work of the IGCC dynamic simulator has been a modification of the combined cycle section to more closely represent a typical natural gas fired combined cycle (NGCC). This paper describes the NGCC dynamic process model and highlights some of the simulator’s current capabilities through a particular startup and shutdown scenario.

  18. Demonstration of combined zero-valent iron and electrical resistance heating for in situ trichloroethene remediation.

    Science.gov (United States)

    Truex, M J; Macbeth, T W; Vermeul, V R; Fritz, B G; Mendoza, D P; Mackley, R D; Wietsma, T W; Sandberg, G; Powell, T; Powers, J; Pitre, E; Michalsen, M; Ballock-Dixon, S J; Zhong, L; Oostrom, M

    2011-06-15

    The effectiveness of in situ treatment using zero-valent iron (ZVI) for nonaqueous phase or significant sediment-associated contaminant mass can be limited by relatively low rates of mass transfer to bring contaminants in contact with the reactive media. For a field test in a trichloroethene (TCE) source area, combining moderate-temperature subsurface electrical resistance heating with in situ ZVI treatment was shown to accelerate TCE treatment by a factor of about 4 based on organic daughter products and a factor about 8 based on chloride concentrations. A mass-discharge-based analysis was used to evaluate reaction, dissolution, and volatilization processes at ambient groundwater temperature (~10 °C) and as temperature was increased up to about 50 °C. Increased reaction and contaminant dissolution were observed with increased temperature, but vapor- or aqueous-phase migration of TCE out of the treatment zone was minimal during the test because reactions maintained low aqueous-phase TCE concentrations.

  19. Angiogenesis inhibition and cell cycle arrest induced by treatment with Pseudolarix acid B alone or combined with 5-fluorouracil

    Institute of Scientific and Technical Information of China (English)

    Jingtao Liu; Wei Guo; Bo Xu; Fuxiang Ran; Mingming Chu; Hongzheng Fu; Jingrong Cui

    2012-01-01

    Angiogenesis inhibitors combined with chemotherapeutic drugs have significant efficacy in the treatment of a variety of cancers.Pseudolarix acid B (PAB) is a traditional pregnancy-terminating agent,which has previously been shown to reduce tumor growth and angiogenesis.In this study,we used the high content screening assay to examine the effects of PAB on human umbilical vein endothelial cells (HUVECs).Two hepatocarcinoma 22-transplanted mouse models were used to determine PAB efficacy in combination with 5-fluorouracil (5-Fu).Our results suggested that PAB (0.156-1.250 μM) inhibited HUVECs motility in a concentration-dependent manner without obvious cytotoxicity in vitro.In vivo,PAB (25 mg/kg/day) promoted the anti-tumor efficacy of 5-Fu (5 mg/kg/2 days) in combination therapy,resulting in significantly higher tumor inhibition rates,lower microvessel density values,and prolonged survival times.It was also demonstrated that PAB acted by blocking the cell cycle at both the G1/S boundary and M phase,down-regulation of vascular endothelial growth factor,hypoxia-inducible factor 1α and cyclin E expression,and up-regulation of cdc2 expression.These observations provide the first evidence that PAB in combination with 5-Fu may be useful in cancer treatment.

  20. Gasification/combined-cycle power generation: environmental assessment of alternative systems

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    This report provides a basis for the comparative assessment of the potential performance capability, technological development, and economic and environmental impact associated with the operation of integrated low-Btu coal-gasification/combined-cycle power systems. Characterization of the integrated power system in terms of fuel processing, power production, and auxiliary systems is followed up with comparisons of alternative integrated-plant-design/fuel combinations with reference to the conventional coal-fired power plant, taking into account both economic and environmental factors. The report includes an assessment of the effects of recent regulatory changes on the prospects for integrated power systems and establishes a timetable for the probable commercial development of such systems by the utilities.

  1. Exergy Analysis of Gas Turbine – Fuel cell based combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    M.Sreeramulu,

    2011-06-01

    Full Text Available The increase in demand for electrical energy leads to the newer power generation systems. Though it is not new, fuel cell technology is one of the promising systems for cleaner and competitive alternate power generation system. When the fuel cells are integrated with the Gas Turbines, the total thermal efficiency of the combined cycle is obtained greater than 60%. In this paper, thermodynamic analysis of SOFC-GT combined system (2.898MW has been carried out, exergy efficiency and exergy destruction of each component are calculated.The effect of compression ratio (rp, turbine inlet temperature (TIT and ambient temperature of air, on the performance of the system has been analyzed. Outcome of the system modeling reveals that SOFC andcombustion chamber are the main sources of exergy destruction. At the optimum compression ratio 9, the total thermal efficiency and exergy efficiency are found to be 63.3% and 60.85% respectively.

  2. Exergetic Analysis of a Novel Solar Cooling System for Combined Cycle Power Plants

    Directory of Open Access Journals (Sweden)

    Francesco Calise

    2016-09-01

    Full Text Available This paper presents a detailed exergetic analysis of a novel high-temperature Solar Assisted Combined Cycle (SACC power plant. The system includes a solar field consisting of innovative high-temperature flat plate evacuated solar thermal collectors, a double stage LiBr-H2O absorption chiller, pumps, heat exchangers, storage tanks, mixers, diverters, controllers and a simple single-pressure Combined Cycle (CC power plant. Here, a high temperature solar cooling system is coupled with a conventional combined cycle, in order to pre-cool gas turbine inlet air in order to enhance system efficiency and electrical capacity. In this paper, the system is analyzed from an exergetic point of view, on the basis of an energy-economic model presented in a recent work, where the obtained main results show that SACC exhibits a higher electrical production and efficiency with respect to the conventional CC. The system performance is evaluated by a dynamic simulation, where detailed simulation models are implemented for all the components included in the system. In addition, for all the components and for the system as whole, energy and exergy balances are implemented in order to calculate the magnitude of the irreversibilities within the system. In fact, exergy analysis is used in order to assess: exergy destructions and exergetic efficiencies. Such parameters are used in order to evaluate the magnitude of the irreversibilities in the system and to identify the sources of such irreversibilities. Exergetic efficiencies and exergy destructions are dynamically calculated for the 1-year operation of the system. Similarly, exergetic results are also integrated on weekly and yearly bases in order to evaluate the corresponding irreversibilities. The results showed that the components of the Joule cycle (combustor, turbine and compressor are the major sources of irreversibilities. System overall exergetic efficiency was around 48%. Average weekly solar collector

  3. Demonstration of Combined Zero-Valent Iron and Electrical Resistance Heating for In Situ Trichloroethene Remediation

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Macbeth, Tamzen; Vermeul, Vincent R.; Fritz, Brad G.; Mendoza, Donaldo P.; Mackley, Rob D.; Wietsma, Thomas W.; Sandberg, Greg; Powell, Thomas; Powers, Jeff; Pitre, Emile; Michalsen, Mandy M.; Ballock-Dixon, Sage; Zhong, Lirong; Oostrom, Martinus

    2011-06-27

    The effectiveness of in situ treatment using zero-valent iron to remediate sites with non-aqueous phase or significant sediment-associated contaminant mass can be limited by relatively low rates of mass transfer to bring contaminants in contact with the reactive media. For a field test in a trichloroethene source area, combining moderate-temperature (maximum 50oC) subsurface electrical resistance heating with in situ ZVI treatment was shown to accelerate dechlorination and dissolution rates by a factor of 4 to 6 based on organic daughter products and a factor 8-16 using a chloride concentrations. A mass-discharge-based analysis was used to evaluate reaction, dissolution, and volatilization at ambient groundwater temperature (~10oC) and as temperature was increased up to about 50oC. Increased reaction and contaminant dissolution were observed with increased temperature, but volatilization was minimal during the test because in situ reactions maintained low aqueous-phase TCE concentrations.

  4. Municipal solid wastes incineration with combined cycle: a case study from Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Cerda Balcazar, Juan Galvarino; Dias, Rubens Alves; Balestieri, Jose Antonio Perrella [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil)], E-mails: pos09007@feg.unesp.br, rubdias@feg.unesp.br

    2010-07-01

    Large urban centers have a huge demand for electricity, for the needs of its residents, and a growing problem of management of solid waste generated by it, that becomes an public administrative and great social problem. The correct disposal of solid waste generated by large urban centers is now one of the most complex engineering problems involving logistics, safety, environment, energy spent among other tools for sound management of municipal solid waste (MSW). This study was carried out a study of the use of incinerators and residue derived fuel and MSW with combined cycles, with the aim of producing thermal and mechanical energy (this later becomes electrical energy) and solid waste treatment in Sao Paulo. We used existing models and real plants in the European Union in this case, with the aim of making it the most viable and compatible with the current context of energy planning and resource today. A technical and economic feasibility study for a plant of this nature, using the scheme, is presented. It is expected a good attractiveness of using incinerators combined-cycle, due to its high efficiency and its ability to thermoelectric generation. (author)

  5. Combined cycles, impacts of technological requirements; Ciclos combinados, impactos de requerimientos tecnologicos

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Santalo, Jose Miguel [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    The fundamental growth of the Mexican electrical sector for the next ten years is planned on base of the installation of 20 thousand Mw plants of combined cycle. This article presents an analysis of the impact of these power stations finding out that the power stations of combined cycle are at the moment cheaper - from 600 to 700 dollars by installed kW- than the alternative coal options or fuel oil, that are in the range of 900 to 1200 dollars per kW, in addition to which the time required for their construction is shorter. [Spanish] El crecimiento fundamental del sector electrico mexicano para los proximos diez anos esta planeado con base en la instalacion de 20 mil Mw de plantas de ciclo combinado. Este articulo presenta un analisis del impacto de dichas centrales encontrando que las centrales de ciclo combinado actualmente resultan mas baratas - de 600 a 700 dolares por kW instalado - que las opciones alternativas de carbon o combustoleo que estan en el rango de 900 a 1200 dolares por kW, ademas de que los tiempos requeridos para su construccion son menores.

  6. Analysis of R&D Strategy for Advanced Combined Cycle Power Systems

    Science.gov (United States)

    Akimoto, Keigo; Hayashi, Ayami; Kosugi, Takanobu; Tomoda, Toshimasa

    This article analyzes and evaluates the R&D strategy for advanced power generation technologies, such as natural gas combined cycles, IGCCs (Integrated coal Gasification Combined Cycles), and large-scale fuel cell power generation systems with a mixed-integer programming model. The R&D processes are explicitly formulated in the model through GERT (Graphical Evaluation and Review Technique), and the data on each required time of R&D was collected through questionnaire surveys among the experts. The obtained cost-effective strategy incorporates the optimum investment allocation among the developments of various elemental technologies, and at the same time, it incorporates the least-cost expansion planning of power systems in Japan including other power generation technologies such as conventional coal, oil, and gas fired, and hydro and wind power. The simulation results show the selection of the cost-effective technology developments and the importance of the concentrated investments in them. For example, IGCC, which has a relatively high thermal efficiency, and LNG-CCs of the assumed two efficiencies are the cost-effective investment targets in the no-CO2-regulation case.

  7. Analysis of operation of the gas turbine in a poligeneration combined cycle

    Science.gov (United States)

    Bartela, Łukasz; Kotowicz, Janusz

    2013-12-01

    In the paper the results of analysis of an integrated gasification combined cycle IGCC polygeneration system, of which the task is to produce both electricity and synthesis gas, are shown. Assuming the structure of the system and the power rating of a combined cycle, the consumption of the synthesis gas for chemical production makes it necessary to supplement the lack of synthesis gas used for electricity production with the natural gas. As a result a change of the composition of the fuel gas supplied to the gas turbine occurs. In the paper the influence of the change of gas composition on the gas turbine characteristics is shown. In the calculations of the gas turbine the own computational algorithm was used. During the study the influence of the change of composition of gaseous fuel on the characteristic quantities was examined. The calculations were realized for different cases of cooling of the gas turbine expander's blades (constant cooling air mass flow, constant cooling air index, constant temperature of blade material). Subsequently, the influence of the degree of integration of the gas turbine with the air separation unit on the main characteristics was analyzed.

  8. Mantle convection modeling of the supercontinent cycle:Introversion, extroversion, or a combination?

    Institute of Scientific and Technical Information of China (English)

    Masaki Yoshida; M. Santosh

    2014-01-01

    The periodic assembly and dispersal of continental fragments, referred to as the supercontinent cycle, bear close relation to the evolution of mantle convection and plate tectonics. Supercontinent formation involves complex processes of “introversion” (closure of interior oceans), “extroversion” (closure of exterior oceans), or a combination of these processes in uniting dispersed continental fragments. Recent developments in numerical modeling and advancements in computation techniques enable us to simulate Earth’s mantle convection with drifting continents under realistic convection vigor and rheology in Earth-like geometry (i.e., 3D spherical-shell). We report a numerical simulation of 3D mantle convection, incorporating drifting deformable continents, to evaluate supercontinent processes in a realistic mantle convection regime. Our results show that supercontinents are assembled by a combi-nation of introversion and extroversion processes. Small-scale thermal heterogeneity dominates deep mantle convection during the supercontinent cycle, although large-scale upwelling plumes intermit-tently originate under the drifting continents and/or the supercontinent.

  9. Prospective gas turbine and combined-cycle units for power engineering (a Review)

    Science.gov (United States)

    Ol'khovskii, G. G.

    2013-02-01

    The modern state of technology for making gas turbines around the world and heat-recovery combined-cycle units constructed on their basis are considered. The progress achieved in this field by Siemens, Mitsubishi, General Electric, and Alstom is analyzed, and the objectives these companies set forth for themselves for the near and more distant future are discussed. The 375-MW gas turbine unit with an efficiency of 40% produced by Siemens, which is presently the largest one, is subjected to a detailed analysis. The main specific features of this turbine are that the gas turbine unit's hot-path components have purely air cooling, due to which the installation has enhanced maneuverability. The single-shaft combined-cycle plant constructed on the basis of this turbine has a capacity of 570 MW and efficiency higher than 60%. Programs adopted by different companies for development of new-generation gas turbine units firing synthesis gas and fitted with low-emission combustion chambers and new cooling systems are considered. Concepts of rotor blades for new gas turbine units with improved thermal barrier coatings and composite blades different parts of which are made of materials selected in accordance with the conditions of their operation are discussed.

  10. Single and combined effects of beetroot juice and caffeine supplementation on cycling time trial performance.

    Science.gov (United States)

    Lane, Stephen C; Hawley, John A; Desbrow, Ben; Jones, Andrew M; Blackwell, James R; Ross, Megan L; Zemski, Adam J; Burke, Louise M

    2014-09-01

    Both caffeine and beetroot juice have ergogenic effects on endurance cycling performance. We investigated whether there is an additive effect of these supplements on the performance of a cycling time trial (TT) simulating the 2012 London Olympic Games course. Twelve male and 12 female competitive cyclists each completed 4 experimental trials in a double-blind Latin square design. Trials were undertaken with a caffeinated gum (CAFF) (3 mg·kg(-1) body mass (BM), 40 min prior to the TT), concentrated beetroot juice supplementation (BJ) (8.4 mmol of nitrate (NO3(-)), 2 h prior to the TT), caffeine plus beetroot juice (CAFF+BJ), or a control (CONT). Subjects completed the TT (females: 29.35 km; males: 43.83 km) on a laboratory cycle ergometer under conditions of best practice nutrition: following a carbohydrate-rich pre-event meal, with the ingestion of a carbohydrate-electrolyte drink and regular oral carbohydrate contact during the TT. Compared with CONT, power output was significantly enhanced after CAFF+BJ and CAFF (3.0% and 3.9%, respectively, p supplementation when used alone (-0.4%, p = 0.6 compared with CONT) or when combined with caffeine (-0.9%, p = 0.4 compared with CAFF). We conclude that caffeine (3 mg·kg(-1) BM) administered in the form of a caffeinated gum increased cycling TT performance lasting ∼50-60 min by ∼3%-4% in both males and females. Beetroot juice supplementation was not ergogenic under the conditions of this study.

  11. Optimization of advenced liquid natural gas-fuelled combined cycle machinery systems for a high-speed ferry

    DEFF Research Database (Denmark)

    Tveitaskog, Kari Anne; Haglind, Fredrik

    2012-01-01

    This paper is aimed at designing and optimizing combined cycles for marine applications. For this purpose, an in-house numerical simulation tool called DNA (Dynamic Network Analysis) and a genetic algorithm-based optimization routine are used. The top cycle is modeled as the aero-derivative gas...

  12. Performance analysis of a combined cycle gas turbine power plant by using various inlet air cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Murad A. [Department of Mechanical Engineering, Gazi University (Turkey)], e-mail: mrahim@gazi.edu.tr

    2011-07-01

    In recent years, the use of gas turbines in combined cycle power plants has increased. Turbine inlet air cooling appears to be the best solution for maximizing both production and efficiency, particularly in a hot climate. The aim of this study is to determine the impact of different air cooling systems on the gas turbine's performance and carbon dioxide emissions. Computer simulations were carried out, using the THERMOFLEX program, on fogging, evaporative cooling, adsorption cooling, and electrical chiller cooling systems as well as on a base case without cooling system. Results showed that inlet air cooling systems are effective in increasing the efficiency of gas turbine power plants. In addition it was found that absorption chillers are the best system for increasing power generation but that economic and source analyses should be conducted before installing a cooling system. This paper demonstrated that inlet air cooling systems have the ability to increase net power generation of gas turbine power plants.

  13. Conversion of coal-fired power plants to cogeneration and combined-cycle thermal and economic effectiveness

    CERN Document Server

    Bartnik, Ryszard

    2014-01-01

    This book covers methodology, calculation procedures and tools to support enterprise planning for adapting power stations to cogeneration and combined-cycle forms. It examines the optimum selection of the structure of heat exchangers in a 370 MW power block.

  14. Effect of Gas Turbine Exhaust Temperature, Stack Temperature and Ambient Temperature on Overall Efficiency of Combine Cycle Power Plant

    OpenAIRE

    Khan, M N; K.P.Tyagi

    2010-01-01

    The gas turbine exhaust temperature, stack temperature and ambient temperature play a very important role during the predication of the performance of combine cycle power plant. This paper covers parametric analysis of effects of gas turbine exhaust temperature, stack temperature and ambient temperature on the overall efficiency of combine cycle power plant keeping the gas turbine efficiency as well as steam turbine efficiency constant. The results shows that out of three variables i.e. turbi...

  15. Consequential environmental and economic life cycle assessment of green and gray stormwater infrastructures for combined sewer systems.

    Science.gov (United States)

    Wang, Ranran; Eckelman, Matthew J; Zimmerman, Julie B

    2013-10-01

    A consequential life cycle assessment (LCA) is conducted to evaluate the trade-offs between water quality improvements and the incremental climate, resource, and economic costs of implementing green (bioretention basin, green roof, and permeable pavement) versus gray (municipal separate stormwater sewer systems, MS4) alternatives of stormwater infrastructure expansions against a baseline combined sewer system with combined sewer overflows in a typical Northeast US watershed for typical, dry, and wet years. Results show that bioretention basins can achieve water quality improvement goals (e.g., mitigating freshwater eutrophication) for the least climate and economic costs of 61 kg CO2 eq. and $98 per kg P eq. reduction, respectively. MS4 demonstrates the minimum life cycle fossil energy use of 42 kg oil eq. per kg P eq. reduction. When integrated with the expansion in stormwater infrastructure, implementation of advanced wastewater treatment processes can further reduce the impact of stormwater runoff on aquatic environment at a minimal environmental cost (77 kg CO2 eq. per kg P eq. reduction), which provides support and valuable insights for the further development of integrated management of stormwater and wastewater. The consideration of critical model parameters (i.e., precipitation intensity, land imperviousness, and infrastructure life expectancy) highlighted the importance and implications of varying local conditions and infrastructure characteristics on the costs and benefits of stormwater management. Of particular note is that the impact of MS4 on the local aquatic environment is highly dependent on local runoff quality indicating that a combined system of green infrastructure prior to MS4 potentially provides a more cost-effective improvement to local water quality.

  16. An easy-to-use simulation program demonstrates variations in bacterial cell cycle parameters depending on medium and temperature.

    Science.gov (United States)

    Stokke, Caroline; Flåtten, Ingvild; Skarstad, Kirsten

    2012-01-01

    Many studies are performed on chromosome replication and segregation in Escherichia coli and other bacteria capable of complex replication with C phases spanning several generations. For such investigations an understanding of the replication patterns, including copy numbers of origins and replication forks, is crucial for correct interpretation of the results.Flow cytometry is an important tool for generation of experimental DNA distributions of cell populations. Here, a Visual Basic based simulation program was written for the computation of theoretical DNA distributions for different choices of cell cycle parameters (C and D phase durations, doubling time etc). These cell cycle parameters can be iterated until the best fit between the experimental and theoretical DNA histograms is obtained. The Excel file containing the simulation software is attached as supporting information.Cultures of Escherichia coli were grown at twelve different media and temperature conditions, with following measurements by flow cytometry and simulation of the DNA distributions. A good fit was found for each growth condition by use of our simulation program. The resulting cell cycle parameters displayed clear inter-media differences in replication patterns, but indicated a high degree of temperature independence for each medium. The exception was the poorest medium (acetate), where the cells grew with overlapping replication cycles at 42 °C, but without at the lower temperatures.We have developed an easy-to-use tool for determination of bacteria's cell cycle parameters, and consequently the cells' chromosome configurations. The procedure only requires DNA distribution measurements by flow cytometry. Use of this simulation program for E. coli cultures shows that even cells growing quite slowly can have overlapping replication cycles. It is therefore always important not only to assume cells' replication patterns, but to actually determine the cell cycle parameters when changing growth

  17. An easy-to-use simulation program demonstrates variations in bacterial cell cycle parameters depending on medium and temperature.

    Directory of Open Access Journals (Sweden)

    Caroline Stokke

    Full Text Available Many studies are performed on chromosome replication and segregation in Escherichia coli and other bacteria capable of complex replication with C phases spanning several generations. For such investigations an understanding of the replication patterns, including copy numbers of origins and replication forks, is crucial for correct interpretation of the results.Flow cytometry is an important tool for generation of experimental DNA distributions of cell populations. Here, a Visual Basic based simulation program was written for the computation of theoretical DNA distributions for different choices of cell cycle parameters (C and D phase durations, doubling time etc. These cell cycle parameters can be iterated until the best fit between the experimental and theoretical DNA histograms is obtained. The Excel file containing the simulation software is attached as supporting information.Cultures of Escherichia coli were grown at twelve different media and temperature conditions, with following measurements by flow cytometry and simulation of the DNA distributions. A good fit was found for each growth condition by use of our simulation program. The resulting cell cycle parameters displayed clear inter-media differences in replication patterns, but indicated a high degree of temperature independence for each medium. The exception was the poorest medium (acetate, where the cells grew with overlapping replication cycles at 42 °C, but without at the lower temperatures.We have developed an easy-to-use tool for determination of bacteria's cell cycle parameters, and consequently the cells' chromosome configurations. The procedure only requires DNA distribution measurements by flow cytometry. Use of this simulation program for E. coli cultures shows that even cells growing quite slowly can have overlapping replication cycles. It is therefore always important not only to assume cells' replication patterns, but to actually determine the cell cycle parameters when

  18. Combined Heat and Power Systems Technology Development and Demonstration 370 kW High Efficiency Microturbine

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-10-14

    The C370 Program was awarded in October 2010 with the ambitious goal of designing and testing the most electrically efficient recuperated microturbine engine at a rated power of less than 500 kW. The aggressive targets for electrical efficiency, emission regulatory compliance, and the estimated price point make the system state-of-the-art for microturbine engine systems. These goals will be met by designing a two stage microturbine engine identified as the low pressure spool and high pressure spool that are based on derivative hardware of Capstone’s current commercially available engines. The development and testing of the engine occurred in two phases. Phase I focused on developing a higher power and more efficient engine, that would become the low pressure spool which is based on Capstone’s C200 (200kW) engine architecture. Phase II integrated the low pressure spool created in Phase I with the high pressure spool, which is based on Capstone’s C65 (65 kW) commercially available engine. Integration of the engines, based on preliminary research, would allow the dual spool engine to provide electrical power in excess of 370 kW, with electrical efficiency approaching 42%. If both of these targets were met coupled with the overall CHP target of 85% total combined heating and electrical efficiency California Air Resources Board (CARB) level emissions, and a price target of $600 per kW, the system would represent a step change in the currently available commercial generation technology. Phase I of the C370 program required the development of the C370 low pressure spool. The goal was to increase the C200 engine power by a minimum of 25% — 250 kW — and efficiency from 32% to 37%. These increases in the C200 engine output were imperative to meet the power requirements of the engine when both spools were integrated. An additional benefit of designing and testing the C370 low pressure spool was the possibility of developing a stand-alone product for possible

  19. Combined Heat and Power Systems Technology Development and Demonstration 370 kW High Efficiency Microturbine

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2015-10-14

    The C370 Program was awarded in October 2010 with the ambitious goal of designing and testing the most electrically efficient recuperated microturbine engine at a rated power of less than 500 kW. The aggressive targets for electrical efficiency, emission regulatory compliance, and the estimated price point make the system state-of-the-art for microturbine engine systems. These goals will be met by designing a two stage microturbine engine identified as the low pressure spool and high pressure spool that are based on derivative hardware of Capstone’s current commercially available engines. The development and testing of the engine occurred in two phases. Phase I focused on developing a higher power and more efficient engine, that would become the low pressure spool which is based on Capstone’s C200 (200kW) engine architecture. Phase II integrated the low pressure spool created in Phase I with the high pressure spool, which is based on Capstone’s C65 (65 kW) commercially available engine. Integration of the engines, based on preliminary research, would allow the dual spool engine to provide electrical power in excess of 370 kW, with electrical efficiency approaching 42%. If both of these targets were met coupled with the overall CHP target of 85% total combined heating and electrical efficiency California Air Resources Board (CARB) level emissions, and a price target of $600 per kW, the system would represent a step change in the currently available commercial generation technology. Phase I of the C370 program required the development of the C370 low pressure spool. The goal was to increase the C200 engine power by a minimum of 25% — 250 kW — and efficiency from 32% to 37%. These increases in the C200 engine output were imperative to meet the power requirements of the engine when both spools were integrated. An additional benefit of designing and testing the C370 low pressure spool was the possibility of developing a stand-alone product for possible

  20. The Gonium pectorale genome demonstrates co-option of cell cycle regulation during the evolution of multicellularity

    Science.gov (United States)

    Hanschen, Erik R.; Marriage, Tara N.; Ferris, Patrick J.; Hamaji, Takashi; Toyoda, Atsushi; Fujiyama, Asao; Neme, Rafik; Noguchi, Hideki; Minakuchi, Yohei; Suzuki, Masahiro; Kawai-Toyooka, Hiroko; Smith, David R.; Sparks, Halle; Anderson, Jaden; Bakarić, Robert; Luria, Victor; Karger, Amir; Kirschner, Marc W.; Durand, Pierre M.; Michod, Richard E.; Nozaki, Hisayoshi; Olson, Bradley J. S. C.

    2016-01-01

    The transition to multicellularity has occurred numerous times in all domains of life, yet its initial steps are poorly understood. The volvocine green algae are a tractable system for understanding the genetic basis of multicellularity including the initial formation of cooperative cell groups. Here we report the genome sequence of the undifferentiated colonial alga, Gonium pectorale, where group formation evolved by co-option of the retinoblastoma cell cycle regulatory pathway. Significantly, expression of the Gonium retinoblastoma cell cycle regulator in unicellular Chlamydomonas causes it to become colonial. The presence of these changes in undifferentiated Gonium indicates extensive group-level adaptation during the initial step in the evolution of multicellularity. These results emphasize an early and formative step in the evolution of multicellularity, the evolution of cell cycle regulation, one that may shed light on the evolutionary history of other multicellular innovations and evolutionary transitions. PMID:27102219

  1. The Gonium pectorale genome demonstrates co-option of cell cycle regulation during the evolution of multicellularity.

    Science.gov (United States)

    Hanschen, Erik R; Marriage, Tara N; Ferris, Patrick J; Hamaji, Takashi; Toyoda, Atsushi; Fujiyama, Asao; Neme, Rafik; Noguchi, Hideki; Minakuchi, Yohei; Suzuki, Masahiro; Kawai-Toyooka, Hiroko; Smith, David R; Sparks, Halle; Anderson, Jaden; Bakarić, Robert; Luria, Victor; Karger, Amir; Kirschner, Marc W; Durand, Pierre M; Michod, Richard E; Nozaki, Hisayoshi; Olson, Bradley J S C

    2016-04-22

    The transition to multicellularity has occurred numerous times in all domains of life, yet its initial steps are poorly understood. The volvocine green algae are a tractable system for understanding the genetic basis of multicellularity including the initial formation of cooperative cell groups. Here we report the genome sequence of the undifferentiated colonial alga, Gonium pectorale, where group formation evolved by co-option of the retinoblastoma cell cycle regulatory pathway. Significantly, expression of the Gonium retinoblastoma cell cycle regulator in unicellular Chlamydomonas causes it to become colonial. The presence of these changes in undifferentiated Gonium indicates extensive group-level adaptation during the initial step in the evolution of multicellularity. These results emphasize an early and formative step in the evolution of multicellularity, the evolution of cell cycle regulation, one that may shed light on the evolutionary history of other multicellular innovations and evolutionary transitions.

  2. Durability of Lining Concrete of Subsea Tunnel under Combined Action of Freeze-thaw Cycle and Carbonation

    Institute of Scientific and Technical Information of China (English)

    TIAN Li; CHEN Jingru; ZHAO Tiejun

    2012-01-01

    Through the fast freeze-thaw cycle test,accelerated carbonation test,and natural carbonation test,the durability performance of lining concrete under combined action of freeze-thaw cycle and carbonation were studied.The experimental results indicate that freeze-thaw cycle apparently accelerates the process of concrete carbonation and carbonation deteriorates the freeze resistance of concrete.Under the combined action of freeze-thaw cycle and carbonation,the durability of lining concrete decreases.The carbonation depth of lining concrete at tunnel openings under freeze-thaw cycles and tunnel condition was predicted.For the high performance concrete with proposed mix ratio,the lining concrete tends to be unsafe because predicted carbonation depth exceeds the thickness of reinforced concrete protective coating.Adopting other measurements simultaneously to improve the durability of lining concrete at the tunnel openings is essential.

  3. Process modelling and techno-economic analysis of natural gas combined cycle integrated with calcium looping

    Directory of Open Access Journals (Sweden)

    Erans María

    2016-01-01

    Full Text Available Calcium looping (CaL is promising for large-scale CO2 capture in the power generation and industrial sectors due to the cheap sorbent used and the relatively low energy penalties achieved with this process. Because of the high operating temperatures the heat utilisation is a major advantage of the process, since a significant amount of power can be generated from it. However, this increases its complexity and capital costs. Therefore, not only the energy efficiency performance is important for these cycles, but also the capital costs must be taken into account, i.e. techno-economic analyses are required in order to determine which parameters and configurations are optimal to enhance technology viability in different integration scenarios. In this study the integration scenarios of CaL cycles and natural gas combined cycles (NGCC are explored. The process models of the NGCC and CaL capture plant are developed to explore the most promising scenarios for NGCC-CaL integration with regards to efficiency penalties. Two scenarios are analysed in detail, and show that the system with heat recovery steam generator (HRSG before and after the capture plant exhibited better performance of 49.1% efficiency compared with that of 45.7% when only one HRSG is located after the capture plant. However, the techno-economic analyses showed that the more energy efficient case, with two HRSGs, implies relatively higher cost of electricity (COE, 44.1€/MWh, when compared to that of the reference plant system (33.1€/MWh. The predicted cost of CO2 avoided for the case with two HRSGS is 29.3 €/ton CO2.

  4. Geothermal power plant R and D: an analysis of cost-performance tradeoffs and the Heber Binary-Cycle Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Cassel, T.A.V.; Amundsen, C.B.; Blair, P.D.

    1983-06-30

    A study of advancements in power plant designs for use at geothermal resources in the low to moderate (300 to 400F) temperature range is reported. In 3 case studies, the benefits of R and D to achieve these advancements are evaluated in terms of expected increases in installed geothermal generating capacity over the next 2 decades. A parametric sensitivity study is discussed which analyzes differential power development for combinations of power plant efficiency and capitol cost. Affordable tradeoffs between plant performance and capital costs are illustrated. The independent review and analysis of the expected costs of construction, operation and maintenance of the Heber Binary Cycle Geothermal Power Demonstration Plant are described. Included in this assessment is an analysis of each of the major cost components of the project, including (1) construction cost, (2) well field development costs, (3) fluid purchase costs, and (4) well field and power plant operation and maintenance costs. The total cost of power generated from the Heber Plant (in terms of mills per kWh) is then compared to the cost of power from alternative fossil-fueled base load units. Also evaluated are the provisions of both: (a) the Cooperative Agreement between the federal government and San Diego Gas and Electric (SDG and E); and (b) the Geothermal Heat Sales Contract with Union Oil Company.

  5. Thermoeconomic analysis of Biomass Integrated Gasification Gas Turbine Combined Cycle (BIG GT CC) cogeneration plant

    Energy Technology Data Exchange (ETDEWEB)

    Arrieta, Felipe Raul Ponce; Lora, Electo Silva [Escola Federal de Engenharia de Itajuba, MG (Brazil). Nucleo de Estudos de Sistemas Termicos]. E-mails: aponce@iem.efei.br; electo@iem.efei.br; Perez, Silvia Azucena Nebra de [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: sanebra@fem. unicamp.br

    2000-07-01

    Using thermoeconomics as a tool to identify the location and magnitude of the real thermodynamic losses (energy waste, or exergy destruction and exergy losses) it is possible to assess the production costs of each product (electric power and heat) and the exergetic and exergoeconomic cost of each flow in a cogeneration plant to assist in decision-marketing procedures concerning to plant design, investment, operation and allocations of research funds. Thermo economic analysis of Biomass Integrated Gasification Gas Turbine Combined Cycle (BIG GT CC) cogeneration plant for its applications in sugar cane mills brings the following results: the global exergetic efficiency is low; the highest irreversibilities occur in the following equipment, by order: scrubber (38%), gas turbine (16%), dryer (12%), gasifier and HRSG (6%); due to the adopted cost distribution methodology, the unit exergetic cost of the heat (4,11) is lower than electricity (4,71); the lower market price of biomass is one of the most sensible parameter in the possible implementation of BIG-GT technology in sugar cane industry; the production costs are 31 US$/MWh and 32 US$/MWh for electricity and heat, respectively. The electricity cost is, after all, competitive with the actual market price. The electricity and heat costs are lower or almost equal than other values reported for actual Rankine cycle cogeneration plants. (author)

  6. Thermal Impact of Operating Conditions on the Performance of a Combined Cycle Gas Turbine

    Directory of Open Access Journals (Sweden)

    Thamir K. Ibrahim

    2012-08-01

    Full Text Available The combined cycle gas-turbine (CCGT power plant is a highly developed technology which generates electricalpower at high efficiencies. The first law of thermodynamics is used for energy analysis of the performance of theCCGT plant. The effects of varying the operating conditions (ambient temperature, compression ratio, turbine inlettemperature, isentropic compressor and turbine efficiencies, and mass flow rate of steam on the performance of theCCGT (overall efficiency and total output power were investigated. The programming of the performance model forCCGT was developed utilizing MATLAB software. The simulation results for CCGT show that the overall efficiencyincreases with increases in the compression ratio and turbine inlet temperature and with decreases in ambienttemperature. The total power output increases with increases in the compression ratio, ambient temperature, andturbine inlet temperature. The peak overall efficiency was reached with a higher compression ratio and low ambienttemperature. The overall efficiencies for CCGT were very high compared to the thermal efficiency of GT plants. Theoverall thermal efficiency of the CCGT quoted was around 57%; hence, the compression ratios, ambient temperature,turbine inlet temperature, isentropic compressor and turbine efficiencies, and mass flow rate of steam have a stronginfluence on the overall performance of the CCGT cycle.

  7. Promising Direction of Perfection of the Utilization Combine Cycle Gas Turbine Units

    Directory of Open Access Journals (Sweden)

    Gabdullina Albina I.

    2017-01-01

    Full Text Available Issues of improving the efficiency of combined cycle gas turbines (CCGT recovery type have been presented. Efficiency gas turbine plant reaches values of 45 % due to rise in temperature to a gas turbine to 1700 °C. Modern technologies for improving the cooling gas turbine components and reducing the excess air ratio leads to a further increase of the efficiency by 1-2 %. Based on research conducted at the Tomsk Polytechnic University, it shows that the CCGT efficiency can be increased by 2-3 % in the winter time due to the use of organic Rankine cycle, low-boiling substances, and air-cooled condensers (ACC. It is necessary to apply the waste heat recovery with condensation of water vapor from the flue gas, it will enhance the efficiency of the CCGT by 2-3 % to increase the efficiency of the heat recovery steam boiler (HRSB to 10-12 %. Replacing electric pumps gas turbine engine (GTE helps to reduce electricity consumption for auxiliary needs CCGT by 0.5-1.5 %. At the same time the heat of flue gas turbine engine may be useful used in HRSB, thus will increase the capacity and efficiency of the steam turbine.

  8. Study of the Intercrystalline Corrosion in Pipes of Stainless Steel in a Combined Cycle

    Directory of Open Access Journals (Sweden)

    Raúl Andrés Montejo Serrano

    2014-09-01

    Full Text Available The present work is carried out with the purpose of giving answer to the possible presence ofintercrystalline corrosion and its future consequences in the built tubes of stainless steel 304L anddedicated to the conduction from the water to the boilers of a combined cycle of electricity production.The plant is these in this moments in installation of process investor and assembly and this study wasrequested since during the trial of installation of the pipes of stainless steel that will drive the watertried to the steam generators, they were detected on the part of the operatives some imperfections inthe material, what generated the doubt about the possibility of presence of intercrystalline corrosion orof another type in the pipes. After the realized rehearsals according to international norms and alsousing rehearsals metallography you concludes that the material employee is not sensitive to this typeof corrosion.

  9. Combined nutritional and environmental life cycle assessment of fruits and vegetables

    DEFF Research Database (Denmark)

    Stylianou, Katerina S.; Fantke, Peter; Jolliet, Olivier

    2016-01-01

    -LCA) framework that compares environmental and nutritional effects of foods in a common end -point metric, Disability Adjusted Life Years (DALY). In the assessment, environmental health impact categories include green house gases, particulate matter (PM), and pesticide residues on fruits and vegetables, while......Nutritional health effects from the ‘use stage’ of the life cycle of food products can be substantial, especially for fruits and vegetables. To assess potential one-serving increases in fruit and vegetable consumption in Europe, we employ the Combined Nutritional and Environmental LCA (CONE......; 35 μDALY/serving fruit benefit compared to a factor 10 lower impact. Replacing detrimental foods, such as trans-fat and red meat, with fruits or vegetables further enhances health benefit. This study illustrates the importance of considering nutritional effects in food-LCA....

  10. Family Life Cycle and Deforestation in Amazonia: Combining Remotely Sensed Information with Primary Data

    Science.gov (United States)

    Caldas, M.; Walker, R. T.; Shirota, R.; Perz, S.; Skole, D.

    2003-01-01

    This paper examines the relationships between the socio-demographic characteristics of small settlers in the Brazilian Amazon and the life cycle hypothesis in the process of deforestation. The analysis was conducted combining remote sensing and geographic data with primary data of 153 small settlers along the TransAmazon Highway. Regression analyses and spatial autocorrelation tests were conducted. The results from the empirical model indicate that socio-demographic characteristics of households as well as institutional and market factors, affect the land use decision. Although remotely sensed information is not very popular among Brazilian social scientists, these results confirm that they can be very useful for this kind of study. Furthermore, the research presented by this paper strongly indicates that family and socio-demographic data, as well as market data, may result in misspecification problems. The same applies to models that do not incorporate spatial analysis.

  11. Conceptual design study of a coal gasification combined-cycle powerplant for industrial cogeneration

    Science.gov (United States)

    Bloomfield, H. S.; Nelson, S. G.; Straight, H. F.; Subramaniam, T. K.; Winklepleck, R. G.

    1981-01-01

    A conceptual design study was conducted to assess technical feasibility, environmental characteristics, and economics of coal gasification. The feasibility of a coal gasification combined cycle cogeneration powerplant was examined in response to energy needs and to national policy aimed at decreasing dependence on oil and natural gas. The powerplant provides the steam heating and baseload electrical requirements while serving as a prototype for industrial cogeneration and a modular building block for utility applications. The following topics are discussed: (1) screening of candidate gasification, sulfur removal and power conversion components; (2) definition of a reference system; (3) quantification of plant emissions and waste streams; (4) estimates of capital and operating costs; and (5) a procurement and construction schedule. It is concluded that the proposed powerplant is technically feasible and environmentally superior.

  12. Model predictive control system and method for integrated gasification combined cycle power generation

    Science.gov (United States)

    Kumar, Aditya; Shi, Ruijie; Kumar, Rajeeva; Dokucu, Mustafa

    2013-04-09

    Control system and method for controlling an integrated gasification combined cycle (IGCC) plant are provided. The system may include a controller coupled to a dynamic model of the plant to process a prediction of plant performance and determine a control strategy for the IGCC plant over a time horizon subject to plant constraints. The control strategy may include control functionality to meet a tracking objective and control functionality to meet an optimization objective. The control strategy may be configured to prioritize the tracking objective over the optimization objective based on a coordinate transformation, such as an orthogonal or quasi-orthogonal projection. A plurality of plant control knobs may be set in accordance with the control strategy to generate a sequence of coordinated multivariable control inputs to meet the tracking objective and the optimization objective subject to the prioritization resulting from the coordinate transformation.

  13. Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

    Science.gov (United States)

    Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

    2013-09-17

    System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

  14. Sub-atmospheric disk generators for coal-fired MHD/steam combined cycle power plant

    Energy Technology Data Exchange (ETDEWEB)

    Messerle, H.K.; Fang, Y.; Simpson, S.W.; Marty, S.M. (Sydney Univ. (Australia). School of Electrical Engineering)

    1989-01-01

    A coal fired MHD disk generator in a combined cycle MHD/steam power generation system with a diffuser operating at sub-atmospheric pressure is proposed. The effects of pressure on the performance of a radial outflow MHD disk generator and other system components are analysed. Using a previous study as a reference case, preliminary calculations show that, in such a sub-atmospheric system, improved power station efficiency can be achieved. In addition, operation at reduced values of magnetic field strength would be feasible. Calculations have also been carried out for a 30 MW{sub th} experimental disk generator operating at reduced pressure with a magnetic field strength of 2 T. Flow conditions at sub-atmospheric pressure would provide an improved simulation of a full-scale generator operating at normal pressures. (author).

  15. Combined sulphur cycle based system of hydrogen production and biological treatment of wastewater.

    Science.gov (United States)

    Hua, Li Wei; Lei, Lei; Ningbo, Yang; Wei, Yan

    2009-11-01

    The experiment was conducted to investigate continuous hydrogen production with lower cost and sulphate-rich wastewater treatment. In this paper, both anaerobic bio-treatment of sulphate-rich wastewater and hydrogen production were applied to construct a laboratory-scale combined sulphur cycle based system. The system consisted of two reactors, which were a photocatalytic reactor and an anaerobic bioreactor, respectively. In the anaerobic bioreactor, sulphate-reducing bacteria (SRB) converted SO4(2-) to S(2-). The produced S(2-) yielded by SRB was further used as a sacrificial reagent to produce H2 in the photocatalytic reactor. Then, S(2-) was changed into SO4(2-), which returned to the anaerobic bioreactor for treatment again. The present study highlighted an advantage compared with the conventional method, in that no extra S(2-) was added to the photocatalytic reactor, which reduced the total cost and realized continuous hydrogen production. The average COD removal efficiency was 79.6%.

  16. Family Life Cycle and Deforestation in Amazonia: Combining Remotely Sensed Information with Primary Data

    Science.gov (United States)

    Caldas, M.; Walker, R. T.; Shirota, R.; Perz, S.; Skole, D.

    2003-01-01

    This paper examines the relationships between the socio-demographic characteristics of small settlers in the Brazilian Amazon and the life cycle hypothesis in the process of deforestation. The analysis was conducted combining remote sensing and geographic data with primary data of 153 small settlers along the TransAmazon Highway. Regression analyses and spatial autocorrelation tests were conducted. The results from the empirical model indicate that socio-demographic characteristics of households as well as institutional and market factors, affect the land use decision. Although remotely sensed information is not very popular among Brazilian social scientists, these results confirm that they can be very useful for this kind of study. Furthermore, the research presented by this paper strongly indicates that family and socio-demographic data, as well as market data, may result in misspecification problems. The same applies to models that do not incorporate spatial analysis.

  17. Pre-combustion CO{sub 2} capture: Analysis of integrated reforming combined cycle

    Energy Technology Data Exchange (ETDEWEB)

    Nord, Lars Olof

    2010-06-15

    This thesis presents processes for reducing CO{sub 2} emissions from natural gas (NG) power plants, which could help attenuate the rise in atmospheric temperature. Objectives for the thesis work were process design and integration of NG pre-combustion CO{sub 2} capture plants, and evolution, through process simulation, of the concepts. An important aspect of the evaluation was investigation of plant flexibility, specifically off-design analysis. Contributions comprised detailed heat recovery steam generator (HRSG) design for NG pre-combustion cycles and off-design behavior of the integrated reforming combined cycle (IRCC). Additional contributions were quantification of the efficiency potential of a process, subsystem efficiency losses, and model uncertainties. The IRCC with pre-combustion CO{sub 2} capture is a process for generating power with very low CO{sub 2} emissions, typically below 100 g CO{sub 2}/net kWh electricity. This should be compared to a state-of-the-art natural gas combined cycle (NGCC) with CO{sub 2} emissions around 365 g CO{sub 2}/net kWh electricity. The IRCC process reforms natural gas to a syngas, converts the CO to CO{sub 2} in the shift reactors, separates the CO{sub 2} in the capture subsystem, and the resulting hydrogen-rich fuel is used for the gas turbine (GT) in a combined cycle setup. For the reforming of natural gas, an air-blown auto thermal reformer was selected for the processes studied. Included in the study of the IRCC were process design and integration, reliability analysis, thermodynamic analyses through process simulation, analysis of efficiency losses and efficiency potential, and uncertainty analysis. As part of the design process, HRSG design proved important. The design of an HRSG for an IRCC plant requires the ability to operate on both a hydrogen-rich fuel and on NG. Also, since a significant amount of steam is produced from the heat generated in the auto reforming process, the HRSG design differs from a design in an

  18. Valuing flexibility: The case of an Integrated Gasification Combined Cycle power plant

    Energy Technology Data Exchange (ETDEWEB)

    Abadie, L.M.; Chamorro, J.M. [University of the Basque Country, Bilbao (Spain)

    2008-07-15

    In this paper we analyze the choice between two technologies for producing electricity. In particular, the firm has to decide whether and when to invest either in a Natural Gas Combined Cycle (NGCC) power plant or in an Integrated Gasification Combined Cycle (IGCC) power plant, which may burn either coal or natural gas. Instead of assuming that fuel prices follow standard geometric Brownian motions' here they are assumed to show mean reversion, specifically to follow an inhomogeneous geometric Brownian motion. First we consider the opportunity to invest in a NGCC power plant. We derive the optimal investment rule as a function of natural gas price and the remaining life of the right to invest. In addition, the analytical solution for a perpetual option to invest is obtained. Then we turn to the IGCC power plant. We analyse the valuation of an operating plant when there are switching costs between modes of operation, and the choice of the best operation mode. This serves as an input to evaluate the option to invest in this plant. Finally we derive the value of an opportunity to invest either in a NGCC or IGCC power plant, i.e. to choose between an inflexible and a flexible technology, respectively. Depending on the opportunity's time to maturity, we derive the pairs of coal and gas prices for which it is optimal to invest in NGCC, in IGCC, or simply not to invest. Numerical computations involve the use of one- and two-dimensional binomial lattices that support a mean-reverting process for coal and gas prices. Basic parameter values are taken from an actual IGCC power plant currently in operation. sensitivity of some results with respect to the underlying stochastic process for fuel price is also checked.

