Energy Technology Data Exchange (ETDEWEB)

Kawasaki Heavy Industries, Ltd. has developed a gas turbine combined cycle and cogeneration plant computer aided engineering (CAE) system, which creates cycle heat balance automatically on given configurations of gas turbines, heat recovery boilers, steam turbines and auxiliaries. The system can predict the performance of the plant as a function of control set points, loads, process steam requirements and ambient conditions, which enables accurate and fast design of gas turbine combined cycle and cogeneration plants. (author)

Energy Technology Data Exchange (ETDEWEB)

National Power is building its first gas turbine combined cycle power station at Killingholme, situated to the south of the River Humber in the East of England. NEI ABB Gas Turbines Limited was awarded the turnkey contract in July 1990 to build a nominal 650 MW combined cycle power station based around three Asea Brown Boveri GT13E gas turbines. The project is outlined in this article. The plant is due for completion in July 1993. (author)

International Nuclear Information System (INIS)

This paper presents part-load evaluation of a natural gas-fired chemical looping combustion (CLC) combined cycle with CO2 capture. The novel combined cycle employs an air-based gas turbine, a CO2-turbine and a steam turbine cycle. In this combined cycle, the CLC reactors replace combustion chamber of the gas turbine. The proposed combined cycle has a net plant efficiency of about 52.2% at full-load, including CO2 compression to 200 bar. The part-load evaluation shows that reducing the load down to 60% results in an efficiency drop of 2.6%-points. However, the plant shows better relative part-load efficiency compared to conventional combined cycles. The pressure in CLC-reduction and -oxidation ...

Energy Technology Data Exchange (ETDEWEB)

Rapid technology improvements, resulting in high efficiency, emissions reduction and low generation cost, are making gas turbines the generation technology of choice despite some recent reliability problems. The basic reason for the dominance is high efficiency. The rapid pace of gas-turbine technology improvement in the 1990s drove combined-cycle thermal efficiency to nearly 60 percent with natural gas as the fuel. It will probably go even higher after the year 2000. In addition, the gas-fired combined cycle is a bargain. With natural gas prices where they are right now, it is the least-cost generation operation for power producers with access to gas. Many will replace older, high-cost power plants with new gas-fired combined cycle power ...

Energy Technology Data Exchange (ETDEWEB)

During the last 15 years cycles with CO{sub 2} capture have been in focus, due to the growing concern over our climate. Often, a natural gas fired combined cycle with a chemical absorption plant for CO{sub 2} capture from the flue gases have been used as a reference in comparisons between cycles. Neither the integration of the steam production for regeneration of amines in the combined cycle nor the off-design behaviour of such a plant has been extensively studied before. In this paper, the integration of steam production for regeneration of the amines is modelled at design load and studied in off-design conditions for a combined cycle. Different ambient conditions and part-load strategies and their influence on the cycle performance are also examined. Of particular interest is a ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and ...

Wastenet

... As a consequence the Brazilian government introduced a thermoelectric priority programme covering the construction of new gas fired combined cycle power plants. One such plant has been constructed at the Suape industrial port complex in the state of Pernambuco. The US$350 million Termopernambuco combined cycle gas ...

Energy Technology Data Exchange (ETDEWEB)

The systems analyses and optimization studies performed in connection with a program to design and evaluate a commercial 663 MWe coal-fired combined cycle power plant using pressurized fluidized bed combustion and advanced technology in the hot gas cleanup system and gas turbines are presented. Details on the plant control system are included. (LCL)

Energy Technology Data Exchange (ETDEWEB)

Korea Electric Power Corporation (Kepco) of South Korea has awarded Asea Brown Boveri Switzerland, a member of the ABB Group, a contract to supply the main equipment for two gas-fired combined-cycle power stations. News of the contract followed an announcement last year that Kepco will build a series of gas-fired power stations in the early 1990s to supply electricity to new housing and commercial areas being built in the Seoul-Incheon connurbation. (author).

Energy Technology Data Exchange (ETDEWEB)

This article describes how a natural gas-fired combined cycle with increased firing temperature, reduced cooling air usage, improved component efficiencies, and cycle enhancements could achieve a lower heating value plant efficiency of greater than 60%. Today's gas turbine systems feature high fuel-to-electricity efficiencies. Efficiencies, on a lower-heating-value (LHV) basis, for large natural gas-fired combined-cycle systems for the utility market have been demonstrated at 54%. Even though manufacturers will make improvements in the 1990s, efficiency levels will reach a plateau. Cycle innovations and gas turbine design changes will achieve LHV efficiencies in the 60% range for natural gas-fired utility machines.

Energy Technology Data Exchange (ETDEWEB)

Gas-fired combined cycle plant may be the norm when it comes to new plant but it comes in a variety of shapes and sizes. Samarinda uses aero-derivatives with the famous Rolls-Royce RB211 gas generator. (author)

Energy Technology Data Exchange (ETDEWEB)

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 ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of Formula Not Shown compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings.

International Nuclear Information System (INIS)

The outlook for natural gas (from both supply and price perspectives) has improved dramatically since the late 1970s, and significant advances have been made in electrical generation technologies which use gas. For example, gas-fired combined-cycle turbine units have become even more efficient and reliable. These units can be installed quickly (12 to 24 months versus 8 to 15 years for coal and nuclear units), and they may be brought on-line in small incremental blocks. This modular construction feature offers greater flexibility to utility planners, and the relatively low capital cost of combined-cycle units reduces financial uncertainties. The purpose of this chapter is to compare two electric power generating options, a new coal-fired powerplant and a new natural gas fired combined-cycle unit, from both economic and environmental ...

Energy Technology Data Exchange (ETDEWEB)

The increasing price differential between natural gas and coal will create a demand for technology that can allow the displacement of natural gas with coal in power plants. Coal gasification is the standard approach suggested to allow coal to displace natural gas. However, the relatively high capital investment required for coal gasification will require fuel cost differentials higher than those anticipated in the near term before coal gasification replaces natural gas. One way of achieving shorter term displacement of natural gas by coal would be to develop technology that would allow coal to be used as the heat source for the endothermic reforming of natural gas. In a natural gas-fired combined cycle power plant, the endothermic heat of reforming, which would be provided by coal combustion, is ...

Energy Technology Data Exchange (ETDEWEB)

In most industrial processes operating at elevated temperatures, protective oxide layers perform a vital duty in protecting the underlying metallic alloys from process gases. Coal-fired combined cycle power generation systems present a number of process conditions in which the properties of the protective oxide layers are particularly important. This paper discusses two of these particular conditions: (1) `erosion/corrosion` of in-bed heat exchanger tubing and (2) thermal cycling of hot gas path components. For both these situations, the desirable properties of protective scales are outlined. The behaviour of scales in practice are highlighted. 33 refs., 6 figs., 2 tabs.

International Nuclear Information System (INIS)

This paper reports that there are four combustion technologies upon which U.S. electric utilities are expected to rely for the majority of their future power generating needs. These technologies are pulverized coal- fired combustion (PC); coal-fired fluidized bed combustion (AFBC); coal gasification, combined cycle systems (CGCC); and natural gas-fired combined cycle systems (NGCC). The engineering and economic parameters which affect the choice of a technology include capital costs, operating and maintenance costs, fuel costs, construction schedule, process risk, environmental and site impacts, fuel efficiency and flexibility, plant availability, capacity factors, timing of startup, and the importance of utility economic and financial factors.

Energy Technology Data Exchange (ETDEWEB)

In the research of a more efficient, less costly, more environmentally responsible and less technically difficult method for generating electrical power from coal, `the Partially Gasified Coal Fired Combined Cycle with a CFBC with Different Speeds (DFBC)` is introduced by Tsinghua University. The high efficiency cycle includes gasification, compressed air heating in a fluidized bed immersed air heater followed by a combustor and the heat recovery of gas turbine exhausted gas used as the combustion of coal in the differential-velocity atmospheric circulating fluidized bed. Superheated steam is raised in the DFBC boiler. A preliminary analysis is made for the choice of combined cycle components. The computer program can be used to evaluate the design and off-design performance of the power plant. The simulation results show that the new system ...

Energy Technology Data Exchange (ETDEWEB)

This paper is an application of the economic model developed in Part 1 and programmed in the computer code PEACES (program for the economic analysis of combined energy systems). A case study is presented in which hypothetical energy requirements at an industrial site are considered and an exercise is conducted wherein cogeneration is considered as a means of improving the energy situation at the site. Appropriate technologies that can satisfy the cogeneration requirements are investigated and technical and economic evaluations are carried out for a feasibility assessment. Of the three proposals considered, the gas turbine with heat recovery steam generator and the gas/steam turbine combined cycle cogeneration plant were found to be economically viable, while the steam turbine was not. It was recommended that the gas/steam turbine combined ...

International Nuclear Information System (INIS)

Australian electricity markets and natural gas markets are undergoing rapid reform. Choosing among electricity generation modes is a key issue. Such choices are affected by expectations about the future structure of these markets and future technologies, and how they affect costs and emissions. In the research reported in this paper, the MARKAL model of the Australian energy system is used to evaluate the competitive position of natural gas fired combined cycle gas turbines (CCGTs) in the energy sector as a whole. Competing in the sector are large-scale electricity generation technologies such as refurbished existing coal fired stations and advanced forms of coal fired generation. The modelling incorporates new data on electricity supply technologies and options.

Energy Technology Data Exchange (ETDEWEB)

Pressurized fluidized bed combustion (PFBC) is an emerging coal-fired, combined-cycle power generation technology nearing commercial status through several operating and planned demonstration plants throughout the world. Current-generation PFBC plants use ``ruggedized`` gas turbines that can tolerate dust loading common with conventional cyclone gas cleaning. The next generation of PFBC will apply advanced hot gas cleaning systems that will reuse the dust loading to low levels acceptable to high performance, industrial gas turbines. These advances should result in performance and cost advantages. This article examines the demonstration of PFBC technology at Tidd power station.

International Nuclear Information System (INIS)

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an ...

Energy Technology Data Exchange (ETDEWEB)

Out of concern for the global environment, technologies for coal-fired combined cycle power generation are under development throughout the world today, aiming at highly efficient use of coal. Under these circumstances, the authors and others, with the intention of producing a coal-fired combined cycle power generation system with higher plant efficiency, lower construction cost, and higher reliability than conventional systems, proposed a new gasification combined cycle power generation system that differs from the conventional IGCC system. The authors studied system configuration and conducted elementary research necessary for implementing the system. This report deals with the basic concepts of the system and the results of basic studies carried out to realize of the concepts, including a study on alkali metal vapour concentration in relation to heat ...

Energy Technology Data Exchange (ETDEWEB)

TSS (thermal swing sublimation) method was studied which uses vaporization heat and sensible heat of LNG for solidification and separation of CO2 gas in waste gases of LNG-fired combined cycle power generation system. In experiment, the mixed gas composed of CO2, H2O and N2 was used for simulating waste gas of LNG-fired combined cycle power generation systems, and the growth behavior of ice and dry ice was studied for developing dry ice making technology under low-temperature condition. As the experimental result, the following were clarified: various crystal structures depending on cooling temperature, the effect of gas flow rate on peeling of surface precipitated solids, and solidification characteristics of H2O/CO2 mixed gas. The growth rate of precipitated solid film thickness decreased with an ...

Energy Technology Data Exchange (ETDEWEB)

The objectives of this program are to evaluate the Coal Fired Combined Cycle (CFCC) power plant conceptual design and to conduct supporting development programs for pressurized fluidized bed technology advancement in combustion/steam generator, gas turbine and hot gas cleanup technologies. The Coal-Fired Combined Cycle is the unique power plant concept developed under the leadership of the General Electric Company to provide a direct coal-burning gas turbine and steam turbine combined-cycle power plant. The advantages of the combined cycle for higher efficiency and the potential of the pressurized fluidized bed combustor improvements in emissions could offer a new and attractive option to the electric utility industry. The CFCC approach provides for cooling the fluid bed ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

Modern combined cycle power plants with natural gas as the only fuel reach efficiencies of up to 58% for electric power generation. Nevertheless the reserves of natural gas are more limited compared to the reserves of coal. Therefore possibilities should be investigated to use coal for such plants also. One concept, that combines the use of coal in a combined cycle application with high efficiencies is examined in this paper. According to this concept the exhaust gas of the gas turbine (vitiated air) is the combustion air for the pulverised coal combustion, that takes place in the bottoming steam generator. Due to the low oxygen content of the vitiated air the burnout of the coal may be incomplete. In order to avoid the incomplete combustion of the coal and the resulting decrease of the efficiency of ...

