WorldWideScience

Sample records for rankine cycle energy

  1. Energy analysis of Organic Rankine Cycles for biomass applications

    Directory of Open Access Journals (Sweden)

    Algieri Angelo

    2015-01-01

    Full Text Available The present paper aims at analysing the performances of Organic Rankine Cycles (ORCs adopted for the exploitation of the biomass resulting from the pruning residues in a 3000 hectares district in Southern Italy. A parametric energy analysis has been carried out to define the influence of the main plant operating conditions. To this purpose, both subcritical and transcritical power plants have been examined and saturated and superheated conditions at the turbine inlet have been imposed. Moreover, the effect of the working fluid, condensation temperature, and internal regeneration on system performances has been investigated. The results show that ORC plants represent an interesting and sustainable solution for decentralised and small-scale power production. Furthermore, the analysis highlights the significant impact of the maximum temperature and the noticeable effect of internal regeneration on the performances of the biomass power plants.

  2. Thermodynamic analysis of a Rankine cycle powered vapor compression ice maker using solar energy.

    Science.gov (United States)

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

    To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m(-2) and 7.61 kg m(-2) day(-1) at the generation temperature of 140 °C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker.

  3. Rankine-cycle solar-cooling systems

    Science.gov (United States)

    Weathers, H. M.

    1979-01-01

    Report reviews progress made by three contractors to Marshall Space Flight Center and Department of Energy in developing Rankine-cycle machines for solar cooling and testing of commercially available equipment involved.

  4. Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

    Directory of Open Access Journals (Sweden)

    Bing Hu

    2014-01-01

    Full Text Available To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44 W m−2 and 7.61 kg m−2 day−1 at the generation temperature of 140°C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker.

  5. Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

    National Research Council Canada - National Science Library

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

      To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working...

  6. Thermodynamic analysis of a Rankine cycle powered vapor compression ice maker using solar energy

    National Research Council Canada - National Science Library

    Hu, Bing; Bu, Xianbiao; Ma, Weibin

    2014-01-01

    To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working...

  7. Rankine cycle condenser pressure control using an energy conversion device bypass valve

    Science.gov (United States)

    Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

    2014-04-01

    The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

  8. Energy analysis of a trigeneration plant based on solid oxide fuel cell and organic Rankine cycle

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiman, Fahad A. [Mechanical and Aerospace Engineering Department, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario (Canada); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada); Hamdullahpur, Feridun [Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, Ontario (Canada)

    2010-05-15

    In this study, energy analysis of a trigeneration plant based on solid oxide fuel cell (SOFC) and organic Rankine cycle (ORC) is conducted. The physical and thermodynamic elements of the plant include an SOFC, an ORC, a heat exchanger for the heating process and a single-effect absorption chiller for cooling. The results obtained from this study show that there is at least a 22% gain in efficiency using the trigeneration plant compared with the power cycle (SOFC and ORC). The study also shows that the maximum efficiency of the trigeneration plant is 74%, heating cogeneration is 71%, cooling cogeneration is 57% and net electricity is 46%. Furthermore, it is found that the highest net power output that can be provided by the trigeneration plant considered in this study is 540 kW and, the highest SOFC-AC power is 520 kW. The study reveals that the inlet pressure of the turbine has an insignificant effect on the efficiency. The study also examines the effect of both the SOFC current density and the SOFC inlet flow temperature on the cell voltage and voltage loss. (author)

  9. Exergy and economic analysis of organic rankine cycle hybrid system utilizing biogas and solar energy in rural area of China

    DEFF Research Database (Denmark)

    Zhao, Chunhua; Zheng, Siyu; Zhang, Ji

    2017-01-01

    Due to the existing huge biogas resource in the rural area of China, biogas is widely used for production and living. Cogeneration system provides an opportunity to realize the balanced utilization of the renewable energy such as biogas and solar energy. This paper presented a numerical...... investigation of a hybrid energy-driven organic Rankine cycle (ORC) cogeneration system, involving a solar organic Rankine cycle and a biogas boiler. The biogas boiler with a module of solar Parabolic-Trough Collectors (PTC) is employed to provide heat source to the ORC via two distinct intermediate pressurized...... circuits. The cogeneration supplied the power to the air-condition in summer condition and hot water, which is heated in the condenser, in winter condition. The system performance under the subcritical pressures has been assessed according to the energy-exergy and economic analysis with the organic working...

  10. Thermal energy storage for low grade heat in the organic Rankine cycle

    Science.gov (United States)

    Soda, Michael John

    Limits of efficiencies cause immense amounts of thermal energy in the form of waste heat to be vented to the atmosphere. Up to 60% of unrecovered waste heat is classified as low or ultra-low quality, making recovery difficult or inefficient. The organic Rankine cycle can be used to generate mechanical power and electricity from these low temperatures where other thermal cycles are impractical. A variety of organic working fluids are available to optimize the ORC for any target temperature range. San Diego State University has one such experimental ORC using R245fa, and has been experimenting with multiple expanders. One limitation of recovering waste heat is the sporadic or cyclical nature common to its production. This inconsistency makes sizing heat recovery ORC systems difficult for a variety of reasons including off-design-point efficiency loss, increased attrition from varying loads, unreliable outputs, and overall system costs. Thermal energy storage systems can address all of these issues by smoothing the thermal input to a constant and reliable level and providing back-up capacity for times when the thermal input is deactivated. Multiple types of thermal energy storage have been explored including sensible, latent, and thermochemical. Latent heat storage involves storing thermal energy in the reversible phase change of a phase change material, or PCM, and can have several advantages over other modalities including energy storage density, cost, simplicity, reliability, relatively constant temperature output, and temperature customizability. The largest obstacles to using latent heat storage include heat transfer rates, thermal cycling stability, and potentially corrosive PCMs. Targeting 86°C, the operating temperature of SDSU's experimental ORC, multiple potential materials were explored and tested as potential PCMs including Magnesium Chloride Hexahydrate (MgCl2˙6H2O), Magnesium Nitrate Hexahydrate (Mg(NO3)2˙6H 2O), montan wax, and carnauba wax. The

  11. Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy

    OpenAIRE

    Bing Hu; Xianbiao Bu; Weibin Ma

    2014-01-01

    To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with incr...

  12. Energy performance and economic evaluation of heat pump/organic rankine cycle system with sensible thermal storage

    DEFF Research Database (Denmark)

    Carmo, Carolina; Dumont, Olivier; Nielsen, Mads Pagh

    2016-01-01

    that consists of a ground-source heat pump with possibility of reversing operation as an ORC power cycle combined with solar heating in a single-family building is introduced. The ORC mode enables the use of solar energy in periods of no heat energy demand and reverses the heat pump cycle to supply electrical......-life conditions knowledge, the paper considers two different sensible energy storage (TES) configurations for the reversible heat pump/organic Rankine cycle (HP/ORC) system: a buffer tank for both space heating and domestic hot water and a hot water storage tank used exclusively for domestic hot water......The interaction between electrical and thermal energy demands represent a potential area for balancing supply and demand that could contribute to the integration of intermittent renewables in energy systems. To enable the interaction between thermal and electric energy, an innovative concept...

  13. Energy Performance and Economic Evaluation of Heat Pump/Organic Rankine Cycle System with Sensible Thermal Storage

    DEFF Research Database (Denmark)

    Carmo, C.; Dumont, O.; Nielsen, M. P.

    2016-01-01

    that consists of a ground-source heat pump with possibility of reversing operation as an ORC power cycle combined with solar heating in a single-family building is introduced. The ORC mode enables the use of solar energy in periods of no heat energy demand and reverses the heat pump cycle to supply electrical......-life conditions knowledge, the paper considers two different sensible energy storage (TES) configurations for the reversible heat pump/organic Rankine cycle (HP/ORC) system: a buffer tank for both space heating and domestic hot water and a hot water storage tank used exclusively for domestic hot water......The interaction between electrical and thermal energy demands represent a potential area for balancing supply and demand that could contribute to the integration of intermittent renewables in energy systems. To enable the interaction between thermal and electric energy, an innovative concept...

  14. Organic rankine cycle waste heat applications

    Science.gov (United States)

    Brasz, Joost J.; Biederman, Bruce P.

    2007-02-13

    A machine designed as a centrifugal compressor is applied as an organic rankine cycle turbine by operating the machine in reverse. In order to accommodate the higher pressures when operating as a turbine, a suitable refrigerant is chosen such that the pressures and temperatures are maintained within established limits. Such an adaptation of existing, relatively inexpensive equipment to an application that may be otherwise uneconomical, allows for the convenient and economical use of energy that would be otherwise lost by waste heat to the atmosphere.

  15. Organic Rankine Cycles. Old wine in new bottles; Organic Rankine Cycles. Oude wijn in nieuwe zakken

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, T.L.B. [Cumae, Arnhem (Netherlands)

    2007-05-15

    An overview is given of the renewed interest for the Organic Rankine Cycle technology and new developments with regard to this power generating technology. [Dutch] Een overzicht wordt gegeven van de hernieuwde belangstelling voor de Organic Rankine Cycle (ORC) technologie en nieuwe ontwikkeling m.b.t. deze vorm van elektriciteitopwekking.

  16. Development of an Organic Rankine Cycle system for exhaust energy recovery in internal combustion engines

    Science.gov (United States)

    Cipollone, Roberto; Bianchi, Giuseppe; Gualtieri, Angelo; Di Battista, Davide; Mauriello, Marco; Fatigati, Fabio

    2015-11-01

    Road transportation is currently one of the most influencing sectors for global energy consumptions and CO2 emissions. Nevertheless, more than one third of the fuel energy supplied to internal combustion engines is still rejected to the environment as thermal waste at the exhaust. Therefore, a greater fuel economy might be achieved recovering the energy from exhaust gases and converting it into useful power on board. In the current research activity, an ORC-based energy recovery system was developed and coupled with a diesel engine. The innovative feature of the recovery power unit relies upon the usage of sliding vane rotary machines as pump and expander. After a preliminary exhaust gas mapping, which allowed to assess the magnitude of the thermal power to be recovered, a thermodynamic analysis was carried out to design the ORC system and the sliding vane machines using R236fa as working fluid. An experimental campaign was eventually performed at different operating regimes according to the ESC procedure and investigated the recovery potential of the power unit at design and off-design conditions. Mechanical power recovered ranged from 0.7 kW up to 1.9 kW, with an overall cycle efficiency from 3.8% up to 4.8% respectively. These results candidate sliding vane machines as efficient and reliable devices for waste heat recovery applications.

  17. Economic, Energetic, and Environmental Performance of a Solar Powered Organic Rankine Cycle with Electric Energy Storage in Different Commercial Buildings

    Directory of Open Access Journals (Sweden)

    Emily Spayde

    2018-01-01

    Full Text Available This paper presents an analysis to determine the economic, energetic, and environmental benefits that could be obtained from the implementation of a combined solar-power organic Rankine cycle (ORC with electric energy storage (EES to supply electricity to several commercial buildings including a large office, a small office, and a full service restaurant. The operational strategy for the ORC-EES system consists in the ORC charging the EES when the irradiation level is sufficient to generate power, and the EES providing electricity to the building when there is not irradiation (i.e., during night time. Electricity is purchased from the utility grid unless it is provided by the EES. The potential of the proposed system to reduce primary energy consumption (PEC, carbon dioxide emission (CDE, and cost was evaluated. Furthermore, the available capital cost for a variable payback period for the ORC-EES system was determined for each of the evaluated buildings. The effect of the number of solar collectors on the performance of the ORC-EES is also studied. Results indicate that the proposed ORC-EES system is able to satisfy 11%, 13%, and 18% of the electrical demand for the large office, the small office and the restaurant, respectively.

  18. Emissions-critical charge cooling using an organic rankine cycle

    Science.gov (United States)

    Ernst, Timothy C.; Nelson, Christopher R.

    2014-07-15

    The disclosure provides a system including a Rankine power cycle cooling subsystem providing emissions-critical charge cooling of an input charge flow. The system includes a boiler fluidly coupled to the input charge flow, an energy conversion device fluidly coupled to the boiler, a condenser fluidly coupled to the energy conversion device, a pump fluidly coupled to the condenser and the boiler, an adjuster that adjusts at least one parameter of the Rankine power cycle subsystem to change a temperature of the input charge exiting the boiler, and a sensor adapted to sense a temperature characteristic of the vaporized input charge. The system includes a controller that can determine a target temperature of the input charge sufficient to meet or exceed predetermined target emissions and cause the adjuster to adjust at least one parameter of the Rankine power cycle to achieve the predetermined target emissions.

  19. Cascaded organic rankine cycles for waste heat utilization

    Science.gov (United States)

    Radcliff, Thomas D [Vernon, CT; Biederman, Bruce P [West Hartford, CT; Brasz, Joost J [Fayetteville, NY

    2011-05-17

    A pair of organic Rankine cycle systems (20, 25) are combined and their respective organic working fluids are chosen such that the organic working fluid of the first organic Rankine cycle is condensed at a condensation temperature that is well above the boiling point of the organic working fluid of the second organic Rankine style system, and a single common heat exchanger (23) is used for both the condenser of the first organic Rankine cycle system and the evaporator of the second organic Rankine cycle system. A preferred organic working fluid of the first system is toluene and that of the second organic working fluid is R245fa.

  20. Performance of a reversible heat pump/organic Rankine cycle unit coupled with a passive house to get a positive energy building

    DEFF Research Database (Denmark)

    Dumont, Olivier; Carmo, Carolina; Fontaine, Valentin

    2016-01-01

    and generate electricity, coupled to a solar thermal collector roof. This reversible HP/organic Rankine cycle unit presents three operating modes: direct heating, HP and organic Rankine cycle. This work focuses on describing the dynamic model of the multi-component system followed by a techno-economic analysis......Wh/year and total electrical consumption of 2318 kWh/year) with a 138.8 m2 solar roof in Denmark....

  1. FLUOROETHERS AS A WORKING FLUIDS FOR LOW TEMPERATURE ORGANIC RANKINE CYCLE

    Directory of Open Access Journals (Sweden)

    Artemenko S.V

    2014-12-01

    Full Text Available Hydrofluoroethers as a new class of working fluids for the organic Rankine cycle have been considered to utilize the low-potential waste heat. Temperature range 300…400 K was chosen to provide energy conversion of waste heat from fuel cells. The direct assessment of the efficiency criteria for the Rankine cycle via artificial neural networks (ANN was used. To create ANN the critical parameters of substance and normal boiling temperature as input were chosen. The forecast of efficiency criteria for the Rankine cycle as output parameter which reproduces the coefficient of performance with high accuracy and without thermodynamic property calculations was presented.

  2. Theoretical and experimental research of organic Rankine cycle steam turbine plants

    Science.gov (United States)

    Kishkin, A. A.; Delkov, A. V.; Melkozerov, M. G.

    2017-10-01

    Currently steam power cycles using organic actuation fluid - Freon, ammonia, ethanol, isobutene, etc are becoming increasingly important. Such cycles are called Organic Rankine Cycle (ORC). With the help of such cycles it is possible to use low-grade heat sources in the production of mechanical and electrical energy.

  3. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 7: Metal vapor Rankine topping-steam bottoming cycles. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Deegan, P. B.

    1976-01-01

    Adding a metal vapor Rankine topper to a steam cycle was studied as a way to increase the mean temperature at which heat is added to the cycle to raise the efficiency of an electric power plant. Potassium and cesium topping fluids were considered. Pressurized fluidized bed or pressurized (with an integrated low-Btu gasifier) boilers were assumed. Included in the cycles was a pressurizing gas turbine with its associated recuperator, and a gas economizer and feedwater heater. One of the ternary systems studied shows plant efficiency of 42.3% with a plant capitalization of $66.7/kW and a cost of electricity of 8.19 mills/MJ (29.5 mills/kWh).

  4. Performance analysis a of solar driven organic Rankine cycle using multi-component working fluids

    DEFF Research Database (Denmark)

    Baldasso, E.; Andreasen, J. G.; Modi, A.

    2015-01-01

    Among the different renewable sources of energy, solar power could play a primary role in the development of a more sustainable electricity generation system. While large scale concentrated solar power plants based on the steam Rankine cycle have already been proved to be cost effective, research...... is still under progress for small scale low temperature solar-driven power plants. The steam Rankine cycle is suitable for high temperature applications, but its efficiency drastically decreases as the heat source temperature drops. In these cases a much more promising configuration is the organic Rankine...... field made of parabolic trough collectors and a recuperative organic Rankine cycle. Pressurized water is selected as heat transfer fluid and its maximum temperature is fixed to 150°C. The target power output for the plant is 100 kWel. A part load analysis is carried out in order to define the most...

  5. Energy, Exergy and Economic Evaluation Comparison of Small-Scale Single and Dual Pressure Organic Rankine Cycles Integrated with Low-Grade Heat Sources

    Directory of Open Access Journals (Sweden)

    Armando Fontalvo

    2017-09-01

    Full Text Available Low-grade heat sources such as solar thermal, geothermal, exhaust gases and industrial waste heat are suitable alternatives for power generation which can be exploited by means of small-scale Organic Rankine Cycle (ORC. This paper combines thermodynamic optimization and economic analysis to assess the performance of single and dual pressure ORC operating with different organic fluids and targeting small-scale applications. Maximum power output is lower than 45 KW while the temperature of the heat source varies in the range 100–200 °C. The studied working fluids, namely R1234yf, R1234ze(E and R1234ze(Z, are selected based on environmental, safety and thermal performance criteria. Levelized Cost of Electricity (LCOE and Specific Investment Cost (SIC for two operation conditions are presented: maximum power output and maximum thermal efficiency. Results showed that R1234ze(Z achieves the highest net power output (up to 44 kW when net power output is optimized. Regenerative ORC achieves the highest performance when thermal efficiency is optimized (up to 18%. Simple ORC is the most cost-effective among the studied cycle configurations, requiring a selling price of energy of 0.3 USD/kWh to obtain a payback period of 8 years. According to SIC results, the working fluid R1234ze(Z exhibits great potential for simple ORC when compared to conventional R245fa.

  6. Affordable Rankine Cycle Waste Heat Recovery for Heavy Duty Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Swami Nathan [Eaton Corporation

    2017-06-30

    Nearly 30% of fuel energy is not utilized and wasted in the engine exhaust. Organic Rankine Cycle (ORC) based waste heat recovery (WHR) systems offer a promising approach on waste energy recovery and improving the efficiency of Heavy-Duty diesel engines. Major barriers in the ORC WHR system are the system cost and controversial waste heat recovery working fluids. More than 40% of the system cost is from the additional heat exchangers (recuperator, condenser and tail pipe boiler). The secondary working fluid loop designed in ORC system is either flammable or environmentally sensitive. The Eaton team investigated a novel approach to reduce the cost of implementing ORC based WHR systems to Heavy-Duty (HD) Diesel engines while utilizing safest working fluids. Affordable Rankine Cycle (ARC) concept aimed to define the next generation of waste energy recuperation with a cost optimized WHR system. ARC project used engine coolant as the working fluid. This approach reduced the need for a secondary working fluid circuit and subsequent complexity. A portion of the liquid phase engine coolant has been pressurized through a set of working fluid pumps and used to recover waste heat from the exhaust gas recirculation (EGR) and exhaust tail pipe exhaust energy. While absorbing heat, the mixture is partially vaporized but remains a wet binary mixture. The pressurized mixed-phase engine coolant mixture is then expanded through a fixed-volume ratio expander that is compatible with two-phase conditions. Heat rejection is accomplished through the engine radiator, avoiding the need for a separate condenser. The ARC system has been investigated for PACCAR’s MX-13 HD diesel engine.

  7. Organic Rankine Cycle with Solar Heat Storage in Paraffin Way

    Directory of Open Access Journals (Sweden)

    Constantin LUCA

    2015-06-01

    Full Text Available The paper presents an electricity generation system based on an Organic Rankine Cycle and proposed storing the amount of the heat produced by the solar panels using large volume of paraffin wax. The proposed working fluid is R-134a refrigerant. The cycle operates at very low temperatures. A efficiency of 6,55% was obtained.

  8. Performance analysis of organic Rankine cycles using different working fluids

    Directory of Open Access Journals (Sweden)

    Zhu Qidi

    2015-01-01

    Full Text Available Low-grade heat from renewable or waste energy sources can be effectively recovered to generate power by an organic Rankine cycle (ORC in which the working fluid has an important impact on its performance. The thermodynamic processes of ORCs using different types of organic fluids were analyzed in this paper. The relationships between the ORC’s performance parameters (including evaporation pressure, condensing pressure, outlet temperature of hot fluid, net power, thermal efficiency, exergy efficiency, total cycle irreversible loss, and total heat-recovery efficiency and the critical temperatures of organic fluids were established based on the property of the hot fluid through the evaporator in a specific working condition, and then were verified at varied evaporation temperatures and inlet temperatures of the hot fluid. Here we find that the performance parameters vary monotonically with the critical temperatures of organic fluids. The values of the performance parameters of the ORC using wet fluids are distributed more dispersedly with the critical temperatures, compared with those of using dry/isentropic fluids. The inlet temperature of the hot fluid affects the relative distribution of the exergy efficiency, whereas the evaporation temperature only has an impact on the performance parameters using wet fluid.

  9. Thermodynamic Optimization of a Geothermal- Based Organic Rankine Cycle System Using an Artificial Bee Colony Algorithm

    OpenAIRE

    Osman Özkaraca; Pınar Keçebaş; Cihan Demircan; Ali Keçebaş

    2017-01-01

    Geothermal energy is a renewable form of energy, however due to misuse, processing and management issues, it is necessary to use the resource more efficiently. To increase energy efficiency, energy systems engineers carry out careful energy control studies and offer alternative solutions. With this aim, this study was conducted to improve the performance of a real operating air-cooled organic Rankine cycle binary geothermal power plant (GPP) and its components in the aspects of thermodynamic ...

  10. Method of optimizing performance of Rankine cycle power plants. [US DOE Patent

    Science.gov (United States)

    Pope, W.L.; Pines, H.S.; Doyle, P.A.; Silvester, L.F.

    1980-06-23

    A method is described for efficiently operating a Rankine cycle power plant to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine fluid inlet state which is substantially on the area adjacent and including the transposed critical temperature line.

  11. Biogas Engine Waste Heat Recovery Using Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Alberto Benato

    2017-03-01

    Full Text Available Italy is a leading country in the biogas sector. Energy crops and manure are converted into biogas using anaerobic digestion and, then, into electricity using internal combustion engines (ICEs. Therefore, there is an urgent need for improving the efficiency of these engines taking the real operation into account. To this purpose, in the present work, the organic Rankine cycle (ORC technology is used to recover the waste heat contained in the exhaust gases of a 1 MWel biogas engine. The ICE behavior being affected by the biogas characteristics, the ORC unit is designed, firstly, using the ICE nameplate data and, then, with data measured during a one-year monitoring activity. The optimum fluid and the plant configuration are selected in both cases using an “in-house” optimization tool. The optimization goal is the maximization of the net electric power while the working fluid is selected among 115 pure fluids and their mixtures. Results show that a recuperative ORC designed using real data guarantees a 30% higher net electric power than the one designed with ICE nameplate conditions.

  12. Analysis of Low Temperature Organic Rankine Cycles for Solar Applications

    Science.gov (United States)

    Li, Yunfei

    The present work focuses on Organic Rankine Cycle (ORC) systems and their application to low temperature waste heat recovery, combined heat and power as well as off-grid solar power generation applications. As CO_2 issues come to the fore front and fossil fuels become more expensive, interest in low grade heat recovery has grown dramatically in the past few years. Solar energy, as a clean, renewable, pollution-free and sustainable energy has great potential for the use of ORC systems. Several ORC solutions have been proposed to generate electricity from low temperature sources. The ORC systems discussed here can be applied to fields such as solar thermal, biological waste heat, engine exhaust gases, small-scale cogeneration, domestic boilers, etc. The current work presents a thermodynamic and economic analysis for the use of ORC systems to convert solar energy or low exergy energy to generate electrical power. The organic working fluids investigated here were selected to investigate the effect of the fluid saturation temperature on the performance of ORCs. The working fluids under investigation are R113, R245fa, R123, with boiling points between 40°C and 200°C at pressures from 10 kPa to 10 MPa. Ambient temperature air at 20oC to 30oC is utilized as cooling resource, and allowing for a temperature difference 10°C for effective heat transfer. Consequently, the working fluids are condensed at 40°C. A combined first- and second-law analysis is performed by varying some system independent parameters at various reference temperatures. The present work shows that ORC systems can be viable and economical for the applications such as waste heat use and off-grid power generation even though they are likely to be more expensive than grid power.

  13. Equation of State Selection for Organic Rankine Cycle Modeling Under Uncertainty

    DEFF Research Database (Denmark)

    Frutiger, Jerome; O'Connell, John; Abildskov, Jens

    combustion, geothermal and solar heat sources. The working fluid is essential to the performance of the cycle. In order to evaluate and test promising fluid candidates, an appropriate Equation of State (EoS) [1] is necessary. For ORC applications, an EoS is commonly selected based on goodness-of-fits to data......In recent years there has been a great interest in the design and selection of working fluids for low-temperature Organic Rankine Cycles (ORC), to efficiently produce electrical power from waste heat from chemical engineering applications, as well as from renewable energy sources such as biomass...... cycle, all influence the model output uncertainty. The procedure is highlighted for an ORC for with a low-temperature heat source from exhaust gas from a marine diesel engine.[1] Saleh B, Koglbauer G, Wendland M, Fischer J. Working fluids for lowtemperature organic Rankine cycles. Energy 2007...

  14. Organic Rankine Cycle System Analysis for Low GWP Working Fluids

    OpenAIRE

    Datla, Bala Varma; Brasz, Joost

    2012-01-01

    The last decade has seen a substantial increase in Organic Rankine Cycle system installations for low temperature waste heat power recovery. The availability of HFC245fa has played a major role in this recent surge in ORC systems since it allows the use of existing HVAC hardware (heat exchangers and compressors) to be used as ORC components (turbines, boilers and condensers) with minimal redesign. The environmental drawback of HFC245fa is its relatively high GWP value of 950. The advent of a ...

  15. Application of unscented Kalman filter for condition monitoring of an organic Rankine cycle turbogenerator

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Schlanbusch, Rune; Kandepu, Rambabu

    2014-01-01

    emphasis on compactness and reliability. In such context, organic Rankine cycle turbogenerators are a promising technology. The implementation of an organic Rankine cycle unit is thus considered for the power system of the Draugen offshore platform in the northern sea, which is the case study......This work relates to a project focusing on energy optimization on offshore facilities. On oil and gas platforms it is common practice to employ gas turbines for power production. So as to increase the system performance and reduce emissions, a bottoming cycle unit can be designed with particular...... for this project. Considering the plant dynamics, it is of paramount importance to monitor the peak temperatures within the once-through boiler serving the bottoming unit to prevent the decomposition of the working fluid. This paper accordingly aims at applying the unscented Kalman filter to estimate...

  16. Autonomous low-temperature solar Rankine cycle system for reverse osmosis desalination

    Energy Technology Data Exchange (ETDEWEB)

    Manolakos, D.; Makris, G.; Papadakis, G.; Kyritsis, S. [Agricultural University of Athens (Greece). Dept. of Agricultural Engineering; Bouzianas, K. [Hellas Energy K. Bouzianas P. Moschovitis and Co., Athens (Greece)

    2004-07-01

    The research regards the development, application testing and performance evaluation of a low temperature solar organic Rankine cycle system for Reverse Osmosis (RO) desalination. Below is given a technical description of the system under development: Thermal energy produced by the solar array evaporates the working fluid (HFC- 134a) in the evaporator surface. The super-heated vapour is driven to the expanders where the generated mechanical work produced by the Rankine cycle drives the RO unit pumps (high pressure pump, cooling water pump, feed water pump) and circulating pump. The saturated vapour at the expanders' outlet is directed to the condenser and condensates. On the condenser surface, seawater is pre-heated and directed to the seawater reservoir. Seawater pre-heating is applied to increase the fresh water recovery ratio. The seawater tank is insulated. The use of seawater on the condenser surface decreases the temperature of ''Low Temperature Reservoir'' of Rankine cycle thus a better cycle efficiency is achieved. For the prototype system 240 m2 of vacuum tube solar collectors will be deployed. The evaporator and condenser capacity is estimated to be about 100 kW. For these systems' characteristics and considering a water recovery ratio of seawater RO desalination unit of 30%, the average yearly fresh water production is estimated at 1450 m3 (or 4 m3 daily). Specific innovations of the system are: Low temperature thermal sources can be exploited efficiently for fresh water production; solar energy is used indirectly and does not heat the seawater; the RO unit is driven by mechanical work produced from the process; the system condenser acts as sea water pre-heater and this serves a double purpose; (1) increase of feed water temperature implies higher fresh water production (2) decrease of temperature of ''low temperature reservoir'' of Rankine cycle implies higher cycle efficiencies. (orig.)

  17. Exergetic Analysis of an Integrated Tri-Generation Organic Rankine Cycle

    OpenAIRE

    Ratha Z. Mathkor; Brian Agnew; Mohammed A. Al-Weshahi; Fathi Latrsh

    2015-01-01

    This paper reports on a study of the modelling, validation and analysis of an integrated 1 MW (electrical output) tri-generation system energized by solar energy. The impact of local climatic conditions in the Mediterranean region on the system performance was considered. The output of the system that comprised a parabolic trough collector (PTC), an organic Rankine cycle (ORC), single-effect desalination (SED), and single effect LiBr-H2O absorption chiller (ACH) was electrical power, distille...

  18. Optimisation robuste de turbines pour les cycles organiques de Rankine (ORC)

    OpenAIRE

    Bufi, Elio Antonio

    2016-01-01

    In recent years, the Organic Rankine Cycle (ORC) technology has received great interest from the scientific and technical community because of its capability to recover energy from low-grade heat sources. In some applications, as the Waste Heat Recovery (WHR), ORC plants need to be as compact as possible because of geometrical and weight constraints. Recently, these issues have been studied in order to promote the ORC technology for Internal Combustion Engine (ICE) applications. The idea to r...

  19. A proposal for the modular integration of the renewable energy sources, via hydrogen, and the Rankine power cycle; Una propuesta de integracion modular de las fuentes de energia renovables, via hidrogeno, y el ciclo de potencia Rankine

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Dirzo, Rafael

    2004-07-01

    This thesis synthesizes the state-of-the-art of the modular integration of the renewable energy sources and the Ranking power cycle. This is possible to obtain due to the development of the hydrogen production technologies and with it the chemical storage of the energies solar, Aeolian (wind) and tidal, among others. The purpose of this thesis is the assessment of hydrogen as fuel, its obtaining through the breaking of the water molecule using the renewable energies and the thermodynamic analysis of two prototypes for its energy conversion into electricity and power, voltage and fixed frequency: the first one at laboratory scale of 800 W and the second one, on industrial scale of 1 GW of power. Included here is the synthesis of the increasing bibliography on the development of the hydrogen technologies and the renewable energies, passing through the mass and energy balance in the power cycles until proposing, at the level of Process Flow Charts of the results of the proposed prototypes. The products show the possibility of constructing and operating the experimental prototype, whereas the thermodynamic analysis suggests that the industrial prototype is viable. The economic analysis of both proposals is part of a doctorate project in process. [Spanish] Esta tesis sintetiza el estado del arte de la integracion modular de las fuentes de energia renovables y el ciclo de potencia Ranking. Esto es posible lograrlo debido al desarrollo de las tecnologias de produccion de hidrogeno y con ello el almacenamiento quimico de las energias solar, eolica y maremotriz, entre otras. Es objetivo de esta tesis la valoracion del hidrogeno como combustible, su obtencion a traves del rompimiento de la molecula del agua utilizando las energias renovables y el analisis termodinamico de dos prototipo para su conversion energetica en electricidad a potencia, voltaje y frecuencia fijos: el primero a escala de laboratorio de 800 W y el segundo, a escala industrial de 1 GW de potencia. Se

  20. Control system to a Rankine cycle with a Tesla turbine using arduino

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Josenei G., E-mail: joseneigodoi@yahoo.com.br [Faculdade de Tecnologia Sao Francisco (FATESF), Jacarei, SP (Brazil); Guimaraes, Lamartine F.; Placco, Guilherme M., E-mail: guimarae@ieav.cta.br, E-mail: placco@ieav.cta.br [Instituto de Estudos Avancados (ENU/IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Departamento de Energia Nuclear

    2013-07-01

    The thermal Rankine cycle is a thermodynamic cycle which converts heat in energy. This cycle occurs in steady state, in other words the cycle is a closed loop circuit with continuous feedback, which guarantees the reuse process one energy transformed in the various stages of the cycle. This cycle is used to drive a turbine type TESLA designed for the system. The objective of this work is to create the control and automation of this cycle using an micro-controlled system with Arduino that will hold the collection of sensors and the system will act to maintain the balance of the cycle causing it to behave continuously and with less interference from human operation for maintenance. Data will be collected and further processed, where it will display all the sensors and the situation of the actuators involved. Using Arduino system ensures the stability and reliability with a low cost of implementation.

  1. Design of organic Rankine cycles using a non-conventional optimization approach

    DEFF Research Database (Denmark)

    Andreasen, J. G.; Larsen, Ulrik; Haglind, F.

    2015-01-01

    The organic Rankine cycle is a suitable technology for utilizing low grade heat for electricity production. Compared to the traditional steam Rankine cycle, the organic Rankine cycle is beneficial, since it enables the choice of a working fluid which performs better than steam at low heat input...... temperatures and at lowpower outputs. Selecting the process layout of the organic Rankine cycle and the working fluid are two key design decisions which are critical for the thermodynamic and economic performance of the cycle. The prevailing approach used in the design and optimization of organic Rankine...... product of the overall heat transfer coefficient and the heat transfer area) is assigned to the cycle, while the distribution of this total UA-value to each of the heat exchangers is optimized. Optimizations are carried out for three different marine engine waste heatsources at temperatures ranging from...

  2. Analysis of hot spots in boilers of organic Rankine cycle units during transient operation

    DEFF Research Database (Denmark)

    Benato, A.; Kærn, Martin Ryhl; Pierobon, Leonardo

    2015-01-01

    This paper is devoted to the investigation of critical dynamic events causing thermochemical decompositionof the working fluid in organic Rankine cycle power systems. The case study is the plant of an oiland gas platform where one of the three gas turbines is combined with an organic Rankine cycl...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    due to the peculiar physical properties of the working fluid and the gas-dynamic phenomena occurring in the machine. Unlike steam Rankine and Brayton engines, organic Rankine cycle expanders combine small enthalpy drops with large expansion ratios. These features yield turbine designs with few highly-loaded...... variables affecting the turbine design. Part B of this two-part paper presents the first application of a design method where the thermodynamic cycle optimization is combined with calculations of the maximum expander performance using the mean-line design tool described in part A. The high computational...

  4. Dual-objective optimization of organic Rankine cycle (ORC) systems using genetic algorithm: a comparison between basic and recuperative cycles

    Science.gov (United States)

    Hayat, Nasir; Ameen, Muhammad Tahir; Tariq, Muhammad Kashif; Shah, Syed Nadeem Abbas; Naveed, Ahmad

    2017-08-01

    Exploitation of low potential waste thermal energy for useful net power output can be done by manipulating organic Rankine cycle systems. In the current article dual-objectives (η_{th} and SIC) optimization of ORC systems [basic organic Rankine cycle (BORC) and recuperative organic Rankine cycle (RORC)] has been done using non-dominated sorting genetic algorithm (II). Seven organic compounds (R-123, R-1234ze, R-152a, R-21, R-236ea, R-245ca and R-601) have been employed in basic cycle and four dry compounds (R-123, R-236ea, R-245ca and R-601) have been employed in recuperative cycle to investigate the behaviour of two systems and compare their performance. Sensitivity analyses show that recuperation boosts the thermodynamic behaviour of systems but it also raises specific investment cost significantly. R-21, R-245ca and R-601 show attractive performance in BORC whereas R-601 and R-236ea in RORC. RORC, due to higher total investment cost and operation & maintenance costs, has longer payback periods as compared to BORC.

  5. Experimental Comparison Of Working Fluids For Organic Rankine Cycle With Single-Screw Expander

    OpenAIRE

    Gusev, Sergei; Ziviani, Davide; Bell, Ian; De Paepe, Michel; van den Broek, Martijn

    2014-01-01

    This paper describes the behavior of an Organic Rankine Cycle (ORC) fed by a heat source with adaptable temperature and mass flow. For a suitable choice of working fluid, the setting of its evaporation pressure is crucial for the performance of an ORC installation. The higher the evaporation pressure, the higher the cycle efficiency on the one hand, but the lower the energy recovered from the heat source due to a higher outlet temperature on the other hand. An optimum has to be found to achie...

  6. Organic Rankine cycle - review and research directions in engine applications

    Science.gov (United States)

    Panesar, Angad

    2017-11-01

    Waste heat to power conversion using Organic Rankine Cycles (ORC) is expected to play an important role in CO2 reductions from diesel engines. Firstly, a review of automotive ORCs is presented focusing on the pure working fluids, thermal architectures and expanders. The discussion includes, but is not limited to: R245fa, ethanol and water as fluids; series, parallel and cascade as architectures; dry saturated, superheated and supercritical as expansion conditions; and scroll, radial turbine and piston as expansion machines. Secondly, research direction in versatile expander and holistic architecture (NOx + CO2) are proposed. Benefits of using the proposed unconventional approaches are quantified using Ricardo Wave and Aspen HYSYS for diesel engine and ORC modelling. Results indicate that, the implementation of versatile piston expander tolerant to two-phase and using cyclopentane can potentially increase the highway drive cycle power by 8%. Furthermore, holistic architecture offering complete utilisation of charge air and exhaust recirculation heat increased the performance noticeably to 5% of engine power at the design point condition.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    Rankine cycle power systems. In this two-part paper, an overall cycle model and a model of an axial turbine were combined in order to provide a comprehensive preliminary design of the organic Rankine cycle unit, taking into account both cycle and turbine optimal designs. Part A presents the preliminary......Axial-flow turbines represent a well-established technology for a wide variety of power generation systems. Compactness, flexibility, reliability and high efficiency have been key factors for the extensive use of axial turbines in conventional power plants and, in the last decades, in organic...... turbine design model, the details of the validation and a sensitivity analysis on the main parameters, in order to minimize the number of decision variables in the subsequent turbine design optimization. Part B analyzes the application of the combined turbine and cycle designs on a selected case study...

  8. Computer modeling of a regenerative solar-assisted Rankine power cycle

    Science.gov (United States)

    Lansing, F. L.

    1977-01-01

    A detailed interpretation of the computer program that describes the performance of one of these cycles; namely, a regenerative Rankine power cycle is presented. Water is used as the working medium throughout the cycle. The solar energy collected at relatively low temperature level presents 75 to 80% of the total heat demand and provides mainly the latent heat of vaporization. Another energy source at high temperature level superheats the steam and supplements the solar energy share. A program summary and a numerical example showing the sequency of computations are included. The outcome from the model comprises line temperatures, component heat rates, specific steam consumption, percentage of solar energy contribution, and the overall thermal efficiency.

  9. Numerical Optimization of an Organic Rankine Cycle Scheme for Co-generation

    OpenAIRE

    Potenza, Marco; Naccarato, Fabrizio; Stigliano, Gianbattista; Risi, Arturo de

    2016-01-01

    The aim of the present work was the optimization of a small size Organic Rankine Cycle (ORC) system powered by a linear Parabolic Trough Collector (PTC) solar field by means of numerical model code developed on purpose. In the proposed scheme the solar energy is collected by a newly designed low cost PTC of 20m2 with a single tracking axis and it is concentrated on an opaque pipe collector in which flows as thermal fluid the Therminol® 66 oil. An oil-free scroll expander coupled with a 2 kW e...

  10. Draft report: application of organic Rankine cycle heat recovery systems to diesel powered marine vessels

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-15

    The analysis and results of an investigation of the application of organic Rankine cycle heat recovery systems to diesel-powered marine vessels are described. The program under which this study was conducted was sponsored jointly by the US Energy Research and Development Administration, the US Navy, and the US Maritime Administration. The overall objective of this study was to investigate diesel bottoming energy recovery systems, currently under development by three US concerns, to determine the potential for application to marine diesel propulsion and auxiliary systems. The study primarily focused on identifying the most promising vessel applications (considering vessel type, size, population density, operational duty cycle, etc.) so the relative economic and fuel conservation merits of energy recovery systems could be determined and assessed. Vessels in the current fleet and the projected 1985 fleet rated at 1000 BHP class and above were investigated.

  11. Analysis and optimization of the low-temperature solar organic Rankine cycle (ORC)

    Energy Technology Data Exchange (ETDEWEB)

    Delgado-Torres, Agustin M. [Dpto. Fisica Fundamental y Experimental, Electronica y Sistemas, Escuela Tecnica Superior de Ingenieria Civil e Industrial, Universidad de La Laguna (ULL), Avda, Astrofisico Francisco Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Garcia-Rodriguez, Lourdes [Dpto. Ingenieria Energetica, Escuela Tecnica Superior de Ingenieros, Universidad de Sevilla, Camino de los Descubrimientos, s/n 41092 Sevilla (Spain)

    2010-12-15

    Solar thermal driven reverse osmosis desalination is a promising renewable energy-driven desalination technology. A joint use of the solar thermal powered organic Rankine cycle (ORC) and the desalination technology of less energy consumption, reverse osmosis (RO), makes this combination interesting in some scarce water resource scenarios. However, prior to any practical experience with any new process, a comprehensive and rigorous theoretical study must be done in order to assess the performance of the new technology or combination of existing technologies. The main objective of the present paper is the expansion of the theoretical analysis done by the authors in previous works to the case in which the thermal energy required by a solar ORC is supplied by means of stationary solar collectors. Twelve substances are considered as working fluids of the ORC and four different models of stationary solar collectors (flat plate collectors, compound parabolic collectors and evacuated tube collectors) are also taken into account. Operating conditions of the solar ORC that minimizes the aperture area needed per unit of mechanical power output of the solar cycle are determined for every working fluid and every solar collector. The former is done considering a direct vapour generation configuration of the solar cycle and also the configuration with water as heat transfer fluid flowing inside the solar collector. This work is part of the theoretical analysis of the solar thermal driven seawater and brackish water reverse osmosis desalination technology. Nevertheless, the supplied information can be also used for the assessment of different applications of the solar ORC. In that case, results presented in this paper can be useful in techno-economic analysis, selection of working fluids of the Rankine cycle, sizing of systems and assessment of solar power cycle configuration. (author)

  12. A Comparative Exergoeconomic Analysis of Waste Heat Recovery from a Gas Turbine-Modular Helium Reactor via Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Naser Shokati

    2014-04-01

    Full Text Available A comparative exergoeconomic analysis is reported for waste heat recovery from a gas turbine-modular helium reactor (GT-MHR using various configurations of organic Rankine cycles (ORCs for generating electricity. The ORC configurations studied are: a simple organic Rankine cycle (SORC, an ORC with an internal heat exchanger (HORC and a regenerative organic Rankine cycle (RORC. Exergoeconomic analyses are performed with the specific exergy costing (SPECO method. First, energy and exergy analyses are applied to the combined cycles. Then, a cost-balance, as well as auxiliary equations are developed for the components to determine the exergoeconomic parameters for the combined cycles and their components. The three combined cycles are compared considering the same operating conditions for the GT-MHR cycle, and a parametric study is done to reveal the effects on the exergoeconomic performance of the combined cycles of various significant parameters, e.g., turbine inlet and evaporator temperatures and compressor pressure ratio. The results show that the GT-MHR/RORC has the lowest unit cost of electricity generated by the ORC turbine. This value is highest for the GT-MHR/HORC. Furthermore, the GT-MHR/RORC has the highest and the GT-MHR/HORC has the lowest exergy destruction cost rate.

  13. Radial turbine expander design for organic rankine cycle, waste heat recovery in high efficiency, off-highway vehicles

    OpenAIRE

    Alshammari, F.; Karvountzis-Kontakiotis, A; Pesiridis, A

    2016-01-01

    Although state-of-the-art, heavy duty diesel engines of today can reach peak thermal efficiencies of approximately 45%, still most of the fuel energy is transformed into wasted heat in the internal combustion process. Recovering this wasted energy could increase the overall thermal efficiency of the engine as well as reduce the exhaust gas emissions. Compared to other Waste Heat Recovery (WHR) technologies, Organic Rankine Cycle (ORC) systems are regarded favourably due to their relative simp...

  14. Optimization of organic Rankine cycle power systems considering multistage axial turbine design

    DEFF Research Database (Denmark)

    Meroni, Andrea; Andreasen, Jesper Graa; Persico, Giacomo

    2018-01-01

    Organic Rankine cycle power systems represent a viable and efficient solution for the exploitation of medium-to-low temperature heat sources. Despite the large number of commissioned units, there is limited literature on the design and optimization of organic Rankine cycle power systems considering......-butane yields the best compromise in terms of cycle net power output, turbine cost and efficiency for the considered case study. When a conservative design approach is adopted, the turbine features a two-stage configuration with supersonic converging nozzles and post-expansion. Conversely, a single...... multistage turbine design. This work presents a preliminary design methodology and working fluid selection for organic Rankine cycle units featuring multistage axial turbines. The method is then applied to the case of waste heat recovery from a large marine diesel engine. A multistage axial turbine model...

  15. Optimization of organic Rankine cycle power systems considering multistage axial turbine design

    DEFF Research Database (Denmark)

    Meroni, Andrea; Andreasen, Jesper Graa; Persico, Giacomo

    2017-01-01

    Organic Rankine cycle power systems represent a viable and efficient solution for the exploitation of medium-to-low temperature heat sources. Despite the large number of commissioned units, there is limited literature on the design and optimization of organic Rankine cycle power systems considering......-butane yields the best compromise in terms of cycle net power output, turbine cost and efficiency for the considered case study. When a conservative design approach is adopted, the turbine features a two-stage configuration with supersonic converging nozzles and post-expansion. Conversely, a single...... multistage turbine design. This work presents a preliminary design methodology and working fluid selection for organic Rankine cycle units featuring multistage axial turbines. The method is then applied to the case of waste heat recovery from a large marine diesel engine. A multistage axial turbine model...

  16. Performance of a reversible heat pump/organic Rankine cycle unit coupled with a passive house to get a positive energy building

    DEFF Research Database (Denmark)

    Dumont, Olivier; Carmo, Carolina; Fontaine, Valentin

    2016-01-01

    of the system under different operational conditions. Sensitivity studies include: building envelope, climate, appliances, lighting and heat demand profiles. It is concluded that the HP/ORC unit can turn a single-family house into a PEB under certain weather conditions (electrical production of 3012 k......This paper presents an innovative technology that can be used to deliver more renewable electricity production than the total electrical consumption of a building while covering the heat demand on a yearly basis. The technology concept uses a heat pump (HP), slightly modified to revert its cycle...

  17. Organic Rankine Cycle and its application in renewable power engineering

    Directory of Open Access Journals (Sweden)

    G. V. Belov

    2014-01-01

    Full Text Available A considerable part of energy consumed in the world is thermal power that is produced due to burning of hydrocarbon fuels and as a result of controlled course of nuclear reactions. Thus rather large part of thermal power is used ultrainefficiently, often simply dissipates in environment. The rise in prices for energy compels to use low-grade one to be released in large quantities in environment. To utilize the low-grade energy Renkin's cycle with with alternative working bodies is often applied. The corresponding cycle was called Renkin's organic cycle (ROC. A substance with lower boiling temperature, than that of water is used in ROC as a working body to utilize low-grade energy.The review of literature shows that thrust on power sector related to utilization of residual heat (thermal waste and use of alternative energy sources, recently, intensively develops. However there is, essentially, a lack of publications on this subject in Russian. The objective of given article is to analyse modern sources of information (mainly, foreign ones which consider various aspects of ROC and its application potential in alternative power engineering. The article focuses much attention on the choice of ROC working body. It presents a list of main requirements for a working body. The article studies the matters of ROC simulation.It is shown that ROC application enables using the low-grade power of exhaust gases, geothermal sources, other thermal streams with rather low temperature. Integration of ROC with ICE (internal combustion engine is in position to increase an efficiency of used fuel energy and to reduce amount of toxic impurity in exhaust gases. Essential influence of working body properties on its characteristics of ROC is noted.

  18. Modelling of organic Rankine cycle power systems in off-design conditions: an experimentally-validated comparative study

    OpenAIRE

    Dickes, Rémi; Dumont, Olivier; Daccord, Rémi; Quoilin, Sylvain; Lemort, Vincent

    2017-01-01

    Because of environmental issues and the depletion of fossil fuels, the world energy sector is undergoing many changes toward increased sustainability. Among the many fields of research and development, power generation from low-grade heat sources is gaining interest and the organic Rankine cycle (ORC) is seen as one of the most promising technologies for such applications. In this paper, it is proposed to perform an experimentally-validated comparison of different modelling methods for the of...

  19. Parametric theoretical study of a two-stage solar organic Rankine cycle for RO desalination

    Energy Technology Data Exchange (ETDEWEB)

    Kosmadakis, G.; Manolakos, D.; Papadakis, G. [Department of Natural Resources and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos Street, 11855 Athens (Greece)

    2010-05-15

    The present work concerns the parametric study of an autonomous, two-stage solar organic Rankine cycle for RO desalination. The main goal of the current simulation is to estimate the efficiency, as well as to calculate the annual mechanical energy available for desalination in the considered cases, in order to evaluate the influence of various parameters on the performance of the system. The parametric study concerns the variation of different parameters, without changing actually the baseline case. The effect of the collectors' slope and the total number of evacuated tube collectors used, have been extensively examined. The total cost is also taken into consideration and is calculated for the different cases examined, along with the specific fresh water cost (EUR/m{sup 3}). (author)

  20. Optimal design of compact organic Rankine cycle units for domestic solar applications

    DEFF Research Database (Denmark)

    Barbazza, Luca; Pierobon, Leonardo; Mirandola, Alberto

    2014-01-01

    Organic Rankine cycle turbogenerators are a promising technology to transform the solar radiation harvested by solar collectors into electric power. The present work aims at sizing a small-scale organic Rankine cycle unit by tailoring its design for domestic solar applications. Stringent design...... solar collectors (hot water temperature equal to 75 degrees C), R1234yf is the optimal solution. The heat exchanger volume ranges between 6.0 and 23.0 dm(3), whereas the thermal efficiency is around 4.5%. R1234ze is the best working fluid employing parabolic solar collectors (hot water temperature equal...

  1. Exergy analysis of micro-organic Rankine power cycles for a small scale solar driven reverse osmosis desalination system

    Energy Technology Data Exchange (ETDEWEB)

    Tchanche, B.F.; Lambrinos, Gr.; Frangoudakis, A.; Papadakis, G. [Department of Natural Resources and Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos Street, 11855 Athens (Greece)

    2010-04-15

    Exergy analysis of micro-organic Rankine heat engines is performed to identify the most suitable engine for driving a small scale reverse osmosis desalination system. Three modified engines derived from simple Rankine engine using regeneration (incorporation of regenerator or feedliquid heaters) are analyzed through a novel approach, called exergy-topological method based on the combination of exergy flow graphs, exergy loss graphs, and thermoeconomic graphs. For the investigations, three working fluids are considered: R134a, R245fa and R600. The incorporated devices produce different results with different fluids. Exergy destruction throughout the systems operating with R134a was quantified and illustrated using exergy diagrams. The sites with greater exergy destruction include turbine, evaporator and feedliquid heaters. The most critical components include evaporator, turbine and mixing units. A regenerative heat exchanger has positive effects only when the engine operates with dry fluids; feedliquid heaters improve the degree of thermodynamic perfection of the system but lead to loss in exergetic efficiency. Although, different modifications produce better energy conversion and less exergy destroyed, the improvements are not significant enough and subsequent modifications of the simple Rankine engine cannot be considered as economically profitable for heat source temperature below 100 C. As illustration, a regenerator increases the system's energy efficiency by 7%, the degree of thermodynamic perfection by 3.5% while the exergetic efficiency is unchanged in comparison with the simple Rankine cycle, with R600 as working fluid. The impacts of heat source temperature and pinch point temperature difference on engine's performance are also examined. Finally, results demonstrate that energy analysis combined with the mathematical graph theory is a powerful tool in performance assessments of Rankine based power systems and permits meaningful comparison of

  2. Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel...... enters then into the anode side of the SOFC. The remaining fuels after the SOFC stacks enter a burner for further burning. The off-gases are then used to produce steam for a Rankine cycle in a Heat Recovery Steam Generator (HRSG). Different system setups are suggested. Cyclic efficiencies up to 67......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation....

  3. Thermal analysis of a Phase Change Material for a Solar Organic Rankine Cycle

    Science.gov (United States)

    Iasiello, M.; Braimakis, K.; Andreozzi, A.; Karellas, S.

    2017-11-01

    Organic Rankine Cycle (ORC) is a promising technology for low temperature power generation, for example for the utilization of medium temperature solar energy. Since heat generated from solar source is variable throughout the day, the implementation of Thermal Energy Storage (TES) systems to guarantee the continuous operation of solar ORCs is a critical task, and Phase Change Materials (PCM) rely on latent heat to store large amounts of energy. In the present study, a thermal analysis of a PCM for a solar ORC is carried out. Three different types of PCMs are analyzed. The energy equation for the PCM is modeled by using the heat capacity method, and it is solved by employing a 1Dexplicit finite difference scheme. The solar source is modeled with a time-variable temperature boundary condition, with experimental data taken from the literature for two different solar collectors. Results are presented in terms of temperature profiles and stored energy. It has been shown that the stored energy depends on the heat source temperature, on the employed PCM and on the boundary conditions. It has been demonstrated that the use of a metal foam can drastically enhance the stored energy due to the higher overall thermal conductivity.

  4. Comparison of Organic Rankine Cycle Under Varying Conditions Using Turbine and Twin-Screw Expanders

    OpenAIRE

    Read, M G; Smith, I.K.; Stosic, N.

    2015-01-01

    A multi-variable optimization program has been developed to investigate the performance of Organic Rankine Cycles (ORCs) for low temperature heat recovery applications. This cycle model contains detailed thermodynamic models of the system components, and the methods used to match the operation of the expander to the requirements of the cycle are described. Two types of ORC system are considered; one containing a turbine to expand dry saturated or superheated vapour, and one with a twin-screw ...

  5. Organic Rankine Cycle Analysis: Finding the Best Way to Utilize Waste Heat

    Directory of Open Access Journals (Sweden)

    Nadim Chakroun

    2012-01-01

    Full Text Available An Organic Rankine Cycle (ORC is a type of power cyclethat uses organic substances such as hydrocarbons orrefrigerants as the working fluid. ORC technology is usedto generate electricity in waste heat recovery applications,because the available heat is not at a high enoughtemperature to operate with other types of cycles. Theoptimum amount of working fluid required for the cycle(i.e., optimum charge level was investigated. Three chargelevels (13, 15, and 18 lbm were tested, and their effect onefficiency and performance of the system was analyzed.The heat source for the fluid was waste steam from thePurdue Power Plant, which had an average temperatureof 120oC. Regular city tap water at a temperature of 15oCwas used as the heat sink. For each charge level, multipletests were performed by measuring the temperaturesand pressures at all state points in the cycle, in order tounderstand any overarching patterns within the data.An important parameter that was analyzed is the 2nd lawefficiency. This efficiency is a measure of the effectivenessof the energy utilization compared to that of an idealcase. The peak efficiency increased from 24% to 27% asthe charge in the system decreased. Therefore, movingforward, this research suggests that a lower charge levelin the system will increase efficiency. However, testingbelow 13 lbm might cause mechanical complications inthe equipment as there may not be enough fluid to flowaround; thus, a compromise had to be made.

  6. Effect of Regenerative Organic Rankine Cycle (RORC on the Performance of Solar Thermal Power in Yogyakarta, Indonesia

    Directory of Open Access Journals (Sweden)

    Ghalya Pikra

    2013-07-01

    Full Text Available This paper presents effect of Regenerative Organic Rankine Cycle (RORC on the performance of solar thermal power in Yogyakarta, Indonesia. Solar thermal power is a plant that uses solar energy as heat source. Indonesia has high humidity level, so that parabolic trough is the most suitable type of solar thermal power technology to be developed, where the design is made with small focal distance. Organic Rankine Cycle (ORC is a Rankine cycle that use organic fluid as working fluid to utilize low temperature heat sources. RORC is used to increase ORC performance. The analysis was done by comparing ORC system with and without regenerator addition. Refrigerant that be used in the analysis is R123. Preliminary data was taken from the solar collector system that has been installed in Yogyakarta. The analysis shows that with 36 m total parabolic length, the resulting solar collector capacity is 63 kW, heat input/evaporator capacity is determined 26.78 kW and turbine power is 3.11 kW for ORC, and 3.38 kW for RORC. ORC thermal efficiency is 11.28% and RORC is 12.26%. Overall electricity efficiency is 4.93% for ORC, and 5.36% for RORC. With 40°C condensing temperature and evaporation at 10 bar saturated condition, efficiency of RORC is higher than ORC. Greater evaporation temperature at the same pressure (10 bar provide greater turbine power and efficiency.

  7. A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Meroni, Andrea; Haglind, Fredrik

    2017-01-01

    %) fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane), toluene, n-pentane, i-pentane and c-pentane. The results of the comparison...... indicate that the net power output of the steam Rankine cycle process is higher at high engine loads, while the performance of the organic Rankine cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit......This paper presents a comparison of the conventional dual pressure steam Rankine cycle process and the organic Rankine cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt %) and low-sulfur (0.5 wt...

  8. Final Report. Conversion of Low Temperature Waste Heat Utilizing Hermetic Organic Rankine Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Robert L.

    2005-04-20

    The design of waste heat recovery using the organic Rankine cycle (ORC) engine is updated. Advances in power electronics with lower cost enable the use of a single shaft, high-speed generator eliminating wear items and allowing hermetic sealing of the working fluid. This allows maintenance free operation and a compact configuration that lowers cost, enabling new market opportunities.

  9. The simulation of organic rankine cycle power plant with n-pentane working fluid

    Science.gov (United States)

    Nurhilal, Otong; Mulyana, Cukup; Suhendi, Nendi; Sapdiana, Didi

    2016-02-01

    In the steam power plant in Indonesia the dry steam from separator directly used to drive the turbin. Meanwhile, brine from the separator with low grade temperature reinjected to the earth. The brine with low grade temperature can be converted indirectly to electrical power by organic Rankine cycle (ORC) methods. In ORC power plant the steam are released from vaporization of organic working fluid by brine. The steam released are used to drive an turbine which in connected to generator to convert the mechanical energy into electric energy. The objective of this research is the simulation ORC power plant with n-pentane as organic working fluid. The result of the simulation for brine temperature around 165°C and the pressure 8.001 bar optained the net electric power around 1173 kW with the cycle thermal efficiency 14.61% and the flow rate of n-pentane around 15.51 kg/s. This result enable to applied in any geothermal source in Indonesia.

  10. Comparison of organic rankine cycle systems under varying conditions using turbine and twin-screw expanders

    OpenAIRE

    Read, M G; Smith, I.K.; Stosic, N.; Kovacevic, A.

    2016-01-01

    A multi-variable optimization program has been developed to investigate the performance of Organic Rankine Cycles (ORCs) for low temperature heat recovery applications using both turbine and twin-screw expanders when account is taken of performance variation due to changes in ambient conditions. The cycle simulation contains thermodynamic models of both types of expander. In the case of the twin-screw machine, the methods used to match the operation of the expander to the requirements of the ...