  19. Demonstration of Combined Food and Landscape Waste Composting at Fort Leonard Wood, MO: Fort Leonard Wood Installation Strategic Sustainable Plan

    Science.gov (United States)

    2016-01-01

    university postconsumer food wastes . Compost Science and Utilization 6:75-81. Epstein, E. 1997. The Science of Composting. Lancaster, PA: Technomic...Sustainability Innovations (CASI) ERDC/CERL TR-16-1 January 2016 Demonstration of Combined Food and Landscape Waste Composting at Fort Leonard Wood, MO...amendments and organic fertilizers using simple composting technologies, less than 3% of food wastes are recovered and recycled and the remainder are

  20. Ampicillin in Combination with Ceftaroline, Cefepime, or Ceftriaxone Demonstrates Equivalent Activities in a High-Inoculum Enterococcus faecalis Infection Model.

    Science.gov (United States)

    Luther, Megan K; Rice, Louis B; LaPlante, Kerry L

    2016-05-01

    Ampicillin-ceftriaxone combination therapy has become a predominant treatment for serious Enterococcus faecalis infections, such as endocarditis. Unfortunately, ceftriaxone use is associated with future vancomycin-resistant enterococcus colonization. We evaluated E. faecalis in an in vitro pharmacodynamic model against simulated human concentration-time profiles of ampicillin plus ceftaroline, cefepime, ceftriaxone, or gentamicin. Ampicillin-cefepime and ampicillin-ceftaroline demonstrated activities similar to those of ampicillin-ceftriaxone against E. faecalis.

  1. Nuclear Air-Brayton Combined Cycle Power Conversion Design, Physical Performance Estimation and Economic Assessment

    Science.gov (United States)

    Andreades, Charalampos

    The combination of an increased demand for electricity for economic development in parallel with the widespread push for adoption of renewable energy sources and the trend toward liberalized markets has placed a tremendous amount of stress on generators, system operators, and consumers. Non-guaranteed cost recovery, intermittent capacity, and highly volatile market prices are all part of new electricity grids. In order to try and remediate some of these effects, this dissertation proposes and studies the design and performance, both physical and economic, of a novel power conversion system, the Nuclear Air-Brayton Combined Cycle (NACC). The NACC is a power conversion system that takes a conventional industrial frame type gas turbine, modifies it to accept external nuclear heat at 670°C, while also maintaining its ability to co-fire with natural gas to increase temperature and power output at a very quick ramp rate. The NACC addresses the above issues by allowing the generator to gain extra revenue through the provision of ancillary services in addition to energy payments, the grid operator to have a highly flexible source of capacity to back up intermittent renewable energy sources, and the consumer to possibly see less volatile electricity prices and a reduced probability of black/brown outs. This dissertation is split into six sections that delve into specific design and economic issues related to the NACC. The first section describes the basic design and modifications necessary to create a functional externally heated gas turbine, sets a baseline design based upon the GE 7FB, and estimates its physical performance under nominal conditions. The second section explores the off-nominal performance of the NACC and characterizes its startup and shutdown sequences, along with some of its safety measures. The third section deals with the power ramp rate estimation of the NACC, a key performance parameter in a renewable-heavy grid that needs flexible capacity. The

  2. Field operation test of Wakamatsu PFBC combined cycle power plant; Wakamatsu PFBC jissho shiken no genkyo

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T. [Center for Coal Utilization, Japan, Tokyo (Japan); Takanishi, K. [Electric Power Development Co. Ltd., Tokyo (Japan)

    1996-09-01

    At the Wakamatsu Coal Utilization Research Center, the verification test was conducted of atmospheric pressure fluidized bed boilers and ultra-high temperature turbines. The Wakamatsu PFBC (pressurized fluidized bed combustion) is a combined cycle power generation system combining steam turbine power generation in which the turbine is driven by steam generated from the fluidized bed boiler installed inside the pressure vessel and gas turbine power generation in which high temperature/pressure exhaust gas is used from the boiler, having a total output of 71 MW. The operation started in fiscal 1995, stopped due to damage of the tube of CTF (ceramic tube filter), and is now continuing after the repair. As a result of the test conducted in fiscal 1995, it was confirmed in the two-stage cyclone test that the diameter of ash particle and cyclone efficiency change by kind of coal and amount of limestone and that by coal kind gas turbine blades show different states of abrasion, indicating greater abrasion when there is much SiO2 in ash. As a result of the continued high load operation of CTF, ash blockade inside the tube occurred and tube damage was generated by thermal shock, etc. 5 figs., 4 tabs.

  3. Recovery Act: Johnston Rhode Island Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    Energy Technology Data Exchange (ETDEWEB)

    Galowitz, Stephen

    2013-06-30

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Central Landfill in Johnston, Rhode Island. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting project reflected a cost effective balance of the following specific sub-objectives. 1) Meet environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas. 2) Utilize proven and reliable technology and equipment. 3) Maximize electrical efficiency. 4) Maximize electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Central Landfill. 5) Maximize equipment uptime. 6) Minimize water consumption. 7) Minimize post-combustion emissions. To achieve the Project Objective the project consisted of several components. 1) The landfill gas collection system was modified and upgraded. 2) A State-of-the Art gas clean up and compression facility was constructed. 3) A high pressure pipeline was constructed to convey cleaned landfill gas from the clean-up and compression facility to the power plant. 4) A combined cycle electric generating facility was constructed consisting of combustion turbine generator sets, heat recovery steam generators and a steam turbine. 5) The voltage of the electricity produced was increased at a newly constructed transformer/substation and the electricity was delivered to the local transmission system. The Project produced a myriad of beneficial impacts. 1) The Project created 453 FTE construction and manufacturing jobs and 25 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. 2) By combining state-of-the-art gas clean up systems with post combustion emissions control

  4. CHANGES OF BUOYANT DENSITY DURING THE S-PHASE OF THE CELL-CYCLE - DIRECT EVIDENCE DEMONSTRATED IN ACUTE MYELOID-LEUKEMIA BY FLOW-CYTOMETRIC

    NARCIS (Netherlands)

    DAENEN, S; HUIGES, W; MODDERMAN, E; HALIE, MR

    Studies with synchronized or exponentially growing bacteria and mammalian cell lines are not able to demonstrate small changes in buoyant density during the cell cycle. Flowcytometric analysis of density separated acute myeloid leukemia cells, a system not dependent on time-related variables, shows

  5. Heart failure patients demonstrate impaired changes in brachial artery blood flow and shear rate pattern during moderate-intensity cycle exercise.

    NARCIS (Netherlands)

    Benda, N.M.M.; Seeger, J.P.; Lier, D.P. van; Bellersen, L.; Dijk, A.P.J. van; Hopman, M.T.E.; Thijssen, D.H.

    2015-01-01

    NEW FINDINGS: What is the central question of this study? We explored whether heart failure (HF) patients demonstrate different exercise-induced brachial artery shear rate patterns compared with control subjects. What is the main finding and its importance? Moderate-intensity cycle exercise in HF

  6. CHANGES OF BUOYANT DENSITY DURING THE S-PHASE OF THE CELL-CYCLE - DIRECT EVIDENCE DEMONSTRATED IN ACUTE MYELOID-LEUKEMIA BY FLOW-CYTOMETRIC

    NARCIS (Netherlands)

    DAENEN, S; HUIGES, W; MODDERMAN, E; HALIE, MR

    1993-01-01

    Studies with synchronized or exponentially growing bacteria and mammalian cell lines are not able to demonstrate small changes in buoyant density during the cell cycle. Flowcytometric analysis of density separated acute myeloid leukemia cells, a system not dependent on time-related variables, shows

  7. Traveling Wave Tube (TVT) RF Power Combining Demonstration for use in the Jupiter Icy Moons Orbiter (JIMO)

    Science.gov (United States)

    Downey, Joseph A.

    2004-01-01

    The Jupiter Icy Moons Orbiter (JIMO) is set to launch between the years 2012 and 2015. It will possibly utilize a nuclear reactor power source and ion engines as it travels to the moons of Jupiter. The nuclear reactor will produce hundreds of kilowatts of power for propulsion, communication and various scientific instruments. Hence, the RF amplification devices aboard will be able to operate at a higher power level and data rate. The initial plan for the communications system is for an output of 1000 watts of RF power, a data rate of at least 10 megabits a second, and a frequency of 32 GHz. A higher data rate would be ideal to fully utilize the instruments aboard JIMO. At NASA Glenn, one of our roles in the JIMO project is to demonstrate RF power combining using multiple traveling wave tubes (TWT). In order for the power of separate TWT s to be combined, the RF output waves from each must be in-phase and have the same amplitude. Since different tubes act differently, we had to characterize each tube using a Network Analyzer. We took frequency sweeps and power sweeps to characterize each tube to ensure that they will behave similarly under the same conditions. The 200 watt Dornier tubes had been optimized to run at a lower power level (120 watts) for their extensive use in the ACTS program, so we also had to experiment with adjusting the voltage settings on several internal components (helix, anode, collector) of the tubes to reach the full 200 watt potential. from the ACTS program. Phase shifters and power attenuators were placed in the waveguide circuit at the inputs to the tubes so that adjustments could be made individually to match them exactly. A magic tee was used to route and combine the amplified electromagnetic RF waves on the tube output side. The demonstration of 200 watts of combined power was successful with efficiencies greater than 90% over a 500 MHz bandwidth. The next step will be to demonstrate the use of three amplifiers using two magic tees by

  8. Cell-cycle fate-monitoring distinguishes individual chemosensitive and chemoresistant cancer cells in drug-treated heterogeneous populations demonstrated by real-time FUCCI imaging.

    Science.gov (United States)

    Miwa, Shinji; Yano, Shuya; Kimura, Hiroaki; Yamamoto, Mako; Toneri, Makoto; Matsumoto, Yasunori; Uehara, Fuminari; Hiroshima, Yukihiko; Murakami, Takashi; Hayashi, Katsuhiro; Yamamoto, Norio; Bouvet, Michael; Fujiwara, Toshiyoshi; Tsuchiya, Hiroyuki; Hoffman, Robert M

    2015-01-01

    Essentially every population of cancer cells within a tumor is heterogeneous, especially with regard to chemosensitivity and resistance. In the present study, we utilized the fluorescence ubiquitination-based cell cycle indicator (FUCCI) imaging system to investigate the correlation between cell-cycle behavior and apoptosis after treatment of cancer cells with chemotherapeutic drugs. HeLa cells expressing FUCCI were treated with doxorubicin (DOX) (5 μM) or cisplatinum (CDDP) (5 μM) for 3 h. Cell-cycle progression and apoptosis were monitored by time-lapse FUCCI imaging for 72 h. Time-lapse FUCCI imaging demonstrated that both DOX and CDDP could induce cell cycle arrest in S/G2/M in almost all the cells, but a subpopulation of the cells could escape the block and undergo mitosis. The subpopulation which went through mitosis subsequently underwent apoptosis, while the cells arrested in S/G2/M survived. The present results demonstrate that chemoresistant cells can be readily identified in a heterogeneous population of cancer cells by S/G2/M arrest, which can serve in future studies as a visible target for novel agents that kill cell-cycle-arrested cells.

  9. The potential for control of carbon dioxide emissions from integrated gasification/combined-cycle systems

    Energy Technology Data Exchange (ETDEWEB)

    Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.; Berry, G.F.

    1994-06-01

    Initiatives to limit carbon dioxide (CO{sub 2}) emissions have drawn considerable interest to integrated gasification/combined-cycle (IGCC) power generation, a process that reduces CO{sub 2} production through efficient fuel used is amenable to CO{sub 2} capture. This paper presents a comparison of energy systems that encompass fuel supply, an IGCC system, CO{sub 2} recovery using commercial technologies, CO{sub 2} transport by pipeline, and land-based sequestering in geological reservoirs. The intent is to evaluate the energy-efficiency impacts of controlling CO{sub 2} in such systems and to provide the CO{sub 2} budget, or an to equivalent CO{sub 2}`` budget, associated with each of the individual energy-cycle steps. The value used for the ``equivalent CO{sub 2}`` budget is 1 kg/kWh CO{sub 2}. The base case for the comparison is a 457-MW IGCC system that uses an air-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal, and in-bed sulfur removal. Mining, preparation, and transportation of the coal and limestone result in a net system electric power production of 454 MW with a 0.835 kg/kwh CO{sub 2} release rate. For comparison, the gasifier output is taken through a water-gas shift to convert CO to CO{sub 2} and then processed in a glycol-based absorber unit to recover CO{sub 2} Prior to the combustion turbine. A 500-km pipeline then transports the CO{sub 2} for geological sequestering. The net electric power production for the system with CO{sub 2} recovery is 381 MW with a 0.156 kg/kwh CO{sub 2} release rate.

  10. Oocytes with a dark zona pellucida demonstrate lower fertilization, implantation and clinical pregnancy rates in IVF/ICSI cycles.

    Science.gov (United States)

    Shi, Wei; Xu, Bo; Wu, Li-Min; Jin, Ren-Tao; Luan, Hong-Bing; Luo, Li-Hua; Zhu, Qing; Johansson, Lars; Liu, Yu-Sheng; Tong, Xian-Hong

    2014-01-01

    The morphological assessment of oocytes is important for embryologists to identify and select MII oocytes in IVF/ICSI cycles. Dysmorphism of oocytes decreases viability and the developmental potential of oocytes as well as the clinical pregnancy rate. Several reports have suggested that oocytes with a dark zona pellucida (DZP) correlate with the outcome of IVF treatment. However, the effect of DZP on oocyte quality, fertilization, implantation, and pregnancy outcome were not investigated in detail. In this study, a retrospective analysis was performed in 268 infertile patients with fallopian tube obstruction and/or male factor infertility. In 204 of these patients, all oocytes were surrounded by a normal zona pellucida (NZP, control group), whereas 46 patients were found to have part of their retrieved oocytes enclosed by NZP and the other by DZP (Group A). In addition, all oocytes enclosed by DZP were retrieved from 18 patients (Group B). No differences were detected between the control and group A. Compared to the control group, the rates of fertilization, good quality embryos, implantation and clinical pregnancy were significantly decreased in group B. Furthermore, mitochondria in oocytes with a DZP in both of the two study groups (A and B) were severely damaged with several ultrastructural alterations, which were associated with an increased density of the zona pellucida and vacuolization. Briefly, oocytes with a DZP affected the clinical outcome in IVF/ICSI cycles and appeared to contain more ultrastructural alterations. Thus, DZP could be used as a potential selective marker for embryologists during daily laboratory work.

  11. Experimental demonstration of half cycle 64-QAM Nyquist-SCM direct-detection optical communication system with data-aided estimation and overlap frequency-domain equalization

    Science.gov (United States)

    Li, Danyu; He, Jing; Tang, Jin; Chen, Ming; Chen, Lin

    2014-12-01

    A half cycle 64-quadrature amplitude modulation (QAM) Nyquist subcarrier modulation (SCM) polarization division multiplexing (PDM) intensity modulation direct detection optical communication system is experimentally demonstrated. At the receiver, training sequences-based channel estimation and an overlap frequency domain equalization method are proposed to enhance the system performance. The experimental results show that the half cycle 64-QAM Nyquist-SCM PDM signal can be transmitted over 43-km standard single-mode fibers with a bit error rate below the forward error coding threshold of 2.4×10-2.

  12. Energy and Exergy Analyses of a Combined Power Cycle Using the Organic Rankine Cycle and the Cold Energy of Liquefied Natural Gas

    Directory of Open Access Journals (Sweden)

    Ho Yong Lee

    2015-09-01

    Full Text Available In this work, energy and exergy analyses are carried out for a combined cycle consisting of an organic Rankine cycle (ORC and a liquefied natural gas (LNG Rankine cycle for the recovery of low-grade heat sources and LNG cold energy. The effects of the turbine inlet pressure and the working fluid on the system performance are theoretically investigated. A modified temperature-enthalpy diagram is proposed, which can be useful to see the characteristics of the combined cycle, as well as the temperature distributions in the heat exchangers. Results show that the thermal efficiency increases with an increasing turbine inlet pressure and critical temperature of the working fluid. However, the exergy efficiency has a peak value with respect to the turbine inlet pressure, and the maximum exergy efficiency and the corresponding optimum turbine inlet pressure are significantly influenced by the selection of the working fluid. The exergy destruction at the condenser is generally the greatest among the exergy destruction components of the system.

  13. Combined cycle power unit with a binary system based on waste geothermal brine at Mutnovsk geothermal power plant

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Nikol'skii, A. I.; Semenov, V. N.

    2016-06-01

    The Russian geothermal power systems developed in the last few decades outperform their counterparts around the world in many respects. However, all Russian geothermal power stations employ steam as the geothermal fluid and discard the accompanying geothermal brine. In reality, the power of the existing Russian geothermal power stations may be increased without drilling more wells, if the waste brine is employed in combined cycle systems with steam and binary turbine units. For the example of the 50 MW Mutnovsk geothermal power plant, the optimal combined cycle power unit based on the waste geothermal brine is considered. It is of great interest to determine how the thermodynamic parameters of the secondary steam in the expansion unit and the pressure in the condenser affect the performance of the equipment in the combined cycle power unit at Mutnovsk geothermal power plant. For the utilization of the waste geothermal brine at Mutnovsk geothermal power plant, the optimal air temperature in the condensers of the combined cycle power unit is +5°C. The use of secondary steam obtained by flashing of the geothermal brine at Mutnovsk geothermal power plant 1 at a pressure of 0.2 MPa permits the generation of up to 8 MW of electric power in steam turbines and additional power of 5 MW in the turbines of the binary cycle.

  14. Recovery Act: Brea California Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    Energy Technology Data Exchange (ETDEWEB)

    Galowitz, Stephen

    2012-12-31

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Olinda Landfill near Brea, California. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting Project reflected a cost effective balance of the following specific sub-objectives: • Meeting the environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas • Utilizing proven and reliable technology and equipment • Maximizing electrical efficiency • Maximizing electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Olinda Landfill • Maximizing equipment uptime • Minimizing water consumption • Minimizing post-combustion emissions • The Project produced and will produce a myriad of beneficial impacts. o The Project created 360 FTE construction and manufacturing jobs and 15 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. o By combining state-of-the-art gas clean up systems with post combustion emissions control systems, the Project established new national standards for best available control technology (BACT). o The Project will annually produce 280,320 MWh’s of clean energy o By destroying the methane in the landfill gas, the Project will generate CO2 equivalent reductions of 164,938 tons annually. The completed facility produces 27.4 MWnet and operates 24 hours a day, seven days a week.

  15. Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

    KAUST Repository

    Missimer, Thomas M.

    2013-01-01

    Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great potential to reduce the need for conventional power, to use solely renewable energy sources, and to reduce the overall cost of water treatment. This technology can desalt seawater or water of even higher salinity using waste heat, solar heat, or geothermal heat. An AD system can operate effectively at temperatures ranging from 55 to 80 °C with perhaps an optimal temperature of 80 °C. The generally low temperature requirement for the feedwater allows the system to operate quite efficiently using an alternative energy source, such as solar power. Solar power, particularly in warm dry regions, can generate a consistent water temperature of about 90 °C. Although this temperature is more than adequate to run the system, solar energy collection only can occur during daylight hours, thereby necessitating the use of heat storage during nighttime or very cloudy days. With increasing capacity, the need for extensive thermal storage may be problematic and could add substantial cost to the development of an AD system. However, in many parts of the world, there are subsurface geothermal energy sources that have not been extensively used. Combining a low to moderate geothermal energy recovery system to an AD system would provide a solution to the thermal storage issue. However, geothermal energy development from particularly Hot Dry Rock is limited by the magnitude of the heat flow required for the process and the thermal conductivity of the rock material forming the heat reservoir. Combining solar and geothermal energy using an alternating 12-h cycle would reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of renewable energy. © 2013 Desalination Publications.

  16. Oocytes with a dark zona pellucida demonstrate lower fertilization, implantation and clinical pregnancy rates in IVF/ICSI cycles.

    Directory of Open Access Journals (Sweden)

    Wei Shi

    Full Text Available The morphological assessment of oocytes is important for embryologists to identify and select MII oocytes in IVF/ICSI cycles. Dysmorphism of oocytes decreases viability and the developmental potential of oocytes as well as the clinical pregnancy rate. Several reports have suggested that oocytes with a dark zona pellucida (DZP correlate with the outcome of IVF treatment. However, the effect of DZP on oocyte quality, fertilization, implantation, and pregnancy outcome were not investigated in detail. In this study, a retrospective analysis was performed in 268 infertile patients with fallopian tube obstruction and/or male factor infertility. In 204 of these patients, all oocytes were surrounded by a normal zona pellucida (NZP, control group, whereas 46 patients were found to have part of their retrieved oocytes enclosed by NZP and the other by DZP (Group A. In addition, all oocytes enclosed by DZP were retrieved from 18 patients (Group B. No differences were detected between the control and group A. Compared to the control group, the rates of fertilization, good quality embryos, implantation and clinical pregnancy were significantly decreased in group B. Furthermore, mitochondria in oocytes with a DZP in both of the two study groups (A and B were severely damaged with several ultrastructural alterations, which were associated with an increased density of the zona pellucida and vacuolization. Briefly, oocytes with a DZP affected the clinical outcome in IVF/ICSI cycles and appeared to contain more ultrastructural alterations. Thus, DZP could be used as a potential selective marker for embryologists during daily laboratory work.

  17. Combustion oscillation study in a kerosene fueled rocket-based combined-cycle engine combustor

    Science.gov (United States)

    Huang, Zhi-Wei; He, Guo-Qiang; Qin, Fei; Xue, Rui; Wei, Xiang-Geng; Shi, Lei

    2016-12-01

    This study reports the combustion oscillation features in a three-dimensional (3D) rocket-based combined-cycle (RBCC) engine combustor under flight Mach number (Mflight) 3.0 conditions both experimentally and numerically. Experiment is performed on a direct-connect ground test facility, which measures the wall pressure along the flow-path. High-speed imaging of the flame luminosity and schlieren is carried out at exit of the primary rocket. Compressible reactive large eddy simulation (LES) with reduced chemical kinetics of a surrogate model for kerosene is performed to further understand the combustion oscillation mechanisms in the combustor. LES results are validated with experimental data by the time-averaged and root mean square (RMS) pressure values, and show acceptable agreement. Effects of the primary rocket jet on pressure oscillation in the combustor are analyzed. Relation of the high speed rocket jet oscillation, which is thought to among the most probable sources of combustion oscillation, with the RBCC combustor is recognized. Results reveal that the unsteady over-expanded rocket jet has significant impacts on the combustion oscillation feature of the RBCC combustor, which is different from a thermo-acoustics type oscillation. The rocket jet/air inflow physical interactions under different rocket jet expansion degrees are experimentally studied.

  18. Reprocessed and combined thorium fuel cycles in a PER system with a micro heterogeneous approaches

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Fabiana B.A.; Castro, Victor F.; Faria, Rochkhudson B. de; Pereira, Claubia; Fortini, Angela, E-mail: fabianabeghini@yahoo.com.br, E-mail: victorfariacastro@gmail.com, E-mail: rochkdefaria@yahoo.com.br, E-mail: claubia@nuclear.ufmg.br, E-mail: fortini@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2015-07-01

    A micro heterogeneous approaches were used to study the behavior of reprocessed fuel spiked with thorium in a PWR fuel element considering (TRU-Th) cycle. The goal is to achieve a higher burnup using three different configurations to model the fuel element using SCALE 6.0. The reprocessed fuels were obtained using the ORIGEN 2.1 code from a spent PWR standard fuel (33,000 MWd/tHM burned), with 3.1% of initial enrichment. The spent fuel remained in the cooling pool for five years and then reprocessed using the UREX+ technique. Three configurations of micro heterogeneous approaches were analyzed, and the k{sub inf} and plutonium evolution during the burnup were evaluated. The preliminary results show that the behavior of advanced fuel based on transuranic elements spiked with thorium, and micro heterogeneous approach are satisfactory in PWRs, and the configuration that use a combination of Th and TRU (configuration 1) seems to be the most promising once has higher values for k{sub inf} during the burnup, compared with other configurations. (author)

  19. Wabash River Coal Gasification Combined Cycle Repowering Project: Clean Coal Technology Program. Environmental Assessment

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    The proposed project would result in a combined-cycle power plant with lower emissions and higher efficiency than most existing coal-fired power plants of comparable size. The net plant heat rate (energy content of the fuel input per useable electrical generation output; i.e., Btu/kilowatt hour) for the new repowered unit would be a 21% improvement over the existing unit, while reducing SO{sub 2} emissions by greater than 90% and limiting NO{sub x} emissions by greater than 85% over that produced by conventional coal-fired boilers. The technology, which relies on gasified coal, is capable of producing as much as 25% more electricity from a given amount of coal than today`s conventional coal-burning methods. Besides having the positive environmental benefit of producing less pollutants per unit of power generated, the higher overall efficiency of the proposed CGCC project encourages greater utilization to meet base load requirements in order to realize the associated economic benefits. This greater utilization (i.e., increased capacity factor) of a cleaner operating plant has global environmental benefits in that it is likely that such power would replace power currently being produced by less efficient plants emitting a greater volume of pollutants per unit of power generated.

  20. Advanced Energy Harvesting from Macroalgae—Innovative Integration of Drying, Gasification and Combined Cycle

    Directory of Open Access Journals (Sweden)

    Muhammad Aziz

    2014-12-01

    Full Text Available State-of-the-art integrated macroalgae utilization processes, consisting of drying, gasification, and combined cycle, are proposed and their performance with respect to energy efficiency are evaluated. To achieve high exergy efficiency, the integration is performed through two main principles: exergy recovery and process integration. Initially, the energy involved in one process is recirculated intensively through exergy elevation and effective heat coupling. Furthermore, the unrecoverable energy from one process will be utilized in the other processes through process integration. As the result, the total exergy destruction from the whole integrated processes can be minimized significantly leading to significant improvement in energy efficiency. The first analysis relates to the performance of integrated drying process, especially the influence of target moisture content to energy consumption. Furthermore, the influences of gasification fluidization velocity to the total generated power and power generation efficiency are also calculated. As the results of study, the proposed integrated-processes proved a very high energy efficiency. A positive energy harvesting with the total power generation efficiency of about 40% could be achieved.

  1. Coal waste slurries as a fuel for integrated gasification combined cycle plants

    Directory of Open Access Journals (Sweden)

    Lutynski Marcin A.

    2016-01-01

    Full Text Available The article summarizes recent development in integrated gasification combined cycle technology and lists existing and planned IGCC plants. A brief outlook on the IGCC gasification technology is given with focus on entrained-flow gasifiers where the low-quality coal waste slurry fuel can be used. Desired properties of coal and ash for entrained-flow gasifiers are listed. The coal waste slurries, which were deposited at impoundments in Upper Silesian Coal Basin, were considered as a direct feed for such gasifiers. The average ash content, moisture content and lower heating value were analysed and presented as an average values. Entrained-flow commercial gasifiers can be considered as suitable for the coal slurry feed, however the ash content of coal slurries deposited in impoundments is too high for the direct use as the feed for the gasifiers. The moisture content of slurries calculated on as received basis meets the requirements of entrained-flow slurry feed gasifiers. The content of fines is relatively high which allow to use the slurries in entrained-flow gasifiers.

  2. Analysis and Optimization of a Compressed Air Energy Storage—Combined Cycle System

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-06-01

    Full Text Available Compressed air energy storage (CAES is a commercial, utility-scale technology that provides long-duration energy storage with fast ramp rates and good part-load operation. It is a promising storage technology for balancing the large-scale penetration of renewable energies, such as wind and solar power, into electric grids. This study proposes a CAES-CC system, which is based on a conventional CAES combined with a steam turbine cycle by waste heat boiler. Simulation and thermodynamic analysis are carried out on the proposed CAES-CC system. The electricity and heating rates of the proposed CAES-CC system are lower than those of the conventional CAES by 0.127 kWh/kWh and 0.338 kWh/kWh, respectively, because the CAES-CC system recycles high-temperature turbine-exhausting air. The overall efficiency of the CAES-CC system is improved by approximately 10% compared with that of the conventional CAES. In the CAES-CC system, compressing intercooler heat can keep the steam turbine on hot standby, thus improving the flexibility of CAES-CC. This study brought about a new method for improving the efficiency of CAES and provided new thoughts for integrating CAES with other electricity-generating modes.

  3. The cost of carbon capture and storage for natural gas combined cycle power plants.

    Science.gov (United States)

    Rubin, Edward S; Zhai, Haibo

    2012-03-20

    This paper examines the cost of CO(2) capture and storage (CCS) for natural gas combined cycle (NGCC) power plants. Existing studies employ a broad range of assumptions and lack a consistent costing method. This study takes a more systematic approach to analyze plants with an amine-based postcombustion CCS system with 90% CO(2) capture. We employ sensitivity analyses together with a probabilistic analysis to quantify costs for plants with and without CCS under uncertainty or variability in key parameters. Results for new baseload plants indicate a likely increase in levelized cost of electricity (LCOE) of $20-32/MWh (constant 2007$) or $22-40/MWh in current dollars. A risk premium for plants with CCS increases these ranges to $23-39/MWh and $25-46/MWh, respectively. Based on current cost estimates, our analysis further shows that a policy to encourage CCS at new NGCC plants via an emission tax or carbon price requires (at 95% confidence) a price of at least $125/t CO(2) to ensure NGCC-CCS is cheaper than a plant without CCS. Higher costs are found for nonbaseload plants and CCS retrofits.

  4. Thermodynamic and design considerations of organic Rankine cycles in combined application with a solar thermal gas turbine

    Science.gov (United States)

    Braun, R.; Kusterer, K.; Sugimoto, T.; Tanimura, K.; Bohn, D.

    2013-12-01

    Concentrated Solar Power (CSP) technologies are considered to provide a significant contribution for the electric power production in the future. Different kinds of technologies are presently in operation or under development, e.g. parabolic troughs, central receivers, solar dish systems and Fresnel reflectors. This paper takes the focus on central receiver technologies, where the solar radiation is concentrated by a field of heliostats in a receiver on the top of a tall tower. To get this CSP technology ready for the future, the system costs have to reduce significantly. The main cost driver in such kind of CSP technologies are the huge amount of heliostats. To reduce the amount of heliostats, and so the investment costs, the efficiency of the energy conversion cycle becomes an important issue. An increase in the cycle efficiency results in a decrease of the solar heliostat field and thus, in a significant cost reduction. The paper presents the results of a thermodynamic model of an Organic Rankine Cycle (ORC) for combined cycle application together with a solar thermal gas turbine. The gas turbine cycle is modeled with an additional intercooler and recuperator and is based on a typical industrial gas turbine in the 2 MW class. The gas turbine has a two stage radial compressor and a three stage axial turbine. The compressed air is preheated within a solar receiver to 950°C before entering the combustor. A hybrid operation of the gas turbine is considered. In order to achieve a further increase of the overall efficiency, the combined operation of the gas turbine and an Organic Rankine Cycle is considered. Therefore an ORC has been set up, which is thermally connected to the gas turbine cycle at two positions. The ORC can be coupled to the solar-thermal gas turbine cycle at the intercooler and after the recuperator. Thus, waste heat from different cycle positions can be transferred to the ORC for additional production of electricity. Within this investigation

  5. Comparing of letrozole versus clomiphene citrate combined with gonadotropins in intrauterine insemination cycles

    Directory of Open Access Journals (Sweden)

    Fatemeh Ayazi Roozbahani

    2012-01-01

    Full Text Available Background: Clomiphene citrate (CC an agonist and antagonist of estrogen, is the first line treatment in ovarian stimulation. Anti-estrogenic effect of CC in endometrial thickness and cervical mucus has negative effect on pregnancy rate. Letrozole is an Aromatase Inhibitor has been seen that has acceptable pregnancy rate compared to CC.Objective: The aim of this study was to compare the efficacy of letrozole and clomiphene citrate (CC with gonadotropins for ovarian stimulation in women candidate for intrauterine insemination (IUI.Materials and Methods: One hundred sixty patients eligible to IUI therapy enrolled in this study. Patients randomized to two groups: group A (received letrozole-gonadotropin and group B (received CC-gonadotropin. In group A (n=80 letrozole was given on days 3-7 of the menstrual cycles. In group B clomiphen citrate was given like letrozole combined with human menopausal gonadotropin (hMG administered every day starting on day 8. Ovulation was triggered with urinary HCG when the leading follicle (s reached 18 mm in diameter. A single IUI was performed 36-40 hours later. The ovarian stimulation response (E2 levels and number of follicles, clinical pregnancy and endometrial thickness was primary outcome.Results: Both groups were similar in demographic characteristics. There was a significantly lower peak serum E2 level in the letrozole group compared with CC. (236±86 Vs. 283±106 pg/mL, respectively; p18 mm preovulatory follicles was significantly higher in CC group than letrozole group (2.2±.68 Vs. 2.02±0.63 respectively; p=0.025. Endometrial thickness measured at the time of hCG administration was significantly higher in letrozole group. (9.08±1.2 mm Vs. 8.1±1.9 mm; p=0.0001. The clinical pregnancy rate was comparable between two groups.Conclusion: Letrozole is a good and cost-effective alternative to CC in IUI cycles

  6. [Demonstration of the existence of a marine cycle in the strigeides: Cardiocephalus longicollis Szidat, 1928 (Trematoda: Strigeidae)].

    Science.gov (United States)

    Prevot, G; Bartoli, P

    1980-01-01

    During their investigations on parasitism of fishes and birds in the lagoon of Brusc (Var), the authors have discovered the life cycle of Cardiocephalus longicollis. Cercariae of pharyngeate furcocercous type develop in sporocysts in the digestive gland of the marine prosobranch Nassa corniculum. The cercaria is identified as Cercaria nassae (Dolgikh, 1965) from Nassa reticulata in Black sea; it closely resembles Cercaria nassa (Martin, 1945) from Ilyanassa obsolseta (syn. Nassa obsoleta) at Woods Hole (U.S.A.). Several intermediate hosts have been related; they are the marine fishes Diplodus annularis, D. vulgaris, Boops salpa, Pagellus mormyrus (Sparidae) and Belone belone (Scombresocidae). Metacercariae of tetracotyle type were found in the cavity of optical lobes of the brain. Experimental contamination of fishes: Potamoschistus microps, Blennius sp., Mugil cephalus and Syngnathus abaster has been negative; that of Diplodus annularis and D. sargus, positive. It allowed to follow the development from cercaria to tetracotyle. In Provence natural definitive hosts are Larus argentatus and L. ribidundus; contaminations of these birds with metacercariae experimentally raised in Diplodus annularis and D. vulgaris were successfull. Some observations are pointed out especially the development of the parasite in the definitive host, the organisation of tribocytic organ and the geographical distribution of the parasite.

  7. Thermodynamic analysis of an integrated gasification solid oxide fuel cell plant combined with an organic Rankine cycle

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud; Larsen, Ulrik

    2013-01-01

    into a fixed bed gasification plant to produce syngas which fuels the combined solid oxide fuel cells e organic Rankine cycle system to produce electricity. More than a hundred fluids are considered as possible alternative for the organic cycle using non-ideal equations of state (or state-of-the-art equations......A 100 kWe hybrid plant consisting of gasification system, solid oxide fuel cells and organic Rankine cycle is presented. The nominal power is selected based on cultivation area requirement. For the considered output a land of around 0.5 km2 needs to be utilized. Woodchips are introduced...... of state). A genetic algorithm is employed to select the optimal working fluid and the maximum pressure for the bottoming cycle. Thermodynamic and physical properties, environmental impacts and hazard specifications are also considered in the screening process. The results suggest that efficiencies...

  8. Non-Space Heating Electrical Consumption in Manufactured Homes: Residential Construction Demonstration Project Cycle II : Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Onisko, Stephen A.; Roos, Carolyn; Baylon, David

    1993-06-01

    This report summarizes submeter data of the non-space heating electrical energy use in a sample of manufactured homes. These homes were built to Super Good Cents insulation standards in 1988 and 1989 under the auspices of RCDP Cycle 2 of the Bonneville Power Administration. They were designed to incorporate innovations in insulation and manufacturing techniques developed to encourage energy conservation in this important housing type. Domestic water heating (DWH) and other non-space heat energy consumption, however, were not generally affected by RCDP specifications. The purpose of this study is to establish a baseline for energy conservation in these areas and to present a method for estimating total energy saving benefits associated with these end uses. The information used in this summary was drawn from occupant-read submeters and manufacturersupplied specifications of building shell components, appliances and water heaters. Information was also drawn from a field review of ventilation systems and building characteristics. The occupant survey included a census of appliances and occupant behavior in these manufactured homes. A total of 150 manufactured homes were built under this program by eight manufacturers. An additional 35 homes were recruited as a control group. Of the original 185 houses, approximately 150 had some usable submeter data for domestic hot water and 126 had usable submeter data for all other nonheating consumption. These samples were used as the basis for all consumption analysis. The energy use characteristics of these manufactured homes were compared with that of a similar sample of RCDP site-built homes. In general, the manufactured homes were somewhat smaller and had fewer occupants than the site-built homes. The degree to which seasonal variations were present in non-space heat uses was reviewed.

  9. A Turbine Based Combined Cycle Engine Inlet Model and Mode Transition Simulation Based on HiTECC Tool

    Science.gov (United States)

    Csank, Jeffrey T.; Stueber, Thomas J.

    2012-01-01

    An inlet system is being tested to evaluate methodologies for a turbine based combined cycle propulsion system to perform a controlled inlet mode transition. Prior to wind tunnel based hardware testing of controlled mode transitions, simulation models are used to test, debug, and validate potential control algorithms. One candidate simulation package for this purpose is the High Mach Transient Engine Cycle Code (HiTECC). The HiTECC simulation package models the inlet system, propulsion systems, thermal energy, geometry, nozzle, and fuel systems. This paper discusses the modification and redesign of the simulation package and control system to represent the NASA large-scale inlet model for Combined Cycle Engine mode transition studies, mounted in NASA Glenn s 10- by 10-Foot Supersonic Wind Tunnel. This model will be used for designing and testing candidate control algorithms before implementation.

  10. Wabash Valley Integrated Gasification Combined Cycle, Coal to Fischer Tropsch Jet Fuel Conversion Study

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Jayesh [Lummus Technology Inc., Bloomfield, NJ (United States); Hess, Fernando [Lummus Technology Inc., Bloomfield, NJ (United States); Horzen, Wessel van [Lummus Technology Inc., Bloomfield, NJ (United States); Williams, Daniel [Lummus Technology Inc., Bloomfield, NJ (United States); Peevor, Andy [JM Davy, London (United Kingdom); Dyer, Andy [JM Davy, London (United Kingdom); Frankel, Louis [Canonsburgh, PA (United States)

    2016-06-01

    This reports examines the feasibility of converting the existing Wabash Integrated Gasification Combined Cycle (IGCC) plant into a liquid fuel facility, with the goal of maximizing jet fuel production. The fuels produced are required to be in compliance with Section 526 of the Energy Independence and Security Act of 2007 (EISA 2007 §526) lifecycle greenhouse gas (GHG) emissions requirements, so lifecycle GHG emissions from the fuel must be equal to or better than conventional fuels. Retrofitting an existing gasification facility reduces the technical risk and capital costs associated with a coal to liquids project, leading to a higher probability of implementation and more competitive liquid fuel prices. The existing combustion turbine will continue to operate on low cost natural gas and low carbon fuel gas from the gasification facility. The gasification technology utilized at Wabash is the E-Gas™ Technology and has been in commercial operation since 1995. In order to minimize capital costs, the study maximizes reuse of existing equipment with minimal modifications. Plant data and process models were used to develop process data for downstream units. Process modeling was utilized for the syngas conditioning, acid gas removal, CO2 compression and utility units. Syngas conversion to Fischer Tropsch (FT) liquids and upgrading of the liquids was modeled and designed by Johnson Matthey Davy Technologies (JM Davy). In order to maintain the GHG emission profile below that of conventional fuels, the CO2 from the process must be captured and exported for sequestration or enhanced oil recovery. In addition the power utilized for the plant’s auxiliary loads had to be supplied by a low carbon fuel source. Since the process produces a fuel gas with sufficient energy content to power the plant’s loads, this fuel gas was converted to hydrogen and exported to the existing gas turbine for low carbon power production. Utilizing low carbon fuel gas and

  11. Determination of Fuel Consumption Indexes of Co-generation Combined Cycle Steam and Gas Units with unfired waste heat boilers

    Directory of Open Access Journals (Sweden)

    S. A. Kachan

    2010-01-01

    Full Text Available The paper presents the developed methodology and the results of determination of fuel consumption indexes of co-generation combined cycle steam and gas units (PGU with unfired waste heat boilers apply to PGU-230 of 3-d co-generation power plant ofMinsk. 

  12. Smart Operation of Gas Turbine Combined Cycle Plants: Prediction and Improvement of Thermal Efficiency at Part Load

    NARCIS (Netherlands)

    Boksteen, S.Z.

    2014-01-01

    This thesis investigates various operational aspects of Gas Turbine Combined Cycle Power Plants (GTCC). GTCC power plants are expected to play an increasingly important role in the balancing of supply and demand in the electricity grid. Although originally meant for predominantly base load operatio

  13. Smart Operation of Gas Turbine Combined Cycle Plants: Prediction and Improvement of Thermal Efficiency at Part Load

    NARCIS (Netherlands)

    Boksteen, S.Z.

    2014-01-01

    This thesis investigates various operational aspects of Gas Turbine Combined Cycle Power Plants (GTCC). GTCC power plants are expected to play an increasingly important role in the balancing of supply and demand in the electricity grid. Although originally meant for predominantly base load

  14. Smart Operation of Gas Turbine Combined Cycle Plants: Prediction and Improvement of Thermal Efficiency at Part Load

    NARCIS (Netherlands)

    Boksteen, S.Z.

    2014-01-01

    This thesis investigates various operational aspects of Gas Turbine Combined Cycle Power Plants (GTCC). GTCC power plants are expected to play an increasingly important role in the balancing of supply and demand in the electricity grid. Although originally meant for predominantly base load operatio

  15. Combined Cycle Engine Large-Scale Inlet for Mode Transition Experiments: System Identification Rack Hardware Design

    Science.gov (United States)

    Thomas, Randy; Stueber, Thomas J.

    2013-01-01

    The System Identification (SysID) Rack is a real-time hardware-in-the-loop data acquisition (DAQ) and control instrument rack that was designed and built to support inlet testing in the NASA Glenn Research Center 10- by 10-Foot Supersonic Wind Tunnel. This instrument rack is used to support experiments on the Combined-Cycle Engine Large-Scale Inlet for Mode Transition Experiment (CCE? LIMX). The CCE?LIMX is a testbed for an integrated dual flow-path inlet configuration with the two flow paths in an over-and-under arrangement such that the high-speed flow path is located below the lowspeed flow path. The CCE?LIMX includes multiple actuators that are designed to redirect airflow from one flow path to the other; this action is referred to as "inlet mode transition." Multiple phases of experiments have been planned to support research that investigates inlet mode transition: inlet characterization (Phase-1) and system identification (Phase-2). The SysID Rack hardware design met the following requirements to support Phase-1 and Phase-2 experiments: safely and effectively move multiple actuators individually or synchronously; sample and save effector control and position sensor feedback signals; automate control of actuator positioning based on a mode transition schedule; sample and save pressure sensor signals; and perform DAQ and control processes operating at 2.5 KHz. This document describes the hardware components used to build the SysID Rack including their function, specifications, and system interface. Furthermore, provided in this document are a SysID Rack effectors signal list (signal flow); system identification experiment setup; illustrations indicating a typical SysID Rack experiment; and a SysID Rack performance overview for Phase-1 and Phase-2 experiments. The SysID Rack described in this document was a useful tool to meet the project objectives.

  16. Membrane separation of carbon dioxide in the integrated gasification combined cycle systems

    Science.gov (United States)

    Kotowicz, Janusz; Skorek-osikowska, Anna; Janusz-szymańska, Katarzyna

    2010-09-01

    Integrated gasification combined cycle systems (IGCC) are becoming more popular because of the characteristics, by which they are characterized, including low pollutants emissions, relatively high efficiency of electricity production and the ability to integrate the installation of carbon capture and storage (CCS). Currently, the most frequently used CO2 capture technology in IGCC systems is based on the absorption process. This method causes a significant increase of the internal load and decreases the efficiency of the entire system. It is therefore necessary to look for new methods of carbon dioxide capture. The authors of the present paper propose the use of membrane separation. The paper reviews available membranes for use in IGCC systems, indicates, inter alia, possible places of their implementation in the system and the required operation parameters. Attention is drawn to the most important parameters of membranes (among other selectivity and permeability) influencing the cost and performance of the whole installation. Numerical model of a membrane was used, among others, to analyze the influence of the basic parameters of the selected membranes on the purity and recovery ratio of the obtained permeate, as well as to determine the energetic cost of the use of membranes for the CO2 separation in IGCC systems. The calculations were made within the environment of the commercial package Aspen Plus. For the calculations both, membranes selective for carbon dioxide and membranes selective for hydrogen were used. Properly selected pressure before and after membrane module allowed for minimization of energy input on CCS installation assuring high purity and recovery ratio of separated gas.

  17. Potential of Atkinson cycle combined with EGR for pollutant control in a HD diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Benajes, J.; Serrano, J.R.; Molina, S.; Novella, R. [CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-01-15

    An experimental investigation has been performed on the potential of the Atkinson cycle and reducing intake oxygen concentration for pollutant control in a heavy-duty diesel engine. In this study the Atkinson cycle has been reproduced advancing the intake valve closing angle towards the intake stroke. In addition, the intake oxygen concentration has been reduced introducing exhaust gas recirculation. This research has been carried out at low engine load (25%), where the Atkinson cycle is known to improve the efficiency of the spark-ignition engines. The main interest of this investigation has been the comparison between the Atkinson cycle and the conventional diesel cycle at the same oxygen concentration in the intake gas. This analysis has been focused on in-cylinder gas thermodynamic conditions, combustion process, exhaust emissions and engine efficiency. In compression ignition engines, the Atkinson cycle basically promotes the premixed combustion, but in the range of these tests, a complete premixed combustion was not attained. Regarding exhaust emissions, the Atkinson cycle reduces notably the nitrous oxides but increases soot emissions. Finally, better global results have been found reducing intake oxygen concentration by the recirculation of exhaust gas than by the operation of an Atkinson cycle. (author)

  18. Combined use of stable isotopes and hydrologic modeling to better understand nutrient sources and cycling in highly altered systems (Invited)

    Science.gov (United States)

    Young, M. B.; Kendall, C.; Guerin, M.; Stringfellow, W. T.; Silva, S. R.; Harter, T.; Parker, A.

