WorldWideScience

Sample records for cell auxiliary power

  1. Solid Oxide Fuel Cell Auxiliary Power Unit

    International Nuclear Information System (INIS)

    Solid Oxide Fuel Cell (SOFC) is an attractive, efficient, clean source of power for transportation, military, and stationary applications. Delphi has pioneered its application as an auxiliary Power Unit (APU) for transportation. Delphi is also interested in marketing this technology for stationary applications. Its key advantages are high efficiency and compatibility with gasoline, natural gas and diesel fuel. It's consistent with mechanizations that support the trend to low emissions. Delphi is committed to working with customers and partners to bring this novel technology to market

  2. Development of a solid oxide fuel cell (SOFC) automotive auxiliary power unit (APU) fueled by gasoline

    International Nuclear Information System (INIS)

    This paper describes the design and the development progress of a 3 to 5 auxiliary power unit (APU) based on a gasoline fueled solid oxide fuel cell (SOFC). This fuel cell was supplied reformate gas (reactant) by a partial oxidation (POx) catalytic reformer utilizing liquid gasoline and designed by Delphi Automotive Systems. This reformate gas consists mainly of hydrogen, carbon monoxide and nitrogen and was fed directly in to the SOFC stack without any additional fuel reformer processing. The SOFC stack was developed by Global Thermoelectric and operates around 700oC. This automotive APU produces power to support future 42 volt vehicle electrical architectures and loads. The balance of the APU, designed by Delphi Automotive Systems, employs a packaging and insulation design to facilitate installation and operation on-board automobiles. (author)

  3. Auxiliary power unit based on a solid oxide fuel cell and fuelled with diesel

    Science.gov (United States)

    Lawrence, Jeremy; Boltze, Matthias

    An auxiliary power unit (APU) is presented that is fuelled with diesel, thermally self-sustaining, and based on a solid oxide fuel cell (SOFC). The APU is rated at 1 kW electrical, and can generate electrical power after a 3 h warm-up phase. System features include a "dry" catalytic partial oxidation (CPOX) diesel reformer, a 30 cell SOFC stack with an open cathode, and a porous-media afterburner. The APU does not require a supply of external water. The SOFC stack is an outcome of a development partnership with H.C. Starck GmbH and Fraunhofer IKTS, and is discussed in detail in an accompanying paper.

  4. PEMFC Optimization Strategy with Auxiliary Power Source in Fuel Cell Hybrid Vehicle

    Directory of Open Access Journals (Sweden)

    Tinton Dwi Atmaja

    2012-02-01

    Full Text Available Page HeaderOpen Journal SystemsJournal HelpUser You are logged in as...aulia My Journals My Profile Log Out Log Out as UserNotifications View (27 new ManageJournal Content SearchBrowse By Issue By Author By Title Other JournalsFont SizeMake font size smaller Make font size default Make font size largerInformation For Readers For Authors For LibrariansKeywords CBPNN Displacement FLC LQG/LTR Mixed PMA Ventilation bottom shear stress direct multiple shooting effective fuzzy logic geoelectrical method hourly irregular wave missile trajectory panoramic image predator-prey systems seawater intrusion segmentation structure development pattern terminal bunt manoeuvre Home About User Home Search Current Archives ##Editorial Board##Home > Vol 23, No 1 (2012 > AtmajaPEMFC Optimization Strategy with Auxiliary Power Source in Fuel Cell Hybrid VehicleTinton Dwi Atmaja, Amin AminAbstractone of the present-day implementation of fuel cell is acting as main power source in Fuel Cell Hybrid Vehicle (FCHV. This paper proposes some strategies to optimize the performance of Polymer Electrolyte Membrane Fuel Cell (PEMFC implanted with auxiliary power source to construct a proper FCHV hybridization. The strategies consist of the most updated optimization method determined from three point of view i.e. Energy Storage System (ESS, hybridization topology and control system analysis. The goal of these strategies is to achieve an optimum hybridization with long lifetime, low cost, high efficiency, and hydrogen consumption rate improvement. The energy storage system strategy considers battery, supercapacitor, and high-speed flywheel as the most promising alternative auxiliary power source. The hybridization topology strategy analyzes the using of multiple storage devices injected with electronic components to bear a higher fuel economy and cost saving. The control system strategy employs nonlinear control system to optimize the ripple factor of the voltage and the current

  5. Fuel Cell Auxiliary Power Study Volume 1: RASER Task Order 5

    Science.gov (United States)

    Mak, Audie; Meier, John

    2007-01-01

    This study evaluated the feasibility of a hybrid solid oxide fuel cell (SOFC) auxiliary power unit (APU) and the impact in a 90-passenger More-Electric Regional Jet application. The study established realistic hybrid SOFC APU system weight and system efficiencies, and evaluated the impact on the aircraft total weight, fuel burn, and emissions from the main engine and the APU during cruise, landing and take-off (LTO) cycle, and at the gate. Although the SOFC APU may be heavier than the current conventional APU, its weight disadvantage can be offset by fuel savings in the higher SOFC APU system efficiencies against the main engine bleed and extraction during cruise. The higher SOFC APU system efficiency compared to the conventional APU on the ground can also provide considerable fuel saving and emissions reduction, particularly at the gate, but is limited by the fuel cell stack thermal fatigue characteristic.

  6. Solid Oxide Fuel Cell/Gas Turbine Hybrid Cycle Technology for Auxiliary Aerospace Power

    Science.gov (United States)

    Steffen, Christopher J., Jr.; Freeh, Joshua E.; Larosiliere, Louis M.

    2005-01-01

    A notional 440 kW auxiliary power unit has been developed for 300 passenger commercial transport aircraft in 2015AD. A hybrid engine using solid-oxide fuel cell stacks and a gas turbine bottoming cycle has been considered. Steady-state performance analysis during cruise operation has been presented. Trades between performance efficiency and system mass were conducted with system specific energy as the discriminator. Fuel cell performance was examined with an area specific resistance. The ratio of fuel cell versus turbine power was explored through variable fuel utilization. Area specific resistance, fuel utilization, and mission length had interacting effects upon system specific energy. During cruise operation, the simple cycle fuel cell/gas turbine hybrid was not able to outperform current turbine-driven generators for system specific energy, despite a significant improvement in system efficiency. This was due in part to the increased mass of the hybrid engine, and the increased water flow required for on-board fuel reformation. Two planar, anode-supported cell design concepts were considered. Designs that seek to minimize the metallic interconnect layer mass were seen to have a large effect upon the system mass estimates.

  7. The modeling of a standalone solid-oxide fuel cell auxiliary power unit

    Science.gov (United States)

    Lu, N.; Li, Q.; Sun, X.; Khaleel, M. A.

    In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module, two heat exchanger modules, and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components, as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will help design engineers to adjust design parameters to optimize the performance. The modeling results of the SOFC APU heat-up stage and the output voltage response to a sudden load change are presented in this paper. The fuel flow regulation based on fuel utilization is also briefly discussed.

  8. Techno-economic analysis of fuel cell auxiliary power units as alternative to idling

    Science.gov (United States)

    Jain, Semant; Chen, Hsieh-Yeh; Schwank, Johannes

    This paper presents a techno-economic analysis of fuel-cell-based auxiliary power units (APUs), with emphasis on applications in the trucking industry and the military. The APU system is intended to reduce the need for discretionary idling of diesel engines or gas turbines. The analysis considers the options for on-board fuel processing of diesel and compares the two leading fuel cell contenders for automotive APU applications: proton exchange membrane fuel cell and solid oxide fuel cell. As options for on-board diesel reforming, partial oxidation and auto-thermal reforming are considered. Finally, using estimated and projected efficiency data, fuel consumption patterns, capital investment, and operating costs of fuel-cell APUs, an economic evaluation of diesel-based APUs is presented, with emphasis on break-even periods as a function of fuel cost, investment cost, idling time, and idling efficiency. The analysis shows that within the range of parameters studied, there are many conditions where deployment of an SOFC-based APU is economically viable. Our analysis indicates that at an APU system cost of 100 kW -1, the economic break-even period is within 1 year for almost the entire range of conditions. At 500 kW -1 investment cost, a 2-year break-even period is possible except for the lowest end of the fuel consumption range considered. However, if the APU investment cost is 3000 kW -1, break-even would only be possible at the highest fuel consumption scenarios. For Abram tanks, even at typical land delivered fuel costs, a 2-year break-even period is possible for APU investment costs as high as 1100 kW -1.

  9. Hovercraft auxiliary power units (APUs)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, B.J.

    1983-08-01

    Auxiliary power units (APU) manufactured by British firms for use in hovercraft are characterized. Both diesel and gas-turbine APUs are found to be well suited to the demands of this application. The design features, dimensions, performance data, and installation requirements are discussed for the SS 90, SS 923, DA-1, BA-1, HM 5, and Gevaudan 9 APUs, as well as the TRS 18 gas-turbine smoke generator. The progress made in improving the fuel efficiency of gas turbines and reducing the weight of diesel engines is considered significant.

  10. A review of high-temperature polymer electrolyte membrane fuel-cell (HT-PEMFC)-based auxiliary power units for diesel-powered road vehicles

    Science.gov (United States)

    Liu, Yongfeng; Lehnert, Werner; Janßen, Holger; Samsun, Remzi Can; Stolten, Detlef

    2016-04-01

    This paper presents an extensive review of research on the development of auxiliary power units with enhanced reformate tolerance for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Developments in diesel reforming for fuel cells as auxiliary power units (APUs), single fuel cells and stacks and systems are outlined in detail and key findings are presented. Summaries of HT-PEMFC APU applications and start-up times for HT-PEMFC systems are then given. A summary of cooling HT-PEMFC stacks using a classic schematic diagram of a 24-cell HT-PEMFC stack, with a cooling plate for every third cell, is also presented as part of a stack analysis. Finally, a summary of CO tolerances for fuel cells is given, along with the effects of different CO volume fractions on polarization curves, the fraction of CO coverage, hydrogen coverage, anode overpotential and cell potential.

  11. Engineering aspects and hardware verification of a volume producable solid oxide fuel cell stack design for diesel auxiliary power units

    Science.gov (United States)

    Stelter, Michael; Reinert, Andreas; Mai, Björn Erik; Kuznecov, Mihail

    A solid oxide fuel cell (SOFC) stack module is presented that is designed for operation on diesel reformate in an auxiliary power unit (APU). The stack was designed using a top-down approach, based on a specification of an APU system that is installed on board of vehicles. The stack design is planar, modular and scalable with stamped sheet metal interconnectors. It features thin membrane electrode assemblies (MEAs), such as electrolyte supported cells (ESC) and operates at elevated temperatures around 800 °C. The stack has a low pressure drop in both the anode and the cathode to facilitate a simple system layout. An overview of the technical targets met so far is given. A stack power density of 0.2 kW l -1 has been demonstrated in a fully integrated, thermally self-sustaining APU prototype running with diesel and without an external water supply.

  12. Study of Electrical and Thermal Behaviour of Li-ion Polymer Cells for Auxiliary Power Supply in Underwater Applications

    Directory of Open Access Journals (Sweden)

    T.V.S.L. Satyavani

    2012-03-01

    Full Text Available Lithium  ion  polymer (Li-Po battery technology is the latest technology for portable use and the most promising technology for exercise torpedoes. These batteries are technologically evolved from Lithium ion batteries. In this paper, extensive experimental studies on Li-Po cells which include studies on electrical characteristics during charge-discharge cycles, discharge at different C rates, self discharge throughout  charge stand, temperature profiles at the cathode and anode during the discharges, etc. are reported and discussed. The extensive electrical characterisation done on these cells indicates the capability of these cells for use as auxiliary power supply in underwater weapon applications.Defence Science Journal, 2012, 62(2, pp.127-131, DOI:http://dx.doi.org/10.14429/dsj.62.995

  13. Solid Oxide Fuel Cell Development for Auxiliary Power in Heavy Duty Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Daniel T. Hennessy

    2010-06-15

    Changing economic and environmental needs of the trucking industry is driving the use of auxiliary power unit (APU) technology for over the road haul trucks. The trucking industry in the United States remains the key to the economy of the nation and one of the major changes affecting the trucking industry is the reduction of engine idling. Delphi Automotive Systems, LLC (Delphi) teamed with heavy-duty truck Original Equipment Manufacturers (OEMs) PACCAR Incorporated (PACCAR), and Volvo Trucks North America (VTNA) to define system level requirements and develop an SOFC based APU. The project defines system level requirements, and subsequently designs and implements an optimized system architecture using an SOFC APU to demonstrate and validate that the APU will meet system level goals. The primary focus is on APUs in the range of 3-5 kW for truck idling reduction. Fuels utilized were derived from low-sulfur diesel fuel. Key areas of study and development included sulfur remediation with reformer operation; stack sensitivity testing; testing of catalyst carbon plugging and combustion start plugging; system pre-combustion; and overall system and electrical integration. This development, once fully implemented and commercialized, has the potential to significantly reduce the fuel idling Class 7/8 trucks consume. In addition, the significant amounts of NOx, CO2 and PM that are produced under these engine idling conditions will be virtually eliminated, inclusive of the noise pollution. The environmental impact will be significant with the added benefit of fuel savings and payback for the vehicle operators / owners.

  14. Conceptual design and selection of a biodiesel fuel processor for a vehicle fuel cell auxiliary power unit

    Science.gov (United States)

    Specchia, S.; Tillemans, F. W. A.; van den Oosterkamp, P. F.; Saracco, G.

    Within the European project BIOFEAT (biodiesel fuel processor for a fuel cell auxiliary power unit for a vehicle), a complete modular 10 kW e biodiesel fuel processor capable of feeding a PEMFC will be developed, built and tested to generate electricity for a vehicle auxiliary power unit (APU). Tail pipe emissions reduction, increased use of renewable fuels, increase of hydrogen-fuel economy and efficient supply of present and future APU for road vehicles are the main project goals. Biodiesel is the chosen feedstock because it is a completely natural and thus renewable fuel. Three fuel processing options were taken into account at a conceptual design level and compared for hydrogen production: (i) autothermal reformer (ATR) with high and low temperature shift (HTS/LTS) reactors; (ii) autothermal reformer (ATR) with a single medium temperature shift (MTS) reactor; (iii) thermal cracker (TC) with high and low temperature shift (HTS/LTS) reactors. Based on a number of simulations (with the AspenPlus® software), the best operating conditions were determined (steam-to-carbon and O 2/C ratios, operating temperatures and pressures) for each process alternative. The selection of the preferential fuel processing option was consequently carried out, based on a number of criteria (efficiency, complexity, compactness, safety, controllability, emissions, etc.); the ATR with both HTS and LTS reactors shows the most promising results, with a net electrical efficiency of 29% (LHV).

  15. Auxiliary power unit for moving a vehicle

    Science.gov (United States)

    Akasam, Sivaprasad; Johnson, Kris W.; Johnson, Matthew D.; Slone, Larry M.; Welter, James Milton

    2009-02-03

    A power system is provided having at least one traction device and a primary power source configured to power the at least one traction device. In addition, the power system includes an auxiliary power source also configured to power the at least one traction device.

  16. Off-Design Performance Analysis of a Solid-Oxide Fuel Cell/Gas Turbine Hybrid for Auxiliary Aerospace Power

    Science.gov (United States)

    Freeh, Joshua E.; Steffen, J., Jr.; Larosiliere, Louis M.

    2005-01-01

    A solid-oxide fuel cell/gas turbine hybrid system for auxiliary aerospace power is analyzed using 0-D and 1-D system-level models. The system is designed to produce 440 kW of net electrical power, sized for a typical long-range 300-passenger civil airplane, at both sea level and cruise flight level (12,500 m). In addition, a part power level of 250 kW is analyzed at the cruise condition, a requirement of the operating power profile. The challenge of creating a balanced system for the three distinct conditions is presented, along with the compromises necessary for each case. A parametric analysis is described for the cruise part power operating point, in which the system efficiency is maximized by varying the air flow rate. The system is compared to an earlier version that was designed solely for cruise operation. The results show that it is necessary to size the turbomachinery, fuel cell, and heat exchangers at sea level full power rather than cruise full power. The resulting estimated mass of the system is 1912 kg, which is significantly higher than the original cruise design point mass, 1396 kg. The net thermal efficiencies with respect to the fuel LHV are calculated to be 42.4 percent at sea level full power, 72.6 percent at cruise full power, and 72.8 percent at cruise part power. The cruise conditions take advantage of pre-compressed air from the on-board Environmental Control System, which accounts for a portion of the unusually high thermal efficiency at those conditions. These results show that it is necessary to include several operating points in the overall assessment of an aircraft power system due to the variations throughout the operating profile.

  17. Dynamic evaluation of low-temperature metal-supported solid oxide fuel cell oriented to auxiliary power units

    Science.gov (United States)

    Wang, Zhenwei; Berghaus, Jörg Oberste; Yick, Sing; Decès-Petit, Cyrille; Qu, Wei; Hui, Rob; Maric, Radenka; Ghosh, Dave

    A metal-supported solid oxide fuel cell (SOFC) composed of a Ni-Ce 0.8Sm 0.2O 2- δ (Ni-SDC) cermet anode and an SDC electrolyte was fabricated by suspension plasma spraying on a Hastelloy X substrate. The cathode, an Sm 0.5Sr 0.5CoO 3 (SSCo)-SDC composite, was screen-printed and fired in situ. The dynamic behaviour of the cell was measured while subjected to complete fuel shutoff and rapid start-up cycles, as typically encountered in auxiliary power units (APU) applications. A promising performance - with a maximum power density (MPD) of 0.176 W cm -2 at 600 °C - was achieved using humidified hydrogen as fuel and air as the oxidant. The cell also showed excellent resistance to oxidation at 600 °C during fuel shutoff, with only a slight drop in performance after reintroduction of the fuel. The Cr and Mn species in the Hastelloy X alloy appeared to be preferentially oxidized while the oxidation of nickel in the metallic substrate was temporarily alleviated. In rapid start-up cycles with a heating rate of 60 °C min -1, noticeable performance deterioration took place in the first two thermal cycles, and then continued at a much slower rate in subsequent cycles. A postmortem analysis of the cell suggested that the degradation was mainly due to the mismatch of the thermal expansion coefficient across the cathode/electrolyte interface.

  18. Study on Use of Fuel-Cell Auxiliary Power Units in Refrigerator Cars Employed for Delivery to Convenience Store

    Science.gov (United States)

    Katayama, Noboru; Kamiyama, Hideyuki; Kogoshi, Sumio; Kudo, Yusuke; Fukada, Takafumi; Ogawa, Makoto

    The use of fuel-cell auxiliary power units (FC-APU) in refrigerator cars employed delivery to for convenience store delivery has been studied. The delivery pattern is assumed to be a typical pattern that includes driving between convenience stores or between a delivery center and a convenience store, unloading, driver's lunch break. The M15 driving mode, which simulates the driving condition in urban areas, is used as the driving mode in the delivery pattern. The FC-APU system includes a proton-exchange membrane fuel cell (PEFC) module, an inverter, and DC/DC converter. Bench tests of the FC-APU are performed to determine the hydrogen fuel consumption rate and the energy efficiency; these values depend on the output power of the PEFC module. The calculated relationship between the output power and fuel consumption rate of a current used system, which consists of an alternator and a secondary battery, are used to estimate the energy efficiency of the current used system. On the basis of the measurement data in this study and the results for the model proposed by Brodric et al. [C. J. Brodrick et al., Trans. Res. D, vol 7, pp. 303 (2002)], the payback period is calculated. The results indicate that the payback period would be 2.1 years when the FC-APU operates at a load of 70%.

  19. A techno-economic comparison of fuel processors utilizing diesel for solid oxide fuel cell auxiliary power units

    Science.gov (United States)

    Nehter, Pedro; Hansen, John Bøgild; Larsen, Peter Koch

    Ultra-low sulphur diesel (ULSD) is the preferred fuel for mobile auxiliary power units (APU). The commercial available technologies in the kW-range are combustion engine based gensets, achieving system efficiencies about 20%. Solid oxide fuel cells (SOFC) promise improvements with respect to efficiency and emission, particularly for the low power range. Fuel processing methods i.e., catalytic partial oxidation, autothermal reforming and steam reforming have been demonstrated to operate on diesel with various sulphur contents. The choice of fuel processing method strongly affects the SOFC's system efficiency and power density. This paper investigates the impact of fuel processing methods on the economical potential in SOFC APUs, taking variable and capital cost into account. Autonomous concepts without any external water supply are compared with anode recycle configurations. The cost of electricity is very sensitive on the choice of the O/C ratio and the temperature conditions of the fuel processor. A sensitivity analysis is applied to identify the most cost effective concept for different economic boundary conditions. The favourite concepts are discussed with respect to technical challenges and requirements operating in the presence of sulphur.

  20. BIOFEAT: Biodiesel fuel processor for a vehicle fuel cell auxiliary power unit. Study of the feed system

    Science.gov (United States)

    Sgroi, M.; Bollito, G.; Saracco, G.; Specchia, S.

    An integrated auxiliary power unit (APU) based on a 10 kW e integrated biodiesel fuel processor has been designed and is being developed. Auto-thermal reforming (ATR) and thermal cracking (TC) were considered for converting the fuel into a hydrogen-rich gas suitable for PEM fuel cells. The fuel processor includes also a gas clean-up system that will reduce the carbon monoxide in the primary processor exit gas to below 10 ppm via a new heat-integrated CO clean-up unit, based on the assembly of catalytic heat exchange plates, so as to meet the operational requirements of a PEMFC stack. This article is devoted to the study and selection of the proper feed strategy for the primary fuel processor. Different pre-treatment and feed alternatives (e.g. based on nozzles or simple coils) were devised and tested for the ATR processors, which turned out to be the preferred primary processing route. A nozzle-based strategy was finally selected along with special recommendations about the constituent materials and the operating procedures to be adopted to avoid coking and nozzle corrosion as well as to allow a wide turn down ratio.

  1. EVALUATION OF FUEL CELL AUXILIARY POWER UNITS FOR HEAVY-DUTY DIESEL TRUCKS

    Science.gov (United States)

    A large number of heavy-duty trucks idle a significant amount. Heavy-duty line-haul truck engines idle about 30-50% of the time the engine is running. Drivers idle engines to power climate control devices (e.g., heaters and air conditioners) and sleeper compartment accessories (e...

  2. Evaluation of Fuel Cell Auxiliary Power Units for Heavy-Duty Diesel Trucks

    OpenAIRE

    Brodrick, Christie-Joy; Lipman, Timothy; Farshchi, Mohammad; Lutsey, Nicholas P.; Dwyer, Harry A.; Sperling, Dan; Gouse, Bill; Harris, D. Bruce; King, Foy G

    2002-01-01

    A large number of heavy-duty trucks idle a significant amount. Heavy-duty line-haul truck engines idle about 20-40% of the time the engine is running, depending on season and operation. Drivers idle engines to power climate control devices (e.g., heaters and air conditioners) and sleeper compartment accessories (e.g., refrigerators, microwave ovens, and televisions) and to avoid start-up problems in cold weather. Idling increases air pollution and energy use, as well as wear and tear on engin...

  3. Evaluation of Fuel Cell Auxiliary Power Units for Heavy-Duty Diesel Trucks

    OpenAIRE

    Brodrick, Christie-Joy; Lipman, Timothy; Farshchi, Mohammad; Lutsey, Nicholas; Dwyer, Harry; Sperling, Daniel; Gouse, S. William; King, Foy

    2002-01-01

    A large number of heavy-duty trucks idle a significant amount. Heavy-duty line-haul engines idle about 20-40% of the time the engine is running, depending on season and operation. Drivers idle engines to power climate control devices (e.g., heaters and air conditioners) and sleeper compartment accessories (e.g., refrigerators, microwave ovens, and televisions) and to avoid start-up problems in cold weather. Idling increases air pollution and energy use, as well as wear and tear on engines....

  4. Investigation of the Start-up Strategy for a Solid Oxide Fuel Cell Based Auxiliary Power Unit under Transient Conditions

    Directory of Open Access Journals (Sweden)

    Michael R. von Spakovsky

    2005-06-01

    Full Text Available

    A typical approach to the synthesis/design optimization of energy systems is to only use steady state operation and high efficiency (or low total life cycle cost at full load as the basis for the synthesis/design. Transient operation as reflected by changes in power demand, shut-down, and start-up are left as secondary tasks to be solved by system and control engineers once the synthesis/design is fixed. However, start-up and shut-down may be events that happen quite often and, thus, may be quite important in the creative process of developing the system. This is especially true for small power units used in transportation applications or for domestic energy supplies, where the load demand changes frequently and peaks in load of short duration are common. The duration of start-up is, of course, a major factor which must be considered since rapid system response is an important factor in determining the feasibility of solid oxide fuel cell (SOFC based auxiliary power units (APUs. Start-up and shut-down may also significantly affect the life span of the system due to thermal stresses on all system components. Therefore, a proper balance must be struck between a fast response and the costs of owning and operating the system so that start-up or any other transient process can be accomplished in as short a time as possible yet with a minimum in fuel consumption.

    In this research work we have been studying the effects of control laws and strategies and transients on system performance. The results presented in this paper are based on a set of transient models developed and implemented for the components of a 5 kWe net power SOFC based APU and for the high-fidelity system which results from their integration. The simulation results given below are for two different start-up approaches: one with steam recirculation and component pre-heating and the second without either. These start-up simulations were performed for fixed values of a number of

  5. Effects of auxiliary source connections in multichip power module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon;

    2016-01-01

    Auxiliary source bond wires and connections are widely used to in the power module with paralleled MOSFETs or IGBTs. This paper investigates the working mechanism and the effects of the auxiliary source connections in multichip power modules. It reveals that the auxiliary source connections cannot...

  6. Dedicated auxiliary power units for Hybrid Electric Vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de

    1998-01-01

    The use of a dedicated auxiliary power unit is essential to utilize the potential that hybrid vehicles offer for efficient and ultra-clean transportation. An example of a hybrid project at the TNO Road-Vehicles Research Institute shows the development and the results of a dedicated auxiliary power u

  7. Orbiter Auxiliary Power Unit Flight Support Plan

    Science.gov (United States)

    Guirl, Robert; Munroe, James; Scott, Walter

    1990-01-01

    This paper discussed the development of an integrated Orbiter Auxiliary Power Unit (APU) and Improved APU (IAPU) Flight Suuport Plan. The plan identifies hardware requirements for continued support of flight activities for the Space Shuttle Orbiter fleet. Each Orbiter vehicle has three APUs that provide power to the hydraulic system for flight control surface actuation, engine gimbaling, landing gear deployment, braking, and steering. The APUs contain hardware that has been found over the course of development and flight history to have operating time and on-vehicle exposure time limits. These APUs will be replaced by IAPUs with enhanced operating lives on a vehicle-by-vehicle basis during scheduled Orbiter modification periods. This Flight Support Plan is used by program management, engineering, logistics, contracts, and procurement groups to establish optimum use of available hardware and replacement quantities and delivery requirements for APUs until vehicle modifications and incorporation of IAPUs. Changes to the flight manifest and program delays are evaluated relative to their impact on hardware availability.

  8. Indirect combustion noise of auxiliary power units

    Science.gov (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill

    2013-08-01

    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  9. Auxiliary pattern for cell-based OPC

    Science.gov (United States)

    Kahng, Andrew B.; Park, Chul-Hong

    2006-10-01

    The runtime of model-based optical proximity correction (OPC) tools has grown unacceptably with each successive technology generation, and has emerged as one of the major bottlenecks for turnaround time (TAT) of IC data preparation and manufacturing. The cell-based OPC approach improves runtime by performing OPC once per cell definition as opposed to once per cell instantiation in the layout. However, cell-based OPC does not comprehend inter-cell optical interactions that affect feature printability in a layout context. In this work, we propose auxiliary pattern-enabled cell-based OPC which can minimize the CD differences between cell-based OPC and model-based OPC. To enable effective insertion of auxiliary pattern (AP) in the design, we also propose a post-placement optimization of a standard cell block with respect to detailed placement. By dynamic programming-based placement perturbation, we achieve 100% AP applicability in designs with placement utilizations of cell-based OPC with AP can match gate edge placement error (EPE) count of model-based OPC within 4%. This is an improvement of 90%, on average, over cell-based OPC without APs. The AP-based OPC approach can reduce OPC runtimes versus model-based OPC by up to 40X in our benchmark designs. We can also achieve reduction of GDSII file size and ORC runtimes due to hierarchy maintenance of cell-based OPC.

  10. Power consumption of the ASCV and auxiliary equipment

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Pedersen, Jørgen Kaas

    1998-01-01

    Operating an ASCV requires power - to cover the losses in the ASCV itself and to run auxiliary equipment. It is necessary to take this power consumption into account when considering the economical aspects of installing an ASCV.Field measurements of this consumption of the ASCV in Rejsby Hede are...

  11. Space Shuttle Orbiter auxiliary power unit status

    Science.gov (United States)

    Reck, M.; Loken, G.; Horton, J.; Lukens, W.; Scott, W.; Baughman, J.; Bauch, T.

    An overview of the United States Space Shuttle Orbiter APU, which provides power to the Orbiter vehicle hydraulic system, is presented. Three complete APU systems, each with its own separate fuel system, supply power to three dedicated hydraulic systems. These in turn provide power to all Orbiter vehicle critical flight functions including launch, orbit, reentry, and landing. The basic APU logic diagram is presented. The APU includes a hydrazine-powered turbine that drives a hydraulic pump and various accessories through a high-speed gearbox. The APU also features a sophisticated thermal management system designed to ensure safe and reliable operation in the various launch, orbit, reentry, and landing environments.

  12. 40 CFR 1033.510 - Auxiliary power units.

    Science.gov (United States)

    2010-07-01

    ... locomotive is equipped with an auxiliary power unit (APU) that operates during an idle shutdown mode, you must account for the APU's emissions rates as specified in this section, unless the APU is part of an... emission rate (g/hr) as specified in § 1033.530. Add the APU emission rate (g/hr) that you determine...

  13. Compact propane fuel processor for auxiliary power unit application

    Science.gov (United States)

    Dokupil, M.; Spitta, C.; Mathiak, J.; Beckhaus, P.; Heinzel, A.

    With focus on mobile applications a fuel cell auxiliary power unit (APU) using liquefied petroleum gas (LPG) is currently being developed at the Centre for Fuel Cell Technology (Zentrum für BrennstoffzellenTechnik, ZBT gGmbH). The system is consisting of an integrated compact and lightweight fuel processor and a low temperature PEM fuel cell for an electric power output of 300 W. This article is presenting the current status of development of the fuel processor which is designed for a nominal hydrogen output of 1 k Wth,H2 within a load range from 50 to 120%. A modular setup was chosen defining a reformer/burner module and a CO-purification module. Based on the performance specifications, thermodynamic simulations, benchmarking and selection of catalysts the modules have been developed and characterised simultaneously and then assembled to the complete fuel processor. Automated operation results in a cold startup time of about 25 min for nominal load and carbon monoxide output concentrations below 50 ppm for steady state and dynamic operation. Also fast transient response of the fuel processor at load changes with low fluctuations of the reformate gas composition have been achieved. Beside the development of the main reactors the transfer of the fuel processor to an autonomous system is of major concern. Hence, concepts for packaging have been developed resulting in a volume of 7 l and a weight of 3 kg. Further a selection of peripheral components has been tested and evaluated regarding to the substitution of the laboratory equipment.

  14. 14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine tests in auxiliary power unit (APU... Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which... in operation, and remain stopped during operation of the engine as an auxiliary power unit (“APU...

  15. Comparative LCA of methanol-fuelled SOFCs as auxiliary power systems on-board ships

    Energy Technology Data Exchange (ETDEWEB)

    Strazza, C.; Del Borghi, A.; Costamagna, P. [Department of Chemical and Process Engineering ' ' G.B. Bonino' ' (DICheP), University of Genoa, Via all' Opera Pia 15, 16145 Genova (Italy); Traverso, A.; Santin, M. [Department of Machines, Energetic Systems and Transport (DIMSET), University of Genoa, Via all' Opera Pia 15, 16145 Genova (Italy)

    2010-05-15

    Fuel cells own the potential for significant environmental improvements both in terms of air quality and climate protection. Through the use of renewable primary energies, local pollutant and greenhouse gas emissions can be significantly minimized over the full life cycle of the electricity generation process, so that marine industry accounts renewable energy as its future energy source. The aim of this paper is to evaluate the use of methanol in Solid Oxide Fuel Cells (SOFC), as auxiliary power systems for commercial vessels, through Life Cycle Assessment (LCA). The LCA methodology allows the assessment of the potential environmental impact along the whole life cycle of the process. The unit considered is a 20 kWel fuel cell system. In a first part of the study different fuel options have been compared (methanol, bio-methanol, natural gas, hydrogen from cracking, electrolysis and reforming), then the operation of the cell fed with methanol has been compared with the traditional auxiliary power system, i.e. a diesel engine. The environmental benefits of the use of fuel cells have been assessed considering different impact categories. The results of the analysis show that fuel production phase has a strong influence on the life cycle impacts and highlight that feeding with bio-methanol represents a highly attractive solution from a life cycle point of view. The comparison with the conventional auxiliary power system shows extremely lower impacts for SOFCs. (author)

  16. Green Propulsion Auxiliary Power Unit Demonstration at MSFC

    Science.gov (United States)

    Robinson, Joel W.

    2014-01-01

    In 2012, the National Aeronautics & Space Administration (NASA) Space Technology Mission Directorate (STMD) began the process of building an integrated technology roadmap, including both technology pull and technology push strategies. Technology Area 1 (TA-01)1 for Launch Propulsion Systems is one of fourteen TAs that provide recommendations for the overall technology investment strategy and prioritization of NASA's space technology activities. Identified within TA-01 was the need for a green propulsion auxiliary power unit (APU) for hydraulic power by 2015. Engineers led by the author at the Marshall Space Flight Center (MSFC) have been evaluating green propellant alternatives and have begun the development of an APU test bed to demonstrate the feasibility of use. NASA has residual APU assets remaining from the retired Space Shuttle Program. Likewise, the F-16 Falcon fighter jet also uses an Emergency Power Unit (EPU) that has similar characteristics to the NASA hardware. Both EPU and APU components have been acquired for testing at MSFC. This paper will summarize the status of the testing efforts of green propellant from the Air Force Research Laboratory (AFRL) propellant AFM315E based on hydroxyl ammonium nitrate (HAN) with these test assets.

  17. Development and design of experiments optimization of a high temperature proton exchange membrane fuel cell auxiliary power unit with onboard fuel processor

    Science.gov (United States)

    Karstedt, Jörg; Ogrzewalla, Jürgen; Severin, Christopher; Pischinger, Stefan

    In this work, the concept development, system layout, component simulation and the overall DOE system optimization of a HT-PEM fuel cell APU with a net electric power output of 4.5 kW and an onboard methane fuel processor are presented. A highly integrated system layout has been developed that enables fast startup within 7.5 min, a closed system water balance and high fuel processor efficiencies of up to 85% due to the recuperation of the anode offgas burner heat. The integration of the system battery into the load management enhances the transient electric performance and the maximum electric power output of the APU system. Simulation models of the carbon monoxide influence on HT-PEM cell voltage, the concentration and temperature profiles within the autothermal reformer (ATR) and the CO conversion rates within the watergas shift stages (WGSs) have been developed. They enable the optimization of the CO concentration in the anode gas of the fuel cell in order to achieve maximum system efficiencies and an optimized dimensioning of the ATR and WGS reactors. Furthermore a DOE optimization of the global system parameters cathode stoichiometry, anode stoichiometry, air/fuel ratio and steam/carbon ratio of the fuel processing system has been performed in order to achieve maximum system efficiencies for all system operating points under given boundary conditions.

  18. Green Propulsion Auxiliary Power Unit Demonstration at MSFC

    Science.gov (United States)

    Robinson, Joel W.; Beckel, Steve

    2014-01-01

    In 2012, the National Aeronautics & Space Administration (NASA) Space Technology Mission Directorate (STMD) began the process of building an integrated technology roadmap, including both technology pull and technology push strategies. Technology Area 1 (TA-01) for Launch Propulsion Systems is one of fourteen TA's that provide recommendations for the overall technology investment strategy and prioritization of NASA's space technology activities. Identified within TA-01 was the need for a green propulsion auxiliary power unit (APU) for hydraulic power by 2015. Engineers led by the author at the Marshall Space Flight Center (MSFC) have been evaluating green propellant alternatives and have begun the development of an APU testbed to demonstrate the feasibility of use. NASA has residual APU assets remaining from the retired Space Shuttle Program. Likewise, the F-16 Falcon fighter jet also uses an Emergency Power Unit (EPU) that has similar characteristics to the NASA hardware. Both EPU's and APU components have been acquired for testing at MSFC. In concert with this effort, ATK has been developing green propellant technology based on the Swedish Space Corp ECAPS LMP-103S propellant. Propellant blending and test facilities have been established at ATK's Elkton MD facility with the intent to provide suitable propellant blends for application to green APU systems as well as thrusters. This paper will summarize the status of the testing efforts with ATK for use of the green propellant LMP-103S based on ammonium dinitramide and use of the Air Force Research Laboratory (AFRL) propellant AF-M315E based on hydroxyl ammonium nitrate with these test assets.

  19. Model-based prediction of suitable operating range of a SOFC for an Auxiliary Power Unit

    Science.gov (United States)

    Pfafferodt, Matthias; Heidebrecht, Peter; Stelter, Michael; Sundmacher, Kai

    This paper presents a one-dimensional steady state model of a solid oxide fuel cell (SOFC) to be used in an Auxiliary Power Unit (APU). The fuel cell is fed a prereformed gas from an external autothermic reformer. In addition to the three electrochemical reactions (reduction of oxygen at the cathode, oxidation of hydrogen and carbon monoxide at the anode) the water-gas shift reaction and the methane steam reforming reaction are taken into account in the anode channel. The model predicts concentrations and temperatures and uses an equivalent circuit approach to describe the current-voltage characteristics of the cell. The model equations are presented and their implementation into the commercial mathematical software FEMLAB is discussed. An application of this model is used to determine suitable operating parameters with respect to optimum performance and allowable temperature.

  20. Using auxiliary gas power for CCS energy needs in retrofitted coal power plants

    OpenAIRE

    Bashadi, Sarah O.; Herzog, Howard J.

    2011-01-01

    Adding post-combustion capture technology to existing coal-fired power plants is being considered as a near-term option for mitigating CO[subscript 2] emissions. To supply the thermal energy needed for CO[subscript 2] capture, much of the literature proposes thermal integration of the existing coal plant’s steam cycle with the capture process’ stripper reboiler. This paper examines the option of using an auxiliary natural gas turbine plant to meet the energetic demands of carbon capture and c...

  1. ASCERTAINMENT OF ELECTRIC-SUPPLY SCHEMES RELIABILITY FOR THE ATOMIC POWER PLANT AUXILIARIES

    Directory of Open Access Journals (Sweden)

    A. L. Starzhinskij

    2015-01-01

    Full Text Available The paper completes ascertainment of electrical-supply scheme reliability for the auxiliaries of a nuclear power plant. Thereat the author considers the system behavior during the block normal operation, carrying out current maintenance, and capital repairs in combination with initiating events. The initiating events for reactors include complete blackout, i.e. the loss of outside power supply (normal and reserve; emergency switching one of the working turbogenerators; momentary dumping the normal rating to the level of auxiliaries with seating the cutout valve of one turbo-generator. The combination of any initiating event with the repairing mode in case of one of the system elements failure should not lead to blackout occurrence of more than one system of the reliable power supply. This requirement rests content with the help of the reliable power supply system self-dependence (electrical and functional and the emergency power-supply operational autonomy (diesel generator and accumulator batteries.The reliability indicators of the power supply system for the nuclear power plant auxiliaries are the conditional probabilities of conjoined blackout of one, two, and three sections of the reliable power supply conditional upon an initiating event emerging and the blackout of one, two, and three reliable power-supply sections under the normal operational mode. Furthermore, they also are the blackout periodicity of one and conjointly two, three, and four sections of normal operation under the block normal operational mode. It is established that the blackout of one bus section of normal operation and one section of reliable power-supply system of the auxiliaries that does not lead to complete blackout of the plant auxiliaries may occur once in three years. The probability of simultaneous power failure of two or three normal-operation sections and of two reliable power-supply sections during the power plant service life is unlikely.

  2. Development and implementation of thermal signature testing protocol of auxiliary power unit (APU) and diesel tractor

    Science.gov (United States)

    Jenkins, Chelsea L.; Bourne, Stefanie M.; Rowley, Matthew J.; Miles, Jonathan J.

    2004-04-01

    Thermal signature may be one of the defining factors in determining the applicability of fuel cell auxiliary power unit (APU) technology in military applications. Thermal characterization is important for military applications given that identification and detection may be accomplished through observation of its thermal signature. The operating modes and power takeoff operations of a vehicle will likely determine the thermal profile. The objective of our study was to develop and implement a protocol for quantifying the thermal characteristics of a methanol fuel cell and an idling tractor engine under representative characteristic operations. APU thermal characteristics are a special case for which standardized testing procedures do not presently exist. A customized testing protocol was developed and applied that is specific to an APU-equipped vehicle. Initial testing was conducted on the methanol APU-equipped Freightliner tractor using a high-performance radiometric infrared system. The APU profile calls for a series of infrared images to be collected at three different viewing angles and two different elevations under various loads. The diesel engine was studied in a similar fashion using seven different viewing angles and two different elevations. Raw data collected according to the newly developed methodology provided the opportunity for computer analysis and thermal profiling of both the fuel cell and the diesel engine.

  3. Strategic analysis of a manufacturing company and the North American auxiliary power unit market

    OpenAIRE

    Fisher, Craig B.

    2005-01-01

    Power Systems has been the leader in the truck auxiliary power unit business since 2000 and has been making significant advancements in the price of the product as well as its reliability and robustness. Unfortunately the reliability and robustness requirement is increasing further and the profit margin is shrinking to the point that Power Systems needs to undertake a new product development program. The new product offering will result in zero increase in the price to the customer but provid...

  4. Performance of turbine auxiliaries and service systems at Rajasthan Atomic Power Station

    International Nuclear Information System (INIS)

    Performance of the turbine auxiliaries and service systems at the Rajasthan Atomic Power Station, India are described. Some of the specific problems encountered in connection with the feed water, turbine governing and common services like compressed air, chilled water, water treatment and chlorination systems are outlined. (K.B.)

  5. Power Conversion System Strategies for Fuel Cell Vehicles

    Institute of Scientific and Technical Information of China (English)

    Kaushik Rajashekara

    2005-01-01

    Power electronics is an enabling technology for the development of environmental friendly fuel cell vehicles, and to implement the various vehicle electrical architectures to obtain the best performance. In this paper, power conversion strategies for propulsion and auxiliary power unit applications are described. The power electronics strategies for the successful development of the fuel cell vehicles are presented. The fuel cell systems for propulsion and for auxiliary power unit applications are also discussed.

  6. Equipment Reliability Improvement for Koeberg Nuclear Power Plant Auxiliary Feedwater System

    International Nuclear Information System (INIS)

    This paper investigated how the performance of the Koeberg Auxiliary Feedwater System could be improved using the 'maintenance rule'. As a conclusion, this paper figured out AFWS pumps and the TDP control circuit need special attention in improving the reliability of the AFWS, this lead to an improved maintenance strategy for the system. The purpose of this study is to apply maintenance rule to enhance the Auxiliary Feedwater System (AFWS) maintenance strategy at Koeberg Nuclear Power Plant (KNPP). Currently, Koeberg AFWS health status is red, needing an improvement. This study seeks to use maintenance rule to identify components that enable AFWS to fulfill its essential functions so as to focus maintenance resources and have the greatest beneficial impact on improving reliability and availability of the system

  7. IEC 61850. Integrated supervision of auxiliary power equipment; IEC 61850. Prozess und Eigenbedarf wachsen zusammen

    Energy Technology Data Exchange (ETDEWEB)

    Ostertag, Robert; Jung, Matthias [Siemens AG, Erlangen (Germany)

    2009-07-01

    It is state of technology today: Having process control and auxiliary power control integrated in one DCS. The integration is based on the international standard IEC 61850 which allows standardization of electrical structures from the process interface up to the DCS level. Modern control systems are designed to realize a system structure according to IEC 61850. A wide range of systems is available from systems with interfaces to realize a standardized data exchange up to systems with a complete integration of the standard IEC 61850. (orig.)

  8. STS-31 Discovery, OV-103, auxiliary power unit 1 (APU-1) controller

    Science.gov (United States)

    1990-01-01

    The controller for Discovery's, Orbiter Vehicle (OV) 103's, auxiliary power unit 1 (APU-1) is documented before removal following the launch scrub on 04-10-90. The controller weighs about 15 pounds and controls the speed of the APU. It was flown to the vendor, Sundstrand Corp., Rockford, Illinois, for analysis and testing. Launch of OV-103 on mission STS-31 has been rescheduled for 04-24-90 following the successful replacement of the APU-1 and the recharging of the Hubble Space Telescope's (HST's) nickel-hydrogen batteries. View provided by the Kennedy Space Center (KSC) with alternate KSC number KSC-90PC-663.

  9. Diesel Fueled SOFC for Class 7/Class 8 On-Highway Truck Auxiliary Power

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, Charles John-Paul [Cummins Power Generation; Fuchs, Benjamin S. [Cummins Power Generation; Booten, Chuck W. [Protonex Technology, LLC

    2010-03-31

    The following report documents the progress of the Cummins Power Generation (CPG) Diesel Fueled SOFC for Class 7/Class 8 On-Highway Truck Auxiliary Power (SOFC APU) development and final testing under the U.S. Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) contract DE-FC36-04GO14318. This report overviews and summarizes CPG and partner development leading to successful demonstration of the SOFC APU objectives and significant progress towards SOFC commercialization. Significant SOFC APU Milestones: Demonstrated: Operation meeting SOFC APU requirements on commercial Ultra Low Sulfur Diesel (ULSD) fuel. SOFC systems operating on dry CPOX reformate. Successful start-up and shut-down of SOFC APU system without inert gas purge. Developed: Low cost balance of plant concepts and compatible systems designs. Identified low cost, high volume components for balance of plant systems. Demonstrated efficient SOFC output power conditioning. Demonstrated SOFC control strategies and tuning methods.

  10. Fuel Cell and Battery Powered Forklifts

    DEFF Research Database (Denmark)

    Zhang, Zhe; Mortensen, Henrik H.; Jensen, Jes Vestervang;

    2013-01-01

    A hydrogen-powered materials handling vehicle with a fuel cell combines the advantages of diesel/LPG and battery powered vehicles. Hydrogen provides the same consistent power and fast refueling capability as diesel and LPG, whilst fuel cells provide energy efficient and zero emission Electric...... propulsion similar to batteries. In this paper, the performance of a forklift powered by PEM fuel cells and lead acid batteries as auxiliary energy source is introduced and investigated. In this electromechanical propulsion system with hybrid energy/power sources, fuel cells will deliver average power...

  11. 75 FR 3622 - Revisions to Rules Authorizing the Operation of Low Power Auxiliary Stations in the 698-806 MHz...

    Science.gov (United States)

    2010-01-22

    .... The Commission will assist consumers, including those who have previously purchased wireless... Street, SW., Room CY-A257, Washington, DC 20554. It also may be purchased from the Commission's... option, notify any entity operating low power auxiliary stations of its intention to initiate...

  12. Auxiliary power unit noise of Boeing B737 and B747 aircraft

    Science.gov (United States)

    Kwan, Jimmy S. W.; Yang, S. J. Eric

    Most modern civil aircraft have an Auxiliary Power Unit (APU) which provides compressed air for engine starting and the air-conditioning system on ground and electrical power for aircraft use both on-ground and in-fligth. It is basically a gas turbine engine and it consists of a compressor section, a turbine section, and an accessory drive section. For Boeing B737 and B747 aircraft, the APU is located inside a compartment in the tail section of the aircraft and is completely enclosed by a sound-reduction fire-proof titanium shroud. APU noise is one of the major noise sources at many airports and is extremely important for a densely populated city such as Hong Kong. The noise from APU can affect many people, including ground crew aircraft maintenance staff, and people living in the vicinity of the airport. However, there is very little information available in the literature about APU noise. This paper describes the noise measurement method and presents the measurement results for APUs of one B747 and two B737 aircraft under both 'loaded' and 'no-load' conditions.

  13. Electric power plant technology. Generators, transformers, auxiliary installations, protective systems. Lecture notes. 5. rev. ed.; Elektrische Kraftwerkstechnik. Generatoren, Transformatoren, Eigenbedarfsanlagen, Schutzeinrichtungen. Vorlesungsskript

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Ulrich

    2009-07-01

    The lecture series on electric power plant engineering was initiated in 1969 by Prof. Helmut Schaefer, founder of the then department of power economy and power plant engineering. The lecture series was continuously updated in its contents and didactic approach, e.g. by integrating innovative power generation concepts like micro cogeneration plants and fuel cell systems. The focus is on the fundamentals and function of generators, main transformers, auxiliary installations and protective systems in power plant. Apart from the electrotechnical aspects, also aspects of mechanical engineering are gone into. Also discussed are energy conversion concepts fo renewable power generation plants like wind turbines and PV systems. This is the 5th, completely revised edition. It addresses primarily attendants of the lectures but may also serve as a textbook and reference manual for interested experts.

  14. Optimization of Fuel Consumption and Emissions for Auxiliary Power Unit Based on Multi-Objective Optimization Model

    OpenAIRE

    Yongpeng Shen; Zhendong He; Dongqi Liu; Binjie Xu

    2016-01-01

    Auxiliary power units (APUs) are widely used for electric power generation in various types of electric vehicles, improvements in fuel economy and emissions of these vehicles directly depend on the operating point of the APUs. In order to balance the conflicting goals of fuel consumption and emissions reduction in the process of operating point choice, the APU operating point optimization problem is formulated as a constrained multi-objective optimization problem (CMOP) firstly. The four comp...

  15. Novel high power impulse magnetron sputtering enhanced by an auxiliary electrical field

    Science.gov (United States)

    Li, Chunwei; Tian, Xiubo

    2016-08-01

    The high power impulse magnetron sputtering (HIPIMS) technique is a novel highly ionized physical vapor deposition method with a high application potential. However, the electron utilization efficiency during sputtering is rather low and the metal particle ionization rate needs to be considerably improved to allow for a large-scale industrial application. Therefore, we enhanced the HIPIMS technique by simultaneously applying an electric field (EF-HIPIMS). The effect of the electric field on the discharge process was studied using a current sensor and an optical emission spectrometer. Furthermore, the spatial distribution of the electric potential and electric field during the EF-HIPIMS process was simulated using the ANSYS software. The results indicate that a higher electron utilization efficiency and a higher particle ionization rate could be achieved. The auxiliary anode obviously changed the distribution of the electric potential and the electric field in the discharge region, which increased the plasma density and enhanced the degree of ionization of the vanadium and argon gas. Vanadium films were deposited to further compare both techniques, and the morphology of the prepared films was investigated by scanning electron microscopy. The films showed a smaller crystal grain size and a denser growth structure when the electric field was applied during the discharge process.

  16. Novel high power impulse magnetron sputtering enhanced by an auxiliary electrical field.

    Science.gov (United States)

    Li, Chunwei; Tian, Xiubo

    2016-08-01

    The high power impulse magnetron sputtering (HIPIMS) technique is a novel highly ionized physical vapor deposition method with a high application potential. However, the electron utilization efficiency during sputtering is rather low and the metal particle ionization rate needs to be considerably improved to allow for a large-scale industrial application. Therefore, we enhanced the HIPIMS technique by simultaneously applying an electric field (EF-HIPIMS). The effect of the electric field on the discharge process was studied using a current sensor and an optical emission spectrometer. Furthermore, the spatial distribution of the electric potential and electric field during the EF-HIPIMS process was simulated using the ANSYS software. The results indicate that a higher electron utilization efficiency and a higher particle ionization rate could be achieved. The auxiliary anode obviously changed the distribution of the electric potential and the electric field in the discharge region, which increased the plasma density and enhanced the degree of ionization of the vanadium and argon gas. Vanadium films were deposited to further compare both techniques, and the morphology of the prepared films was investigated by scanning electron microscopy. The films showed a smaller crystal grain size and a denser growth structure when the electric field was applied during the discharge process.

  17. Novel high power impulse magnetron sputtering enhanced by an auxiliary electrical field.

    Science.gov (United States)

    Li, Chunwei; Tian, Xiubo

    2016-08-01

    The high power impulse magnetron sputtering (HIPIMS) technique is a novel highly ionized physical vapor deposition method with a high application potential. However, the electron utilization efficiency during sputtering is rather low and the metal particle ionization rate needs to be considerably improved to allow for a large-scale industrial application. Therefore, we enhanced the HIPIMS technique by simultaneously applying an electric field (EF-HIPIMS). The effect of the electric field on the discharge process was studied using a current sensor and an optical emission spectrometer. Furthermore, the spatial distribution of the electric potential and electric field during the EF-HIPIMS process was simulated using the ANSYS software. The results indicate that a higher electron utilization efficiency and a higher particle ionization rate could be achieved. The auxiliary anode obviously changed the distribution of the electric potential and the electric field in the discharge region, which increased the plasma density and enhanced the degree of ionization of the vanadium and argon gas. Vanadium films were deposited to further compare both techniques, and the morphology of the prepared films was investigated by scanning electron microscopy. The films showed a smaller crystal grain size and a denser growth structure when the electric field was applied during the discharge process. PMID:27587123

  18. A CAE package for design of auxiliary buildings in nuclear power plants

    International Nuclear Information System (INIS)

    Nuclear power plants have a large number of auxiliary buildings housing various services and control systems in addition to the main reactor building. These are usually of the framed construction of two or three floors falling under seismic class I or II. Class I structures have to be qualified for seismic forces of intensity as given by SSE (safe shutdown earthquake) for three orthogonal components acting simultaneously while class II structures need to be qualified for seismic forces of intensity as given by OBE (operating basis earthquake) for two component motion-one horizontal and one vertical acting simultaneously. The seismic analysis of these buildings is carried out using the BLOCK model. For the analysis of three component motion, USNRC R.G. 1.92 permits time history method of analysis and timewise combination of responses of the three components in the proper phases. However, such a method of analysis is uneconomical for the buildings in question, more so when the layouts of such buildings during the planning phases undergo quite a few revisions necessitating reanalysis. As such, the response spectrum method of analysis is adopted for each directional component and the responses to the three component excitation are combined by adopting the SRSS criteria

  19. Fuel handling machine and auxiliary systems for a fuel handling cell

    International Nuclear Information System (INIS)

    This working report is an update for as well as a supplement to an earlier fuel handling machine design (Kukkola and Roennqvist 2006). A focus in the earlier design proposal was primarily on the selection of a mechanical structure and operating principle for the fuel handling machine. This report introduces not only a fuel handling machine design but also auxiliary fuel handling cell equipment and its operation. An objective of the design work was to verify the operating principles of and space allocations for fuel handling cell equipment. The fuel handling machine is a remote controlled apparatus capable of handling intensely radiating fuel assemblies in the fuel handling cell of an encapsulation plant. The fuel handling cell is air tight space radiation-shielded with massive concrete walls. The fuel handling machine is based on a bridge crane capable of traveling in the handling cell along wall tracks. The bridge crane has its carriage provided with a carousel type turntable having mounted thereon both fixed and telescopic masts. The fixed mast has a gripper movable on linear guides for the transfer of fuel assemblies. The telescopic mast has a manipulator arm capable of maneuvering equipment present in the fuel handling cell, as well as conducting necessary maintenance and cleaning operations or rectifying possible fault conditions. The auxiliary fuel handling cell systems consist of several subsystems. The subsystems include a service manipulator, a tool carrier for manipulators, a material hatch, assisting winches, a vacuum cleaner, as well as a hose reel. With the exception of the vacuum cleaner, the devices included in the fuel handling cell's auxiliary system are only used when the actual encapsulation process is not ongoing. The malfunctions of mechanisms or actuators responsible for the motion actions of a fuel handling machine preclude in a worst case scenario the bringing of the fuel handling cell and related systems to a condition appropriate for

  20. Fuel handling machine and auxiliary systems for a fuel handling cell

    Energy Technology Data Exchange (ETDEWEB)

    Suikki, M. [Optimik Oy, Turku (Finland)

    2013-10-15

    This working report is an update for as well as a supplement to an earlier fuel handling machine design (Kukkola and Roennqvist 2006). A focus in the earlier design proposal was primarily on the selection of a mechanical structure and operating principle for the fuel handling machine. This report introduces not only a fuel handling machine design but also auxiliary fuel handling cell equipment and its operation. An objective of the design work was to verify the operating principles of and space allocations for fuel handling cell equipment. The fuel handling machine is a remote controlled apparatus capable of handling intensely radiating fuel assemblies in the fuel handling cell of an encapsulation plant. The fuel handling cell is air tight space radiation-shielded with massive concrete walls. The fuel handling machine is based on a bridge crane capable of traveling in the handling cell along wall tracks. The bridge crane has its carriage provided with a carousel type turntable having mounted thereon both fixed and telescopic masts. The fixed mast has a gripper movable on linear guides for the transfer of fuel assemblies. The telescopic mast has a manipulator arm capable of maneuvering equipment present in the fuel handling cell, as well as conducting necessary maintenance and cleaning operations or rectifying possible fault conditions. The auxiliary fuel handling cell systems consist of several subsystems. The subsystems include a service manipulator, a tool carrier for manipulators, a material hatch, assisting winches, a vacuum cleaner, as well as a hose reel. With the exception of the vacuum cleaner, the devices included in the fuel handling cell's auxiliary system are only used when the actual encapsulation process is not ongoing. The malfunctions of mechanisms or actuators responsible for the motion actions of a fuel handling machine preclude in a worst case scenario the bringing of the fuel handling cell and related systems to a condition appropriate for

  1. Experimental simulation of a light aircraft crash on to a nuclear power plant auxiliary building roof

    International Nuclear Information System (INIS)

    The experiments described were conducted at a reduced scale with geometric dimensions of prototype structures of one-fifth full size. The target was based on the auxiliary buildings for the proposed Sizewell PWR. Descriptions of the simulated aircraft model and the test panels are given, together with the instrumentation. Details are given of the test programme and the results are summarized and discussed. Comparison is made of the model aircraft tests with an equivalent hard missile impact. (U.K.)