  11. Preliminary Design and Simulation of a Turbo Expander for Small Rated Power Organic Rankine Cycle (ORC

    Directory of Open Access Journals (Sweden)

    Roberto Capata

    2014-11-01

    Full Text Available Nowadays, the Organic Rankine Cycle (ORC system, which operates with organic fluids, is one of the leading technologies for “waste energy recovery”. It works as a conventional Rankine Cycle but, as mentioned, instead of steam/water, an organic fluid is used. This change allows it to convert low temperature heat into electric energy where required. Large numbers of studies have been carried out to identify the most suitable fluids, system parameters and the various configurations. In the present market, most ORC systems are designed and manufactured for the recovery of thermal energy from various sources operating at “large power rating” (exhaust gas turbines, internal combustion engines, geothermal sources, large melting furnaces, biomass, solar, etc.; from which it is possible to produce a large amount of electric energy (30 kW ÷ 300 kW. Such applications for small nominal power sources, as well as the exhaust gases of internal combustion engines (car sedan or town, ships, etc. or small heat exchangers, are very limited. The few systems that have been designed and built for small scale applications, have, on the other hand, different types of expander (screw, scroll, etc.. These devices are not adapted for placement in small and restricted places like the interior of a conventional car. The aim of this work is to perform the preliminary design of a turbo-expander that meets diverse system requirements such as low pressure, small size and low mass flow rates. The expander must be adaptable to a small ORC system utilizing gas of a diesel engine or small gas turbine as thermal source to produce 2–10 kW of electricity. The temperature and pressure of the exhaust gases, in this case study (400–600 °C and a pressure of 2 bar, imposes a limit on the use of an organic fluid and on the net power that can be produced. In addition to water, fluids such as CO2, R134a and R245fa have been considered. Once the operating fluids has been chosen

  12. Part-Load Performance of a Wet Indirectly Fired Gas Turbine Integrated with an Organic Rankine Cycle Turbogenerator

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Nguyen, Tuong-Van; Mazzucco, Andrea

    2014-01-01

    ) fueled by woodchips and an organic Rankine cycle (ORC) turbogenerator. An exergy analysis is performed to identify the sources of inefficiencies, the optimal design variables, and the most suitable working fluid for the organic Rankine process. This step enables to parametrize the part-load model...

  13. Multi-Objective Optimization of Organic Rankine Cycle Power Plants Using Pure and Mixed Working Fluids

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Kærn, Martin Ryhl; Pierobon, Leonardo

    2016-01-01

    For zeotropic mixtures, the temperature varies during phase change, which is opposed to the isothermal phase change of pure fluids. The use of such mixtures as working fluids in organic Rankine cycle power plants enables a minimization of the mean temperature difference of the heat exchangers......, which is beneficial for cycle performance. On the other hand, larger heat transfer surface areas are typically required for evaporation and condensation when zeotropic mixtures are used as working fluids. In order to assess the feasibility of using zeotropic mixtures, it is, therefore, important...... to consider the additional costs of the heat exchangers. In this study, we aim at evaluating the economic feasibility of zeotropic mixtures compared to pure fluids. We carry out a multi-objective optimization of the net power output and the component costs for organic Rankine cycle power plants using low...

  14. Prospects of the use of nanofluids as working fluids for organic Rankine cycle power systems

    DEFF Research Database (Denmark)

    Mondejar, Maria E.; Andreasen, Jesper G.; Regidor, Maria

    2017-01-01

    The search of novel working fluids for organic Rankine cycle power systems is driven by the recent regulations imposing additional phase-out schedules for substances with adverse environmental characteristics. Recently, nanofluids (i.e. colloidal suspensions of nanoparticles in fluids) have been...... suggested as potential working fluids for organic Rankine cycle power systems due to their enhanced thermal properties, potentially giving advantages with respect to the design of the components and the cycle performance. Nevertheless, a number of challenges concerning the use of nanofluids must...... be investigated prior to their practical use. Among other things, the trade-off between enhanced heat transfer and increased pressure drop in heat exchangers, and the impact of the nanoparticles on the working fluid thermophysical properties, must be carefully analyzed. This paper is aimed at evaluating...

  15. Organic Rankine-cycle power systems working fluids study: Topical report No. 2, Toluene

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R.L.; Demirgian, J.C.; Allen, J.W.

    1987-02-01

    The US Department of Energy initiated an investigation at Argonne National Laboratory in 1982 to experimentally determine the thermal stability limits and degradation rates of toluene as a function of maximum cycle temperature. Following the design and construction of a dynamic test loop capable of closely simulating the thermodynamic conditions of typical organic Rankine-cycle (ORC) power systems, four test runs, totaling about 3900 h of test time and covering a temperature range of 600-677(degree)F, were completed. Both liquid and noncondensable-vapor (gaseous) samples were drawn periodically and analyzed using capillary-column gas chromatography, gas chromatography/mass spectrometry, and mass spectrometry. A computer program that can predict degradation in an ORC engine was developed. Experimental results indicate that, if oxygen can be excluded from the system, toluene is a stable fluid up to the maximum test temperature; the charge of toluene could be used for several years before replacement became necessary. (Additional data provided by Sundstrand Corp. from tests sponsored by the National Aeronautics and Space Administration indicate that toluene may be used at temperatures up to 750(degree)F.) Degradation products are benign; the main liquid degradation products are bibenzyls, and the main gaseous degradation products are hydrogen and methane. A cold trap to remove gaseous degradation products from the condenser is necessary for extended operation. 21 figs., 22 tabs.

  16. A Comparison of Organic and Steam Rankine Cycle Power Systems for Waste Heat Recovery on Large Ships

    Directory of Open Access Journals (Sweden)

    Jesper Graa Andreasen

    2017-04-01

    Full Text Available This paper presents a comparison of the conventional dual pressure steam Rankine cycle process and the organic Rankine cycle process for marine engine waste heat recovery. The comparison was based on a container vessel, and results are presented for a high-sulfur (3 wt % and low-sulfur (0.5 wt % fuel case. The processes were compared based on their off-design performance for diesel engine loads in the range between 25% and 100%. The fluids considered in the organic Rankine cycle process were MM(hexamethyldisiloxane, toluene, n-pentane, i-pentane and c-pentane. The results of the comparison indicate that the net power output of the steam Rankine cycle process is higher at high engine loads, while the performance of the organic Rankine cycle units is higher at lower loads. Preliminary turbine design considerations suggest that higher turbine efficiencies can be obtained for the ORC unit turbines compared to the steam turbines. When the efficiency of the c-pentane turbine was allowed to be 10% points larger than the steam turbine efficiency, the organic Rankine cycle unit reaches higher net power outputs than the steam Rankine cycle unit at all engine loads for the low-sulfur fuel case. The net power production from the waste heat recovery units is generally higher for the low-sulfur fuel case. The steam Rankine cycle unit produces 18% more power at design compared to the high-sulfur fuel case, while the organic Rankine cycle unit using MM produces 33% more power.

  17. 10-75-kWe-reactor-powered organic Rankine-cycle electric power systems (ORCEPS) study. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1977-03-30

    This 10-75 kW(e) Reactor-ORCEPS study was concerned with the evaluation of several organic Rankine cycle energy conversion systems which utilized a /sup 235/U-ZrH reactor as a heat source. A liquid metal (NaK) loop employing a thermoelectric converter-powered EM pump was used to transfer the reactor energy to the organic working fluid. At moderate peak cycle temperatures (750/sup 0/F), power conversion unit cycle efficiencies of up to 25% and overall efficiencies of 20% can be obtained. The required operating life of seven years should be readily achievable. The CP-25 (toluene) working fluid cycle was found to provide the highest performance levels at the lowest system weights. Specific weights varies from 100 to 50 lb/kW(e) over the power level range 10 to 75 kW(e). (DLC)

  18. Selected aspects of operation of supercritical (transcritical organic Rankine cycle

    Directory of Open Access Journals (Sweden)

    Mocarsk Szymon

    2015-06-01

    Full Text Available The paper presents a literature review on the topic of vapour power plants working according to the two-phase thermodynamic cycle with supercritical parameters. The main attention was focused on a review of articles and papers on the vapour power plants working using organic circulation fluids powered with low- and medium-temperature heat sources. Power plants with water-steam cycle supplied with a high-temperature sources have also been shown, however, it has been done mainly to show fundamental differences in the efficiency of the power plant and applications of organic and water-steam cycles. Based on a review of available literature references a comparative analysis of the parameters generated by power plants was conducted, depending on the working fluid used, the type and parameters of the heat source, with particular attention to the needs of power plant internal load.

  19. Exergetic Analysis of an Integrated Tri-Generation Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Ratha Z. Mathkor

    2015-08-01

    Full Text Available This paper reports on a study of the modelling, validation and analysis of an integrated 1 MW (electrical output tri-generation system energized by solar energy. The impact of local climatic conditions in the Mediterranean region on the system performance was considered. The output of the system that comprised a parabolic trough collector (PTC, an organic Rankine cycle (ORC, single-effect desalination (SED, and single effect LiBr-H2O absorption chiller (ACH was electrical power, distilled water, and refrigerant load. The electrical power was produced by the ORC which used cyclopentane as working fluid and Therminol VP-1 was specified as the heat transfer oil (HTO in the collectors with thermal storage. The absorption chiller and the desalination unit were utilize the waste heat exiting from the steam turbine in the ORC to provide the necessary cooling energy and drinking water respectively. The modelling, which includes an exergetic analysis, focuses on the performance of the solar tri-generation system. The simulation results of the tri-generation system and its subsystems were produced using IPSEpro software and were validated against experimental data which showed good agreement. The tri-generation system was able to produce about 194 Ton of refrigeration, and 234 t/day distilled water.

  20. Experimental and Thermoeconomic Analysis of Small-Scale Solar Organic Rankine Cycle (SORC System

    Directory of Open Access Journals (Sweden)

    Suresh Baral

    2015-04-01

    Full Text Available A small-scale solar organic Rankine cycle (ORC is a promising renewable energy-driven power generation technology that can be used in the rural areas of developing countries. A prototype was developed and tested for its performance characteristics under a range of solar source temperatures. The solar ORC system power output was calculated based on the thermal and solar collector efficiency. The maximum solar power output was observed in April. The solar ORC unit power output ranged from 0.4 kW to 1.38 kW during the year. The highest power output was obtained when the expander inlet pressure was 13 bar and the solar source temperature was 120 °C. The area of the collector for the investigation was calculated based on the meteorological conditions of Busan City (South Korea. In the second part, economic and thermoeconomic analyses were carried out to determine the cost of energy per kWh from the solar ORC. The selling price of electricity generation was found to be $0.68/kWh and $0.39/kWh for the prototype and low cost solar ORC, respectively. The sensitivity analysis was carried out in order to find the influencing economic parameters for the change in NPV. Finally, the sustainability index was calculated to assess the sustainable development of the solar ORC system.

  1. Reciprocating Expander for an Exhaust Heat Recovery Rankine Cycle for a Passenger Car Application

    Directory of Open Access Journals (Sweden)

    Osoko Shonda

    2012-06-01

    Full Text Available Nowadays, on average, two thirds of the fuel energy consumed by an engine is wasted through the exhaust gases and the cooling liquid. The recovery of this energy would enable a substantial reduction in fuel consumption. One solution is to integrate a heat recovery system based on a steam Rankine cycle. The key component in such a system is the expander, which has a strong impact on the system’s performance. A survey of different expander technologies leads us to select the reciprocating expander as the most promising one for an automotive application. This paper therefore proposes a steady-state semi-empirical model of the expander device developed under the Engineering Equation Solver (EES environment. The ambient and mechanical losses as well as internal leakage were taken into account by the model. By exploiting the expander manufacturer’s data, all the parameters of the expander model were identified. The model computes the mass flow rate, the power output delivered and the exhaust enthalpy of the steam. The maximum deviation between predictions and measurement data is 4.7%. A performance study of the expander is carried out and shows that the isentropic efficiency is quite high and increases with the expander rotary speed. The mechanical efficiency depends on mechanical losses which are quite high, approximately 90%. The volumetric efficiency was also evaluated.

  2. Thermodynamic Optimization of a Geothermal- Based Organic Rankine Cycle System Using an Artificial Bee Colony Algorithm

    Directory of Open Access Journals (Sweden)

    Osman Özkaraca

    2017-10-01

    Full Text Available Geothermal energy is a renewable form of energy, however due to misuse, processing and management issues, it is necessary to use the resource more efficiently. To increase energy efficiency, energy systems engineers carry out careful energy control studies and offer alternative solutions. With this aim, this study was conducted to improve the performance of a real operating air-cooled organic Rankine cycle binary geothermal power plant (GPP and its components in the aspects of thermodynamic modeling, exergy analysis and optimization processes. In-depth information is obtained about the exergy (maximum work a system can make, exergy losses and destruction at the power plant and its components. Thus the performance of the power plant may be predicted with reasonable accuracy and better understanding is gained for the physical process to be used in improving the performance of the power plant. The results of the exergy analysis show that total exergy production rate and exergy efficiency of the GPP are 21 MW and 14.52%, respectively, after removing parasitic loads. The highest amount of exergy destruction occurs, respectively, in condenser 2, vaporizer HH2, condenser 1, pumps 1 and 2 as components requiring priority performance improvement. To maximize the system exergy efficiency, the artificial bee colony (ABC is applied to the model that simulates the actual GPP. Under all the optimization conditions, the maximum exergy efficiency for the GPP and its components is obtained. Two of these conditions such as Case 4 related to the turbine and Case 12 related to the condenser have the best performance. As a result, the ABC optimization method provides better quality information than exergy analysis. Based on the guidance of this study, the performance of power plants based on geothermal energy and other energy resources may be improved.

  3. Experimental Study of a Low-Temperature Power Generation System in an Organic Rankine Cycle

    DEFF Research Database (Denmark)

    Mu, Yongchao; Zhang, Yufeng; Deng, Na

    2015-01-01

    as the engine of the power generator. The style of the preheater was a shell and tube heat exchanger, which could provide a long path for the working fluid. A flooded heat exchanger with a high heat transfer coefficient was taken as the evaporator. R134a was used as working fluid for the Rankine cycle......This paper presents a new power generation system under the principle of organic Rankine cycle which can generate power with a low-temperature heat source. A prototype was built to investigate the proposed system. In the prototype, an air screw compressor was converted into an expander and used...... in the system. This study compared and analyzed the experimental performance of the prototype at different heat source temperatures. The results show that the preheater and flooded evaporator was used for sensible heating and latent heating of the working fluid, respectively, as expected. When the temperature...

  4. Study of toluene stability for an Organic Rankine Cycle (ORC) space-based power system

    Science.gov (United States)

    Havens, Vance; Ragaller, Dana

    1988-01-01

    The design, fabrication, assembly, and endurance operation of a dynamic test loop, built to evaluate the thermal stability of a proposed Organic Rankine Cycle (ORC) working fluid, is discussed. The test fluid, toluene, was circulated through a heater, simulated turbine, regenerator, condenser and pump to duplicate an actual ORC system. The maximum nominal fluid temperature, 750 F, was at the turbine simulator inlet. Samples of noncondensible gases and liquid toluene were taken periodically during the test. The samples were analyzed to identify the degradation products formed and the quantity of these products. From these data it was possible to determine the degradation rate of the working fluid and the generation rate of noncondensible gases. A further goal of this work was to relate the degradation observed in the dynamic operating loop to degradation obtained in isothermal capsule tests. This relationship was the basis for estimating the power loop degradation in the Space Station Organic Rankine Cycle system.

  5. Working fluid selection for the Organic Rankine Cycle (ORC) exhaust heat recovery of an internal combustion engine power plant

    Science.gov (United States)

    Douvartzides, S.; Karmalis, I.

    2016-11-01

    Organic Rankine cycle technology is capable to efficiently convert low-grade heat into useful mechanical power. In the present investigation such a cycle is used for the recovery of heat from the exhaust gases of a four stroke V18 MAN 51/60DF internal combustion engine power plant operating with natural gas. Design is focused on the selection of the appropriate working fluid of the Rankine cycle in terms of thermodynamic, environmental and safety criteria. 37 candidate fluids have been considered and all Rankine cycles examined were subcritical. The thermodynamic analysis of all fluids has been comparatively undertaken and the effect of key operation conditions such as the evaporation pressure and the superheating temperature was taken into account. By appropriately selecting the working fluid and the Rankine cycle operation conditions the overall plant efficiency was improved by 5.52% and fuel consumption was reduced by 12.69%.

  6. Development of an Organic Rankine-Cycle power module for a small community solar thermal power experiment

    Science.gov (United States)

    Kiceniuk, T.

    1985-01-01

    An organic Rankine-cycle (ORC) power module was developed for use in a multimodule solar power plant to be built and operated in a small community. Many successful components and subsystems, including the reciever, power conversion subsystem, energy transport subsystem, and control subsystem, were tested. Tests were performed on a complete power module using a test bed concentrator in place of the proposed concentrator. All major single-module program functional objectives were met and the multimodule operation presented no apparent problems. The hermetically sealed, self-contained, ORC power conversion unit subsequently successfully completed a 300-hour endurance run with no evidence of wear or operating problems.

  7. System and method for regulating EGR cooling using a Rankine cycle

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Timothy C.; Morris, Dave

    2017-08-29

    This disclosure relates to a waste heat recovery (WHR) system and method for regulating exhaust gas recirculation (EGR) cooling, and more particularly, to a Rankine cycle WHR system and method, including a recuperator bypass arrangement to regulate EGR exhaust gas cooling for engine efficiency improvement and thermal management. This disclosure describes other unique bypass arrangements for increased flexibility in the ability to regulate EGR exhaust gas cooling.

  8. SORCE: A design tool for solar organic Rankine cycle systems in distributed generation applications

    OpenAIRE

    Orosz, Matthew; Quoilin, Sylvain; Hemond, Harold

    2010-01-01

    Recent interest in small-scale solar thermal combined heat and power (CHP) power systems has coincided with demand growth for distributed electricity supplies in areas poorly served by centralized power stations. One potential technical approach to meeting this demand is the parabolic trough solar thermal collector coupled with an organic Rankine cycle (ORC) heat engine. Much existing research touches on aspects of the underlying physics and mechanics of this technology, but a holistic treatm...

  9. Design and optimization of a novel organic Rankine cycle with improved boiling process

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Larsen, U.; Knudsen, Thomas

    2015-01-01

    to improve the boiling process. Optimizations are carried out for eight hydrocarbon mixtures for hot fluid inlet temperatures at 120 °C and 90 °C, using a genetic algorithm to determine the cycle conditions for which the net power output is maximized. The most promising mixture is an isobutane....../pentane mixture which, for the 90 °C hot fluid inlet temperature case, achieves a 14.5% higher net power output than an optimized organic Rankine cycle using the same mixture. Two parameter studies suggest that optimum conditions for the organic split-cycle are when the temperature profile allows the minimum...

  10. Investigations on the application of zeotropic fluid mixtures in the organic rankine cycle for the geothermal power generation; Untersuchung zum Einsatz von zeotropen Fluidgemischen im Organic Rankine Cycle fuer die geothermische Stromerzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Heberle, Florian

    2013-04-01

    The organic rankine cycle is a thermodynamic cycle process which uses an organic fluid working fluid instead of water in comparison to the commercial rankine process. The organic rankine cycle facilitates sufficiently high pressures at moderate temperatures. The organic rankine cycle significantly expands the technically possible and economically feasible ranges of application of such heat and power processes. The geothermal power is a very attractive field of application. Thermal water with a temperature of nearly 100 Celsius can be used for the power generation by means of the organic rankine cycle. Especially zeotropic mixtures are interesting as a working fluid. This is due to a non-isothermal phase change to a temperature glide which adapts very well to the temperature progress of the heat source. The author of the book under consideration reports on the application of different mixtures in the organic rankine cycle. The evaluation is based on a thermodynamic analysis and considers also toxicological, ecologic, technical as well as economic aspects.

  11. Evaluation of a solar-powered organic Rankine cycle using dry organic working fluids

    Directory of Open Access Journals (Sweden)

    Emily Spayde

    2015-12-01

    Full Text Available This paper presents a model to evaluate the performance of a solar-powered organic Rankine cycle (ORC. The system was evaluated in Jackson, MS, using five dry organic working fluids, R218, R227ea, R236ea, R236fa, and RC318. The purpose of this study is to investigate how hourly temperature change affects the electricity production and exergy destruction rates of the solar ORC, and to determine the effect of the working fluid on the proposed system. The system was also evaluated in Tucson, AZ, to investigate the effect of average hourly outdoor temperatures on its performance. The potential of the system to reduce primary energy consumption and carbon dioxide emissions is also investigated. A parametric analysis to determine how temperature and pressure of the organic working fluid, the solar collector area, and the turbine efficiency affect the electricity production is performed. Results show that the ORC produces the most electricity during the middle of the day, when the temperatures are the highest and when the solar collectors have the highest efficiency. Also, R-236ea is the working fluid that shows the best performance of the evaluated fluids. An economic analysis was performed to determine the capital cost available for the proposed system.

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

    Directory of Open Access Journals (Sweden)

    Eileen Tortora

    2013-03-01

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

  13. Staging Rankine Cycles Using Ammonia for OTEC Power Production

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.

    2011-03-01

    Recent focus on renewable power production has renewed interest in looking into ocean thermal energy conversion (OTEC) systems. Early studies in OTEC applicability indicate that the island of Hawaii offers a potential market for a nominal 40-MWe system. a 40-MWe system represents a large leap in the current state of OTEC technology. Lockheed Martin Inc. is currently pursuing a more realistic goal of developing a 10-MWe system under U.S. Navy funding (Lockheed 2009). It is essential that the potential risks associated with the first-of-its-kind plant should be minimized for the project's success. Every means for reducing costs must also be pursued without increasing risks. With this in mind, the potential for increasing return on the investment is assessed both in terms of effective use of the seawater resource and of reducing equipment costs.

  14. Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

    Science.gov (United States)

    Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

    2016-02-01

    A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

  15. Moteurs composites à allumage par compression et cycle de Rankine Dual Fuel Compression Ignition Engines Operating on the Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Daugas C.

    2006-11-01

    Full Text Available Sur les 60 % de l'énergie introduite dans un groupe électrogène et perdue sous forme de chaleur, une bonne partie peut être utilisée pour fabriquer à nouveau de l'électricité à partir d'une turbine à vapeur. Les moteurs dual fuel brûlant essentiellement du gaz naturel sont remarquablement placés pour une telle récupération, dont le rendement est meilleur aux charges partielles que celui des moteurs diesel classiques. Les différents types de fluides utilisés pour la récupération sont examinés : avantages des fluides organiques sur l'eau. Études d'une réalisation concrète. Fonctionnement aux charges partielles. Influence des différents paramètres pour obtenir le meilleur rapport prix/puissance. Of the 60% of input energy lost in the form of heat in a generating set, a sizeable part can be used to generate electricity again by means of a steam turbine. Dual fuel engines which mainly burn natural gas are outstandingly suitable for such a recovery process, the efficiency under partial loads being better than that of conventional diesel engines. The author considers the different types of fluids used for the recovery process superiority of organic fluids over water. Study of a concrete example. Operation with partial loads. Influence of the different parameters in the quest for the best cost-power ratio.

  16. Integrated working fluid-thermodynamic cycle design of organic Rankine cycle power systems for waste heat recovery

    DEFF Research Database (Denmark)

    Cignitti, Stefano; Andreasen, Jesper Graa; Haglind, Fredrik

    2017-01-01

    recovery. Inthis paper, an organic Rankine cycle process and its pure working fluid are designed simultaneously forwaste heat recovery of the exhaust gas from a marine diesel engine. This approach can overcome designissues caused by the high sensitivity between the fluid and cycle design variables...... the simultaneousdesign approach the optimum solution was found in 5.04 s, while a decomposed approach found thesame solution in 5.77 h. However, the decomposed approach provided insights on the correlationbetween the fluid and cycle design variables by analyzing all possible solutions. It was shown that thehigh...

  17. Advanced Rankine and Brayton cycle power systems: Materials needs and opportunities

    Science.gov (United States)

    Grisaffe, S. J.; Guentert, D. C.

    1974-01-01

    Conceptual advanced potassium Rankine and closed Brayton power conversion cycles offer the potential for improved efficiency over steam systems through higher operating temperatures. However, for utility service of at least 100,000 hours, materials technology advances will be needed for such high temperature systems. Improved alloys and surface protection must be developed and demonstrated to resist coal combustion gases as well as potassium corrosion or helium surface degradation at high temperatures. Extensions in fabrication technology are necessary to produce large components of high temperature alloys. Long time property data must be obtained under environments of interest to assure high component reliability.

  18. Advanced Rankine and Brayton cycle power systems - Materials needs and opportunities

    Science.gov (United States)

    Grisaffe, S. J.; Guentert, D. C.

    1974-01-01

    Conceptual advanced potassium Rankine and closed Brayton power conversion cycles offer the potential for improved efficiency over steam systems through higher operating temperatures. However, for utility service of at least 100,000 hours, materials technology advances will be needed for such high temperature systems. Improved alloys and surface protection must be developed and demonstrated to resist coal combustion gases as well as potassium corrosion or helium surface degradation at high temperatures. Extensions in fabrication technology are necessary to produce large components of high temperature alloys. Long-time property data must be obtained under environments of interest to assure high component reliability.

  19. Theoretical study of thermally driven heat pumps based on double organic rankine cycle

    OpenAIRE

    Demierre, Jonathan; Favrat, Daniel

    2013-01-01

    Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458] This study deals with a type of thermally driven heat pumps that consists of a reverse Rankine heat pump cycle, the compressor of which is driven by the turbine of a supercritical Organi...

  20. Uncertainty assessment of equations of state with application to an organic Rankine cycle

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Bell, Ian; O’Connell, John P.

    2017-01-01

    Evaluations of equations of state (EoS) should include uncertainty. This study presents a genericmethod to analyse EoS from a detailed uncertainty analysis of the mathematical form and the dataused to obtain EoS parameter values. The method is illustrated by comparison of Soave–Redlich–Kwong (SRK......) cubic EoS with perturbed-chain statistical associating fluid theory (PC-SAFT) EoS for anorganic Rankine cycle (ORC) for heat recovery to power fromthe exhaust gas of a marine diesel engineusing cyclopentane as working fluid. Uncertainties of the EoS input parameters including...

  1. Performance analysis of different organic Rankine cycle configurations on board liquefied natural gas-fuelled vessels

    DEFF Research Database (Denmark)

    Baldasso, Enrico; Andreasen, Jesper Graa; Meroni, Andrea

    2017-01-01

    natural gas (LNG). The study compares the performance of six different ORC configurations both in design and off-design operation, and provides guidelines with respect to the most promising heat sources and sinks to be utilized by an ORC unit in order to maximize the annual fuel savings. In addition......Gas-fuelled shipping is expected to increase significantly in the coming years. Similarly, much effort is devoted to the study of waste heat recovery systems to be implemented on board ships. In this context, the organic Rankine cycle (ORC) technology is considered one of the most promising...

  2. Utilization of recently developed codes for high power Brayton and Rankine cycle power systems

    Science.gov (United States)

    Doherty, Michael P.

    1993-01-01

    Two recently developed FORTRAN computer codes for high power Brayton and Rankine thermodynamic cycle analysis for space power applications are presented. The codes were written in support of an effort to develop a series of subsystem models for multimegawatt Nuclear Electric Propulsion, but their use is not limited just to nuclear heat sources or to electric propulsion. Code development background, a description of the codes, some sample input/output from one of the codes, and state future plans/implications for the use of these codes by NASA's Lewis Research Center are provided.

  3. Waste Heat-to-Power Using Scroll Expander for Organic Rankine Bottoming Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, John [TIAX LLC, Lexington, MA (United States); Smutzer, Chad [TIAX LLC, Lexington, MA (United States); Sinha, Jayanti [TIAX LLC, Lexington, MA (United States)

    2017-05-30

    The objective of this program was to develop a novel, scalable scroll expander for conversion of waste heat to power; this was accomplished and demonstrated in both a bench-scale system as well as a full-scale system. The expander is a key component in Organic Rankine Cycle (ORC) waste heat recovery systems which are used to convert medium-grade waste heat to electric power in a wide range of industries. These types of waste heat recovery systems allow for the capture of energy that would otherwise just be exhausted to the atmosphere. A scroll expander has the benefit over other technologies of having high efficiency over a broad range of operating conditions. The speed range of the TIAX expander (1,200 to 3,600 RPM) enables the shaft power output to directly drive an electric generator and produce 60 Hz electric power without incurring the equipment costs or losses of electronic power conversion. This greatly simplifies integration with the plant electric infrastructure. The TIAX scroll expander will reduce the size, cost, and complexity of a small-scale waste heat recovery system, while increasing the system efficiency compared to the prevailing ORC technologies at similar scale. During this project, TIAX demonstrated the scroll expander in a bench-scale test setup to have isentropic efficiency of 70-75% and operated it successfully for ~200 hours with minimal wear. This same expander was then installed in a complete ORC system driven by a medium grade waste heat source to generate 5-7 kW of electrical power. Due to funding constraints, TIAX was unable to complete this phase of testing, although the initial results were promising and demonstrated the potential of the technology.

  4. Applied studies in advanced boiler technology for Rankine cycle power systems

    Energy Technology Data Exchange (ETDEWEB)

    Paul, F.W.; Negreanu, M.J.

    1978-02-01

    A study is presented on a new rotational boiler design which has improved passive dynamic response and two-phase flow stability characteristics. A survey of small boiler manufacturers in the United States indicated that currently available designs are based on steady-state operating requirements rather than for dynamic performance. Recent work by EPA and ERDA which addressed boiler designs for mobile automotive Rankine cycle power systems showed that boilers of a monotube or multipass tube configuration design could be developed which were physically compact, but still were subject to the two-phase flow instability problem when coupled within an operating power system. The objectives of this work were to evaluate alternative boiler configurations which would improve boiler dynamic response and also have good two-phase liquid-vapor interface flow stability. The major physical design limitation of any boiler is the small external hot gas heat transfer coefficient. Such a low coefficient requires considerable design enhancements to increase the rate of energy transfer to the circulation system fluid. The rotational boiler is a physical design configuration which addresses this problem. The results of an analytic study using several mathematical model formulations showed that a rotational boiler could have a passive response time constant which was approximately one-half the magnitude for an equivalent single pass monotube boiler. An experimental prototype rotational boiler was designed, manufactured and tested, with the experimental results confirming that the experimental passive response time constants were comparable to the estimates from the analytic models. The experimental boiler operating in two-phase flow was found to be stable and responsive to external inputs. A rotational boiler configuration is a good alternative design configuration for small compact vapor generator designs based on fast transient passive response and two-phase flow stability.

  5. Research of efficiency of the organic Rankine cycle on a mathematical model

    Directory of Open Access Journals (Sweden)

    Galashov N.

    2017-01-01

    Full Text Available The object of the study are the organic Rankine cycle. The purpose of research is to evaluate the impact on the net efficiency of the initial and final properties of the cycle at work on a saturated and superheated steam. Investigations were carried out on the basis of a mathematical model, in which the thermodynamic properties of materials are determined on the basis of “REFPROP”. On the basis of the available scientific publications on the use of working fluids in an organic Rankine cycle analysis was selected ozone-safe pentane. A mathematical model has been developed on condition that condenser is used as air cooler which allows the substance to condense at a temperature below 0 °С. Numerical study on the mathematical model shown that net efficiency at work on pentane linearly depends on the condensation temperature and parabolically depends on the initial temperature with the saturated steam. During work at the superheated steam efficiency strongly depends on both the initial temperature and of the initial pressure. With rising initial temperature is necessary to gradually increase the initial pressure under certain conditions.

  6. Multi-Objective Optimization of Organic Rankine Cycle Power Plants Using Pure and Mixed Working Fluids

    Directory of Open Access Journals (Sweden)

    Jesper G. Andreasen

    2016-04-01

    Full Text Available For zeotropic mixtures, the temperature varies during phase change, which is opposed to the isothermal phase change of pure fluids. The use of such mixtures as working fluids in organic Rankine cycle power plants enables a minimization of the mean temperature difference of the heat exchangers, which is beneficial for cycle performance. On the other hand, larger heat transfer surface areas are typically required for evaporation and condensation when zeotropic mixtures are used as working fluids. In order to assess the feasibility of using zeotropic mixtures, it is, therefore, important to consider the additional costs of the heat exchangers. In this study, we aim at evaluating the economic feasibility of zeotropic mixtures compared to pure fluids. We carry out a multi-objective optimization of the net power output and the component costs for organic Rankine cycle power plants using low-temperature heat at 90 ∘ C to produce electrical power at around 500 kW. The primary outcomes of the study are Pareto fronts, illustrating the power/cost relations for R32, R134a and R32/R134a (0.65/0.35 mole . The results indicate that R32/R134a is the best of these fluids, with 3.4 % higher net power than R32 at the same total cost of 1200 k$.

  7. Application of Biomass from Palm Oil Mill for Organic Rankine Cycle to Generate Power in North Sumatera Indonesia

    Science.gov (United States)

    Nur, T. B.; Pane, Z.; Amin, M. N.

    2017-03-01

    Due to increasing oil and gas demand with the depletion of fossil resources in the current situation make efficient energy systems and alternative energy conversion processes are urgently needed. With the great potential of resources in Indonesia, make biomass has been considered as one of major potential fuel and renewable resource for the near future. In this paper, the potential of palm oil mill waste as a bioenergy source has been investigated. An organic Rankine cycle (ORC) small scale power plant has been preliminary designed to generate electricity. The working fluid candidates for the ORC plant based on the heat source temperature domains have been investigated. The ORC system with a regenerator has higher thermal efficiency than the basic ORC system. The study demonstrates the technical feasibility of ORC solutions in terms of resources optimizations and reducing of greenhouse gas emissions.

  8. Waste Heat Recovery of a PEMFC System by Using Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Tianqi He

    2016-04-01

    Full Text Available In this study, two systems are brought forward to recover the waste heat of a proton exchange membrane fuel cell (PEMFC, which are named the organic Rankine cycle (ORC, and heat pump (HP combined organic Rankine cycle (HPORC. The performances of both systems are simulated on the platform of MATLAB with R123, R245fa, R134a, water, and ethanol being selected as the working fluid, respectively. The results show that, for PEMFC where operating temperature is constantly kept at 60 °C, there exists an optimum working temperature for each fluid in ORC and HPORC. In ORC, the maximal net power can be achieved with R245fa being selected as the working fluid. The corresponding thermal efficiency of the recovery system is 4.03%. In HPORC, the maximal net power can be achieved with water being selected in HP and R123 in ORC. The thermal efficiency of the recovery system increases to 4.73%. Moreover, the possibility of using ORC as the cooling system of PEMFC is also studied. The heat released from PEMFC stack is assumed to be wholly recovered by the ORC or HPORC system. The results indicate that the HPORC system is much more feasible for the cooling system of a PEMFC stack, since the heat recovery ability can be promoted due to the presence of HP.

  9. Selection and optimization of pure and mixed working fluids for low grade heat utilization using organic Rankine cycles

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Larsen, Ulrik; Knudsen, Thomas

    2014-01-01

    We present a generic methodology for organic Rankine cycle optimization, where the working fluid is included as an optimization parameter, in order to maximize the net power output of the cycle. The method is applied on two optimization cases with hot fluid inlet temperatures at 120°C and 90°C. P...

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

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud; Larsen, Ulrik

    2013-01-01

    into a fixed bed gasification plant to produce syngas which fuels the combined solid oxide fuel cells e organic Rankine cycle system to produce electricity. More than a hundred fluids are considered as possible alternative for the organic cycle using non-ideal equations of state (or state-of-the-art equations...

  11. Optimal design of compact organic Rankine cycle units for domestic solar applications

    Directory of Open Access Journals (Sweden)

    Barbazza Luca

    2014-01-01

    Full Text Available Organic Rankine cycle turbogenerators are a promising technology to transform the solar radiation harvested by solar collectors into electric power. The present work aims at sizing a small-scale organic Rankine cycle unit by tailoring its design for domestic solar applications. Stringent design criteria, i. e., compactness, high performance and safe operation, are targeted by adopting a multi-objective optimization approach modeled with the genetic algorithm. Design-point thermodynamic variables, e. g., evaporating pressure, the working fluid, minimum allowable temperature differences, and the equipment geometry, are the decision variables. Flat plate heat exchangers with herringbone corrugations are selected as heat transfer equipment for the preheater, the evaporator and the condenser. The results unveil the hyperbolic trend binding the net power output to the heat exchanger compactness. Findings also suggest that the evaporator and condenser minimum allowable temperature differences have the largest impact on the system volume and on the cycle performances. Among the fluids considered, the results indicate that R1234yf and R1234ze are the best working fluid candidates. Using flat plate solar collectors (hot water temperature equal to 75 °C, R1234yf is the optimal solution. The heat exchanger volume ranges between 6.0 and 23.0 dm3, whereas the thermal efficiency is around 4.5%. R1234ze is the best working fluid employing parabolic solar collectors (hot water temperature equal to 120 °C. In such case the thermal efficiency is around 6.9%, and the heat exchanger volume varies from 6.0 to 18.0 dm3.

  12. A Burst Mode, Ultrahigh Temperature UF4 Vapor Core Reactor Rankine Cycle Space Power System Concept

    Science.gov (United States)

    Dugan, E. T.; Kahook, S. D.; Diaz, N. J.

    1996-01-01

    Static and dynamic neutronic analyses have been performed on an innovative burst mode (100's of MW output for a few thousand seconds) Ulvahigh Temperature Vapor Core Reactor (UTVR) space nuclear power system. The NVTR employs multiple, neutronically-coupled fissioning cores and operates on a direct, closed Rankine cycle using a disk Magnetohydrodynamic (MHD) generater for energy conversion. The UTVR includes two types of fissioning core regions: (1) the central Ultrahigh Temperature Vapor Core (UTVC) which contains a vapor mixture of highly enriched UF4 fuel and a metal fluoride working fluid and (2) the UF4 boiler column cores located in the BeO moderator/reflector region. The gaseous nature of the fuel the fact that the fuel is circulating, the multiple coupled fissioning cores, and the use of a two phase fissioning fuel lead to unique static and dynamic neutronic characteristics. Static neutronic analysis was conducted using two-dimensional S sub n, transport theory calculations and three-dimensional Monte Carlo transport theory calculations. Circulating-fuel, coupled-core point reactor kinetics equations were used for analyzing the dynamic behavior of the UTVR. In addition to including reactivity feedback phenomena associated with the individual fissioning cores, the effects of core-to-core neutronic and mass flow coupling between the UTVC and the surrounding boiler cores were also included in the dynamic model The dynamic analysis of the UTVR reveals the existence of some very effectlve inherent reactivity feedback effects that are capable of quickly stabilizing this system, within a few seconds, even when large positive reactivity insertions are imposed. If the UTVC vapor fuel density feedback is suppressed, the UTVR is still inherently stable because of the boiler core liquid-fuel volume feedback; in contrast, suppression of the vapor fuel density feedback in 'conventional" gas core cavity reactors causes them to become inherently unstable. Due to the

  13. Working fluid selection for organic Rankine cycles - Impact of uncertainty of fluid properties

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Andreasen, Jesper Graa; Liu, Wei

    2016-01-01

    This study presents a generic methodology to select working fluids for ORC (Organic Rankine Cycles)taking into account property uncertainties of the working fluids. A Monte Carlo procedure is described as a tool to propagate the influence of the input uncertainty of the fluid parameters on the ORC...... modeloutput, and provides the 95%-confidence interval of the net power output with respect to the fluid property uncertainties. The methodology has been applied to a molecular design problem for an ORCusing a low-temperature heat source and consisted of the following four parts: 1) formulation...... of processmodels and constraints 2) selection of property models, i.e. Penge Robinson equation of state 3)screening of 1965 possible working fluid candidates including identification of optimal process parametersbased on Monte Carlo sampling 4) propagating uncertainty of fluid parameters to the ORC netpower output...

  14. Effectiveness of Operation of Organic Rankine Cycle Installation Applied in the Liquid Natural Gas Regasification Plant

    Science.gov (United States)

    Kaczmarek, R.; Stachel, A. A.

    2017-05-01

    An analysis of the operation of an Organic Rankine Cycle (ORC) installation heated by a low-temperature heat source is presented for the case where a condenser of a working fluid is cooled by a liquid of ultralow temperature. For this purpose, the process of regasification of liquid natural gas (LNG) is considered. In the process, the condensation heat of the working fluid in ORC is taken by the LNG evaporating subsequently (i.e., undergoing regasification). The paper presents the schematic of this installation and its application, as well as the results of calculations on the basis of the analysis in terms of the power and efficiency. In the analysis, organic fluids used in the ORC as working ones have been selected.

  15. Linear Active Disturbance Rejection Control of Waste Heat Recovery Systems with Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Fang Fang

    2012-12-01

    Full Text Available In this paper, a linear active disturbance rejection controller is proposed for a waste heat recovery system using an organic Rankine cycle process, whose model is obtained by applying the system identification technique. The disturbances imposed on the waste heat recovery system are estimated through an extended linear state observer and then compensated by a linear feedback control strategy. The proposed control strategy is applied to a 100 kW waste heat recovery system to handle the power demand variations of grid and process disturbances. The effectiveness of this controller is verified via a simulation study, and the results demonstrate that the proposed strategy can provide satisfactory tracking performance and disturbance rejection.

  16. Thermal Stability of Hexamethyldisiloxane (MM for High-Temperature Organic Rankine Cycle (ORC

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2016-03-01

    Full Text Available The design of efficient Organic Rankine Cycle (ORC units for the usage of industrial waste heat at high temperatures requires direct contact evaporators without intermediate thermal oil circuits. Therefore, the thermal stability of high-temperature working fluids gains importance. In this study, the thermal degradation of hexamethyldisiloxane (MM is investigated in an electrically heated tube. Qualitative results concerning remarks on degradation products as well as quantitative results like the annual degradation rate are presented. It is shown that MM is stable up to a temperature of 300 °C with annual degradation rates of less than 3.5%. Furthermore, the break of a silicon–carbon bond can be a main chemical reaction that influences the thermal degradation. Finally, it is discussed how the results may impact the future design of ORC units.

  17. Organic Rankine cycle unit for waste heat recovery on ships (PilotORC)

    DEFF Research Database (Denmark)

    Haglind, Fredrik; Montagud, Maria E. Mondejar; Andreasen, Jesper Graa

    The project PilotORC was aimed at evaluating the technical and economic feasibility of the use of organic Rankine cycle (ORC) units to recover low-temperature waste heat sources (i.e. exhaust gases, scavenge air, engine cooling system, and lubricant oil system) on container vessels. The project...... included numerical simulations and experimental tests on a 125 kW demonstration ORC unit that utilizes the waste heat of the main engine cooling system on board one of Mærsk's container vessels. During the design of the demonstration ORC unit, different alternatives for the condenser were analyzed in order...... to minimize the size of the heat exchanger area. Later on the ORC unit was successfully installed on board, and it has been working uninterruptedly since, demonstrating the matureness of the ORC technology for maritime applications. During the onboard testing, additional measuring devices were installed...

  18. Recent research trends in organic Rankine cycle technology: A bibliometric approach

    DEFF Research Database (Denmark)

    Imran, Muhammad; Haglind, Fredrik; Asim, Muhammad

    2018-01-01

    Expanded. Different aspects of the publications were analyzed, such as publication type, major research areas, journals, citations, authorship pattern, affiliations as well as the keyword occurrence frequency. The impact factor, h-index and number of citations were used to investigate the strength...... of active countries, institutes, authors, and journals in the organic Rankine cycle technology field. From 2000 to 2016, there were 2120 articles published by 3443 authors from 997 research institutes scattered over 71 countries. The total number of citations and impact factor are 36,739 and 4597......, respectively, corresponding to 17 citations per paper and an impact factor of 2.168 per publication. The research articles originate primarily from China, the USA, and European countries. Results indicate that China, the United States, Italy, Greece, Belgium, Spain, Germany and the United Kingdom...

  19. Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems

    OpenAIRE

    Ho, Tony

    2012-01-01

    The Organic Flash Cycle (OFC) is proposed as a vapor power cycle that could potentially increase power generation and improve the utilization efficiency of renewable energy and waste heat recovery systems. A brief review of current advanced vapor power cycles including the Organic Rankine Cycle (ORC), the zeotropic Rankine cycle, the Kalina cycle, the transcritical cycle, and the trilateral flash cycle is presented. The premise and motivation for the OFC concept is that essentially by impro...

  20. Performance analysis of an organic Rankine cycle with internal heat exchanger having zeotropic working fluid

    Directory of Open Access Journals (Sweden)

    Thoranis Deethayat

    2015-09-01

    Full Text Available In this study, performance of a 50 kW organic Rankine cycle (ORC with internal heat exchanger (IHE having R245fa/R152a zeotropic refrigerant with various compositions was investigated. The IHE could reduce heat rate at the ORC evaporator and better cycle efficiency could be obtained. The zeotropic mixture could reduce the irreversibilities during the heat exchanges at the ORC evaporator and the ORC condenser due to its gliding temperature; thus the cycle working temperatures came closer to the temperatures of the heat source and the heat sink. In this paper, effects of evaporating temperature, mass fraction of R152a and effectiveness of internal heat exchanger on the ORC performances for the first law and the second law of thermodynamics were considered. The simulated results showed that reduction of R245fa composition could reduce the irreversibilities at the evaporator and the condenser. The suitable composition of R245fa was around 80% mass fraction and below this the irreversibilities were nearly steady. Higher evaporating temperature and higher internal heat exchanger effectiveness also increased the first law and second law efficiencies. A set of correlations to estimate the first and the second law efficiencies with the mass fraction of R245fa, the internal heat exchanger effectiveness and the evaporating temperature were also developed.

  1. Development and a Validation of a Charge Sensitive Organic Rankine Cycle (ORC Simulation Tool

    Directory of Open Access Journals (Sweden)

    Davide Ziviani

    2016-05-01

    Full Text Available Despite the increasing interest in organic Rankine cycle (ORC systems and the large number of cycle models proposed in the literature, charge-based ORC models are still almost absent. In this paper, a detailed overall ORC simulation model is presented based on two solution strategies: condenser subcooling and total working fluid charge of the system. The latter allows the subcooling level to be predicted rather than specified as an input. The overall cycle model is composed of independent models for pump, expander, line sets, liquid receiver and heat exchangers. Empirical and semi-empirical models are adopted for the pump and expander, respectively. A generalized steady-state moving boundary method is used to model the heat exchangers. The line sets and liquid receiver are used to better estimate the total charge of the system and pressure drops. Finally, the individual components are connected to form a cycle model in an object-oriented fashion. The solution algorithm includes a preconditioner to guess reasonable values for the evaporating and condensing temperatures and a main cycle solver loop which drives to zero a set of residuals to ensure the convergence of the solution. The model has been developed in the Python programming language. A thorough validation is then carried out against experimental data obtained from two test setups having different nominal size, working fluids and individual components: (i a regenerative ORC with a 5 kW scroll expander and an oil flooding loop; (ii a regenerative ORC with a 11 kW single-screw expander. The computer code is made available through open-source dissemination.

  2. Organic Rankine cycle – review and research directions in engine applications

    Directory of Open Access Journals (Sweden)

    Panesar Angad

    2017-01-01

    Full Text Available Waste heat to power conversion using Organic Rankine Cycles (ORC is expected to play an important role in CO2 reductions from diesel engines. Firstly, a review of automotive ORCs is presented focusing on the pure working fluids, thermal architectures and expanders. The discussion includes, but is not limited to: R245fa, ethanol and water as fluids; series, parallel and cascade as architectures; dry saturated, superheated and supercritical as expansion conditions; and scroll, radial turbine and piston as expansion machines. Secondly, research direction in versatile expander and holistic architecture (NOx + CO2 are proposed. Benefits of using the proposed unconventional approaches are quantified using Ricardo Wave and Aspen HYSYS for diesel engine and ORC modelling. Results indicate that, the implementation of versatile piston expander tolerant to two-phase and using cyclopentane can potentially increase the highway drive cycle power by 8%. Furthermore, holistic architecture offering complete utilisation of charge air and exhaust recirculation heat increased the performance noticeably to 5% of engine power at the design point condition.

  3. Analysis of a rotating spool expander for Organic Rankine Cycle applications

    Science.gov (United States)

    Krishna, Abhinav

    Increasing interest in recovering or utilizing low-grade heat for power generation has prompted a search for ways in which the power conversion process may be enhanced. Amongst the conversion systems, the Organic Rankine Cycle (ORC) has generated an enormous amount of interest amongst researchers and system designers. Nevertheless, component level technologies need to be developed and match the range of potential applications. In particular, technical challenges associated with scaling expansion machines (turbines) from utility scale to commercial scale have prevented widespread adoption of the technology. In this regard, this work focuses on a novel rotating spool expansion machine at the heart of an Organic Rankine Cycle. A comprehensive, deterministic simulation model of the rotating spool expander is developed. The comprehensive model includes a detailed geometry model of the spool expander and the suction valve mechanism. Sub-models for mass flow, leakage, heat transfer and friction within the expander are also developed. Apart from providing the ability to characterize the expander in a particular system, the model provides a valuable tool to study the impact of various design variables on the performance of the machine. The investigative approach also involved an experimental program to assess the performance of a working prototype. In general, the experimental data showed that the expander performance was sub-par, largely due to the mismatch of prevailing operating conditions and the expander design criteria. Operating challenges during the shakedown tests and subsequent sub-optimal design changes also detracted from performance. Nevertheless, the results of the experimental program were sufficient for a proof-of-concept assessment of the expander and for model validation over a wide range of operating conditions. The results of the validated model reveal several interesting details concerning the expander design and performance. For example, the match

  4. Optimization of Cycle and Expander Design of an Organic Rankine Cycle Unit using Multi-Component Working Fluids

    DEFF Research Database (Denmark)

    Meroni, Andrea; Andreasen, Jesper Graa; Pierobon, Leonardo

    2016-01-01

    for an organic Rankine cycle unit utilizing waste heat from low temperature heat sources. The study addresses a case where the minimum temperature of the heat source is constrained and a case where no constraint is imposed. The former case is the wasteheat recovery from jacket cooling water of a marine diesel...... engine onboard a large ship, and the latter is representative of a low-temperature geothermal, solar or waste heat recovery application. Multi-component working fluids are investigated, as they allow improving the match between the temperature pro-files in the heat exchangers and, consequently, reducing...... the irreversibility in the ORC system. This work considers mixtures of R245fa/pentane and propane/isobutane. The use of multi-component working fluids typically results in increased heat transfer areas and different expander designs compared to purefluids. In order to properly account for turbine performance...

  5. About the prediction of Organic Rankine Cycles performances integrating local high-fidelity turbines simulation and uncertainties

    Science.gov (United States)

    Congedo, Pietro; de Santis, Dante; Geraci, Gianluca

    2014-11-01

    Organic Rankine Cycles (ORCs) are of key-importance when exploiting energy systems with a high efficiency. The variability of renewable heat sources makes more complex the global performance prediction of a cycle. The thermodynamic properties of the complex fluids used in the process are another source of uncertainty. The need for a predictive and robust simulation tool of ORCs remains strong. A high-order accurate Residual Distribution scheme has been recently developed for efficiently computing a turbine stage on unstructured grids, including advanced equations of state in order to take into account the complex fluids used in ORCs. Advantages in using high-order methods have been highlighted, in terms of number of degrees of freedom and computational time used, for computing the numerical solution with a greater accuracy compared to lower-order methods, even for shocked flows. The objective of this work is to quantify the numerical error with respect to the various sources of uncertainty of the ORC turbine, thus providing a very high-fidelity prediction in the coupled physical/stochastic space.

  6. Simulation of a passive house coupled with a heat pump/organic Rankine cycle reversible unit

    DEFF Research Database (Denmark)

    Dumont, Olivier; Carmo, Carolina; Randaxhe, François

    2014-01-01

    This paper presents a dynamic model of a passive house located in Denmark with a large solar absorber, a horizontal ground heat exchanger coupled with a HP/ORC unit. The HP/ORC reversible unit is a module able to work as an Organic Rankine Cycle (ORC) or as a heat pump (HP). There are 3 possible...... modes that need to be chosen optimally depending on the weather conditions, the heat demand and the temperature level of the storage. The ORC mode is activated, as long as the heat demand of the house is covered by the storage to produce electricity based upon the heat generated by the solar roof...... of the year in the Modelica language. A peak of 3.28 kW of power is reached in ORC mode with a heat input of 59.5 kW from the solar roof (23.9 kWh are produced during a typical summer day). In a representative winter day, 17.28 kWh are consumed by the heat pump with a daily average COP of 4.1. Conclusions...

  7. Thermo-Economic Evaluation of Organic Rankine Cycles for Geothermal Power Generation Using Zeotropic Mixtures

    Directory of Open Access Journals (Sweden)

    Florian Heberle

    2015-03-01

    Full Text Available We present a thermo-economic evaluation of binary power plants based on the Organic Rankine Cycle (ORC for geothermal power generation. The focus of this study is to analyse if an efficiency increase by using zeotropic mixtures as working fluid overcompensates additional requirements regarding the major power plant components. The optimization approach is compared to systems with pure media. Based on process simulations, heat exchange equipment is designed and cost estimations are performed. For heat source temperatures between 100 and 180 °C selected zeotropic mixtures lead to an increase in second law efficiency of up to 20.6% compared to pure fluids. Especially for temperatures about 160 °C, mixtures like propane/isobutane, isobutane/isopentane, or R227ea/R245fa show lower electricity generation costs compared to the most efficient pure fluid. In case of a geothermal fluid temperature of 120 °C, R227ea and propane/isobutane are cost-efficient working fluids. The uncertainties regarding fluid properties of zeotropic mixtures, mainly affect the heat exchange surface. However, the influence on the determined economic parameter is marginal. In general, zeotropic mixtures are a promising approach to improve the economics of geothermal ORC systems. Additionally, the use of mixtures increases the spectrum of potential working fluids, which is important in context of present and future legal requirements considering fluorinated refrigerants.

  8. An Innovative Application of a Solar Storage Wall Combined with the Low-Temperature Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Tzu-Chen Hung

    2014-01-01

    Full Text Available The objective of this study is to collect energy on the waste heat from air produced by solar ventilation systems. This heat used for electricity generation by an organic Rankine cycle (ORC system was implemented. The advantages of this method include the use of existing building’s wall, and it also provides the region of energy scarcity for reference. This is also an innovative method, and the results will contribute to the efforts made toward improving the design of solar ventilation in the field of solar thermal engineering. In addition, ORC system would help generate electricity and build a low-carbon building. This study considered several critical parameters such as length of the airflow channel, intensity of solar radiation, pattern of the absorber plate, stagnant air layer, and operating conditions. The simulation results show that the highest outlet temperature and heat collecting efficiency of solar ventilation system are about 120°C and 60%, respectively. The measured ORC efficiency of the system was 6.2%. The proposed method is feasible for the waste heat from air produced by ventilation systems.

  9. Study on Mixed Working Fluids with Different Compositions in Organic Rankine Cycle (ORC Systems for Vehicle Diesel Engines

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2014-08-01

    Full Text Available One way to increase the thermal efficiency of vehicle diesel engines is to recover waste heat by using an organic Rankine cycle (ORC system. Tests were conducted to study the running performances of diesel engines in the whole operating range. The law of variation of the exhaust energy rate under various engine operating conditions was also analyzed. A diesel engine-ORC combined system was designed, and relevant evaluation indexes proposed. The variation of the running performances of the combined system under various engine operating conditions was investigated. R245fa and R152a were selected as the components of the mixed working fluid. Thereafter, six kinds of mixed working fluids with different compositions were presented. The effects of mixed working fluids with different compositions on the running performances of the combined system were revealed. Results show that the running performances of the combined system can be improved effectively when mass fraction R152a in the mixed working fluid is high and the engine operates with high power. For the mixed working fluid M1 (R245fa/R152a, 0.1/0.9, by mass fraction, the net power output of the combined system reaches the maximum of 34.61 kW. Output energy density of working fluid (OEDWF, waste heat recovery efficiency (WHRE, and engine thermal efficiency increasing ratio (ETEIR all reach their maximum values at 42.7 kJ/kg, 10.90%, and 11.29%, respectively.

  10. Performance analysis of exhaust heat recovery using organic Rankine cycle in a passenger car with a compression ignition engine

    Science.gov (United States)

    Ghilvacs, M.; Prisecaru, T.; Pop, H.; Apostol, V.; Prisecaru, M.; Pop, E.; Popescu, Gh; Ciobanu, C.; Mohanad, A.; Alexandru, A.

    2016-08-01

    Compression ignition engines transform approximately 40% of the fuel energy into power available at the crankshaft, while the rest part of the fuel energy is lost as coolant, exhaust gases and other waste heat. An organic Rankine cycle (ORC) can be used to recover this waste heat. In this paper, the characteristics of a system combining a compression ignition engine with an ORC which recover the waste heat from the exhaust gases are analyzed. The performance map of the diesel engine is measured on an engine test bench and the heat quantities wasted by the exhaust gases are calculated over the engine's entire operating region. Based on this data, the working parameters of ORC are defined, and the performance of a combined engine-ORC system is evaluated across this entire region. The results show that the net power of ORC is 6.304kW at rated power point and a maximum of 10% reduction in brake specific fuel consumption can be achieved.

  11. Part-Load Performance of a Wet Indirectly Fired Gas Turbine Integrated with an Organic Rankine Cycle Turbogenerator

    OpenAIRE

    Leonardo Pierobon; Tuong-Van Nguyen; Andrea Mazzucco; Ulrik Larsen; Fredrik Haglind

    2014-01-01

    Over the last years, much attention has been paid to the development of efficient and low-cost power systems for biomass-to-electricity conversion. This paper aims at investigating the design- and part-load performance of an innovative plant based on a wet indirectly fired gas turbine (WIFGT) fueled by woodchips and an organic Rankine cycle (ORC) turbogenerator. An exergy analysis is performed to identify the sources of inefficiencies, the optimal design variables, and the most suitable worki...

  12. Test results of an organic Rankine-cycle power module for a small community solar thermal power experiment

    Science.gov (United States)

    Clark, T. B.

    1985-01-01

    The organic Rankine-cycle (ORC) power conversion assembly was tested. Qualification testing of the electrical transport subsystem was also completed. Test objectives were to verify compatibility of all system elements with emphasis on control of the power conversion assembly, to evaluate the performance and efficiency of the components, and to validate operating procedures. After 34 hours of power generation under a wide range of conditions, the net module efficiency exceeded 18% after accounting for all parasitic losses.

  13. Performance of Siloxane Mixtures in a High-Temperature Organic Rankine Cycle Considering the Heat Transfer Characteristics during Evaporation

    OpenAIRE

    Theresa Weith; Florian Heberle; Markus Preißinger; Dieter Brüggemann

    2014-01-01

    The application of the Organic Rankine Cycle to high temperature heat sources is investigated on the case study of waste heat recovery from a selected biogas plant. Two different modes of operation are distinguished: pure electric power and combined heat and power generation. The siloxanes hexamethyldisiloxane (MM) and octamethyltrisiloxane (MDM) are chosen as working fluids. Moreover, the effect of using mixtures of these components is analysed. Regarding pure electricity generation, process...

  14. Experimental and thermodynamic analysis of a bottoming Organic Rankine Cycle (ORC) of gasoline engine using swash-plate expander

    OpenAIRE

    Galindo, José,; Ruiz Rosales, Santiago; Dolz Ruiz, Vicente; ROYO PASCUAL, LUCÍA; Haller, R.; Nicolas, B.; Glavatskaya, Y.

    2015-01-01

    This paper deals with the experimental testing of an Organic Rankine Cycle (ORC) integrate in a 2 liter turbocharged gasoline engine using ethanol as working fluid. The main components of the cycle are a boiler, a condenser, a pump and a swash-plate expander. Five engine operating points have been tested, they correspond to a nominal heat input into the boiler of 5, 12, 20, 25 and 30 kW. With the available bill of material based on prototypes, power balances and cycles efficiencies were estim...