    2013-12-01

    The Sacramento and San Joaquin Rivers provide the majority of freshwater for the San Francisco Bay Delta. Both rivers are important sources of drinking and irrigation water for California, and play critical roles in the health of California fisheries. Understanding the factors controlling water quality and primary productivity in these rivers and the Delta is essential for making sound economic and environmental water management decisions. However, these highly altered surface water systems present many challenges for water quality monitoring studies due to factors such as multiple potential nutrient and contaminant inputs, dynamic source water inputs, and changing flow regimes controlled by both natural and engineered conditions. The watersheds for both rivers contain areas of intensive agriculture along with many other land uses, and the Sacramento River receives significant amounts of treated wastewater from the large population around the City of Sacramento. We have used a multi-isotope approach combined with mass balance and hydrodynamic modeling in order to better understand the dominant nutrient sources for each of these rivers, and to track nutrient sources and cycling within the complex Delta region around the confluence of the rivers. High nitrate concentrations within the San Joaquin River fuel summer algal blooms, contributing to low dissolved oxygen conditions. High δ15N-NO3 values combined with the high nitrate concentrations suggest that animal manure is a significant source of nitrate to the San Joaquin River. In contrast, the Sacramento River has lower nitrate concentrations but elevated ammonium concentrations from wastewater discharge. Downstream nitrification of the ammonium can be clearly traced using δ15N-NH4. Flow conditions for these rivers and the Delta have strong seasonal and inter-annual variations, resulting in significant changes in nutrient delivery and cycling. Isotopic measurements and estimates of source water contributions

  19. Heart failure patients demonstrate impaired changes in brachial artery blood flow and shear rate pattern during moderate-intensity cycle exercise.

    Science.gov (United States)

    Benda, Nathalie M M; Seeger, Joost P H; van Lier, Dirk P T; Bellersen, Louise; van Dijk, Arie P J; Hopman, Maria T E; Thijssen, Dick H J

    2015-04-01

    What is the central question of this study? We explored whether heart failure (HF) patients demonstrate different exercise-induced brachial artery shear rate patterns compared with control subjects. What is the main finding and its importance? Moderate-intensity cycle exercise in HF patients is associated with an attenuated increase in brachial artery anterograde and mean shear rate and skin temperature. Differences between HF patients and control subjects cannot be explained fully by differences in workload. HF patients demonstrate a less favourable shear rate pattern during cycle exercise compared with control subjects. Repeated elevations in shear rate (SR) in conduit arteries, which occur during exercise, represent a key stimulus to improve vascular function. We explored whether heart failure (HF) patients demonstrate distinct changes in SR in response to moderate-intensity cycle exercise compared with healthy control subjects. We examined brachial artery SR during 40 min of cycle exercise at a work rate equivalent to 65% peak oxygen uptake in 14 HF patients (65 ± 7 years old, 13 men and one woman) and 14 control subjects (61 ± 5 years old, 12 men and two women). Brachial artery diameter, SR and oscillatory shear index (OSI) were assessed using ultrasound at baseline and during exercise. The HF patients demonstrated an attenuated increase in mean and anterograde brachial artery SR during exercise compared with control subjects (time × group interaction, P = 0.003 and P exercise and remained increased throughout the exercise period in both groups (time × group interaction, P = 0.11). In control subjects, the immediate increase in OSI during exercise (time, P exercise did not normalize in HF patients (time × group interaction, P = 0.029). Subgroup analysis of five HF patients and five control subjects with comparable workload (97 ± 13 versus 90 ± 22 W, P = 0.59) confirmed the presence of distinct changes in mean SR during exercise (time × group

  20. Why a Combination of WP 631 and Epo B is an Improvement on the Drugs Singly - Involvement in the Cell Cycle and Mitotic Slippage.

    Science.gov (United States)

    Bukowska, Barbara; Rogalska, Aneta; Forma, Ewa; Brys, Magdalena; Marczak, Agnieszka

    2016-01-01

    Our previous studies clearly demonstrated that a combination of WP 631 and Epo B has higher activity against ovarian cancer cells than either of these compounds used separately. In order to fully understand the exact mechanism of action in combination, we assessed effects on the cell cycle of SKOV-3 cells. We evaluated three control points essential for WP 631 and Epo B action to determine which cell cycle-regulating proteins (CDK1/cyclin B complex, EpCAM or HMGB1) mediate activity. The effects of the drug on the cell cycle were measured based on the nuclear DNA content using flow cytometry. Expression of cell cycle-regulating genes was analyzed using real-time PCR. It was discovered that WP 631, at the tested concentration, did not affect the SKOV-3 cell cycle. Epo B caused significant G2/M arrest, whereas the drug combination induced stronger apoptosis and lower mitotic arrest than Epo B alone. This is very important information from the point of view of the fight against cancer, as, while mitotic arrest in Epo B-treated cells could be overcame after DNA damage repair, apoptosis which occurs after mitotic slippage in combination-treated cells is irreversible. It clearly explains the higher activity of the drug combination in comparison to Epo B alone. Epo B acts via the CDK1/cyclin B complex and has the ability to inhibit CDK1, which may be a promising strategy for ovarian cancer treatment in the future. The drug combination diminishes EpCAM and HMGB1 expression to a greater degree than either WP 631 and Epo B alone. Owing to the fact that the high expression of these two proteins is a poor prognostic factor for ovarian cancer, a decrease in their expression, observed in our studies, may result in improved efficacy of cancer therapy. The presented findings show that the combination of WP 631 and Epo B is a better therapeutic option than either of these drugs alone.

  1. Myricetin and methyl eugenol combination enhances the anticancer activity, cell cycle arrest and apoptosis induction of cis-platin against HeLa cervical cancer cell lines.

    Science.gov (United States)

    Yi, Jin-Ling; Shi, Song; Shen, Yan-Li; Wang, Ling; Chen, Hai-Yan; Zhu, Jun; Ding, Yan

    2015-01-01

    Drug combination therapies are common practice in the treatment of cancer. In this study, we evaluated the anticancer effects of myricetin (MYR), methyl eugenol (MEG) and cisplatin (CP) both separately as well as in combination against cervical cancer (HeLa) cells. To demonstrate whether MYR and MEG enhance the anticancer activity of CP against cervical cancer cells, we treated HeLa cells with MYR and MEG alone or in combination with cisplatin and evaluated cell growth and apoptosis using MTT (3 (4, 5 dimethyl thiazol 2yl) 2, 5 diphenyltetrazolium bromide) assay, LDH release assay, flow cytometry and fluorescence microscopy. The results revealed that, as compared to single drug treatment, the combination of MYR or MEG with CP resulted in greater effect in inhibiting cancer cell growth and inducing apoptosis. Cell apoptosis induction, Caspase-3 activity, cell cycle arrest and mitochondrial membrane potential loss were systematically studied to reveal the mechanisms of synergy between MYR, MEG and CP. Combination of MYR or MEG with CP resulted in more potent apoptosis induction as revealed by fluorescence microscopy using Hoechst 33258 and AO-ETBR staining. The combination treatment also increased the number of cells in G0/G1 phase dramatically as compared to single drug treatment. Mitochondrial membrane potential loss (ΛΨm) as well as Caspase-3 activity was much higher in combination treatment as compared to single drug treatment. Findings of this investigation suggest that MYR and MEG combined with cisplatin is a potential clinical chemotherapeutic approach in human cervical cancer.

  2. Development of a dynamic simulator for a natural gas combined cycle (NGCC) power plant with post-combustion carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Liese, E.; Zitney, S.

    2012-01-01

    The AVESTAR Center located at the U.S. Department of Energy’s National Energy Technology Laboratory and West Virginia University is a world-class research and training environment dedicated to using dynamic process simulation as a tool for advancing the safe, efficient and reliable operation of clean energy plants with CO{sub 2} capture. The AVESTAR Center was launched with a high-fidelity dynamic simulator for an Integrated Gasification Combined Cycle (IGCC) power plant with pre-combustion carbon capture. The IGCC dynamic simulator offers full-scope Operator Training Simulator (OTS) Human Machine Interface (HMI) graphics for realistic, real-time control room operation and is integrated with a 3D virtual Immersive Training Simulator (ITS), thus allowing joint control room and field operator training. The IGCC OTS/ITS solution combines a “gasification with CO{sub 2} capture” process simulator with a “combined cycle” power simulator into a single high-performance dynamic simulation framework. This presentation will describe progress on the development of a natural gas combined cycle (NGCC) dynamic simulator based on the syngas-fired combined cycle portion of AVESTAR’s IGCC dynamic simulator. The 574 MW gross NGCC power plant design consisting of two advanced F-class gas turbines, two heat recovery steam generators (HRSGs), and a steam turbine in a multi-shaft 2x2x1 configuration will be reviewed. Plans for integrating a post-combustion carbon capture system will also be discussed.

  3. Highlights of NASA's Special ETO Program Planning Workshop on rocket-based combined-cycle propulsion system technologies

    Science.gov (United States)

    Escher, W. J. D.

    1992-01-01

    A NASA workshop on rocket-based combined-cycle propulsion technologies is described emphasizing the development of a starting point for earth-to-orbit (ETO) rocket technologies. The tutorial is designed with attention given to the combined development of aeronautical airbreathing propulsion and space rocket propulsion. The format, agenda, and group deliberations for the tutorial are described, and group deliberations include: (1) mission and space transportation infrastructure; (2) vehicle-integrated propulsion systems; (3) development operations, facilities, and human resource needs; and (4) spaceflight fleet applications and operations. Although incomplete the workshop elevates the subject of combined-cycle hypersonic propulsion and develops a common set of priniciples regarding the development of these technologies.

  4. Performance analysis of a bio-gasification based combined cycle power plant employing indirectly heated humid air turbine

    Science.gov (United States)

    Mukherjee, S.; Mondal, P.; Ghosh, S.

    2016-07-01

    Rapid depletion of fossil fuel has forced mankind to look into alternative fuel resources. In this context, biomass based power generation employing gas turbine appears to be a popular choice. Bio-gasification based combined cycle provides a feasible solution as far as grid-independent power generation is concerned for rural electrification projects. Indirectly heated gas turbine cycles are promising alternatives as they avoid downstream gas cleaning systems. Advanced thermodynamic cycles have become an interesting area of study to improve plant efficiency. Water injected system is one of the most attractive options in this field of applications. This paper presents a theoretical model of a biomass gasification based combined cycle that employs an indirectly heated humid air turbine (HAT) in the topping cycle. Maximum overall electrical efficiency is found to be around 41%. Gas turbine specific air consumption by mass is minimum when pressure ratio is 6. The study reveals that, incorporation of the humidification process helps to improve the overall performance of the plant.

  5. HA demonstration in the Atalante facility of the Ganex 1. cycle for the selective extraction of Uranium from HLW

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M.; Sorel, C.; Cames, B.; Bisel, I.; Baron, P.; Espinoux, D.; Calor, J.N.; Viallesoubranne, C.; Lorrain, B.; Masson, M. [CEA/DEN/MAR/DRCP, Marcoule, BP17171, 30207 Bagnols/Ceze (France)

    2009-06-15

    The selective separation of uranium(VI) in the GANEX process (Group Actinide Extraction) is operated by a hydrometallurgical process using a monoamide extractant DEHiBA (N,N-di- (ethyl-2-hexyl)isobutyramide) diluted in an industrial aliphatic solvent HTP. Based on batch experimental results, a physicochemical model was developed to describe the extraction of uranium, neptunium, plutonium, and technetium by DEHiBA. With the help of this model, a flowsheet was designed and tested first in a counter-current process on a surrogate uranium/nitric acid feed in order to validate the computer code calculations and the effective recovery of uranium. After this successful 'cold' demonstration, the flowsheet was tested in 28 mixer-settlers (laboratory scale) on a genuine High Liquid Waste (HLW) in the CBP hot cell (Atalante facility) in June 2008. The HLW was obtained from the dissolution of an irradiated uranium oxide fuel (70 GWd/t). After running 60 hours, high recovery of uranium was achieved with a good purity versus transuranium elements and fission products. The decontamination factors obtained versus the other actinides and the major fission products were around 6000 for Pu, 300 for Np, 10{sup 4} for Cs and Ru, and 40 for Tc. The organic and aqueous profiles of uranium concentration in the different stages were measured and compared to the calculated data. (authors)

  6. Development of a plant-wide dynamic model of an integrated gasification combined cycle (IGCC) plant

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2009-01-01

    In this presentation, development of a plant-wide dynamic model of an advanced Integrated Gasification Combined Cycle (IGCC) plant with CO2 capture will be discussed. The IGCC reference plant generates 640 MWe of net power using Illinois No.6 coal as the feed. The plant includes an entrained, downflow, General Electric Energy (GEE) gasifier with a radiant syngas cooler (RSC), a two-stage water gas shift (WGS) conversion process, and two advanced 'F' class combustion turbines partially integrated with an elevated-pressure air separation unit (ASU). A subcritical steam cycle is considered for heat recovery steam generation. Syngas is selectively cleaned by a SELEXOL acid gas removal (AGR) process. Sulfur is recovered using a two-train Claus unit with tail gas recycle to the AGR. A multistage intercooled compressor is used for compressing CO2 to the pressure required for sequestration. Using Illinois No.6 coal, the reference plant generates 640 MWe of net power. The plant-wide steady-state and dynamic IGCC simulations have been generated using the Aspen Plus{reg_sign} and Aspen Plus Dynamics{reg_sign} process simulators, respectively. The model is generated based on the Case 2 IGCC configuration detailed in the study available in the NETL website1. The GEE gasifier is represented with a restricted equilibrium reactor model where the temperature approach to equilibrium for individual reactions can be modified based on the experimental data. In this radiant-only configuration, the syngas from the Radiant Syngas Cooler (RSC) is quenched in a scrubber. The blackwater from the scrubber bottom is further cleaned in the blackwater treatment plant. The cleaned water is returned back to the scrubber and also used for slurry preparation. The acid gas from the sour water stripper (SWS) is sent to the Claus plant. The syngas from the scrubber passes through a sour shift process. The WGS reactors are modeled as adiabatic plug flow reactors with rigorous kinetics based on

  7. Combination of ascorbate/epigallocatechin-3-gallate/gemcitabine synergistically induces cell cycle deregulation and apoptosis in mesothelioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Martinotti, Simona [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “Amedeo Avogadro”, viale T. Michel 11, 15121 Alessandria (Italy); Ranzato, Elia, E-mail: ranzato@unipmn.it [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “Amedeo Avogadro”, viale T. Michel 11, 15121 Alessandria (Italy); Parodi, Monica [IRCCS A.O.U. S. Martino-IST, Istituto Nazionale per la Ricerca sul Cancro, 16132 Genova (Italy); DI.ME.S., Università degli Studi di Genova, Via L. Alberti 2, 16132 Genova (Italy); Vitale, Massimo [IRCCS A.O.U. S. Martino-IST, Istituto Nazionale per la Ricerca sul Cancro, 16132 Genova (Italy); Burlando, Bruno [Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “Amedeo Avogadro”, viale T. Michel 11, 15121 Alessandria (Italy)

    2014-01-01

    Malignant mesothelioma (MMe) is a poor-prognosis tumor in need of innovative therapies. In a previous in vivo study, we showed synergistic anti-MMe properties of the ascorbate/epigallocatechin-3-gallate/gemcitabine combination. We have now focused on the mechanism of action, showing the induction of apoptosis and cell cycle arrest through measurements of caspase 3, intracellular Ca{sup 2+}, annexin V, and DNA content. StellArray™ PCR technology and Western immunoblotting revealed DAPK2-dependent apoptosis, upregulation of cell cycle promoters, downregulation of cell cycle checkpoints and repression of NFκB expression. The complex of data indicates that the mixture is synergistic in inducing cell cycle deregulation and non-inflammatory apoptosis, suggesting its possible use in MMe treatment. - Highlights: • Ascorbate/epigallocathechin-gallate/gemcitabine has been tested on mesothelioma cells • A synergistic mechanism has been shown for cell cycle arrest and apoptosis • PCR-array analysis has revealed the de-regulation of apoptosis and cell cycle genes • Maximum upregulation has been found for the Death-Associated Protein Kinase-2 gene • Data suggest that the mixture could be used as a clinical treatment.

  8. Transient studies of an Integrated Gasification Combined Cycle (IGCC) plant with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2010-01-01

    Next-generation coal-fired power plants need to consider the option for CO2 capture as stringent governmental mandates are expected to be issued in near future. Integrated gasification combined cycle (IGCC) plants are more efficient than the conventional coal combustion processes when the option for CO2 capture is considered. However, no IGCC plant with CO2 capture currently exists in the world. Therefore, it is important to consider the operability and controllability issues of such a plant before it is commercially built. To facilitate this objective, a detailed plant-wide dynamic simulation of an IGCC plant with 90% CO2 capture has been developed in Aspen Plus Dynamics{reg_sign}. The plant considers a General Electric Energy (GEE)-type downflow radiant-only gasifier followed by a quench section. A two-stage water gas shift (WGS) reaction is considered for conversion of CO to CO2. A two-stage acid gas removal (AGR) process based on a physical solvent is simulated for selective capture of H2S and CO2. Compression of the captured CO2 for sequestration, an oxy-Claus process for removal of H2S and NH3, black water treatment, and the sour water treatment are also modeled. The tail gas from the Claus unit is recycled to the SELEXOL unit. The clean syngas from the AGR process is sent to a gas turbine followed by a heat recovery steam generator. This turbine is modeled as per published data in the literature. Diluent N2 is used from the elevated-pressure ASU for reducing the NOx formation. The heat recovery steam generator (HRSG) is modeled by considering generation of high-pressure, intermediate-pressure, and low-pressure steam. All of the vessels, reactors, heat exchangers, and the columns have been sized. The basic IGCC process control structure has been synthesized by standard guidelines and existing practices. The steady state results are validated with data from a commercial gasifier. In the future grid-connected system, the plant should satisfy the environmental

  9. Mixing and reaction processes in rocket based combined cycle and conventional rocket engines

    Science.gov (United States)

    Lehman, Matthew Kurt

    Raman spectroscopy was used to make species measurements in two rocket engines. An airbreathing rocket, the rocket based combined cycle (RBCC) engine, and a conventional rocket were investigated. A supersonic rocket plume mixing with subsonic coflowing air characterizes the ejector mode of the RBCC engine. The mixing length required for the air and plume to become homogenous is a critical dimension. For the conventional rocket experiments, a gaseous oxygen/gaseous hydrogen single-element shear coaxial injector was used. Three chamber Mach number conditions, 0.1, 0.2 and 0.3, were chosen to assess the effect of Mach number on mixing. The flow within the chamber was entirely subsonic. For the RBCC experiments, vertical Raman line measurements were made at multiple axial locations downstream from the rocket nozzle plane. Species profiles assessed the mixing progress between the supersonic plume and subsonic air. For the conventional rocket, Raman line measurements were made downstream from the injector face. The goal was to evaluate the effect of increased chamber Mach number on injector mixing/reaction. For both engines, quantitative and qualitative information was collected for computational fluid dynamics (CFD development. The RBCC experiments were conducted for three distinct geometries. The primary flow path was a diffuse and afterburner design with a direct-connect air supply. A sea-level static (SLS) version and a thermally choked variant were also tested. The experimental results show that mixing length increases with additional coflow air in the DAB geometry. Operation of variable rocket mixture ratios at identical air flow rates did not significantly affect the mixing length. The thermally choked variant had a longer mixing length compared to the DAB geometry, and the SLS modification had a shorter mixing length due to a reduced air flow. The conventional rocket studies focused on the effect of chamber Mach number on primary injector mixing. Chamber Mach

  10. Intertidal foraminifera (Protista) and carbon-nitrogen cycling: combined effects of temperature and diet quality

    Science.gov (United States)

    Wukovits, Julia; Enge, Annekatrin Julie; Oberrauch, Max; Watzka, Margarete; Wanek, Wolfgang; Heinz, Petra

    2017-04-01

    Benthic foraminifera (eukaryotic protists) are to a large extent acting as detrivores, feeding on microalgal detritus. Phytodetritus constitutes a main component of the intertidal carbon (C) and nitrogen (N) pool, thus making foraminifera important players in intertidal nutrient fluxes. These fluxes are strongly dependent on interactions between biotic and abiotic environmental factors, as e.g. the energetic value or the quality of phytodetritus that depends on environmental nutrient availability. Increased inorganic C concentrations in coastal water bodies (e.g. due to increased atmospheric CO2) can have a negative effect on the phytodetrital quality by increasing microalgal C:N ratios. Simultanous warming of the environment can cause increased metabolic rates of exposed heterotrophic organisms, like foraminifera. The combination of lower food quality and increased metabolic rates is supposed to cause cascading effects on organismic C cycling, potentially diminishing the role of detrivorous food as a C sink in marine food webs by increased discharge of excess C. In this study, the above described scenario was tested in laboratory feeding experiments on a common and abundant intertidal foraminiferal species (Haynesina germanica, collected in the German Wadden Sea). Two batches of artificially produced and dual isotope labeled (13C and 15N) chlorophyte detritus (1.5 gDW m-2) with different C:N ratios (5.5 and 7.6) and one batch of isotopically labelled diatom detritus (C:N 5.6) were fed under controlled conditions at three different temperatures. Results were extrapolated to the in situ abundance of live H. germanica individuals in the sampling area (sediment core data), to estimate the magnitude of the effect on an areal basis within the natural habitat. The study revealed significant, temperature induced variations in the carbon and nitrogen processing of H. germanica. The food source with an increased C:N ratio doubled the release of carbon from the H. germanica

  11. Life cycle assessment and evaluation of sustainable product design strategies for combined cycle power plants; Lebenszyklusanalyse und Bestimmung von Einflussfaktoren zur nachhaltigen Produktgestaltung von GuD-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Parthey, Falko

    2010-03-26

    The growth of the national GDP on a worldwide level and the associated increasing demand for primary energy inevitably result in higher emissions levels. According to recent international scientific studies the energy sector (including electricity generation, industrial activities and traffic) contributes up to 83 % to the worldwide greenhouse gas emissions. Climate change and the projection of its impacts have been acknowledged also on the political level and concise measures are being considered. Since access to electricity and sustainable development are inseparable, the question arises whether and how adequate answers can be given within the coming years. Furthermore, the definite lifetime of the existing power plant fleet will result in a gap of up to 12.000 MWh in 2020, depending on the scenario. One part of the answer lies in the sustainable design of power plants. The main contribu-tion of this work is therefore the life cycle analysis of a combined cycle power plant from of a manufacturer's perspective. The visualisation of the entire product system and the re-sults of the impact assessment facilitate the determination of improvement potential. The system boundaries for this study include all relevant phases of the product life cycle (materials, manufacturing, transport, operation, service and end of life). The life cycle inventory consists of all bills of materials and energy consumption for all components and life cycle phases. The interpretation of the results of the impact assessment showed the expected significant contribution in kg CO{sub 2}e for the emission of the full load operation. Nevertheless, the results for all impact categories over the entire lifecycle are given. Various operation scenarios and configurations can now be analysed based on the elaborated modules, and can now serve as decision support already during product development. The visualisation of impacts of design decisions on the ecological footprint of the product system in

  12. Experimental demonstration of using divergence cost-function in SPGD algorithm for coherent beam combining with tip/tilt control.

    Science.gov (United States)

    Geng, Chao; Luo, Wen; Tan, Yi; Liu, Hongmei; Mu, Jinbo; Li, Xinyang

    2013-10-21

    A novel approach of tip/tilt control by using divergence cost function in stochastic parallel gradient descent (SPGD) algorithm for coherent beam combining (CBC) is proposed and demonstrated experimentally in a seven-channel 2-W fiber amplifier array with both phase-locking and tip/tilt control, for the first time to our best knowledge. Compared with the conventional power-in-the-bucket (PIB) cost function for SPGD optimization, the tip/tilt control using divergence cost function ensures wider correction range, automatic switching control of program, and freedom of camera's intensity-saturation. Homemade piezoelectric-ring phase-modulator (PZT PM) and adaptive fiber-optics collimator (AFOC) are developed to correct piston- and tip/tilt-type aberrations, respectively. The PIB cost function is employed for phase-locking via maximization of SPGD optimization, while the divergence cost function is used for tip/tilt control via minimization. An average of 432-μrad of divergence metrics in open loop has decreased to 89-μrad when tip/tilt control implemented. In CBC, the power in the full width at half maximum (FWHM) of the main lobe increases by 32 times, and the phase residual error is less than λ/15.

  13. Combined effects of short-term rainfall patterns and soil texture on nitrogen cycling -- A Modeling Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gu, C.; Riley, W.J.

    2009-11-01

    Precipitation variability and magnitude are expected to change in many parts of the world over the 21st century. We examined the potential effects of intra-annual rainfall patterns on soil nitrogen (N) transport and transformation in the unsaturated soil zone using a deterministic dynamic modeling approach. The model (TOUGHREACT-N), which has been tested and applied in several experimental and observational systems, mechanistically accounts for microbial activity, soil-moisture dynamics that respond to precipitation variability, and gaseous and aqueous tracer transport in the soil. Here, we further tested and calibrated the model against data from a precipitation variability experiment in a tropical system in Costa Rica. The model was then used to simulate responses of soil moisture, microbial dynamics, nitrogen (N) aqueous and gaseous species, N leaching, and N trace-gas emissions to changes in rainfall patterns; the effect of soil texture was also examined. The temporal variability of nitrate leaching and NO, N{sub 2}, and N{sub 2}O effluxes were significantly influenced by rainfall dynamics. Soil texture combined with rainfall dynamics altered soil moisture dynamics, and consequently regulated soil N responses to precipitation changes. The clay loam soil more effectively buffered water stress during relatively long intervals between precipitation events, particularly after a large rainfall event. Subsequent soil N aqueous and gaseous losses showed either increases or decreases in response to increasing precipitation variability due to complex soil moisture dynamics. For a high rainfall scenario, high precipitation variability resulted in as high as 2.4-, 2.4-, 1.2-, and 13-fold increases in NH{sub 3}, NO, N{sub 2}O and NO{sub 3}{sup -} fluxes, respectively, in clay loam soil. In sandy loam soil, however, NO and N{sub 2}O fluxes decreased by 15% and 28%, respectively, in response to high precipitation variability. Our results demonstrate that soil N cycling

  14. Environmental Product Development Combining the Life Cycle Perspective with Chemical Hazard Information

    DEFF Research Database (Denmark)

    Askham, Cecilia

    Concerns regarding the short- and long-term detrimental effects of chemicals on human health and ecosystems have made the minimisation of chemical hazards a vitally important issue. If sustainable development is to be achieved, environmental efficient products (and product life cycles......) are essential. Many life cycle assessments of product systems are performed without the inclusion of toxicity data and indicators. Ecodesign processes for products are often based upon just one, or very few, environmental indicators. Regulatory issues are sometimes addressed in an ad hoc fashion, often late...... in the design or redesign process. This thesis concerns marrying the life cycle perspective with chemical hazard information, in order to advance the practice of environmental product development, and hence takes further steps towards sustainable development. The need to consider the full value chain...

  15. Demonstration of 48-Gb/s 16-QAM signal transmission using half cycle sub-carrier modulation in intensity modulation/direct detection system

    Science.gov (United States)

    Tang, Jin; He, Jing; Chen, Ming; Li, Danyu; Chen, Lin

    2015-01-01

    A simple spectral-efficiency intensity modulation/direct detection (IM/DD) system based on half cycle sub-carrier modulation (SCM) signal is proposed for short reach fiber communications in this paper. The signal impairment of frequency selective fading due to fiber chromatics dispersion (CD) is mathematically analyzed. To reduce the performance deterioration caused by the non-flat transfer function, digital pre- and post-equalization is applied in the system. The peak to average power ratio (PAPR) of the signal is also discussed in comparison with that of orthogonal frequency division multiplexing (OFDM). The transmission of 16-QAM half cycle SCM signal with a sub-carrier frequency of half the symbol rate and Nyquist pulse shaping is experimentally demonstrated. The bit-error rate (BER) of 48 Gb/s polarization multiplexing division (PDM) 16 QAM half cycle SCM signal is less than 7% forward-error-correction (FEC) threshold of 3.8 ×10-3 after transmission over 83 km standard single-mode fiber (SSMF).

  16. Integrated solar combined cycles using gas turbines with partial recuperation and solar integration at different pressure levels

    Science.gov (United States)

    Rovira, Antonio; Sánchez, Consuelo; Fernández, Santiago; Muñoz, Marta; Barbero, Rubén

    2017-06-01

    This work studies and compares two alternatives to improve the solar-to-electricity energy conversion efficiency in integrated solar combined cycle power plants (ISCC), which are based on the use of combined cycles including partial recuperative gas turbines. Each alternative has been integrated into dual and triple pressure levels with reheat heat recovery steam generators (HRSG). Partial recuperation conveys lower heat recovery at the steam generator than in conventional plants, because each MW exchanged in the recuperator is not available at the HRSG. This thermal power decrease at the HRSG may be overcome by the integration of solar energy that is implemented using parabolic trough collectors. Moreover, with such an implementation each solar thermal MW integrated allows a MW of heat recuperation and, thus a MW of fossil fuel saving, thus the solar heat-to-electricity energy conversion rate may reach values up to 50 %, which makes the proposal interesting.

  17. Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Gas turbine performance

    DEFF Research Database (Denmark)

    Haglind, Fredrik

    2010-01-01

    -load performance. Subsequently, in another paper, the effects of variable geometry on the part-load performance for combined cycles used for ship propulsion will be presented. Moreover, this paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis......The part-load performance of gas and steam turbine combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry on the gas turbine part...... of various components within gas turbines. Two different gas turbine configurations are studied, a two-shaft aero-derivative configuration and a single-shaft industrial configuration. When both gas turbine configurations are running in part-load using fuel flow control, the results indicate better part...

  18. Nutrient limitation reduces land carbon uptake in simulations with a model of combined carbon, nitrogen and phosphorus cycling

    Directory of Open Access Journals (Sweden)

    D. S. Goll

    2012-09-01

    Full Text Available Terrestrial carbon (C cycle models applied for climate projections simulate a strong increase in net primary productivity (NPP due to elevated atmospheric CO2 concentration during the 21st century. These models usually neglect the limited availability of nitrogen (N and phosphorus (P, nutrients that commonly limit plant growth and soil carbon turnover. To investigate how the projected C sequestration is altered when stoichiometric constraints on C cycling are considered, we incorporated a P cycle into the land surface model JSBACH (Jena Scheme for Biosphere–Atmosphere Coupling in Hamburg, which already includes representations of coupled C and N cycles.

    The model reveals a distinct geographic pattern of P and N limitation. Under the SRES (Special Report on Emissions Scenarios A1B scenario, the accumulated land C uptake between 1860 and 2100 is 13% (particularly at high latitudes and 16% (particularly at low latitudes lower in simulations with N and P cycling, respectively, than in simulations without nutrient cycles. The combined effect of both nutrients reduces land C uptake by 25% compared to simulations without N or P cycling. Nutrient limitation in general may be biased by the model simplicity, but the ranking of limitations is robust against the parameterization and the inflexibility of stoichiometry. After 2100, increased temperature and high CO2 concentration cause a shift from N to P limitation at high latitudes, while nutrient limitation in the tropics declines. The increase in P limitation at high-latitudes is induced by a strong increase in NPP and the low P sorption capacity of soils, while a decline in tropical NPP due to high autotrophic respiration rates alleviates N and P limitations. The quantification of P limitation remains challenging. The poorly constrained processes of soil P sorption and biochemical mineralization are identified as the main uncertainties in the strength of P limitation

  19. Assessing environmental performance by combining life cycle assessment, multi-criteria analysis and environmental performance indicators

    NARCIS (Netherlands)

    Hermann, B.G.; Kroeze, C.; Jawjit, W.

    2007-01-01

    We present a new analytical tool, called COMPLIMENT, which can be used to provide detailed information on the overall environmental impact of a business. COMPLIMENT integrates parts of tools such as life cycle assessment, multi-criteria analysis and environmental performance indicators. It avoids di

  20. Experimental demonstration of 608Gbit/s short reach transmission employing half-cycle 16QAM Nyquist-SCM signal and direct detection with 25Gbps EML.

    Science.gov (United States)

    Zhong, Kangping; Zhou, Xian; Wang, Yiguang; Wang, Liang; Yuan, Jinhui; Yu, Changyuan; Lau, Alan Pak Tao; Lu, Chao

    2016-10-31

    In this paper, we experimentally demonstrated an IM/DD short reach transmission system with a total capacity of 608Gbit/s (net capacity of 565.4Gbit/s exclude 7% FEC overhead) employing half-cycle 16QAM Nyquist-SCM signal and 25Gbps EML at O band. Direct detection-faster than Nyquist (DD-FTN) technique was employed to compensate channel impairments. Number of taps of DD-LMS and tap coefficient of post filter in DD-FTN were experimentally studied for different baud rates. Single-lane 152Gbit/s transmission over 10km of SSMF was experimentally demonstrated. Employing a 4-lanes LAN-WDM architecture, a total capacity of 608Gbit/s transmission over 2km was successfully achieved with a receiver sensitivity lower than -4dBm. To the best of authors' knowledge, this is the highest reported baud rate of half-cycle 16QAM Nyquist-SCM signal and the highest bit rate employing IM/DD and 25Gbps EML in a four lanes LAN-WDM architecture for short reach systems in the O band.

  1. Model studies for determining whether combined-cycle plants can participate in control of frequency and power flows in unified energy systems of Russia

    Science.gov (United States)

    Davydov, N. I.; Zorchenko, N. V.; Davydov, A. V.; Radin, Yu. A.

    2009-10-01

    Approximating transfer functions of a PGU-39 combined-cycle plant as a technological system with a controlled power output are presented, a structure of a system for automatic closed-loop control of the combined-cycle plant power output is proposed, and results from model investigations of this system are presented.

  2. Hydrogen production by water decomposition using a combined electrolytic-thermochemical cycle

    Science.gov (United States)

    Farbman, G. H.; Brecher, L. E.

    1976-01-01

    A proposed dual-purpose power plant generating nuclear power to provide energy for driving a water decomposition system is described. The entire system, dubbed Sulfur Cycle Water Decomposition System, works on sulfur compounds (sulfuric acid feedstock, sulfur oxides) in a hybrid electrolytic-thermochemical cycle; performance superior to either all-electrolysis systems or presently known all-thermochemical systems is claimed. The 3345 MW(th) graphite-moderated helium-cooled reactor (VHTR - Very High Temperature Reactor) generates both high-temperature heat and electric power for the process; the gas stream at core exit is heated to 1850 F. Reactor operation is described and reactor innards are illustrated. A cost assessment for on-stream performance in the 1990's is optimistic.

  3. Selecting the process arrangement for preparing the gas turbine working fluid for an integrated gasification combined-cycle power plant

    Science.gov (United States)

    Ryzhkov, A. F.; Gordeev, S. I.; Bogatova, T. F.

    2015-11-01

    Introduction of a combined-cycle technology based on fuel gasification integrated in the process cycle (commonly known as integrated gasification combined cycle technology) is among avenues of development activities aimed at achieving more efficient operation of coal-fired power units at thermal power plants. The introduction of this technology is presently facing the following difficulties: IGCC installations are characterized by high capital intensity, low energy efficiency, and insufficient reliability and availability indicators. It was revealed from an analysis of literature sources that these drawbacks are typical for the gas turbine working fluid preparation system, the main component of which is a gasification plant. Different methods for improving the gasification plant chemical efficiency were compared, including blast air high-temperature heating, use of industrial oxygen, and a combination of these two methods implying limited use of oxygen and moderate heating of blast air. Calculated investigations aimed at estimating the influence of methods for achieving more efficient air gasification are carried out taking as an example the gasifier produced by the Mitsubishi Heavy Industries (MHI) with a thermal capacity of 500 MW. The investigation procedure was verified against the known experimental data. Modes have been determined in which the use of high-temperature heating of blast air for gasification and cycle air upstream of the gas turbine combustion chamber makes it possible to increase the working fluid preparation system efficiency to a level exceeding the efficiency of the oxygen process performed according to the Shell technology. For the gasification plant's configuration and the GTU working fluid preparation system be selected on a well-grounded basis, this work should be supplemented with technical-economic calculations.

  4. A review on the use of gas and steam turbine combined cycles as prime movers for large ships. Part II: Previous work and implications

    Energy Technology Data Exchange (ETDEWEB)

    Haglind, Fredrik [Technical University of Denmark, Department of Mechanical Engineering, Building 402, DK-2800 Kgs. Lyngby (Denmark)

    2008-12-15

    The aim of the present paper is to review the prospects of using combined cycles as prime movers for large ships, like, container ships, tankers and bulk carriers. The paper is divided into three parts of which this paper constitutes Part II. In Part I, the environmental and human health concerns of international shipping were outlined. The regulatory framework relevant for shipping and the design of combined cycles were discussed. Here, previous work and experience are reviewed, and an overview of the implications of introducing combined cycles as prime movers is included. In Part III, marine fuels are discussed and the pollutant emissions of gas turbines are compared with those of two-stroke, slow-speed diesel engines. In the past, combined cycles of COGAS and COGES configurations have been considered for ship propulsion. Another application where gas turbine-based systems have been considered as prime movers is for LNG ships, which are traditionally powered by steam turbines with gas-burning boilers. Previous experience for a cruiser shows that combined cycles weigh less and require a smaller volume than diesel engines, resulting in increased passenger capacity and/or voyage performance. Diesel engines respond faster to a load change than combined cycles. Provided parts within the steam cycle are warm, the start-up times of combined cycles and diesel engines are similar. (author)

  5. Fossil fuel savings, carbon emission reduction and economic attractiveness of medium-scale integrated biomass gasification combined cycle cogeneration plants

    Directory of Open Access Journals (Sweden)

    Kalina Jacek

    2012-01-01

    Full Text Available The paper theoretically investigates the system made up of fluidized bed gasifier, SGT-100 gas turbine and bottoming steam cycle. Different configurations of the combined cycle plant are examined. A comparison is made between systems with producer gas (PG and natural gas (NG fired turbine. Supplementary firing of the PG in a heat recovery steam generator is also taken into account. The performance of the gas turbine is investigated using in-house built Engineering Equation Solver model. Steam cycle is modeled using GateCycleTM simulation software. The results are compared in terms of electric energy generation efficiency, CO2 emission and fossil fuel energy savings. Finally there is performed an economic analysis of a sample project. The results show relatively good performance in the both alternative configurations at different rates of supplementary firing. Furthermore, positive values of economic indices were obtained. [Acknowledgements. This work was carried out within the frame of research project no. N N513 004036, titled: Analysis and optimization of distributed energy conversion plants integrated with gasification of biomass. The project is financed by the Polish Ministry of Science.

  6. Performance analysis of endoreversible combined Carnot cycles based on new maximum efficient power (MEP) approach

    National Research Council Canada - National Science Library

    Maheshwari, Govind; Chaudhary, S; Somani, S.K

    2010-01-01

    The efficient power, defined as the product of power output and efficiency of the engine, is taken as the objective for performance analysis and optimization of an endoreversible combined Carnot heat...

  7. Dual capillary tube / heat exchanger in combination with cycle priming for reducing charge migration

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Alberto Regio; Kuehl, Steven J.; Litch, Andrew D.; Wu, Guolian

    2017-07-04

    A refrigerator appliance including a multi-capacity compressor and a refrigerant circuit with two conduits and pressure reducing devices arranged in parallel between an evaporator and a condenser. Refrigerant can flow through one, both or none of the conduits and pressure reducing devices. The appliance also has a heat exchanger in contact with either one pressure reducing device, or one conduit between the pressure reducing device and the valve system. The appliance also includes a controller for priming the compressor above a nominal capacity for a predetermined or calculated duration at the beginning of an ON-cycle.

  8. Effect of cell cycle phase on the sensitivity of SAS cells to sonodynamic therapy using low-intensity ultrasound combined with 5-aminolevulinic acid in vitro.

    Science.gov (United States)

    Li, Nan; Sun, Miao; Wang, Yao; Lv, Yanhong; Hu, Zheng; Cao, Wenwu; Zheng, Jinhua; Jiao, Xiaohui

    2015-08-01

    Sonodynamic therapy (SDT) with 5-aminolevulinic acid (5-ALA) can effectively inhibit various types of tumor in vitro and in vivo. However, the association between the efficacy of SDT and the phase of the cell cycle remains to be elucidated. 5-ALA may generate different quantities of sonosensitizer, protoporphyrin IX (PpIX), in different phases of the cell cycle, which may result in differences in sensitivity to 5-ALA-induced SDT. The present study aimed to investigate the effect of the cell cycle on the susceptibility of SAS cells to SDT following synchronization to different cell cycle phases. These results indicates that the rates of cell death and apoptosis of the SAS cells in the S and G2/M phases were significantly higher following SDT, compared with those in the G1-phase cells and unsynchronized cells, with a corresponding increase in PpIX in the S and G2/M cells. In addition, the expression of caspase-3 increased, while that of B-cell lymphoma (Bcl)-2 decreased markedly in theS and G2/M cells following SDT. Cyclin A was also expressed at higher levels in the S and G2/M cells, compared with the G1-phase cells. SDT also caused a significant upregulation of cyclin A in all phases of the cell cycle, however this was most marked in the S and G2/M cells. It was hypothesized that high expression levels of cyclin A in the S and G2/M cells may promote the induction of caspase-3 and reduce the induction of Bcl-2 by SDT and, therefore, enhance apoptosis. Taken together, these data demonstrated that cells in The S and G2/M phases generate more intracellular PpIX, have higher levels of cyclin A and are, therefore, more sensitive to SDT-induced cytotoxicity. These findings indicate the potential novel approach to preventing the onset of cancer by combining cell-cycle regulators with SDT. This sequential combination therapy may be a simple and cost-effective way of enhancing the effects of SDT in clinical settings.

  9. Combined solar organic Rankine cycle with reverse osmosis desalination process: Energy, exergy, and cost evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Nafey, A.S.; Sharaf, M.A. [Department of Engineering Science, Faculty of Petroleum and Mining Engineering, Suez Canal University, Suez (Egypt)

    2010-11-15

    Organic Rankine cycles (ORC) have unique properties that are well suited to solar power generation. In this work design and performance calculations are performed using MatLab/SimuLink computational environment. The cycle consists of thermal solar collectors (Flat Plate Solar Collector (FPC), or Parabolic Trough Collector (PTC), or Compound Parabolic Concentrator (CPC)) for heat input, expansion turbine for work output, condenser unit for heat rejection, pump unit, and Reverse Osmosis (RO) unit. Reverse osmosis unit specifications used in this work is based on Sharm El-Shiekh RO desalination plant. Different working fluids such as: butane, isobutane, propane, R134a, R152a, R245ca, and R245fa are examined for FPC. R113, R123, hexane, and pentane are investigated for CPC. Dodecane, nonane, octane, and toluene are allocated for PTC. The proposed process units are modeled and show a good validity with literatures. Exergy and cost analysis are performed for saturation and superheated operating conditions. Exergy efficiency, total exergy destruction, thermal efficiency, and specific capital cost are evaluated for direct vapor generation (DVG) process. Toluene and Water achieved minimum results for total solar collector area, specific total cost and the rate of exergy destruction. (author)

  10. Combined climate and carbon-cycle effects of large-scale deforestation.

    Science.gov (United States)

    Bala, G; Caldeira, K; Wickett, M; Phillips, T J; Lobell, D B; Delire, C; Mirin, A

    2007-04-17

    The prevention of deforestation and promotion of afforestation have often been cited as strategies to slow global warming. Deforestation releases CO(2) to the atmosphere, which exerts a warming influence on Earth's climate. However, biophysical effects of deforestation, which include changes in land surface albedo, evapotranspiration, and cloud cover also affect climate. Here we present results from several large-scale deforestation experiments performed with a three-dimensional coupled global carbon-cycle and climate model. These simulations were performed by using a fully three-dimensional model representing physical and biogeochemical interactions among land, atmosphere, and ocean. We find that global-scale deforestation has a net cooling influence on Earth's climate, because the warming carbon-cycle effects of deforestation are overwhelmed by the net cooling associated with changes in albedo and evapotranspiration. Latitude-specific deforestation experiments indicate that afforestation projects in the tropics would be clearly beneficial in mitigating global-scale warming, but would be counterproductive if implemented at high latitudes and would offer only marginal benefits in temperate regions. Although these results question the efficacy of mid- and high-latitude afforestation projects for climate mitigation, forests remain environmentally valuable resources for many reasons unrelated to climate.

  11. Combined Climate and Carbon-Cycle Effects of Large-Scale Deforestation

    Energy Technology Data Exchange (ETDEWEB)

    Bala, G; Caldeira, K; Wickett, M; Phillips, T J; Lobell, D B; Delire, C; Mirin, A

    2006-10-17

    The prevention of deforestation and promotion of afforestation have often been cited as strategies to slow global warming. Deforestation releases CO{sub 2} to the atmosphere, which exerts a warming influence on Earth's climate. However, biophysical effects of deforestation, which include changes in land surface albedo, evapotranspiration, and cloud cover also affect climate. Here we present results from several large-scale deforestation experiments performed with a three-dimensional coupled global carbon-cycle and climate model. These are the first such simulations performed using a fully three-dimensional model representing physical and biogeochemical interactions among land, atmosphere, and ocean. We find that global-scale deforestation has a net cooling influence on Earth's climate, since the warming carbon-cycle effects of deforestation are overwhelmed by the net cooling associated with changes in albedo and evapotranspiration. Latitude-specific deforestation experiments indicate that afforestation projects in the tropics would be clearly beneficial in mitigating global-scale warming, but would be counterproductive if implemented at high latitudes and would offer only marginal benefits in temperate regions. While these results question the efficacy of mid- and high-latitude afforestation projects for climate mitigation, forests remain environmentally valuable resources for many reasons unrelated to climate.

  12. Development of a thermal scheme for a cogeneration combined-cycle unit with an SVBR-100 reactor

    Science.gov (United States)

    Kasilov, V. F.; Dudolin, A. A.; Krasheninnikov, S. M.

    2017-02-01

    At present, the prospects for development of district heating that can increase the effectiveness of nuclear power stations (NPS), cut down their payback period, and improve protection of the environment against harmful emissions are being examined in the nuclear power industry of Russia. It is noted that the efficiency of nuclear cogeneration power stations (NCPS) is drastically affected by the expenses for heat networks and heat losses during transportation of a heat carrier through them, since NPSs are usually located far away from urban area boundaries as required for radiation safety of the population. The prospects for using cogeneration power units with small or medium power reactors at NPSs, including combined-cycle units and their performance indices, are described. The developed thermal scheme of a cogeneration combined-cycle unit (CCU) with an SBVR-100 nuclear reactor (NCCU) is presented. This NCCU should use a GE 6FA gasturbine unit (GTU) and a steam-turbine unit (STU) with a two-stage district heating plant. Saturated steam from the nuclear reactor is superheated in a heat-recovery steam generator (HRSG) to 560-580°C so that a separator-superheater can be excluded from the thermal cycle of the turbine unit. In addition, supplemental fuel firing in HRSG is examined. NCCU effectiveness indices are given as a function of the ambient air temperature. Results of calculations of the thermal cycle performance under condensing operating conditions indicate that the gross electric efficiency η el NCCU gr of = 48% and N el NCCU gr = 345 MW can be achieved. This efficiency is at maximum for NCCU with an SVBR-100 reactor. The conclusion is made that the cost of NCCU installed kW should be estimated, and the issue associated with NCCUs siting with reference to urban area boundaries must be solved.