  2. Holistic Modeling, Design & Analysis of Integrated Stirling and Auxiliary Clean Energy Systems for Combined Heat and Power Applications

    Science.gov (United States)

    Nayak, Amrit Om

    The research revolves around the development of a model to design and analyze Stirling systems. Lack of a standard approach to study Stirling systems and difficulty in generalizing existing approaches pose stiff challenges. A stable mathematical model (integrated second order adiabatic and dynamic model) is devised and validated for general use. The research attempts to design compact combined heat and power (CHP) system to run on multiple biomass fuels and solar energy. Analysis is also carried out regarding the design of suitable auxiliary systems like thermal energy storage system, biomass moisture removal system and Fresnel solar collector for the CHP Stirling system.

  3. Preliminary safety analysis report for the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    OSCAR,DEBBY S.; WALKER,SHARON ANN; HUNTER,REGINA LEE; WALKER,CHERYL A.

    1999-12-01

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) will be a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material and waste for reuse, recycling, or ultimate disposal. A significant upgrade to a previous facility, the Temporary Hot Cell, will be implemented to perform this mission. The following major features will be added: a permanent shield wall; eight floor silos; new roof portals in the hot-cell roof; an upgraded ventilation system; and upgraded hot-cell jib crane; and video cameras to record operations and facilitate remote-handled operations. No safety-class systems, structures, and components will be present in the AHCF. There will be five safety-significant SSCs: hot cell structure, permanent shield wall, shield plugs, ventilation system, and HEPA filters. The type and quantity of radionuclides that could be located in the AHCF are defined primarily by SNL/NM's legacy materials, which include radioactive, transuranic, and mixed waste. The risk to the public or the environment presented by the AHCF is minor due to the inventory limitations of the Hazard Category 3 classification. Potential doses at the exclusion boundary are well below the evaluation guidelines of 25 rem. Potential for worker exposure is limited by the passive design features incorporated in the AHCF and by SNL's radiation protection program. There is no potential for exposure of the public to chemical hazards above the Emergency Response Protection Guidelines Level 2.

  4. Preliminary safety analysis report for the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico

    International Nuclear Information System (INIS)

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) will be a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material and waste for reuse, recycling, or ultimate disposal. A significant upgrade to a previous facility, the Temporary Hot Cell, will be implemented to perform this mission. The following major features will be added: a permanent shield wall; eight floor silos; new roof portals in the hot-cell roof; an upgraded ventilation system; and upgraded hot-cell jib crane; and video cameras to record operations and facilitate remote-handled operations. No safety-class systems, structures, and components will be present in the AHCF. There will be five safety-significant SSCs: hot cell structure, permanent shield wall, shield plugs, ventilation system, and HEPA filters. The type and quantity of radionuclides that could be located in the AHCF are defined primarily by SNL/NM's legacy materials, which include radioactive, transuranic, and mixed waste. The risk to the public or the environment presented by the AHCF is minor due to the inventory limitations of the Hazard Category 3 classification. Potential doses at the exclusion boundary are well below the evaluation guidelines of 25 rem. Potential for worker exposure is limited by the passive design features incorporated in the AHCF and by SNL's radiation protection program. There is no potential for exposure of the public to chemical hazards above the Emergency Response Protection Guidelines Level 2

  5. Aging and service wear of auxiliary feedwater pumps for PWR nuclear power plants

    International Nuclear Information System (INIS)

    This paper describes investigations on auxiliary feedwater pumps being done under the Nuclear Plant Aging Research (NPAR) Program. Objectives of these studies are: to identify and evaluate practical, cost-effective methods for detecting, monitoring, and assessing the severity of time-dependent degradation (aging and service wear); recommend inspection and maintenance practices; establish acceptance criteria; and help facilitate use of the results. Emphasis is given to identifying and assessing methods for detecting failure in the incipient stage and to developing degradation trends to allow timely maintenance, repair or replacement actions. 3 refs

  6. Operation auxiliary system (SAO)

    International Nuclear Information System (INIS)

    This work presents an auxiliary system for nuclear power plants operation (SAO). The development purpose consisted in a computing supervision system to be installed at different sites of a reactor, mainly in the control room. The inclusion of this system to a nuclear power plant minimizes the possibility of human error for the facility operation. (Author)

  7. Sensitivity Analysis of Core Damage by Loss of Auxiliary Feed Water during the Extended Loss of All AC Power

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Woo Jae; Chung, Soon Il; Hwang, Su Hyun; Lee, Kyung Jin; Lee, Byung Chul [FNC Tech., Yongin (Korea, Republic of); Yun, Duk Joo; Lee, Seung Chan [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

    2015-10-15

    In this study, the reactor core damage time for OPR1000 type Nuclear Power Plant (NPP) was analyzed to develop a strategy to handle ELAP and to apply to the EOP. The reactor core damage time in the ELAP condition was calculated according to the time of Auxiliary Feedwater (AFW) loss. Fukushima accident was caused by long hours of Station Black Out (SBO) caused by natural disaster beyond Design Based Accident (DBA) criteria. It led to the reactor core damage. After the accident, the regulatory authorities of each country (Japan, US, EU, IAEA, and etc.) recommended developing the necessary systems and strategies in order to cover up the Extended Loss of All AC Power (ELAP) such as one occurred in the Fukushima accident. And the need of procedure or guideline to cope with ELAP has been raised through the stress test for Wolsong Nuclear Power Plant unit 1. Current Emergency Operating Procedures (EOP) used in domestic nuclear power plant are seemed to be insufficient to cope with ELAP. Therefore, it has been required to be improved. As the result, the time of AFW loss in the ELAP condition influences greatly on core damage time.

  8. Auxiliary systems

    International Nuclear Information System (INIS)

    For a undisturbed reactor operation, the various Auxiliary and Ancillary Systems must function perfectly with the Reactor Coolant System together. While the Auxiliary Systems are directly connected to the Reactor Coolant System and therefore have contact with the Reactor Coolant, the Ancillary Systems perform tasks which do not directly influence reactor operation and in part are necessary exclusively for environment protection. The design criteria of the individual systems are a result of these tasks, especially in relation to availability, operational readiness and probability of failure. (orig.)

  9. Investigations in the modelling and control of a medium voltage hybrid inverter system that uses a low voltage /low power rated auxiliary current source inverter

    OpenAIRE

    Papadopoulos, Savvas; Rashed, Mohamed; Klumpner, Christian; Wheeler, Patrick

    2016-01-01

    Hybrid converters consist of a main inverter processing the bulk of the power with poor waveform performance and a fast and versatile auxiliary inverter to correct the distortion. In this paper, the main converter is a medium voltage NPC inverter and the auxiliary inverter is a low-voltage and low-current rated current source inverter (CSI), with series capacitor being used to minimize the CSI voltage stress. The result is a high output current quality which is obtained with a very low switch...

  10. Optimization of Fuel Consumption and Emissions for Auxiliary Power Unit Based on Multi-Objective Optimization Model

    Directory of Open Access Journals (Sweden)

    Yongpeng Shen

    2016-02-01

    Full Text Available Auxiliary power units (APUs are widely used for electric power generation in various types of electric vehicles, improvements in fuel economy and emissions of these vehicles directly depend on the operating point of the APUs. In order to balance the conflicting goals of fuel consumption and emissions reduction in the process of operating point choice, the APU operating point optimization problem is formulated as a constrained multi-objective optimization problem (CMOP firstly. The four competing objectives of this CMOP are fuel-electricity conversion cost, hydrocarbon (HC emissions, carbon monoxide (CO emissions and nitric oxide (NO x emissions. Then, the multi-objective particle swarm optimization (MOPSO algorithm and weighted metric decision making method are employed to solve the APU operating point multi-objective optimization model. Finally, bench experiments under New European driving cycle (NEDC, Federal test procedure (FTP and high way fuel economy test (HWFET driving cycles show that, compared with the results of the traditional fuel consumption single-objective optimization approach, the proposed multi-objective optimization approach shows significant improvements in emissions performance, at the expense of a slight drop in fuel efficiency.

  11. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100 M Wt, about 25 M We). CAREM design is based on light water integrated reactor with slightly enriched uranium. In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented. Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor. (author)

  12. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100MWt, about 25MWe).CAREM design is based on light water integrated reactor with slightly enriched uranium.In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented.Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor

  13. Mechanical (turbines and auxiliary equipment)

    CERN Document Server

    Sherry, A; Cruddace, AE

    2013-01-01

    Modern Power Station Practice, Volume 3: Mechanical (Turbines and Auxiliary Equipment) focuses on the development of turbines and auxiliary equipment used in power stations in Great Britain. Topics covered include thermodynamics and steam turbine theory; turbine auxiliary systems such as lubrication systems, feed water heating systems, and the condenser and cooling water plants. Miscellaneous station services, and pipework in power plants are also described. This book is comprised of five chapters and begins with an overview of thermodynamics and steam turbine theory, paying particular attenti

  14. Design Considerations for a PEM Fuel Cell Powered Truck APU

    OpenAIRE

    Grupp, David J; Forrest, Matthew E.; Mader, Pippin G.; Brodrick, Christie-Joy; Miller, Marshall; Dwyer, Harry A.

    2004-01-01

    In recent years interest has been growing in using fuel cell powered auxiliary power units (APUs) to reduce idling in line-haul trucks. Demonstrations of this technology have been constructed at universities and within industry, each with its own advantages and disadvantages. Invariably, in every design, tradeoffs need to be made and this has resulted in a multitude of different APU solutions that address different aspects of the problem. This paper reviews some of the recent work re...

  15. French wind generator systems. [as auxiliary power sources for electrical networks

    Science.gov (United States)

    Noel, J. M.

    1973-01-01

    The experimental design of a wind driven generator with a rated power of 800 kilovolt amperes and capable of being connected to the main electrical network is reported. The rotor is a three bladed propeller; each blade is twisted but the fixed pitch is adjustable. The asynchronous 800-kilovolt ampere generator is driven by the propeller through a gearbox. A dissipating resistor regulates the machine under no-load conditions. The first propeller on the machine lasted 18 months; replacement of the rigid propeller with a flexible structure resulted in breakdown due to flutter effects.

  16. CRH2型动车组辅助电源系统故障分析%Fault analysis of auxiliary power system in CRH2 bullet train

    Institute of Scientific and Technical Information of China (English)

    李向超; 王亦军

    2013-01-01

    探讨了300 km速度级CRH2C型动车组辅助电源系统的供电电压、工作原理以及内部构成。针对CRH2C型动车组辅助电源系统的常见故障,分析了故障发生的原因,并提出了有效的应急处理措施。%The supply voltage, working principle and internal structure of auxiliary power supply system in 300 km/h grade CRH2C bullet train are discussed. The common fault causes of auxiliary power supply system in CRH2C bullet train are analyzed. The effective emergent measures for the fault treatment are put forward.

  17. Performance Based Logistics (PBL) for the FA-18/S-3/P-3/C-2 auxiliary power unit (APU) at Honeywell: an applied analysis

    OpenAIRE

    Landreth, Clifford J.; Corporon, Laura L.; Wilhelm, Richard H.

    2005-01-01

    The purpose of this MBA project is to evaluate and assess the metrics, incentives and other terms and conditions of the Performance Based Logistics (PBL) contract between Naval Aviation Inventory Control Point (NAVICP) and Honeywell in support of FA-18/S-3/P-3/C-2 Auxiliary Power Unit (APU) to determine if the contractual terms and conditions established are effective in facilitating and encouraging the full potential of PBL savings and improved performance. PBL is an acquisition reform initi...

  18. 发电厂高压厂用电系统的安全与稳定性研究%Study on Security and Stability of High Voltage Auxiliary Power System of Power Plant

    Institute of Scientific and Technical Information of China (English)

    黄亚军; 杨开黎; 姜平

    2012-01-01

    The supercritical capacity units are popularized in China now, the security and stability of high voltage auxiliary power system of power plant need to be taken into account when designing the auxiliary power system. This paper discusses some detailed questions of designing the auxiliary power system from four aspects of the voltage level choice, choosing neutral ground of auxiliary power system, relay protection, integration multi-function relay protection applying, electrical source quick switch device. The purpose of the paper is to provide basis for improving the security and stability of high voltage auxiliary power system of supercritical capacity thermal power plant, nuclear power plant and hydro-power station.%随着超临界大容量机组的普及,发电厂高压厂用电系统在设计时需要考虑其安全与稳定性方面的问题.本文分别从厂用电电压等级选择、厂用电系统中性点接地方式的选择、厂用电的继电保护、集成化的多功能综合继电保护装置的应用及厂用电电源快切装置发展等方面,论述了厂用电系统优化设计时需要注意的一些细节问题,为提高大型火电、核电、水电发电厂厂用电系统的安全与稳定性奠定了基础.

  19. Determination of power and power descriptions at walking with auxiliary facilities of pushing (by sticks away from lower support

    Directory of Open Access Journals (Sweden)

    Adashevskiy V.M.

    2012-04-01

    Full Text Available A purpose of work is a design of motions in Nordic walking, and analysis of power and power descriptions of motion. The basic aspects of walking with sticks and their influence on quality of life of people of different age are considered. Directions of the use of physical exercises for the people of senior age are selected. Possibilities of the use of walking in the physical rehabilitation of patients and people with a hyposthenic health is shown. It is set that, walking extend the use of models of Nordic possibility of leadthrough of researches and theoretical ground for more deep study of features of such type of movements. It is marked that the model of motion is expedient to utillize in combination with cinegram walking and by the indexes of dynamometry. It is recommended at lowering to observe the rules of technique of motion and safety.

  20. Optimization of relay protection for a auxiliary power system%厂用电系统继电保护优化

    Institute of Scientific and Technical Information of China (English)

    李子峰

    2015-01-01

    基于对厂用电系统继电保护中存在的配置不完整、后备保护动作时间过长等问题的分析,提出了配置6 kV 母线专用主保护、在低压厂用电系统变压器高压侧增加限时电流速断保护装置、优化后备保护之间配合的方案,并以此对厂用电系统的继电保护配置进行了优化,以600 MW机组为例,进行了保护整定计算,结果表明,优化后的厂用电系统继电保护配置完整,保护范围合理,后备保护动作时间显著缩短。从而,提高了厂用电系统继电保护动作的快速性和厂用电系统运行安全性。%On the basis of analysis on some questions of relay protection in auxiliary power systems,like the imperfection in configuration and the actuation time is too long,a scheme was proposed for relay protection design,such as configuring a specialized main protection for 6 kV busbar,adding a time limited current fast-trip protection on the high-voltage side of low-voltage transformers in auxiliary power system,optimizing the cooperation of reserve protections and then designing the configuration of relay protection in auxiliary power system according to the optimizing rule.Taking a 600 MW unit as the example,settings calculation was carried out.The results proved that the configuration of relay protection in auxiliary power system is integrated perfectly due to the optimization,the coverage of protection is reasonable and the actuation time of reserve protection has been remarkably shortened.Thus,the actuation speed and security of the auxiliary power system are promoted.

  1. Connection of auxiliary power supply to the power plant's main instrumentation and control system by way of IEC 61850; Anbindung des elektrischen Kraftwerks-Eigenbedarfs an die Hauptleittechnik mittels IEC 61850

    Energy Technology Data Exchange (ETDEWEB)

    Ciuches, Joerg [RWE Technology GmbH, Essen (Germany). Technical Project Management Project BoA 2 and 3; Wittner, Stephan [RWE Technology GmbH, Essen (Germany). Electrical Engineering

    2010-07-01

    Based on the positive experience with the integration of control and signalling of the auxiliary power supply switchgear into the I and C system SPPA-T-3000 of Siemens by way of the IEC 61850 protocol in the Neurath power plant F/G project, the concept was further advanced for the power plant new build projects of the Westfalen power plant at Hamm and the Eemshaven power station in the Netherlands. The development aimed to integrate all other components of auxiliary power supply, such as transformers, battery systems as well as rectifiers and inverters, directly into the main I and C system on the basis of the IEC 61850 protocol, apart from the medium-voltage and low-voltage switchgear. (orig.)

  2. Design and modeling of power system for a fuel cell hybrid switcher locomotive

    Energy Technology Data Exchange (ETDEWEB)

    Guo Liping, E-mail: lguo@niu.ed [Department of Engineering Technology, Northern Illinois University, DeKalb, IL 60115 (United States); Yedavalli, Karthik; Zinger, Donald [Department of Electrical Engineering, Northern Illinois University, DeKalb, IL 60115 (United States)

    2011-02-15

    This paper discusses the design and modeling of power system for a fuel cell hybrid locomotive. Different types of fuel cells for appropriate application to locomotives were compared, fuel cell and auxiliary storage devices were modeled, and a control strategy for the overall system was developed in this paper. By using the proposed control strategy, the power control system regulates the sharing of power demand between fuel cell and auxiliary storage units including batteries and ultracapacitors. Experimental data of the power duty cycle of a typical switcher locomotive is analyzed. The proposed control system is tested using the experimental data. Results show that the control system is able to maintain output voltage from different power sources within a certain range, keep the state of charge of the batteries within an optimal range and meet power demand of the locomotive at a high efficiency.

  3. Design and modeling of power system for a fuel cell hybrid switcher locomotive

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Liping [Department of Engineering Technology, Northern Illinois University, DeKalb, IL 60115 (United States); Yedavalli, Karthik; Zinger, Donald [Department of Electrical Engineering, Northern Illinois University, DeKalb, IL 60115 (United States)

    2011-02-15

    This paper discusses the design and modeling of power system for a fuel cell hybrid locomotive. Different types of fuel cells for appropriate application to locomotives were compared, fuel cell and auxiliary storage devices were modeled, and a control strategy for the overall system was developed in this paper. By using the proposed control strategy, the power control system regulates the sharing of power demand between fuel cell and auxiliary storage units including batteries and ultracapacitors. Experimental data of the power duty cycle of a typical switcher locomotive is analyzed. The proposed control system is tested using the experimental data. Results show that the control system is able to maintain output voltage from different power sources within a certain range, keep the state of charge of the batteries within an optimal range and meet power demand of the locomotive at a high efficiency. (author)

  4. Optimizationin Operational Analysis of Auxiliary Steam System in Thermal Power Plant%火力发电厂辅汽系统优化运行分析

    Institute of Scientific and Technical Information of China (English)

    王乃军; 白秀春; 王俊俊

    2015-01-01

    For choosing different steam source for the auxiliary steam system in Inner Mongolia Daihai Electric Power Generation Co.,Ltd., carry on the quantitative analysis to the influence of the unit efficiency, the result is the most economical when choosing No.4 extraction steam of second unit supplying, while slightly economical as using second unit cold reheater as first unit. According to the results of the analysis, it provides a theoretical basis and guidance for selecting the source of auxiliary steam in power plants, so as to achieve the purpose of saving energy and reducing consumption, improve the operation efficiency. At the same time, based on the actual operating mode, unit start-up and shutdown, accident conditions, combined with different seasons and temperature, auxiliary steam consumption, it proposes operation precautions.%对内蒙古岱海发电有限责任公司辅助蒸汽系统选择不同供汽汽源时,机组运行经济性受到的影响进行了定量分析,认为由二期机组四段抽汽供汽经济性最优,由二期机组冷段再热蒸汽供汽的经济性略优于由一期机组冷段再热蒸汽供汽。并结合机组实际运行方式、机组启停方式及机组发生事故时的运行情况等,根据不同季节环境温度及各辅汽用户用汽量情况,提出辅汽系统优化运行注意事项。

  5. 辅助动力装置建模及数值仿真%Model and numerical simulation of auxiliary power unit

    Institute of Scientific and Technical Information of China (English)

    常博博; 苏三买; 刘铁庚; 刘美凤

    2011-01-01

    In order to supporting auxiliary power unit(APU) design,the widely used APU with load compressor in structure was discussed and modeled.Firstly,the structural characteristics and regulation law are introduced and then how the load compressor works on APU was analyzed.Finally the mathematic model of APU was established based on components.Take a kind of APU as the object for numerical simulation and then compare with the actual test data.The results show that the dynamic simulation error is less than 5%.The mathematic model of APU is suitable for engineering usage.%为辅助APU(auxiliary power unit)的研发,以目前广泛应用的带负载压气机结构APU为研究对象,进行建模分析与研究.首先介绍了APU结构特点与调节规律,然后分析了负载压气机对APU共同工作的影响,最后采用部件法建立了该类型APU数学模型并设计仿真软件.以某型APU为对象,数值仿真与实际试车数据比较,结果表明所采用的建模方法是正确的,计算误差小于5%,所建立的模型能够满足工程需求.

  6. Analysis and Comparing of Urban Rail Locomotive Auxiliary System AC Power Supply Mode%城轨列车辅助系统交流供电方式的分析与比较

    Institute of Scientific and Technical Information of China (English)

    阎纯洁

    2015-01-01

    Through analyzing the urban rail locomotive auxiliary system AC power system supply mode, comparing the ad-vantages and disadvantages of general power supply mode and individual supply mode, prove accordance to urban rail auxil-iary system AC power supply mode selection.%通过对城轨列车辅助系统交流供电方式进行分析,比较集中供电方式和分散供电方式的各自优劣,为城轨列车辅助系统交流供电供电方式选型提供依据。

  7. Modeling, analysis and control of fuel cell hybrid power systems

    Science.gov (United States)

    Suh, Kyung Won

    Transient performance is a key characteristic of fuel cells, that is sometimes more critical than efficiency, due to the importance of accepting unpredictable electric loads. To fulfill the transient requirement in vehicle propulsion and portable fuel cell applications, a fuel cell stack is typically coupled with a battery through a DC/DC converter to form a hybrid power system. Although many power management strategies already exist, they all rely on low level controllers that realize the power split. In this dissertation we design controllers that realize various power split strategies by directly manipulating physical actuators (low level commands). We maintain the causality of the electric dynamics (voltage and current) and investigate how the electric architecture affects the hybridization level and the power management. We first establish the performance limitations associated with a stand-alone and power-autonomous fuel cell system that is not supplemented by an additional energy storage and powers all its auxiliary components by itself. Specifically, we examine the transient performance in fuel cell power delivery as it is limited by the air supplied by a compressor driven by the fuel cell itself. The performance limitations arise from the intrinsic coupling in the fluid and electrical domain between the compressor and the fuel cell stack. Feedforward and feedback control strategies are used to demonstrate these limitations analytically and with simulations. Experimental tests on a small commercial fuel cell auxiliary power unit (APU) confirm the dynamics and the identified limitations. The dynamics associated with the integration of a fuel cell system and a DC/DC converter is then investigated. Decentralized and fully centralized (using linear quadratic techniques) controllers are designed to regulate the power system voltage and to prevent fuel cell oxygen starvation. Regulating these two performance variables is a difficult task and requires a compromise

  8. On the Improvement of Grounding Protection and Cable Insulation of Auxiliary Power in Taishan Nuclear Power Plant%台山核电站厂用电接地保护及电缆绝缘的改进

    Institute of Scientific and Technical Information of China (English)

    张进

    2015-01-01

    Based on Taishan Nuclear Power Plant, this paper analyzed the necessary to set single-phase earth fault protection in MV power system and to improve MV cable insulation level due to the insulated neutral point of medium voltage auxiliary power system in nuclear power plant. The feedback is useful for the design of the subsequent nuclear power plant construction.%以台山核站为例,分析了在核电站中压厂用电系统中性点不接地的条件下,为中压负荷回路配置单相接地保护及提高中压电缆绝缘水平的必要性。对后续核电站的设计建设具有参考借鉴的作用。

  9. Auxiliary verbs in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2007-01-01

    Dinka, a Western Nilotic language, has a class of auxiliary verbs which is remarkable in the following four respects: (i) It is unusually large, comprising some 20 members; (ii) it is grammatically homogeneous in terms of both morphology and syntax; (iii) most of the auxiliary verbs correspond...... to adverbs in languages like English, while the rest are tense-aspect markers; and (iv) it is possible to combine several auxiliary verbs in a single clause. For some of the auxiliary verbs there are extant full verbs from which they have evolved. To some extent, therefore, it is possible to observe what...... semantic changes the auxiliary verbs have undergone or are undergoing during the process of grammaticalization....

  10. The Subsection Control Strategy Used for the Auxiliary Power Unit Electrical Start%应用于APU电起动的分段式控制策略

    Institute of Scientific and Technical Information of China (English)

    袁海宵

    2013-01-01

    The auxiliary power unit ( APU) is an important system of the civil aircraft for the aircraft safety and comfort. Large current output for long time will cause disadvantage effect on battery usage life. Also the too long start time will damage APU. So when start the APU by using the battery as the input power, for the purpose of re-ducing the damage to battery and APU, it is needed to start the APU in a shorter time by a lower battery output cur-rent. The subsection of power-current control strategy can start the APU in shorter time with the lowest damage to the battery and APU. This is important for extending the use life of APU and battery.%民用飞机辅助动力装置( APU)是保证飞机安全和舒适性的重要系统。大电流长时放电对蓄电池的使用寿命有不利影响,同时起动时间过长对APU也有不利影响。在使用蓄电池作为起动APU的功率来源时,为了减小对蓄电池和APU的损害,需要使用较小的蓄电池输出电流在较短的时间内将APU起动。采用功率-电流分段式控制的起动方式可以在较短的时间内,以对蓄电池和APU损伤最小的方式实现APU的起动。对延长蓄电池和APU使用寿命具有重要意义。

  11. Fuel Cell Powered Lift Truck

    Energy Technology Data Exchange (ETDEWEB)

    Moulden, Steve [Sysco Food Service, Houston, TX (United States)

    2015-08-20

    This project, entitled “Recovery Act: Fuel Cell-Powered Lift Truck Sysco (Houston) Fleet Deployment”, was in response to DOE funding opportunity announcement DE-PS36-08GO98009, Topic 7B, which promotes the deployment of fuel cell powered material handling equipment in large, multi-shift distribution centers. This project promoted large-volume commercialdeployments and helped to create a market pull for material handling equipment (MHE) powered fuel cell systems. Specific outcomes and benefits involved the proliferation of fuel cell systems in 5-to 20-kW lift trucks at a high-profile, real-world site that demonstrated the benefits of fuel cell technology and served as a focal point for other nascent customers. The project allowed for the creation of expertise in providing service and support for MHE fuel cell powered systems, growth of existing product manufacturing expertise, and promoted existing fuel cell system and component companies. The project also stimulated other MHE fleet conversions helping to speed the adoption of fuel cell systems and hydrogen fueling technology. This document also contains the lessons learned during the project in order to communicate the successes and difficulties experienced, which could potentially assist others planning similar projects.

  12. A reliability centered maintenance model applied to the auxiliary feedwater system of a nuclear power plant; Um modelo de manutencao centrada em confiabilidade aplicada ao sistema de agua de alimentacaco auxiliar de uma usina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jefferson Borges

    1998-01-15

    The main objective of maintenance in a nuclear power plant is to assure that structures, systems and components will perform their design functions with reliability and availability in order to obtain a safety and economic electric power generation. Reliability Centered Maintenance (RCM) is a method of systematic review to develop or optimize Preventive Maintenance Programs. This study presents the objectives, concepts, organization and methods used in the development of RCM application to nuclear power plants. Some examples of this application are included, considering the Auxiliary Feedwater System of a generic two loops PWR nuclear power plant of Westinghouse design. (author)

  13. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Science.gov (United States)

    2010-07-01

    ... auxiliary fan failure due to malfunction, accident, power failure, or other such unplanned or unscheduled... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed...

  14. Digital Control of a power conditioner for fuel cell/super-capacitor hybrid system

    DEFF Research Database (Denmark)

    Caballero, Juan C Trujillo; Gomis-Bellmunt, Oriol; Montesinos-Miracle, Daniel;

    2014-01-01

    This article proposes a digital control scheme to operate a proton exchange membrane fuel cell module of 1.2 kW and a super-capacitor through a DC/DC hybrid converter. A fuel cell has been proposed as a primary source of energy, and a super-capacitor has been proposed as an auxiliary source of...... energy. Experimental validation of the system implemented in the laboratory is provided. Several tests have been performed to verify that the system achieves excellent output voltage (V0) regulation and super-capacitor voltage (V SC) control under disturbances from fuel cell power (PFC) and output power...

  15. Resolution of concerns in auxiliary feedwater piping

    International Nuclear Information System (INIS)

    Auxiliary feedwater piping systems at pressurized water reactor (PWR) nuclear power plants have experienced unanticipated operating conditions during plant operation. These unanticipated conditions have included plant events involving backleakage through check valves, temperatures in portions of the auxiliary feedwater piping system that exceed design conditions, and the occurrence of unanticipated severe fluid transients. The impact of these events has had an adverse effect at some nuclear stations on plant operation, installed plant components and hardware, and design basis calculations. Beaver Valley Unit 2, a three loop pressurized water reactor nuclear plant, has observed anomalies with the auxiliary feedwater system since the unit went operational in 1987. The consequences of these anomalies and plant events have been addressed and resolved for Beaver Valley Unit 2 by performing engineering and construction activities. These activities included pipe stress, pipe support and pipe rupture analysis, the monitoring of auxiliary feedwater system temperature and pressure, and the modification to plant piping, supports, valves, structures and operating procedures

  16. Dynamic modeling and control of power density in a PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Meidanshahi, V.; Karimi, G.; Farsi, M. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). School of Chemical and Petroleum Engineering

    2010-07-01

    Polymer electrolyte membrane (PEM) fuel cells are well suited to transportation applications because they provide a continuous electrical energy supply from fuel at high levels of efficiency and power density. However a robust control strategy is necessary to satisfy power demand fluctuations. This study considered a nonlinear one-dimensional along-the-channel dynamic model to model and simulate the power generation in a PEM fuel cell. The proposed model was based on conservation laws and electrochemical and auxiliary equations. A proper fuzzy controller designed to control the average power density in the fuel cell was also proposed. The fuzzy controller was applied to the process and the results were compared with those of a tuned conventional PI controller. The dynamic properties of PEM fuel cell system showed that the average power density can be controlled by using fuzzy controller and the fuzzy controller has a faster response than the PI controller. 15 refs., 1 tab., 7 figs.

  17. Clean, Efficient, and Reliable Heat and Power for the 21st Century, Fuel Cell Technologies Program (FCTP) (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-01

    This overview of the U.S. Department of Energy's Fuel Cell Technologies Program describes the program's focus and goals, along with current fuel cell applications and future potential. The program focuses on research and development of fuel cell systems for diverse applications in the stationary power, portable power, and transportation sectors. It works to reduce costs and improve technologies to advance fuel cell uses in areas such as combined heat and power, auxiliary power units, portable power systems, and stationary and backup power. To help ensure that fuel cell advances are realized, the program rigorously analyzes energy efficiency, economic, and environmental benefits of fuel cells and seeks to optimize synergies among fuel cell applications and other renewable technologies.

  18. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae;

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave...... the generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections. Our findings suggest that more expressive and properly specified deep generative models converge...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

  19. 燃料电池汽车空辅系统噪声有源控制技术%Active Noise Control Technology of Air Auxiliary System in Fuel Cell Vehicles

    Institute of Scientific and Technical Information of China (English)

    胡佳杰; 左曙光; 何吕昌; 张孟浩

    2013-01-01

      燃料电池汽车(FCV)的动力系统及噪声特性与传统汽车相比有着很大差异,其中空气辅助系统已成为主要的噪声源。虽然有源噪声控制(ANC)是近年来的研究热点;但是,由于噪声源与环境的时变性,对空辅系统的中低频段噪声更有效的对策是使用自适应有源噪声控制技术(AANC)。在归纳总结有源噪声控制技术的发展进程及基本原理的基础上,阐述近年来有源噪声控制的研究现状,并重点分析关注自适应算法的研究进展;由此对自适应有源噪声控制在燃料电池汽车空辅系统减振降噪方面的应用前景进行预测和展望。%The power system and its noise characteristic of Fuel Cell Vehicle (FCV) are quite different from those of traditional cars. In FCV, the air auxiliary system becomes one of the main noise sources. In recent years, active noise control (ANC) has become a research focus. It has advantages for the traditional passive noise control in middle-and low-frequency range. However, because of the time-variation property of noise sources and environments, it is necessary to use adaptive active noise control (AANC) in middle-and low-frequency noise control of the air auxiliary system in FCV. In this paper, the development progress of ANC technology was summarized, and the research of ANC in recent years was expatiated. Analysis was focused on the research progress of adaptive algorithm. Finally, the prospect of the ANNC application in the field of vibration and noise reduction of the air auxiliary system in FCV was forecasted.

  20. PS auxiliary magnet

    CERN Multimedia

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  1. 试论火力发电厂汽机辅机现状及优化策略%On the Current Situation and Optimization Strategies of Thermal Power Plant Steam Turbine Auxiliary

    Institute of Scientific and Technical Information of China (English)

    辛继群; 梁健

    2013-01-01

    随着我国社会的不断进步,经济的快速发展,对火力发电需求越来越高,汽机辅机是整个火力发电中的一个重要组成部分,它在火力发电中起到了决定性的作用。可随着现在用电量的日渐加大,火力发电厂的发电量也在逐日上涨,这对汽机辅机造成了一定程度的影响。%With the continuous progress of our society and the rapid economic development, the demand for power generation is increasing. Steam turbine auxiliary is an important part in the whole power generation, and it plays a decisive role in thermal power. With the gradually increased electricity consumption, the generating capacity of thermal power is also rising day by day, which has caused a certain influence on the auxiliary turbine.

  2. Low emission fuel cell ship. Environmental account of fuel cell powered ships

    International Nuclear Information System (INIS)

    Shipping is the dominant mode of global transport, accounting for total global anthropogenic NOx and SOx emissions of 10-14% and 4-6% respectively. Future environmental requirements signalled for shipping may exceed the possibilities within current conventional technology. The work presented document the environmental benefits of using fuel cells compared to diesel engines. The work describes the general principles for modelling emissions to air for ships. The model was calibrated by measurements onboard an offshore supply vessel and a car carrier. For the offshore vessel, the FC model includes 100% of onboard power delivered by FC's. For the car carrier, the FC replaces the auxiliary engines. FC type modelled was a high temperature FC running on natural gas. The work quantifies yearly reduction in atmospheric emissions of CO2, NOx, SOx and PM. Our results show that the installation of fuel cells in ships will improve the environmental performance significantly (e.g. global warming and acidification). (author)

  3. Transport in Auxiliary Heated NSTX Discharges

    International Nuclear Information System (INIS)

    The NSTX spherical torus (ST) provides a unique platform to investigate magnetic confinement in auxiliary-heated plasmas at low aspect ratio. Auxiliary power is routinely coupled to ohmically heated plasmas by deuterium neutral-beam injection (NBI) and by high-harmonic fast waves (HHFW) launch. While theory predicts both techniques to preferentially heat electrons, experiment reveals the electron temperature is greater than the ion temperature during HHFW, but the electron temperature is less than the ion temperature during NBI. In the following we present the experimental data and the results of transport analyses

  4. Design of Auxiliary Power Supply for Multi-Axis Motion Platform of Linear Motor%直线电机多轴联动平台辅助电源设计

    Institute of Scientific and Technical Information of China (English)

    陈辉; 余海涛; 沈蛟骁; 王亚鲁; 徐鸣飞

    2015-01-01

    基于单端反激电路,设计了一款85~265VAC输入、24VDC输出的控制系统辅助电源.阐述了单端反激变换器的变压器设计过程,对反馈环路进行了小信号分析,并进行补偿网络优化.经制作样机测试,实验结果表明,该电源工作稳定,动态性能良好,整机效率可达89.4%,满足直线电机多轴联动平台辅助电源的要求.%Based on the single-ended flyback circuit, this paper designed an auxiliary power supply of control system with alternating cur-rent input voltage from 85 to 265 and 24 voltage of direct current output and expounded the transformer design process of single-ended lfyback converter, carrying out the small signal analysis of feedback loops and compensation network optimization. The prototype was produced and comprehensive experiments were conducted. The experimental results show that the power supply is stable and has good dynamic performance, whose overall efficiency reaches 89.4%, which can meet the auxiliary power supply requirements for the multi-axis motion platform of linear mo-tor.

  5. 机车辅助电源电快速瞬变脉冲群试验案例分析%Investigation on Locomotive Auxiliary Power in EFT Testing Cases

    Institute of Scientific and Technical Information of China (English)

    窦爱玉; 赵阳; 颜伟; 慈文彦; 王珏

    2014-01-01

    The mechanism of production and harassment to EFT is employed to investigate the EFT problems of the locomotive auxiliary power. This paper studies the processing method and puts forward the solution to EFT problems of power line and IGBT. The experimental results show that, the EFT level of locomotive auxiliary power is efficiently improved,conformable to GB/T17626. 4-2008.%针对机车辅助电源电快速瞬变脉冲群( EFT)抗扰度问题,分析了脉冲群产生和骚扰机理,研究了脉冲群的处理方法,提出了针对电源线EFT问题的解决方法.试验结果表明,所提方法可以有效提高机车辅助电源EFT抗扰度等级,达到GB/T 17626.4—2008标准要求.

  6. Hydrogen Fuel Cell Performance as Telecommunications Backup Power in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-03-01

    Working in collaboration with the U.S. Department of Energy (DOE) and industry project partners, the National Renewable Energy Laboratory (NREL) acts as the central data repository for the data collected from real-world operation of fuel cell backup power systems. With American Recovery and Reinvestment Act of 2009 (ARRA) co-funding awarded through DOE's Fuel Cell Technologies Office, more than 1,300 fuel cell units were deployed over a three-plus-year period in stationary, material handling equipment, auxiliary power, and backup power applications. This surpassed a Fuel Cell Technologies Office ARRA objective to spur commercialization of an early market technology by installing 1,000 fuel cell units across several different applications, including backup power. By December 2013, 852 backup power units out of 1,330 fuel cell units deployed were providing backup service, mainly for telecommunications towers. For 136 of the fuel cell backup units, project participants provided detailed operational data to the National Fuel Cell Technology Evaluation Center for analysis by NREL's technology validation team. NREL analyzed operational data collected from these government co-funded demonstration projects to characterize key fuel cell backup power performance metrics, including reliability and operation trends, and to highlight the business case for using fuel cells in these early market applications. NREL's analyses include these critical metrics, along with deployment, U.S. grid outage statistics, and infrastructure operation.

  7. Monolithic fuel cell based power source for burst power generation

    Science.gov (United States)

    Fee, D. C.; Blackburn, P. E.; Busch, D. E.; Dees, D. W.; Dusek, J.; Easler, T. E.; Ellingson, W. A.; Flandermeyer, B. K.; Fousek, R. J.; Heiberger, J. J.

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The monolithic fuel cell looks attractive for space applications and represents a quantum jump in fuel cell technology. Such a breakthrough in design is the enabling technology for lightweight, low volume power sources for space based pulse power systems. The monolith is unique among fuel cells in being an all solid state device. The capability for miniaturization, inherent in solid state devices, gives the low volume required for space missions. In addition, the solid oxide fuel cell technology employed in the monolith has high temperature reject heat and can be operated in either closed or open cycles. Both these features are attractive for integration into a burst power system.

  8. Water reactive hydrogen fuel cell power system

    Science.gov (United States)

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  9. Low power proton exchange membrane fuel cell system identification and adaptive control

    Science.gov (United States)

    Yang, Yee-Pien; Wang, Fu-Cheng; Chang, Hsin-Ping; Ma, Ying-Wei; Weng, Biing-Jyh

    This paper proposes a systematic method of system identification and control of a proton exchange membrane (PEM) fuel cell. This fuel cell can be used for low-power communication devices involving complex electrochemical reactions of nonlinear and time-varying dynamic properties. From a system point of view, the dynamic model of PEM fuel cell is reduced to a configuration of two inputs, hydrogen and air flow rates, and two outputs, cell voltage and current. The corresponding transfer functions describe linearized subsystem dynamics with finite orders and time-varying parameters, which are expressed as discrete-time auto-regression moving-average with auxiliary input models for system identification by the recursive least square algorithm. In the experiments, a pseudo-random binary sequence of hydrogen or air flow rate is fed to a single fuel cell device to excite its dynamics. By measuring the corresponding output signals, each subsystem transfer function of reduced order is identified, while the unmodeled, higher-order dynamics and disturbances are described by the auxiliary input term. This provides a basis of adaptive control strategy to improve the fuel cell performance in terms of efficiency, as well as transient and steady state specifications. Simulation shows that adaptive controller is robust to the variation of fuel cell system dynamics, and it has proved promising from the experimental results.

  10. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  11. Regulation of Power Conversion in Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    SHEN Mu-zhong; ZHANG J.; K. Scott

    2004-01-01

    Here we report a regulation about power conversion in fuel cells. This regulation is expressed as that total power produced by fuel cells is always proportional to the square of the potential difference between the equilibrium potential and work potential. With this regulation we deduced fuel cell performance equation which can describe the potential vs. the current performance curves, namely, polarization curves of fuel cells with three power source parameters: equilibrium potential E0; internal resistance R; and power conversion coefficient K. The concept of the power conversion coefficient is a new criterion to evaluate and compare the characteristics and capacity of different fuel cells. The calculated values obtained with this equation agree with practical performance of different types of fuel cells.

  12. Analysis and Measurement of NOx Emissions in Port Auxiliary Vessels

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2013-09-01

    Full Text Available This paper is made NOx pollution emitted by port auxiliary vessels, specifically by harbour tugs, due to its unique operating characteristics of operation, require a large propulsion power changes discontinuously, also possess some peculiar technical characteristics, large tonnage and high propulsive power, that differentiate them from other auxiliary vessels of the port. Taking into account all the above features, there are no studies of the NOx emission engines caused by different working regimes of power because engine manufacturers have not measured these emissions across the range of operating power, but usually we only report the pollution produced by its engines to a maximum continuous power.

  13. TDDFT screening auxiliary withdrawing group and design the novel D-A-π-A organic dyes based on indoline dye for highly efficient dye-sensitized solar cells

    Science.gov (United States)

    Yang, Zhenqing; Liu, Yun; Liu, Chunmeng; Lin, Chundan; Shao, Changjin

    2016-10-01

    Based on the experimentally synthesized dye JZ145, we designed a series of novel D-A-π-A dyes SPL201-SPL211 with different π-conjugated bridges and a new auxiliary withdrawing group for highly efficient dye-sensitized solar cells (DSSCs) using density functional theory (DFT) and time-dependent DFT(TDDFT). The molecular structures, energy levels, absorption spectra, light-harvesting efficiency (LHE), driving force of injection(ΔGinj) and regeneration(ΔGreg), electron dipole moment (μnormal) and lifetime of the first excited state(τ) were all scrutinized in details. Results reveal that the additional withdrawing group A2 and the π-conjugated group di-η-hexyl-substituted cyclopentadithiophene (CPDT) are more promising functional groups for the organic dyes with D-A-π-A structure. We further designed SPL212 and SPL213 by employing indoline group as donor, the above screened functional groups as π-conjugated bridge and additional withdrawing group, biscarbodithiolic acid and dicyanovinyl sulfonic acid groups as acceptor group. We found that SPL212 exhibits not only a higher molar extinction coefficient with an increment of 30.8%, larger excited state lifetime and an obvious redshift of 201 nm but also a broader absorption spectrum covering the entire visible range even up to near-IR of 1200 nm compared to JZ145. So, SPL212 can be used as a promising candidate for DSSCs. In addition, the results also prove that biscarbodithiolic acid may be more favorable than dicyanovinylsulfonic acid as acceptor group in DSSCs.

  14. TDDFT screening auxiliary withdrawing group and design the novel D-A-π-A organic dyes based on indoline dye for highly efficient dye-sensitized solar cells.

    Science.gov (United States)

    Yang, Zhenqing; Liu, Yun; Liu, Chunmeng; Lin, Chundan; Shao, Changjin

    2016-10-01

    Based on the experimentally synthesized dye JZ145, we designed a series of novel D-A-π-A dyes SPL201-SPL211 with different π-conjugated bridges and a new auxiliary withdrawing group for highly efficient dye-sensitized solar cells (DSSCs) using density functional theory (DFT) and time-dependent DFT(TDDFT). The molecular structures, energy levels, absorption spectra, light-harvesting efficiency (LHE), driving force of injection(ΔGinj) and regeneration(ΔGreg), electron dipole moment (μnormal) and lifetime of the first excited state(τ) were all scrutinized in details. Results reveal that the additional withdrawing group A2 and the π-conjugated group di-η-hexyl-substituted cyclopentadithiophene (CPDT) are more promising functional groups for the organic dyes with D-A-π-A structure. We further designed SPL212 and SPL213 by employing indoline group as donor, the above screened functional groups as π-conjugated bridge and additional withdrawing group, biscarbodithiolic acid and dicyanovinyl sulfonic acid groups as acceptor group. We found that SPL212 exhibits not only a higher molar extinction coefficient with an increment of 30.8%, larger excited state lifetime and an obvious redshift of 201nm but also a broader absorption spectrum covering the entire visible range even up to near-IR of 1200nm compared to JZ145. So, SPL212 can be used as a promising candidate for DSSCs. In addition, the results also prove that biscarbodithiolic acid may be more favorable than dicyanovinylsulfonic acid as acceptor group in DSSCs. PMID:27269476

  15. Micro space power system using MEMS fuel cell for nano-satellites

    Science.gov (United States)

    Lee, Jongkwang; Kim, Taegyu

    2014-08-01

    A micro space power system using micro fuel cell was developed for nano-satellites. The power system was fabricated using microelectromechanical system (MEMS) fabrication technologies. Polymer electrolyte membrane (PEM) fuel cell was selected in consideration of space environment. Sodium borohydride (NaBH4) was selected as a hydrogen source while hydrogen peroxide (H2O2) was selected as an oxygen source. The power system consists of a micro fuel cell, micro-reactor, micro-pump, and fuel cartridges. The micro fuel cell was fabricated on a light-weight and corrosion-resistant glass plates. The micro-reactor was used to generate hydrogen from NaBH4 alkaline solution via a catalytic hydrolysis reaction. All components such as micro-pump, fuel cartridges, and auxiliary battery were integrated for a complete power system. The storability of NaBH4 solution was evaluated at -25 °C and the performance of the micro power system was measured at various operating conditions. The power output of micro power system reasonably followed up the given electric load conditions.

  16. Design of a Wide-input Auxiliary Power Supply in the PV Inverter System%一种光伏并网系统用的宽输入辅助电源设计

    Institute of Scientific and Technical Information of China (English)

    胡天友; 张晓博; 王海; 刘洋

    2012-01-01

    根据光伏并网逆变系统的供电需求,设计了一种120 ~ 850 V宽输入的辅助电源.为防止在输入电压过高时丢失开通脉冲,在传统的单端反激式拓扑电路的基础上加入了变频电路.输入电压升高时,降低开关频率,保证导通时间大于开关管的最小导通时间,实现了宽输入范围电压的要求.采用DCM工作模式,峰值电流控制,在反馈电路中加入了2型补偿网络,保证了输出电压快速调节性和稳定性.样机实验结果表明,该电源能够适应输入电压在大范围波动,可靠地为光伏并网实验系统供电.%According to the requirement of the PV grid-connected inverter system, an auxiliary power supply with an input voltage of 120 -850 V is designed. To avoid losing the opening pulse at a high input voltage, a circuit that can change switching frequency based on the input voltage is introduced. The peak current control and DCM work mode is used, and the type-2 compensation circuit in the feedback loop guarantees the rapid adjustment of output voltage and stability of the system. Experimental results show that this auxiliary power supply can adapt to a wide fluctuation of input voltage and provide long-term reliable DC voltage to the PV system.

  17. Simulation of Multi output Fly back Converter with Integrated Auxiliary Buck Converter with reduced components

    Directory of Open Access Journals (Sweden)

    J.KOMATHI

    2015-04-01

    Full Text Available The fly back converter has been widely used for multi outputs due to the simple structure and low cost in low-power applications. This paper presents a new multi output converter. It consists of a half-bridge inverter with boost converter in primary side and a fly back rectifier that is integrated with an auxiliary buck converter in secondary side. The boost converter is used to generate high voltage dc from Low voltage PV cells. The primary switches control the main output voltage and the secondary synchronous switches control the auxiliary output voltage. The main advantages of the proposed converter are that the transformer size can be reduced due to the less magnetizing offset current, all the power switches including synchronous ones can achieve the zero-voltage switching (ZVS and it has no output cross regulation problems. The circuit is simulated using MATLAB. The performance is verified with simulation results.

  18. System Studies of Fuel Cell Power Plants

    OpenAIRE

    Kivisaari, Timo

    2001-01-01

    This thesis concerns system studies of power plants wheredifferent types of fuel cells accomplish most of the energyconversion. Ever since William Grove observed the fuel cell effect inthe late 1830s fuel cells have been the subject or more or lessintense research and development. Especially in the USA theseactivities intensified during the second part of the 1950s,resulting in the development of the fuel cells used in theApollo-program. Swedish fuel cell activities started in themid-1960s, w...

  19. A Parallel Auxiliary Grid AMG Method for GPU

    OpenAIRE

    Wang, Lu; Hu, Xiaozhe; Cohen, Jonathan; Xu, Jinchao

    2012-01-01

    In this paper, we develop a new parallel auxiliary grid algebraic multigrid (AMG) method to leverage the power of graphic processing units (GPUs). In the construction of the hierarchical coarse grid, we use a simple and fixed coarsening procedure based on a region quadtree generated from an auxiliary grid. This allows us to explicitly control the sparsity patterns and operator complexities of the AMG solver. This feature provides (nearly) optimal load balancing and predictable communication p...

  20. SEPP-ZVS High Frequency Inverter Incorporating Auxiliary Switch

    Science.gov (United States)

    Ogiwara, Hiroyuki; Itoi, Misao; Nakaoka, Mutsuo

    This paper presents a novel circuit topology to attain ZVS operation of a high frequency inverter over a wide range output power regulation using a PWM control technique by connecting an auxiliary switch to the conventional single ended push-pull (SEPP) ZVS high frequency inverter. A switching current is injected into the main switches via the auxiliary switch only during the short period between its turn-on and off times to supply a current required for its ZVS operation.

  1. Current State of Technology of Fuel Cell Power Systems for Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Alejandro Mendez

    2014-07-01

    Full Text Available Autonomous Underwater Vehicles (AUVs are vehicles that are primarily used to accomplish oceanographic research data collection and auxiliary offshore tasks. At the present time, they are usually powered by lithium-ion secondary batteries, which have insufficient specific energies. In order for this technology to achieve a mature state, increased endurance is required. Fuel cell power systems have been identified as an effective means to achieve this endurance but no implementation in a commercial device has yet been realized. This paper summarizes the current state of development of the technology in this field of research. First, the most adequate type of fuel cell for this application is discussed. The prototypes and design concepts of AUVs powered by fuel cells which have been developed in the last few years are described. Possible commercial and experimental fuel cell stack options are analyzed, examining solutions adopted in the analogous aerial vehicle applications, as well as the underwater ones, to see if integration in an AUV is feasible. Current solutions in oxygen and hydrogen storage systems are overviewed and energy density is objectively compared between battery power systems and fuel cell power systems for AUVs. A couple of system configuration solutions are described including the necessary lithium-ion battery hybrid system. Finally, some closing remarks on the future of this technology are given.

  2. System Study: Auxiliary Feedwater 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-12-01

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  3. System Study: Auxiliary Feedwater 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2014-12-31

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  4. Scheduling of Power System Cells Integrating Stochastic Power Generation

    International Nuclear Information System (INIS)

    Energy supply and climate change are nowadays two of the most outstanding problems which societies have to cope with under a context of increasing energy needs. Public awareness of these problems is driving political willingness to take actions for tackling them in a swift and efficient manner. Such actions mainly focus in increasing energy efficiency, in decreasing dependence on fossil fuels, and in reducing greenhouse gas emissions. In this context, power systems are undergoing important changes in the way they are planned and managed. On the one hand, vertically integrated structures are being replaced by market structures in which power systems are un-bundled. On the other, power systems that once relied on large power generation facilities are witnessing the end of these facilities' life-cycle and, consequently, their decommissioning. The role of distributed energy resources such as wind and solar power generators is becoming increasingly important in this context. However, the large-scale integration of such type of generation presents many challenges due, for instance, to the uncertainty associated to the variability of their production. Nevertheless, advanced forecasting tools may be combined with more controllable elements such as energy storage devices, gas turbines, and controllable loads to form systems that aim to reduce the impacts that may be caused by these uncertainties. This thesis addresses the management under market conditions of these types of systems that act like independent societies and which are herewith named power system cells. From the available literature, a unified view of power system scheduling problems is also proposed as a first step for managing sets of power system cells in a multi-cell management framework. Then, methodologies for performing the optimal day-ahead scheduling of single power system cells are proposed, discussed and evaluated under both a deterministic and a stochastic framework that directly integrates the

  5. Design of Power Shift Auxiliary Gearbox in Transmission for Tractor%拖拉机负载增扭/梭行换挡副变速器设计

    Institute of Scientific and Technical Information of China (English)

    高翔; 王志晨

    2016-01-01

    动力换挡变速器换挡时动力不中断,且能够将复杂的换挡过程简化为按钮操作,在国外的拖拉机上已得到了广泛应用。为此,设计了一种新型的负载换挡行星齿轮副变速器,增加了原变速箱的挡位数,并实现了增扭负载换挡与梭行换挡。在分析了整体功能要求的基础上,确定了变速器的传动方案及结构,设计了副变速器液压控制系统,并对拖拉机各挡总传动比及理论车速进行了设计计算。同时,绘制了拖拉机牵引力和比油耗曲线,定义拖拉机牵引功率利用率和比油耗损失率用以评价拖拉机动力性和燃油经济性,并通过计算比较了改进前后拖拉机的动力性和燃油经济性情况。%With the advantage of uninterrupted output power in the process of gear shift, power shift transmission is wide-ly used on Tractor abroad.In this paper, a new type power shift auxiliary gearbox is developed.The new type auxiliary gearbox increases the number of gear positions and has the function of torque booster and shuttle shift.Based on the anal-ysis of function requirements, the general drive scheme and structural style is obtained.The hydraulic control system is designed, and gear ratios and theoretical travel speeds are calculated.The tractor traction and specific fuel consumption curves are drawn.The traction power utilization and specific fuel consumption loss rate is defined to evaluate the tractor dynamic and fuel economy performance .The tractor dynamic and fuel economy performance of original tractor and im-proved tractor is compared through calculation.