Energy Technology Data Exchange (ETDEWEB)

The Coal Fired Combined Cycle (CFCC) is the unique powerplant concept developed under the leadership of the General Electric Company to provide a direct coal-burning gas turbine and steam turbine combined cycle powerplant. On the basis of previous studies and confirming work under this contract, General Electric continues to believe that the CFCC approach offers important advantages over alternate approaches: higher powerplant efficiency in the combustor temperature range of interest; reduced combustor/steam generator corrosion potential, due to low fluid-bed tube temperature (as contrasted to the air in tube cycle); and increased gas turbine bucket life from improved material protection systems. The objective of this program is to evaluate the coal fired combined cycle powerplant conceptual design, ...

Energy Technology Data Exchange (ETDEWEB)

The competitiveness of a new nuclear plant vs. a new oil or gas fired combined cycle plant or a coal fired plant in East-Asia, is reviewed in the paper. Both the nuclear and the fossil fired plants are evaluated as either utility financed or independent power producer (IPP) financed. Two types of advanced light water reactors (ALWRs) are considered in this paper, namely evolutionary ALWRs (1200 MWe size) and passive ALWRs (600 MWe class). A range of capital and total generation costs for each plant type is reported here. The comparison centers on three elements of overall competitiveness: generation costs, hard currency requirements, and employment requirements. Each of these aspects is considered perspective. Year-by-Year generation cost history over the plant lifetime is shown in some cases. It is found here that a utility financed evolutionary and passive ALWRs are broadly competitive with an IPP financed ...

Energy Technology Data Exchange (ETDEWEB)

The first 750 MW block of the new South Humber Bank gas-fired combined cycle power plant, sited about 300 km north from London, was officially commissioned in September 12th 1997. The project has been a major success story for Imatran Voima Oy (IVO), which developed the concept and managed the project and owns 22.5 % of the plant; and ABB Power Plants Limited, responsible for the turnkey delivery. IVO Generation Services (UK) is responsible for the running and maintenance of the facility. IVO also manages two other existing plants in Britain, at Brigg (240 MW) and Peterborough (360 MW)

Energy Technology Data Exchange (ETDEWEB)

The results of a study assessing natural-gas-fired combined-cycle (GFCC) power generation in the electric-utility sector are presented. This study quantified the economic benefits attributable to GFCC generation and examined the characteristics of GFCC technology that produce these benefits and the ways that these benefits vary among regions in the country. The impacts of changes in important economic parameters (capital cost, fuel price, etc.) as well as the impact of advances in GFCC technology were considered. Use of GFCC technology in the electric-utility sector could play an important role in a least-cost planning strategy and thereby provide significant benefits to the utilities and their customers. Potential benefits include reduced capital and operating costs, more effective matching of load growth and capacity additions, and greater system reliability. 8 refs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

Low-dust flue gases can be washed efficiently of SO/sub 2/, and the flue gas heat can be utilized. The residual heat fraction still required by the process is characterized by a temperature of 15/sup 0/K above the temperature of the purified flue gas. Marketable crystalline ammonium sulfate is produced. The high efficiency and low heat consumption are achieved by combining all process stages in a single, fully integrated cycle process free of heat and materials losses. The process is characterized by high efficiency, low investment and operating costs, recovery of thermal energy, and production of an ammonium sulfate fertilizer.

Energy Technology Data Exchange (ETDEWEB)

The goal of this DOE Vision-21 project work scope is to develop an integrated suite of software tools that can be used to simulate and visualize advanced plant concepts. Existing process simulation software does not meet the DOE's objective of ''virtual simulation'' which is needed to evaluate complex cycles. The overall intent of the DOE is to improve predictive tools for cycle analysis, and to improve the component models that are used in turn to simulate the cycle. Advanced component models are available; however, a generic coupling capability that will link the advanced component models to the cycle simulation software remains to be developed. In the current project, the coupling of the cycle analysis and cycle component simulation software will be based on an existing suite of programs. The challenge is to ...

Energy Technology Data Exchange (ETDEWEB)

The combustion/emissions control island of the CFTCC plant produces cleaned coal combustion gases for expansion in the gas turbine. The gases are cleaned to protect the turbine from flow-path degeneration due to coal contaminants and to reduce environmental emissions to comparable or lower levels than alternate clean coal power plant tedmologies. An advantage of the CFTCC system over other clean coal technologies using gas turbines results from the CFTCC system having been designed as an adaptation to coal of a natural gas-fired combined cycle plant. Gas turbines are built for compactness and simplicity. The RQL combustor is designed using gas turbine combustion technology rather than process plant reactor technology used in other pressurized coal systems. The result is simpler and more compact combustion equipment than for alternate ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes EPRI`s computer based Performance, Operation and Maintenance Management System (``POMMS``) consisting of four (4) modules (``Modules``). These Modules are used to monitor, evaluate and analyze the cost effective operation of simple cycle and combined cycle gas turbine power plants. Inputs to POMMS relating to plant performance, availability and maintenance are monitored, stored in a data acquisition system and analyzed to determine their impact on performance and cost parameters. POMMS was developed by EPRI, Project Manager Fluor Daniel Power Generation Company and by the subcontractors who, together, engineered the individual POMMS Modules while working on EPRI`s Durability Surveillance of Advanced Gas Turbines Project (``Project``). The following modules are described in this paper and may be applied together or individually: Rotating Blade Temperature ...

Energy Technology Data Exchange (ETDEWEB)

The externally fired combined cycle (EFCC) process utilises a high temperature heat exchanger to transfer the heat of a dirty flue gas to a clean working medium. In comparison to other combined cycle concepts, like integrated gasification combined cycle or pressurized pulverized coal combustion, the problems of hot gas cleaning are avoided. The first part of the publication deals with the possible concepts and the efficiency potential of the externally fired combined cycle. The applicability of metallic and ceramic heat exchanger materials are discussed. The second part (BWK 6/02) summarizes the state of the art and presents the basic design of a ceramic heat exchanger. (orig.) [German] Der extern gefeuerte Gasturbinenprozess arbeitet mit einem Waermeuebertrager, um ein ...

Energy Technology Data Exchange (ETDEWEB)

Amidst the explosion of greenfield natural gas-fired combined-cycle plant development, opportunities still exist for valuable plant repowering and retrofits by taking advantages of unique technical and market conditions. One of the projects discussed is the rebuilding of the coal-fired Hawthorne unit 5 damaged by a boiler explosion. 3 tabs., 5 photos.

International Nuclear Information System (INIS)

This is a manuscript for a lecture contents: 1) Steam power and fundamentals of the steam power process, 3) conventional, nuclear and other steam generation processes, 4) cooling systems for steam power plants, 5) gas turbine power plants and combined-cycle power plants, 6) cogeneration, 7) development of thermal power plants and environmental effects. (GL).

Energy Technology Data Exchange (ETDEWEB)

Combined energy plants operating on the Brayton-Rankine cycle have gained wide acceptance as the most efficient energy conversion system. The technology is well proven and numerous research activities are underway to develop it further past its present plateau of performance. In developed and emerging economies alike, the current situation in the global economic market has caused the liberalisation of the energy industry in some countries, and in others it is causing a rethink of economic and energy policies. A result is that electric utility companies that have enjoyed a monopoly in power generation and distribution are seeing this privilege being eroded. This is opening up opportunities for independent power production and, consequently, for gas/steam turbine plants because of the technical merits of the technology and its ability to fill the vacuum being created in the energy industry. An economic model has been ...

Energy Technology Data Exchange (ETDEWEB)

In this study, sensitivity analysis of 100 MWth chemical looping combustion combined cycle (CLC-CC) plant based on fuel cost were performed. By performance analysis, net efficiency of natural gas/syngas fueled CLC-CC plant was 53-54%, corresponding to previous research. We used Chemical Engineering Plant Cost Index and Guthrie method to evaluate plant cost. For syngas fueled CLC-CC plant, the plant cost was higher since lower heating value (LHV) of syngas was lower than that of natural gas and cost of electricity (COE) was also higher since the cost of syngas was higher than that of natural gas. By sensitivity analysis, it was shown that the cost of syngas should be less than 5.3 $/GJ in order to make COE lower than 5.8 c/kWh which was COE of natural gas CLC-CC plant. 15 refs., 2 figs., 5 tabs.

Energy Technology Data Exchange (ETDEWEB)

Taiwan`s LNG consumption is planned to rise more than threefold over the next four years as medium-term plans to develop power generation facilities increasingly rely on gas-fired combined-cycle stations to avoid the threat of power shortages. State-run Taiwan Power Company (Taipower) expects its LNG consumption to rise from 1.1 mn tonnes in 1996 to 3.4 mn tonnes in the year 2000. By then the first of several gas-fired private power stations is expected to enter service, further increasing Taiwan`s total LNG requirement for power generation. (Author)

Energy Technology Data Exchange (ETDEWEB)

Preliminary plans for the 90 to 100-MW coal-fired combined cycle plant due to be built by a team headed by Southern California Edison and Texaco in the mid-1980s are reviewed. The basic operating goals call for having a gasifier with a 1,000 ton coal capacity per day feeding a 70-MW turbine which then provides waste heat to run a 30-MW steam turbine. Texaco will have responsibility for the gasifier part of the facility with the turbine-generator vendor charged with providing both gas and steam turbine equipment. If the 100-MW demonstration plant achieves 32 to 33% design efficiency, then a commercial plant with expansion turbines and steam reheat should hit 38% and require 20 to 30% less water than a conventional coal fired plant.

Energy Technology Data Exchange (ETDEWEB)

The Externally-Fired Combined Cycle (EFCC) offers a method for operating high-efficiency gas and steam turbine combined cycles on coal. In the EFCC, an air heater replaces the gas turbine combustor so that the turbine can be indirectly fired. Ceramic materials are required for the heat exchange surfaces to accommodate the operating temperatures of modern gas turbines. The ceramic air heater or heat exchanger is the focus of this program, and the two primary objectives are (1) to demonstrate that a ceramic air heater can be reliably pressurized to a level of 225 psia (1.5 MPa); and (2) to show that the air heater can withstand exposure to the products of coal combustion at elevated temperatures. By replacing the gas turbine combustor with a ceramic air heater, the cycle can use coal or other ...

Energy Technology Data Exchange (ETDEWEB)

The most developed systems for the generation of electricity from coal are the Integrated coal Gasification Combined Cycle (IGCC) and the Pressurized Fluidized Bed Combustion (PFBC) system. They both represent state-of-the-art technology and provide electric power at 41-46% LHV efficiency. However, the high level of complexity leads to lower reliability and higher costs. A simpler system, based on a coal-fired steam boiler integrated with a gas turbine, has been proposed. In such a plant, known as the externally fired combined cycle (EFCC), compressed air is heated indirectly in a heat exchanger located in the coal furnace. The hot air is then expanded in a turbine, and the exhaust is passed on to the coal furnace as preheated combustion air. Steam produced in the boiler generates additional power in a steam turbine. The exclusion of coal combustion products from the ...

Energy Technology Data Exchange (ETDEWEB)

This paper reviews different helium-cooled first wall and blanket designs; and compares the selection of structural materials. The authors found that the solid breeder, SiC-composite material option generates the lowest amount of induced radioactivity and afterheat and has the highest temperature capability. When combined with the direct cycle gas turbine system, it has the potential to be the most economical fusion system and can compete with advanced fission reactors. When compared to martensitic steel and V-alloy, SiC-composite is the least developed of these three structural materials, a focused development effort will be needed. Fundamental research has begun in addressing the issues of optimized composite materials, irradiation effects, leak tightness and low activation braze materials. Development of helium-cooled high heat flux components and further development of the direct cycle ...

Energy Technology Data Exchange (ETDEWEB)

The successful development of coal-fired combined cycle power generation systems require that all component parts are manufactured from appropriate materials and that these materials give predictable in-service performance. High temperature corrosion resulting from coal-derived particulates, deposition and gaseous species, is potentially life limiting for many components in these systems. Realistic laboratory test methods are outlined for gasifier and gas turbine environments and these have been combined with a materials assessment method based on accurate dimensional metrology. Such tests have allowed the production of models of materials performance as well as accurate comparisons between laboratory and plant derived data. These initial models predict the performance of materials well in the gas turbine environment, but tend to under-predict the damage observed in real gasifier ...

Science.gov (United States)

The goal of this project is to demonstrate that, by combining state-of-the-art technology, highly efficient plant operation and maintenance capabilities and by-product gypsum sales, significant reductions of SO{sub 2} emissions can be achieved at approximately one-half the life cycle cost of a conventional Flue Gas Desulfurization (FGD) system. Further, this emission reduction is achieved without generating solid waste and while minimizing liquid wastewater effluent. Basically, this project entails the design, construction and operation of a nominal 600 MWe AFGD facility to remove SO{sub 2} from coal-fired power plant flue gas at the Northern Indiana Public Service Company`s Bailly Generating Station.