  13. 75 FR 17397 - Hydrogen Energy California's Integrated Gasification Combined Cycle Project, Kern County, CA...

    Science.gov (United States)

    2010-04-06

    ... performance. The financial risk associated with such large- scale demonstration projects is often too high for..., administration buildings, water and wastewater treatment systems, and management facilities for handling... of the plant and associated facilities, equipment procurement, construction, startup, operations,...

  14. Cryogenic hydrogen-induced air-liquefaction technologies for combined-cycle propulsion applications

    Science.gov (United States)

    Escher, William J. D.

    1992-01-01

    Given here is a technical assessment of the realization of cryogenic hydrogen induced air liquefaction technologies in a prospective onboard aerospace vehicle process setting. The technical findings related to the status of air liquefaction technologies are reviewed. Compact lightweight cryogenic heat exchangers, heat exchanger atmospheric constituent fouling alleviation measures, para/ortho-hydrogen shift-conversion catalysts, cryogenic air compressors and liquid air pumps, hydrogen recycling using slush hydrogen as a heat sink, liquid hydrogen/liquid air rocket-type combustion devices, and technically related engine concepts are discussed. Much of the LACE work is related to aerospaceplane propulsion concepts that were developed in the 1960's. Emphasis is placed on the Liquid Air Cycle Engine (LACE).

  15. Combined use of semantics and metadata to manage Research Data Life Cycle in Environmental Sciences

    Science.gov (United States)

    Aguilar Gómez, Fernando; de Lucas, Jesús Marco; Pertinez, Esther; Palacio, Aida

    2017-04-01

    The use of metadata to contextualize datasets is quite extended in Earth System Sciences. There are some initiatives and available tools to help data managers to choose the best metadata standard that fit their use cases, like the DCC Metadata Directory (http://www.dcc.ac.uk/resources/metadata-standards). In our use case, we have been gathering physical, chemical and biological data from a water reservoir since 2010. A well metadata definition is crucial not only to contextualize our own data but also to integrate datasets from other sources like satellites or meteorological agencies. That is why we have chosen EML (Ecological Metadata Language), which integrates many different elements to define a dataset, including the project context, instrumentation and parameters definition, and the software used to process, provide quality controls and include the publication details. Those metadata elements can contribute to help both human and machines to understand and process the dataset. However, the use of metadata is not enough to fully support the data life cycle, from the Data Management Plan definition to the Publication and Re-use. To do so, we need to define not only metadata and attributes but also the relationships between them, so semantics are needed. Ontologies, being a knowledge representation, can contribute to define the elements of a research data life cycle, including DMP, datasets, software, etc. They also can define how the different elements are related between them and how they interact. The first advantage of developing an ontology of a knowledge domain is that they provide a common vocabulary hierarchy (i.e. a conceptual schema) that can be used and standardized by all the agents interested in the domain (either humans or machines). This way of using ontologies is one of the basis of the Semantic Web, where ontologies are set to play a key role in establishing a common terminology between agents. To develop an ontology we are using a graphical tool

  16. Studies of an extensively axisymmetric rocket based combined cycle (RBCC) engine powered single-stage-to-orbit (SSTO) vehicle

    Science.gov (United States)

    Foster, Richard W.; Escher, William J. D.; Robinson, John W.

    1989-01-01

    The present comparative performance study has established that rocket-based combined cycle (RBCC) propulsion systems, when incorporated by essentially axisymmetric SSTO launch vehicle configurations whose conical forebody maximizes both capture-area ratio and total capture area, are capable of furnishing payload-delivery capabilities superior to those of most multistage, all-rocket launchers. Airbreathing thrust augmentation in the rocket-ejector mode of an RBCC powerplant is noted to make a major contribution to final payload capability, by comparison to nonair-augmented rocket engine propulsion systems.

  17. A retrospective on early cryogenic primary rocket subsystem designs as integrated into rocket-based combined-cycle (RBCC) engines

    Science.gov (United States)

    Escher, William J. D.; Schnurstein, Robert E.

    1993-06-01

    A study (Escher and Flornes, 1966) of aerospace propulsion systems for a fully reusable earth-to-orbit space transport application that was performed in 1965-67 is reviewed. The present review provides a detailed, subject-focused technical retrospective on a key subsystem element of the rocket-based combined-cycle (RBCC) class of aerospace propulsion systems. The RBCC concept is considered to be a leading candidate propulsion approach for either SSTO or two-stage-to-orbit space transportaion applications.

  18. Determining Reliability Parameters for a Closed-Cycle Small Combined Heat and Power Plant

    Directory of Open Access Journals (Sweden)

    Vysokomorny Vladimir S.

    2016-01-01

    Full Text Available The paper provides numerical values of the reliability parameters for independent power sources within the ambient temperature and output power range corresponding to the operation under the climatic conditions of Eastern Siberia and the Far East of the Russian Federation. We have determined the optimal values of the parameters necessary for the reliable operation of small CHP plants (combined heat and power plants providing electricity for isolated facilities.

  19. Life cycle analysis of distributed concentrating solar combined heat and power: economics, global warming potential and water

    Science.gov (United States)

    Norwood, Zack; Kammen, Daniel

    2012-12-01

    We report on life cycle assessment (LCA) of the economics, global warming potential and water (both for desalination and water use in operation) for a distributed concentrating solar combined heat and power (DCS-CHP) system. Detailed simulation of system performance across 1020 sites in the US combined with a sensible cost allocation scheme informs this LCA. We forecast a levelized cost of 0.25 kWh-1 electricity and 0.03 kWh-1 thermal, for a system with a life cycle global warming potential of ˜80 gCO2eq kWh-1 of electricity and ˜10 gCO2eq kWh-1 thermal, sited in Oakland, California. On the basis of the economics shown for air cooling, and the fact that any combined heat and power system reduces the need for cooling while at the same time boosting the overall solar efficiency of the system, DCS-CHP compares favorably to other electric power generation systems in terms of minimization of water use in the maintenance and operation of the plant. The outlook for water desalination coupled with distributed concentrating solar combined heat and power is less favorable. At a projected cost of 1.40 m-3, water desalination with DCS-CHP would be economical and practical only in areas where water is very scarce or moderately expensive, primarily available through the informal sector, and where contaminated or salt water is easily available as feed-water. It is also interesting to note that 0.40-1.90 m-3 is the range of water prices in the developed world, so DCS-CHP desalination systems could also be an economical solution there under some conditions.

  20. Hydrogen-or-Fossil-Combustion Nuclear Combined-Cycle Systems for Base- and Peak-Load Electricity Production

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, Charles W [ORNL; Conklin, Jim [ORNL

    2007-09-01

    A combined-cycle power plant is described that uses (1) heat from a high-temperature nuclear reactor to meet base-load electrical demands and (2) heat from the same high-temperature reactor and burning natural gas, jet fuel, or hydrogen to meet peak-load electrical demands. For base-load electricity production, fresh air is compressed; then flows through a heat exchanger, where it is heated to between 700 and 900 C by heat provided by a high-temperature nuclear reactor via an intermediate heat-transport loop; and finally exits through a high-temperature gas turbine to produce electricity. The hot exhaust from the Brayton-cycle gas turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, the air is first compressed and then heated with the heat from a high-temperature reactor. Natural gas, jet fuel, or hydrogen is then injected into the hot air in a combustion chamber, combusts, and heats the air to 1300 C-the operating conditions for a standard natural-gas-fired combined-cycle plant. The hot gas then flows through a gas turbine and a heat recovery steam generator before being sent to the exhaust stack. The higher temperatures increase the plant efficiency and power output. If hydrogen is used, it can be produced at night using energy from the nuclear reactor and stored until needed. With hydrogen serving as the auxiliary fuel for peak power production, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the various fuels and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the electric grid. This combined cycle uses the

  1. Combined approach to demonstrate acetylcholinesterase activity changes in the rat brain following tabun intoxication and its treatment.

    Science.gov (United States)

    Bajgar, Jiri; Hajek, Petr; Kassa, Jiri; Slizova, Dasa; Krs, Otakar; Karasova, Jana Zdarova; Fusek, Josef; Capek, Lukas; Voicu, Victor A

    2012-01-01

    Reactivation effects of K203 and currently available oximes (obidoxime, HI-6) in combination with atropine on acetylcholinesterase activities in the brain parts of rats poisoned with tabun were studied. The activity was determined by quantitative histochemical and biochemical methods correlating between them very well. The tabun-induced changes in acetylcholinsterase activity as well as in reactivation potency of reactivators used were different in various parts of the brain. Pontomedullar area seems to be important for observed changes following tabun intoxication and its treatment. From the oximes studied, the reactivation effect of K203 was comparable with obidoxime; HI-6 was ineffective. Combination of bio- and histochemical methods allow fine differentiation among the action of different oximes following tabun poisoning.

  2. The impact of using the combined oral contraceptive pill for cycle scheduling on gene expression related to endometrial receptivity.

    Science.gov (United States)

    Bermejo, Alfonso; Iglesias, Carlos; Ruiz-Alonso, María; Blesa, David; Simón, Carlos; Pellicer, Antonio; García-Velasco, Juan

    2014-06-01

    Does the combined oral contraceptive pill (COCP) change endometrial gene expression when used for cycle programming? COCP used for scheduling purposes does not have a significant impact on endometrial gene expression related to endometrial receptivity. Controversy exists around COCP pretreatment for IVF cycle programming, as some authors claim that it might be detrimental to the live birth rate. Microarray technology applied to the study of tissue gene expression has previously revealed the behavior of genes related to endometrial receptivity under different conditions. Proof-of-concept study of 10 young healthy oocyte donors undergoing controlled ovarian stimulation (COS) recruited between June 2012 and February 2013. Microarray data were obtained from endometrial biopsies from 10 young healthy oocyte donors undergoing COS with GnRH antagonists and recombinant FSH. In group A (n = 5), COCP pretreatment was used for 12-16 days, and stimulation began after a 5-day pill-free interval. Stimulation in group B (n = 5) was initiated on cycle day 3 after a spontaneous menses. Endometrial biopsies were collected 7 days after triggering with hCG. No individual genes exhibited increased or decreased expression (fold change (FC) >2) in patients with prior COCP treatment (group A) compared with controls (group B). However, the results of the functional analysis showed a total of 11 biological processes that were significantly enriched in group A compared with group B (non-COCP). The Endometrial Receptivity Array (ERA) has only been validated on endometrial samples obtained in natural cycles and after hormonal replacement treatment (HRT). Therefore, it was not possible in this study to classify the endometrial samples as receptive or non-receptive. We used the ERA to focus on 238 genes that are intimately related to endometrial receptivity, thus simplifying the analysis and understanding of the data. Cycle scheduling is common in IVF units and is used to avoid weekend

  3. Evaluation of effects of groundwater withdrawals at the proposed Allen combined-cycle combustion turbine plant, Shelby County, Tennessee

    Science.gov (United States)

    Haugh, Connor J.

    2016-08-10

    The Mississippi Embayment Regional Aquifer Study groundwater-flow model was used to simulate the potential effects of future groundwater withdrawals at the proposed Allen combined-cycle combustion turbine plant in Shelby County, Tennessee. The scenario used in the simulation consisted of a 30-year average withdrawal period followed by a 30-day maximum withdrawal period. Effects of withdrawals at the Allen plant site on the Mississippi embayment aquifer system were evaluated by comparing the difference in simulated water levels in the aquifers at the end of the 30-year average withdrawal period and at the end of the scenario to a base case without the Allen combined-cycle combustion turbine plant withdrawals. Simulated potentiometric surface declines in the Memphis aquifer at the Allen plant site were about 7 feet at the end of the 30-year average withdrawal period and 11 feet at the end of the scenario. The affected area of the Memphis aquifer at the Allen plant site as delineated by the 4-foot potentiometric surface-decline contour was 2,590 acres at the end of the 30-year average withdrawal period and 11,380 acres at the end of the scenario. Simulated declines in the underlying Fort Pillow aquifer and overlying shallow aquifer were both less than 1 foot at the end of the 30-year average withdrawal period and the end of the scenario.

  4. Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Gas turbine performance

    Energy Technology Data Exchange (ETDEWEB)

    Haglind, F. [Technical University of Denmark, Department of Mechanical Engineering, DK-2800 Kgs. Lyngby (Denmark)

    2010-02-15

    The part-load performance of gas and steam turbine combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry on the gas turbine part-load performance. Subsequently, in another paper, the effects of variable geometry on the part-load performance for combined cycles used for ship propulsion will be presented. Moreover, this paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within gas turbines. Two different gas turbine configurations are studied, a two-shaft aero-derivative configuration and a single-shaft industrial configuration. When both gas turbine configurations are running in part-load using fuel flow control, the results indicate better part-load performance for the two-shaft gas turbine. Reducing the load this way is accompanied by a much larger decrease in exhaust gas temperature for the single-shaft gas turbine than for the two-shaft configuration. As used here, the results suggest that variable geometry generally deteriorates the gas turbine part-load performance. (author)

  5. High-Yield Superovulation in Adult Mice by Anti-Inhibin Serum Treatment Combined with Estrous Cycle Synchronization.

    Science.gov (United States)

    Hasegawa, Ayumi; Mochida, Keiji; Inoue, Hiroki; Noda, Yoshihiro; Endo, Tamao; Watanabe, Gen; Ogura, Atsuo

    2016-01-01

    Producing many mature oocytes is of great importance for assisted reproductive technologies. In mice, superovulation by consecutive injections of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) has been the gold standard for oocyte collection. However, the yield of mature oocytes by this regimen can fluctuate according to the stage of the estrous cycle, strain, and age. Therefore, our objective was to develop a high-yield superovulation protocol to collect higher numbers of oocytes from adult female mice of different strains and ages. First, we aimed to synchronize the estrous cycle using C57BL/6 (B6) female mice. Most (93%) were synchronized to metestrus after two daily injections of progesterone. Second, we found that with the injection of anti-inhibin serum (AIS) instead of eCG, the mean number of ovulated oocytes almost doubled (21 vs. 41 per mouse). Third, by combining estrous cycle synchronization with two AIS injections, we obtained 62 oocytes per mouse, about three times that with the eCG-hCG protocol. Importantly, this approach increased the proportion of mice that ovulated >25 oocytes from about 40% (eCG-hCG) to 90%. The same protocol was also effective in other inbred (BALB/cA), outbred (ICR), and hybrid (B6D2F1) strains. In addition, B6 female mice aged over 1 yr ovulated 1.8-fold more oocytes by this protocol. Thus, estrous cycle synchronization followed by AIS-hCG yielded a broadly applicable, highly efficient superovulation. This protocol should promote the effective use of invaluable female mouse strains and decrease the numbers of animals euthanized. © 2016 by the Society for the Study of Reproduction, Inc.

  6. Combined application of Artificial Neural Networks and life cycle assessment in lentil farming in Iran

    Directory of Open Access Journals (Sweden)

    Behzad Elhami

    2017-03-01

    Full Text Available In this study, an Artificial Neural Network (ANN was applied to model yield and environmental emissions from lentil cultivation in Esfahan province of Iran. Data was gathered from lentil farmers using face to face questionnaire method during 2014–2015 cropping season. Life cycle assessment (LCA was applied to investigate the environmental impact categories associated with lentil production. Based on the results, total energy input, energy output to input ratio and energy productivity were determined to be 32,970.10 MJ ha−1, 0.902 and 0.06 kg MJ−1, respectively. The greatest amount of energy consumption was attributed to chemical fertilizer (42.76%. Environmental analysis indicated that the acidification potential was higher than other environmental impact categories in lentil production system. Also results showed that the production of agricultural machinery was the main hotspot in abiotic depletion, eutrophication, global warming, human toxicity, fresh water aquatic ecotoxicity, marine aquatic ecotoxicity and terrestrial ecotoxicity impact categories, while direct emissions associated with lentil cultivation was the main hotspot in acidification potential and photochemical oxidation potential. In addition, diesel fuel was the main hotspot only in ozone layer depletion. The ANN model with 9-10-6-11 structure was identified as the most appropriate network for predicting yield and related environmental impact categories of lentil cultivation. Overall, the results of sensitivity analysis revealed that farmyard manure had the greatest effect on the most of the environmental impacts, while machinery was the most affecting parameter on the yield of the crop.

  7. Combined cycle power plant with circulating fluidized bed combustion. Final report; Kombikraftwerk mit zirkulierender Druckwirbelschicht-Feuerung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-05-01

    In the frame of this study the concept of a combined cycle power plant with circulating fluidized bed combustion was investigated for the application of national brown coal. The aims of this study which is subsidised by the FMTR are the following: - evaluation of the experiences which have been made so far in the frame of developing circulating fluidized bed combustion; - reaching of reliable statements about the process technology, about technical risks as well as about the time frame and the costs; - developing a task for a possible realisation of a 150 MW{sub el}-pilot plant in the new Laender. The present study shows that combined cycle power plants which are fuelled by brown coal can be realised according to the principle of circulating fluidized bed combustion with a plant net efficiency of 45% for a power of 150 MW{sub el} (pilot plant) and a plant net efficiency clearly above 47% for a power of 500 MW{sub el} (reference power plant). The combination of this efficient combined cycle power plant technology with a simple brown coal gasification module, that is integrated into a combustion reactor will almost certainly lead to plant net efficiencies of 50% and more, especially for ZDSWF plants of the second generation. (orig./GL) [Deutsch] Im Rahmen dieser Studie ist fuer den Einsatz einheimischer Braunkohle das Konzept eines Kombikraftwerkes auf der Basis der zirkulierenden Druckwirbelschichtfeuerung untersucht worden. Ziele dieser mit BMFT-Mitteln gefoerderten Studie sind: - die Bewertung der bisher im Rahmen der Entwicklung von Druckwirbelschichtfeuerungen gesammelten Erfahrungen, - die Gewinnung belastbarer Aussagen zum verfahrenstechnischen Konzept, zu technischen Risiken sowie zum Zeit- und Kostenrahmen sowie - die Ausarbeitung einer Aufgabenstellung fuer die moegliche Realisierung einer 150-MW{sub el}-Pilotanlage in den neuen Bundeslaendern. Die vorliegende Studie zeigt, dass mit Braunkohle befeuerte Kombikraftwerksanlagen nach dem Prinzip der

  8. Combined Refrigeration Cycle for Thermal Power Plant Using Low Grade Waste Steam

    Directory of Open Access Journals (Sweden)

    Satish Maurya*,

    2014-02-01

    Full Text Available Now a days, In most of the thermal power plant, where low-pressure steam is being exhausted to the atmosphere as a waste steam. This waste heat could be use to operate many small preheating or cooling equipments or small scale plants. There are many refrigeration systems present for refrigeration and air condition purpose. Such as air refrigeration, vapour compression, vapour absorption etc. In this paper we have presented the concept of combined vapour absorption and vapour compression refrigeration system. We present about the idea discuss here that how a vapour absorption and vapour compression can be used together as one complete working refrigeration plant. By using such concept of refrigeration we can improve the co-efficient of performance of whole plant by minimizing the input. We can also named the system as waste heat recovery refrigeration system.

  9. Preclinical demonstration of synergistic Active Nutrients/Drug (AND combination as a potential treatment for malignant pleural mesothelioma.

    Directory of Open Access Journals (Sweden)

    Viviana Volta

    Full Text Available Malignant pleural mesothelioma (MPM is a poor prognosis disease lacking adequate therapy. We have previously shown that ascorbic acid administration is toxic to MPM cells. Here we evaluated a new combined therapy consisting of ascorbate/epigallocatechin-3-gallate/gemcitabine mixture (called AND, for Active Nutrients/Drug. In vitro effects of AND therapy on various MPM cell lines revealed a synergistic cytotoxic mechanism. In vivo experiments on a xenograft mouse model for MPM, obtained by REN cells injection in immunocompromised mice, showed that AND strongly reduced the size of primary tumor as well as the number and size of metastases, and prevented abdominal hemorrhage. Kaplan Meier curves and the log-rank test indicated a marked increase in the survival of AND-treated animals. Histochemical analysis of dissected tumors showed that AND induced a shift from cell proliferation to apoptosis in cancer cells. Lysates of tumors from AND-treated mice, analyzed with an antibody array, revealed decreased TIMP-1 and -2 expressions and no effects on angiogenesis regulating factors. Multiplex analysis for signaling protein phosphorylation exhibited inactivation of cell proliferation pathways. The complex of data showed that the AND treatment is synergistic in vitro on MPM cells, and blocks in vivo tumor progression and metastasization in REN-based xenografts. Hence, the AND combination is proposed as a new treatment for MPM.

  10. Brute force optimization: combining mass energy simulation and life cycle analysis to optimize building design

    Energy Technology Data Exchange (ETDEWEB)

    Fix, Stuart; Richman, Russell [Department of Architectural Science, Faculty of Engineering, Architecture and Science, Ryerson University (Canada)], email: sfix@ryerson.ca, email: richman@ryerson.ca

    2011-07-01

    With the depletion of energy resources and the rising concerns about the environment, building designers are shifting towards green building designs. However since no design optimization for an entire building exists, a significant degree of uncertainty is involved in design decisions. The aim of this paper is to present the brute force optimization process which is a method removing the uncertainty from green building designs. This method relies on the selection of optimization criteria and then several simulations are performed. A demonstration pilot was carried out in Toronto and over one million design permutations were conducted. Results showed that parameters such as total building area, window performance and infiltration level are the most important to the lifetime energy consumption of a building. This study pointed out the important parameters to optimize in order to reduce a building's energy consumption.

  11. Power and Efficiency Analysis of a Solar Central Receiver Combined Cycle Plant with a Small Particle Heat Exchanger Receiver

    Science.gov (United States)

    Virgen, Matthew Miguel

    Two significant goals in solar plant operation are lower cost and higher efficiencies. To achieve those goals, a combined cycle gas turbine (CCGT) system, which uses the hot gas turbine exhaust to produce superheated steam for a bottoming Rankine cycle by way of a heat recovery steam generator (HRSG), is investigated in this work. Building off of a previous gas turbine model created at the Combustion and Solar Energy Laboratory at SDSU, here are added the HRSG and steam turbine model, which had to handle significant change in the mass flow and temperature of air exiting the gas turbine due to varying solar input. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Variable guide vanes (VGVs) were found in the earlier model to be an effective tool in providing operational flexibility to address the variable nature of solar input. Combined cycle efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit leads to two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the CIT limit. This drawback can be partially addressed through strategic use of the VGVs. Since system response is fully established for the relevant range of solar input and variable guide vane angles, the System Advisor Model (SAM) from NREL can be used to find what the actual expected solar input would be over the course of the day, and plan accordingly. While the SAM software is not yet equipped to model a Brayton cycle cavity receiver, appropriate approximations were made in order to produce a suitable heliostat field to fit this system. Since the SPHER uses carbon nano-particles as the solar absorbers, questions of particle longevity and how the particles might affect the flame behavior in the combustor were addressed using the chemical kinetics software Chemkin

  12. Combined use of solar and geothermal energy. Demonstration project for sports centers; Kombinierte Solar- und Geothermienutzung. Demonstrationsprojekt fuer Sportstaetten

    Energy Technology Data Exchange (ETDEWEB)

    Sorg, M. [Metric Mess- und Energiespartechnik GmbH, Ganderkesee (Germany)

    2003-04-01

    A new sports hall at Hessisch Oldendorf in the German state of Niedersachsen demonstrates the consequent application of energy-saving technologies and their good ecological and economic effects. [German] Im Rahmen der Unterstuetzung von Sportprojekten mit besonderer Vorbildfunktion hat der Niedersaechsische Landessportbund den Neubau einer Sporthalle in Hessisch Oldendorf gefoerdert. Der oekologische Modellcharakter der Zweifelder-Halle mit 200 Besucherplaetzen wird vorwiegend durch den konsequenten Einsatz ressourcensparender Technik gepraegt. Mit der Sporthalle wird demonstriert, wie richtungsweisend die angewandten Techniken hinsichtlich ihres oekologischen und wirtschaftlichen Nutzens fuer zukuenftige Bauvorhaben sein koennen. (orig.)

  13. Combined Pre-Precipitation, Biological Sludge Hydrolysis and Nitrogen Reduction - A Pilot Demonstration of Integrated Nutrient Removal

    DEFF Research Database (Denmark)

    Kristensen, G. H.; Jørgensen, P. E.; Strube, R.

    1992-01-01

    A pilot study was performed to investigate advanced wastewater treatment by pre-precipitation in combination with biological nitrogen removal supported by biological sludge hydrolysis. The influent wastewater was pretreated by addition of a pre-polymerized aluminum salt, followed by flocculation...... solubilization was 10-13% of the suspended COD. The liquid phase of the hydrolyzed sludge, the hydrolysate, was separated from the suspended fraction by centrifugation and added to the biological nitrogen removal stage to support denitrification. The hydrolysate COD consisted mainly of volatile fatty acids......, resulting in high denitrification rates. Nitrogen reduction was performed based on the Bio-Denitro principle in an activated sludge system. Nitrogen was reduced from 45 mg/l to 9 mg/l and phosphorus was reduced from 11 mg/l to 0.5 mg/l. The sludge yield was low, approx. 0.3-0.4 gCOD/gCOD removed...

  14. Combined Pre-Precipitation, Biological Sludge Hydrolysis and Nitrogen Reduction - A Pilot Demonstration of Integrated Nutrient Removal

    DEFF Research Database (Denmark)

    Kristensen, G. H.; Jørgensen, P. E.; Strube, R.

    1992-01-01

    A pilot study was performed to investigate advanced wastewater treatment by pre-precipitation in combination with biological nitrogen removal supported by biological sludge hydrolysis. The influent wastewater was pretreated by addition of a pre-polymerized aluminum salt, followed by flocculation...... solubilization was 10-13% of the suspended COD. The liquid phase of the hydrolyzed sludge, the hydrolysate, was separated from the suspended fraction by centrifugation and added to the biological nitrogen removal stage to support denitrification. The hydrolysate COD consisted mainly of volatile fatty acids......, resulting in high denitrification rates. Nitrogen reduction was performed based on the Bio-Denitro principle in an activated sludge system. Nitrogen was reduced from 45 mg/l to 9 mg/l and phosphorus was reduced from 11 mg/l to 0.5 mg/l. The sludge yield was low, approx. 0.3-0.4 gCOD/gCOD removed...

  15. System study of an MHD/gas turbine combined-cycle baseload power plant. HTGL report No. 134

    Energy Technology Data Exchange (ETDEWEB)

    Annen, K.D.

    1981-08-01

    The MHD/gas turbine combined-cycle system has been designed specifically for applications where the availability of cooling water is very limited. The base case systems which were studied consisted of an MHD plant with a gas turbine bottoming plant, and required no cooling water. The gas turbine plant uses only air as its working fluid and receives its energy input from the MHD exhaust gases by means of metal tube heat exchangers. In addition to the base case systems, vapor cycle variation systems were considered which included the addition of a vapor cycle bottoming plant to improve the thermal efficiency. These systems required a small amount of cooling water. The MHD/gas turbine systems were modeled with sufficient detail, using realistic component specifications and costs, so that the thermal and economic performance of the system could be accurately determined. Three cases of MHD/gas turbine systems were studied, with Case I being similar to an MHD/steam system so that a direct comparison of the performances could be made, with Case II being representative of a second generation MHD system, and with Case III considering oxygen enrichment for early commercial applications. The systems are nominally 800 MW/sub e/ to 1000 MW/sub e/ in size. The results show that the MHD/gas turbine system has very good thermal and economic performances while requiring either little or no cooling water. Compared to the MHD/steam system which has a cooling tower heat load of 720 MW, the Base Case I MHD/gas turbine system has a heat rate which is 13% higher and a cost of electricity which is only 7% higher while requiring no cooling water. Case II results show that an improved performance can be expected from second generation MHD/gas turbine systems. Case III results show that an oxygen enriched MHD/gas turbine system may be attractive for early commercial applications in dry regions of the country.

  16. Environmental control implications of generating electric power from coal. Appendix C. Gasification/combined-cycle power generation: comparison of alternative systems. 1977 technology status report. [246 references w. abstracts

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    The technical, economic, and environmental aspects of low-Btu gasification/combined-cycle power-generation (LBG/CCPG) plants are assessed, using available published data. Six base-case plants, based on three different gasifiers and two different coals, are investigated. A representative combined power cycle is selected for analysis, and material and energy balances for the six systems are developed. Emissions of various air pollutants, including sulfur dioxide and nitrogen oxides, and discharge rates of aqueous effluents are also calculated. The costs of electricity produced are derived for the six systems, using estimated plant-investment and operating costs. These costs and the emissions of various pollutants are compared with those for a conventional 500-MWe coal-based power plant using flue-gas cleaning and in compliance with the federal New Source Performance Standards. Finally, the commercialization potential of coal-based combined-cycle plants, based on the technical feasibility of building a first plant in the 1985 period and on economic viability, is evaluated. This evaluation is based on the current status of research and development programs for various components of the combined-cycle plant, such as gas turbines and fuel-gas-cleaning systems, and on the status of the demonstration plant.

  17. A Co-Powered Biomass and Concentrated Solar Power Rankine Cycle Concept for Small Size Combined Heat and Power Generation

    Directory of Open Access Journals (Sweden)

    Eileen Tortora

    2013-03-01

    Full Text Available The present work investigates the matching of an advanced small scale Combined Heat and Power (CHP Rankine cycle plant with end-user thermal and electric load. The power plant consists of a concentrated solar power field co-powered by a biomass furnace to produce steam in a Rankine cycle, with a CHP configuration. A hotel was selected as the end user due to its high thermal to electric consumption ratio. The power plant design and its operation were modelled and investigated by adopting transient simulations with an hourly distribution. The study of the load matching of the proposed renewable power technology and the final user has been carried out by comparing two different load tracking scenarios, i.e., the thermal and the electric demands. As a result, the power output follows fairly well the given load curves, supplying, on a selected winter day, about 50 GJ/d of thermal energy and the 6 GJ/d of electric energy, with reduced energy dumps when matching the load.

  18. Environmental impacts of combining pig slurry acidification and separation under different regulatory regimes - a life cycle assessment

    DEFF Research Database (Denmark)

    ten Hoeve, Marieke; Gomez Muñoz, Beatriz; Jensen, Lars Stoumann

    2016-01-01

    -house acidification and separation on marine eutrophication potential compared to these technologies individually. The model was sensitive to the chosen ammonia emission coefficients and to the choice of inclusion of indirect nitrous oxide emissions, since scenarios changed ranking for certain impact categories.......Global livestock production is increasing rapidly, leading to larger amounts of manure and environmental impacts. Technologies that can be applied to treat manure in order to decrease certain environmental impacts include separation and acidification. In this study, a life cycle assessment was used...... to investigate the environmental effects of slurry acidification and separation, and whether there were synergetic environmental benefits to combining these technologies. Furthermore, an analysis was undertaken into the effect of implementing regulations restricting the P application rate to soils...

  19. Ongoing Analyses of Rocket Based Combined Cycle Engines by the Applied Fluid Dynamics Analysis Group at Marshall Space Flight Center

    Science.gov (United States)

    Ruf, Joseph H.; Holt, James B.; Canabal, Francisco

    2001-01-01

    This paper presents the status of analyses on three Rocket Based Combined Cycle (RBCC) configurations underway in the Applied Fluid Dynamics Analysis Group (TD64). TD64 is performing computational fluid dynamics (CFD) analysis on a Penn State RBCC test rig, the proposed Draco axisymmetric RBCC engine and the Trailblazer engine. The intent of the analysis on the Penn State test rig is to benchmark the Finite Difference Navier Stokes (FDNS) code for ejector mode fluid dynamics. The Draco analysis was a trade study to determine the ejector mode performance as a function of three engine design variables. The Trailblazer analysis is to evaluate the nozzle performance in scramjet mode. Results to date of each analysis are presented.

  20. Energy and Exergy Analyses of a New Combined Cycle for Producing Electricity and Desalinated Water Using Geothermal Energy

    Directory of Open Access Journals (Sweden)

    Mehri Akbari

    2014-04-01

    Full Text Available A new combined cogeneration system for producing electrical power and pure water is proposed and analyzed from the viewpoints of thermodynamics and economics. The system uses geothermal energy as a heat source and consists of a Kalina cycle, a LiBr/H2O heat transformer and a water purification system. A parametric study is carried out in order to investigate the effects on system performance of the turbine inlet pressure and the evaporator exit temperature. For the proposed system, the first and second law efficiencies are found to be in the ranges of 16%–18.2% and 61.9%–69.1%, respectively. For a geothermal water stream with a mass flow rate of 89 kg/s and a temperature of 124 °C, the maximum production rate for pure water is found to be 0.367 kg/s.

  1. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

    1976-01-01

    The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

  2. Retinyl Propionate and Climbazole Combination Demonstrates Clinical Improvement to the Appearance of Hyperpigmentation and Deep Wrinkling with Minimal Irritation.

    Science.gov (United States)

    Hawkins, Stacy; Adamus, Jean; Chiang, Chung-Yi; Covell, Edwin; O'Leary, Jaime; Lee, Jian-Ming

    2017-07-22

    To evaluate a combination of retinyl propionate and climbazole (RPC) compared to 0.1% retinol for its efficacy, tolerance and aging appearance. Forty-five healthy Caucasian females, ages 40-70, with moderately photodamaged facial skin, were recruited for a 16 week randomized, double-blind, IRB approved facial study. The efficacy of RPC treatment was compared to 0.1% retinol, in the same product base formulation, with twice daily, split-face product application. Changes in overall photodamage, fine lines and wrinkles, pigmentation and irritation were visually evaluated and measured by instrumentation. Subjective appraisal of efficacy was self-assessed from images where subjects were blinded to treatment and time point. Irritancy potential was also evaluated in a 5 day randomized, double-blind, IRB approved patch study. Treatment with RPC resulted in significant (p<0.05) improvement in aging attributes compared to 0.1% retinol treatment, with minimal irritation. More than 50% of subjects showed improvement to deep wrinkles in the crow's feet area after 5 weeks of product application, and continued improvement to deep wrinkles was observed throughout the course of the study. Similarly, improvement was observed for the appearance of lines and wrinkles in the nasolabial fold (NLF) and for mottled hyperpigmentation. The results from subjective self-assessment confirmed in vivo clinical assessments. In a separate patch study, significantly less irritation was observed with the RPC product as compared to the 0.1% retinol control product. RPC delivered significant skin antiaging benefits comparable or greater than 0.1% retinol, with minimal irritation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Surgical treatment of adult moyamoya disease with combined STA-MCA bypass and EDAS: demonstration of technique in video presentation.

    Science.gov (United States)

    Li, Yiping; Cikla, Ulas; Baggott, Christopher; Yilmaz, Tevfik; Chao, Clifford; Baskaya, Mustafa K

    2015-01-01

    The natural history of Moyamoya disease (MD) is variable. Moyamoya disease in children mostly presents with progressive ischemic complications and in adulthood it tends to present with hemorrhage. Surgical strategies depend on augmenting cerebral blood flow to the anterior cerebral circulation. Revascularization is the mainstay treatment for MD. We introduce a 31 year old female with a history of MD and leftsided revascularization as a child, who presented with headache, confusion, and worsening left sided weakness. Cranial computed tomography (CT) showed a right sided putaminal hemorrhage. Cerebral angiogram with selective external runs revealed MD, hypoplastic parietal branch of the superficial temporal artery (STA) on the right side and previous revascularization on the left side. Thus, our decision was made to perform a bypass with the frontal branch of the STA to an M3-M4 segment of the middle cerebral artery and an encephaloduroarteriomyosynangiosis with the parietal branch of the STA. The patient's postoperative course was uneventful. Postoperative CT angiogram confirmed patency of bypass. This technique provides immediate revascularization and seems to provide risk reduction for ischemic and hemorrhagic stroke. We review the natural history and surgical treatment of MD along with a case presentation in which surgical technique is demonstrated in video.

  4. Thermochemical recuperative combined cycle with methane-steam reforming combustion; Tennengasu kaishitsu nensho ni yoru konbaindo saikuru hatsuden no kokoritsuka oyobi denryoku fuka heijunka taio

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, R.; Essaki, K.; Tsutsumi, A. [The University of Tokyo, Tokyo (Japan). Dept. of Chemical System Engineering; Kaganoi, S.; Kurimura, H. [Teikoku Sekiyu Co., Tokyo (Japan); Sasaki, T.; Ogawa, T. [Toshiba Co., Tokyo (Japan)

    2000-03-10

    Thermochemical recuperative combined cycles with methane-steam reforming are proposed for improving their thermal efficiency and for peak-load leveling. For targeting higher thermal efficiency, a cycle with methane-steam reforming reaction heated by gas turbine exhaust was analyzed. The inlet temperature of gas turbine was set at 1,350 degree C. Low-pressure steam extracted from a steam turbine is mixed with methane, and then this mixture is heated by part of the gas turbine exhaust to promote a reforming reaction. The rest of the exhaust heat is used to produce steam, which drives steam turbines to generate electricity. The effect of steam-to-methane ratio (S/C) on thermal efficiency of the cycle, as well as on methane conversion, is investigated by using the ASPEN Plus process simulator. The methane feed rate was fixed at constant and S/C ratio was varied from 2.25 to 4.75. Methane conversion shows an increasing trend toward the ratio and has a maximum value of 17.9 % at S/C=4.0. Thermal efficiency for the system is about 51 % higher than that calculated for a conventional 1,300 degree C class combined cycle under similar conditions. A thermochemical recuperative combined cycle is designed for peak-load leveling. In night-time operation from 20 : 00 to 8 : 00 it stores hydrogen produced by methane steam reforming at S/C=3.9 to save power generation. The gas turbine inlet temperature is 1,330 degree C. In daytime operation from 8 : 00 to 20 : 00 the chemically recuperated combined cycle operated at S/C=2.0 is driven by the mixture of a combined cycle operated at constant load with the same methane feed rate, whereas daytime operation generated power 1.26 times larger than that of the combined cycle. (author)

  5. Test, Evaluation, and Demonstration of Practical Devices/Systems to Reduce Aerodynamic Drag of Tractor/Semitrailer Combination Unit Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Scott Smith; Karla Younessi; Matt Markstaller; Dan Schlesinger; Bhaskar Bhatnagar; Donald Smith; Bruno Banceu; Ron Schoon; V.K. Sharma; Mark Kachmarsky; Srikant Ghantae; Michael Sorrels; Conal Deedy; Justin Clark; Skip Yeakel; Michael D. Laughlin; Charlotte Seigler; Sidney Diamond

    2007-04-30

    Class 8 heavy-duty trucks account for over three-quarters of the total diesel fuel used by commercial trucks (trucks with GVWRs more than 10,000 pounds) in the United States each year. At the highway speeds at which these trucks travel (i.e., 60 mph or greater), aerodynamic drag is a major part of total horsepower needed to move the truck down the highway, Reductions in aerodynamic drag can yield measurable benefits in fuel economy through the use of relatively inexpensive and simple devices. The goal of this project was to examine a number of aerodynamic drag reduction devices and systems and determine their effectiveness in reducing aerodynamic drag of Class 8 tractor/semitrailer combination-units, thus contributing to DOE's goal of reducing transportation petroleum use. The project team included major heavy truck manufacturers in the United States, along with the management and industry expertise of the Truck Manufacturers Association as the lead investigative organization. The Truck Manufacturers Association (TMA) is the national trade association representing the major North American manufacturers of Class 6-8 trucks (GVWRs over 19,500 lbs). Four major truck manufacturers participated in this project with TMA: Freightliner LLC; International Truck and Engine Corporation; Mack Trucks Inc.; and Volvo Trucks North America, Inc. Together, these manufacturers represent over three-quarters of total Class 8 truck sales in the United States. These four manufacturers pursued complementary research efforts as part of this project. The project work was separated into two phases conducted over a two-year period. In Phase I, candidate aerodynamic devices and systems were screened to focus research and development attention on devices that offered the most potential. This was accomplished using full-size vehicle tests, scale model tests, and computational fluid dynamics analyses. In Phase II, the most promising devices were installed on full-size trucks and their

  6. Bleeding pattern and cycle control with estetrol-containing combined oral contraceptives: results from a phase II, randomised, dose-finding study (FIESTA).

    Science.gov (United States)

    Apter, Dan; Zimmerman, Yvette; Beekman, Louise; Mawet, Marie; Maillard, Catherine; Foidart, Jean-Michel; Coelingh Bennink, Herjan J T

    2016-10-01

    This study aims to assess vaginal bleeding patterns and cycle control of oral contraceptives containing estetrol (E4) combined with either drospirenone (DRSP) or levonorgestrel (LNG). An open-label, multicentre, randomised, dose-finding study lasting six cycles in healthy women aged 18-35 years was used. Four treatments (15 mg or 20 mg E4, combined with either 3 mg DRSP or 150 mcg LNG) were administered in a 24/4-day regimen. A marketed dosing regimen of estradiol valerate with dienogest (E2V/DNG) served as reference since it contains (like E4) a natural oestrogen. A total of 396 women were randomised, of whom 389 received study medication, and 316 completed the study. By cycle 6, the frequencies of unscheduled bleeding and/or spotting and absence of withdrawal bleeding were the lowest in the 15 mg E4/DRSP group (33.8% and 3.5%, respectively). In the E2V/DNG reference group, these frequencies were 47.8% and 27.1%, respectively. By cycle 6, the frequency of women with absence of withdrawal bleeding was <20% for all E4 treatment groups: 3.5-3.8% combined with DRSP and 14.0-18.5% combined with LNG. By cycle 6, unscheduled intracyclic bleeding was reported by <20% of women in the 20 mg E4/LNG group (18.9%) and in the 15 mg E4/DRSP group (16.9%). This study showed that, of the four treatment modalities investigated, the 15 mg E4/DRSP combination has the most favourable bleeding pattern and cycle control. Due to its favourable bleeding pattern and cycle control, the 15 mg E4/DRSP combination is the preferred combination for further phase III clinical development. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Prototype Demonstration of Gamma- Blind Tensioned Metastable Fluid Neutron/Multiplicity/Alpha Detector – Real Time Methods for Advanced Fuel Cycle Applications

    Energy Technology Data Exchange (ETDEWEB)

    McDeavitt, Sean M. [Texas A & M Univ., College Station, TX (United States)

    2016-12-20

    The content of this report summarizes a multi-year effort to develop prototype detection equipment using the Tensioned Metastable Fluid Detector (TMFD) technology developed by Taleyarkhan [1]. The context of this development effort was to create new methods for evaluating and developing advanced methods for safeguarding nuclear materials along with instrumentation in various stages of the fuel cycle, especially in material balance areas (MBAs) and during reprocessing of used nuclear fuel. One of the challenges related to the implementation of any type of MBA and/or reprocessing technology (e.g., PUREX or UREX) is the real-time quantification and control of the transuranic (TRU) isotopes as they move through the process. Monitoring of higher actinides from their neutron emission (including multiplicity) and alpha signatures during transit in MBAs and in aqueous separations is a critical research area. By providing on-line real-time materials accountability, diversion of the materials becomes much more difficult. The Tensioned Metastable Fluid Detector (TMFD) is a transformational technology that is uniquely capable of both alpha and neutron spectroscopy while being “blind” to the intense gamma field that typically accompanies used fuel – simultaneously with the ability to provide multiplicity information as well [1-3]. The TMFD technology was proven (lab-scale) as part of a 2008 NERI-C program [1-7]. The bulk of this report describes the advancements and demonstrations made in TMFD technology. One final point to present before turning to the TMFD demonstrations is the context for discussing real-time monitoring of SNM. It is useful to review the spectrum of isotopes generated within nuclear fuel during reactor operations. Used nuclear fuel (UNF) from a light water reactor (LWR) contains fission products as well as TRU elements formed through neutron absorption/decay chains. The majority of the fission products are gamma and beta emitters and they represent the

  8. ATR-FTIR study of water in Nafion membrane combined with proton conductivity measurements during hydration/dehydration cycle.

    Science.gov (United States)

    Kunimatsu, Keiji; Bae, Byungchan; Miyatake, Kenji; Uchida, Hiroyuki; Watanabe, Masahiro

    2011-04-21

    We have conducted combined time-resolved attenuated total reflection Fourier transform infrared (ATR-FTIR) and proton conductivity measurements of Nafion NRE211 membrane during hydration/dehydration cycles at room temperature. Conductivity change was interpreted in terms of different states of water in the membrane based on its δ(HOH) vibrational spectra. It was found that hydration of a dry membrane leads first to complete dissociation of the sulfonic acid groups to liberate hydrated protons, which are isolated from each other and have δ(HOH) vibrational frequency around 1740 cm(-1). The initial hydration is not accompanied by a significant increase of the proton conductivity. Further hydration gives rise to a rapid increase of the conductivity in proportion to intensity of a new δ(HOH) band around 1630 cm(-1). This was interpreted in terms of formation of channels of weakly hydrogen-bonded water to combine the isolated hydrophilic domains containing hydrated protons and hydrated sulfonate ions produced during the initial stage of hydration. Upon dehydration, proton conductivity drops first very rapidly due to loss of the weakly hydrogen bonded water from the channels to leave hydrophilic domains isolated in the membrane. Dehydration of the protons proceeds very slowly after significant loss of the proton conductivity.

  9. Working fluids of a low-temperature geothermally-powered Rankine cycle for combined power and heat generation system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel combined power and heat generation system was investigated in this study. This system consists of a low-temperature geothermally-powered organic Rankine cycle (ORC) subsystem, an intermediate heat exchanger and a commercial R134a-based heat pump subsystem. The advantages of the novel combined power and heat generation system are free of using additional cooling water circling system for the power generation subsystem as well as maximizing the use of thermal energy in the low-temperature geothermal source. The main purpose is to identify suitable working fluids (wet, isentropic and dry flu-ids) which may yield high PPR (the ratio of power produced by the power generation subsystem to power consumed by the heat pump subsystem) value and QQR (the ratio of heat supplied to the user to heat produced by the geothermal source) value. Parameters under investigation were evaporating temperature, PPR value and QQR value. Results indicate that there exits an optimum evaporating temperature to maximize the PPR value and minimize the QQR value at the same time for individual fluid. And dry fluids show higher PPR values but lower QQR values. NH3 and R152a outstand among wet fluids. R134a out-stands among isentropic fluids. R236ea, R245ca, R245fa, R600 and R600a outstand among dry fluids. R236ea shows the highest PPR value among the recommended fluids.

  10. Extended cycle combined oral contraceptives and prophylactic frovatriptan during the hormone-free interval in women with menstrual-related migraines.