  6. WMO Selected, Supplemenatary, Auxiliary Ships

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Meteorological Organization International List of Selected, Supplementary and Auxiliary Ships, recognized as Publication 47. 1973-1998 editions, gathered from...

  7. Air breathing lithium power cells

    Science.gov (United States)

    Farmer, Joseph C.

    2014-07-15

    A cell suitable for use in a battery according to one embodiment includes a catalytic oxygen cathode; a stabilized zirconia electrolyte for selective oxygen anion transport; a molten salt electrolyte; and a lithium-based anode. A cell suitable for use in a battery according to another embodiment includes a catalytic oxygen cathode; an electrolyte; a membrane selective to molecular oxygen; and a lithium-based anode.

  8. Fuel cell power system for utility vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Graham, M.; Barbir, F.; Marken, F.; Nadal, M. [Energy Partners, Inc., West Palm Beach, FL (United States)

    1996-12-31

    Based on the experience of designing and building the Green Car, a fuel cell/battery hybrid vehicle, and Genesis, a hydrogen/oxygen fuel cell powered transporter, Energy Partners has developed a fuel cell power system for propulsion of an off-road utility vehicle. A 10 kW hydrogen/air fuel cell stack has been developed as a prototype for future mass production. The main features of this stack are discussed in this paper. Design considerations and selection criteria for the main components of the vehicular fuel cell system, such as traction motor, air compressor and compressor motor, hydrogen storage and delivery, water and heat management, power conditioning, and control and monitoring subsystem are discussed in detail.

  9. Research and Application of Auxiliary Optimization Technology of Power Grid Accident Processing Based on the Mode of Regulation and Control Integration

    Directory of Open Access Journals (Sweden)

    Cui Houzhen

    2015-01-01

    Full Text Available Accident processing is the most important link of the scheduling of daily monitoring. The improvement of intelligent level is of great significance for improving the efficiency of accident processing scheduling, shortening the time of accident processing and preventing further deterioration of accidents. According to features of accident processing scheduling, this paper puts forward an integrated framework of aid decision-making of online accident processing based on large power grid, and carries out a study from five aspects, namely integrated information support platform, risk perception in advance, online fault diagnosis, aid decision-making afterwards and visual display, so as to conduct real-time tracking on operating state of power grid, eliminate potential safety hazards of power grid and upgrade power grid from “manual analysis” scheduling to “intelligent analysis” scheduling.

  10. Wireless sensors powered by microbial fuel cells.

    Science.gov (United States)

    Shantaram, Avinash; Beyenal, Haluk; Raajan, Raaja; Veluchamy, Angathevar; Lewandowski, Zbigniew

    2005-07-01

    Monitoring parameters characterizing water quality, such as temperature, pH, and concentrations of heavy metals in natural waters, is often followed by transmitting the data to remote receivers using telemetry systems. Such systems are commonly powered by batteries, which can be inconvenient at times because batteries have a limited lifetime and must be recharged or replaced periodically to ensure that sufficient energy is available to power the electronics. To avoid these inconveniences, a microbial fuel cell was designed to power electrochemical sensors and small telemetry systems to transmit the data acquired by the sensors to remote receivers. The microbial fuel cell was combined with low-power, high-efficiency electronic circuitry providing a stable power source for wireless data transmission. To generate enough power for the telemetry system, energy produced by the microbial fuel cell was stored in a capacitor and used in short bursts when needed. Since commercial electronic circuits require a minimum 3.3 V input and our cell was able to deliver a maximum of 2.1 V, a DC-DC converter was used to boost the potential. The DC-DC converter powered a transmitter, which gathered the data from the sensor and transmitted it wirelessly to a remote receiver. To demonstrate the utility of the system, temporal variations in temperature were measured, and the data were wirelessly transmitted to a remote receiver. PMID:16053108

  11. 基于年费用法的电站辅机投资项目经济评价研究%Economic Evaluation of Auxiliary Equipment Project in Power Plants Based on the Annualized Cost Method

    Institute of Scientific and Technical Information of China (English)

    陈晓霞

    2013-01-01

    The economic evaluation is an important part of feasibility study and project proposals. It also can help making decision. The thesis, in accordance with characteristics of the electric power project and the specific property of evaluation, analyzes the component elements, establishes evaluating indicator, and constructs economic assessment method of auxiliary equipment project in power plants. Through empirical analysis, scientific and practiced characters of index system and evaluating method have been validated.%  经济评价是电力项目可行性研究与项目建议书的重要组成部分,是项目决策科学化的据。论文从电站辅机项目的特点和评价独特性入手,分析和甄别构成要素、设置评价指标,构建了基年费用法的电站辅机设备的经济性评价方法,并通过实证分析,验证了指标体系和评价方法的科学性和实践可行性。

  12. Exoelectrogenic bacteria that power microbial fuel cells

    KAUST Repository

    Logan, Bruce E.

    2009-03-30

    There has been an increase in recent years in the number of reports of microorganisms that can generate electrical current in microbial fuel cells. Although many new strains have been identified, few strains individually produce power densities as high as strains from mixed communities. Enriched anodic biofilms have generated power densities as high as 6.9 W per m2 (projected anode area), and therefore are approaching theoretical limits. To understand bacterial versatility in mechanisms used for current generation, this Progress article explores the underlying reasons for exocellular electron transfer, including cellular respiration and possible cell-cell communication.

  13. Fuel-Cell-Powered Vehicle with Hybrid Power Management

    Science.gov (United States)

    Eichenberg, Dennis J.

    2010-01-01

    Figure 1 depicts a hybrid electric utility vehicle that is powered by hydrogenburning proton-exchange-membrane (PEM) fuel cells operating in conjunction with a metal hydride hydrogen-storage unit. Unlike conventional hybrid electric vehicles, this vehicle utilizes ultracapacitors, rather than batteries, for storing electric energy. This vehicle is a product of continuing efforts to develop the technological discipline known as hybrid power management (HPM), which is oriented toward integration of diverse electric energy-generating, energy-storing, and energy- consuming devices in optimal configurations. Instances of HPM were reported in five prior NASA Tech Briefs articles, though not explicitly labeled as HPM in the first three articles: "Ultracapacitors Store Energy in a Hybrid Electric Vehicle" (LEW-16876), Vol. 24, No. 4 (April 2000), page 63; "Photovoltaic Power Station With Ultracapacitors for Storage" (LEW- 17177), Vol. 27, No. 8 (August 2003), page 38; "Flasher Powered by Photovoltaic Cells and Ultracapacitors" (LEW-17246), Vol. 27, No. 10 (October 2003), page 37; "Hybrid Power Management" (LEW-17520), Vol. 29, No. 12 (December 2005), page 35; and "Ultracapacitor-Powered Cordless Drill" (LEW-18116-1), Vol. 31, No. 8 (August 2007), page 34. To recapitulate from the cited prior articles: The use of ultracapacitors as energy- storage devices lies at the heart of HPM. An ultracapacitor is an electrochemical energy-storage device, but unlike in a conventional rechargeable electrochemical cell or battery, chemical reactions do not take place during operation. Instead, energy is stored electrostatically at an electrode/electrolyte interface. The capacitance per unit volume of an ultracapacitor is much greater than that of a conventional capacitor because its electrodes have much greater surface area per unit volume and the separation between the electrodes is much smaller.

  14. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    entitled "High Efficiency Reversible Fuel Cell Power Converter" and it presents the design of a high efficiency dc-dc converter developed and optimized for bidirectional fuel cell applications. First, a brief overview of fuel cell and energy storage technologies is presented. Different system topologies...... as well as different dc-ac and dc-dc converter topologies are presented and analyzed. A new ac-dc topology for high efficiency data center applications is proposed and an efficiency characterization based on the fuel cell stack I-V characteristic curve is presented. The second part discusses the main...... of magnetic components especially for large production volumes. At last, the complete converter design is presented in detailed and characterized in efficiency terms. Both benefits, provided by SiC power devices and by a redesign of the converter layout increased the converter power density up to 2.2 k...

  15. Portable power applications of fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Weston, M.; Matcham, J.

    2002-07-01

    This report describes the state-of-the-art of fuel cell technology for portable power applications. The study involved a comprehensive literature review. Proton exchange membrane fuel cells (PEMFCs) have attracted much more interest than either direct methanol fuel cells (DMFCs) or solid oxide fuel cells (SOFCs). However, issues relating to fuel choice and catalyst design remain with PEMFCs; DMFCs have excellent potential provided issues relating to the conducting membrane can be resolved but the current high temperature of operation and low power density currently makes SOFCs less applicable to portable applications. Available products are listed and the obstacles to market penetration are discussed. The main barriers are cost and the size/weight of fuel cells compared with batteries. Another key problem is the lack of a suitable fuel infrastructure.

  16. POWERED LED LIGHTING SUPPLIED FROM PV CELLS

    Directory of Open Access Journals (Sweden)

    Tirshu M.

    2011-12-01

    Full Text Available The paper deals with practical realization of efficient lighting system based on LED’s of 80W total power mounted on corridor ceiling total length of which is 120m and substitutes existing traditional lighting system consisting of 29 lighting blocks with 4 fluorescent lamps each of them and summary power 2088W. Realized lighting system is supplied from two photovoltaic panels of power 170W. Generated energy by PV cells is accumulated in two accumulators of 75Ah capacity and from battery by means of specialized convertor is applied to lighting system. Additionally, paper present data measured by digital weather station (solar radiation and UV index, which is mounted near of PV cells and comparative analyze of solar energy with real energy generated by PV cells is done. Measured parameters by digital weather station are stored by computer in on-line mode.

  17. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  18. Experimental study of a fuel cell power train for road transport application

    Science.gov (United States)

    Corbo, P.; Corcione, F. E.; Migliardini, F.; Veneri, O.

    The development of fuel cell electric vehicles requires the on-board integration of fuel cell systems and electric energy storage devices, with an appropriate energy management system. The optimization of performance and efficiency needs an experimental analysis of the power train, which has to be effected in both stationary and transient conditions (including standard driving cycles). In this paper experimental results concerning the performance of a fuel cell power train are reported and discussed. In particular characterization results for a small sized fuel cell system (FCS), based on a 2.5 kW PEM stack, alone and coupled to an electric propulsion chain of 3.7 kW are presented and discussed. The control unit of the FCS allowed the main stack operative parameters (stoichiometric ratio, hydrogen and air pressure, temperature) to be varied and regulated in order to obtain optimized polarization and efficiency curves. Experimental runs effected on the power train during standard driving cycles have allowed the performance and efficiency of the individual components (fuel cell stack and auxiliaries, dc-dc converter, traction batteries, electric engine) to be evaluated, evidencing the role of output current and voltage of the dc-dc converter in directing the energy flows within the propulsion system.

  19. Novel Chiral Auxiliaries of BIAZOLs

    Institute of Scientific and Technical Information of China (English)

    CHEN; Arh-Hwang

    2001-01-01

    Asymmetric catalysis is one of the most challenging and formidable endeavor in organic synthesis. The development of chiral auxiliaries is a key in the asymmetric catalysis. Azulenoids, a parent structure of bicyclo[5.3.0]decapentaene with 10 πelectrons, are useful as dye materials, medical treatment of inflammation and hypertension, and the development of liquid crystals. In continuing to investigate synthetic application of azulenoids, we have studied to develop novel chiral auxiliaries of BIAZOLs. The BIAZOLs were synthesized from dicyclopentadiene and characterized using spectroscopies.  ……

  20. Novel Chiral Auxiliaries of BIAZOLs

    Institute of Scientific and Technical Information of China (English)

    CHEN Arh-Hwang; YUAN Shou-Bin; CHIU Shu-Ching

    2001-01-01

    @@ Asymmetric catalysis is one of the most challenging and formidable endeavor in organic synthesis. The development of chiral auxiliaries is a key in the asymmetric catalysis. Azulenoids, a parent structure of bicyclo[5.3.0]decapentaene with 10 πelectrons, are useful as dye materials, medical treatment of inflammation and hypertension, and the development of liquid crystals. In continuing to investigate synthetic application of azulenoids, we have studied to develop novel chiral auxiliaries of BIAZOLs. The BIAZOLs were synthesized from dicyclopentadiene and characterized using spectroscopies.

  1. Stationary power fuel cell commercialization status worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M.C. [Dept. of Energy, Morgantown, WV (United States)

    1996-12-31

    Fuel cell technologies for stationary power are set to play a role in power generation applications worldwide. The worldwide fuel cell vision is to provide powerplants for the emerging distributed generation and on-site markets. Progress towards commercialization has occurred in all fuel cell development areas. Around 100 ONSI phosphoric acid fuel cell (PAFC) units have been sold, with significant foreign sales in Europe and Japan. Fuji has apparently overcome its PAFC decay problems. Industry-driven molten carbonate fuel cell (MCFC) programs in Japan and the U.S. are conducting megawatt (MW)-class demonstrations, which are bringing the MCFC to the verge of commercialization. Westinghouse Electric, the acknowledged world leader in tubular solid oxide fuel cell (SOFC) technology, continues to set performance records and has completed construction of a 4-MW/year manufacturing facility in the U.S. Fuel cells have also taken a major step forward with the conceptual development of ultra-high efficiency fuel cell/gas turbine plants. Many SOFC developers in Japan, Europe, and North America continue to make significant advances.

  2. Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Esparza Gutierrez, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in order to control the performance, compare them among similar units and power stations, and inclusively verify possible recurrent causes of low availability in the referred systems. [Espanol] En este articulo se presenta la metodologia seguida para diagnosticar el comportamiento de equipos en los que se transfiere calor de los sistemas de agua de alimentacion, condensado y circulacion de las centrales termoelectricas (CTE). La toma de datos se realiza con la unidad en operacion normal, utilizando instrumentacion local sin necesidad de sacar de servicio a los equipos para su instalacion, ya que se ocupan los mismos puntos para instrumentos con que cuentan por diseno. El diagnostico de los equipos se realiza mediante el analisis de los datos recopilados, tanto de operacion real como de diseno; para ello, se efectua un balance termico de los sistemas de interes para obtener todas las condiciones y los datos de operacion. Posteriormente, se calculan los parametros indicativos de

  3. 一种高压宽范围输入辅助电源的设计%The Design of Auxiliary Power Supply with Wide Range and High Input Voltage

    Institute of Scientific and Technical Information of China (English)

    张翔; 郑晟; 张军明

    2011-01-01

    Based on input-series and output-parallel(ISOP) converter and multiple output flyback converter,a kind of auxiliary power supply applicated to high power system is proposed.In the proposed scheme,a new control method with primary side current feedback is presented,so it ensures input voltage sharing and output current sharing of the modules among the ISOP converter,improves the degree of isolation between primary side and secondary side,and e-liminates the opto-coupler from the circuit.Some problems of the new method of control and the design of transformer are analysed.Finally the experimental results verify the effectiveness of the proposed control method and the design.%基于输入串联输出并联(ISOP)变换器和多路输出反激变换器,提出了一种应用于中大功率系统的辅助电源.该电源采用一种初级电流反馈的输入均压输出均流的控制方法,保证了输入电压均压与输出电流均流,提高了初、次级电路之间的绝缘等级,省掉了光耦.分析了电源系统的控制方法和变压器的设计等问题,实验结果验证了控制和设计的正确性.

  4. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  5. Intelligent Power Management of hybrid Wind/ Fuel Cell/ Energy Storage Power Generation System

    OpenAIRE

    A. Hajizadeh; Hassanzadeh, F.

    2013-01-01

    This paper presents an intelligent power management strategy for hybrid wind/ fuel cell/ energy storage power generation system. The dynamic models of wind turbine, fuel cell and energy storage have been used for simulation of hybrid power system. In order to design power flow control strategy, a fuzzy logic control has been implemented to manage the power between power sources. The optimal operation of the hybrid power system is a main goal of designing power management strategy. The hybrid ...

  6. Hydraulic turbines and auxiliary equipment

    Energy Technology Data Exchange (ETDEWEB)

    Luo Gaorong [Organization of the United Nations, Beijing (China). International Centre of Small Hydroelectric Power Plants

    1995-07-01

    This document presents a general overview on hydraulic turbines and auxiliary equipment, emphasizing the turbine classification, in accordance with the different types of turbines, standard turbine series in China, turbine selection based on the basic data required for the preliminary design, general hill model curves, chart of turbine series and the arrangement of application for hydraulic turbines, hydraulic turbine testing, and speed regulating device.

  7. Solid oxide fuel cell power system development

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Rick [Delphi Automotive Systems, LLC., Troy, MI (United States); Wall, Mark [Independent Energy Partners Technology, LLC., Parker, CO (United States); Sullivan, Neal [Colorado School of Mines, Golden, CO (United States)

    2015-06-26

    This report summarizes the progress made during this contractual period in achieving the goal of developing the solid oxide fuel cell (SOFC) cell and stack technology to be suitable for use in highly-efficient, economically-competitive, commercially deployed electrical power systems. Progress was made in further understanding cell and stack degradation mechanisms in order to increase stack reliability toward achieving a 4+ year lifetime, in cost reduction developments to meet the SECA stack cost target of $175/kW (in 2007 dollars), and in operating the SOFC technology in a multi-stack system in a real-world environment to understand the requirements for reliably designing and operating a large, stationary power system.

  8. A magnetorheological clutch for efficient automotive auxiliary device actuation

    OpenAIRE

    F. Bucchi; Forte, P; F. Frendo; R. Squarcini

    2013-01-01

    In this paper the results of a project funded by Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR) is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in order to reduce the device power absorption. Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are...

  9. 核电厂辅助给水系统控制方案设计研究%Study on Control System of Auxiliary Feedwater System of Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    鲁超

    2015-01-01

    Auxiliary water supply system is an important system in the design of safety facilities of nuclear power station. The common cause fault of software and the power plant station blackout are two key factors for control system of ASG. So in the design of the control system, in order to deal with the two failure factors, the control strategy of diversity and emergency power supply are respectively adopted. Through analysis diversity control strategy is an effect method to prevent the failure of the safety functions resulting from software common cause failure which meets single failure criterion. In the case of station blackout, it is necessary to provide emergency power supply for control system of the starting ASG, and ensure the system safety functions workable.%辅助给水系统(ASG)是核电厂专设安全设施中重要的系统。对于实现对ASG功能控制的安全级系统,软件共因故障和全厂失电是导致控制失效的两个关键因素。因此,在进行控制系统设计时,为应对这两大失效因素,分别采用了多样性和增加应急电源的控制策略。通过分析,采用多样性控制策略可以有效地防止软件共因故障导致安全功能丧失的风险,保证系统满足单一故障的要求。同时在全厂断电的情况下,增加应急供电电源,对启动ASG功能的控制系统进行紧急供电,保证系统安全功能可执行。

  10. Fuel cell power trains for road traffic

    Science.gov (United States)

    Höhlein, Bernd; Biedermann, Peter; Grube, Thomas; Menzer, Reinhard

    Legal regulations, especially the low emission vehicle (LEV) laws in California, are the driving forces for more intensive technological developments with respect to a global automobile market. In the future, high efficient vehicles at very low emission levels will include low temperature fuel cell systems (e.g., polymer electrolyte fuel cell (PEFC)) as units of hydrogen-, methanol- or gasoline-based electric power trains. In the case of methanol or gasoline/diesel, hydrogen has to be produced on-board using heated steam or partial oxidation reformers as well as catalytic burners and gas cleaning units. Methanol could also be used for direct electricity generation inside the fuel cell (direct methanol fuel cell (DMFC)). The development potentials and the results achieved so far for these concepts differ extremely. Based on the experience gained so far, the goals for the next few years include cost and weight reductions as well as optimizations in terms of the energy management of power trains with PEFC systems. At the same time, questions of fuel specification, fuel cycle management, materials balances and environmental assessment will have to be discussed more intensively. On the basis of process engineering analyses for net electricity generation in PEFC-powered power trains as well as on assumptions for both electric power trains and vehicle configurations, overall balances have been carried out. They will lead not only to specific energy demand data and specific emission levels (CO 2, CO, VOC, NO x) for the vehicle but will also present data of its full fuel cycle (FFC) in comparison to those of FFCs including internal combustion engines (ICE) after the year 2005. Depending on the development status (today or in 2010) and the FFC benchmark results, the advantages of balances results of FFC with PEFC vehicles are small in terms of specific energy demand and CO 2 emissions, but very high with respect to local emission levels.

  11. Fuel cells for electric power generation

    International Nuclear Information System (INIS)

    After having first briefly illustrated the basic design, construction and operating principles of fuel cells, this paper assesses the progress that has been achieved to date in the development of the phosphoric acid (PAFC), molten carbonate (MCFC) and solid oxide (SOFC) fuel cells. Special attention is given to the design, performance and cost characteristics of the phosphoric acid fuel cells. For example, the paper cites the IFC/Toshiba 4.8 and 11.0 MW models, which have attained efficiencies of 37.5 and 41.0% respectively, and points out that these fuel cells, with efficiencies comparable to those of conventional poly-fuelled and combined cycle power plants, offer the advantages of compact size and better environmental compatibility with respect to the latter. However, fuel cells cannot yet compete with the lower per kWh costs of fossil fuel power plants. The paper concludes with an assessment of Italian fuel cell commercialization efforts, especially those centered around the use of methane fuelled PAFC's, and reviews the status of coordinated international research programs involving Japan, the USA and Italy

  12. 田阳县那坡镇宝美村龙达屯水利配套工程隧洞设计%The Tunnel Design of Water & Power Auxiliary Project in Longda Village of Baomei Hamlet in Napo Town of Tianyang County

    Institute of Scientific and Technical Information of China (English)

    钟顺钠

    2013-01-01

    The paper introduces the tunnel condition of water&power auxiliary project in Longda village of Baomei hamlet in Napo town of Tianyang county, and explains the design description of the drainage tunnel.%  文章介绍了田阳县那坡镇宝美村龙达屯水利配套工程隧洞概况,并对其排涝隧洞进行设计说明。

  13. 45 CFR 707.10 - Auxiliary aids.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Auxiliary aids. 707.10 Section 707.10 Public Welfare Regulations Relating to Public Welfare (Continued) COMMISSION ON CIVIL RIGHTS ENFORCEMENT OF... § 707.10 Auxiliary aids. (a) The Agency shall furnish appropriate auxiliary aids where necessary...

  14. 7 CFR 15b.37 - Auxiliary aids.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Auxiliary aids. 15b.37 Section 15b.37 Agriculture... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Other Aid, Benefits, or Services § 15b.37 Auxiliary aids... appropriate auxiliary aids to persons with impaired sensory, manual, or speaking skills, where necessary...

  15. Fuel processor for fuel cell power system

    Science.gov (United States)

    Vanderborgh, Nicholas E.; Springer, Thomas E.; Huff, James R.

    1987-01-01

    A catalytic organic fuel processing apparatus, which can be used in a fuel cell power system, contains within a housing a catalyst chamber, a variable speed fan, and a combustion chamber. Vaporized organic fuel is circulated by the fan past the combustion chamber with which it is in indirect heat exchange relationship. The heated vaporized organic fuel enters a catalyst bed where it is converted into a desired product such as hydrogen needed to power the fuel cell. During periods of high demand, air is injected upstream of the combustion chamber and organic fuel injection means to burn with some of the organic fuel on the outside of the combustion chamber, and thus be in direct heat exchange relation with the organic fuel going into the catalyst bed.

  16. Advanced DC-DC converter for power conditioning in hydrogen fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Kovacevic, G.; Tenconi, A.; Bojoi, R. [Department of Electrical Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2008-06-15

    The fuel cell (FC) generators can produce electric energy directly from hydrogen and oxygen. The DC voltage generated by FC is generally low amplitude and it is not constant, depending on the operating conditions. Furthermore, FC systems have dynamic response that is slower than the transient responses typically requested by the load. For this reason, in many applications the FC generators must be interfaced with other energy/power sources by means of an electronic power converter. An advanced full-bridge (FB) DC-DC converter, which effectively achieves zero-voltage switching and zero-current switching (ZVS-ZCS), is proposed for power-conditioning (PC) in hydrogen FC applications. The operation and features of the converter are analyzed and verified by simulations results. The ZVS-ZCS operation is obtained by means of a simple auxiliary circuit. Introduction of the soft-switching operation in PC unit brings improvements not only from the converter efficiency point of view, but also in terms of increased converter power density. Quantitative analysis of hard and soft-switching operating of the proposed converter is also made, bringing in evidence the benefits of soft-switching operation mode. The proposed converter can be a suitable solution for PC in hydrogen FC systems, especially for the medium to high-power applications. (author)

  17. Radio frequency auxiliary heating systems design in ITER

    International Nuclear Information System (INIS)

    A combination of radio frequency (RF) auxiliary heating systems will provide at least one half of the required 100 MW of auxiliary power in ITER. Five of the 20 equatorial ports are assigned to RF heating systems. Recent work has focused on developing an integrated equatorial port-plug design concept for all of the RF auxiliary heating systems as well as other equatorial port systems such as diagnostics. Common features of the design approach include the use of identical interfaces to services such as cooling water, vacuum, mechanical connection to the vessel, and maintenance. Based on the integrated port concept, a high level of design integration has been achieved for the RF heating systems. Implementation of the integrated design concept has been accomplished without significantly affecting the individual system performance and with limited impact on the torus layout. (author)

  18. The Marginalized Auxiliary Particle Filter

    OpenAIRE

    Fritsche, Carsten; Schön, Thomas; Klein, Anja

    2010-01-01

    In this paper we are concerned with nonlinear systems subject to a conditionally linear, Gaussian sub-structure. This structure is often exploited in high-dimensional state estimation problems using the marginalized (aka Rao-Blackwellized) particle filter. The main contribution in the present work is to show how an efficient filter can be derived by exploiting this structure within the auxiliary particle filter. Based on a multisensor aircraft tracking example, the superior performance of the...

  19. Intelligent Power Management of hybrid Wind/ Fuel Cell/ Energy Storage Power Generation System

    Directory of Open Access Journals (Sweden)

    A. Hajizadeh

    2013-12-01

    Full Text Available This paper presents an intelligent power management strategy for hybrid wind/ fuel cell/ energy storage power generation system. The dynamic models of wind turbine, fuel cell and energy storage have been used for simulation of hybrid power system. In order to design power flow control strategy, a fuzzy logic control has been implemented to manage the power between power sources. The optimal operation of the hybrid power system is a main goal of designing power management strategy. The hybrid power system is simulated in MATLAB/ SIMIULINK environment and different operating conditions have been considered to evaluate the response of power management strategy.

  20. 湿性脂肪干细胞辅助自体颗粒脂肪移植五年临床回顾总结%The five-year review of autologous fat transplantation with stem cell auxiliary

    Institute of Scientific and Technical Information of China (English)

    刘乃军; 王艳

    2013-01-01

    Objective Retrospective summary of clinical experience of wet autologous fat particles grafting with the stromal vascular cells and adipose stem cell-assisted,autologous fat transplantation withwith fat stem cell auxiliary during January 2008~April2013.Methods In 549 cases,532 were completed by one stage of filling injection.In the other 17 cases,the second procedure had been done due to the bad fat survival.Almost of the cases got significantly improvements and achieved desired clinical effect.In 2 cases minor complications happened.Results Conclusion Follow-up of 1~5,this kind of fat autologous transplantation can improve the survival rate of transplanted fat.Conclusion Autologous fat transplantation with with fat stem cell auxiliary can significantly improve the survival rate of transplanted fat cells and get good long-term effect.%目的:回顾总结2008 ~ 2013年笔者行湿性脂肪干细胞辅助自体颗粒脂肪注射填充移植术五年的临床经验.方法:549例均采用湿性脂肪干细胞辅助自体颗粒脂肪移植术,单次注射填充移植完成532例(96.91%),17例(3.09%)脂肪存活率较低(30% ~ 40%)需二次注射填充移植完成.结果:本组仅2例(0.36%)出现轻微并发症,成活率和远期效果明显提高,取得预期临床效果.结论:随访1~5,采用规范的湿性肿胀技术和注射器吸脂法抽吸颗粒脂肪及湿性新鲜原代血管基质细胞和脂肪干细胞辅助自体颗粒脂肪移植注射填充移植技术效果明显持久,遵循其正确的临床操作原则和技术指南及标准操作流程,能明显提高移植脂肪成活率和良好远期效果,是一种切实、可行、有效的临床方法.

  1. Solar-auxiliary Coal-fired Power Generation System Thermal Economic Analysis%太阳能辅助燃煤发电系统经济性分析

    Institute of Scientific and Technical Information of China (English)

    葛晓霞; 邵娜; 邵成; 钱晨; 姜晨峰

    2015-01-01

    介绍了太阳能辅助锅炉受热面替代部分省煤器作用和太阳能辅助给水回热加热的两种发电系统。应用等效热降法对这两种太阳能辅助燃煤发电集成方案的热经济指标进行了计算与比较,选择了太阳能辅助给水回热加热为优化的集成方案。对槽式集热器的换热效率,光热电转换效率及投资节煤比3个技术经济性相关指标进行研究,在太阳能辅助给水回热加热的方案中,通过综合比较利用太阳能产生的汽替换各级抽汽的计算结果后,得出了替换第六级抽汽最为合理的结论。%Two power generation systems were introduced about solar assisted part replace of boiler economizer heating surface effects and the solar-assisted heating feed water regenerator .It was calculated and compared these two types of solar assisted heat economic indicators coal-fired integrated solutions by using of Equivalent Heat Drop .It was selected a solar-assisted water heating for the optimization of regenerative integrated solution ., Three related indicators of technical and economic were studied On heat transfer efficiency of trough collector and the light thermoelectric conversion efficiency as well as investment in coal saving ratio .In the solar thermal heating auxiliary feedwater back scheme , By comprehensive comparison of the use of solar energy to produce steam to replace the calculation of results at all levels extraction .It was obtained the most reasonable conclusion of replacing sixth stage extraction .

  2. High efficiency fuel cell/advanced turbine power cycles

    Energy Technology Data Exchange (ETDEWEB)

    Morehead, H. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-19

    An outline of the Westinghouse high-efficiency fuel cell/advanced turbine power cycle is presented. The following topics are discussed: The Westinghouse SOFC pilot manufacturing facility, cell scale-up plan, pressure effects on SOFC power and efficiency, sureCell versus conventional gas turbine plants, sureCell product line for distributed power applications, 20 MW pressurized-SOFC/gas turbine power plant, 10 MW SOFC/CT power plant, sureCell plant concept design requirements, and Westinghouse SOFC market entry.

  3. Neoclassical offset toroidal velocity and auxiliary ion heating in tokamaks

    Science.gov (United States)

    Lazzaro, E.

    2016-05-01

    In conditions of ideal axisymmetry, for a magnetized plasma in a generic bounded domain, necessarily toroidal, the uniform absorption of external energy (e.g., RF or any isotropic auxiliary heating) cannot give rise to net forces or torques. Experimental evidence on contemporary tokamaks shows that the near central absorption of RF heating power (ICH and ECH) and current drive in presence of MHD activity drives a bulk plasma rotation in the co- I p direction, opposite to the initial one. Also the appearance of classical or neoclassical tearing modes provides a nonlinear magnetic braking that tends to clamp the rotation profile at the q-rational surfaces. The physical origin of the torque associated with P RF absorption could be due the effects of asymmetry in the equilibrium configuration or in power deposition, but here we point out also an effect of the response of the so-called neoclassical offset velocity to the power dependent heat flow increment. The neoclassical toroidal viscosity due to internal magnetic kink or tearing modes tends to relax the plasma rotation to this asymptotic speed, which in absence of auxiliary heating is of the order of the ion diamagnetic velocity. It can be shown by kinetic and fluid calculations, that the absorption of auxiliary power by ions modifies this offset proportionally to the injected power thereby forcing the plasma rotation in a direction opposite to the initial, to large values. The problem is discussed in the frame of the theoretical models of neoclassical toroidal viscosity.

  4. The dynamic responses of the soil-auxiliary buildings structure interaction system

    International Nuclear Information System (INIS)

    The dynamic responses of the soil-auxiliary buildings structure interaction system in the nuclear power plant are concerned. The main distinguished feature of this study is that the extreme un-symmetry of the auxiliary buildings and reactor containment are considered. A Synthetical mechanical model for study is established. Finally, the analysis of the dynamic response of the Qinshan Nuclear Power Plant structure is taken as a simple example of applying this method and the numerical results are given

  5. Flasher Powered by Photovoltaic Cells and Ultracapacitors

    Science.gov (United States)

    Eichenberg, Dennis J.; Soltis, Richard F.

    2003-01-01

    A unique safety flasher powered by photovoltaic cells and ultracapacitors has been developed. Safety flashers are used wherever there are needs to mark actually or potentially hazardous locations. Examples of such locations include construction sites, highway work sites, and locations of hazardous operations. Heretofore, safety flashers have been powered by batteries, the use of which entails several disadvantages: Batteries must be kept adequately charged, and must not be allowed to become completely discharged. Batteries have rather short cycle lives, and their internal constituents that react chemically to generate electricity deteriorate (and hence power-generating capacities decrease) over time. The performances of batteries are very poor at low temperatures, which often occur in the circumstances in which safety flashers are most needed. The disposal of batteries poses a threat to the environment. The development of the present photovoltaic/ultracapacitor- powered safety flasher, in which the ultracapacitors are used to store energy, overcomes the aforementioned disadvantages of using batteries to store energy. The ultracapacitors in this flasher are electrochemical units that have extremely high volumetric capacitances because they contain large-surface-area electrodes separated by very small gaps. Ultracapacitors have extremely long cycle lives, as compared to batteries; consequently, it will never be necessary to replace the ultracapacitors in the safety flasher. The reliability of the flasher is correspondingly increased, and the life-of-system cost and the adverse environmental effects of the flasher are correspondingly reduced. Moreover, ultracapacitors have excellent low-temperature characteristics, are maintenance-free, and provide consistent performance over time.

  6. Perfects, resultatives and auxiliaries in early English

    OpenAIRE

    McFadden, Thomas; Alexiadou, Artemis

    2008-01-01

    In this paper, we will argue for a novel analysis of the auxiliary alternation in Early English, its development and subsequent loss which has broader consequences for the way that auxiliary selection is looked at cross-linguistically. We will present evidence that the choice of auxiliaries accompanying past participles in Early English differed in several significant respects from that in the familiar modern European languages. Specifically, while the construction with have became a full-fle...

  7. Auxiliary bearing design and rotor dynamics analysis of blower fan for HTR-10

    International Nuclear Information System (INIS)

    The electromagnetic bearing instead of ordinary mechanical bearing was chosen to support the rotor in the blower fan system with helium of 10 MW high temperature gas-cooled test reactor (HTR-10), and the auxiliary bearing was applied in the HTR-10 as the backup protector. When the electromagnetic bearing doesn't work suddenly for the power broken, the auxiliary bearing is used to support the falling rotor with high rotating speed. The rotor system will be protected by the auxiliary bearing. The design of auxiliary bearing is the ultimate safeguard for the system. This rotor is vertically mounted to hold the blower fan. The rotor's length is about 1.5 m, its weight is about 240 kg and the rotating speed is about 5400 r/min. Auxiliary bearing design and rotor dynamics analysis are very important for the design of blower fan to make success. The research status of the auxiliary bearing was summarized in the paper. A sort of auxiliary bearing scheme was proposed. MSC.Marc was selected to analyze the vibration mode and the natural frequency of the rotor. The scheme design of auxiliary bearing and analysis result of rotor dynamics offer the important theoretical base for the protector design and control system of electromagnetic bearing of the blower fan. (authors)

  8. Novel power electronic interface for grid-connected fuel cell power generation system

    International Nuclear Information System (INIS)

    Highlights: • A fuel cell power generation system was composed of a DC–DC power converter and a DC–AC inverter. • A voltage doubler based topology was adopted to configure the DC–DC power converter. • A dual buck power converter and a full-bridge power converter were applied to the DC–AC inverter. • The DC–AC inverter outputs a five-level voltage. • The DC–AC inverter performs the functions of DC–AC power conversion and active power filter. - Abstract: A novel power electronic interface for the grid-connected fuel cell power generation system is proposed in this paper. This power electronic interface is composed of a DC–DC power converter and a DC–AC inverter. A voltage doubler based topology is adopted to configure the DC–DC power converter to perform high step-up gain for boosting the output voltage of the fuel cell to a higher voltage. Moreover, the input current ripple of the fuel cell is suppressed by controlling the DC–DC power converter. The DC–AC inverter is configured by a dual buck power converter and a full-bridge power converter to generate a five-level AC output voltage. The DC–AC inverter can perform the functions of DC–AC power conversion and active power filtration. A 1.2 kW hardware prototype is developed to verify the performance of the proposed power electronic interface for the grid-connected fuel cell power generation system. The experimental results show that the proposed power electronic interface for the grid-connected fuel cell power generation system has the expected performance

  9. 福清核电1、2号机组增大应急给水箱容积安全分析%Safety Analysis on the Volume Increase of Auxiliary Water Tank for Number One and Two Units of Fuqing Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    佟立丽; 邵舸; 顾健; 薛峻峰; 彭建平; 王志强

    2013-01-01

    When main feed water system or start-up feed water system is unavailable, auxiliary feed water system, as Engineered Safety Facility (ESF), provides water for Steam Generators (SG) to remove the stored and decay heat from the reactor core. In order to improve the safety of Nuclear Power Plants (NPPs) and increase operational flexibility, the water inventory of the auxiliary feed water tank is increased in the number one and two units of Fuqing NPP. The model of the NPP is built based on mechanical safety analytical code, and conservative assumptions are used in the calculation. Three typical accident sequences, such as loss of main feed water, loss of offsite power in category Ⅱ accident, and main feed water line break in category IV, are selected to analyze whether or not the inventory in auxiliary water tank after improvement satisfies the relevant requirements in RCC-R The results show that auxiliary water inventory of 713m3 is needed for loss of main feed water accident, auxiliary water inventory of 723m3 is needed for loss of offsite power accident, and auxiliary water inventory of 799m3 is needed for main feed water line break accident. The inventory in auxiliary water tank after improvement satisfies the requirements for category Ⅱ and Ⅳ accidents. The safety of NPP is improved due to the inventory redundancy and a time window is also provided for the operators to perform related accident procedures.%辅助给水系统(ASG)作为专设安全设施在主给水或启动给水不可用时向蒸汽发生器供水,以导出堆芯余热.为了提高电厂安全性,增加运行灵活性,福清核电1、2号机组对应急给水箱的有效容积进行了增加.本文采用机理性安全分析程序,建立核电厂分析模型,在计算过程中采用保守假设条件,选取Ⅱ类工况下正常给水丧失事故,厂外电丧失事故,Ⅳ类工况下主给水管道破裂事故3条典型事故序列,分析改进后的应急给水箱容量是否满足压水

  10. AC power generation from microbial fuel cells

    Science.gov (United States)

    Lobo, Fernanda Leite; Wang, Heming; Forrestal, Casey; Ren, Zhiyong Jason

    2015-11-01

    Microbial fuel cells (MFCs) directly convert biodegradable substrates to electricity and carry good potential for energy-positive wastewater treatment. However, the low and direct current (DC) output from MFC is not usable for general electronics except small sensors, yet commercial DC-AC converters or inverters used in solar systems cannot be directly applied to MFCs. This study presents a new DC-AC converter system for MFCs that can generate alternating voltage in any desired frequency. Results show that AC power can be easily achieved in three different frequencies tested (1, 10, 60 Hz), and no energy storage layer such as capacitors was needed. The DC-AC converter efficiency was higher than 95% when powered by either individual MFCs or simple MFC stacks. Total harmonic distortion (THD) was used to investigate the quality of the energy, and it showed that the energy could be directly usable for linear electronic loads. This study shows that through electrical conversion MFCs can be potentially used in household electronics for decentralized off-grid communities.

  11. Airport electric vehicle powered by fuel cell

    Science.gov (United States)

    Fontela, Pablo; Soria, Antonio; Mielgo, Javier; Sierra, José Francisco; de Blas, Juan; Gauchia, Lucia; Martínez, Juan M.

    Nowadays, new technologies and breakthroughs in the field of energy efficiency, alternative fuels and added-value electronics are leading to bigger, more sustainable and green thinking applications. Within the Automotive Industry, there is a clear declaration of commitment with the environment and natural resources. The presence of passenger vehicles of hybrid architecture, public transport powered by cleaner fuels, non-aggressive utility vehicles and an encouraging social awareness, are bringing to light a new scenario where conventional and advanced solutions will be in force. This paper presents the evolution of an airport cargo vehicle from battery-based propulsion to a hybrid power unit based on fuel cell, cutting edge batteries and hydrogen as a fuel. Some years back, IBERIA (Major Airline operating in Spain) decided to initiate the replacement of its diesel fleet for battery ones, aiming at a reduction in terms of contamination and noise in the surrounding environment. Unfortunately, due to extreme operating conditions in airports (ambient temperature, intensive use, dirtiness, …), batteries suffered a very severe degradation, which took its toll in terms of autonomy. This reduction in terms of autonomy together with the long battery recharge time made the intensive use of this fleet impractical in everyday demanding conditions.

  12. 47 CFR 73.1675 - Auxiliary antennas.

    Science.gov (United States)

    2010-10-01

    ... Class A TV licensees may request a decrease from the authorized facility's ERP in the license application. An FM, TV or Class A TV licensee may also increase the ERP of the auxiliary facility in a license... licensed main facility as an auxiliary facility with an ERP less than or equal to the ERP specified on...

  13. Nonlinear predictive control for durability enhancement and efficiency improvement in a fuel cell power system

    Science.gov (United States)

    Luna, Julio; Jemei, Samir; Yousfi-Steiner, Nadia; Husar, Attila; Serra, Maria; Hissel, Daniel

    2016-10-01

    In this work, a nonlinear model predictive control (NMPC) strategy is proposed to improve the efficiency and enhance the durability of a proton exchange membrane fuel cell (PEMFC) power system. The PEMFC controller is based on a distributed parameters model that describes the nonlinear dynamics of the system, considering spatial variations along the gas channels. Parasitic power from different system auxiliaries is considered, including the main parasitic losses which are those of the compressor. A nonlinear observer is implemented, based on the discretised model of the PEMFC, to estimate the internal states. This information is included in the cost function of the controller to enhance the durability of the system by means of avoiding local starvation and inappropriate water vapour concentrations. Simulation results are presented to show the performance of the proposed controller over a given case study in an automotive application (New European Driving Cycle). With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a two-phase water model and the effects of liquid water on the catalyst active area. The control model is a simplified version that does not consider two-phase water dynamics.

  14. Progress and prospects for phosphoric acid fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J. [International Fuel Cells Corp., South Windsor, CT (United States)

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

  15. Fuel cells multi-stack power architectures and experimental validation of 1 kW parallel twin stack PEFC generator based on high frequency magnetic coupling dedicated to on board power unit

    International Nuclear Information System (INIS)

    This paper presents a study of a polymer electrolyte fuel cell (PEFC) multi-stack generator and its power electronic interface dedicated to an on board vehicle power unit. A parallel electric architecture has been designed and tested. First, a dynamic model of the PEFC stack, valid for high frequencies and compatible with power converter interactions, has been developed. This model is used for simulations of the global fuel cell and power converter behaviors. Second, an inventory of generic multi-stack fuel cells architectures is presented in order to couple electrically the fuel cell stacks to an on board DC bus (in series, parallel, through magnetic coupling..). This state of the art is completed by an overview of several candidate power converter topologies for fuel cells. Then, among all the possible technical solutions, an original power converter architecture using a high frequency planar transformer is proposed, which allows parallel and series magnetic couplings of two fuel cell stacks. Then, the study focuses on a first step, which is the association of two PEFC stacks. Such a structure, having good efficiency, is well adapted for testing and operation of fuel cells in normal and degraded working modes, which correspond to real constraints on board a vehicle. Finally, experimental validations on a 2 x 500 W twin stack PEFC with power converter interface demonstrate the technological feasibility for the embarked multi-stack fuel cells generator. The 1 kW power level chosen for the experimentation is close to that of a small on board PEFC auxiliary power unit (APU)

  16. Fuel cells make gains in power generation market

    International Nuclear Information System (INIS)

    The ultra-low emission, highly efficient natural gas-fueled fuel cell system is beginning to penetrate the electric power generation market in the US and abroad as the fuel cell industry lowers product costs. And, even as the current market continues to grow, fuel cell companies are developing new technology with even higher levels of energy efficiency. The paper discusses fuel cell efficiency, business opportunities, work to reduce costs, and evolving fuel cell technology

  17. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  18. 46 CFR 58.01-35 - Main propulsion auxiliary machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main propulsion auxiliary machinery. 58.01-35 Section 58... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-35 Main propulsion auxiliary machinery. Auxiliary machinery vital to the main propulsion system must be provided in duplicate unless the...

  19. Process modeling of fuel cell vehicle power system

    Institute of Scientific and Technical Information of China (English)

    CHEN LiMing; LIN ZhaoJia; MA ZiFeng

    2009-01-01

    Constructed here is a mathematic model of PEM Fuel Cell Vehicle Power System which is composed of fuel supply model, fuel cell stack model and water-heat management model. The model was developed by Matiab/Simulink to evaluate how the major operating variables affect the output performances. Itshows that the constructed model can represent characteristics of the power system closely by comparing modeling results with experimental data, and it can be used in the study and design of fuel cell vehicle power system.

  20. Photovoltaic cells for laser power beaming

    Science.gov (United States)

    Landis, Geoffrey A.; Jain, Raj K.

    1992-01-01

    To better understand cell response to pulsed illumination at high intensity, the PC-1DC finite-element computer model was used to analyze the response of solar cells to pulsed laser illumination. Over 50% efficiency was calculated for both InP and GaAs cells under steady-state illumination near the optimum wavelength. The time-dependent response of a high-efficiency GaAs concentrator cell to a laser pulse was modelled, and the effect of laser intensity, wavelength, and bias point was studied. Designing a cell to accommodate pulsed input can be done either by accepting the pulsed output and designing a cell to minimize adverse effects due to series resistance and inductance, or to design a cell with a long enough minority carrier lifetime, so that the output of the cell will not follow the pulse shape. Two such design possibilities are a monolithic, low-inductance voltage-adding GaAs cell, or a high-efficiency, light-trapping silicon cell. The advantages of each design will be discussed.

  1. Integrated Solid Oxide Fuel Cell Power System Characteristics Prediction

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2009-07-01

    Full Text Available The main objective of this paper is to deduce the specific characteristics of the CHP 100kWe Solid Oxide Fuel Cell (SOFC Power System from the steady state experimental data. From the experimental data, the authors have been developed and validated the steady state mathematical model. From the control room the steady state experimental data of the SOFC power conditioning are available and using the developed steady state mathematical model, the authors have been obtained the characteristic curves of the system performed by Siemens-Westinghouse Power Corporation. As a methodology the backward and forward power flow analysis has been employed. The backward power flow makes possible to obtain the SOFC power system operating point at different load levels, resulting as the load characteristic. By knowing the fuel cell output characteristic, the forward power flow analysis is used to predict the power system efficiency in different operating points, to choose the adequate control decision in order to obtain the high efficiency operation of the SOFC power system at different load levels. The CHP 100kWe power system is located at Gas Turbine Technologies Company (a Siemens Subsidiary, TurboCare brand in Turin, Italy. The work was carried out through the Energia da Ossidi Solidi (EOS Project. The SOFC stack delivers constant power permanently in order to supply the electric and thermal power both to the TurboCare Company and to the national grid.

  2. Dynamic simulation of a direct carbonate fuel cell power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ernest, J.B. [Fluor Daniel, Inc., Irvine, CA (United States); Ghezel-Ayagh, H.; Kush, A.K. [Fuel Cell Engineering, Danbury, CT (United States)

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  3. The coolest power in the district

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-04-01

    Gas turbines for both power generation and for cooling have been successfully installed at Kuala Lumpur Airport. The system provides 40 MWe through two gas turbines and 80 MWth through nine steam absorption chillers. The three basic elements to the plant are (i) cogeneration plant, (ii) district cooling plant and (iii) auxiliary plant; all are described briefly. Phase 1 has been completed; phase 2, due for completion in 2012 will consist of 1 x 20 MWe turbine, 1 x 40 t/h HRSG, 1 x 25 t/h auxiliary boiler, 5 x 8.8 MWt steam chillers and three additional cooling tower cells. (UK)

  4. The Power and the Promise of Cell Reprogramming: Personalized Autologous Body Organ and Cell Transplantation

    OpenAIRE

    Ana Belen Alvarez Palomo; Michaela Lucas; Dilley, Rodney J.; Samuel McLenachan; Fred Kuanfu Chen; Jordi Requena; Marti Farrera Sal; Andrew Lucas; Inaki Alvarez; Dolores Jaraquemada; Michael J. Edel

    2014-01-01

    Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) or direct reprogramming to desired cell types are powerful and new in vitro methods for the study of human disease, cell replacement therapy, and drug development. Both methods to reprogram cells are unconstrained by the ethical and social questions raised by embryonic stem cells. iPSC technology promises to enable personalized autologous cell therapy and has the potential to revolutionize cell replacement therapy and rege...

  5. A Lemon Cell Battery for High-Power Applications

    Science.gov (United States)

    Muske, Kenneth R.; Nigh, Christopher W.; Weinstein, Randy D.

    2007-04-01

    This article discusses the development of a lemon cell battery for high-power applications. The target application is the power source of a dc electric motor for a model car constructed by first-year engineering students as part of their introductory course design project and competition. The battery is composed of a series of lemon juice cells made from UV vis cuvets that use a magnesium anode and copper cathode. Dilution of the lemon juice to reduce the rate of corrosion of the magnesium anode and the addition of table salt to reduce the internal resistance of the cell are examined. Although our specific interest is the use of this lemon cell battery to run an electric dc motor, high-power applications such as radios, portable cassette or CD players, and other battery-powered toys are equally appropriate for demonstration and laboratory purposes using this battery.

  6. Advanced Space Power Systems (ASPS): Regenerative Fuel Cells (RFC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the regenerative fuel cell project element is to develop power and energy storage technologies that enable new capabilities for future human space...

  7. Modeling and Nonlinear Control of Electric Power Stage in Hybrid Electric Vehicle

    DEFF Research Database (Denmark)

    Tahri, A.; El Fadil, H.; Guerrero, Josep M.;

    2014-01-01

    This paper deals with the problem of modeling and controlling the electric power stage of hybrid electric vehicle. The controlled system consists of a fuel cell (FC) as a main source, a supercapacitor as an auxiliary source, two DC-DC power converters, an inverter and a traction induction motor...

  8. Accelerating Acceptance of Fuel Cell Backup Power Systems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Petrecky, James; Ashley, Christopher

    2014-07-21

    Since 2001, Plug Power has installed more than 800 stationary fuel cell systems worldwide. Plug Power’s prime power systems have produced approximately 6.5 million kilowatt hours of electricity and have accumulated more than 2.5 million operating hours. Intermittent, or backup, power products have been deployed with telecommunications carriers and government and utility customers in North and South America, Europe, the United Kingdom, Japan and South Africa. Some of the largest material handling operations in North America are currently using the company’s motive power units in fuel cell-powered forklifts for their warehouses, distribution centers and manufacturing facilities. The low-temperature GenSys fuel cell system provides remote, off-grid and primary power where grid power is unreliable or nonexistent. Built reliable and designed rugged, low- temperature GenSys delivers continuous or backup power through even the most extreme conditions. Coupled with high-efficiency ratings, low-temperature GenSys reduces operating costs making it an economical solution for prime power requirements. Currently, field trials at telecommunication and industrial sites across the globe are proving the advantages of fuel cells—lower maintenance, fuel costs and emissions, as well as longer life—compared with traditional internal combustion engines.

  9. High power density yeast catalyzed microbial fuel cells

    Science.gov (United States)

    Ganguli, Rahul

    Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

  10. Builtin vs. auxiliary detection of extrapolation risk.

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Miles Arthur; Kegelmeyer, W. Philip,

    2013-02-01

    A key assumption in supervised machine learning is that future data will be similar to historical data. This assumption is often false in real world applications, and as a result, prediction models often return predictions that are extrapolations. We compare four approaches to estimating extrapolation risk for machine learning predictions. Two builtin methods use information available from the classification model to decide if the model would be extrapolating for an input data point. The other two build auxiliary models to supplement the classification model and explicitly model extrapolation risk. Experiments with synthetic and real data sets show that the auxiliary models are more reliable risk detectors. To best safeguard against extrapolating predictions, however, we recommend combining builtin and auxiliary diagnostics.

  11. Photovoltaic Test and Demonstration Project. [for solar cell power systems

    Science.gov (United States)

    Forestieri, A. F.; Brandhorst, H. W., Jr.; Deyo, J. N.

    1976-01-01

    The Photovoltaic Test and Demonstration Project was initiated by NASA in June, 1975, to develop economically feasible photovoltaic power systems suitable for a variety of terrestrial applications. Objectives include the determination of operating characteristic and lifetimes of a variety of solar cell systems and components and development of methodology and techniques for accurate measurements of solar cell and array performance and diagnostic measurements for solar power systems. Initial work will be concerned with residential applications, with testing of the first prototype system scheduled for June, 1976. An outdoor 10 kW array for testing solar power systems is under construction.

  12. Fuel cell and advanced turbine power cycle

    Energy Technology Data Exchange (ETDEWEB)

    White, D.J. [Solar Turbines, Inc., San Diego, CA (United States)

    1995-10-19

    Solar Turbines, Incorporated (Solar) has a vested interest in the integration of gas turbines and high temperature fuel cells and in particular, solid oxide fuel cells (SOFCs). Solar has identified a parallel path approach to the technology developments needed for future products. The primary approach is to move away from the simple cycle industrial machines of the past and develop as a first step more efficient recuperated engines. This move was prompted by the recognition that the simple cycle machines were rapidly approaching their efficiency limits. Improving the efficiency of simple cycle machines is and will become increasingly more costly. Each efficiency increment will be progressively more costly than the previous step.

  13. Solar energy powered microbial fuel cell with a reversible bioelectrode

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Hamelers, H.V.M.; Buisman, C.J.N.

    2010-01-01

    The solar energy powered microbial fuel cell is an emerging technology for electricity generation via electrochemically active microorganisms fueled by solar energy via in situ photosynthesized metabolites from algae, cyanobacteria, or living higher plants. A general problem with microbial fuel cell

  14. Nuclear reactors with auxiliary boiler circuit

    International Nuclear Information System (INIS)

    A gas-cooled nuclear reactor has a main circulatory system for the gaseous coolant incorporating one or more main energy converting units, such as gas turbines, and an auxiliary circulatory system for the gaseous coolant incorporating at least one steam generating boiler arranged to be heated by the coolant after its passage through the reactor core to provide steam for driving an auxiliary steam turbine, such an arrangement providing a simplified start-up procedure also providing emergency duties associated with long term heat removal on reactor shut down

  15. High performance monolithic power management system with dynamic maximum power point tracking for microbial fuel cells.