International Nuclear Information System (INIS)

Geologically estimated natural gas resources are 500 Tcm. With the advance in geological science increase of estimated resources is expected. Natural gas reserves in 2000 have been proved to be around 165 Tcm. As it is known the reserves are subject to two constraints, namely: capital invested in the exploration and drilling technologies used to discover new reserves. The natural gas scarcity factor, i.e. ratio between available reserves and natural gas consumption, is around 300 years for the last 50 years. The new discovery of natural gas reserves has given rise to a new energy strategy based on natural gas. Natural gas utilization is constantly increasing in the last 50 years. With new technologies for deep drilling, we have come to know that there are enormous gas resources available at relatively low price. These ...

Energy Technology Data Exchange (ETDEWEB)

Use of gas-fired combined-cycle technology (GFCC) in the electric-utility sector could play an important role in a least-cost planning strategy and thereby provide significant benefits to the utilities and their customers. Potential benefits include reduced capital and operating costs, more-effective matching of load growth and capacity additions, greater system reliability, and reduced environmental emissions. GFCC technology was examined in eight utility systems in six geographic regions to estimate the potential benefits of its use. In all systems, GFCC technology was shown to have the potential to reduce the cumulative capital costs for adding new capacity. The overall conclusion of the study is that GFCC technology offers the potential for significant savings in many regions of the United States and that these benefits would appear over a wide range of economic conditions. The study provides insight into the important technological and ...

Energy Technology Data Exchange (ETDEWEB)

Deregulation and restructuring changes in the electric power industry have provided opportunities to build new power plants. These power plants, however, will not enjoy long-term power purchase agreements with the utilities they serve, but will have to respond to the market. This is where the term `merchant plant` originates. Calpine Corp. presented its reasons for believing that now is the best time to be building new merchant plants based on modern natural gas-fired, combined-cycle power plants. Among those reasons are: (1) construction of new nuclear power plants has been rejected by people on both sides of the border, (2) attempts to promote alternative energy sources such as solar, wind and biomass have not added significant generation capacity and are not likely to do so in the near future because of their high cost, and (3) coal-fired plants are also facing environmental challenges. For all these reasons, modern natural ...

Energy Technology Data Exchange (ETDEWEB)

The Coal Fired Combined Cycle (CFCC) power system thermodynamic cycle is illustrated schematically. Pressurized air supplied at the discharge of gas turbine compressors is ducted to the pressure vessel of pressurized, fluidized-bed, combustor-steam generator modules. The air is introduced in parallel to the beds, entering through distribution grids beneath each bed. Steam generation tubes are buried within the beds and are also arranged as membrane tube walls enclosing the four sides. Crushed coal (1/4 inch x 0) is pneumatically fed at locations just above the air inlet grids at the bottom of each bed. Dolomite is similarly fed to the individual beds. The coal is burned at a temperature below the ash fusion point. Sulfur is removed in the fluid beds through reaction of the SO/sub 2/ with CaCO/sub 3/ and O/sub 2/ to form solid CaSO/sub 4/ and CO/sub 2/ gas. The combustion gases leave ...

Energy Technology Data Exchange (ETDEWEB)

The report outlines the role of the IEA Greenhouse Gas R and D Programme, gives details of participants and of publications and summarises achievements of 1998. A successful conference on Greenhouse Gas Control Technologies was held in Interlaken, Switzerland. Technical studies reported include novel power generation concepts for removing carbon dioxide prior to or after combustion, using seawater for CO{sub 2} capture, investigating carbon dioxide sequestration in conjunction with enhanced coalbed methane recovery and applying retrofitting to power plants and to offshore oil and gas platforms. Systems studies taking a broader view include investigating the potential for combined energy systems (power generation with district heating, power with district cooling etc.) to reduce CO{sub 2} abatement cost, studies on the LNG/power generation fuel cycle, assessing the potential of ...

Science.gov (United States)

This paper examines the relationships between the socio-demographic characteristics of small

Energy Technology Data Exchange (ETDEWEB)

This paper examines the global impacts of a policy that internalizes the external costs (related to air pollution damage, excluding climate costs) of electricity generation using a combined energy systems and macroeconomic model. Starting point are estimates of the monetary damage costs for SO{sub 2}, NOX, and PM per kWh electricity generated, taking into account the fuel type, sulfur content, removal technology, generation efficiency, and population density. Internalizing these externalities implies that clean and advanced technologies increase their share in global electricity production. Particularly, advanced coal power plants, natural gas combined cycles, natural gas fuel cells, wind and biomass technologies gain significant market shares at the expense of traditional coal- and gas-fired plants. Global carbon dioxide emissions are lowered by 3% to 5%. ...

Energy Technology Data Exchange (ETDEWEB)

In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled chemical-looping combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H{sub 2}/O{sub 2} combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled chemical-looping combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), and then instead of air or pure oxygen, the reduced metal is successively oxidized by the saturated air. As a result, the new hydrogen-fueled gas turbine cycle has a breakthrough performance, with at least about 12 percentage-point higher efficiency compared to the ...

Energy Technology Data Exchange (ETDEWEB)

By retrofitting the existing steam turbine dual purpose power plant with a gas turbine plant and a secondary waste heat boiler the Technische Werke Ludwigshafen AG have considerably improved the energy generation in energetic, economic and ecological terms. The extension of the existing system to a combined cycle process has lead to this positive effect. The erection of a boiler plant during the first two construction phases has fully met the optimistic expectations. (orig.) [Deutsch] Mit der Nachruestung eines vorhandenen Dampfturbinen-HKW um eine Gasturbinenanlage mit nachgeschaltetem Abhitzekessel haben die Technischen Werke Ludwigshafen AG ihre Energieerzeugung entscheidend in energetischer, oekonomischer und oekologischer Sicht optimiert. Insbesondere die Erweiterung des vorhandenen Systems zu einem GuD-Prozess fuehrt zu dieser positiven Bilanz. Die Errichtung der Kesselanlage in den ersten beiden Bauabschnitten hat ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

Restructured power markets require concepts not only for extending the lifetime of existing plants, but also concepts for reducing the life-cycle costs of existing older steam power plants in order to remain competitive with the most modern and advanced power generation technology such as combined cycle power plants. Out of the broad range of methods to extend service life and increase availability, and to increase power output and efficiency, this paper focuses on full repowering. Full repowering replaces the old fired boiler with gas turbine(s) and heat-recovery steam generators (HRSG) as heat input to the existing bottoming cycle and reuses the steam turbine (ST) condenser and further balance of plant (BOP) equipment. The potential offered by this concept is demonstrated. Repowering and modernization projects are executed if they result in economic benefits for the operator. ...

Energy Technology Data Exchange (ETDEWEB)

The object of this study was to identify those areas in California where synthetic fuel-fired power plants could be sited in the 1990 time frame, from an air quality perspective. The synfuel-fired power plants considered in this new study were 500 Mw methanol-fired combined cycle (MFCC) and 500 Mw integrated gasifier combined-cycle (IGCC) units. For comparison purposes, 500 Mw direct coal-fired boilers and 500 Mw natural gas-fired combined-cycle units were also considered. Staff did not attempt to locate plants at any specific sites, but relied primarily upon a regional countywide analysis. The study provides an approximation, for planning purposes, of a reasonable limit of the state's power plant siting capacity, given the plant types and sizes, conditions, and assumptions specified. The study shows that local emission limitations often preclude certain types of power ...

Energy Technology Data Exchange (ETDEWEB)

Three systems for the heat supply in the built environment have been compared for the costs, the energy consumption and emissions of CO{sub 2}, NO{sub x} and SO{sub 2}. The heating systems compared are based on central heating boilers, district heating systems in combination with combined steam and gas turbine cycles, and heating by means of several gas engines. From the results it appears that the boilers demand the lowest investments. The district heating systems are more expensive. Both heating systems, however, show considerable savings of energy (55 to 70%). The exploitation costs depend strongly on the fuel price scenarios used and the assumptions with regard to interest and inflation. The emissions of CO{sub 2} are also considerably lower for both combined heat and power generating systems. The use of gas engines results in higher ...

Energy Technology Data Exchange (ETDEWEB)

A catalytic converter of a ceramic monolith honeycomb substrate, coated with a washcoat of catalyst and attached to a natural gas/diesel dual fuel engine was simulated and studied experimentally. The paper describes the application of one-dimensional finite element model for the transient and steady state operation. Laminar flow was approximated using a dispersed plug flow model, and chemical kinetics were simulated using LHHW (Langmuir/ Hinshelwood/ Hougan/ Watson) type expressions. Simulation results were compared with experimental results for heating and cooling cycles which resulted from speed and load changes on the engine. The comparison showed a maximum difference between the two sets of emission levels of about 10 per cent, showing that the one-dimensional model is acceptable model for this dual fuel engine converter combination. 50 refs., 3 tabs., 13 figs.

Energy Technology Data Exchange (ETDEWEB)

Adding capacity to coal-fired plants in small increments of an overall integrated program may be the solution to the 10-year lead time required for the construction of a new plant. A preliminary study evaluates the technical and economic feasibility of a modular natural gas and coal-fired combined-cycle power plant which can be installed in three distinct phases. The plant sizes are suitable for large industrial and utility applications. The Modular Block Power Plant (MBPP) concept offers the advantages of phase construction, lower capital cost, lower cost electricity, lower air emissions, lower water requirements, and reduced solid waste discharge. Other advantages include part load availability, reduced coal inventory requirements, and easier plant siting. 11 figures, 4 tables.

British Library Electronic Table of Contents (United Kingdom)

A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat e...

Energy Technology Data Exchange (ETDEWEB)

No abstract available.

Energy Technology Data Exchange (ETDEWEB)

A combined gas/steam turbine process includes a high-pressure furnace and a high pressure gasification unit with a mounted upstream of a combustion chamber there is a gas turbine with a waste heat system. Combustion heat which is not needed to heat the flue gas to combustion temperature is released from the furnace and transferred to ths combustion air going into the combustion chamber.

Energy Technology Data Exchange (ETDEWEB)

The development of a silicon carbide (SiC) heat exchanger is a critical step in the development of the Externally-Fired Combined Cycle (EFCC) power system. SiC is the only material that provides the necessary combination of resistance to creep, thermal shock, and oxidation. While the SiC structure materials provide the thermomechanical and thermophysical properties needed for an efficient system, the mechanical properties of the SiC tubes are severely degraded through corrosion by the coal combustion products. To obtain the necessary service life of thousands of hours at temperature, a protective coating is needed that is stable with both the SiC tube and the coal combustion products, resists erosion from the particle laden gas stream, is thermal shock resistant, adheres to SiC during repeated thermal shocks (start-up, process upsets, shut-down), and allows the EFCC system to be cost competitive. This ...

Energy Technology Data Exchange (ETDEWEB)

Over the past 40 years, cavern storage of LPG's, petrochemicals, such as ethylene and propylene, and other petroleum products has increased dramatically. In 1991, the Gas Processors Association (GPA) lists the total U.S. underground storage capacity for LPG's and related products of approximately 519 million barrels (82.5 million cubic meters) in 1,122 separate caverns. Of this total, 70 are hard rock caverns and the remaining 1,052 are caverns in salt deposits. However, along the eastern seaboard of the U.S. and the Pacific northwest, salt deposits are not available and therefore, storage in hard rocks is required. Limited demand and high cost has prevented the construction of hard rock caverns in this country for a number of years. The storage of natural gas in mined caverns may prove technically feasible if the geology of the targeted market area is suitable; and economically feasible if the cost and convenience of service ...

Energy Technology Data Exchange (ETDEWEB)

The 380 MW combined cycle gas turbine power station in Peterborough changed its water supply from town mains to high purity reverse osmosis permeate in October 2000. The high purity water is produced from secondary treated sewage effluent using advanced membrane technology. Alpheus Environmental and British Gas staff have recently completed a study of the power station's demineralization plant to identify the differences in operating costs associated with the change in feedwater. The results show that the ultrapure water produced after the change to a high purity feed is of improved quality and that the demineralization plant regeneration operating costs have been reduced by over 90%. The demineralization plant availability has increased from 78 to 98% enabling almost 20% more ultra pure water to be produced. The change in feedwater has also improved the local environment by significantly ...

Energy Technology Data Exchange (ETDEWEB)

Large amounts of US public funds are deviated to energy-related R and D conflicts with the country's simultaneous attempts to control inflation and to limit federal government expansion. Congress must concentrate the funds at its disposal upon a manageable number of energy technologies - those most likely to improve the supply side of the domestic energy equation while maintaining an adequate return on investment. An examination of a wide array to technology alternatives concludes that (1) the development of unconventional gas would yield a large return while requiring only limited federal R and D support, (2) combined-cycle coal gasification and the manufacture of low- and medium-Btu gas need relatively little government aid and produce moderate returns, (3) although requiring limited support, energy from municipal solid waste (MSW) yields a small return, and (4) high-Btu coal gasification needs extensive federal ...