    Science.gov (United States)

    Coffee, Andrea L; Sulak, Patricia J; Hill, Alexandria J; Hansen, Darci J; Kuehl, Thomas J; Clark, Jeffrey W

    2014-04-01

    Migraine headaches are a significant problem for American women with many of them suffering from headaches around the time of their menstrual cycle. Women taking oral contraceptives in the standard 21/7 cycle regimen often suffer from headaches around the time of the hormone free intervals (HFIs) as well. Extended oral contraceptive regimens have been shown to decrease the frequency, but not eliminate these headaches. This study is a double-blind, randomized, placebo-controlled pilot study of participants with menstrual-related migraines (MRMs) who were initiated on extended combined oral contraceptives and given frovatriptan prophylactically during HFIs. Participants having spontaneous menstrual cycles or taking daily combined oral contraceptives in a 21/7 regimen with MRMs were placed on a contraceptive containing levonorgestrel and ethinyl estradiol. Analyses compared headache scores during pre-study baseline cycles to those in a 168-day extended regimen with placebo versus frovatriptan treatments during HFIs. Daily headache scores decreased (p=0.034) from 1.29 ± 0.10 during pre-study cycles to 1.10 ± 0.14 during extended combined oral contraceptive use. Frovatriptan blocked the increase in headache score over the placebo during HFIs. However, following the withdrawal of frovatriptan, headache scores increased (p>0.01) despite resuming combined oral contraceptive use. Extended combined oral contraceptive regimen reduces MRM severity. Frovatriptan prevents headaches during HFIs, but is associated with new headache symptoms when withdrawn.

  11. Durability of Concrete Subjected to the Combined Actions of Flexural Stress,Freeze-thaw Cycles and Bittern Solutions

    Institute of Scientific and Technical Information of China (English)

    YU Hongfa; SUN Wei; ZHANG Yunsheng; GUO Liping; LI Meidan

    2008-01-01

    Freeze-thaw durabilities of three types of concretes-normal portland cement concrete (OPC),high strength concrete (HSC) and steel fiber reinforced high strength concrete (SFRHSC)were systemically investigated under the attacks of chemical solution,and combination of external flexural stress and chemical solution.Four kinds of bitterns from salt lakes in Sinkiang,Qinghai,Inner Mongolia and Tibet provinces of China were used as chemical attack solutions.The relative dynamic modulus (RDM) was used as an index for evaluating the damage degree during the course of chemical attack and stress corrosion.The experimental results show that the freeze-thaw durability of concrete is visibly reduced in the present of the flexural stress,i e,stress accelerates the damage process.In order to quantify the stress accelerated effect,a stress accelerating coefficient was proposed.The stress accelerating coefficient is closely related with the types of bitterns and the numbers of freeze-thaw cycles is.The more numbers of freeze-thaw cycles is,the greater the stress accelerating coefficient for various concretes will be.In addition,there also exists a critical ratio of external stress to the maximum flexural stress.If the stress ratio exceeds the critical one,the freeze-thaw durability of various concretes will be greatly decreased compared to the responding concretes without applied stress.The critical stress ratio of OPC,HSC and SFRHSC is 0.30,0.40 and 0.40,respectively,indicating that HSC and SFRHSC have advantages over OPC and are suitable to use in the bittern erosion regions.

  12. Recovery, transport, and disposal of CO{sub 2} from an integrated gasification combined-cycle power plant

    Energy Technology Data Exchange (ETDEWEB)

    Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.; Berry, G.F.

    1993-12-31

    Initiatives to limit CO{sub 2} emissions have drawn considerable interest to integrated gasification combined-cycle (IGCC) power generation, a process that reduces CO{sub 2} production and is amenable to CO{sub 2} capture. This paper presents a comparison of energy systems that encompass fuel supply, an IGCC system, CO{sub 2} recovery using commercial technologies, CO{sub 2} transport by pipeline, and land-based sequestering in geological reservoirs. The intent is to evaluate the energy efficiency impacts of controlling CO{sub 2} in such a system, and to provide the CO{sub 2} budget, or an equivalent CO{sub 2} budget, associated with each of the individual energy-cycle steps. The value used for the equivalent CO{sub 2} budget is 1 kg CO{sub 2}/kWh. The base case for the comparison is a 458-MW IGCC system using an air-blown Kellogg Rust Westinghouse (KRW) agglomerating fluidized-bed gasifier, Illinois No.6 bituminous coal, and in-bed sulfur removal. Mining, transportation, and preparation of the coal and limestone result in a net electric power production of 448 MW with a 0.872 kg/kWh CO{sub 2} release rate. For comparison, the gasifier output was taken through a water-gas shift to convert CO to CO{sub 2}, and processed in a Selexol unit to recover CO{sub 2} prior to the combustion turbine. A 500-km pipeline then took the CO{sub 2} to geological sequestering. The net electric power production was 383 MW with a 0.218 kg/kWh CO{sub 2} release rate.

  13. Focal Adhesion Kinase Inhibitors in Combination with Erlotinib Demonstrate Enhanced Anti-Tumor Activity in Non-Small Cell Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Grant A Howe

    Full Text Available Blockade of epidermal growth factor receptor (EGFR activity has been a primary therapeutic target for non-small cell lung cancers (NSCLC. As patients with wild-type EGFR have demonstrated only modest benefit from EGFR tyrosine kinase inhibitors (TKIs, there is a need for additional therapeutic approaches in patients with wild-type EGFR. As a key component of downstream integrin signalling and known receptor cross-talk with EGFR, we hypothesized that targeting focal adhesion kinase (FAK activity, which has also been shown to correlate with aggressive stage in NSCLC, would lead to enhanced activity of EGFR TKIs. As such, EGFR TKI-resistant NSCLC cells (A549, H1299, H1975 were treated with the EGFR TKI erlotinib and FAK inhibitors (PF-573,228 or PF-562,271 both as single agents and in combination. We determined cell viability, apoptosis and 3-dimensional growth in vitro and assessed tumor growth in vivo. Treatment of EGFR TKI-resistant NSCLC cells with FAK inhibitor alone effectively inhibited cell viability in all cell lines tested; however, its use in combination with the EGFR TKI erlotinib was more effective at reducing cell viability than either treatment alone when tested in both 2- and 3-dimensional assays in vitro, with enhanced benefit seen in A549 cells. This increased efficacy may be due in part to the observed inhibition of Akt phosphorylation when the drugs were used in combination, where again A549 cells demonstrated the most inhibition following treatment with the drug combination. Combining erlotinib with FAK inhibitor was also potent in vivo as evidenced by reduced tumor growth in the A549 mouse xenograft model. We further ascertained that the enhanced sensitivity was irrespective of the LKB1 mutational status. In summary, we demonstrate the effectiveness of combining erlotinib and FAK inhibitors for use in known EGFR wild-type, EGFR TKI resistant cells, with the potential that a subset of cell types, which includes A549, could be

  14. Vuosaari B, the largest combined cycle power plant in the Nordic Countries. Vuosaari B Pohjoismaiden suurin kombivoimalaitos

    Energy Technology Data Exchange (ETDEWEB)

    Tuominen, J. (Ahlstroem Thermoflow, Varkaus (Finland))

    1994-01-01

    The plant concept is so called gas turbine combined cycle power plant. The natural gas fueled gas turbines produce electric power in total 320 MW. The energy of the flue gases of the gas turbines is recovered using heat recovery boilers, and the steam produced by them is used at 140 MW[sub e] back-pressure steam turbine. In addition to the electric power about 410 MW of district heat is generated. The gas turbines will be equipped with Dry-LowNo[sub x] combustion chambers so the emissions of the plant will be lower than the limits required by the authorities. Both heat recovery boilers have been combined parallel, and both of them will produce 75 bar steam and at the 7.5 bar pressure level the amount of high-pressure steam is 68 kg/s and that of the low-pressure steam 14.0 kg/s. The intermediate tapping steam will be led into the district heat exchanger, there the energy content of it will transferred into the district heating water. The boilers are under supported natural circulation boilers, in which the gas flows horizontally through the boiler. The steam generators of the boilers are also based on natural circulation. The heat exchanger packages of the boiler are made of curved finned tube supported by the sliding posts to the base of the boiler room. The steel smoke pipes are also supported directly on the base so the wind load on the pipes can be passed while dimensioning the steel construction of the boiler room. All the heat delivery surfaces of the boiler have modular construction

  15. Large eddy simulation of combustion characteristics in a kerosene fueled rocket-based combined-cycle engine combustor

    Science.gov (United States)

    Huang, Zhi-wei; He, Guo-qiang; Qin, Fei; Cao, Dong-gang; Wei, Xiang-geng; Shi, Lei

    2016-10-01

    This study reports combustion characteristics of a rocket-based combined-cycle engine combustor operating at ramjet mode numerically. Compressible large eddy simulation with liquid kerosene sprayed and vaporized is used to study the intrinsic unsteadiness of combustion in such a propulsion system. Results for the pressure oscillation amplitude and frequency in the combustor as well as the wall pressure distribution along the flow-path, are validated using experimental data, and they show acceptable agreement. Coupled with reduced chemical kinetics of kerosene, results are compared with the simultaneously obtained Reynolds-Averaged Navier-Stokes results, and show significant differences. A flow field analysis is also carried out for further study of the turbulent flame structures. Mixture fraction is used to determine the most probable flame location in the combustor at stoichiometric condition. Spatial distributions of the Takeno flame index, scalar dissipation rate, and heat release rate reveal that different combustion modes, such as premixed and non-premixed modes, coexisted at different sections of the combustor. The RBCC combustor is divided into different regions characterized by their non-uniform features. Flame stabilization mechanism, i.e., flame propagation or fuel auto-ignition, and their relative importance, is also determined at different regions in the combustor.

  16. Numerical Investigation of Cowl Lip Adjustments for a Rocket-Based Combined-Cycle Inlet in Takeoff Regime

    Science.gov (United States)

    Shi, Lei; Liu, Xiaowei; He, Guoqiang; Qin, Fei; Wei, Xianggeng; Yang, Bing; Wu, Lele

    2016-09-01

    Numerical integration simulations were performed on a ready-made central strut-based rocket-based combined-cycle (RBCC) engine operating in the ejector mode during the takeoff regime. The effective principles of various cowl lip positions and shapes on the inlet operation and the overall performance of the entire engine were investigated in detail. Under the static condition, reverse cowl lip rotation in a certain range was found to contribute comprehensive improvement to the RBCC inlet and the entire engine. However, the reverse rotation of the cowl lip contributed very little enhancement of the RBCC inlet under the low subsonic flight regime and induced extremely negative impacts in the high subsonic flight regime, especially in terms of a significant increase in the drag of the inlet. Changes to the cowl lip shape provided little improvement to the overall performance of the RBCC engine, merely shifting the location of the leeward area inside the RBCC inlet, as well as the flow separation and eddy, but not relieving or eliminating those phenomena. The results of this study indicate that proper cowl lip rotation offers an efficient variable geometry scheme for a RBCC inlet in the takeoff regime.

  17. Performance of an Axisymmetric Rocket Based Combined Cycle Engine During Rocket Only Operation Using Linear Regression Analysis

    Science.gov (United States)

    Smith, Timothy D.; Steffen, Christopher J., Jr.; Yungster, Shaye; Keller, Dennis J.

    1998-01-01

    The all rocket mode of operation is shown to be a critical factor in the overall performance of a rocket based combined cycle (RBCC) vehicle. An axisymmetric RBCC engine was used to determine specific impulse efficiency values based upon both full flow and gas generator configurations. Design of experiments methodology was used to construct a test matrix and multiple linear regression analysis was used to build parametric models. The main parameters investigated in this study were: rocket chamber pressure, rocket exit area ratio, injected secondary flow, mixer-ejector inlet area, mixer-ejector area ratio, and mixer-ejector length-to-inlet diameter ratio. A perfect gas computational fluid dynamics analysis, using both the Spalart-Allmaras and k-omega turbulence models, was performed with the NPARC code to obtain values of vacuum specific impulse. Results from the multiple linear regression analysis showed that for both the full flow and gas generator configurations increasing mixer-ejector area ratio and rocket area ratio increase performance, while increasing mixer-ejector inlet area ratio and mixer-ejector length-to-diameter ratio decrease performance. Increasing injected secondary flow increased performance for the gas generator analysis, but was not statistically significant for the full flow analysis. Chamber pressure was found to be not statistically significant.

  18. Exergy Analysis of a Syngas-Fueled Combined Cycle with Chemical-Looping Combustion and CO2 Sequestration

    Directory of Open Access Journals (Sweden)

    Álvaro Urdiales Montesino

    2016-08-01

    Full Text Available Fossil fuels are still widely used for power generation. Nevertheless, it is possible to attain a short- and medium-term substantial reduction of greenhouse gas emissions to the atmosphere through a sequestration of the CO2 produced in fuels’ oxidation. The chemical-looping combustion (CLC technique is based on a chemical intermediate agent, which gets oxidized in an air reactor and is then conducted to a separated fuel reactor, where it oxidizes the fuel in turn. Thus, the oxidation products CO2 and H2O are obtained in an output flow in which the only non-condensable gas is CO2, allowing the subsequent sequestration of CO2 without an energy penalty. Furthermore, with shrewd configurations, a lower exergy destruction in the combustion chemical transformation can be achieved. This paper focus on a second law analysis of a CLC combined cycle power plant with CO2 sequestration using syngas from coal and biomass gasification as fuel. The key thermodynamic parameters are optimized via the exergy method. The proposed power plant configuration is compared with a similar gas turbine system with a conventional combustion, finding a notable increase of the power plant efficiency. Furthermore, the influence of syngas composition on the results is investigated by considering different H2-content fuels.

  19. Mineralization of integrated gasification combined-cycle power-station wastewater effluent by a photo-Fenton process.

    Science.gov (United States)

    Durán, A; Monteagudo, J M; San Martín, I; Aguirre, M

    2010-09-01

    The aim of this work was to study the mineralization of wastewater effluent from an integrated-gasification combined-cycle (IGCC) power station sited in Spain to meet the requirements of future environmental legislation. This study was done in a pilot plant using a homogeneous photo-Fenton oxidation process with continuous addition of H(2)O(2) and air to the system. The mineralization process was found to follow pseudo-first-order kinetics. Experimental kinetic constants were fitted using neural networks (NNs). The NNs model reproduced the experimental data to within a 90% confidence level and allowed the simulation of the process for any values of the parameters within the experimental range studied. At the optimum conditions (H(2)O(2) flow rate=120 mL/h, [Fe(II)]=7.6 mg/L, pH=3.75 and air flow rate=1 m(3)/h), a 90% mineralization was achieved in 150 min. Determination of the hydrogen peroxide consumed and remaining in the water revealed that 1.2 mol of H(2)O(2) was consumed per each mol of total organic carbon removed from solution. This result confirmed that an excess of dissolved H(2)O(2) was needed to achieve high mineralization rates, so continuous addition of peroxide is recommended for industrial application of this process. Air flow slightly improved the mineralization rate due to the formation of peroxo-organic radicals which enhanced the oxidation process.

  20. Are integrated coal gasification combined-cycle power plants competitive?; Sind Kombi-Kraftwerke mit integrierter Kohlevergasung wettbewerbsfaehig?

    Energy Technology Data Exchange (ETDEWEB)

    Pruschek, R. [Essen Univ. (Gesamthochschule) (Germany); Haupt, G.; Zimmermann, G. [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Ullrich, N. [Krupp Uhde GmbH, Dortmund (Germany)

    1999-08-01

    From investigations into improvements that are feasible already today for integrated coal gasification combined-cycle power plants net plant efficiencies of 51.5% (with reference to the calorifica value), not considering the calorific value of the separated elemental sulfur. Specific investment costs (plant supply price) have been determined with US-dollars 1100/kW. With the given market conditions, assumptions and investigation results the IGCC power plant is in a position to compete with a modern hard coal-fired steam power plant. Detailed investigations show a further efficiency potential of about 56% under consideration of future developments. With SOFC fuel cells upstream of the plant a further increase is conceivable. (orig.) [Deutsch] Aus Untersuchungen von bereits heute durchfuehrbaren Verbesserungen bei Kombi-Kraftwerken mit integrierter Kohlevergasung errechnet sich ein Netto-Anlagenwirkungsgrad von 51,5% (auf den Heizwert bezogen). Dabei ist der Heizwert des in der Entschwefelungsanlage abgetrennten elementaren Schwefels nicht beruecksichtigt. Die spezifische Investition (Anlagenlieferpreis) wurde zu US-Dollar 1100/kW ermittelt. Unter den beschriebenen Marktbedingungen, Annahmen und Untersuchungsergebnissen kann das IGCC-Kraftwerk bei einer Ausnutzungsdauer von 7000 h/a mit einem modernen Steinkohle-Dampfkraftwerk konkurrieren. Detaillierte Untersuchungen zeigen unter Einbeziehung zukuenftiger Entwicklungsschritte ein weiteres Wirkungsgradpotential bis etwa 56%. Mit SOFC-Brennstoffzellen als Vorschaltstufe ist eine weitere Erhoehung denkbar. (orig.)

  1. Numerical analysis of flow features and operation characteristics of a rocket-based combined-cycle inlet in ejector mode

    Science.gov (United States)

    Shi, Lei; Liu, Xiaowei; He, Guoqiang; Qin, Fei; Wei, Xianggeng; Yang, Bin; Liu, Jie

    2016-10-01

    A ready-made central strut-based rocket-based combined-cycle (RBCC) engine was numerically investigated in the ejector mode. The flow features in the RBCC inlet and the matching characteristics between the inlet and the embedded rocket during different flight regimes were examined in detail. It was necessary to perform integrated numerical simulations in the ejector mode within considerable pressure far fields around the inlet/exhaust system. The observed flow features and operation characteristics in the RBCC inlet were strongly correlated with the flight conditions, inlet configuration, and operation of the embedded rocket. It was further found that the integrated function status of multiple factors significantly influenced the performance of the RBCC engine in the ejector mode. The two parameters that macroscopically affected the performance most were the air entrainment mass and the drag of the RBCC inlet. To improve these parameters, it is vital to employ an appropriate design of the RBCC inlet and establish the optimal flight trajectory of the flight vehicle.

  2. Computational Fluid Dynamics (CFD) Simulation of Hypersonic Turbine-Based Combined-Cycle (TBCC) Inlet Mode Transition

    Science.gov (United States)

    Slater, John W.; Saunders, John D.

    2010-01-01

    Methods of computational fluid dynamics were applied to simulate the aerodynamics within the turbine flowpath of a turbine-based combined-cycle propulsion system during inlet mode transition at Mach 4. Inlet mode transition involved the rotation of a splitter cowl to close the turbine flowpath to allow the full operation of a parallel dual-mode ramjet/scramjet flowpath. Steady-state simulations were performed at splitter cowl positions of 0deg, -2deg, -4deg, and -5.7deg, at which the turbine flowpath was closed half way. The simulations satisfied one objective of providing a greater understanding of the flow during inlet mode transition. Comparisons of the simulation results with wind-tunnel test data addressed another objective of assessing the applicability of the simulation methods for simulating inlet mode transition. The simulations showed that inlet mode transition could occur in a stable manner and that accurate modeling of the interactions among the shock waves, boundary layers, and porous bleed regions was critical for evaluating the inlet static and total pressures, bleed flow rates, and bleed plenum pressures. The simulations compared well with some of the wind-tunnel data, but uncertainties in both the windtunnel data and simulations prevented a formal evaluation of the accuracy of the simulation methods.

  3. The extension of Ubungo power plant in Dar es Salaam, Tanzania, to a combined cycle - A prestudy

    Energy Technology Data Exchange (ETDEWEB)

    Grinneland, L.; Oehrstroem, K.

    1996-05-01

    The report deals with the consequences concerning a future extension of Ubungo Power Plant. Today the power plant consists of four gas turbines, two of model General Electric LM6000 and two of model ABB Stal GT10 of which the latter were the ones focused on. In the report four different applications are presented; Simple two pressure system, Two pressure system with reheat, Two pressure system with heat exchange between feedwater and condensate, and single pressure system with an additional evaporating loop. The calculations are divided into three sections; thermodynamic calculations, calculations of the heat exchanger surface areas, and economic calculations. From the thermodynamic calculations the applications with the highest thermal efficiency was selected. The power output increased with about 55% and the thermal efficiency of the complete combined cycle is 48.2%. This is, of course, a theoretical value calculated without consideration to a number of losses that will decrease both the power output and the thermal efficiency. At part load (50% load assumed, i.e. one gas turbine is operating) the thermal efficiency is 46.7%. The economic calculations indicated that the extension is highly worthwhile in an economic point of view; both cases studied have a payback time of less than six years for full load operation, provided that the charging system which is to be imposed by the World Bank has come into force. 18 refs, 33 figs

  4. Coordinated control of a combined cycle thermoelectric central; Control coordinado de una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Parra, Marino; Castelo Cuevas, Luis [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-03-01

    In this paper the coordinated control (CC) of the Distributed Control System (Sistema de Control Distribuido) (SICODI) of the Combined Cycle Central of Gomez Palacio, Durango, is presented. The description of the control scheme and its realization in software is made. From the scheme the operation strategies and automation, supervision and control are described in detail. The software components of the programming are described, the program structure and control data and its implementation in working stations VAX 3100 under the operating system VMS (Virtual Memory System), are described. [Espanol] En este articulo se presenta el control coordinado (CC) del Sistema de Control Distribuido (Sicodi) de la central de ciclo combinado Gomez Palacio, Durango. Se describe el esquema de control y su realizacion en software. Del esquema se detallan las estrategias de operacion y automatizacion, supervision y control. Del software se describen los componentes de la programacion, la estructura de programas y datos del control y su implementacion en estaciones de trabajo VAX 3100 bajo el sistema operativo VMS (Virtual Memory System).

  5. Combined GnRH-agonist and human chorionic gonadotropin trigger improves ICSI cycle outcomes in patients with history of poor fertilization.

    Science.gov (United States)

    Elias, Rony T; Pereira, Nigel; Artusa, Lisa; Kelly, Amelia G; Pasternak, Monica; Lekovich, Jovana P; Palermo, Gianpiero D; Rosenwaks, Zev

    2017-06-01

    The purpose of this study was to investigate the utility of a combined GnRH-agonist (GnRH-a) and human chorionic gonadotropin (hCG) trigger in improving ICSI cycle outcomes in patients with poor fertilization history after standard hCG trigger in prior ICSI cycles. Retrospective cohort study. Patients with a fertilization rate of trigger were compared to those who underwent another ICSI cycle with a combined GnRH-a and hCG trigger. Oocyte maturity, fertilization, clinical pregnancy, and live birth rates were compared. A multiple linear regression model was used to explore the association between combined GnRH-a and hCG trigger (vs hCG trigger alone) and fertilization rate. A total of 427 patients with mean age of 37.3 ± 1.94 years and mean baseline fertilization rate of 17.9 ± 2.03% were included, of which 318 (74.5%) and 109 (25.5%) patients underwent a subsequent ICSI cycle with hCG and combined GnRH-a and hCG trigger, respectively. The baseline parameters of the male and female partner were similar. The mean fertilization rate in the combined trigger group was 16.4% (95% CI: 7.58-25.2%) higher than the hCG trigger group, even after adjustment for confounders. Patients in the combined trigger group had higher oocyte maturity (82.1 vs 69.8%), higher clinical pregnancy (27.5 vs 5.67%), and higher live birth rates (20.2 vs 3.46%) compared to the hCG trigger group. Combined GnRH-a and hCG trigger in ICSI cycles increase oocyte maturity, fertilization, clinical pregnancy, and live birth rates in patients with a history of poor fertilization after standard hCG trigger alone.

  6. Combining Unsteady Blade Pressure Measurements and a Free-Wake Vortex Model to Investigate the Cycle-to-Cycle Variations in Wind Turbine Aerodynamic Blade Loads in Yaw

    Directory of Open Access Journals (Sweden)

    Moutaz Elgammi

    2016-06-01

    Full Text Available Prediction of the unsteady aerodynamic flow phenomenon on wind turbines is challenging and still subject to considerable uncertainty. Under yawed rotor conditions, the wind turbine blades are subjected to unsteady flow conditions as a result of the blade advancing and retreating effect and the development of a skewed vortical wake created downstream of the rotor plane. Blade surface pressure measurements conducted on the NREL Phase VI rotor in yawed conditions have shown that dynamic stall causes the wind turbine blades to experience significant cycle-to-cycle variations in aerodynamic loading. These effects were observed even though the rotor was subjected to a fixed speed and a uniform and steady wind flow. This phenomenon is not normally predicted by existing dynamic stall models integrated in wind turbine design codes. This paper couples blade pressure measurements from the NREL Phase VI rotor to a free-wake vortex model to derive the angle of attack time series at the different blade sections over multiple rotor rotations and three different yaw angles. Through the adopted approach it was possible to investigate how the rotor self-induced aerodynamic load fluctuations influence the unsteady variations in the blade angles of attack and induced velocities. The hysteresis loops for the normal and tangential load coefficients plotted against the angle of attack were plotted over multiple rotor revolutions. Although cycle-to-cycle variations in the angles of attack at the different blade radial locations and azimuth positions are found to be relatively small, the corresponding variations in the normal and tangential load coefficients may be significant. Following a statistical analysis, it was concluded that the load coefficients follow a normal distribution at the majority of blade azimuth angles and radial locations. The results of this study provide further insight on how existing engineering models for dynamic stall may be improved through

  7. IL-2R{gamma} gene microdeletion demonstrates that canine X-linked severe combined immunodeficiency is a homologue of the human disease

    Energy Technology Data Exchange (ETDEWEB)

    Henthorn, P.S.; Fimiani, V.M.; Patterson, D.F. [Univ. of Pennsylvania School of Veterinary Medicine, Philadelphia, PA (United States)] [and others

    1994-09-01

    X-linked severe combined immunodeficiency (SCID) is characterized by profound defects in cellular and humoral immunity and, in humans, is associated with mutations in the gene for the {gamma} chain of the IL-2 receptor (IL-2R{gamma}). We have examined this gene in a colony of dogs established from a single X-linked SCID carrier female. Affected dogs have a 4-bp deletion in the first exon of the IL-2R{gamma} gene, which precludes the production of a functional protein, demonstrating that the canine disease is a true homologue of human X-linked SCID. 37 refs., 3 figs.

  8. The United States of America and the People`s Republic of China experts report on integrated gasification combined-cycle technology (IGCC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    A report written by the leading US and Chinese experts in Integrated Gasification Combined Cycle (IGCC) power plants, intended for high level decision makers, may greatly accelerate the development of an IGCC demonstration project in the People`s Republic of China (PRC). The potential market for IGCC systems in China and the competitiveness of IGCC technology with other clean coal options for China have been analyzed in the report. Such information will be useful not only to the Chinese government but also to US vendors and companies. The goal of this report is to analyze the energy supply structure of China, China`s energy and environmental protection demand, and the potential market in China in order to make a justified and reasonable assessment on feasibility of the transfer of US Clean Coal Technologies to China. The Expert Report was developed and written by the joint US/PRC IGCC experts and will be presented to the State Planning Commission (SPC) by the President of the CAS to ensure consideration of the importance of IGCC for future PRC power production.

  9. Biogeochemical Cycles for Combining Chemical Knowledge and ESD Issues in Greek Secondary Schools Part II: Assessing the Impact of the Intervention

    Science.gov (United States)

    Koutalidi, Sophia; Psallidas, Vassilis; Scoullos, Michael

    2016-01-01

    In searching for effective ways to combine science/chemical education with EE/ESD, new didactic materials were designed and produced focussing on biogeochemical cycles and their connection to sustainable development. The materials were experimentally applied in 16 Greek schools under the newly introduced compulsory "school project" which…

  10. Biogeochemical Cycles for Combining Chemical Knowledge and ESD Issues in Greek Secondary Schools Part II: Assessing the Impact of the Intervention

    Science.gov (United States)

    Koutalidi, Sophia; Psallidas, Vassilis; Scoullos, Michael

    2016-01-01

    In searching for effective ways to combine science/chemical education with EE/ESD, new didactic materials were designed and produced focussing on biogeochemical cycles and their connection to sustainable development. The materials were experimentally applied in 16 Greek schools under the newly introduced compulsory "school project" which…

  11. Joule II - programme. Clean coal technology R & D; 2nd phase. Volume V. Enhancement of the efficiency of integrated gasification combined cycle (IGCC) power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Minchener, A.J.; Pruschek, R.; Roberts, P.A. [eds.

    1998-12-31

    Methods of enhancing the efficiency of integrated gasification combined cycle (IGCC) power plants were investigated under the JOULE II extension project JOU2-CT94-0454. These included thermodynamic analysis of measures for efficiency enhancement, and development and design of advanced heat recovery steam generator. All 3 papers have been abstracted separately.

  12. Is there an environmental benefit from remediation of a contaminated site? Combined assessments of the risk reduction and life cycle impact of remediation

    DEFF Research Database (Denmark)

    Lemming, Gitte; Chambon, Julie Claire Claudia; Binning, Philip John;

    2012-01-01

    determined by a numerical risk assessment and remedial performance model, which predicted the contaminant mass discharge over time at a point of compliance in the aquifer and at the waterworks. The combined assessment of risk reduction and life cycle impacts showed that all management options result...

  13. Thermodynamic System Studies for a Natural Gas Combined Cycle (NGCC) Plant with CO2 Capture and Hydrogen Storage with Metal Hydrides

    NARCIS (Netherlands)

    Thallam Thattai, A.; Wittebrood, B.J.; Woudstra, T.; Geerlings, J.J.C.; Aravind, P.V.

    2014-01-01

    Flexibility in natural gas combined cycle power plants (NGCC) with pre-combustion CO2 capture could be introduced with co-production of hydrogen and subsequent hydrogen storage with metal hydrides (MH). The current work presents a thermodynamic analysis and comparison between steady state ASPEN Plus

  14. ``Turbo-KWK `99``. Combined-cycle power stations with gas turbines. Technical meeting; Turbo-KWK `99. Kraft-Waerme-Kopplung mit Gasturbinen. Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    This conference report comprises 18 contributions on the technological success of gas turbines in power generation, e.g.: Maximum power generation efficiency of combined cycle systems, flexibility of power generation, reduction of air pollution, hot gas production for drying processes and environment-friendly cold generation in the pharmaceutical and printing industries. The final contribution presents an outlook to the future.

  15. Modelling and simulation of a thermal electric station with cogeneration and combined cycle; Modelagem e simulacao de uma central termeletrica com cogeracao e ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Kalid, Ricardo [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Dept. de Engenharia Quimica; Sales, Emerson [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Kiperstok, Asher [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Dept. de Engenharia Ambiental], e-mail: asher@ufba.br; Souza, Leonardo; Freitas, Adriano de Sena [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Faculdade de Engenharia Quimica; Pires, Victor Matta; Almeida, Edgar Nunes de [Braskem S.A., Camacari, BA (Brazil). Unidade de Insumos Basicos], e-mail: victor.mattapires@braskem.com.br

    2008-01-15

    This paper presents a simulator used in the managing of thermoelectric unit of the Petrochemical Complex of Camacari, Bahia, Brazil which disposes of cogeneration and combined cycle. This simulator allows the integrated assessment of different operational configurations giving a visualization of the operational condition with the smaller operational cost, and consequently smaller environmental impact.

  16. ``Turbo-KWK `99``. Combined-cycle power stations with gas turbines. Technical meeting; Turbo-KWK `99. Kraft-Waerme-Kopplung mit Gasturbinen. Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    This conference report comprises 18 contributions on the technological success of gas turbines in power generation, e.g.: Maximum power generation efficiency of combined cycle systems, flexibility of power generation, reduction of air pollution, hot gas production for drying processes and environment-friendly cold generation in the pharmaceutical and printing industries. The final contribution presents an outlook to the future.

  17. Thermodynamic System Studies for a Natural Gas Combined Cycle (NGCC) Plant with CO2 Capture and Hydrogen Storage with Metal Hydrides

    NARCIS (Netherlands)

    Thallam Thattai, A.; Wittebrood, B.J.; Woudstra, T.; Geerlings, J.J.C.; Aravind, P.V.

    2014-01-01

    Flexibility in natural gas combined cycle power plants (NGCC) with pre-combustion CO2 capture could be introduced with co-production of hydrogen and subsequent hydrogen storage with metal hydrides (MH). The current work presents a thermodynamic analysis and comparison between steady state ASPEN Plus

  18. Single and Combined Effects of Beetroot Crystals and Sodium Bicarbonate on 4-km Cycling Time Trial Performance.

    Science.gov (United States)

    Callahan, Marcus J; Parr, Evelyn B; Hawley, John A; Burke, Louise M

    2017-06-01

    When ingested alone, beetroot juice and sodium bicarbonate are ergogenic for high-intensity exercise performance. This study sought to determine the independent and combined effects of these supplements. Eight endurance trained (VO2max 65 mL·kg·min(-1)) male cyclists completed four × 4-km time trials (TT) in a doubleblind Latin square design supplementing with beetroot crystals (BC) for 3 days (15 g·day(-1) + 15 g 1 h before TT, containing 300 mg nitrate per 15 g), bicarbonate (Bi 0.3 g·kg(-1) body mass [BM] in 5 doses every 15 min from 2.5 h before TT); BC+Bi or placebo (PLA). Subjects completed TTs on a Velotron cycle ergometer under standardized laboratory conditions. Plasma nitrite concentrations were significantly elevated only in the BC+Bi trial before the TT (1520 ± 786 nmol·L(-1)) compared with baseline (665 ± 535 nmol·L(-1), p = .02) and the Bi and PLA conditions (Bi: 593 ± 203 nmol·L(-1), p .05). Blood bicarbonate concentrations were increased in the BC+Bi and Bi trials before the TT (BC+Bi: 30.9 ± 2.8 mmol·L(-1); Bi: 31.7 ± 1.1 mmol·L(-1)). There were no differences in mean power output (386-394 W) or the time taken to complete the TT (335.8-338.1 s) between any conditions. Under the conditions of this study, supplementation was not ergogenic for 4-km TT performance.

  19. Steady-state simulation and optimization of an integrated gasification combined cycle power plant with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2011-01-01

    Integrated gasification combined cycle (IGCC) plants are a promising technology option for power generation with carbon dioxide (CO2) capture in view of their efficiency and environmental advantages over conventional coal utilization technologies. This paper presents a three-phase, top-down, optimization-based approach for designing an IGCC plant with precombustion CO2 capture in a process simulator environment. In the first design phase, important global design decisions are made on the basis of plant-wide optimization studies with the aim of increasing IGCC thermal efficiency and thereby making better use of coal resources and reducing CO2 emissions. For the design of an IGCC plant with 90% CO2 capture, the optimal combination of the extent of carbon monoxide (CO) conversion in the water-gas shift (WGS) reactors and the extent of CO2 capture in the SELEXOL process, using dimethylether of polyethylene glycol as the solvent, is determined in the first phase. In the second design phase, the impact of local design decisions is explored considering the optimum values of the decision variables from the first phase as additional constraints. Two decisions are made focusing on the SELEXOL and Claus unit. In the third design phase, the operating conditions are optimized considering the optimum values of the decision variables from the first and second phases as additional constraints. The operational flexibility of the plant must be taken into account before taking final design decisions. Two studies on the operational flexibility of the WGS reactors and one study focusing on the operational flexibility of the sour water stripper (SWS) are presented. At the end of the first iteration, after executing all the phases once, the net plant efficiency (HHV basis) increases to 34.1% compared to 32.5% in a previously published study (DOE/NETL-2007/1281; National Energy Technology Laboratory, 2007). The study shows that the three-phase, top-down design approach presented is very

  20. Biogeochemical Cycles for Combining Chemical Knowledge and ESD Issues in Greek Secondary Schools Part I: Designing the Didactic Materials

    Science.gov (United States)

    Koutalidi, Sophia; Scoullos, Michael

    2016-01-01

    Biogeochemical cycles support all anthropogenic activities and are affected by them, therefore they are intricately interlinked with global environmental and socioeconomic issues. Elements of these cycles that are already included in the science/chemical curriculum and textbooks intended for formal education in Greek secondary schools were…

  1. Biogeochemical Cycles for Combining Chemical Knowledge and ESD Issues in Greek Secondary Schools Part I: Designing the Didactic Materials

    Science.gov (United States)

    Koutalidi, Sophia; Scoullos, Michael

    2016-01-01

    Biogeochemical cycles support all anthropogenic activities and are affected by them, therefore they are intricately interlinked with global environmental and socioeconomic issues. Elements of these cycles that are already included in the science/chemical curriculum and textbooks intended for formal education in Greek secondary schools were…

  2. Directing Hybrid Structures by Combining Self-Assembly of Functional Block Copolymers and Atomic Layer Deposition: A Demonstration on Hybrid Photovoltaics.

    Science.gov (United States)

    Moshonov, Moshe; Frey, Gitti L

    2015-11-24

    The simplicity and versatility of block copolymer self-assembly offers their use as templates for nano- and meso-structured materials. However, in most cases, the material processing requires multiple steps, and the block copolymer is a sacrificial building block. Here, we combine a self-assembled block copolymer template and atomic layer deposition (ALD) of a metal oxide to generate functional hybrid films in a simple process with no etching or burning steps. This approach is demonstrated by using the crystallization-induced self-assembly of a rod-coil block copolymer, P3HT-b-PEO, and the ALD of ZnO. The block copolymer self-assembles into fibrils, ∼ 20 nm in diameter and microns long, with crystalline P3HT cores and amorphous PEO corona. The affinity of the ALD precursors to the PEO corona directs the exclusive deposition of crystalline ZnO within the PEO domains. The obtained hybrid structure possesses the properties desired for photovoltaic films: donor-acceptor continuous nanoscale interpenetrated networks. Therefore, we integrated the films into single-layer hybrid photovoltaics devices, thus demonstrating that combining self-assembly of functional block copolymers and ALD is a simple approach to direct desired complex hybrid morphologies.

  3. Finding Your Way from the Bed to the Kitchen: Re-enacting and Re-combining Sensorimotor Episodes Learned from Human Demonstration

    Directory of Open Access Journals (Sweden)

    Erik A. Billing

    2016-03-01

    Full Text Available Several simulation theories have been proposed as an explanation for how humans and other agents internalize an inner world that allows them to simulate interactions with the external real world -- prospectively and retrospectively. Such internal simulation of interaction with the environment has been argued to be a key mechanism behind mentalizing and planning. In the present work, we study internal simulations in a robot acting in a simulated human environment. A model of sensory-motor interactions with the environment is generated from human demonstrations, and tested on a Robosoft Kompai robot. The model is used as a controller for the robot, reproducing the demonstrated behavior. Information from several different demonstrations is mixed, allowing the robot to produce novel paths through the environment, towards a goal specified by top-down contextual information. The robot model is also used in a covert mode, where actions are inhibited and perceptions are generated by a forward model. As a result, the robot generates an internal simulation of the sensory-motor interactions with the environment. Similar to the overt mode, the model is able to reproduce the demonstrated behavior as internal simulations. When experiences from several demonstrations are combined with a top-down goal signal, the system produces internal simulations of novel paths through the environment. These results can be understood as the robot imagining an inner world generated from previous experience, allowing it to try out different possible futures without executing actions overtly. We found that the success rate in terms of reaching the specified goal was higher during internal simulation, compared to overt action. These results are linked to a reduction in prediction errors generated during covert action. Despite the fact that the model is quite successful in terms of generating covert behavior towards specified goals, internal simulations display different temporal

  4. Development of Natural Gas Fired Combined Cycle Plant for Tri-Generation of Power, Cooling and Clean Water Using Waste Heat Recovery: Techno-Economic Analysis

    Directory of Open Access Journals (Sweden)

    Gowtham Mohan

    2014-10-01

    Full Text Available Tri-generation is one of the most efficient ways for maximizing the utilization of available energy. Utilization of waste heat (flue gases liberated by the Al-Hamra gas turbine power plant is analyzed in this research work for simultaneous production of: (a electricity by combining steam rankine cycle using heat recovery steam generator (HRSG; (b clean water by air gap membrane distillation (AGMD plant; and (c cooling by single stage vapor absorption chiller (VAC. The flue gases liberated from the gas turbine power cycle is the prime source of energy for the tri-generation system. The heat recovered from condenser of steam cycle and excess heat available at the flue gases are utilized to drive cooling and desalination cycles which are optimized based on the cooling energy demands of the villas. Economic and environmental benefits of the tri-generation system in terms of cost savings and reduction in carbon emissions were analyzed. Energy efficiency of about 82%–85% is achieved by the tri-generation system compared to 50%–52% for combined cycles. Normalized carbon dioxide emission per MW·h is reduced by 51.5% by implementation of waste heat recovery tri-generation system. The tri-generation system has a payback period of 1.38 years with cumulative net present value of $66 million over the project life time.

  5. Evaluation and demonstration of methods for improved fuel utilization. Fort Calhoun Poolside Inspection Programs: end-of-cycles 4 and 5

    Energy Technology Data Exchange (ETDEWEB)

    LaVake, J.C.; Smith, G.P.

    1980-08-01

    The purpose of this program is to demonstrate two techniques for improving fuel utilization in current Pressurized Water Reactors (PWR): (1) more efficient fuel management, and (2) high burnup. These improvements are being demonstrated in the Fort Calhoun reactor, a 1420 Mwt PWR. A more efficient fuel management scheme called SAVFUEL (Shimmed And Very Flexible Uranium Element Loading), will be demonstrated which reduces neutron leakage and is expected to reduce uranium requirements. Another part of the demonstration program will increase the fuel burnup of the current 14 x 14 fuel design to further reduce uranium requirements. The program is a joint Department of Energy (DOE), Omaha Public Power District (OPPD) and Combustion Engineering (C-E) endeavor and is part of a national effort to improve uranium utilization in light water reactors.

  6. Combined Life Cycle Assessment and Life Cycle Costing in the Eco-Care-Matrix: A case study on the performance of a modernized manufacturing system for glass containers

    DEFF Research Database (Denmark)

    Auer, Johannes; Bey, Niki; Schäfer, Johannes-Marius

    2017-01-01

    The objects of Life Cycle Assessment (LCA) case studies are often individual components or individual products. Studies focusing on larger industrial manufacturing systems are relatively rare. The purpose of this case study was to assess environmental and cost-related performance of an updated...... levers, (ii) efficiency of the LCA process and (iii) their relevance for the speed and cost of the decision-making process. The LCA results of the production stage of the optimized components showed that the largest contributors to the potential environmental impact of the manufacturing system...... glass bottle's GWP showed that it was reduced by about 40% through optimizing the production system. The LCC showed that the modernization pays off after about five years of service life and that the decision for making an Investment should not only be based on the required capital expenditure (CAPEX...

  7. A modeling software linking approach for the analysis of an integrated reforming combined cycle with hot potassium carbonate CO[subscript 2] capture

    OpenAIRE

    Nord, Lars Olof; Kothandaraman, Anusha; BOLLAND, Olav; Herzog, Howard J.; McRae, Gregory J.

    2009-01-01

    The focus of this study is the analysis of an integrated reforming combined cycle (IRCC) with natural gas as fuel input. This IRCC consisted of a hydrogen-fired gas turbine (GT) with a single-pressure steam bottoming cycle for power production. The reforming process section consisted of a pre-reformer and an air-blown auto thermal reformer (ATR) followed by water-gas shift reactors. The air to the ATR was discharged from the GT compressor and boosted up to system pressure by an air booster co...

  8. Combined insulin treatment and intense exercise training improved basal cardiac function and Ca(2+)-cycling proteins expression in type 1 diabetic rats.

    Science.gov (United States)

    Le Douairon Lahaye, Solène; Gratas-Delamarche, Arlette; Malardé, Ludivine; Zguira, Sami; Vincent, Sophie; Lemoine Morel, Sophie; Carré, François; Rannou Bekono, Françoise

    2012-02-01

    This study investigated the effects of 8 weeks of intense exercise training combined with insulin treatment on the Ca(2+)-cycling protein complex expression and their functional consequences on cardiac function in type 1 diabetic rat hearts. Diabetic Wistar rats were randomly assigned into the following groups: received no treatment, insulin-treated diabetic, trained diabetic, and trained insulin-treated diabetic. A control group was also included. Insulin treatment and (or) treadmill intense exercise training were conducted over 8 weeks. Basal cardiac function was evaluated by Langendorff technique. Cardiac expression of the main Ca(2+)-cycling proteins (RyR2, FKBP 12.6, SERCA2, PLB, NCX1) was assessed by Western blot. Diabetes altered basal cardiac function (±dP/dt) and decrease the expression of the main Ca(2+)-cycling proteins expression: RyR2, SERCA2, and NCX1 (p < 0.05). Whereas combined treatment was not able to normalize -dP/dt, it succeeded to normalize +dP/dt of diabetic rats (p < 0.05). Moreover, both insulin and intense exercise training, applied solely, increased the expression of the Ca(2+)-cycling proteins: RyR2, SERCA2, PLB. and NCX1 (p < 0.05). But this effect was higher when the 2 treatments were combined. These data are the first to show that combined insulin treatment and intense exercise training during diabetes synergistically act on the expression of the main Ca(2+)-cycling proteins, providing insights into mechanisms by which the dual treatment during diabetes improves cardiac function.

  9. Fuel reactivity and release of pollutants and alkali vapours in pressurized combustion for combined cycle power generation

    Energy Technology Data Exchange (ETDEWEB)

    Aho, M.; Haemaelaeinen, J.; Paakkinen, K.; Rantanen, J. [VTT Energy, Jyvaeskylae (Finland); Hernberg, R.; Haeyrinen, V.; Joutsenoja, T. [Tampere Univ. of Technology (Finland). Lab. of Plasma Technology

    1996-12-01

    This project forms a part of the overall Pressurized Power Coal Combustion Project Area (PPFC) which aims at an assessment of the viability and technical merits of pressurized pulverized coal combustion, in an atmosphere of recycled flue gas and oxygen in a coordinated and harmonized programme. The objective of the research at Technical Research Centre of Finland (VTT) and Tampere University of Technology (TUT) is aimed at determining the consequences of solid fuel burning in a mixture of oxygen and recycled flue gases. Combustion conditions of a pressurized entrained flow of pulverized coal and char particles in PEFR are determined with high precision. The effects of experimental parameters on the formation of nitrogen oxides (N{sub 2}O, NO and NO{sub 2}) and gaseous alkali compounds (indicated as NaX(g) and KX(g)) are studied. An effective on-line analysis method for vaporised Na and K compounds was developed. The dependency between particle temperatures and the vaporisation of Na and K was measured with three coals. The results show that alkali removal before gas turbines is always necessary with these coals if combusted in combined cycles. Pressure decreases the formation of NO and has usually no clear effect on the formation of N{sub 2}O. The order of NO/N{sub 2}O ratios correspond to fuel-O/fuel-N ratios. Increase of PO{sub 2} (oxygen concentration) of combustion gas increases the formation of NO{sub 2}. Remarkable concentrations of NO{sub 2} were often measured at high PO{sub 2} at 800-850 deg C. Therefore, NO{sub 2} should be measured from pressurized fluidized bed reactors. Some trends of the formation of NO{sub 2} with coal differ clearly from those with its parent char: N{sub 2}O formation is not strongly temperature dependent with char, and the concentrations of N{sub 2}O formed from char are much lower than those of coal. PO{sub 2} does not effect on the formation of NO from char in the studied range

  10. An approach to holistically assess (dairy) farm eco-efficiency by combining Life Cycle Analysis with Data Envelopment Analysis models and methodologies.