    Science.gov (United States)

    Erbay, Celal; Carreon-Bautista, Salvador; Sanchez-Sinencio, Edgar; Han, Arum

    2014-12-01

    Microbial fuel cell (MFC) that can directly generate electricity from organic waste or biomass is a promising renewable and clean technology. However, low power and low voltage output of MFCs typically do not allow directly operating most electrical applications, whether it is supplementing electricity to wastewater treatment plants or for powering autonomous wireless sensor networks. Power management systems (PMSs) can overcome this limitation by boosting the MFC output voltage and managing the power for maximum efficiency. We present a monolithic low-power-consuming PMS integrated circuit (IC) chip capable of dynamic maximum power point tracking (MPPT) to maximize the extracted power from MFCs, regardless of the power and voltage fluctuations from MFCs over time. The proposed PMS continuously detects the maximum power point (MPP) of the MFC and matches the load impedance of the PMS for maximum efficiency. The system also operates autonomously by directly drawing power from the MFC itself without any external power. The overall system efficiency, defined as the ratio between input energy from the MFC and output energy stored into the supercapacitor of the PMS, was 30%. As a demonstration, the PMS connected to a 240 mL two-chamber MFC (generating 0.4 V and 512 μW at MPP) successfully powered a wireless temperature sensor that requires a voltage of 2.5 V and consumes power of 85 mW each time it transmit the sensor data, and successfully transmitted a sensor reading every 7.5 min. The PMS also efficiently managed the power output of a lower-power producing MFC, demonstrating that the PMS works efficiently at various MFC power output level. PMID:25365216

  16. Smart Energy Management of Multiple Full Cell Powered Applications

    Energy Technology Data Exchange (ETDEWEB)

    MOhammad S. Alam

    2007-04-23

    In this research project the University of South Alabama research team has been investigating smart energy management and control of multiple fuel cell power sources when subjected to varying demands of electrical and thermal loads together with demands of hydrogen production. This research has focused on finding the optimal schedule of the multiple fuel cell power plants in terms of electric, thermal and hydrogen energy. The optimal schedule is expected to yield the lowest operating cost. Our team is also investigating the possibility of generating hydrogen using photoelectrochemical (PEC) solar cells through finding materials for efficient light harvesting photoanodes. The goal is to develop an efficient and cost effective PEC solar cell system for direct electrolysis of water. In addition, models for hydrogen production, purification, and storage will be developed. The results obtained and the data collected will be then used to develop a smart energy management algorithm whose function is to maximize energy conservation within a managed set of appliances, thereby lowering O/M costs of the Fuel Cell power plant (FCPP), and allowing more hydrogen generation opportunities. The Smart Energy Management and Control (SEMaC) software, developed earlier, controls electrical loads in an individual home to achieve load management objectives such that the total power consumption of a typical residential home remains below the available power generated from a fuel cell. In this project, the research team will leverage the SEMaC algorithm developed earlier to create a neighborhood level control system.

  17. Electrochemical power sources batteries, fuel cells, and supercapacitors

    CERN Document Server

    Bagotsky, Vladimir S; Volfkovich, Yurij M

    2015-01-01

    Electrochemical Power Sources (EPS) provides in a concise way theoperational features, major types, and applications of batteries,fuel cells, and supercapacitors Details the design, operational features, andapplications of batteries, fuel cells, and supercapacitors Covers improvements of existing EPSs and thedevelopment of new kinds of EPS as the results of intense R&Dwork Provides outlook for future trends in fuel cells andbatteries Covers the most typical battery types, fuel cells andsupercapacitors; such as zinc-carbon batteries, alkaline manganesedioxide batteries, mercury-zinc cells, lead

  18. Design and performance of a prototype fuel cell powered vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, P.A.; Chamberlin, C.E. [Humboldt State Univ., Arcata, CA (United States)

    1996-12-31

    The Schatz Energy Research Center (SERC) is now engaged in the Palm Desert Renewable Hydrogen Transportation System Project. The Project involves a consortium which includes the City of Palm Desert, SERC, the U.S. Department of Energy, the South Coast Air Quality Management District, and Sandia and Lawrence Livermore National Laboratories. Its goal to develop a clean and sustainable transportation system for a community will be accomplished by producing a fleet of fuel cell vehicles, installing a refueling infrastructure utilizing hydrogen generated from solar and wind power, and developing and staffing a fuel cell service and diagnostic center. We will describe details of the project and performance goals for the fuel cell vehicles and associated peripheral systems. In the past year during the first stage in the project, SERC has designed and built a prototype fuel cell powered personal utility vehicle (PUV). These steps included: (1) Designing, building, and testing a 4.0 kW proton exchange membrane (PEM) fuel cell as a power plant for the PUV. (2) Designing, building and testing peripherals including the air delivery, fuel storage/delivery, refueling, water circulation, cooling, and electrical systems. (3) Devising a control algorithm for the fuel cell power plant in the PUV. (4) Designing and building a test bench in which running conditions in the PUV could be simulated and the fuel cell and its peripheral systems tested. (5) Installing an onboard computer and associated electronics into the PUV (6) Assembling and road testing the PUV.

  19. Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices

    Science.gov (United States)

    Zebda, A.; Cosnier, S.; Alcaraz, J.-P.; Holzinger, M.; Le Goff, A.; Gondran, C.; Boucher, F.; Giroud, F.; Gorgy, K.; Lamraoui, H.; Cinquin, P.

    2013-01-01

    We describe the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal's body fluids to act as the sole power source for electronic devices. This GBFC is based on carbon nanotube/enzyme electrodes, which utilize glucose oxidase for glucose oxidation and laccase for dioxygen reduction. The GBFC, implanted in the abdominal cavity of a rat, produces an average open-circuit voltage of 0.57 V. This implanted GBFC delivered a power output of 38.7 μW, which corresponded to a power density of 193.5 μW cm−2 and a volumetric power of 161 μW mL−1. We demonstrate that one single implanted enzymatic GBFC can power a light-emitting diode (LED), or a digital thermometer. In addition, no signs of rejection or inflammation were observed after 110 days implantation in the rat. PMID:23519113

  20. Modeling and Nonlinear Control of Fuel Cell / Supercapacitor Hybrid Energy Storage System for Electric Vehicles

    DEFF Research Database (Denmark)

    El Fadil, Hassan; Giri, Fouad; Guerrero, Josep M.;

    2014-01-01

    This paper deals with the problem of controlling hybrid energy storage system (HESS) for electric vehicle. The storage system consists of a fuel cell (FC), serving as the main power source, and a supercapacitor (SC), serving as an auxiliary power source. It also contains a power block for energy...

  1. Curricular Guidelines for Dental Auxiliary Radiology.

    Science.gov (United States)

    Journal of Dental Education, 1981

    1981-01-01

    AADS curricular guidelines suggest objectives for these areas of dental auxiliary radiology: physical principles of X-radiation in dentistry, related radiobiological concepts, principles of radiologic health, radiographic technique, x-ray films and intensifying screens, factors contributing to film quality, darkroom, and normal variations in…

  2. Geostatistical modeling of topography using auxiliary maps

    NARCIS (Netherlands)

    T. Hengl; B. Bajat; D. Blagojević; H.I. Reuter

    2008-01-01

    This paper recommends computational procedures for employing auxiliary maps, such as maps of drainage patterns, land cover and remote-sensing-based indices, directly in the geostatistical modeling of topography. The methodology is based on the regression-kriging technique, as implemented in the R pa

  3. Window-mounted auxiliary solar heater

    Science.gov (United States)

    Anthony, K. G.; Herndon, E. P.

    1977-01-01

    System uses hot-air collectors, no thermal storage, and fan with thermostat switches. At cost of heating efficiency, unit could be manufactured and sold at price allowing immediate entry to market as auxiliary heating system. Its simplicity allows homeowner installation, and maintenance is minimal.

  4. A high-power carbohydrate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Ragnar [SuFuCell AB, Bytaregatan 23, SE 222 21 Lund (Sweden); Folkesson, Boerje [Bronsaaldersvaegen 21, SE-226 54 Lund (Sweden); Spaziante, Placido M. [Cellennium Co., Ltd., 14th Floor Gypsum Metropolitan Tower, 539 Sri Ayudhaya Rd., Bangkok 10400 (Thailand); Veerasai, Waret [Chemistry Department, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Exell, Robert H.B. [Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, 91 Prachauthit Rd., Bangmod, Tungkru, Bangkok 10140 (Thailand)

    2006-04-01

    This paper reports the development of a fuel cell consisting of a vanadium flow battery in which the vanadium ions are reduced by sugar (from a carbohydrate) to oxidation state +3 on one side of a membrane, and are oxidized to state +5 on the other side by oxygen. The theoretical upper limit to the conversion efficiency of the energy in sugar by this method under standard conditions is 54%. We have obtained efficiencies up to 45% in our laboratory tests. This way of using biomass for electricity production avoids the Carnot cycle losses in heat engines. (author)

  5. A portable power system using PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Long, E. [Ball Aerospace and Technologies Corp., Boulder, CO (United States)

    1997-12-31

    Ball has developed a proof-of-concept, small, lightweight, portable power system. The power system uses a proton exchange membrane (PEM) fuel cell stack, stored hydrogen, and atmospheric oxygen as the oxidant to generate electrical power. Electronics monitor the system performance to control cooling air and oxidant flow, and automatically do corrective measures to maintain performance. With the controller monitoring the system health, the system can operate in an ambient environment from 0 C to +50 C. The paper describes system testing, including load testing, thermal and humidity testing, vibration and shock testing, field testing, destructive testing of high-pressure gas tanks, and test results on the fuel cell power system, metal hydride hydrogen storage, high-pressure hydrogen gas storage, and chemical hydride hydrogen storage.

  6. Performance Analysis of Reconfigurable SRAM Cell for Low Power Applications

    Directory of Open Access Journals (Sweden)

    Dillibabu.Mannem

    2012-06-01

    Full Text Available The majority of space taken in an integrated circuit is the memory. SRAM design consists of key considerations, such as increased speed, low power and reduced layout area. A cell which is functional at the nominal supply voltage, can fail at a lower voltage. From a system perspective this leads to a higher bit-error rate with voltage scaling and limits the opportunity for power saving. While this is a serious bottleneck for SRAM arrays used for data storage. This paper presents a performance analysis of reconfigurable SRAM cell for low power application. Simulations using TSMC 0.35um technology show that the SRAM cell read & write access times are 1.53ns and 1.93ns. Mentor Graphics ELDO and EZ-wave are used for simulations.

  7. Modeling and optimization of a heat-pump-assisted high temperature proton exchange membrane fuel cell micro-combined-heat-and-power system for residential applications

    DEFF Research Database (Denmark)

    Arsalis, Alexandros; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2015-01-01

    In this study a micro-combined-heat-and-power (micro-CHP) system is coupled to a vapor-compression heat pump to fulfill the residential needs for heating (space heating and water heating) and electricity in detached single-family households in Denmark. Such a combination is assumed to be attractive...... for application, since both fuel cell technology and electric heat pumps are found to be two of the most efficient technologies for generation/conversion of useful energy. The micro-CHP system is fueled with natural gas and includes a fuel cell stack, a fuel processor and other auxiliary components. The micro....... The variational loads are considered from full to quarter load, and the micro-CHP system is optimized in terms of operating thermophysical parameters for every different load. The results clearly indicate the capability of the proposed system to perform efficiently throughout all necessary load changes to fulfill...

  8. Computer determination of event maps with application to auxiliary supply systems

    International Nuclear Information System (INIS)

    A method of evaluating the reliability of sequential operations in systems containing standby and alternate supply facilities is presented. The method is based upon the use of a digital computer for automatic development of event maps. The technique is illustrated by application to a nuclear power plant auxiliary supply system. (author)

  9. Soft switching DC/DC converter using controlled output rectifier with auxiliary circuit

    OpenAIRE

    Dudrik, Jaroslav; BODOR Marcel; TRIP Daniel Nistor

    2010-01-01

    Auxiliary circuit for DC/DC converter withcontrolled output rectifier is presented in this paper.Soft switching for power switches of the inverter isachieved by using controlled output rectifier and softswitching of the controlled rectifier by using losslessauxiliary circuit. The principle of converter operationis explained and analyzed and experimental results onthe laboratory model are presented.

  10. Integrating fuel cell power systems into building physical plants

    Energy Technology Data Exchange (ETDEWEB)

    Carson, J. [KCI Technologies, Inc., Hunt Valley, MD (United States)

    1996-12-31

    This paper discusses the integration of fuel cell power plants and absorption chillers to cogenerate chilled water or hot water/steam for all weather air conditioning as one possible approach to building system applications. Absorption chillers utilize thermal energy in an absorption based cycle to chill water. It is feasible to use waste heat from fuel cells to provide hydronic heating and cooling. Performance regimes will vary as a function of the supply and quality of waste heat. Respective performance characteristics of fuel cells, absorption chillers and air conditioning systems will define relationships between thermal and electrical load capacities for the combined systems. Specifically, this paper develops thermodynamic relationships between bulk electrical power and cooling/heating capacities for combined fuel cell and absorption chiller system in building applications.

  11. Solar combisystems with forecast control to increase the solar fraction and lower the auxiliary energy cost

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua;

    2011-01-01

    Solar Combi systems still need quite a lot of auxiliary energy especially in small systems without seasonal storage possibilities. The control of the auxiliary energy input both in time and power is important to utilize as much as possible of the solar energy available from the collectors and also...... energy sources. It can be either direct electric heating elements or a heat pump upgrading ambient energy in the air, ground, solar collector or waste heat from the house. The paper describes system modeling and simulation results. Advanced laboratory experiments are also starting now with three...

  12. Study and Application of Universal Model for Quantitative Exergy Analysis of Auxiliary Steam and Water for the Coal-fired Power Unit%火电厂辅助汽水系统定量(火用)分析计算通用模型的研究与应用

    Institute of Scientific and Technical Information of China (English)

    吴智泉; 安连锁; 韩中合

    2011-01-01

    根据(火用)平衡方程,利用(火用)效率的概念对火电厂各回热加热器进行了分析,通过论证推导,提出了火电机组辅助汽水系统定量(火用)分析计算的通用模型.运用此模型定量计算某电厂328.5MW机组高压缸轴封漏汽利用对汽轮机装置系统(火用)效率的影响;为辅助系统局部定量分析提供了便利方法.%Based on exergy balanced equation, with the concept of exergy efficiency the exergy analysis of heaters is worked.Based on strict deduction and demonstration, the general quantitative exergy calculation model of auxiliary steam and water for the coal-fired power unit is given. With this model,take the utilization of shaft-packing leakage in HP cylinder of a 328.5MW unit to define its effect on steam turbine thermal system. What is more,it provides new theoretic base for coal-fired power unit's thermal exergy analysis especially for partial qualitative exergy analysis.

  13. CMOS Low Power Cell Library for Digital Design

    Directory of Open Access Journals (Sweden)

    Kanika Kaur

    2013-06-01

    Full Text Available Historically, VLSI designers have focused on increasing the speed and reducing the area of digital systems. However, the evolution of portable systems and advanced Deep Sub-Micron fabrication technologies have brought power dissipation as another critical design factor. Low power design reduces cooling cost and increases reliability especially for high density systems. Moreover, it reduces the weight and size of portable devices. The power dissipation in CMOS circuits consists of static and dynamic components. Since dynamic power is proportional to V2 dd and static power is proportional to Vdd, lowering the supply voltage and device dimensions, the transistor threshold voltage also has to be scaled down to achieve the required performance. In case of static power, the power is consumed during the steady state condition i.e when there are no input/output transitions. Static power has two sources: DC power and Leakage power. Consecutively to facilitate voltage scaling without disturbing the performance, threshold voltage has to be minimized. Furthermore it leads to better noise margins and helps to avoid the hot carrier effects in short channel devices. In this paper we have been proposed the new CMOS library for the complex digital design using scaling the supply voltage and device dimensions and also suggest the methods to control the leakage current to obtain the minimum power dissipation at optimum value of supply voltage and transistor threshold. In this paper CMOS Cell library has been implemented using TSMC (0.18um and TSMC (90nm technology using HEP2 tool of IC designing from Mentor Graphics for various analysis and simulations.

  14. FINFET-BASED LOW POWER & HIGH SPEED SRAM CELL DESIGN

    Directory of Open Access Journals (Sweden)

    SHILPA SAXENA

    2016-07-01

    Full Text Available In digital circuits designing the SRAM design constraints are very important. In the integrated circuits fabrication the majority of space is taken by the memories.. The design considerations of SRAM consist of: increased speed and reduced power. CMOS devices are shrinking to nanometer regime, thereby, increasing short channel effects and process parameter variations that degrades the reliability of the circuit as well as performance. To solve these issues of CMOS, FinFET proves to be better technology, without sacrificing reliability and performance for its applications and the circuit design. The use of FinFETs, transmission gates are used in the access path of the SRAM Cell and the Sleep transistors power gating technique are used for low leakage power and high performance. The transient and dc analysis of the proposed ST11T, ST13T and with sleep transistors SRAM cell has been obtained using Cadence Virtuoso tool and BSIMCMG model 107.0.0 for 22nm FinFETs to achieve high performance. It can be observed from the results that the percentage improvement of 97.30% in power dissipation 27.77% in delay, 98.05% in PDP and 38.37% increase in speed is obtained for the proposed finFET-based ST13T circuit with power gating technique are that shows the high performance for SRAM Cell as compared to design based on CMOS technology.

  15. FUEL CELL OPERATION ON LANDFILL GAS AT PENROSE POWER STATION

    Science.gov (United States)

    This demonstration test successfully demonstrated operation of a commercial phosphoric acid fuel cell (FC) on landfill gas (LG) at the Penrose Power Station in Sun Valley, CA. Demonstration output included operation up to 137 kW; 37.1% efficiency at 120 kW; exceptionally low sec...

  16. Modified Darboux transformations with foreign auxiliary equations

    International Nuclear Information System (INIS)

    We construct a new type of first-order Darboux transformations for the stationary Schroedinger equation. In contrast to the conventional case, our Darboux transformations support arbitrary (foreign) auxiliary equations. We show that among other applications, our formalism can be used to systematically construct Darboux transformations for Schroedinger equations with energy-dependent potentials, including a recent result (Lin et al., 2007) as a special case. -- Highlights: → We generalize the Darboux transformation for the Schroedinger equation. → By admitting arbitrary auxiliary functions, we provide a new tool for generating solutions. → As a special case we recover a recent result on energy-dependent potentials. → We extend the latter result to very general energy-dependence.

  17. Heterotopic Auxiliary Liver Transplantation with Portal Flow

    OpenAIRE

    Laureano Lorente; Jaime Arias; Maria Angeles Aller; José Ignacio Ispizua; José Rodriguez; Hipólito Durán

    1990-01-01

    One of the causes of auxiliary liver transplantation failure is the inter-liver competition between the host liver and the graft for the hepatotrophic factors of the portal blood. We have developed an experimental model of heterotopic partial (30%) liver isotransplant using Wistar rats so as to study this competition. Splenoportography and dissection demonstrate the existence of collateral circulation. The collaterals at 90 days post-transplant (PT) consisted of veins from the portal vein to ...

  18. Auxiliary nRules of Quantum Mechanics

    OpenAIRE

    Mould, Richard A

    2005-01-01

    Standard quantum mechanics makes use of four auxiliary rules that allow the Schrodinger solutions to be related to laboratory experience, such as the Born rule that connects square modulus to probability. These rules (here called the sRules) lead to some unacceptable results. They do not allow the primary observer to be part of the system. They do not allow individual observations (as opposed to ensembles) to be part of the system. They make a fundamental distinction between microscopic and m...

  19. Retinal ganglion cell distribution and spatial resolving power in elasmobranchs.

    Science.gov (United States)

    Lisney, Thomas J; Collin, Shaun P

    2008-01-01

    The total number, distribution and peak density of presumed retinal ganglion cells was assessed in 10 species of elasmobranch (nine species of shark and one species of batoid) using counts of Nissl-stained cells in retinal wholemounts. The species sampled include a number of active, predatory benthopelagic and pelagic sharks that are found in a variety of coastal and oceanic habitats and represent elasmobranch groups for which information of this nature is currently lacking. The topographic distribution of cells was heterogeneous in all species. Two benthic species, the shark Chiloscyllium punctatum and the batoid Taeniura lymma, have a dorsal or dorso-central horizontal streak of increased cell density, whereas the majority of the benthopelagic and pelagic sharks examined exhibit a more concentric pattern of increasing cell density, culminating in a central area centralis of higher cell density located close to the optic nerve head. The exception is the shark Alopias superciliosus, which possesses a ventral horizontal streak. Variation in retinal ganglion cell topography appears to be related to the visual demands of different habitats and lifestyles, as well as the positioning of the eyes in the head. The upper limits of spatial resolving power were calculated for all 10 species, using peak ganglion cell densities and estimates of focal length taken from cryo-sectioned eyes in combination with information from the literature. Spatial resolving power ranged from 2.02 to 10.56 cycles deg(-1), which is in accordance with previous studies. Species with a lower spatial resolving power tend to be benthic and/or coastal species that feed on benthic invertebrates and fishes. Active, benthopelagic and pelagic species from more oceanic habitats which feed on larger, more active prey, possess a higher resolving power. Additionally, ganglion cells in a juvenile of C. punctatum, were retrogradely-labeled from the optic nerve with biotinylated dextran amine (BDA). A comparison

  20. WORKING PARK-FUEL CELL COMBINED HEAT AND POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Allan Jones

    2003-09-01

    This report covers the aims and objectives of the project which was to design, install and operate a fuel cell combined heat and power (CHP) system in Woking Park, the first fuel cell CHP system in the United Kingdom. The report also covers the benefits that were expected to accrue from the work in an understanding of the full technology procurement process (including planning, design, installation, operation and maintenance), the economic and environmental performance in comparison with both conventional UK fuel supply and conventional CHP and the commercial viability of fuel cell CHP energy supply in the new deregulated energy markets.

  1. Auxiliary nRules of Quantum Mechanics

    CERN Document Server

    Mould, R A

    2005-01-01

    Standard quantum mechanics makes use of four auxiliary rules that allow the Schrodinger solutions to be related to laboratory experience, such as the Born rule that connects square modulus to probability. These rules (here called the sRules) lead to some unacceptable results. They do not allow the primary observer to be part of the system. They do not allow individual observations (as opposed to ensembles) to be part of the system. They make a fundamental distinction between microscopic and macroscopic things, and they are ambiguous in their description of secondary observers such as Schrodingers cat. The nRules are an alternative set of auxiliary rules that avoid the above difficulties. In this paper we look at a wide range of representative experiments showing that the nRules adequately relate the Schrodinger solutions to empirical experience. This suggests that the sRules should be abandoned in favor of the more satisfactory nRules, or a third auxiliary rule-set called the oRules. Keywords: brain states, c...

  2. Microbial Reverse Electrodialysis Cells for Synergistically Enhanced Power Production

    KAUST Repository

    Kim, Younggy

    2011-07-01

    A new type of bioelectrochemical system for producing electrical power, called a microbial reverse-electrodialysis cell (MRC), was developed to increase voltages and power densities compared to those generated individually by microbial fuel cells (MFCs) or reverse electrodialysis (RED) systems. In RED systems, electrode overpotentials create significant energy losses due to thermodynamically unfavorable electrode reactions, and therefore a large number of stacked cells must be used to have significant energy recovery. This results in high capital costs for the large number of membranes, and increases energy losses from pumping water through a large number of cells. In an MRC, high overpotentials are avoided through oxidation of organic matter by exoelectrogenic bacteria on the anode and oxygen reduction on the cathode. An MRC containing only five pairs of RED cells, fed solutions typical of seawater (600 mM NaCl) and river water (12 mM NaCl) at 0.85 mL/min, produced up to 3.6 W/m2 (cathode surface area) and 1.2-1.3 V with acetate as a substrate. Pumping accounted for <2% of the produced power. A higher flow rate (1.55 mL/min) increased power densities up to 4.3 W/m2. COD removal was 98% with a Coulombic efficiency of 64%. Power production by the individual components was substantially lower with 0.7 W/m2 without salinity driven energy, and <0.015 W/m2 with reduced exoelectrogenic activity due to substrate depletion. These results show that the combination of an MFC and a RED stack synergistically increases performance relative to the individual systems, producing a new type of system that can be used to more efficiently capture salinity driven energy from seawater and river water. © 2011 American Chemical Society.

  3. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    W.L. Lundberg; G.A. Israelson; R.R. Moritz(Rolls-Royce Allison); S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann (Consultant)

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  4. Microbial fuel cells as power supply of a low-power temperature sensor

    Science.gov (United States)

    Khaled, Firas; Ondel, Olivier; Allard, Bruno

    2016-02-01

    Microbial fuel cells (MFCs) show great promise as a concomitant process for water treatment and as renewable energy sources for environmental sensors. The small energy produced by MFCs and the low output voltage limit the applications of MFCs. Specific converter topologies are required to step-up the output voltage of a MFC. A Power Management Unit (PMU) is proposed for operation at low input voltage and at very low power in a completely autonomous way to capture energy from MFCs with the highest possible efficiency. The application of sensors for monitoring systems in remote locations is an important approach. MFCs could be an alternative energy source in this case. Powering a sensor with MFCs may prove the fact that wastewater may be partly turned into renewable energy for realistic applications. The Power Management Unit is demonstrated for 3.6 V output voltage at 1 mW continuous power, based on a low-cost 0.7-L MFC. A temperature sensor may operate continuously on 2-MFCs in continuous flow mode. A flyback converter under discontinuous conduction mode is also tested to power the sensor. One continuously fed MFC was able to efficiently and continuously power the sensor.

  5. High efficiency carbonate fuel cell/turbine hybrid power cycles

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, G. [Energy Research Corp., Danbury, CT (United States)

    1995-10-19

    Carbonate fuel cells developed by Energy Research Corporation, in commercial 2.85 MW size, have an efficiency of 57.9 percent. Studies of higher efficiency hybrid power cycles were conducted in cooperation with METC to identify an economically competitive system with an efficiency in excess of 65 percent. A hybrid power cycle was identified that includes a direct carbonate fuel cell, a gas turbine and a steam cycle, which generates power at a LHV efficiency in excess of 70 percent. This new system is called a Tandem Technology Cycle (TTC). In a TTC operating on natural gas fuel, 95 percent of the fuel is mixed with recycled fuel cell anode exhaust, providing water for the reforming of the fuel, and flows to a direct carbonate fuel cell system which generates 72 percent of the power. The portion of the fuel cell anode exhaust which is not recycled, is burned and heat is transferred to the compressed air from a gas turbine, raising its temperature to 1800{degrees}F. The stream is then heated to 2000{degrees}F in the gas turbine burner and expands through the turbine generating 13 percent of the power. Half the exhaust from the gas turbine flows to the anode exhaust burner, and the remainder flows to the fuel cell cathodes providing the O{sub 2} and CO{sub 2} needed in the electrochemical reaction. Exhaust from the fuel cells flows to a steam system which includes a heat recovery steam generator and stages steam turbine which generates 15 percent of the TTC system power. Studies of the TTC for 200-MW and 20-MW size plants quantified performance, emissions and cost-of-electricity, and compared the characteristics of the TTC to gas turbine combined cycles. A 200-MW TTC plant has an efficiency of 72.6 percent, and is relatively insensitive to ambient temperature, but requires a heat exchanger capable of 2000{degrees}F. The estimated cost of electricity is 45.8 mills/kWhr which is not competitive with a combined cycle in installations where fuel cost is under $5.8/MMBtu.

  6. PSA effect analysis of a design modification of the auxiliary feedwater system for a Westinghouse type plant

    International Nuclear Information System (INIS)

    The auxiliary feedwater system is an important system used to mitigate most accidents considered in probabilistic safety assessment (PSA). The reference plant has produced electric power for about thirty years. Due to age related deterioration and lack of parts, a turbine driven auxiliary feedwater pump (TD AFWP), some valves, and piping of the auxiliary feedwater system should be replaced. This change includes relocation of some valves, installation of valves for maintenance of the steam generator, and a new cross tie line. According to the design change, the Final Safety Analysis Report (FSAR) has been revised. Therefore, this design modification affects the PSA. It is thus necessary to assess the improvement of plant safety. In this paper, the impact of the design change of the auxiliary feedwater system on the PSA is assessed. The results demonstrate that this modification considering the plant safety decreased the total CDF

  7. Inverters for interfacing of solar cells with the power grid

    Science.gov (United States)

    Karamanzanis, G. N.; Jackson, R. D.

    In this work, based on a research course in the Engineering Dep. Cambridge University, some non-classical inverter circuits are studied. They can be used for interfacing solar cells with the power grid at low voltage (230V) and at low power level. They are based on d.c. choppers which have a fast switching transistor. Their theoretical efficiency is 100 percent and they provide a satisfactory output current waveform in phase to the a.c. line voltage. The problems of control are also studied using a suitable mathematical model.

  8. Solid Oxide Fuel Cell Technology Stationary Power Application Project

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Pierre

    2009-03-05

    The objectives of this program were to: (1) Develop a reliable, cost-effective, and production-friendly technique to apply the power-enhancing layer at the interface of the air electrode and electrolyte of the Siemens SOFC; (2) Design, build, install, and operate in the field two 5 kWe SOFC systems fabricated with the state-of-the-art cylindrical, tubular cell and bundle technology and incorporating advanced module design features. Siemens successfully demonstrated, first in a number of single cell tests and subsequently in a 48-cell bundle test, a significant power enhancement by employing a power-enhancing composite interlayer at the interface between the air electrode and electrolyte. While successful from a cell power enhancement perspective, the interlayer application process was not suitable for mass manufacturing. The application process was of inconsistent quality, labor intensive, and did not have an acceptable yield. This program evaluated the technical feasibility of four interlayer application techniques. The candidate techniques were selected based on their potential to achieve the technical requirements of the interlayer, to minimize costs (both labor and material), and suitably for large-scale manufacturing. Preliminary screening, utilizing lessons learned in manufacturing tubular cells, narrowed the candidate processes to two, ink-roller coating (IRC) and dip coating (DC). Prototype fixtures were successfully built and utilized to further evaluate the two candidate processes for applying the interlayer to the high power density Delta8 cell geometry. The electrical performance of interlayer cells manufactured via the candidate processes was validated. Dip coating was eventually selected as the application technique of choice for applying the interlayer to the high power Delta8 cell. The technical readiness of the DC process and product quality was successfully and repeatedly demonstrated, and its throughput and cost are amenable to large scale

  9. Visualization Design and Auxiliary Decision-making of Maintenance Scheduling for the Provincial Power Grid%面向省级电网的检修可视化设计和辅助决策实现

    Institute of Scientific and Technical Information of China (English)

    廖胜利; 应小诚; 李刚; 程春田; 蔡华祥; 杨后东

    2011-01-01

    In view of the provincial grid's complex structure,close connection between the elements,and difficulty in maintenance scheduling planning,a decision support system(DSS) based on rich Internet applications(RIA) technique is presented to monitor and dynamically display maintenance scheduling.The object-oriented method is adopted to Abstract and describe the primary components' characteristics of the electric power system.The RIA technique is used to display the whole electric power topological structure.More important,the DSS is capable of detecting the "detached islands" of automatic maintenance scheduling using the breadth-first search approach.Meanwhile,the incorrect maintenance arrangements detected will be automatically presented to users together with suggestions for correct and rational scheduling,effectively enhancing the accuracy and reliability of maintenance scheduling.The practicality and flexibility of the DSS proposed are verified in Yunnan power grid. This work is supported by National Natural Science Foundation of China(No.50909011),Special Fund of National Basic Research Program of China(No.2009CB226111),and National Natural Science Foundation of China for National Outstanding Young Investigator(No.51025934).%针对省网电力系统拓扑结构复杂、各要素间联系紧密、检修计划安排困难等问题,设计了一种基于富互联网应用(rich Internet applications,RIA)技术的检修计划监测和动态显示辅助决策系统。通过深入分析网络元件特点,采用面向对象思想对拓扑结构进行抽象和描述,应用RIA技术对电网结构进行可视化展示,结合广度优先搜索技术对各元件进行遍历,找出检修过程中存在的"孤立岛",对可能存在的错误检修安排进行自动提示,同时给出建议的检修计划,有效地提高了电网检修的准确性和可靠性。结合云南电网实际检修安排过程,验证了系统的实用性和灵活性。

  10. Fuel cells - a new contributor to stationary power

    Science.gov (United States)

    Dufour, Angelo U.

    Stationary power generation historically started as distributed generation near the user, with the configuration of a very open market, where a lot of small competing utilities were offering electricity to the customers. At a second time it became a `monopolistic' business because of technical reasons. Big steam turbines and electric generators, allowing better efficiencies, were more conveniently installed in very large power plants, necessarily located in sites far away from where the power was needed, and the transmission losses were bounded by AC high voltage technology. The Governments were, therefore, trying to balance the power of monopolies, that were limiting the economical development of the countries, by strengthening the concept of electrical energy price public control and, alternatively, by establishing rules to allow a free flow of electricity from one region to the other, or taking direct control through ownership of big and small utilities. The most effective way of making the electric energy system competitive has proved to be the opening of a partial competition in the generation field by forcing the utilities to compare the cost of their energy, produced with new centralised plants, to the price of the available energy, coming from combined heat and power dispersed generators. In fact, with reference to this cost, all the peculiar features of large central stations and dispersed generators were taken into account, like the widespread use of natural gas, the investment risk reduction with single smaller increments of capacity, the transmission and distribution siting difficulties and high costs, the improved system reliability, and, finally, the high quality electric power. Fuel Cells are a recently become available technology for distributed electrical energy production, because they share the main typical aspects, relevant for a distributed power system, like compatibility with other modular subsystem packages, fully automation possibility

  11. Starting characteristics of direct current motors powered by solar cells

    Science.gov (United States)

    Singer, S.; Appelbaum, J.

    1989-01-01

    Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

  12. Reexamination of molecular integrals arising from the Dirac equation. Analytical evaluation of molecular auxiliary functions integrals

    CERN Document Server

    Bagci, A

    2016-01-01

    The author in his previous works were presented a numerical integration method, namely, global-adaptive with the Gauss-Kronrod numerical integration extension in order to accurate calculation of molecular auxiliary functions integrals involve power functions with non-integer exponents. They are constitute elements of molecular integrals arising in Dirac equation when Slater-type orbitals with non-integer principal quantum numbers are used. Binomial series representation of power functions method, so far, is used for analytical evaluation of the molecular auxiliary function integrals however, intervals of integration cover areas beyond the condition of convergence. In the present study, analytical evaluation of these integrals is re-examined. They are expressed via prolate spheroidal coordinates. An alternative analytical approximation are derived. Slowly convergent binomial series representation formulae for power functions is investigated through nonlinear sequence transformations for the acceleration of con...

  13. A magnetorheological clutch for efficient automotive auxiliary device actuation

    Directory of Open Access Journals (Sweden)

    F. Bucchi

    2013-01-01

    Full Text Available In this paper the results of a project funded by Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in order to reduce the device power absorption. Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are illustrated. The final choice consisted in an MR clutch with permanent magnet, which satisfied size, torque and fail-safe specifications. The clutch characteristics, in terms of torque versus slip, were obtained experimentally for three different clutch prototypes on an ad-hoc developed test bench.As result of a preliminary simulation, a comparison between the power absorption of a current production vacuum pump, an innovative vacuum pump and both vacuum pumps coupled with the MR clutch is presented. The New European Driving Cycle is considered for simulating the vacuum pump operation both in urban and highway driving. Results show that the use of the innovative vacuum pump reduces the device consumption of about 35%, whereas the use of MR clutch coupled with the innovative vacuum pump reduces it up to about 44% in urban driving and 50% in highway driving.

  14. Investigation of Solar Cells Power Degradation Due to Electrostatic Discharge

    Directory of Open Access Journals (Sweden)

    Hossein Fayazi

    2014-07-01

    Full Text Available Satellites are surrounded with protons, electrons and heavy charged particles. Space radiation impact on satellite sub-systems cause several anomalies which are important problem for satellite designers. Until recently, the majority of spacecraft primary power systems used solar arrays and rechargeable batteries to supply 28 V. For low-inclination spacecraft, 28 V systems have not been observed to arc. As the power requirements for spacecraft increased, however, high-voltage solar arrays were baselined to minimize total mass and increase power production efficiency. With the advent of 100 V systems in the late 1980s, arcing began to be observed on a number of spacecraft. The mechanism proposed in this paper, described electrical and physical degradation of solar cells due to electrostatic discharge anomalies on satellites. The cell was characterized again after arcing to determine the change in efficiency. This paper details the process for designing the circuit to create the arcing, and the different setups used to degrade the cells electrically and physically. It also describes the final setups to be used in space laboratory. This model is designed using Matlab and SPENVIS. Identification and simulation this mechanism is an important step in solar array design for space application

  15. Advanced tendencies in development of photovoltaic cells for power engineering

    Science.gov (United States)

    Strebkov, D. S.

    2015-01-01

    Development of solar power engineering must be based on original innovative Russian and world technologies. It is necessary to develop promising Russian technologies of manufacturing of photovoltaic cells and semiconductor materials: chlorine-free technology for obtaining solar silicon; matrix solar cell technology with an efficiency of 25-30% upon the conversion of concentrated solar, thermal, and laser radiation; encapsulation technology for high-voltage silicon solar modules with a voltage up to 1000 V and a service life up to 50 years; new methods of concentration of solar radiation with the balancing illumination of photovoltaic cells at 50-100-fold concentration; and solar power systems with round-the-clock production of electrical energy that do not require energy storage devices and reserve sources of energy. The advanced tendency in silicon power engineering is the use of high-temperature reactions in heterogeneous modular silicate solutions for long-term (over one year) production of heat and electricity in the autonomous mode.

  16. Homotopy Perturbation Method with an Auxiliary Term

    Directory of Open Access Journals (Sweden)

    Ji-Huan He

    2012-01-01

    Full Text Available The two most important steps in application of the homotopy perturbation method are to construct a suitable homotopy equation and to choose a suitable initial guess. The homotopy equation should be such constructed that when the homotopy parameter is zero, it can approximately describe the solution property, and the initial solution can be chosen with an unknown parameter, which is determined after one or two iterations. This paper suggests an alternative approach to construction of the homotopy equation with an auxiliary term; Dufing equation is used as an example to illustrate the solution procedure.

  17. Efficiency measurement and uncertainty discussion of an electric engine powered by a "self-breathing" and "self-humidified" proton exchange membrane fuel cell.

    Science.gov (United States)

    Schiavetti, Pierluigi; Del Prete, Zaccaria

    2007-08-01

    The efficiency of an automotive engine based on a "self-breathing" and "self-humidified" proton exchange membrane fuel cell stack (PEM FC) connected to a dc brushless electrical motor was measured under variable power load conditions. Experiments have been carried out on a small scale 150 W engine model. After determining the fuel cell static polarization curve and the time response to power steps, the system was driven to copy on the test bench a "standard urban load cycle" and its instantaneous efficiencies were measured at an acquisition rate of 5 Hz. The integral system efficiency over the entire urban load cycle, comprising the losses of the unavoidable auxiliary components of the engine, was then calculated. The fuel cell stack was operated mainly in "partial" dead-end mode, with a periodic anode flow channel purging, and one test was carried out in "pure" dead-end mode, with no anode channel purging. An uncertainty analysis of the efficiencies was carried out, taking into account either type A and type B evaluation methods, strengthening the discussion about the outcomes obtained for a system based on this novel simplified FC type. For our small scale engine we measured over the standard urban cycle, on the basis of the H(2) high heating value (HHV), a tank-to-wheel integral efficiency of (18.2+/-0.8)%, when the fuel cell was operated with periodic flow channel purging, and of (21.5+/-1.3)% in complete dead-end operation mode.

  18. ERC product improvement activities for direct fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, C.; Carlson, G.; Doyon, J. [and others

    1995-08-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  19. Evaluating the performance of microbial fuel cells powering electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Dewan, Alim; Beyenal, Haluk [Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Center for Environmental, Sediment and Aquatic Research, Pullman, WA (United States); Donovan, Conrad; Heo, Deukhyoun [School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99163-2710 (United States)

    2010-01-01

    A microbial fuel cell (MFC) is capable of powering an electronic device if we store the energy in an external storage device, such as a capacitor, and dispense that energy intermittently in bursts of high-power when needed. Therefore its performance needs to be evaluated using an energy-storing device such as a capacitor which can be charged and discharged rather than other evaluation techniques, such as continuous energy dissipation through a resistor. In this study, we develop a method of testing microbial fuel cell performance based on storing energy in a capacitor. When a capacitor is connected to a MFC it acts like a variable resistor and stores energy from the MFC at a variable rate. In practice the application of this method to testing microbial fuel cells is very challenging and time consuming; therefore we have custom-designed a microbial fuel cell tester (MFCT). The MFCT evaluates the performance of a MFC as a power source. It uses a capacitor as an energy storing device and waits until a desired amount of energy is stored then discharges the capacitor. The entire process is controlled using an analog-to-digital converter (ADC) board controlled by a custom-written computer program. The utility of our method and the MFCT is demonstrated using a laboratory microbial fuel cell (LMFC) and a sediment microbial fuel cell (SMFC). We determine (1) how frequently a MFC can charge a capacitor, (2) which electrode is current-limiting, (3) what capacitor value will allow the maximum harvested energy from a MFC, which is called the ''optimum charging capacitor value,'' and (4) what capacitor charging potential will harvest the maximum energy from a MFC, which is called the ''optimum charging potential.'' Using a LMFC we find that (1) the time needed to charge a 3-F capacitor from 0 to 500 mV is 108 min, (2) the optimum charging capacitor value is 3 F, and (3) the optimum charging potential is 300 mV. Using a SMFC we find that (1

  20. Fuel cell - An alternative for power and heat generating

    International Nuclear Information System (INIS)

    One of the most promising energy generating technologies is the fuel cell (FC) because of its high efficiency and low emissions. There are even zero chemical emissions FC and cogeneration plants based on FC generate low heat emissions too. FC was invented 160 years ago but it was usually used only since 1960 in space missions. A FC farm tractor was tested 40 years ago. FC was again taken into account by power engineering since 1990 and it is now considered a credible alternative to power and heat generating. The thermal power engineers (and not only they) have two problems of cardinal importance for mankind to solve: - Energy saving (by increasing of energy generating efficiency) and - Environmental protection (by reducing chemical and heat emissions). The possibilities to use FC to generate power and heat are practically endless: on the earth, in the air and outer space, by and under water, in numberless areas of human activities. FC are now powering buses, cars, trains, boats, plains, scooters, highway road signs etc. There are already miniature FC for portable electronics. Homes, schools, hospitals, institutes, banks, police stations, etc are using FC to generate power and heat for their facilities. The methane gas produced by wastewater treatment plants and landfills is converted into electricity by using FC. Being less expensive than nuclear and solar source of energy, FC is now generally used in the space missions (in addition FC generates water). In this work an analysis of the possibilities to use FC especially for combined power and heat generating is presented. FC is favourite as energy source in space missions because it is less expensive than nuclear or solar sources. All major automobile companies have FC powered automobiles in testing stage. Mini FC for phone, laptop, and electronics are already on market. FC will be use to pagers, video recorders, small portable tools, miniature robots, special devices as hearing aid various devices, smoke detectors

  1. Fuel Cell Shaft Power Pack - Regulering af brændselsceller

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl

    2009-01-01

    Afsluttende formidling af forskningsresultater i forbindelse med projektet Fuel Cell Shaft Power Pack......Afsluttende formidling af forskningsresultater i forbindelse med projektet Fuel Cell Shaft Power Pack...

  2. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: RESIDENTIAL ELECTRIC POWER GENERATION USING THE PLUG POWER SU1 FUEL CELL SYSTEM

    Science.gov (United States)

    The Environmental Technology Verification report discusses the technology and performance of the Plug Power SU1 Fuel Cell System manufactured by Plug Power. The SU1 is a proton exchange membrane fuel cell that requires hydrogen (H2) as fuel. H2 is generally not available, so the ...

  3. Minimal RED Cell Pairs Markedly Improve Electrode Kinetics and Power Production in Microbial Reverse Electrodialysis Cells

    KAUST Repository

    Cusick, Roland D.

    2013-12-17

    Power production from microbial reverse electrodialysis cell (MRC) electrodes is substantially improved compared to microbial fuel cells (MFCs) by using ammonium bicarbonate (AmB) solutions in multiple RED cell pair stacks and the cathode chamber. Reducing the number of RED membranes pairs while maintaining enhanced electrode performance could help to reduce capital costs. We show here that using only a single RED cell pair (CP), created by operating the cathode in concentrated AmB, dramatically increased power production normalized to cathode area from both acetate (Acetate: from 0.9 to 3.1 W/m 2-cat) and wastewater (WW: 0.3 to 1.7 W/m2), by reducing solution and charge transfer resistances at the cathode. A second RED cell pair increased RED stack potential and reduced anode charge transfer resistance, further increasing power production (Acetate: 4.2 W/m2; WW: 1.9 W/m2). By maintaining near optimal electrode power production with fewer membranes, power densities normalized to total membrane area for the 1-CP (Acetate: 3.1 W/m2-mem; WW: 1.7 W/m2) and 2-CP (Acetate: 1.3 W/m2-mem; WW: 0.6 W/m2) reactors were much higher than previous MRCs (0.3-0.5 W/m2-mem with acetate). While operating at peak power, the rate of wastewater COD removal, normalized to reactor volume, was 30-50 times higher in 1-CP and 2-CP MRCs than that in a single chamber MFC. These findings show that even a single cell pair AmB RED stack can significantly enhance electrical power production and wastewater treatment. © 2013 American Chemical Society.

  4. Assessment of Microbial Fuel Cell Configurations and Power Densities

    KAUST Repository

    Logan, Bruce E.

    2015-07-30

    Different microbial electrochemical technologies are being developed for a many diverse applications, including wastewater treatment, biofuel production, water desalination, remote power sources, and as biosensors. Current and energy densities will always be limited relative to batteries and chemical fuel cells, but these technologies have other advantages based on the self-sustaining nature of the microorganisms that can donate or accept electrons from an electrode, the range of fuels that can be used, and versatility in the chemicals that can be produced. The high cost of membranes will likely limit applications of microbial electrochemical technologies that might require a membrane. For microbial fuel cells, which do not need a membrane, questions remain on whether larger-scale systems can produce power densities similar to those obtained in laboratory-scale systems. It is shown here that configuration and fuel (pure chemicals in laboratory media versus actual wastewaters) remain the key factors in power production, rather than the scale of the application. Systems must be scaled up through careful consideration of electrode spacing and packing per unit volume of reactor.

  5. Power management system for a 2.5 W remote sensor powered by a sediment microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, Conrad; Peng, Huan; Heo, Deukhyoun [School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99163-2710 (United States); Dewan, Alim; Beyenal, Haluk [Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Center for Environmental, Sediment and Aquatic Research, Washington State University, Pullman, WA 99163-2710 (United States)

    2011-02-01

    One of the challenges in using wireless sensors that require high power to monitor the environment is finding a renewable power source that can produce enough power. Sediment microbial fuel cells (SMFCs) are considered an alternative renewable power source for remote monitoring, but current research on SMFCs has demonstrated that they can only produce several to tens of mW of continuous power. This limits the use of SMFCs as an alternative renewable remote power source to mW-level power. Such low power is only enough to operate a low-power sensors. However, there are many remote sensors that require higher power, on the order of watts. Current technology using a SMFC to power a remote sensor requiring watts-level intermittent power is limited because of limitations of power management technology. Our goal was to develop a power management system (PMS) that enables a SMFC to operate a remote sensor consuming 2.5 W of power. We designed a custom PMS to store microbial energy in capacitors and use the stored energy in short bursts. Our results demonstrate that SMFCs can be a viable alternative renewable power source for remote sensors requiring high power. (author)

  6. Advanced coal gasifier-fuel cell power plant systems design

    Science.gov (United States)

    Heller, M. E.

    1983-01-01

    Two advanced, high efficiency coal-fired power plants were designed, one utilizing a phosphoric acid fuel cell and one utilizing a molten carbonate fuel cell. Both incorporate a TRW Catalytic Hydrogen Process gasifier and regenerator. Both plants operate without an oxygen plant and without requiring water feed; they, instead, require makeup dolomite. Neither plant requires a shift converter; neither plant has heat exchangers operating above 1250 F. Both plants have attractive efficiencies and costs. While the molten carbonate version has a higher (52%) efficiency than the phosphoric acid version (48%), it also has a higher ($0.078/kWh versus $0.072/kWh) ten-year levelized cost of electricity. The phosphoric acid fuel cell power plant is probably feasible to build in the near term: questions about the TRW process need to be answered experimentally, such as weather it can operate on caking coals, and how effective the catalyzed carbon-dioxide acceptor will be at pilot scale, both in removing carbon dioxide and in removing sulfur from the gasifier.

  7. Competition and alliances in fuel cell power train development

    Energy Technology Data Exchange (ETDEWEB)

    Schlecht, L. [Technische Universitaet Berlin (Germany). Fuel Cell and Hydrogen Research Centre

    2003-07-01

    For the realisation of the effective application and cost effectiveness of fuel cell power trains, and competitiveness with the current internal combustion engine technology, it will be necessary to either: (a) produce a large number of vehicles, (b) reduce the production costs by permanent production optimisation, or (c) introduce new materials. Learning curves, which have been derived from empirical data of past energy technologies, are initially used to provide a cost prognosis for the market launch of fuel cell power trains. Drawing on game theory the paper then describes a basic model which addresses the issue of the optimal strategy of the automotive industry, in either a monopoly or oligopoly structure. When this model's outputs are combined with the anticipated rate of fuel cell vehicles (FCVs), learning curves and network effects, from the first section of the paper we can see that if the successful market launch of FCVs is desired, an alliance structure within the automotive industry is the optimal path. (author)

  8. The power of glove: Soft microbial fuel cell for low-power electronics

    Science.gov (United States)

    Winfield, Jonathan; Chambers, Lily D.; Stinchcombe, Andrew; Rossiter, Jonathan; Ieropoulos, Ioannis

    2014-03-01

    A novel, soft microbial fuel cell (MFC) has been constructed using the finger-piece of a standard laboratory natural rubber latex glove. The natural rubber serves as structural and proton exchange material whilst untreated carbon veil is used for the anode. A soft, conductive, synthetic latex cathode is developed that coats the outside of the glove. This inexpensive, lightweight reactor can without any external power supply, start up and energise a power management system (PMS), which steps-up the MFC output (0.06-0.17 V) to practical levels for operating electronic devices (>3 V). The MFC is able to operate for up to 4 days on just 2 mL of feedstock (synthetic tryptone yeast extract) without any cathode hydration. The MFC responds immediately to changes in fuel-type when the introduction of urine accelerates the cycling times (35 vs. 50 min for charge/discharge) of the MFC and PMS. Following starvation periods of up to 60 h at 0 mV the MFC is able to cold start the PMS simply with the addition of 2 mL fresh feedstock. These findings demonstrate that cheap MFCs can be developed as sole power sources and in conjunction with advancements in ultra-low power electronics, can practically operate small electrical devices.

  9. Temperature and Humidity Sensor Powered by an Individual Microbial Fuel Cell in a Power Management System

    Directory of Open Access Journals (Sweden)

    Qi Zheng

    2015-09-01

    Full Text Available Microbial fuel cells (MFCs are of increasing interest as bioelectrochemical systems for decomposing organic materials and converting chemical energy into electricity. The main challenge for this technology is that the low power and voltage of the devices restricts the use of MFCs in practical applications. In this paper, a power management system (PMS is developed to store the energy and export an increased voltage. The designed PMS successfully increases the low voltage generated by an individual MFC to a high potential of 5 V, capable of driving a wireless temperature and humidity sensor based on nRF24L01 data transmission modules. With the PMS, MFCs can intermittently power the sensor for data transmission to a remote receiver. It is concluded that even an individual MFC can supply the energy required to power the sensor and telemetry system with the designed PMS. The presented PMS can be widely used for unmanned environmental monitoring such as wild rivers, lakes, and adjacent water areas, and offers promise for further advances in MFC technology.

  10. Fuel economy and range estimates for fuel cell powered automobiles

    Energy Technology Data Exchange (ETDEWEB)

    Steinbugler, M.; Ogden, J. [Princeton Univ., NJ (United States)

    1996-12-31

    While a number of automotive fuel cell applications have been demonstrated, including a golf cart, buses, and a van, these systems and others that have been proposed have utilized differing configurations ranging from direct hydrogen fuel cell-only power plants to fuel cell/battery hybrids operating on reformed methanol. To date there is no clear consensus on which configuration, from among the possible combinations of fuel cell, peaking device, and fuel type, is the most likely to be successfully commercialized. System simplicity favors direct hydrogen fuel cell vehicles, but infrastructure is lacking. Infrastructure favors a system using a liquid fuel with a fuel processor, but system integration and performance issues remain. A number of studies have analyzed particular configurations on either a system or vehicle scale. The objective of this work is to estimate, within a consistent framework, fuel economies and ranges for a variety of configurations using flexible models with the goal of identifying the most promising configurations and the most important areas for further research and development.

  11. Safety Assessment of Auxiliary Power Unit (APU) System for Civil Aircraft Based on Dynamic Fault Tree Analysis (DFTA)%基于动态故障树分析的民用飞机辅助动力装置系统安全性评估

    Institute of Scientific and Technical Information of China (English)

    王栋

    2014-01-01

    Traditional fault tree analysis method is widely used for system safety assessment in civil aviation indus-try , but dynamic characteristics of systems/subsystems, including operational sequencing interpretation, spare and redundancy expression cannot be represented by traditional fault trees. On the other hand, civil aircraft auxiliary power unit ( APU) often operates as a redundant system and its behavior can be described by using dynamic fault tree appropriately. As a result, the interest of DFTA application is focused on APU system safety assessment. In this paper, two kinds of dynamic gates ( PAND and CSP) were introduced firstly. Their quantitative calculations were presented by applying Markov model. Then two typical cases with auxiliary power unit ( APU) system safety assess-ment were analyzed by traditional fault tree and dynamic fault tree respectively. Finally the comparison between two kinds of Fault Tree Analysis ( FTA ) was provided and the result indicates that Dynamic Fault Tree Analysis ( DFTA) method based on proper application reaches remarkable accuracy ,and the calculation cost is acceptable when second-order approximation of exponential distribution function is applied.%在民用航空工业领域,传统的故障树分析方法广泛运用于系统安全性评估。然而,包含系统/子系统运行的时序阐述以及备份、冗余表达在内的动态特性不能通过传统故障树呈现。另一方面,民用飞机辅助动力装置( APU)经常作为一个冗余系统运作,因而其行为可以通过运用动态故障树进行适当的描述。所以APU的这种特性激发了动态故障树分析在APU系统安全性评估上应用的关注。首先介绍了两种动态门(优先与门和冷备件门),其定量计算通过施用马尔可夫模型来呈现;然后分别通过传统故障树以及动态故障树分析了APU系统安全性评估的两个典型案例;最后进行了两种故障树分析( FTA )的比较,其

  12. The Power and the Promise of Cell Reprogramming: Personalized Autologous Body Organ and Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Ana Belen Alvarez Palomo

    2014-04-01

    Full Text Available Reprogramming somatic cells to induced pluripotent stem cells (iPSCs or direct reprogramming to desired cell types are powerful and new in vitro methods for the study of human disease, cell replacement therapy, and drug development. Both methods to reprogram cells are unconstrained by the ethical and social questions raised by embryonic stem cells. iPSC technology promises to enable personalized autologous cell therapy and has the potential to revolutionize cell replacement therapy and regenerative medicine. Potential applications of iPSC technology are rapidly increasing in ambition from discrete cell replacement applications to the iPSC assisted bioengineering of body organs for personalized autologous body organ transplant. Recent work has demonstrated that the generation of organs from iPSCs is a future possibility. The development of embryonic-like organ structures bioengineered from iPSCs has been achieved, such as an early brain structure (cerebral organoids, bone, optic vesicle-like structures (eye, cardiac muscle tissue (heart, primitive pancreas islet cells, a tooth-like structure (teeth, and functional liver buds (liver. Thus, iPSC technology offers, in the future, the powerful and unique possibility to make body organs for transplantation removing the need for organ donation and immune suppressing drugs. Whilst it is clear that iPSCs are rapidly becoming the lead cell type for research into cell replacement therapy and body organ transplantation strategies in humans, it is not known whether (1 such transplants will stimulate host immune responses; and (2 whether this technology will be capable of the bioengineering of a complete and fully functional human organ. This review will not focus on reprogramming to iPSCs, of which a plethora of reviews can be found, but instead focus on the latest developments in direct reprogramming of cells, the bioengineering of body organs from iPSCs, and an analysis of the immune response induced by i

  13. Synthesis of passive lossless metasurfaces using auxiliary fields for reflectionless beam splitting and perfect reflection

    CERN Document Server

    Epstein, Ariel

    2016-01-01

    We introduce a paradigm for accurate design of metasurfaces for intricate beam manipulation, implementing functionalities previously considered impossible to achieve with passive lossless elements. The key concept involves self-generation of auxiliary evanescent fields which facilitate the required local power conservation, without interfering with the device performance in the far field. We demonstrate our scheme by presenting exact reactive solutions to the challenging problems of reflectionless beam splitting and perfect reflection, verified via full wave simulations.

  14. Ignition delay of a pulsed inductively coupled plasma (ICP) in tandem with an auxiliary ICP

    Science.gov (United States)

    Liu, Lei; Sridhar, Shyam; Donnelly, Vincent M.; Economou, Demetre J.