Energy Technology Data Exchange (ETDEWEB)

The design of a solar heated cavity receiver transferring 60 MW of thermal energy to the working medium (air) for a closed-cycle gas turbine is described. The gas turbine plant with its cycle layout is presented. Then the tubes for the receiver are designed taking into account thermal and mechanical loads. It is shown how the occurring stresses are influenced by the destribution of the locally absorbed hat flux. Calculations for an existing coal fired air heater of a closed-cycle gas turbine give a first impression of the long-term behaviour to be expected of the receiver tubes.

International Nuclear Information System (INIS)

A spreadsheet-based decision support system has been developed that allows easy evaluation of integrated biomass to electricity and biomass to ethanol systems. The Bioenergy Assessment Model (BEAM) has been developed to allow the techno-economic assessment of biomass to electricity and biomass to ethanol schemes, including investigation of the interfacing issues. Technical and economic parameters can be assessed for a variety of feedstocks, conversion technologies and generating cycles. Production modules are currently available for biomass supply from short rotation coppice and conventional forestry relevant to conditions and practices in NW Europe. The biomass conversion modules include pre-treatment (reception, storage, handling, comminution, screening and drying); atmospheric gasification (generic gasifier, wet gas scrubbing, dual fuel engine); pressure gasification (generic gasifier, hot gas filtration, ...

Energy Technology Data Exchange (ETDEWEB)

Tests to measure the maximum horsepower of commercial vehicles converted for use with natural gas fuel indicate a reduction of approximately 20% in horsepower compared with gasoline-driven vehicles. This reduction in horsepower resulting from the use of gas is due basically to the lower thermal efficiency of the cycle of natural gas compared with that of gasoline and to its lower volumetric efficiency, since natural gas is injected into the combustion chamber in gaseous form, unlike gasoline, in which part of the fuel entering the cylinder is in the liquid phase. Natural gas used as a fuel generates lower quantities of air pollutants, particularly unburned hydrocarbons (HCs) and carbon monoxide (CO). Despite the downside of reduced horsepower, the use of natural gas as a fuel for automotive vehicles equipped with ...

Energy Technology Data Exchange (ETDEWEB)

The externally fired combined cycle is emerging as an economically viable repowering options for old non-competitive coal fired steam plants. This paper describes the initial operation of a pilot plant located at Kennebunk, Maine and the initial work on the repowering of a 48MW coal fired steam plant located in Warren, PA.

Energy Technology Data Exchange (ETDEWEB)

Deteriorating air quality in urban areas is leading bus manufacturers to look for cleaner drives of urban buses. Various new systems are now available, but it is difficult to compare them and verify their effects without having a driving cycle accurately representing contemporary average urban bus use. The idealized form (engine cycle, passenger car cycle or different kW/tonnes ratio and traffic conditions) of existing driving cycles disqualifies them for the purpose. For this reason, it was decided to attempt the development of a new driving cycle for urban buses. To this end, measurements were carried out on buses in service in four major Dutch towns. The resulting data were combined to produce a reference cycle comprising all data relating to urban bus use. Statistical methods were then used to compare a large number of 15-20 minute ...

International Nuclear Information System (INIS)

Radiological and environmental protection experience associated with the reactor cover gas processing system at the Fast Flux Test Facility (FFTF) has been excellent. Personnel radiation exposures received from operating and maintaining the reactor cover gas processing system have been very low, the system has remained free of radioactive particulate contamination through the first seven operating cycles (cesium contamination was detected at the end of Cycle 8A), and releases of radioactivity to the environment have been very low, well below environmental standards. This report discusses these three aspects of fast reactor cover gas purification over the first eight operating cycles of the FFTF (a duration of a little more than four years, from April 1982 through July 1986).

Energy Technology Data Exchange (ETDEWEB)

Heat exchangers for high and ultrahigh temperatures are a need and a precondition to realise high efficient fossil fired power plants based on the so-called Externally Fired Combined Cycle (EFCC) or the Indirect Fired Gas Turbines (IFGT). The main target of both processes is to increase the thermal efficiency of existing power plants by approximately 25% resulting in the same decrease in fuel consumption and, therefore, in the same reduction of CO{sub 2} formation. The main activities of the MPA University of Stuttgart in this project is focused on the characterisation and qualification of the structural material of the ultrahigh temperature heat exchanger (UHTHE) necessary in the above mentioned processes. The influence of the temperature and load on the material behaviour have been analysed by means of tensile tests and creep tests. The effectiveness of different coating systems and the interaction between coating system ...

Energy Technology Data Exchange (ETDEWEB)

A comparative process can be shown for the design of combined fuel cell powerstations. It is worth noting that the output of a combined powerstation working reversibly is independent of the thermodynamic state of the cell, and only depends on the reaction and thermodynamic state of the environment. The potential efficiency of gas-fired combined fuel cell powerstations is estimated at 80%. The fuel cell proves to be an isothermal heat source and not an adiabatic fluegas generator. This applies generally for all combustion power processes. Compared with external reforming, the integration of the reforming in the whole process leads to distinct advantages in efficiency if the possibilities of using the waste heat of intermediate thermal power processes are fully exploited. The plant implementation with an SOFC gas turbine process shows that realisation of a relatively simple plant ...

Energy Technology Data Exchange (ETDEWEB)

Preserving customers` investments in capital goods is one of the strategic market services offered by ABB, and to this end the company has developed project-specific retrofit concepts especially for older power generation plant. A prime example of such a modernization is the Umm Al Nar East (UANE) combined cycle power station in Abu Dhabi, UAE. UANE has two gas turbines of type GT13D, which together generate 140 MW of electrical energy, and heat-recovery boilers which supply steam to a seawater desalination plant with a capacity of 80 million liters of drinking water per day. After almost 20 years in operation, UANE is being modernized. To address the owner`s concerns and minimize plant downtime, ABB has introduced Service, Operation and Rehabilitation (SOR) Key Account Management for Abu Dhabi. In the first phase of the modernization project, the static starting equipment was upgraded and the mechanical turbine governor ...

British Library Electronic Table of Contents (United Kingdom)

Long life cycles covering more than one year are known for all orders of insects. There are different mechanisms of prolongation of the life cycle: (1) slow larval development; (2) prolongation of the adult stage with several reproduction periods; (3) prolongation of diapause; (4) combination of these mechanisms in one life cycle. Lasting suboptimal conditions (such as low temperature, low quality of food or instability of food resources, natural enemies, etc.) tend to prolong life cycles of all individuals in a population. In this case, the larvae feed and develop for longer than a year, and the active periods are interrupted by dormancy periods. The nature of this dormancy is unknown: in some cases it appears to be simple quiescence, in others it has been experimentally shown to be a tru...

Energy Technology Data Exchange (ETDEWEB)

The majority of Brazilian big cities served by conventional railroad systems with routes starting in the center of the URBIS, destinate them the long distances transport of passengers and cargo. Actually, these systems are being transformed to become commuter trains which join a great capacity of transportation to a much lower costs of implantation than subway ones. The most important characteristic of this train, when talking about energy consumption, is the possibility of using different kinds of explosion engines from three cycles: Diesel, mixed (Diesel + Natural Gas), and Otto moved by natural gas, besides the traditional electric traction. The use of natural gas in Otto cycle engines shows itself competitive from the point of view of investments, operational costs and environmental preservation. (author). 10 refs., 1 fig

UK PubMed Central (United Kingdom)

The aim of this study was to investigate the supposed vertical diel migration and the accompanying physiology of Beggiatoa bacteria from hypersaline microbial mats. We combined microsensor,...Full Text Available

Science.gov (United States)

The report describes a computer model developed by TVA to simulate the performance and determine the economics of coal cleaning, or coal cleaning combined with flue gas desulfurization (FGD), for power plant emission control processes over a wide range of user-specified condition...

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

Biomass gasification provides the potential to efficiently and economically produce a renewable source of a clean gaseous fuel suitable for power generation or synthesis gas (syngas) applications. An important side benefit of the use of biomass is the effective minimization of the primary greenhouse gas, carbon dioxide (CO{sub 2}), by providing a means to close-loop the CO{sub 2} cycle. However, high molecular weight hydrocarbon constituents (tar) in the product gas from gasification can complicate the downstream uses of the gas. This paper discusses both the development of a low cost, disposable catalyst system that can eliminate these heavy hydrocarbons from the gas and the use of the catalyst in conjunction with the Battelle high-throughput gasification process for power generation and synthesis applications. (author)

Energy Technology Data Exchange (ETDEWEB)

The method of life-cycle assessment (LCA) has been applied to cars with different power trains. As an example, the results for greenhouse gas (GHG) emissions are presented. They show possibilities and limits for the reduction of these emissions in the transportation sector by means of advanced technology. (author) 2 figs., 4 refs.

Energy Technology Data Exchange (ETDEWEB)

Discussion is presented of world CO{sub 2} emissions and the effect rising population and population distribution has on this. Possible ways of decreasing emissions are presented, including potential for heat recovery, exhaust-air purification as an energy supply, shared power supply in industry, the use of cogeneration, and multiple use of heat in industry. 9 refs., 10 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

A guidance document on the instrumentation for monitoring and control of cycle chemistry for the steam-water circuits of fossil-fired and combined-cycle power plants was developed within the IAPWS Power Cycle Chemistry Working Group. This technical guidance document has been authorized by the International Association for the Properties of Water and Steam (IAPWS) at its meeting in Doorwerth, The Netherlands, 6-11 September, 2009, for issue by its Secretariat. The members of the IAPWS are: Britain and Ireland, Canada, the Czech Republic, Denmark, France, Germany, Greece, Japan, Russia, and the United States of America, and the associate members Argentina and Brazil, Italy, and Switzerland. In order to achieve suitable chemical conditions in steam-water circuits it is essential to establish reliable monitoring of key parameters on every plant. This enables the demonstration of operation within cycle ...

Energy Technology Data Exchange (ETDEWEB)

A patent is claimed for a process by which a low-hydrogen gas containing at least 90 percent by volume of methane which is suited for natural gas substitution is produced by transformation of vaporizable hydrocarbons with the aid of steam in the presence of a catalyst containing nickel, at temperatures of 350 to 600/sup 0/C and at increased pressure. Hydrocarbons and steam are supplied to the reaction in mixed form with recycle product gas. Per kilogramme of hydrocarbons to be converted in the high btu gas reactor, less than 1 kilogramme of fresh steam is needed. High btu gas is fed back from the high btu gas reactor to the input end of the same via a gas cycle comprising a cooler, a carbon dioxide absorption device, and a saturator. Between the carbon dioxide absorption device and the saturator a product ...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) is a 400-megawatt (thermal) sodium-cooled reactor designed for irradiation testing of fuels, materials and components for LMRs. It is operated by the Westinghouse Hanford Company for the US Department of Energy on the government-owned Hanford reservation near Richland, Washington. The first 100-day operating cycle began in April 1982 and the eighth operating cycle was completed in July 1986. Argon is used as the cover gas for all sodium systems at the plant. A program for cover gas monitoring has been in effect since the start of sodium fill in 1978. The argon is supplied to the FFTF by a liquid argon Dewar System and used without further purification.

Energy Technology Data Exchange (ETDEWEB)

The combination of wood gasification and high temperature fuel cells like solid oxide fuel cells (SOFC) is an interesting approach to achieve high electrical efficiencies (40%) in small scale combined heat and power plants. This combination is called 'Biomass - Integrated Gasification Fuel Cell System' (B-IGFC). The main challenge is the adjustment of the three main components gasification, gas cleaning and fuel cell. In this technology, the first proof of principle by combining a gasifier with a SOFC in a laboratory scale for more than 100 hours was achieved. During this period, no deactivation of the system was found. (author)

British Library Electronic Table of Contents (United Kingdom)

Independent drilling contractors own all offshore drilling rigs, which they lease to oil and gas companies for use in their pursuit of their exploration and development plans. Oil and gas companies' demand for these rigs can vary quickly and dramatically in response to changes in the world market for oil and natural gas. As a result, drilling contractors often try to manage excess capacity by idling rigs (known in the industry as "stacking" a rig), reactivating them when demand recovers. This paper examines these decisions over the course of a price cycle in 1998-2000 to investigate the role of firm and rig heterogeneity in determining drillers' decisions about idling and reactivating capacity.

Energy Technology Data Exchange (ETDEWEB)

This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel- cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, sulfur oxides, and particulate matter measuring 10 microns or less) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates the total fuel-cycle energy consumption, fossil fuel consumption, and petroleum consumption using various transportation fuels. The GREET model includes 17 fuel cycles: petroleum to conventional gasoline, reformulated gasoline, clean diesel, liquefied petroleum gas, and electricity ...