  15. Analysis and optimization of three main organic Rankine cycle configurations using a set of working fluids with different thermodynamic behaviors

    Science.gov (United States)

    Hamdi, Basma; Mabrouk, Mohamed Tahar; Kairouani, Lakdar; Kheiri, Abdelhamid

    2017-06-01

    Different configurations of organic Rankine cycle (ORC) systems are potential thermodynamic concepts for power generation from low grade heat. The aim of this work is to investigate and optimize the performances of the three main ORC systems configurations: basic ORC, ORC with internal heat exchange (IHE) and regenerative ORC. The evaluation for those configurations was performed using seven working fluids with typical different thermodynamic behaviours (R245fa, R601a, R600a, R227ea, R134a, R1234ze and R1234yf). The optimization has been performed using a genetic algorithm under a comprehensive set of operative parameters such as the fluid evaporating temperature, the fraction of flow rate or the pressure at the steam extracting point in the turbine. Results show that there is no general best ORC configuration for all those fluids. However, there is a suitable configuration for each fluid. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  16. Technical Analysis of Organic Rankine Cycle System Using Low-Temperature Source to Generate Electricity in Ship

    Directory of Open Access Journals (Sweden)

    Akram Faisal

    2017-01-01

    Full Text Available Nowadays, the shipping sector has growth rapidly as followed by the increasing of world population and the demands for public transportation via sea. This issue entails the large attention on emission, energy efficiency and fuel consumption on the ship. Waste Heat Recovery (WHR is one of the solution to overcome the mentioned issue and one of the WHR method is by installing Organic Rankine Cycle (ORC system in ship. ORC demonstrate to recover and exploit the low temperature waste heat rejected by the ship power generation plant. The main source of heat to be utilized is obtained from container ship (7900 kW BHP, DWT 10969 mt ship jacket water cooling system and use R-134a as a refrigerant. The main equipment consists of evaporator, condenser, pump and steam turbine to generate the electricity. The main objective is to quantifying the estimation of electrical power which can be generated at typical loads of the main engine. As the final result of analysis, the ORC system is able to generate the electricity power ranged from 77,5% - 100% of main engine load producing power averagely 57,69 kW.

  17. Alkali Metal Rankine Cycle Boiler Technology Challenges and Some Potential Solutions for Space Nuclear Power and Propulsion Applications

    Science.gov (United States)

    Stone, James R.

    1994-01-01

    Alkali metal boilers are of interest for application to future space Rankine cycle power conversion systems. Significant progress on such boilers was accomplished in the 1960's and early 1970's, but development was not continued to operational systems since NASA's plans for future space missions were drastically curtailed in the early 1970's. In particular, piloted Mars missions were indefinitely deferred. With the announcement of the Space Exploration Initiative (SEI) in July 1989 by President Bush, interest was rekindled in challenging space missions and, consequently in space nuclear power and propulsion. Nuclear electric propulsion (NEP) and nuclear thermal propulsion (NTP) were proposed for interplanetary space vehicles, particularly for Mars missions. The potassium Rankine power conversion cycle became of interest to provide electric power for NEP vehicles and for 'dual-mode' NTP vehicles, where the same reactor could be used directly for propulsion and (with an additional coolant loop) for power. Although the boiler is not a major contributor to system mass, it is of critical importance because of its interaction with the rest of the power conversion system; it can cause problems for other components such as excess liquid droplets entering the turbine, thereby reducing its life, or more critically, it can drive instabilities-some severe enough to cause system failure. Funding for the SEI and its associated technology program from 1990 to 1993 was not sufficient to support significant new work on Rankine cycle boilers for space applications. In Fiscal Year 1994, funding for these challenging missions and technologies has again been curtailed, and planning for the future is very uncertain. The purpose of this paper is to review the technologies developed in the 1960's and 1970's in the light of the recent SEI applications. In this way, future Rankine cycle boiler programs may be conducted most efficiently. This report is aimed at evaluating alkali metal boiler

  18. Stand-Alone Solar Organic Rankine Cycle Water Pumping System and Its Economic Viability in Nepal

    Directory of Open Access Journals (Sweden)

    Suresh Baral

    2015-12-01

    Full Text Available The current study presents the concept of a stand-alone solar organic Rankine cycle (ORC water pumping system for rural Nepalese areas. Experimental results for this technology are presented based on a prototype. The economic viability of the system was assessed based on solar radiation data of different Nepalese geographic locations. The mechanical power produced by the solar ORC is coupled with a water pumping system for various applications, such as drinking and irrigation. The thermal efficiency of the system was found to be 8% with an operating temperature of 120 °C. The hot water produced by the unit has a temperature of 40 °C. Economic assessment was done for 1-kW and 5-kW solar ORC water pumping systems. These systems use different types of solar collectors: a parabolic trough collector (PTC and an evacuated tube collector (ETC. The economic analysis showed that the costs of water are $2.47/m3 (highest and $1.86/m3 (lowest for the 1-kW system and a 150-m pumping head. In addition, the cost of water is reduced when the size of the system is increased and the pumping head is reduced. The minimum volumes of water pumped are 2190 m3 and 11,100 m3 yearly for 1 kW and 5 kW, respectively. The payback period is eight years with a profitability index of 1.6. The system is highly feasible and promising in the context of Nepal.

  19. Thermo-Economic Performance Analysis of a Regenerative Superheating Organic Rankine Cycle for Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Zhonghe Han

    2017-10-01

    Full Text Available The Organic Rankine Cycle (ORC is a promising form of technology for recovering low-grade waste heat. In this study, a regenerative ORC system is established to recover the waste flue gas of 160 °C. Focusing on thermodynamic and economic performance while simultaneously considering the limitations of volume flow ratio (VFR and the effect of superheat, working fluid selection and parameter optimization have been investigated. The optimization of the evaporation temperature is carried out by analyzing the variation of net power output and specific investment cost (SIC. Then, the net power output, specific net power output, total exergy destruction rate, VFR, total capital cost, and levelized electricity cost (LEC are selected as criteria, and a fuzzy multi-criteria evaluation method is adopted to select a more suitable working fluid and determine the optimal degree of superheat. In addition, the preheating coefficient, latent heat coefficient, superheating coefficient, and internal heat coefficient were proposed to explore the effect of working fluid critical temperature on thermal efficiency. Research studies demonstrate that there is an optimal evaporation temperature, maximizing net power output and minimizing the SIC. Isohexane and butane have greater specific net power output due to greater latent heat. A suitable degree of superheat is not only conducive to improving the working capacity of working fluids, but also reduces the VFR, total capital cost, SIC, and LEC for different working fluids. Thus, the system’s thermodynamic and economic performance—as well as the operational stability—are improved. Among the six working fluids, butane exhibits the best comprehensive performance, and its optimal evaporation temperature and degree of superheat are 100 °C and 5 °C, respectively.

  20. Design and development of an automotive propulsion system utilizing a Rankine cycle engine (water based fluid). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Demler, R.L.

    1977-09-01

    Under EPA and ERDA sponsorship, SES successfully designed, fabricated and tested the first federally sponsored steam powered automobile. The automobile - referred to as the simulator - is a 1975 Dodge Monaco standard size passenger car with the SES preprototype Rankine cycle automotive propulsion system mounted in the engine compartment. In the latter half of 1975, the simulator successfully underwent test operations at the facilities of SES in Watertown, Massachusetts and demonstrated emission levels below those of the stringent federally established automotive requirements originally set for implementation by 1976. The demonstration was accomplished during testing over the Federal Driving Cycle on a Clayton chassis dynamometer. The design and performance of the vehicle are described.

  1. Modeling and analysis of a transcritical rankine power cycle with a low grade heat source

    DEFF Research Database (Denmark)

    Nguyen, Chan; Veje, Christian

    efficiency, exergetic efficiency and specific net power output. A generic cycle configuration has been used for analysis of a geothermal energy heat source. This model has been validated against similar calculations using industrial waste heat as the energy source. Calculations are done with fixed...

  2. Part-Load Performance of aWet Indirectly Fired Gas Turbine Integrated with an Organic Rankine Cycle Turbogenerator

    Directory of Open Access Journals (Sweden)

    Leonardo Pierobon

    2014-12-01

    Full Text Available Over the last years, much attention has been paid to the development of efficient and low-cost power systems for biomass-to-electricity conversion. This paper aims at investigating the design- and part-load performance of an innovative plant based on a wet indirectly fired gas turbine (WIFGT fueled by woodchips and an organic Rankine cycle (ORC turbogenerator. An exergy analysis is performed to identify the sources of inefficiencies, the optimal design variables, and the most suitable working fluid for the organic Rankine process. This step enables to parametrize the part-load model of the plant and to estimate its performance at different power outputs. The novel plant has a nominal power of 250 kW and a thermal efficiency of 43%. The major irreversibilities take place in the burner, recuperator, compressor and in the condenser. Toluene is the optimal working fluid for the organic Rankine engine. The part-load investigation indicates that the plant can operate at high efficiencies over a wide range of power outputs (50%–100%, with a peak thermal efficiency of 45% at around 80% load. While the ORC turbogenerator is responsible for the efficiency drop at low capacities, the off-design performance is governed by the efficiency characteristics of the compressor and turbine serving the gas turbine unit.

  3. Final Report: Modifications and Optimization of the Organic Rankine Cycle to Improve the Recovery of Waste Heat

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna Post [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zia, Jalal [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-09-01

    This research and development (R&D) project exemplifies a shared public private commitment to advance the development of energy efficient industrial technologies that will reduce the U.S. dependence upon foreign oil, provide energy savings and reduce greenhouse gas emissions. The purpose of this project was to develop and demonstrate a Direct Evaporator for the Organic Rankine Cycle (ORC) for the conversion of waste heat from gas turbine exhaust to electricity. In conventional ORCs, the heat from the exhaust stream is transferred indirectly to a hydrocarbon based working fluid by means of an intermediate thermal oil loop. The Direct Evaporator accomplishes preheating, evaporation and superheating of the working fluid by a heat exchanger placed within the exhaust gas stream. Direct Evaporation is simpler and up to 15% less expensive than conventional ORCs, since the secondary oil loop and associated equipment can be eliminated. However, in the past, Direct Evaporation has been avoided due to technical challenges imposed by decomposition and flammability of the working fluid. The purpose of this project was to retire key risks and overcome the technical barriers to implementing an ORC with Direct Evaporation. R&D was conducted through a partnership between the Idaho National Laboratory (INL) and General Electric (GE) Global Research Center (GRC). The project consisted of four research tasks: (1) Detailed Design & Modeling of the ORC Direct Evaporator, (2) Design and Construction of Partial Prototype Direct Evaporator Test Facility, (3) Working Fluid Decomposition Chemical Analyses, and (4) Prototype Evaluation. Issues pertinent to the selection of an ORC working fluid, along with thermodynamic and design considerations of the direct evaporator, were identified. The FMEA (Failure modes and effects analysis) and HAZOP (Hazards and operability analysis) safety studies performed to mitigate risks are described, followed by a discussion of the flammability analysis of the

  4. Dataset of working conditions and thermo-economic performances for hybrid organic Rankine plants fed by solar and low-grade energy sources.

    Science.gov (United States)

    Scardigno, Domenico; Fanelli, Emanuele; Viggiano, Annarita; Braccio, Giacobbe; Magi, Vinicio

    2016-06-01

    This article provides the dataset of operating conditions of a hybrid organic Rankine plant generated by the optimization procedure employed in the research article "A genetic optimization of a hybrid organic Rankine plant for solar and low-grade energy sources" (Scardigno et al., 2015) [1]. The methodology used to obtain the data is described. The operating conditions are subdivided into two separate groups: feasible and unfeasible solutions. In both groups, the values of the design variables are given. Besides, the subset of feasible solutions is described in details, by providing the thermodynamic and economic performances, the temperatures at some characteristic sections of the thermodynamic cycle, the net power, the absorbed powers and the area of the heat exchange surfaces.

  5. Altheim geothermal plant. Power generation by means of an ORC turbogenerator; Geothermieanlagen Altheim. Stromerzeugung mittels Organic-Rankine-Cycle Turbogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Pernecker, G. [Marktgemeindeamt Altheim (Austria)

    1997-12-01

    The report describes the project of the Austrian market town of Altheim to generate electricity by means of an ORC turbogenerator using low-temperature thermal water. The project is to improve the technical and economic situation of the existing industrial-scale geothermal project. (orig.) [Deutsch] Der Bericht beschreibt das Vorhaben der Marktgemeinde Altheim in Oberoesterreich, Strom mittels eines Organic-Rankine-Cycle-Turbogenerators unter Verwendung niedrig temperierten Thermalwassers zu produzieren. Ziel bzw. der Zweck des Projektes ist es, die technische und wirtschaftliche Situation der bestehenden Grossthermieanlage zu verbessern. (orig.)

  6. Organic Rankine-Cycle Power Systems Working Fluids Study: Topical report No. 3, 2-methylpyridine/water

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R.L.; Demirgian, J.C.; Allen, J.W.

    1987-09-01

    A mixture of 35 mole percent (mol %) 2-methylpyridine and 65 mol % water was tested at 575, 625, and 675/degree/F in a dynamic loop. Samples of the degraded fluid were chemically analyzed to determine the identities of major degradation products and the quantity of degradation. Computed degradation rates were found to be higher than those for Fluorinol 85 or toluene. For this reason (and other reasons, related to fluid handling), other fluids are recommended as the first choice for service in organic Rankine-cycle systems in preference to 2-methylpyridine/water. 7 refs., 39 figs., 39 tabs.

  7. Possible emissions from electricity and heat generation from geothermal energy by the use of F-gases in the energy conversion process by an Organic Rankine Cycle (ORC); Moegliche Emissionen bei der Strom- und Waermeerzeugung aus Geothermie durch den Einsatz von F-Gasen im Energiewandlungsprozess mittels ORC

    Energy Technology Data Exchange (ETDEWEB)

    Heberle, Florian; Obermeier, Andreas; Brueggemann, Dieter [Steinbeis-Transferzentrum - Angewandte Thermodynamik, Energie- und Verbrennungstechnik (ATEV), Bayreuth (Germany)

    2012-11-15

    In case of low temperature heat sources Organic Rankine Cycle (ORC) is next to Kalina Cycle one of the few thermodynamic cycles suitable for power generation. Optimization strategies provide a better glide matching of the temperature profiles of heat source or sink to the ORC compared to the standard cycle. This leads to an increase in efficiencies in the range of 15 % to 25 %. In this context, selection of suitable working fluids, two-stage expansion, supercritical cycles or the usage of zeotropic mixtures as working fluids has to be mentioned. Due to the use of fluorinated hydrocarbons, the number of potential fluids as well as the efficiency increase significantly. However, an increase in emissions due to leakages during operation, filling and disposal is associated with fluorinated fluids compared to natural hydrocarbons. Such emissions cannot be completely avoided and according to information of manufacturers and operators they are annually in the range of 1 % to 3 % of the capacity. Based on legal regulations recording of the use levels of fluorinated hydrocarbons in ORC systems according to UStatG and EU Regulation 842/2006 is obligatory. The recording obligation exists regarding the national emission inventory based on the framework convention on climate change. To evaluate potential greenhouse gas emissions by geothermal power plants, in this study different scenarios depending on rate of emission and number of power plants are calculated. If a development in geothermal power generation as predicted takes place, the emissions until the year 2030 are to be classified as low. In case of the technical-ecological potential with 2120 power plants and a rate of emission of 3 % the emissions are between 0.24 Million t/a and 3.02 Million t/a depending on the considered scenario. A comparison to the greenhouse gases by fluorinated hydrocarbons in the year 2009 with 15.6 Million t/a shows that the emissions for this number of power plants are definitely relevant

  8. Analyzing the Performance of a Dual Loop Organic Rankine Cycle System for Waste Heat Recovery of a Heavy-Duty Compressed Natural Gas Engine

    Directory of Open Access Journals (Sweden)

    Baofeng Yao

    2014-11-01

    Full Text Available A dual loop organic Rankine cycle (DORC system is designed to recover waste heat from a heavy-duty compressed natural gas engine (CNGE, and the performance of the DORC–CNGE combined system is simulated and discussed. The DORC system includes high-temperature (HT and low-temperature (LT cycles. The HT cycle recovers energy from the exhaust gas emitted by the engine, whereas the LT cycle recovers energy from intake air, engine coolant, and the HT cycle working fluid in the preheater. The mathematical model of the system is established based on the first and second laws of thermodynamics. The characteristics of waste heat energy from the CNGE are calculated according to engine test data under various operating conditions. Moreover, the performance of the DORC–CNGE combined system is simulated and analyzed using R245fa as the working fluid. Results show that the maximum net power output and the maximum thermal efficiency of the DORC system are 29.37 kW and 10.81%, respectively, under the rated power output condition of the engine. Compared with the original CNG engine, the maximum power output increase ratio and the maximum brake specific fuel consumption improvement ratio are 33.73% and 25%, respectively, in the DORC–CNGE combined system.

  9. Performance Evaluation of a Helical Coil Heat Exchanger Working under Supercritical Conditions in a Solar Organic Rankine Cycle Installation

    Directory of Open Access Journals (Sweden)

    Marija Lazova

    2016-06-01

    Full Text Available Worldwide interest in low grade heat valorization using organic Rankine cycle (ORC technologies has increased significantly. A new small-scale ORC with a net capacity of 3 kW was efficiently integrated with a concentrated solar power technology for electricity generation. The excess heat source from Photovoltaic (PV collectors with a maximum temperature of 100 °C was utilized through a supercritical heat exchanger that uses R-404A as working medium. By ensuring supercritical heat transfer leads to a better thermal match in the heat exchanger and improved overall cycle efficiency. A helical coil heat exchanger was designed by using heat transfer correlations from the literature. These heat transfer correlations were derived for different conditions than ORCs and their estimated uncertainty is ~20%. In order to account for the heat transfer correlation uncertainties this component was oversized by 20%. Next, a prototype was built and installed in an integrated concentrated photovoltaic/thermal (CPV/T/Rankine system. The results from the measurements show that for better estimation of the sizing of the heat exchanger a more accurate correlation is required in order to design an optimal configuration and thus employ cheaper components.

  10. Coupling of Modular High-Temperature Gas-Cooled Reactor with Supercritical Rankine Cycle

    OpenAIRE

    Shutang Zhu; Ying Tang; Kun Xiao; Zuoyi Zhang

    2008-01-01

    This paper presents investigations on the possible combination of modular high-temperature gas-cooled reactor (MHTGR) technology with the supercritical (SC) steam turbine technology and the prospective deployments of the MHTGR SC power plant. Energy conversion efficiency of steam turbine cycle can be improved by increasing the main steam pressure and temperature. Investigations on SC water reactor (SCWR) reveal that the development of SCWR power plants still needs further research and develop...

  11. Application Guide for Waste Heat Recovery with Organic Rankine Cycle Equipment.

    Science.gov (United States)

    1983-01-15

    Cycle Development and Its Application to Solar Energy Utilization," Ishikawajima - Harima Heavy Industries Co., Ltd. (AFI), International Congress of...20 , LU z 600 FOR ESTIMATING S800 "PURPOSES ’. Uj100 C 40000 DATA FROM SPS INC. ~t DATA FROM AFI -, 6000 0 DATA FROM ISHIKAWAJIMA - HARIMA 3. Figure 3-6...literature search and industry survey. Engineering criteria for applying ORC tech- nology are established, and a set of nomograms to enable the rapid

  12. An experimental analysis of flow boiling and pressure drop in a brazed plate heat exchanger for organic Rankine cycle power systems

    DEFF Research Database (Denmark)

    Desideri, Adriano; Zhang, Ji; Kærn, Martin Ryhl

    2017-01-01

    Organic Rankine cycle power systems for low quality waste heat recovery applications can play a major role in achieving targets of increasing industrial processes efficiency and thus reducing the emissions of greenhouse gases. Low capacity organic Rankine cycle systems are equipped with brazed...... and pressure drop during vaporization at typical temperatures for low quality waste heat recovery organic Rankine cycle systems are presented for the working fluids HFC-245fa and HFO-1233zd. The experiments were carried out at saturation temperatures of 100°C, 115°C and 130°C and inlet and outlet qualities...... plate heat exchangers which allows for efficient heat transfer with a compact design. Accurate heat transfer correlations characterizing these devices are required from the design phase to the development of model-based control strategies. In this paper, the experimental heat transfer coefficient...

  13. Design and optimisation of organic Rankine cycles for waste heat recovery in marine applications using the principles of natural selection

    DEFF Research Database (Denmark)

    Larsen, Ulrik; Pierobon, Leonardo; Haglind, Fredrik

    2013-01-01

    , boundary conditions, hazard levels and environmental concerns. A generally applicable methodology, based on the principles of natural selection, is presented and used to determine the optimum working fluid, boiler pressure and Rankine cycle process layout for scenarios related to marine engine heat......Power cycles using alternative working fluids are currently receiving significant attention. Selection of working fluid among many candidates is a key topic and guidelines have been presented. A general problem is that the selection is based on numerous criteria, such as thermodynamic performance...... recovery. Included in the solution domain are 109 fluids in sub and supercritical processes, and the process is adapted to the properties of the individual fluid. The efficiency losses caused by imposing process constraints are investigated to help propose a suitable process layout. Hydrocarbon dry type...

  14. Improving the efficiency of heat supply systems on the basis of plants operating on organic Rankine cycle

    Science.gov (United States)

    Solomin, I. N.; Daminov, A. Z.; Sadykov, R. A.

    2017-11-01

    Results of experimental and analytical studies of the plant main element – plant turbomachine (turbo-expander) operating on organic Rankine cycle were obtained for facilities of the heat supply systems of small-scale power generation. At simultaneous mathematical modeling and experimental studies it was found that the best working medium to be used in the turbomachines of these plants is Freon R245fa which has the most suitable calorimetric properties to be used in the cycle. The mathematical model of gas flow in the turbomachine was developed. The main engineering dependencies to calculate the optimal design parameters of the turbomachine were obtained. The engineering problems of providing the minimum axial size of the turbomachine impeller were solved and the main design elements were unified.

  15. Cogenerative Performance of a Wind − Gas Turbine − Organic Rankine Cycle Integrated System for Offshore Applications

    DEFF Research Database (Denmark)

    Bianchi, Michele; Branchini, Lisa; De Pascale, Andrea

    2016-01-01

    Gas Turbines (GT) are widely used for power generationin offshore oil and gas facilities, due to their high reliability,compactness and dynamic response capabilities. Small heavyduty and aeroderivative units in multiple arrangements aretypically used to offer larger load flexibility......, but limitedefficiency of such machines is the main drawback. A solutionto enhance the system performance, also in Combined Heat andPower (CHP) arrangement, is the implementation of OrganicRankine Cycle (ORC) systems at the bottom of the gas turbines.Moreover, the resulting GT-ORC combined cycle could befurther...... a 10MW offshorewind farm and three gas turbines rated for 16:5MW, eachone coupled with an 4:5MW ORC module. The ORC mainparameters are observed under different wind power fluctuations.Due to the non-programmable availability of wind and powerdemand, the part-load and dynamic characteristics...

  16. Selecting working fluids in an organic Rankine cycle for power generation from low temperature heat sources

    Directory of Open Access Journals (Sweden)

    Fredy Vélez

    2014-01-01

    Full Text Available Este trabajo presenta un estudio termodinámico realizado sobre el uso de fuentes de calor de baja temperatura para la generaci ón de energía a través de un ciclo Rankin e subcrítico con fluidos de trabajo orgánicos. Un análisis d el estado del arte de esta tecn ología muestra como línea de investigación abierta, la selección del fluido de trabajo, pues hasta ahora, no existe un fluido que satisfaga t odos los aspectos medioambientales y técnicos a tener en cuenta en estos ciclos. Por ello, se ha desarrollado una serie de simulaciones que permiten estudiar el comportamiento del ciclo Rankine con difer entes configuraciones y fluidos (húmedo, seco e isoentrópico, permitiendo con ello observar de qué manera influyen cambios ta nto en esos tipos de fluidos utilizados (refrigerantes, hidroca rburos y agua, como de condiciones de temperatura, presión, flujo, etc. , sobre la eficiencia total del ciclo. Con el trabajo realizado se demuestra la viabilidad de este tipo de proceso en la recuperación de calore s en la industria y/o aprovechamiento de fuentes renovables de baja y media temperatura para la producción de energía eléctrica.

  17. Coupling of Modular High-Temperature Gas-Cooled Reactor with Supercritical Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Shutang Zhu

    2008-01-01

    Full Text Available This paper presents investigations on the possible combination of modular high-temperature gas-cooled reactor (MHTGR technology with the supercritical (SC steam turbine technology and the prospective deployments of the MHTGR SC power plant. Energy conversion efficiency of steam turbine cycle can be improved by increasing the main steam pressure and temperature. Investigations on SC water reactor (SCWR reveal that the development of SCWR power plants still needs further research and development. The MHTGR SC plant coupling the existing technologies of current MHTGR module design with operation experiences of SC FPP will achieve high cycle efficiency in addition to its inherent safety. The standard once-reheat SC steam turbine cycle and the once-reheat steam cycle with life-steam have been studied and corresponding parameters were computed. Efficiencies of thermodynamic processes of MHTGR SC plants were analyzed, while comparisons were made between an MHTGR SC plant and a designed advanced passive PWR - AP1000. It was shown that the net plant efficiency of an MHTGR SC plant can reach 45% or above, 30% higher than that of AP1000 (35% net efficiency. Furthermore, an MHTGR SC plant has higher environmental competitiveness without emission of greenhouse gases and other pollutants.

  18. Microfabricated rankine cycle steam turbine for power generation and methods of making the same

    Science.gov (United States)

    Frechette, Luc (Inventor); Muller, Norbert (Inventor); Lee, Changgu (Inventor)

    2009-01-01

    In accordance with the present invention, an integrated micro steam turbine power plant on-a-chip has been provided. The integrated micro steam turbine power plant on-a-chip of the present invention comprises a miniature electric power generation system fabricated using silicon microfabrication technology and lithographic patterning. The present invention converts heat to electricity by implementing a thermodynamic power cycle on a chip. The steam turbine power plant on-a-chip generally comprises a turbine, a pump, an electric generator, an evaporator, and a condenser. The turbine is formed by a rotatable, disk-shaped rotor having a plurality of rotor blades disposed thereon and a plurality of stator blades. The plurality of stator blades are interdigitated with the plurality of rotor blades to form the turbine. The generator is driven by the turbine and converts mechanical energy into electrical energy.

  19. Multi-objective optimization of organic Rankine cycle power plants using pure and mixed working fluids

    DEFF Research Database (Denmark)

    Andreasen, Jesper Graa; Kærn, Martin Ryhl; Pierobon, Leonardo

    2015-01-01

    For zeotropic mixtures, the temperature varies during phase change, which is opposed to the isothermalphase change of pure fluids. The use of such mixtures as working fluids in organic Rankine cyclepower plants enables a minimization of the mean temperature difference of the heat exchangers whenthe...... mixturesare usually degraded compared to an ideal mixture heat transfer coefficient linearly interpolatedbetween the pure fluid values. This entails a need for larger and more expensive heat exchangers. Previousstudies primarily focus on the thermodynamic benefits of zeotropic mixtures by employing firstand...... second law analyses. In order to assess the feasibility of using zeotropic mixtures, it is, however,important to consider the additional costs of the heat exchangers. In this study, we aim at evaluatingthe economic feasibility of zeotropic mixtures compared to pure fluids. We carry out a multi...

  20. Comparative investigation of working fluids for an organic Rankine cycle with geothermal water

    Science.gov (United States)

    Liu, Yan-Na; Xiao, Song

    2015-06-01

    In this paper, the thermodynamic investigation on the use of geothermal water (130 °C as maximum) for power generation through a basic Rankine has been presented together with obtained main results. Six typical organic working fluids (i.e., R245fa, R141b, R290, R600, R152a, and 134a) were studied with modifying the input pressure and temperature to the turbine. The results show that there are no significant changes taking place in the efficiency for these working fluids with overheating the inlet fluid to the turbine, i.e., efficiency is a weak function of temperature. However, with the increasing of pressure ratio in the turbine, the efficiency rises more sharply. The technical viability is shown of implementing this type of process for recovering low temperature heat resource.

  1. Thermal-Economic Modularization of Small, Organic Rankine Cycle Power Plants for Mid-Enthalpy Geothermal Fields

    Directory of Open Access Journals (Sweden)

    Yodha Y. Nusiaputra

    2014-07-01

    Full Text Available The costs of the surface infrastructure in mid-enthalpy geothermal power systems, especially in remote areas, could be reduced by using small, modular Organic Rankine Cycle (ORC power plants. Thermal-economic criteria have been devised to standardize ORC plant dimensions for such applications. We designed a modular ORC to utilize various wellhead temperatures (120–170 °C, mass flow rates and ambient temperatures (−10–40 °C. A control strategy was developed using steady-state optimization, in order to maximize net power production at off-design conditions. Optimum component sizes were determined using specific investment cost (SIC minimization and mean cashflow (MCF maximization for three different climate scenarios. Minimizing SIC did not yield significant benefits, but MCF proved to be a much better optimization function.

  2. Experimental study on Rankine cycle evaporator efficiency intended for exhaust waste heat recovery of a diesel engine

    Directory of Open Access Journals (Sweden)

    Milkov Nikolay

    2017-01-01

    Full Text Available The paper pressents an experimental study of Rankine cycle evaporator efficiency. Water was chosen as the working fluid in the system. The experimental test was conducted on a test bench equipped with a burner charged by compressed fresh air. Generated exhaust gases parameters were previously determined over the diesel engine operating range (28 engine operating points were studied. For each test point the working fluid parameters (flow rate and evaporating pressure were varied. Thus, the enthalpy flow through the heat exchanger was determined. Heat exchanger was designed as 23 helical tubes are inserted. On the basis of the results, it was found out that efficiency varies from 25 % to 51,9 %. The optimal working fluid pressure is 20 bar at most of the operating points while the optimum fluid mass flow rate varies from 2 g/s to 10 g/s.

  3. Study on the Characteristics of Expander Power Output Used for Offsetting Pumping Work Consumption in Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Yu-Ting Wu

    2014-07-01

    Full Text Available The circulation pump in an organic Rankine cycle (ORC increases the pressure of the liquid working fluid from low condensing pressure to high evaporating pressure, and the expander utilizes the pressure difference to generate work. A portion of the expander output power is used to offset the consumed pumping work, and the rest of the expander power is exactly the net work produced by the ORC system. Because of the relatively great theoretical pumping work and very low efficiency of the circulation pump reported in previous papers, the characteristics of the expander power used for offsetting the pumping work need serious consideration. In particular, the present work examines those characteristics. It is found that the characteristics of the expander power used for offsetting the pumping work are satisfactory only under the condition that the working fluid absorbs sufficient heat in the evaporator and its specific volume at the evaporator outlet is larger than or equal to a threshold value.

  4. Structural optimisation of a high speed Organic Rankine Cycle generator using a genetic algorithm and a finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Palko, S. [Machines Division, ABB industry Oy, Helsinki (Finland)

    1997-12-31

    The aim in this work is to design a 250 kW high speed asynchronous generator using a genetic algorithm and a finite element method for Organic Rankine Cycle. The characteristics of the induction motors are evaluated using two-dimensional finite element method (FEM) The movement of the rotor and the non-linearity of the iron is included. In numerical field problems it is possible to find several local extreme for an optimisation problem, and therefore the algorithm has to be capable of determining relevant changes, and to avoid trapping to a local minimum. In this work the electromagnetic (EM) losses at the rated point are minimised. The optimisation includes the air gap region. Parallel computing is applied to speed up optimisation. (orig.) 2 refs.

  5. Exergy analysis of an integrated solid oxide fuel cell and organic Rankine cycle for cooling, heating and power production

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiman, Fahad A. [Mechanical and Aerospace Engineering Department, Carleton University 1125 Colonel By Drive, Ottawa, Ontario (Canada); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology 2000 Simcoe Street North, Oshawa, Ontario (Canada); Hamdullahpur, Feridun [Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, Ontario (Canada)

    2010-04-15

    The study examines a novel system that combined a solid oxide fuel cell (SOFC) and an organic Rankine cycle (ORC) for cooling, heating and power production (trigeneration) through exergy analysis. The system consists of an SOFC, an ORC, a heat exchanger and a single-effect absorption chiller. The system is modeled to produce a net electricity of around 500 kW. The study reveals that there is 3-25% gain on exergy efficiency when trigeneration is used compared with the power cycle only. Also, the study shows that as the current density of the SOFC increases, the exergy efficiencies of power cycle, cooling cogeneration, heating cogeneration and trigeneration decreases. In addition, it was shown that the effect of changing the turbine inlet pressure and ORC pump inlet temperature are insignificant on the exergy efficiencies of the power cycle, cooling cogeneration, heating cogeneration and trigeneration. Also, the study reveals that the significant sources of exergy destruction are the ORC evaporator, air heat exchanger at the SOFC inlet and heating process heat exchanger. (author)

  6. Selection of cooling fluid for an organic Rankine cycle unit recovering heat on a container ship sailing in the Arctic region

    DEFF Research Database (Denmark)

    Suárez de la Fuente, Santiago; Larsen, Ulrik; Pierobon, Leonardo

    2017-01-01

    air as coolant. This paper explores the use of two different coolants, air and seawater, for an organic Rankine cycle (ORC) unit using the available waste heat in the scavenge air system of a container ship navigating in Arctic Circle. Using a two-step single objective optimisation process, detailed...

  7. Performance Evaluation of a HP/ORC (Heat Pump/Organic Rankine Cycle) System with Optimal Control of Sensible Thermal Storage

    DEFF Research Database (Denmark)

    Carmo, Carolina; Nielsen, Mads P.; Elmegaard, Brian

    2016-01-01

    come to contribute to the integration of intermittent renewables.This paper describes an innovative concept that consists of the addition of an Organic Rankine Cycle (ORC) toa combined solar system coupled to a ground-source heat pump (HP) in a single-family building. The ORC enables the use of solar...

  8. Preliminary Development of a Free Piston Expander–Linear Generator for Small-Scale Organic Rankine Cycle (ORC Waste Heat Recovery System

    Directory of Open Access Journals (Sweden)

    Gaosheng Li

    2016-04-01

    Full Text Available A novel free piston expander-linear generator (FPE-LG integrated unit was proposed to recover waste heat efficiently from vehicle engine. This integrated unit can be used in a small-scale Organic Rankine Cycle (ORC system and can directly convert the thermodynamic energy of working fluid into electric energy. The conceptual design of the free piston expander (FPE was introduced and discussed. A cam plate and the corresponding valve train were used to control the inlet and outlet valve timing of the FPE. The working principle of the FPE-LG was proven to be feasible using an air test rig. The indicated efficiency of the FPE was obtained from the p–V indicator diagram. The dynamic characteristics of the in-cylinder flow field during the intake and exhaust processes of the FPE were analyzed based on Fluent software and 3D numerical simulation models using a computation fluid dynamics method. Results show that the indicated efficiency of the FPE can reach 66.2% and the maximal electric power output of the FPE-LG can reach 22.7 W when the working frequency is 3 Hz and intake pressure is 0.2 MPa. Two large-scale vortices are formed during the intake process because of the non-uniform distribution of velocity and pressure. The vortex flow will convert pressure energy and kinetic energy into thermodynamic energy for the working fluid, which weakens the power capacity of the working fluid.

  9. Organic Rankine-cycle power systems working fluids study: Topical report No. 1: Fluorinol 85. [85 mole % trofluoroethanol in water

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.L.; Demirgian, J.C.; Cole, R.L.

    1986-09-01

    An investigation to experimentally determine the thermal stability limits and degradation rates of Fluorinol 85 as a function of maximum cycle temperatures was initiated in 1982. Following the design and construction of a dynamic test loop capable of simulating the thermodynamic conditions of possible prototypical organic Rankine-cycle (ORC) power systems, several test runs were completed. The Fluorinol 85 test loop was operated for about 3800 h, covering a temperature range of 525-600/sup 0/F. Both liquid and noncondensable vapor (gas) samples were drawn periodically and analyzed using capillary column gas chromatography, gas chromatography/mass spectrometry and mass spectrometry. Results indicate that Fluorinol 85 would not decompose significantly over an extended period of time, up to a maximum cycle temperature of 550/sup 0/F. However, 506-h data at 575/sup 0/F show initiation of significant degradation. The 770-h data at 600/sup 0/F, using a fresh charge of Fluorinol 85, indicate an annual degradation rate of more than 17.2%. The most significant degradation product observed is hydrofluoric acid, which could cause severe corrosion in an ORC system. Devices to remove the hydrofluoric acid and prevent extreme temperature excursions are necessary for any ORC system using Fluorinol 85 as a working fluid.

  10. Conversion of Low Quality Waste Heat to Electric Power with Small-Scale Organic Rankine Cycle (ORC) Engine/Generator Technology

    Science.gov (United States)

    2016-08-01

    Small-Scale W912H0-12-C-0059 Organic Rankine Cycle (ORC) Engine /Generator Technology 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( SI 5d...same fuel input. This value is used for calculation of Greenhouse Gas (GHG) reductions and economic results. Life cycle economics of the system are...associated with engine and other electric generator systems , waste heat from steam or heat distribution, waste heat from boiler exhausts, and heat

  11. Low-Concentration Solar-Power Systems based on Organic Rankine Cycles for Distributed-Scale Applications:Overview and Further Developments

    Directory of Open Access Journals (Sweden)

    Christos N. Markides

    2015-12-01

    Full Text Available This paper is concerned with the emergence and development of low- to medium-grade thermal-energy conversion systems for distributed power generation based on thermodynamic vapour-phase heat-engine cycles undergone by organic working-fluids, namely organic Rankine cycles (ORCs. ORC power systems are, to some extent, a relatively established and mature technology that is well-suited to converting low-/medium-grade heat (at temperatures up to ~ 300 – 400 °C to useful work, at an output power scale from a few kW to 10s of MW. Thermal efficiencies in excess of 25% are achievable at higher temperatures and larger scales, and efforts are currently in progress to improve the overall economic viability, and thus uptake, of ORC power systems by focusing on advanced architectures, working-fluid selection, heat exchangers and expansion machines. Solar-power systems based on ORC technology have a significant potential to be used for distributed power generation, by converting thermal energy from simple and low-cost non-concentrated or low-concentration collectors to mechanical, hydraulic or electrical energy. Current fields of use include mainly geothermal and biomass/biogas, as well as the recovery and conversion of waste heat, leading to improved energy efficiency, primary energy (i.e. fuel use and emission minimization, yet the technology is highly transferable to solar power generation as an affordable alternative to small- to medium-scale photovoltaic (PV systems. Solar-ORC systems offer naturally the advantages of providing a simultaneous thermal-energy output for hot water provision and/or space heating, and the particularly interesting possibility of relatively straightforward on-site (thermal energy storage. Key performance characteristics are presented, and important heat transfer effects that act to limit performance are identified as noteworthy directions of future research for the further development of this technology.

  12. Performance Analysis and Working Fluid Selection of a Supercritical Organic Rankine Cycle for Low Grade Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Yourong Li

    2012-08-01

    Full Text Available The performance analysis of a supercritical organic Rankine cycle system driven by exhaust heat using 18 organic working fluids is presented. Several parameters, such as the net power output, exergy efficiency, expander size parameter (SP, and heat exchanger requirement of evaporator and the condenser, were used to evaluate the performance of this recovery cycle and screen the working fluids. The results reveal that in most cases, raising the expander inlet temperature is helpful to improve the net power output and the exergy efficiency. However, the effect of the expander inlet pressure on those parameters is related to the expander inlet temperature and working fluid used. Either lower expander inlet temperature and pressure, or higher expander inlet temperature and pressure, generally makes the net power output more. Lower expander inlet temperature results in larger total heat transfer requirement and expander size. According to the screening criteria of both the higher output and the lower investment, the following working fluids for the supercritical ORC system are recommended: R152a and R143a.

  13. Thermo-Economic Analysis of Zeotropic Mixtures and Pure Working Fluids in Organic Rankine Cycles for Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Florian Heberle

    2016-03-01

    Full Text Available We present a thermo-economic analysis of an Organic Rankine Cycle (ORC for waste heat recovery. A case study for a heat source temperature of 150 °C and a subcritical, saturated cycle is performed. As working fluids R245fa, isobutane, isopentane, and the mixture of isobutane and isopentane are considered. The minimal temperature difference in the evaporator and the condenser, as well as the mixture composition are chosen as variables in order to identify the most suitable working fluid in combination with optimal process parameters under thermo-economic criteria. In general, the results show that cost-effective systems have a high minimal temperature difference ΔTPP,C at the pinch-point of the condenser and a low minimal temperature difference ΔTPP,E at the pinch-point of the evaporator. Choosing isobutane as the working fluid leads to the lowest costs per unit exergy with 52.0 €/GJ (ΔTPP,E = 1.2 K; ΔTPP,C = 14 K. Considering the major components of the ORC, specific costs range between 1150 €/kW and 2250 €/kW. For the zeotropic mixture, a mole fraction of 90% isobutane leads to the lowest specific costs per unit exergy. A further analysis of the ORC system using isobutane shows high sensitivity of the costs per unit exergy for the selected cost estimation methods and for the isentropic efficiency of the turbine.

  14. Economic assessment of greenhouse gas reduction through low-grade waste heat recovery using organic Rankine cycle (ORC)

    Energy Technology Data Exchange (ETDEWEB)

    Imran, Muhammad; Park, Byung Sik; Kim, Hyouck Ju; Usman, Muhammad [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Dong Hyun [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2015-02-15

    Low-grade waste heat recovery technologies reduce the environmental impact of fossil fuels and improve overall efficiency. This paper presents the economic assessment of greenhouse gas (GHG) reduction through waste heat recovery using organic Rankine cycle (ORC). The ORC engine is one of the mature low temperature heat engines. The low boiling temperature of organic working fluid enables ORC to recover low-temperature waste heat. The recovered waste heat is utilized to produce electricity and hot water. The GHG emissions for equivalent power and hot water from three fossil fuels-coal, natural gas, and diesel oil-are estimated using the fuel analysis approach and corresponding emission factors. The relative decrease in GHG emission is calculated using fossil fuels as the base case. The total cost of the ORC system is used to analyze the GHG reduction cost for each of the considered fossil fuels. A sensitivity analysis is also conducted to investigate the effect of the key parameter of the ORC system on the cost of GHG reduction. Throughout the 20-year life cycle of the ORC plant, the GHG reduction cost for R245fa is 0.02 $/kg to 0.04 $/kg and that for pentane is 0.04 $/kg to 0.05 $/kg. The working fluid, evaporation pressure, and pinch point temperature difference considerably affect the GHG emission.

  15. Design of organic Rankine cycle power systems accounting for expander performance

    DEFF Research Database (Denmark)

    La Seta, Angelo; Andreasen, Jesper Graa; Pierobon, Leonardo

    2015-01-01

    -loaded stages in supersonic flow regimes. This paper proposes a design method where the conventional cycle analysis is combined with calculations of the maximum expander performance using a validated mean-line design tool. The high computational cost of the turbine optimization is tackled building a model which...

  16. Modelling the Influence of Climate on the Performance of the Organic Rankine Cycle for Industrial Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Ivan Korolija

    2016-05-01

    Full Text Available This paper describes a study of the relative influences of different system design decisions upon the performance of an organic Rankine cycle (ORC used to generate electricity from foundry waste heat. The design choices included concern the working fluid, whether to use a regenerator and the type of condenser. The novelty of the research lies in its inclusion of the influence of both the ORC location and the auxiliary electricity used by the pumps and fans in the ORC power system. Working fluids suitable for high temperature applications are compared, including three cyclic siloxanes, four linear siloxanes and three aromatic fluids. The ORC is modelled from first principles and simulation runs carried out using weather data for 106 European locations and a heat input profile that was derived from empirical data. The impact of design decisions upon ORC nominal efficiency is reported followed by the impact upon annual system efficiency in which variations in heat input and the condition of outdoor air over a year are considered. The main conclusion is that the location can have a significant impact upon the efficiency of ORC systems due to the influence of climate upon the condenser and auxiliary electricity requirements.

  17. Performance of Siloxane Mixtures in a High-Temperature Organic Rankine Cycle Considering the Heat Transfer Characteristics during Evaporation

    Directory of Open Access Journals (Sweden)

    Theresa Weith

    2014-08-01

    Full Text Available The application of the Organic Rankine Cycle to high temperature heat sources is investigated on the case study of waste heat recovery from a selected biogas plant. Two different modes of operation are distinguished: pure electric power and combined heat and power generation. The siloxanes hexamethyldisiloxane (MM and octamethyltrisiloxane (MDM are chosen as working fluids. Moreover, the effect of using mixtures of these components is analysed. Regarding pure electricity generation, process simulations using the simulation tool Aspen Plus show an increase in second law efficiency of 1.3% in case of 97/03 wt % MM/MDM-mixture, whereas for the combined heat and power mode a 60/40 wt % MM/MDM-mixture yields the highest efficiency with an increase of nearly 3% compared to most efficient pure fluid. Next to thermodynamic analysis, measurements of heat transfer coefficients of these siloxanes as well as their mixtures are conducted and Kandlikar’s correlation is chosen to describe the results. Based on that, heat exchanger areas for preheater and evaporator are calculated in order to check whether the poorer heat transfer characteristics of mixtures devalue their efficiency benefit due to increased heat transfer areas. Results show higher heat transfer areas of 0.9% and 14%, respectively, compared to MM.

  18. Preliminary design of seawater and brackish water reverse osmosis desalination systems driven by low-temperature solar organic Rankine cycles (ORC)

    Energy Technology Data Exchange (ETDEWEB)

    Delgado-Torres, Agustin M. [Dpto. Fisica Fundamental y Experimental, Electronica y Sistemas, Escuela Tecnica Superior de Ingenieria Civil e Industrial, Universidad de La Laguna (ULL), Avda. Astrofisico Francisco Sanchez s/n. 38206 La Laguna (Tenerife) (Spain); Garcia-Rodriguez, Lourdes [Dpto. Ingenieria Energetica, Universidad de Sevilla Escuela Tecnica Superior de Ingenieros, Camino de los Descubrimientos, s/n 41092 Sevilla (Spain)

    2010-12-15

    In this paper, the coupling between the low-temperature solar organic Rankine cycle (ORC) and seawater and brackish water reverse osmosis desalination units has been carried out. Four substances have been considered as working fluids of the solar cycle (butane, isopentane, R245fa and R245ca). With these four fluids the volumetric flow of fresh water produced per unit of aperture area of stationary solar collector has been calculated. The former has been made with the optimized direct vapour generation (DVG) configuration and heat transfer fluid (HTF) configuration of the solar ORC. In the first one (DVG), working fluid of the ORC is directly heated inside the absorber of the solar collector. In the second one (HTF), a fluid different than the working fluid of the ORC (water in this paper) is heated without phase change inside the absorber of the solar collector. Once this fluid has been heated it is carried towards a heat exchanger where it is cooled. Thermal energy delivered in this cooling process is transferred to the working fluid of the ORC. Influence of condensation temperature of the ORC and regeneration's process effectiveness over productivity of the system has also been analysed. Finally, parameters of several preliminary designs of the low-temperature solar thermal driven RO desalination are supplied. R245fa is chosen as working fluid of the ORC in these preliminary designs. The information of the proposed preliminary designs can also be used, i.e., for the assessment of the use of thermal energy rejected by the solar cycle. Overall analysis of the efficiency of the solar thermal driven RO desalination technology is given with the results presented in this paper and the results obtained with the medium temperature solar thermal RO desalination system presented by the authors in previous papers. This work has been carried out within the framework of the OSMOSOL and POWERSOL projects. (author)

  19. Optimization of Biomass-Fuelled Combined Cooling, Heating and Power (CCHP) Systems Integrated with Subcritical or Transcritical Organic Rankine Cycles (ORCs)

    OpenAIRE

    Daniel Maraver; Sylvain Quoilin; Javier Royo

    2014-01-01

    This work is focused on the thermodynamic optimization of Organic Rankine Cycles (ORCs), coupled with absorption or adsorption cooling units, for combined cooling heating and power (CCHP) generation from biomass combustion. Results were obtained by modelling with the main aim of providing optimization guidelines for the operating conditions of these types of systems, specifically the subcritical or transcritical ORC, when integrated in a CCHP system to supply typical heating and cooling deman...

  20. Flow boiling heat transfer and pressure drop characteristics of R134a, R1234yf and R1234ze in a plate heat exchanger for organic Rankine cycle units

    DEFF Research Database (Denmark)

    Zhang, Ji; Desideri, Adriano; Kærn, Martin Ryhl

    2017-01-01

    . This paper is aimed at obtaining flow boiling heat transfer and pressure drop characteristics in a plate heat exchanger under the working conditions prevailing in the evaporator of organic Rankine cycle units. Two hydrofluoroolefins R1234yf and R1234ze, and one hydrofluorocarbon R134a, were selected......The optimal design of the evaporator is one of the key issues to improve the efficiency and economics of organic Rankine cycle units. The first step in studying the evaporator design is to understand the thermal-hydraulic performance of the working fluid in the evaporator of organic Rankine cycles......, respectively. The working conditions covered relatively high saturation temperatures (corresponding reduced pressures of 0.35-0.74), which are prevailing in organic Rankine cycles yet absent in the open literature. The experimental data were compared with existing correlations, and new correlations were...

  1. Studi Numerik Dua Dimensi Labyrinth Seal Turbin Uap Organic Rankine Cycle (ORC Type Straight-Through dengan Variasi Tekanan Inlet, Kecepatan Putaran Poros, Jarak Pitch, dan Tinggi Rongga

    Directory of Open Access Journals (Sweden)

    Fungki Setyo Yulianto

    2013-03-01

    Full Text Available ORC (Organic Rankine Cycle merupakan salah satu sistem pembangkit tenaga yang mampu memanfaatkan waste energy dengan menggunakan fluida organik yang mampu menguap pada temperatur dan tekanan rendah. Salah satu komponen utama pada sistem ORC adalah Turbin. Untuk mendapatkan efisiensi yang maksimal,  kebocoran fluida pada turbin uap harus di minimalisir. Untuk itulah di perlukan penggunaan labyrinth seal untuk mengurai kebocoran fluida R123 pada turbin uap ORC. Pada dunia Industri jenis labyrinth seal sangat banyak sekali, salah satunya adalah labyrinth seal tipe Straight-Through. Penelitian ini dilakukan dengan metode numerik (CFD software Fluent. Penelitian ini menggunakan variasi tekanan inlet yaitu 5, 10 dan 15 bar, putaran poros 0, 1500 dan 3000 rpm, panjang pitch 4 mm, 6 mm, 8 mm, 10 mm, serta tinggi rongga 3,415 mm, 3,915 mm dan 5,915 mm. Simulasi menggunakan model turbulensi k-ε RNG. Pada variasi tekanan inlet laju kebocoran paling besar terjadi pada tekanan 15 bar. Pada variasi putaran poros laju kebocoran terjadi berubah secara signifikan pada setiap variasi. Pada variasi tinggi rongga laju kebocoran paling kecil terjadi pada tinggi rongga 3,415 mm. Pada variasi panjang pitch, laju kebocoran paling kecil terjadi pada panjang pitch 10 mm.

  2. Effect of variable heat input on the heat transfer characteristics in an Organic Rankine Cycle system

    Directory of Open Access Journals (Sweden)

    Aboaltabooq Mahdi Hatf Kadhum

    2016-01-01

    Full Text Available This paper analyzes the heat transfer characteristics of an ORC evaporator applied on a diesel engine using measured data from experimental work such as flue gas mass flow rate and flue gas temperature. A mathematical model was developed with regard to the preheater, boiler and the superheater zones of a counter flow evaporator. Each of these zones has been subdivided into a number of cells. The hot source of the ORC cycle was modeled. The study involves the variable heat input's dependence on the ORC system's heat transfer characteristics, with especial emphasis on the evaporator. The results show that the refrigerant's heat transfer coefficient has a higher value for a 100% load from the diesel engine, and decreases with the load decrease. Also, on the exhaust gas side, the heat transfer coefficient decreases with the decrease of the load. The refrigerant's heat transfer coefficient increased normally with the evaporator's tube length in the preheater zone, and then increases rapidly in the boiler zone, followed by a decrease in the superheater zone. The exhaust gases’ heat transfer coefficient increased with the evaporator’ tube length in all zones. The results were compared with result by other authors and were found to be in agreement.

  3. Comparison of a Novel Organic-Fluid Thermofluidic Heat Converter and an Organic Rankine Cycle Heat Engine

    Directory of Open Access Journals (Sweden)

    Christoph J.W. Kirmse

    2016-06-01

    Full Text Available The Up-THERM heat converter is an unsteady, two-phase thermofluidic oscillator that employs an organic working fluid, which is currently being considered as a prime-mover in small- to medium-scale combined heat and power (CHP applications. In this paper, the Up-THERM heat converter is compared to a basic (sub-critical, non-regenerative organic Rankine cycle (ORC heat engine with respect to their power outputs, thermal efficiencies and exergy efficiencies, as well as their capital and specific costs. The study focuses on a pre-specified Up-THERM design in a selected application, a heat-source temperature range from 210 °C to 500 °C and five different working fluids (three n-alkanes and two refrigerants. A modeling methodology is developed that allows the above thermo-economic performance indicators to be estimated for the two power-generation systems. For the chosen applications, the power output of the ORC engine is generally higher than that of the Up-THERM heat converter. However, the capital costs of the Up-THERM heat converter are lower than those of the ORC engine. Although the specific costs (£/kW of the ORC engine are lower than those of the Up-THERM converter at low heat-source temperatures, the two systems become progressively comparable at higher temperatures, with the Up-THERM heat converter attaining a considerably lower specific cost at the highest heat-source temperatures considered.

  4. Performance Evaluation of HP/ORC (Heat Pump/Organic Rankine Cycle) System with Optimal Control of Sensible Thermal Storage

    DEFF Research Database (Denmark)

    Do Carmo, Carolina Madeira Ramos; Dumont, Olivier; Nielsen, Mads Pagh

    2016-01-01

    energy in periods of no thermal energy demand and reverses the heat pump cycle to supply electrical power. A dynamic model based on empirical data of this system is used to determine the annual performance. Furthermore, this work assesses the benefits of different control strategies that address...... of the users. Results show that real load control logic can lessen the adverse effects of cycling in the compressor of the system as well as increase the thermal demand (up to 33%) and the electrical demand (max. 8.4%) covered by renewable energy (solar). However, the extension of these improvements is highly...

  5. Design and development of an automotive organic Rankine-cycle powerplant with a reciprocating expander. Final report. Volume II. Detailed discussion

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    Work performed for the design and development of an organic Rankine-cycle engine for automobile propulsion is reported. An automotive power plant using an organic Rankine-cycle system with a reciprocating expander has been designed, built, and tested on an engine dynamometer in a preprototype configuration. The system is designed to provide performance approximately equivalent to that of a 351-CID internal combustion engine in the reference car, a 1972 Ford Galaxie 500. A description of the preprototype system, major components, and results from component and system testing are presented. The fuel economy based on steady-state measurements is estimated to be 10.2 mpg over the federal driving cycle with a maximum of 16 mpg at 30 mph. Projections of steady-state emission measurements show compliance with the 1970 Clean Air Act standards for 1978 vehicle emissions. The levels for unburned hydrocarbons, carbon monoxide, and oxides of nitrogen were 41 percent, 6 percent, and 69 percent of the standards, respectively. At the conclusion of the preprototype phase of the program, a prototype design effort was initiated to upgrade and improve the performance of the preprototype system. The reference vehicle for this prototype design is a compact car in the weight class of a 1974 Ford Pinto. The results of this design study, including performance projections, are also presented.

  6. Energetic and exergetic analysis of Rankine cycles for solar power plants with parabolic trough and thermal storage

    Directory of Open Access Journals (Sweden)

    Cenuşă Victor-Eduard

    2016-01-01

    Full Text Available The paper analyzes the “secondary” circuit (for thermodynamic conversion of a Concentrated Solar Power (CSP plant with thermodynamic cycle, whose mirrors field supplies a thermal power, averaged over a sunny day, of about 100 MW heat. We study the case of parabolic trough solar collector using silicone oil in the “primary” circuit, which limits the peak temperature below 400 °C. The “primary” circuit uses thermal storage, allowing a delay between the power generation in rapport with the solar energy capture. We choose a water-steam cycle, type Hirn. For increasing its efficiency, it has regenerative feed water preheating and steam reheating. We compared, energetic and exergetic, two types of cycles, using a numerical model with iterative structure, developed by the authors. The results showed that the simplified design achieves practically the same thermodynamic performances with the advanced one.

  7. The dish-Rankine SCSTPE program (Engineering Experiment no. 1)

    Science.gov (United States)

    Pons, R. L.; Grigsby, C. E.

    1980-05-01

    Activities planned for phase 2 Of the Small Community Solar Thermal Power Experiment (PFDR) program are summarized with emphasis on a dish-Rankine point focusing distributed receiver solar thermal electric system. Major design efforts include: (1) development of an advanced concept indirect-heated receiver;(2) development of hardware and software for a totally unmanned power plant control system; (3) implementation of a hybrid digital simulator which will validate plant operation prior to field testing; and (4) the acquisition of an efficient organic Rankine cycle power conversion unit. Preliminary performance analyses indicate that a mass-produced dish-Rankine PFDR system is potentially capable of producing electricity at a levelized busbar energy cost of 60 to 70 mills per KWh and with a capital cost of about $1300 per KW.

  8. A Mathematical Model of Hourly Solar Radiation in Varying Weather Conditions for a Dynamic Simulation of the Solar Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Taehong Sung

    2015-07-01

    Full Text Available A mathematical model of hourly solar radiation with weather variability is proposed based on the simple sky model. The model uses a superposition of trigonometric functions with short and long periods. We investigate the effects of the model variables on the clearness (kD and the probability of persistence (POPD indices and also evaluate the proposed model for all of the kD-POPD weather classes. A simple solar organic Rankine cycle (SORC system with thermal storage is simulated using the actual weather conditions, and then, the results are compared with the simulation results using the proposed model and the simple sky model. The simulation results show that the proposed model provides more accurate system operation characteristics than the simple sky model.

  9. Preliminary Design of Compact Condenser in an Organic Rankine Cycle System for the Low Grade Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Roberto Capata

    2014-11-01

    Full Text Available The aim of this paper is to present a thermodynamic cycle for the production of electrical power in the 2–5 kW range, suitable for all types of thermally propelled vehicles. The sensible heat recovered from the exhaust gases feeds the energy recovery system, which is able to produce sufficient power to sustain the air conditioning system or other auxiliaries. The working fluids R134a and R245fa have been used in the ORC system, and the systems are simulated by CAMEL-ProTM software. The cycles are generated starting from the same heat source: the exhaust gas of a typical 2.0 L Diesel engine (or from a small size turbine engine. The design of the condenser has been performed to obtain a very compact component, evaluating the heat exchanger tube and fins type design. Through empirical formulas, the area of heat exchange, the heat required to exchange and the pressure drop in the element have been calculated. A commercial software package is used to build the model of the condenser, then a thermal and mechanical analysis and a CFD analysis are realized to estimate the heat exchange. Finally the evaluations, the possible future studies and possible improvements of the system are shown.

  10. Test Requirements and Conceptual Design for a Potassium Test Loop to Support an Advanced Potassium Rankine Cycle Power Conversion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, JR.G.L.

    2006-03-08

    Parameters for continuing the design and specification of an experimental potassium test loop are identified in this report. Design and construction of a potassium test loop is part of the Phase II effort of the project ''Technology Development Program for an Advanced Potassium Rankine Power Conversion System''. This program is supported by the National Aeronautics and Space Administration. Design features for the potassium test loop and its instrumentation system, specific test articles, and engineered barriers for ensuring worker safety and protection of the environment are described along with safety and environmental protection requirements to be used during the design process. Information presented in the first portion of this report formed the basis to initiate the design phase of the program; however, the report is a living document that can be changed as necessary during the design process, reflecting modifications as additional design details are developed. Some portions of the report have parameters identified as ''to be determined'' (TBD), reflecting the early stage of the overall process. In cases where specific design values are presently unknown, the report attempts to document the quantities that remain to be defined in order to complete the design of the potassium test loop and supporting equipment.