    2015-12-01

    Plasma ignition delays were observed in a ‘main’ inductively coupled plasma (ICP), in tandem with an ‘auxiliary’ ICP. The Faraday-shielded ICPs were separated by a grounded metal grid. Power (13.56 MHz) to the main ICP was pulsed with a frequency of 1 kHz, while the auxiliary ICP was operated in continuous wave (cw) mode. In chlorine plasmas, ignition delay was observed for duty cycles greater than 60% and, in contrast to expectation, the delay was longer with increasing duty cycle up to ~99.5%. The ignition delay could be varied by changing the auxiliary and/or main ICP power. Langmuir probe measurements provided the temporal evolution of electron temperature, and electron and positive ion densities. These measurements revealed that the plasma was ignited shortly after the decaying positive ion density (n +), in the afterglow of the main ICP, reached the density ({{n}+},\\text{aux} ) prevailing when only the auxiliary ICP was powered. At that time, production of electrons began to dominate their loss in the main ICP, due to hot electron injection from the auxiliary ICP. As a result, {{n}\\text{e}} increased from a value below {{n}\\text{e,\\text{aux}}} , improving inductive power coupling efficiency, further increasing plasma density leading to plasma ignition. Plasma ignition delay occurred when the afterglow of the pulsed plasma was not long enough for the ion density to reach {{n}+},\\text{aux} during the afterglow. Besides Cl2, plasma ignition delays were also observed in other electronegative gases (SF6, CF4/O2 and O2) but not in an electropositive gas (Ar).

  15. Fuel-Cell Power Source Based on Onboard Rocket Propellants

    Science.gov (United States)

    Ganapathi, Gani; Narayan, Sri

    2010-01-01

    The use of onboard rocket propellants (dense liquids at room temperature) in place of conventional cryogenic fuel-cell reactants (hydrogen and oxygen) eliminates the mass penalties associated with cryocooling and boil-off. The high energy content and density of the rocket propellants will also require no additional chemical processing. For a 30-day mission on the Moon that requires a continuous 100 watts of power, the reactant mass and volume would be reduced by 15 and 50 percent, respectively, even without accounting for boiloff losses. The savings increase further with increasing transit times. A high-temperature, solid oxide, electrolyte-based fuel-cell configuration, that can rapidly combine rocket propellants - both monopropellant system with hydrazine and bi-propellant systems such as monomethyl hydrazine/ unsymmetrical dimethyl hydrazine (MMH/UDMH) and nitrogen tetroxide (NTO) to produce electrical energy - overcomes the severe drawbacks of earlier attempts in 1963-1967 of using fuel reforming and aqueous media. The electrical energy available from such a fuel cell operating at 60-percent efficiency is estimated to be 1,500 Wh/kg of reactants. The proposed use of zirconia-based oxide electrolyte at 800-1,000 C will permit continuous operation, very high power densities, and substantially increased efficiency of conversion over any of the earlier attempts. The solid oxide fuel cell is also tolerant to a wide range of environmental temperatures. Such a system is built for easy refueling for exploration missions and for the ability to turn on after several years of transit. Specific examples of future missions are in-situ landers on Europa and Titan that will face extreme radiation and temperature environments, flyby missions to Saturn, and landed missions on the Moon with 14 day/night cycles.

  16. Fission Yeast Germinal Center (GC) Kinase Ppk11 Interacts with Pmo25 and Plays an Auxiliary Role in Concert with the Morphogenesis Orb6 Network (MOR) in Cell Morphogenesis*

    OpenAIRE

    Goshima, Tetsuya; Kume, Kazunori; Koyano, Takayuki; Ohya, Yoshikazu; Toda, Takashi; Hirata, Dai

    2010-01-01

    How cell morphology and the cell cycle are coordinately regulated is a fundamental subject in cell biology. In fission yeast, 2 germinal center kinases (GCKs), Sid1 and Nak1, play an essential role in septation/cytokinesis and cell separation/cell polarity control, respectively, as components of the septation initiation network (SIN) and the morphogenesis Orb6 network (MOR). Here we show that a third GCK, Ppk11, is also required for efficient cell separation particularly, at a high temperatur...

  17. NSTS Orbiter auxiliary power unit turbine wheel cracking risk assessment

    Science.gov (United States)

    Cruse, T. A.; Mcclung, R. C.; Torng, T. Y.

    1992-01-01

    The present investigation of turbine-wheel cracking problems in the hydrazine-fueled APU turbine wheel of the Space Shuttle Orbiter's Main Engines has indicated the efficacy of systematic probabilistic risk assessment in flight certification and safety resolution. Nevertheless, real crack-initiation and propagation problems do not lend themselves to purely analytical studies. The high-cycle fatigue problem is noted to generally be unsuited to probabilistic modeling, due to its extremely high degree of intrinsic scatter. In the case treated, the cracks appear to trend toward crack arrest in a low cycle fatigue mode, due to a detuning of the resonance model.

  18. The Business Case for Fuel Cells 2012. America's Partner in Power

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, Sandra [Fuel Cells 2000, Washington, DC (United States); Gangi, Jennifer [Fuel Cells 2000, Washington, DC (United States); Skukowski, Ryan [Fuel Cells 2000, Washington, DC (United States)

    2012-12-01

    This report, compiled by Fuel Cells 2000 with support from the Fuel Cell Technologies Program, profiles a select group of nationally recognizable companies and corporations that are deploying or demonstrating fuel cells. These businesses are taking advantage of a fuel cell's unique benefits, especially for powering lift trucks and providing combined heat and power to their stores and administrative offices.

  19. 29 CFR 1917.42 - Miscellaneous auxiliary gear.

    Science.gov (United States)

    2010-07-01

    ...) Bridles for handling flush end or box-type pallets shall be designed to prevent disengagement from the... 29 Labor 7 2010-07-01 2010-07-01 false Miscellaneous auxiliary gear. 1917.42 Section 1917.42 Labor... (CONTINUED) MARINE TERMINALS Cargo Handling Gear and Equipment § 1917.42 Miscellaneous auxiliary gear....

  20. The German and English Auxiliary Systems and Complex Predicates

    Science.gov (United States)

    McCormick, Terrence C.

    1976-01-01

    This paper explores the auxiliary systems of English and German and the use of the auxiliary verbs in various complex predicate structures in the two languages. It aims at alleviating two types of problems in learning German involving governing patterns and ordering problems in clauses. (CHK)

  1. 47 CFR 80.290 - Auxiliary receiving antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Auxiliary receiving antenna. 80.290 Section 80... antenna. An auxiliary receiving antenna must be provided when necessary to avoid unauthorized interruption or reduced efficiency of the required watch because the normal receiving antenna is not...

  2. Auxiliary Subunit GSG1L Acts to Suppress Calcium-Permeable AMPA Receptor Function

    Science.gov (United States)

    McGee, Thomas P.; Bats, Cécile

    2015-01-01

    AMPA-type glutamate receptors are ligand-gated cation channels responsible for a majority of the fast excitatory synaptic transmission in the brain. Their behavior and calcium permeability depends critically on their subunit composition and the identity of associated auxiliary proteins. Calcium-permeable AMPA receptors (CP-AMPARs) contribute to various forms of synaptic plasticity, and their dysfunction underlies a number of serious neurological conditions. For CP-AMPARs, the prototypical transmembrane AMPAR regulatory protein stargazin, which acts as an auxiliary subunit, enhances receptor function by increasing single-channel conductance, slowing channel gating, increasing calcium permeability, and relieving the voltage-dependent block by endogenous intracellular polyamines. We find that, in contrast, GSG1L, a transmembrane auxiliary protein identified recently as being part of the AMPAR proteome, acts to reduce the weighted mean single-channel conductance and calcium permeability of recombinant CP-AMPARs, while increasing polyamine-dependent rectification. To examine the effects of GSG1L on native AMPARs, we manipulated its expression in cerebellar and hippocampal neurons. Transfection of GSG1L into mouse cultured cerebellar stellate cells that lack this protein increased the inward rectification of mEPSCs. Conversely, shRNA-mediated knockdown of endogenous GSG1L in rat cultured hippocampal pyramidal neurons led to an increase in mEPSC amplitude and in the underlying weighted mean single-channel conductance, revealing that GSG1L acts to suppress current flow through native CP-AMPARs. Thus, our data suggest that GSG1L extends the functional repertoire of AMPAR auxiliary subunits, which can act not only to enhance but also diminish current flow through their associated AMPARs. SIGNIFICANCE STATEMENT Calcium-permeable AMPA receptors (CP-AMPARs) are an important group of receptors for the neurotransmitter glutamate. These receptors contribute to various forms of

  3. Copper anode corrosion affects power generation in microbial fuel cells

    KAUST Repository

    Zhu, Xiuping

    2013-07-16

    Non-corrosive, carbon-based materials are usually used as anodes in microbial fuel cells (MFCs). In some cases, however, metals have been used that can corrode (e.g. copper) or that are corrosion resistant (e.g. stainless steel, SS). Corrosion could increase current through galvanic (abiotic) current production or by increasing exposed surface area, or decrease current due to generation of toxic products from corrosion. In order to directly examine the effects of using corrodible metal anodes, MFCs with Cu were compared with reactors using SS and carbon cloth anodes. MFCs with Cu anodes initially showed high current generation similar to abiotic controls, but subsequently they produced little power (2 mW m-2). Higher power was produced with microbes using SS (12 mW m-2) or carbon cloth (880 mW m-2) anodes, with no power generated by abiotic controls. These results demonstrate that copper is an unsuitable anode material, due to corrosion and likely copper toxicity to microorganisms. © 2013 Society of Chemical Industry.

  4. Exergetic and exergoeconomic evaluation of a solid-oxide fuel-cell-based combined heat and power generation system

    International Nuclear Information System (INIS)

    Highlights: • Exergy-based evaluations of a SOFC-based power generation system have been made. • The exergy of fuel and the exergy of product are rigorously defined. • Cost balance and auxiliary equations are formulated for the exergoeconomic analysis. • The cost structure of the overall system has been analyzed. • Suggestions are made for improving the cost effectiveness of the entire system. - Abstract: Exergetic and exergoeconomic evaluations have been carried out for a 100 kW-class solid-oxide fuel-cell-based combined heat and power generation system, to find out the measures that would improve its efficiency, and, more importantly, its cost effectiveness. The exergoeconomic analysis is an appropriate combination of an exergetic analysis and an economic analysis; through exergoeconomics, we obtain the real cost associated with each stream and with the inefficiencies within each component in a system. For the analyses, the exergies of fuel and the exergies of product for all components have been defined. Subsequently, the exergetic efficiency of each component has been evaluated. By combining the results obtained from an economic analysis with the results of the exergetic analysis, the cost structure of the overall system has been figured out. The components, showing higher exergoeconomic factors such as SOFC stack, fuel blower, heat recovery water pump, and inverter, need reduction of investment cost, even if the associated efficiency would decreased because of this cost reduction. For the components, exhibiting lower exergoeconomic factors such as integrated reformer, fuel/water pre-heater, and air pre-heater, the main focus should be on efficiency improvements, even if higher investment expenditures would be associated with such improvements

  5. Efficient Cells Cut the Cost of Solar Power

    Science.gov (United States)

    2013-01-01

    If you visit Glenn Research Center, you might encounter a photovoltaic (PV) array that looks unlike anything you've ever seen. In fact, what one would normally identify as the panel is actually a series of curved mirrors called solar concentrators, engineered to reflect sunlight rather than absorb it. These concentrators gather, intensify, and focus sun beams upward, aiming at a fixture containing specialized silicon concentrated PV chips the actual solar cells. If you stay by the array for a while, you'll notice that the solar concentrators follow the path of the sun throughout the day, changing position to best capture and utilize the sunlight. The specialized chips that make the technology possible are the brainchild of Bernard Sater, an engineer who had worked at Glenn since the early 1960s before retiring to pursue his unique ideas for harnessing solar power. Sater contributed to multiple PV projects in the latter part of his career at the Center, including research and development on the International Space Station s solar arrays. In his spare time, he enjoyed tinkering with new approaches to solar power, experiments that resulted in the system installed at Glenn today. Sater s basic idea had two components. First, he wanted to create a silicon cell that was smaller, more efficient, and much lower cost than those available at the time. To ensure that the potential of such a chip could be realized, he also planned on pairing it with a system that could concentrate sunlight and focus it directly on the cell. When he retired from Glenn in 1994 to focus on researching and developing the technology full time, Sater found that NASA was interested in the concept and ready to provide funding, facilities, and expertise in order to assist in its development.

  6. A Low-Power and Low-Voltage Power Management Strategy for On-Chip Micro Solar Cells

    Directory of Open Access Journals (Sweden)

    Ismail Cevik

    2015-01-01

    Full Text Available Fundamental characteristics of on-chip micro solar cell (MSC structures were investigated in this study. Several MSC structures using different layers in three different CMOS processes were designed and fabricated. Effects of PN junction structure and process technology on solar cell performance were measured. Parameters for low-power and low-voltage implementation of power management strategy and boost converter based circuits utilizing fractional voltage maximum power point tracking (FVMPPT algorithm were determined. The FVMPPT algorithm works based on the fraction between the maximum power point operation voltage and the open circuit voltage of the solar cell structure. This ratio is typically between 0.72 and 0.78 for commercially available poly crystalline silicon solar cells that produce several watts of power under typical daylight illumination. Measurements showed that the fractional voltage ratio is much higher and fairly constant between 0.82 and 0.85 for on-chip mono crystalline silicon micro solar cell structures that produce micro watts of power. Mono crystalline silicon solar cell structures were observed to result in better power fill factor (PFF that is higher than 74% indicating a higher energy harvesting efficiency.

  7. NaBH4 (sodium borohydride) hydrogen generator with a volume-exchange fuel tank for small unmanned aerial vehicles powered by a PEM (proton exchange membrane) fuel cell

    International Nuclear Information System (INIS)

    A proton exchange membrane fuel cell system integrated with a NaBH4 (sodium borohydride) hydrogen generator was developed for small UAVs (unmanned aerial vehicles). The hydrogen generator was composed of a catalytic reactor, liquid pump and volume-exchange fuel tank, where the fuel and spent fuel exchange the volume within a single fuel tank. Co–B catalyst supported on a porous ceramic material was used to generate hydrogen from the NaBH4 solution. Considering the power consumption according to the mission profile of a UAV, the power output of the fuel cell and auxiliary battery was distributed passively as an electrical load. A blended wing-body was selected considering the fuel efficiency and carrying capability of fuel cell components. First, the fuel cell stack and hydrogen generator were evaluated under the operating conditions, and integrated into the airframe. The ground test of the complete fuel cell UAV was performed under a range of load conditions. Finally, the fuel cell powered flight test was made for 1 h. The volume-exchange fuel tank minimized the fuel sloshing and the change in center of gravity due to fuel consumption during the flight, so that much stable operation of the fuel cell system was validated at different flight modes. - Highlights: • PEMFC system with a NaBH4 hydrogen source was developed for small UAVs. • Volume-exchange fuel tank was used to reduce the size of the fuel cell system. • Passive power management was used for a stable power output during the flight. • BWB UAV was selected by taking the fuel cell integration into consideration. • Stable operation of the fuel cell system was verified from the flight test

  8. Solid Oxide Fuel Cell/Turbine Hybrid Power System for Advanced Aero-propulsion and Power Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Solid oxide fuel cell (SOFC)/ gas turbine hybrid power systems (HPSs) have been recognized by federal agencies and other entities as having the potential to operate...

  9. High power fuel cell simulator based on artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Chavez-Ramirez, Abraham U.; Munoz-Guerrero, Roberto [Departamento de Ingenieria Electrica, CINVESTAV-IPN. Av. Instituto Politecnico Nacional No. 2508, D.F. CP 07360 (Mexico); Duron-Torres, S.M. [Unidad Academica de Ciencias Quimicas, Universidad Autonoma de Zacatecas, Campus Siglo XXI, Edif. 6 (Mexico); Ferraro, M.; Brunaccini, G.; Sergi, F.; Antonucci, V. [CNR-ITAE, Via Salita S. Lucia sopra Contesse 5-98126 Messina (Italy); Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., Parque Tecnologico Queretaro, Sanfandila, Pedro Escobedo, Queretaro (Mexico)

    2010-11-15

    Artificial Neural Network (ANN) has become a powerful modeling tool for predicting the performance of complex systems with no well-known variable relationships due to the inherent properties. A commercial Polymeric Electrolyte Membrane fuel cell (PEMFC) stack (5 kW) was modeled successfully using this tool, increasing the number of test into the 7 inputs - 2 outputs-dimensional spaces in the shortest time, acquiring only a small amount of experimental data. Some parameters could not be measured easily on the real system in experimental tests; however, by receiving the data from PEMFC, the ANN could be trained to learn the internal relationships that govern this system, and predict its behavior without any physical equations. Confident accuracy was achieved in this work making possible to import this tool to complex systems and applications. (author)

  10. Power generation from furfural using the microbial fuel cell

    Science.gov (United States)

    Luo, Yong; Liu, Guangli; Zhang, Renduo; Zhang, Cuiping

    Furfural is a typical inhibitor in the ethanol fermentation process using lignocellulosic hydrolysates as raw materials. In the literature, no report has shown that furfural can be utilized as the fuel to produce electricity in the microbial fuel cell (MFC), a device that uses microbes to convert organic compounds to generate electricity. In this study, we demonstrated that electricity was successfully generated using furfural as the sole fuel in both the ferricyanide-cathode MFC and the air-cathode MFC. In the ferricyanide-cathode MFC, the maximum power densities reached 45.4, 81.4, and 103 W m -3, respectively, when 1000 mg L -1 glucose, a mixture of 200 mg L -1 glucose and 5 mM furfural, and 6.68 mM furfural were used as the fuels in the anode solution. The corresponding Coulombic efficiencies (CE) were 4.0, 7.1, and 10.2% for the three treatments, respectively. For pure furfural as the fuel, the removal efficiency of furfural reached up to 95% within 12 h. In the air-cathode MFC using 6.68 mM furfural as the fuel, the maximum values of power density and CE were 361 mW m -2 (18 W m -3) and 30.3%, respectively, and the COD removal was about 68% at the end of the experiment (about 30 h). Increase in furfural concentrations from 6.68 to 20 mM resulted in increase in the maximum power densities from 361 to 368 mW m -2, and decrease in CEs from 30.3 to 20.6%. These results indicated that some toxic and biorefractory organics such as furfural might still be suitable resources for electricity generation using the MFC technology.

  11. A Study of the Disturbance in Steam Power Unit Caused by Solar Auxiliary Heating System%太阳能辅助加热系统对蒸汽动力机组运行性能的扰动研究

    Institute of Scientific and Technical Information of China (English)

    安连锁; 徐玫; 陈海平; 冯蕾; 张衡

    2015-01-01

    It is common that variable conditions are considered in the process of solar-assisted coal-fired power system designing. Small disturbance theory tells us that when no obvious water distribution happens complex variable conditions calculation can be saved and the results which meet required precision can be achieved as well. A quantitative analysis was conducted for the impact of the solar auxiliary heating system on the thermal system. The results show that within a small range the impact caused by the solar auxiliary heating system can be regarded as a small disturbance, while in the usual range(30% to 100%) although it can not be regarded as a small disturbance the calculation of steam admission flow and power generation can be simplfied under the coal-saving and power-boosting operation mode. In addition, the calculation of thermal conversion rate, generating heat rate and coal consumption rate can be simplified when the percentage of replacing point 1 extraction steam is under 60%; the calculation of thermal conversion rate, generating heat rate, coal consumption rate in waste heat utilization can be simplified no matter how the percentage of replacing extraction steam changes; the calculation of collector field area and the initial investment can also be simplified when the percentage of replacing point 1 extraction steam is under 55%. That is, the error of the caculation for the above parameters meet the engineering accuracy requirement when small disturbance algorithm is used. The above conclusion provides a theoretical reference for the optimal design and analysis of the solar-aided coal-fired power system.%光煤互补热发电系统的设计过程中通常都要进行变工况计算,由小扰动理论可知,当系统变动不足以引起汽水重新分布时,省去繁杂的变工况计算也可得到精度合乎要求的结果。该文针对太阳能辅助加热系统对热力系统影响进行了定量分析,结果表明太阳能辅助加热系

  12. On Partial Opimality by Auxiliary Submodular Problems

    CERN Document Server

    Shekhovtsov, Alexander

    2011-01-01

    In this work, we prove several relations between three different energy minimization techniques. A recently proposed methods for determining a provably optimal partial assignment of variables by Ivan Kovtun (IK), the linear programming relaxation approach (LP) and the popular expansion move algorithm by Yuri Boykov. We propose a novel sufficient condition of optimal partial assignment, which is based on LP relaxation and called LP-autarky. We show that methods of Kovtun, which build auxiliary submodular problems, fulfill this sufficient condition. The following link is thus established: LP relaxation cannot be tightened by IK. For non-submodular problems this is a non-trivial result. In the case of two labels, LP relaxation provides optimal partial assignment, known as persistency, which, as we show, dominates IK. Relating IK with expansion move, we show that the set of fixed points of expansion move with any "truncation" rule for the initial problem and the problem restricted by one-vs-all method of IK would...

  13. Direct fuel cell power plants: the final steps to commercialization

    Science.gov (United States)

    Glenn, Donald R.

    Since the last paper presented at the Second Grove Fuel Cell Symposium, the Energy Research Corporation (ERC) has established two commercial subsidiaries, become a publically-held firm, expanded its facilities and has moved the direct fuel cell (DFC) technology and systems significantly closer to commercial readiness. The subsidiaries, the Fuel Cell Engineering Corporation (FCE) and Fuel Cell Manufacturing Corporation (FCMC) are perfecting their respective roles in the company's strategy to commercialize its DFC technology. FCE is the prime contractor for the Santa Clara Demonstration and is establishing the needed marketing, sales, engineering, and servicing functions. FCMC in addition to producing the stacks and stack modules for the Santa Clara demonstration plant is now upgrading its production capability and product yields, and retooling for the final stack scale-up for the commercial unit. ERC has built and operated the tallest and largest capacities-to-date carbonate fuel cell stacks as well as numerous short stacks. While most of these units were tested at ERC's Danbury, Connecticut (USA) R&D Center, others have been evaluated at other domestic and overseas facilities using a variety of fuels. ERC has supplied stacks to Elkraft and MTU for tests with natural gas, and RWE in Germany where coal-derived gas were used. Additional stack test activities have been performed by MELCO and Sanyo in Japan. Information from some of these activities is protected by ERC's license arrangements with these firms. However, permission for limited data releases will be requested to provide the Grove Conference with up-to-date results. Arguably the most dramatic demonstration of carbonate fuel cells in the utility-scale, 2 MW power plant demonstration unit, located in the City of Santa Clara, California. Construction of the unit's balance-of-plant (BOP) has been completed and the installed equipment has been operationally checked. Two of the four DFC stack sub-modules, each

  14. Placement of Combined Heat, Power and Hydrogen Production Fuel Cell Power Plants in a Distribution Network

    Directory of Open Access Journals (Sweden)

    Bahman Bahmanifirouzi

    2012-03-01

    Full Text Available This paper presents a new Fuzzy Adaptive Modified Particle Swarm Optimization algorithm (FAMPSO for the placement of Fuel Cell Power Plants (FCPPs in distribution systems. FCPPs, as Distributed Generation (DG units, can be considered as Combined sources of Heat, Power, and Hydrogen (CHPH. CHPH operation of FCPPs can improve overall system efficiency, as well as produce hydrogen which can be stored for the future use of FCPPs or can be sold for profit. The objective functions investigated are minimizing the operating costs of electrical energy generation of distribution substations and FCPPs, minimizing the voltage deviation and minimizing the total emission. In this regard, this paper just considers the placement of CHPH FCPPs while investment cost of devices is not considered. Considering the fact that the objectives are different, non-commensurable and nonlinear, it is difficult to solve the problem using conventional approaches that may optimize a single objective. Moreover, the placement of FCPPs in distribution systems is a mixed integer problem. Therefore, this paper uses the FAMPSO algorithm to overcome these problems. For solving the proposed multi-objective problem, this paper utilizes the Pareto Optimality idea to obtain a set of solution in the multi-objective problem instead of only one. Also, a fuzzy system is used to tune parameters of FAMPSO algorithm such as inertia weight. The efficacy of the proposed approach is validated on a 69-bus distribution system.

  15. Auxiliary signal processing system for a multiparameter radar

    Science.gov (United States)

    Chandrasekar, V.; Gray, G. R.; Caylor, I. J.

    1993-01-01

    The design of an auxiliary signal processor for a multiparameter radar is described with emphasis on low cost, quick development, and minimum disruption of radar operations. The processor is based around a low-cost digital signal processor card and personal computer controller. With the use of such a concept, an auxiliary processor was implemented for the NCAR CP-2 radar during a 1991 summer field campaign and allowed measurement of additional polarimetric parameters, namely, the differential phase and the copolar cross correlation. Sample data are presented from both the auxiliary and existing radar signal processors.

  16. Proton irradiation effects of amorphous silicon solar cell for solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

    1997-03-01

    Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

  17. Lithium Dinitramide as an Additive in Lithium Power Cells

    Science.gov (United States)

    Gorkovenko, Alexander A.

    2007-01-01

    Lithium dinitramide, LiN(NO2)2 has shown promise as an additive to nonaqueous electrolytes in rechargeable and non-rechargeable lithium-ion-based electrochemical power cells. Such non-aqueous electrolytes consist of lithium salts dissolved in mixtures of organic ethers, esters, carbonates, or acetals. The benefits of adding lithium dinitramide (which is also a lithium salt) include lower irreversible loss of capacity on the first charge/discharge cycle, higher cycle life, lower self-discharge, greater flexibility in selection of electrolyte solvents, and greater charge capacity. The need for a suitable electrolyte additive arises as follows: The metallic lithium in the anode of a lithium-ion-based power cell is so highly reactive that in addition to the desired main electrochemical reaction, it engages in side reactions that cause formation of resistive films and dendrites, which degrade performance as quantified in terms of charge capacity, cycle life, shelf life, first-cycle irreversible capacity loss, specific power, and specific energy. The incidence of side reactions can be reduced through the formation of a solid-electrolyte interface (SEI) a thin film that prevents direct contact between the lithium anode material and the electrolyte. Ideally, an SEI should chemically protect the anode and the electrolyte from each other while exhibiting high conductivity for lithium ions and little or no conductivity for electrons. A suitable additive can act as an SEI promoter. Heretofore, most SEI promotion was thought to derive from organic molecules in electrolyte solutions. In contrast, lithium dinitramide is inorganic. Dinitramide compounds are known as oxidizers in rocket-fuel chemistry and until now, were not known as SEI promoters in battery chemistry. Although the exact reason for the improvement afforded by the addition of lithium dinitramide is not clear, it has been hypothesized that lithium dinitramide competes with other electrolyte constituents to react with

  18. Characterization of high performance silicon-based VMJ PV cells for laser power transmission applications

    Science.gov (United States)

    Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsien; Zahuranec, Terry

    2016-03-01

    Continuing improvements in the cost and power of laser diodes have been critical in launching the emerging fields of power over fiber (PoF), and laser power beaming. Laser power is transmitted either over fiber (for PoF), or through free space (power beaming), and is converted to electricity by photovoltaic cells designed to efficiently convert the laser light. MH GoPower's vertical multi-junction (VMJ) PV cell, designed for high intensity photovoltaic applications, is fueling the emergence of this market, by enabling unparalleled photovoltaic receiver flexibility in voltage, cell size, and power output. Our research examined the use of the VMJ PV cell for laser power transmission applications. We fully characterized the performance of the VMJ PV cell under various laser conditions, including multiple near IR wavelengths and light intensities up to tens of watts per cm2. Results indicated VMJ PV cell efficiency over 40% for 9xx nm wavelengths, at laser power densities near 30 W/cm2. We also investigated the impact of the physical dimensions (length, width, and height) of the VMJ PV cell on its performance, showing similarly high performance across a wide range of cell dimensions. We then evaluated the VMJ PV cell performance within the power over fiber application, examining the cell's effectiveness in receiver packages that deliver target voltage, intensity, and power levels. By designing and characterizing multiple receivers, we illustrated techniques for packaging the VMJ PV cell for achieving high performance (> 30%), high power (> 185 W), and target voltages for power over fiber applications.

  19. External magnetic field effect on bifacial silicon solar cell''s electric power and conversion efficiencyExternal magnetic field effect on bifacial silicon solar cell''s electric power and conversion efficiency

    OpenAIRE

    ZERBO, ISSA; ZOUNGRANA, MARTIAL; SOURABIE, IDRISSA; Ouedraogo, Adama; ZOUMA, BERNARD; BATHIEBO, DIEUDONNE JOSEPH

    2015-01-01

    This article presents a modelling study of external magnetic field effect on a bifacial silicon solar cell's electric power and conversion efficiency. After the resolution of the magnetotransport equation and continuity equation of excess minority carriers, we calculate the photocurrent density and the photovoltage and then we deduce the solar cell's electric power before discussing the influence of the magnetic field on those electrical parameters. Using the electric power curves...

  20. Multiphase Isolated DC-DC Converters for Low-Voltage High-Power Fuel Cell Applications

    OpenAIRE

    Moon, Seung-Ryul

    2007-01-01

    Fuel cells provide a clean and highly efficient energy source for power generation; however, in order to efficiently utilize the energy from fuel cells, a power conditioning system is required. Typical fuel cell systems for stand-alone and utility grid-tied stationary power applications are found mostly with low nominal output voltages around 24 V and 48 V, and power levels are found to be 3 to 10 kW [1][2]. A power conditioning system for such applications generally consists of a dc-dc con...

  1. Parallel Auxiliary Space AMG Solver for $H(div)$ Problems

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, Tzanio V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-12-18

    We present a family of scalable preconditioners for matrices arising in the discretization of $H(div)$ problems using the lowest order Raviart--Thomas finite elements. Our approach belongs to the class of “auxiliary space''--based methods and requires only the finite element stiffness matrix plus some minimal additional discretization information about the topology and orientation of mesh entities. Also, we provide a detailed algebraic description of the theory, parallel implementation, and different variants of this parallel auxiliary space divergence solver (ADS) and discuss its relations to the Hiptmair--Xu (HX) auxiliary space decomposition of $H(div)$ [SIAM J. Numer. Anal., 45 (2007), pp. 2483--2509] and to the auxiliary space Maxwell solver AMS [J. Comput. Math., 27 (2009), pp. 604--623]. Finally, an extensive set of numerical experiments demonstrates the robustness and scalability of our implementation on large-scale $H(div)$ problems with large jumps in the material coefficients.

  2. Soft switching DC/DC converter using auxiliary circuits

    OpenAIRE

    Jaroslav Dudrik; Vladimír Ruščin

    2008-01-01

    A novel auxiliary circuit for full-bridge PWMDC/DC converter with controlled secondary side rectifieris presented in this paper. Zero-current turn-on for allpower switches of the inverter is achieved for full loadrange from no-load to short circuit by using controlledrectifier and auxiliary circuit on the secondary side.Modified phase shift PWM control strategy is used for theconverter. The principle of operation is explained andanalyzed and the simulation results are presented.

  3. Alphabet Sizes of Auxiliary Variables in Canonical Inner Bounds

    OpenAIRE

    Jana, Soumya

    2008-01-01

    Alphabet size of auxiliary random variables in our canonical description is derived. Our analysis improves upon estimates known in special cases, and generalizes to an arbitrary multiterminal setup. The salient steps include decomposition of constituent rate polytopes into orthants, translation of a hyperplane till it becomes tangent to the achievable region at an extreme point, and derivation of minimum auxiliary alphabet sizes based on Caratheodory's theorem.

  4. Operating experiences and degradation detection for auxiliary feedwater systems

    International Nuclear Information System (INIS)

    A study of Pressurized Water Reactor Auxiliary Feedwater (AFW) Systems has been conducted by Oak Ridge National Laboratory (ORNL) under the auspices of the Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The results of the study are documented in NUREG/CR-5404, Vol. 1, Auxiliary Feedwater System Aging Study. The study reviewed historical failure experience and current monitoring practices for the AFW System. This paper provides an overview of the study approach and results

  5. Demand-Side Contribution to Primary Frequency Control With Wind Farm Auxiliary Control

    DEFF Research Database (Denmark)

    Gomez-Lazaro, Emilio; Munoz-Benavente, Irene; Hansen, Anca Daniela;

    2014-01-01

    Maintaining a close balance between power generation and demand is essential for sustaining the quality and reliability of a power system. Currently, due to increased renewable energy generation, frequency deviations and power fluctuations of greater concern are being introduced to the grid......, particularly in regions that are weakly interconnected with their surrounding areas, such as small islands. This paper addresses the problem of frequency control in isolated power systems with relevant inclusion of wind power generation. With this aim, we have analyzed the contribution of the demand side...... to the primary frequency control together with an auxiliary frequency control, which is carried out by variable-speed wind turbines through an additional control loop that synthesizes virtual inertia. We have evaluated both the suitability of these two additional control actions counteracting frequency deviation...

  6. Power law relationship between cell cycle duration and cell volume in the early embryonic development of Caenorhabditis elegans.

    Science.gov (United States)

    Arata, Yukinobu; Takagi, Hiroaki; Sako, Yasushi; Sawa, Hitoshi

    2014-01-01

    Cell size is a critical factor for cell cycle regulation. In Xenopus embryos after midblastula transition (MBT), the cell cycle duration elongates in a power law relationship with the cell radius squared. This correlation has been explained by the model that cell surface area is a candidate to determine cell cycle duration. However, it remains unknown whether this second power law is conserved in other animal embryos. Here, we found that the relationship between cell cycle duration and cell size in Caenorhabditis elegans embryos exhibited a power law distribution. Interestingly, the powers of the time-size relationship could be grouped into at least three classes: highly size-correlated, moderately size-correlated, and potentially a size-non-correlated class according to C. elegans founder cell lineages (1.2, 0.81, and power law relationship is conserved in Xenopus and C. elegans, while the absolute powers in C. elegans were different from that in Xenopus. Furthermore, we found that the volume ratio between the nucleus and cell exhibited a power law relationship in the size-correlated classes. The power of the volume relationship was closest to that of the time-size relationship in the highly size-correlated class. This correlation raised the possibility that the time-size relationship, at least in the highly size-correlated class, is explained by the volume ratio of nuclear size and cell size. Thus, our quantitative measurements shed a light on the possibility that early embryonic C. elegans cell cycle duration is coordinated with cell size as a result of geometric constraints between intracellular structures.

  7. Fuel Cell-Powered Lift Truck Fleet Deployment Projects Final Technical Report May 2014

    Energy Technology Data Exchange (ETDEWEB)

    Klingler, James J [GENCO Infrastructure Solutions, Inc.

    2014-05-06

    The overall objectives of this project were to evaluate the performance, operability and safety of fork lift trucks powered by fuel cells in large distribution centers. This was accomplished by replacing the batteries in over 350 lift trucks with fuel cells at five distribution centers operated by GENCO. The annual cost savings of lift trucks powered by fuel cell power units was between $2,400 and $5,300 per truck compared to battery powered lift trucks, excluding DOE contributions. The greatest savings were in fueling labor costs where a fuel cell powered lift truck could be fueled in a few minutes per day compared to over an hour for battery powered lift trucks which required removal and replacement of batteries. Lift truck operators where generally very satisfied with the performance of the fuel cell power units, primarily because there was no reduction in power over the duration of a shift as experienced with battery powered lift trucks. The operators also appreciated the fast and easy fueling compared to the effort and potential risk of injury associated with switching heavy batteries in and out of lift trucks. There were no safety issues with the fueling or operation of the fuel cells. Although maintenance costs for the fuel cells were higher than for batteries, these costs are expected to decrease significantly in the next generation of fuel cells, making them even more cost effective.

  8. Nonlinear Recurrent Neural Network Predictive Control for Energy Distribution of a Fuel Cell Powered Robot

    Directory of Open Access Journals (Sweden)

    Qihong Chen

    2014-01-01

    Full Text Available This paper presents a neural network predictive control strategy to optimize power distribution for a fuel cell/ultracapacitor hybrid power system of a robot. We model the nonlinear power system by employing time variant auto-regressive moving average with exogenous (ARMAX, and using recurrent neural network to represent the complicated coefficients of the ARMAX model. Because the dynamic of the system is viewed as operating- state- dependent time varying local linear behavior in this frame, a linear constrained model predictive control algorithm is developed to optimize the power splitting between the fuel cell and ultracapacitor. The proposed algorithm significantly simplifies implementation of the controller and can handle multiple constraints, such as limiting substantial fluctuation of fuel cell current. Experiment and simulation results demonstrate that the control strategy can optimally split power between the fuel cell and ultracapacitor, limit the change rate of the fuel cell current, and so as to extend the lifetime of the fuel cell.

  9. Nonlinear recurrent neural network predictive control for energy distribution of a fuel cell powered robot.

    Science.gov (United States)

    Chen, Qihong; Long, Rong; Quan, Shuhai; Zhang, Liyan

    2014-01-01

    This paper presents a neural network predictive control strategy to optimize power distribution for a fuel cell/ultracapacitor hybrid power system of a robot. We model the nonlinear power system by employing time variant auto-regressive moving average with exogenous (ARMAX), and using recurrent neural network to represent the complicated coefficients of the ARMAX model. Because the dynamic of the system is viewed as operating- state- dependent time varying local linear behavior in this frame, a linear constrained model predictive control algorithm is developed to optimize the power splitting between the fuel cell and ultracapacitor. The proposed algorithm significantly simplifies implementation of the controller and can handle multiple constraints, such as limiting substantial fluctuation of fuel cell current. Experiment and simulation results demonstrate that the control strategy can optimally split power between the fuel cell and ultracapacitor, limit the change rate of the fuel cell current, and so as to extend the lifetime of the fuel cell.

  10. A PPS Sampling Scheme Using Harmonic Mean of An Auxiliary Variable

    OpenAIRE

    L.N. Sahoo; Dalabehera, M.; A.K. Mangaraj

    2012-01-01

    We consider a probability proportional to size sampling scheme by using harmonic mean of an auxiliary variable, when the correlation between study variable and auxiliary variable is highly negative. This is achieved by considering inverse transformation of the auxiliary variable and then utilizing the transformed auxiliary variable values at the design stage of the survey operation in selecting a sample.

  11. Modeling of High Efficiency Solar Cells Under Laser Pulse for Power Beaming Applications

    Science.gov (United States)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells may be used as receivers for laser power beaming. To understand the behavior of solar cells when illuminated by a pulsed laser, the time response of gallium arsenide and silicon solar cells to pulsed monochromatic input has been modeled using a finite element solar cell model.

  12. Power

    OpenAIRE

    Samuel Bowles; Herbert Gintis

    2007-01-01

    We consider the exercise of power in competitive markets for goods, labour and credit. We offer a definition of power and show that if contracts are incomplete it may be exercised either in Pareto-improving ways or to the disadvantage of those without power. Contrasting conceptions of power including bargaining power, market power, and consumer sovereignty are considered. Because the exercise of power may alter prices and other aspects of exchanges, abstracting from power may miss essential a...

  13. Hyperspectral Polymer Solar Cells, Integrated Power for Microsystems

    Energy Technology Data Exchange (ETDEWEB)

    Stiebitz, Paul [Rochester Institute of Technology, NY (United States)

    2014-05-27

    The purpose of this research is to address a critical technology barrier to the deployment of next generation autonomous microsystems – the availability of efficient and reliable power sources. The vast majority of research on microsystems has been directed toward the development and miniaturization of sensors and other devices that enhance their intelligence, physical, and networking capabilities. However, the research into power generating and power storage technologies has not keep pace with this development. This research leveraged the capabilities of RIT’s NanoPower Research Laboratories (NPRL) in materials for advanced lithium ion batteries, nanostructured photovoltaics, and hybrid betavoltaics to develop reliable power sources for microsystems.

  14. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    Science.gov (United States)

    2005-03-01

    ESO Video Newsreel 15, released on March 14, 2005. It provides an introduction to the VLT Interferometer (VLTI) and the two Auxiliary Telescopes (ATs) now installed at Paranal. ESO PR Photo 07a/05 shows the impressive ensemble at the summit of Paranal. From left to right, the enclosure of VLT Antu, Kueyen and Melipal, AT1, the VLT Survey Telescope (VST) in the background, AT2 and VLT Yepun. Located at the summit of the 2,600-m high Cerro Paranal in the Atacama Desert (Chile), ESO's Very Large Telescope (VLT) is at the forefront of astronomical technology and is one of the premier facilities in the world for optical and near-infrared observations. The VLT is composed of four 8.2-m Unit Telescope (Antu, Kueyen, Melipal and Yepun). They have been progressively put into service together with a vast suite of the most advanced astronomical instruments and are operated every night in the year. Contrary to other large astronomical telescopes, the VLT was designed from the beginning with the use of interferometry as a major goal. The href="/instruments/vlti">VLT Interferometer (VLTI) combines starlight captured by two 8.2- VLT Unit Telescopes, dramatically increasing the spatial resolution and showing fine details of a large variety of celestial objects. The VLTI is arguably the world's most advanced optical device of this type. It has already demonstrated its powerful capabilities by addressing several key scientific issues, such as determining the size and the shape of a variety of stars (ESO PR 22/02, PR 14/03 and PR 31/03), measuring distances to stars (ESO PR 25/04), probing the innermost regions of the proto-planetary discs around young stars (ESO PR 27/04) or making the first detection by infrared interferometry of an extragalactic object (ESO PR 17/03). "Little Brothers" ESO PR Photo 07b/05 ESO PR Photo 07b/05 [Preview - JPEG: 597 x 400 pix - 47k] [Normal - JPEG: 1193 x 800 pix - 330k] [HiRes - JPEG: 5000 x 3354 pix - 10.0M] ESO PR Photo 07c/05 ESO PR Photo 07c/05

  15. Auxiliary services offered to operator of transmissive system - the primary and secondary regulation of active capacity in ENO, o.z

    International Nuclear Information System (INIS)

    The change of outmoded analogue regulators of turbogenerators of Novaky Thermal Power Plant (TG ENO) B1 and B2 to new digital assigned the basic condition for fulfilment of strict rules for providing of auxiliary services - of primary and secondary regulation of active capacity and regulation of turns. The paper deals with technical and program sources for realisation of marked auxiliary services on the level of direct regulation of bloc, with fulfilment and evaluating of auxiliary services according to valid norm PNE 34-01/2002 in condensation and power take off operation of blocks after realisation of extraction of heat in hot water from ENO B. The paper argues, that regulation attributes of block - regulation zone of active capacity for primary and secondary regulation as like as the parameters of these regulations have been not changed by power take off operation. (author)

  16. Power system with an integrated lubrication circuit

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, Brian D. (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL); Algrain, Marcelo C. (Peoria, IL); Johnson, Kris W. (Washington, IL); Lane, William H. (Chillicothe, IL)

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  17. Challenges for fuel cells as stationary power resource in the evolving energy enterprise

    Science.gov (United States)

    Rastler, Dan

    The primary market challenges for fuel cells as stationary power resources in evolving energy markets are reviewed. Fuel cell power systems have significant barriers to overcome in their anticipated role as decentralized energy power systems. Market segments for fuel cells include combined heat and power; low-cost energy, premium power; peak shaving; and load management and grid support. Understanding the role and fit of fuel cell systems in evolving energy markets and the highest value applications are a major challenge for developers and government funding organizations. The most likely adopters of fuel cell systems and the challenges facing each adopter in the target market segment are reviewed. Adopters include generation companies, utility distribution companies, retail energy service providers and end-users. Key challenges include: overcoming technology risk; achieving retail competitiveness; understanding high value markets and end-user needs; distribution and service channels; regulatory policy issues; and the integration of these decentralized resources within the electrical distribution system.

  18. Environmental impact assessment of the incineration of municipal solid waste with auxiliary coal in China.

    Science.gov (United States)

    Zhao, Yan; Xing, Wei; Lu, Wenjing; Zhang, Xu; Christensen, Thomas H

    2012-10-01

    The environmental impacts of waste incineration with auxiliary coal were investigated using the life-cycle-based software, EASEWASTE, based on the municipal solid waste (MSW) management system in Shuozhou City. In the current system, MSW is collected, transported, and incinerated with 250 kg of coal per ton of waste. Based on observed environmental impacts of incineration, fossil CO(2) and heavy metals were primary contributors to global warming and ecotoxicity in soil, respectively. Compared with incinerators using excess coal, incineration with adequate coal presents significant benefits in mitigating global warming, whereas incineration with a mass of coal can avoid more impacts to acidification, photochemical ozone and nutrient enrichment because of increased electricity substitution and reduced emission from coal power plants. The "Emission standard of air pollutants for thermal power plants (GB13223-2011)" implemented in 2012 introduced stricter policies on controlling SO(2) and NO(x) emissions from coal power plants. Thus, increased use of auxiliary coal during incineration yields fewer avoided impacts on acidification and nutrient enrichment. When two-thirds of ash is source-separated and landfilled, the incineration of rest-waste presents better results on global warming, acidification, nutrient enrichment, and even ecotoxicity in soil. This process is considered a promising solution for MSW management in Shuozhou City. Weighted normalized environmental impacts were assessed based on Chinese political reduction targets. Results indicate that heavy metal and acidic gas emissions should be given more attention in waste incineration. This study provides scientific support for the management of MSW systems dominated by incineration with auxiliary coal in China. PMID:22683228

  19. Direct power generation from waste coffee grounds in a biomass fuel cell

    Science.gov (United States)

    Jang, Hansaem; Ocon, Joey D.; Lee, Seunghwa; Lee, Jae Kwang; Lee, Jaeyoung

    2015-11-01

    We demonstrate the possibility of direct power generation from waste coffee grounds (WCG) via high-temperature carbon fuel cell technology. At 900 °C, the WCG-powered fuel cell exhibits a maximum power density that is twice than carbon black. Our results suggest that the heteroatoms and hydrogen contained in WCG are crucial in providing good cell performance due to its in-situ gasification, without any need for pre-reforming. As a first report on the use of coffee as a carbon-neutral fuel, this study shows the potential of waste biomass (e.g. WCG) in sustainable electricity generation in fuel cells.

  20. Performance evaluation of aluminum/phosphate cell for powering small electronic devices

    Directory of Open Access Journals (Sweden)

    Gymama Slaughter

    2015-12-01

    Full Text Available We report on an innovative membrane-free aluminum/phosphate cell based on the activation of aluminum (Al as anodic material using ZnO nanocrystal in phosphate rich electrolyte that is capable of generating sufficient power to power a light-emitting diode (LED, selected as a model of a small electronic device. The energy from the cell is periodically supplied in high power bursts due to the charge and discharge cycle of the capacitor. The entire process is controlled by a switched capacitor regulator. The Al/phosphate cell was studied in neutral 100 mM phosphate buffer solution (7.4 at a temperature of 25 °C. We demonstrate that two Al/phosphate cells connected in series can generate an open circuit voltage (Voc up to 1.66 V to continuously power a LED via a switched capacitor regulator circuit. The switched capacitor regulator circuit enabled the 1 μF capacitor to store the incoming power from the cell and discharge it in a large power burst to supply the necessary drive strength required by the LED. This new Al/phosphate cell configuration is a ‘green’ alternative to the use of glucose abiotic and biofuel cells for powering ultra-low power implantable electronic devices.

  1. Special considerations on operating a fuel cell power plant using natural gas with marginal heating value

    Energy Technology Data Exchange (ETDEWEB)

    Moses, L. Ng; Chien-Liang Lin [Industrial Technology Research Institute, Taiwan (China); Ya-Tang Cheng [Power Research Institute, Taiwan (China)

    1996-12-31

    In realizing new power generation technologies in Taiwan, a phosphoric acid fuel cell power plant (model PC2513, ONSI Corporation) has been installed in the premises of the Power Research Institute of the Taiwan Power Company in Taipei County of Taiwan. The pipeline gas supplying to the site of this power plant has a high percentage of carbon dioxide and thus a slightly lower heating value than that specified by the manufacturer. Because of the lowering of heating value of input gas, the highest Output power from the power plant is understandably less than the rated power of 200 kW designed. Further, the transient response of the power plant as interrupted from the Grid is also affected. Since this gas is also the pipeline gas supplying to the heavily populated Taipei Municipal area, it is conceivable that the success of the operations of fuel cells using this fuel is of vital importance to the promotion of the use of this power generation technology in Taiwan. Hence, experiments were set up to assess the feasibility of this fuel cell power plant using the existing pipeline gas in this part of Taiwan where fuel cells would most likely find useful.

  2. Power conversion and quality of the Santa Clara 2 MW direct carbonate fuel cell demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    Skok, A.J. [Fuel Cell Engineering Corp., Danbury, CT (United States); Abueg, R.Z. [Basic Measuring Instruments, Santa Clara, CA (United States); Schwartz, P. [Fluor Daniel, Inc., Irvine, CA (United States)] [and others

    1996-12-31

    The Santa Clara Demonstration Project (SCDP) is the first application of a commercial-scale carbonate fuel cell power plant on a US electric utility system. It is also the largest fuel cell power plant ever operated in the United States. The 2MW plant, located in Santa Clara, California, utilizes carbonate fuel cell technology developed by Energy Research Corporation (ERC) of Danbury, Connecticut. The ultimate goal of a fuel cell power plant is to deliver usable power into an electrical distribution system. The power conversion sub-system does this for the Santa Clara Demonstration Plant. A description of this sub-system and its capabilities follows. The sub-system has demonstrated the capability to deliver real power, reactive power and to absorb reactive power on a utility grid. The sub-system can be operated in the same manner as a conventional rotating generator except with enhanced capabilities for reactive power. Measurements demonstrated the power quality from the plant in various operating modes was high quality utility grade power.

  3. High-power biofuel cell textiles from woven biscrolled carbon nanotube yarns

    Science.gov (United States)

    Kwon, Cheong Hoon; Lee, Sung-Ho; Choi, Young-Bong; Lee, Jae Ah; Kim, Shi Hyeong; Kim, Hyug-Han; Spinks, Geoffrey M.; Wallace, Gordon G.; Lima, Márcio D.; Kozlov, Mikhail E.; Baughman, Ray H.; Kim, Seon Jeong

    2014-06-01

    Biofuel cells that generate electricity from glucose in blood are promising for powering implantable biomedical devices. Immobilizing interconnected enzyme and redox mediator in a highly conducting, porous electrode maximizes their interaction with the electrolyte and minimizes diffusion distances for fuel and oxidant, thereby enhancing power density. Here we report that our separator-free carbon nanotube yarn biofuel cells provide an open-circuit voltage of 0.70 V, and a maximum areal power density of 2.18 mW cm-2 that is three times higher than for previous carbon nanotube yarn biofuel cells. Biofuel cell operation in human serum provides high areal power output, as well as markedly increased lifetime (83% remained after 24 h), compared with previous unprotected biofuel cells. Our biscrolled yarn biofuel cells are woven into textiles having the mechanical robustness needed for implantation for glucose energy harvesting.

  4. Accuracy of marker-assisted selection with auxiliary traits

    Indian Academy of Sciences (India)

    P Narain

    2003-09-01

    Genetic information on molecular markers is increasingly being used in plant and animal improvement programmes particularly as indirect means to improve a metric trait by selection either on an individual basis or on the basis of an index incorporating such information. This paper examines the utility of an index of selection that not only combines phenotypic and molecular information on the trait under improvement but also combines similar information on one or more auxiliary traits. The accuracy of such a selection procedure has been theoretically studied for sufficiently large populations so that the effects of detected quantitative trait loci can be perfectly estimated. The theory is illustrated numerically by considering one auxiliary trait. It is shown that the use of an auxiliary trait improves the selection accuracy; and, hence, the relative efficiency of index selection compared to individual selection which is based on the same intensity of selection. This is particularly so for higher magnitudes of residual genetic correlation and environmental correlation having opposite signs, lower values of the proportion of genetic variation in the main trait associated with the markers, negligible proportion of genetic variation in the auxiliary trait associated with the markers, and lower values of the heritability of the main trait but higher values of the heritability of the auxiliary trait.

  5. Feasibility of AN Ecrh System for Jet:. Plant Layout, Auxiliaries and Services

    Science.gov (United States)

    Lennholm, M.; Bouquey, F.; Braune, H.; Farthing, J.; Garavaglia, S.; Giruzzi, G.; Granucci, G.; Jennison, M.; Parkin, A.

    2011-02-01

    A study conducted over the last year to asses the desirability and feasibility of installing an ECRH system on the JET tokamak has concluded that such a system is indeed both desirable and feasible. Details of physics studies, launcher and transmission line design, and power supplies are presented elsewhere in these proceedings. This paper concentrates on the logistical implications of installing this system at JET. The paper addresses issues such as port allocation and plant location. The study has concluded that a new building will be needed to house the ECRH plant. Building layout proposals are presented together with considerations regarding the required auxiliary equipment.

  6. Implementation of electromagnetically induced transparency in a metamaterial controlled with auxiliary waves

    CERN Document Server

    Nakanishi, Toshihiro

    2015-01-01

    We propose a metamaterial to realize true electromagnetically induced transparency (EIT), where the incidence of an auxiliary electromagnetic wave called the control wave induces transparency for a probe wave. The analogy to the original EIT effect in an atomic medium is shown through analytical and numerical calculations derived from a circuit model for the metamaterial. We performed experiments to demonstrate the EIT effect of the metamaterial in the microwave region. The width and position of the transparent region can be controlled by the power and frequency of the control wave. We also observed asymmetric transmission spectra unique to the Fano resonance.

  7. Modelling of Auxiliary Devices for a Hardware-in-the-Loop Application

    OpenAIRE

    Olsén, Johan

    2005-01-01

    The engine torque is an important control signal. This signal is disturbed by the devices mounted on the belt. To better be able to estimate the torque signal, this work aims to model the auxiliary devices'influence on the crankshaft torque. Physical models have been developed for the air conditioning compressor, the alternator and the power steering pump. If these models are to be used in control unit function development and testing, they have to be fast enough to run on a hardware-in-the-l...

  8. Maintenance centered on reliability applied to a NPP auxiliary feedwater system

    International Nuclear Information System (INIS)

    The main objective of maintenance in a NPP is to assure that structures, systems and components will perform their design functions with reliability and/or availability in order to allow a safe and economic electric power generation. Reliability-Centered Maintenance (RCM) is a method of systematic review to either develop or optimize Preventive Maintenance Programs. This paper presents the objectives, concepts, organization and methods used in the application of RCM to NPP. Some application examples are include in this paper, considering some components of the Auxiliary Feedwater System of a generic Westinghouse designed two-loop PWR NPP. (author). 4 refs., 3 figs

  9. Fuel Cell Powered Vehicles Using Supercapacitors: Device Characteristics, Control Strategies, and Simulation Results

    OpenAIRE

    Zhao, Hengbing; Burke, Andy

    2010-01-01

    The fuel cell powered vehicle is one of the most attractive candidates for the future due to its high efficiency and capability to use hydrogen as the fuel. However, its relatively poor dynamic response, high cost, and limited life time have impeded its widespread adoption. With the emergence of large supercapacitors (also know as ultracapacitors, UCs) with high power density and the shift to hybridization in the vehicle technology, fuel cell/supercapacitor hybrid fuel cell vehicles are gaini...

  10. Solid Oxide Fuel Cell – Gas Turbine Hybrid Power Plant

    OpenAIRE

    Henke, Moritz; Willich, Caroline; Steilen, Mike; Kallo, Josef; Friedrich, K. Andreas

    2013-01-01

    A model of a hybrid power plant consisting of SOFC and a gas turbine is presented. Simulations are carried out for a different number of SOFC stacks while keeping the output power of the SOFC constant. Results show that the effect of stack number on system performance is only marginal within the investigated range. Operating conditions of the SOFC, however, are strongly influenced.

  11. Effects of the β1 auxiliary subunit on modification of Rat Na(v)1.6 sodium channels expressed in HEK293 cells by the pyrethroid insecticides tefluthrin and deltamethrin.