Energy Technology Data Exchange (ETDEWEB)

To address the need for integrated models of advanced power generation systems and for improved analysis techniques, the US Department of Energy (DOE), through the Morgantown Energy Technology Center (METC), has supported the development of performance, emissions, and cost models of several advanced power generation systems, including integrated gasification combined cycle (IGCC), externally-fired combined cycle (EFCC) and pressurized fluidized bed combustion (PFBC) concepts. Simultaneously, numerical methods for simulation of uncertainties and optimization of process flowsheets have been implemented in the DOE`s public version of ASPEN. The new process models and computational capabilities have been applied to demonstrate the benefits of quantitative approaches to dealing with uncertainty and for optimizing technologies in the face of uncertainty. This paper focuses on modeling and assessment of the ...

British Library Electronic Table of Contents (United Kingdom)

A commonly reported consequence of post-treatment nausea or vomiting is the development of anticipatory nausea and vomiting (ANV). In most published work, nausea is reported to occur before chemotherapy drugs are administered by approximately 20% of patients at any one chemotherapy cycle and by 25?30% of patients by their fourth chemotherapy cycle. Most studies in adult patients strongly support the view that the development of ANV involves elements of classical conditioning. The best method to avoid development of ANV is to adequately prevent both vomiting and nausea from the first exposure to chemotherapy. If anticipatory side effects develop, behavioral treatment techniques, such as systematic desensitization, have been shown effective. Benzodiazepines used in combination with behaviora...

Energy Technology Data Exchange (ETDEWEB)

In the context of the special research area 561 (Thermally highly loaded, open-porous and cooled multi-layer systems for combined-cycle power stations), the actual technical and scientific realizations are to be extended and new scientific bases are to be created in order to realize total efficiencies of 65 %. In addition, innovative material solutions and new concepts must be compiled for the cooling and drainage. Under this aspect, the author of the contribution under consideration reports on the development of open-porous multi-layer systems for steam turbines of the 700 C technology. It results an efficiency potential of 12 % and a potential of 15 % with the reduction of CO{sub 2} in relation to the actual state of the art. Thereby, the potential of future combined-cycle power stations is not yet exhausted.

Energy Technology Data Exchange (ETDEWEB)

Tohoku Electric Power Co., Ltd., is now building an LNG-fired No. 4 System (combined cycle of 1.61-million kW) for its Higashi Niigata Thermoelectric Power Station sited in the Niigata East Harbor industrial zone. This is a unit that aims at a thermal efficiency of 50% first in the world by using high-efficiency gas turbines, etc. After the completion of the No. 4 System, the station (No. 1 Machine, No. 2 Machine; No. 3 System, No. 4 System; Harbor No. 1 Machine, Harbor No. 2 Machine) will be generating a total power of 4.6kW, providing the company with its maximum power source which ranks among the largest-grade thermoelectric power stations in this country. Since the construction work was started in April, 1996, approximately 40% had been completed as of March-end, 1997, including foundations for the power station main building, stack, etc. The power station main building uses a raft foundation while the boilers and stack ...

International Nuclear Information System (INIS)

We describe a new apparatus that combines pulsed laser excitation in a molecular beam with surface-science methods for preparation of clean single-crystal surfaces and detection of adsorbates to enable state-selected studies of gas-surface reaction dynamics. Reactant molecules are prepared in specific vibrationally excited states via overtone pumping using tunable, narrow-band laser radiation. The collision-free environment of the molecular beam prevents relaxation of the prepared molecules before impact on the target surface and enables complete control over the collision energy and incidence angle. Chemisorption products are detected after a given deposition time by Auger electron spectroscopy. To achieve sufficient beam flux of state-selected reactant molecules for product detection by standard surface-science techniques, we use a high-intensity, short-pulse molecular-beam source matched to the low duty cycle of the ...

International Nuclear Information System (INIS)

In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost ...

Energy Technology Data Exchange (ETDEWEB)

This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu-Cl cycle ...

Science.gov (United States)

This combined analytical and experimental program is aimed at generating a manual that will permit the design of 3.0 MDN cylindrical roller bearings. The roller bearing analysis will be correlated with the results from a series of bearing tests designed t...

Science.gov (United States)

Progress made during the first phase effort of the Solar-Thermal Full-System Experiment is summarized. This is one of a number of projects in the Solar-Thermal Subprogram involved with the development of solar central receiver hardware and systems for future use by utilities. The main emphasis is on systems that use Brayton-Cycle (gas turbine) equipment. The project summarized involves the planning and design of a complete Brayton-Cycle solar central receiver experimental system that would include all components of a commercial-size electric utility solar power plant. The objective of the overall project is to demonstrate the technical feasibility of a complete Brayton-Cycle, solar-fossil hybrid central receiver system. Major objectives of the Phase I effort summarized are to plan and design the experiment in detail and to organize a utility Test and Operating Group that would be directly involved in ...

International Nuclear Information System (INIS)

The use of natural energy sources and their conversion to secondary forms of energy are a crucial base for the development of our society with its continuous change of requirements due to an increase in population and the broadening of the needs in our modern life. As a consequence the consumption of primary energy resources rose drastically worldwide during the last 5 decades in particular in the industrialized regions such as Europe. Parallel in time the increasing awareness of negative effects of fuel dependent pollution on the environment and the introduction of stringent emission control regulations about 3 decades ago initiated extensive development and retrofit activities resulting in the today applied high level state of the art. As an additional challenge the worldwide debate about the potential effects of the emission of the s.c green house gases on the global climate in particular carbon dioxide from the use of predominantly fossil fuels have initiated in the European Union ...

International Nuclear Information System (INIS)

Electricity generation from natural gas in gas turbine units can be made substantially more efficient by preliminary methane conversion to a synthesis gas containing hydrogen and carbon monoxide and/or by the use of some of the synthesis gas produced in industry. An alternative improvement involves the introduction of solid oxide fuel cells (SOFCs) and the use of the synthesis gas in them. In this study, a modified scheme of gas turbine cycle that includes an SOFC, a membrane reactor (instead of a traditional combustion chamber), and a catalytic reactor to perform methane conversion to produce hydrogen (synthesis gas) is proposed. Variations of the energy and exergy efficiencies of the integrated system with operating conditions are provided, showing, for example, that SOFC efficiency is enhanced if the fuel cell active ...

International Nuclear Information System (INIS)

A powder mixture of #alpha#-Si_3N_4, Al_2O_3, and TiO_2 was hot-pressed using different sintering cycles to search for an optimum in situ formed #beta#-O-sialon-TiN composite. The impulse excitation technique (IET), high-temperature X-ray diffraction (HTXRD), and scanning electron microscopy (SEM) were used to investigate the microstructure. Below the temperature of 1300 deg. C, the high-temperature internal friction (Q "-"1) decreases with the increase of sintering temperature, whereas the density of the material increases with the increase of sintering temperature. At a sintering temperature higher than 1850 deg. C, the ceramic could not be densified and O-sialon was not formed. Also, the mechanical properties of ceramics hot-pressed using different sintering cycles were assessed. The ceramic hot-pressed at 1700 deg. C for 10 min displays a combination of high hardness and good fracture toughness, due to an optimum ...

Science.gov (United States)

The Gas Research Institute established the Gas Appliance Technology Center (GATC) in 1982 to develop improved gas appliances. Between 1986 and 1992, the scope of GATC activities at Battelle included technology transfer and overall industry support, residential appliances, commercial appliances, and residential space conditioning. The following tasks are representative of the GATC activities described in the report; gas burner technology, appliance venting, emissions, water heating, range/oven technology, self-powered appliances, commercial cooktop burners, reconstituting ovens, appliance reliability improvement, combination space-heating/water-heating systems, condensing heat exchangers, corrosion testing, and space heating technology. The report includes references to available sources for further reading.

British Library Electronic Table of Contents (United Kingdom)

The genetic type, source and charging history of natural gas in the Yulin gas field in the Ordos Basin have been studied by combining the carbon isotopic composition of natural gas and geochemical characteristics of light hydrocarbons with carbon isotope fractionation model results and fluid inclusion analysis. The carbon isotopic composition of methane and ethane in the Yulin gas field is relatively enriched in ^1^3C with d^1^3C1 values ranging from -35.3%% to -29.8%% (average value=-32.4%%) and d^1^3C2 ranging from -26.3%% to -23.5%% (average value=-24.8%%). The C7 light hydrocarbons are predominated by methylcyclohexane, accounting for 65.8% to 80.9% (average value=71.6%), which is characteristic of coal-derived gas. Furthermore, the gas geochemistry indicates that, although marine lime...

Energy Technology Data Exchange (ETDEWEB)

Two important greenhouse gases, CO{sub 2} and CH{sub 4}, are closely connected to the carbon cycling of wetlands. Although virgin wetlands are mostly carbon accumulating ecosystems, major proportion of the CO{sub 2} bound annually in photosynthesis is released back to the atmosphere. Main portion of the carbon cycling in wetlands is quite fast while a small proportion of carbon diffusing from soil is released from organic matter, which may be ten thousand years old. Methane is formed in the anaerobic layers of wetlands, from where it is released gradually to the atmosphere. The decomposition in anaerobic conditions is very slow, which means that usually only a few percent of the annual carbon cycling takes place as methane. Research on CO{sub 2} fluxes of different virgin and managed peatlands was the main topic of this project during the first phase of SILMU. The measurements were made during two seasons in varying ...

Energy Technology Data Exchange (ETDEWEB)

Propane and Butane are the main components of LPG as an automotive fuel in the eighties. The worldwide supply of gas will expand, the infrastructure necessary for the transport, storage and distribution of the extra quantities will be supplied. A percentage of 5-10% of the total German gasoline consumption is propable. LPG is an excellent fuel for Otto-cycle-engines, not only from an environmental point of view. Experience gathered with LPG in car engines will be reported on as well as on developments concerning the application field.

Energy Technology Data Exchange (ETDEWEB)

The theoretical analysis of a partially-ionized hydrogen gas flow (gas temperatures of approximately 10,000 to 20,000 K) through a particular class of magnetohydrodynamic (MHD) generators and the preliminary design of these MHD generators as open cycle, electric power supplies are performed. Analysis of the gas flow through these ultra-high temperature MHD generators requires a coupled gas dynamics/radiative heat transfer solution. Gas dynamics are modeled by a set of quasi-one-dimensional, nonlinear differential equations which account for friction, convective and radiative heat transfer and the interaction between the ionized gas and applied magnetic field. Radiative heat transfer is modeled using non-gray, absorbing-emitting two- and three-dimensional P-1 approximations which permit an arbitrary variation of the spectral absorption ...

Energy Technology Data Exchange (ETDEWEB)

Buses, operating within a Florence (Italy) municipal transportation system, and equipped with Otto cycle engines, were selected for retrofitting taking into account the suitability of each vehicle`s specific routing and service requirements. Cost benefit analyses indicated that it wouldn`t be economically feasible to retrofit buses equipped with diesel engines. A computerized refuelling system was set up at the fleet`s central service station which was hooked up to the natural gas utility`s supply line. This paper tables the cost benefit analysis data comparing gasoline and methane operation and reflecting the cost savings which are expected to be accrued through this methanization program over a span of 14 years.

British Library Electronic Table of Contents (United Kingdom)

The rational use of energy has become a priority for all industries in Brazil, mainly after the energy rationing in 2001. Methodologies to quantify and improve the performance of plants that consume and generate electricity and thermal energy are being used to reach this goal. Exergoeconomic analysis provides a complete diagnosis of a plant, both in exergetic and in monetary values. This study shows the methodology used to assess the power generation system of the Companhia Siderurgica Tubarao (CST). The current system is based on a regenerative Rankine cycle using two gases from steel production - blast furnace gas (BFG) and coke oven gas (COG) - to generate electric power and occasionally steam for the process. Use of the Theory of Exergetic Cost allowed determination of monetary and exe...

Energy Technology Data Exchange (ETDEWEB)

The coke plant at the Sparrows Point Plant consist of three coke oven batteries and two coal chemical plants. The by-product coke oven gas (COG) consists primarily of hydrogen, methane, carbon monoxide, nitrogen and contaminants consisting of tars, light oils (benzene, toluene, and xylene) hydrogen sulfide, ammonia, water vapor and other hydrocarbons. This raw coke oven gas needs to be cleaned of most of its contaminants before it can be used as a fuel at other operations at the Sparrows Point Plant. In response to environmental concerns, BSC decided to replace much of the existing coke oven gas treatment facilities in the two coal chemical Plants (A and B) with a group of technologies consisting of: Secondary Cooling of the Coke oven Gas; Hydrogen Sulfide Removal; Ammonia Removal; Deacification of Acid Gases Removed; Ammonia Distillation and Destruction; and, Sulfur Recovery. This ...

Energy Technology Data Exchange (ETDEWEB)

The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the W7-AS stellarator. ...