  11. Thermo-Economic and Heat Transfer Optimization of Working-Fluid Mixtures in a Low-Temperature Organic Rankine Cycle System

    Directory of Open Access Journals (Sweden)

    Oyeniyi A. Oyewunmi

    2016-06-01

    Full Text Available In the present paper, we consider the employment of working-fluid mixtures in organic Rankine cycle (ORC systems with respect to thermodynamic and heat-transfer performance, component sizing and capital costs. The selected working-fluid mixtures promise reduced exergy losses due to their non-isothermal phase-change behaviour, and thus improved cycle efficiencies and power outputs over their respective pure-fluid components. A multi-objective cost-power optimization of a specific low-temperature ORC system (operating with geothermal water at 98 °C reveals that the use of working-fluid-mixtures does indeed show a thermodynamic improvement over the pure-fluids. At the same time, heat transfer and cost analyses, however, suggest that it also requires larger evaporators, condensers and expanders; thus, the resulting ORC systems are also associated with higher costs. In particular, 50% n-pentane + 50% n-hexane and 60% R-245fa + 40% R-227ea mixtures lead to the thermodynamically optimal cycles, whereas pure n-pentane and pure R-245fa have lower plant costs, both estimated as having ∼14% lower costs per unit power output compared to the thermodynamically optimal mixtures. These conclusions highlight the importance of using system cost minimization as a design objective for ORC plants.

  12. Rankine-Brayton engine powered solar thermal aircraft

    Science.gov (United States)

    Bennett, Charles L [Livermore, CA

    2009-12-29

    A solar thermal powered aircraft powered by heat energy from the sun. A Rankine-Brayton hybrid cycle heat engine is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller or other mechanism for enabling sustained free flight. The Rankine-Brayton engine has a thermal battery, preferably containing a lithium-hydride and lithium mixture, operably connected to it so that heat is supplied from the thermal battery to a working fluid. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

  13. A quantitative risk-assessment system (QR-AS) evaluating operation safety of Organic Rankine Cycle using flammable mixture working fluid.

    Science.gov (United States)

    Tian, Hua; Wang, Xueying; Shu, Gequn; Wu, Mingqiang; Yan, Nanhua; Ma, Xiaonan

    2017-09-15

    Mixture of hydrocarbon and carbon dioxide shows excellent cycle performance in Organic Rankine Cycle (ORC) used for engine waste heat recovery, but the unavoidable leakage in practical application is a threat for safety due to its flammability. In this work, a quantitative risk assessment system (QR-AS) is established aiming at providing a general method of risk assessment for flammable working fluid leakage. The QR-AS covers three main aspects: analysis of concentration distribution based on CFD simulations, explosive risk assessment based on the TNT equivalent method and risk mitigation based on evaluation results. A typical case of propane/carbon dioxide mixture leaking from ORC is investigated to illustrate the application of QR-AS. According to the assessment results, proper ventilation speed, safe mixture ratio and location of gas-detecting devices have been proposed to guarantee the security in case of leakage. The results revealed that this presented QR-AS was reliable for the practical application and the evaluation results could provide valuable guidance for the design of mitigation measures to improve the safe performance of ORC system. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Experimental Assessment of a Helical Coil Heat Exchanger Operating at Subcritical and Supercritical Conditions in a Small-Scale Solar Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Marija Lazova

    2017-05-01

    Full Text Available In this study, the performance of a helical coil heat exchanger operating at subcritical and supercritical conditions is analysed. The counter-current heat exchanger was specially designed to operate at a maximal pressure and temperature of 42 bar and 200 °C, respectively. The small-scale solar organic Rankine cycle (ORC installation has a net power output of 3 kWe. The first tests were done in a laboratory where an electrical heater was used instead of the concentrated photovoltaic/thermal (CPV/T collectors. The inlet heating fluid temperature of the water was 95 °C. The effects of different parameters on the heat transfer rate in the heat exchanger were investigated. Particularly, the performance analysis was elaborated considering the changes of the mass flow rate of the working fluid (R-404A in the range of 0.20–0.33 kg/s and the inlet pressure varying from 18 bar up to 41 bar. Hence, the variation of the heat flux was in the range of 5–9 kW/m2. The results show that the working fluid’s mass flow rate has significant influence on the heat transfer rate rather than the operational pressure. Furthermore, from the comparison between the experimental results with the heat transfer correlations from the literature, the experimental results fall within the uncertainty range for the supercritical analysis but there is a deviation of the investigated subcritical correlations.

  15. Exergetic and environmental impact assessments of an integrated organic Rankine cycle with a biomass combustor for combined cooling, heating and power production

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiman, F.A. [Carleton Univ., Ottawa, ON (Canada). Dept. of Mechanical and Aerospace Engineering; Hamdullahpur, F. [Waterloo Univ., ON (Canada). Dept. of Mechanical and Mechatronics Engineering; Dincer, I. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

    2010-07-01

    A trigeneration thermal system produces cooling, heating and power from the same source. In trigeneration plants, waste heat is used for heating and cooling. In this paper, exergetic and environmental impact analyses of a trigeneration system based on an integrated organic Rankine cycle (ORC) with a biomass combustor were conducted. The analyses were extended to include electrical-power, cooling-cogeneration and heating-cogeneration cases. The objective was to understand the working phenomena of the proposed system, and identify and quantify the sources of the irreversibilities in the system associated with each component. The environmental impact of the proposed system was also quantified. The exergy efficiency, exergy destruction rate and carbon dioxide (CO{sub 2}) emissions were examined under the variations of pump inlet temperature and turbine inlet pressure. The results showed that exergy efficiency increased to 27 per cent when trigeneration was used as compared 11 per cent when the electrical power system was used. The main two sources of exergy destruction were the biomass combustor and the ORC evaporator. Emissions of CO{sub 2} were much higher in the case of the the electrical-power system compared to the trigeneration system. 11 refs., 1 tab., 8 figs.

  16. Ideal Point Design and Operation of CO2-Based Transcritical Rankine Cycle (CTRC System Based on High Utilization of Engine’s Waste Heats

    Directory of Open Access Journals (Sweden)

    Lingfeng Shi

    2017-10-01

    Full Text Available This research conducted a study specially to systematically analyze combined recovery of exhaust gas and engine coolant and related influence mechanism, including a detailed theoretical study and an assistant experimental study. In this research, CO2-based transcritical Rankine cycle (CTRC was used for fully combining the wastes heats. The main objective of theoretical research was to search an ‘ideal point’ of the recovery system and related influence mechanism, which was defined as operating condition of complete recovery of two waste heats. The theoretical methodology of this study could also provide a design reference for effective combined recovery of two or multiple waste heats in other fields. Based on a kW-class preheated CTRC prototype that was designed by the ‘ideal point’ method, an experimental study was conducted to verify combined utilization degree of two engine waste heats by the CTRC system. The operating results showed that the prototype can gain 44.4–49.8 kW and 22.7–26.7 kW heat absorption from exhaust gas and engine coolant, respectively. To direct practical operation, an experimental optimization work on the operating process was conducted for complete recovery of engine coolant exactly, which avoided deficient or excessive recovery.

  17. Thermodynamic Performance Analysis of a Biogas-Fuelled Micro-Gas Turbine with a Bottoming Organic Rankine Cycle for Sewage Sludge and Food Waste Treatment Plants

    Directory of Open Access Journals (Sweden)

    Sunhee Kim

    2017-02-01

    Full Text Available In the Republic of Korea, efficient biogas-fuelled power systems are needed to use the excess biogas that is currently burned due to a lack of suitable power technology. We examined the performance of a biogas-fuelled micro-gas turbine (MGT system and a bottoming organic Rankine cycle (ORC. The MGT provides robust operation with low-grade biogas, and the exhaust can be used for heating the biodigester. Similarly, the bottoming ORC generates additional power output with the exhaust gas. We selected a 1000-kW MGT for four co-digestion plants with 28,000-m3 capacity. A 150-kW ORC system was selected for the MGT exhaust gas. We analysed the effects of the system size, methane concentration, and ORC operating conditions. Based on the system performance, we analysed the annual performance of the MGT with a combined heat and power (CHP system, bottoming ORC, or both a bottoming ORC and CHP system. The annual net power outputs for each system were 7.4, 8.5, and 9.0 MWh per year, respectively.

  18. Geometry Analysis and Effect of Turbulence Model on the Radial Rotor Turbo-Expander Design for Small Organic Rankine Cycle System

    Directory of Open Access Journals (Sweden)

    Maulana Arifin

    2015-07-01

    Full Text Available Organic Rankine Cycle (ORC is one of the most promising technology for small electric power generations. The geometry analysis and the effect of turbulence model on the radial turbo-expanders design for small ORC power generation systems were discussed in this paper. The rotor blades and performance were calculated using several working fluids such as R134a, R143a, R245fa, n-Pentane, and R123. Subsequently, a numerical study was carried out in the fluid flow area with R134a and R123 as the working fluids. Analyses were performed using Computational Fluid Dynamics (CFD ANSYS Multiphysics on two real gas models, with the k-epsilon and SST (shear stress transport turbulence models. The result shows the distribution of Mach number, pressure, velocity and temperature along the rotor blade of the radial turbo-expanders and estimation of performance at various operating conditions. The operating conditions are as follow: 250,000 grid mesh flow area, real gas model SST at steady state condition, 0.4 kg/s of mass flow rate, 15,000 rpm rotor speed, 5 bar inlet pressure, and 373K inlet temperature. By using those conditions, CFD analysis shows that the turbo-expander able to produce 6.7 kW and 5.5 kW of power when using R134a and R123, respectively.

  19. Milestone Report #2: Direct Evaporator Leak and Flammability Analysis Modifications and Optimization of the Organic Rankine Cycle to Improve the Recovery of Waste Heat

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna Post [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-09-01

    The direct evaporator is a simplified heat exchange system for an Organic Rankine Cycle (ORC) that generates electricity from a gas turbine exhaust stream. Typically, the heat of the exhaust stream is transferred indirectly to the ORC by means of an intermediate thermal oil loop. In this project, the goal is to design a direct evaporator where the working fluid is evaporated in the exhaust gas heat exchanger. By eliminating one of the heat exchangers and the intermediate oil loop, the overall ORC system cost can be reduced by approximately 15%. However, placing a heat exchanger operating with a flammable hydrocarbon working fluid directly in the hot exhaust gas stream presents potential safety risks. The purpose of the analyses presented in this report is to assess the flammability of the selected working fluid in the hot exhaust gas stream stemming from a potential leak in the evaporator. Ignition delay time for cyclopentane at temperatures and pressure corresponding to direct evaporator operation was obtained for several equivalence ratios. Results of a computational fluid dynamic analysis of a pinhole leak scenario are given.

  20. Modeling and Experimental Validation of a Volumetric Expander Suitable for Waste Heat Recovery from an Automotive Internal Combustion Engine Using an Organic Rankine Cycle with Ethanol

    Directory of Open Access Journals (Sweden)

    José Galindo

    2016-04-01

    Full Text Available Waste heat recovery (WHR in exhaust gas flow of automotive engines has proved to be a useful path to increase the overall efficiency of internal combustion engines (ICE. Recovery potentials of up to 7% are shown in several works in the literature. However, most of them are theoretical estimations. Some present results from prototypes fed by steady flows generated in an auxiliary gas tank and not with actual engine exhaust gases. This paper deals with the modeling and experimental validation of an organic Rankine cycle (ORC with a swash-plate expander integrated in a 2 L turbocharged petrol engine using ethanol as working fluid. A global simulation model of the ORC was developed with a maximum difference of 5%, validated with experimental results. Considering the swash-plate as the main limiting factor, an additional specific submodel was implemented to model the physical phenomena in this element. This model allows simulating the fluid dynamic behavior of the swash-plate expander using a 0D model (Amesim. Differences up to 10.5% between tests and model results were found.

  1. Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2017-02-01

    Full Text Available Industrial waste heat recovery by means of an Organic Rankine Cycle (ORC can contribute to the reduction of CO2 emissions from industries. Before market penetration, high efficiency modular concepts have to be developed to achieve appropriate economic value for industrial decision makers. This paper aims to investigate modularly designed ORC systems from a thermoeconomic point of view. The main goal is a recommendation for a suitable chemical class of working fluids, preferable ORC design and a range of heat source temperatures and thermal capacities in which modular ORCs can be economically feasible. For this purpose, a thermoeconomic model has been developed which is based on size and complexity parameters of the ORC components. Special emphasis has been laid on the turbine model. The paper reveals that alkylbenzenes lead to higher exergetic efficiencies compared to alkanes and siloxanes. However, based on the thermoeconomic model, the payback periods of the chemical classes are almost identical. With the ORC design, the developed model and the boundary conditions of this study, hexamethyldisiloxane is a suitable working fluid and leads to a payback period of less than 5 years for a heat source temperature of 400 to 600 °C and a mass flow rate of the gaseous waste heat stream of more than 4 kg/s.

  2. A hybrid solar photovoltaic-wind turbine-Rankine cycle for electricity generation in Turkish Republic of Northern Cyprus

    Directory of Open Access Journals (Sweden)

    Samuel Asumadu-Sarkodie

    2016-12-01

    Full Text Available This paper presents an energy demand model by designing a hybrid solar-wind-thermal power generation system of the Turkish Republic of Northern Cyprus, a promising substitute for the expensive battery banks. The study models the future energy demand of Turkish Republic of Northern Cyprus based on the IPCC emissions scenario A1B and A2 by designing a new hybrid solar-wind-thermal power system that satisfies the current and future requirements of firm capacity during peak periods. The study suggests an improvement in a hybrid solar-wind-thermal power system performance by predicting reliable outputs that can integrate renewable energy technologies to conventional power generation. The energy consumption prediction model emphasizes the energy requirement that has a growing demand from 300 to 400 GWh in scenario A1B and 150–450 GWh in scenario A2 from 2010 to 2050. The proposed design can meet 400 GWh of electricity demand in TRNC based on IPCC scenario A1B and 450 GWh of electricity demand in TRNC based on IPCC scenario A2. The percentage contribution of solar, wind and thermal energy for 2010, 2020, 2030, 2040 and 2050 are presented along with CO2 emissions and water consumption for each of the years.

  3. Working Fluid Stability in Large-Scale Organic Rankine Cycle-Units Using Siloxanes—Long-Term Experiences and Fluid Recycling

    Directory of Open Access Journals (Sweden)

    Tobias G. Erhart

    2016-05-01

    Full Text Available The results in this work show the influence of long-term operation on the decomposition of working fluids in eight different organic rankine cycle (ORC power plants (both heat-led and electricity-led in a range of 900 kW el to 2 MW el . All case study plants are using octamethyltrisiloxane (MDM as a working fluid; the facilities are between six to 12 years old. Detailed analyses, including the fluid distribution throughout the cycle, are conducted on one system. All presented fluid samples are analyzed via head space gas chromatography mass spectrometry (HS-GC-MS. Besides the siloxane composition, the influence of contaminants, such as mineral oil-based lubricants (and their components, is examined. In most cases, the original working fluid degrades to fractions of siloxanes with a lower boiling point (low boilers and fractions with a higher boiling point (high boilers. As a consequence of the analyses, a new fluid recycling and management system was designed and tested in one case study plant (Case Study #8. Pre-post comparisons of fluid samples prove the effectiveness of the applied methods. The results show that the recovery of used working fluid offers an alternative to the purchase of fresh fluid, since operating costs can be significantly reduced. For large facilities, the prices for new fluid range from € 15 per liter (in 2006 to € 22 per liter (in 2013, which is a large reinvestment, especially in light of filling volumes of 4000 liters to 7000 liters per unit. Using the aforementioned method, a price of € 8 per liter of recovered MDM can be achieved.

  4. Mirador - Water and Energy Cycles

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. Through water and energy cycle research we can improve hurricane prediction, quantify tropical rainfall and eventually begin...

  5. Economic analysis of a dish-Rankine solar thermal power system

    Science.gov (United States)

    Pons, R. L.; Irwin, R. E.

    An analysis of the performance and costs of a first generation dish Rankine solar thermal power system for small community and industrial applications is presented. The system is of the point-focusing distributed receiver type, with distributed generation and employs multiple paraboloidal concentrators with organic Rankine cycle power conversion systems at the focus of each dish. Projected life cycle energy costs for a fully developed and mass produced system are shown to be competitive with costs projected in the near future for electricity generated by more conventional means. It is shown that: (1) the method of rating plant poer output has a minor influence on life cycle energy cost, (2) optimum dish size is greater than 12m, (3) energy cost is virtually independent of plant size above 1 MW sub e and (4) dish spacing and geometric arrangement can be optimized to reduce energy cost.

  6. Comparative Evaluation of Integrated Waste Heat Utilization Systems for Coal-Fired Power Plants Based on In-Depth Boiler-Turbine Integration and Organic Rankine Cycle

    Directory of Open Access Journals (Sweden)

    Shengwei Huang

    2018-01-01

    Full Text Available To maximize the system-level heat integration, three retrofit concepts of waste heat recovery via organic Rankine cycle (ORC, in-depth boiler-turbine integration, and coupling of both are proposed, analyzed and comprehensively compared in terms of thermodynamic and economic performances. For thermodynamic analysis, exergy analysis is employed with grand composite curves illustrated to identify how the systems are fundamentally and quantitatively improved, and to highlight key processes for system improvement. For economic analysis, annual revenue and investment payback period are calculated based on the estimation of capital investment of each component to identify the economic feasibility and competitiveness of each retrofit concept proposed. The results show that the in-depth boiler-turbine integration achieves a better temperature match of heat flows involved for different fluids and multi-stage air preheating, thus a significant improvement of power output (23.99 MW, which is much larger than that of the system with only ORC (6.49 MW. This is mainly due to the limitation of the ultra-low temperature (from 135 to 75 °C heat available from the flue gas for ORC. The thermodynamic improvement is mostly contributed by the reduction of exergy destruction within the boiler subsystem, which is eventually converted to mechanical power; while the exergy destruction within the turbine system is almost not changed for the three concepts. The selection of ORC working fluids is performed to maximize the power output. Due to the low-grade heat source, the cycle with R11 offers the largest additional net power generation but is not significantly better than the other preselected working fluids. Economically, the in-depth boiler-turbine integration is the most economic completive solution with a payback period of only 0.78 year. The ORC concept is less attractive for a sole application due to a long payback time (2.26 years. However, by coupling both

  7. Energy and exergy analysis of the Kalina cycle for use in concentrated solar power plants with direct steam generation

    DEFF Research Database (Denmark)

    Knudsen, Thomas; Clausen, Lasse Røngaard; Haglind, Fredrik

    2014-01-01

    In concentrated solar power plants using direct steam generation, the usage of a thermal storage unit based only on sensible heat may lead to large exergetic losses during charging and discharging, due to a poor matching of the temperature profiles. By the use of the Kalina cycle, in which...... with direct steam generation. The following two scenarios were addressed using energy and exergy analysis: generating power using heat from only the receiver and using only stored heat. For each of these scenarios comparisons were made for mixture concentrations ranging from 0.1 mole fraction of ammonia to 0.......9, and compared to the conventional Rankine cycle. This comparison was then also carried out for various turbine inlet pressures (100 bar to critical pressures). The results suggest that there would be no benefit from using a Kalina cycle instead of a Rankine cycle when generating power from heat taken directly...

  8. Performance Analysis of an Evaporator for a Diesel Engine–Organic Rankine Cycle (ORC Combined System and Influence of Pressure Drop on the Diesel Engine Operating Characteristics

    Directory of Open Access Journals (Sweden)

    Chen Bei

    2015-06-01

    Full Text Available The main purpose of this research is to analyze the performance of an evaporator for the organic Rankine cycle (ORC system and discuss the influence of the evaporator on the operating characteristics of diesel engine. A simulation model of fin-and-tube evaporator of the ORC system is established by using Fluent software. Then, the flow and heat transfer characteristics of the exhaust at the evaporator shell side are obtained, and then the performance of the fin-and-tube evaporator of the ORC system is analyzed based on the field synergy principle. The field synergy angle (β is the intersection angle between the velocity vector and the temperature gradient. When the absolute values of velocity and temperature gradient are constant and β < 90°, heat transfer enhancement can be achieved with the decrease of the β. When the absolute values of velocity and temperature gradient are constant and β >90°, heat transfer enhancement can be achieved with the increase of the β. Subsequently, the influence of the evaporator of the ORC system on diesel engine performance is studied. A simulation model of the diesel engine is built by using GT–Power software under various operating conditions, and the variation tendency of engine power, torque, and brake specific fuel consumption (BSFC are obtained. The variation tendency of the power output and BSFC of diesel engine–ORC combined system are obtained when the evaporation pressure ranges from 1.0 MPa to 3.5 MPa. Results show that the field synergy effect for the areas among the tube bundles of the evaporator main body and the field synergy effect for the areas among the fins on the windward side are satisfactory. However, the field synergy effect in the areas among the fins on the leeward side is weak. As a result of the pressure drop caused by the evaporator of the ORC system, the diesel engine power and torque decreases slightly, whereas the BSFC increases slightly with the increase of exhaust back

  9. Nant-De-Chatillon: electric power generation by ORC (organic Rankine cycle) using waste heat from the Chatillon biogas plant; Nant-de-Chatillon: Production d'electricite par ORC a partir des rejets de chaleur du site de methanisation de Chatillon. Resume

    Energy Technology Data Exchange (ETDEWEB)

    Kane, M.; Gay, B.

    2005-07-01

    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.

  10. Annual Cycle Energy System (ACES)

    Science.gov (United States)

    Holman, A. S.; Abbatiello, L. A.

    1980-05-01

    A single family residence near Knoxville, Tennessee, is being used to demonstrate the energy conserving features of the annual cycle energy system (ACES), an integrated heating and cooling system that utilizes a unidirectional heat pump and low temperature thermal storage. A second house, the control house, is being used to compare the performance of the ACES with that of an electric resistance heating and hot water system combined with a central air conditioning system. The ACES reduced peak utility system demands significantly: a reduction from 11.7 to 3.1 kW was achieved in the winter and from 4.1 to 0.7 kW in the summer. The only problems encountered were a heat leak into the storage bin that was twice the calculated value and control logic errors that produced excessive hot water in the winter, requiring extensive use of the night heat rejection mode in the summer. These problems are currently being corrected.

  11. Conceptual design and analysis of a Dish-Rankine solar thermal power system

    Science.gov (United States)

    Pons, R. L.

    1980-08-01

    A Point Focusing Distributed Receiver (PFDR) solar thermal electric system which employs small Organic Rankine Cycle (ORC) engines is examined with reference to its projected technical/economic performance. With mass-produced power modules (about 100,000 per year), the projected life-cycle energy cost for an optimized no-storage system is estimated at 67 mills/kWh (Levelized Busbar Energy Cost) without the need for advanced development of any of its components. At moderate production rates (about 50 MWe/yr) system energy costs are competitive with conventional power generation systems in special remote-site types of applications.

  12. Organic Rankine Kilowatt Isotope Power System. Final phase I report

    Energy Technology Data Exchange (ETDEWEB)

    1978-07-15

    On 1 August 1975 under Department of Energy Contract EN-77-C-02-4299, Sundstrand Energy Systems commenced development of a Kilowatt Isotope Power System (KIPS) directed toward satisfying the higher power requirements of satellites of the 1980s and beyond. The KIPS is a /sup 238/PuO/sub 2/ fueled organic Rankine cycle turbine power system which will provide design output power in the range of 500 to 2000 W/sub (e)/ with a minimum of system changes. The principal objectives of the Phase 1 development effort were to: conceptually design a flight system; design a Ground Demonstration System (GDS) that is prototypic of the flight system in order to prove the feasibility of the flight system design; fabricate and assemble the GDS; and performance and endurance test the GDS using electric heaters in lieu of the isotope heat source. Results of the work performed under the Phase 1 contract to 1 July 1978 are presented.

  13. Solar-powered Rankine heat pump for heating and cooling

    Science.gov (United States)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  14. Low-power heat pump systems combining two organic Rankine cycles; Applications de pompe a chaleur. A l'exemple des systemes ORC-ORC de petite puissance

    Energy Technology Data Exchange (ETDEWEB)

    Demierre, J.

    2009-07-01

    In this basic article that includes many diagrams and equations illustrating a research project conducted at the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland the author describes the first part of his thesis. A new concept of thermally driven heat pump (TDHP) is presented, which could be a real alternative to today's heating systems in buildings that are mainly based on less efficient fuel-fired boilers. Nowadays, the heat pump market is dominated by two kinds of systems: the electrically driven vapor compression heat pumps, which are the most widely used in residential heating applications, and the thermally driven heat pumps that are usually based on a sorption process. In this research project, the investigated TDHP - designated by ORC-ORC - is based on the coupling of a vapor compression heat pump cycle and an organic Rankine cycle (ORC). The studied concept uses a single stage centrifugal compressor directly coupled to a single stage radial inflow turbine. The shaft is rotating on gas bearings, which allows the system to be oil-free. Like most of the other TDHP's, this system has the advantage to work with a variety of fuels or heat sources like wood pellets, natural gas, solar heat, geothermal heat or waste heat. The concept studied in this work is a gas fired system for space heating and domestic hot water production in small residential buildings (power range: 20 kW). A systematic approach has been used to theoretically evaluate, in terms of energy efficiency, the potential of ORC-ORC systems. The method is based on the optimization which allows identifying the best configurations at each design step with respect to the designer choices. This approach is divided into three steps. In the first step, a model of the complete system has been developed based on a process integration approach. This step allows to quickly determine whether the system is potentially attractive or not, for given conditions, before going deeper into

  15. Energy Conversion Advanced Heat Transport Loop and Power Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Oh, C. H.

    2006-08-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various

  16. Energy Conservative Limit Cycle Oscillations

    NARCIS (Netherlands)

    Stramigioli, Stefano; van Dijk, Michel

    This paper shows how globally attractive limit cycle oscillations can be induced in a system with a nonlinear feedback element. Based on the same principle as the Van der Pol oscillator, the feedback behaves as a negative damping for low velocities but as an ordinary damper for high velocities. This

  17. Toluene stability Space Station Rankine power system

    Science.gov (United States)

    Havens, V. N.; Ragaller, D. R.; Sibert, L.; Miller, D.

    1987-01-01

    A dynamic test loop is designed to evaluate the thermal stability of an organic Rankine cycle working fluid, toluene, for potential application to the Space Station power conversion unit. Samples of the noncondensible gases and the liquid toluene were taken periodically during the 3410 hour test at 750 F peak temperature. The results obtained from the toluene stability loop verify that toluene degradation will not lead to a loss of performance over the 30-year Space Station mission life requirement. The identity of the degradation products and the low rates of formation were as expected from toluene capsule test data.

  18. Free Energy and Internal Combustion Engine Cycles

    OpenAIRE

    Harris, William D.

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  19. The dish-Rankine SCSTPE program (Engineering Experiment no. 1). [systems engineering and economic analysis for a small community solar thermal electric system

    Science.gov (United States)

    Pons, R. L.; Grigsby, C. E.

    1980-01-01

    Activities planned for phase 2 Of the Small Community Solar Thermal Power Experiment (PFDR) program are summarized with emphasis on a dish-Rankine point focusing distributed receiver solar thermal electric system. Major design efforts include: (1) development of an advanced concept indirect-heated receiver;(2) development of hardware and software for a totally unmanned power plant control system; (3) implementation of a hybrid digital simulator which will validate plant operation prior to field testing; and (4) the acquisition of an efficient organic Rankine cycle power conversion unit. Preliminary performance analyses indicate that a mass-produced dish-Rankine PFDR system is potentially capable of producing electricity at a levelized busbar energy cost of 60 to 70 mills per KWh and with a capital cost of about $1300 per KW.

  20. Comparing the Life Cycle Energy Consumption, Global ...

    Science.gov (United States)

    Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability

  1. Life cycle assessment of renewable energy sources

    CERN Document Server

    Singh, Anoop; Olsen, Stig Irving

    2013-01-01

    Governments are setting challenging targets to increase the production of energy and transport fuel from sustainable sources. The emphasis is increasingly on renewable sources including wind, solar, geothermal, biomass based biofuel, photovoltaics or energy recovery from waste. What are the environmental consequences of adopting these other sources? How do these various sources compare to each other? Life Cycle Assessment of Renewable Energy Sources tries to answer these questions based on the universally adopted method of Life Cycle Assessment (LCA). This book introduces the concept and impor

  2. Part-load performance of a high temperature Kalina cycle

    DEFF Research Database (Denmark)

    Modi, Anish; Andreasen, Jesper Graa; Kærn, Martin Ryhl

    2015-01-01

    The Kalina cycle has recently seen increased interest as an alternative to the conventional steam Rankine cycle. The cycle has been studied for use with both low and high temperature applications such as geothermal power plants, ocean thermal energy conversion, waste heat recovery, gas turbine...

  3. Storing Renewable Energy in the Hydrogen Cycle.

    Science.gov (United States)

    Züttel, Andreas; Callini, Elsa; Kato, Shunsuke; Atakli, Züleyha Özlem Kocabas

    2015-01-01

    An energy economy based on renewable energy requires massive energy storage, approx. half of the annual energy consumption. Therefore, the production of a synthetic energy carrier, e.g. hydrogen, is necessary. The hydrogen cycle, i.e. production of hydrogen from water by renewable energy, storage and use of hydrogen in fuel cells, combustion engines or turbines is a closed cycle. Electrolysis splits water into hydrogen and oxygen and represents a mature technology in the power range up to 100 kW. However, the major technological challenge is to build electrolyzers in the power range of several MW producing high purity hydrogen with a high efficiency. After the production of hydrogen, large scale and safe hydrogen storage is required. Hydrogen is stored either as a molecule or as an atom in the case of hydrides. The maximum volumetric hydrogen density of a molecular hydrogen storage is limited to the density of liquid hydrogen. In a complex hydride the hydrogen density is limited to 20 mass% and 150 kg/m(3) which corresponds to twice the density of liquid hydrogen. Current research focuses on the investigation of new storage materials based on combinations of complex hydrides with amides and the understanding of the hydrogen sorption mechanism in order to better control the reaction for the hydrogen storage applications.

  4. Methods of increasing net work output of organic Rankine cycles for low-grade waste heat recovery with a detailed analysis using a zeotropic working fluid mixture and scroll expander

    Science.gov (United States)

    Woodland, Brandon Jay

    An organic Rankine cycle (ORC) is a thermodynamic cycle that is well-suited for waste heat recovery. It is generally employed for waste heat with temperatures in the range of 80 °C -- 300 °C. When the application is strictly to convert waste heat into work, thermal efficiency is not recommended as a key performance metric. In such an application, maximization of the net power output should be the objective rather than maximization of the thermal efficiency. Two alternative cycle configurations that can increase the net power produced from a heat source with a given temperature and flow rate are proposed and analyzed. These cycle configurations are 1) an ORC with two-phase flash expansion and 2) an ORC with a zeotropic working fluid mixture (ZRC). A design-stage ORC model is presented for consistent comparison of multiple ORC configurations. The finite capacity of the heat source and heat sink fluids is a key consideration in this model. Of all working fluids studied for the baseline ORC, R134a and R245fa yield the highest net power output from a given heat source. Results of the design-stage model indicate that the ORC with two-phase flash expansion offers the most improvement over the baseline ORC. However, the level of improvement that could be achieved in practice is highly uncertain due to the requirement of highly efficient two-phase expansion. The ZRC shows improvement over the baseline as long as the condenser fan power requirement is not negligible. At the highest estimated condenser fan power, the ZRC shows the most improvement, while the ORC with flash expansion is no longer beneficial. The ZRC was selected for detailed study because it does not require two-phase expansion. An experimental test rig was used to evaluate baseline ORC performance with R134a and with R245fa. The ZRC was tested on the same rig with a mixture of 62.5% R134a and 37.5% R245fa. The tested expander is a minimally-modified, of-the-shelf automotive scroll compressor. The high

  5. Performance Analysis of Organic Rankine-vapor Compression Ice Maker Utilizing Food Industry Waste Heat

    OpenAIRE

    Bing Hu; Yuanshu Cao; Weibin Ma

    2015-01-01

    To develop the organic Rankine-vapor compression ice maker driven by food industry exhaust gases and engine cooling water, an organic Rankine-vapor compression cycle system was employed for ice making and a thermodynamic model was developed and the effects of working fluid types, hot water temperature and condensation temperature on the system performance were analyzed and the ice making capacity from unit mass hot water and unit power waste heat were evaluated. The calculated results show th...

  6. Hybrid power plants consisting of geothermal power plants and cogeneration plants for the combined heat and power generation on the basis of an Organic Rankine Cycle; Geothermie-BHKW-Hybridkraftwerke zur Kraft-Waerme-Kopplung auf Basis des Organic Rankine Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Heberle, F.; Hartmann, A.; Brueggemann, D. [Bayreuth Univ. (DE). Lehrstuhl fuer Technische Thermodynamik und Transportprozesse (LTTT)

    2011-10-24

    The combined use of renewable energy sources in hybrid power plants has a significant potential to increase energy efficiency under energetic and economic issues. The indirect heat supply by heating thermal water via a waste heat source is a promising variant of coupling. Due to an additional heat generation more interconnection options and regulation technical degrees of freedom are resulting which must be considered in the design and dimensioning. The authors of the contribution under consideration report on a thermodynamic and economic analysis of a hybrid geothermal cogeneration power plant for combined heat and power generation using selected examples. An all-the-year coverage of the heat demand can be guaranteed for all hybrid concepts.

  7. Annual Cycle Energy System: initial investigations

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, H.C.; Christian, J.C.; Hise, E.C.; Holman, A.S.; Miller, A.J.; Mixon, W.R.; Moyers, J.C.; Nephew, E.A.

    1976-10-01

    Initial analytical and experimental investigations were conducted to establish data and design procedures prior to a demonstration of the Annual Cycle Energy System (ACES) in an actual building. ACES is an integrated system for supplying space heating and cooling, and domestic hot water to a building through the use of a heat pump, a thermal storage unit, and an outdoor radiative/convective panel. The heat pump extracts energy from a tank of stored water to provide winter heating. The ice that is formed is accumulated for subsequent use in meeting the cooling requirements of the building in the summer. A components test assembly was constructed to measure the rates of heat transfer during ice buildup and brine chilling operations, to assess the design requirements of the evaporator and the desuperheater for producing domestic hot water using refrigerant superheat, and to investigate the mechanical stability characteristics of the ACES freezing coils which are submerged in the water storage tank. The findings of the experimental program are presented and analytical methods for optimally sizing system components according to the thermal characteristics of a building and the climatic zone where it is located are developed. The calculation of the annual coefficient of performance for the ACES is illustrated.

  8. Life-cycle analysis of renewable energy systems

    DEFF Research Database (Denmark)

    Sørensen, Bent

    1994-01-01

    An imlementation of life-cycle analysis (LCA) for energy systems is presented and applied to two renewable energy systems (wind turbines and building-integrated photovoltaic modules) and compared with coal plants......An imlementation of life-cycle analysis (LCA) for energy systems is presented and applied to two renewable energy systems (wind turbines and building-integrated photovoltaic modules) and compared with coal plants...

  9. closed cycle solar refrigeration with the calcium chloride system

    African Journals Online (AJOL)

    user

    1986-09-01

    Sep 1, 1986 ... gives an option tree of the alternative schemes. When the energy of the vapour compression machine is solar, the electrical power for driving the compressor can be provided by photovoltaic panels. Alternatively, a concentrating or flat plate solar collector may be used to replace the boiler in a rankine cycle.

  10. Thermo-Economic Comparison and Parametric Optimizations among Two Compressed Air Energy Storage System Based on Kalina Cycle and ORC

    Directory of Open Access Journals (Sweden)

    Ruixiong Li

    2016-12-01

    Full Text Available The compressed air energy storage (CAES system, considered as one method for peaking shaving and load-levelling of the electricity system, has excellent characteristics of energy storage and utilization. However, due to the waste heat existing in compressed air during the charge stage and exhaust gas during the discharge stage, the efficient operation of the conventional CAES system has been greatly restricted. The Kalina cycle (KC and organic Rankine cycle (ORC have been proven to be two worthwhile technologies to fulfill the different residual heat recovery for energy systems. To capture and reuse the waste heat from the CAES system, two systems (the CAES system combined with KC and ORC, respectively are proposed in this paper. The sensitivity analysis shows the effect of the compression ratio and the temperature of the exhaust on the system performance: the KC-CAES system can achieve more efficient operation than the ORC-CAES system under the same temperature of exhaust gas; meanwhile, the larger compression ratio can lead to the higher efficiency for the KC-CAES system than that of ORC-CAES with the constant temperature of the exhaust gas. In addition, the evolutionary multi-objective algorithm is conducted between the thermodynamic and economic performances to find the optimal parameters of the two systems. The optimum results indicate that the solutions with an exergy efficiency of around 59.74% and 53.56% are promising for KC-CAES and ORC-CAES system practical designs, respectively.

  11. long term energy long term energy performan performan power pla

    African Journals Online (AJOL)

    User

    This study is aimed at providing an energy perfo operates on Regenerative Rankine cycle with s formulated based on some performance paramet were plant efficiency, plant internal consumptio. The calculation were based. The calculation were based on annual perform on annual perform results of the analysis with ...

  12. Life Cycle Cost Optimization of a BOLIG+ Zero Energy Building

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna

    Buildings consume approximately 40% of the world’s primary energy use. Considering the total energy consumption throughout the whole life cycle of a building, the energy performance and supply is an important issue in the context of climate change, scarcity of energy resources and reduction......, and if applicable (7) the requirements of the building-grid interaction. Moreover, the study revealed that the future ZEB definitions applied in the Denmark should mostly be focused on grid-connected ZEBs – Net ZEBs, and the annual primary energy balance. The Life Cycle Cost (LCC) analysis conducted with a study...... included in the current building code, and ten renewable energy supply systems including both on-site and off-site options. The results indicated that although the off-site options have lower life cycle costs than the on-site alternatives, their application would promote renewable technologies over energy...

  13. Systematic Methods for Working Fluid Selection and the Design, Integration and Control of Organic Rankine Cycles—A Review

    Directory of Open Access Journals (Sweden)

    Patrick Linke

    2015-05-01

    Full Text Available Efficient power generation from low to medium grade heat is an important challenge to be addressed to ensure a sustainable energy future. Organic Rankine Cycles (ORCs constitute an important enabling technology and their research and development has emerged as a very active research field over the past decade. Particular focus areas include working fluid selection and cycle design to achieve efficient heat to power conversions for diverse hot fluid streams associated with geothermal, solar or waste heat sources. Recently, a number of approaches have been developed that address the systematic selection of efficient working fluids as well as the design, integration and control of ORCs. This paper presents a review of emerging approaches with a particular emphasis on computer-aided design methods.

  14. Life cycle energy and GHG emission within the Turin metropolitan area urban water cycle

    OpenAIRE

    Zappone, Mariantonia; Fiore, Silvia; Genon, Giuseppe

    2014-01-01

    The aim of this study is to analyze the urban water cycle in the Turin Metropolitan Area (Northwestern Italy), with a focus on quantifying the annual life cycle energy consumption and greenhouse gas emissions. The study made use Material Flow Analysis and Life Cycle Assessment methods for a defined urban water cycle system (ATO3) operated by one water utility (SMAT S.p.A.), and examines all main sub-systems of the entire urban water cycle. The study quantified the annual direct and indirect e...

  15. Comparison of the dielectric electroactive polymer generator energy harvesting cycles

    DEFF Research Database (Denmark)

    Dimopoulos, Emmanouil; Trintis, Ionut; Munk-Nielsen, Stig

    2013-01-01

    The Dielectric ElectroActive Polymer (DEAP) generator energy harvesting cycles have been in the spotlight of the scientific interest for the past few years. Indeed, several articles have demonstrated thorough and comprehensive comparisons of the generator fundamental energy harvesting cycles......, namely Constant Charge (CC), Constant Voltage (CV) and Constant E-field (CE), based on averaged theoretical models. Yet, it has not been possible until present to validate the outcome of those comparisons via respective experimental results. In this paper, all three primary energy harvesting cycles...... are experimentally compared, based upon the coupling of a DEAP generator with a bidirectional non-isolated power electronic converter, by means of energy gain, energy harvesting efficiency and energy conversion efficiency....

  16. A Learning Cycle on Exponential Growth and the Energy Crises.

    Science.gov (United States)

    Dykstra, D. I., Jr.

    1982-01-01

    Describes nature and logistics of a learning cycle approach to teaching exponential growth and the energy crisis. Used with both science and nonscience majors, the cycle uses no algebra, never mentions the terms exponential or logarithmic, and requires a calculator. Instructions for obtaining student and instructor materials are provided.…

  17. Economic optimization of a Kalina cycle for a parabolic trough solar thermal power plant

    DEFF Research Database (Denmark)

    Modi, Anish; Kærn, Martin Ryhl; Andreasen, J. G.

    2015-01-01

    technology for the conversion of solar thermal energy into electricity. In this paper, a Kalina cycle and a steam Rankine cycle are compared in terms of the total capital investment cost for use in a parabolic trough solar thermal power plant without storage. In order to minimize the total capital investment...... cost of the Kalina cycle power plant (the solar field plus the power cycle), an optimization was performed by varying the turbine outlet pressure, the separator inlet temperature and the separator inlet ammonia mass fraction. All the heat exchangers were modelled as shell and tube type using suitable......The Kalina cycle has recently seen increased interest as a replacement for the more traditional steam Rankine cycle for geothermal, solar, ocean thermal energy conversion and waste heat recovery applications. The Kalina cycle uses a mixture of ammonia and water as the working fluid. The ammonia...

  18. Modeling the Q-cycle mechanism of transmembrane energy conversion

    OpenAIRE

    Smirnov, Anatoly Yu.; Nori, Franco

    2011-01-01

    The Q-cycle mechanism plays an important role in the conversion of the redox energy into the energy of the proton electrochemical gradient across the biomembrane. The bifurcated electron transfer reaction, which is built into this mechanism, recycles one electron, thus, allowing to translocate two protons per one electron moving to the high-potential redox chain. We study a kinetic model of the Q-cycle mechanism in an artificial system which mimics the bf complex of plants and cyanobacteria i...

  19. Life Cycle Cost Optimization of a Bolig+ Zero Energy Building

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna

    Buildings consume approximately 40% of the world’s primary energy use. Considering the total energy consumption throughout the whole life cycle of a building, the energyperformance and supply is an important issue in the context of climate change, scarcity of energy resources and reduction......, and if applicable (7) the requirements of the building-grid interaction. Moreover, the studyrevealed that the future ZEB definitions applied in the Denmark should mostly be focused on grid-connected ZEBs – Net ZEBs, and the annual primary energy balance. The Life Cycle Cost (LCC) analysis conducted with a study...... included in the current building code, and ten renewable energy supply systems including both on-site and off-site options. Theresults indicated that although the off-site options have lower life cycle costs than the on-site alternatives, their application would promote renewable technologies overenergy...

  20. Energy cycling and hypothetical organisms in Europa's ocean.

    Science.gov (United States)

    Schulze-Makuch, Dirk; Irwin, Louis N

    2002-01-01

    While Europa has emerged as a leading candidate for harboring extraterrestrial life, the apparent lack of a source of free energy for sustaining living systems has been argued. In this theoretical analysis, we have quantified the amount of energy that could in principle be obtained from chemical cycling, heat, osmotic gradients, kinetic motion, magnetic fields, and gravity in Europa's subsurface ocean. Using reasonable assumptions based on known organisms on Earth, our calculations suggest that chemical oxidation-reduction cycles in Europa's subsurface ocean could support life. Osmotic and thermal gradients, as well as the kinetic energy of convection currents, also represent plausible alternative sources of energy for living systems at Europa. Organisms thriving on these gradients could interact with each other to form the complex energy cycling necessary for establishing a stable ecosystem.

  1. Working fluids selection for fishing boats waste heat powered organic Rankine-vapor compression ice maker

    Science.gov (United States)

    Bu, Xianbiao; Wang, Lingbao; Li, Huashan

    2014-10-01

    To utilize waste heat from fishing boats, an organic Rankine cycle/vapor compression cycle system was employed for ice making and a thermodynamic model was developed. Six working fluids were selected and compared in order to identify suitable working fluids which may yield high system efficiencies. The calculated results show that R600a is most suitable working fluid through comprehensive comparison of efficiency, size parameter, pressure ratio, coefficient of performance, system pressure and safety.

  2. Energy Efficient Waste Heat Recovery from an Engine Exhaust System

    Science.gov (United States)

    2016-12-01

    of energy in the country [1]. In 2012, the Secretary of the Navy (SECNAV) published the “Strategy for Renewable Energy ” in which he laid out his... energy independence. He stated that, by the year 2020, the DON should produce at least 50% of its energy consumption by renewable methods [2]. For...compare different types of the same cycle to determine the most effective solution. B. COMPARISON OF RANKINE, TRANSCRITICAL AND BRAYTON CYCLES USING

  3. 78 FR 43870 - Hydrogen Energy California's Integrated Gasification Combined Cycle Project; Preliminary Staff...

    Science.gov (United States)

    2013-07-22

    ... of Availability Hydrogen Energy California's Integrated Gasification Combined Cycle Project... availability of the Hydrogen Energy California's Integrated Gasification Combined Cycle Project Preliminary... the Hydrogen Energy California's (HECA) Integrated Gasification Combined Cycle Project, which would be...

  4. Energy Harvesting Cycles of Dielectric ElectroActive Polymer Generators

    DEFF Research Database (Denmark)

    Dimopoulos, Emmanouil; Trintis, Ionut; Munk-Nielsen, Stig

    2012-01-01

    . Their higher energy density, superior low-speed performance, light-weighted nature as well as their shapely structure have rendered DEAPs candidate solutions for various actuation and energy harvesting applications. In this paper, a thoroughly analysis of all energy harvesting operational cycles of a DEAP...... generator, coupled to a non-isolated power electronics converter, is conducted and for the first time experimental results for each one of them are presented....

  5. LIFE CYCLE ASSESSMENT ON GEOTHERMAL ENERGY SYSTEM.pdf

    OpenAIRE

    Nag, Rajat

    2016-01-01

    Life Cycle Assessment (LCA) addresses the environmental aspects and potential environmental impacts(e.g. use of resource and the environmental consequence of releases) through a product’s life cycle fromraw material acquisition through production, use, end-of-life treatment, recycling and final disposal(ISO14040). Renewable energy sources such as wind, tidal, solar, wave, geothermal, biomass have beenobserved as the potential solution to mitigate environmental pollution created by the use of ...

  6. Indonesian residential high rise buildings: A life cycle energy assessment

    Energy Technology Data Exchange (ETDEWEB)

    Utama, Agya; Gheewala, Shabbir H. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand)

    2009-11-15

    This study evaluates the effect of building envelopes on the life cycle energy consumption of high rise residential buildings in Jakarta, Indonesia. For high rise residential buildings, the enclosures contribute 10-50% of the total building cost, 14-17% of the total material mass and 20-30% of the total heat gain. The direct as well as indirect influence of the envelope materials plays an important role in the life cycle energy consumption of buildings. The initial embodied energy of typical double wall and single wall envelopes for high residential buildings is 79.5 GJ and 76.3 GJ, respectively. Over an assumed life span of 40 years, double walls have better energy performance than single walls, 283 GJ versus 480 GJ, respectively. Material selection, which depends not only on embodied energy but also thermal properties, should, therefore, play a crucial role during the design of buildings. (author)

  7. Life cycle primary energy analysis of residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Leif; Joelsson, Anna [Ecotechnology, Department of Engineering and Sustainable Development, Mid Sweden University, SE-831 25 Oestersund (Sweden)

    2010-02-15

    The space heating demand of residential buildings can be decreased by improved insulation, reduced air leakage and by heat recovery from ventilation air. However, these measures result in an increased use of materials. As the energy for building operation decreases, the relative importance of the energy used in the production phase increases and influences optimization aimed at minimizing the life cycle energy use. The life cycle primary energy use of buildings also depends on the energy supply systems. In this work we analyse primary energy use and CO{sub 2} emission for the production and operation of conventional and low-energy residential buildings. Different types of energy supply systems are included in the analysis. We show that for a conventional and a low-energy building the primary energy use for production can be up to 45% and 60%, respectively, of the total, depending on the energy supply system, and with larger variations for conventional buildings. The primary energy used and the CO{sub 2} emission resulting from production are lower for wood-framed constructions than for concrete-framed constructions. The primary energy use and the CO{sub 2} emission depend strongly on the energy supply, for both conventional and low-energy buildings. For example, a single-family house from the 1970s heated with biomass-based district heating with cogeneration has 70% lower operational primary energy use than if heated with fuel-based electricity. The specific primary energy use with district heating was 40% lower than that of an electrically heated passive row house. (author)

  8. Life-Cycle Evaluation of Domestic Energy Systems

    Science.gov (United States)

    Bando, Shigeru; Hihara, Eiji

    Among the growing number of environmental issues, the global warming due to the increasing emission of greenhouse gases, such as carbon dioxide CO2, is the most serious one. In order to reduce CO2 emissions in energy use, it is necessary to reduce primary energy consumption, and to replace energy sources with alternatives that emit less CO2.One option of such ideas is to replace fossil gas for water heating with electricity generated by nuclear power, hydraulic power, and other methods with low CO2 emission. It is also important to use energy efficiently and to reduce waste heat. Co-generation system is one of the applications to be able to use waste heat from a generator as much as possible. The CO2 heat pump water heaters, the polymer electrolyte fuel cells, and the micro gas turbines have high potential for domestic energy systems. In the present study, the life-cycle cost, the life-cycle consumption of primary energy and the life-cycle emission of CO2 of these domestic energy systems are compare. The result shows that the CO2 heat pump water heaters have an ability to reduce CO2 emission by 10%, and the co-generation systems also have another ability to reduce primary energy consumption by 20%.

  9. Energy and water cycle over the Tibetan plateau : surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Zhongbo; Zhang, Ting; Ma, Yaoming; Jia, Li; Wen, Jun

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy

  10. Energy and water cycle over the Tibetan Plateau: surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Z.; Zhang, T.; Ma, Y.; Jia, L.; Wen, J.

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy

  11. A Satellite View of Global Water and Energy Cycling

    Science.gov (United States)

    Houser, P. R.

    2012-12-01

    The global water cycle describes liquid, solid and vapor water dynamics as it moves through the atmosphere, oceans and land. Life exists because of water, and civilization depends on adapting to the constraints imposed by water availability. The carbon, water and energy cycles are strongly interdependent - energy is moved through evaporation and condensation, and photosynthesis is closely related to transpiration. There are significant knowledge gaps about water storage, fluxes and dynamics - we currently do not really know how much water is stored in snowpacks, groundwater or reservoirs. The view from space offers a vision for water science advancement. This vision includes observation, understanding, and prediction advancements that will improve water management and to inform water-related infrastructure that planning to provide for human needs and to protect the natural environment. The water cycle science challenge is to deploy a series of coordinated earth observation satellites, and to integrate in situ and space-borne observations to quantify the key water-cycle state variables and fluxes. The accompanying societal challenge is to integrate this information along with water cycle physics, and ecosystems and societal considerations as a basis for enlightened water resource management and to protect life and property from effects of water cycle extremes. Better regional to global scale water-cycle observations and predictions need to be readily available to reduce loss of life and property caused by water-related hazards. To this end, the NASA Energy and Water cycle Study (NEWS) has been documenting the satellite view of the water cycle with a goal of enabling improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. NEWS has fostered broad interdisciplinary collaborations to study experimental and operational satellite observations and has developed analysis tools for characterizing air

  12. Life Cycle Cost optimization of a BOLIG+ Zero Energy Building

    Energy Technology Data Exchange (ETDEWEB)

    Marszal, A.J.

    2011-12-15

    Buildings consume approximately 40% of the world's primary energy use. Considering the total energy consumption throughout the whole life cycle of a building, the energy performance and supply is an important issue in the context of climate change, scarcity of energy resources and reduction of global energy consumption. An energy consuming as well as producing building, labelled as the Zero Energy Building (ZEB) concept, is seen as one of the solutions that could change the picture of energy consumption in the building sector, and thus contribute to the reduction of the global energy use. However, before being fully implemented in the national building codes and international standards, the ZEB concept requires a clear understanding and a uniform definition. The ZEB concept is an energy-conservation solution, whose successful adaptation in real life depends significantly on private building owners' approach to it. For this particular target group, the cost is often an obstacle when investing money in environmental or climate friendly products. Therefore, this PhD project took the perspective of a future private ZEB owner to investigate the cost-optimal Net ZEB definition applicable in the Danish context. The review of the various ZEB approaches indicated a general concept of a Zero Energy Building as a building with significantly reduced energy demand that is balanced by an equivalent energy generation from renewable sources. And, with this as a general framework, each ZEB definition should further specify: (1) the connection or the lack of it to the energy infrastructure, (2) the unit of the balance, (3) the period of the balance, (4) the types of energy use included in the balance, (5) the minimum energy performance requirements (6) the renewable energy supply options, and if applicable (7) the requirements of the building-grid interaction. Moreover, the study revealed that the future ZEB definitions applied in Denmark should mostly be focused on grid

  13. Battery energy storage systems life cycle costs case studies

    Energy Technology Data Exchange (ETDEWEB)

    Swaminathan, S.; Miller, N.F.; Sen, R.K. [SENTECH, Inc., Bethesda, MD (United States)

    1998-08-01

    This report presents a comparison of life cycle costs between battery energy storage systems and alternative mature technologies that could serve the same utility-scale applications. Two of the battery energy storage systems presented in this report are located on the supply side, providing spinning reserve and system stability benefits. These systems are compared with the alternative technologies of oil-fired combustion turbines and diesel generators. The other two battery energy storage systems are located on the demand side for use in power quality applications. These are compared with available uninterruptible power supply technologies.

  14. Long term energy performance analysis of Egbin thermal power ...

    African Journals Online (AJOL)

    This study is aimed at providing an energy performance analysis of Egbin thermal power plant. The plant operates on Regenerative Rankine cycle with steam as its working fluid .The model equations were formulated based on some performance parameters used in power plant analysis. The considered criteria were plant ...

  15. Energy-based analysis of biochemical cycles using bond graphs.

    Science.gov (United States)

    Gawthrop, Peter J; Crampin, Edmund J

    2014-11-08

    Thermodynamic aspects of chemical reactions have a long history in the physical chemistry literature. In particular, biochemical cycles require a source of energy to function. However, although fundamental, the role of chemical potential and Gibb's free energy in the analysis of biochemical systems is often overlooked leading to models which are physically impossible. The bond graph approach was developed for modelling engineering systems, where energy generation, storage and transmission are fundamental. The method focuses on how power flows between components and how energy is stored, transmitted or dissipated within components. Based on the early ideas of network thermodynamics, we have applied this approach to biochemical systems to generate models which automatically obey the laws of thermodynamics. We illustrate the method with examples of biochemical cycles. We have found that thermodynamically compliant models of simple biochemical cycles can easily be developed using this approach. In particular, both stoichiometric information and simulation models can be developed directly from the bond graph. Furthermore, model reduction and approximation while retaining structural and thermodynamic properties is facilitated. Because the bond graph approach is also modular and scaleable, we believe that it provides a secure foundation for building thermodynamically compliant models of large biochemical networks.

  16. High-Energy Solar Particle Events in Cycle 24

    Science.gov (United States)

    Gopalswamy, N.; Makela, P.; Yashiro, S.; Xie, H.; Akiyama, S.; Thakur, N.

    2015-01-01

    The Sun is already in the declining phase of cycle 24, but the paucity of high-energy solar energetic particle (SEP) events continues with only two ground level enhancement (GLE) events as of March 31, 2015. In an attempt to understand this, we considered all the large SEP events of cycle 24 that occurred until the end of 2014. We compared the properties of the associated CMEs with those in cycle 23. We found that the CME speeds in the sky plane were similar, but almost all those cycle-24 CMEs were halos. A significant fraction of (16%) of the frontside SEP events were associated with eruptive prominence events. CMEs associated with filament eruption events accelerate slowly and attain peak speeds beyond the typical GLE release heights. When we considered only western hemispheric events that had good connectivity to the CME nose, there were only 8 events that could be considered as GLE candidates. One turned out to be the first GLE event of cycle 24 (2012 May 17). In two events, the CMEs were very fast (>2000 km/s) but they were launched into a tenuous medium (high Alfven speed). In the remaining five events, the speeds were well below the typical GLE CME speed (2000 km/s). Furthermore, the CMEs attained their peak speeds beyond the typical heights where GLE particles are released. We conclude that several factors contribute to the low rate of high-energy SEP events in cycle 24: (i) reduced efficiency of shock acceleration (weak heliospheric magnetic field), (ii) poor latitudinal and longitudinal connectivity), and (iii) variation in local ambient conditions (e.g., high Alfven speed).

  17. Projections of Full-Fuel-Cycle Energy and Emissions Metrics

    Energy Technology Data Exchange (ETDEWEB)

    Coughlin, Katie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-01-01

    To accurately represent how conservation and efficiency policies affect energy demand, both direct and indirect impacts need to be included in the accounting. The indirect impacts are defined here as the resource savings that accrue over the fuel production chain, which when added to the energy consumed at the point of use, constitute the full-fuel- cycle (FFC) energy. This paper uses the accounting framework developed in (Coughlin 2012) to calculate FFC energy metrics as time series for the period 2010-2040. The approach is extended to define FFC metrics for the emissions of greenhouse gases (GHGs) and other air-borne pollutants. The primary focus is the types of energy used in buildings and industrial processes, mainly natural gas and electricity. The analysis includes a discussion of the fuel production chain for coal, which is used extensively for electric power generation, and for diesel and fuel oil, which are used in mining, oil and gas operations, and fuel distribution. Estimates of the energy intensity parameters make use of data and projections from the Energy Information Agency’s National Energy Modeling System, with calculations based on information from the Annual Energy Outlook 2012.

  18. Solar power satellite life-cycle energy recovery consideration

    Energy Technology Data Exchange (ETDEWEB)

    Weingartner, S.; Blumenberg, J. [Deutsche Aerospace AG, Munich (Germany)]|[Technical Univ. of Munich, Munich (Germany)

    1994-12-31

    The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead on monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on earth (rectenna) requires about 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production installation and operation, is about two years.

  19. Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier...... recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization unit...

  20. Organic Rankine kilowatt isotope power system. First annual summary report, August 1, 1975--August 1, 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Sundstrand Energy Systems is developing a Kilowatt Isotope Power System (KIPS) directed toward satisfying the higher power requirements of satellites of the 1980's. The KIPS is a plutonium oxide fueled organic Rankine cycle turbine power system which will provide design output power in the range of 500 to 2000 W(e) with a minimum of system changes. Research progress is reported on Phase I comprising: (1) flight system conceptual design and ground demonstration; (2) flight system design and ground qualification; and (3) flight system production, acceptance testing and delivery. The principal objectives of Phase I are to: (1) conceptually design the flight system, (2) based on the flight system concept, design and build the ground demonstration system (GDS), (3) conduct performance and endurance testing using electric heaters to simulate the radioisotope heat source, (4) identify and initiate long lead development efforts required to achieve the initial flight qualification hardware availability date of April 1981, and (5) finalize the flight concept design and prepare the program plan for the Phase II effort.

  1. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 6: Closed-cycle gas turbine systems. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Amos, D. J.; Fentress, W. K.; Stahl, W. F.