    Science.gov (United States)

    He, Bingjun; Soderlund, David M

    2016-01-15

    We expressed rat Nav1.6 sodium channels with or without the rat β1 subunit in human embryonic kidney (HEK293) cells and evaluated the effects of the pyrethroid insecticides tefluthrin and deltamethrin on whole-cell sodium currents. In assays with the Nav1.6 α subunit alone, both pyrethroids prolonged channel inactivation and deactivation and shifted the voltage dependence of channel activation and steady-state inactivation toward hyperpolarization. Maximal shifts in activation were ~18 mV for tefluthrin and ~24 mV for deltamethrin. These compounds also caused hyperpolarizing shifts of ~10-14 mV in the voltage dependence of steady-state inactivation and increased in the fraction of sodium current that was resistant to inactivation. The effects of pyrethroids on the voltage-dependent gating greatly increased the size of sodium window currents compared to unmodified channels; modified channels exhibited increased probability of spontaneous opening at membrane potentials more negative than the normal threshold for channel activation and incomplete channel inactivation. Coexpression of Nav1.6 with the β1 subunit had no effect on the kinetic behavior of pyrethroid-modified channels but had divergent effects on the voltage-dependent gating of tefluthrin- or deltamethrin-modified channels, increasing the size of tefluthrin-induced window currents but decreasing the size of corresponding deltamethrin-induced currents. Unexpectedly, the β1 subunit did not confer sensitivity to use-dependent channel modification by either tefluthrin or deltamethrin. We conclude from these results that functional reconstitution of channels in vitro requires careful attention to the subunit composition of channel complexes to ensure that channels in vitro are faithful functional and pharmacological models of channels in neurons.

  12. Effects of the β1 auxiliary subunit on modification of Rat Na(v)1.6 sodium channels expressed in HEK293 cells by the pyrethroid insecticides tefluthrin and deltamethrin.

    Science.gov (United States)

    He, Bingjun; Soderlund, David M

    2016-01-15

    We expressed rat Nav1.6 sodium channels with or without the rat β1 subunit in human embryonic kidney (HEK293) cells and evaluated the effects of the pyrethroid insecticides tefluthrin and deltamethrin on whole-cell sodium currents. In assays with the Nav1.6 α subunit alone, both pyrethroids prolonged channel inactivation and deactivation and shifted the voltage dependence of channel activation and steady-state inactivation toward hyperpolarization. Maximal shifts in activation were ~18 mV for tefluthrin and ~24 mV for deltamethrin. These compounds also caused hyperpolarizing shifts of ~10-14 mV in the voltage dependence of steady-state inactivation and increased in the fraction of sodium current that was resistant to inactivation. The effects of pyrethroids on the voltage-dependent gating greatly increased the size of sodium window currents compared to unmodified channels; modified channels exhibited increased probability of spontaneous opening at membrane potentials more negative than the normal threshold for channel activation and incomplete channel inactivation. Coexpression of Nav1.6 with the β1 subunit had no effect on the kinetic behavior of pyrethroid-modified channels but had divergent effects on the voltage-dependent gating of tefluthrin- or deltamethrin-modified channels, increasing the size of tefluthrin-induced window currents but decreasing the size of corresponding deltamethrin-induced currents. Unexpectedly, the β1 subunit did not confer sensitivity to use-dependent channel modification by either tefluthrin or deltamethrin. We conclude from these results that functional reconstitution of channels in vitro requires careful attention to the subunit composition of channel complexes to ensure that channels in vitro are faithful functional and pharmacological models of channels in neurons. PMID:26708501

  13. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  14. Powering microbial electrolysis cells by capacitor circuits charged using microbial fuel cell

    KAUST Repository

    Hatzell, Marta C.

    2013-05-01

    A microbial electrolysis cell (MEC) was powered by a capacitor based energy storage circuit using energy from a microbial fuel cell (MFC) to increase MEC hydrogen production rates compared to that possible by the MFC alone. To prevent voltage reversal, MFCs charged the capacitors in a parallel configuration, and then the capacitors were discharged in series to boost the voltage that was used to power the MECs. The optimal capacitance for charging was found to be ∼0.01 F for each MFC. The use of the capacitor charging system increased energy recoveries from 9 to 13%, and hydrogen production rates increased from 0.31 to 0.72 m3 m-3-day-1, compared to coupled systems without capacitors. The circuit efficiency (the ratio of the energy that was discharged to the MEC to the energy provided to the capacitor from the MFCs) was ∼90%. These results provide an improved method for linking MFCs to MECs for renewable hydrogen gas production. © 2012 Elsevier B.V. All rights reserved.

  15. Small Cell Lung Cancer Auxiliary Detection Method Based on Convolution Neural Network%基于卷积神经网络的小细胞型肺癌辅助检测方法

    Institute of Scientific and Technical Information of China (English)

    李学沧; 贾识桢

    2013-01-01

    Lung cancer is one of the highest mortality in the world, due to its largest density and a lot of image factors, small cell lung cancer is the best to diagnose. This paper introduces a new method-Deep Learning which belongs to machine learning to diagnose small cell lung cancer. Convolution Neural Networks (CNN) has gained a lot of fame in Face recognition, vehicle identification and text discrimination fields. With the mode of Convolution Neural Networks, we can reduce the ratio of misdiagnosis largely. Moreover, if appending new complementing samples, the detection rate can be improved significantly, only adjusting a few adding neurons' weights while keeping previous weights unchanging.%肺癌是世界上患病率并且死亡率最高的疾病之一,而小细胞型肺癌由于密度差最大以及涉及较多的图像因素,是脏器中最容易诊断的癌症。创新性地提出一种新的辅助检测方法,即采取卷积神经网络算法辅助检测小细胞型肺癌,该算法已经在人脸识别、车辆识别和文字判别等领域取得了丰硕的成果。卷积神经网络很好地结合了之前检测算法的优点,又能兼顾准确性,更好地减少误诊率,提高学习效率。此外当有新的学习样本加入,在保持原有学习结果的基础上,只调整神经元的权值就能明显提高诊断率。

  16. Low power and reliable SRAM memory cell and array design

    CERN Document Server

    Ishibashi, Koichiro

    2011-01-01

    Success in the development of recent advanced semiconductor device technologies is due to the success of SRAM memory cells. This book addresses various issues for designing SRAM memory cells for advanced CMOS technology. To study LSI design, SRAM cell design is the best materials subject because issues about variability, leakage and reliability have to be taken into account for the design.

  17. Development of a 400 W High Temperature PEM Fuel Cell Power Pack

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Bang, Mads; Korsgaard, Anders;

    2006-01-01

    . This work demonstrates the use of HTPEM fuel cells (HTPEM) in a 400 W fuel cell power pack. The fuel cell system concept uses a 30 cell HTPEM fuel cell stack designed at the Institute of Energy Technology, Aalborg University. The MEAs employed are Celtec P-series by Pemeas, with an active area of 45cm...... in a power pack, a high efficiency DC/DC-converter is designed. The overall control of the power conditioning and the power pack itself is also derived from modelling of the DC/DC converter. Comparing the LTPEM and the HTPEM, the HTPEM fuel cell has a lower cell voltage than the LTPEM, but the developed...... power pack demonstrates some of the advantages by using a HTPEM fuel cell. This initial system is very simple and there is no need for humidification of the species like in a LTPEM fuel cell system. The use of the HTPEM fuel cell makes it possible to use reformed gas at high CO concentrations without...

  18. A Maximum Power Point Tracking Control Method of a Photovoltaic Power Generator with Consideration of Dynamic Characteristics of Solar Cells

    Science.gov (United States)

    Watanabe, Takashi; Yoshida, Toshiya; Ohniwa, Katsumi

    This paper discusses a new control strategy for photovoltaic power generation systems with consideration of dynamic characteristics of the photovoltaic cells. The controller estimates internal currents of an equivalent circuit for the cells. This estimated, or the virtual current and the actual voltage of the cells are fed to a conventional Maximum-Power-Point-Tracking (MPPT) controller. Consequently, this MPPT controller still tracks the optimum point even though it is so designed that the seeking speed of the operating point is extremely high. This system may suit for applications, which are installed in rapidly changeable insolation and temperature-conditions e.g. automobiles, trains, and airplanes. The proposed method is verified by experiment with a combination of this estimating function and the modified Boehringer's MPPT algorithm.

  19. Improving Semi-Supervised Learning with Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae;

    Deep generative models based upon continuous variational distributions parameterized by deep networks give state-of-the-art performance. In this paper we propose a framework for extending the latent representation with extra auxiliary variables in order to make the variational distribution more...... expressive for semi-supervised learning. By utilizing the stochasticity of the auxiliary variable we demonstrate how to train discriminative classifiers resulting in state-of-the-art performance within semi-supervised learning exemplified by an 0.96% error on MNIST using 100 labeled data points. Furthermore...

  20. Auxiliary tensor fields for Sp(2,R) self-duality

    CERN Document Server

    Ivanov, Evgeny A; Zupnik, Boris M

    2014-01-01

    The coset Sp(2,R)/U(1) is parametrized by two real scalar fields. We generalize the formalism of auxiliary tensor (bispinor) fields in U(1) self-dual nonlinear models of abelian gauge fields to the case of Sp(2,R) self-duality. In this new formulation, Sp(2,R) duality of the nonlinear scalar-gauge equations of motion is equivalent to an Sp(2,R) invariance of the auxiliary interaction. We derive this result in two different ways, aiming at its further application to supersymmetric theories. We also consider an extension to interactions with higher derivatives.

  1. Bispinor Auxiliary Fields in Duality-Invariant Electrodynamics Revisited

    OpenAIRE

    Ivanov, E. A.; Zupnik, B. M.

    2012-01-01

    Motivated by a recent progress in studying the duality-symmetric models of nonlinear electrodynamics, we revert to the auxiliary tensorial (bispinor) field formulation of the O(2) duality proposed by us in arXiv:hep-th/0110074, arXiv:hep-th/0303192. In this approach, the entire information about the given duality-symmetric system is encoded in the O(2) invariant interaction Lagrangian which is a function of the auxiliary fields V_{\\alpha\\beta}, \\bar V_{\\dot \\alpha\\dot \\beta}. We extend this s...

  2. PARALLEL AUXILIARY SPACE AMG FOR H(curl) PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Tzanio V. Kolev; Panayot S. Vassilevski

    2009-01-01

    In this paper we review a number of auxiliary space based preconditioners for the second order definite and semi-definite Maxwell problems discretized with the lowest order Nedelec finite elements. We discuss the parallel implementation of the most promising of these methods, the ones derived from the recent Hiptmair-Xu (HX) auxiliary space decomposition [Hiptmair and Xu, SIAM J. Numer. Anal., 45 (2007), pp. 2483-2509]. An extensive set of numerical experiments demonstrate the scalability of our implementation on large-scale H(curl) problems.

  3. Sampling designs dependent on sample parameters of auxiliary variables

    CERN Document Server

    Wywiał, Janusz L

    2015-01-01

    The book offers a valuable resource for students and statisticians whose work involves survey sampling. An estimation of the population parameters in finite and fixed populations assisted by auxiliary variables is considered. New sampling designs dependent on moments or quantiles of auxiliary variables are presented on the background of the classical methods. Accuracies of the estimators based on original sampling design are compared with classical estimation procedures. Specific conditional sampling designs are applied to problems of small area estimation as well as to estimation of quantiles of variables under study. .

  4. TMI-2 auxiliary building elevator shaft and pit decontamination

    International Nuclear Information System (INIS)

    Decontamination of the elevator pit and shaft in the auxiliary building at Three Mile Island Unit 2 (TMI-2) was performed to remove high radiation and contamination levels which prevented personnel from utilizing the elevator. The radiation and contamination levels in the TMI-2 auxiliary building elevator shaft have been reduced to the point where plant personnel are again permitted to ride in the elevator without a radiation work permit, with the exception of access to the 281-ft (basement) level. Based on the declassification and expanded use of the elevator, the task goal has been met. The tax expended 16.16 man-rem and 621 man-hours

  5. Vanishing auxiliary variables in PPS sampling - with applications in microscopy

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute; Jensen, Eva B. Vedel

    Recently, non-uniform sampling has been suggested in microscopy to increase efficiency. More precisely, sampling proportional to size (PPS) has been introduced where the probability of sampling a unit in the population is proportional to the value of an auxiliary variable. Unfortunately, vanishing...... auxiliary variables are a common phenomenon in microscopy and, accordingly, part of the population is not accessible, using PPS sampling. We propose a modification of the design, for which an optimal solution can be found, using a model assisted approach. The optimal design has independent interest...

  6. A Simple and Efficient MPPT Method for Low-Power PV Cells

    Directory of Open Access Journals (Sweden)

    Maria Teresa Penella

    2014-01-01

    Full Text Available Small-size PV cells have been used to power sensor nodes. These devices present limited computing resources and so low complexity methods have been used in order to extract the maximum power from the PV cells. Among them, the fractional open circuit voltage (FOCV method has been widely proposed, where the maximum power point of the PV cell is estimated from a fraction of its open circuit voltage. Here, we show a generalization of the FOCV method that keeps its inherent simplicity and improves the tracking efficiency. First, a single-diode model for PV cells was used to compute the tracking efficiency versus irradiance. Computations were carried out for different values of the parameters involved in the PV cell model. The proposed approach clearly outperformed the FOCV method, specially at low irradiance, which is significant for powering sensor nodes. Experimental tests performed with a 500 mW PV panel agreed with these results.

  7. Integration of A Solid Oxide Fuel Cell into A 10 MW Gas Turbine Power Plant

    Directory of Open Access Journals (Sweden)

    Denver F. Cheddie

    2010-04-01

    Full Text Available Power generation using gas turbine power plants operating on the Brayton cycle suffers from low efficiencies. In this work, a solid oxide fuel cell (SOFC is proposed for integration into a 10 MW gas turbine power plant, operating at 30% efficiency. The SOFC system utilizes four heat exchangers for heat recovery from both the turbine outlet and the fuel cell outlet to ensure a sufficiently high SOFC temperature. The power output of the hybrid plant is 37 MW at 66.2% efficiency. A thermo-economic model predicts a payback period of less than four years, based on future projected SOFC cost estimates.

  8. A New Green Power Inverter for Fuel Cells

    DEFF Research Database (Denmark)

    Andersen, Gert Karmisholt; Klumpner, Christian; Kjær, Søren Bækhøj;

    2002-01-01

    power to the grid. The proposed converter consists of an isolated dc-dc converter cascaded with a single phase H-bridge inverter. The dc-dc converter is a current-fed push-pull converter. A new dedicated voltage mode startup procedure has been developed in order to limit the inrush current during......%) and the inverter operates with a near unity power factor and a low current THD....

  9. Binary co-generation power plant with night-temperature (SOFC) fuel cells of natural gas, v. 15(57)

    International Nuclear Information System (INIS)

    Binary co-generation power plant with height-temperature SOFC fuel cells of natural gas are presented in this paper. Based on before optimization calculations for this type of power plants is made: basic measures, number of modules, electric power and fuel cell efficiency; gas turbine electric power and efficiency; co-generation steam turbine electric and heat power efficiency. Compare analysis of binary co-generation power plant with SOFC fuel cells and co-generative power plant without fuel cells in relation of efficiency, ecological benefits and profitability (economy analysis) is given. (Author)

  10. Development of a thin film solar cell interconnect for the PowerSphere concept

    International Nuclear Information System (INIS)

    Progressive development of microsatellite technologies has resulted in increased demand for lightweight electrical power subsystems including solar arrays. The use of thin film photovoltaics has been recognized as a key solution to meet the power needs. The lightweight cells can generate sufficient power and still meet critical mass requirements. Commercially available solar cells produced on lightweight substrates are being studied as an option to fulfill the power needs. The commercially available solar cells are relatively inexpensive and have a high payoff potential. Commercially available thin film solar cells are primarily being produced for terrestrial applications. The need to convert the solar cell from a terrestrial to a space compatible application is the primary challenge. Solar cell contacts, grids and interconnects need to be designed to be atomic oxygen resistant and withstand rapid thermal cycling environments. A mechanically robust solar cell interconnect is also required in order to withstand handling during fabrication and survive during launch. The need to produce the solar cell interconnects has been identified as a primary goal of the PowerSphere program and is the topic of this paper. Details of the trade study leading to the final design involving the solar cell wrap around contact, flex blanket, welding process, and frame will be presented at the conference

  11. Hybrid Power Management Program Evaluated Fuel Cell/Ultracapacitor Combinations and Developed Other New Applications

    Science.gov (United States)

    Eichenberg, Dennis J.

    2004-01-01

    In fiscal year 2003, the continuation of the Hybrid Power Management (HPM) Program through NASA Glenn Research Center's Commercial Technology Office resulted in several new successful applications of this pioneering technology. HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors, fuel cells, and photovoltaics. HPM has extremely wide potential, with applications from nanowatts to megawatts--including power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy. Fuel cells provide excellent efficiency and energy density, but do not have good power density. In contrast, ultracapacitors have excellent power density and virtually unlimited cycle life. To improve the power density of the fuel cell, the combination of fuel cells and ultracapacitors was evaluated.

  12. Critical assessment of power trains with fuel-cell systems and different fuels

    Science.gov (United States)

    Höhlein, B.; von Andrian, S.; Grube, Th; Menzer, R.

    Legal regulations (USA, EU) are a major driving force for intensifying technological developments with respect to the global automobile market. In the future, highly efficient vehicles with very low emission levels will include low-temperature fuel-cell systems (PEFC) as units of electric power trains. With alcohols, ether or hydrocarbons used as fuels for these new electric power trains, hydrogen as PEFC fuel has to be produced on board. These concepts including the direct use of methanol in fuel-cell systems, differ considerably in terms of both their development prospects and the results achieved so far. Based on process engineering analyses for net electricity generation in PEFC-powered power trains, as well as on assumptions for electric power trains and vehicle configurations, different fuel-cell performances and fuel processing units for octane, diesel, methanol, ethanol, propane and dimethylether have been evaluated as fuels. The possible benefits and key challenges for different solutions of power trains with fuel-cell systems/on-board hydrogen production and with direct methanol fuel-cell (DMFC) systems have been assessed. Locally, fuel-cell power trains are almost emission-free and, unlike battery-powered vehicles, their range is comparable to conventional vehicles. Therefore, they have application advantages cases of particularly stringent emission standards requiring zero emission. In comparison to internal combustion engines, using fuel-cell power trains can lead to clear reductions in primary energy demand and global, climate-relevant emissions providing the advantage of the efficiency of the hydrogen/air reaction in the fuel cell is not too drastically reduced by additional conversion steps of on-board hydrogen production, or by losses due to fuel supply provision.

  13. Impute DC link (IDCL) cell based power converters and control thereof

    Energy Technology Data Exchange (ETDEWEB)

    Divan, Deepakraj M.; Prasai, Anish; Hernendez, Jorge; Moghe, Rohit; Iyer, Amrit; Kandula, Rajendra Prasad

    2016-04-26

    Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.

  14. Harnessing the power of Vδ2 cells in cancer immunotherapy.

    Science.gov (United States)

    Fowler, D W; Bodman-Smith, M D

    2015-04-01

    γδ T cells are a subset of T lymphocytes that have been implicated in immunosurveillance against infections and tumours. In the peripheral blood of humans the γδ T cell pool is made up predominantly of Vδ2 cells, which can detect both foreign and self-metabolites of the isoprenoid biosynthesis pathway. This unique axis of antigen recognition enables Vδ2 cells to respond to a range of pathogenic infections as well as perturbations in endogenous isoprenoid biosynthesis that can occur during cell stress and malignant transformation. There has been growing interest in Vδ2 cells as a potential avenue for cancer immunotherapy, and a number of strategies have been utilized in an attempt to boost the anti-tumour response of Vδ2 cells in patients. In this review we discuss critically the evidence that Vδ2 cells contribute to the cytotoxic response against tumours and evaluate current immunotherapeutic approaches that target these cells in cancer patients, with specific focus on their shortcomings and how they may be improved.

  15. Multi-cell thermionic fuel element for nuclear electric power and propulsion system

    Science.gov (United States)

    Nikolaev, Yuri V.; Gontar, Alexander S.; Eremin, Stanislav A.; Lapochkin, Nikolai V.; Andreev, Pavel V.; Zhabotinsky, Evgeny E.

    1999-01-01

    Conceptual problems of development of two-mode multi-cell thermionic fuel element (TFE) for nuclear electric power and propulsion system are considered. The results of analysis of the design and TFE output parameters are presented. It is shown that application of advanced high effective materials and technologies provides operating of the TFE in two modes: a) in nominal mode of power generation for power supply of spacecraft payload at operational orbit and b) in forced mode of power generation for power supply of electric thrusters under spacecraft orbit transfer from intermediate to operational one.

  16. Experimental Study on a Passive Fuel Cell/Battery Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Yong-Song Chen

    2013-12-01

    Full Text Available A laboratory-scale passive hybrid power system for transportation applications is constructed and tested in this study. The hybrid power system consists of a fuel cell stack connected with a diode, a lithium-ion battery pack connected with a DC/DC power converter and another diode. The power converter is employed to regulate the output voltage of the battery pack. The dynamic responses of current and voltage of the stack to the start-up and acceleration of the load are experimentally investigated at two different selected output voltages of the DC/DC converter in the battery line. The power sharing of each power source and efficiency are also analyzed and discussed. Experimental results show that the battery can compensate for the shortage of supplied power for the load demand during the start-up and acceleration. The lowest operating voltage of the fuel cell stack is limited by the regulated output voltage of the DC/DC converter. The major power loss in the hybrid power system is attributed to the diodes. The power train efficiency can be improved by lowering the ratio of forward voltage drop of the diode to the operating voltage of the fuel cell stack.

  17. Skin color modeling using the radiative transfer equation solved by the auxiliary function method: inverse problem.

    Science.gov (United States)

    Magnain, Caroline; Elias, Mady; Frigerio, Jean-Marc

    2008-07-01

    In a previous article [J. Opt. Soc. Am. A 24, 2196 (2007)] we have modeled skin color using the radiative transfer equation, solved by the auxiliary function method. Three main parameters have been determined as being predominant in the diversity of skin color: the concentrations of melanosomes and of red blood cells and the oxygen saturation of blood. From the reflectance spectrum measured on real Caucasian skin, these parameters are now evaluated by minimizing the standard deviation on the adjusted wavelength range between the experimental spectrum and simulated spectra gathered in a database.

  18. A new approach for AC loss reduction in HTS transformer using auxiliary windings, case study: 25 kA HTS current injection transformer

    International Nuclear Information System (INIS)

    AC loss is one of the important parameters in HTS (high temperature superconducting) AC devices. Among the HTS AC power devices, the transformer is an essential part in the electrical power system. The AC losses in an HTS tape depend on the magnetic field. One of the techniques usually adopted to mitigate the unwanted magnetic field is using a system of coils that produce a magnetic field opposite to the incident one, reducing the total magnetic field. In this paper adding two auxiliary windings to the HTS transformer to produce this opposite magnetic field is proposed. The proper use of these auxiliary windings could reduce the leakage flux and, therefore, the AC loss. A mathematical model is used to describe the behaviour of a transformer operating with auxiliary windings, based on the theory of electromagnetic coupled circuits. The influence of the auxiliary windings on the leakage field is studied by the finite element method (FEM) and the AC loss of an HTS transformer was calculated. Also, the simulation results show that employing auxiliary windings will improve the HTS transformer efficiency

  19. Automotive Power Trains.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide mechanics with an understanding of the operation, maintenance, and troubleshooting of automotive power trains and certain auxiliary equipment. The course contains six study units covering basic power trains; clutch principles and operations; conventional…

  20. Retroperitoneal laparoscopic partial nephrectomy combined with auxiliary small-incision and real-time B ultrasonic imaging in treatment of central renal cell carcinoma: a report of 12 cases%经后腹腔镜辅助小切口超声引导下中心型肾癌部分切除术12例报道

    Institute of Scientific and Technical Information of China (English)

    纪家涛; 王林辉; 刘冰; 徐斌; 孙颖浩

    2013-01-01

    目的 评价经后腹腔镜联合经腰小切口及超声辅助下行中心型肾癌保留肾单位手术的临床疗效,总结手术经验.方法 回顾性分析2010年8月至2012年3月12例经后腹腔镜联合经腰小切口及超声辅助下行保留肾单位手术治疗中心型肾癌患者的临床资料.男9例、女3例,平均年龄(56.2±2.8)岁;肿瘤平均直径(2.2±1.4) cm.术前均经超声、CT、MRI或CT动脉造影检查.患者全身麻醉后取健侧卧位,后腹腔镜常规方法游离出肾动脉、肾静脉及肾脏,切开腋后线与腋前线的两个Trocar之间的皮肤及肌肉,建立小切口,将超声探头从小切口置于肾表面,对肿瘤进行定位并标记手术切缘,放置冰屑于肾周,行肾动脉阻断或动、静脉阻断下保留肾单位手术.结果 12例手术均获成功,手术平均时间(124.5±5.8) min,术中平均热缺血时间(26.3±8.6) min,术中平均出血量(65.8±21.6) mL.切缘阴性率100%,平均手术切口(8.8±2.4) cm,术后平均住院时间(12.4±2.6)d;术后无并发症发生.随访平均(13.6±7.4)个月,未见肿瘤复发及转移.结论 后腹腔镜联合经腰小切口及超声辅助下对中心型肾癌行保留肾单位手术具有创伤小、出血少、热缺血时间短、恢复快的优点,是一种安全、有效的治疗方法,具有良好的临床应用前景.%Objective To evaluate the clinical efficiency of retroperitoneal laparoscopic partial nephrectomy combined with auxiliary small-incision and real-time B ultrasonic imaging in treatment of central renal cell carcinoma and to summarize the surgical experience. Methods The clinical data of 12 patients (9 males and 3 females) with central renal cell carcinoma, who were treated from Aug. 2010 to Mar. 2012, were retrospectively analyzed. The patients had a mean age of (56. 2 ± 2.8) years old and a mean tumor diameter of (2. 2 ± 1. 4) cm. The patients underwent preoperative ultrasonograpy, CT, MRI or CT angiography. The renal

  1. A direct methanol fuel cell system to power a humanoid robot

    Science.gov (United States)

    Joh, Han-Ik; Ha, Tae Jung; Hwang, Sang Youp; Kim, Jong-Ho; Chae, Seung-Hoon; Cho, Jae Hyung; Prabhuram, Joghee; Kim, Soo-Kil; Lim, Tae-Hoon; Cho, Baek-Kyu; Oh, Jun-Ho; Moon, Sang Heup; Ha, Heung Yong

    In this study, a direct methanol fuel cell (DMFC) system, which is the first of its kind, has been developed to power a humanoid robot. The DMFC system consists of a stack, a balance of plant (BOP), a power management unit (PMU), and a back-up battery. The stack has 42 unit cells and is able to produce about 400 W at 19.3 V. The robot is 125 cm tall, weighs 56 kg, and consumes 210 W during normal operation. The robot is integrated with the DMFC system that powers the robot in a stable manner for more than 2 h. The power consumption by the robot during various motions is studied, and load sharing between the fuel cell and the back-up battery is also observed. The loss of methanol feed due to crossover and evaporation amounts to 32.0% and the efficiency of the DMFC system in terms of net electric power is 22.0%.

  2. A Lemon Cell Battery for High-Power Applications

    Science.gov (United States)

    Muske, Kenneth R.; Nigh, Christopher W.; Weinstein, Randy D.

    2007-01-01

    The use of lemon cell battery to run an electric DC motor is demonstrated for chemistry students. This demonstration aids the students in understanding principles behind the design and construction of the lemon cell battery and principles governing the electric DC motor and other basic principles.

  3. Analysis of fuel cell hybrid locomotives

    Science.gov (United States)

    Miller, Arnold R.; Peters, John; Smith, Brian E.; Velev, Omourtag A.

    Led by Vehicle Projects LLC, an international industry-government consortium is developing a 109 t, 1.2 MW road-switcher locomotive for commercial and military railway applications. As part of the feasibility and conceptual-design analysis, a study has been made of the potential benefits of a hybrid power plant in which fuel cells comprise the prime mover and a battery or flywheel provides auxiliary power. The potential benefits of a hybrid power plant are: (i) enhancement of transient power and hence tractive effort; (ii) regenerative braking; (iii) reduction of capital cost. Generally, the tractive effort of a locomotive at low speed is limited by wheel adhesion and not by available power. Enhanced transient power is therefore unlikely to benefit a switcher locomotive, but could assist applications that require high acceleration, e.g. subway trains with all axles powered. In most cases, the value of regeneration in locomotives is minimal. For low-speed applications such as switchers, the available kinetic energy and the effectiveness of traction motors as generators are both minimal. For high-speed heavy applications such as freight, the ability of the auxiliary power device to absorb a significant portion of the available kinetic energy is low. Moreover, the hybrid power plant suffers a double efficiency penalty, namely, losses occur in both absorbing and then releasing energy from the auxiliary device, which result in a net storage efficiency of no more than 50% for present battery technology. Capital cost in some applications may be reduced. Based on an observed locomotive duty cycle, a cost model shows that a hybrid power plant for a switcher may indeed reduce capital cost. Offsetting this potential benefit are the increased complexity, weight and volume of the power plant, as well as 20-40% increased fuel consumption that results from lower efficiency. Based on this analysis, the consortium has decided to develop a pure fuel cell road-switcher locomotive

  4. Small-Scale Low Cost Solid Oxide Fuel Cell Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    S. D. Vora

    2008-02-01

    Progress in tasks seeking greater cell power density and lower cost through new cell designs, new cell materials and lower operating temperature is summarized. The design of the program required Proof-of-Concept unit of residential capacity scale is reviewed along with a summary of results from its successful test. Attachment 1 summarizes the status of cell development. Attachment 2 summarizes the status of generator design, and Attachment 3 of BOP design.

  5. Verb and auxiliary movement in agrammatic Broca's aphasia

    NARCIS (Netherlands)

    Bastiaanse, Y.R.M.; Thompson, C.K.

    2003-01-01

    Verb production in agrammatic Broca's aphasia has repeatedly been shown to be impaired by a number of investigators. Not only is the number of verbs produced often significantly reduced, but verb inflections and auxiliaries are often omitted as well (e.g., Bastiaanse, Jonkers, & Moltmaker-Osinga, 19

  6. 76 FR 22295 - National Poultry Improvement Plan and Auxiliary Provisions

    Science.gov (United States)

    2011-04-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection 9 CFR Part 145 RIN 0579-AD21 National Poultry Improvement Plan and Auxiliary Provisions Correction In rule document 2011-6539 appearing on pages 15791-15798 in the issue...

  7. 29 CFR 1918.62 - Miscellaneous auxiliary gear.

    Science.gov (United States)

    2010-07-01

    ... box-type pallets shall be designed to prevent disengagement from the pallet under load. (5) Pallets... 29 Labor 7 2010-07-01 2010-07-01 false Miscellaneous auxiliary gear. 1918.62 Section 1918.62 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Cargo Handling Gear and Equipment Other Than...

  8. Auxiliary-field quantum Monte Carlo methods in nuclei

    CERN Document Server

    Alhassid, Y

    2016-01-01

    Auxiliary-field quantum Monte Carlo methods enable the calculation of thermal and ground state properties of correlated quantum many-body systems in model spaces that are many orders of magnitude larger than those that can be treated by conventional diagonalization methods. We review recent developments and applications of these methods in nuclei using the framework of the configuration-interaction shell model.

  9. Continuous Market Engineering - Focusing Agent Behavior, Interfaces, and Auxiliary Services

    OpenAIRE

    Kranz, Tobias Theodor

    2015-01-01

    Electronic markets spread out amongst business entities as well as private individuals. Albeit numerous approaches on developing electronic markets exist, a unified approach targeting market development, redesign, and refinement has been lacking. This thesis studies the potential of continuously improving electronic markets. Thereby, the experiments? design focuses on Agent Behavior, Interfaces, and Auxiliary Services and thus unveils the potential of continuously improving electronic markets.

  10. Regulation of Glutamate Receptors by Their Auxiliary Subunits

    OpenAIRE

    Tomita, Susumu

    2010-01-01

    Glutamate receptors are major excitatory receptors in the brain. Recent findings have established auxiliary subunits of glutamate receptors as critical modulators of synaptic transmission, synaptic plasticity and neurological disorder. The elucidation of the molecular rules governing glutamate receptors and subunits will improve our understanding of synapses and of neural-circuit regulation in the brain.

  11. The high intensity solar cell: Key to low cost photovoltaic power

    Science.gov (United States)

    Sater, B. L.; Goradia, C.

    1975-01-01

    The design considerations and performance characteristics of the 'high intensity' (HI) solar cell are presented. A high intensity solar system was analyzed to determine its cost effectiveness and to assess the benefits of further improving HI cell efficiency. It is shown that residential sized systems can be produced at less than $1000/kW peak electric power. Due to their superior high intensity performance characteristics compared to the conventional and VMJ cells, HI cells and light concentrators may be the key to low cost photovoltaic power.

  12. DPAL: A new class of lasers for cw power beaming at ideal photovoltaic cell wavelengths

    Science.gov (United States)

    Krupke, W. F.; Beach, R. J.; Payne, S. A.; Kanz, V. K.; Early, J. T.

    2004-03-01

    The new class of diode pumped alkali vapor lasers (DPALs) offers high efficiency cw laser beams at wavelengths which efficiently couple to photovoltaic (PV) cells: silicon cells at 895 nm (cesium), and GaAs cells at 795 nm (rubidium) and at 770 nm (potassium). DPAL electrical efficiencies of 25-30% are projected, enabling PV cell efficiencies ~40% (Si) and ~60% (GaAs). Near-diffraction-limited DPAL device power scaling into the multi-kilowatt regime from a single aperture is projected. The potential application to power beaming propulsion to raise satellites from LEO to Geo is discussed.

  13. Rapid Evaluation of Power Degradation in Series Connection of Single Feeding Microsized Microbial Fuel Cells

    KAUST Repository

    Rojas, Jhonathan Prieto

    2014-07-08

    We have developed a sustainable, single feeding, microsized, air-cathode and membrane-free microbial fuel cells with a volume of 40 mu L each, which we have used for rapid evaluation of power generation and viability of a series array of three cells seeking higher voltage levels. Contrary to expectations, the achieved power density was modest (45 mWm(-3)), limited due to non-uniformities in assembly and the single-channel feeding system.

  14. Cochlear Outer-Hair-Cell Power Generation and Viscous Fluid Loss

    OpenAIRE

    Yanli Wang; Steele, Charles R.; Sunil Puria

    2016-01-01

    Since the discovery of otoacoustic emissions and outer hair cell (OHC) motility, the fundamental question of whether the cochlea produces mechanical power remains controversial. In the present work, direct calculations are performed on power loss due to fluid viscosity and power generated by the OHCs. A three-dimensional box model of the mouse cochlea is used with a feed-forward/feed-backward approximation representing the organ of Corti cytoarchitecture. The model is fit to in vivo basilar m...

  15. Hydrogen-chlorine fuel cell for production of hydrochloric acid and electric power : chlorine kinetics and cell design

    OpenAIRE

    Thomassen, Magnus Skinlo

    2005-01-01

    This thesis work is the continuation and final part of a joint project between the Department of Materials Technology, NTNU and Norsk Hydro Research Center in Porsgrunn, looking at the possibility of using fuel cells for production of hydrogen chloride and electric power. The experimental work encompass an evaluation of three hydrogen - chlorine fuel cell design concepts, development and implementation of a mathematical fuel cell model and a kinetic study of the chlorine reduction reaction. T...

  16. Power loss analysis of n-PASHA cells validated by 2D simulations

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, G.J.M.; Gutjahr, A.; Burgers, A.R.; Saynova, D.S.; Cesar, I.; Romijn, I.G.

    2013-10-15

    To reach >21% efficiency for the n-Pasha (passivated all sides H-pattern) cell of ECN, reliable power-loss analyses are essential. A power-loss analysis is presented that is based on experimental data but validated and completed by 2D simulations. The analysis is used to identify the key factors that will contribute most to achieving >21% efficiency.

  17. A New Very-High-Efficiency R4 Converter for High-Power Fuel Cell Applications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael Andreas E.

    2009-01-01

    A new very high efficiency 10 kW isolated R4 boost converter for low-voltage high-power fuel cell applications is presented. Using a new concept for partially paralleling of isolated boost converters, only the critical high ac-current parts are paralleled. Four 2.5 kW power stages, consisting...

  18. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Gail E. [Delphi Automotive Systems, LLC., Gillingham (United Kingdom)

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  19. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Zawodzinski, C.; Wilson, M.; Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1996-10-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. A central objective of a LANL/Industry collaborative effort supported by the Hydrogen Program is to integrate PEM fuel cell and novel stack designs at LANL with stack technology of H-Power Corporation (H-Power) in order to develop a manufacturable, low-cost/high-performance hydrogen/air fuel cell stack for stationary generation of electric power. A LANL/H-Power CRADA includes Tasks ranging from exchange, testing and optimization of membrane-electrode assemblies of large areas, development and demonstration of manufacturable flow field, backing and bipolar plate components, and testing of stacks at the 3-5 cell level and, finally, at the 4-5 kW level. The stack should demonstrate the basic features of manufacturability, overall low cost and high energy conversion efficiency. Plans for future work are to continue the CRADA work along the time line defined in a two-year program, to continue the LANL activities of developing and testing stainless steel hardware for longer term stability including testing in a stack, and to further enhance air cathode performance to achieve higher energy conversion efficiencies as required for stationary power application.

  20. Power loss for high-voltage solar-cell arrays

    Science.gov (United States)

    Parker, L. W.

    1979-01-01

    Electric field particle collection and power loss are calculated in program written in FORTRAN IV for use on UNIVAC 1100/40 computer. Program incorporates positive and negative and negative charge flows and balance between positive and negative flows is performed by iteration.

  1. Voltage-gated calcium channels and their auxiliary subunits: physiology and pathophysiology and pharmacology.

    Science.gov (United States)

    Dolphin, Annette C

    2016-10-01

    Voltage-gated calcium channels are essential players in many physiological processes in excitable cells. There are three main subdivisions of calcium channel, defined by the pore-forming α1 subunit, the CaV 1, CaV 2 and CaV 3 channels. For all the subtypes of voltage-gated calcium channel, their gating properties are key for the precise control of neurotransmitter release, muscle contraction and cell excitability, among many other processes. For the CaV 1 and CaV 2 channels, their ability to reach their required destinations in the cell membrane, their activation and the fine tuning of their biophysical properties are all dramatically influenced by the auxiliary subunits that associate with them. Furthermore, there are many diseases, both genetic and acquired, involving voltage-gated calcium channels. This review will provide a general introduction and then concentrate particularly on the role of auxiliary α2 δ subunits in both physiological and pathological processes involving calcium channels, and as a therapeutic target.

  2. Auxiliary anatomical labels for joint segmentation and atlas registration

    Science.gov (United States)

    Gass, Tobias; Szekely, Gabor; Goksel, Orcun

    2014-03-01

    This paper studies improving joint segmentation and registration by introducing auxiliary labels for anatomy that has similar appearance to the target anatomy while not being part of that target. Such auxiliary labels help avoid false positive labelling of non-target anatomy by resolving ambiguity. A known registration of a segmented atlas can help identify where a target segmentation should lie. Conversely, segmentations of anatomy in two images can help them be better registered. Joint segmentation and registration is then a method that can leverage information from both registration and segmentation to help one another. It has received increasing attention recently in the literature. Often, merely a single organ of interest is labelled in the atlas. In the presense of other anatomical structures with similar appearance, this leads to ambiguity in intensity based segmentation; for example, when segmenting individual bones in CT images where other bones share the same intensity profile. To alleviate this problem, we introduce automatic generation of additional labels in atlas segmentations, by marking similar-appearance non-target anatomy with an auxiliary label. Information from the auxiliary-labeled atlas segmentation is then incorporated by using a novel coherence potential, which penalizes differences between the deformed atlas segmentation and the target segmentation estimate. We validated this on a joint segmentation-registration approach that iteratively alternates between registering an atlas and segmenting the target image to find a final anatomical segmentation. The results show that automatic auxiliary labelling outperforms the same approach using a single label atlasses, for both mandibular bone segmentation in 3D-CT and corpus callosum segmentation in 2D-MRI.

  3. Fuel cell programs in the United States for stationary power applications

    Energy Technology Data Exchange (ETDEWEB)

    Singer, M.

    1996-04-01

    The Department of Energy (DOE), Office of Fossil Energy, is participating with the private sector in sponsoring the development of molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) technologies for application in the utility, commercial and industrial sectors. Phosphoric acid fuel cell (PAFC) development was sponsored by the Office of Fossil Energy in previous years and is now being commercialized by the private sector. Private sector participants with the Department of Energy include the Electric Power Research Institute (EPRI), the Gas Research institute (GRI), electric and gas utilities, universities, manufacturing companies and their suppliers. through continued government and private sector support, fuel cell systems are emerging power generation technologies which are expected to have significant worldwide impacts. An industry with annual sales of over a billion dollars is envisioned early in the 21st century. PAFC power plants have begun to enter the marketplace and MCFC and SOFC power plants are expected to be ready to enter the marketplace in the late 1990s. In support of the efficient and effective use of our natural resources, the fuel cell program seeks to increase energy efficiency and economic effectiveness of power generation. This is to be accomplished through effectiveness of power generation. This is accomplished through the development and commercialization of cost-effective, efficient and environmentally desirable fuel cell systems which will operate on fossil fuels in multiple and end use sectors.

  4. Indigenous manufacturing realization of twin source and its auxiliary system

    International Nuclear Information System (INIS)

    operation) as well as Vacuum mode (DNB type vacuum immersed operation). The Twin Source shall be manufactured as per ASME guidelines for pressure vessel. Experiments on the Twin Source are foreseen in the near future, as all the auxiliary systems like 180 kW, RF generator system, vacuum vessel with Pumping station, Cooling water system, Data acquisition and control system (DACS) and other power supply systems are already installed in the lab premises. The paper discusses the FEA based engineering design, simplified manufacturing design, manufacturing experience with highlighting quality control and the system integration activities undertaken for the TWIN source test facility. (author)

  5. Using a Voltage Domain Programmable Technique for Low-Power Management Cell-Based Design

    Directory of Open Access Journals (Sweden)

    Ching-Hwa Cheng

    2011-09-01

    Full Text Available The Multi-voltage technique is an effective way to reduce power consumption. In the proposed cell-based voltage domain programmable (VDP technique, the high and low voltages applied to logic gates are programmable. The flexible voltage domain reassignment allows the chip performance and power consumption to be dynamically adjusted. In the proposed technique, the power switches possess the feature of flexible programming after chip manufacturing. This VDP method does not use an external voltage regulator to regulate the supply voltage level from outside of the chip but can be easily integrated within the design. This novel technique is proven by use of a video decoder test chip, which shows 55% and 61% power reductions compared to conventional single-Vdd and low-voltage designs, respectively. This power-aware performance adjusting mechanism shows great power reduction with a good power-performance management mechanism.

  6. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  7. Accuracy of sentinel lymph node biopsy for the assessment of auxiliary status in patients with early (T1) breast carcinoma

    International Nuclear Information System (INIS)

    Objective: To determine the accuracy of SLN biopsy for the assessment of auxiliary status, and prognostic markers leading to lymphatic metastasis in patients with early (T1) breast cancer. Design: Cross-sectional study. Place and Duration of Study: Department of Surgery, Teaching and Research Hospital. Between January 2000 and August 2004. Patients and Methods: SLN mapping by blue dye method was performed on 39 patients with T1 breast carcinoma. SLNs, level 1 and 2 auxiliary nodes were dissected and excised. The size, pathologic features of the primary tumor, SLNs and other auxiliary nodes, and hormone receptors were evaluated by histopathologic examination. The rate of SLNs and non SLNs involvement, and demographic, clinical and pathologic risk factors leading to nodal metastasis were established. The diagnostic accuracy of SLN for auxiliary status was calculated. Results: SLNs were identified in 37 (95%) patients. The axilla had metastasis in 11 (28%) patients. Malignant cells involved SLNs in 8 patients. Non-SLNs had metastasis in 3 patients without SLN involvement. The sensitivity, specificity and accuracy of SLN biopsy for predicting auxiliary status was calculated as 73%, 100% and 92% respectively. Four of 5 patients T1c tumors (p=0.14) and lymphovascular invasion (p=0.0004). Conclusion: SLN biopsy with high diagnostic accuracy may prevent unnecessary disection of the axilla in the majority of patients with early (T1) breast carcinoma. Some risk factors as pre-menopausal status, absence of hormone receptors, and presence of lymphovascular invasion must be taken into account as important determinant of non-SLNs metastasis. (author)

  8. The direct borohydride fuel cell for UUV propulsion power

    Science.gov (United States)

    Lakeman, J. Barry; Rose, Abigail; Pointon, Kevin D.; Browning, Darren J.; Lovell, Keith V.; Waring, Susan C.; Horsfall, Jackie A.

    The development of proton exchange membrane and direct methanol fuel cell stacks is now well advanced for many applications. However, the significant performance advantages that these have over the battery for small to moderate scale applications will not be realised until a credible fuel source has been developed. The deficiencies of the PEMFC and DMFC can be eliminated by cation or anion-conducting membranes incorporated into a direct sodium borohydride fuel cell (DSBFC). The characterisation of membranes for the DSBFC is discussed. Novel membranes have been prepared which have resistance of an equal magnitude to the commercially available Nafion ® membrane.

  9. The AC Impedance Characteristic of High Power Li4Ti5O12-based Battery Cells

    DEFF Research Database (Denmark)

    Stroe, Ana-Irina; Stroe, Daniel Loan; Swierczynski, Maciej Jozef;

    2015-01-01

    This paper studies the impedance characteristics of a fresh 13 Ah high-power lithium titanate oxide (LTO) battery cell and analyses its dependence on the temperature and state-of-charge. The impedance of the battery cell was measured by means of the electrochemical impedance spectroscopy (EIS) te...

  10. Dynamic behaviour of Li batteries in hydrogen fuel cell power trains

    Science.gov (United States)

    Veneri, O.; Migliardini, F.; Capasso, C.; Corbo, P.

    A Li ion polymer battery pack for road vehicles (48 V, 20 Ah) was tested by charging/discharging tests at different current values, in order to evaluate its performance in comparison with a conventional Pb acid battery pack. The comparative analysis was also performed integrating the two storage systems in a hydrogen fuel cell power train for moped applications. The propulsion system comprised a fuel cell generator based on a 2.5 kW polymeric electrolyte membrane (PEM) stack, fuelled with compressed hydrogen, an electric drive of 1.8 kW as nominal power, of the same typology of that installed on commercial electric scooters (brushless electric machine and controlled bidirectional inverter). The power train was characterized making use of a test bench able to simulate the vehicle behaviour and road characteristics on driving cycles with different acceleration/deceleration rates and lengths. The power flows between fuel cell system, electric energy storage system and electric drive during the different cycles were analyzed, evidencing the effect of high battery currents on the vehicle driving range. The use of Li batteries in the fuel cell power train, adopting a range extender configuration, determined a hydrogen consumption lower than the correspondent Pb battery/fuel cell hybrid vehicle, with a major flexibility in the power management.

  11. Major design issues of molten carbonate fuel cell power generation unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  12. Reliability considerations of a fuel cell backup power system for telecom applications

    Science.gov (United States)

    Serincan, Mustafa Fazil

    2016-03-01

    A commercial fuel cell backup power unit is tested in real life operating conditions at a base station of a Turkish telecom operator. The fuel cell system responds to 256 of 260 electric power outages successfully, providing the required power to the base station. Reliability of the fuel cell backup power unit is found to be 98.5% at the system level. On the other hand, a qualitative reliability analysis at the component level is carried out. Implications of the power management algorithm on reliability is discussed. Moreover, integration of the backup power unit to the base station ecosystem is reviewed in the context of reliability. Impact of inverter design on the stability of the output power is outlined. Significant current harmonics are encountered when a generic inverter is used. However, ripples are attenuated significantly when a custom design inverter is used. Further, fault conditions are considered for real world case studies such as running out of hydrogen, a malfunction in the system, or an unprecedented operating scheme. Some design guidelines are suggested for hybridization of the backup power unit for an uninterrupted operation.

  13. Feasibility Study on Passive Auxiliary Feedwater System in Loss of Condenser Vacuum Accident

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Soon Joon; Lee, Byung Chul [FNC Tech., Daejeon (Korea, Republic of); Cheon, Jong; Kim, Han Gon [NETEC, Daejeon (Korea, Republic of)

    2009-05-15

    Nuclear leading countries are developing and constructing technology intensive pressurized water reactors (PWRs) such as AP1000 (United State), EPR (Europe), and US-APWR (Japan), and these advanced reactors adopt several passive safety features in order to enhance the safety and reliability. Domestic advanced reactor APR1400 already completed the earlier development in 2002, and technology gap from the nuclear leading countries become large. In particular, China requires technology transfer in the order of new power plant construction. Thus it is expected difficult to export the power plant to the newly developing countries without our own technology. Therefore, the improvement of competitive power and establishment of infra structure of advanced nuclear industry through innovative technology enhancement are urgent and essential to international competitive marketing. Passive safety features have been always adopted as an improved design concept in the development of innovative reactor design. Domestic nuclear industry has stated the development of APR+ as a Korean specific reactor for the export strategy. In the development of APR+ a passive auxiliary feedwater system (PAFS) has been considered as a noticeable candidate of improved design. Reference 2 reported that the adoption of PAFS, which can replace the auxiliary feedwater system, can prevent core damage in the accident of station black out (SBO), since Class 1E DC power operates the related valves, and 8 hours hot standby operation of plant without operation action is achievable. This PAFS contributes to the safety and economics, in that it decreases the core damage frequency 26% from 2.45E- 06/r-y to 1.80E-06/r-y, and it saves the construction cost 20 million Kr-Won. This paper discusses on the performance of PAFS for the accident of loss of condenser vacuum as a precursor of detailed design specification.

  14. A Convergent Method of Auxiliary Sources for Two-Dimensional Impedance Scatterers With Edges

    DEFF Research Database (Denmark)

    Karamehmedovic, Mirza; Breinbjerg, Olav

    2001-01-01

    A modification to the Method of Auxiliary Sources (MAS) is introduced which renders the method operational for two-dimensional impedance scatterers with edges. The modification consists in letting the auxiliary surface converge to the scatterer physical surface for increasing number of auxiliary ...

  15. A review and design of power electronics converters for fuel cell hybrid system applications

    DEFF Research Database (Denmark)

    Zhang, Zhe; Pittini, Riccardo; Andersen, Michael A. E.;

    2012-01-01

    This paper presents an overview of most promising power electronics topologies for a fuel cell hybrid power conversion system which can be utilized in many applications such as hybrid electrical vehicles (HEV), distributed generations (DG) and uninterruptible-power-supply (UPS) systems. Then, a...... multiple-input power conversion system including a decoupled dual-input converter and a three-phase neutral-point-clamped (NPC) inverter is proposed. The system can operate in both stand-alone and grid-connected modes. Simulation and experimental results are provided to show the feasibility of the proposed...

  16. Experimental Study on a Passive Fuel Cell/Battery Hybrid Power System

    OpenAIRE

    Yong-Song Chen; Sheng-Miao Lin; Boe-Shong Hong

    2013-01-01

    A laboratory-scale passive hybrid power system for transportation applications is constructed and tested in this study. The hybrid power system consists of a fuel cell stack connected with a diode, a lithium-ion battery pack connected with a DC/DC power converter and another diode. The power converter is employed to regulate the output voltage of the battery pack. The dynamic responses of current and voltage of the stack to the start-up and acceleration of the load are experimentally investig...

  17. Fuzzy Logic Based Controller for a Grid-Connected Solid Oxide Fuel Cell Power Plant

    OpenAIRE

    Chatterjee, Kalyan; Shankar, Ravi; Kumar, Amit

    2014-01-01

    This paper describes a mathematical model of a solid oxide fuel cell (SOFC) power plant integrated in a multimachine power system. The utilization factor of a fuel stack maintains steady state by tuning the fuel valve in the fuel processor at a rate proportional to a current drawn from the fuel stack. A suitable fuzzy logic control is used for the overall system, its objective being controlling the current drawn by the power conditioning unit and meet a desirable output power demand. The prop...

  18. Battery Management System—Balancing Modularization Based on a Single Switched Capacitor and Bi-Directional DC/DC Converter with the Auxiliary Battery

    Directory of Open Access Journals (Sweden)

    Mohamed Daowd

    2014-04-01

    Full Text Available Lithium-based batteries are considered as the most advanced batteries technology, which can be designed for high energy or high power storage systems. However, the battery cells are never fully identical due to the fabrication process, surrounding environment factors and differences between the cells tend to grow if no measures are taken. In order to have a high performance battery system, the battery cells should be continuously balanced for maintain the variation between the cells as small as possible. Without an appropriate balancing system, the individual cell voltages will differ over time and battery system capacity will decrease quickly. These issues will limit the electric range of the electric vehicle (EV and some cells will undergo higher stress, whereby the cycle life of these cells will be shorter. Quite a lot of cell balancing/equalization topologies have been previously proposed. These balancing topologies can be categorized into passive and active balancing. Active topologies are categorized according to the active element used for storing the energy such as capacitor and/or inductive component as well as controlling switches or converters. This paper proposes an intelligent battery management system (BMS including a battery pack charging and discharging control with a battery pack thermal management system. The BMS user input/output interfacing. The battery balancing system is based on battery pack modularization architecture. The proposed modularized balancing system has different equalization systems that operate inside and outside the modules. Innovative single switched capacitor (SSC control strategy is proposed to balance between the battery cells in the module (inside module balancing, IMB. Novel utilization of isolated bidirectional DC/DC converter (IBC is proposed to balance between the modules with the aid of the EV auxiliary battery (AB. Finally an experimental step-up has been implemented for the validation of the

  19. Experimental 1 kW 20 cell PEFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Marmy, C.A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M. [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

    1999-08-01

    A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

  20. Construction and characterization of spherical Si solar cells combined with SiC electric power inverter

    Science.gov (United States)

    Oku, Takeo; Matsumoto, Taisuke; Hiramatsu, Kouichi; Yasuda, Masashi; Shimono, Akio; Takeda, Yoshikazu; Murozono, Mikio

    2015-02-01

    Spherical silicon (Si) photovoltaic solar cell systems combined with an electric power inverter using silicon carbide (SiC) field-effect transistor (FET) were constructed and characterized, which were compared with an ordinary Si-based converter. The SiC-FET devices were introduced in the direct current-alternating current (DC-AC) converter, which was connected with the solar panels. The spherical Si solar cells were used as the power sources, and the spherical Si panels are lighter and more flexible compared with the ordinary flat Si solar panels. Conversion efficiencies of the spherical Si solar cells were improved by using the SiC-FET.

  1. AMPA receptors commandeer an ancient cargo exporter for use as an auxiliary subunit for signaling.

    Directory of Open Access Journals (Sweden)

    Nadine Harmel

    Full Text Available Fast excitatory neurotransmission in the mammalian central nervous system is mainly mediated by ionotropic glutamate receptors of the AMPA subtype (AMPARs. AMPARs are protein complexes of the pore-lining α-subunits GluA1-4 and auxiliary β-subunits modulating their trafficking and gating. By a proteomic approach, two homologues of the cargo exporter cornichon, CNIH-2 and CNIH-3, have recently been identified as constituents of native AMPARs in mammalian brain. In heterologous reconstitution experiments, CNIH-2 promotes surface expression of GluAs and modulates their biophysical properties. However, its relevance in native AMPAR physiology remains controversial. Here, we have studied the role of CNIH-2 in GluA processing both in heterologous cells and primary rat neurons. Our data demonstrate that CNIH-2 serves an evolutionarily conserved role as a cargo exporter from the endoplasmic reticulum (ER. CNIH-2 cycles continuously between ER and Golgi complex to pick up cargo protein in the ER and then to mediate its preferential export in a coat protein complex (COP II dependent manner. Interaction with GluA subunits breaks with this ancestral role of CNIH-2 confined to the early secretory pathway. While still taking advantage of being exported preferentially from the ER, GluAs recruit CNIH-2 to the cell surface. Thus, mammalian AMPARs commandeer CNIH-2 for use as a bona fide auxiliary subunit that is able to modify receptor signaling.

  2. Power

    OpenAIRE

    Hafford-Letchfield, Trish

    2015-01-01

    This chapter looks at the concept of power in social work by focusing on what this means as a ‘professional’ and theorizes competing discourses of empowerment in social work and its key concepts, drawing in particular on the explanatory powers of critical theorist Michel Foucault (1991). The chapter problematizes the concept of power by explicitly drawing on both users’ and carers’ accounts from the literature to demonstrate different external and internal influences on the root causes of dis...