International Nuclear Information System (INIS)

A numerical investigation of the mixing of gaseous uranium and hydrogen inside an open-cycle gas core nuclear rocket engine (spherical geometry) is presented. The gaseous uranium fuel is injected near the centerline of the spherical engine cavity at a constant mass flow rate, and the hydrogen propellant is injected around the periphery of the engine at a five degree angle to the wall, at a constant mass flow rate. The main objective is to seek ways to minimize the mixing of uranium and hydrogen by choosing a suitable injector geometry for the mixing of light and heavy gas streams. Three different uranium inlet areas are presented, and also three different turbulent models (k-var-epsilon model, RNG k-var-epsilon model, and RSM model) are investigated. The commercial CFD code, FLUENT, is used to model the flow field. Uranium mole fraction, axial mass flux, and radial mass flux contours are obtained. copyright 1997 American ...

Energy Technology Data Exchange (ETDEWEB)

The US National Energy Policy of 2001 advocated the development of advanced fuel and fuel cycle technologies that are cleaner, more efficient, less waste-intensive, and more proliferation resistant. The need for advanced fuel development is emphasized in on-going DOE-supported programs, e.g., Global Nuclear Energy Initiative (GNEI), Advanced Fuel Cycle Initiative (AFCI), and GEN-IV Technology Development. The Directorates of Energy & Environment (E&E) and Chemistry & Material Sciences (C&MS) at Lawrence Livermore National Laboratory (LLNL) are interested in advanced fuel research and manufacturing using its multi-disciplinary capability and facilities to support a design concept of a small, secure, transportable, and autonomous reactor (SSTAR). The E&E and C&MS Directorates co-sponsored this Laboratory Directed Research & Development (LDRD) Project on Mono-Uranium Nitride Fuel Development for SSTAR ...

Energy Technology Data Exchange (ETDEWEB)

The interaction of thermal radiation with conduction and convection in thermally developing absorbing, emitting, nongray gas-particulate turbulent suspension flow through a circular tube is investigated. The contribution of thermal radiation is obtained through evaluation of the total hemispherical emittance of the particulate cloud and through evaluation of single band absorptances for molecular gases, modified to account for the interaction with the particles. The governing differential equation is derived as a (nonlinear) energy equation, coupled with integral equations to find the thermal radiation contributions. The energy equation is solved numerically by an implicit finite difference method with an iterative procedure. Qualitative results for Nusselt numbers are shown for a variety and range of parameters, such as optical thickness of particulates and single molecular gas bands, relative gas band position and band ...

Energy Technology Data Exchange (ETDEWEB)

Slowly, scientists come to realize that there are huge quantities of natural methan hydrates and their interest is awakened. Important questions in this connection are their possible use as future energy sources, the consequences of using methan hydrates on the climate, their integration into the carbon cycle, the cementation of the continental slopes by gas hydrates and their stability and their role in some geological-biological-geochemical processes, especially in the marine area. Towards the end of the 20th century, the basic problems and applied problem scenarios, e.g. the foundation of production platforms dor petroleum and natural gas in gas-hydrate-containing sediments, was the reason for Japan, Canada, USA, China, Germany and India to install national research programmes of various sorts in order to deal with the problems of gas hydrates. Also international programmes like ...

British Library Electronic Table of Contents (United Kingdom)

Background, Aim, and Scope The identification and assessment of environmental tradeoffs is a strongpoint of life cycle assessment (LCA). A tradeoff made in many product systems is the exchange of potential for occupational accidents with the additional use of energy and materials. Net benefits of safety measures with respect to human health are best illustrated if the consequences avoided and health impacts induced by additional emissions are assessed using commensurable metrics. Our aim is to develop a human health impact indicator for offshore crane lifts. Crane lifts are a major cause of accidents on offshore oil and gas (O & G) rigs, and health impacts from crane lift accidents should be included in comparative LCA of O & G technologies if the alternatives differ in the use of crane li...

Science.gov (United States)

We show that accretion disks, both in the subcritical and supercritical accretion rate regime, may exhibit significant amplitude luminosity oscillations. The luminosity time behavior has been obtained by performing a set of time-dependent 2D SPH simulations of accretion disks with different values of ? and accretion rate. An explanation of this luminosity behavior is proposed in terms of limit-cycle thermal instability: the disk oscillates between a radiation pressure dominated configuration (with a high luminosity value) and a gas pressure dominated one (with a low luminosity value). We support this hypothesis showing that the limit-cycle behavior produces a sequence of collapsing and refilling states of the innermost disk region.

CERN Document Server

Tolerancing of assembly mechanisms is a major interest in the product life cycle. One can distinguish several models with growing complexity, from 1-dimensional (1D) to 3-dimensional (3D) (including form deviations), and two main tolerancing assumptions, the worst case and the statistical hypothesis. This paper presents an approach to 3D statistical tolerancing using a new acceptance criterion. Our approach is based on the 1D inertial acceptance criterion that is extended to 3D and form acceptance. The modal characterisation is used to describe the form deviation of a geometry as the combination of elementary deviations (location, orientation and form). The proposed 3D statistical tolerancing is applied on a simple mechanism with lever arm. It is also compared to the traditional worst-case tolerancing using a tolerance zone.

International Nuclear Information System (INIS)

High-resolution sequence stratigraphy has been applied widely in the petroleum exploration and development, many achievements have been achieved. However, it is in the beginning stage that high-resolution sequence stratigraphy is applied to explore the sandstone-type uranium deposits in Erlian Basin. By applying principles of high-resolution sequence stratigraphy and taking typical boreholes as an example, sedimentary cycles of Saihan Formation, the ore-bearing formation in Baiyinwula area are divided and correlated through cross sections. One long-term cycle (LSC_1), two middle-term cycles (MSC_1, MSC_2) have been identified in this study. Based on this and combined with the mineralization character of sandstone uranium deposits in this area, it is presented that the interlayer oxidation zone is developed mainly in the rising hemicycle of MSC_1 and uranium ore bodies predominantly in channel sand ...

Energy Technology Data Exchange (ETDEWEB)

A flowing carbon dioxide laser was operated at low pressures up to 4 torr. Excitation of the laser was provided using various combinations of direct current (DC), pulsed microwave, and continuous wave (CW) microwave excitation. The microwaves were in the 2.45 GHz band and were coupled into the gas using a slow-wave interdigital transmission line. Laser output of 25 milliwatts (mw) was achieved using a DC discharge only. A combination of a DC discharge and pulsed microwaves doubled the output and resulted in some modulation. Changing the laser gas mixture and pulsed microwave field characteristics allowed some flexibility in the modulation. Lasing was not achieved with excitation from the CW microwaves alone due to the formation of localized discharges. Using pulsed microwaves to sustain the discharge and CW microwaves to pump the laser, a quasi-CW output of 55 mw was achieved.

British Library Electronic Table of Contents (United Kingdom)

Isotopic analyses of radioactive materials such as irradiated nuclear fuel are of major importance for the optimization of the nuclear fuel cycle and for safeguard aspects. Among the mass-spectrometric techniques available, inductively coupled plasma mass spectrometry (ICP-MS) and thermal ionization mass spectrometry are the most frequently applied methods for nuclear applications. Because of the low detection limits, the ability to analyze the isotopic composition of the elements and the applicability of the techniques for measuring stable as well as radioactive nuclides with similar sensitivity, both mass-spectrometric techniques are an excellent amendment to classical radioactivity counting methods. The paper describes selected applications of multicollector ICP-MS in combination with c...

Energy Technology Data Exchange (ETDEWEB)

High voltage cathode materials Li-excess layered oxide compounds Li[Ni{sub x}Li{sub 1/3-2x/3}Mn{sub 2/3-x/3}]O{sub 2} (0 < x < 1/2) are investigated in a joint study combining both computational and experimental methods. The bulk and surface structures of pristine and cycled samples of Li[Ni{sub 1/5}Li{sub 1/5}Mn{sub 3/5}]O{sub 2} are characterized by synchrotron X-Ray diffraction together with aberration corrected Scanning Transmission Electron Microscopy (a-S/TEM). Electron Energy Loss Spectroscopy (EELS) is carried out to investigate the surface changes of the samples before/after electrochemical cycling. Combining first principles computational investigation with our experimental observations, a detailed lithium de-intercalation mechanism is proposed for this family of Li-excess layered oxides. The most striking characteristics in these high voltage high energy density cathode ...

Energy Technology Data Exchange (ETDEWEB)

Puffer gas circuit breaker used widely in interrupters with from middle capacity to large capacity does not keep away from reacting force of the puffer with high functions in principle and there is a limit in low operation. In this study, aiming at low operation of the interrupters, in order to clarify the basic motions of hybrid circuit interrupter that is the combination of thermal puffer gas circuit breaker and vacuum circuit breaker, the interrupting ability of simple thermal puffer gas breaker and the voltage sharing characteristics in the cases of series connection with the vacuum circuit breaker are studied. The results of the study are as follows. In comparing terminal short circuit accident interrupting ability of single flow typed thermal puffer gas breaker with that of double flow typed thermal puffer gas breaker, the interrupting ability of the ...

Energy Technology Data Exchange (ETDEWEB)

Based on the IAPWS technical guidance on ''Instrumentation for Monitoring and Control of Cycle Chemistry for Steam-Water Circuits of Fossil-Fired and Combined Cycle Power Plants,'' the latest situation regarding instrumentation for nuclear power plants is discussed. As a result of the discussion, it is concluded that: (1) Reliable and safe operation of plants is established by the application of suitable chemical conditions in plant cooling systems, which should be supported by the selection of suitable control targets for monitoring and by the application of reliable instruments. (2) The minimum level of key instrumentation consists of on-line as well as off-line instruments for monitoring the key parameters: - on-line: pH, conductivity, cation conductivity, O{sub 2} and H{sub 2} concentrations, electrochemical corrosion potential; - off-line: radioactive nuclides ({sup 60}Co, {sup ...

Energy Technology Data Exchange (ETDEWEB)

Only about 25% of residue accumulating in the Federal Republic of Germany is currently used for the purposes of energy. This residue will be converted into fuel for power stations by the Omega process when the dumping of waste with a calorific value in excess of 5 MJ/kg is prohibited with effect from 2005. This oxygen melting process is suitable for the local use of substitute fuels. Waste is converted into a high-quality synthesis gas with a wide range of uses. The Omega process combines drying, thermal decomposition, gasification and melting of the material used in a single-stage process. This is now technologically possible for the first time by combining a metallurgical cupola furnace with a traditional gas producer. The highly-calorific synthesis gas produced by the Omega process can be used in block heat and power stations or as an industrial fuel gas, ...

Energy Technology Data Exchange (ETDEWEB)

Software has been developed for the calculation of the thermodynamic cycle and the entropy changes in a turbocharged, direct injection, diesel engine based upon the measured cylinder pressure and a shaft encoder output. Assumptions of homogeneous mixture and equilibrium thermodynamic properties are made for the products of combustion and temporal variation in the fluid thermodynamic state is followed in a quasi-steady manner through a series of adjacent equilibrium states, each separated by finite intervals of one degree crank angle (1degCA). The thermodynamic properties are calculated by either of two equivalent formulations -- equilibrium constant or minimisation of Gibbs free energy, and are expressed in algebraic equations of the partial derivative of internal energy and gas constant with respect to temperature, pressure and equivalence ratio. The effect of the engine operating conditions on the thermodynamic cycle is ...

Energy Technology Data Exchange (ETDEWEB)

This report prepared for the Swiss Federal Office of Energy (SFOE) describes the practical realisation and testing of a heat recovery system based on a one-stage organic Rankine cycle with R134a as the working fluid. The waste heat has a temperature of 95 {sup o}C and originates from a gas engine that powers a small co-generation plant fuelled with biogas produced on-site. Two similar cycles have been built, ORC1 with one and ORC2 with two turbines. Only ORC1 has been tested so far. The maximum efficiency measured in these tests was 6.64% (theoretical Carnot-efficiency: 17 %) and the electric power output was 5.0 kW. The problems encountered during commissioning are described and recommendations for further improvements are given.

Energy Technology Data Exchange (ETDEWEB)

The basic principle of the green building philosophy is to design buildings that consider environmental performance. Residential and commercial buildings in Canada consume about 30 per cent of the total secondary energy use and are responsible for approximately 29 per cent of carbon dioxide equivalent greenhouse gas emissions and many other wastes. An optimization model was developed which minimizes life cycle cost and life cycle environmental impact. The model distinguishes different energy sources and incorporates their impacts, such as resource depletion, global warming and acidification. The model also considers design variables such as window type, orientation, building orientation, window-to-wall ratio, wall type and roof type. The model can be used to identify optimum green building designs for given conditions. The model uses expanded cumulative exergy consumption as the indicator for life cycle ...