    1976-01-01

    Both recuperated and bottomed closed cycle gas turbine systems in electric power plants were studied. All systems used a pressurizing gas turbine coupled with a pressurized furnace to heat the helium for the closed cycle gas turbine. Steam and organic vapors are used as Rankine bottoming fluids. Although plant efficiencies of over 40% are calculated for some plants, the resultant cost of electricity was found to be 8.75 mills/MJ (31.5 mills/kWh). These plants do not appear practical for coal or oil fired plants.

  2. Numerical evaluation of the Kalina cycle for concentrating solar power plants

    DEFF Research Database (Denmark)

    Modi, Anish

    of using a Kalina cycle is evaluated with a thermoeconomic optimization with a turbine inlet temperature of 500 C for a central receiver solar power plant with direct vapour generation, and 370 C for a parabolic trough solar power plant with Therminol VP-1 as the solar field heat transfer fluid. No thermal...... a higher specific capital investment cost and a higher levelized cost of electricity than the state-of-the-art steam Rankine cycle for both the central receiver and the parabolic trough plants. This is mainly because of worse power cycle design point efficiency than the corresponding steam Rankine cycle......Concentrating solar power plants use a number of reflecting mirrors to focus and convert the incident solar energy to heat, and a power cycle to convert this heat into electricity. One of the key challenges currently faced by the solar industry is the high cost of electricity production...

  3. Long-term global nuclear energy and fuel cycle strategies

    Energy Technology Data Exchange (ETDEWEB)

    Krakowski, R.A. [Los Alamos National Lab., NM (United States). Technology and Safety Assessment Div.

    1997-09-24

    The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E{sup 3} (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E{sup 3} model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E{sup 3} model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues.

  4. Solar energy demand (SED) of commodity life cycles.

    Science.gov (United States)

    Rugani, Benedetto; Huijbregts, Mark A J; Mutel, Christopher; Bastianoni, Simone; Hellweg, Stefanie

    2011-06-15

    The solar energy demand (SED) of the extraction of 232 atmospheric, biotic, fossil, land, metal, mineral, nuclear, and water resources was quantified and compared with other energy- and exergy-based indicators. SED represents the direct and indirect solar energy required by a product or service during its life cycle. SED scores were calculated for 3865 processes, as implemented in the Ecoinvent database, version 2.1. The results showed that nonrenewable resources, and in particular minerals, formed the dominant contribution to SED. This large share is due to the indirect solar energy required to produce these resource inputs. Compared with other energy- and exergy-based indicators, SED assigns higher impact factors to minerals and metals and smaller impact factors to fossil energetic resources, land use, and nuclear energy. The highest differences were observed for biobased and renewable energy generation processes, whose relative contribution of renewable resources such as water, biomass, and land occupation was much lower in SED than in energy- and exergy-based indicators.

  5. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W

    2007-12-15

    This report contains the description of the S-CO{sub 2} Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For system development, a computer code was developed to calculate heat balance of 100% power operation condition. Based on the computer code, the S-CO{sub 2} Brayton cycle energy conversion system was constructed for the KALIMER-600. Using the developed turbomachinery models, the off-design characteristics and the sensitivities of the S-CO{sub 2} turbomachinery were investigated. For the development of PCHE models, a one-dimensional analysis computer code was developed to evaluate the performance of the PCHE. Possible control schemes for power control in the KALIMER-600 S-CO{sub 2} Brayton cycle were investigated by using the MARS code. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na/CO{sub 2} boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO{sub 2} gas. The long term behavior of a Na/CO{sub 2} boundary failure event and its consequences which lead to a system pressure transient were evaluated.

  6. The NASA Energy and Water Cycle Extreme (NEWSE) Integration Project

    Science.gov (United States)

    House, P. R.; Lapenta, W.; Schiffer, R.

    2008-01-01

    Skillful predictions of water and energy cycle extremes (flood and drought) are elusive. To better understand the mechanisms responsible for water and energy extremes, and to make decisive progress in predicting these extremes, the collaborative NASA Energy and Water cycle Extremes (NEWSE) Integration Project, is studying these extremes in the U.S. Southern Great Plains (SGP) during 2006-2007, including their relationships with continental and global scale processes, and assessment of their predictability on multiple space and time scales. It is our hypothesis that an integrative analysis of observed extremes which reflects the current understanding of the role of SST and soil moisture variability influences on atmospheric heating and forcing of planetary waves, incorporating recently available global and regional hydro- meteorological datasets (i.e., precipitation, water vapor, clouds, etc.) in conjunction with advances in data assimilation, can lead to new insights into the factors that lead to persistent drought and flooding. We will show initial results of this project, whose goals are to provide an improved definition, attribution and prediction on sub-seasonal to interannual time scales, improved understanding of the mechanisms of decadal drought and its predictability, including the impacts of SST variability and deep soil moisture variability, and improved monitoring/attributions, with transition to applications; a bridging of the gap between hydrological forecasts and stakeholders (utilization of probabilistic forecasts, education, forecast interpretation for different sectors, assessment of uncertainties for different sectors, etc.).

  7. Rankine cycle load limiting through use of a recuperator bypass

    Science.gov (United States)

    Ernst, Timothy C.

    2011-08-16

    A system for converting heat from an engine into work includes a boiler coupled to a heat source for transferring heat to a working fluid, a turbine that transforms the heat into work, a condenser that transforms the working fluid into liquid, a recuperator with one flow path that routes working fluid from the turbine to the condenser, and another flow path that routes liquid working fluid from the condenser to the boiler, the recuperator being configured to transfer heat to the liquid working fluid, and a bypass valve in parallel with the second flow path. The bypass valve is movable between a closed position, permitting flow through the second flow path and an opened position, under high engine load conditions, bypassing the second flow path.

  8. Optimization of Organic Rankine Cycles for Off-Shore Applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Larsen, Ulrik; Nguyen, Tuong-Van

    2013-01-01

    the optimal working fluid is identified by removing the restriction on the maximum pressure. Different limits on hazards and global warming potential (GWP) are also set. The study is focused on the SGT-500 gas turbine installed on the Draugen platform in the Norwegian Sea. The simulations suggest that, when...... characteristics of the fluids, e.g. stability, environmental and human health impacts, and safety issues. Both supercritical and subcritical ORCs are included in the analysis. The optimization procedure is first applied to a conservative ORC where the maximum pressure is limited to 20 bar. Subsequently...

  9. Integrated energy and emission management for heavy-duty diesel engines with waste heat recovery system

    NARCIS (Netherlands)

    Willems, F.P.T.; Kupper, F.; Rascanu, G.; Feru, E.

    2015-01-01

    Rankine-cycleWasteHeatRecovery (WHR)systems are promising solutions to reduce fuel consumption for trucks. Due to coupling between engine andWHR system, control of these complex systems is challenging. This study presents an integrated energy and emission management strategy for an Euro-VI Diesel

  10. Energy comparison between solar thermal power plant and photovoltaic power plant

    Science.gov (United States)

    Novosel, Urška; Avsec, Jurij

    2017-07-01

    The combined use of renewable energy and alternative energy systems and better efficiency of energy devices is a promising approach to reduce effects due to global warming in the world. On the basis of first and second law of thermodynamics we could optimize the processes in the energy sector. The presented paper shows the comparison between solar thermal power plant and photovoltaic power plant in terms of energy, exergy and life cycle analysis. Solar thermal power plant produces electricity with basic Rankine cycle, using solar tower and solar mirrors to produce high fluid temperature. Heat from the solar system is transferred by using a heat exchanger to Rankine cycle. Both power plants produce hydrogen via electrolysis. The paper shows the global efficiency of the system, regarding production of the energy system.

  11. The nuclear power cycle; Le cycle de l'energie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Fifty years after the first nuclear reactor come on-line, nuclear power is fourth among the world's primary energy sources, after oil, coal and gas. In 2002, there were 441 reactors in operation worldwide. The United States led the world with 104 reactors and an installed capacity of 100,000 MWe, or more than one fourth of global capacity. Electricity from nuclear energy represents 78% of the production in France, 57% in Belgium, 46% in Sweden, 40% in Switzerland, 39% in South Korea, 34% in Japan, 30% in Germany, 30% in Finland, 26% in Spain, 22% in Great Britain, 20% in the United States and 16% in Russia. Worldwide, 32 reactors are under construction, including 21 in Asia. This information document presents the Areva activities in the nuclear power cycle: the nuclear fuel, the nuclear reactors, the spent fuel reprocessing and recycling and nuclear cleanup and dismantling. (A.L.B.)

  12. Modeling the Q-cycle mechanism of transmembrane energy conversion

    Science.gov (United States)

    Smirnov, Anatoly Yu; Nori, Franco

    2012-02-01

    The Q-cycle mechanism plays an important role in the conversion of the redox energy into the energy of the proton electrochemical gradient across the biomembrane. The bifurcated electron transfer reaction, which is built into this mechanism, recycles one electron, thus allowing us to translocate two protons per one electron moving to the high-potential redox chain. We study a kinetic model of the Q-cycle mechanism in an artificial system which mimics the bf complex of plants and cyanobacteria in the regime of ferredoxin-dependent cyclic electron flow. Using methods of condensed matter physics, we derive a set of master equations and describe a time sequence of electron and proton transfer reactions in the complex. We find energetic conditions when the bifurcation of the electron pathways at the positive side of the membrane occurs naturally, without any additional gates. For reasonable parameter values, we show that this system is able to translocate more than 1.8 protons, on average, per one electron, with a thermodynamic efficiency of the order of 32% or higher.

  13. Energy life cycle assessment of rice straw bio-energy derived from potential gasification technologies.

    Science.gov (United States)

    Shie, Je-Lueng; Chang, Ching-Yuan; Chen, Ci-Syuan; Shaw, Dai-Gee; Chen, Yi-Hung; Kuan, Wen-Hui; Ma, Hsiao-Kan

    2011-06-01

    To be a viable alternative, a biofuel should provide a net energy gain and be capable of being produced in large quantities without reducing food supplies. Amounts of agricultural waste are produced and require treatment, with rice straw contributing the greatest source of such potential bio-fuel in Taiwan. Through life-cycle accounting, several energy indicators and four potential gasification technologies (PGT) were evaluated. The input energy steps for the energy life cycle assessment (ELCA) include collection, generator, torrefaction, crushing, briquetting, transportation, energy production, condensation, air pollution control and distribution of biofuels to the point of end use. Every PGT has a positive energy benefit. The input of energy required for the transportation and pre-treatment are major steps in the ELCA. On-site briquetting of refused-derived fuel (RDF) provides an alternative means of reducing transportation energy requirements. Bio-energy sources, such as waste rice straw, provide an ideal material for the bio-fuel plant. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Finite time thermodynamics of power and refrigeration cycles

    CERN Document Server

    Kaushik, Shubhash C; Kumar, Pramod

    2017-01-01

    This book addresses the concept and applications of Finite Time Thermodynamics to various thermal energy conversion systems including heat engines, heat pumps, and refrigeration and air-conditioning systems. The book is the first of its kind, presenting detailed analytical formulations for the design and optimisation of various power producing and cooling cycles including but not limited to: • Vapour power cycles • Gas power cycles • Vapour compression cycles • Vapour absorption cyclesRankine cycle coupled refrigeration systems Further, the book addresses the thermoeconomic analysis for the optimisation of thermal cycles, an important field of study in the present age and which is characterised by multi-objective optimization regarding energy, ecology, the environment and economics. Lastly, the book provides the readers with key techniques associated with Finite Time Thermodynamics, allowing them to understand the relevance of irreversibilitie s associated with real processes and the scientific r...

  15. Application of Solar Energy to Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    M, Nash J; J, Harstad A

    1976-11-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/ Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  16. Application of solar energy to air conditioning systems

    Science.gov (United States)

    Nash, J. M.; Harstad, A. J.

    1976-01-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  17. Water and Energy Cycle EOS House web portal (WECHO)

    Science.gov (United States)

    Li, Z.; Huang, Q.; Li, W.; Zhu, H.; Yang, C.; Houser, P.; Larko, M.

    2008-12-01

    Water is the origin of life, the vast amount of water related Earth observation is of great value to water community users. This paper reports our research and development in providing the Water and Energy Cycle EOS House web portal (WECHO), a web-based tool, for the community to access water resource archived in EOS ClearingHouse (ECHO). WECHO aims to provide users the capabilities to search, browse and visualize data through common browsers, such as Internet Explore and Firefox. WECHO supports users to 1) access all ECHO functionalities, including registering as a new user, querying metadata and ordering delivery of earth observing data, subscribing to updates of interested metadata items and specific events; 2) semantically search ECHO with water ontologies integrated; 3) interactively access Earth Information Exchange (EIE) with the support of Semantic Web for Earth and Environmental Terminology (SWEET) and NOESIS.

  18. The NASA Energy and Water cycle Extreme (NEWSE) Integration Project

    Science.gov (United States)

    Houser, P. R.; Lapenta, W.; Schiffer, R.

    2008-05-01

    Skillful predictions of water and energy cycle extremes (flood and drought) are elusive. To better understand the mechanisms responsible for water and energy extremes, and to make decisive progress in predicting these extremes, the collaborative NASA Energy and Water cycle Extremes (NEWSE) Integration Project, is studying these extremes in the U.S. Southern Great Plains (SGP) during 2006-2007, including their relationships with continental and global scale processes, and assessment of their predictability on multiple space and time scales. It is our hypothesis that an integrative analysis of observed extremes which reflects the current understanding of the role of SST and soil moisture variability influences on atmospheric heating and forcing of planetary waves, incorporating recently available global and regional hydro- meteorological datasets (i.e., precipitation, water vapor, clouds, etc.) in conjunction with advances in data assimilation, can lead to new insights into the factors that lead to persistent drought and flooding. We will show initial results of this project, whose goals are toprovide an improved definition, attribution and prediction on sub-seasonal to interannual time scales, improved understanding of the mechanisms of decadal drought and its predictability, including the impacts of SST variability and deep soil moisture variability, and improved monitoring/attributions, with transition to applications; a bridging of the gap between hydrological forecasts and stakeholders (utilization of probabilistic forecasts, education, forecast interpretation for different sectors, assessment of uncertainties for different sectors, etc.). *The NEWSE Team is: Romanou, Anastasiam, Columbia U.; Brian Soden, U. Miami; William Lapenta, NASA- MSFC; Megan Larko, CREW; Bing Lin, NASA-LaRC; Christa Peters-Lidard, NASA-GSFC; Xiquan Dong, U. North Dakota; Debbie Belvedere, CREW; Mathew Sapiano, U. Maryland; Duane Waliser, NASA-JPL; Eni Njoku, NASA/JPL; Eric Fetzer, NASA

  19. Bayesian Zero-Failure (BAZE) reliability demonstration testing procedure and its application to a Rankine dynamic radioisotope power conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Martz, H.F. Jr.; Waller, R.A.

    1976-07-01

    A Bayesian Zero-Failure (BAZE) reliability demonstration testing procedure is developed. The procedure may be used to verify component failure rates associated with both real-time dependent and cycle-dependent chance failure mechanisms. A constant falure-rate model with a gamma prior distribution is assumed. The procedure is used to obtain sample test plans for components of a proposed Rankine power conversion system.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-02-01

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

  2. The hybrid two stage anticlockwise cycle for ecological energy conversion

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2016-01-01

    Full Text Available The anticlockwise cycle is commonly used for refrigeration, air conditioning and heat pumps applications. The application of refrigerant in the compression cycle is within the temperature limits of the triple point and the critical point. New refrigerants such as 1234yf or 1234ze have many disadvantages, therefore natural refrigerants application is favourable. The carbon dioxide and water can be applied only in the hybrid two stages cycle. The possibilities of this solutions are shown for refrigerating applications, as well some experimental results of the adsorption-compression double stages cycle, powered with solar collectors are shown. As a high temperature cycle the adsorption system is applied. The low temperature cycle is the compression stage with carbon dioxide as a working fluid. This allows to achieve relatively high COP for low temperature cycle and for the whole system.

  3. Energy system analyses of the marginal energy technology in life cycle assessments

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Münster, Marie; Fruergaard, Thilde

    2007-01-01

    In life cycle assessments consequential LCA is used as the “state-of-the-art” methodology, which focuses on the consequences of decisions made in terms of system boundaries, allocation and selection of data, simple and dynamic marginal technology, etc.(Ekvall & Weidema 2004). In many LCA studies......, the energy demand applied is decisive for the results. In this extended abstract, consequential LCA methodology is examined with electricity as the case. The aim is to answer three questions: Which are the expected vs. the actual marginal electricity production technologies and what may be the future...... in historical and potential future energy systems. Subsequently, key LCA studies of products and different waste flows are analysed in relation to the recom- mendations in consequential LCA. Finally, a case of increased waste used for incineration is examined using an energy system analysis model...

  4. The influence of the menstrual cycle on energy balance and taste preference in Asian Chinese women.

    Science.gov (United States)

    Elliott, Sarah A; Ng, Janet; Leow, Melvin Khee-Shing; Henry, Christiani J K

    2015-12-01

    In Caucasian women, research has shown that energy balance and taste preference change throughout the menstrual cycle. However, the contributory role of the menstrual cycle to obesity and insulin resistance among Asian women remains unclear. We investigate the impact of the menstrual cycle on energy balance and taste preference in Singaporean Chinese females. Thirty-one healthy young Chinese female subjects with regular menstrual cycles were recruited. Anthropometrics, body composition, energy intake, resting metabolic rate, premenstrual syndrome (PMS) severity and taste preference to sucrose were assessed during three phases (menses, follicular and luteal), over one (N = 18) to two (N = 13) menstrual cycles. For all subjects (N = 31), we found significant reductions in energy, fat intake (p energy and macronutrient intake throughout Cycle 2. RMR was similar across the three phases. However, non-significant cyclic variations were noted within and between the cycles. Cyclic variations in energy intake and expenditure contributed by sensory and behavioural changes occur during the menstrual cycle. Whether this contributes to cyclic weight gain is speculative and remains to be proven. Further research in non-Caucasians spanning more than one menstrual cycle is needed to establish the impact of the menstrual cycle on taste preference and energy balance.

  5. Electromechanical conversion efficiency for dielectric elastomer generator in different energy harvesting cycles

    Directory of Open Access Journals (Sweden)

    Jian-Bo Cao

    2017-11-01

    Full Text Available In order to improve electromechanical conversion efficiency for dielectric elastomer generators (DEG, on the base of studying DEG energy harvesting cycles of constant voltage, constant charge and constant electric field intensity, a new combined cycle mode and optimization theory in terms of the generating mechanism and electromechanical coupling process have been built. By controlling the switching point to achieve the best energy conversion cycle, the energy loss in the energy conversion process is reduced. DEG generating test bench which was used to carry out comparative experiments has been established. Experimental results show that the collected energy in constant voltage cycle, constant charge cycle and constant electric field intensity energy harvesting cycle decreases in turn. Due to the factors such as internal resistance losses, electrical losses and so on, actual energy values are less than the theoretical values. The electric energy conversion efficiency by combining constant electric field intensity cycle with constant charge cycle is larger than that of constant electric field intensity cycle. The relevant conclusions provide a basis for the further applications of DEG.

  6. Electromechanical conversion efficiency for dielectric elastomer generator in different energy harvesting cycles

    Science.gov (United States)

    Cao, Jian-Bo; E, Shi-Ju; Guo, Zhuang; Gao, Zhao; Luo, Han-Pin

    2017-11-01

    In order to improve electromechanical conversion efficiency for dielectric elastomer generators (DEG), on the base of studying DEG energy harvesting cycles of constant voltage, constant charge and constant electric field intensity, a new combined cycle mode and optimization theory in terms of the generating mechanism and electromechanical coupling process have been built. By controlling the switching point to achieve the best energy conversion cycle, the energy loss in the energy conversion process is reduced. DEG generating test bench which was used to carry out comparative experiments has been established. Experimental results show that the collected energy in constant voltage cycle, constant charge cycle and constant electric field intensity energy harvesting cycle decreases in turn. Due to the factors such as internal resistance losses, electrical losses and so on, actual energy values are less than the theoretical values. The electric energy conversion efficiency by combining constant electric field intensity cycle with constant charge cycle is larger than that of constant electric field intensity cycle. The relevant conclusions provide a basis for the further applications of DEG.

  7. Uncertainties related to the identification of the marginal energy technology in consequential life cycle assessments

    DEFF Research Database (Denmark)

    Mathiesen, B.V.; Münster, Marie; Fruergaard, Thilde

    2009-01-01

    When performing life cycle assessment (LCA) assumptions regarding the energy use are often decisive for the outcome. In this paper, current approaches of identifying marginal electricity and heat technologies for consequential LCAs are challenged. The identification of marginal energy technologies...

  8. The Sleep/Wake Cycle is Directly Modulated by Changes in Energy Balance

    OpenAIRE

    Collet Tinh-Hai; van, der Klaauw Agatha A; Henning Elana; Keogh Julia M.; Suddaby Diane; Dachi Sekesai V; Dunbar Síle; Kelway Sarah; Dickson Suzanne L; Farooqi I. Sadaf; Schmid Sebastian M

    2016-01-01

    The rise in obesity has been paralleled by a decline in sleep duration in epidemiological studies. However the potential mechanisms linking energy balance and the sleep/wake cycle are not well understood. We aimed to examine the effects of manipulating energy balance on the sleep/wake cycle. Twelve healthy normal weight men were housed in a clinical research facility and studied at three time points: baseline after energy balance was disrupted by 2 days of caloric restriction to 10 of energy ...

  9. Energy from CO2 using capacitive electrodes - a model for energy extraction cycles.

    Science.gov (United States)

    Paz-Garcia, J M; Dykstra, J E; Biesheuvel, P M; Hamelers, H V M

    2015-03-15

    A model is presented for the process of harvesting electrical energy from CO2 emissions using capacitive cells. The principle consists of controlling the mixing process of a concentrated CO2 gas stream with a dilute CO2 gas stream (as, for example, exhaust gas and air), thereby converting part of the released mixing energy into electrical energy. The model describes the transient reactive transport of CO2 gas absorbed in water or in monoethanolamine (MEA) solutions, under the assumption of local chemical equilibrium. The model combines the selective transport of ions through ion-exchange membranes, the accumulation of charge in the porous carbon electrodes and the coupling between the ionic current and the produced electrical current and power. We demonstrate that the model can be used to calculate the energy that can be extracted by mixing concentrated and dilute CO2 containing gas streams. Our calculation results for the process using MEA solutions have various counterintuitive features, including: 1. When dynamic equilibrium is reached in the cyclical process, the electrical charge in the anode is negative both during charging and discharging; 2. Placing an anion-exchange membrane (AEM) in the system is not required, the energy per cycle is just as large with or without an AEM. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Erroneous energy-generating cycles in published genome scale metabolic networks: Identification and removal

    Science.gov (United States)

    Hartleb, Daniel; Papp, Balázs

    2017-01-01

    Energy metabolism is central to cellular biology. Thus, genome-scale models of heterotrophic unicellular species must account appropriately for the utilization of external nutrients to synthesize energy metabolites such as ATP. However, metabolic models designed for flux-balance analysis (FBA) may contain thermodynamically impossible energy-generating cycles: without nutrient consumption, these models are still capable of charging energy metabolites (such as ADP→ATP or NADP+→NADPH). Here, we show that energy-generating cycles occur in over 85% of metabolic models without extensive manual curation, such as those contained in the ModelSEED and MetaNetX databases; in contrast, such cycles are rare in the manually curated models of the BiGG database. Energy generating cycles may represent model errors, e.g., erroneous assumptions on reaction reversibilities. Alternatively, part of the cycle may be thermodynamically feasible in one environment, while the remainder is thermodynamically feasible in another environment; as standard FBA does not account for thermodynamics, combining these into an FBA model allows erroneous energy generation. The presence of energy-generating cycles typically inflates maximal biomass production rates by 25%, and may lead to biases in evolutionary simulations. We present efficient computational methods (i) to identify energy generating cycles, using FBA, and (ii) to identify minimal sets of model changes that eliminate them, using a variant of the GlobalFit algorithm. PMID:28419089

  11. Waste-to-energy: A review of life cycle assessment and its extension methods.

    Science.gov (United States)

    Zhou, Zhaozhi; Tang, Yuanjun; Chi, Yong; Ni, Mingjiang; Buekens, Alfons

    2018-01-01

    This article proposes a comprehensive review of evaluation tools based on life cycle thinking, as applied to waste-to-energy. Habitually, life cycle assessment is adopted to assess environmental burdens associated with waste-to-energy initiatives. Based on this framework, several extension methods have been developed to focus on specific aspects: Exergetic life cycle assessment for reducing resource depletion, life cycle costing for evaluating its economic burden, and social life cycle assessment for recording its social impacts. Additionally, the environment-energy-economy model integrates both life cycle assessment and life cycle costing methods and judges simultaneously these three features for sustainable waste-to-energy conversion. Life cycle assessment is sufficiently developed on waste-to-energy with concrete data inventory and sensitivity analysis, although the data and model uncertainty are unavoidable. Compared with life cycle assessment, only a few evaluations are conducted to waste-to-energy techniques by using extension methods and its methodology and application need to be further developed. Finally, this article succinctly summarises some recommendations for further research.

  12. Large Scale Duty Cycle (LSDC) Project: Tractive Energy Analysis Methodology and Results from Long-Haul Truck Drive Cycle Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    LaClair, Tim J [ORNL

    2011-05-01

    This report addresses the approach that will be used in the Large Scale Duty Cycle (LSDC) project to evaluate the fuel savings potential of various truck efficiency technologies. The methods and equations used for performing the tractive energy evaluations are presented and the calculation approach is described. Several representative results for individual duty cycle segments are presented to demonstrate the approach and the significance of this analysis for the project. The report is divided into four sections, including an initial brief overview of the LSDC project and its current status. In the second section of the report, the concepts that form the basis of the analysis are presented through a discussion of basic principles pertaining to tractive energy and the role of tractive energy in relation to other losses on the vehicle. In the third section, the approach used for the analysis is formalized and the equations used in the analysis are presented. In the fourth section, results from the analysis for a set of individual duty cycle measurements are presented and different types of drive cycles are discussed relative to the fuel savings potential that specific technologies could bring if these drive cycles were representative of the use of a given vehicle or trucking application. Additionally, the calculation of vehicle mass from measured torque and speed data is presented and the accuracy of the approach is demonstrated.

  13. Task Order 20: Supercritical Carbon Dioxide Brayton Cycle Energy Conversion Study

    Energy Technology Data Exchange (ETDEWEB)

    Murray, Paul [AREVA Federal Services, LLC, Charlotte, NC (United States); Lindsay, Edward [AREVA Federal Services, LLC, Charlotte, NC (United States); McDowell, Michael [AREVA Federal Services, LLC, Charlotte, NC (United States); Huang, Megan [AREVA Federal Services, LLC, Charlotte, NC (United States)

    2015-04-23

    AREVA Inc. developed this study for the US Department of Energy (DOE) office of Nuclear Energy (NE) in accordance with Task Order 20 Statement of Work (SOW) covering research and development activities for the Supercritical Carbon Dioxide (sCO2) Brayton Cycle energy conversion. The study addresses the conversion of sCO2 heat energy to electrical output by use of a Brayton Cycle system and focuses on the potential of a net efficiency increase via cycle recuperation and recompression stages. The study also addresses issues and study needed to advance development and implementation of a 10 MWe sCO2 demonstration project.

  14. Life Cycle Assessment of High Temperature Geothermal Energy Systems

    OpenAIRE

    Marchand, Mathilde; Blanc, Isabelle; Marquand, Aline; Beylot, Antoine; Bezelgues-Courtade, Sophie; Traineau, Hervé

    2015-01-01

    International audience; European and French regulations state that 50% of the energy mix in the French Caribbean should be sourced from renewable energies by 2020. Because of the volcanic conditions of the French Caribbean islands, geothermal energy would seem to be a very favorable solution to reach this ambitious objective, as, unlike other renewable sources, it is continuous and weather independent. According to the Intergovernmental Panel on Climate Change (IPCC), geothermal energy source...

  15. Life cycle assessments of energy from solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Finnveden, Goeran; Johansson, Jessica; Lind, Per; Moberg, Aasa [Stockholm Univ. (Sweden). Dept. of Systems Ecology/Natural Resoruces Management Inst.]|[Defence Research Establishment, Stockholm (Sweden). Div. of Defence Analysis

    2000-09-01

    The overall aim of the present study is to evaluate different strategies for treatment of solid waste based on a life-cycle perspective. Important goals are to identify advantages and disadvantages of different methods for treatment of solid waste, and to identify critical factors in the systems, including the background systems, which may significantly influence the results. Included in the study are landfilling, incineration, recycling, digestion and composting. The waste fractions considered are the combustible and recyclable or compostable fractions of municipal solid waste. The methodology used is Life Cycle Assessment. The results can be used for policy decisions as well as strategic decisions on waste management systems.

  16. A fuel cycle assessment guide for utility and state energy planners

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    This guide, one in a series of documents designed to help assess fuel cycles, is a framework for setting parameters, collecting data, and analyzing fuel cycles for supply-side and demand-side management. It provides an automated tool for entering comparative fuel cycle data that are meaningful to state and utility integrated resource planning, collaborative, and regional energy planning activities. It outlines an extensive range of energy technology characteristics and environmental, social, and economic considerations within each stage of a fuel cycle. The guide permits users to focus on specific stages or effects that are relevant to the technology being evaluated and that meet the user`s planning requirements.

  17. Life-cycle energy analyses of electric vehicle storage batteries. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D; Morse, T; Patel, P; Patel, S; Bondar, J; Taylor, L

    1980-12-01

    The results of several life-cycle energy analyses of prospective electric vehicle batteries are presented. The batteries analyzed were: Nickel-zinc; Lead-acid; Nickel-iron; Zinc-chlorine; Sodium-sulfur (glass electrolyte); Sodium-sulfur (ceramic electrolyte); Lithium-metal sulfide; and Aluminum-air. A life-cycle energy analysis consists of evaluating the energy use of all phases of the battery's life, including the energy to build it, operate it, and any credits that may result from recycling of the materials in it. The analysis is based on the determination of three major energy components in the battery life cycle: Investment energy, i.e., The energy used to produce raw materials and to manufacture the battery; operational energy i.e., The energy consumed by the battery during its operational life. In the case of an electric vehicle battery, this energy is the energy required (as delivered to the vehicle's charging circuit) to power the vehicle for 100,000 miles; and recycling credit, i.e., The energy that could be saved from the recycling of battery materials into new raw materials. The value of the life-cycle analysis approach is that it includes the various penalties and credits associated with battery production and recycling, which enables a more accurate determination of the system's ability to reduce the consumption of scarce fuels. The analysis of the life-cycle energy requirements consists of identifying the materials from which each battery is made, evaluating the energy needed to produce these materials, evaluating the operational energy requirements, and evaluating the amount of materials that could be recycled and the energy that would be saved through recycling. Detailed descriptions of battery component materials, the energy requirements for battery production, and credits for recycling, and the operational energy for an electric vehicle, and the procedures used to determine it are discussed.

  18. Sustainable Energy Solutions Task 3.0:Life-Cycle Database for Wind Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Twomey, Janet M. [Wichita State Univ., KS (United States)

    2010-03-01

    The benefits of wind energy had previously been captured in the literature at an overview level with relatively low transparency or ability to understand the basis for that information. This has limited improvement and decision-making to larger questions such as wind versus other electrical sources (such as coal-fired plants). This research project has established a substantially different approach which is to add modular, high granularity life cycle inventory (lci) information that can be used by a wide range of decision-makers, seeking environmental improvement. Results from this project have expanded the understanding and evaluation of the underlying factors that can improve both manufacturing processes and specifically wind generators. The use of life cycle inventory techniques has provided a uniform framework to understand and compare the full range of environmental improvement in manufacturing, hence the concept of green manufacturing. In this project, the focus is on 1. the manufacturing steps that transform materials and chemicals into functioning products 2. the supply chain and end-of-life influences of materials and chemicals used in industry Results have been applied to wind generators, but also impact the larger U.S. product manufacturing base. For chemicals and materials, this project has provided a standard format for each lci that contains an overview and description, a process flow diagram, detailed mass balances, detailed energy of unit processes, and an executive summary. This is suitable for integration into other life cycle databases (such as that at NREL), so that broad use can be achieved. The use of representative processes allows unrestricted use of project results. With the framework refined in this project, information gathering was initiated for chemicals and materials in wind generation. Since manufacturing is one of the most significant parts of the environmental domain for wind generation improvement, this project research has

  19. Life Cycle Energy Assessment of a Multi-storey Residential Building

    Science.gov (United States)

    Mehta, Sourabh; Chandur, Arjun; Palaniappan, Sivakumar

    2017-06-01

    This study presents the findings of life cycle energy assessment of two multi-storey residential buildings. These buildings consist of a total of 60 homes. The usable floor area is 43.14 m2 (463.36 ft2) per home. A detailed estimation of embodied energy is carried out by considering the use of materials during building construction. Major contributors of embodied energy are found to be steel, cement and aluminum. Monthly building operation energy was assessed using a total of 2520 data samples corresponding to 3 years of building operation. Analysis of a base case scenario, with 50 years of service life and average monthly operation energy, indicates that the embodied energy and the operation energy account for 16 and 84% of the life cycle energy respectively. Sensitivity analysis is carried out to study the influence of service life and operation energy on the relative contribution of embodied energy and operation energy. It is found that the embodied energy represents as high as 31% of the life cycle energy depending upon the variation in the operation energy and the service life. Hence, strategies towards sustainable building construction should also focus on reducing the embodied energy in the design and construction phases in addition to operation energy.

  20. Earth's changing global atmospheric energy cycle in response to climate change

    Science.gov (United States)

    Pan, Yefeng; Li, Liming; Jiang, Xun; Li, Gan; Zhang, Wentao; Wang, Xinyue; Ingersoll, Andrew P.

    2017-01-01

    The Lorenz energy cycle is widely used to investigate atmospheres and climates on planets. However, the long-term temporal variations of such an energy cycle have not yet been explored. Here we use three independent meteorological data sets from the modern satellite era, to examine the temporal characteristics of the Lorenz energy cycle of Earth's global atmosphere in response to climate change. The total mechanical energy of the global atmosphere basically remains constant with time, but the global-average eddy energies show significant positive trends. The spatial investigations suggest that these positive trends are concentrated in the Southern Hemisphere. Significant positive trends are also found in the conversion, generation and dissipation rates of energies. The positive trends in the dissipation rates of kinetic energies suggest that the efficiency of the global atmosphere as a heat engine increased during the modern satellite era.

  1. A Biologically Inspired Energy-Efficient Duty Cycle Design Method for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jie Zhou

    2017-01-01

    Full Text Available The recent success of emerging wireless sensor networks technology has encouraged researchers to develop new energy-efficient duty cycle design algorithm in this field. The energy-efficient duty cycle design problem is a typical NP-hard combinatorial optimization problem. In this paper, we investigate an improved elite immune evolutionary algorithm (IEIEA strategy to optimize energy-efficient duty cycle design scheme and monitored area jointly to enhance the network lifetimes. Simulation results show that the network lifetime of the proposed IEIEA method increased compared to the other two methods, which means that the proposed method improves the full coverage constraints.

  2. ENERGY AND OUR ENVIRONMENT: A SYSTEMS AND LIFE CYCLE PERSPECTIVE

    Science.gov (United States)

    This is a presentation to the North Carolina BREATE Conference on March 28, 2017. This presentation provides an overview of energy modeling capabilities in ORD, and includes examples related to scenario development, water-energy nexus, bioenergy, etc. The focus is on system ap...

  3. Designing renewable energy systems a life cycle assessment approach

    CERN Document Server

    Gerber, Leda

    2014-01-01

    The book discusses a multi-objective optimization approach in LCA that allows the flexible construction of comprehensive Pareto fronts to help understand the weightings and relative importance of its elements. The methodology is applied to the pertinent topics of thermochemical wood conversion, deep geothermal energy, and regional energy planning.

  4. Life cycle analysis of underground thermal energy storage

    NARCIS (Netherlands)

    Tomasetta, Camilla; van Ree, Derk; Griffioen, Jasper

    2015-01-01

    Underground Thermal Energy Storage (UTES) systems are used to buffer the seasonal difference between heat and cold supply and demand and, therefore, represent an interesting option to conserve energy. Even though UTES are considered environmental friendly solutions they are not completely free of

  5. THERMODYNAMIC CYCLE OPTIMIZATION IN THE GEOTHERMAL ENERGY PRODUCTION

    Directory of Open Access Journals (Sweden)

    Miroslav Golub

    2004-12-01

    Full Text Available Optimization of geothermal energy production process means the minimization of all energy losses from the reservoir conditions to the user. As the available energy is being utilized mostly in the wellbore and in the surface equipment, process optimization requires scientific access including the extraction technology parameters.Specific energy on the geothermal wellhead is calculated for two possible cases. The first embraces only geothermal water production, while the other takes into account the saturated steam production as well. Each of these working conditions defines unambiguously designed pressure on the wellhead.The steam and water energy ratio, in function of predicted sink temperature for reinjection of geothermal water, points out the possibilities for commercialization of reservoir Velika Ciglena.

  6. NASA Contributions to Improve Understanding of Extreme Events in the Global Energy and Water Cycle

    Science.gov (United States)

    Lapenta, William M.

    2008-01-01

    The U.S. Climate Change Science Program (CCSP) has established the water cycle goals of the Nation's climate change program. Accomplishing these goals will require, in part, an accurate accounting of the key reservoirs and fluxes associated with the global water and energy cycle, including their spatial and temporal variability. through integration of all necessary observations and research tools, To this end, in conjunction with NASA's Earth science research strategy, the overarching long-term NASA Energy and Water Cycle Study (NEWS) grand challenge can he summarized as documenting and enabling improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. This challenge requires documenting and predicting trends in the rate of the Earth's water and energy cycling that corresponds to climate change and changes in the frequency and intensity of naturally occurring related meteorological and hydrologic events, which may vary as climate may vary in the future. The cycling of water and energy has obvious and significant implications for the health and prosperity of our society. The importance of documenting and predicting water and energy cycle variations and extremes is necessary to accomplish this benefit to society.

  7. Life-cycle energy impacts for adapting an urban water supply system to droughts.

    Science.gov (United States)

    Lam, Ka Leung; Stokes-Draut, Jennifer R; Horvath, Arpad; Lane, Joe L; Kenway, Steven J; Lant, Paul A

    2017-12-15

    In recent years, cities in some water stressed regions have explored alternative water sources such as seawater desalination and potable water recycling in spite of concerns over increasing energy consumption. In this study, we evaluate the current and future life-cycle energy impacts of four alternative water supply strategies introduced during a decade-long drought in South East Queensland (SEQ), Australia. These strategies were: seawater desalination, indirect potable water recycling, network integration, and rainwater tanks. Our work highlights the energy burden of alternative water supply strategies which added approximately 24% life-cycle energy use to the existing supply system (with surface water sources) in SEQ even for a current post-drought low utilisation status. Over half of this additional life-cycle energy use was from the centralised alternative supply strategies. Rainwater tanks contributed an estimated 3% to regional water supply, but added over 10% life-cycle energy use to the existing system. In the future scenario analysis, we compare the life-cycle energy use between "Normal", "Dry", "High water demand" and "Design capacity" scenarios. In the "Normal" scenario, a long-term low utilisation of the desalination system and the water recycling system has greatly reduced the energy burden of these centralised strategies to only 13%. In contrast, higher utilisation in the unlikely "Dry" and "Design capacity" scenarios add 86% and 140% to life-cycle energy use of the existing system respectively. In the "High water demand" scenario, a 20% increase in per capita water use over 20 years "consumes" more energy than is used by the four alternative strategies in the "Normal" scenario. This research provides insight for developing more realistic long-term scenarios to evaluate and compare life-cycle energy impacts of drought-adaptation infrastructure and regional decentralised water sources. Scenario building for life-cycle assessments of water supply

  8. Energy life-cycle analysis modeling and decision support tool

    Energy Technology Data Exchange (ETDEWEB)

    Hoza, M.; White, M.E.

    1993-06-01

    As one of DOE`s five multi-program national laboratories, Pacific Northwest Laboratory (PNL) develops and deploys technology for national missions in energy and the environment. The Energy Information Systems Group, within the Laboratory`s Computer Sciences Department, focuses on the development of the computational and data communications infrastructure and automated tools for the Transmission and Distribution energy sector and for advanced process engineering applications. The energy industry is being forced to operate in new ways and under new constraints. It is in a reactive mode, reacting to policies and politics, and to economics and environmental pressures. The transmission and distribution sectors are being forced to find new ways to maximize the use of their existing infrastructure, increase energy efficiency, and minimize environmental impacts, while continuing to meet the demands of an ever increasing population. The creation of a sustainable energy future will be a challenge for both the soft and hard sciences. It will require that we as creators of our future be bold in the way we think about our energy future and aggressive in its development. The development of tools to help bring about a sustainable future will not be simple either. The development of ELCAM, for example, represents a stretch for the computational sciences as well as for each of the domain sciences such as economics, which will have to be team members.

  9. Life cycle assessment of the wave energy converter: Wave Dragon

    DEFF Research Database (Denmark)

    Hans Chr., Sørensen; Stefan, Naef; Stefan, Anderberg

    Any power production technology should be able to demonstrate that it's able to comply with current and future environmental regulation and that it demonstrates a considerable surplus in the energy balance being a part of the entire power system. This means that the energy used throughout all...... the lifecycle stages; from provision of materials over manufacturing of components and assembly, to deployment and use and eventually the disposal stage, is considerably less than the energy produced by the devise during its use/production stage....

  10. Determination of optimal pacing strategy in track cycling with an energy flow model

    NARCIS (Netherlands)

    de Koning, J.J.; Bobbert, M.F.; Foster, C.

    1999-01-01

    The purpose of this study was to investigate the effect of pacing strategies on performance times in the 1000 m time trial event and the 4000 m pursuit event in track cycling. For this purpose, we simulated these events with a model based on the flow of energy in cycling. Different strategies in

  11. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 3: Energy conversion subsystems and components. Part 1: Bottoming cycles and materials of construction

    Science.gov (United States)

    Shah, R. P.; Solomon, H. D.

    1976-01-01

    Energy conversion subsystems and components were evaluated in terms of advanced energy conversion systems. Results of the bottoming cycles and materials of construction studies are presented and discussed.

  12. Kinetic energy budgets during the life cycle of intense convective activity

    Science.gov (United States)

    Fuelberg, H. E.; Scoggins, J. R.

    1978-01-01

    Synoptic-scale data at three- and six-hour intervals are employed to study the relationship between changing kinetic energy variables and the life cycles of two severe squall lines. The kinetic energy budgets indicate a high degree of kinetic energy generation, especially pronounced near the jet-stream level. Energy losses in the storm environment are due to the transfer of kinetic energy from grid to subgrid scales of motion; large-scale upward vertical motion carries aloft the kinetic energy generated by storm activity at lower levels. In general, the time of maximum storm intensity is also the time of maximum energy conversion and transport.

  13. Global Energy and Water Cycle Experiment (GEWEX) and the Continental-scale International Project (GCIP)

    Science.gov (United States)

    Vane, Deborah

    1993-01-01

    A discussion of the objectives of the Global Energy and Water Cycle Experiment (GEWEX) and the Continental-scale International Project (GCIP) is presented in vugraph form. The objectives of GEWEX are as follows: determine the hydrological cycle by global measurements; model the global hydrological cycle; improve observations and data assimilation; and predict response to environmental change. The objectives of GCIP are as follows: determine the time/space variability of the hydrological cycle over a continental-scale region; develop macro-scale hydrologic models that are coupled to atmospheric models; develop information retrieval schemes; and support regional climate change impact assessment.

  14. Biologically enhanced energy and carbon cycling on Titan?

    Science.gov (United States)

    Schulze-Makuch, Dirk; Grinspoon, David H

    2005-08-01

    With the Cassini-Huygens Mission in orbit around Saturn, the large moon Titan, with its reducing atmosphere, rich organic chemistry, and heterogeneous surface, moves into the astrobiological spotlight. Environmental conditions on Titan and Earth were similar in many respects 4 billion years ago, the approximate time when life originated on Earth. Life may have originated on Titan during its warmer early history and then developed adaptation strategies to cope with the increasingly cold conditions. If organisms originated and persisted, metabolic strategies could exist that would provide sufficient energy for life to persist, even today. Metabolic reactions might include the catalytic hydrogenation of photochemically produced acetylene, or involve the recombination of radicals created in the atmosphere by ultraviolet radiation. Metabolic activity may even contribute to the apparent youth, smoothness, and high activity of Titan's surface via biothermal energy.

  15. A Spatial Model of the Biomass to Energy Cycle

    DEFF Research Database (Denmark)

    Möller, Bernd

    2003-01-01

    by location. This paper aims to contribute to the development of a biomass to energy evaluation and mapping system, using geographical information systems (GIS). A GIS-based in-forest residue model considers forest growth and choice of harvest method. Data from a sawmill survey is used to assess sawmill resi......A major source of biomass for energy production is the New Zealand forest industry, with 1.5 M tons of in-forest residues and additional 0.4 M tons as unused residues from sawmills. Transportation and handling are the main contributors for biomass costs at a specific consumer site, and they vary......-dues. For both sources the costs of road transportation have been modelled using spatial cost allocation. As emphasis has been on using public data, the model is still a rough es-timate, which could be improved using forest industry data and refined algorithms. As a first result, the cost distribution...

  16. An Interactive Environmental Economy Model for Energy Cycle in Iran

    Directory of Open Access Journals (Sweden)

    M Shafie-Pour Motlagh, MM Farsiabi, HR Kamalan

    2005-04-01

    Full Text Available The growing world economy calls for saving natural resources with sustainable development framework. This paper intends to look at the environment-energy interface (impacts on the environment stemming form the energy sector and to propose measures for reducing this impact without trying to impede economic development. In addition, this paper estimates the amounts of energy subsidies about 20% of Gross Domestic Product (GDP in 2019 if the conditions do not change. Meanwhile, environmental damage from air pollution has been assessed by scaling according to GDP per capita measured in purchase power parity (PPP terms. Using this approach, the total damage from air pollution in 2001 was assessed about $7billion; equivalent to 8.4% of nominal GDP. Lacking price reform and control policies, the authors estimate that damage in Iran will grow to 10.9% of GDP by 2019. In line with difficulties of eliminating subsidies, a list of 25 measures has been analyzed, using the environmental cost-benefit analysis and based on cost-effectiveness of the policies to verify which ones would be implemented. Finally the financial effects of implementing different combinations of price reform and carrying out those policies on the state budget, damage costs and subsidies have been calculated.

  17. Number theory and modular forms papers in memory of Robert A Rankin

    CERN Document Server

    Ono, Ken

    2003-01-01

    Robert A. Rankin, one of the world's foremost authorities on modular forms and a founding editor of The Ramanujan Journal, died on January 27, 2001, at the age of 85. Rankin had broad interests and contributed fundamental papers in a wide variety of areas within number theory, geometry, analysis, and algebra. To commemorate Rankin's life and work, the editors have collected together 25 papers by several eminent mathematicians reflecting Rankin's extensive range of interests within number theory. Many of these papers reflect Rankin's primary focus in modular forms. It is the editors' fervent hope that mathematicians will be stimulated by these papers and gain a greater appreciation for Rankin's contributions to mathematics. This volume would be an inspiration to students and researchers in the areas of number theory and modular forms.

  18. 75 FR 17397 - Hydrogen Energy California's Integrated Gasification Combined Cycle Project, Kern County, CA...

    Science.gov (United States)

    2010-04-06

    ... Hydrogen Energy California's Integrated Gasification Combined Cycle Project, Kern County, CA--Notice of... by Hydrogen Energy California LLC (HECA). DOE selected this project for an award of financial... produce synthesis gas (syngas), which would then be processed and purified to produce a hydrogen-rich fuel...

  19. Long-term shifts in life-cycle energy efficiency and carbon intensity.

    Science.gov (United States)

    Yeh, Sonia; Mishra, Gouri Shankar; Morrison, Geoff; Teter, Jacob; Quiceno, Raul; Gillingham, Kenneth; Riera-Palou, Xavier

    2013-03-19

    The quantity of primary energy needed to support global human activity is in large part determined by how efficiently that energy is converted to a useful form. We estimate the system-level life-cycle energy efficiency (EF) and carbon intensity (CI) across primary resources for 2005-2100. Our results underscore that although technological improvements at each energy conversion process will improve technology efficiency and lead to important reductions in primary energy use, market mediated effects and structural shifts toward less efficient pathways and pathways with multiple stages of conversion will dampen these efficiency gains. System-level life-cycle efficiency may decrease as mitigation efforts intensify, since low-efficiency renewable systems with high output have much lower GHG emissions than some high-efficiency fossil fuel systems. Climate policies accelerate both improvements in EF and the adoption of renewable technologies, resulting in considerably lower primary energy demand and GHG emissions. Life-cycle EF and CI of useful energy provide a useful metric for understanding dynamics of implementing climate policies. The approaches developed here reiterate the necessity of a combination of policies that target efficiency and decarbonized energy technologies. We also examine life-cycle exergy efficiency (ExF) and find that nearly all of the qualitative results hold regardless of whether we use ExF or EF.

  20. Energy based study of quasi-static delamination as a low cycle fatigue process

    NARCIS (Netherlands)

    Amaral, L.; Yao, L.; Alderliesten, R.C.; Benedictus, R.

    2015-01-01

    This work proposes to treat quasi-static mode I delamination growth of CFRP as a low-cycle fatigue process. To this end, mode I quasi-static and fatigue delamination tests were performed. An average physical Strain Energy Release Rate (SERR), derived from an energy balance, is used to characterize

  1. The Sleep/Wake Cycle is Directly Modulated by Changes in Energy Balance.

    OpenAIRE

    Collet Tinh-Hai; van, der Klaauw Agatha A; Henning Elana; Keogh Julia M.; Suddaby Diane; Dachi Sekesai V; Dunbar Síle; Kelway Sarah; Dickson Suzanne L; Farooqi I. Sadaf; Schmid Sebastian M

    2016-01-01

    STUDY OBJECTIVES:The rise in obesity has been paralleled by a decline in sleep duration in epidemiological studies. However the potential mechanisms linking energy balance and the sleep/wake cycle are not well understood. We aimed to examine the effects of manipulating energy balance on the sleep/wake cycle. METHODS:Twelve healthy normal weight men were housed in a clinical research facility and studied at three time points: baseline after energy balance was disrupted by 2 days of caloric re...

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

    Science.gov (United States)

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

    2017-06-01

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

  3. Life cycle inventory energy consumption and emissions for biodiesel versus petroleum diesel fueled construction vehicles.

    Science.gov (United States)

    Pang, Shih-Hao; Frey, H Christopher; Rasdorf, William J

    2009-08-15

    Substitution of soy-based biodiesel fuels for petroleum diesel will alter life cycle emissions for construction vehicles. A life cycle inventory was used to estimate fuel cycle energy consumption and emissions of selected pollutants and greenhouse gases. Real-world measurements using a portable emission measurement system (PEMS) were made forfive backhoes, four front-end loaders, and six motor graders on both fuels from which fuel consumption and tailpipe emission factors of CO, HC, NO(x), and PM were estimated. Life cycle fossil energy reductions are estimated it 9% for B20 and 42% for B100 versus petroleum diesel based on the current national energy mix. Fuel cycle emissions will contribute a larger share of total life cycle emissions as new engines enter the in-use fleet. The average differences in life cycle emissions for B20 versus diesel are: 3.5% higher for NO(x); 11.8% lower for PM, 1.6% higher for HC, and 4.1% lower for CO. Local urban tailpipe emissions are estimated to be 24% lower for HC, 20% lower for CO, 17% lower for PM, and 0.9% lower for NO(x). Thus, there are environmental trade-offs such as for rural vs urban areas. The key sources of uncertainty in the B20 LCI are vehicle emission factors.

  4. Rethinking Racism in Claudia Rankine's Citizen: An American Lyric

    OpenAIRE

    Hersi, Asli

    2016-01-01

    The issue of race in America in the twenty-first century is still a turbulent matter. The end of segregation in schools, politics, marriages and workplaces created a mask that hid racial inequalities and injustices (Whitmarsh 1). In a time where police brutalities have frequently surfaced in the media in a supposed “post-racial America”, Claudia Rankine writes a thought-provoking 160 page long “book-length poem” about everyday racism arguing that the overlooking of microaggressions (brief dai...

  5. Rethinking Racism in Claudia Rankine's Citizen: An American Lyric

    OpenAIRE

    Hersi, Asli

    2016-01-01

    Master's thesis in Literacy studies The issue of race in America in the twenty-first century is still a turbulent matter. The end of segregation in schools, politics, marriages and workplaces created a mask that hid racial inequalities and injustices (Whitmarsh 1). In a time where police brutalities have frequently surfaced in the media in a supposed “post-racial America”, Claudia Rankine writes a thought-provoking 160 page long “book-length poem” about everyday racism arguing that the ove...

  6. The challenge of storage in the hydrogen energy cycle: nanostructured hydrides as a potential solution

    OpenAIRE

    Hanlon, James M.; Reardon, Hazel; Tapia-Ruiz, Nuria; Gregory, Duncan H.

    2012-01-01

    Hydrogen has the capacity to provide society with the means to carry ‘green’ energy between the point of generation and the point of use. A sustainable energy society in which a hydrogen economy predominates will require renewable generation provided, for example, by artificial photosynthesis and clean, efficient energy conversion effected, for example, by hydrogen fuel cells. Vital in the hydrogen cycle is the ability to store hydrogen safely and effectively. Solid-state storage in hydrides ...

  7. Life Cycle Energy and CO2 Analysis of a Student Residential Building in Ningbo, China.

    OpenAIRE

    Medel Jimenez, Francisco Javier

    2017-01-01

    Buildings with installed photovoltaic power systems tend to consume less energy and create less environmental damage. However, these photovoltaic power systems also can generate a significant amount of energy and environmental impacts during their manufacturing and installation processes. There are numerous life cycle assessment studies evaluating the amount of energy and carbon emissions that photovoltaic systems generate, but normally the system boundaries of these assessments are limited t...

  8. Simulation of Steam Gasification in a Fluidized Bed Reactor with Energy Self-Sufficient Condition

    OpenAIRE

    Ajaree Suwatthikul; Siripong Limprachaya; Paisan Kittisupakorn; Iqbal Mohammed Mujtaba

    2017-01-01

    The biomass gasification process is widely accepted as a popular technology to produce fuel for the application in gas turbines and Organic Rankine Cycle (ORC). Chemical reactions of this process can be separated into three reaction zones: pyrolysis, combustion, and reduction. In this study, sensitivity analysis with respect to three input parameters (gasification temperature, equivalence ratio, and steam-to-biomass ratio) has been carried out to achieve energy self-sufficient conditions in a...

  9. Application of thermal and flywheel energy storage in orbiting nuclear burst power systems

    Energy Technology Data Exchange (ETDEWEB)

    Wichner, R.P.; Olszewski, M.

    1987-03-01

    A survey was conducted of currently available thermal energy storage and flywheel energy storage technology and development programs as they may apply to nuclear-based, burst power systems. The manner in which such storage systems may be used in closed cycle, regenerable burst systems is described for a number of cases utilizing the Boiling Potassium Rankine and Dual Loop Lithium Cooled LMRs and the Direct Cycle Brayton HTGR. In general, energy storage devices for such systems enable use of smaller power system components by allowing continuous operation over the duration of both the bursts and the regeneration time. The degree of size reduction depends principally on the required regeneration time.

  10. Thermoeconomic optimization of a Kalina cycle for a central receiver concentrating solar power plant

    DEFF Research Database (Denmark)

    Modi, Anish; Kærn, Martin Ryhl; Andreasen, Jesper Graa

    2016-01-01

    with direct vapour generation and without storage. The use of the ammonia-water mixture as the power cycle working fluid with non-isothermal evaporation and condensation presents the potential to improve the overall performance of the plant. This however comes at a price of requiring larger heat exchangers......Concentrating solar power plants use a number of reflecting mirrors to focus and convert the incident solar energy to heat, and a power cycle to convert this heat into electricity. This paper evaluates the use of a high temperature Kalina cycle for a central receiver concentrating solar power plant...... because of lower thermal pinch and heat transfer degradation for mixtures as compared with using a pure fluid in a conventional steam Rankine cycle, and the necessity to use a complex cycle arrangement. Most of the previous studies on the Kalina cycle focused solely on the thermodynamic aspects...

  11. Iron oxide-decorated carbon for supercapacitor anodes with ultrahigh energy density and outstanding cycling stability.

    Science.gov (United States)

    Guan, Cao; Liu, Jilei; Wang, Yadong; Mao, Lu; Fan, Zhanxi; Shen, Zexiang; Zhang, Hua; Wang, John

    2015-05-26

    Supercapacitor with ultrahigh energy density (e.g., comparable with those of rechargeable batteries) and long cycling ability (>50000 cycles) is attractive for the next-generation energy storage devices. The energy density of carbonaceous material electrodes can be effectively improved by combining with certain metal oxides/hydroxides, but many at the expenses of power density and long-time cycling stability. To achieve an optimized overall electrochemical performance, rationally designed electrode structures with proper control in metal oxide/carbon are highly desirable. Here we have successfully realized an ultrahigh-energy and long-life supercapacitor anode by developing a hierarchical graphite foam-carbon nanotube framework and coating the surface with a thin layer of iron oxide (GF-CNT@Fe2O3). The full cell of anode based on this structure gives rise to a high energy of ∼74.7 Wh/kg at a power of ∼1400 W/kg, and ∼95.4% of the capacitance can be retained after 50000 cycles of charge-discharge. These performance features are superior among those reported for metal oxide based supercapacitors, making it a promising candidate for the next generation of high-performance electrochemical energy storage.

  12. Survey of solar thermal energy storage subsystems for thermal/electric applications

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C. L.

    1978-08-01

    A survey of the current technology and estimated costs of subsystems for storing the thermal energy produced by solar collectors is presented. The systems considered were capable of producing both electricity and space conditioning for three types of loads: a single-family detached residence, an apartment complex of 100 units, and a city of 30,000 residents, containing both single-family residences and apartments. Collector temperatures will be in four ranges: (1) 100 to 250/sup 0/F (used for space heating and single-cycle air conditioners and organic Rankine low-temperature turbines); (2) 300 to 400/sup 0/F (used for dual-cycle air conditioners and low-temperature turbines); (3) 400 to 600/sup 0/F (using fluids from parabolic trough collectors to run Rankine turbines); (4) 800 to 1000/sup 0/F (using fluids from heliostats to run closed-cycle gas turbines and steam Rankine turbines). The solar thermal energy subsystems will require from 60 to 36 x 10/sup 5/ kWhr (2.05 x 10/sup 5/ to 1.23 x 10/sup 10/ Btu) of thermal storage capacity. In addition to sensible heat and latent heat storage materials, several other media were investigated as potential thermal energy storage materials, including the clathrate and semiclathrate hydrates, various metal hydrides, and heat storage based on inorganic chemical reactions.

  13. Time domain Rankine-Green panel method for offshore structures

    Science.gov (United States)

    Li, Zhifu; Ren, Huilong; Liu, Riming; Li, Hui

    2017-02-01

    To solve the numerical divergence problem of the direct time domain Green function method for the motion simulation of floating bodies with large flare, a time domain hybrid Rankine-Green boundary element method is proposed. In this numerical method, the fluid domain is decomposed by an imaginary control surface, at which the continuous condition should be satisfied. Then the Rankine Green function is adopted in the inner domain. The transient free surface Green function is applied in the outer domain, which is used to find the relationship between the velocity potential and its normal derivative for the inner domain. Besides, the velocity potential at the mean free surface between body surface and control surface is directly solved by the integration scheme. The wave exciting force is computed through the convolution integration with wave elevation, by introducing the impulse response function. Additionally, the nonlinear Froude-Krylov force and hydrostatic force, which is computed under the instantaneous incident wave free surface, are taken into account by the direct pressure integration scheme. The corresponding numerical computer code is developed and first used to compute the hydrodynamic coefficients of the hemisphere, as well as the time history of a ship with large flare; good agreement is obtained with the analytical solutions as well as the available numerical results. Then the hydrodynamic properties of a FPSO are studied. The hydrodynamic coefficients agree well with the results computed by the frequency method; the influence of the time interval and the truncated time is investigated in detail.