  3. Design and analysis of single- ended robust low power 8T SRAM cell

    Directory of Open Access Journals (Sweden)

    Gupta Neha

    2016-01-01

    Full Text Available This paper is based on the observation of 8T single ended static random access memory (SRAM and two techniques for reducing the sub threshold leakage current, power consumption are examined. In the first technique, effective supply voltage and ground node voltages are changed using a dynamic variable voltage level technique(VVL. In the second technique power supply is scaled down. This 8T SRAM cell uses one word line, two bitlinesand a transmission gate. Simulations and analytical results show that when the two techniques combine the new SRAM cell has correct read and write operation and also the cell contains 55.6% less leakage and the dynamic power is 98.8% less than the 8T single ended SRAM cell. Simulations are performed using cadence virtuoso tool at 45nm technology.

  4. Micro-tubular flame-assisted fuel cells for micro-combined heat and power systems

    Science.gov (United States)

    Milcarek, Ryan J.; Wang, Kang; Falkenstein-Smith, Ryan L.; Ahn, Jeongmin

    2016-02-01

    Currently the role of fuel cells in future power generation is being examined, tested and discussed. However, implementing systems is more difficult because of sealing challenges, slow start-up and complex thermal management and fuel processing. A novel furnace system with a flame-assisted fuel cell is proposed that combines the thermal management and fuel processing systems by utilizing fuel-rich combustion. In addition, the flame-assisted fuel cell furnace is a micro-combined heat and power system, which can produce electricity for homes or businesses, providing resilience during power disruption while still providing heat. A micro-tubular solid oxide fuel cell achieves a significant performance of 430 mW cm-2 operating in a model fuel-rich exhaust stream.

  5. Power conditioning system topology for grid integration of wind and fuell cell energy

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2006-12-01

    Full Text Available This paper shows the topology of the hybrid grid-connected power system and the performances of the front-end three-phase power inverter. The renewable sources of the hybrid power system consist of a solid oxide fuel cell and a wind-turbine. This type of combination is the most efficient one. The proposed topology benefits of the one common DC-AC inverter which injects the generated power into the grid. The architecture diminishes the cost of the power conditioning system. Moreover, due to the power balance control of the entire power conditioning system the bulk dc link electrolytic capacitor is replaced with a small plastic film one. The final power conditioning system has the following advantages: independent control of the reactive power, minimize harmonic current distortion offering a nearly unity power factor operation (0,998 operation capability, dc link voltage regulation (up to 5% ripple in the dc-link voltage in any operated conditions, fast disturbance compensation capability, high reliability, and low cost. The experimental test has been performed and the performances of the grid power inverter are shown.

  6. Impact of power converter current ripple on the durability of a fuel cell stack

    OpenAIRE

    WAHDAME, B; GIRARDOT, L; Hissel, D.; Harel, F.; Francois, X.; Candusso, D.; PERA, MC; DUMERCY, L

    2008-01-01

    The durability and performance of Polymer Electrolyte Membrane Fuel Cell (PEMFC) have a major impact on the most important challenges facing fuel cell commercialization including final cost, mass production, system integration, functionality and reliability. This work is supported by French Government via an ANR' project (PAN'H) named SPACT80. The global objective is to develop and validate the use of a fuel cell based power system for heavy-duty vehicles (dedicated to railway applications or...

  7. A Power Allocation Algorithm Based on Cooperative Game Theory in Multi-cell OFDM Systems

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2011-11-01

    Full Text Available A centralized resource allocation algorithm in multi-cell OFDM systems is studied, which aims at improving the performance of wireless communication systems and enhancing user’s spectral efficiency on the edge of the cell. The proposed resource allocation algorithm can be divided into two steps. The first step is sub-carrier allocation based on matrix searching in single cell and the second one is joint power allocation based on cooperative game theory in multi-cell. By comparing with traditional resource allocation algorithms in multi-cell scenario, we find that the proposed algorithm has lower computational complexity and good fairness performance.

  8. Radiation resistance of thin-film solar cells for space photovoltaic power

    Science.gov (United States)

    Woodyard, James R.; Landis, Geoffrey A.

    1991-01-01

    Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

  9. Fuel cell power systems for remote applications. Phase 1 final report and business plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    The goal of the Fuel Cell Power Systems for Remote Applications project is to commercialize a 0.1--5 kW integrated fuel cell power system (FCPS). The project targets high value niche markets, including natural gas and oil pipelines, off-grid homes, yachts, telecommunication stations and recreational vehicles. Phase 1 includes the market research, technical and financial analysis of the fuel cell power system, technical and financial requirements to establish manufacturing capability, the business plan, and teaming arrangements. Phase 1 also includes project planning, scope of work, and budgets for Phases 2--4. The project is a cooperative effort of Teledyne Brown Engineering--Energy Systems, Schatz Energy Research Center, Hydrogen Burner Technology, and the City of Palm Desert. Phases 2 through 4 are designed to utilize the results of Phase 1, to further the commercial potential of the fuel cell power system. Phase 2 focuses on research and development of the reformer and fuel cell and is divided into three related, but potentially separate tasks. Budgets and timelines for Phase 2 can be found in section 4 of this report. Phase 2 includes: Task A--Develop a reformate tolerant fuel cell stack and 5 kW reformer; Task B--Assemble and deliver a fuel cell that operates on pure hydrogen to the University of Alaska or another site in Alaska; Task C--Provide support and training to the University of Alaska in the setting up and operating a fuel cell test lab. The Phase 1 research examined the market for power systems for off-grid homes, yachts, telecommunication stations and recreational vehicles. Also included in this report are summaries of the previously conducted market reports that examined power needs for remote locations along natural gas and oil pipelines. A list of highlights from the research can be found in the executive summary of the business plan.

  10. Abuse behavior of high-power, lithium-ion cells

    Science.gov (United States)

    Spotnitz, R.; Franklin, J.

    Published accounts of abuse testing of lithium-ion cells and components are summarized, including modeling work. From this summary, a set of exothermic reactions is selected with corresponding estimates of heats of reaction. Using this set of reactions, along with estimated kinetic parameters and designs for high-rate batteries, models for the abuse behavior (oven, short-circuit, overcharge, nail, crush) are developed. Finally, the models are used to determine that fluorinated binder plays a relatively unimportant role in thermal runaway.

  11. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    Science.gov (United States)

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter.

  12. Increasing the solar cell power output by coating with transition metal-oxide nanorods

    International Nuclear Information System (INIS)

    Highlights: → Nanoparticles enhance solar cell efficiency. → Solar cell power increase by nanorod coating. → Metal-oxide nanorods are prepared in flames. → Molybdenum oxide nanorods effectively scatter light on solar cell surface. → Scattering efficiency depends on coating density. -- Abstract: Photovoltaic cells produce electric current through interactions among photons from an ambient light source and electrons in the semiconductor layer of the cell. However, much of the light incident on the panel is reflected or absorbed without inducing the photovoltaic effect. Transition metal-oxide nanoparticles, an inexpensive product of a process called flame synthesis, can cause scattering of light. Scattering can redirect photon flux, increasing the fraction of light absorbed in the thin active layer of silicon solar cells. This research aims to demonstrate that the application of transition metal-oxide nanorods to the surface of silicon solar panels can enhance the power output of the panels. Several solar panels were coated with a nanoparticle-methanol suspension, and the power outputs of the panels before and after the treatment were compared. The results demonstrate an increase in power output of up to 5% after the treatment. The presence of metal-oxide nanorods on the surface of the coated solar cells is confirmed by electron microscopy.

  13. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    Science.gov (United States)

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  14. Modelling of TEXTOR edge plasma in discharges with auxiliary heating and neon puffing

    International Nuclear Information System (INIS)

    The problem of hot plasma interaction with the material walls is one of the burning questions, the solution of which is essential for the creation of a viable thermonuclear reactor. One of the ways to reduce the temperature of the plasma in contact with the wall elements and the heat loads on them is an increase of impurity radiation from the discharge. However, the source of radiation should be localized in the peripheral region and impurities should not contribute significantly to the energy balance of the central plasma and hinder its heating up to thermonuclear temperatures. The light impurities - from boron to neon - satisfy these requirements since they are ionized up to the helium-like states in a relatively thin layer at the discharge edge. The TEXTOR experiments have shown, that in discharges with auxiliary heating more than 95 % of the power can be radiated by neon puffing without the onset of Marfe or detachment and with the source of radiation staying in the vicinity of the last closed magnetic surface (LCMS), touching the limiter. It is remarkable that this state is compatible with a good exhaust of injected helium by the pump limiter ALT-II. In the present paper we elaborate a model of the edge plasma particle and energy balances for the case of discharges with auxiliary heating and neon puffing and compare the results of calculations with experimental data from TEXTOR. (author) 4 refs., 4 figs

  15. Feasibility study of helically coiled tube condensation heat exchanger for a passive auxiliary feedwater system

    International Nuclear Information System (INIS)

    The Passive Auxiliary Feedwater System (PAFS) with nearly-horizontal heat exchangers is one of passive safety features of APR+ (Advanced Power Reactor Plus) which provides the auxiliary feedwater by means of natural circulation with condensation. It is feasible to increase the heat transfer capacity of the PAFS by employing a helically coiled heat exchanger due to additional secondary flow effect by centrifugal force. In addition, a compact and flexible design can be achieved in a fixed volume by using the helically coiled heat exchanger, which is one of the most important merits of implementing this heat exchanger. In this paper, the helically coiled heat exchanger has been employed for the PAFS instead of nearly-horizontal heat exchanger. In order to evaluate the heat transfer performance of the helically coiled heat exchanger, an in-tube condensation heat transfer correlation by Wongwises has been introduced into the system analysis code, MARS-KS. A comparative numerical study was conducted for both heat exchangers. The result shows that helically coiled heat exchanger has 20% higher heat transfer efficiency than existing nearly-horizontal heat exchanger. (author)

  16. Contracted auxiliary Gaussian basis integral and derivative evaluation.

    Science.gov (United States)

    Giese, Timothy J; York, Darrin M

    2008-02-14

    The rapid evaluation of two-center Coulomb and overlap integrals between contracted auxiliary solid harmonic Gaussian functions is examined. Integral expressions are derived from the application of Hobson's theorem and Dunlap's product and differentiation rules of the spherical tensor gradient operator. It is shown that inclusion of the primitive normalization constants greatly simplifies the calculation of contracted functions corresponding to a Gaussian multipole expansion of a diffuse charge density. Derivative expressions are presented and it is shown that chain rules are avoided by expressing the derivatives as a linear combination of auxiliary integrals involving no more than five terms. Calculation of integrals and derivatives requires the contraction of a single vector corresponding to the monopolar result and its scalar derivatives. Implementation of the method is discussed and comparison is made with a Cartesian Gaussian-based method. The current method is superior for the evaluation of both integrals and derivatives using either primitive or contracted functions. PMID:18282025

  17. [The design of bionic left ventricular auxiliary pump].

    Science.gov (United States)

    Jin, Henglin; Hu, Xiaobing; Du, Lei

    2015-01-01

    This paper reports a novel design of bionic left ventricular auxiliary pump, and the characteristic is that elastic diaphragm of pump driven by hydraulic, having smooth, reliable blood supply, can prevent blood clots, can use the flow sensor, pressure sensor detection showing the blood pressure and blood volume at the inlet and outlet of the pump. The pump can go with heart rate synchronization or asynchronous auxiliary by the R wave of human body's ECG. The design goal is realization of bionic throb. Through the animal experiment, the blood pressure waveforms are close to expectations, stable flow can stroke according to the set value, which prove that the pump can meet the requirement for heart disease patients for bionic left ventricular assistant.

  18. Contracted auxiliary Gaussian basis integral and derivative evaluation

    OpenAIRE

    Giese, Timothy J.; York, Darrin M.

    2008-01-01

    The rapid evaluation of 2-center Coulomb and overlap integrals between contracted auxiliary solid harmonic Gaussian functions is examined. Integral expressions are derived from the application of Hobson’s theorem and Dunlap’s product and differentiation rules of the spherical tensor gradient operator. It is shown that inclusion of the primitive normalization constants greatly simplifies the calculation of contracted functions corresponding to a Gaussian multipole expansion of a diffuse charge...

  19. Mixed Bayesian Networks with Auxiliary Variables for Automatic Speech Recognition

    OpenAIRE

    Stephenson, Todd Andrew; Magimai.-Doss, Mathew; Bourlard, Hervé

    2001-01-01

    Standard hidden Markov models (HMMs), as used in automatic speech recognition (ASR), calculate their emission probabilities by an artificial neural network (ANN) or a Gaussian distribution conditioned on the hidden state variable, considering the emissions independent of any other variable in the model. Recent work showed the benefit of conditioning the emission distributions on a discrete auxiliary variable, which is observed in training and hidden in recognition. Related work has shown the ...

  20. Bayesian Analysis of Geostatistical Models With an Auxiliary Lattice

    KAUST Repository

    Park, Jincheol

    2012-04-01

    The Gaussian geostatistical model has been widely used for modeling spatial data. However, this model suffers from a severe difficulty in computation: it requires users to invert a large covariance matrix. This is infeasible when the number of observations is large. In this article, we propose an auxiliary lattice-based approach for tackling this difficulty. By introducing an auxiliary lattice to the space of observations and defining a Gaussian Markov random field on the auxiliary lattice, our model completely avoids the requirement of matrix inversion. It is remarkable that the computational complexity of our method is only O(n), where n is the number of observations. Hence, our method can be applied to very large datasets with reasonable computational (CPU) times. The numerical results indicate that our model can approximate Gaussian random fields very well in terms of predictions, even for those with long correlation lengths. For real data examples, our model can generally outperform conventional Gaussian random field models in both prediction errors and CPU times. Supplemental materials for the article are available online. © 2012 American Statistical Association, Institute of Mathematical Statistics, and Interface Foundation of North America.

  1. Robust video transmission with distributed source coded auxiliary channel.

    Science.gov (United States)

    Wang, Jiajun; Majumdar, Abhik; Ramchandran, Kannan

    2009-12-01

    We propose a novel solution to the problem of robust, low-latency video transmission over lossy channels. Predictive video codecs, such as MPEG and H.26x, are very susceptible to prediction mismatch between encoder and decoder or "drift" when there are packet losses. These mismatches lead to a significant degradation in the decoded quality. To address this problem, we propose an auxiliary codec system that sends additional information alongside an MPEG or H.26x compressed video stream to correct for errors in decoded frames and mitigate drift. The proposed system is based on the principles of distributed source coding and uses the (possibly erroneous) MPEG/H.26x decoder reconstruction as side information at the auxiliary decoder. The distributed source coding framework depends upon knowing the statistical dependency (or correlation) between the source and the side information. We propose a recursive algorithm to analytically track the correlation between the original source frame and the erroneous MPEG/H.26x decoded frame. Finally, we propose a rate-distortion optimization scheme to allocate the rate used by the auxiliary encoder among the encoding blocks within a video frame. We implement the proposed system and present extensive simulation results that demonstrate significant gains in performance both visually and objectively (on the order of 2 dB in PSNR over forward error correction based solutions and 1.5 dB in PSNR over intrarefresh based solutions for typical scenarios) under tight latency constraints.

  2. Matching of Silicon Thin-Film Tandem Solar Cells for Maximum Power Output

    Directory of Open Access Journals (Sweden)

    C. Ulbrich

    2013-01-01

    Full Text Available We present a meaningful characterization method for tandem solar cells. The experimental method allows for optimizing the output power instead of the current. Furthermore, it enables the extraction of the approximate AM1.5g efficiency when working with noncalibrated spectra. Current matching of tandem solar cells under short-circuit condition maximizes the output current but is disadvantageous for the overall fill factor and as a consequence does not imply an optimization of the output power of the device. We apply the matching condition to the maximum power output; that is, a stack of solar cells is power matched if the power output of each subcell is maximal at equal subcell currents. The new measurement procedure uses additional light-emitting diodes as bias light in the JV characterization of tandem solar cells. Using a characterized reference tandem solar cell, such as a hydrogenated amorphous/microcrystalline silicon tandem, it is possible to extract the AM1.5g efficiency from tandems of the same technology also under noncalibrated spectra.

  3. Power-Law Modeling of Cancer Cell Fates Driven by Signaling Data to Reveal Drug Effects

    Science.gov (United States)

    Zhang, Fan; Wu, Min; Kwoh, Chee Keong; Zheng, Jie

    2016-01-01

    Extracellular signals are captured and transmitted by signaling proteins inside a cell. An important type of cellular responses to the signals is the cell fate decision, e.g., apoptosis. However, the underlying mechanisms of cell fate regulation are still unclear, thus comprehensive and detailed kinetic models are not yet available. Alternatively, data-driven models are promising to bridge signaling data with the phenotypic measurements of cell fates. The traditional linear model for data-driven modeling of signaling pathways has its limitations because it assumes that the a cell fate is proportional to the activities of signaling proteins, which is unlikely in the complex biological systems. Therefore, we propose a power-law model to relate the activities of all the measured signaling proteins to the probabilities of cell fates. In our experiments, we compared our nonlinear power-law model with the linear model on three cancer datasets with phosphoproteomics and cell fate measurements, which demonstrated that the nonlinear model has superior performance on cell fates prediction. By in silico simulation of virtual protein knock-down, the proposed model is able to reveal drug effects which can complement traditional approaches such as binding affinity analysis. Moreover, our model is able to capture cell line specific information to distinguish one cell line from another in cell fate prediction. Our results show that the power-law data-driven model is able to perform better in cell fate prediction and provide more insights into the signaling pathways for cancer cell fates than the linear model. PMID:27764199

  4. A Terrestrial Microbial Fuel Cell for Powering a Single-Hop Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Daxing Zhang

    2016-05-01

    Full Text Available Microbial fuel cells (MFCs are envisioned as one of the most promising alternative renewable energy sources because they can generate electric current continuously while treating waste. Terrestrial Microbial Fuel Cells (TMFCs can be inoculated and work on the use of soil, which further extends the application areas of MFCs. Energy supply, as a primary influential factor determining the lifetime of Wireless Sensor Network (WSN nodes, remains an open challenge in sensor networks. In theory, sensor nodes powered by MFCs have an eternal life. However, low power density and high internal resistance of MFCs are two pronounced problems in their operation. A single-hop WSN powered by a TMFC experimental setup was designed and experimented with. Power generation performance of the proposed TMFC, the relationships between the performance of the power generation and the environment temperature, the water content of the soil by weight were measured by experiments. Results show that the TMFC can achieve good power generation performance under special environmental conditions. Furthermore, the experiments with sensor data acquisition and wireless transmission of the TMFC powering WSN were carried out. We demonstrate that the obtained experimental results validate the feasibility of TMFCs powering WSNs.

  5. A Terrestrial Microbial Fuel Cell for Powering a Single-Hop Wireless Sensor Network.

    Science.gov (United States)

    Zhang, Daxing; Zhu, Yingmin; Pedrycz, Witold; Guo, Yongxian

    2016-01-01

    Microbial fuel cells (MFCs) are envisioned as one of the most promising alternative renewable energy sources because they can generate electric current continuously while treating waste. Terrestrial Microbial Fuel Cells (TMFCs) can be inoculated and work on the use of soil, which further extends the application areas of MFCs. Energy supply, as a primary influential factor determining the lifetime of Wireless Sensor Network (WSN) nodes, remains an open challenge in sensor networks. In theory, sensor nodes powered by MFCs have an eternal life. However, low power density and high internal resistance of MFCs are two pronounced problems in their operation. A single-hop WSN powered by a TMFC experimental setup was designed and experimented with. Power generation performance of the proposed TMFC, the relationships between the performance of the power generation and the environment temperature, the water content of the soil by weight were measured by experiments. Results show that the TMFC can achieve good power generation performance under special environmental conditions. Furthermore, the experiments with sensor data acquisition and wireless transmission of the TMFC powering WSN were carried out. We demonstrate that the obtained experimental results validate the feasibility of TMFCs powering WSNs. PMID:27213346

  6. Hydrogen Fuel Cell Analysis: Lessons Learned from Stationary Power Generation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Scott E. Grasman; John W. Sheffield; Fatih Dogan; Sunggyu Lee; Umit O. Koylu; Angie Rolufs

    2010-04-30

    This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and a combination of distributed power generating stations, and provides an overview of stationary power markets, benefits of hydrogen-based stationary power systems, and competitive and technological challenges. The motivation for this project was to identify the lessons learned from prior stationary power programs, including the most significant obstacles, how these obstacles have been approached, outcomes of the programs, and how this information can be used by the Hydrogen, Fuel Cells & Infrastructure Technologies Program to meet program objectives primarily related to hydrogen pathway technologies (production, storage, and delivery) and implementation of fuel cell technologies for distributed stationary power. In addition, the lessons learned address environmental and safety concerns, including codes and standards, and education of key stakeholders.

  7. Polymer Separators for High-Power, High-Efficiency Microbial Fuel Cells

    KAUST Repository

    Chen, Guang

    2012-12-26

    Microbial fuel cells (MFCs) with hydrophilic poly(vinyl alcohol) (PVA) separators showed higher Coulombic efficiencies (94%) and power densities (1220 mW m-2) than cells with porous glass fiber separators or reactors without a separator after 32 days of operation. These remarkable increases in both the coublomic efficiency and the power production of the microbial fuel cells were made possible by the separator\\'s unique characteristics of fouling mitigation of the air cathode without a large increase in ionic resistance in the cell. This new type of polymer gel-like separator design will be useful for improving MFC reactor performance by enabling compact cell designs. © 2012 American Chemical Society.

  8. Evaluation of the Total Cost of Ownership of Fuel Cell-Powered Material Handling Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Ramsden, T.

    2013-04-01

    This report discusses an analysis of the total cost of ownership of fuel cell-powered and traditional battery-powered material handling equipment (MHE, or more typically 'forklifts'). A number of fuel cell MHE deployments have received funding support from the federal government. Using data from these government co-funded deployments, DOE's National Renewable Energy Laboratory (NREL) has been evaluating the performance of fuel cells in material handling applications. NREL has assessed the total cost of ownership of fuel cell MHE and compared it to the cost of ownership of traditional battery-powered MHE. As part of its cost of ownership assessment, NREL looked at a range of costs associated with MHE operation, including the capital costs of battery and fuel cell systems, the cost of supporting infrastructure, maintenance costs, warehouse space costs, and labor costs. Considering all these costs, NREL found that fuel cell MHE can have a lower overall cost of ownership than comparable battery-powered MHE.

  9. Fuel cell-shaft power packs (FC-SPP)

    Energy Technology Data Exchange (ETDEWEB)

    Elefsen, F.; Frandsen, S. [Danish Technological Institute, Renewable Energy and transport (Denmark)

    2007-05-15

    Danish companies will be able to obtain a unique international competitive position by combining our leadership in renewable energy with a focused and dedicated effort in hydrogen technology. The purpose of the present consortium is to establish the foundation for producing small hydrogen-based motor units. The consortium develops the technology in three concrete projects within two areas: small transportation equipment and mobile units. This assures that the research is directed towards specific market segments and that a synergy is obtained between technology development and market demand. Furthermore, the consortium involves developing concepts and tools for commercializing the technology and employing user-driven innovation. The consortium includes a number of innovative SMEs in close interaction with larger established companies. The large companies are primarily component suppliers, thus assuring that the necessary components are developed and produced. The participating SME's are both component and system suppliers, thus assuring that the products developed will also be carried to the market. Ultimately, the projects may contribute to the start of a new industrial success story similar to the Danish wind power industry, which would simultaneously lead to exports and an improved environment. (au)

  10. A low-power DCO using inverter interlaced cascaded delay cell

    Institute of Scientific and Technical Information of China (English)

    Huang Qiang; Fan Tao; Dai Xiangming; Yuan Guoshun

    2014-01-01

    This paper presents a low-power small-area digitally controlled oscillator (DCO) using an inverters interlaced cascaded delay cell (ⅡCDC).It uses a coarse-fine architecture with binary-weighted delay stages for the delay range and resolution.The coarse-tuning stage of the DCO uses ⅡCDC,which is power and area efficient with low phase noise,as compared with conventional delay cells.The ADPLL with a DCO is fabricated in the UMC 180-nm CMOS process with an active area of 0.071 mm2.The output frequency range is 140-600 MHz at the power supply of 1.8 V.The power consumption is 2.34 mW@a 200 MHz output.

  11. The changing nature of the power generation market — does it create opportunities for fuel cells?

    Science.gov (United States)

    Cragg, C. T.

    This paper surveys the global power industry seeking trends that might encourage greater use of full cells. The subject is broken into four basic themes: (i) an increasing demand for electricity, and this may not be solved by the traditional form of the integrated state-owned, centralised power utility, with a large infrastructure grid attached, the load curves of these integrated grids becoming unmanageable; (ii) a general trend towards privatisation and deregulation in the power sector, that is shifting its control from an engineering to a commercial paradigm, with unforseen consequences; (iii) contrary to (ii), the need for supplying security in its most basic sense is increasing rather than declining as power-dependent technology becomes progressively more important in the modern economy, and (iv) the trend in technology, particularly environmental-friendly technology, is towards smaller size of production centres. Within these inter-related themes these are encouraging prospects for the fuel cell community.

  12. Photo-Activated Low Temperature, Micro Fuel Cell Power Source

    Energy Technology Data Exchange (ETDEWEB)

    Harry L. Tuller

    2007-03-30

    A Key objective of this program is to identify electrodes that will make it possible to significantly reduce the operating temperature of micro-SOFC and thin film-based SOFCs. Towards this end, efforts are directed towards: (a) identifying the key rate limiting steps which limit presently utilized electrodes from performing at reduced temperatures, as well as, (b) investigating the use of optical, as opposed to thermal energy, as a means for photocatalyzing electrode reactions and enabling reduced operating temperatures. During Phase I, the following objectives were achieved: (a) assembly and testing of our unique Microprobe Thin Film Characterization System; (b) fabrication of the model cathode materials system in thin film form by both PLD and ink jet printing; and (c) the successful configuration and testing of the model materials as cathodes in electrochemical cells. A further key objective (d) to test the potential of illumination in enhancing electrode performance was also achieved.

  13. Power Harvesting from Human Serum in Buckypaper-Based Enzymatic Biofuel Cell

    Directory of Open Access Journals (Sweden)

    Güray eGüven

    2016-02-01

    Full Text Available The requirement for a miniature, high density, long life, rechargeable power source is common to a vast majority of microsystems, including the implantable devices for medical applications. A model biofuel cell system operating in human serum has been studied for future applications of biomedical and implantable medical devices. Anodic and cathodic electrodes were made of carbon nanotube –buckypaper modified with PQQ-dependent glucose dehydrogenase and laccase, respectively. Modified electrodes were characterized electrochemically and assembled in a biofuel cell set-up. Power density of 16.12 μW/cm2 was achieved in human serum for lower than physiological glucose concentrations. Increasing the glucose concentration and biofuel cell temperature caused an increase on power output leading up to 49.16 μW/cm2.

  14. Small proton exchange membrane fuel cell power station by using bio-hydrogen

    Institute of Scientific and Technical Information of China (English)

    刘志祥; 毛宗强; 王诚; 任南琪

    2006-01-01

    In fermentative organic waste water treatment process, there was hydrogen as a by-product. After some purification,there was about 50% ~ 70% hydrogen in the bio-gas, which could be utilized for electricity generation with fuel cell. Half a year ago, joint experiments between biological hydrogen production in Harbin Institute of Technology (HIT) and proton exchange membrane fuel cell (PEMFC) power station in Tsinghua University were conducted for electricity generation with bio-hydrogen from the pilot plant in HIT. The results proved the feasibility of the bio-hydrogen as a by-product utilization with PEMFC power station and revealed some problems of fuel cell power station for this application.

  15. Design and Comparison of Power Systems for a Fuel Cell Hybrid Electric Vehicle

    DEFF Research Database (Denmark)

    Schaltz, Erik; Rasmussen, Peter Omand

    2008-01-01

    In a fuel cell hybrid electric vehicle (FCHEV) the fuel cell stack is assisted by one or more energy storage devices. Thereby the system cost, mass, and volume can be decreased, and a significant better performance can be obtained. Two often used energy storage devices are the battery...... ultracapacitors are the only energy storage device the system becomes too big and heavy. A fuel cell/battery/ultracapacitor hybrid provides the longest life time of the batteries. If the fuel cell stack power is too small, the system will be big, heavy, and have a poor efficiency....

  16. DPAL: A New Class of Lasers for CW Power Beaming at Ideal Photovoltaic Cell Wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Krupke, W F; Beach, R J; Payne, S A; Kanz, V K; Early, J T

    2003-09-15

    The new class of diode pumped alkali vapor lasers (DPALs) offers high efficiency cw laser beams at wavelengths which efficiently couple to photovoltaic (PV) cells: silicon cells at 895 nm (cesium), and GaAs cells at 795 nm (rubidium) and at 770 nm (potassium). DPAL electrical efficiencies of 25-30% are projected, enabling PV cell efficiencies {approx}40% (Si) and {approx}60% (GaAs). Near-diffraction-limited DPAL device power scaling into the multi-kilowatt regime from a single aperture is projected.

  17. Roles of HIV-1 auxiliary proteins in viral pathogenesis and host-pathogen interactions

    Institute of Scientific and Technical Information of China (English)

    Lin LI; Hai Shan LI; C.David PAUZA; Michael BUKRINSKY; Richard Y ZHAO

    2005-01-01

    Active host-pathogen interactions take place during infection of human immunodeficiency virus type 1 (HIV-1).Outcomes of these interactions determine the efficiency of viral infection and subsequent disease progression. HIV-infected cells respond to viral invasion with various defensive strategies such as innate, cellular and humoral immune antiviral mechanisms. On the other hand, the virus has also developed various offensive tactics to suppress these host cellular responses. Among many of the viral offensive strategies, HIV- 1 viral auxiliary proteins (Tat, Rev, Nef, Vif, Vpr and Vpu) play important roles in the host-pathogen interaction and thus have significant impacts on the outcome of HIV infection. One of the best examples is the interaction of Vif with a host cytidine deaminase APOBEC3G. Although specific roles of other auxiliary proteins are not as well described as Vif-APOBEC3G interaction, it is the goal of this brief review to summarize some of the preliminary findings with the hope to stimulate further discussion and investigation in this exhilarating area of research.

  18. Auxiliary liver organ formation by implantation of spleen-encapsulated hepatocytes.

    Science.gov (United States)

    Nishio, Reiji; Nakayama, Miyuki; Ikekita, Masahiko; Watanabe, Yoshifumi

    2006-09-01

    Hepatocyte transplantation is an attractive alternative to orthotopic liver transplantation. However, its application has been limited because of its short-term success only. Here we report a new approach to hepatocyte transplantation resulting in the generation of an auxiliary liver in vivo. Isolated primary hepatocytes were encapsulated in isolated spleens and then transplanted by attaching the spleens to the livers of recipient animals (mice or rats) using biodegradable adhesive. A vascular network was rapidly established, and protein molecules circulated freely between the transplanted spleen and the liver, to which they adhered. In contrast, the spleen, which did not adhere to the liver or adhered elsewhere (adipose tissue or peritoneum), did not become vascularized but shrank and died. Encapsulation of hepatocytes in an isolated spleen enhanced their survival significantly, and co-encapsulation of Engelbreth- Holm-Swarm gel together with the hepatocytes further enhanced it. The encapsulated hepatocytes expressed liver-specific differentiation genes for more than 3 weeks. Plasma albumin concentrations in Nagase analbuminemic rats began to increase 3 days after transplantation. The transplanted hepatic cells migrated into the liver parenchyma, whereas the spleen was absorbed. Thus, we have developed a novel, simple approach for the rapid and efficient formation of functional auxiliary liver using a modified hepatocyte transplantation method.

  19. System design impacts on optimization of the advanced radioisotope power system (ARPS) AMTEC cell

    International Nuclear Information System (INIS)

    Several NASA deep space missions require Advanced Radioisotope Power Systems (ARPS) to supply spacecraft power for various internal functions and mission instruments and experiments. AMTEC (Alkali-Metal Thermal-Electric Conversion) power conversion is the DOE-selected technology for an advanced, next- generation RPS to power these spacecraft. Advanced Modular Power Systems, Inc. (AMPS) has begun investigating the design of an AMTEC-based ARPS using the General Purpose Heat Source (GPHS) and the latest PX-5 AMTEC cell technology with refractory materials in critical components. This paper presents and discusses the system design methodology, and results of important system design tradeoffs and system design impacts on the ARPS AMTEC cell design. This work investigated dual 2-GPHS system configurations and 4-GPHS system configurations with 16 side-mounted AMTEC cells operating at beginning-of-mission (BOM) and end-of-mission (EOM) GPHS heat dissipation conditions. Current design studies indicate using a refractory material AMTEC cell with 8-BASE tubes, 5.0 inches long, and 1.75 inches diameter in the 4-GPHS system configuration is the strongest design candidate to satisfy system performance requirements

  20. Numerical Investigation of Thermal Effect in Plasma Electrode Pockels Cell for High Average Power

    Institute of Scientific and Technical Information of China (English)

    CAO Ding-Xiang; ZHANG Xiong-Jun; ZHENG Wan-Guo; HE Shao-Bo; SUI Zhan

    2006-01-01

    @@ The average power of a Pockels cell is limited by thermal effects arising from the optical absorption of the laser pulse. These thermal effects can be managed by configuring the switch as a plasma-electrode thin plate Pockels cell, which works under heat-capacity operation. Simulation results show that, based on KD*P (in thickness 0.5cm) at an average power loading of 1 kW, the aperture integrated depolarization loss at 1.06 um is less than 10% in 5min working time.

  1. Subcarrier and power allocation algorithm based on inter-cell interference mitigation for OFDMA system

    Institute of Scientific and Technical Information of China (English)

    ZOU Ting; DENG Gang; WANG Ying; ZHANG Ping

    2007-01-01

    This article proposes a dynamic subcarrier and power allocation algorithm for multicell orthogonal frequency division multiple access (OFDMA) downlink system, based on inter-cell interference (ICI) mitigation. Different from other ICI mitigation schemes, which pay little attention to power allocation in the system, the proposed algorithm assigns channels to each user, based on proportional-fair (PF) scheduling and ICI coordination, whereas allocating power is based on link gain distribution and the loading bit based on adaptive modulation and coding (AMC) in base transceiver station (BTS). Simulation results show that the algorithm yields better performance for data services under fast fading.

  2. Power losses in bilayer inverted small molecule organic solar cells

    KAUST Repository

    Trinh, Cong

    2012-01-01

    Inverted bilayer organic solar cells using copper phthalocyanine (CuPc) as a donor and C60 as an acceptor with the structure: glass/indium tin oxide (ITO)/ZnO/C60/CuPc/MoO3/Al, in which the zinc oxide (ZnO) was deposited by atomic layer deposition, are compared with a conventional device: glass/ITO/CuPc/C60/bathocuproine/Al. These inverted and conventional devices give short circuit currents of 3.7 and 4.8 mA/cm 2, respectively. However, the inverted device gives a reduced photoresponse from the CuPc donor compared to that of the conventional device. Optical field models show that the arrangement of organic layers in the inverted devices leads to lower absorption of long wavelengths by the CuPc donor; the low energy portion of the spectrum is concentrated near the metal oxide electrode in both devices. © 2012 American Institute of Physics.

  3. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders - A Reference Solution for the Numerical Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    To facilitate the validation of the numerical Method of Auxiliary Sources an analytical Method of Auxiliary Sources solution is derived in this paper. The Analytical solution is valid for transverse magnetic, and electric, plane wave scattering by circular impedance Cylinders, and it is derived...

  4. Increasing the Cruise Range and Reducing the Capital Cost of Electric Vehicles by Integrating Auxiliary Unit with the Traction Drive

    Directory of Open Access Journals (Sweden)

    N. Satheesh Kumar

    2016-01-01

    Full Text Available Poor cruise performance of Electric Vehicles (EVs continues to be the primary reason that impends their market penetration. Adding more battery to extend the cruise range is not a viable solution as it increases the structural weight and capital cost of the EV. Simulations identified that a vehicle spends on average 15% of its total time in braking, signifying an immense potential of the utilization of regenerative braking mechanism. Based on the analysis, a 3 kW auxiliary electrical unit coupled with the traction drive during braking events increases the recoverable energy by 8.4%. In addition, the simulation revealed that, on average, the energy drawn from the battery is reduced by 3.2% when traction drive is integrated with the air-conditioning compressor (an auxiliary electrical load. A practical design solution of the integrated unit is also included in the paper. Based on the findings, it is evident that the integration of an auxiliary unit with the traction drive results in enhancing the energy capturing capacity of the regenerative braking mechanism and decreases the power consumed from the battery. Further, the integrated unit boosts other advantages such as reduced material cost, improved reliability, and a compact and lightweight design.

  5. An Interleaved Reduced-Component-Count Multivoltage Bus DC/DC Converter for Fuel Cell Powered Electric Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

    2008-01-01

    An interleaved reduced-component-count dc/dc converter is proposed for power management in fuel cell powered vehicles with a multivoltage electric net. The converter is based on a simplified topology and can handle more power with less ripple current, therefore reducing the capacitor requirements, making it more suited for fuel cell powered vehicles in the near future. A prototype rated at 4.3 kW was built and tested to verify the proposed topology.

  6. Fuel-Cell-Powered Electric Motor Drive Analyzed for a Large Airplane

    Science.gov (United States)

    Brown, Gerald V.; Choi, Benjamin B.

    2005-01-01

    Because of its high efficiency, fuel cell technology may be used to launch a new generation of more-electric aeropropulsion and power systems for future aircraft. Electric-motor-driven airplanes using fuel-cell powerplants would be beneficial to the environment because of fuel savings, low noise, and zero carbon-dioxide emissions. In spite of the fuel cell s efficiency benefit, to produce the same shaft drive power, a fuel cell- powered electric-drive system must be definitely heavier than a turbine-drive system. However, the fuel-cell system s overall efficiency from fuel-to-shaft power is higher than for a turbine-drive system. This means that the fuel consumption rate could be lower than for a conventional system. For heavier, fuel-laden planes for longer flights, we might achieve substantial fuel savings. In the airplane industry, in fact, an efficiency gain of even a few percentage points can make a major economic difference in operating costs.

  7. Improvement of hydrogenated microcrystalline silicon solar cell performance by VHF power profiling technique

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xiaoyan; Hou, Guofu; Zhang, Xiaodan; Wei, Changchun; Li, Guijun; Zhang, Jianjun; Chen, Xinliang; Zhang, Dekun; Sun, Jian; Zhao, Ying; Geng, Xinhua [Institute of Photo-electronics, Nankai University, Weijin Road 94, Tianjin 300071 (China)

    2010-02-15

    Hydrogenated microcrystalline silicon ({mu}c-Si:H) solar cells were deposited with very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) process at high deposition rates in high-power and a high-pressure regime. A novel VHF power profiling technique, designed by dynamically decreasing the VHF power step by step during the deposition of {mu}c-Si:H intrinsic layers, has been developed for the first time to control the structural evolution along the growth direction. The profiling parameters such as the amount and the rate of change in VHF power were optimized in detail and the experimental results demonstrate that this technique not only controls the microstructure evolution but also results in reduced ion bombardments on growth surface. Using this method, a significant improvement in the solar cell performance has been achieved. A high conversion efficiency of 9.36% (V{sub oc}=542 mV, J{sub sc}=25.4 mA/cm{sup 2}, FF=68%) was obtained for a single-junction {mu}c-Si:H p-i-n solar cell at a deposition rate of 12 Aa/s. Then, the single-junction solar cell was used as a bottom component in micromorph solar cell, which leads to an efficiency of 11.14% (V{sub oc}=1.367 V, J{sub sc}=11.92 mA/cm{sup 2}, FF=69.4%). (author)

  8. Study of a molten carbonate fuel cell combined heat, hydrogen and power system

    International Nuclear Information System (INIS)

    To address the problem of fossil fuel usage and high greenhouse gas emissions at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and greenhouse gas emissions. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed the design of CHHP (combined heat, hydrogen and power) system for the campus using local resources. An energy flow and resource availability study is performed to identify the type and source of feedstock required to continuously run the fuel cell system at peak capacity. Following the resource assessment study, the team selects FuelCell Energy DFC (direct fuel cell) 1500™ unit as a molten carbonate fuel cell. The CHHP system provides electricity to power the university campus, thermal energy for heating the anaerobic digester, and hydrogen for transportation, back-up power and other needs. In conclusion, the CHHP system will be able to reduce fossil fuel usage, and greenhouse gas emissions at the university campus. - Highlights: • A molten carbonate fuel cell tri-generation by using anaerobic digestion system. • Anaerobic digestion system will be able to supply fuel for the DFC1500™ unit. • Use locally available feedstock to production electric power, hydrogen and heat. • Application energy end-uses on the university. • CHHP system will reduce energy consumption, fossil fuel usage, and GHG emissions

  9. Multi-cell uplink power allocation game for user minimum performance guarantee in OFDMA systems

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tian-kui; XIAO Lin; ZENG Zhi-min; Laurie Cuthbert

    2010-01-01

    The multi-cell uplink power allocation problem for orthogonal frequency division multiplexing access (OFDMA) cellular networks is investigated with the uplink transmission power allocation on each co-frequency subchannel being defined as a multi-cell non-cooperative power allocation game (MNPG). The principle of the design oftbe utility function is given and a novel utility function is proposed for MNPG. By using this utility function, the minimum signal to interference plus noise ratio (SINR) requirement of a user can be guaranteed. It can be shown that MNPG will converge to the Nash equilibrium and that this Nash equilibrium is unique. In considering the simulation results, the effect of the algorithm parameters on the system performance is discussed, and the convergence of the MNPG is verified. The performance of MNPG is compared with that of traditional power allocation schemes, the simulation results showing that the proposed algorithm increases the cell-edge user throughput greatly with only a small decrease in cell total throughput; this gives a good tradeoff between the throughput of cell-edge users and the system spectrum efficiency.

  10. Stabilizing Canonical-Ensemble Calculations in the Auxiliary-Field Monte Carlo Method

    CERN Document Server

    Gilbreth, C N

    2014-01-01

    Quantum Monte Carlo methods are powerful techniques for studying strongly interacting Fermi systems. However, implementing these methods on computers with finite-precision arithmetic requires careful attention to numerical stability. In the auxiliary-field Monte Carlo (AFMC) method, low-temperature or large-model-space calculations require numerically stabilized matrix multiplication. When adapting methods used in the grand-canonical ensemble to the canonical ensemble of fixed particle number, the numerical stabilization increases the number of required floating-point operations for computing observables by a factor of the size of the single-particle model space, and thus can greatly limit the systems that can be studied. We describe an improved method for stabilizing canonical-ensemble calculations in AFMC that exhibits better scaling, and present numerical tests that demonstrate the accuracy and improved performance of the method.

  11. Modelling of Temperature Profiles and Transport Scaling in Auxiliary Heated Tokamaks

    DEFF Research Database (Denmark)

    Callen, J.D.; Christiansen, J.P.; Cordey, J.G.;

    1987-01-01

    in detail: (i) a heat pinch or excess temperature gradient model with constant coefficients; and (ii) a non-linear heat diffusion coefficient (χ) model. Both models predict weak (lesssim20%) temperature profile responses to physically relevant changes in the heat deposition profile – primarily because...... the temperature profile is a double integral of the heating profile. The model predictions are shown to agree with JET data for a variety of heating profiles ranging from peaked on-axis through approximately flat (NBI at high density) to localized off-axis (ICRH). The modest temperature profile responses......-mode) scaling with input power, . The constant heat pinch or excess temperature gradient model leads to the offset linear law for the total stored energy W with Pin, W = τinc Pin + W(0), which describes JET auxiliary heating data quite well. It also provides definitions for the incremental energy confinement...

  12. Designs for remote inspection of the ALMR Reactor Vessel Auxiliary Cooling System (RVACS)

    International Nuclear Information System (INIS)

    One of the most important safety systems in General Electric's (GI) Advanced Liquid Metal Reactor (ALMR) is the Reactor Vessel Auxiliary Cooling System (RVACS). Because of high temperature, radiation, and restricted space conditions, GI desired methods to remotely inspect the RVACS, emissive coatings, and reactor vessel welds during normal refueling operations. The DOE/NE Robotics for Advanced Reactors program formed a team to evaluate the ALMR design for remote inspection of the RVACS. Conceptual designs for robots to perform the required inspection tasks were developed by the team. Design criteria for these remote systems included robot deployment, power supply, navigation, environmental hardening of components, tether management, communication with an operator, sensing, and failure recovery. The operation of the remote inspection concepts were tested using 3-D simulation models of the ALMR. In addition, the team performed an extensive technology review of robot components that could survive the environmental conditions in the RVACS

  13. Seismic response of base isolated auxiliary building with age related degradation

    International Nuclear Information System (INIS)

    The aging of an isolator affects not only the mechanical properties of the isolator but also the dynamic properties of the upper structure, such as the change in stiffness, deformation capacity, load bearing capacity, creep, and damping. Therefore, the seismic response of base isolated structures will change with time. The floor response in the base isolated nuclear power plants (NPPs) can be particularly changed because of the change in stiffness and damping for the isolator. The increased seismic response due to the aging of isolator can cause mechanical problems for many equipment located in the NPPs. Therefore, it is necessary to evaluate the seismic response of base isolated NPPs with age related degradation. In this study, the seismic responses for a base isolated auxiliary building of SHIN KORI 3 and 4 with age related degradation were investigated using a nonlinear time history analysis. Floor response spectrums (FRS) were presented with time for identifying the change in seismic demand under the aging of isolator

  14. Metal Interconnects for Solid Oxide Fuel Cell Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    S. Elangovan

    2006-04-01

    Interconnect development is identified by the US Department of energy as a key technical area requiring focused research to meet the performance and cost goals under the Solid State Energy Conversion Alliance initiative. In the Phase I SECA Core Technology Program, Ceramatec investigated a commercial ferritic stainless steel composition for oxidation resistance properties by measuring the weight gain when exposed to air at the fuel cell operating temperature. A pre-treatment process that results in a dense, adherent scale was found to reduce the oxide scale growth rate significantly. A process for coating the surface of the alloy in order to reduce the in-plane resistance and potentially inhibit chromium oxide evaporation was also identified. The combination of treatments provided a very low resistance through the scale. The resistance measured was as low as 10 milliohm-cm2 at 750 C in air. The oxide scale was also found to be stable in humidified air at 750 C. The resistance value was stable over several thermal cycles. A similar treatment and coating for the fuel side of the interconnect also showed an exceptionally low resistance of one milliohm-cm2 in humidified hydrogen at 750 c, and was stable through multiple thermal cycles. Measurement of interconnect resistance when it was exposed to both air and humidified hydrogen on opposite sides also showed low, stable resistance after additional modification to the pre-treatment process. Resistance stacks, using an interconnect stack with realistic gas flows, also provided favorable results. Chromium evaporation issue however requires testing of fuel stacks and was outside of the scope of this project. based on results to-date, the alloy selection and the treatment processes appear to be well suited for SOFC interconnect application.

  15. A power pack based on organometallic perovskite solar cell and supercapacitor.

    Science.gov (United States)

    Xu, Xiaobao; Li, Shaohui; Zhang, Hua; Shen, Yan; Zakeeruddin, Shaik M; Graetzel, Michael; Cheng, Yi-Bing; Wang, Mingkui

    2015-02-24

    We present an investigation on a power pack combining a CH3NH3PbI3-based solar cell with a polypyrrole-based supercapacitor and evaluate its performance as an energy pack. The package achieved an energy storage efficiency of 10%, which is much higher than that of other systems combining a PV cell with a supercapacitor. We find a high output voltage of 1.45 V for the device under AM 1.5G illumination when the CH3NH3PbI3-based solar cell is connected in series with a polypyrrole-based supercapacitor. This system affords continuous output of electric power by using CH3NH3PbI3-based solar cell as an energy source mitigating transients caused by light intensity fluctuations or the diurnal cycle.

  16. Retinal Ganglion Cell Distribution and Spatial Resolving Power in Deep-Sea Lanternfishes (Myctophidae)

    KAUST Repository

    De Busserolles, Fanny

    2014-01-01

    Topographic analyses of retinal ganglion cell density are very useful in providing information about the visual ecology of a species by identifying areas of acute vision within the visual field (i.e. areas of high cell density). In this study, we investigated the neural cell distribution in the ganglion cell layer of a range of lanternfish species belonging to 10 genera. Analyses were performed on wholemounted retinas using stereology. Topographic maps were constructed of the distribution of all neurons and both ganglion and amacrine cell populations in 5 different species from Nissl-stained retinas using cytological criteria. Amacrine cell distribution was also examined immunohistochemically in 2 of the 5 species using anti-parvalbumin antibody. The distributions of both the total neuron and the amacrine cell populations were aligned in all of the species examined, showing a general increase in cell density toward the retinal periphery. However, when the ganglion cell population was topographically isolated from the amacrine cell population, which comprised up to 80% of the total neurons within the ganglion cell layer, a different distribution was revealed. Topographic maps of the true ganglion cell distribution in 18 species of lanternfishes revealed well-defined specializations in different regions of the retina. Different species possessed distinct areas of high ganglion cell density with respect to both peak density and the location and/or shape of the specialized acute zone (i.e. elongated areae ventro-temporales, areae temporales and large areae centrales). The spatial resolving power was calculated to be relatively low (varying from 1.6 to 4.4 cycles per degree), indicating that myctophids may constitute one of the less visually acute groups of deep-sea teleosts. The diversity in retinal specializations and spatial resolving power within the family is assessed in terms of possible ecological functions and evolutionary history.

  17. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

  18. Mind-controlled transgene expression by a wireless-powered optogenetic designer cell implant

    OpenAIRE

    Marc Folcher; Sabine Oesterle; Katharina Zwicky; Thushara Thekkottil; Julie Heymoz; Muriel Hohmann; Matthias Christen; Marie Daoud El-Baba; Peter Buchmann; Martin Fussenegger

    2014-01-01

    Synthetic devices for traceless remote control of gene expression may provide new treatment opportunities in future gene- and cell-based therapies. Here we report the design of a synthetic mind-controlled gene switch that enables human brain activities and mental states to wirelessly programme the transgene expression in human cells. An electroencephalography (EEG)-based brain–computer interface (BCI) processing mental state-specific brain waves programs an inductively linked wireless-powered...

  19. Direct alcohol fuel cells: toward the power densities of hydrogen-fed proton exchange membrane fuel cells.

    Science.gov (United States)

    Chen, Yanxin; Bellini, Marco; Bevilacqua, Manuela; Fornasiero, Paolo; Lavacchi, Alessandro; Miller, Hamish A; Wang, Lianqin; Vizza, Francesco

    2015-02-01

    A 2 μm thick layer of TiO2 nanotube arrays was prepared on the surface of the Ti fibers of a nonwoven web electrode. After it was doped with Pd nanoparticles (1.5 mgPd  cm(-2) ), this anode was employed in a direct alcohol fuel cell. Peak power densities of 210, 170, and 160 mW cm(-2) at 80 °C were produced if the cell was fed with 10 wt % aqueous solutions of ethanol, ethylene glycol, and glycerol, respectively, in 2 M aqueous KOH. The Pd loading of the anode was increased to 6 mg cm(-2) by combining four single electrodes to produce a maximum peak power density with ethanol at 80 °C of 335 mW cm(-2) . Such high power densities result from a combination of the open 3 D structure of the anode electrode and the high electrochemically active surface area of the Pd catalyst, which promote very fast kinetics for alcohol electro-oxidation. The peak power and current densities obtained with ethanol at 80 °C approach the output of H2 -fed proton exchange membrane fuel cells.

  20. Structure and Control Strategies of Fuel Cell Vehicle

    Institute of Scientific and Technical Information of China (English)

    宋建国; 张承宁; 孙逢春; 钟秋海

    2004-01-01

    The structure and kinds of the fuel cell vehicle (FCV) and the mathematical model of the fuel cell processor are discussed in detail. FCV includes many parts: the fuel cell thermal and water management, fuel supply, air supply and distribution, AC motor drive, main and auxiliary power management, and overall vehicle control system. So it requires different kinds of control strategies, such as the PID method, zero-pole method, optimal control method, fuzzy control and neural network control. Along with the progress of control method, the fuel cell vehicle's stability and reliability is up-and-up. Experiment results show FCV has high energy efficiency.

  1. Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Joesph W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Klebanoff, Leonard E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Munoz-Ramos, Karina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Akhil, Abbas A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Curgus, Dita B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schenkman, Benjamin L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today’s technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  2. Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes.

    Energy Technology Data Exchange (ETDEWEB)

    Curgus, Dita Brigitte; Munoz-Ramos, Karina (Sandia National Laboratories, Albuquerque, NM); Pratt, Joseph William; Akhil, Abbas Ali (Sandia National Laboratories, Albuquerque, NM); Klebanoff, Leonard E.; Schenkman, Benjamin L. (Sandia National Laboratories, Albuquerque, NM)

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today's technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  3. Validation of Novel Planar Cell Design for MW-Scale SOFC Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Scott Swartz; Lora Thrun; Gene Arkenberg; Kellie Chenault

    2011-09-30

    This report describes the work completed by NexTech Materials, Ltd. during a three-year project to validate an electrolyte-supported planar solid oxide fuel cell design, termed the FlexCell, for coal-based, megawatt-scale power generation systems. This project was focused on the fabrication and testing of electrolyte-supported FlexCells with yttria-stabilized zirconia (YSZ) as the electrolyte material. YSZ based FlexCells were made with sizes ranging from 100 to 500 cm{sup 2}. Single-cell testing was performed to confirm high electrochemical performance, both with diluted hydrogen and simulated coal gas as fuels. Finite element analysis modeling was performed at The Ohio State University was performed to establish FlexCell architectures with optimum mechanical robustness. A manufacturing cost analysis was completed, which confirmed that manufacturing costs of less than $50/kW are achievable at high volumes (500 MW/year). DISCLAIMER

  4. Final Report, Validation of Novel Planar Cell Design for MW-Scale SOFC Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, Dr Scott L.; Thrun, Dr Lora B.; Arkenberg, Mr Gene B.; Chenault, Ms Kellie M.

    2012-01-03

    This report describes the work completed by NexTech Materials, Ltd. during a three-year project to validate an electrolyte-supported planar solid oxide fuel cell design, termed the FlexCell, for coal-based, megawatt-scale power generation systems. This project was focused on the fabrication and testing of electrolyte-supported FlexCells with yttria-stabilized zirconia (YSZ) as the electrolyte material. YSZ based FlexCells were made with sizes ranging from 100 to 500 cm2. Single-cell testing was performed to confirm high electrochemical performance, both with diluted hydrogen and simulated coal gas as fuels. Finite element analysis modeling was performed at The Ohio State University was performed to establish FlexCell architectures with optimum mechanical robustness. A manufacturing cost analysis was completed, which confirmed that manufacturing costs of less than $50/kW are achievable at high volumes (500 MW/year).

  5. A statistical model of uplink inter-cell interference with slow and fast power control mechanisms

    KAUST Repository

    Tabassum, Hina

    2013-09-01

    Uplink power control is in essence an interference mitigation technique that aims at minimizing the inter-cell interference (ICI) in cellular networks by reducing the transmit power levels of the mobile users while maintaining their target received signal quality levels at base stations. Power control mechanisms directly impact the interference dynamics and, thus, affect the overall achievable capacity and consumed power in cellular networks. Due to the stochastic nature of wireless channels and mobile users\\' locations, it is important to derive theoretical models for ICI that can capture the impact of design alternatives related to power control mechanisms. To this end, we derive and verify a novel statistical model for uplink ICI in Generalized-K composite fading environments as a function of various slow and fast power control mechanisms. The derived expressions are then utilized to quantify numerically key network performance metrics that include average resource fairness, average reduction in power consumption, and ergodic capacity. The accuracy of the derived expressions is validated via Monte-Carlo simulations. Results are generated for multiple network scenarios, and insights are extracted to assess various power control mechanisms as a function of system parameters. © 1972-2012 IEEE.

  6. Strategies for the commercial introduction of modular low power fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, H.V.; Laufer, A. [EnergiaH, Rio de Janeiro (Brazil); Miranda, P.E.V. [Coppe-Federal Univ., Rio de Janeiro (Brazil). Hydrogen Lab.