International Nuclear Information System (INIS)

The accurate prediction of local hot spot during normal operation is important to ensure core thermal margin in a very high temperature gas-cooled reactor because of production of its high temperature output. The active cooling of the reactor core determining local hot spot is strongly affected by core bypass flows through the inter-column gaps between graphite blocks and the cross gaps between two stacked fuel blocks. The bypass gap sizes vary during core life cycle by the thermal expansion at the elevated temperature and the shrinkage/swelling by fast neutron irradiation. This study is to investigate the impacts of the variation of bypass gaps during core life cycle as well as core restraint mechanism on the amount of bypass flow and thus maximum fuel temperature. The core thermo fluid analysis is performed using the GAMMA+ code for the PMR200 block-core design. For the analysis not only are some modeling features, ...

British Library Electronic Table of Contents (United Kingdom)

The tribological properties of gas pressure sintered SiAlON and its composite with 18wt% silicon carbide (SiC) against two different mating materials, i.e., alumina and SiAlON are evaluated. SiAlON and SiAlON-18%SiC composite ceramics were prepared by pressure less sintering and gas pressure sintering. Fretting wear tests were carried out under dry unlubricated ambient conditions (room temperature 23-25^oC; relative humidity 50-55%) with a load of 8N for 45,000 cycles. Friction and wear properties of SiAlON-SiC proved better than the monolithic SiAlON. The formation of silica roll like structure on the composite worn surface was observed.

Energy Technology Data Exchange (ETDEWEB)

MCrAlY coatings are widely used on hot section components of gas turbines to provide hot corrosion and/or oxidation protection by formation of an oxide layer on the surface. As the protective oxide scale exfoliates during service, aluminum from the coating diffuses outward for reformation of the protective scale. Aluminum may also diffuse inward due to the differences in composition between the coating and the substrate. Thus, the coatings degrade due to oxidation, oxide scale spallation, and inward and outward diffusion of aluminum. Service life of these coatings is controlled by the aluminum content in the coating, operating temperature and start- shutdown cycles. In-service degradation of CoCrAlY and CoNiCrAlY coatings is presented. A procedure to predict the remaining service life of coatings under oxidizing conditions is discussed. (orig.) 12 refs.

Science.gov (United States)

This report--the forty-fifth of a series--is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion process development, materials engineering, alkali metal vapor topping cycles, a coal equipment test program, an AFB coal combustor for cogeneration (CCC), engineering and support studies, process and program assistance, evironmental assessment studies, magnetic beneficiation, and AFBC demonstration plant.

Energy Technology Data Exchange (ETDEWEB)

In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.

Energy Technology Data Exchange (ETDEWEB)

The ultrasonic inspection pig system was described as being under development. This system was said to adopt the unique wheel type ultrasonic sensor which does not need couplant. This pig was designed to detect external corrosion in long-distance pipelines without interruption of the gas service. The wall-thickness measurement performance test and the travel performance test of the inspection pig in the test line confirmed that these performances satisfied the development specifications. However, the effect induced by the inner surface properties of the pipe and the influence of the pipe`s performance over long distances and for a long period of time still needed to be verified in an actual gas pipeline, and while the pipeline was actually in service. Improvements to the prototype model of the inspection pig were expected to include combinations of inspection pigs, with increases in battery and memory capacities to permit ...

International Nuclear Information System (INIS)

Pattern formation on GaAs by Ga"+ focused-ion-beam (FIB) irradiation and subsequent Cl_2 gas etching was carried out. A higher etch rate at the FIB-irradiated area compared with that not irradiated under Cl_2 gas allows pattern construction without a mask process. The degree of residual crystal damage was evaluated using photoluminescence (PL) intensity measurements. The PL intensity in the etched region was one order of magnitude stronger than that of FIB sputtering, and was several times stronger than that of Ga"+ FIB-assisted Cl_2 etching. Etch depths of the order of 100 nm, which is five times deeper than that obtained by FIB sputtering, were efficiently performed using moderate Ga"+-ion doses.

Energy Technology Data Exchange (ETDEWEB)

Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 C indicated that all oxygen carriers had a stable performance at 800 C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but there was no effect on the capacity due to the presence of H2S ...

British Library Electronic Table of Contents (United Kingdom)

A joint experimental and theoretical analyses based on the grounds of DFT anharmonic potential and the use of a variational method allow us to revisit and assign the gas phase spectra of vinylarsine in the mid-IR area until 6300cm-1. Several weak and very weak bands corresponding to overtones and combinations are newly observed and assigned in complement to the fundamental bands.

Energy Technology Data Exchange (ETDEWEB)

The Construction of a natural gas-fired combined heat and power plant at the site of the Pernis refinery will further reduce the emission of SO2 and NOx. [mk]. [Dutch] Met de bouw van een aardgasgestookte warmte/kracht-installatie op het terrein van de raffinaderij Pernis wordt de emissie van SO2 en NOx verder gereduceerd.

International Nuclear Information System (INIS)

An improved coating for Advanced Gas Cooled Nuclear Reactor austenitic stainless steel fuel cans is described which, tests have shown, inhibits the deposition of carbon on the cans in carbon-containing ionising radiation environments. The coating comprises a refractory oxide which has been prepared by a vapour phase condensation method, in combination with a noble metal. (U.K.).

Energy Technology Data Exchange (ETDEWEB)

During thirty years the techniques used for sensing the environment have changed dramatically. This paper describes the latest generation of sensors available. This new generation of sensors includes those two most critical gas sensors for methane and carbon monoxide and new sensors for airflow and air temperature. When these sensors are combined with the new sensors for machine condition monitoring it forms the heart of the Sentex system. 2 figs.

Energy Technology Data Exchange (ETDEWEB)

In pursuing its mission of helping U.S. independent oil and gas producers make timely, informed technology decisions, the Petroleum Technology Transfer Council (PTTC) functions as a cohesive national organization that implements industry's directives through active regional programs. The role of the national headquarters (HQ) organization includes planning and managing the PTTC program, conducting nation-wide technology transfer activities, and implementing a comprehensive communications effort. PTTC relies on 10 Regional Lead Organizations (RLOs) as its main program delivery mechanism to industry. Through its regions, PTTC connects with independent oil and gas producers--through technology workshops, resources centers, websites, newsletters, and other outreach efforts. The organization effectively combines federal, state, and industry funding to achieve important goals for all of these sectors. This integrated ...

Energy Technology Data Exchange (ETDEWEB)

High temperature components of power plants are in many cases subjected to variable loading conditions such as cyclic creep or strain cycling. Therefore the cyclic behaviour of important heat resistant steels has been investigated under stress control and to a smaller extent under strain control. The behaviour under cyclic creep rupture conditions was determined in long term experiments covering a wide range of loading conditions. This behaviour can be described with the modified life fraction rule and a factor concept of relative life for single stage cycles and additionally with a multistep hypothesis for multi-stage cycles. The description can be adapted to estimate the life consumption under service type random conditions. The strain cycling behaviour was investigated in regard to the conditions of the heated surface of large components. To simulate this type of loading and to generate long term ...

Energy Technology Data Exchange (ETDEWEB)

This report presents the results of cladding technology development under the Coal-Fired Combined Cycle DOE Project for the period July 1976 through June 1978. Sub-task 3.1, Clad Alloy Development, involved the selection, fabrication and burner rig evaluation of advanced clad alloy compositions diffusion-bonded to IN-738. Testing was conducted for up to 5800 hours at 1600/sup 0/F in a simulated PFB environment. Metallographic evaluation showed Co-base cladding alloys PFB-5PM and PFB-6PM (aluminided) and Fe-base alloy GE-2541 to be the most corrosion resistant. The formability and fabricability of sheet material was significantly improved for these alloys by utilizing powder metallurgy techniques. Sub-task 3.2, Clad Process Development, encompassed processing activities to evaluate sheet alloy formability, bucket surface preparation techniques, platform clad forming, and the activated diffusion bonding (ADB) of corrosion resistant tips to MS5001 ...

Energy Technology Data Exchange (ETDEWEB)

Studies are made of optimum materials and methods for manufacturing low-carbon fuels for reduction in greenhouse gas emissions. When their thermal dynamic limits and the technological maturity are considered, it is inferred that no extensive improvement will be achieved by merely improving on the efficiency of the existing fuels. The use of various high-efficiency driving power sources utterly different in mechanism from the conventional ones, such as those for fuel cell-powered automobiles, and the promotion of the use of low-carbon fuels such as methanol and methane for all kinds of driving power sources including those for the said fuel cell-powered automobiles, will become necessary. The use will also be necessary of recyclable materials. The biomass resources, in particular, since they absorb CO2 gas in their growing process by virtue of photosynthesis, may be said to be free of CO2 gas emissions. They have their own ...

Energy Technology Data Exchange (ETDEWEB)

This fourteenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period November 1, 1990 to January 31, 1991. Testing of the High Pressure Cooling Subsystem electrical isolator was completed. The PEEK material successfully passed the high temperature, high pressure duration tests (50 hours). The Combustion Subsystem drawings were CADAM released. The procurement process is in progress. An equipment specification and RFP were prepared for the new Low Pressure Cooling System (LPCS) and released for quotation. Work has been conducted on confirmation tests leading to final gas-side designs and studies to assist in channel fabrication.The final cathode gas-side design and the proposed gas-side designs of the anode and sidewall are presented. Anode confirmation tests and related analyses of anode wear mechanisms used in the selection of the ...

Energy Technology Data Exchange (ETDEWEB)

In this paper, we report the electrochemical characteristics of a novel cathode material, Li{sub 2}CoPO{sub 4}F, prepared by solid-state reactions. The solid-state reaction mechanism involved in synthesizing the Li{sub 2}CoPO{sub 4}F also is analyzed in this paper. When cycled between 2.0 V and 5.0 V during cyclic voltammetry measurements, the Li{sub 2}CoPO{sub 4}F samples present one, fully reversible anodic reaction at 4.81 V. When cycled between 2.0 V and 5.5 V, peaks occurring at 4.81 V and 5.12 V in the first anodic scan evolved to one broad oxidative, mound-like pattern in subsequent cycles. Correspondingly, the X-ray diffraction (XRD) pattern of the Li{sub 2}CoPO{sub 4}F electrode discharged from 5.5 V to 2.0 V is slightly different from the patterns exhibited by a fresh sample and the sample discharged from 5.0 V to 2.0 V. This difference may correspond to a structural relaxation that appears above 5 V. In the ...

Energy Technology Data Exchange (ETDEWEB)

Seven generic types of collectors, together with associated subsystems for electric power generation, were considered. The collectors can be classified into three categories: (1) two-axis tracking (with compound-curvature reflecting surfaces); (2) one-axis tracking (with single-curvature reflecting surfaces); and (3) nontracking (with low-concentration reflecting surfaces). All seven collectors were analyzed in conceptual system configurations with Rankine-cycle engines. In addition, two of the collectors were analyzed with Brayton-cycle engines, and one was analyzed with a Stirling-cycle engine. With these engine options, and the consideration of both thermal and electrical storage for the Brayton-cycle central receiver, 11 systems were formulated for analysis. Conceptual designs developed for the 11 systems were based on common assumptions of available technology in the 1990 to 2000 time frame. No ...

International Nuclear Information System (INIS)

The aim of the work in this thesis is to investigate the convective and diffusive transport in the TM chemistry transport model, and to investigate some aspects of the consequences for NOx. The large inaccuracy and uncertainty in the description of processes like convection and turbulent diffusion, the strong dependence of the radiative forcing of ozone on its vertical distribution, and the strong dependence of the ozone production on the distribution of NOx, are the main motivation. The availability of the ERA-40 data, where convective data and vertical diffusion coefficients are archived, allows a study of the effect of different convective mass flux sets, and different vertical diffusion coefficients on the model-simulated distribution of tracers. In this thesis the following questions are addressed : (1) How large is the sensitivity of the (model simulated) distribution of ozone and nitrogen oxides on (the) convection (parameterisation)?; (2) What requirements should be fulfilled ...

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This paper describes potentials on fuel economy and NO{sub x} exhaust emissions of a series hybrid urban bus system equipped with a ceramic gas turbine engine (CGT). The simulating program developed in-house was used to analyze influences of several parameters of each main components of the hybrid vehicle system on the performance of the bus running on the modified bus driving cycle. The basic data used in this analysis for a CGT was derived from the results of 'the Automotive 100kW CGT Project' of Japan. A dynamic response of a CGT-Generator rotating system was very much improved by introducing of 'Assisting system' in which the generator was used as an acceleration-deceleration assisting device when much acceleration or deceleration was needed. This system would make a CGT operate along the optimum operating line (fuel minimum line) even under the unsteady driving conditions. This analysis showed that the ...