  14. Inability to match energy intake with energy expenditure at sustained near-maximal rates of energy expenditure in older men during a 14-d cycling expedition

    DEFF Research Database (Denmark)

    Rosenkilde Larsen, Mads; Morville, Thomas; Riis Andersen, Peter

    2015-01-01

    , and food and drink intake was recorded by the accompanying scientific staff. Energy balance was calculated as the discrepancy between EI and EE and from changes in body energy stores as derived from deuterium dilution. Fasting hormones were measured before and after cycling, and appetite ratings were...... it is sufficiently matched by EI to maintain energy balance. In addition, we investigated appetite ratings and concentrations of appetite-regulating hormones. DESIGN: Six men (mean ± SE age: 61 ± 3 y) completed 2706 km of cycling, from Copenhagen to Nordkapp, in 14 d. EE was measured by using doubly labeled water...... recorded twice daily. RESULTS: EE (±SE) increased from 17 ± 1 MJ/d before to 30 ± 2 MJ/d during the cycling trip (P body weight remained stable during the 14 d of cycling, body fat decreased (-2.2 ± 0.7 kg; P = 0...

  15. Theory and design of an Annual Cycle Energy System (ACES) for residences

    Energy Technology Data Exchange (ETDEWEB)

    Nephew, E.A.; Abbatiello, L.A.; Ballou, M.L.

    1980-05-01

    The basic concept of the Annual Cycle Energy System (ACES) - an integrated system for supplying space heating, hot water, and air conditioning to a building - and the theory underlying its design and operation are described. Practical procedures for designing an ACES for a single-family residence, together with recommended guidelines for the construction and installation of system components, are presented. Methods are discussed for estimating the life-cycle cost, component sizes, and annual energy consumption of the system for residential applications in different climatic regions of the US.

  16. Revolutions in energy input and material cycling in Earth history and human history

    Science.gov (United States)

    Lenton, Timothy M.; Pichler, Peter-Paul; Weisz, Helga

    2016-04-01

    Major revolutions in energy capture have occurred in both Earth and human history, with each transition resulting in higher energy input, altered material cycles and major consequences for the internal organization of the respective systems. In Earth history, we identify the origin of anoxygenic photosynthesis, the origin of oxygenic photosynthesis, and land colonization by eukaryotic photosynthesizers as step changes in free energy input to the biosphere. In human history we focus on the Palaeolithic use of fire, the Neolithic revolution to farming, and the Industrial revolution as step changes in free energy input to human societies. In each case we try to quantify the resulting increase in energy input, and discuss the consequences for material cycling and for biological and social organization. For most of human history, energy use by humans was but a tiny fraction of the overall energy input to the biosphere, as would be expected for any heterotrophic species. However, the industrial revolution gave humans the capacity to push energy inputs towards planetary scales and by the end of the 20th century human energy use had reached a magnitude comparable to the biosphere. By distinguishing world regions and income brackets we show the unequal distribution in energy and material use among contemporary humans. Looking ahead, a prospective sustainability revolution will require scaling up new renewable and decarbonized energy technologies and the development of much more efficient material recycling systems - thus creating a more autotrophic social metabolism. Such a transition must also anticipate a level of social organization that can implement the changes in energy input and material cycling without losing the large achievements in standard of living and individual liberation associated with industrial societies.

  17. A framework for energy use indicators and their reporting in life cycle assessment.

    Science.gov (United States)

    Arvidsson, Rickard; Svanström, Magdalena

    2016-07-01

    Energy use is a common impact category in life cycle assessment (LCA). Many different energy use indicators are used in LCA studies, accounting for energy use in different ways. Often, however, the choice behind which energy use indicator is applied is poorly described and motivated. To contribute to a more purposeful selection of energy use indicators and to ensure consistent and transparent reporting of energy use in LCA, a general framework for energy use indicator construction and reporting in LCA studies will be presented in this article. The framework differentiates between 1) renewable and nonrenewable energies, 2) primary and secondary energies, and 3) energy intended for energy purposes versus energy intended for material purposes. This framework is described both graphically and mathematically. Furthermore, the framework is illustrated through application to a number of energy use indicators that are frequently used in LCA studies: cumulative energy demand (CED), nonrenewable cumulative energy demand (NRCED), fossil energy use (FEU), primary fossil energy use (PFEU), and secondary energy use (SEU). To illustrate how the application of different energy use indicators may lead to different results, cradle-to-gate energy use of the bionanomaterial cellulose nanofibrils (CNF) is assessed using 5 different indicators and showing a factor of 3 differences between the highest and lowest results. The relevance of different energy use indicators to different actors and contexts will be discussed, and further developments of the framework are then suggested. Integr Environ Assess Manag 2016;12:429-436. © 2015 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. © 2015 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.

  18. Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy.

    Science.gov (United States)

    Fintelman, D M; Sterling, M; Hemida, H; Li, F-X

    2014-06-03

    The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists׳ power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. The effect of wheel running and the estrous cycle on energy expenditure in female rats.

    Science.gov (United States)

    Anantharaman-Barr, H G; Decombaz, J

    1989-08-01

    In female rats, food intake and wheel running fluctuate with the estrous cycle, creating a state of oscillating energy balance. The effect of the estrous cycle on the energy expenditure of conventionally housed rats (S) and of rats given access to an activity wheel (A) was compared. Over 24 weeks, the weight gain of the groups was similar although the body fat content of A was 30 g lower than that of S at the end of the study. During the assessment of energy expenditure by indirect calorimetry estrous cycles were disrupted and food intake and wheel running reduced. However, a correlation between expenditure and wheel running was obtained from which the cost of activity was derived (21 kJ/kg/km) and from which data were extrapolated to normal circumstances. This revealed that A, running on average 6214 rev/day, expended approximately 64 kJ/day more than S. This they compensated for by increasing their food intake by 6 g/day (70 kJ/day). Over the estrous cycle wheel running was maximal at proestrus and minimal at metestrus--the reverse trend in food intake was observed. This cyclic difference in energy balance between metestrus and proestrus was estimated to be equivalent to 23% of the 'maintenance' requirement. Thus voluntary activity bears a marked impact on day to day energy balance but has little effect in the long-term since in the female rat intake is precisely regulated to meet expenditure.

  20. Cycling efficiency and energy cost of walking in young and older adults.

    Science.gov (United States)

    Gaesser, Glenn A; Tucker, Wesley J; Sawyer, Brandon J; Bhammar, Dharini M; Angadi, Siddhartha S

    2018-02-01

    To determine whether age affects cycling efficiency and the energy cost of walking (Cw), 190 healthy adults, ages 18-81 yr, cycled on an ergometer at 50 W and walked on a treadmill at 1.34 m/s. Ventilation and gas exchange at rest and during exercise were used to calculate net Cw and net efficiency of cycling. Compared with the 18-40 yr age group (2.17 ± 0.33 J·kg -1 ·m -1 ), net Cw was not different in the 60-64 yr (2.20 ± 0.40 J·kg -1 ·m -1 ) and 65-69 yr (2.20 ± 0.28 J·kg -1 ·m -1 ) age groups, but was significantly ( P 60 yr, net Cw was significantly correlated with age ( R 2  = 0.123; P = 0.002). Cycling net efficiency was not different between 18-40 yr (23.5 ± 2.9%), 60-64 yr (24.5 ± 3.6%), 65-69 yr (23.3 ± 3.6%) and ≥70 yr (24.7 ± 2.7%) age groups. Repeat tests on a subset of subjects (walking, n = 43; cycling, n = 37) demonstrated high test-retest reliability [intraclass correlation coefficients (ICC), 0.74-0.86] for all energy outcome measures except cycling net energy expenditure (ICC = 0.54) and net efficiency (ICC = 0.50). Coefficients of variation for all variables ranged from 3.1 to 7.7%. Considerable individual variation in Cw and efficiency was evident, with a ~2-fold difference between the least and most economical/efficient subjects. We conclude that, between 18 and 81 yr, net Cw was only higher for ages ≥70 yr, and that cycling net efficiency was not different across age groups. NEW & NOTEWORTHY This study illustrates that the higher energy cost of walking in older adults is only evident for ages ≥70 yr. For older adults ages 60-69 yr, the energy cost of walking is similar to that of young adults. Cycling efficiency, by contrast, is not different across age groups. Considerable individual variation (∼2-fold) in cycling efficiency and energy cost of walking is observed in young and older adults.

  1. Easetech Energy: Advanced Life Cycle Assessment of Energy from Biomass and Waste

    DEFF Research Database (Denmark)

    Astrup, Thomas Fruergaard; Turconi, Roberto; Tonini, Davide

    SUMMARY: Biomass and waste are expected to play a key role in future energy systems based on large shares of renewable energy resources. The LCA model EASETECH Energy was developed specifically for modelling large and complex energy systems including various technologies and several processing...... steps. The model allows simultaneous balancing of mass and energy flows of the system under assessment, and is equipped with advanced tools for sensitivity/uncertainty analysis. EASETECH Energy was used to assess the environmental footprint of the Danish energy system in 2050 (based on 100% renewables......) and compare it to the current situation. The results show that the future Danish energy systems will have a rather different environmental footprint than the current one....

  2. Procyclic Trypanosoma brucei do not use Krebs cycle activity for energy generation.

    Science.gov (United States)

    van Weelden, Susanne W H; Fast, Beate; Vogt, Achim; van der Meer, Pieter; Saas, Joachim; van Hellemond, Jaap J; Tielens, Aloysius G M; Boshart, Michael

    2003-04-11

    The importance of a functional Krebs cycle for energy generation in the procyclic stage of Trypanosoma brucei was investigated under physiological conditions during logarithmic phase growth of a pleomorphic parasite strain. Wild type procyclic cells and mutants with targeted deletion of the gene coding for aconitase were derived by synchronous in vitro differentiation from wild type and mutant (Delta aco::NEO/Delta aco::HYG) bloodstream stage parasites, respectively, where aconitase is not expressed and is dispensable. No differences in intracellular levels of glycolytic and Krebs cycle intermediates were found in procyclic wild type and mutant cells, except for citrate that accumulated up to 90-fold in the mutants, confirming the absence of aconitase activity. Surprisingly, deletion of aconitase did not change differentiation nor the growth rate or the intracellular ATP/ADP ratio in those cells. Metabolic studies using radioactively labeled substrates and NMR analysis demonstrated that glucose and proline were not degraded via the Krebs cycle to CO(2). Instead, glucose was degraded to acetate, succinate, and alanine, whereas proline was degraded to succinate. Importantly, there was absolutely no difference in the metabolic products released by wild type and aconitase knockout parasites, and both were for survival strictly dependent on respiration via the mitochondrial electron transport chain. Hence, although the Krebs cycle enzymes are present, procyclic T. brucei do not use Krebs cycle activity for energy generation, but the mitochondrial respiratory chain is essential for survival and growth. We therefore propose a revised model of the energy metabolism of procyclic T. brucei.

  3. Life-cycle primary energy implication of the new Swedish Building Code

    Energy Technology Data Exchange (ETDEWEB)

    Dodoo, Ambrose; Gustavsson, Leif; Sathre, Roger (Dept. of Engineering and Sustainable Development, Mid Sweden Univ., Oestersund (Sweden))

    2009-07-01

    In this study we analyze the life-cycle primary energy use of apartment buildings made with wood- and concrete-frames, and built to meet either the Swedish building code of the mid-1990s or the maximum energy use standard of the new Swedish code (BBR 09). The analysis includes the primary energy use during the production, operation and end-of-life phases. Scenarios are analyzed in which the buildings are heated by district heating or electric resistance heating. We find that an electric resistance heated building built to the new code has greater life-cycle primary energy use relative to a district heated building, although the standard for the electric heating is more stringent. Making an electric resistance heated building to the new code's standard instead of the mid-1990s standard results in a large reduction in primary energy use. However, relatively little primary energy use reduction is achieved if a district heated building is made to the new standard instead of the old standard. Still, the primary energy use is on average 20-34% higher for the electric heated buildings than the district heated buildings. The wood-frame buildings have significantly lower production primary energy and also give greater end-of-life benefit than concrete-frame buildings. The primary energy for production is small relative to that for operation, but it is more significant for the district heated buildings.

  4. Energy conversion efficiency of hybrid electric heavy-duty vehicles operating according to diverse drive cycles

    Energy Technology Data Exchange (ETDEWEB)

    Banjac, Titina [AVL-AST d.o.o., Trg Leona Stuklja 5, SI-2000 Maribor (Slovenia); Trenc, Ferdinand; Katrasnik, Tomaz [Faculty of Mechanical Engineering, Univ. of Ljubljana, Askerceva 6, SI-1000 Ljubljana (Slovenia)

    2009-12-15

    Energy consumption and exhaust emissions of hybrid electric vehicles (HEVs) strongly depend on the HEV topology, power ratios of their components and applied control strategy. Combined analytical and simulation approach was applied to analyze energy conversion efficiency of different HEV topologies. Analytical approach is based on the energy balance equations and considers all energy paths in the HEVs from the energy sources to the wheels and to other energy sinks. Simulation approach is based on a fast forward-facing simulation model for simulating parallel and series HEVs as well as for conventional internal combustion engine vehicles, and considers all components relevant for modeling energy conversion phenomena. Combined approach enables evaluation of energy losses on different energy paths and provides their impact on the fuel economy. It therefore enables identification of most suitable HEV topology and of most suitable power ratios of the components for targeted vehicle application, since it reveals and quantifies the mechanisms that could lead to improved energy conversion efficiency of particular HEV. The paper exposes characteristics of the test cycles that lead to improved energy conversion efficiency of HEVs. Mechanisms leading to improved fuel economy of parallel HEVs through drive-away and vehicle propulsion at low powertrain loads by electric motor are also analyzed. It was also shown that control strategies managing energy flow through electric storage devices significantly influence energy conversion efficiency of series HEVs. (author)

  5. The Sleep/Wake Cycle is Directly Modulated by Changes in Energy Balance.

    Science.gov (United States)

    Collet, Tinh-Hai; van der Klaauw, Agatha A; Henning, Elana; Keogh, Julia M; Suddaby, Diane; Dachi, Sekesai V; Dunbar, Síle; Kelway, Sarah; Dickson, Suzanne L; Farooqi, I Sadaf; Schmid, Sebastian M

    2016-09-01

    The rise in obesity has been paralleled by a decline in sleep duration in epidemiological studies. However, the potential mechanisms linking energy balance and the sleep/wake cycle are not well understood. We aimed to examine the effects of manipulating energy balance on the sleep/wake cycle. Twelve healthy normal weight men were housed in a clinical research facility and studied at three time points: baseline, after energy balance was disrupted by 2 days of caloric restriction to 10% of energy requirements, and after energy balance was restored by 2 days of ad libitum/free feeding. Sleep architecture, duration of sleep stages, and sleep-associated respiratory parameters were measured by polysomnography. Two days of caloric restriction significantly increased the duration of deep (stage 4) sleep (16.8% to 21.7% of total sleep time; P = 0.03); an effect which was entirely reversed upon free feeding (P = 0.01). Although the apnea-hypopnea index stayed within the reference range (sleep (Spearman rho = 0.83, P = 0.01) and negatively with the number of awakenings in caloric restriction (Spearman rho = -0.79, P = 0.01). We demonstrate that changes in energy homeostasis directly and reversibly impact on the sleep/wake cycle. These findings provide a mechanistic framework for investigating the association between sleep duration and obesity risk. © 2016 Associated Professional Sleep Societies, LLC.

  6. High-Dimensional Mutant and Modular Thermodynamic Cycles, Molecular Switching, and Free Energy Transduction.

    Science.gov (United States)

    Carter, Charles W

    2017-05-22

    Understanding how distinct parts of proteins produce coordinated behavior has driven and continues to drive advances in protein science and enzymology. However, despite consensus about the conceptual basis for allostery, the idiosyncratic nature of allosteric mechanisms resists general approaches. Computational methods can identify conformational transition states from structural changes, revealing common switching mechanisms that impose multistate behavior. Thermodynamic cycles use factorial perturbations to measure coupling energies between side chains in molecular switches that mediate shear during domain motion. Such cycles have now been complemented by modular cycles that measure energetic coupling between separable domains. For one model system, energetic coupling between domains has been shown to be quantitatively equivalent to that between dynamic side chains. Linkages between domain motion, switching residues, and catalysis make nucleoside triphosphate hydrolysis conditional on domain movement, confirming an essential yet neglected aspect of free energy transduction and suggesting the potential generality of these studies.

  7. Energy Management Strategy Based on the Driving Cycle Model for Plugin Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiaoling Fu

    2014-01-01

    Full Text Available The energy management strategy (EMS for a plugin hybrid electric vehicle (PHEV is proposed based on the driving cycle model and dynamic programming (DP algorithm. A driving cycle model is constructed by collecting and processing the driving data of a certain school bus. The state of charge (SOC profile can be obtained by the DP algorithm for the whole driving cycle. In order to optimize the energy management strategy in the hybrid power system, the optimal motor torque control sequence can be calculated using the DP algorithm for the segments between the traffic intersections. Compared with the traditional charge depleting-charge sustaining (CDCS strategy, the test results on the ADVISOR platform show a significant improvement in fuel consumption using the EMS proposed in this paper.

  8. Daily cycle of the surface energy balance in Antarctica and the influence of clouds

    NARCIS (Netherlands)

    van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Reijmer, C.H.|info:eu-repo/dai/nl/229345956; van As, D.; Boot, W.

    2006-01-01

    We present the summertime daily cycle of the Antarctic surface energy balance (SEB) and its sensitivity to cloud cover. We use data of automatic weather stations (AWS) located in four major Antarctic climate zones: the coastal ice shelf, the coastal and interior katabatic wind zone and the interior

  9. Dissipation of energy during the respiratory cycle: conditional importance of ergotrauma to structural lung damage.

    Science.gov (United States)

    Marini, John J

    2017-11-16

    To describe and put into context recent conceptual advances regarding the relationship of energy load and power to ventilator-induced lung injury (VILI). Investigative emphasis regarding VILI has almost exclusively centered on the static characteristics of the individual tidal cycle - tidal volume, plateau pressure, positive end-expiratory pressure, and driving pressure. Although those static characteristics of the tidal cycle are undeniably important, the 'dynamic' characteristics of ventilation must not be ignored. To inflict the nonrupturing damage we identify as VILI, work must be performed and energy expended by high stress cycles applied at rates that exceed the capacity of endogenous repair. Machine power, the pace at which the work performing energy load is applied by the ventilator, has received increasing scrutiny as a candidate for the proximate and integrative cause of VILI. Although the unmodified values of machine-delivered energy or power (which are based on airway pressures and tidal volumes) cannot serve unconditionally as a rigid and quantitative guide to ventilator adjustment for lung protection, bedside consideration of the dynamics of ventilation and potential for ergotrauma represents a clear conceptual advance that complements the static parameters of the individual tidal cycle that with few exceptions have held our scientific attention.

  10. Procyclic Trypanosoma brucei do not use Krebs cycle activity for energy generation

    NARCIS (Netherlands)

    Weelden, van S.W.H.; Fast, B.; Vogt, A.; Meer, van der P.; Saas, J.; Hellemond, van J.J.; Tielens, A.G.M.; Boshart, M.

    2003-01-01

    The importance of a functional Krebs cycle for energy generation in the procyclic stage of Trypanosoma brucei was investigated under physiological conditions during logarithmic phase growth of a pleomorphic parasite strain. Wild type procyclic cells and mutants with targeted deletion of the gene

  11. Wader energy balance & tidal cycle simulator WEBTICS; technical documentation Version 1.1

    NARCIS (Netherlands)

    Rappoldt, C.; Ens, B.J.; Kersten, M.A.J.M.; Dijkman, E.M.

    2004-01-01

    This report describes the Wader Energy Balance and Tidal Cycle Simulator WEBTICS. The model simulates food uptake of Oystercatchers (Haematopus ostralegus) and a distribution of the birds over exposed parts of tidal areas. The mudflats are described on input as a number of spots which have a

  12. Energy-Efficient Assessment of Physical Activity Level Using Duty-Cycled Accelerometer Data

    NARCIS (Netherlands)

    Bosch, S.; Marin Perianu, Raluca; Havinga, Paul J.M.; Havinga, W.K.; Marin Perianu, Mihai

    This paper describes an energy efficiency improvement of the IMA accelerometer-based method for estimating the level of physical activity of a person. The sensor sampling and data processing requirements are significantly reduced by duty-cycling sensor sampling, thus making implementation and

  13. Energy expenditure of cycle rickshaw pullers in different places in India.

    Science.gov (United States)

    Pradhan, Chandan K; Thakur, Sridhar; Mukherjee, Ajay K; Roychowdhury, Amal

    2008-09-01

    The cycle rickshaw is a popular transportation device. The aim of the study was to assess workload of cycle rickshaw pullers--physiological and subjective at four different places in India. Subjects were instructed to pull a cycle rickshaw with two passengers, for 20 min. Working and recovery heart rates were recorded. The mean values of energy expenditure of pulling a cycle rickshaw varied from 23.5 +/- 2.66 to 25.35 +/- 1.51 kJ/min. Relative cardiac strain and cardiac cost indicated that the job is 'heavy' to 'very heavy'. Subjective assessment of workload was 'heavy' to 'very heavy'. The combined workload assessed from physiological parameters and subjective assessment indicated that the job could be categorised as 'heavy' to 'very heavy' at all the places studied and needs to be reduced by redesigning the structural and functional components of the cycle rickshaw. The rickshaw pullers carry out the jobs many times per day, sometimes without proper rest pauses between trips. The outcome of the research project is beneficial for cycle rickshaw pullers, health administrators as well as manufacturers of cycle rickshaws. Primarily, the manufacturers would be able to use the data for producing a newer model of cycle rickshaw, which would require less energy to drive. The health administrators would be able to take policy decisions for administering better health care for the unorganised and underprivileged workers. The pullers could be guided into taking care of their health by improving their work practice, i.e. taking a sufficient rest pause between trips.

  14. Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 1: technical report

    Energy Technology Data Exchange (ETDEWEB)

    Cuenca, R.; Formento, J.; Gaines, L.; Marr, B.; Santini, D.; Wang, M. [Argonne National Lab., IL (United States); Adelman, S.; Kline, D.; Mark, J.; Ohi, J.; Rau, N. [National Renewable Energy Lab., Golden, CO (United States); Freeman, S.; Humphreys, K.; Placet, M. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-01-01

    This report compares the energy use, oil use and emissions of electric vehicles (EVs) with those of conventional, gasoline-powered vehicles (CVs) over the total life cycle of the vehicles. The various stages included in the vehicles` life cycles include vehicle manufacture, fuel production, and vehicle operation. Disposal is not included. An inventory of the air emissions associated with each stage of the life cycle is estimated. Water pollutants and solid wastes are reported for individual processes, but no comprehensive inventory is developed. Volume I contains the major results, a discussion of the conceptual framework of the study, and summaries of the vehicle, utility, fuel production, and manufacturing analyses. It also contains summaries of comments provided by external peer reviewers and brief responses to these comments.

  15. Assessment of energy performance in the life-cycle of biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Maria; Boerjesson, Paal [Environmental and Energy Systems Studies LTH, Lund University, Gerdagatan 13, SE-223 62 Lund (Sweden)

    2006-03-15

    Energy balances are analysed from a life-cycle perspective for biogas systems based on 8 different raw materials. The analysis is based on published data and relates to Swedish conditions. The results show that the energy input into biogas systems (i.e. large-scale biogas plants) overall corresponds to 20-40% (on average approximately 30%) of the energy content in the biogas produced. The net energy output turns negative when transport distances exceed approximately 200km (manure), or up to 700km (slaughterhouse waste). Large variations exist in energy efficiency among the biogas systems studied. These variations depend both on the properties of the raw materials studied and on the system design and allocation methods chosen. The net energy output from biogas systems based on raw materials that have high water content and low biogas yield (e.g. manure) is relatively low. When energy-demanding handling of the raw materials is required, the energy input increases significantly. For instance, in a ley crop-based biogas system, the ley cropping alone corresponds to approximately 40% of the energy input. Overall, operation of the biogas plant is the most energy-demanding process, corresponding to 40-80% of the energy input into the systems. Thus, the results are substantially affected by the assumptions made about the allocation of a plant's entire energy demand among raw materials, e.g. regarding biogas yield or need of additional water for dilution. (author)

  16. Life-cycle energy production and emissions mitigation by comprehensive biogas-digestate utilization.

    Science.gov (United States)

    Chen, Shaoqing; Chen, Bin; Song, Dan

    2012-06-01

    In the context of global energy shortages and climate change, developing biogas plants with links to agricultural system has become an important strategy for cleaner rural energy and renewable agriculture. In this study, a life-cycle energy and environmental assessment was performed for a biogas-digestate utilization system in China. The results suggest that biogas utilization (heating, illumination, and fuel) and comprehensive digestate reuse are of equal importance in the total energy production of the system, and they also play an important role in systemic greenhouse gas mitigation. Improvement can be achieved in both energy production and emissions mitigation when the ratio of the current three biogas utilization pathways is adjusted. Regarding digestate reuse, a tradeoff between energy and environmental performance can be obtained by focusing on the substitution for top-dressing, base fertilizers, and the application to seed soaking. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Converting energy from fusion into useful forms

    CERN Document Server

    Kovari, M; Jenkins, I; Kiely, C

    2014-01-01

    If fusion power reactors are to be feasible, it will still be necessary to convert the energy of the nuclear reaction into usable form. The heat produced will be removed from the reactor core by a primary coolant, which might be water, helium, molten lithium-lead, molten lithium-containing salt, or CO2. The heat could then be transferred to a conventional Rankine cycle or Brayton (gas turbine) cycle. Alternatively it could be used for thermochemical processes such as producing hydrogen or other transport fuels. Fusion presents new problems because of the high energy neutrons released. These affect the selection of materials and the operating temperature, ultimately determining the choice of coolant and working cycle. The limited temperature ranges allowed by present day irradiated structural materials, combined with the large internal power demand of the plant, will limit the overall thermal efficiency. The operating conditions of the fusion power source, the materials, coolant, and energy conversion system w...

  18. Waste-to-energy advanced cycles and new design concepts for efficient power plants

    CERN Document Server

    Branchini, Lisa

    2015-01-01

    This book provides an overview of state-of-the-art technologies for energy conversion from waste, as well as a much-needed guide to new and advanced strategies to increase Waste-to-Energy (WTE) plant efficiency. Beginning with an overview of municipal solid waste production and disposal, basic concepts related to Waste-To-Energy conversion processes are described, highlighting the most relevant aspects impacting the thermodynamic efficiency of WTE power plants. The pervasive influences of main steam cycle parameters and plant configurations on WTE efficiency are detailed and quantified. Advanc

  19. Functional unit, technological dynamics, and scaling properties for the life cycle energy of residences.

    Science.gov (United States)

    Frijia, Stephane; Guhathakurta, Subhrajit; Williams, Eric

    2012-02-07

    Prior LCA studies take the operational phase to include all energy use within a residence, implying a functional unit of all household activities, but then exclude related supply chains such as production of food, appliances, and household chemicals. We argue that bounding the functional unit to provision of a climate controlled space better focuses the LCA on the building, rather than activities that occur within a building. The second issue explored in this article is how technological change in the operational phase affects life cycle energy. Heating and cooling equipment is replaced at least several times over the lifetime of a residence; improved efficiency of newer equipment affects life cycle energy use. The third objective is to construct parametric models to describe LCA results for a family of related products. We explore these three issues through a case study of energy use of residences: one-story and two-story detached homes, 1,500-3,500 square feet in area, located in Phoenix, Arizona, built in 2002 and retired in 2051. With a restricted functional unit and accounting for technological progress, approximately 30% of a building's life cycle energy can be attributed to materials and construction, compared to 0.4-11% in previous studies.

  20. Life Cycle Analysis of Energy Production from Food Waste through Anaerobic Digestion, Pyrolysis and Integrated Energy System

    OpenAIRE

    Suraj Adebayo Opatokun; Ana Lopez-Sabiron; German Ferreira; Vladimir Strezov

    2017-01-01

    The environmental performance of industrial anaerobic digestion (AD), pyrolysis, and integrated system (AD sequence with pyrolysis) on food waste treatment were evaluated using life cycle assessment. The integrated treatment system indicated similar environmental benefits to AD with the highest benefits in climate change and water depletion in addition to the increased energy generation potential and the production of valuable products (biochar and bio-oil). Pyrolysis results illustrated high...

  1. Technologies for High-Energy and Long Cycle Life Lithium-Sulfur Pouch-Cell Batteries

    Science.gov (United States)

    Bruckner, Jan; Thieme, Soren; Bauer, Ingolf; Thummler, Philipp; Althues, Holger; Kaskel, Stefan

    2014-08-01

    The current lithium-ion battery technology is limited to about 250 Wh kg-1. In contrast the lithium-sulfur battery is expected to achieve more than 400 Wh kg-1 on cell level.[1,2] To date the biggest drawback of lithium- sulfur is its limited cycle stability of less than 200 cycles. Further, high energy densities can only be achieved if no excess of lithium and electrolyte is used and the areal loading of sulfur is high.[3]Here we demonstrate how the cycle stability can be extended to 1000 cycles using alternative silicon-carbon and all-carbon anodes instead of metallic lithium.[4] We also present a dry-processing technology for the sulfur cathode preparation. Besides no drying step and no toxic solvents, our process enables also twice the areal capacity (4-5 mAh cm-2) of slurry based technologies.[5] In addition we give results on the cycle stability and energy density of our lithium-sulfur pouch- cells (2.5+ Ah).

  2. Life cycle comparison of waste-to-energy alternatives for municipal waste treatment in Chilean Patagonia.

    Science.gov (United States)

    Bezama, Alberto; Douglas, Carla; Méndez, Jacqueline; Szarka, Nóra; Muñoz, Edmundo; Navia, Rodrigo; Schock, Steffen; Konrad, Odorico; Ulloa, Claudia

    2013-10-01

    The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, previous studies have concluded that energy recovery systems are not suitable from an economic perspective in Chile. Therefore, this work intends to evaluate these technical options from an environmental perspective, using life cycle assessment as a tool for a comparative analysis, considering Coyhaique city as a case study. Three technical alternatives were evaluated: (i) landfill gas recovery and flaring without energy recovery; (ii) landfill gas recovery and energy use; and (iii) the implementation of an anaerobic digestion system for the organic waste fraction coupled with energy recovery from the biogas produced. Mass and energy balances of the three analyzed alternatives have been modeled. The comparative LCA considered global warming potential, abiotic depletion and ozone layer depletion as impact categories, as well as required raw energy and produced energy as comparative regional-specific indicators. According to the results, the use of the recovered landfill gas as an energy source can be identified as the most environmentally appropriate solution for Coyhaique, especially when taking into consideration the global impact categories.

  3. Long-term change of the atmospheric energy cycles and weather disturbances

    Science.gov (United States)

    Kim, WonMoo; Choi, Yong-Sang

    2017-11-01

    Weather disturbances are the manifestation of mean atmospheric energy cascading into eddies, thus identifying atmospheric energy structure is of fundamental importance to understand the weather variability in a changing climate. The question is whether our observational data can lead to a consistent diagnosis on the energy conversion characteristics. Here we investigate the atmospheric energy cascades by a simple framework of Lorenz energy cycle, and analyze the energy distribution in mean and eddy fields as forms of potential and kinetic energy. It is found that even the widely utilized independent reanalysis datasets, NCEP-DOE AMIP-II Reanalysis (NCEP2) and ERA-Interim (ERA-INT), draw different conclusions on the change of weather variability measured by eddy-related kinetic energy. NCEP2 shows an increased mean-to-eddy energy conversion and enhanced eddy activity due to efficient baroclinic energy cascade, but ERA-INT shows relatively constant energy cascading structure between the 1980s and the 2000s. The source of discrepancy mainly originates from the uncertainties in hydrological variables in the mid-troposphere. Therefore, much efforts should be made to improve mid-tropospheric observations for more reliable diagnosis of the weather disturbances as a consequence of man-made greenhouse effect.

  4. Study of a Combined Power and Ejector Refrigeration Cycle with Low-temperature Heat Sources by Applying Various Working Fluids

    Science.gov (United States)

    Jafarmadar, S.; Habibzadeh, A.

    2017-08-01

    A power and cooling cycle which combines the organic Rankine cycle and the ejector refrigeration cycle supplied by waste heat energy sources is discussed in this paper. Thirteen working fluids including one wet, eight dry and four isentropic fluids are studied in order to find their performances on the combined cycle. First and second law analysis has been performed by using a computer program in order to investigate various operating conditions’ effects on the proposed cycle by fixing power/refrigeration ratio and varying waste heat source and evaporator temperature. According to the results, in general, dry and isentropic ORC fluids have better performance compared with wet fluids. The increase in evaporator temperature leads to the decrease in exergy efficiency. On the other hand, exergy efficiency rises with the turbine inlet temperature decrease and an increase of heat source temperature. Rising expansion ratio and inlet temperature of the turbine causes an increase in the thermal efficiency of the cycle.

  5. A Didactic Model of the Seasonal Cycle in Energy Fluxes and Climate

    Science.gov (United States)

    Donohoe, A.; Battisti, D.

    2009-12-01

    In the annual mean, the polar regions receive a deficit of solar insolation relative to the global average. The local energy budget is balanced primarily by atmospheric heat transport into the region, with smaller contributions from ocean heat transport and anomalously low outgoing longwave radiation (relative to the global average). In contrast, the annual cycle features large seasonal anomalies (departures from the local annual average) in solar insolation in the polar regions that are primarily balanced by ocean heat storage anomalies; changes in meridional heat transport, emitted long wave radiation, and atmospheric heat storage play a decreasingly important role in the seasonal energy balance. Land-ocean contrasts also have a large impact on the seasonal energetics of the polar climate system. Over the ocean, zonal heat transport from the land domain is maximized during the summer, and the sum of the insolation and zonal heat transport anomalies is balanced by ocean heat storage. In contrast, over the land, the primary summertime balance is excess solar insolation balanced by an enhanced zonal heat export. In this study we examine the global scale climate and the aforementioned seasonal cycle of energy fluxes using an aquaplanet atmospheric general circulation model coupled to a slab ocean and a simplified energy balance model that interacts with the underlying ocean. The gross climate and seasonal energetics in both models are highly sensitive to the specification of ocean mixed layer depth. The observed seasonal cycle of energy fluxes and the land and ocean temperatures are also replicated in a simplified energy balance model that includes land-ocean contrast and the hemispheric differences in fractional land area. The sensitivity of the seasonal cycle in climate (atmosphere and ocean temperatures) - and in the gross partitioning of the mix of energy flux processes that determine the climate - to the fractional land area is further explored in an ensemble of

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

    Directory of Open Access Journals (Sweden)

    José Carbia Carril

    2015-01-01

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

  7. Air Evaporation closed cycle water recovery technology - Advanced energy saving designs

    Science.gov (United States)

    Morasko, Gwyndolyn; Putnam, David F.; Bagdigian, Robert

    1986-01-01

    The Air Evaporation water recovery system is a visible candidate for Space Station application. A four-man Air Evaporation open cycle system has been successfully demonstrated for waste water recovery in manned chamber tests. The design improvements described in this paper greatly enhance the system operation and energy efficiency of the air evaporation process. A state-of-the-art wick feed design which results in reduced logistics requirements is presented. In addition, several design concepts that incorporate regenerative features to minimize the energy input to the system are discussed. These include a recuperative heat exchanger, a heat pump for energy transfer to the air heater, and solar collectors for evaporative heat. The addition of the energy recovery devices will result in an energy reduction of more than 80 percent over the systems used in earlier manned chamber tests.

  8. EASETECH Energy: Life Cycle Assessment of current and future Danish power systems

    DEFF Research Database (Denmark)

    Turconi, Roberto; Damgaard, Anders; Bisinella, Valentina

    A new life cycle assessment (LCA) model software has been developed by DTU Environment, to facilitate detailed LCA of energy technologies. The model, EASETECH Energy, is dedicated to the specific technologies needed to assess energy production and energy systems and provides an unprecedented...... flexibility with respect to LCA modeling of these technologies. To illustrate the functionality of the model, preliminary results from a LCA of the Danish power system in 2010 as well as two future scenarios for 2030 are presented. In addition to providing a general overview of the environmental profile...... of a renewable based power system, specific focus is placed on the typical challenges encountered when performing an LCA of a power system. Further, the key characteristics of EASETECH Energy that can expedite the set-up of multiple scenarios and enhance transparency in the modelling are explained....

  9. The methodological features of studying energy efficiency of a combined mini-TPP on the basis of a gas-piston unit and a steam turbine

    Science.gov (United States)

    Shchinnikov, P. A.; Marasanov, N. V.

    2017-07-01

    The technology of electricity production by a mini-thermal power plant, operating on combined cycles of Otto and Rankine, is considered. The main aspects of the investigation methodology are outlined. It is shown that the design and layout parameters of all the major energy elements of the developed technology allow implementing it in a block and modular version; and the efficiency of electricity supply for the proposed technology will be at least 50 %.

  10. Strategy on energy saving reconstruction of distribution networks based on life cycle cost

    Science.gov (United States)

    Chen, Xiaofei; Qiu, Zejing; Xu, Zhaoyang; Xiao, Chupeng

    2017-08-01

    Because the actual distribution network reconstruction project funds are often limited, the cost-benefit model and the decision-making method are crucial for distribution network energy saving reconstruction project. From the perspective of life cycle cost (LCC), firstly the research life cycle is determined for the energy saving reconstruction of distribution networks with multi-devices. Then, a new life cycle cost-benefit model for energy-saving reconstruction of distribution network is developed, in which the modification schemes include distribution transformers replacement, lines replacement and reactive power compensation. In the operation loss cost and maintenance cost area, the operation cost model considering the influence of load season characteristics and the maintenance cost segmental model of transformers are proposed. Finally, aiming at the highest energy saving profit per LCC, a decision-making method is developed while considering financial and technical constraints as well. The model and method are applied to a real distribution network reconstruction, and the results prove that the model and method are effective.

  11. Cell cycle dependent changes in membrane stored curvature elastic energy: evidence from lipidomic studies.

    Science.gov (United States)

    Hague, Charlotte V; Postle, Anthony D; Attard, George S; Dymond, Marcus K

    2013-01-01

    One of the most developed theories of phospholipid homeostasis is the intrinsic curvature hypothesis, which, in broad terms, postulates that cells regulate their lipid composition so as to keep constant the membrane stored curvature elastic energy. The implication of this hypothesis is that lipid composition is determined by a ratio control function consisting of the weighted sum of concentrations of type II lipids in the numerator and the weighted sum of concentrations of Type 0 lipids in the denominator. In previous work we used a data-driven approach, based on lipidomic data from asynchronous cell cultures, to determine a criterion that allows the different lipid species to be assigned to the set of type 0 or of type II lipids, and hence construct a ratio control function that serves as a proxy for the lipid contribution to total membrane stored curvature elastic energy in vivo. Here we apply the curvature elastic energy proxy to the analysis of lipid composition data from synchronous HeLa cells as they traverse the cell cycle. Our analysis suggests HeLa cells modify their membrane stored elastic energy through the cell cycle. In S-phase type 0 lipids are the most abundant, whilst in G2 type II lipids are most abundant. Changes in our proxy for membrane stored elastic energy correlate with membrane curvature dependent processes in the HeLa cell around division, providing some insights into the interplay between the individual lipid and protein contributions to membrane free energy.

  12. Life cycle water use of energy production and its environmental impacts in China.

    Science.gov (United States)

    Zhang, Chao; Anadon, Laura Diaz

    2013-12-17

    The energy sector is a major user of fresh water resources in China. We investigate the life cycle water withdrawals, consumptive water use, and wastewater discharge of China's energy sectors and their water-consumption-related environmental impacts, using a mixed-unit multiregional input-output (MRIO) model and life cycle impact assessment method (LCIA) based on the Eco-indicator 99 framework. Energy production is responsible for 61.4 billion m(3) water withdrawals, 10.8 billion m(3) water consumption, and 5.0 billion m(3) wastewater discharges in China, which are equivalent to 12.3%, 4.1% and 8.3% of the national totals, respectively. The most important feature of the energy-water nexus in China is the significantly uneven spatial distribution of consumptive water use and its corresponding environmental impacts caused by the geological discrepancy among fossil fuel resources, fresh water resources, and energy demand. More than half of energy-related water withdrawals occur in the east and south coastal regions. However, the arid north and northwest regions have much larger water consumption than the water abundant south region, and bear almost all environmental damages caused by consumptive water use.

  13. Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, G.L.

    2005-10-03

    This report documents the work performed during the first phase of the National Aeronautics and Space Administration (NASA), National Research Announcement (NRA) Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs. The document includes an optimization of both 100-kW{sub e} and 250-kW{sub e} (at the propulsion unit) Rankine cycle power conversion systems. In order to perform the mass optimization of these systems, several parametric evaluations of different design options were investigated. These options included feed and reheat, vapor superheat levels entering the turbine, three different material types, and multiple heat rejection system designs. The overall masses of these Nb-1%Zr systems are approximately 3100 kg and 6300 kg for the 100- kW{sub e} and 250-kW{sub e} systems, respectively, each with two totally redundant power conversion units, including the mass of the single reactor and shield. Initial conceptual designs for each of the components were developed in order to estimate component masses. In addition, an overall system concept was presented that was designed to fit within the launch envelope of a heavy lift vehicle. A technology development plan is presented in the report that describes the major efforts that are required to reach a technology readiness level of 6. A 10-year development plan was proposed.

  14. Energy valuation methods for biofuels in South Florida: Introduction to life cycle assessment and emergy approaches

    Energy Technology Data Exchange (ETDEWEB)

    Treese II, J. Van [Southwest Florida Research and Education Center, Immokalee, FL (United States); Hanlon, Edward A. [Southwest Florida Research and Education Center, Immokalee, FL (United States); Amponsah, Nana [Intelligentsia International, LaBelle, FL (United States); Izursa, Jose -Luis [Intelligentsia International, LaBelle, FL (United States); Capece, John C. [Univ. of Florida, Gainesville, FL (United States)

    2013-03-01

    Here, recent changes in the United States requiring the use of ethanol in gasoline for most vehicular transportation have created discussion about important issues, such as shifting the use of certain plants from food production to energy supply, related federal subsidies, effects on soil, water and atmosphere resources, tradeoffs between food production and energy production, speculation about biofuels as a possible means for energy security, potential reduction of greenhouse gas (GHG) emissions or development and expansion of biofuels industry. A sustainable approach to biofuel production requires understanding inputs (i.e., energy required to carry out a process, both natural and anthropogenic) and outputs (i.e., energy produced by that process) and cover the entire process, as well as environmental considerations that can be overlooked in a more traditional approach. This publication gives an overview of two methods for evaluating energy transformations in biofuels production: (1) Life Cycle Assessment (LCA) and (2) Emergy Assessment (EA). The LCA approach involves measurements affecting greenhouse gases (GHG), which can be linked to the energy considerations used in the EA. Although these two methods have their basis in energy or GHG evaluations, their approaches can lead to a reliable judgment regarding a biofuel process. Using these two methods can ensure that the energy components are well understood and can help to evaluate the economic environmental component of a biofuel process. In turn, using these two evaluative tools will allow for decisions about biofuel processes that favor sustainability

  15. Energy-containing beverages: reproductive hormones and ovarian function in the BioCycle Study.

    Science.gov (United States)

    Schliep, Karen C; Schisterman, Enrique F; Mumford, Sunni L; Pollack, Anna Z; Perkins, Neil J; Ye, Aijun; Zhang, Cuilin J; Stanford, Joseph B; Porucznik, Christina A; Hammoud, Ahmad O; Wactawski-Wende, Jean

    2013-03-01

    Energy-containing beverages are widely consumed among premenopausal women, but their association with reproductive hormones is not well understood. The objective was to assess the association of energy-containing beverages, added sugars, and total fructose intake with reproductive hormones among ovulatory cycles and sporadic anovulation in healthy premenopausal women. Women (n = 259) in the BioCycle Study were followed for up to 2 menstrual cycles; they provided fasting blood specimens during up to 8 visits/cycle and four 24-h dietary recalls/cycle. Women who consumed ≥1 cup (1 cup = 237 mL) sweetened soda/d had 16.3% higher estradiol concentrations compared with women who consumed less sweetened soda (86.5 pg/mL compared with 74.4 pg/mL, P = 0.01) after adjustment for age, BMI, race, dietary factors, and physical activity. Similarly elevated estradiol concentrations were found for ≥1 cup cola/d and noncola soda intake. Neither artificially sweetened soda nor fruit juice intake ≥1 cup/d was significantly associated with reproductive hormones. Added sugar above the average US woman's intake (≥73.2 g/d) or above the 66th percentile in total fructose intake (≥41.5 g/d) was associated with significantly elevated estradiol but not consistently across all models. No associations were found between beverages, added sugars, or total fructose intake and anovulation after multivariate adjustment. Even at moderate consumption amounts, sweetened soda is associated with elevated follicular estradiol concentrations among premenopausal women but does not appear to affect ovulatory function. Further research into the mechanism driving the association between energy-containing beverages and reproductive hormones, and its potential implications for women's health, is warranted.

  16. Energy-containing beverages: reproductive hormones and ovarian function in the BioCycle Study123

    Science.gov (United States)

    Schliep, Karen C; Mumford, Sunni L; Pollack, Anna Z; Perkins, Neil J; Ye, Aijun; Zhang, Cuilin J; Stanford, Joseph B; Porucznik, Christina A; Hammoud, Ahmad O; Wactawski-Wende, Jean

    2013-01-01

    Background: Energy-containing beverages are widely consumed among premenopausal women, but their association with reproductive hormones is not well understood. Objective: The objective was to assess the association of energy-containing beverages, added sugars, and total fructose intake with reproductive hormones among ovulatory cycles and sporadic anovulation in healthy premenopausal women. Design: Women (n = 259) in the BioCycle Study were followed for up to 2 menstrual cycles; they provided fasting blood specimens during up to 8 visits/cycle and four 24-h dietary recalls/cycle. Results: Women who consumed ≥1 cup (1 cup = 237 mL) sweetened soda/d had 16.3% higher estradiol concentrations compared with women who consumed less sweetened soda (86.5 pg/mL compared with 74.4 pg/mL, P = 0.01) after adjustment for age, BMI, race, dietary factors, and physical activity. Similarly elevated estradiol concentrations were found for ≥1 cup cola/d and noncola soda intake. Neither artificially sweetened soda nor fruit juice intake ≥1 cup/d was significantly associated with reproductive hormones. Added sugar above the average US woman's intake (≥73.2 g/d) or above the 66th percentile in total fructose intake (≥41.5 g/d) was associated with significantly elevated estradiol but not consistently across all models. No associations were found between beverages, added sugars, or total fructose intake and anovulation after multivariate adjustment. Conclusions: Even at moderate consumption amounts, sweetened soda is associated with elevated follicular estradiol concentrations among premenopausal women but does not appear to affect ovulatory function. Further research into the mechanism driving the association between energy-containing beverages and reproductive hormones, and its potential implications for women's health, is warranted. PMID:23364018

  17. Evaluations of thermocline and half cycle figure of merit of a thermal energy storage tank

    Directory of Open Access Journals (Sweden)

    Abd Majid Mohd Amin

    2017-01-01

    Full Text Available Two main criteria that are commonly used to evaluate thermal energy storage systems are thermocline thickness and half cycle figure of merit. For the thermocline thickness, the preference is to achieve as thin as possible the thermocline thickness. While the preference for half cycle figure of merit is to achieve the value of greater than 90 per cent. These two criteria were used to evaluate a thermal storage system at University Teknologi PETRONAS district cooling plant. The capacity of the thermal energy storage tank of the plant is 10,000 RTh. Operating data was used for the evaluation. The values of evaluated thermocline thickness ranges from 2.248 meters to 5.445 meters with an average of 3.251 meters. These values are very much higher in comparison to findings of other studies. One possible reason is due to higher flow rates. For the half cycle figure of merit the evaluated values ranges from 0.9469 to 0.9847, with the average of 0.9698, which are within the acceptable range. For future work a model should be developed which could automatically evaluate both the thermocline thickness and half cycle figure of merit. This would enable both of these parameters to be continuously evaluated.

  18. Technical Feasibility Study of Thermal Energy Storage Integration into the Conventional Power Plant Cycle

    Directory of Open Access Journals (Sweden)

    Jacek D. Wojcik

    2017-02-01

    Full Text Available The current load balance in the grid is managed mainly through peaking fossil-fuelled power plants that respond passively to the load changes. Intermittency, which comes from renewable energy sources, imposes additional requirements for even more flexible and faster responses from conventional power plants. A major challenge is to keep conventional generation running closest to the design condition with higher load factors and to avoid switching off periods if possible. Thermal energy storage (TES integration into the power plant process cycle is considered as a possible solution for this issue. In this article, a technical feasibility study of TES integration into a 375-MW subcritical oil-fired conventional power plant is presented. Retrofitting is considered in order to avoid major changes in the power plant process cycle. The concept is tested based on the complete power plant model implemented in the ProTRAX software environment. Steam and water parameters are assessed for different TES integration scenarios as a function of the plant load level. The best candidate points for heat extraction in the TES charging and discharging processes are evaluated. The results demonstrate that the integration of TES with power plant cycle is feasible and provide a provisional guidance for the design of the TES system that will result in the minimal influence on the power plant cycle.

  19. Accelerator-Reactor Coupling for Energy Production in Advanced Nuclear Fuel Cycles

    Science.gov (United States)

    Heidet, Florent; Brown, Nicholas R.; Haj Tahar, Malek

    This article is a review of several accelerator-reactor interface issues and nuclear fuel cycle applications of accelerator-driven subcritical systems. The systems considered here have the primary goal of energy production, but that goal is accomplished via a specific application in various proposed nuclear fuel cycles, such as breed-and-burn of fertile material or burning of transuranic material. Several basic principles are reviewed, starting from the proton beam window including the target, blanket, reactor core, and up to the fuel cycle. We focus on issues of interest, such as the impact of the energy required to run the accelerator and associated systems on the potential electricity delivered to the grid. Accelerator-driven systems feature many of the constraints and issues associated with critical reactors, with the added challenges of subcritical operation and coupling to an accelerator. Reliable accelerator operation and avoidance of beam trips are critically important. One interesting challenge is measurement of blanket subcriticality level during operation. We also review the potential benefits of accelerator-driven systems in various nuclear fuel cycle applications. Ultimately, accelerator-driven subcritical systems with the goal of transmutation of transuranic material have lower 100,000-year radioactivity than a critical fast reactor with recycling of uranium and plutonium.

  20. Instantaneous charging & discharging cycle analysis of a novel supercapacitor based energy harvesting circuit

    Science.gov (United States)

    Khan, MD Shahrukh Adnan; Kuni, Sharsad Kara; Rajkumar, Rajprasad; Syed, Anas; Hawladar, Masum; Rahman, Md. Moshiur

    2017-12-01

    In this paper, an extensive effort has been made to design and develop a prototype in a laboratory setup environment in order to investigate experimentally the response of a novel Supercapacitor based energy harvesting circuit; particularly the phenomena of instantaneous charging and discharging cycle is analysed. To maximize battery lifespan and storage capacity, charging/discharging cycles need to be optimized in such a way, it ultimately enhances the system performances reliably. Keeping this into focus, an Arduino-MOSFET based control system is developed to charge the Supercapacitor from a low wind Vertical Axis Turbine (VAWT) and discharge it through a 6V battery. With a wind speed of 5m/s, the wind turbine requires approximately 8.1 hours to charge the 6V battery through Supercapacitor bank that constitutes 18 cycles in which each cycle consumes 27 minutes. The overall performance of the proposed system was quite convincing in a sense that the efficiency of the developed Energy Harvesting Circuit EHC raises to 19% in comparison to direct charging of the battery from the Vertical wind turbine. At low wind speed, such value of efficiency margin is quite encouraging which essentially validates the system design.

  1. Energy expenditure of constant- and variable-intensity cycling: power meter estimates.

    Science.gov (United States)

    Haakonssen, Eric C; Martin, David T; Burke, Louise M; Jenkins, David G

    2013-09-01

    The objective of this study is to compare the effects of constant- and variable-intensity cycling on gross efficiency (GE) and to compare estimates of energy expenditure (EE) made using indirect calorimetry (CAL) with estimates derived from commercially available power meters. Nine national team female road cyclists completed a GE test (GEtest = 4 min at approximately 45%, approximately 55%, approximately 65%, and approximately 75% maximal aerobic power (MAP)) before and after 10.5 min of either constant- (CON)- or variable- (VAR)-intensity cycling averaging approximately 55% MAP. GE measured before, after, and during CON and VAR cycling was compared. Total EE (kJ) for 10.5 min of VAR cycling was estimated using indirect CAL and compared with estimates on the basis of mechanical power [Schoberer Rad Messtechnik (SRM)] using the group mean GE, each athlete's mean GE, and each athlete's power to GE regression. There was no effect of VAR on GEtests (P = 0.74). GE reduced from 19.1% ± 0.4% (mean ± SE) during the pretrial GEtests to 18.7% ± 0.4% during the posttrial GEtests (P Equation is included in full-text article.)(%) ± 90% CI, 0.3 ± 0.8; R 0.98, P intensity cycling <75% MAP, although determining each athlete's GE improves accuracy greatly.

  2. Evaluation of catalyst for closed cycle operation of high energy pulsed CO2 lasers

    Science.gov (United States)

    Rogowski, R. S.; Miller, I. M.; Wood, G.; Schryer, D. R.; Hess, R. V.; Upchurch, B. T.

    1983-01-01

    Several catalyst materials have been tested for efficiency of converting CO and O2 to CO2 for use in a high energy CO2 laser. The composition of the gas mixtures was monitored by mass spectrometry and gas chromatography. A copper/copper oxide catalyst and a platinum/tin oxide catalyst were used for closed cycle operation of a CO2 laser (0.7 joules/pulse), operating at 10 pulses/sec.

  3. Análise teórica da recuperação de calor para geração de energia em indústrias de cimento e cal utilizando o ciclo de Rankine orgânico

    Directory of Open Access Journals (Sweden)

    Ricardo Carrasco Carpio

    2015-06-01

    Full Text Available O presente trabalho consiste em uma apresentação do estado da arte do Ciclo Rankine Orgânico, um ciclo termodinâmico que usa um fluido orgânico como fluido de trabalho e que pode ser usado para recuperação de calor rejeitado em processos industriais, gerando assim energia elétrica para abastecer a própria indústria, o que consequentemente causa uma redução no custo de produção da empresa. São apresentados alguns fluidos orgânicos e alguns de seus parâmetros termodinâmicos.Palavras-chave: Cogeração. Ciclo Rankine Orgânico. Fluidos de Trabalho.ABSTRACTTheoretical analysis of heat recovery for power generation in cement and lime industries using the organic Rankine cycleThis work aims to present the state of the art of the Organic Rankine Cycle, a thermodynamic cycle that uses an organic fluid as a working fluid that can be used to recover the rejected heat in industrial processes, thus generating electricity to supply industry itself, which causes a reduction in the production cost of the company. It also presents some organic fluids and some of their thermodynamic parameters.Keywords: Cogeneration. Organic Rankine Cycle. Working Fluids.

  4. Energy from CO2 using capacitive electrodes – A model for energy extraction cycles

    NARCIS (Netherlands)

    Paz-García, J.M.; Dykstra, J.E.; Biesheuvel, P.M.; Hamelers, H.V.M.

    2015-01-01

    A model is presented for the process of harvesting electrical energy from CO2 emissions using capacitive cells. The principle consists of controlling the mixing process of a concentrated CO2 gas stream with a dilute CO2 gas stream (as, for example, exhaust gas and air), thereby converting part of

  5. Energy use and life cycle greenhouse gas emissions of drones for commercial package delivery.

    Science.gov (United States)

    Stolaroff, Joshuah K; Samaras, Constantine; O'Neill, Emma R; Lubers, Alia; Mitchell, Alexandra S; Ceperley, Daniel

    2018-02-13

    The use of automated, unmanned aerial vehicles (drones) to deliver commercial packages is poised to become a new industry, significantly shifting energy use in the freight sector. Here we find the current practical range of multi-copters to be about 4 km with current battery technology, requiring a new network of urban warehouses or waystations as support. We show that, although drones consume less energy per package-km than delivery trucks, the additional warehouse energy required and the longer distances traveled by drones per package greatly increase the life-cycle impacts. Still, in most cases examined, the impacts of package delivery by small drone are lower than ground-based delivery. Results suggest that, if carefully deployed, drone-based delivery could reduce greenhouse gas emissions and energy use in the freight sector. To realize the environmental benefits of drone delivery, regulators and firms should focus on minimizing extra warehousing and limiting the size of drones.

  6. Life Cycle Multi-Criteria Analysis Of Alternative Energy Supply Systems For A Residential Building

    Directory of Open Access Journals (Sweden)

    Artur Rogoža

    2013-12-01

    Full Text Available The article analyses energy supply alternatives for a partially renovated residential building. In addition to the existing district heating (base case alternative systems, gas boilers, heat pumps (air-water and ground-water, solar collectors, solar cells, and combinations of these systems have been examined. Actual heat consumption of the building and electricity demand determined by the statistical method are used for simulating the systems. The process of simulation is performed using EnergyPro software. In order to select an optimal energy supply option, the life cycle analysis of all systems has been carried out throughout a life span of the building, and the estimated results of energy, environmental and economic evaluation have been converted into non-dimensional variables (3E using multi–criteria analysis.Article in Lithuanian

  7. Analyzing the Life Cycle Energy Savings of DOE Supported Buildings Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Cort, Katherine A.; Hostick, Donna J.; Dirks, James A.; Elliott, Douglas B.

    2009-08-31

    This report examines the factors that would potentially help determine an appropriate analytical timeframe for measuring the U.S. Department of Energy's Building Technology (BT) benefits and presents a summary-level analysis of the life cycle savings for BT’s Commercial Buildings Integration (CBI) R&D program. The energy savings for three hypothetical building designs are projected over a 100-year period using Building Energy Analysis and Modeling System (BEAMS) to illustrate the resulting energy and carbon savings associated with the hypothetical aging buildings. The report identifies the tasks required to develop a long-term analytical and modeling framework, and discusses the potential analytical gains and losses by extending an analysis into the “long-term.”

  8. Numerical analysis of energy piles under different boundary conditions and thermal loading cycles

    Directory of Open Access Journals (Sweden)

    Khosravi Ali

    2016-01-01

    Full Text Available The thermo- mechanical behavior of energy piles has been studied extensively in recent years. In the present study, a numerical model was adapted to study the effect of various parameters (e.g. heating/cooling temperature, head loading condition and soil stiffness on the thermo-mechanical behavior of an energy pile installed in unsaturated sandstone. The results from the simulations were compared with measurements from a thermal response test on a prototype energy pile installed beneath a 1-story building at the US Air Force Academy (USAFA in Colorado Springs, CO. A good agreement was achieved between the results obtained from the prototype and the numerical models. A parametric evaluation were also carried out which indicated the significance of the stiffness of the unsaturated sandstone and pile’s head loading condition on stress-strain response of the energy pile during heating/cooling cycles.