    Science.gov (United States)

    Soteriades, A D; Faverdin, P; Moreau, S; Charroin, T; Blanchard, M; Stott, A W

    2016-11-01

    Eco-efficiency is a useful guide to dairy farm sustainability analysis aimed at increasing output (physical or value added) and minimizing environmental impacts (EIs). Widely used partial eco-efficiency ratios (EIs per some functional unit, e.g. kg milk) can be problematic because (i) substitution possibilities between EIs are ignored, (ii) multiple ratios can complicate decision making and (iii) EIs are not usually associated with just the functional unit in the ratio's denominator. The objective of this study was to demonstrate a 'global' eco-efficiency modelling framework dealing with issues (i) to (iii) by combining Life Cycle Analysis (LCA) data and the multiple-input, multiple-output production efficiency method Data Envelopment Analysis (DEA). With DEA each dairy farm's outputs and LCA-derived EIs are aggregated into a single, relative, bounded, dimensionless eco-efficiency score, thus overcoming issues (i) to (iii). A novelty of this study is that a model providing a number of additional desirable properties was employed, known as the Range Adjusted Measure (RAM) of inefficiency. These properties altogether make RAM advantageous over other DEA models and are as follows. First, RAM is able to simultaneously minimize EIs and maximize outputs. Second, it indicates which EIs and/or outputs contribute the most to a farm's eco-inefficiency. Third it can be used to rank farms in terms of eco-efficiency scores. Thus, non-parametric rank tests can be employed to test for significant differences in terms of eco-efficiency score ranks between different farm groups. An additional DEA methodology was employed to 'correct' the farms' eco-efficiency scores for inefficiencies attributed to managerial factors. By removing managerial inefficiencies it was possible to detect differences in eco-efficiency between farms solely attributed to uncontrollable factors such as region. Such analysis is lacking in previous dairy studies combining LCA with DEA. RAM and the 'corrective

  11. Corrosion behavior of Haynes {sup registered} 230 {sup registered} nickel-based super-alloys for integrated coal gasification combined cycle syngas plants. A plant exposure study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungkyu; Lee, Jieun; Kang, Suk-Hwan; Lee, Seung-Jong; Yun, Yongseung [Institute for Advanced Engineering (IAE), Gyeonggi-do (Korea, Republic of). Plant Engineering Center; Kim, Min Jung [Sungkyunkwan Univ, Gyeonggi-do (Korea, Republic of). Advanced Materials Technology Research Center

    2015-07-01

    The corrosion behavior of commercially available Haynes {sup registered} 230 {sup registered} nickel-based alloy samples was investigated by exposure to coal-gasifying integrated coal gasification combined cycle pilot plant facilities affiliated with the Institute for Advanced Engineering (2.005 MPa and 160-300 C). The morphological and microstructural analyses of the exposed samples were conducted using scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis on the external surface of the recovered corrosion test samples to obtain information of the corrosion scale. These analyses based on the pre- and post-exposure corrosion test samples combined with thermodynamic Ellingham-Pourbaix stability diagrams provided preliminary insight into the mechanism of the observed corrosion behavior prevailing in the piping materials that connected the particulate removal unit and water scrubber of the integrated coal gasification combined cycle pilot plant. Uniform material wastage was observed after 46 hours of operation, and a preliminary corrosion mechanism was suggested: the observed material waste and corrosion behavior of the Haynes {sup registered} 230 {sup registered} nickel-based alloy samples cut off from the coal syngas integrated coal gasification combined cycle plant were explained by the formation of discontinuous (complex) oxide phases and subsequent chlorine-induced active oxidation under the predominantly reducing environment encountered. This contribution continues the already published studies of the Fe-Ni-Cr-Co alloy Haynes {sup registered} 556 {sup registered}.

  12. Parametric and exergetic analysis of a two-stage transcritical combined organic Rankine cycle used for multiple grades waste heat recovery of diesel engine

    Science.gov (United States)

    Tian, H.; Zhang, J.; Xu, X. F.; Shu, G. Q.; Wei, H. Q.

    2013-12-01

    Diesel engine has multiple grades of waste heat with different ratios of combustion heat, exhaust is 400 °C with the ratio of 21% and coolant is 90 °C with 19%. Few previous publications investigate the recovery of multiple grades waste heat together. In this paper, a two-stage transcritical combined organic rankine cycle (CORC) is presented and analyzed. In the combined system, the high and low temperature stages transcritical cycle recover the high grades waste heat, and medium to low grades waste heat respectively, and being combined efficiently. Meanwhile, the suitable working fluids for high stage are chosen and analyzed. The cycle parameters, including thermal efficiency (ηth), net power output (Pnet), energy efficiency (ηexg) and global thermal efficiency of DE-CORC(ηglo) have also been analyzed and optimized. The results indicate that this combined system could recover all the waste heat with a high recovery ratio (above 90%) and obtain a maximum power output of 37kW for a DE of 243kW. The global thermal efficiency of DE-CORC can get a max value of 46.2% compared with 40% for single DE. The results also indicate that all the energy conversion process have a high exergy efficiency.

  13. Combination of Ethanolic Extract of Citrus aurantifolia Peels with Doxorubicin Modulate Cell Cycle and Increase Apoptosis Induction on MCF-7 Cells.

    Science.gov (United States)

    Adina, Anugerah Budipratama; Goenadi, Fina Aryani; Handoko, Franciscus Feby; Nawangsari, Dwi Ana; Hermawan, Adam; Jenie, Riris Istighfari; Meiyanto, Edy

    2014-01-01

    New approach of breast cancer therapy is developed toward combination therapy with agents that have a specific molecular target. Our previous study showed that Citrus aurantifolia lime peels ethanolic extract (CPE) increased the sensitivity of MCF-7 cells againts doxorubicin. This study aims to observe the mechanism of combination CPE and doxorubicin in cell cycle modulation and apoptosis on MCF-7 cells. The assays were performed in the study were cell cycle assay, apoptosis induction, and immunocytochemistry of MCF-7 cells.The effect on the modulation of cell cycle and apoptosis were observed by flowcytometry assay in both single dose of CPE and its combination with Doxorubicin. Cell cycle distribution were observed with flowcytometer FACS-Calibur and its data was analyzed by Cell Quest program. Apoptotic induction in MCF-7 cells was examined using acrydine orange-ethidium bromide (AO-EtBr) double staining. Immunocytochemistry assay was done to observe the expression of apoptotic regulation protein p53 and Bcl-2. The result showed that CPE 6 μg/mL induced apoptosis and cell accumulation at G1 phase, while CPE 15 μg/mL induced apoptosis and cell accumulation at G2/M phase. The combination of doxorubicin 200 nM with CPE 6 μg/mL increased apoptosis induction than their single treatment, and cell accumulation at G2/M phase. Evidence of apoptosis and protein expression of p53 and Bcl-2 indicated that both single applications and combinations of CPE and doxorubicin are able to increase apoptotic bodies of MCF-7 cells by increasing the proteins expression. This result suggested that CPE could perform as co-chemotherapeutic agent with doxorubicin on breast cancer cells.

  14. Performance of air breathing combined cycle engines with a turbofan; Leistungsverhalten luftatmender Kombinationstriebwerke mit Zweistrom-Turboteil

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, H.

    2003-07-01

    In this paper the influence of the design and control parameters on the performance characteristic of a combined cycle engine consisting of a turbofan engine with a reheat system and a convergent-divergent nozzle is investigated. The studies are not based on a special mission but the two sections of a mission dominating the fuel consumption of the propulsion system - the acceleration flight and the cruise segment - are considered seperately. By that it is shown which design of the turbo engine is suitable for each section of the mission and how far these designs differ from each other. The studies start with the so-called baseline engine. Applying a performance calculation program the performance characteristic of the engine is calculated for given flight conditions and engine control parameter settings. The particularly for high speed propulsion systems important interaction between the engine and the aircraft is considered, iteratively adjusting the angle of attack of the aircraft given for the performance calculation to the one fulfilling the equations of motion of the aircraft. Based on the results of the baseline engine the design parameters of the turbo engine, namely (a) the turbine inlet temperature T{sub t4,A}, (b) the overall pressure ratio {pi}{sub tV,A} and (c) the bypass ratio {mu}{sub A} are varied systematically and the effect of these changes on the performance of the engine along the flight Mach Number is investigated. First the studies are carried out for the acceleration flight and afterwards they are being extended to the cruise flight segment. The valuation criteria for the engine performance in the acceleration section is the so-called acceleration efficiency. This efficiency is defined as the ratio of the potential and kinetic energy rise and the therefore needed fuel energy. In the cruise section the engine performance is valuated using a so-called cruise number which considers the quality of the conversion of fuel energy into propulsive

  15. IGCC technology and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J. [A. Ahlstrom Corporation, Karhula (Finland). Hans Ahlstrom Lab.; Lundqvist, R.G. [A. Ahlstrom Corporation, Helsinki (Finland); Staahl, K. [Sydkraft AB, Malmoe (Sweden)

    1996-12-31

    Future energy production will be performed by advanced technologies that are more efficient, more environmentally friendly and less expensive than current technologies. Integrated gasification combined cycle (IGCC) power plants have been proposed as one of these systems. Utilising biofuels in future energy production will also be emphasised since this lowers substantially carbon dioxide emissions into the atmosphere due to the fact that biomass is a renewable form of energy. Combining advanced technology and biomass utilisation is for this reason something that should and will be encouraged. A. Ahlstrom Corporation of Finland and Sydkraft AB of Sweden have as one part of company strategies adopted this approach for the future. The companies have joined their resources in developing a biomass-based IGCC system with the gasification part based on pressurised circulating fluidized-bed technology. With this kind of technology electrical efficiency can be substantially increased compared to conventional power plants. As a first concrete step, a decision has been made to build a demonstration plant. This plant, located in Vaernamo, Sweden, has already been built and is now in commissioning and demonstration stage. The system comprises a fuel drying plant, a pressurised CFB gasifier with gas cooling and cleaning, a gas turbine, a waste heat recovery unit and a steam turbine. The plant is the first in the world where the integration of a pressurised gasifier with a gas turbine will be realised utilising a low calorific gas produced from biomass. The capacity of the Vaernamo plant is 6 MW of electricity and 9 MW of district heating. Technology development is in progress for design of plants of sizes from 20 to 120 MWe. The paper describes the Bioflow IGCC system, the Vaernamo demonstration plant and experiences from the commissioning and demonstration stages. (orig.)

  16. Experimental results of ammonia operated condensate polishing plants in combined cycle power plants; Untersuchungsergebnisse zur Ammoniumfahrweise einer Kondensatreinigungsanlage bei GuD-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Ochsmann, Christian [Erlangen-Nuernberg Univ., Erlangen (Germany); Jahr, Henrik; Glueck, Wolfgang [Siemens AG, Erlangen (Germany); Neumann, Stefan; Wedemeyer, Hans-Juergen [Lanxess Deutschland GmbH, Leverkusen (Germany)

    2013-04-01

    Modern combined cycle power plants with once-through boilers require highly pure boiler feedwater. Typically a condensate polishing plant (CPP) is used as 'salt sink' in the water-steam cycle, with a combination of cation and anion exchanger resin in a mixed bed filter. Ammonia ions are removed which reduces the lifetime of CPP. An alternative is the so-called 'ammonium form operation' which is being presented and discussed. This mode was investigated. The experimental results show that the 'ammonium form operation' is an attractive technology, which offers reduced operating costs and therefore meets economical expectations of power plant operators. (orig.)

  17. Construction of a visible light-driven hydrocarboxylation cycle of alkenes by the combined use of Rh(i) and photoredox catalysts.

    Science.gov (United States)

    Murata, Kei; Numasawa, Nobutsugu; Shimomaki, Katsuya; Takaya, Jun; Iwasawa, Nobuharu

    2017-03-09

    A visible light driven catalytic cycle for hydrocarboxylation of alkenes with CO2 was established using a combination of a Rh(i) complex as a carboxylation catalyst and [Ru(bpy)3](2+) (bpy = 2,2'- bipyridyl) as a photoredox catalyst. Two key steps, the generation of Rh(i) hydride species and nucleophilic addition of π-benzyl Rh(i) species to CO2, were found to be mediated by light.

  18. Combining charcoal and elemental black carbon analysis in sedimentary archives : implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions

    OpenAIRE

    2010-01-01

    This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles >0.2 mu m(2) remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after therma...

  19. Combining charcoal and elemental black carbon analysis in sedimentary archives : implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions

    OpenAIRE

    Thevenon, Florian; Williamson, David; Bard, Edouard; Flavio S. Anselmetti; Beaufort, Luc; Cachier, Hélène

    2010-01-01

    This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles >0.2 mu m(2) remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after therma...

  20. Development of Natural Gas Fired Combined Cycle Plant for Tri-Generation of Power, Cooling and Clean Water Using Waste Heat Recovery: Techno-Economic Analysis

    OpenAIRE

    Gowtham Mohan; Sujata Dahal; Uday Kumar; Andrew Martin; Hamid Kayal

    2014-01-01

    Tri-generation is one of the most efficient ways for maximizing the utilization of available energy. Utilization of waste heat (flue gases) liberated by the Al-Hamra gas turbine power plant is analyzed in this research work for simultaneous production of: (a) electricity by combining steam rankine cycle using heat recovery steam generator (HRSG); (b) clean water by air gap membrane distillation (AGMD) plant; and (c) cooling by single stage vapor absorption chiller (VAC). The flue gases liber...

  1. Biomass energy for the twenty first century: commercial demonstration of a modern biomass power system based on gasification -combined cycle technology

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Philip; Booth, Roger [Shell International Petroleum Co. Ltd., London (United Kingdom)

    1996-10-01

    A review by Shell of the potential role of renewable energy sources in a scenario of sustained growth in the world economy is reported. It is envisaged that certain technologies will expand by capturing niche markets and by 2020, rapid expansion should be possible. (UK)

  2. The effectiveness of using the combined-cycle technology in a nuclear power plant unit equipped with an SVBR-100 reactor

    Science.gov (United States)

    Kasilov, V. F.; Dudolin, A. A.; Gospodchenkov, I. V.

    2015-05-01

    The design of a modular SVBR-100 reactor with a lead-bismuth alloy liquid-metal coolant is described. The basic thermal circuit of a power unit built around the SVBR-100 reactor is presented together with the results of its calculation. The gross electrical efficiency of the turbine unit driven by saturated steam at a pressure of 6.7 MPa is estimated at η{el/gr} = 35.5%. Ways for improving the efficiency of this power unit and increasing its power output by applying gas-turbine and combined-cycle technologies are considered. With implementing a combined-cycle power-generating system comprising two GE-6101FA gas-turbine units with a total capacity of 140 MW, it becomes possible to obtain the efficiency of the combined-cycle plant equipped with the SVBR-100 reactor η{el/gr} = 45.39% and its electrical power output equal to 328 MW. The heat-recovery boiler used as part of this power installation generates superheated steam with a temperature of 560°C, due to which there is no need to use a moisture separator/steam reheater in the turbine unit thermal circuit.

  3. Release and sorption of alkali metals in coal fired combined cycle power systems; Freisetzung und Einbindung von Alkalimetallverbindungen in kohlebefeuerten Kombikraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Michael

    2009-07-01

    Coal fired combined cycle power systems will be a sufficient way to increase the efficiency of coal combustion. However, combined cycle power systems require a reliable hot gas cleanup. Especially alkali metals, such as sodium and potassium, can lead to hot corrosion of the gas turbine blading if they condensate as sulphates. The actual work deals with the release and sorption of alkali metals in coal fired combined cycle power systems. The influence of coal composition, temperature and pressure on the release of alkali species in coal combustion was investigated and the relevant release mechanisms identified. Alumosilicate sorbents have been found that reduce the alkali concentration in the hot flue gas of the Circulating Pressurized Fluidized Bed Combustion 2{sup nd} Generation (CPFBC 2{sup nd} Gen.) at 750 C to values sufficient for use in a gas turbine. Accordingly, alumosilicate sorbents working at 1400 C have been found for the Pressurized Pulverized Coal Combustion (PPCC). The sorption mechanisms have been identified. Thermodynamic calculations were performed to upscale the results of the laboratory experiments to conditions prevailing in power systems. According to these calculations, there is no risk of hot corrosion in both processes. Furthermore, thermodynamic calculations were performed to investigate the behaviour of alkali metals in an IGCC with integrated hot gas cleanup and H{sub 2} membrane for CO{sub 2} sequestration. (orig.)

  4. The possible role of enterohepatic cycling on bioavailability of norethisterone and gestodene in women using combined oral contraceptives.

    Science.gov (United States)

    Elomaa, K; Ranta, S; Tuominen, J; Lähteenmäki, P

    2001-01-01

    Using steady-state conditions we aimed to test if administration of oral activated charcoal affects the bioavailability of norethisterone acetate (NET Ac) and gestodene (GEST) by inhibiting their enterohepatic recirculation. Thirteen volunteers received, in a randomized order, Minulet (75 microg GEST and 30 microg ethinylestradiol [EE(2)]) and Econ/30 (1 mg NET Ac and 30 microg EE(2)), each for 4 months. Serum GEST and norethisterone (NET) levels were evaluated with respect to C(max,) t(max) and 24-h area under the curve (AUC(0-24h)) in the middle of the control (3rd) cycle and the charcoal treatment (4th) cycle during both pill treatments. No statistically significant difference was seen in any of the aforementioned variables between the control and charcoal treatment cycles of either pill. Neither was a difference seen in the bioavailability of GEST and NET as evaluated by the ratios of two 24-h AUCs calculated in the control and charcoal cycles of each pill treatment (p = 0.29). The results suggest that enterohepatic circulation of GEST and NET is not of clinical importance. We conclude that women on oral contraceptives can take activated charcoal for the treatment of diarrhea when administered 3 h after and at least 12 h before pill intake.

  5. 一个新的吸收-喷射复合制冷循环%A NOVEL COMBINED EJECTOR-ABSORPTION REFRIGERATION CYCLE

    Institute of Scientific and Technical Information of China (English)

    洪大良; 唐黎明; 邹云霞; 何一坚; 陈光明

    2011-01-01

    提出了一个新的吸收-喷射复合制冷循环.在新循环中,部分冷凝器出口的饱和液态制冷剂被冷剂泵加压到制冷剂在发生温度下对应的饱和压力,这股高压制冷剂液体在一个沸腾器里被加热成饱和高压蒸气后将预热器出口的过热制冷剂蒸气引射到冷凝压力.由于在新循环中发生压力可以比冷凝压力低,因此该系统可以利用较低品位的热量制取低温下的冷量.研究结果表明:新循环可以利用比传统两级吸收式制冷循环温度更低的热源,制取同一温度下的冷量.此外,在蒸发温度或发生温度较低时,新循环的COP比单效循环高得多;当发生温度或蒸发温度较高时,新循环和传统单效循环的COP相同.%To make refrigeration at low temperature with low-grade heat source, a novel combined ejector-absorption refrigeration cycle was proposed in this paper. In the new cycle, part of saturated liquid refrigerant from the condenser was pumped to saturated pressure of the refrigerant at generation temperature. This stream was heated into saturated vapor in a boiler and injected the superheating refrigerant vapor from a preheater to condenser pressure. Since the generation pressure is lower than condenser pressure in the new cycle, the system can make refrigeration at low temperature with low-grade heat source. The research results show that the generation temperature of the new cycle is even lower than that of the conventional two-stage absorption refrigeration cycle to make refrigeration at the same low temperature. In addition, the COP of the new cycle is much higher than that of single-effect cycle at the low refrigeration temperature and generation temperature. If the refrigeration temperature or the temperature of heat source is high enough, the COP of the new cycle is the same as that of the conventional single-effect cycle.

  6. Life Cycle Assessment for environmentally sustainable aquaculture management : a case study of combined aquaculture systems for carp and tilapia

    OpenAIRE

    2013-01-01

    Life Cycle Assessment (LCA) was applied to evaluate the potential environmental impacts associated with two-net cage aquaculture systems of common carp (Cyprinus carpio carpio) and tilapia (Oreochromis niloticus) in the Cirata reservoir, Indonesia. The studied system included fingerling production in hatcheries, fish rearing in cages, and transport of fry and feed as well as that of harvested fish to markets. The environmental impact indicators were calculated based on the annual production i...

  7. Dual trigger with combination of gonadotropin-releasing hormone agonist and human chorionic gonadotropin significantly improves the live-birth rate for normal responders in GnRH-antagonist cycles.

    Science.gov (United States)

    Lin, Ming-Huei; Wu, Frank Shao-Ying; Lee, Robert Kuo-Kuang; Li, Sheng-Hsiang; Lin, Shyr-Yeu; Hwu, Yuh-Ming

    2013-11-01

    To investigate whether dual triggering of final oocyte maturation with a combination of gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG) can improve the live-birth rate for normal responders in GnRH-antagonist in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI) cycles. Retrospective cohort study. Infertility unit of a university-affiliated medical center. Normal responders to controlled ovarian hyperstimulation who were undergoing IVF-ICSI with a GnRH antagonist protocol. Standard dosage of hCG trigger (6,500 IU of recombinant hCG) versus dual trigger (0.2 mg of triptorelin and 6,500 IU of recombinant hCG). Live-birth, clinical pregnancy, and implantation rates per cycle. A total of 376 patients with 378 completed cycles with embryo transfer were enrolled (hCG trigger/control group: n = 187; dual trigger/study group: n = 191). The dual trigger group demonstrated statistically significantly higher implantation (29.6% vs. 18.4%), clinical pregnancy (50.7% vs. 40.1%), and live-birth (41.3% vs. 30.4%) rates as compared with the hCG trigger group. There was no statistically significant difference in terms of patient demographics, cycle parameters, or embryo quality. Dual trigger of final oocyte maturation with a GnRH-agonist and a standard dosage of hCG in normal responders statistically significantly improves implantation, clinical pregnancy, and live-birth rates in GnRH-antagonist IVF cycles. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  8. GASIS demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Vidas, E.H. [Energy and Environmental Analysis, Inc., Arlington, VA (United States)

    1995-04-01

    A prototype of the GASIS database and retrieval software has been developed and is the subject of this poster session and computer demonstration. The prototype consists of test or preliminary versions of the GASIS Reservoir Data System and Source Directory datasets and the software for query and retrieval. The prototype reservoir database covers the Rocky Mountain region and contains the full GASIS data matrix (all GASIS data elements) that will eventually be included on the CD-ROM. It is populated for development purposes primarily by the information included in the Rocky Mountain Gas Atlas. The software has been developed specifically for GASIS using Foxpro for Windows. The application is an executable file that does not require Foxpro to run. The reservoir database software includes query and retrieval, screen display, report generation, and data export functions. Basic queries by state, basin, or field name will be assisted by scrolling selection lists. A detailed query screen will allow record selection on the basis of any data field, such as depth, cumulative production, or geological age. Logical operators can be applied to any-numeric data element or combination of elements. Screen display includes a {open_quotes}browse{close_quotes} display with one record per row and a detailed single record display. Datasets can be exported in standard formats for manipulation with other software packages. The Source Directory software will allow record retrieval by database type or subject area.

  9. A preliminary investigation demonstrating the effect of quercetin on the expression of genes related to cell-cycle arrest, apoptosis and xenobiotic metabolism in human CO115 colon-adenocarcinoma cells using DNA microarray.

    Science.gov (United States)

    Murtaza, Imtiyaz; Marra, Giancarlo; Schlapbach, Ralph; Patrignani, Andrea; Künzli, Marzana; Wagner, Ulrich; Sabates, Jacob; Dutt, Amit

    2006-07-01

    The role of the natural dietary flavonoid chemical quercetin (an antioxidant) in the prevention and treatment of colon cancer is receiving a great deal of attention. However, little is known about the molecular mechanisms of action of this flavonoid. In the present study, whole genome DNA microarrays were used to evaluate the effect of quercetin on gene expression in the CO115 colon-adenocarcinoma cell line with the completely deleted chromosome 18 harbouring the SMAD4 tumour-suppressor gene related to colon carcinogenesis. The study demonstrated that quercetin, widely present in fruit and vegetables, inhibited the growth of CO115 cells at 100 microM concentration in both the G(1)/S and the G(2)/M phases by modulating cell-cycle and apoptosis-related genes. Differential changes in accumulation of transcripts analysed for cells treated with 100 microM quercetin for 24 and 48 h in three independent repeated experiments revealed 5060-7000 differentially expressed genes. This means that quercetin probably does have a broad modulatory effect on gene expression in colon cancer. Out of these differentially expressed genes, the expression of 35 and 23 unique set of genes involved in cell-cycle control, apoptosis and xenobiotic metabolism were significantly altered after 24 and 48 h quercetin treatment respectively. Our results represent a novel aspect of the biological profile of quercetin that induces cell-cycle arrest through modulation of cell-cycle-related and apoptosis genes. The present study demonstrates a new step in elucidating the underlying molecular mechanisms of the antitumour action of quercetin, which could become a chemopreventive or chemotherapeutic agent for colon cancer.

  10. Use of the available energy in the re-gasification process of liquefied natural gas by coupling combined heat and power cycles

    Energy Technology Data Exchange (ETDEWEB)

    Sgarbi, P.V.; Schmeda Lopez, D.R.; Indrusiak, M.L.S.; Schneider, P. Smith [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. of Mechanical Engineering], Emails: guetuso@gmail.com, diego.schmeda@ufrgs.br, sperbindrusiak@via-rs.net, pss@mecanica.ufrgs.br

    2009-07-01

    This work evaluates the possibilities of taking advantage of the heat transferred in the re-gasification process of liquid natural gas (LNG). It is proposed the coupling of a Brayton-Rankine combined heat and power plant (CHP) to a LNG re-gasification plant in order to use the heat involved in this process as cold source for the CHP plant. For comparison, the same CHP is simulated exchanging heat with a reference environment. An analysis is performed assuming that the amount of natural gas fed to the Brayton sub-cycle combustion chamber is equal for both cases. The CHP coupled to the re-gasification plant present a net power generation of 22.7 MW and the efficiency is 45.5%. It represents a gain of 2.98 MW in the power generation and 15% in the cycle efficiency, when compared to the reference cycle. The exergetic efficiency with this proposal is 49.3%, which is 9% higher than the reference cycle. (author)

  11. Polyimide-coated carbon electrodes combined with redox mediators for superior Li-O2 cells with excellent cycling performance and decreased overpotential

    Science.gov (United States)

    Yoon, Seon Hye; Park, Yong Joon

    2017-02-01

    We report an air electrode employing polyimide-coated carbon nanotubes (CNTs) combined with a redox mediator for Li-O2 cells with enhanced electrochemical performance. The polyimide coating on the carbon surface suppresses unwanted side reactions, which decreases the amount of accumulated reaction products on the surface of the air electrode during cycling. The redox mediators lower the overpotential of the Li-O2 cells because they can easily transfer electrons from the electrode to the reaction products. The low overpotential can also decrease the side reactions that activate at a high potential range. Specifically, the CsI redox mediator effectively interrupted dendrite growth on the Li anode during cycling due to the shielding effect of its Cs+ ions and acted as a redox mediator due to its I‑ ions. LiNO3 also facilitates the decrease in side reactions and the stabilization of the Li anode. The synergic effect of the polyimide coating and the electrolyte containing the LiNO3/CsI redox mediator leads to a low overpotential and excellent cycling performance (over 250 cycles with a capacity of 1,500 mAh·gelectrode‑1).

  12. Polyimide-coated carbon electrodes combined with redox mediators for superior Li-O2 cells with excellent cycling performance and decreased overpotential

    Science.gov (United States)

    Yoon, Seon Hye; Park, Yong Joon

    2017-01-01

    We report an air electrode employing polyimide-coated carbon nanotubes (CNTs) combined with a redox mediator for Li-O2 cells with enhanced electrochemical performance. The polyimide coating on the carbon surface suppresses unwanted side reactions, which decreases the amount of accumulated reaction products on the surface of the air electrode during cycling. The redox mediators lower the overpotential of the Li-O2 cells because they can easily transfer electrons from the electrode to the reaction products. The low overpotential can also decrease the side reactions that activate at a high potential range. Specifically, the CsI redox mediator effectively interrupted dendrite growth on the Li anode during cycling due to the shielding effect of its Cs+ ions and acted as a redox mediator due to its I− ions. LiNO3 also facilitates the decrease in side reactions and the stabilization of the Li anode. The synergic effect of the polyimide coating and the electrolyte containing the LiNO3/CsI redox mediator leads to a low overpotential and excellent cycling performance (over 250 cycles with a capacity of 1,500 mAh·gelectrode−1). PMID:28198419

  13. Life cycle tools combined with multi-criteria and participatory methods for agricultural sustainability: Insights from a systematic and critical review.

    Science.gov (United States)

    De Luca, Anna Irene; Iofrida, Nathalie; Leskinen, Pekka; Stillitano, Teodora; Falcone, Giacomo; Strano, Alfio; Gulisano, Giovanni

    2017-10-01

    Life cycle (LC) methodologies have attracted a great interest in agricultural sustainability assessments, even if, at the same time, they have sometimes been criticized for making unrealistic assumptions and subjective choices. To cope with these weaknesses, Multi-Criteria Decision Analysis (MCDA) and/or participatory methods can be used to balance and integrate different sustainability dimensions. The purpose of this study is to highlight how life cycle approaches were combined with MCDA and participatory methods to address agricultural sustainability in the published scientific literature. A systematic and critical review was developed, highlighting the following features: which multi-criterial and/or participatory methods have been associated with LC tools; how they have been integrated or complemented (methodological relationships); the intensity of the involvement of stakeholders (degree of participation); and which synergies have been achieved by combining the methods. The main typology of integration was represented by multi-criterial frameworks integrating LC evaluations. LC tools can provide MCDA studies with local and global information on how to reduce negative impacts and avoid burden shifts, while MCDA methods can help LC practitioners deal with subjective assumptions in an objective way, to take into consideration actors' values and to overcome trade-offs among the different dimensions of sustainability. Considerations concerning the further development of Life Cycle Sustainability Assessment (LCSA) have been identified as well. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Deuterium retention in tungsten under combined high cycle ELM-like heat loads and steady-state plasma exposure

    Directory of Open Access Journals (Sweden)

    A. Huber

    2016-12-01

    Enhanced blister formation has been observed under combined loading conditions at power densities close to the threshold for damaging. It is shown that blisters are not mainly responsible for the pronounced increase of the D retention.

  15. Strandby Harbour on solar cooling. Demonstration of 8.000 m{sup 2} solar collectors combined with flue gas cooling with a absorption cooling system; Combined heat and power plant (CHP); Strandby havn paa solkoeling. Demonstration af 8.000 m{sup 2} solfangere kombineret med roeggaskoeling med absorptionskoeleanlaeg

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Flemming (Strandby Varmevaerk, Strandby (Denmark)); Soerensen, Per Alex (PlanEnergi, Skoerping (Denmark)); Ulbjerg, F. (Ramboell, Odense (Denmark)); Sloth, H. (Houe and Olsen, Thisted (Denmark))

    2010-04-15

    The aim of the project was to demonstrate 1) high solar heating ratio (18% annually) at a decentralized natural gas combined heat and power plant; 2) increased efficiency (5% of the heat consumption) in a natural gas CHP by using an extra flue gas cooler and an absorption heat pump; 3) a double tank system where a new tank during winter is used for cooling/ heat storage for the absorption heat pump and during summer for solar heat storage in serial operation with the old tank. The concept of combining solar power, absorption cooling and natural gas-fired small-scale CHP in Strandby met expectations and could be replicated in other CHP plants. However, it is important to note that if major construction modifications in the flue gas condensation system in the boiler or engine are required, the operating hours must not be reduced significantly in the amortisation period for the conversion. (ln)

  16. Combined inhibition of glycolysis, the pentose cycle, and thioredoxin metabolism selectively increases cytotoxicity and oxidative stress in human breast and prostate cancer

    Directory of Open Access Journals (Sweden)

    Ling Li

    2015-04-01

    Full Text Available Inhibition of glycolysis using 2-deoxy-d-glucose (2DG, 20 mM, 24–48 h combined with inhibition of the pentose cycle using dehydroepiandrosterone (DHEA, 300 µM, 24–48 h increased clonogenic cell killing in both human prostate (PC-3 and DU145 and human breast (MDA-MB231 cancer cells via a mechanism involving thiol-mediated oxidative stress. Surprisingly, when 2DG+DHEA treatment was combined with an inhibitor of glutathione (GSH synthesis (l-buthionine sulfoximine; BSO, 1 mM that depleted GSH>90% of control, no further increase in cell killing was observed during 48 h exposures. In contrast, when an inhibitor of thioredoxin reductase (TrxR activity (Auranofin; Au, 1 µM, was combined with 2DG+DHEA or DHEA-alone for 24 h, clonogenic cell killing was significantly increased in all three human cancer cell lines. Furthermore, enhanced clonogenic cell killing seen with the combination of DHEA+Au was nearly completely inhibited using the thiol antioxidant, N-acetylcysteine (NAC, 20 mM. Redox Western blot analysis of PC-3 cells also supported the conclusion that thioredoxin-1 (Trx-1 oxidation was enhanced by treatment DHEA+Au and inhibited by NAC. Importantly, normal human mammary epithelial cells (HMEC were not as sensitive to 2DG, DHEA, and Au combinations as their cancer cell counterparts (MDA-MB-231. Overall, these results support the hypothesis that inhibition of glycolysis and pentose cycle activity, combined with inhibition of Trx metabolism, may provide a promising strategy for selectively sensitizing human cancer cells to oxidative stress-induced cell killing.

  17. Simulation of a new combined absorption-compression refrigeration cycle%一种新型吸收-压缩复合制冷循环模拟

    Institute of Scientific and Technical Information of China (English)

    唐鹏武; 陈光明; 唐黎明; 刘利华

    2011-01-01

    A program compiled by Visual Basic language was used to simulate a new combined absorption-compression refrigeration cycle for performance research, including the effect of generation temperature , evaporation temperature, condensation temperature, heat flux and refrigeration capacity on system performance which was compared with a conventional vapour compression refrigeration cycle. Simulation results show that when generation temperature increases, the coefficient of performance ( COP) of new cycle increases first and then decreases. When evaporation temperature or heat flux increases, the COP of new cycle increases. When condensation temperature or refrigeration capacity increases, the COP of new cycle decreases. Under most simulation conditions, the COP of new cycle can be 10% higher than that of conventional vapour compression refrigeration cycle. The new cycle can not only reduce air conditioning load greatly, but also provide the possibility of efficient utilization of low grade energy such as solar energy.%为了对一种新型吸收-压缩复合制冷循环的性能进行模拟,使用Visual Basic语言自行编制了一个程序.该程序模拟了发生温度、蒸发温度、冷凝温度、加热量、制冷量对系统性能的影响,并将其性能与传统蒸气压缩式制冷循环作了对比.模拟结果表明:当发生温度升高时,新循环的制冷系数先增大后减小;当蒸发温度升高或加热量增大时,新循环的制冷系数增大;当冷凝温度升高或制冷量增大时,新循环的制冷系数减小.在大部分假定工况下,新循环的制冷系数比传统蒸气压缩式循环的高10%以上.新循环的提出不仅能够大幅度减少空调电力负荷,还为太阳能等低品位能源的高效利用提供了可能.

  18. Thermodynamics of the CO2–Absorption/Desorption Section in the Integrated Gasifying Combined cycle — II. Analysis

    Directory of Open Access Journals (Sweden)

    Jaroslav KOZACZKA

    2012-06-01

    Full Text Available The thermodynamic analysis of the absorption/desorption section of the ICGC–cycle has been presented using the Second Law with special emphasis on the thermodynamic effectivity concept and usability for complex systems investigations. Essential problems have been discussed based on the classical bibliographical items on the subject. Numerical calculations have been accomplished using results obtained in the first part, which contained absorption and desorption modeling approach oriented onto thermodynamic analyzes. Additionally the special properties of dilute solutions, especially the CO2/water system, have been presented and the problem of the solute chemical concentration exergy change suggested.

  19. The Relationships of the Maxillary Sinus With the Superior Alveolar Nerves and Vessels as Demonstrated by Cone-Beam CT Combined With μ-CT and Histological Analyses.

    Science.gov (United States)

    Kasahara, Norio; Morita, Wataru; Tanaka, Ray; Hayashi, Takafumi; Kenmotsu, Shinichi; Ohshima, Hayato

    2016-05-01

    There are no available detailed data on the three-dimensional courses of the human superior alveolar nerves and vessels. This study aimed to clarify the relationships of the maxillary sinus with the superior alveolar nerves and vessels using cone-beam computed tomography (CT) combined with μ-CT and histological analyses. Digital imaging and communication in medicine data obtained from the scanned heads/maxillae of cadavers used for undergraduate/postgraduate dissection practice and skulls using cone-beam CT were reconstructed into three-dimensional (3D) images using software. The 3D images were compared with μ-CT images and histological sections. Cone-beam CT clarified the relationships of the maxillary sinus with the superior alveolar canals/grooves. The main anterior superior alveolar canal/groove ran anteriorly through the upper part of the sinus and terminated at the bottom of the nasal cavity near the piriform aperture. The main middle alveolar canal ran downward from the upper part of the sinus to ultimately join the anterior one. The main posterior alveolar canal ran through the lateral lower part of the sinus and communicated with the anterior one. Histological analyses demonstrated the existence of nerves and vessels in these canals/grooves, and the quantities of these structures varied across each canal/groove. Furthermore, the superior dental nerve plexus exhibited a network that was located horizontally to the occlusal plane, although these nerve plexuses appeared to be the vertical network that is described in most textbooks. In conclusion, cone-beam CT is suggested to be a useful method for clarifying the superior alveolar canals/grooves including the nerves and vessels.

  20. Proof-of-concept demonstration of free-form optics enhanced confocal Raman spectroscopy in combination with optofluidic lab-on-chip

    Science.gov (United States)

    Liu, Qing; De Coster, Diane; Loterie, Damien; Van Erps, Jürgen; Vervaeke, Michael; Missinne, Jeroen; Thienpont, Hugo; Ottevaere, Heidi

    2016-07-01

    Raman spectroscopy is a powerful optical and non-destructive technique and a well-known method for analysis purposes, especially to determine the molecular fingerprint of substances. Traditionally, such analyses are done in a specialized lab, with considerable requirements in terms of equipment, time and manual sampling of substances of interest. In this paper we take a step from bulky Raman spectroscopy laboratory analyses towards lab-on-chip (LOC) analyses. We present an optofluidic lab-on-chip for confocal Raman spectroscopy, which can be used for the analysis of liquids. The confocal detection suppresses the unwanted background from the polymer material out of which the chip is fabricated. We design the free-form optical reflector using non-sequential ray-tracing combined with a mathematical code to simulate the Raman scattering behavior of the substance under test. We prototype the device in Polymethyl methacrylate (PMMA) by means of ultraprecision diamond tooling. In a proof-of-concept demonstration, we first show the confocal behavior of our Raman lab-on-chip system by measuring the Raman spectrum of ethanol. In a next step, we compare the Raman spectra measured in our lab-on-chip with spectra measured with a commercial Raman spectrometer. Finally, to calibrate the system we perform Raman measurements on urea solutions with different concentrations. We achieve a detection limit that corresponds to a noise equivalent concentration of 20mM. Apart from strongly reducing the background perturbations, our confocal Raman spectroscopy system has other advantages as well. The reflector design is robust from a mechanical point of view and has the potential for mass-manufacturing using hot embossing or injection molding.

  1. Responses of bacterial community and functional marker genes of nitrogen cycling to biochar, compost and combined amendments in soil.

    Science.gov (United States)

    Wu, Haipeng; Zeng, Guangming; Liang, Jie; Chen, Jin; Xu, Jijun; Dai, Juan; Li, Xiaodong; Chen, Ming; Xu, Piao; Zhou, Yaoyu; Li, Fei; Hu, Liang; Wan, Jia

    2016-10-01

    Biochar and compost are seen as two attractive waste management options and are used for soil amendment and pollution remediation. The interaction between biochar and composting may improve the potential benefits of biochar and compost. We investigated soil physicochemical properties, bacterial community, bacterial 16S rRNA, and functional marker genes of nitrogen cycling of the soil remedied with nothing (S), compost (SC), biochar (SB), a mixture of compost and biochar (SBC), composted biochar (SBced), and a composted mixture of biochar and biomass (SBCing). The results were that all amendments (1) increased the bacterial community richness (except SB) and SBCing showed the greatest efficiency; (2) increased the bacterial community diversity (SBCing > SBC > SC > SBced > SB > S); and (3) changed the gene copy numbers of 16S rRNA, nirK, nirS, and nosZ genes of bacteria, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB). All amendments (except SB) could increase the gene copy number of 16S rRNA, and SBCing had the greatest efficiency. The changes of soil bacterial community richness and diversity and the gene copy numbers of 16S rRNA, nirK, nirS, nosZ, AOA, and AOB would affect carbon and nitrogen cycling of the ecosystem and also implied that BCing had the greatest efficiency on soil amendment.

  2. Is there an environmental benefit from remediation of a contaminated site? Combined assessments of the risk reduction and life cycle impact of remediation.

    Science.gov (United States)

    Lemming, Gitte; Chambon, Julie C; Binning, Philip J; Bjerg, Poul L

    2012-12-15

    A comparative life cycle assessment is presented for four different management options for a trichloroethene-contaminated site with a contaminant source zone located in a fractured clay till. The compared options are (i) long-term monitoring (ii) in-situ enhanced reductive dechlorination (ERD), (iii) in-situ chemical oxidation (ISCO) with permanganate and (iv) long-term monitoring combined with treatment by activated carbon at the nearby waterworks. The life cycle assessment included evaluation of both primary and secondary environmental impacts. The primary impacts are the local human toxic impacts due to contaminant leaching into groundwater that is used for drinking water, whereas the secondary environmental impacts are related to remediation activities such as monitoring, drilling and construction of wells and use of remedial amendments. The primary impacts for the compared scenarios were determined by a numerical risk assessment and remedial performance model, which predicted the contaminant mass discharge over time at a point of compliance in the aquifer and at the waterworks. The combined assessment of risk reduction and life cycle impacts showed that all management options result in higher environmental impacts than they remediate, in terms of person equivalents and assuming equal weighting of all impacts. The ERD and long-term monitoring were the scenarios with the lowest secondary life cycle impacts and are therefore the preferred alternatives. However, if activated carbon treatment at the waterworks is required in the long-term monitoring scenario, then it becomes unfavorable because of large secondary impacts. ERD is favorable due to its low secondary impacts, but only if leaching of vinyl chloride to the groundwater aquifer can be avoided. Remediation with ISCO caused the highest secondary impacts and cannot be recommended for the site. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. An investigation and characterization on alginate hydogel dressing loaded with metronidazole prepared by combined inotropic gelation and freeze-thawing cycles for controlled release.

    Science.gov (United States)

    Sarheed, Omar; Rasool, Bazigha K Abdul; Abu-Gharbieh, Eman; Aziz, Uday Sajad

    2015-06-01

    The purpose of this study was to investigate the effect of combined Ca(2+) cross-linking and freeze-thawing cycle method on metronidazole (model drug) drug release and prepare a wound film dressing with improved swelling property. The hydrogel films were prepared with sodium alginate (SA) using the freeze-thawing method alone or in combination with ionotropic gelation with CaCl2. The gel properties such as morphology, swelling, film thickness, and content uniformity and in vitro dissolution profiles using Franz diffusion cell were investigated. The cross-linking process was confirmed by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. In vitro protein adsorption test, in vivo wound-healing test, and histopathology were also performed. The hydrogel (F2) composed of 6% sodium alginate and 1% metronidazole prepared by combined Ca(2+) cross-linking and freeze-thawing cycles showed good swelling. This will help to provide moist environment at the wound site. With the in vivo wound-healing and histological studies, F2 was found to improve the wound-healing effect compared with the hydrogel without the drug, and the conventional product.

  4. Thermal analysis of the heat recuperator of a combined cycle thermoelectric central; Analisis termico del recuperador de calor de una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, Hernando; Sanchez, I.; Lazcano, L. C.; Ambriz, Juan Jose; Alvarez, M. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico); Gonzalez, O. [Comision Federal de Electricidad, Tula (Mexico)

    1996-12-31

    The thermoelectric centrals of the combined cycle type (Brayton Cycle and Rankine Cycle) present a series of opportunities to increase the efficiency of the combined cycle or of the generated power. This paper shows the methodology for the performance of energy balances in a heat recuperator (H. R.), typically employed in the combined cycle stations operating in Mexico, for the assessment of the energy harnessing in the different sections conforming a H. R. The effect of the installation of evaporative coolers and/or an absorption cooling system at the gas turbine compressor intake on the steam generation in the heat recuperator, is evaluated. This extra generation of steam is quantified for its potential use in the same absorption refrigeration system. From the assessment, it follows up that the steam generation in the H.R. is inversely proportional to the ambient temperature and that, although the increased amount of steam generated can not be harnessed in total by the steam turbine, the remaining fraction is good enough to cover the heat demand for the operation of the refrigeration system. [Espanol] Las centrales termoelectricas del tipo ciclo combinado (ciclo Brayton y ciclo Rankine) presentan un conjunto de oportunidades para incrementar la eficiencia del ciclo combinado o bien la potencia generada. En el presente trabajo se expone la metodologia para realizar los balances de energia en un recuperador de calor (R.C.) tipicamente utilizado en las Centrales de Ciclo Combinado (CCC) que operan en Mexico, para evaluar el aprovechamiento de la energia en las diferentes secciones que conforman un R.C. Se evalua el efecto que tiene la instalacion de enfriadores evaporativos y/o un sistema de enfriamiento por absorcion en la succion del compresor de la turbina de gas sobre la generacion de vapor en el recuperador de calor. Se cuantifica esta generacion extra de vapor para su posible utilizacion en el mismo sistema de refrigeracion por absorcion. De la evaluacion se

  5. Optimization Study for Integrated Solar Combined Cycle System%太阳能燃气联合循环系统集成优化研究

    Institute of Scientific and Technical Information of China (English)

    李元媛; 袁晶; 杨勇平

    2014-01-01

    Integrated Solar Combined Cycle System,which integrates parabolic trough solar technology with combined cycle power plant,is an efficient way to make full use of solar energy,improve system thermal efficiency,save the fossil fuels and reduce CO2 emission.Based on an Integrated Solar Combined Cycle consisting of a Direct Steam Generation parabolic trough field,this paper analyzes how and where solar energy is input into ISCC system would have impact on the solar and system overall efficiencies.A preliminary economic assessment is also carried out,showing that the optimal system performance can be achieved when the solar heat input is 75% of the total latent heat required for water evaporation.%太阳能燃气联合循环系统(ISCC)将槽式太阳能与燃气轮机联合循环相结合,充分利用太阳能作为中低温加热热源,是提高太阳能发电效率,降低太阳能发电成本,并减少系统CO2排放的有效途径.本文针对太阳能直接蒸汽发生系统(DSG)与燃气轮机联合循环(CCGT)集成的系统,研究了太阳能蒸发给水份额对系统性能的影响,寻求最佳的系统集成模式,并对其经济性能做了初步的探讨.结果表明,太阳能蒸发给水份额为75%时,系统性能最优.