Energy Technology Data Exchange (ETDEWEB)

A lightweight, low permeability liner for graphite epoxy composite compressed gas storage vessels. The liner is composed of polymers that may or may not be coated with a thin layer of a low permeability material, such as silver, gold, or aluminum, deposited on a thin polymeric layer or substrate which is formed into a closed bladder using torispherical or near torispherical end caps, with or without bosses therein, about which a high strength to weight material, such as graphite epoxy composite shell, is formed to withstand the storage pressure forces. The polymeric substrate may be laminated on one or both sides with additional layers of polymeric film. The liner may be formed to a desired configuration using a dissolvable mandrel or by inflation techniques and the edges of the film seamed by heat sealing. The liner may be utilized in most any type of gas storage system, and is particularly applicable for hydrogen, gas ...

Energy Technology Data Exchange (ETDEWEB)

This study is part of a greater project from IPT (Sao Paulo's Institute of Technology), which foresaw an energetic use for elephant-grass (Pennisetum purpureum). Biomass gasification is an sustainable option for energy supply, which presents low pollutants emission rate and allows - through the global cycle of growing and consumption of feedstock (vegetables), a balance between consumption and production of carbonic gas, preventing an increase of the carbonic gas levels in the atmosphere. A gasifier was built with internal diameter of 400 mm and total height of 4600 mm . The equipment was tested for gasification of elephant-grass (Pennisetum purpureum) at a 100 kg/h rate. The equipment was tested and some constructive faults were detected. In the countryside, this biomass is commonly used for cattle feeding It was evaluated an adequate diesel-electric-generator. to work at hybrid regime, using 70% biomass ...

Energy Technology Data Exchange (ETDEWEB)

This thesis surveys the concepts of exergy and extends the exergy method of analysis from the standpoint of its applications to the power plant systems. After a brief historical review of exergy concepts, the general exergy equation is derived from the combined equation of First and Second Law, and it is shown that any special case of exergy equation is a simplified form of the general exergy equation. The mathematical method for the exergy analysis of a steady-state, steady-flow system, analogous to that of the First Law, is given. The exergy losses in a power plant are discussed. Then in order to examine these losses, the Second Law performance of major processes of combustion, compression, heat transfer, mixing and throttling have been analyzed analytically, and the exergy efficiencies are defined that accurately assess the thermodynamic performance of the corresponding processes. The methods for computation of exergy loss and exergy efficiency are given and ...

Energy Technology Data Exchange (ETDEWEB)

The influence of Cr on the structure and electrochemical properties of LiCoVO{sub 4} was studied using X-Ray diffraction, scanning electron microscopy, Raman Spectroscopy and cycle tests. Doping levels up to 10 mol% were achieved, which improved the electrochemical stability of the structure of LiCoVO{sub 4}, resulting in a significant increase in the initial charge and discharge capacity. The Raman spectroscopy data for the Cr-doped LiCoVO{sub 4} is similar as for LiCoVO{sub 4}. The replacement of a dopant for the Co-ion in the inverse spinel structure causes several Raman shifts. The X-ray diffraction patterns show no new phases and combined with the Raman spectroscopy data it is concluded that the Cr dopant will be located at the octahedral site (16d) where they create an electronic pathway that enhances the electronic conductivity. However, the capacity dropped significantly after prolonged cycling, which is due to the ...

International Nuclear Information System (INIS)

Heavy-duty trucks and buses are substantial contributors to the atmospheric oxides of nitrogen (NO_x) inventory, but prediction of their emissions in real use remains inchoate. Continuous emissions of NO_x were recorded from Chassis dynamometer testing of eight vehicles using a variety of transient cycles, including the Central Business District schedule. NO_x data were treated to account for sampling time lag and presented against instantaneous vehicle axle power. Data were repeatable from run to run and test schedule, but vehicle type and test cycle both influenced the instantaneous emissions rates. However, the resulting correlations may be used for mobile source NO_x contribution estimation when combined with vehicle activity data. The emissions data were also presented as NO_x/CO_2, which are valuable for comparison with remote sensing emissions data. The overall average ratio for all of the data considered was 0.0141, ...

International Nuclear Information System (INIS)

Full text: The surface properties of poly (tetrafluoroethylene) (PTFE) are changed by the exposure to synchrotron radiation (SR). We succeeded in controlling the wettability of the PTFE surface from hydrophobic to hydrophilic by varying the substrate temperature during the SR irradiation and found that the wettability was ascribable to microstructure and chemical composition of surface.In these previous works, oxygen atoms were found to inhabit on the hydrophobic surface of PTFE. In this study, we investigated the surface modification of PTFE from the SR exposure experiment under the O_2 gas atmosphere. The SR exposure to the PTFE sheet was carried out at beamline 6 (BL6) of the New- SUBARU. The PTFE sheet was irradiated to the white beam, ranging 50-1000 eV at BL6 at room temperature. The gas cell was mounted at the irradiation chamber. The O_2 gas pressure in the gas cell can be maintained at about ...

Energy Technology Data Exchange (ETDEWEB)

Crankshafts of the pearlitic-sorbitic nodular cast iron type JUS NL.80 (similar to DIN GGG-80) heat treated to get a tensile strength of 820-900 GPa (i.e. a Vickers hardness of 268-295 HV) were plasma and ammonia gas nitrided. The glow discharge plasma nitriding was performed for 20 h at about 500degC in a gas mixture of 55% N{sub 2} and 45% H{sub 2}. The gas nitriding was performed for 28 h at 510degC in the ammonia gas. Evaluation of the nitrided surfaces was conducted by optical microscopy, X-ray diffractometry and microhardness measurements. Journal and crank pin dimensions and surface roughness were measured both before and after nitriding. Bending fatigue testing of crankshafts was performed using a fatigue testing rig. The fatigue limit was evaluated at 5.0x10{sup 6} cycles. The fractures happened at the transition radius of the journal with cracks starting beneath the ...

Energy Technology Data Exchange (ETDEWEB)

Various engine concepts that are in the race to be the dominant bus-engine type five years from now were reviewed. Three types of engines, the Otto cycle (CNG and propane), diesel and DME (dimethyl ether) received most of the attention. Emission standards, engine size and reliability are the main demands on bus engines. Each of these engine concepts were reviewed against these criteria. In terms of emission standards (as measured by the EEV emission limits) Otto cycle engines have the advantage since they are currently in production. Advanced diesel technology is on the prototype level, but not yet in production. DME-engines are still on the testbed, not in the demonstration stage and much less in the production stage. Otto cycle engines also have the most experience with EEV emission limits. Among the Otto-cycle engines, propane-fuelled engines appear to have the upper hand since propane is very ...

Energy Technology Data Exchange (ETDEWEB)

The retention indices of cycloalkenes and cycloalkadienes with C/sub 6/-C/sub 13/ rings are determined by gas-liquid chromatography (GLC) on glass capillary columns coated with OV-1 and Ucon LB 550X and by gas-solid chromatrography (GSC) on a microcolumn packed with uncoated graphitized thermal carbon black (GTCB). Structure-retention correlations are derived on using index differences such as H/sup OV/, H/sup GTCB/ and ..delta..I values, considering the differences in the stereochemistry of these compounds. It is shown that the combined application of index increments obtained in GLC and GSC provides more detaled structure informations. The value of the retention index units agree with the most stable conformations of the alicyclic compounds. The high value for the energy equivalent to an index unit (..delta..G/sub I.U./ = 4.18 kJ/mol) confirms that graphitized thermal carbon black causes much stronger dispersive ...

Energy Technology Data Exchange (ETDEWEB)

Bethlehem Steel Corporation (BSC), in conjunction with the Department of Energy (DOE) is conducting a Clean Coal Technology (CCT) project at its Sparrows Point, Maryland Coke Oven Plant. This innovative coke oven gas cleaning system combines several existing technologies into an integrated system for removing impurities from Coke Oven Gas (COG) to make it an acceptable fuel. DOE provided cost-sharing under a Cooperative Agreement with BSC. This Cooperative Agreement requires BSC to develop and conduct and Environmental Monitoring Plan for the Clean Coal Technology project and to report the status of the EMP on a quarterly basis. It also requires the preparation of a final report on the results of the Baseline Compliance and Supplemental Sampling Programs that are part of the EMP and which were conducted prior to the startup of the innovative coke oven gas cleaning system. This report is the Baseline ...

Energy Technology Data Exchange (ETDEWEB)

In this paper the simulation of hybrid processes containing membrane units will be discussed. For this purpose a user-defined module for simulation and design of membrane processes was implemented into the simulation program AspenPlus. The advantages can be summarized as follows: - any combination of membrane processes with all other units already implemented in AspenPlus is possible, including internal recycle streams, - utilization of the physical property models and data bases of AspenPlus is possible, - cost and sensitivity analysis can be performed. These benefits are demonstrated in detail for a membrane vapor recovery unit for the treatment of tank farm off-gas, for a two-stage reverse osmosis plant for organic/-organic separations and for a combination of distillation and pervaporation for the separation of a dimethylcarbonate/methanol mixture. (orig.)

Energy Technology Data Exchange (ETDEWEB)

A fusion reactor (such as NET/ITER) which breeds its own tritium fuel requires tritium recovery, purification and separation from the other isotopes. Cyclic adsorption processes are strong candidates for several of the processes involved: amongst other advantages, they promise a low tritium inventory. A good adsorbent for such processes must have high adsorption capacity, high selectivity and very low tritium retention after each cycle. Pure zeolite powder is shown to have an excellent combination of these three properties. However, in practice problems can arise from tritium which is not removed by reactivation. In this paper we show that tritium retention in zeolites can be caused either by water retained in the zeolite structure, which can be removed by ore rigorous activation, or by water tapped on binders in commercial pellets. (orig.).

British Library Electronic Table of Contents (United Kingdom)

This experimental study investigates the effectiveness of crossed inclined bars (X-bars) as joint shear reinforcement in exterior reinforced concrete beam-column connections under cyclic deformations. Test results of 20 joint subassemblages with various reinforcement ratios and arrangements including X-bars in the joint area are presented. The X-type, non-conventional reinforcement is examined as the only joint reinforcement and in combination with common stirrups or vertical bars. The experimental results reported herein include full loading cycle curves, energy dissipation values and a categorization of the observed damage modes. Based on the comparisons between the overall hysteretic responses of the tested specimens, it is deduced that joints with X-bars exhibited enhanced cyclic perfo...

British Library Electronic Table of Contents (United Kingdom)

Remote sensing is the most practical method available to managers of fire-prone forests for quantifying and mapping fire impacts. Differenced Normalised Burn Ratio (?NBR) is among the most widely used spectral indices for the mapping of burn severity but is difficult to interpret in terms of fire-related changes in key biophysical attributes and processes. We propose to quantify burn severity as a change in the leaf area index (?LAI) of a stand. LAI is a key biophysical attribute of forests, and is central to understanding their water and carbon cycles. Previous studies have suggested that changes in canopy LAI may be a major contributor to ?NBR and to the composite burn index (CBI) that is frequently used in combination with the NBR to assess burn severity on the ground. We applied remote...

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle fatigue, crack initiation was most likely caused by inclusions like Titanium Carbon nitrides or Aluminium Oxides. A micro mechanical model for the crack initiation by inclusions was developed. Another model was developed to describe the influence of these inclusions on the lifetime. A weakest-link model, using the statistical distribution of inclusions and surface flaws, was used to describe the endurance limit. (orig.)

CERN Document Server

We consider the effect of distributed delays in neural feedback systems. The avian optic tectum is reciprocally connected with the nucleus isthmi. Extracellular stimulation combined with intracellular recordings reveal a range of signal delays from 4 to 9 ms between isthmotectal elements. This observation together with prior mathematical analysis concerning the influence of a delay distribution on system dynamics raises the question whether a broad delay distribution can impact the dynamics of neural feedback loops. For a system of reciprocally connected model neurons, we found that distributed delays enhance system stability in the following sense. With increased distribution of delays, the system converges faster to a fixed point and converges slower toward a limit cycle. Further, the introduction of distributed delays leads to an increased range of the average delay value for which the system's equilibrium point is stable. The enhancement of ...

Energy Technology Data Exchange (ETDEWEB)

A methanol car means a car driven with a fuel that has part of or the whole of the gasoline or kerosene replaced with methanol. Fuel methanol is abundantly available, relatively easy to transport and store and has few environmental pollutants in its exhaust gas. Its octane value is high, but ignitionability is not good due to its low cetane value. It is good for Otto cycle engines, but not adequate for diesel cycle engines. As a technological problem, the point is ignitionability and development of Otto type methanol engines ahead of that of diesel type methanol engines. Evaluation of methanol cars is internationally high and its development is done vigorously, but there are also problems including a short continuous travel distance due to the low heating value of methanol. Although methanol cars are deemed to be most promising for commercialization among cars using alternative fuel, it is necessary to cope systematically ...