  9. Life cycle assessment of thermal Waste-to-Energy technologies: Review and recommendations

    DEFF Research Database (Denmark)

    Astrup, Thomas Fruergaard; Tonini, Davide; Turconi, Roberto

    2015-01-01

    -studies published in 136 peer-reviewed journal articles within 1995 and 2013. The studies were evaluated with respect to critical aspects such as: (i) goal and scope definitions (e.g. functional units, system boundaries, temporal and geographic scopes), (ii) detailed technology parameters (e.g. related to waste...... composition, technology, gas cleaning, energy recovery, residue management, and inventory data), and (iii) modeling principles (e.g. energy/mass calculation principles, energy substitution, inclusion of capital goods and uncertainty evaluation). Very few of the published studies provided full and transparent......Life cycle assessment (LCA) has been used extensively within the recent decade to evaluate the environmental performance of thermal Waste-to-Energy (WtE) technologies: incineration, co-combustion, pyrolysis and gasification. A critical review was carried out involving 250 individual case...

  10. High Temperature Fusion Reactor Cooling Using Brayton Cycle Based Partial Energy Conversion

    Science.gov (United States)

    Juhasz, Albert J.; Sawicki, Jerzy T.

    2003-01-01

    For some future space power systems using high temperature nuclear heat sources most of the output energy will be used in other than electrical form, and only a fraction of the total thermal energy generated will need to be converted to electrical work. The paper describes the conceptual design of such a partial energy conversion system, consisting of a high temperature fusion reactor operating in series with a high temperature radiator and in parallel with dual closed cycle gas turbine (CCGT) power systems, also referred to as closed Brayton cycle (CBC) systems, which are supplied with a fraction of the reactor thermal energy for conversion to electric power. Most of the fusion reactor's output is in the form of charged plasma which is expanded through a magnetic nozzle of the interplanetary propulsion system. Reactor heat energy is ducted to the high temperature series radiator utilizing the electric power generated to drive a helium gas circulation fan. In addition to discussing the thermodynamic aspects of the system design the authors include a brief overview of the gas turbine and fan rotor-dynamics and proposed bearing support technology along with performance characteristics of the three phase AC electric power generator and fan drive motor.

  11. Life cycle assessment of energy from waste via anaerobic digestion: a UK case study.

    Science.gov (United States)

    Evangelisti, Sara; Lettieri, Paola; Borello, Domenico; Clift, Roland

    2014-01-01

    Particularly in the UK, there is potential for use of large-scale anaerobic digestion (AD) plants to treat food waste, possibly along with other organic wastes, to produce biogas. This paper presents the results of a life cycle assessment to compare the environmental impacts of AD with energy and organic fertiliser production against two alternative approaches: incineration with energy production by CHP and landfill with electricity production. In particular the paper investigates the dependency of the results on some specific assumptions and key process parameters. The input Life Cycle Inventory data are specific to the Greater London area, UK. Anaerobic digestion emerges as the best treatment option in terms of total CO2 and total SO2 saved, when energy and organic fertiliser substitute non-renewable electricity, heat and inorganic fertiliser. For photochemical ozone and nutrient enrichment potentials, AD is the second option while incineration is shown to be the most environmentally friendly solution. The robustness of the model is investigated with a sensitivity analysis. The most critical assumption concerns the quantity and quality of the energy substituted by the biogas production. Two key issues affect the development and deployment of future anaerobic digestion plants: maximising the electricity produced by the CHP unit fuelled by biogas and to defining the future energy scenario in which the plant will be embedded. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. A multi-scale life-cycle energy and greenhouse-gas emissions analysis model for residential buildings

    OpenAIRE

    Stephan, André; Crawford, Robert

    2014-01-01

    Current assessments of residential building energy demand focus mainly on their operational aspect, notably in terms of space heating and cooling. The embodied energy of buildings and the transport energy consumption of their occupants are typically overlooked. Recent studies have shown that these two energy demands can represent more than half of the life-cycle energy of a building over 50 years. This study presents a holistic model and software tool which take into account energy requiremen...

  13. Determination of Duty Cycle for Energy Storage Systems in a PV Smoothing Application

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwald, David A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellison, James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-04-01

    This report supplements the document, "Protocol for Uniformly Measuring and Expressing the Performance of Energy Storage Systems," issued in a revised version in April 2016 (see [4]), which will include the photovoltaic (PV) smoothing application for an energy storage system (ESS). This report provides the background and documentation associated with the determination of a duty cycle for an ESS operated in a PV smoothing application for the purpose of measuring and expressing ESS performance in accordance with the ESS performance protocol. ACKNOWLEDGEMENTS The authors gratefully acknowledge the support of Dr. Imre Gyuk, program manager for the DOE Energy Storage Systems Program. The authors would also like to express their appreciation to all the stakeholders who participated as members of the PV Smoothing Subgroup. Without their thoughtful input and recommendations, the definitions, metrics, and duty cycle provided in this report would not have been possible. A complete listing of members of the PV Smoothing Subgroup appears in the first chapter of this report. Special recognition should go to the staffs at Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratories (SNL) in collaborating on this effort. In particular, Mr. David Conover and Dr. Vish Viswanathan of PNNL and Dr. Summer Ferreira of SNL were especially helpful in their suggestions for the determination of a duty cycle for the PV Smoothing application.

  14. Dynamic Simulation of an Organic Rankine Cycle—Detailed Model of a Kettle Boiler

    Directory of Open Access Journals (Sweden)

    Roberto Pili

    2017-04-01

    Full Text Available Organic Rankine Cycles (ORCs are nowadays a valuable technology to produce electricity from low and medium temperature heat sources, e.g., in geothermal, biomass and waste heat recovery applications. Dynamic simulations can help improve the flexibility and operation of such plants, and guarantee a better economic performance. In this work, a dynamic model for a multi-pass kettle evaporator of a geothermal ORC power plant has been developed and its dynamics have been validated against measured data. The model combines the finite volume approach on the tube side and a two-volume cavity on the shell side. To validate the dynamic model, a positive and a negative step function in heat source flow rate is applied. The simulation model performed well in both cases. The liquid level appeared the most challenging quantity to simulate. A better agreement in temperature was achieved by increasing the volume flow rate of the geothermal brine by 2% over the entire simulation. Measurement errors, discrepancies in working fluid and thermal brine properties and uncertainties in heat transfer correlations can account for this. In the future, the entire geothermal power plant will be simulated, and suggestions to improve its dynamics and control by means of simulations will be provided.

  15. Energy analyses and greenhouse gas emissions assessment for saffron production cycle.

    Science.gov (United States)

    Bakhtiari, Amir Abbas; Hematian, Amir; Sharifi, Azin

    2015-10-01

    Population growth and world climate changes are putting high pressure on agri-food production systems. Exacerbating use of energy sources and expanding the environmental damaging symptoms are the results of these difficult situations. This study was conducted to determine the energy balance for saffron production cycle and investigate the corresponding greenhouse gas (GHG) emissions in Iran. Saffron (Crocus sativus L.) is one of the main spice that historically cultivated in Iran. Data were obtained from 127 randomly selected saffron growers using a face to face questionnaire technique. The results revealed that in 5 years of saffron production cycle, the overall input and output energy use were to be 163,912.09 and 184,868.28 MJ ha(-1), respectively. The highest-level of energy consumption belongs to seeds (23.7 %) followed by chemical fertilizers (23.4 %). Energy use efficiency, specific energy, net energy, and energy productivity of saffron production were 1.1, 13.4 MJ kg(-1), 20,956.2 MJ ha(-1), and 0.1 kg MJ(-1), respectively. The result shows that the cultivation of saffron emits 2325.5 kg CO2 eq. ha(-1) greenhouse gas, in which around 46.5 % belonged to electricity followed by chemical fertilizers. In addition the Cobb-Douglas production function was applied into EViews 7 software to define the functional relationship. The results of econometric model estimation showed that the impact of human labor, electricity, and water for irrigation on stigma, human labor, electricity, and seed on corm and also human labor and farmyard manure (FYM) on flower and leaf yield were found to be statistically significant. Sensitivity analysis results of the energy inputs demonstrated that the marginal physical productivity (MPP) worth of electricity energy was the highest for saffron stigma and corm, although saffron flower and leaf had more sensitivity on chemicals energy inputs. Moreover, MPP values of renewable and indirect energies were higher than non-renewable and

  16. An assessment of the effectiveness of fuel cycle technologies for the national energy security enhancement in the electricity sector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jun [Department of Nuclear and Quantum Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)], E-mail: hjkim@kaeri.re.kr; Jun, Eunju; Chang, Soon Heung [Department of Nuclear and Quantum Engineering, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Won Joon [Business Economics Program and Center for Science-based Entrepreneurship, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2009-05-15

    Energy security, in the 21st century, draws significant attention in most countries worldwide, because the national security and sustainable development depend largely on energy security. The anticipated fossil energy depletion and the instability of their supply drive many countries to consider nuclear energy as their alternative energy source for the enhancement of their national energy security. In this study, indicators measuring the level of energy security in the electric power sector are developed and applied for the assessment of the effectiveness of four electric power system schemes which deploy different nuclear fuel cycle technologies, with consideration for the diversification of the energy markets and the vulnerability to economic disruption. Results show that the contribution of the closed fuel cycle scheme is larger than the once-through fuel cycle scheme in the perspective of energy security. In addition, the completely closed fuel cycle with the spent fuel recycling enhances the national energy security to the maximum extent compared to all other fuel cycle schemes. Since a completely closed fuel cycle is hardly affected by the uranium price changes, this scheme is found to be the most favorable scheme, ensuring the stable profit of utilities and stabilizing the electricity tariff. In addition, the completely closed fuel cycle scheme provides the best enhancement of national energy security with respect to energy supply, under reasonable price conditions. The indicators developed in this study can be utilized as a useful instrument for the measurement of the level of the energy security, especially by the countries importing energy resources for the generation of electric power.

  17. Rankin-Selberg methods for closed string amplitudes

    CERN Document Server

    Pioline, Boris

    2014-01-01

    After integrating over supermoduli and vertex operator positions, scattering amplitudes in superstring theory at genus $h\\leq 3$ are reduced to an integral of a Siegel modular function of degree $h$ on a fundamental domain of the Siegel upper half plane. A direct computation is in general unwieldy, but becomes feasible if the integrand can be expressed as a sum over images under a suitable subgroup of the Siegel modular group: if so, the integration domain can be extended to a simpler domain at the expense of keeping a single term in each orbit -- a technique known as the Rankin-Selberg method. Motivated by applications to BPS-saturated amplitudes, Angelantonj, Florakis and I have applied this technique to one-loop modular integrals where the integrand is the product of a Siegel-Narain theta function times a weakly, almost holomorphic modular form. I survey our main results, and take some steps in extending this method to genus greater than one.

  18. Deriving modified Rankin scores from medical case-records.

    Science.gov (United States)

    Quinn, Terence J; Ray, Gautamananda; Atula, Sari; Walters, Matthew R; Dawson, Jesse; Lees, Kennedy R

    2008-12-01

    Modified Rankin score (mRS) is traditionally graded using a face-to-face or telephone interview. Certain stroke assessment scales can be derived from a review of a patient's case-record alone. We hypothesized that mRS could be successfully derived from the narrative within patient case-records. Sequential patients attending our cerebrovascular outpatient clinic were included. Two independent, blinded clinicians, trained in mRS, assessed case-records to derive mRS. They scored "certainty" of their grading on a 5-point Likert scale. Agreement between derived and traditional face-to-face mRS was calculated using attribute agreement analysis. Fifty patients with a range of disabilities were included. Case-record appraisers were poor at deriving mRS (k=0.34 against standard). Derived mRS grades showed poor agreement between observers (k=0.33). There was no relationship between certainty of derived mRS and proportion of correct grades (P=0.727). Accurate mRS cannot be derived from standard hospital records. Direct mRS interview is still required for clinical trials.

  19. Few-cycle high energy mid-infrared pulse from Ho:YLF laser

    Energy Technology Data Exchange (ETDEWEB)

    Murari, Krishna

    2017-04-15

    Over the past decade, development of high-energy ultrafast laser sources has led to important breakthroughs in attoscience and strong-field physics study in atoms and molecules. Coherent pulse synthesis of few-cycle high-energy laser pulse is a promising tool to generate isolated attosecond pulses via high harmonics generation (HHG). An effective way to extend the HHG cut-off energy to higher values is making use of long mid-infrared (MIR) driver wavelength, as the ponderomotive potential scales quadratically with wavelength. If properly scaled in energy to multi-mJ level and few-cycle duration, such pulses provide a direct path to intriguing attoscience experiments in gases and solids, which even permit the realization of bright coherent table-top HHG sources in the water-window and keV X-ray region. However, the generation of high-intensity long-wavelength MIR pulses has always remained challenging, in particular starting from high-energy picosecond 2-μm laser driver, that is suitable for further energy scaling of the MIR pulses to multi-mJ energies by utilizing optical parametric amplifiers (OPAs). In this thesis, a front-end source for such MIR OPA is presented. In particular, a novel and robust strong-field few-cycle 2-μm laser driver directly from picosecond Ho:YLF laser and utilizing Kagome fiber based compression is presented. We achieved: a 70-fold compression of 140-μJ, 3.3-ps pulses from Ho:YLF amplifier to 48 fs with 11 μJ energy. The work presented in this thesis demonstrates a straightforward path towards generation of few-cycle MIR pulses and we believe that in the future the ultrafast community will benefit from this enabling technology. The results are summarized in mainly four parts: The first part is focused on the development of a 2-μm, high-energy laser source as the front-end. Comparison of available technology in general and promising gain media at MIR wavelength are discussed. Starting from the basics of an OPA, the design criteria

  20. Liquid-metal binary cycles for stationary power

    Science.gov (United States)

    Gutstein, M.; Furman, E. R.; Kaplan, G. M.

    1975-01-01

    The use of topping cycles to increase electric power plant efficiency is discussed, with particular attention to mercury and alkali metal Rankine cycle systems that could be considered for topping cycle applications. An overview of this technology, possible system applications, the required development, and possible problem areas is presented.

  1. Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 3: appendix E to technical report, comprehensive EVTECA results tables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report compares the energy use, oil use and emissions of electric vehicles (EVs) with those of conventional, gasoline-powered vehicles (CVs) over the total life cycle of the vehicles. The various stages included in the vehicles` life cycles include vehicle manufacture, fuel production, and vehicle operation. Disposal is not included. An inventory of the air emissions associated with each stage of the life cycle is estimated. Water pollutants and solid wastes are reported for individual processes, but no comprehensive inventory is developed. Volume III presents the results of the total energy cycle model runs, which are summarized in Volume I.

  2. Factors influencing the life cycle burdens of the recovery of energy from residual municipal waste.

    Science.gov (United States)

    Burnley, Stephen; Coleman, Terry; Peirce, Adam

    2015-05-01

    A life cycle assessment was carried out to assess a selection of the factors influencing the environmental impacts and benefits of incinerating the fraction of municipal waste remaining after source-separation for reuse, recycling, composting or anaerobic digestion. The factors investigated were the extent of any metal and aggregate recovery from the bottom ash, the thermal efficiency of the process, and the conventional fuel for electricity generation displaced by the power generated. The results demonstrate that incineration has significant advantages over landfill with lower impacts from climate change, resource depletion, acidification, eutrophication human toxicity and aquatic ecotoxicity. To maximise the benefits of energy recovery, metals, particularly aluminium, should be reclaimed from the residual bottom ash and the energy recovery stage of the process should be as efficient as possible. The overall environmental benefits/burdens of energy from waste also strongly depend on the source of the power displaced by the energy from waste, with coal giving the greatest benefits and combined cycle turbines fuelled by natural gas the lowest of those considered. Regardless of the conventional power displaced incineration presents a lower environmental burden than landfill. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Energy-Saving Optimization of Water Supply Pumping Station Life Cycle Based on BIM Technology

    Science.gov (United States)

    Qun, Miao; Wang, Jiayuan; Liu, Chao

    2017-12-01

    In the urban water supply system, pump station is the main unit of energy consumption. In the background of pushing forward the informatization in China, using BIM technology in design, construction and operations of water supply pumping station, can break through the limitations of the traditional model and effectively achieve the goal of energy conservation and emissions reduction. This work researches the way to solve energy-saving optimization problems in the process of whole life cycle of water supply pumping station based on BIM technology, and put forward the feasible strategies of BIM application in order to realize the healthy and sustainable development goals by establishing the BIM model of water supply pumping station of Qingdao Guzhenkou water supply project.

  4. Life cycle assessment (LCA) of an energy recovery plant in the olive oil industries

    Energy Technology Data Exchange (ETDEWEB)

    Intini, Francesca; Kuhtz, Silvana [Dep. Engineering and Environmental Physics, Faculty of Engineering, University of Basilicata (Italy); Gianluca Rospi, [Dep. Engineering and Environmental Physics, Faculty of Architecture, University of Basilicata (Italy)

    2012-07-01

    To reduce the GHG emissions in the UE and to increase the produced energy it is important to spread out decentralized technologies for renewable energy production. In this paper a power plant fed with biomass is studied, in particular the biomass considered is the waste of the olive oil industries. This study focuses on the possibility of using the de-oiled pomace and waste wood as fuel. A life cycle assessment (LCA) of a biomass power plant located in the South of Italy was performed. The global warming potential has been calculated and compared with that of a plant for energy production that uses refuse derived fuel (RDF) and that of one that uses coal. The LCA shows the important environmental advantages of biomass utilization in terms of greenhouse gas emissions reduction. An improved impact assessment methodology may better underline the advantages due to the biomass utilization.

  5. Life cycle evaluation of an intercooled gas turbine plant used in conjunction with renewable energy

    Directory of Open Access Journals (Sweden)

    Thank-God Isaiah

    2016-09-01

    Full Text Available The life cycle estimation of power plants is important for gas turbine operators. With the introduction of wind energy into the grid, gas turbine operators now operate their plants in Load–Following modes as back-ups to the renewable energy sources which include wind, solar, etc. The motive behind this study is to look at how much life is consumed when an intercooled power plant with 100 MW power output is used in conjunction with wind energy. This operation causes fluctuations because the wind energy is unpredictable and overtime causes adverse effects on the life of the plant – The High Pressure Turbine Blades. Such fluctuations give rise to low cycle fatigue and creep failure of the blades depending on the operating regime used. A performance based model that is capable of estimating the life consumed of an intercooled power plant has been developed. The model has the capability of estimating the life consumed based on seasonal power demands and operations. An in-depth comparison was undertaken on the life consumed during the seasons of operation and arrives at the conclusion that during summer, the creep and low cycle life is consumed higher than the rest periods. A comparison was also made to determine the life consumed between Load–Following and stop/start operating scenarios. It was also observed that daily creep life consumption in summer was higher than the winter period in-spite of having lower average daily operating hours in a Start–Stop operating scenario.

  6. A Cumulative Energy Demand indicator (CED), life cycle based, for industrial waste management decision making

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Rita, E-mail: rita.puig@eei.upc.edu [Escola d’Enginyeria d’Igualada (EEI), Universitat Politècnica de Catalunya (UPC), Plaça del Rei, 15, 08700 Igualada (Spain); Fullana-i-Palmer, Pere [UNESCO Chair in Life Cycle and Climate Change, Escola Superior de Comerç Internacional, Universitat Pompeu Fabra (UPF), c/Passeig Pujades, 1, 08003 Barcelona (Spain); Baquero, Grau; Riba, Jordi-Roger [Escola d’Enginyeria d’Igualada (EEI), Universitat Politècnica de Catalunya (UPC), Plaça del Rei, 15, 08700 Igualada (Spain); Bala, Alba [UNESCO Chair in Life Cycle and Climate Change, Escola Superior de Comerç Internacional, Universitat Pompeu Fabra (UPF), c/Passeig Pujades, 1, 08003 Barcelona (Spain)

    2013-12-15

    Highlights: • We developed a methodology useful to environmentally compare industrial waste management options. • The methodology uses a Net Energy Demand indicator which is life cycle based. • The method was simplified to be widely used, thus avoiding cost driven decisions. • This methodology is useful for governments to promote the best environmental options. • This methodology can be widely used by other countries or regions around the world. - Abstract: Life cycle thinking is a good approach to be used for environmental decision-support, although the complexity of the Life Cycle Assessment (LCA) studies sometimes prevents their wide use. The purpose of this paper is to show how LCA methodology can be simplified to be more useful for certain applications. In order to improve waste management in Catalonia (Spain), a Cumulative Energy Demand indicator (LCA-based) has been used to obtain four mathematical models to help the government in the decision of preventing or allowing a specific waste from going out of the borders. The conceptual equations and all the subsequent developments and assumptions made to obtain the simplified models are presented. One of the four models is discussed in detail, presenting the final simplified equation to be subsequently used by the government in decision making. The resulting model has been found to be scientifically robust, simple to implement and, above all, fulfilling its purpose: the limitation of waste transport out of Catalonia unless the waste recovery operations are significantly better and justify this transport.

  7. EMISSION OF POLLUTANTS AND ENERGY CONSUMPTION IN LIFE CYCLE OF DIESEL OIL

    Directory of Open Access Journals (Sweden)

    Piotr Haller

    2013-10-01

    Full Text Available The following article is an analysis of designed processes of the life cycle of the most popular fuel for Diesel engines: diesel oil. This fuel is produced from petroleum, which is a non-renewable source of energy. Analysis was carried out with the assumptions of Life Cycle Assessment, which is a tool to test the environmental impact of the product. The life cycle of diesel was divided into five unit processes: petroleum extraction, transport of petroleum to the refinery, refining petroleum to diesel, transport of diesel to the recipient and utilization of delivered fuel by transport company. For every process the energy consumption and emission of carbon monoxide, nitrogen oxides and sulphursulphur oxides was calculated, with assumption of probable data, that could occur in real processes. The analysis has shown, that the process of refining petroleum is highly pollution-intensive. Also the combustion of diesel generates a significant amount of pollutants’ emission, which is why it is necessary to develop technologies that could contribute to the reduction of emission.

  8. Technology for Bayton-cycle powerplants using solar and nuclear energy

    Science.gov (United States)

    English, R. E.

    1986-01-01

    Brayton cycle gas turbines have the potential to use either solar heat or nuclear reactors for generating from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power generating system. Their development for solar energy dynamic power generation for the space station could be the first step in an evolution of such powerplants for a very wide range of applications. At the low power level of only 10 kWe, a power generating system has already demonstrated overall efficiency of 0.29 and operated 38 000 hr. Tests of improved components show that these components would raise that efficiency to 0.32, a value twice that demonstrated by any alternate concept. Because of this high efficiency, solar Brayton cycle power generators offer the potential to increase power per unit of solar collector area to levels exceeding four times that from photovoltaic powerplants using present technology for silicon solar cells. The technologies for solar mirrors and heat receivers are reviewed and assessed. This Brayton technology for solar powerplants is equally suitable for use with the nuclear reactors. The available long time creep data on the tantalum alloy ASTAR-811C show that such Brayton cycles can evolve to cycle peak temperatures of 1500 K (2240 F). And this same technology can be extended to generate 10 to 100 MW in space by exploiting existing technology for terrestrial gas turbines in the fields of both aircraft propulsion and stationary power generation.

  9. Testing of High Thermal Cycling Stability of Low Strength Concrete as a Thermal Energy Storage Material

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2016-09-01

    Full Text Available Concrete has the potential to become a solution for thermal energy storage (TES integrated in concentrating solar power (CSP systems due to its good thermal and mechanical properties and low cost of material. In this study, a low strength concrete (C20 is tested at high temperatures up to 600 °C. Specimens are thermally cycled at temperatures in the range of 400–300 °C, 500–300 °C, and 600–300 °C, which TES can reach in operation. For comparison, specimens also cycled at temperature in the range of 400–25 °C (room temperature, 500–25 °C, and 600–25 °C. It is found from the test results that cracks are not observed on the surfaces of concrete specimens until the temperature is elevated up to 500 °C. There is mechanical deterioration of concrete after exposure to high temperature, especially to high thermal cycles. The residual compressive strength of concrete after 10 thermal cycles between 600 °C and 300 °C is about 58.3%, but the specimens remain stable without spalling, indicating possible use of low strength concrete as a TES material.

  10. Life cycle assessment of thermal waste-to-energy technologies: review and recommendations.

    Science.gov (United States)

    Astrup, Thomas Fruergaard; Tonini, Davide; Turconi, Roberto; Boldrin, Alessio

    2015-03-01

    Life cycle assessment (LCA) has been used extensively within the recent decade to evaluate the environmental performance of thermal Waste-to-Energy (WtE) technologies: incineration, co-combustion, pyrolysis and gasification. A critical review was carried out involving 250 individual case-studies published in 136 peer-reviewed journal articles within 1995 and 2013. The studies were evaluated with respect to critical aspects such as: (i) goal and scope definitions (e.g. functional units, system boundaries, temporal and geographic scopes), (ii) detailed technology parameters (e.g. related to waste composition, technology, gas cleaning, energy recovery, residue management, and inventory data), and (iii) modeling principles (e.g. energy/mass calculation principles, energy substitution, inclusion of capital goods and uncertainty evaluation). Very few of the published studies provided full and transparent descriptions of all these aspects, in many cases preventing an evaluation of the validity of results, and limiting applicability of data and results in other contexts. The review clearly suggests that the quality of LCA studies of WtE technologies and systems including energy recovery can be significantly improved. Based on the review, a detailed overview of assumptions and modeling choices in existing literature is provided in conjunction with practical recommendations for state-of-the-art LCA of Waste-to-Energy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Comparing the Life Cycle Energy Consumption, Global Warming and Eutrophication Potentials of Several Water and Waste Service Options

    Science.gov (United States)

    Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG...

  12. Results of the GABLS3 diurnal-cycle benchmark for wind energy applications

    Science.gov (United States)

    Sanz Rodrigo, J.; Allaerts, D.; Avila, M.; Barcons, J.; Cavar, D.; Chávez Arroyo, RA; Churchfield, M.; Kosovic, B.; Lundquist, JK; Meyers, J.; Muñoz Esparza, D.; Palma, JMLM; Tomaszewski, JM; Troldborg, N.; van der Laan, MP; Veiga Rodrigues, C.

    2017-05-01

    We present results of the GABLS3 model intercomparison benchmark revisited for wind energy applications. The case consists of a diurnal cycle, measured at the 200-m tall Cabauw tower in the Netherlands, including a nocturnal low-level jet. The benchmark includes a sensitivity analysis of WRF simulations using two input meteorological databases and five planetary boundary-layer schemes. A reference set of mesoscale tendencies is used to drive microscale simulations using RANS k-ɛ and LES turbulence models. The validation is based on rotor-based quantities of interest. Cycle-integrated mean absolute errors are used to quantify model performance. The results of the benchmark are used to discuss input uncertainties from mesoscale modelling, different meso-micro coupling strategies (online vs offline) and consistency between RANS and LES codes when dealing with boundary-layer mean flow quantities. Overall, all the microscale simulations produce a consistent coupling with mesoscale forcings.

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

    KAUST Repository

    Missimer, Thomas M.

    2013-01-01

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

  14. Ocean Thermal Energy Conversion Life Cycle Cost Assessment, Final Technical Report, 30 May 2012

    Energy Technology Data Exchange (ETDEWEB)

    Martel, Laura [Lockheed Martin, Manassas, VA (United States); Smith, Paul [John Halkyard and Associates: Glosten Associates, Houston, TX (United States); Rizea, Steven [Makai Ocean Engineering, Waimanalo, HI (United States); Van Ryzin, Joe [Makai Ocean Engineering, Waimanalo, HI (United States); Morgan, Charles [Planning Solutions, Inc., Vancouver, WA (United States); Noland, Gary [G. Noland and Associates, Inc., Pleasanton, CA (United States); Pavlosky, Rick [Lockheed Martin, Manassas, VA (United States); Thomas, Michael [Lockheed Martin, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates: Glosten Associates, Houston, TX (United States)

    2012-05-30

    The Ocean Thermal Energy Conversion (OTEC) Life Cycle Cost Assessment (OLCCA) is a study performed by members of the Lockheed Martin (LM) OTEC Team under funding from the Department of Energy (DOE), Award No. DE-EE0002663, dated 01/01/2010. OLCCA objectives are to estimate procurement, operations and maintenance, and overhaul costs for two types of OTEC plants: -Plants moored to the sea floor where the electricity produced by the OTEC plant is directly connected to the grid ashore via a marine power cable (Grid Connected OTEC plants) -Open-ocean grazing OTEC plant-ships producing an energy carrier that is transported to designated ports (Energy Carrier OTEC plants) Costs are developed using the concept of levelized cost of energy established by DOE for use in comparing electricity costs from various generating systems. One area of system costs that had not been developed in detail prior to this analysis was the operations and sustainment (O&S) cost for both types of OTEC plants. Procurement costs, generally referred to as capital expense and O&S costs (operations and maintenance (O&M) costs plus overhaul and replacement costs), are assessed over the 30 year operational life of the plants and an annual annuity calculated to achieve a levelized cost (constant across entire plant life). Dividing this levelized cost by the average annual energy production results in a levelized cost of electricity, or LCOE, for the OTEC plants. Technical and production efficiency enhancements that could result in a lower value of the OTEC LCOE were also explored. The thermal OTEC resource for Oahu, Hawaii and projected build out plan were developed. The estimate of the OTEC resource and LCOE values for the planned OTEC systems enable this information to be displayed as energy supplied versus levelized cost of the supplied energy; this curve is referred to as an Energy Supply Curve. The Oahu Energy Supply Curve represents initial OTEC deployment starting in 2018 and demonstrates the

  15. Coupling a groundwater model with a land surface model to improve water and energy cycle simulation

    Directory of Open Access Journals (Sweden)

    W. Tian

    2012-12-01

    Full Text Available Water and energy cycles interact, making these two processes closely related. Land surface models (LSMs can describe the water and energy cycles on the land surface, but their description of the subsurface water processes is oversimplified, and lateral groundwater flow is ignored. Groundwater models (GWMs describe the dynamic movement of the subsurface water well, but they cannot depict the physical mechanisms of the evapotranspiration (ET process in detail. In this study, a coupled model of groundwater flow with a simple biosphere (GWSiB is developed based on the full coupling of a typical land surface model (SiB2 and a 3-D variably saturated groundwater model (AquiferFlow. In this coupled model, the infiltration, ET and energy transfer are simulated by SiB2 using the soil moisture results from the groundwater flow model. The infiltration and ET results are applied iteratively to drive the groundwater flow model. After the coupled model is built, a sensitivity test is first performed, and the effect of the groundwater depth and the hydraulic conductivity parameters on the ET are analyzed. The coupled model is then validated using measurements from two stations located in shallow and deep groundwater depth zones. Finally, the coupled model is applied to data from the middle reach of the Heihe River basin in the northwest of China to test the regional simulation capabilities of the model.

  16. Energy metabolism and glutamate-glutamine cycle in the brain: a stoichiometric modeling perspective

    Science.gov (United States)

    2013-01-01

    Background The energetics of cerebral activity critically relies on the functional and metabolic interactions between neurons and astrocytes. Important open questions include the relation between neuronal versus astrocytic energy demand, glucose uptake and intercellular lactate transfer, as well as their dependence on the level of activity. Results We have developed a large-scale, constraint-based network model of the metabolic partnership between astrocytes and glutamatergic neurons that allows for a quantitative appraisal of the extent to which stoichiometry alone drives the energetics of the system. We find that the velocity of the glutamate-glutamine cycle (Vcyc) explains part of the uncoupling between glucose and oxygen utilization at increasing Vcyc levels. Thus, we are able to characterize different activation states in terms of the tissue oxygen-glucose index (OGI). Calculations show that glucose is taken up and metabolized according to cellular energy requirements, and that partitioning of the sugar between different cell types is not significantly affected by Vcyc. Furthermore, both the direction and magnitude of the lactate shuttle between neurons and astrocytes turn out to depend on the relative cell glucose uptake while being roughly independent of Vcyc. Conclusions These findings suggest that, in absence of ad hoc activity-related constraints on neuronal and astrocytic metabolism, the glutamate-glutamine cycle does not control the relative energy demand of neurons and astrocytes, and hence their glucose uptake and lactate exchange. PMID:24112710

  17. Statistical Characterization of Medium-Duty Electric Vehicle Drive Cycles; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Prohaska, R.; Duran, A.; Ragatz, A.; Kelly, K.

    2015-05-03

    With funding from the U.S. Department of Energy’s Vehicle Technologies Office, the National Renewable Energy Laboratory (NREL) conducts real-world performance evaluations of advanced medium- and heavy-duty fleet vehicles. Evaluation results can help vehicle manufacturers fine-tune their designs and assist fleet managers in selecting fuel-efficient, low-emission vehicles that meet their economic and operational goals. In 2011, NREL launched a large-scale performance evaluation of medium-duty electric vehicles. With support from vehicle manufacturers Smith and Navistar, NREL research focused on characterizing vehicle operation and drive cycles for electric delivery vehicles operating in commercial service across the nation.

  18. High Energy, Long Cycle Life Lithium-ion Batteries for PHEV Application

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Donghai [Pennsylvania State Univ., University Park, PA (United States); Manthiram, Arumugam [Univ. of Texas, Austin, TX (United States); Wang, Chao-Yang [EC Power LLC, State College, PA (United States); Liu, Gao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zhang, Zhengcheng [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-05-15

    cell fabrication and test, full pouch cells with high capacity of 2.2 Ah and 1.2 Ah have been fabricated and delivered. The cells show great uniformity and good cycling performance. The prelithiation method effectively compensate the loss in the first cycle. The cell with high energy density and long-cycle life has been achieved.

  19. Ketogenesis in isolated rat liver mitochondria I. Relationships with the citric acid cycle and with the mitochondrial energy state

    NARCIS (Netherlands)

    Lopes-Cardozo, M.; Bergh, S.G. van den

    1972-01-01

    1. A method is described to calculate the distribution of acetyl-CoA over the citric acid cycle and ketogenesis during the oxidation of fatty acids in the presence of added malate. 2. Increasing concentrations of added Krebs cycle intermediates lower the rate of ketogenesis both in the low-energy

  20. A Life-Cycle Assessment of Biofuels: Tracing Energy and Carbon through a Fuel-Production System

    Science.gov (United States)

    Krauskopf, Sara

    2010-01-01

    A life-cycle assessment (LCA) is a tool used by engineers to make measurements of net energy, greenhouse gas production, water consumption, and other items of concern. This article describes an activity designed to walk students through the qualitative part of an LCA. It asks them to consider the life-cycle costs of ethanol production, in terms of…

  1. Holistic energy system modeling combining multi-objective optimization and life cycle assessment

    Science.gov (United States)

    Rauner, Sebastian; Budzinski, Maik

    2017-12-01

    Making the global energy system more sustainable has emerged as a major societal concern and policy objective. This transition comes with various challenges and opportunities for a sustainable evolution affecting most of the UN’s Sustainable Development Goals. We therefore propose broadening the current metrics for sustainability in the energy system modeling field by using industrial ecology techniques to account for a conclusive set of indicators. This is pursued by including a life cycle based sustainability assessment into an energy system model considering all relevant products and processes of the global supply chain. We identify three pronounced features: (i) the low-hanging fruit of impact mitigation requiring manageable economic effort; (ii) embodied emissions of renewables cause increasing spatial redistribution of impact from direct emissions, the place of burning fuel, to indirect emissions, the location of the energy infrastructure production; (iii) certain impact categories, in which more overall sustainable systems perform worse than the cost minimal system, require a closer look. In essence, this study makes the case for future energy system modeling to include the increasingly important global supply chain and broaden the metrics of sustainability further than cost and climate change relevant emissions.

  2. An RF energy harvesting power management circuit for appropriate duty-cycled operation

    Science.gov (United States)

    Shirane, Atsushi; Ito, Hiroyuki; Ishihara, Noboru; Masu, Kazuya

    2015-04-01

    In this study, we present an RF energy harvesting power management unit (PMU) for battery-less wireless sensor devices (WSDs). The proposed PMU realizes a duty-cycled operation that is divided into the energy charging time and discharging time. The proposed PMU detects two types of timing, thus, the appropriate timing for the activation can be recognized. The activation of WSDs at the proper timing leads to energy efficient operation and stable wireless communication. The proposed PMU includes a hysteresis comparator (H-CMP) and an RF signal detector (RF-SD) to detect the timings. The proposed RF-SD can operate without the degradation of charge efficiency by reusing the RF energy harvester (RF-EH) and H-CMP. The PMU fabricated in a 180 nm Si CMOS demonstrated the charge operation using the RF signal at 915 MHz and the two types of timing detection with less than 124 nW in the charge phase. Furthermore, in the active phase, the PMU generates a 0.5 V regulated power supply from the charged energy.

  3. The Temperature Dependence on Intermolecular Potential Energy in the Design of a Supercritical Stirling Cycle Heat Engine

    OpenAIRE

    Marko, Matthew David

    2017-01-01

    The Stirling thermodynamic heat engine cycle is modified, where instead of an ideal gas, a real, supercritical, monatomic working fluid subjected to intermolecular attractive forces is used. The potential energy of real gases is redefined to show it decreasing with temperature as a result of the attractive Keesom forces, which are temperature dependent. This new definition of potential energy is used to thermodynamically design a Stirling cycle heat engine with supercritical xenon gas, and an...

  4. Life cycle assessment modelling of waste-to-energy incineration in Spain and Portugal.

    Science.gov (United States)

    Margallo, M; Aldaco, R; Irabien, A; Carrillo, V; Fischer, M; Bala, A; Fullana, P

    2014-06-01

    In recent years, waste management systems have been evaluated using a life cycle assessment (LCA) approach. A main shortcoming of prior studies was the focus on a mixture of waste with different characteristics. The estimation of emissions and consumptions associated with each waste fraction in these studies presented allocation problems. Waste-to-energy (WTE) incineration is a clear example in which municipal solid waste (MSW), comprising many types of materials, is processed to produce several outputs. This paper investigates an approach to better understand incineration processes in Spain and Portugal by applying a multi-input/output allocation model. The application of this model enabled predictions of WTE inputs and outputs, including the consumption of ancillary materials and combustibles, air emissions, solid wastes, and the energy produced during the combustion of each waste fraction. © The Author(s) 2014.

  5. Speeding up DFT: A faster method for integrating band energy in SCF cycles

    Science.gov (United States)

    Burbidge, Matthew M.; Jorgensen, Jeremy J.; Rosenbrock, Conrad W.; Thomas, Derek C.; Hess, Bret C.; Forcade, Rodney W.; Curtarolo, Stefano; Hart, Gus L. W.

    2015-03-01

    Typically in SCF cycles, a ``rectangle rule'' is used on uniformly spaced points (Monk Pack meshes)1 to integrate the band energy. The use of rectangles is motivated by their fast convergence when used on the fully occupied bands of semiconductors. Unfortunately integration with rectangles is extremely inefficient for metals. This motivates the use of gauss quadrature (or other higher order methods) for integrating the band energy. As we show, however, even in the case of semiconductors where the rectangle convergence is extremely efficient, higher order methods are still more efficient. The savings in semiconductors alone are sufficient to motivate the implementation of a higher order method in current DFT codes. Even though higher order quadrature methods were discussed immediately following the original Monkhorst and Pack1 paper, we revisit the issue in light of modern DFT calculations. MMB acknowledges support by NSF (DMR-0908753). JJJ, CWR, DCT, RWF, SC, GLWH was supported by ONR (MURI N00014-13-1-0635).

  6. From Homodimer to Heterodimer and Back: Elucidating the TonB Energy Transduction Cycle.

    Science.gov (United States)

    Gresock, Michael G; Kastead, Kyle A; Postle, Kathleen

    2015-11-01

    The TonB system actively transports large, scarce, and important nutrients through outer membrane (OM) transporters of Gram-negative bacteria using the proton gradient of the cytoplasmic membrane (CM). In Escherichia coli, the CM proteins ExbB and ExbD harness and transfer proton motive force energy to the CM protein TonB, which spans the periplasmic space and cyclically binds OM transporters. TonB has two activity domains: the amino-terminal transmembrane domain with residue H20 and the periplasmic carboxy terminus, through which it binds to OM transporters. TonB is inactivated by all substitutions at residue H20 except H20N. Here, we show that while TonB trapped as a homodimer through its amino-terminal domain retained full activity, trapping TonB through its carboxy terminus inactivated it by preventing conformational changes needed for interaction with OM transporters. Surprisingly, inactive TonB H20A had little effect on homodimerization through the amino terminus and instead decreased TonB carboxy-terminal homodimer formation prior to reinitiation of an energy transduction cycle. That result suggested that the TonB carboxy terminus ultimately interacts with OM transporters as a monomer. Our findings also suggested the existence of a separate equimolar pool of ExbD homodimers that are not in contact with TonB. A model is proposed where interaction of TonB homodimers with ExbD homodimers initiates the energy transduction cycle, and, ultimately, the ExbD carboxy terminus modulates interactions of a monomeric TonB carboxy terminus with OM transporters. After TonB exchanges its interaction with ExbD for interaction with a transporter, ExbD homodimers undergo a separate cycle needed to re-energize them. Canonical mechanisms of active transport across cytoplasmic membranes employ ion gradients or hydrolysis of ATP for energy. Gram-negative bacterial outer membranes lack these resources. The TonB system embodies a novel means of active transport across the outer

  7. Caffeine improves supramaximal cycling but not the rate of anaerobic energy release.

    Science.gov (United States)

    Simmonds, Michael J; Minahan, Clare L; Sabapathy, Surendran

    2010-05-01

    The purpose of this study was to determine if improved supramaximal exercise performance in trained cyclists following caffeine ingestion was associated with enhanced O(2) uptake (VO2 kinetics), increased anaerobic energy provision (accumulated O(2)-AO(2)-deficit), or a reduction in the accumulation of metabolites (for example, K(+)) associated with muscular fatigue. Six highly trained male cyclists (VO2peak 68 +/- 8 mL kg(-1) min(-1)) performed supramaximal (120% VO2peak) exercise bouts to exhaustion on an electronically braked cycle ergometer, following double-blind and randomized ingestion of caffeine/placebo (5 mg kg(-1)). Time to exhaustion (TE), VO2 kinetics, AO(2) deficit, blood lactate (La(-)), plasma potassium (K(+)), caffeine and paraxanthine concentrations were measured. Caffeine ingestion elicited significant increases in TE (14.8%, p caffeine ingestion. However, [K(+)] was significantly reduced (13.4%, p caffeine trials, compared with placebo. It appears that caffeine ingestion is beneficial to supramaximal cycling performance in highly trained men. The reduced plasma [K(+)] during submaximal warm-up cycling may prolong the time taken to reach critical [K(+)] at exhaustion, thus delaying fatigue. Considering caffeine ingestion did not change VO2 kinetics or isotime AO(2) deficit, increases in absolute AO(2) deficit may be a consequence of prolonged TE, rather than causal.

  8. Effects of acute sprint interval cycling and energy replacement on postprandial lipemia.

    Science.gov (United States)

    Freese, Eric C; Levine, Ari S; Chapman, Donald P; Hausman, Dorothy B; Cureton, Kirk J

    2011-12-01

    High postprandial blood triglyceride (TG) levels increase cardiovascular disease risk. Exercise interventions may be effective in reducing postprandial blood TG. The purpose of this study was to determine the effects of sprint interval cycling (SIC), with and without replacement of the energy deficit, on postprandial lipemia. In a repeated-measures crossover design, six men and six women participated in three trials, each taking place over 2 days. On the evening of the first day of each trial, the participants either did SIC without replacing the energy deficit (Ex-Def), did SIC and replaced the energy deficit (Ex-Bal), or did not exercise (control). SIC was performed on a cycle ergometer and involved four 30-s all-out sprints with 4-min active recovery. In the morning of day 2, responses to a high-fat meal were measured. Venous blood samples were collected in the fasted state and at 0, 30, 60, 120, and 180 min postprandial. There was a trend toward a reduction with treatment in fasting TG (P = 0.068), but no significant treatment effect for fasting insulin, glucose, nonesterified fatty acids, or betahydroxybutryrate (P > 0.05). The postprandial area under the curve (mmol·l(-1)·3 h(-1)) TG response was significantly lower in Ex-Def (21%, P = 0.006) and Ex-Bal (10%, P = 0.044) than in control, and significantly lower in Ex-Def (12%, P = 0.032) than in Ex-Bal. There was no treatment effect (P > 0.05) observed for area under the curve responses of insulin, glucose, nonesterified fatty acids, or betahydroxybutryrate. SIC reduces postprandial lipemia, but the energy deficit alone does not fully explain the decrease observed.

  9. Life cycle assessment of the production of rare earth elements for energy applications: a review

    Directory of Open Access Journals (Sweden)

    Julio eNavarro

    2014-11-01

    Full Text Available Rare earth elements (REEs are a group of seventeen elements with similar chemical properties, including fifteen in the lanthanide group, yttrium, and scandium. Due to their unique physical and chemical properties REEs gain increasing importance in many new energy technologies and systems that contribute to reduce greenhouse gas emissions and fossil fuel depletion (e.g., wind turbine, electric vehicles, high efficiency lighting, batteries, and hydrogen storage. However, it is well known that production of REEs is far from environmentally sustainable as it requires significant material and energy consumption while generating large amounts of air/water emissions and solid waste. Although life cycle assessment (LCA has been accepted as the most comprehensive approach to quantify the environmental sustainability of a product or process, to date, there have been only very limited LCA studies on the production of REEs. With the continual growth of renewable energy and energy efficient technologies, global production of REEs will increase. Therefore reducing environmental footprints of REE production becomes critical and identifying environmental hotspots based on a holistic and comprehensive assessment on environmental impacts serves as an important starting point. After providing an overview of LCA methodology and a high-level description of the major REE production routes used from 1990s to today, this paper reviews the published LCA studies on the production of REEs. To date, almost all the LCA studies are based on process information collected from the operation of Mountain Pass facility in U.S. in 1990s and the operation of facilities in Bayan Obo, China. Knowledge gaps are identified and future research efforts are suggested to advance understanding on environmental impacts of REE production from the life cycle perspective.

  10. Life cycle cost-based risk model for energy performance contracting retrofits

    Science.gov (United States)

    Berghorn, George H.

    Buildings account for 41% of the primary energy consumption in the United States, nearly half of which is accounted for by commercial buildings. Among the greatest energy users are those in the municipalities, universities, schools, and hospitals (MUSH) market. Correctional facilities are in the upper half of all commercial building types for energy intensity. Public agencies have experienced reduced capital budgets to fund retrofits; this has led to the increased use of energy performance contracts (EPC), which are implemented by energy services companies (ESCOs). These companies guarantee a minimum amount of energy savings resulting from the retrofit activities, which in essence transfers performance risk from the owner to the contractor. Building retrofits in the MUSH market, especially correctional facilities, are well-suited to EPC, yet despite this potential and their high energy intensities, efficiency improvements lag behind that of other public building types. Complexities in project execution, lack of support for data requests and sub-metering, and conflicting project objectives have been cited as reasons for this lag effect. As a result, project-level risks must be understood in order to support wider adoption of retrofits in the public market, in particular the correctional facility sub-market. The goal of this research is to understand risks related to the execution of energy efficiency retrofits delivered via EPC in the MUSH market. To achieve this goal, in-depth analysis and improved understanding was sought with regard to ESCO risks that are unique to EPC in this market. The proposed work contributes to this understanding by developing a life cycle cost-based risk model to improve project decision making with regard to risk control and reduction. The specific objectives of the research are: (1) to perform an exploratory analysis of the EPC retrofit process and identify key areas of performance risk requiring in-depth analysis; (2) to construct a

  11. Life Cycle Greenhouse Gas Emissions from Electricity Generation: A Comparative Analysis of Australian Energy Sources

    Directory of Open Access Journals (Sweden)

    Robert G. Hynes

    2012-03-01

    Full Text Available Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribution. Availability of life cycle GHG intensity data will allow decision-makers to move away from overly simplistic assertions about the relative merits of certain fuels, and focus on the complete picture, especially the critical roles of technology selection and application of best practice. This analysis compares the life-cycle greenhouse gas (GHG intensities per megawatt-hour (MWh of electricity produced for a range of Australian and other energy sources, including coal, conventional liquefied natural gas (LNG, coal seam gas LNG, nuclear and renewables, for the Australian export market. When Australian fossil fuels are exported to China, life cycle greenhouse gas emission intensity in electricity production depends to a significant degree on the technology used in combustion. LNG in general is less GHG intensive than black coal, but the gap is smaller for gas combusted in open cycle gas turbine plant (OCGT and for LNG derived from coal seam gas (CSG. On average, conventional LNG burned in a conventional OCGT plant is approximately 38% less GHG intensive over its life cycle than black coal burned in a sub-critical plant, per MWh of electricity produced. However, if OCGT LNG combustion is compared to the most efficient new ultra-supercritical coal power, the GHG intensity gap narrows considerably. Coal seam gas LNG is approximately 13–20% more GHG intensive across its life cycle, on a like-for like basis, than conventional LNG. Upstream fugitive emissions from CSG (assuming best practice gas extraction techniques do not materially alter the life cycle

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

    Directory of Open Access Journals (Sweden)

    Mehri Akbari

    2014-04-01

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

  13. Life Cycle Analysis of Energy Production from Food Waste through Anaerobic Digestion, Pyrolysis and Integrated Energy System

    Directory of Open Access Journals (Sweden)

    Suraj Adebayo Opatokun

    2017-10-01

    Full Text Available The environmental performance of industrial anaerobic digestion (AD, pyrolysis, and integrated system (AD sequence with pyrolysis on food waste treatment were evaluated using life cycle assessment. The integrated treatment system indicated similar environmental benefits to AD with the highest benefits in climate change and water depletion in addition to the increased energy generation potential and the production of valuable products (biochar and bio-oil. Pyrolysis results illustrated higher impact across water, fossil fuel, and mineral depletion, although still providing a better option than conventional landfilling of food waste. The dewatering phase in the AD process accounted for 70% of the treatment impact while the pre-treatment of the food waste was responsible for the main burden in the pyrolysis process. The study indicated that the three treatment options of food waste management are environmentally more favorable than the conventional landfilling of the wastes.

  14. Thermal energy harvesting for application at MEMS scale

    CERN Document Server

    Percy, Steven; McGarry, Scott; Post, Alex; Moore, Tim; Cavanagh, Kate

    2014-01-01

    This book discusses the history of thermal heat generators and focuses on the potential for these processes using micro-electrical mechanical systems (MEMS) technology for this application. The main focus is on the capture of waste thermal energy for example from industrial processes, transport systems or the human body to generate useable electrical power.  A wide range of technologies is discussed, including external combustion heat cycles at MEMS ( Brayton, Stirling and Rankine), Thermoacoustic, Shape Memory Alloys (SMAs), Multiferroics, Thermionics, Pyroelectric, Seebeck, Alkali Metal Thermal, Hydride Heat Engine, Johnson Thermo Electrochemical Converters, and the Johnson Electric Heat Pipe.

  15. Determination of optimal pacing strategy in track cycling with an energy flow model.

    Science.gov (United States)

    de Koning, J J; Bobbert, M F; Foster, C

    1999-10-01

    The purpose of this study was to investigate the effect of pacing strategies on performance times in the 1000 m time trial event and the 4000 m pursuit event in track cycling. For this purpose, we simulated these events with a model based on the flow of energy in cycling. Different strategies in distributing the available anaerobic energy were evaluated and we compared model predictions of split times and final times with values achieved by cyclists during championships. The best result at the 1000 m time trial was obtained when the cyclist had the highest anaerobic peak power output and used an 'all-out' strategy. The fastest time on the 4000 m pursuit was achieved with an 'all-out' start at a high level of initial power output, followed by a constant anaerobic power output after 12 seconds, resulting in an evenly paced race. The results show that even small variations in pacing strategy may have substantial effects on performance. There seems to be an opportunity to gain a competitive advantage when individual athletes experiment with small variations in pacing strategy to find the precise individual strategy that works best under specific conditions.

  16. Experimental Study of Magnesium Production with Laser for Clean Energy Cycle

    Science.gov (United States)

    Sato, Y.; Yabe, T.; Sakurai, Y.; Mohamed, M. S.; Uchida, S.; Baasandash, C.; Ohkubo, T.; Mori, Y.; Sato, H.

    2008-04-01

    A new scheme of generating power called magnesium injection cycle [MAGIC] engine was developed. Magnesium [Mg] and water are put into the chamber and ignited at 500 degree Celsius. Mg reaction with water produces hydrogen [H2] gas. The hydrogen blows out and reacts with oxygen [O2] gas to generate H2O and energy at the exit nozzle. These reactions occur simultaneously and generate thrust. In order to reproduce Mg, the residual MgO is irradiated by focused cw CO2 laser (1000 W) at 20 Pa. Then, high temperature (over 4000 degree Celsius) is exerted in tiny spot thus MgO reduction in equilibrium is achievable. Spectroscopic analysis was conducted on the Mg/MgO vapor under atmospheric condition. The Mg line at 518 nm, MgO line at 500 nm and O+ line were confirmed. This proves that the MgO is dissociated by laser irradiation These experiments confirm that the scheme can be used for magnesium energy cycle system with practical efficiency and large throughput.

  17. Fan cycling strategies and heat pipe heat exchangers provide energy efficient dehumidification

    Energy Technology Data Exchange (ETDEWEB)

    Shirey, D.B. III [Florida Solar Energy Center, Cape Canaveral, FL (United States)

    1995-03-01

    This article describes two methods to reduce energy consumption and peak demand in buildings that require humidity control that were demonstrated at the Salvador Dali Museum in St. Petersburg, Florida. The first method centered on alternative indoor fan cycling strategies and the second method involved the use of heat pipe heat exchangers. Both approaches increased the dehumidification performance of the existing air-conditioning systems and provided substantial savings. Simple, low cost alternative fan cycling strategies were used. When possible, auto fan control replaced constant fan operation to avoid excess fan energy consumption, ventilation load and compressor operation. The alternative fan control strategies reduced indoor humidity fluctuations in all zones, and significantly reduced overall humidity levels in the museum lobby and storage area. An HPHX was installed within one of the two gallery RTUs to improve the unit`s dehumidification performance. The passive HPHX significantly reduced electric reheat and compressor operation while maintaining the precise temperature and humidity requirements within the gallery. The second gallery RTU now operates primarily as a back-up unit to the heat pipe-assisted air-conditioning unit.

  18. The effects of Red Bull energy drink compared with caffeine on cycling time-trial performance.

    Science.gov (United States)

    Quinlivan, Alannah; Irwin, Christopher; Grant, Gary D; Anoopkumar-Dukie, Sheilandra; Skinner, Tina; Leveritt, Michael; Desbrow, Ben

    2015-10-01

    This study investigated the ergogenic effects of a commercial energy drink (Red Bull) or an equivalent dose of anhydrous caffeine in comparison with a noncaffeinated control beverage on cycling performance. Eleven trained male cyclists (31.7 ± 5.9 y 82.3 ± 6.1 kg, VO2max = 60.3 ± 7.8 mL · kg-1 · min-1) participated in a double-blind, placebo-controlled, crossover-design study involving 3 experimental conditions. Participants were randomly administered Red Bull (9.4 mL/kg body mass [BM] containing 3 mg/kg BM caffeine), anhydrous caffeine (3 mg/kg BM given in capsule form), or a placebo 90 min before commencing a time trial equivalent to 1 h cycling at 75% peak power output. Carbohydrate and fluid volumes were matched across all trials. Performance improved by 109 ± 153 s (2.8%, P = .039) after Red Bull compared with placebo and by 120 ± 172 s (3.1%, P = .043) after caffeine compared with placebo. No significant difference (P > .05) in performance time was detected between Red Bull and caffeine treatments. There was no significant difference (P > .05) in mean heart rate or rating of perceived exertion among the 3 treatments. This study demonstrated that a moderate dose of caffeine consumed as either Red Bull or in anhydrous form enhanced cycling time-trial performance. The ergogenic benefits of Red Bull energy drink are therefore most likely due to the effects of caffeine, with the other ingredients not likely to offer additional benefit.

  19. Life-cycle energy and greenhouse gas emission impacts of different corn ethanol plant types

    Science.gov (United States)

    Wang, Michael; Wu, May; Huo, Hong

    2007-04-01

    Since the United States began a programme to develop ethanol as a transportation fuel, its use has increased from 175 million gallons in 1980 to 4.9 billion gallons in 2006. Virtually all of the ethanol used for transportation has been produced from corn. During the period of fuel ethanol growth, corn farming productivity has increased dramatically, and energy use in ethanol plants has been reduced by almost by half. The majority of corn ethanol plants are powered by natural gas. However, as natural gas prices have skyrocketed over the last several years, efforts have been made to further reduce the energy used in ethanol plants or to switch from natural gas to other fuels, such as coal and wood chips. In this paper, we examine nine corn ethanol plant types—categorized according to the type of process fuels employed, use of combined heat and power, and production of wet distiller grains and solubles. We found that these ethanol plant types can have distinctly different energy and greenhouse gas emission effects on a full fuel-cycle basis. In particular, greenhouse gas emission impacts can vary significantly—from a 3% increase if coal is the process fuel to a 52% reduction if wood chips are used. Our results show that, in order to achieve energy and greenhouse gas emission benefits, researchers need to closely examine and differentiate among the types of plants used to produce corn ethanol so that corn ethanol production would move towards a more sustainable path.

  20. Identifying energy and carbon footprint optimization potentials of a sludge treatment line with Life Cycle Assessment.

    Science.gov (United States)

    Remy, C; Lesjean, B; Waschnewski, J

    2013-01-01

    This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO(2), CH(4), N(2)O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (-162 MJ/PE(COD) * a) and carbon footprint (-11.6 kg CO(2)-eq/PE(COD) * a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general.

  1. Design Optimization of a Natural Gas Substation with Intensification of the Energy Cycle

    Directory of Open Access Journals (Sweden)

    Arcangelo Pellegrino

    2010-01-01

    Full Text Available Natural gas is currently the natural substitute of petroleum as an energy source, since the foreseen ending up of this latter in the next decades. As a matter of fact, natural gas is easier to handle, less dangerous to be transported, somehow environmentally more friendly. The gas ducts operate with large flow rates over very long distances at high pressures, which are usually lowered in proximity of the final substations by lamination valves which, in fact, dissipate energy. However, a careful management of the pressure reduction may allow an energy recovery while using the gas expansion to operate a turbine. In this case, gas must be preheated to compensate for the energy required by the expansion. A proper control of all the parameters involved becomes crucial to an intelligent use of these resources. In this paper, the possibility of using a pre-heating system has been examined as a way to intensify the energy cycle in an expansion substation of the city gas network. Fuzzy logic has been used to optimize the natural gas expansion in a turbine to produce electrical energy. A fuzzy system has been designed and realized to control the whole process of gas expansion, from the gas pre-heating to the pressure reduction. The system operates over the whole year, accounting for the pressure, temperature, and gas flow rate variations experienced in the gas line. The exit values of the latter and the inlet value of the gas pressure are selected as input variables, being the output variable the temperature of the pre-heating water at the heat exchanger inlet.

  2. Effects Of Urbanization On Interconnected Water Cycle, Microclimate And Energy Usage In Semi-Arid Regions

    Science.gov (United States)

    Jeyachandran, I.; Burian, S. J.; Pardyjak, E.