  6. The graded cycling test combined with the talk test is reliable for patients with ischemic heart disease

    DEFF Research Database (Denmark)

    Nielsen, Susanne Grøn; Buus, Lise; Hage, Tine

    2014-01-01

    PURPOSE: To assess relative reliability and measurement error of the Graded Cycling Test (GCT) with the Talk Test (TT) for patients with cardiac disease. METHODS: Patients (N = 64; women, n = 30) with ischemic heart disease performed the GCT with the TT twice in 1 day. Every minute the patient...... with cardiac disease in clinical settings with small measurement error and an excellent relative reliability. These results apply to both patient-rated and PT-rated TT.......)2.1 and absolute reliability: standard error of measurement with 95% CI (SEM95) and smallest real difference (SRD) were calculated. RESULTS: Intraclass correlation coefficient values of 0.90, 0.91, and 0.90 were observed for TT+, TT±, and TT-, respectively. Physiotherapist ICCs ranged between 0...

  7. Dynamic performance of a combined gas turbine and air bottoming cycle plant for off-shore applications

    DEFF Research Database (Denmark)

    Benato, Alberto; Pierobon, Leonardo; Haglind, Fredrik;

    2014-01-01

    and the air bottoming cycle turbogenerator includes dynamic equations for the combustion chamber, the shell-and-tube recuperator and the turbine shafts. Turbines are modelled by the Stodola equation and by a correlation between the isentropic efficiency and the non-dimensional flow coefficient. Compressors...... are modelled using quasi steady-state conditions by scaling the maps of axial compressors employing a similar design point. The recuperator, which recovers the exhaust heat from the gas turbine, is modelled using correlations relating the heat transfer coefficient and the pressure drop at part......, findings suggest that decreasing the core weight of the recuperator leads to limiting the frequency fluctuations, thus minimizing the risk of failure of the power system....

  8. Interplanetary Coronal Mass Ejections Resulting from Earth-Directed CMEs Using SOHO and ACE Combined Data During Solar Cycle 23

    Science.gov (United States)

    Paouris, Evangelos; Mavromichalaki, Helen

    2017-02-01

    In this work a total of 266 interplanetary coronal mass ejections observed by the Solar and Heliospheric Observatory/ Large Angle and Spectrometric Coronagraph (SOHO/LASCO) and then studied by in situ observations from Advanced Composition Explorer (ACE) spacecraft, are presented in a new catalog for the time interval 1996 - 2009 covering Solar Cycle 23. Specifically, we determine the characteristics of the CME which is responsible for the upcoming ICME and the associated solar flare, the initial/background solar wind plasma and magnetic field conditions before the arrival of the CME, the conditions in the sheath of the ICME, the main part of the ICME, the geomagnetic conditions of the ICME's impact at Earth and finally we remark on the visual examination for each event. Interesting results revealed from this study include the high correlation coefficient values of the magnetic field Bz component against the Ap index (r = 0.84), as well as against the Dst index (r = 0.80) and of the effective acceleration against the CME linear speed (r = 0.98). We also identify a north-south asymmetry for X-class solar flares and an east-west asymmetry for CMEs associated with strong solar flares (magnitude ≥ M1.0) which finally triggered intense geomagnetic storms (with Ap ≥179). The majority of the geomagnetic storms are determined to be due to the ICME main part and not to the extreme conditions which dominate inside the sheath. For the intense geomagnetic storms the maximum value of the Ap index is observed almost 4 hours before the minimum Dst index. The amount of information makes this new catalog the most comprehensive ICME catalog for Solar Cycle 23.

  9. Tested Demonstrations.

    Science.gov (United States)

    Sands, Robert; And Others

    1982-01-01

    Procedures for two demonstrations are provided. The solubility of ammonia gas in water is demonstrated by introducing water into a closed can filled with the gas, collapsing the can. The second demonstration relates scale of standard reduction potentials to observed behavior of metals in reactions with hydrogen to produce hydrogen gas. (Author/JN)

  10. Short-term carbon and nitrogen cycling in urine patches assessed by combined carbon-13 and nitrogen-15 labelling

    DEFF Research Database (Denmark)

    Ambus, Per; Petersen, S.O.; Soussana, J.F.

    2007-01-01

    Urine deposition by grazing animals is known to, induce large NO emissions as a result of increased nitrification and denitrification in the soil. This is brought about by the increased N availability from the urine, in combination very likely also with increased organic C availability. Possible...... sources for C include the urine itself, increased solubility of soil C, lysis of microbial cells and leakage of C from scorched roots. The objective of this experiment was to test the hypothesis that: (i) urine deposition causes an increase in root-derived degradable C compounds in the soil, which (ii......) fuel denitrification activity and N2O production. The study took advantage of carbon-13 pulse labelling the plant tissue combined with application of nitrogen-15 labelled synthetic urine as an attempt to identify the sources of N2O. Over a 6 weeks course, the CO2 evolved in response to urine...

  11. Recovery of flue gas energy in heat-integrated gasification combined cycle (IGCC) power plants using the contact economizer system

    CSIR Research Space (South Africa)

    Madzivhandila, VA

    2011-03-01

    Full Text Available temperature. Recovery of the flue gas heat to preheat the boiler feedwater was demonstrated to be capable of further increasing the thermal efficiency of the plant. The methodology developed is divided into two parts, i.e., determining the maximum boiler...

  12. Combined heart rate variability and dynamic measures for quantitatively characterizing the cardiac stress status during cycling exercise.

    Science.gov (United States)

    Chen, Szi-Wen; Liaw, Jiunn-Woei; Chang, Ya-Ju; Chuang, Li-Ling; Chien, Chun-Tse

    2015-08-01

    In this study, we aimed to seek for different ways of measuring cardiac stress in terms of heart rate variability (HRV) and heart rate (HR) dynamics, and to develop a novel index that can effectively summarize the information reflected by these measures to continuously and quantitatively characterize the cardiac stress status during physical exercise. Standard deviation, spectral measure of HRV as well as a nonlinear detrended fluctuation analysis (DFA) based fractal-like behavior measure of HR dynamics were all evaluated on the RR time series derived from windowed electrocardiogram (ECG) data for the subjects undergoing cycling exercise. We recruited eleven young healthy subjects in our tests. Each subject was asked to maintain a fixed speed under a constant load during the pedaling test. We obtained the running estimates of the standard deviation of the normal-to-normal interval (SDNN), the high-fidelity power spectral density (PSD) of HRV, and the DFA scaling exponent α, respectively. A trend analysis and a multivariate linear regression analysis of these measures were then performed. Numerical experimental results produced by our analyses showed that a decrease in both SDNN and α was seen during the cycling exercise, while there was no significant correlation between the standard lower frequency to higher frequency (LF-to-HF) spectral power ratio of HRV and the exercise intensity. In addition, while the SDNN and α were both negatively correlated with the Borg rating of perceived exertion (RPE) scale value, it seemed that the LF-to-HF power ratio might not have substantial impact on the Borg value, suggesting that the SDNN and α may be further used as features to detect the cardiac stress status during the physical exercise. We further approached this detection problem by applying a linear discriminant analysis (LDA) to both feature candidates for the task of cardiac stress stratification. As a result, a time-varying parameter, referred to as the cardiac

  13. An Innovative Application of a Solar Storage Wall Combined with the Low-Temperature Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Tzu-Chen Hung

    2014-01-01

    Full Text Available The objective of this study is to collect energy on the waste heat from air produced by solar ventilation systems. This heat used for electricity generation by an organic Rankine cycle (ORC system was implemented. The advantages of this method include the use of existing building’s wall, and it also provides the region of energy scarcity for reference. This is also an innovative method, and the results will contribute to the efforts made toward improving the design of solar ventilation in the field of solar thermal engineering. In addition, ORC system would help generate electricity and build a low-carbon building. This study considered several critical parameters such as length of the airflow channel, intensity of solar radiation, pattern of the absorber plate, stagnant air layer, and operating conditions. The simulation results show that the highest outlet temperature and heat collecting efficiency of solar ventilation system are about 120°C and 60%, respectively. The measured ORC efficiency of the system was 6.2%. The proposed method is feasible for the waste heat from air produced by ventilation systems.

  14. An object-oriented computational model for combined cycle cogeneration analysis; Um modelo computacional para analise de ciclos combinados para projetos de sistemas de cogeracao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandre M. da; Balestieri, Jose A.P.; Magalhaes Filho, Paulo [UNESP, Guaratingueta, SP (Brazil). Escola de Engenharia. Dept. de Energia]. E-mails: amarcial@uol.com.br; perella@feg.unesp.br; pfilho@feg.unesp.br

    2000-07-01

    This paper presents the use of computational resources in a simulation procedure to predict the performance of combined cycle cogeneration systems in which energetic analysis is used in the modeling. Thermal demand of a consuming process are used as the main entrance data and, associated to the performance characteristics of each component of the system, it is evaluated the influence of some parameters of the system such as thermal efficiency and global efficiency. The computational language is Visual Basic for Applications associated to an electronic sheet. Two combined cycle cogeneration schemes are pre-defined: one is composed of a gas turbine, heat recovery steam generator and a back pressure steam turbine with one extraction, in which both are connected to the different pressure level process plant; the other scheme has a difference a two extraction-condensing steam turbine instead of the back pressure one. Some illustrative graphics are generated for allowing comparison of the appraised systems. The strategy of the system simulation is obtained by carefully linking the information of various components according to the flow diagrams. (author)

  15. Development and application of performance and cost models for the externally-fired combined cycle. Task 1, Volume 2. Topical report, June 1995

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, P.; Frey, H. [North Carolina State Univ., Raleigh, NC (United States); Rubin, E.S. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1995-07-01

    Increasing restrictions on emission of pollutants from conventional pulverized coal fired steam (PCFS) plant generating electrical power is raising capital and operating cost of these plants and at the same time lowering plant efficiency. This is creating a need for alternative technologies which result in lower emissions of regulated pollutants and which are thermally more efficient. Natural gas-fired combined cycle power generation systems have lower capital cost and higher efficiencies than conventional coal fired steam plants, and at this time they are the leading contender for new power plant construction in the U.S. But the intermediate and long term cost of these fuels is high and there is uncertainty regarding their long-term price and availability. Coal is a relatively low cost fuel which will be abundantly available in the long term. This has motivated the development of advanced technologies for power production from coal which will have advantages of other fuels. The Externally Fired Combined Cycle (EFCC) is one such technology. Air pollution control/hot gas cleanup issues associated with this technology are described.

  16. Effect of thermal barrier coatings on the performance of steam and water-cooled gas turbine/steam turbine combined cycle system

    Science.gov (United States)

    Nainiger, J. J.

    1978-01-01

    An analytical study was made of the performance of air, steam, and water-cooled gas-turbine/steam turbine combined-cycle systems with and without thermal-barrier coatings. For steam cooling, thermal barrier coatings permit an increase in the turbine inlet temperature from 1205 C (2200 F), resulting in an efficiency improvement of 1.9 percentage points. The maximum specific power improvement with thermal barriers is 32.4 percent, when the turbine inlet temperature is increased from 1425 C (2600 F) to 1675 C (3050 F) and the airfoil temperature is kept the same. For water cooling, the maximum efficiency improvement is 2.2 percentage points at a turbine inlet temperature of 1683 C (3062 F) and the maximum specific power improvement is 36.6 percent by increasing the turbine inlet temperature from 1425 C (2600 F) to 1730 C (3150 F) and keeping the airfoil temperatures the same. These improvements are greater than that obtained with combined cycles using air cooling at a turbine inlet temperature of 1205 C (2200 F). The large temperature differences across the thermal barriers at these high temperatures, however, indicate that thermal stresses may present obstacles to the use of coatings at high turbine inlet temperatures.

  17. Alternative analysis to increase the power in combined-cycle power plants; Analisis de alternativas para el incremento de potencia en plantas termoelectricas de Ciclo Combinado

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Cruz, Hector; Arriola Medellin, Alejandro M. [Gerencia de Procesos Termicos, Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: hpacheco@iie.org.mx; aarriola@iie.org.mx

    2010-11-15

    The electricity industry traditionally had two thermodynamic cycles for power generation: conventional steam turbine (Rankine cycle) used to supply a base load during the day, and gas turbines (Brayton cycle), for its speed response, normally used to cover peak loads. However, to provide variable peak loads, the gas turbine, as a volumetric machine is affected by the change in air density by changing the combustion temperature. This paper shows the scheme of integration of both systems, that it's known as combined cycle and the different options that would have these power plants, to maintain or increase their power in variable ambient conditions. It analyzes different options, such as: 1. Supplementary fire in the stove. 2. Air cooling intake in the gas turbine (evaporation system or mechanical system). 3. Steam injection in the combustion chamber. [Spanish] La industria electrica tradicionalmente a contado con dos ciclos termodinamicos para generacion electrica: las turbinas convencionales de vapor (ciclo de Rankine) se utilizan para suministrar una carga base durante el dia, y las turbinas de gas (ciclo de Brayton), por su rapidez de respuesta, se utilizan normalmente para cubrir las cargas pico. Sin embargo, para suministrar las cargas variables pico, la turbina a gas, por ser una maquina volumetrica, se ve afectada por el cambio de la densidad del aire de combustion al cambiar la temperatura ambiente. En este trabajo se muestra el esquema de integracion de ambos sistemas, en lo que se conoce como ciclo combinado y las diferentes opciones que tendrian estas plantas de generacion electrica para mantener o incrementar su potencia en condiciones ambiente variable. Para ello se analizan diferentes opciones, tales como: 1.- Combustion suplementaria en el recuperador de calor. 2.- Enfriamiento del aire de admision a la turbina de gas (mediante un sistema de evaporacion o mediante un sistema mecanico). 3.- Inyeccion de vapor a la camara de combustion. Palabras

  18. Reynolds-averaged Navier-Stokes analysis of the flow through a model rocket-based combined-cycle engine with an independently-fueled ramjet stream

    Science.gov (United States)

    Bond, Ryan Bomar

    A new concept for the low speed propulsion mode in rocket based combined cycle (RBCC) engines has been developed as part of the NASA GTX program. This concept, called the independent ramjet stream (IRS) cycle, is a variation of the traditional ejector ramjet (ER) design and involves the injection of hydrogen fuel directly into the air stream, where it is ignited by the rocket plume. Experiments and computational fluid dynamics (CFD) are currently being used to evaluate the feasibility of the new design. In this work, a Navier-Stokes code valid for general reactive flows is applied to the model engine under cold flow, ejector ramjet, and IRS cycle operation. Pressure distributions corresponding to cold-flow and ejector ramjet operation are compared with experimental data. The engine response under independent ramjet stream cycle operation is examined for different reaction models and grid sizes. The engine response to variations in fuel injection is also examined. Mode transition simulations are also analyzed both with and without a nitrogen purge of the rocket. The solutions exhibit a high sensitivity to both grid resolution and reaction mechanism, but they do indicate that thermal throat ramjet operation is possible through the injection and burning of additional fuel into the air stream. The solutions also indicate that variations in fuel injection location can affect the position of the thermal throat. The numerical simulations predicted successful mode transition both with and without a nitrogen purge of the rocket; however, the reliability of the mode transition results cannot be established without experimental data to validate the reaction mechanism.

  19. EXPLOIT STUDY OF NUCLEAR COMBINE CYCLE SYSTEM WITH TOPPING BRAYTON CYCLE%顶置燃气轮机核能联合循环系统开拓研究

    Institute of Scientific and Technical Information of China (English)

    林汝谋; 高林; 段立强

    2001-01-01

    本文探索研究核电站更新改造新技术。基于系统综合和能的梯级利用的思路,设计构筑压水堆核电站与燃气轮机相结合的核能联合循环系统流程超结构,通过对其综合优化,提出两种可供选用的顶置燃气轮机核能联合循环总体技术方案,还结合实例进行模拟分析,揭示了它们的热力学特性,从而提出核电站联合循环技术更新改造(NRCC-Repowering)的新途径与新方案及其设计分析方法。%Nuclear combine cycle systems with topping Braytoncycle for existing nuclear power stations have been exploited inthis paper. Based on the principle of energy cascadesutilization and system synthesis, the system flow superstructureof the combine cycle has been schemed out and have been syntheticallyoptimized, then two kind of system schemes havebeen put forward. At the same time, by setting up mathematicalmodel with four independent variables for this system, we have pointedout the relationship between system performanceand independent variables. These promising results obtained herewill be valuable for NRCC-Repowering of existing nuclear power stations.

  20. A 6-Month, Double-Blind, Maintenance Trial of Lithium Monotherapy Versus the Combination of Lithium and Divalproex for Rapid-Cycling Bipolar Disorder and Co-Occurring Substance Abuse or Dependence

    Science.gov (United States)

    Kemp, David E.; Gao, Keming; Ganocy, Stephen J.; Rapport, Daniel J.; Elhaj, Omar; Bilali, Sarah; Conroy, Carla; Findling, Robert L.; Calabrese, Joseph R.

    2011-01-01

    Objective To assess whether combination treatment with lithium and divalproex is more effective than lithium monotherapy in prolonging the time to mood episode recurrence in patients with rapid-cycling bipolar disorder (RCBD) and comorbid substance abuse and/or dependence. Method A 6-month, double-blind, parallel group comparison was carried out in recently manic/hypomanic/mixed patients who had demonstrated a persistent bimodal response to combined treatment with lithium and divalproex. Subjects were randomly assigned to remain on combination treatment or to discontinue divalproex and remain on lithium monotherapy. Results Of 149 patients enrolled into the open-label acute stabilization phase, 79% discontinued prematurely (poor adherence: 42%; nonresponse: 25%; intolerable side effects: 10%). Of 31 patients (21%) randomly assigned to double-blind maintenance treatment, 55% relapsed (24% into depression and 76% into a manic/hypomanic/mixed episode), 26% completed the study, and 19% were poorly adherent or exited prematurely. The median time to recurrence of a new mood episode was 15.9 weeks for patients receiving lithium monotherapy and 17.8 weeks for patients receiving the combination of lithium and divalproex (p=NS). The rate of relapse into a mood episode for those receiving lithium monotherapy or the combination of lithium and divalproex was 56% and 53%, respectively. The rate of depressive relapse in both arms was 13%, while the rate of relapse into a manic, hypomanic, or mixed episode was 44% for lithium monotherapy and 40% for the combination of lithium and divalproex. Conclusion A small subgroup of patients in this study stabilized after six months of treatment with lithium plus divalproex. Of those who did, the addition of divalproex to lithium conferred no additional prophylactic benefit over lithium alone. Although depression is regarded as the hallmark of RCBD in general, these data suggest that recurrent episodes of mania tend to be more common in

  1. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1983-01-01

    Free radical chlorination of methane is used in organic chemistry to introduce free radical/chain reactions. In spite of its common occurrence, demonstrations of the reaction are uncommon. Therefore, such a demonstration is provided, including background information, preparation of reactants/reaction vessel, introduction of reactants, irradiation,…

  2. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1983-01-01

    Discusses a supplement to the "water to rose" demonstration in which a pink color is produced. Also discusses blood buffer demonstrations, including hydrolysis of sodium bicarbonate, simulated blood buffer, metabolic acidosis, natural compensation of metabolic acidosis, metabolic alkalosis, acidosis treatment, and alkalosis treatment. Procedures…

  3. Complete Demonstration.

    Science.gov (United States)

    Yelon, Stephen; Maddocks, Peg

    1986-01-01

    Describes four-step approach to educational demonstration: tell learners they will have to perform; what they should notice; describe each step before doing it; and require memorization of steps. Examples illustrate use of this process to demonstrate a general mental strategy, and industrial design, supervisory, fine motor, and specific…

  4. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1987-01-01

    Describes two laboratory demonstrations in chemistry. One uses dry ice, freon, and freezer bags to demonstrate volume changes, vapor-liquid equilibrium, a simulation of a rain forest, and vaporization. The other uses the clock reaction technique to illustrate fast reactions and kinetic problems in releasing carbon dioxide during respiration. (TW)

  5. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1986-01-01

    Outlines a simple, inexpensive way of demonstrating electroplating using the reaction between nickel ions and copper metal. Explains how to conduct a demonstration of the electrolysis of water by using a colored Na2SO4 solution as the electrolyte so that students can observe the pH changes. (TW)

  6. Short-term carbon and nitrogen cycling in urine patches assessed by combined carbon-13 and nitrogen-15 labelling

    DEFF Research Database (Denmark)

    Ambus, Per; Petersen, S.O.; Soussana, J.F.

    2007-01-01

    sources for C include the urine itself, increased solubility of soil C, lysis of microbial cells and leakage of C from scorched roots. The objective of this experiment was to test the hypothesis that: (i) urine deposition causes an increase in root-derived degradable C compounds in the soil, which (ii......Urine deposition by grazing animals is known to, induce large NO emissions as a result of increased nitrification and denitrification in the soil. This is brought about by the increased N availability from the urine, in combination very likely also with increased organic C availability. Possible...... application was equal to the quantity of organic C added. Immediately after the application, 87% of the respired CO2 appeared to be from the urine, and respiration of plant-derived C was temporarily decreased. The cumulated amount of respired C-13 plant carbon, however, was unaltered by the urine treatment...

  7. A New Solar Thermal Combined Cycle Using Kalina Cycle%太阳能燃气轮机与卡林那循环联合的热发电系统

    Institute of Scientific and Technical Information of China (English)

    彭烁; 洪慧; 金红光

    2012-01-01

    本文提出了一种带间冷回热的太阳能燃气轮机与卡林那循环组成的联合循环发电系统,对其热力性能进行了分析,并研究了关键运行参数对热力性能影响。塔式太阳能接收器将经过间冷压缩的压缩空气加热至1000℃用以驱动燃气轮机做功。卡林那循环用以回收燃气余热发电。基于蔡睿贤的比较法,推导出了该系统太阳能热发电效率的简明解析式。结果表明,当燃气轮机入口温度为1000℃时,该系统的炯效率和太阳能热发电效率分别可达到29%和27.5%,比太阳能燃气蒸汽联合循环分别高1.8%和1.6%。该系统的提出,为提高太阳能热发电系统的太阳能热发电效率提供了一种方法,并且对太阳能热发电耗水大的问题提供了一个解决途径。%A new solar thermal combined cycle using Kalina cycle is proposed in the present paper. The thermodynamic performance of the proposed system is investigated. On the top cycle of the proposed system, the compressed air after being intercooled is heated at 1000℃ or higher at the solar tower receiver and is used to drive the gas turbine to generate power. The ammonia-water mixture as the working substance of the bottom cycle recovers the waste heat from the gas turbine to generate power. As a result, the peak solar-to-electric efficiency of the proposed system is 27.5% at a gas turbine inlet temperature of 1000℃. The results obtained in the current study provide an approach to improve solar-to-electric efficiency and offer a potential to conserve water for solar thermal power plants in arid area.

  8. Combining Life Cycle Thinking with Social Theory: Case Study of Compact Fluorescent Lamps (CFL in the Philippines

    Directory of Open Access Journals (Sweden)

    Marlyne D. Sahakian

    2010-07-01

    Full Text Available Resource depletion remains central to human economic activity with resulting negative consequences for the local and global environment. Material and energy consumption patterns are also increasing globally, as developing countries follow the trail blazed by more industrialized countries. Consumers play a role in shifting towards more sustainable forms of consumption. However, consumer-oriented public-policy measures are often restricted to informational campaigns based on moral and price arguments. A multidisciplinary approach to sustainable consumption must go beyond this limited vision of consumers if transitions toward more environmentally friendly consumption patterns are to be made possible. Both a biophysical and social understanding of consumption is necessary. This paper proposes a systemic approach to consumption studies, combining an assessment of consumption patterns with an understanding of the drivers behind them. The concepts will be illustrated using a case study of the government-led promotion of compact fluorescent lamps (CFL in Metro Manila, the Philippines. Conclusions will include general policy-recommendations.

  9. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L.

    1990-01-01

    Included are three demonstrations that include the phase change of ice when under pressure, viscoelasticity and colloid systems, and flame tests for metal ions. The materials, procedures, probable results, and applications to real life situations are included. (KR)

  10. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1980-01-01

    Presented is a Corridor Demonstration which can be set up in readily accessible areas such as hallways or lobbies. Equipment is listed for a display of three cells (solar cells, fuel cells, and storage cells) which develop electrical energy. (CS)

  11. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1987-01-01

    Presents three demonstrations suitable for undergraduate chemistry classes. Focuses on experiments with calcium carbide, the induction by iron of the oxidation of iodide by dichromate, and the classical iodine clock reaction. (ML)

  12. Performance study of a combined cycle power plant with integral gasification; Estudio del desempeno de una planta de potencia de ciclo combinado con gasificacion integral

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Rocha, Jose Clemente

    2007-04-15

    At world-wide level, in the last decade the interest has been increased in the use of petroleum coke as fuel in the clean generation of energy applying the gasification technology. This interest is mainly due to the increment the production of petroleum coke as a result of processing larger volumes of crude processed in the refineries and to the increment in the yield of products with high added value, such as turbo-fuel or diesel, among others. With the new reconfiguration of the Mexican refinery of Cd. Madero and Cadereyta and soon with the completion of the reconfiguration of the Minatitlan, Veracruz refinery, larger amounts of coke will be produced, with the possibility of using it, by means of the appropriate gasification technology, to produce a clean synthetic gas (gasl) with the appropriate energy characteristic to be used as fuel in a combined cycle existing in Mexico. In Mexico the possibilities of generation of electrical energy from the utilization of petroleum coke have been considered departing from the use of petroleum coke using the gasification technology or using fluidized bed steam generators as is the case of the power plant TEG in Taquin, San Luis Potosi. Such is the fact, that at the moment PEMEX Refinacion, has completed the project of constructing in Tuxpan, Veracruz a crude processing refinery of Mayan crude with a high sulfur content and next to the Tuxpan Power Plant, being contemplated the possibility of applying the concept of combined cycle with integrated gasification (CCGI); with this infrastructure it will be possible to consume the coke generated by the Mexican refineries. The expected electrical generation is of 500 MW, of which 100 MW will be for own consumption of the refinery and 400 MW free to cover the electrical energy demand within the North East and Center Zone of the country. The petroleum coke derived from the refineries of the country can be used for the clean generation of electricity by means of its gasification and

  13. Energy and exergy analyses of an integrated gasification combined cycle power plant with CO2 capture using hot potassium carbonate solvent.

    Science.gov (United States)

    Li, Sheng; Jin, Hongguang; Gao, Lin; Mumford, Kathryn Anne; Smith, Kathryn; Stevens, Geoff

    2014-12-16

    Energy and exergy analyses were studied for an integrated gasification combined cycle (IGCC) power plant with CO2 capture using hot potassium carbonate solvent. The study focused on the combined impact of the CO conversion ratio in the water gas shift (WGS) unit and CO2 recovery rate on component exergy destruction, plant efficiency, and energy penalty for CO2 capture. A theoretical limit for the minimal efficiency penalty for CO2 capture was also provided. It was found that total plant exergy destruction increased almost linearly with CO2 recovery rate and CO conversion ratio at low CO conversion ratios, but the exergy destruction from the WGS unit and the whole plant increased sharply when the CO conversion ratio was higher than 98.5% at the design WGS conditions, leading to a significant decrease in plant efficiency and increase in efficiency penalty for CO2 capture. When carbon capture rate was over around 70%, via a combination of around 100% CO2 recovery rate and lower CO conversion ratios, the efficiency penalty for CO2 capture was reduced. The minimal efficiency penalty for CO2 capture was estimated to be around 5.0 percentage points at design conditions in an IGCC plant with 90% carbon capture. Unlike the traditional aim of 100% CO conversion, it was recommended that extremely high CO conversion ratios should not be considered in order to decrease the energy penalty for CO2 capture and increase plant efficiency.

  14. Identification of hazards in non-nuclear power plants. [Public health hazards of fossil-fuel, combined cycle, combustion turbine, and geothermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Roman, W.S.; Israel, W.J.; Sacramo, R.F.

    1978-07-01

    Public health and safety hazards have been identified for five types of power plants: coal-fired, oil-fired steam turbine, combined cycle, combustion (gas) turbine, and geothermal. The results of the analysis show that air pollutants are the major hazard that affects the health and safety of the general public. A total of ninety plant hazards were identified for the five plant types. Each of these hazards were rated in six categories as to their affect on the general public. The criteria used in the analysis were: area/population exposed; duration; mitigation; quantity to toxicity ratio; nature of health effects; and public attitude. Even though ninety hazards were identified for the five plants analyzed, the large majority of hazards were similar for each plant. Highest ratings were given to the products of the combustion cycle or to hydrogen sulfide emissions from geothermal plants. Water pollution, cooling tower effects and noise received relatively low ratings. The highest rated of the infrequent or hypothetical hazards were those associated with potential fires, explosions, and chlorine releases at the plant. Hazards associated with major cooling water releases, water pollution and missiles received the lowest ratings. Since the results of the study clearly show that air pollutants are currently considered the most severe hazard, additional effort must be made to further understand the complex interactions of pollutants with man and his environment. Of particular importance is the determination of dose-response relationships for long term, low level exposure to air pollutants. (EDB)

  15. Solid-Fueled Pressurized Chemical Looping with Flue-Gas Turbine Combined Cycle for Improved Plant Efficiency and CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Kunlei; Chen, Liangyong; Zhang, Yi; Richburg, Lisa; Simpson, James; White, Jay; Rossi, Gianalfredo

    2013-12-31

    The purpose of this document is to report the final result of techno-economic analysis for the proposed 550MWe integrated pressurized chemical looping combustion combined cycle process. An Aspen Plus based model is delivered in this report along with the results from three sensitivity scenarios including the operating pressure, excess air ratio and oxygen carrier performance. A process flow diagram and detailed stream table for the base case are also provided with the overall plant energy balance, carbon balance, sulfur balance and water balance. The approach to the process and key component simulation are explained. The economic analysis (OPEX and CAPX) on four study cases via DOE NETL Reference Case 12 are presented and explained.

  16. Technical and environmental aspects of combined cycle power stations with integrated gasification (CCGI); Aspectos tecnicos y medioambientales de las centrales de ciclo combinado con gasificacion integrada (CCGI)

    Energy Technology Data Exchange (ETDEWEB)

    Beltran Mora, Hector Alejandro; Urias Romero, Francisco [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2004-06-15

    A description is presented of the operation of the Combined Cycle Power Stations with Integrated Gasification (CCGI) where the use of solid fuels (coal, vacuum residues, petroleum coke, and biomass) or liquids is possible in a thermal power station with the efficiency and many of the own environmental benefits of the combined cycles. The gasification process is analyzed, that is a thermo-chemical process by means of which a fuel that is in solid state or liquid becomes to the gaseous state by means of a partial oxidation and the obtained gas of this process is called synthesis gas (syngas, by its abbreviations in English) that is used in Combined Cycle Power Stations as a substitute for the natural gas. Also the other components of this type of power stations are shown, such as the air separating unit, and some of the modifications that are due to make to adapt a gas turbine so that it uses syngas, and the considerations of their integration with the air separating unit to optimize the operation of the plant are detailed. A comparison of efficiency values of power stations CCGI with the conventional carbon-electric and the power stations of combined cycle that use natural gas is also shown. Finally the emissions of pollutants of SO{sub 2}, NO{sub x} and CO{sub 2} are analyzed. The possibility of using fuels like petroleum coke and vacuum tower residues that are produced in the Cadereyta refinery is studied for the possible construction of a CCGI power station in Mexico. [Spanish] Se presenta la descripcion del funcionamiento de las centrales ciclo combinado con gasificacion integrada (CCGI) donde es posible el uso de combustibles solidos (carbon, residuos de vacio, coque de petroleo, biomasa) o liquidos en una central termica con la eficiencia y muchos de los beneficios ambientales propios de los ciclos combinados. Se analiza el proceso de gasificacion, que es un proceso termoquimico mediante el cual se convierte un combustible que se encuentra en estado solido o

  17. Fes cycling

    Directory of Open Access Journals (Sweden)

    Berkelmans Rik

    2008-01-01

    Full Text Available Many research with functional electrical stimulation (FES has been done to regain mobility and for health benefits. Better results have been reported for FES-cycling than for FES-walking. The majority of the subjects during such research are people with a spinal cord injury (SCI, cause they often lost skin sensation. Besides using surface stimulation also implanted stimulators can be used. This solves the skin sensation problem, but needs a surgery. Many physiological effects of FES-cycling has been reported, e.g., increase of muscles, better blood flow, reduction of pressure ulcers, improved self-image and some reduction of bone mineral density (BMD loss. Also people with an incomplete SCI benefit by FES-cycling, e.g. cycling time without FES, muscle strength and also the walking abilities increased. Hybrid exercise gives an even better cardiovascular training. Presently 4 companies are involved in FES-cycling. They all have a stationary mobility trainer. Two of them also use an outdoor tricycle. One combined with voluntary arm cranking. By optimizing the stimulation parameters the power output and fatigue resistance will increase, but will still be less compared to voluntary cycling.

  18. The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J.J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

    1995-12-31

    Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

  19. Simulación de Plantas de Cogeneración de Ciclo Combinado usando ASPEN® Simulation of Combined Cycle Cogeneration Plants using ASPEN®

    Directory of Open Access Journals (Sweden)

    S.G. Guerra

    2005-01-01

    Full Text Available El objetivo de este trabajo fue generar una estrategia para el diseño de plantas de cogeneración de ciclo combinado, basada en el uso del simulador ASPEN®. La estrategia comprende la simulación, así como la definición de todas las variables clave del proceso. Como caso de estudio, se consideró satisfacer la demanda real de vapor y electricidad en una refinería usando un esquema de cogeneración de ciclo combinado. Aspectos relevantes de la situación actual de esta tecnología tal como el cálculo del punto de rocío ácido, para restringir la temperatura de los gases de salida, fueron considerados en el modelo. Se revisaron tres esquemas para determinar la mejor opción para el caso de estudio. Se concluye que la estrategia aplicada en este análisis puede generalizarse a otros casos y podría ser aplicada en el diseño futuro de plantas de cogeneración en MéxicoThe objective of this work was to generate a strategy for combined cycle cogeneration plant design based on the ASPEN® process simulator. The approach included process simulation as well as definition of all key variables. Satisfaction of real vapor and electricity demands in a refinery was considered as a case study, using a scheme of combined cycle cogeneration. Considered in the model were the outstanding aspects of the state of the art for this technology, such as the calculation of the dew acid point to restrict the temperature of exhaust gases. Three schemes were analyzed to determine the best option for the case under study. It was concluded that this approach could be extended to other cases and could be applied to the future design of cogeneration plants in Mexico.

  20. Combination of lentivirus-mediated silencing of PPM1D and temozolomide chemotherapy eradicates malignant glioma through cell apoptosis and cell cycle arrest

    Science.gov (United States)

    Wang, Peng; Ye, Jing-An; Hou, Chong-Xian; Zhou, Dong; Zhan, Sheng-Quan

    2016-01-01

    Temozolomide (TMZ) is approved for use as first-line treatment for glioblastoma multiforme (GBM). However, GBM shows chemoresistance shortly after the initiation of treatment. In order to detect whether silencing of human protein phosphatase 1D magnesium dependent (PPM1D) gene could increase the effects of TMZ in glioma cells, glioma cells U87-MG were infected with lentiviral shRNA vector targeting PPM1D silencing. After PPM1D silencing was established, cells were treated with TMZ. The multiple functions of human glioma cells after PPM1D silencing and TMZ chemotherapy were detected by flow cytometry and MTT assay. Significantly differentially expressed genes were distinguished by microarray-based gene expression profiling and analyzed by gene pathway enrichment analysis and ontology assessment. Western blotting was used to establish the protein expression of the core genes. PPM1D gene silencing improves TMZ induced cell proliferation and induces cell apoptosis and cell cycle arrest. When PPM1D gene silencing combined with TMZ was performed in glioma cells, 367 genes were upregulated and 444 genes were downregulated compared with negative control. The most significant differential expression pathway was pathway in cancer and IGFR1R, PIK3R1, MAPK8 and EP300 are core genes in the network. Western blotting showed that MAPK8 and PIK3R1 protein expression levels were upregulated and RB1 protein expression was decreased. It was consistent with that detected in gene expression profiling. In conclusion, PPM1D gene silencing combined with TMZ eradicates glioma cells through cell apoptosis and cell cycle arrest. PIK3R1/AKT pathway plays a role in the multiple functions of glioma cells after PPM1D silencing and TMZ chemotherapy. PMID:27633132

  1. Tested Demonstrations.

    Science.gov (United States)

    Gilbert, George L., Ed.

    1987-01-01

    Describes two demonstrations to illustrate characteristics of substances. Outlines a method to detect the changes in pH levels during the electrolysis of water. Uses water pistols, one filled with methane gas and the other filled with water, to illustrate the differences in these two substances. (TW)

  2. ICT Demonstration

    DEFF Research Database (Denmark)

    Jensen, Tine Wirenfeldt; Bay, Gina

    In this demonstration we present and discuss two interrelated on-line learning resources aimed at supporting international students at Danish universities in building study skills (the Study Metro) and avoiding plagiarism (Stopplagiarism). We emphasize the necessity of designing online learning r...

  3. Open cycle thermoacoustics

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Robert Stowers [Georgia Inst. of Technology, Atlanta, GA (United States)

    2000-01-01

    A new type of thermodynamic device combining a thermodynamic cycle with the externally applied steady flow of an open thermodynamic process is discussed and experimentally demonstrated. The gas flowing through this device can be heated or cooled in a series of semi-open cyclic steps. The combination of open and cyclic flows makes possible the elimination of some or all of the heat exchangers (with their associated irreversibility). Heat is directly exchanged with the process fluid as it flows through the device when operating as a refrigerator, producing a staging effect that tends to increase First Law thermodynamic efficiency. An open-flow thermoacoustic refrigerator was built to demonstrate this concept. Several approaches are presented that describe the physical characteristics of this device. Tests have been conducted on this refrigerator with good agreement with a proposed theory.

  4. Novel composite efficacy measure to demonstrate the rationale and efficacy of combination antiviral-anti-inflammatory treatment for recurrent herpes simplex labialis.

    Science.gov (United States)

    Hull, Christopher M; Levin, Myron J; Tyring, Stephen K; Spruance, Spotswood L

    2014-01-01

    Historically, the primary target for research and treatment of recurrent herpes simplex labialis (HSL) has been limited to inhibiting herpes simplex virus (HSV) replication. Antiviral monotherapy, however, has proven only marginally effective in curtailing the duration and severity of recurrent lesions. Recently, the role of inflammation in the progression and resolution of recurrences has been identified as an additional target. This was evaluated in a randomized study comparing combination topical 5% acyclovir-1% hydrocortisone cream (AHC) with 5% acyclovir alone (AC; in the AHC vehicle) and the vehicle. The efficacy of each topical therapy was evaluated for cumulative lesion size--a novel composite efficacy endpoint incorporating episode duration, lesion area, and proportion of nonulcerative lesions. In that study, cumulative lesion area was significantly decreased with AHC compared with AC (25% decrease; P<0.05) and the vehicle (50% decrease; P<0.0001). As research continues in this arena, cumulative lesion area should be included as a measure of efficacy in clinical trials of recurrent HSL therapies.

  5. A preclinical orthotopic model for glioblastoma recapitulates key features of human tumors and demonstrates sensitivity to a combination of MEK and PI3K pathway inhibitors.

    Science.gov (United States)

    El Meskini, Rajaa; Iacovelli, Anthony J; Kulaga, Alan; Gumprecht, Michelle; Martin, Philip L; Baran, Maureen; Householder, Deborah B; Van Dyke, Terry; Weaver Ohler, Zoë

    2015-01-01

    Current therapies for glioblastoma multiforme (GBM), the highest grade malignant brain tumor, are mostly ineffective, and better preclinical model systems are needed to increase the successful translation of drug discovery efforts into the clinic. Previous work describes a genetically engineered mouse (GEM) model that contains perturbations in the most frequently dysregulated networks in GBM (driven by RB, KRAS and/or PI3K signaling and PTEN) that induce development of Grade IV astrocytoma with properties of the human disease. Here, we developed and characterized an orthotopic mouse model derived from the GEM that retains the features of the GEM model in an immunocompetent background; however, this model is also tractable and efficient for preclinical evaluation of candidate therapeutic regimens. Orthotopic brain tumors are highly proliferative, invasive and vascular, and express histology markers characteristic of human GBM. Primary tumor cells were examined for sensitivity to chemotherapeutics and targeted drugs. PI3K and MAPK pathway inhibitors, when used as single agents, inhibited cell proliferation but did not result in significant apoptosis. However, in combination, these inhibitors resulted in a substantial increase in cell death. Moreover, these findings translated into the in vivo orthotopic model: PI3K or MAPK inhibitor treatment regimens resulted in incomplete pathway suppression and feedback loops, whereas dual treatment delayed tumor growth through increased apoptosis and decreased tumor cell proliferation. Analysis of downstream pathway components revealed a cooperative effect on target downregulation. These concordant results, together with the morphologic similarities to the human GBM disease characteristics of the model, validate it as a new platform for the evaluation of GBM treatment.

  6. Combined structural, biochemical and cellular evidence demonstrates that both FGDF motifs in alphavirus nsP3 are required for efficient replication.

    Science.gov (United States)

    Schulte, Tim; Liu, Lifeng; Panas, Marc D; Thaa, Bastian; Dickson, Nicole; Götte, Benjamin; Achour, Adnane; McInerney, Gerald M

    2016-07-01

    Recent findings have highlighted the role of the Old World alphavirus non-structural protein 3 (nsP3) as a host defence modulator that functions by disrupting stress granules, subcellular phase-dense RNA/protein structures formed upon environmental stress. This disruption mechanism was largely explained through nsP3-mediated recruitment of the host G3BP protein via two tandem FGDF motifs. Here, we present the 1.9 Å resolution crystal structure of the NTF2-like domain of G3BP-1 in complex with a 25-residue peptide derived from Semliki Forest virus nsP3 (nsP3-25). The structure reveals a poly-complex of G3BP-1 dimers interconnected through the FGDF motifs in nsP3-25. Although in vitro and in vivo binding studies revealed a hierarchical interaction of the two FGDF motifs with G3BP-1, viral growth curves clearly demonstrated that two intact FGDF motifs are required for efficient viral replication. Chikungunya virus nsP3 also binds G3BP dimers via a hierarchical interaction, which was found to be critical for viral replication. These results highlight a conserved molecular mechanism in host cell modulation.

  7. FINAL SIMULATION RESULTS FOR DEMONSTRATION CASE 1 AND 2

    Energy Technology Data Exchange (ETDEWEB)

    David Sloan; Woodrow Fiveland

    2003-10-15

    The goal of this DOE Vision-21 project work scope was to develop an integrated suite of software tools that could be used to simulate and visualize advanced plant concepts. Existing process simulation software did not meet the DOE's objective of ''virtual simulation'' which was needed to evaluate complex cycles. The overall intent of the DOE was to improve predictive tools for cycle analysis, and to improve the component models that are used in turn to simulate equipment in the cycle. Advanced component models are available; however, a generic coupling capability that would link the advanced component models to the cycle simulation software remained to be developed. In the current project, the coupling of the cycle analysis and cycle component simulation software was based on an existing suite of programs. The challenge was to develop a general-purpose software and communications link between the cycle analysis software Aspen Plus{reg_sign} (marketed by Aspen Technology, Inc.), and specialized component modeling packages, as exemplified by industrial proprietary codes (utilized by ALSTOM Power Inc.) and the FLUENT{reg_sign} computational fluid dynamics (CFD) code (provided by Fluent Inc). A software interface and controller, based on an open CAPE-OPEN standard, has been developed and extensively tested. Various test runs and demonstration cases have been utilized to confirm the viability and reliability of the software. ALSTOM Power was tasked with the responsibility to select and run two demonstration cases to test the software--(1) a conventional steam cycle (designated as Demonstration Case 1), and (2) a combined cycle test case (designated as Demonstration Case 2). Demonstration Case 1 is a 30 MWe coal-fired power plant for municipal electricity generation, while Demonstration Case 2 is a 270 MWe, natural gas-fired, combined cycle power plant. Sufficient data was available from the operation of both power plants to complete the cycle

  8. FINAL SIMULATION RESULTS FOR DEMONSTRATION CASE 1 AND 2

    Energy Technology Data Exchange (ETDEWEB)

    David Sloan; Woodrow Fiveland

    2003-10-15

    The goal of this DOE Vision-21 project work scope was to develop an integrated suite of software tools that could be used to simulate and visualize advanced plant concepts. Existing process simulation software did not meet the DOE's objective of ''virtual simulation'' which was needed to evaluate complex cycles. The overall intent of the DOE was to improve predictive tools for cycle analysis, and to improve the component models that are used in turn to simulate equipment in the cycle. Advanced component models are available; however, a generic coupling capability that would link the advanced component models to the cycle simulation software remained to be developed. In the current project, the coupling of the cycle analysis and cycle component simulation software was based on an existing suite of programs. The challenge was to develop a general-purpose software and communications link between the cycle analysis software Aspen Plus{reg_sign} (marketed by Aspen Technology, Inc.), and specialized component modeling packages, as exemplified by industrial proprietary codes (utilized by ALSTOM Power Inc.) and the FLUENT{reg_sign} computational fluid dynamics (CFD) code (provided by Fluent Inc). A software interface and controller, based on an open CAPE-OPEN standard, has been developed and extensively tested. Various test runs and demonstration cases have been utilized to confirm the viability and reliability of the software. ALSTOM Power was tasked with the responsibility to select and run two demonstration cases to test the software--(1) a conventional steam cycle (designated as Demonstration Case 1), and (2) a combined cycle test case (designated as Demonstration Case 2). Demonstration Case 1 is a 30 MWe coal-fired power plant for municipal electricity generation, while Demonstration Case 2 is a 270 MWe, natural gas-fired, combined cycle power plant. Sufficient data was available from the operation of both power plants to complete the cycle

  9. Combining transcranial ultrasound with intelligent communication methods to enhance the remote assessment and management of stroke patients: Framework for a technology demonstrator.