    2010-07-01

    The reality of the infrastructure in emerging economies brings the opportunity to build up a hydrogen compatible economy. For the Brazilian case, the fast development in many fields coexists with a considerable amount of potential renewable fuels available. Costs of energy distribution and of power grid maintenance throughout a continental size country may lead to a distributed generation system based in a diversified fuels matrix. This pathway drives attention to simpler low power fuel cell devices, with easier maintenance procedures, friendly integration with small power demands, and the capability of being applied separately or integrated to deliver higher power demands. Big cities and small distant agriculture based locations, such as Rio de Janeiro or rain forest extractive communities, could be able to produce fuel and energy in their own infrastructure projects. This article presents a market roadmap for the commercial introduction of direct oxidation type solid oxide fuel cells in Brazil, specifying fuel cell technological features and the specificities for each type of application, either in grid connected or in stand alone low power electric energy generation. (orig.)

  7. A direct methanol fuel cell system to power a humanoid robot

    Energy Technology Data Exchange (ETDEWEB)

    Joh, Han-Ik [Center for Fuel Cell Research, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongyang, Seoul 130-650 (Korea); School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, San 56-1, Shillim-dong, Kwanak-ku, Seoul 151-744 (Korea); Ha, Tae Jung; Hwang, Sang Youp; Kim, Jong-Ho; Chae, Seung-Hoon; Cho, Jae Hyung; Prabhuram, Joghee; Kim, Soo-Kil; Lim, Tae-Hoon; Ha, Heung Yong [Center for Fuel Cell Research, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongyang, Seoul 130-650 (Korea); Cho, Baek-Kyu; Oh, Jun-Ho [HUBO Laboratory, Humanoid Robot Research Center, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea); Moon, Sang Heup [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, San 56-1, Shillim-dong, Kwanak-ku, Seoul 151-744 (Korea)

    2010-01-01

    In this study, a direct methanol fuel cell (DMFC) system, which is the first of its kind, has been developed to power a humanoid robot. The DMFC system consists of a stack, a balance of plant (BOP), a power management unit (PMU), and a back-up battery. The stack has 42 unit cells and is able to produce about 400 W at 19.3 V. The robot is 125 cm tall, weighs 56 kg, and consumes 210 W during normal operation. The robot is integrated with the DMFC system that powers the robot in a stable manner for more than 2 h. The power consumption by the robot during various motions is studied, and load sharing between the fuel cell and the back-up battery is also observed. The loss of methanol feed due to crossover and evaporation amounts to 32.0% and the efficiency of the DMFC system in terms of net electric power is 22.0%. (author)

  8. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Y.; Wang, W. X.; LeBlanc, B. P.; Guttenfelder, W.; Kaye, S. M.; Ethier, S.; Mazzucato, E.; Bell, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-11-15

    In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. The observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport.

  9. Comment: ``On the computation of molecular auxiliary functions and ”

    Indian Academy of Sciences (India)

    Frank E Harris

    2003-10-01

    Guseinov, Mamedov, Kara and Orbay (Pramana – J. Phys. 56, 691 (2001)) propose methods for evaluating the molecular auxiliary functions () and () for the range 17 ≤ ≤ 60 and 25 ≤ ≤ 60. However, their procedure for () is not new, and that for () is less efficient for their target range than another well-known method. Their approach does have merit for smaller non-zero values of . Two minor errors in table 1 of their paper are also identified.

  10. Installation in Dakar of a pump powered by solar cell pannels. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Naaijer, C.J.

    1976-06-01

    The installation of a solar-powered water pumping system in Dakar (Franch Sahara) is described. The interrelation of the various constraints is detailed together with the reasons for choosing photovoltaic cells. The solar collector pump, engine, buffer battery, and control unit are discussed. The functional characteristics for the automation of the system is elaborated upon.

  11. Fuel Cell-Powered Go-Kart: Project Mimics Real-World Product Development

    Science.gov (United States)

    Fuller, Amanda

    2010-01-01

    Five years ago, Leon Strecker's technology education class at Darien High School came up with the idea of building a fuel cell-powered go-kart. In previous years, the class had worked on other creations, such as electric cars that competed in a state-sponsored race and a full-size hovercraft. But students had not taken on anything anywhere near…

  12. Biomass-powered Solid Oxide Fuel Cells: Experimental and Modeling Studies for System Integrations

    NARCIS (Netherlands)

    Liu, M.

    2013-01-01

    Biomass is a sustainable energy source which, through thermo-chemical processes of biomass gasification, is able to be converted from a solid biomass fuel into a gas mixture, known as syngas or biosyngas. A solid oxide fuel cell (SOFC) is a power generation device that directly converts the chemical

  13. Electric power generation by a submersible microbial fuel cell equipped with a membrane electrode assembly

    DEFF Research Database (Denmark)

    Min, Booki; Poulsen, Finn Willy; Thygesen, Anders;

    2012-01-01

    Membrane electrode assemblies (MEAs) were incorporated into the cathode chamber of a submersible microbial fuel cell (SMFC). A close contact of the electrodes could produce high power output from SMFC in which anode and cathode electrodes were connected in parallel. In polarization test, the maxi...

  14. American Recovery & Reinvestment Act: Fuel Cell Hybrid Power Packs and Hydrogen Refueling for Lift Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Block, Gus

    2011-07-31

    HEB Grocery Company, Inc. (H-E-B) is a privately-held supermarket chain with 310 stores throughout Texas and northern Mexico. H-E-B converted 14 of its lift reach trucks to fuel cell power using Nuvera Fuel Cells’ PowerEdge™ units to verify the value proposition and environmental benefits associated with the technology. Issues associated with the increasing power requirements of the distribution center operation, along with high ambient temperature in the summer and other operating conditions (such as air quality and floor surface condition), surfaced opportunities for improving Nuvera’s PowerEdge fuel cell system design in high-throughput forklift environments. The project included on-site generation of hydrogen from a steam methane reformer, called PowerTap™ manufactured by Nuvera. The hydrogen was generated, compressed and stored in equipment located outside H-E-B’s facility, and provided to the forklifts by hydrogen dispensers located in high forklift traffic areas. The PowerEdge fuel cell units logged over 25,300 operating hours over the course of the two-year project period. The PowerTap hydrogen generator produced more than 11,100 kg of hydrogen over the same period. Hydrogen availability at the pump was 99.9%. H-E-B management has determined that fuel cell forklifts help alleviate several issues in its distribution centers, including truck operator downtime associated with battery changing, truck and battery maintenance costs, and reduction of grid electricity usage. Data collected from this initial installation demonstrated a 10% productivity improvement, which enabled H-E-B to make economic decisions on expanding the fleet of PowerEdge and PowerTap units in the fleet, which it plans to undertake upon successful demonstration of the new PowerEdge reach truck product. H-E-B has also expressed interst in other uses of hydrogen produced on site in the future, such as for APUs used in tractor trailers and refrigerated transport trucks in its fleet.

  15. Assessment and comparison of 100-MW coal gasification phosphoric acid fuel cell power plants

    Science.gov (United States)

    Lu, Cheng-Yi

    1988-01-01

    One of the advantages of fuel cell (FC) power plants is fuel versatility. With changes only in the fuel processor, the power plant will be able to accept a variety of fuels. This study was performed to design process diagrams, evaluate performance, and to estimate cost of 100 MW coal gasifier (CG)/phosphoric acid fuel cell (PAFC) power plant systems utilizing coal, which is the largest single potential source of alternate hydrocarbon liquids and gases in the United States, as the fuel. Results of this study will identify the most promising integrated CG/PAFC design and its near-optimal operating conditions. The comparison is based on the performance and cost of electricity which is calculated under consistent financial assumptions.

  16. A Simple Power Management Scheme with Enhanced Stability for a Solar PV/Wind/Fuel Cell/Grid Fed Hybrid Power Supply Designed for Industrial Loads

    OpenAIRE

    Saravanan, S.; S. Thangavel

    2014-01-01

    This paper proposes a new power conditioner topology with an intelligent power management controller that integrates multiple renewable energy sources such as solar energy, wind energy, and fuel cell energy with battery and AC grid supply as backup to make the best use of their operating characteristics with better reliability than that could be obtained by single renewable energy source based power supply. The proposed embedded controller is programmed to perform MPPT for solar PV panel and ...

  17. Constant Power Control of a Proton Exchange Membrane Fuel Cell through Adaptive Fuzzy Sliding Mode

    Directory of Open Access Journals (Sweden)

    Minxiu Yan

    2013-05-01

    Full Text Available Fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. The paper describes a mathematical model of proton exchange membrane fuel cells by analyzing the working mechanism of the proton exchange membrane fuel cell. Furthermore, an adaptive fuzzy sliding mode controller is designed for the constant power output of PEMFC system. Simulation results prove that adaptive fuzzy sliding mode control has better control effect than conventional fuzzy sliding mode control.

  18. Design of a high voltage input ? output ratio dc-dc converter dedicated to small power fuel cell systems

    OpenAIRE

    O. Béthoux; Cathelin, J.

    2010-01-01

    Abstract Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andujar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells ar...

  19. Embryonic hybrid cells: a powerful tool for studying pluripotency and reprogramming of the differentiated cell chromosomes

    Directory of Open Access Journals (Sweden)

    SEROV OLEG

    2001-01-01

    Full Text Available The properties of embryonic hybrid cells obtained by fusion of embryonic stem (ES or teratocarcinoma (TC cells with differentiated cells are reviewed. Usually, ES-somatic or TC-somatic hybrids retain pluripotent capacity at high levels quite comparable or nearly identical with those of the pluripotent partner. When cultured in vitro, ES-somatic- and TC-somatic hybrid cell clones, as a rule, lose the chromosomes derived from the somatic partner; however, in some clones the autosomes from the ES cell partner were also eliminated, i.e. the parental chromosomes segregated bilaterally in the ES-somatic cell hybrids. This opens up ways for searching correlation between the pluripotent status of the hybrid cells and chromosome segregation patterns and therefore for identifying the particular chromosomes involved in the maintenance of pluripotency. Use of selective medium allows to isolate in vitro the clones of ES-somatic hybrid cells in which "the pluripotent" chromosome can be replaced by "the somatic" counterpart carrying the selectable gene. Unlike the TC-somatic cell hybrids, the ES-somatic hybrids with a near-diploid complement of chromosomes are able to contribute to various tissues of chimeric animals after injection into the blastocoel cavity. Analysis of the chimeric animals showed that the "somatic" chromosome undergoes reprogramming during development. The prospects for the identification of the chromosomes that are involved in the maintenance of pluripotency and its cis- and trans-regulation in the hybrid cell genome are discussed.

  20. Trade Study on Aggregation of Multiple 10-KW Solid Ozide Fuel Cell Power Modules

    Energy Technology Data Exchange (ETDEWEB)

    Ozpineci, B.

    2004-12-03

    According to the Solid State Energy Conversion Alliance (SECA) program guidelines, solid oxide fuel cells (SOFC) will be produced in the form of 3-10 kW modules for residential use. In addition to residential use, these modules can also be used in apartment buildings, hospitals, etc., where a higher power rating would be required. For example, a hospital might require a 250 kW power generating capacity. To provide this power using the SECA SOFC modules, 25 of the 10 kW modules would be required. These modules can be aggregated in different architectures to yield the necessary power. This report will show different approaches for aggregating numerous SOFC modules and will evaluate and compare each one with respect to cost, control complexity, ease of modularity, and fault tolerance.

  1. Maximizing power production in a stack of microbial fuel cells using multiunit optimization method.

    Science.gov (United States)

    Woodward, Lyne; Perrier, Michel; Srinivasan, Bala; Tartakovsky, Boris

    2009-01-01

    This study demonstrates real-time maximization of power production in a stack of two continuous flow microbial fuel cells (MFCs). To maximize power output, external resistances of two air-cathode membraneless MFCs were controlled by a multiunit optimization algorithm. Multiunit optimization is a recently proposed method that uses multiple similar units to optimize process performance. The experiment demonstrated fast convergence toward optimal external resistance and algorithm stability during external perturbations (e.g., temperature variations). Rate of the algorithm convergence was much faster than in traditional maximum power point tracking algorithms (MPPT), which are based on temporal perturbations. A power output of 81-84 mW/L(A) (A = anode volume) was achieved in each MFC. PMID:19496144

  2. Cost Study for Manufacturing of Solid Oxide Fuel Cell Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Weimar, Mark R.; Chick, Lawrence A.; Gotthold, David W.; Whyatt, Greg A.

    2013-09-30

    Solid oxide fuel cell (SOFC) power systems can be designed to produce electricity from fossil fuels at extremely high net efficiencies, approaching 70%. However, in order to penetrate commercial markets to an extent that significantly impacts world fuel consumption, their cost will need to be competitive with alternative generating systems, such as gas turbines. This report discusses a cost model developed at PNNL to estimate the manufacturing cost of SOFC power systems sized for ground-based distributed generation. The power system design was developed at PNNL in a study on the feasibility of using SOFC power systems on more electric aircraft to replace the main engine-mounted electrical generators [Whyatt and Chick, 2012]. We chose to study that design because the projected efficiency was high (70%) and the generating capacity was suitable for ground-based distributed generation (270 kW).

  3. A real time fuzzy logic power management strategy for a fuel cell vehicle

    International Nuclear Information System (INIS)

    Highlights: • We present a real time fuzzy logic power management strategy. • This strategy is applied to hybrid electric vehicle dynamic model. • Three configurations evaluated during a drive cycle. • The hydrogen consumption is analysed for the three configurations. - Abstract: This paper presents real time fuzzy logic controller (FLC) approach used to design a power management strategy for a hybrid electric vehicle and to protect the battery from overcharging during the repetitive braking energy accumulation. The fuel cell (FC) and battery (B)/supercapacitor (SC) are the primary and secondary power sources, respectively. This paper analyzes and evaluates the performance of the three configurations, FC/B, FC/SC and FC/B/SC during real time driving conditions and unknown driving cycle. The MATLAB/Simulink and SimPowerSystems software packages are used to model the electrical and mechanical elements of hybrid vehicles and implement a fuzzy logic strategy

  4. Enhancing VHTR passive safety and economy with thermal radiation based direct reactor auxiliary cooling system

    International Nuclear Information System (INIS)

    One of the most important requirements for Gen. IV Very High Temperature Reactor (VHTR) is passive safety. Currently all the gas cooled version of VHTR designs use Reactor Vessel Auxiliary Cooling System (RVACS) for passive decay heat removal. The RVACS can be characterized as a surface-based decay heat removal system. It is especially suitable for smaller power reactors since small systems have relatively larger surface area to volume ratio. However, RVACS limits the maximum achievable power level for modular VHTRs due to the mismatch between the reactor power (proportional to the core volume) and decay heat removal capability (proportional to the vessel surface area). Besides the safety considerations, VHTRs also need to be economical in order to compete with other reactor concepts and other types of energy sources. The limit of decay heat removal capability set by using RVACS has affected the economy of VHTRs. A potential alternative solution is to use a volume-based passive decay heat removal system, called Direct Reactor Auxiliary Cooling Systems (DRACS), to remove or mitigate the limitation on decay heat removal capability. DRACS composes of natural circulation loops with two sets of heat exchangers, one on the reactor side and another on the environmental side. For the reactor side, cooling pipes will be inserted into holes made in the outer or inner graphite reflector blocks. There will be gaps or annular regions formed between these cooling pipes and their corresponding surrounding graphite surfaces. Graphite has an excellent heat conduction property. By taking advantage of this feature, we can have a volume-based method to remove decay heat. The scalability can be achieved, if needed, by employing more rows of cooling pipes to accommodate higher decay heat rates. Since heat can easily conduct through the graphite regions among the holes made for the cooling pipes, those cooling pipes located further away from the active core region can still be very

  5. Power-Controlled CDMA Cell Sectorization with Multiuser Detection: A Comprehensive Analysis on Uplink and Downlink

    Directory of Open Access Journals (Sweden)

    Aylin Yener

    2007-12-01

    Full Text Available We consider the joint optimization problem of cell sectorization, transmit power control and multiuser detection for a CDMA cell. Given the number of sectors and user locations, the cell is appropriately sectorized such that the total transmit power, as well as the receiver filters, is optimized. We formulate the corresponding joint optimization problems for both the uplink and the downlink and observe that in general, the resulting optimum transmit and receive beamwidth values for the directional antennas at the base station are different. We present the optimum solution under a general setting with arbitrary signature sets, multipath channels, realistic directional antenna responses and identify its complexity. We propose a low-complexity sectorization algorithm that performs near optimum and compare its performance with that of optimum solution. The results suggest that by intelligently combining adaptive cell sectorization, power control, and linear multiuser detection, we are able to increase the user capacity of the cell. Numerical results also indicate robustness of optimum sectorization against Gaussian channel estimation error.

  6. Development of planar solid oxide fuel cells for power generation applications

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.Q. [AlliedSignal Aerospce Equipment Systems, Torrance, CA (United States)

    1996-04-01

    Planar solid oxide fuel cells (SOFCs) are presently being developed for a variety of electric power generation application. The planar design offers simple cell geometry, high power density, and multiple fabrication and gas manifolding options. Planar SOFC technology has received much attention recently, and significant progress has been made in this area. Recent effort at AlliedSignal has focused on the development of high-performance, lightweight planar SOFCs, having thin-electrolyte films, that can be operated efficiently at reduced temperatures (< 1000{degrees}C). The advantages of reduced-temperature operation include wider material choice (including use of metallic interconnects), expected longer cell life, reduced thermal stress, improved reliability, and reduced fuel cell cost. The key aspect in the development of thin-film SIFCs is to incorporate the thin electrolyte layer into the desired structure of cells in a manner that yields the required characteristics. AlliedSignal has developed a simple and cost-effective method based on tape calendering for the fabrication of thin-electrolyte SOFCs. Thin-electrolyte cells made by tape calendering have shown extraordinary performance, e.g., producing more than 500mW/cm{sup 2} at 700{degrees}C and 800mW/cm{sup 2} at 800{degrees}C with hydrogen as fuel and air is oxidant. thin-electrolyte single cells have been incorporated into a compliant metallic stack structure and operated at reduced and operated at reduced-temperature conditions.

  7. A High Power-Density Mediator-Free Microfluidic Biophotovoltaic Device for Cyanobacterial Cells

    CERN Document Server

    Bombelli, Paolo; Herling, Therese W; Howe, Christopher J; Knowles, Tuomas P J

    2014-01-01

    Biophotovoltaics has emerged as a promising technology for generating renewable energy since it relies on living organisms as inexpensive, self-repairing and readily available catalysts to produce electricity from an abundant resource - sunlight. The efficiency of biophotovoltaic cells, however, has remained significantly lower than that achievable through synthetic materials. Here, we devise a platform to harness the large power densities afforded by miniaturised geometries. To this effect, we have developed a soft-lithography approach for the fabrication of microfluidic biophotovoltaic devices that do not require membranes or mediators. Synechocystis sp. PCC 6803 cells were injected and allowed to settle on the anode, permitting the physical proximity between cells and electrode required for mediator-free operation. We demonstrate power densities of above 100 mW/m2 for a chlorophyll concentration of 100 {\\mu}M under white light, a high value for biophotovoltaic devices without extrinsic supply of additional...

  8. Thermal abuse performance of high-power 18650 Li-ion cells

    Science.gov (United States)

    Roth, E. P.; Doughty, D. H.

    High-power 18650 Li-ion cells have been developed for hybrid electric vehicle applications as part of the DOE Advanced Technology Development (ATD) program. The thermal abuse response of two advanced chemistries (Gen1 and Gen2) were measured and compared with commercial Sony 18650 cells. Gen1 cells consisted of an MCMB graphite based anode and a LiNi 0.85Co 0.15O 2 cathode material while the Gen2 cells consisted of a MAG10 anode graphite and a LiNi 0.80Co 0.15 Al 0.05O 2 cathode. Accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC) were used to measure the thermal response and properties of the cells and cell materials up to 400 °C. The MCMB graphite was found to result in increased thermal stability of the cells due to more effective solid electrolyte interface (SEI) formation. The Al stabilized cathodes were seen to have higher peak reaction temperatures that also gave improved cell thermal response. The effects of accelerated aging on cell properties were also determined. Aging resulted in improved cell thermal stability with the anodes showing a rapid reduction in exothermic reactions while the cathodes only showed reduced reactions after more extended aging.

  9. Controlling the occurrence of power overshoot by adapting microbial fuel cells to high anode potentials

    KAUST Repository

    Zhu, Xiuping

    2013-04-01

    Power density curves for microbial fuel cells (MFCs) often show power overshoot, resulting in inaccurate estimation of MFC performance at high current densities. The reasons for power overshoot are not well understood, but biofilm acclimation and development are known factors. In order to better explore the reasons for power overshoot, exoelectrogenic biofilms were developed at four different anode potentials (-0.46 V, -0.24 V, 0 V, and 0.50 V vs. Ag/AgCl), and then the properties of the biofilms were examined using polarization tests and cyclic voltammetry (CV). The maximum power density of the MFCs was 1200±100 mW/m2. Power overshoot was observed in MFCs incubated at -0.46 V, but not those acclimated atmore positive potentials, indicating that bacterial activitywas significantly influenced by the anode acclimation potential. CV results further indicated that power overshoot of MFCs incubated at the lowest anode potential was associatedwith a decreasing electroactivity of the anodic biofilm in the high potential region,which resulted from a lack of sufficient electron transfer components to shuttle electrons at rates needed for these more positive potentials. © 2012 Elsevier B.V.

  10. The ATLAS FTK Auxiliary Card: A Highly Functional VME Rear Transition Module for a Hardware Track Finding Processing Unit

    CERN Document Server

    Alison, J; The ATLAS collaboration; Bogdan, M; Bryant, P; Cheng, YY; Krizka, K; Shochet, M; Tompkins, L; Webster, J

    2014-01-01

    The ATLAS Fast TracKer is a hardware-based track finder for the ATLAS High Level Trigger. Pattern recognition and preliminary track fitting are performed by VME Processing Units consisting of an Associative Memory Board (AMB) containing custom associative memory chips for pattern recognition, and the Auxiliary Card (AUX), a powerful rear transition module which formats the data for the AMB and performs linearized fits on AMB track candidates. We report on the design and testing of the AUX, which utilizes six FPGAs to process up to 32 Gbps of hit data and fit one track candidate per nanosecond.

  11. Combined small bowel and reduced auxiliary liver transplantation: case report

    Institute of Scientific and Technical Information of China (English)

    Wei-Jie Zhang; Dun-Gui Liu; Qi-Fa Ye; Bo Sha; Fan-Jun Zhen; Hui Guo; Sui-Sheng Xia

    2002-01-01

    AIM: To present a case of combined small bowel andreduced auxiliary liver transplantation.METHODS: A 55-year-old patient with short bowelsyndrome and TPN-related liver dysfunction received smallbowel transplantation combined with a reduced auxiliaryliver graft. A liver was added to restore the patient′s liverfunction and to protect the intestinal allograft from rejection.His own liver was not removed.RESULTS: Without donor pretreatment and by conventionalimmunosuppresive therapy following transplantation, thepatient experienced had only one episode of mild intestinalrejection, which was easily reversed by treatment withMethylprednisolone. No liver rejection occurred.Unfortunately, the patient died of heart and lung failure30d after transplantation, despite successful graftreplacement. Histopathologic examination of specimens afterdeath demonstrated normal structure in both intestinal andliver grafts.CONCLUSION: The auxiliary liver graft might play a role inpreventing intestinal allograft rejection. However, theobservation period in this case is short. Further study isneeded to determine the risks, effect on the protecting thesmall-bowel from rejection, and feasibility of generalapplication of this procedure.

  12. Assembly auxiliary system for narrow cabins of spacecraft

    Science.gov (United States)

    Liu, Yi; Li, Shiqi; Wang, Junfeng

    2015-09-01

    Due to the narrow space and complex structure of spacecraft cabin, the existing asssembly systems can not well suit for the assembly process of cabin products. This paper aims to introduce an assembly auxiliary system for cabin products. A hierarchical-classification method is proposed to re-adjust the initial assembly relationship of cabin into a new hierarchical structure for efficient assembly planning. An improved ant colony algorithm based on three assembly principles is established for searching a optimizational assembly sequence of cabin parts. A mixed reality assembly environment is constructed with enhanced information to promote interaction efficiency of assembly training and guidance. Based on the machine vision technology, the inspection of left redundant objects and measurement of parts distance in inner cabin are efficiently performed. The proposed system has been applied to the assembly work of a spacecraft cabin with 107 parts, which includes cabin assembly planning, assembly training and assembly quality inspection. The application result indicates that the proposed system can be an effective assistant tool to cabin assembly works and provide an intuitive and real assembly experience for workers. This paper presents an assembly auxiliary system for spacecraft cabin products, which can provide technical support to the spacecraft cabin assembly industry.

  13. Use of Auxiliary Electrode to Prevent Alkalinization of Soil in Electrokinetic Remediation

    OpenAIRE

    Mori, Yuki; Wada, Shin-ichiro

    2004-01-01

    We devised an improved electrokinetic remendiatioin method in whoch an auxiliary electrode was placed at the cathode-side end of the soil to be treated. The electric potential difference between tne anode and the auxiliary electrode was fixed constant whole that between the cathode and the auxiloary electode was controlled to make the auxiliary electode function as a secondary anode. To test the performance of the method, we carried out a bench scale remediatioin experiment on cadmium-contam...

  14. Portable ammonia-borane-based H2 power-pack for unmanned aerial vehicles

    Science.gov (United States)

    Seo, Jung-Eun; Kim, Yujong; Kim, Yongmin; Kim, Kibeom; Lee, Jin Hee; Lee, Dae Hyung; Kim, Yeongcheon; Shin, Seock Jae; Kim, Dong-Min; Kim, Sung-Yug; Kim, Taegyu; Yoon, Chang Won; Nam, Suk Woo

    2014-05-01

    An advanced ammonia borane (AB)-based H2 power-pack is designed to continually drive an unmanned aerial vehicle (UAV) for 57 min using a 200-We polymer electrolyte membrane fuel cell (PEMFC). In a flight test with the UAV platform integrated with the developed power-pack, pure hydrogen with an average flow rate of 3.8 L(H2) min-1 is generated by autothermal H2-release from AB with tetraethylene glycol dimethylether (T4EGDE) as a promoter. During take-off, a hybridized power management system (PMS) consisting of the fuel cell and an auxiliary lithium-ion battery supplies 500 We at full power simultaneously, while the fuel cell alone provides 150-200 We and further recharges the auxiliary battery upon cruising. Gaseous byproducts identified by in situ Fourier transform infrared (FT-IR) spectroscopy during AB dehydrogenation are sequestrated using a mixed absorbent in an H2 purification system. In addition, a real-time monitoring system is employed to determine the remaining filter capacity of the purifier at a ground control system for rapidly responding unpredictable circumstances during flight. Separate experiments are conducted to screen potential materials and methods for enhancing filter capacity in the current H2 refining system. A prospective reactor concept for long-term fuel cell applications is proposed based on the results.

  15. Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes

    International Nuclear Information System (INIS)

    Highlights: ► We examine proton exchange membrane fuel cells on-board commercial airplanes. ► We model the added fuel cell system’s effect on overall airplane performance. ► It is feasible to implement an on-board fuel cell system with current technology. ► Systems that maximize waste heat recovery are the best performing. ► Current PEM and H2 storage technology results in an airplane performance penalty. -- Abstract: Deployed on a commercial airplane, proton exchange membrane (PEM) fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they could offer a performance advantage for the airplane when using today’s off-the-shelf technology. We also examine the effects of the fuel cell system on airplane performance with (1) different electrical loads, (2) different locations on the airplane, and (3) expected advances in fuel cell and hydrogen storage technologies. Through hardware analysis and thermodynamic simulation, we found that an additional fuel cell system on a commercial airplane is technically feasible using current technology. Although applied to a Boeing 787-type airplane, the method presented is applicable to other airframes as well. Recovery and on-board use of the heat and water that is generated by the fuel cell is an important method to increase the benefit of such a system. The best performance is achieved when the fuel cell is coupled to a load that utilizes the full output of the fuel cell for the entire flight. The effects of location are small and location may be better determined by other considerations such as safety and modularity. Although the PEM fuel cell generates power more efficiently than the gas turbine generators currently used, when considering the effect of the fuel cell system on the airplane’s overall performance we found that an overall

  16. Power electronics for local fuel cell/-battery plants; Leistungselektronik fuer dezentrale Brennstoffzellen/-Batterieanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Krykunov, Oleksandr

    2009-10-13

    With their high efficiency and modular structure, fuel cells are an attractive option for decentral power supply. An important component of decentral power supply systems is the power-electronic control element for supply of electric power from the fuel cell to the three-phase electricity grid. Control elements can be constructed of a unidirectional DC/DC converter with a current inverter connnected in series. The investigation focused on the development of the DC/DC converter with minimum constructional and control requirements and optimum adaption of the DC/DC converter to the characteristics of the fuel cell. (orig.) [German] Die Brennstoffzelle stellt mit ihrem hohen Wirkungsgrad und ihrem modularen Aufbau eine attraktive Option fuer die Verwendung in einem dezentralen Energieversorgungssystem dar. Eine wichtige Komponente des dezentralen Energieversorgungssystems sind die leistungselektronischen Stellglieder fuer die Einspeisung der elektrischen Energie aus der Brennstoffzelle in das dreiphasige Netz. Die leistungselektronischen Stellglieder koennen aus einem undirektionalen DC/DC-Wandler und einem nachgeschalteten Wechselrichter realisiert werden. Die Entwicklung des DC/DC-Wandlers mit einem moeglichst geringeren Bauelemente- und Steuerungsaufwand fuer diese leistungselektronischen Stellglieder und die Anpassung des DC/DC-Wandlers an die Eigenschaften der Brennstoffzelle war das Ziel dieser Arbeit. (orig.)

  17. The reasons for the high power density of fuel cells fabricated with directly deposited membranes

    Science.gov (United States)

    Vierrath, Severin; Breitwieser, Matthias; Klingele, Matthias; Britton, Benjamin; Holdcroft, Steven; Zengerle, Roland; Thiele, Simon

    2016-09-01

    In a previous study, we reported that polymer electrolyte fuel cells prepared by direct membrane deposition (DMD) produced power densities in excess of 4 W/cm2. In this study, the underlying origins that give rise to these high power densities are investigated and reported. The membranes of high power, DMD-fabricated fuel cells are relatively thin (12 μm) compared to typical benchmark, commercially available membranes. Electrochemical impedance spectroscopy, at high current densities (2.2 A/cm2) reveals that mass transport resistance was half that of reference, catalyst-coated-membranes (CCM). This is attributed to an improved oxygen supply in the cathode catalyst layer by way of a reduced propensity of flooding, and which is facilitated by an enhancement in the back diffusion of water from cathode to anode through the thin directly deposited membrane. DMD-fabricated membrane-electrode-assemblies possess 50% reduction in ionic resistance (15 mΩcm2) compared to conventional CCMs, with contributions of 9 mΩcm2 for the membrane resistance and 6 mΩcm2 for the contact resistance of the membrane and catalyst layer ionomer. The improved mass transport is responsible for 90% of the increase in power density of the DMD fuel cell, while the reduced ionic resistance accounts for a 10% of the improvement.

  18. Development of molten carbonate fuel cell technology at M-C Power Corporation

    Energy Technology Data Exchange (ETDEWEB)

    Dilger, D. [M-C Power Corp., Burr Ridge, IL (United States)

    1996-04-01

    M-C Power Corporation was founded in 1987 with the mission to further develop and subsequently commercialize molten carbonate fuel cells (MCFC). The technology chosen for commercialization was initially developed by the Institute of Gas technology (IGT). At the center of this MCFC technology is the Internally Manifolded Heat EXchange (IMHEX) separator plate design. The IMHEX technology design provides several functions within one component assembly. These functions include integrating the gas manifold structure into the fuel cell stack, separating the fuel gas stream from the oxidant gas stream, providing the required electrical contact between cells to achieve desired power output, and removing excess heat generated in the electrochemical process. Development of this MCFC technology from lab-scale sizes too a commercial area size of 1m{sup 2} has focused our efforts an demonstrating feasibility and evolutionary progress. The development effort will culminate in a proof-of-concept- 250kW power plant demonstration in 1996. The remainder of our commercialization program focuses upon lowering the costs associated with the MCFC power plant system in low production volumes.

  19. Simulation of the PEM fuel cell hybrid power train of an automated guided vehicle and comparison with experimental results

    NARCIS (Netherlands)

    Veenhuizen, Bram; Bosma, J.C.N.

    2009-01-01

    At HAN University research has been started into the development of a PEM fuel cell hybrid power train to be used in an automated guided vehicle. For this purpose a test facility is used with the possibility to test all important functional aspects of a PEM fuel cell hybrid power train. In this pape

  20. Optical Frequency Optimization of a High Intensity Laser Power Beaming System Utilizing VMJ Photovoltaic Cells

    Science.gov (United States)

    Raible, Daniel E.; Dinca, Dragos; Nayfeh, Taysir H.

    2012-01-01

    An effective form of wireless power transmission (WPT) has been developed to enable extended mission durations, increased coverage and added capabilities for both space and terrestrial applications that may benefit from optically delivered electrical energy. The high intensity laser power beaming (HILPB) system enables long range optical 'refueling" of electric platforms such as micro unmanned aerial vehicles (MUAV), airships, robotic exploration missions and spacecraft platforms. To further advance the HILPB technology, the focus of this investigation is to determine the optimal laser wavelength to be used with the HILPB receiver, which utilizes vertical multi-junction (VMJ) photovoltaic cells. Frequency optimization of the laser system is necessary in order to maximize the conversion efficiency at continuous high intensities, and thus increase the delivered power density of the HILPB system. Initial spectral characterizations of the device performed at the NASA Glenn Research Center (GRC) indicate the approximate range of peak optical-to-electrical conversion efficiencies, but these data sets represent transient conditions under lower levels of illumination. Extending these results to high levels of steady state illumination, with attention given to the compatibility of available commercial off-the-shelf semiconductor laser sources and atmospheric transmission constraints is the primary focus of this paper. Experimental hardware results utilizing high power continuous wave (CW) semiconductor lasers at four different operational frequencies near the indicated band gap of the photovoltaic VMJ cells are presented and discussed. In addition, the highest receiver power density achieved to date is demonstrated using a single photovoltaic VMJ cell, which provided an exceptionally high electrical output of 13.6 W/sq cm at an optical-to-electrical conversion efficiency of 24 percent. These results are very promising and scalable, as a potential 1.0 sq m HILPB receiver of

  1. Altering Anode Thickness To Improve Power Production in Microbial Fuel Cells with Different Electrode Distances

    KAUST Repository

    Ahn, Yongtae

    2013-01-17

    A better understanding of how anode and separator physical properties affect power production is needed to improve energy and power production by microbial fuel cells (MFCs). Oxygen crossover from the cathode can limit power production by bacteria on the anode when using closely spaced electrodes [separator electrode assembly (SEA)]. Thick graphite fiber brush anodes, as opposed to thin carbon cloth, and separators have previously been examined as methods to reduce the impact of oxygen crossover on power generation. We examined here whether the thickness of the anode could be an important factor in reducing the effect of oxygen crossover on power production, because bacteria deep in the electrode could better maintain anaerobic conditions. Carbon felt anodes with three different thicknesses were examined to see the effects of thicker anodes in two configurations: widely spaced electrodes and SEA. Power increased with anode thickness, with maximum power densities (604 mW/m 2, 0.32 cm; 764 mW/m2, 0.64 cm; and 1048 mW/m2, 1.27 cm), when widely spaced electrodes (4 cm) were used, where oxygen crossover does not affect power generation. Performance improved slightly using thicker anodes in the SEA configuration, but power was lower (maximum of 689 mW/m2) than with widely spaced electrodes, despite a reduction in ohmic resistance to 10 Ω (SEA) from 51-62 Ω (widely spaced electrodes). These results show that thicker anodes can work better than thinner anodes but only when the anodes are not adversely affected by proximity to the cathode. This suggests that reducing oxygen crossover and improving SEA MFC performance will require better separators. © 2012 American Chemical Society.

  2. Single-tube condensation experiment in Passive Auxiliary Feedwater System of APR1400+

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chang Wook; No, Hee Cheon; Yun, Bong Yo; Jeon, Byong Guk [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2012-05-15

    Conventional Korean nuclear power plants, Advanced Power Reactors (APR), are characterized by an active cooling system. However, Active cooling system may not prevent significant damage without any AC power source available for its operation as vividly illustrated through the recent Fukushima incident. In the APR1400+ to be designed, an independent passive cooling system was added in order to overcome the aforementioned shortcomings. In the Passive Auxiliary Feedwater System (PAFS), gravity force and density difference between steam and water are used. The system comprises of 240 condensation tubes to efficiently remove decay heat. Before applying the PAFS to APR1400+, the system's safety and heat removal performance must be verified. The present study experimentally evaluates the heat removal performance of a single tube in the PAFS. The objectives of SCOP (Single-tube Condensation experiment facility of PAFS) are the evaluation of the heat removal performance in the tube of the PAFS and database construction under various tube designs and test conditions. Reaching these objectives, we developed advanced measurement techniques for the amount of moisture, heat flux, and water film thickness.

  3. Operation and Control of a Direct-Driven PMSG-Based Wind Turbine System with an Auxiliary Parallel Grid-Side Converter

    Directory of Open Access Journals (Sweden)

    Jiawei Chu

    2013-07-01

    Full Text Available In this paper, based on the similarity, in structure and principle, between a grid-connected converter for a direct-driven permanent magnet synchronous generator (D-PMSG and an active power filter (APF, a new D-PMSG-based wind turbine (WT system configuration that includes not only an auxiliary converter in parallel with the grid-side converter, but also a coordinated control strategy, is proposed to enhance the low voltage ride through (LVRT capability and improve power quality. During normal operation, the main grid-side converter maintains the DC-link voltage constant, whereas the auxiliary grid-side converter functions as an APF with harmonic suppression and reactive power compensation to improve the power quality. During grid faults, a hierarchical coordinated control scheme for the generator-side converter, main grid-side converter and auxiliary grid-side converter, depending on the grid voltage sags, is presented to enhance the LVRT capability of the direct-driven PMSG WT. The feasibility and the effectiveness of the proposed system’s topology and hierarchical coordinated control strategy were verified using MATLAB/Simulink simulations.

  4. High efficiency direct fuel cell hybrid power cycle for near term application

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, G.; Maru, H.C. [Energy Research Corp., Danbury, CT (United States); Sanderson, R.A. [Fuel Cell Systems Consultant, Wethersfield, CT (United States)

    1996-12-31

    Direct carbonate fuel cells being developed by Energy Research Corporation can generate power at an efficiency approaching 60% LHV. This unique fuel cell technology can consume natural gas and other hydrocarbon based fuels directly without requiring an external reformer, thus providing a simpler and inherently efficient power generation system. A 2 MW power plant demonstration of this technology has been initiated at an installation in the city of Santa Clara in California. A 2.85 MW commercial configuration shown in Figure 1 is presently being developed. The complete plant includes the carbonate fuel cell modules, an inverter, transformer and switchgear, a heat recovery unit and supporting instrument air and water treatment systems. The emission levels for this 2.85 MW plant are projected to be orders of magnitude below existing or proposed standards. The 30 year levelized cost of electricity, without inflation, is projected to be approximately 5{cents}/kW-h assuming capital cost for the carbonate fuel cell system of $1000/kW.

  5. Vancouver Olympic rings powered by fuel cell and IESO records winning goal

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-04-15

    The fuel cell system that provided power to the 30-foot tall floating Olympic Rings in Vancouver's harbour during the 2010 Winter Olympic Games was developed and manufactured by IdaTech in Bend, Oregon. The power source altered between a biodiesel generator and IdaTech's ElectraGen H2 zero emission hydrogen fuel cell system. The technology was chosen as a source of reliable, clean energy for applications in remote locations. The ElectraGen H2 is a hydrogen fueled proton exchange membrane (PEM) fuel cell system that emits only water vapour and heat, without any greenhouse gases. These solid state electric generators combine the best features of generators and batteries. IdaTech has sold over 400 of these fuel cell units to India and Asia to provide backup power to telecommunications networks. The 2010 Winter Olympic Games also provided an opportunity for Ontario's Independent Electricity System Operator (IESO) to track electricity consumption as people turned on their televisions to watch the Men's hockey final between Canada and the United States. An increase in electricity use of 300 MW occurred just before the game started and a similar increase occurred during the intermissions as viewers prepared snacks. Electricity consumption dropped considerably after overtime began and then climbed in the final stages of the game after the winning goal was scored. 2 figs.

  6. Low power laser effects in cancer cells and fibroblasts submitted the ionizing radiation

    International Nuclear Information System (INIS)

    Cancer is considered a public health problem worldwide. According to Brazil's the National Cancer Institute (INCA), 576,000 new cases of cancer were estimated for 2015 in Brazil, representing the second leading cause of death. Radiotherapy may be a treatment to several of types of cancer, frequently using ionizing radiation to eradicate or prevent the proliferation of tumor cells. This treatment, however, can lead to death of non-tumor cells around in irradiated tissue. Given this, adjuvant therapies that can minimize the side effects of ionizing radiation are of extremely importance. In this context, low power laser (LPL) may be an alternative to modulate the response of healthy cells to ionizing radiation. In this study, cells of human gingival fibroblasts (FMM1) and breast cancer (MDAMB- 231) were exposed to gamma radiation at doses of 2.5 and 10 Gy. After twenty-four hours, cell were irradiated with LPL ( λ= 660 nm, 40 mW and total area of 0.04 cm²) with energy densities of 30, 60, 90, 120 and 150 J/cm². The cell viability was measured during four days, using the trypan blue technique. The influence of LPL on the cell cycle and on expression of the nuclear antigen of cellular proliferation (PCNA) was evaluated by flow cytometry. The expression of β-Galactosidase was the chosen method to assess cell senescence. Considering our adopted parameters, and focusing on the non-tumor cells, we have observed an increase in: 1) cell viability; 2) cell population in phases S and G2/M cell cycle; 3) PCNA expression with decrease in senescence. No alterations were observed in the cell viability, with greater population in phases S and G2/M cell cycle, while the number of senescent cells and the expression of PCNA were decreased. Therefore, we have concluded that the LPL promoted effects on both cell lineages, with increased cell viability on FMM1 cells, whether cancer cells maintained a decreased proliferation. (author)

  7. Two-loop controller for maximizing performance of a grid-connected photovoltaic - fuel cell hybrid power plant

    Science.gov (United States)

    Ro, Kyoungsoo

    The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime COsb2 emissions, and then compared with that of the conventional fossil-fuel power generating forms.

  8. Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal

    KAUST Repository

    Kim, Younggy

    2011-01-01

    Voltages produced by microbial fuel cells (MFCs) cannot be sustainably increased by linking them in series due to voltage reversal, which substantially reduces stack voltages. It was shown here that MFC voltages can be increased with continuous power production using an electronic circuit containing two sets of multiple capacitors that were alternately charged and discharged (every one second). Capacitors were charged in parallel by the MFCs, but linked in series while discharging to the circuit load (resistor). The parallel charging of the capacitors avoided voltage reversal, while discharging the capacitors in series produced up to 2.5 V with four capacitors. There were negligible energy losses in the circuit compared to 20-40% losses typically obtained with MFCs using DC-DC converters to increase voltage. Coulombic efficiencies were 67% when power was generated via four capacitors, compared to only 38% when individual MFCs were operated with a fixed resistance of 250 Ω. The maximum power produced using the capacitors was not adversely affected by variable performance of the MFCs, showing that power generation can be maintained even if individual MFCs perform differently. Longer capacitor charging and discharging cycles of up to 4 min maintained the average power but increased peak power by up to 2.6 times. These results show that capacitors can be used to easily obtain higher voltages from MFCs, allowing for more useful capture of energy from arrays of MFCs. © 2011 The Royal Society of Chemistry.

  9. Increasing power generation for scaling up single-chamber air cathode microbial fuel cells

    KAUST Repository

    Cheng, Shaoan

    2011-03-01

    Scaling up microbial fuel cells (MFCs) requires a better understanding the importance of the different factors such as electrode surface area and reactor geometry relative to solution conditions such as conductivity and substrate concentration. It is shown here that the substrate concentration has significant effect on anode but not cathode performance, while the solution conductivity has a significant effect on the cathode but not the anode. The cathode surface area is always important for increasing power. Doubling the cathode size can increase power by 62% with domestic wastewater, but doubling the anode size increases power by 12%. Volumetric power density was shown to be a linear function of cathode specific surface area (ratio of cathode surface area to reactor volume), but the impact of cathode size on power generation depended on the substrate strength (COD) and conductivity. These results demonstrate the cathode specific surface area is the most critical factor for scaling-up MFCs to obtain high power densities. © 2010 Elsevier Ltd.

  10. Analysis of polarization methods for elimination of power overshoot in microbial fuel cells

    KAUST Repository

    Watson, Valerie J.

    2011-01-01

    Polarization curves from microbial fuel cells (MFCs) often show an unexpectedly large drop in voltage with increased current densities, leading to a phenomenon in the power density curve referred to as "power overshoot". Linear sweep voltammetry (LSV, 1 mV s- 1) and variable external resistances (at fixed intervals of 20 min) over a single fed-batch cycle in an MFC both resulted in power overshoot in power density curves due to anode potentials. Increasing the anode enrichment time from 30 days to 100 days did not eliminate overshoot, suggesting that insufficient enrichment of the anode biofilm was not the primary cause. Running the reactor at a fixed resistance for a full fed-batch cycle (~ 1 to 2 days), however, completely eliminated the overshoot in the power density curve. These results show that long times at a fixed resistance are needed to stabilize current generation by bacteria in MFCs, and that even relatively slow LSV scan rates and long times between switching circuit loads during a fed-batch cycle may produce inaccurate polarization and power density results for these biological systems. © 2010 Elsevier B.V. All rights reserved.

  11. Estimates of power requirements for a manned Mars rover powered by a nuclear reactor

    Science.gov (United States)

    Morley, Nicholas J.; El-Genk, Mohamed S.; Cataldo, Robert; Bloomfield, Harvey

    1991-01-01

    This paper assesses the power requirement for a Manned Mars Rover vehicle. Auxiliary power needs are fulfilled using a hybrid solar photovoltaic/regenerative fuel cell system, while the primary power needs are met using an SP-100 type reactor. The primary electric power needs, which include 30-kWe net user power, depend on the reactor thermal power and the efficiency of the power conversion system. Results show that an SP-100 type reactor coupled to a Free Piston Stirling Engine (FPSE) yields the lowest total vehicle mass and lowest specific mass for the power system. The second lowest mass was for a SP-100 reactor coupled to a Closed Brayton Cycle (CBC) using He/Xe as the working fluid. The specific mass of the nuclear reactor power systrem, including a man-rated radiation shield, ranged from 150-kg/kWe to 190-kg/kWe and the total mass of the Rover vehicle varied depend upon the cruising speed.

  12. Evaluation of Effect of N{sub 2} Gas on the Cooling Capability of Passive Auxiliary Feedwater System (PAFS) in APR+

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yun Je; Kang, Kyong Ho; Yun, Byong Jo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    In Korea, Advanced Power Reactor Plus (APR+) has being developed by adding passive safety features to Advanced Power Reactor 1400MWe (APR1400). Passive Auxiliary Feedwater System (PAFS) is one of passive system adopted in the APR+ to replace the conventional active auxiliary feedwater system. Because PAFS removes decay heat from the reactor core, it is required to verify the performance of PAFS in postulated accidents cases. In addition, an effect of noncondensable gas on the heat removal capability of PAFS should be evaluated since the non-condensable gas may deteriorate a condensation heat transfer through the condensation heat exchanger in PAFS. In this study, the effect of N{sub 2} gas was evaluated using MARS

  13. Low-power laser irradiation did not stimulate breast cancer cells following ionizing radiation

    Science.gov (United States)

    Silva, C. R.; Camargo, C. F. M.; Cabral, F. V.; Ribeiro, M. S.

    2016-03-01

    Cancer has become a public health problem worldwide. Radiotherapy may be a treatment to a number of types of cancer, frequently using gamma-radiation with sources such as 137Cs and 60Co, with varying doses, dose rates, and exposure times to obtain a better as a stimulant for cell proliferation and tissue healing process. However, its effects on cancer cells are not yet well elucidated. The purpose of this work was to evaluate the effects of the LPL on breast cancer cultures after ionizing radiation. The breast cancer-MDA-MB-231 cells were gamma irradiated by a 60Co source, with dose of 2.5 Gy. After 24h, cells were submitted to LPL irradiation using a red laser emitting at λ= 660 nm, with output power of 40 mW and exposure time of 30 s and 60 s. The plates were uniformly irradiated, with energy of 1.2 J and 2.4 J, respectively. Cell viability was analyzed using the exclusion method with trypan blue. Our results show that breast cancer cells submitted to LPL after ionizing radiation remained 95 % viable. No statistically significant differences were observed between laser and control untreated cells, (P > 0.05). These findings suggest that LPL did not influenced cancer cells viability.

  14. Fuel Cell/Battery Powered Bus System. Final Report for period August 1987 - December 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Wimmer, R.

    1999-01-01

    Today, fuel cell systems are getting much attention from the automotive industry as a future replacement for the internal combustion engine (ICE). Every US automobile manufacturer and most foreign firms have major programs underway to develop fuel cell engines for transportation. The objective of this program was to investigate the feasibility of using fuel cells as an alternative to the ICE. Three such vehicles (30-foot buses) were introduced beginning in 1994. Extensive development and operational testing of fuel cell systems as a vehicle power source has been accomplished under this program. The development activity investigated total systems configuration and effectiveness for vehicle operations. Operational testing included vehicle performance testing, road operations, and extensive dynamometer emissions testing.

  15. Market survey of fuel cells in Mexico: Niche for low power portable systems

    Science.gov (United States)

    Ramírez-Salgado, Joel; Domínguez-Aguilar, Marco A.

    This work provides an overview of the potential market in Mexico for portable electronic devices to be potentially powered by direct methanol fuel cells. An extrapolation method based on data published in Mexico and abroad served to complete this market survey. A review of electronics consumption set the basis for the future forecast and technology assimilation. The potential market for fuel cells for mobile phones in Mexico will be around 5.5 billion USD by 2013, considering a cost of 41 USD per cell in a market of 135 million mobile phones. Likewise, the market for notebook computers, PDAs and other electronic devices will likely grow in the future, with a combined consumption of fuel cell technology equivalent to 1.6 billion USD by 2014.

  16. Thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell in combined heat and power applications

    Science.gov (United States)

    Abraham, F.; Dincer, I.

    2015-12-01

    This paper presents a comprehensive steady state modelling and thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell integrated with Gas Turbine power cycle (DU-SOFC/GT). The use of urea as direct fuel mitigates public health and safety risks associated with the use of hydrogen and ammonia. The integration scheme in this study covers both oxygen ion-conducting solid oxide fuel cells (SOFC-O) and hydrogen proton-conducting solid oxide fuel cells (SOFC-H). Parametric case studies are carried out to investigate the effects of design and operating parameters on the overall performance of the system. The results reveal that the fuel cell exhibited the highest level of exergy destruction among other system components. Furthermore, the SOFC-O based system offers better overall performance than that with the SOFC-H option mainly due to the detrimental reverse water-gas shift reaction at the SOFC anode as well as the unique configuration of the system.

  17. Stability of electric characteristics of solar cells for continuous power supply

    Directory of Open Access Journals (Sweden)

    Stojanović Nebojša M.

    2015-01-01

    Full Text Available This paper investigates the output characteristics of photovoltaic solar cells working in hostile working conditions. Examined cells, produced by different innovative procedures, are available in the market. The goal was to investigate stability of electric characteristics of solar cells, which are used today in photovoltaic solar modules for charging rechargeable batteries which, coupled with batteries, supply various electronic systems such as radio repeaters on mountains tops, airplanes, mobile communication stations and other remote facilities. Charging of rechargeable batteries requires up to 25 % higher voltage compared to nominal output voltage of the battery. This paper presents results of research of solar cells, which also apply to cases in which continuous power supply is required. [Projekat Ministarstva nauke Republike Srbije, br. III 171007

  18. High power n-type metal-wrap-through cells and modules using industrial processes

    Energy Technology Data Exchange (ETDEWEB)

    Guillevin, N.; Heurtault, B.J.B.; Geerligs, L.J.; Van Aken, B.B.; Bennett, I.J.; Jansen, M.J.; Weeber, A.W.; Bultman, J.H. [ECN Solar Energy, P.O. Box 1, NL-1755 ZG Petten (Netherlands); Jianming, Wang; Ziqian, Wang; Jinye, Zhai; Zhiliang, Wan; Shuquan, Tian; Wenchao, Zhao; Zhiyan, Hu; Gaofei, Li; Bo, Yu; Jingfeng, Xiong [Yingli Green Energy Holding Co.,Ltd. 3399 North Chaoyang Avenue, Baoding (China)

    2013-10-15

    This paper reviews our recent progress in the development of metal wrap through (MWT) cells and modules, produced from n-type Czochralski silicon wafers. The use of n-type silicon as base material allows for high efficiencies: for front emitter-contacted industrial cells, efficiencies above 20% have been reported. N-type MWT (nMWT) cells produced by industrial process technologies allow even higher efficiency due to reduced front metal coverage. Based on the same industrial technology, the efficiency of the bifacial n-MWT cells exceeds the efficiency of the n-type front-and-rear contact and bifacial 'Pasha' technology (n-Pasha) by 0.1-0.2% absolute, with a maximum nMWT efficiency of 20.1% so far. Additionally, full back-contacting of the MWT cells in a module results in reduced cell to module (CTM) fill factor losses. In a direct 60-cell module performance comparison, the n-MWT module, based on integrated backfoil, produced 3% higher power output than the comparable tabbed front emitter-contacted n-Pasha module. Thanks to reduced resistive losses in copper circuitry on the backfoil compared to traditional tabs, the CTM FF loss of the MWT module was reduced by about 2.2%abs. compared to the tabbed front emitter contact module. A full-size module made using MWT cells of 19.6% average efficiency resulted in a power output close to 280W. Latest results of the development of the n-MWT technology at cell and module level are discussed in this paper, including a recent direct comparison run between n-MWT and n-Pasha cells and results of n-MWT cells from 140{mu}m thin mono-crystalline wafers, with only very slight loss (1% of Isc) for the thin cells. Also reverse characteristics and effects of reverse bias for extended time at cell and module level are reported, where we find a higher tolerance of MWT modules than tabbed front contact modules for hotspots.

  19. Improved Power Conversion Efficiency of InP Solar Cells Using Organic Window Layers

    Energy Technology Data Exchange (ETDEWEB)

    Li, N; Lee, K.; Renshaw, C. K.; Xiao, X.; Forrest, Stephen R.

    2011-01-01

    We employ the organic semiconductor 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) as a nanometer thick window layer for p-InP/indium tin oxide (ITO) Schottky barrierdiodesolar cells. The power conversion efficiency is enhanced compared to ITO/InP cells lacking the PTCDA window layer, primarily due to neutralizing InP surface state charges via hole injection from the PTCDA. This leads to an increased ITO/p-InP Schottky barrier height, and hence to an increased open circuit voltage. The power conversion efficiency of the cells increases from 13.2±0.5% for the ITO/InP cell to 15.4±0.4% for the ITO/4 nm PTCDA/p-InP cell under 1 sun, AM1.5G simulated solar illumination. The PTCDA window layer is also shown to contribute to the photocurrent by light absorption followed by exciton dissociation at the organic/inorganic semiconductor interface.

  20. Develop and test fuel cell powered on-site integrated total energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, A.; Werth, J.

    1988-12-01

    This report describes the design, fabrication and testing of a 25kW phosphoric acid fuel cell system aimed at stationary applications, and the technology development underlying that system. The 25kW fuel cell ran at rated power in both the open and closed loop mode in the summer of 1988. Problems encountered and solved include acid replenishment leakage, gas cross-leakage and edge-leakage in bipolar plates, corrosion of metallic cooling plates and current collectors, cooling groove depth variations, coolant connection leaks, etc. 84 figs., 7 tabs.