    2008-12-01

    Landscape changes induced by urbanization have been found to influence urban water cycle components including evapotranspiration (ET), runoff and water use. For instance, residential areas in semi-arid regions with vegetation subjected to lawn watering have higher ET rates when compared to the other areas in an urban environment. This increase associated with lawn irrigation can contribute to water scarcity problems. Conversely, development of more built surfaces with reduced vegetation leads to increased temperatures and Urban Heat Islands. This increase in temperature, can lead to an increase in energy usage. In order, to quantify the relationship of interconnected landscape, water cycle, microclimate and energy usage there is a need for a modeling system to represent landscape and surface characteristics specific to location and time. A methodology capable of modeling the interconnected urban scenario via a three-step process is presented in this paper. To account for the variability of urban form, the roughness length variation should be represented. An approach to estimate roughness length from Synthetic Aperture Radar (SAR) data has been introduced and the results are included in this paper. The effect of varying urban form and lawn irrigation practices on latent and sensible heat fluxes is represented and modeled by the Urban Heat Flux Model introduced in this paper. The Urban Heat Flux (UHFL) model has the capability to model the sensible and latent heat fluxes spatially and temporally by being able to represent varying conditions of roughness length, surface resistance and lawn irrigation patterns (soil moisture). The UHFL model has an advantage over the existing models by being driven by easily acquirable meteorological data and remote sensing data (which are available for all regions). The overall modeling framework consists of three sub-models: UHFL, the urban climate model (to simulate urban microclimate) and the energy and water usage simulation

  3. Life cycle assessment of innovative technology for energy production from automotive shredder residue.

    Science.gov (United States)

    Rinaldi, Caterina; Masoni, Paolo; Salvati, Fabio; Tolve, Pietro

    2015-07-01

    Automotive Shredder Residue (ASR) is a problematic waste material remaining after shredding and recovery processes of end-of-life vehicles (ELVs). Its heterogeneous grain size and composition make difficult its recovery or disposal. Although ASR accounts for approximately 20% to 25% of the weight of an ELV, the European Union (EU)'s ELV Directive (2000/53/EC) requires that by 2015 a minimum 95% of the weight of an ELV must be reused or recovered, including a 10% weight energy recovery. The quantity of ASR is relevant: Approximately 2.4 million tons are generated in the EU each year and most of it is sent to landfills. This article describes a life cycle model of the "TEKNE-Fluff" process designed to make beneficial use of ASR that is based on the results of an experimental pilot plant for pyro-gasification, combustion, cogeneration, and emissions treatment of ASR. The goal of the research was the application of life cycle assessment (LCA) methodology to identify the environmental hot spots of the "TEKNE system" and use scenario analysis to check solutions to improve its environmental profile, supporting the design and industrialization process. The LCA was conducted based on data modeled from the experimental campaign. Moreover, different scenarios on shares of electricity and thermal energy produced by the cogeneration system and alternative treatment processes for the waste produced by the technology were compared. Despite the limitation of the research (results based on scaling up experimental data by modeling), impact assessment results are promising and sufficiently robust, as shown by Monte Carlo analysis. The TEKNE technology may become an interesting solution for the problem of ASR management: Besides representing an alternative to landfill disposal, the energy produced could avoid significant impacts on fossil resources depletion (a plant of 40,000 tons/y capacity could produce ∼ 147,000 GJ/yr, covering the annual need of ∼ 13,500 households). © 2015

  4. Strengthening of the hydrological cycle in future scenarios: atmospheric energy and water balance perspective

    Directory of Open Access Journals (Sweden)

    A. Alessandri

    2012-11-01

    Full Text Available Future climate scenarios experiencing global warming are expected to strengthen the hydrological cycle during the 21st century (21C. We analyze the strengthening of the global-scale increase in precipitation from the perspective of changes in whole atmospheric water and energy balances. By combining energy and water equations for the whole atmosphere, we obtain constraints for the changes in surface fluxes and partitioning at the surface between sensible and latent components. We investigate the differences in the strengthening of the hydrological cycle in two centennial simulations performed with an Earth system model forced with specified atmospheric concentration pathways. Alongside the Special Report on Emissions Scenario (SRES A1B, which is a medium-high non-mitigation scenario, we consider a new aggressive-mitigation scenario (E1 with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K.

    Our results show that the mitigation scenario effectively constrains the global warming with a stabilization below 2 K with respect to the 1950–2000 historical period. On the other hand, the E1 precipitation does not follow the temperature field toward a stabilization path but continues to increase over the mitigation period. Quite unexpectedly, the mitigation scenario is shown to strengthen the hydrological cycle even more than SRES A1B till around 2070. We show that this is mostly a consequence of the larger increase in the negative radiative imbalance of atmosphere in E1 compared to A1B. This appears to be primarily related to decreased sulfate aerosol concentration in E1, which considerably reduces atmospheric absorption of solar radiation compared to A1B.

    The last decades of the 21C show a marked increase in global precipitation in A1B compared to E1, despite the fact that the two scenarios display almost the same overall increase of radiative imbalance with respect to the 20th century. Our

  5. Life-cycle greenhouse gas emissions and energy payback time of current and prospective silicon heterojunction solar cell designs

    NARCIS (Netherlands)

    Louwen, A.|info:eu-repo/dai/nl/375268456; van Sark, W. G J H M|info:eu-repo/dai/nl/074628526; Schropp, R. E I|info:eu-repo/dai/nl/072502584; Turkenburg, W. C.|info:eu-repo/dai/nl/073416355; Faaij, A. P C

    2015-01-01

    Silicon heterojunction (SHJ) cells offer high efficiencies and several advantages in the production process compared to conventional crystalline silicon solar cells. We performed a life-cycle assessment to identify the greenhouse gas (GHG) footprint, energy payback time (EPBT) and cumulative energy

  6. Energy Efficiency as a Factor of Engineering Product Competitiveness and its Formation on Product Economic Life Cycle Stages

    Directory of Open Access Journals (Sweden)

    Ivan V. Evstratov

    2011-11-01

    Full Text Available This article discusses the concept of energy efficiency of enterprises and engineering products. The author research how energy efficiency effect on engineering product competitiveness and how rate of enterprise and engineering product formation on stages of the economic product life cycle.

  7. Thermal energy storage for a space solar dynamic power system

    Science.gov (United States)

    Faget, N. M.; Fraser, W. M., Jr.; Simon, W. E.

    1985-01-01

    In the past, NASA has employed solar photovoltaic devices for long-duration missions. Thus, the Skylab system has operated with a silicon photovoltaic array and a nickel-cadmium electrochemical system energy storage system. Difficulties regarding the employment of such a system for the larger power requirements of the Space Station are related to a low orbit system efficiency and the large weight of the battery. For this reason the employment of a solar dynamic power system (SDPS) has been considered. The primary components of an SDPS include a concentrating mirror, a heat receiver, a thermal energy storage (TES) system, a thermodynamic heat engine, an alternator, and a heat rejection system. The heat-engine types under consideration are a Brayton cycle engine, an organic Rankine cycle engine, and a free-piston/linear-alternator Stirling cycle engine. Attention is given to a system description, TES integration concepts, and a TES technology assessment.

  8. Importance of light scattering properties of cloud particles on calculating the earth energy cycle

    Science.gov (United States)

    Letu, H.; Nakajima, T. Y.; Nagao, T. M.; Ishimoto, H.

    2013-12-01

    The Earth is an open system, and the energy cycle of the Earth is not always a certain amount. In other words, the energy cycle in the nature is imbalance. A better understanding of the earth energy cycle is very important to study global climate change. the IPCC-AR4 reported that the cloud in the atmosphere are still characterized by large uncertainties in the estimation of their effects on energy sysle of the Earth's atmosphere. There are two types of cloud in the atmosphere, which are Cirrus and warm water cloud. In order to strongly reflect visible wavelength from sun light, thick water cloud has the effect of cooling the earth surface. When Cirrus is compared to water cloud, temperature is almost lower. Thus, there is a feature that Cirrus is easy to absorb long-wave radiation than warm water cloud. However, in order to quantitatively evaluate the reflection and absorption characteristics of cloud on remote senssing application and energy cycle of the imbalance of nature, it is necessary to obtain the scattering properties of cloud particles. Since the shapes of the water cloud particle are close to spherical, scattering properties of the particles can be calculated accurately by the Mie theory. However, Cirrus particles have a complex shape, including hexagonal, plate, and other non- spherical shapes. Different from warm water cloud partical, it is required to use several different light scattering methods when calculating the light scattering properties of the non-spherical Cirrus cloud particals. Ishimoto et al. [2010, 2012] and Masuda et al. [2012] developed the Finite-Difference Time Domain method (FDTD) and Improved Geometrical-Optics Method (IGOM) for the solution of light scattering by non-spherical particles. Nakajima et al [1997,2009] developed the LIght Scattering solver for Arbitral Shape particle (Lisas)-Geometrical-Optics Method (GOM) and Surface Integral Equations Method of Müller-type (SIEMM) to calculate the light scattering properties for

  9. BioEnergy transport systems. Life cycle assessment of selected bioenergy systems

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, Goeran

    1999-07-01

    Biomass for energy conversion is usually considered as a local resource. With appropriate logistic systems, access to biomass can be improved over a large geographical area. In this study, life cycle assessment (LCA) has been used as method to investigate the environmental impacts of selected bioenergy transport chains. As a case study, chains starting in Sweden and ending in Holland have been investigated. Biomass originates from tree sections or forest residues, the latter upgraded to bales or pellets. The study is concentrated on production of electricity, hot cooling water is considered as a loss. Electricity is, as the main case, produced from solid biomass in the importing country. Electricity can also be produced in the country of origin and exported via the trans-national grid as transportation media. As an alternative, a comparison is made with a coal cycle. The results show that contribution of emissions from long-range transportation is of minor importance. The use of fuels and electricity for operating machines and transportation carriers requires a net energy input in bioenergy systems which amounts to typically 7-9% of delivered electrical energy from the system. Emissions of key substances such as NO{sub x}, CO, S, hydrocarbons, and particles are low. Emissions of CO{sub 2} from biocombustion are considered to be zero since there is approximately no net contribution of carbon to the biosphere in an energy system based on biomass. A method to quantify non-renewability is presented. For coal, the non-renewability factor is calculated to be 110%. For most of the cases with bioenergy, the non-renewability factor is calculated to be between 6 and 11%. Reclamation of biomass results in certain losses of nutrients such as nitrogen, phosphorus and base cations such as K, Ca and Mg. These are balanced by weathering, vitalisation or ash recirculation procedures. Withdrawal of N from the ecological system is approximately 10 times the load from the technical

  10. Accumulation of energy reserves in algae: From cell cycles to biotechnological applications.

    Science.gov (United States)

    Vitova, Milada; Bisova, Katerina; Kawano, Shigeyuki; Zachleder, Vilem

    2015-11-01

    Starch and lipids are key components of algal cells and responsible for buffering variable supplies of energy and carbon that are vital for cell growth and reproduction, particularly DNA replication, nuclear and cellular division. The basic characteristics of energy reserves, their ultrastructure and localization inside the cell, regulation of their synthesis in relation to cell cycle phases, and their control by external factors, including light intensity, temperature, and carbon dioxide are described. Over the last two decades, research in this field has been boosted by possible biotechnological applications of algae for the production of biofuels from energy conserving compounds (bioethanol from starch and biodiesel from lipids). Recent findings on mechanisms that lead to an accumulation of exceptionally high levels of starch and lipids in algae will be summarized in this review. Macroelement (N, S, P) limitation, or depletion in mineral medium, as the most widely used approaches for enhancing both starch and lipid accumulation, are reviewed in detail. Potential biotechnological strategies for the economically viable overproduction of lipid and starch, such as a two-step procedure exploiting the effects of nutrient limitation and depletion, as well as the means and rationale for selecting appropriate strains, are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. A creatine-driven substrate cycle enhances energy expenditure and thermogenesis in beige fat.

    Science.gov (United States)

    Kazak, Lawrence; Chouchani, Edward T; Jedrychowski, Mark P; Erickson, Brian K; Shinoda, Kosaku; Cohen, Paul; Vetrivelan, Ramalingam; Lu, Gina Z; Laznik-Bogoslavski, Dina; Hasenfuss, Sebastian C; Kajimura, Shingo; Gygi, Steve P; Spiegelman, Bruce M

    2015-10-22

    Thermogenic brown and beige adipose tissues dissipate chemical energy as heat, and their thermogenic activities can combat obesity and diabetes. Herein the functional adaptations to cold of brown and beige adipose depots are examined using quantitative mitochondrial proteomics. We identify arginine/creatine metabolism as a beige adipose signature and demonstrate that creatine enhances respiration in beige-fat mitochondria when ADP is limiting. In murine beige fat, cold exposure stimulates mitochondrial creatine kinase activity and induces coordinated expression of genes associated with creatine metabolism. Pharmacological reduction of creatine levels decreases whole-body energy expenditure after administration of a β3-agonist and reduces beige and brown adipose metabolic rate. Genes of creatine metabolism are compensatorily induced when UCP1-dependent thermogenesis is ablated, and creatine reduction in Ucp1-deficient mice reduces core body temperature. These findings link a futile cycle of creatine metabolism to adipose tissue energy expenditure and thermal homeostasis. PAPERCLIP. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Life cycle assessment of energy products: environmental impact assessment of biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Zah, R.; Boeni, H.; Gauch, M.; Hischier, R.; Lehmann, M.; Waeger, P.

    2007-05-15

    This final report for the Swiss Federal Office of Energy (SFOE) deals with the results of a study that evaluated the environmental impact of the entire production chain of fuels made from biomass and used in Switzerland. Firstly, the study supplies an analysis of the possible environmental impacts of biofuels that can be used as a basis for political decisions. Secondly, an environmental life cycle assessment (LCA) of various biofuels is presented. In addition, the impacts of fuel use are compared with other uses for bioenergy such as the generation of electricity and heat. The methods used in the LCA are discussed, including the Swiss method of ecological scarcity (Environmental Impact Points, UBP 06), and the European Eco-indicator 99 method. The results of the study are discussed, including the finding that not all biofuels can reduce environmental impacts as compared to fossil fuels. The role to be played by biofuels produced in an environmentally-friendly way together with other forms of renewable energy in our future energy supply is discussed.

  13. Life cycle cost analysis of commercial buildings with energy efficient approach

    Directory of Open Access Journals (Sweden)

    Nilima N. Kale

    2016-09-01

    Full Text Available In any construction project, cost effectiveness plays a crucial role. The Life Cycle Cost (LCC analysis provides a method of determining entire cost of a structure over its expected life along with operational and maintenance cost. LCC can be improved by adopting alternative modern techniques without much alteration in the building. LCC effectiveness can be calculated at various stages of entire span of the building. Moreover this provides decision makers with the financial information necessary for maintaining, improving, and constructing facilities. Financial benefits associated with energy use can also be calculated using LCC analysis. In the present work, case study of two educational buildings has been considered. The LCC of these buildings has been calculated with existing condition and with proposed energy efficient approach (EEA using net present value method. A solar panel having minimum capacity as well as solar panel with desired capacity as per the requirements of the building has been suggested. The comparison of LCC of existing structure with proposed solar panel system shows that 4% of cost can be reduced in case of minimum capacity solar panel and 54% cost can be reduced for desired capacity solar panel system, along with other added advantages of solar energy.

  14. Battery cycle life balancing in a microgrid through flexible distribution of energy and storage resources

    Science.gov (United States)

    Khasawneh, Hussam J.; Illindala, Mahesh S.

    2014-09-01

    In this paper, a microgrid consisting of four fuel cell-battery hybrid Distributed Energy Resources (DERs) is devised for an industrial crusher-conveyor load. Each fuel cell was accompanied by a Li-ion battery to provide energy storage support under islanded condition of the microgrid since the fuel cells typically have poor transient response characteristics. After carrying out extensive modeling and analysis in MATLAB®, the battery utilization was found to vary significantly based on the DER's 'electrical' placement within the microgrid. This paper presents, under such conditions, a variety of battery life balancing solutions through the use of the new framework of Flexible Distribution of EneRgy and Storage Resources (FDERS). It is based on an in-situ reconfiguration approach through 'virtual' reactances that help in changing the 'electrical' position of each DER without physically displacing any component in the system. Several possible approaches toward balancing the battery utilization are compared in this paper taking advantage of the flexibility that FDERS offers. It was observed that the estimated battery life is dependent on factors such as cycling sequence, pattern, and occurrence.

  15. A cumulative energy demand indicator (CED), life cycle based, for industrial waste management decision making.

    Science.gov (United States)

    Puig, Rita; Fullana-I-Palmer, Pere; Baquero, Grau; Riba, Jordi-Roger; Bala, Alba

    2013-12-01

    Life cycle thinking is a good approach to be used for environmental decision-support, although the complexity of the Life Cycle Assessment (LCA) studies sometimes prevents their wide use. The purpose of this paper is to show how LCA methodology can be simplified to be more useful for certain applications. In order to improve waste management in Catalonia (Spain), a Cumulative Energy Demand indicator (LCA-based) has been used to obtain four mathematical models to help the government in the decision of preventing or allowing a specific waste from going out of the borders. The conceptual equations and all the subsequent developments and assumptions made to obtain the simplified models are presented. One of the four models is discussed in detail, presenting the final simplified equation to be subsequently used by the government in decision making. The resulting model has been found to be scientifically robust, simple to implement and, above all, fulfilling its purpose: the limitation of waste transport out of Catalonia unless the waste recovery operations are significantly better and justify this transport. Copyright © 2013. Published by Elsevier Ltd.

  16. Life Cycle Energy and CO2 Emission Optimization for Biofuel Supply Chain Planning under Uncertainties

    DEFF Research Database (Denmark)

    Ren, Jingzheng; An, Da; Liang, Hanwei

    2016-01-01

    The purpose of this paper is to develop a model for the decision-makers/stakeholders to design biofuel supply chain under uncertainties. Life cycle energy and CO2 emission of biofuel supply chain are employed as the objective functions, multiple feedstocks, multiple transportation modes, multiple...... sites for building biofuel plants, multiple technologies for biofuel production, and multiple markets for biofuel distribution are considered, and the amount of feedstocks in agricultural system, transportation capacities, yields of crops, and market demands are considered as uncertainty variables...... in this study. A bi-objective interval mix integer programming model has been developed for biofuel supply chain design under uncertainties, and the bio-objective interval programming method has been developed to solve this model. An illustrative case of a multiple-feedstock-bioethanol system has been studied...

  17. Life cycle assessment of a wastewater treatment plant focused on material and energy flows.

    Science.gov (United States)

    Wu, Jian-Guang; Meng, Xiang-Yu; Liu, Xiao-Meng; Liu, Xian-Wei; Zheng, Zhi-Xia; Xu, De-Qian; Sheng, Guo-Ping; Yu, Han-Qing

    2010-10-01

    Life cycle assessment (LCA) was applied to analyze a food-processing wastewater treatment plant and investigate the economic and environmental effects of the plant. With the long-term operational data of this plant, an inventory of relative inputs, e.g., flow rate, chemical oxygen demand (COD), and suspended solids, etc., and outputs of the plant, e.g., effluent COD and suspended solids, methane production, etc., was compiled. The potential environmental effects associated with those inputs and outputs were evaluated, and the results of the inventory analysis and impact assessment phases of the plant were interpreted. One feature of this study was the assessment of the treatment plant based on both energy and material flows. Another feature was the establishment of an assessment model with an integration of plant operating parameters, system recognition and grey relation. The analytical results are helpful for the design and operation of wastewater treatment plants.

  18. Étude expérimentale d'une installation de micro-cogénération solaire couplant un concentrateur cylindro-parabolique et un moteur à cycle de Hirn

    OpenAIRE

    Bouvier, Jean-Louis

    2014-01-01

    The objective of this thesis is the experimental study of the energy performances of a micro combined solar heat and power (micro-CHP) unit. The prototype is composed of a solar parabolic trough collector coupled to a Hirn (superheated Rankine) cycle engine. The originalities of this project are the use of solar energy which is renewable and inexhaustible but intermittent, the direct steam generation with a reduced size parabolic trough collector (46.5 m²), the two axis tracking system and th...

  19. Life-cycle thinking and the LEED rating system: global perspective on building energy use and environmental impacts.

    Science.gov (United States)

    Al-Ghamdi, Sami G; Bilec, Melissa M

    2015-04-07

    This research investigates the relationship between energy use, geographic location, life cycle environmental impacts, and Leadership in Energy and Environmental Design (LEED). The researchers studied worldwide variations in building energy use and associated life cycle impacts in relation to the LEED rating systems. A Building Information Modeling (BIM) of a reference 43,000 ft(2) office building was developed and situated in 400 locations worldwide while making relevant changes to the energy model to meet reference codes, such as ASHRAE 90.1. Then life cycle environmental and human health impacts from the buildings' energy consumption were calculated. The results revealed considerable variations between sites in the U.S. and international locations (ranging from 394 ton CO2 equiv to 911 ton CO2 equiv, respectively). The variations indicate that location specific results, when paired with life cycle assessment, can be an effective means to achieve a better understanding of possible adverse environmental impacts as a result of building energy consumption in the context of green building rating systems. Looking at these factors in combination and using a systems approach may allow rating systems like LEED to continue to drive market transformation toward sustainable development, while taking into consideration both energy sources and building efficiency.

  20. Biodynamics. Effect of pacing strategy on energy expenditure during a 1500-m cycling time trial.

    Science.gov (United States)

    Hettinga, Florentina J; De Koning, Jos J; Meijer, Emiel; Teunissen, Lennart; Foster, Carl

    2007-12-01

    A critical assumption in modeling optimal pacing strategy is that the amount of anaerobic energy that can be produced during a time trial is a constant value, independent of pacing strategy. To test this assumption, the effect of manipulations of pacing strategy on anaerobic work produced during a 1500-m cycling time trial was studied. Additionally, the effect of pacing strategy on aerobic and total work was studied. Nine well-trained cyclists performed three 1500-m cycle ergometer time trials with different strategies (conservative (SUB), even paced (EVEN), and aggressive (SUPRA)). Anaerobic work, aerobic work, and total work were calculated on the basis of V O2, RER, gross efficiency, and external power output. ANOVA showed that total anaerobic work did not differ per strategy (EVEN: 27,604 +/- 1103 J, SUB: 26,495 +/- 1958 J, and SUPRA: 26,949 +/- 2062 J). No differences in aerobic work (EVEN: 28,266 +/- 1623 J,SUB: 27,950 +/- 1418 J, SUPRA: 27,844 +/- 1965 J) were evident, either. Subjects were able to accomplish significantly (P < 0.05) more total work during EVEN (55,870 +/- 2245 J) than during SUB and SUPRA (54,444 +/- 2306 and 54,794 +/- 2402 J, respectively). No difference in anaerobic and aerobic work was found per pacing strategy. Though relevant for sports performance, the differences in total work were relatively small (approximately 2%), considering the broad range of imposed strategies. The assumption that anaerobic work is a constant value, independent of pacing strategy, seems valid in the range of different strategies that are currently simulated in the energy flow models.

  1. Fracture energy evolution of two concretes resistant to the action of freeze-thaw cycles

    Directory of Open Access Journals (Sweden)

    Enfedaque, A.

    2014-03-01

    Full Text Available The current standards that regulate use of structural concrete have highlighted the durability of concrete. However, how the fracture energy of concrete evolves under the action of freeze-thaw cycles is not well known. The fracture energy of two types of concrete, one with an air-entraining additive and the other with silica fume addition, is studied after four, 14 and 28 freeze-thaw cycles. The results obtained show that the concrete with an air-entraining additive was undamaged and that fracture energy grew slightly. In addition to this, they also showed that the concrete with silica fume addition suffered severe surface scaling and its fracture energy changed due to the greater fracture areas generated.La actual normativa que rige el empleo de hormigón estructural ha puesto enfásis en la durabilidad del hormigón. Sin embargo, no se conoce cómo evoluciona la energía de fractura del hormigón sometido a ciclos hielo- deshielo, lo cual es de vital importancia para asegurar la durabilidad y el correcto comportamiento mecánico de las estructuras de hormigón en entornos con heladas durante su vida útil. Se ha estudiado la evolución de la energía de fractura de un hormigón con aireante y de un hormigón con humo de sílice después de 4, 14 y 28 ciclos hielo-deshielo realizando ensayos de fractura. Los resultados muestran cómo el hormigón con aireante no sufre daño por los ciclos hielo-deshielo y cómo la energía de fractura del mismo aumenta ligeramente. El hormigón con humo de sílice se daña por los ciclos hielo-deshielo y reduce su energía de fractura al aumentar el area fracturada.

  2. Life Cycle Assessment of Energy and CO2 Emissions for Residential Buildings in Jakarta and Bandung, Indonesia

    Directory of Open Access Journals (Sweden)

    Usep Surahman

    2015-10-01

    Full Text Available The objective of this study is to analyze life cycle energy and CO2 emission profiles by employing an input–output analysis method for urban houses in major cities of Indonesia. Two surveys investigating building material inventory and household energy consumption within individual houses were conducted in Bandung in 2011 and 2012. The results show that, if reused and recycled materials were assumed to be zero, the averaged embodied energy for simple, medium and luxurious houses in Bandung was larger than that for their respective houses in Jakarta. Overall, the average annual energy consumption of all samples in Jakarta was approximately 20.6 GJ, which is 5.0 GJ larger than that in Bandung. In terms of life cycle energy, the operational energy accounted for 79%–86% and 69%–81% of the total for respective houses in Jakarta and Bandung. The profiles of life cycle CO2 emissions are similar to those of energy. The results of the scenario analysis prove that the promotion of reusing/recycling is important to reduce building material inputs/waste and their corresponding embodied energy. It is also important to reduce the use of air-conditioning for operational energy in the future by adopting passive cooling techniques wherever possible.

  3. Life cycle assessment: an application to poplar for energy cultivated in Italy

    Directory of Open Access Journals (Sweden)

    Jacopo Bacenetti

    2012-09-01

    Full Text Available The development of the bioenergy sector has led to an increasing interest in energy crops. Short rotation coppices (SRC are forestry management systems in which fast-growing tree species are produced under intensive cultivation practices to obtain high wood chips yields. In Italy, most SRC plantations consist of poplar biomass-clones. SRC plantations can be carried out with different management systems with diverse cutting times; consequently, the cultivation system can be crucial for attaining high yields depending on: i short and ii medium cutting frequency. Nowadays, the larger part of Italian SRC is based on 2-year cutting short rotation forestry (SRF but the best quality of wood chips is linked to 5-year plantation medium rotation forestry (MRF. This work compares an SRF and an MRF poplar plantation located in the Po Valley in northern Italy. In particular, a life cycle assessment (LCA was carried out to evaluate their energy demand and greenhouse gas emissions. The LCA software SimaPro 7.10 was used to create the LCA model and to assure an accurate impact assessment calculation. The analysis shows several differences between MRF and SRF in terms of fertiliser requirements and intensive agricultural activities. Results highlight that MRF produces a more sustainable wood chip production than SRF according to energy and environmental concerns. Furthermore, hot spots were identified in both SRF and MRF due to the high energy consumption and the related emissions. These hot spots were: i mineral fertilisation; ii mechanical weed-control; iii harvesting and biomass transport.

  4. Environmental & economic life cycle assessment of current & future sewage sludge to energy technologies.

    Science.gov (United States)

    Mills, N; Pearce, P; Farrow, J; Thorpe, R B; Kirkby, N F

    2014-01-01

    The UK Water Industry currently generates approximately 800GWh pa of electrical energy from sewage sludge. Traditionally energy recovery from sewage sludge features Anaerobic Digestion (AD) with biogas utilisation in combined heat and power (CHP) systems. However, the industry is evolving and a number of developments that extract more energy from sludge are either being implemented or are nearing full scale demonstration. This study compared five technology configurations: 1 - conventional AD with CHP, 2 - Thermal Hydrolysis Process (THP) AD with CHP, 3 - THP AD with bio-methane grid injection, 4 - THP AD with CHP followed by drying of digested sludge for solid fuel production, 5 - THP AD followed by drying, pyrolysis of the digested sludge and use of the both the biogas and the pyrolysis gas in a CHP. The economic and environmental Life Cycle Assessment (LCA) found that both the post AD drying options performed well but the option used to create a solid fuel to displace coal (configuration 4) was the most sustainable solution economically and environmentally, closely followed by the pyrolysis configuration (5). Application of THP improves the financial and environmental performance compared with conventional AD. Producing bio-methane for grid injection (configuration 3) is attractive financially but has the worst environmental impact of all the scenarios, suggesting that the current UK financial incentive policy for bio-methane is not driving best environmental practice. It is clear that new and improving processes and technologies are enabling significant opportunities for further energy recovery from sludge; LCA provides tools for determining the best overall options for particular situations and allows innovation resources and investment to be focused accordingly. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Multiple regression models for the prediction of the maximum obtainable thermal efficiency of organic Rankine cycles

    DEFF Research Database (Denmark)

    Larsen, Ulrik; Pierobon, Leonardo; Wronski, Jorrit

    2014-01-01

    to power. In this study we propose four linear regression models to predict the maximum obtainable thermal efficiency for simple and recuperated ORCs. A previously derived methodology is able to determine the maximum thermal efficiency among many combinations of fluids and processes, given the boundary...... conditions of the process. Hundreds of optimised cases with varied design parameters are used as observations in four multiple regression analyses. We analyse the model assumptions, prediction abilities and extrapolations, and compare the results with recent studies in the literature. The models...

  6. Dynamic Response of a 50 kW Organic Rankine Cycle System in Association with Evaporators

    Directory of Open Access Journals (Sweden)

    Yuh-Ren Lee

    2014-04-01

    Full Text Available The influences of various evaporators on the system responses of a 50 kW ORC system using R-245fa are investigated in this study. First the effect of the supplied hot water flowrate into the evaporator is examined and the exit superheat on the system performance between plate and shell-and-tube evaporator is also reported. Test results show that the effect of hot water flowrate on the evaporator imposes a negligible effect on the transient response of the ORC system. These results prevail even for a 3.5-fold increase of the hot water flowrate and the system shows barely any change subject to this drastic hot water flowrate change. The effect of exit superheat on the ORC system depends on the type of the evaporator. For the plate evaporator, an exit superheat less than 10 °C may cause ORC system instability due to considerable liquid entrainment. To maintain a stable operation, the corresponding Jakob number of the plate heat evaporator must be above 0.07. On the other hand, by employing a shell and tube heat evaporator connected to the ORC system, no unstable oscillation of the ORC system is observed for exit superheats ranging from 0 to 17 °C.

  7. Uncertainty Assessment of Equations of State with Application to an Organic Rankine Cycle

    DEFF Research Database (Denmark)

    Frutiger, Jerome; Bell, Ian; O’Connell, John P.

    2017-01-01

    Evaluations of equations of state (EoS) with application to process systems should include uncertainty analysis. A generic method is presented for determining such uncertainties from both the mathematical formand the data for obtaining EoS parameter values. The method is implemented for the Soave...

  8. Performance Analysis of Cold Energy Recovery from CO2 Injection in Ship-Based Carbon Capture and Storage (CCS)

    OpenAIRE

    Hwalong You; Youngkyun Seo; Cheol Huh; Daejun Chang

    2014-01-01

    Carbon capture and storage (CCS) technology is one of the practical solutions for mitigating the effects of global warming. When captured CO 2 is injected into storage sites, the CO 2 is subjected to a heating process. In a conventional CO 2 injection system, CO 2 cold energy is wasted during this heating process. This study proposes a new CO 2 injection system that takes advantage of the cold energy using the Rankine cycle. The study compared the conventional system with the new CO 2 injecti...

  9. Life Cycle Analysis on Fossil Energy Ratio of Algal Biodiesel: Effects of Nitrogen Deficiency and Oil Extraction Technology

    Science.gov (United States)

    Jian, Hou; Jing, Yang; Peidong, Zhang

    2015-01-01

    Life cycle assessment (LCA) has been widely used to analyze various pathways of biofuel preparation from “cradle to grave.” Effects of nitrogen supply for algae cultivation and technology of algal oil extraction on life cycle fossil energy ratio of biodiesel are assessed in this study. Life cycle fossil energy ratio of Chlorella vulgaris based biodiesel is improved by growing algae under nitrogen-limited conditions, while the life cycle fossil energy ratio of biodiesel production from Phaeodactylum tricornutum grown with nitrogen deprivation decreases. Compared to extraction of oil from dried algae, extraction of lipid from wet algae with subcritical cosolvents achieves a 43.83% improvement in fossil energy ratio of algal biodiesel when oilcake drying is not considered. The outcome for sensitivity analysis indicates that the algal oil conversion rate and energy content of algae are found to have the greatest effects on the LCA results of algal biodiesel production, followed by utilization ratio of algal residue, energy demand for algae drying, capacity of water mixing, and productivity of algae. PMID:26000338

  10. Life Cycle Analysis on Fossil Energy Ratio of Algal Biodiesel: Effects of Nitrogen Deficiency and Oil Extraction Technology

    Directory of Open Access Journals (Sweden)

    Hou Jian

    2015-01-01

    Full Text Available Life cycle assessment (LCA has been widely used to analyze various pathways of biofuel preparation from “cradle to grave.” Effects of nitrogen supply for algae cultivation and technology of algal oil extraction on life cycle fossil energy ratio of biodiesel are assessed in this study. Life cycle fossil energy ratio of Chlorella vulgaris based biodiesel is improved by growing algae under nitrogen-limited conditions, while the life cycle fossil energy ratio of biodiesel production from Phaeodactylum tricornutum grown with nitrogen deprivation decreases. Compared to extraction of oil from dried algae, extraction of lipid from wet algae with subcritical cosolvents achieves a 43.83% improvement in fossil energy ratio of algal biodiesel when oilcake drying is not considered. The outcome for sensitivity analysis indicates that the algal oil conversion rate and energy content of algae are found to have the greatest effects on the LCA results of algal biodiesel production, followed by utilization ratio of algal residue, energy demand for algae drying, capacity of water mixing, and productivity of algae.

  11. Life cycle analysis on fossil energy ratio of algal biodiesel: effects of nitrogen deficiency and oil extraction technology.

    Science.gov (United States)

    Jian, Hou; Jing, Yang; Peidong, Zhang

    2015-01-01

    Life cycle assessment (LCA) has been widely used to analyze various pathways of biofuel preparation from "cradle to grave." Effects of nitrogen supply for algae cultivation and technology of algal oil extraction on life cycle fossil energy ratio of biodiesel are assessed in this study. Life cycle fossil energy ratio of Chlorella vulgaris based biodiesel is improved by growing algae under nitrogen-limited conditions, while the life cycle fossil energy ratio of biodiesel production from Phaeodactylum tricornutum grown with nitrogen deprivation decreases. Compared to extraction of oil from dried algae, extraction of lipid from wet algae with subcritical cosolvents achieves a 43.83% improvement in fossil energy ratio of algal biodiesel when oilcake drying is not considered. The outcome for sensitivity analysis indicates that the algal oil conversion rate and energy content of algae are found to have the greatest effects on the LCA results of algal biodiesel production, followed by utilization ratio of algal residue, energy demand for algae drying, capacity of water mixing, and productivity of algae.

  12. Element Cycling and Energy Flux Responses in Ecosystem Simulations Conducted at the Chinese Lunar Palace-1

    Science.gov (United States)

    Dong, Chen; Fu, Yuming; Xie, Beizhen; Wang, Minjuan; Liu, Hong

    2017-01-01

    Bioregenerative life-support systems (BLSS) address interactions between organisms and their environment as an integrated system through the study of factors that regulate the pools and fluxes of materials and energy through ecological systems. As a simple model, using BLSS is very important in the investigation of element cycling and energy flux for sustainable development on Earth. A 105-day experiment with a high degree of closure was carried out in this system from February to May, 2014, with three volunteers. The results indicate that 247 g·d-1 carbon was imported into the system from stored food. Most hydrogen is circulated as water, and more than 99% H2O can be lost through leaf transpiration into the atmosphere. A total of 1.8 g·d-1 "unknown oxygen" emerged between the input and output of the plant growth module. For the urine processing module, 20.5% nitrogen was reused and 5.35 g·d-1 was put into the nutrient solution.

  13. Biomass pyrolysis for biochar or energy applications? A life cycle assessment.

    Science.gov (United States)

    Peters, Jens F; Iribarren, Diego; Dufour, Javier

    2015-04-21

    The application of biochar as a soil amendment is a potential strategy for carbon sequestration. In this paper, a slow pyrolysis system for generating heat and biochar from lignocellulosic energy crops is simulated and its life-cycle performance compared with that of direct biomass combustion. The use of the char as biochar is also contrasted with alternative use options: cofiring in coal power plants, use as charcoal, and use as a fuel for heat generation. Additionally, the influence on the results of the long-term stability of the biochar in the soil, as well as of biochar effects on biomass yield, is evaluated. Negative greenhouse gas emissions are obtained for the biochar system, indicating a significant carbon abatement potential. However, this is achieved at the expense of lower energy efficiency and higher impacts in the other assessed categories when compared to direct biomass combustion. When comparing the different use options of the pyrolysis char, the most favorable result is obtained for char cofiring substituting fossil coal, even assuming high long-term stability of the char. Nevertheless, a high sensitivity to biomass yield increase is found for biochar systems. In this sense, biochar application to low-quality soils where high yield increases are expected would show a more favorable performance in terms of global warming.

  14. The effect of average cycling current on total energy of lithium-ion batteries for electric vehicles

    Science.gov (United States)

    Barai, Anup; Uddin, Kotub; Widanalage, W. D.; McGordon, Andrew; Jennings, Paul

    2016-01-01

    Predicting the remaining range of a battery reliably, accurately and simply is imperative for effective power management of electrified vehicles and reducing driver anxiety resulting from perceived low driving range. Techniques for predicting the remaining range of an electric vehicle exist; in the best cases they are scaled by factors that account for expected energy losses due to driving style, environmental conditions and the use of on-board energy consuming devices such as air-conditioning. In this work, experimental results that establish the dependence of remaining electrical energy on the vehicle battery immediate cycling history are presented. A method to estimate the remaining energy given short-term cycling history is presented. This method differs from the traditional state of charge methods typically used in battery management systems by considering energy throughput more directly.

  15. Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 4: peer review comments on technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report compares the energy use, oil use and emissions of electric vehicles (EVs) with those of conventional, gasoline-powered vehicles (CVs) over the total life cycle of the vehicles. The various stages included in the vehicles` life cycles include vehicle manufacture, fuel production, and vehicle operation. Disposal is not included. An inventory of the air emissions associated with each stage of the life cycle is estimated. Water pollutants and solid wastes are reported for individual processes, but no comprehensive inventory is developed. Volume IV includes copies of all the external peer review comments on the report distributed for review in July 1997.

  16. Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 2: appendices A-D to technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report compares the energy use, oil use and emissions of electric vehicles (EVs) with those of conventional, gasoline- powered vehicles (CVs) over the total life cycle of the vehicles. The various stages included in the vehicles` life cycles include vehicle manufacture, fuel production, and vehicle operation. Disposal is not included. An inventory of the air emissions associated with each stage of the life cycle is estimated. Water pollutants and solid wastes are reported for individual processes, but no comprehensive inventory is developed. Volume II contains additional details on the vehicle, utility, and materials analyses and discusses several details of the methodology.

  17. Comparing the Life Cycle Energy Consumption, Global Warming and Eutrophication Potentials of Several Water and Waste Service Options

    Directory of Open Access Journals (Sweden)

    Xiaobo Xue

    2016-04-01

    Full Text Available Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energy- and carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability and sensitivity were evaluated, the carbon intensity of the local electricity grid and the efficiency of electricity production by the co-digestion with the energy recovery process were the most important for determining the relative global warming potential results.

  18. A Practical Approach to a Closed Nuclear Fuel Cycle and Sustained Nuclear Energy - 12383

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Emory D.; Del Cul, Guillermo D.; Spencer, Barry B.; Williams, Kent A. [Oak Ridge National Laboratory, P.O. Box 2008, MS-6152, Oak Ridge TN 37831 (United States)

    2012-07-01

    Recent systems analysis studies at Oak Ridge National Laboratory (ORNL) have shown that sufficient information is available from previous research and development (R and D), industrial experience, and current studies to make rational decisions on a practical approach to a closed nuclear fuel cycle in the United States. These studies show that a near-term decision is needed to recycle used nuclear fuel (UNF) in the United States, to encourage public recognition that a practical solution to disposal of nuclear energy wastes, primarily UNF, is achievable, and to ensure a focus on essential near-term actions and future R and D. Recognition of the importance of time factors is essential, including the multi-decade time period required to implement industrial-scale fuel recycle at the capacity needed, and the effects of radioactive decay on proliferation resistance, recycling complexity, radioactive emissions, and high-level-waste storage, disposal form development, and eventual emplacement in a geologic repository. Analysis of time factors led to identification of the benefits of processing older fuel and an 'optimum decay storage time'. Further benefits of focused R and D can ensure more complete recycling of UNF components and minimize wastes requiring disposal. Analysis of recycling costs and nonproliferation requirements, which are often cited as reasons for delaying a decision to recycle, shows that (1) the differences in costs of nuclear energy with open or closed fuel cycles are insignificant and (2) nonproliferation requirements can be met by a combination of 'safeguards-by-design' co-location of back-end fuel cycle facilities, and applied engineered safeguards and monitoring. The study shows why different methods of separating and recycling used fuel components do not have a significant effect on nonproliferation requirements and can be selected on other bases, such as process efficiency, maturity, and cost-effectiveness. Finally, the study

  19. A Conceptual Study of Using an Isothermal Compressor on a Supercritical CO{sub 2} Brayton Cycle for SMART Application

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Jin Young; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Ahn, Yoonhan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    To maximize the benefits of modularization, the supercritical CO{sub 2} (S-CO{sub 2}) power cycle can replace the conventional steam Rankine cycle to increase the cycle efficiency and reduce its system size. Previous works have been conducted to evaluate potential advantages of applying the S-CO{sub 2} cycle to SMRs, specifically to SMART (System-integrated Modular Advanced Reactor) which is an integral SMR developed by KAERI (Korea Atomic Energy Institute). One of the optimized S-CO{sub 2} cycle layouts is the recompressing Brayton cycle. This paper attempts to improve the cycle layout by replacing the conventional compressor with an isothermal compressor, of which its potential in the S-CO{sub 2} power cycle is conceptually being evaluated. The SMR applications, for which SMART reactor has been represented, can take advantage of the currently developing S-CO{sub 2} cycle greatly by the reduction of size. By introducing the isothermal compressor, the cycle layout considered in has been further improved by increasing the cycle net efficiency by around 0.5%.

  20. USAF advanced terrestrial energy study. Volume 2: Technology handbook

    Science.gov (United States)

    Daniels, E. J.; Yudow, B. D.; Donakowski, T. D.

    1983-04-01

    This report presents the results of the USAF Advanced Terrestrial Energy Study. The objective of that study was to develop a data base of key parameters of selected energy conversion and energy storage technologies. The data base includes present and expected (through 2000) performance goals of the systems. The data base was established through an extensive literature search, surveys of manufacturers and researchers, and statistical and qualitative analyses of the available input data. The results of the study are reported in four documents: (1) Project Summary; (2) Technology Handbook; (3) Parameter Survey; (4) Analysis, Data, Bibliography. Contents (Volume II): Diesels, Gas Turbines, Stirlings, Organic Rankine Cycle, Fuel Cells, Photovoltaic Energy Conversion System, Wind Turbines, Batteries, Thermal Energy Storage System.

  1. Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

    KAUST Repository

    Ng, Kim Choon

    2015-01-01

    The energy, water and environment nexus is a crucial factor when considering the future development of desalination plants or industry in the water-stressed economies. New generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increase around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available thermally-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent of MED with AD cycles, or simply called the MEDAD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-steam at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60 and 80. °C. In this paper, the authors have reported their pioneered research on aspects of AD and related hybrid MEDAD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concept, the authors examined the cost apportionment of fuel cost by the quality or exergy of working steam for such cogeneration configurations.

  2. Bioenergy co-products derived from microalgae biomass via thermochemical conversion--life cycle energy balances and CO2 emissions.

    Science.gov (United States)

    Khoo, H H; Koh, C Y; Shaik, M S; Sharratt, P N

    2013-09-01

    An investigation of the potential to efficiently convert lipid-depleted residual microalgae biomass using thermochemical (gasification at 850 °C, pyrolysis at 550 °C, and torrefaction at 300 °C) processes to produce bioenergy derivatives was made. Energy indicators are established to account for the amount of energy inputs that have to be supplied to the system in order to gain 1 MJ of bio-energy output. The paper seeks to address the difference between net energy input-output balances based on a life cycle approach, from "cradle-to-bioenergy co-products", vs. thermochemical processes alone. The experimental results showed the lowest results of Net Energy Balances (NEB) to be 0.57 MJ/MJ bio-oil via pyrolysis, and highest, 6.48 MJ/MJ for gas derived via torrefaction. With the complete life cycle process chain factored in, the energy balances of NEBLCA increased to 1.67 MJ/MJ (bio-oil) and 7.01 MJ/MJ (gas). Energy efficiencies and the life cycle CO2 emissions were also calculated. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Dynamics of carbon, water and energy cycles in a heterogeneous landscape and a changing climate

    Science.gov (United States)

    Schmidt, A.; Law, B. E.; Still, C. J.; Hilker, T.

    2016-12-01

    The combined effects of changes in land-use and land cover (LULC) and climate on carbon and water cycling need to be assessed at regional scales. LULC changes over time have many drivers such as expanding urban areas, exploration of new agricultural areas due to overused natural resources of current agricultural areas (e.g. degraded soil), economical reasons, or policy changes that encourage the use of alternative energy resources. Our study assesses the effects of conversion of semi-arid sagebrush and agricultural crops to bioenergy production on carbon, water and energy cycling, and resulting heating or cooling effects. Our project focusses on Oregon, where agricultural crops, significant forest area, and urban expansion are coupled with a strong spatial climate gradient that allows us to examine influences on carbon sequestration by the terrestrial biosphere. Our inverse modeling results showed that the prior fluxes modelled with CLM4.5 underestimated NEE in the highly productive western Douglas fir forests by more than 50%. Based on the results of our Bayesian inversion, we optimized ecosystem fluxes and changed CLM model parameters accordingly. By integrating remote sensing LULC data, eddy covariance data from flux sites, tall tower CO2 observations, biomass estimates from field samples, and CLM4.5, we predict current and future statewide carbon sequestration with unprecedented accuracy. Using inventories and tower flux data, we determined the effect of conversion of hay and grass seed cropland (323,200 ha) to hybrid poplar and found the state NEP increased from 4 TgCO2 per year to 13 TgCO2 per year for that area. The last coal power plant in the state (Boardman) is in the process of switching from coal combustion to biofuel burning to meet the state's goal for the reduction of greenhouse gas emissions. Our results show that the 7816 tons of biomass per day to keep the 518 MW power plant running at base load would amount to 35,000 hectares of hybrid poplar per

  4. Life-Cycle Analyses of Energy Consumption and GHG Emissions of Natural Gas-Based Alternative Vehicle Fuels in China

    OpenAIRE

    Xunmin Ou; Xiliang Zhang

    2013-01-01

    Tsinghua life-cycle analysis model (TLCAM) has been used to examine the primary fossil energy consumption and greenhouse gas (GHG) emissions for natural gas- (NG-) based alternative vehicle fuels in China. The results show that (1) compress NG- and liquid NG-powered vehicles have similar well-to-wheels (WTW) fossil energy uses to conventional gasoline- and diesel-fueled vehicles, but differences emerge with the distance of NG transportation. Additionally, thanks to NG having a lower carbon c...

  5. Summary of annual cycle energy system workshop I held October 29--30, 1975, at Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, H.C.; Moyers, J.C.; Hise, E.C.; Nephew, E.A. (eds.)

    1976-07-01

    The Annual Cycle Energy System (ACES) concept provides space heating, air conditioning, and water heating by means of a heat pump and an energy storage tank. Heat is removed in winter from the water in the tank and is added during the following summer. A workshop was held on October 29-30, 1975 in Oak Ridge, Tenn. to disseminate information on ACES. This report gives summaries of the presentations, which covered technical, economic, and institutional aspects of the concept.

  6. Direct generation of steam and electricity in a open cycle Rankine; Generacion directa de vapor y electricidad en un ciclo Rankine abierto

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Alvaro; Almanza, Rafael; Flores, Vicente [UNAM, Mexico, D.F. (Mexico)

    2000-07-01

    In this work the results of the experimental tests about steam and electricity generation are presented. This work carried out in the solar thermal power plant of the Institute of Engineering with direct steam generation in parabolic through. The global efficiency of the system is studied as for the conversion solar-electricity. The efficiency is determined and it describes the obtaining process of the main plant components, like they are, the solar steam generator, the steam motor and the electric generator. [Spanish] En este trabajo se presentan los resultados de las pruebas experimentales de la generacion de vapor y electricidad realizadas en la planta solar del Instituto de Ingenieria con generacion directa de vapor en concentradores de canal parabolico. Se estudia la eficiencia global del sistema en cuanto a la conversion de energia solar-electricidad. Se determina la eficiencia y describe el proceso de obtencion de la misma y de los principales componentes de la planta como son, el generador de vapor solar, el motor de pistones de vapor y el alternador electrico.

  7. A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage.

    Science.gov (United States)

    Pasta, Mauro; Wessells, Colin D; Huggins, Robert A; Cui, Yi

    2012-01-01

    New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles.

  8. A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage

    KAUST Repository

    Pasta, Mauro

    2012-10-23

    New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. © 2012 Macmillan Publishers Limited. All rights reserved.

  9. A life cycle assessment of distributed energy production from organic waste: Two case studies in Europe.

    Science.gov (United States)

    Evangelisti, Sara; Clift, Roland; Tagliaferri, Carla; Lettieri, Paola

    2017-06-01

    By means of the life cycle assessment methodology, the purpose of this study is to assess the environmental impact when biomethane from organic waste produced at residential level is used to supply energy to a group of dwellings in the distributed generation paradigm. Three different Combined Heat and Power systems, such as fuel cells, Stirling engine and micro gas turbine, installed at household level are assessed in two different settings: one in Northern Europe (UK) and one in Southern Europe (Italy). Different operating strategies are investigated for each technology. Moreover, marginal electricity production technologies are analysed to assess their influence on the results. This study has demonstrated that the type of bio-methane fed micro-CHP technology employed has a significantly different environmental impact: fuel cells are the most environmentally friendly solution in every category analysed; Stirling engines, although can supply heat to the largest number of dwellings are the least environmentally friendly technology. However, key factors investigated in the model presented in this paper influence the decision making on the type of technology adopted and the operating strategy to be implemented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. A comprehensive energy and mass balance firn model for simulations over multiple glacial cycles

    Science.gov (United States)

    Imhof, Michael; Born, Andreas; Stocker, Thomas

    2017-04-01

    We present a fast yet physically comprehensive glacier surface mass balance model capable of simulations that cover the entire Northern Hemisphere over several glacial cycles. Fluxes of energy and mass are calculated between the atmosphere and a multilayer snow cover, including internal processes like densification and water percolation as well as snow and ice melt. The model is especially designed to provide upper boundary conditions to force ice sheet models on time scales of up to 106 years. To achieve a high numerical efficiency, the model employs a variable time stepping scheme on the grid point level and a Lagrangian grid attached to the snow mass. The input variables are short wave radiation, air temperature and precipitation with half-weekly or daily time steps. This new surface mass balance model has been tested in extensive ensemble simulations and yields realistic representations of present-day ice sheets. The extent of the intra-annual snow cover on the Northern Hemisphere correlates temporally and spatially well with satellite measurements. Perennial firn aquifers are simulated realistically in Greenland and the simulated densification and snow temperature at two bore hole sites in central Greenland yield promising results.

  11. Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere

    Science.gov (United States)

    Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

    2007-01-01

    We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

  12. Terawatt Post compression of high energy fs pulses using ionization: A way to overcome the conventional limitation in energy of few optical cycle pulses

    Directory of Open Access Journals (Sweden)

    Descamps D.

    2013-03-01

    Full Text Available By using optical-field-ionization of helium we postcompress 50 fs pulses to 8 fs with a pulse energy of 8,7 mJ. Hence few cycle pulses were obtained with TW peak power and a good shot-to-shot stability.

  13. Integrating Simplified and Full Life Cycle Approaches in Decision Making for Building Energy Refurbishment: Benefits and Barriers

    Directory of Open Access Journals (Sweden)

    Xabat Oregi

    2015-05-01

    Full Text Available The life cycle assessment (LCA method is a powerful tool that can serve to aid decision making regarding the environmental benefits of refurbishment projects. However, due to the relative complexity of LCA studies, simplified LCA methodologies are frequently used, focusing on just some of the building life cycle phases or a reduced number of indicators. The most common and widespread simplification is to only evaluate the differences a refurbishment project makes on the operational energy use of the building. This paper compares the results of applying full LCA, simplified LCA and operational energy use assessment in a refurbishment case study. Results show that simplified LCA methodologies including building use phase and product manufacturing phase can generally be sufficiently accurate to aid decision making for building energy refurbishment, as other building life cycle phases related to transport of products, on site construction, deconstruction or end of life represent a generally negligible part of the total life cycle impacts, both in terms of resource use or environmental impacts. Barriers and benefits of applying simplified LCA approaches to building energy refurbishment projects are subsequently discussed.

  14. Municipal solid waste conversion to transportation fuels: a life-cycle estimation of global warming potential and energy consumption

    DEFF Research Database (Denmark)

    Pressley, Phillip N.; Aziz, Tarek N.; DeCarolis, Joseph F.

    2014-01-01

    This paper utilizes life cycle assessment (LCA) methodology to evaluate the conversion of U.S. municipal solid waste (MSW) to liquid transportation fuels via gasification and Fischer-Tropsch (FT). The model estimates the cumulative energy demand and global warming potential (GWP) associated...

  15. Effect of adjusting pulse durations of functional electrical stimulation cycling on energy expenditure and fatigue after spinal cord injury.

    Science.gov (United States)

    Gorgey, Ashraf S; Poarch, Hunter J; Dolbow, David D; Castillo, Teodoro; Gater, David R

    2014-01-01

    The purpose of the current study was to determine the effects of three different pulse durations (200, 350, and 500 microseconds [P200, P350, and P500, respectively]) on oxygen uptake (VO2), cycling performance, and energy expenditure (EE) percentage of fatigue of the knee extensor muscle group immediately and 48 to 72 h after cycling in persons with spinal cord injury (SCI). A convenience sample of 10 individuals with motor complete SCI participated in a repeated-measures design using a functional electrical stimulation (FES) cycle ergometer over a 3 wk period. There was no difference among the three FES protocols on relative VO2 or cycling EE. Delta EE between exercise and rest was 42% greater in both P500 and P350 compared with P200 (p = 0.07), whereas recovery VO2 was 23% greater in P350 compared with P200 (p = 0.03). There was no difference in the outcomes of the three pulse durations on muscle fatigue. Knee extensor torque significantly decreased immediately after (p < 0.001) and 48 to 72 h after (p < 0.001) FES leg cycling. Lengthening pulse duration did not affect submaximal or relative VO2 or EE, total EE, and time to fatigue. Greater recovery VO2 and delta EE were noted in P350 and P500 compared with P200. An acute bout of FES leg cycling resulted in torque reduction that did not fully recover 48 to 72 h after cycling.

  16. Power cycles with ammonia-water mixtures as working fluid

    Energy Technology Data Exchange (ETDEWEB)

    Thorin, Eva

    2000-05-01

    It is of great interest to improve the efficiency of power generating processes, i.e. to convert more of the energy in the heat source to power. This is favorable from an environmental point of view and can also be an economic advantage. To use an ammonia-water mixture instead of water as working fluid is a possible way to improve the efficiency of steam turbine processes. This thesis includes studies of power cycles with ammonia-water mixtures as working fluid utilizing different kinds of heat sources for power and heat generation. The thermophysical properties of the mixture are also studied. They play an important role in the calculations of the process performance and for the design of its components, such as heat exchangers. The studies concern thermodynamic simulations of processes in applications suitable for Swedish conditions. Available correlations for the thermophysical properties are compared and their influence on simulations and heat exchanger area predictions is investigated. Measurements of ammonia-water mixture viscosities using a vibrating wire viscometer are also described. The studies performed show that power cycles with ammonia-water mixtures as the working fluid are well suited for utilization of waste heat from industry and from gas engines. The ammonia-water power cycles can give up to 32 % more power in the industrial waste heat application and up to 54 % more power in the gas engine bottoming cycle application compared to a conventional Rankine steam cycle. However, ammonia-water power cycles in small direct-fired biomass-fueled cogeneration plants do not show better performance than a conventional Rankine steam cycle. When different correlations for the thermodynamic properties are used in simulations of a simple ammonia-water power cycle the difference in efficiency is not larger than 4 %, corresponding to about 1.3 percentage points. The differences in saturation properties between the correlations are, however, considerable at high

  17. Performance comparison of different thermodynamic cycles for an innovative central receiver solar power plant

    Science.gov (United States)

    Reyes-Belmonte, Miguel A.; Sebastián, Andrés; González-Aguilar, José; Romero, Manuel

    2017-06-01

    The potential of using different thermodynamic cycles coupled to a solar tower central receiver that uses a novel heat transfer fluid is analyzed. The new fluid, named as DPS, is a dense suspension of solid particles aerated through a tubular receiver used to convert concentrated solar energy into thermal power. This novel fluid allows reaching high temperatures at the solar receiver what opens a wide range of possibilities for power cycle selection. This work has been focused into the assessment of power plant performance using conventional, but optimized cycles but also novel thermodynamic concepts. Cases studied are ranging from subcritical steam Rankine cycle; open regenerative Brayton air configurations at medium and high temperature; combined cycle; closed regenerative Brayton helium scheme and closed recompression supercritical carbon dioxide Brayton cycle. Power cycle diagrams and working conditions for design point are compared amongst the studied cases for a common reference thermal power of 57 MWth reaching the central cavity receiver. It has been found that Brayton air cycle working at high temperature or using supercritical carbon dioxide are the most promising solutions in terms of efficiency conversion for the power block of future generation by means of concentrated solar power plants.

  18. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-01

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

  19. Heat recovery from a thermal energy storage based on the Ca(OH){sub 2}/CaO cycle

    Energy Technology Data Exchange (ETDEWEB)

    Azpiazu, M.N. [E.T.S. Ingenieros, Bilbao (Spain). Dpto. de Ingenieria Quimica y del Medio Ambiente; Morquillas, J.M. [E.T.S. Ingenieros, Bilbao (Spain). Dpto. de Maquinas y Motores Termicos; Vazquez, A. [E.S. da Marina Civil, La Coruna (Spain). Dpto. de Energia y Propulsion Maritima

    2003-04-01

    Thermal energy storage is very important in many applications related to the use of waste heat from industrial processes, renewable energies or from other sources. Thermochemical storage is very interesting for long-term storage as it can be carried out at room temperature with no energy losses. Dehydration/hydration cycle of Ca(OH){sub 2}/CaO has been applied for thermal energy storage in two types of reactors. One of them was a prototype designed by the authors, and in the other type conventional laboratory glassware was used. Parameters such as specific heats, reaction rate and enthalpy, mass losses and heat release were monitored during cycles. Although in the hydration step water is normally added in vapour phase, liquid water, at 0{sup o}C has been used in these experiences. Results indicated that the energy storage system performance showed no significant differences, when we compared several hydration/dehydration cycles. The selected chemical reaction did not exhibit a complete reversibility because complete Ca(OH){sub 2} dehydration, was not achieved. However the system could be used satisfactorily along 20 cycles at least. Heat recovery experiments showed general system behaviour during the hydration step in both types of reactors. The designed prototype was more efficient in this step. Main conclusions suggested carrying out one complete cycle at a higher dehydration temperature to recover total system reversibility. A modification of the prototype design trying to enhance heat transfer from the Ca(OH){sub 2} bed could also be proposed. (author)

  20. Low cycle fatigue properties and an energy-based approach for as-extruded AZ31 magnesium alloy

    Science.gov (United States)

    Kwon, S. H.; Song, K. S.; Shin, K. S.; Kwun, S. I.

    2011-04-01

    Low cycle fatigue tests were conducted to investigate the cyclic deformation behavior and the energy-based criterion of AZ31 magnesium alloy. The alloy exhibited an asymmetric hysteresis loop due to the twinning and detwinning effect. The cyclic stress responses showed cyclic hardening at all total strain amplitudes. To evaluate the plastic strain energy, the Halford-Morrow equation and a modified equation for magnesium alloy were compared. The effect of twinning on the total plastic strain energy dissipated during fatigue life was discussed. The variations of the twin and dislocation densities were also investigated using optical microscopy and transmission electron microscopy, respectively.