    Science.gov (United States)

    Mort, Alasdair; Eadie, Leila; Regan, Luke; Macaden, Ashish; Heaney, David; Bouamrane, Matt-Mouley; Rushworth, Gordon; Wilson, Philip

    2016-09-01

    With over 150,000 strokes in the United Kingdom every year, and more than 1 million living survivors, stroke is the third most common cause of death and the leading cause of severe physical disability among adults. A major challenge in administering timely treatment is determining whether the stroke is due to vascular blockage (ischaemic) or haemorrhage. For patients with ischaemic stroke, thrombolysis (i.e. pharmacological 'clot-busting') can improve outcomes when delivered swiftly after onset, and current National Health Service Quality Improvement Scotland guidelines are for thrombolytic therapy to be provided to at least 80 per cent of eligible patients within 60 min of arrival at hospital. Thrombolysis in haemorrhagic stroke could severely compound the brain damage, so administration of thrombolytic therapy currently requires near-immediate care in a hospital, rapid consultation with a physician and access to imaging services (X-ray computed tomography or magnetic resonance imaging) and intensive care services. This is near impossible in remote and rural areas, and stroke mortality rates in Scotland are 50 per cent higher than in London. We here describe our current project developing a technology demonstrator with ultrasound imaging linked to an intelligent, multi-channel communication device - connecting to multiple 2G/3G/4G networks and/or satellites - in order to stream live ultrasound images, video and two-way audio streams to hospital-based specialists who can guide and advise ambulance clinicians regarding diagnosis. With portable ultrasound machines located in ambulances or general practices, use of such technology is not confined to stroke, although this is our current focus. Ultrasound assessment is useful in many other immediate care situations, suggesting potential wider applicability for this remote support system. Although our research programme is driven by rural need, the ideas are potentially applicable to urban areas where access to

  10. An overview of integrated solar combined cycle technology%太阳能-燃气联合循环发电技术

    Institute of Scientific and Technical Information of China (English)

    郑建涛; 徐越; 许世森

    2014-01-01

    The characteristics of solar thermal power generation technology and integrated solar combined cycle (ISCC)technology were described.Moreover,the development and operation of current solar hybrid power plant at home and abroad were introduced.ISCC technology provides a feasible solution for compre-hensive utilization of clean energy.It can not only make use of renewable energy to generate power,but also overcome the instability of its resources.According to the features of solar energy (only working at day-time),the ISCC technology can realize auto peak load regulation,making the power generation agree well with load curve that the users require.Currently,the solar energy and gas combined cycle power generation system includes several types,like the tower type,disc type,slot type,Fresnel type and other types.Appro-priate form of the ISCC system should be selected according to specific situation of each power plant,to en-hance the comprehensive utilization of energy as much as possible.%概述了太阳能热发电技术和太阳能-燃气联合循环发电(ISCC)技术的特点,介绍了目前国内外研发和运行的太阳能混合电站。总结发现:ISCC 发电技术为清洁能源的综合利用提供了一种切实可行的应用方案,既利用了可再生能源发电,又克服了其资源的不稳定性,根据太阳能白天发电夜晚不发电的特点,实现电网昼夜自然调峰;目前 ISCC 系统具有塔式、碟式、槽式和菲涅尔式等重要形式,可根据电厂具体情况,选择适宜的形式,最大化地提高综合能源利用效率。

  11. Dynamic simulation and load-following control of an integrated gasification combined cycle (IGCC) power plant with CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, D,; Turton, R.; Zitney, S.

    2012-01-01

    Load-following control of future integrated gasification combined cycle (IGCC) plants with pre-combustion CO{sub 2} capture is expected to be far more challenging as electricity produced by renewable energy is connected to the grid and strict environmental limits become mandatory requirements. To study control performance during load following, a plant-wide dynamic simulation of a coal-fed IGCC plant with CO{sub 2} capture has been developed. The slurry-fed gasifier is a single-stage, downward-fired, oxygen-blown, entrained-flow type with a radiant syngas cooler (RSC). The syngas from the outlet of the RSC goes to a scrubber followed by a two-stage sour shift process with inter-stage cooling. The acid gas removal (AGR) process is a dual-stage physical solvent-based process for selective removal of H{sub 2}S in the first stage and CO{sub 2} in the second stage. Sulfur is recovered using a Claus unit with tail gas recycle to the AGR. The recovered CO{sub 2} is compressed by a split-shaft multistage compressor and sent for sequestration after being treated in an absorber with triethylene glycol for dehydration. The clean syngas is sent to two advanced “F”-class gas turbines (GTs) partially integrated with an elevated-pressure air separation unit. A subcritical steam cycle is used for heat recovery steam generation. A treatment unit for the sour water strips off the acid gases for utilization in the Claus unit. The steady-state model developed in Aspen Plus® is converted to an Aspen Plus Dynamics® simulation and integrated with MATLAB® for control studies. The results from the plant-wide dynamic model are compared qualitatively with the data from a commercial plant having different configuration, operating condition, and feed quality than what has been considered in this work. For load-following control, the GT-lead with gasifier-follow control strategy is considered. A modified proportional–integral–derivative (PID) control is considered for the syngas

  12. Using a combination of weighting factor method and imperialist competitive algorithm to improve speed and enhance process of reloading pattern optimization of VVER-1000 reactors in transient cycles

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, Yashar, E-mail: yashar.rahmani@gmail.com [Department of Physics, Faculty of Engineering, Islamic Azad University, Sari Branch, Sari (Iran, Islamic Republic of); Shahvari, Yaser [Department of Computer Engineering, Payame Noor University (PNU), P.O. Box 19395-3697, Tehran (Iran, Islamic Republic of); Kia, Faezeh [Golestan Institute of Higher Education, Gorgan 49139-83635 (Iran, Islamic Republic of)

    2017-03-15

    Highlights: • This article was an attempt to optimize reloading pattern of Bushehr VVER-1000 reactor. • A combination of weighting factor method and the imperialist competitive algorithm was used. • The speed of optimization and desirability of the proposed pattern increased considerably. • To evaluate arrangements, a coupling of WIMSD5-B, CITATION-LDI2 and WERL codes was used. • Results reflected the considerable superiority of the proposed method over direct optimization. - Abstract: In this research, an innovative solution is described which can be used with a combination of the new imperialist competitive algorithm and the weighting factor method to improve speed and increase globality of search in reloading pattern optimization of VVER-1000 reactors in transient cycles and even obtain more desirable results than conventional direct method. In this regard, to reduce the scope of the assumed searchable arrangements, first using the weighting factor method and based on values of these coefficients in each of the 16 types of loadable fuel assemblies in the second cycle, the fuel assemblies were classified in more limited groups. In consequence, the types of fuel assemblies were reduced from 16 to 6 and consequently the number of possible arrangements was reduced considerably. Afterwards, in the first phase of optimization the imperialist competitive algorithm was used to propose an optimum reloading pattern with 6 groups. In the second phase, the algorithm was reused for finding desirable placement of the subset assemblies of each group in the optimum arrangement obtained from the previous phase, and thus the retransformation of the optimum arrangement takes place from the virtual 6-group mode to the real mode with 16 fuel types. In this research, the optimization process was conducted in two states. In the first state, it was tried to obtain an arrangement with the maximum effective multiplication factor and the smallest maximum power peaking factor. In

  13. Dynamic Modeling and Plantwide Control of a Hybrid Power and Chemical Plant: An Integrated Gasification Combined Cycle Coupled with a Methanol Plant

    Science.gov (United States)

    Robinson, Patrick J.

    Gasification has been used in industry on a relatively limited scale for many years, but it is emerging as the premier unit operation in the energy and chemical industries. The switch from expensive and insecure petroleum to solid hydrocarbon sources (coal and biomass) is occurring due to the vast amount of domestic solid resources, national security and global warming issues. Gasification (or partial oxidation) is a vital component of "clean coal" technology. Sulfur and nitrogen emissions can be reduced, overall energy efficiency is increased and carbon dioxide recovery and sequestration are facilitated. Gasification units in an electric power generation plant produce a fuel gas for driving combustion turbines. Gasification units in a chemical plant generate synthesis gas, which can be used to produce a wide spectrum of chemical products. Future plants are predicted to be hybrid power/chemical plants with gasification as the key unit operation. The coupling of an Integrated Gasification Combined Cycle (IGCC) with a methanol plant can handle swings in power demand by diverting hydrogen gas from a combustion turbine and synthesis gas from the gasifier to a methanol plant for the production of an easily-stored, hydrogen-consuming liquid product. An additional control degree of freedom is provided with this hybrid plant, fundamentally improving the controllability of the process. The idea is to base-load the gasifier and use the more responsive gas-phase units to handle disturbances. During the summer days, power demand can fluctuate up to 50% over a 12-hour period. The winter provides a different problem where spikes of power demand can go up 15% within the hour. The following dissertation develops a hybrid IGCC / methanol plant model, validates the steady-state results with a National Energy Technical Laboratory study, and tests a proposed control structure to handle these significant disturbances. All modeling was performed in the widely used chemical process

  14. Comparing the sustainability impacts of solar thermal and natural gas combined cycle for electricity production in Mexico: Accounting for decision makers' priorities

    Science.gov (United States)

    Rodríguez-Serrano, Irene; Caldés, Natalia; Oltra, Christian; Sala, Roser

    2017-06-01

    The aim of this paper is to conduct a comprehensive sustainability assessment of the electricity generation with two alternative electricity generation technologies by estimating its economic, environmental and social impacts through the "Framework for Integrated Sustainability Assessment" (FISA). Based on a Multiregional Input Output (MRIO) model linked to a social risk database (Social Hotspot Database), the framework accounts for up to fifteen impacts across the three sustainability pillars along the supply chain of the electricity production from Solar Thermal Electricity (STE) and Natural Gas Combined Cycle (NGCC) technologies in Mexico. Except for value creation, results show larger negative impacts for NGCC, particularly in the environmental pillar. Next, these impacts are transformed into "Aggregated Sustainability Endpoints" (ASE points) as a way to support the decision making in selecting the best sustainable project. ASE points obtained are later compared to the resulting points weighted by the reported priorities of Mexican decision makers in the energy sector obtained from a questionnaire survey. The comparison shows that NGCC achieves a 1.94 times worse negative score than STE, but after incorporating decision makerś priorities, the ratio increases to 2.06 due to the relevance given to environmental impacts such as photochemical oxidants formation and climate change potential, as well as social risks like human rights risks.

  15. Power generation from coal and biomass based on integrated gasification combined cycle concept with pre- and post-combustion carbon capture methods

    Energy Technology Data Exchange (ETDEWEB)

    Calin-Cristian Cormos; Ana-Maria Cormos; Serban Agachi [Babes-Bolyai University, Cluj-Napoca (Romania)

    2009-11-15

    Gasification technology is a process in which solid fuel is partially oxidised by oxygen and steam/water to produce a combustible gas called syngas (mainly a mixture of hydrogen and carbon monoxide). Syngas can be used either for power generation or processed to obtain various chemicals (hydrogen, ammonia, methanol, etc.). This article evaluates the possibilities of solid fuel decarbonisation by capturing carbon dioxide resulting from thermo-chemical conversion of solid fuel using gasification. Evaluation is focused on power generation technology using syngas produced by solid fuel gasification (so-called integrated gasification combined cycle IGCC). Case studies analysed in the article are using a mixture of coal and biomass (sawdust) to produce around 400 MW electricity simultaneously with capturing about 90% of the feedstock carbon. Various carbon dioxide capture options (post- and pre-combustion) are compared with situation of no carbon capture in terms of plant configurations, energy penalty, CO{sub 2} emissions, etc. Plant options are modelled using ChemCAD, and simulation results are used to assess the plant performances. Plant flexibility and future improvements are also discussed.

  16. Combined use of VUV and UVC photoreactors for the treatment of hospital laundry wastewaters: Reduction of load parameters, detoxification and life cycle assessment of different configurations.

    Science.gov (United States)

    de Oliveira Schwaickhardt, Rômulo; Machado, Ênio Leandro; Lutterbeck, Carlos Alexandre

    2017-03-07

    The present research investigated the treatment of hospital laundry wastewaters by the combined use of photochemical VUV and UVC reactors. Seven different configurations were tested and the performances of each of them were evaluated based on the removal of the load parameters, detoxification and life cycle assessment (LCA). The characterization of studied wastewaters included analysis of the following parameters: COD, BOD5, TKN, total P, pH, turbidity and conductivity. Acute ecotoxicity was evaluated using Daphnia magna. Ultraviolet-Visible (UV-Vis) spectroscopy was performed to determine the organic fraction and chromatography coupled to the mass spectrometer (GC-MS) was used for the qualitative characterization of priority pollutants. Characterization parameters showed the presence of drugs like lidocaine and dipyrone and a high organic load with a poor biodegradability. Wastewaters presented an extreme acute toxicity against D. magna (EC50 6.7%). The ozonation process (mainly generated by the VUV reactor) obtained the best results concerning the ratio between the consumed energy and the removed COD and the UVC process presented the lowest environmental impacts for the characterization and normalization parameters of the LCA. Normalization revealed that the highest environmental burdens were associated with human toxicity, ecotoxicity and eutrophication of surface waters as well as to the use of non-renewable resources. VUV/UVC/O3 process presented the best results considering detoxification (EC50 100%).

  17. Optimization of Biomass-Fuelled Combined Cooling, Heating and Power (CCHP Systems Integrated with Subcritical or Transcritical Organic Rankine Cycles (ORCs

    Directory of Open Access Journals (Sweden)

    Daniel Maraver

    2014-04-01

    Full Text Available This work is focused on the thermodynamic optimization of Organic Rankine Cycles (ORCs, coupled with absorption or adsorption cooling units, for combined cooling heating and power (CCHP generation from biomass combustion. Results were obtained by modelling with the main aim of providing optimization guidelines for the operating conditions of these types of systems, specifically the subcritical or transcritical ORC, when integrated in a CCHP system to supply typical heating and cooling demands in the tertiary sector. The thermodynamic approach was complemented, to avoid its possible limitations, by the technological constraints of the expander, the heat exchangers and the pump of the ORC. The working fluids considered are: n-pentane, n-heptane, octamethyltrisiloxane, toluene and dodecamethylcyclohexasiloxane. In addition, the energy and environmental performance of the different optimal CCHP plants was investigated. The optimal plant from the energy and environmental point of view is the one integrated by a toluene recuperative ORC, although it is limited to a development with a turbine type expander. Also, the trigeneration plant could be developed in an energy and environmental efficient way with an n-pentane recuperative ORC and a volumetric type expander.

  18. Design, development, and demonstration of a fully LabVIEW controlled in situ electrochemical Fourier transform infrared setup combined with a wall-jet electrode to investigate the electrochemical interface of nanoparticulate electrocatalysts under reaction conditions.

    Science.gov (United States)

    Nesselberger, Markus; Ashton, Sean J; Wiberg, Gustav K H; Arenz, Matthias

    2013-07-01

    We present a detailed description of the construction of an in situ electrochemical ATR-FTIR setup combined with a wall-jet electrode to investigate the electrocatalytic properties of nanoparticulate catalysts in situ under controlled mass transport conditions. The presented setup allows the electrochemical interface to be probed in combination with the simultaneous determination of reaction rates. At the same time, the high level of automation allows it to be used as a standard tool in electrocatalysis research. The performance of the setup was demonstrated by probing the oxygen reduction reaction on a platinum black catalyst in sulfuric electrolyte.

  19. 新型双重热化学吸附制冷热力循环研究%Study on an Innovative Combined Double-Way Thermochemical Sorption Refrigeration Cycle

    Institute of Scientific and Technical Information of China (English)

    李廷贤; 王如竹; 陈恒; 王丽伟

    2011-01-01

    本文提出了一种全新的基于吸附-再吸附技术的双重热化学吸附制冷热力循环.实验研究表明该新型双重热化学吸附制冷热力循环用于制冷空调领域是完全可行的,在每次循环过程中仅从外界热源输入一次高温解吸热,就可以实现吸附制冷和再吸附制冷两次制冷过程;相对传统热化学再吸附制冷循环和吸附制冷循环,双重热化学吸附制冷热力循环可显著提高吸附制冷系统的工作性能,在相同制冷剂循环量下,双重热化学吸附制冷循环可将制冷系数COPi分别提高60%和167%.%In this paper, an innovative combined double-way thermochemical sorption refrigeration cycle based on adsorption and resorption processes is proposed. Experimental results showed that the presented combined double-way sorption cycle is feasible for refrigeration application, and two cold productions (adsorption refrigeration and resorption refrigeration) can be obtained during one cycle at the expense of only one heat input from an external heat source. In comparison with conventional thermochemical resorption cycle or adsorption cycle, the double-way sorption cycle has a distinct advantage of higher Coefficient of Performance (COP). At the same cycled mass of refrigerant, the ideal COP can be improved by 60% and 167% when compared with conventional resorption cycle and adsorption cycle, respectively.

  20. Total environmental impacts of biofuels from corn stover using a hybrid life cycle assessment (LCA) model combining Process LCA and Economic Input-Output LCA.

    Science.gov (United States)

    Liu, Changqi; Huang, Yaji; Wang, Xinye; Tai, Yang; Liu, Lingqin; Liu, Hao

    2017-08-10

    Studies on the environmental analysis of biofuels by fast pyrolysis and hydroprocessing (BFPH) have so far only focused on the environmental impacts from direct emissions and included few indirect emissions. The influence of ignoring some indirect emissions on the environmental performance of BFPH has not been well investigated and hence is not really understood. In addition, in order to avoid shifting environmental problems from one media to another, a comprehensive assessment of environmental impacts caused by the processes must quantify the environmental emissions to all media (air, water, and land) in relation to each life cycle stage. A well-to-wheels assessment of the total environmental impacts resulting from direct emissions and indirect emissions of a BFPH system with corn stover is conducted using a hybrid life cycle assessment (LCA) model combining the economic input-output LCA and the process LCA. The Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI) has been used to estimate the environmental impacts in terms of acidification, eutrophication, global climate change, ozone depletion, human health criteria, photochemical smog formation, ecotoxicity, human health cancer and human health non-cancer, caused by 1 MJ biofuel production. Taking account of all the indirect greenhouse gas (GHG) emissions, the net GHG emissions (81.8 gCO2-eq /MJ) of the biofuels are still less than those of petroleum-based fuels (94 gCO2-eq /MJ). Maize production and pyrolysis and hydroprocessing make major contributions to all impact categories except the human health criteria. All impact categories resulting from indirect emissions except the eutrophication and smog air make more than 24% contribution to the total environmental impacts. Therefore, the indirect emissions are important and can't be ignored. Sensitivity analysis has shown that corn stover yield and bio-oil yield affect the total environment impacts of the biofuels more

  1. State estimation of an acid gas removal (AGR) plant as part of an integrated gasification combined cycle (IGCC) plant with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2012-01-01

    An accurate estimation of process state variables not only can increase the effectiveness and reliability of process measurement technology, but can also enhance plant efficiency, improve control system performance, and increase plant availability. Future integrated gasification combined cycle (IGCC) power plants with CO2 capture will have to satisfy stricter operational and environmental constraints. To operate the IGCC plant without violating stringent environmental emission standards requires accurate estimation of the relevant process state variables, outputs, and disturbances. Unfortunately, a number of these process variables cannot be measured at all, while some of them can be measured, but with low precision, low reliability, or low signal-to-noise ratio. As a result, accurate estimation of the process variables is of great importance to avoid the inherent difficulties associated with the inaccuracy of the data. Motivated by this, the current paper focuses on the state estimation of an acid gas removal (AGR) process as part of an IGCC plant with CO2 capture. This process has extensive heat and mass integration and therefore is very suitable for testing the efficiency of the designed estimators in the presence of complex interactions between process variables. The traditional Kalman filter (KF) (Kalman, 1960) algorithm has been used as a state estimator which resembles that of a predictor-corrector algorithm for solving numerical problems. In traditional KF implementation, good guesses for the process noise covariance matrix (Q) and the measurement noise covariance matrix (R) are required to obtain satisfactory filter performance. However, in the real world, these matrices are unknown and it is difficult to generate good guesses for them. In this paper, use of an adaptive KF will be presented that adapts Q and R at every time step of the algorithm. Results show that very accurate estimations of the desired process states, outputs or disturbances can be

  2. Diffuse control of gas turbines in power stations of combined cycle; Contral difuso de turbinas de gas en centrales de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez P, Marino; Garduno R, Raul; De Lara J, Salvadror; Castelo C, Luis [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In this article the application of the technology of the fuzzy logic to the control of gas turbines is presented in order to evaluate it in one of the most difficult processes and with stricter control requirements that exist in the electrical generation industry. For being important for the generation electrical sector, given their use in Comision Federal de Electricidad (CFE), the first selected prototype was the gas turbines model W501 of Westinghouse, installed in the of combined cycle power stations of Dos Bocas, Veracruz, Gomez Palacio, Durango and Tula, Hidalgo, Mexico. The second selected prototype was the one of the turbo gas units type 5001 (that applies to the GE 5001 models and Westinghouse of series 191 and 251). Based on the analysis of the performance of the system of conventional control previously made, the controllers of speed and generation of electrical power were selected to be replaced by diffuse controllers. [Spanish] En este articulo se presenta la aplicacion de la tecnologia de la logica difusa al control de turbinas de gas con el proposito de evaluarla en uno de los procesos mas dificiles y con requerimientos mas estrictos de control que existen en la industria de generacion electrica. Por ser importantes para el sector electrico de generacion, dada su utilizacion en Comision Federal de Electricidad (CFE), el primer prototipo seleccionado fueron las turbinas de gas modelo W501 de Westinghouse, instaladas en la central de ciclo combinado de Dos Bocas, Veracruz, Gomez Palacio, Durango y Tula, Hidalgo, Mexico. El segundo prototipo seleccionado fue el de unidades turbogas tipo 5001 (que aplica a los modelos GE 5001 y Westinghouse de la serie 191 y 251). Basados en el analisis del desempeno del sistema de control convencional realizado previamente, los controladores de velocidad y de generacion de potencia electrica fueron seleccionados para ser sustituidos por controladores difusos.

  3. Technological tendencies for the improvement of the performance of combined cycle power stations; Tendencias tecnologicas para el mejoramiento del desempeno de centrales de cilco combinado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez P, Marino; Garduno R, Raul; Chavez T, Rafael [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In this article are dealt some the aspects that have turned the combined cycle generating power stations (CCGPS) into the dominant way for the electrical generation in the world. In the first part it is presented the plan of expansion of the national electrical generation and similar information that the U.S.A. has for the CCGPS, which will give an idea of the importance and the impact that has this technology at the moment. The basic characteristics that are necessary to specify in order to satisfy the environmental and operation requirements, and the available technologies to increase the global efficiency of the CCGPS are also exposed. Finally it describes the evolution of the technology of control for CCGPS developed in the Gerencia de Control e Instrumentacion (GCI), as well as the capacities available to support the electrical sector in this technological discipline. [Spanish] En este articulo se tratan algunos de los aspectos que han convertido a las centrales de generacion de ciclo combinado (CGCC) en el modo dominante para la generacion electrica en el mundo. En la primera parte se presenta el plan de expansion de la generacion electrica nacional e informacion similar que los EE.UU. tienen para las CGCC, lo que dara una idea de la importancia y del impacto que tiene actualmente esta tecnologia. Se exponen tambien las caracteristicas principales que es necesario especificar a fin de satisfacer los requerimientos ambientales y de operacion, y las tecnologias disponibles para incrementar la eficiencia global de las CGCC. Finalmente se describe la evolucion de la tecnologia de control para CGCC desarrollada en la Gerencia de Control e Instrumentacion (GCI), asi como las capacidades disponibles para apoyar al sector electrico en esta disciplina tecnologica.

  4. Conventional and intelligent generalized supervisory control for combined cycle generating power stations.; Control supervisiorio generalizado convencional e inteligente para centrales de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, Miguel A; Sanchez P, Marino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gonzalez Rubio S, Jose L [Cento Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

    2005-07-01

    Under the expectations of expansion of electric power generation in Mexico, this work exposes the development of a conventional and intelligent generalized supervisory control (CSG) for a combined cycle generation power plant. This one allows to obtain the optimal operation of the power plant through the automatic starting of the generating units and to obtain the maximum possible amount of electrical power in automatic and safe form. For the development of the CSG a control loop by temperature was implemented for the gas turbine system and a control loop by strangled pressure for the gas turbine and a control loop by strangled pressure for the steam turbine. The design of these supervisory systems was made with base in the critical limits on the involved variables of the process: blading average temperature, for the gas turbine (GT) and strangled pressure for the steam turbine (ST) [Spanish] Bajo estas expectativas de expansion de generacion de energia en Mexico, este trabajo expone el desarrollo de un control supervisorio generalizado (CSG) para una central generacion de ciclo combinado. Este permite lograr la operacion optima de la planta a traves del arranque automatico de las unidades generadoras y obtener la maxima cantidad posible de potencia electrica en forma automatica y segura. Para el desarrollo del CSG se implanto un lazo de control por temperatura para el sistema de turbina de gas y un lazo de control por presion estrangulada para la turbina de gas y un lazo de control por presion estrangulada para la turbina de vapor. El diseno de estos sistemas supervisorio se realizo con base en los limites criticos de las variables del proceso involucradas: temperatura promedio de empaletado para la turbina de gas (TG) y presion estrangulada para la turbina de vapor (TV)

  5. Performance Analysis of an Evaporator for a Diesel Engine–Organic Rankine Cycle (ORC Combined System and Influence of Pressure Drop on the Diesel Engine Operating Characteristics

    Directory of Open Access Journals (Sweden)

    Chen Bei

    2015-06-01

    Full Text Available The main purpose of this research is to analyze the performance of an evaporator for the organic Rankine cycle (ORC system and discuss the influence of the evaporator on the operating characteristics of diesel engine. A simulation model of fin-and-tube evaporator of the ORC system is established by using Fluent software. Then, the flow and heat transfer characteristics of the exhaust at the evaporator shell side are obtained, and then the performance of the fin-and-tube evaporator of the ORC system is analyzed based on the field synergy principle. The field synergy angle (β is the intersection angle between the velocity vector and the temperature gradient. When the absolute values of velocity and temperature gradient are constant and β < 90°, heat transfer enhancement can be achieved with the decrease of the β. When the absolute values of velocity and temperature gradient are constant and β >90°, heat transfer enhancement can be achieved with the increase of the β. Subsequently, the influence of the evaporator of the ORC system on diesel engine performance is studied. A simulation model of the diesel engine is built by using GT–Power software under various operating conditions, and the variation tendency of engine power, torque, and brake specific fuel consumption (BSFC are obtained. The variation tendency of the power output and BSFC of diesel engine–ORC combined system are obtained when the evaporation pressure ranges from 1.0 MPa to 3.5 MPa. Results show that the field synergy effect for the areas among the tube bundles of the evaporator main body and the field synergy effect for the areas among the fins on the windward side are satisfactory. However, the field synergy effect in the areas among the fins on the leeward side is weak. As a result of the pressure drop caused by the evaporator of the ORC system, the diesel engine power and torque decreases slightly, whereas the BSFC increases slightly with the increase of exhaust back

  6. Basic survey project for joint implementation in fiscal 1998. Study of BFG mono-firing gas turbine combined cycle power plant application for the steel mill of China; 1998 nendo kyodo jisshi nado suishin kiso chosa. Chugoku seitetsu kaishamuke koro gas sensho combined cycle hatsuden setsubi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Discussions were given on application to the steel mills in China of a 1100-degree C class high-efficiency combined cycle power plant (CCPP) exclusively firing blast furnace gas developed jointly by Kawasaki Heavy Industries Ltd. of Japan and ABB Corporation of Switzerland. The CCPP can utilize the energy possessed by a fuel without waste from high temperature zones to low temperature zones, being capable of attaining high efficiency that cannot be achieved with the single cycle. The CCPP has the efficiency exceeding that of the BTGP by about 10% or more in absolute value. The investigations and discussions were given on Shougang General Corporation, Anshan Steel Corporation and Wuhan Steel Corporation. As a result, in the plan for the power plant of Shougang General Corporation on which both parties have agreed, the project implementation can be expected to result in electric power generation of 110 MW in annual average, factory air supply of about 100 tons per hour in annual average, and annual reduction of carbon dioxide of 841 kilo tons. Wuhan Steel and Anshan Steel will require implementation of further detailed investigation, but the possibility of realization is considered high (NEDO)

  7. Parameter Discrimination of a Combined Cycle Unit Based on the Genetic Algorithm%基于遗传算法的联合循环机组模型参数辨识

    Institute of Scientific and Technical Information of China (English)

    仇晓智; 王卫; 司派友; 黄葆华

    2012-01-01

    针对将联合循环机组模型引入电力系统稳定性分析程序的实际需求,在对常规联合循环机组数学模型分析的基础上,提出了适用于电力系统稳定性分析的联合循环机组模型.将遗传算法应用于模型参数辨识过程中,开发了基于Delphi平台的联合循环机组模型辨识软件.应用实例表明:模型的仿真结果与实测信号相一致,证明了所提模型和辨识算法的有效性,为后续联合循环机组的一次调频和动态特性分析奠定了基础.%In the light of the actual demand of introducing a model for combined cycle units into an electric power system stability analytic programme, presented was a combined cycle unit model applicable for the stability analysis of an electric power system on the basis of an analysis of the mathematical model for conventional combined cycle units. The authors have applied the genetic algorithm in the model parameter discrimination process and developed a software for discriminating a model for combined cycle units based on Delphi platform. The application cases show that the simulation results by using the model are in agreement with the actually measured signals, proving that the model under discussion and the discrimination algorithm are effective, thus laying a foundation for subsequent primary frequency modulation and dynamic characteristics analysis of a combined cycle unit.

  8. TIDD PFBC Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    In fluidized bed combustion, coal and sorbent (dolomite or limestone) are fed into a boiler in which air, entering from the bottom, maintains the bed material in a highly turbulent suspended state called fluidization. This turbulence creates good contact between the air and fuel, allowing for high combustion efficiency and excellent adsorption of sulfur dioxide (SO{sub 2}) during the combustion process. In PFBC applications, pressurized air is supplied to the combustor. Pressurizing the air concentrates a larger quantity of oxygen per unit volume. This results in a lower velocity of air through the fuel bed. The lower velocity reduces the total height required for the bed and freeboard above the bed. Also, a smaller plan area is required for the bed area as compared to an atmospheric fluidized bed. This has the advantage of requiring a much smaller pressure vessel to contain the boiler enclosure. The mean bed temperature of a pressurized fluidized bed combustor is typically maintained in the range 1540 to 1580 F. This is well below the ash fusion temperature of coal, yet above the ignition temperature of the coal. Advantages of the low bed temperature are no slag formation and a reduction of NO{sub x} emissions to less than half that of a conventional boiler. The Tidd Plant is a combined cycle pressurized fluidized bed combustion system with a topping gas cycle and a bottoming steam cycle.

  9. Spatial and temporal variations in nitrogen sources and cycling in north San Francisco Bay: Combining multi-isotope and hydrologic modeling approaches

    Science.gov (United States)

    Young, M. B.; Kendall, C.; Silva, S. R.; Guerin, M.; Kraus, T. E.

    2010-12-01

    In order to better understand the factors controlling nitrogen sources and cycling within Suisun Bay and the Sacramento-San Joaquin River confluence, stable isotope measurements of nitrate (NO3), water, and particulate organic matter (POM) were combined with estimates of volumetric water source contributions calculated using the DSM2-HYDRO hydrodynamic model. The San Joaquin River (SJR) typically carries high concentrations of NO3, while the Sacramento River downstream of the Sacramento Regional Waste Water Treatment Plant (SRWWTP) has high concentrations of ammonium (NH4). Samples were collected at established USGS stations from the lower Sacramento River and north San Francisco Bay on 16 occasions between August 2006 and May 2008, and along transects of the SJR between March 2005 and December 2007. The average δ15N of NO3 discharging from the SJR was consistently higher (13.0 ± 2.1 ‰, upstream of pumping diversion) in comparison to the Sacramento River (5.3 ± 0.9 ‰, sampled at Rio Vista), indicating that δ15N-NO3 can be useful for tracking NO3 from the two watersheds as it mixes in the confluence region. Results from the DSM2-HYDRO model show that during the study period the SJR contributed very little water (less than 1.5 %) to sites located at the Sacramento/SJR confluence and downstream in Suisun Bay. The distribution of δ15N-NO3 values in the confluence area and north Bay was consistent with this result, showing a fairly narrow range of lower values (3.5 to 9.5 ‰), indicating that little to no NO3 from the SJR watershed was reaching the confluence area and the north Bay during the sampling times. In the SJR, the C:N ratio of POM was usually between 6 and 10 except during periods of high winter flows, indicating that the POM was primarily algae most of the year. The δ15N of POM within the SJR was generally between 2 and 4 per mil lower than the δ15N of the NO3 and followed a similar pattern to the NO3, reflecting algal uptake of the NO3. In

  10. The lowest-dose, extended-cycle combined oral contraceptive pill with continuous ethinyl estradiol in the United States: a review of the literature on ethinyl estradiol 20 µg/levonorgestrel 100 µg + ethinyl estradiol 10 µg

    Directory of Open Access Journals (Sweden)

    Sheila Krishnan

    2010-08-01

    Full Text Available Sheila Krishnan, Jessica KileyDepartment of Obstetrics and Gynecology, Northwestern University, Chicago, Illinois, USAAbstract: Extended-cycle oral contraceptives (OCs are increasing in popularity in the United States. A new extended-cycle OC that contains the lowest doses of ethinyl estradiol (EE and levonorgestrel (LNG + continuous EE throughout the cycle is now available. It provides 84 days of a low-dose, combined active pill containing levonorgestrel 100 µg and ethinyl estradiol 20 µg. Instead of 7 days of placebo following the active pills, the regimen delivers 7 days of ethinyl estradiol 10 µg. Existing studies reveal a similar efficacy and adverse effect profile compared with other extended-regimen OCs. Specifically, the unscheduled bleeding profile is similar to other extended-cycle OCs and improves with the increase in the duration of use. Although lower daily doses of hormonal exposure have potential benefit, to our knowledge, there are no published studies indicating that this specific regimen offers a lower incidence of hormone-related side effects or adverse events. In summary, this new extended-cycle OC provides patients a low-dose, extended-regimen OC option without sacrificing efficacy or tolerability.Keywords: continuous regimen, ethinyl estradiol, extended cycle, oral contraceptive

  11. Degradation of thermal barrier coatings on an Integrated Gasification Combined Cycle (IGCC) simulated film-cooled turbine vane pressure surface due to particulate fly ash deposition

    Science.gov (United States)

    Luo, Kevin

    Coal synthesis gas (syngas) can introduce contaminants into the flow of an Integrated Gasification Combined Cycle (IGCC) industrial gas turbine which can form molten deposits onto components of the first stage of a turbine. Research is being conducted at West Virginia University (WVU) to study the effects of particulate deposition on thermal barrier coatings (TBC) employed on the airfoils of an IGCC turbine hot section. WVU had been working with U.S. Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane to study the effects on film cooling. To simulate the particulate deposition, TBC coated, angled film-cooled test articles were subjected to accelerated deposition injected into the flow of a combustor facility with a pressure of approximately 4 atm and a gas temperature of 1560 K. The particle characteristics between engine conditions and laboratory are matched using the Stokes number and particulate loading. To investigate the degradation on the TBC from the particulate deposition, non-destructive evaluations were performed using a load-based multiple-partial unloading micro-indentation technique and were followed by scanning electron microscopy (SEM) evaluation and energy dispersive X-ray spectroscopy (EDS) examinations. The micro-indentation technique used in the study was developed by Kang et al. and can quantitatively evaluate the mechanical properties of materials. The indentation results found that the Young's Modulus of the ceramic top coat is higher in areas with deposition formation due to the penetration of the fly ash. The increase in the modulus of elasticity has been shown to result in a reduction of strain tolerance of the 7% yttria-stabilized zirconia (7YSZ) TBC coatings. The increase in the Young's modulus of the ceramic top coat is due to the stiffening of the YSZ columnar microstructure from the cooled particulate fly ash. SEM evaluation was used to

  12. Sensor placement algorithm development to maximize the efficiency of acid gas removal unit for integrated gasification combined cycle (IGCC) power plant with CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2012-01-01

    Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel

  13. Combining charcoal and elemental black carbon analysis in sedimentary archives: Implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions

    Science.gov (United States)

    Thevenon, Florian; Williamson, David; Bard, Edouard; Anselmetti, Flavio S.; Beaufort, Luc; Cachier, Hélène

    2010-07-01

    This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles > 0.2 µm 2 remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after thermal and chemical oxidative treatments is quantified as black carbon (BC). The obtained pyrogenic carbon records from three sediment core-based case studies, (i) the Late Pleistocene equatorial Pacific Ocean, (ii) the mid-Holocene European Lake Lucerne, and (iii) the Late Holocene African Lake Masoko, are interpreted as proxy records of regional transportation mechanisms and biomass burning activities. The results show that the burial of dark carbon-rich particles in the 360 kyr-long record from the west equatorial Pacific is controlled by the combination of sea-level changes and low-latitude atmospheric circulation patterns (summer monsoon dynamics). However, the three fold increases in charcoal and BC sediment influxes between 53-43 and 12-10 kyr BP suggest that major shifts in fire activity occur synchronously with human colonization in the Indo/Pacific region. The coarse charcoal distribution from a 7.2 kyr record from Lake Lucerne in Switzerland closely matches the regional timing of major technical, land-use, and socio-economic changes during the Neolithic (between ca. 5.7 and 5.2 kyr BP and 4.9-4.5 kyr BP), the Bronze and Iron Ages (at ca. 3.3 and 2.4 kyr BP, respectively), and the industrialization (after AD 1838), pointing to the key impact of human activities on the sources, transportation processes and reservoirs of refractory carbon during the Holocene. In the tropical Masoko maar lake in Tanzania, where charcoal and BC records are highly sensitive to the local climate

  14. LIMB Demonstration Project Extension and Coolside Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Goots, T.R.; DePero, M.J.; Nolan, P.S.

    1992-11-10

    This report presents results from the limestone Injection Multistage Burner (LIMB) Demonstration Project Extension. LIMB is a furnace sorbent injection technology designed for the reduction of sulfur dioxide (SO[sub 2]) and nitrogen oxides (NO[sub x]) emissions from coal-fired utility boilers. The testing was conducted on the 105 Mwe, coal-fired, Unit 4 boiler at Ohio Edison's Edgewater Station in Lorain, Ohio. In addition to the LIMB Extension activities, the overall project included demonstration of the Coolside process for S0[sub 2] removal for which a separate report has been issued. The primary purpose of the DOE LIMB Extension testing, was to demonstrate the generic applicability of LIMB technology. The program sought to characterize the S0[sub 2] emissions that result when various calcium-based sorbents are injected into the furnace, while burning coals having sulfur content ranging from 1.6 to 3.8 weight percent. The four sorbents used included calcitic limestone, dolomitic hydrated lime, calcitic hydrated lime, and calcitic hydrated lime with a small amount of added calcium lignosulfonate. The results include those obtained for the various coal/sorbent combinations and the effects of the LIMB process on boiler and plant operations.

  15. Menstrual Cycle

    Science.gov (United States)

    ... Luteal (after egg release) Changes During the Menstrual Cycle The menstrual cycle is regulated by the complex interaction of ... egg release) Luteal (after egg release) The menstrual cycle begins with menstrual bleeding (menstruation), which marks the first day of ...

  16. Population pharmacokinetic modeling and noncompartmental analysis demonstrated bioequivalence between metformin component of metformin/vildagliptin fixed-dose combination products and metformin immediate-release tablet sourced from various countries.

    Science.gov (United States)

    Chitnis, Shripad D; Han, Yi; Yamaguchi, Masayuki; Mita, Sachiko; Zhao, Rong; Sunkara, Gangadhar; Kulmatycki, Kenneth

    2016-01-01

    Metformin is the first-line pharmacotherapy choice for treating type-2 diabetes mellitus, alone or in combination with other antidiabetic drugs. During the development of immediate-release (IR) metformin containing novel fixed-dose combination (FDC) products, several health-authorities require sponsors to demonstrate bioequivalence between FDC products and the country-sourced metformin for market approval. Eight bioequivalence studies that compared metformin/vildagliptin FDC product (test) to metformin IR tablet sourced from various countries (reference) were conducted. A population pharmacokinetic (PPK) analysis of pooled metformin concentration-time data was performed to evaluate whether country-sourced metformin is a significant covariate. The PPK analysis demonstrated that there was no clinically relevant effect of metformin source or race/ethnicity on metformin pharmacokinetics. Also, noncompartmental analysis conducted showed that 90%CI of geometric mean ratios of test to reference metformin formulations, calculated for maximum-concentration and exposure parameters, were within the 80%-125% criteria, indicating comparable metformin exposure regardless of the country-sourced metformin IR formulation. These results are consistent with the biopharmaceutics properties of metformin and provide scientific evidence that after assessing in vitro dissolution of novel FDC formulation, additional bioequivalence studies with multiple countries' reference products may not be required once bioequivalence is established with 1 country-sourced IR metformin formulation.

  17. Investigation of dynamic load changes of a combined cycle power plant with circulating pressurized fluidized bed using a simulation model; Untersuchungen zum dynamischen Lastaenderungsverhalten eines Kombi-Kraftwerks mit zirkulierender Druckwirbelschicht mit Hilfe eines Simulationsmodells

    Energy Technology Data Exchange (ETDEWEB)

    Bockamp, S.; Krumm, W.

    2001-07-01

    Fluidized bed combustion technology offers high efficient power plants with low emissions using coal, biomass or waste as fuel input. Mathematical models support the optimisation and design of power plants. The mathematical fluidized bed system model developed at the Institut fuer Energietechnik, Universitaet Siegen, allows the simulation of steady state or dynamic process operation behaviour. This model is used for detailed examining of the overall combined cycle power plant and the interactions between the single components gas turbine, furnace and water-/steam cycle. The described simulation model presented in this paper is applied for the determination of the transient operation behaviour of a combined cycle power plant based on pressurized circulating fluidized bed combustion. The effects of a step function load change on the temperature profile, the emissions and on process reaction of water/steam cycle and on gas turbine is analysed and discussed in detail at different component outlets. (orig.) [German] Das Kombi-Kraftwerk mit zirkulierender Druckwirbelschichtfeuerung stellt ein effizientes und emissionsarmes Konzept dar. Neben den wirbelschichtinhaerenten Eigenschaften wie geringerer Schadstoffbildung durch niedrige Feuerraumtemperaturen und der integrierten Schadstoffreduktion durch die Zugabe von Zuschlagstoffen verspricht die druckaufgeladenen Variante aufgrund der hohen Querschnittsbelastung eine kompakte Bauart sowie einen fuer die Verstromung von Kohlen hohen Wirkungsgrad. Kohle kann mit diesem Verfahren direkt innerhalb eines Gasturbinenprozesses genutzt werden. Mit Hilfe der mathematischen Modellbildung koennen die dynamischen Auswirkungen auf das Gesamtsystem Kombi-Kraftwerk untersucht werden. (orig.)

  18. Technical evaluation of biomass gasification technology integrated with combined cycle using bagasse as fuel; Avaliacao tecnica da tecnologia de gaseificacao de biomassa integrada a ciclos combinados utilizando bagaco como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Silva; Venturini, Osvaldo Jose; Lora, Electo Silva [Universidade Federal de Itajuba (NEST/UNIFEI), MG (Brazil). Nucleo de Excelencia em Geracao Termeletrica e Distribuida], email: pablo.silvaortiz@gmail.com; Campo, Andres Perez [Universidade Automona de Bucaramanga (UNAB) (Colombia). Fac. de Engenharia Fisico- Mecanica, Engenharia em Energia

    2010-07-01

    Biomass Integrated Gasification Combined Cycle (BIGCC) was identified as an advanced technology with potential to be competitive for electricity generation. The BIGCC technology uses biomass and the sub products of some industrial sectors processing, like sugar cane, as feedstock. The current Brazilian energy matrix is mainly based on renewable generation sources, making it important to assess these gasification technologies in the production of sugar, ethanol and electricity. In this work, a technical evaluation of the technologies incorporated in BIGCC power plants is done: the gasification process and the combined cycle power plant. On the other hand, the generated costs of these systems are analyzed, and the potential for implementation in Brazil plants from sugar cane bagasse is studied, in which a 10% increase in efficiency is obtained. (author)

  19. Automatic system of tests for control equipment in combined cycle power stations; Sistema automatico de pruebas para equipos de control en centrales de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, Miguel A; Flores L, Zenon; Delgadillo V, Miguel A; Gutierrez A, Ruben [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    This article deals on the Automatic System of Tests, denominated PROBADOR, used by the Gerencia de Control e Instrumentation (GCI) of the Instituto de Investigaciones Electricas (IIE)for the accomplishment of dynamic tests in laboratory, to the systems of acquisition and control developed with the electronic line SAC-IIE that are installed in the Thermoelectric Power station of Combined Cycle (CTCC) of Dos Bocas, Veracruz and Gomez Palacio, Durango, Mexico. Also the architecture, the functions that are carried out in the equipment of the System of Acquisition and control (SAC) and in the personal computer (PC) that conforms it are described, as well as the methodology used for the development of the tests. The PC constitutes Interface Man-Machine (IMM) and in the SAC equipment the simulation of the processes is made (by means of the execution of algebraic-differential equations) in the compressor, combustion chamber, gas turbine, heat recuperators, steam turbines and condenser equipment that integrate a CTCC. The equations that are used are based in the thermodynamics, flow dynamics and heat transfer; they become attached to the real process with a margin of error that is estimated in 10%. Finally, the tendencies of the PROBADOR and the technical and economic advantages are described that it has provided for the improvement in the performance of the control systems, before different situations, with no need to have the real process. [Spanish] Este articulo versa sobre el Sistema Automatico de Pruebas, denominado PROBADOR, utilizado por la Gerencia de Control e Instrumentacion (GCI) del Instituto de Investigaciones Electricas para la realizacion de pruebas dinamicas en laboratorio, a los sistemas de adquisicion y control desarrollado con la linea electronica SAC-IIE que estan instalados en las Centrales Termoelectricas de Ciclo Combinado (CTCC) de Dos Bocas, Veracruz y Gomez Palacio, Durango, Mexico. Tambien se describen la arquitectura, las funciones que se llevan

  20. Development of a ceramic heat exchanger for a combined cycle plant with pressurized coal dust combustion. Final report; Entwicklung eines keramischen Waermeaustauschers fuer eine Kombianlage mit Kohlenstaubdruckfeuerung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Leithner, R.; Ehlers, C.

    2001-12-01

    State of Research: The Pressurized Pulverized Coal Combustion Combined Cycle (PPCCCC) with a directly fired gas turbine can reach electrical efficiencies beyond 50%. The required gas quality upstream the gas turbine has not been reached yet at temperatures above 1000 C. One approach tested is the precipitation of ash and alkalines at temperatures above the ash melting point. This principle contains problems concerning the remaining content of ash and alkalines in the flue gas and damages to the refractory materials due to corrosion. Goal of the Investigation: An alternative process had to be investigated in which the flue gas is cleaned according to the state of the art, i.e. below the ash fusion temperature. This principle requires cooling down the flue gas and heating it up again after cleaning in a high temperature heat exchanger. Method: A ceramic tube-and-shell heat exchanger in a model scale was designed and was operated at realistic conditions in an atmospheric test plant in connection with a high temperture precipitation. Result: The heat exchanger showed a good performance concerning design and material. The expected temperatures were not reached totally because of untight joints. Clogging occurred in the tube entrances at high temperatures because of sintered ash agglomerates. First tests to clean the entrances during operation showed positive results. The ash precipitation by means of a cyclone and ceramic filter candles was performed without difficulties. Conclusion: Avoiding and improving joints will help to achieve higher temperatures. A process of cleaning the tubes in-line has to be introduced to prevent the clogging effects. If this is successfully done for high temperatures, an attractive principle for a PPCCCC-process is available which reaches the gas purity required. (orig.) [German] Derzeitiger Stand der Forschung: Der Kohlenstaubdruckfeuerungs-Kombiprozess mit direkt befeuerter Gasturbine verspricht elektrische Wirkungsgrade ueber 50%. Die

  1. Modeling and optimization of a modified claus process as part of an integrted gasification combined cycle (IGCC) power plant with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2011-01-01

    The modified Claus process is one of the most common technologies for sulfur recovery from acid gas streams. Important design criteria for the Claus unit, when part of an Integrated Gasification Combined Cycle (IGCC) power plant, are the ability to destroy ammonia completely and recover sulfur thoroughly from a relatively low purity acid gas stream without sacrificing flame stability. Due to these criteria, modifications are often required to the conventional process, resulting in a modified Claus process. For the studies discussed here, these modifications include the use of a 95% pure oxygen stream as the oxidant, a split flow configuration, and the preheating of the feeds with the intermediate pressure steam generated in th