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Loadability of power systems with steady-state and dynamic security constraints
06 Electrical power supply and utilization (scientific, technical)
03/01198 Genetic algorithms applied to turbine extraction optimization of a pressurized-water reactor Sacco, W. F et al. Applied Energy, 2002, 73. (3S4), 217-222. In this work, the use of a genetic algorithm (GA) is proposed for the determination of the optimal fraction of mass flow rate to be extracted from each stage of the turbines of a typical pressurized-water reactor (PWR) secondary side, in order to increase cycle efficiency. Here, some preliminary results obtained in a case study were shown in which the PEPSE” system was used as simulation tool.
Loadability of power systems with steady-state and dynamic security constraints
03/01199
Gan. D. CI ul. International Journal of Electricul Power & Energy S~.s~enrs. 2003, 25. (2). 91-96. Estimating loadability of a generation and transmission system is of practical importance in power system operations and planning. This paper presents a new formulation for the problem using mathematical programming theory. Both steady-state and dynamic security are taken into account in the proposed formulation. The difference between the proposed formulation and existing ones is that dynamic security is handled by an integration method. Using the new formulation, an iterative solution procedure is developed to solve the corresponding mathematical programming problem numerically. The method normally yields a slightly conservative estimate on the loadability of a generation/transmission system. Simulation results of a test power system are provided. 03/01200 Mechanical strength of porous nickel plates containing lithium and their performance as the cathode for MCFC
Kim, S. er cl/. Journal ofPower Sources, 2002, 110, (I), 80-85. To improve the mechanical properties of MCFC cathode materials, pre-lithiated porous nickel plates containing l-5 mol% of lithium were fabricated by the tape casting method, and the microstructures, mechanical properties, and performance was examined. The microstructure and pore distribution was not changed until the lithum content reached 3 mol%. The sample containing 5 mol% of lithium had patch structure on the skeleton and a smaller volume of primary pores. XRD analysis showed that lithium-containing porous nickel plates can easily form solid solutions without any undesirable byproducts after the oxidation. Both the bending strength and Young’s modulus of the porous plates increased with the increase of lithium content. The average bending strengths of the samples containing 1, 3, and 5 mol% of lithium were 1.29, 1.33, and 1.49 kgf/mm’ which were 2.9, 3.0, and 3.4 times higher than that of pure porous nickel plate. The Young’s modulus increased up to 1.35 kgf/mm in the case of the 5 mol% lithium containing sample that is 5.4 times higher than that of pure porous nickel plate. The OCV of single cells using pre-lithiated cathodes were between 1.065 and 1.067 V, and comparable cell performance was obtained for 500 h of single cell operation.
Metallceria water-gas shift catalysts for automotive polymer electrolyte fuel cell systems
03/01201
et crl. Preprints Di~~i.siwrof’Furl Chemistry,
Myers, D.
of Symposia
American 2002, 47, (2). 671-672.
Chemical
Society.
In order to produce a Ha rich fuel gas for polymer electrolyte membrane fuel cells for mobile application from gasoline or methanol, these fuels had to be reformed and the CO had to be eliminated by the water-gas shift reaction. Catalyst supports were prepared from ceria and ceria with small amounts of Gd, Sm, Zr, Y, and Pr, and the sp. surface of these materials was detected before loading with 10.14-1.0% Pt and activation. The prepared catalysts were tested on their water-gas shift activity with two simulated reformate feeds of low (1.02%) and high (10%) dry CO content. The water-gas shift activity of all doped ceria catalyst supports was higher than that of pure ceria, and the support with the composition Ceo.sZr~.L72Pr0.DZs01.99 was the highest due to its high sp. surface. The water-gas shift reaction rate was independent of the CO concentration from 1.0-10 mol% CO, while at lower CO concentrations the 1% Pt doped catalyst activity was comparable to the commercial Cu/ZnO catalysts.
Method and system for generation of electric power using sludge digestion gas
03/01202
Su, Q L’Iul. Jpn. Kokai Tokkyo Koho JP 2002 275,482 (Cl. ClOL3/00), 25 Sep 2002. Appl. 2001/77,301. (In Japanese) Digestion gas, obtained by methanation of biomass and organic waste, is purified by removal of CO* and preferably HaS by contacting with an alkaline adsorbent solution and then used for power generation. The alkaline adsorbent solution is regenerated, by using waste gas from power generation, and recirculated. Power generation may be carried out using fuel cells, gas turbines, or gas engines. 03/01203
supply
Holladay,
228
Microfuel processor for use in a miniature power J. D. (‘I rrl. Journul of Power Sources, 2002, 108, (l-2)
Fuel and Energy Abstracts
July 2003
21-27.
A microscale fuel reformer for use with a miniature fuel cell has been built and operated at efficiencies that make them attractive for use as a miniature power supply for microelectronics. The fuel reformer and the results of initial tests are discussed. The fuel processor assembly consists of two vapourizeripreheaters, a heat exchanger, a combustor. and a steam reformer. Methanol was identified as a good candidate for use in the microscale reformer. A proprietary catalyst was developed to reform methanol. The catalyst was able to process a methanol water mixture (1:l by weight) into a hydrogen-rich stream composed of 7374 ~01% H2, 25-26 ~01% COz, and 0.6-1.2 ~01% CO on H dry basis. Almost 3 mols of hydrogen per mol of methanol reacted, which approached the theoretical maximum. An integrated fuel processor that used proprietary catalyst in the reformer and catalytic combustion to provide the heat was designed and built. The reformer and combustor were each less than 5 mm in volume. When 100 mW, of hydrogen was produced, a thermal efficiency of 9%, or an estimated 4.5% net efficiency (including a hypothetical fuel cell), was achieved.
03/01204 Modelling multiple FACTS devices into multimachine power systems and applications Wang,
H. F. hternationul
Systems,
Journal 2003. 25, (3), 227-237.
of’ Electrircrl
Powtv
& Ener,yv
This paper presents a systematic approach to derive the dynamic model of a multi-machine power system installed with multiple FACTS devices, including SVCs, TCSCs, TCPSs, STATCOMs and UPFCs. The derivation of the model is demonstrated comprehensively for a general n-machine power system. Based on the approach to model the multimachine power system with multiple FACTS devices installed. two study cases of applications are presented in the paper. They are: (1) the multi-agent co-ordination of the secondary voltage control of SVC and STATCOM and (2) the investigation into the dynamic interactions between STATCOM and UPFC control. Study results are demonstrated by example power systems.
03lO1205 Procedure for the recovery of excess water from reforming gases in fuel cells B. et al. Ger. Offen. DE IO. I 12,604 (Cl. CO1 83150). I9 Sep Uckermann 2002, Appl.’ 10.112.604. (In German) This procedure recovers excess water from a reforming gas manufactured in a reformer by condensation of the vapour excess, whereby an optimum of electric energy is produced by the fuel cell. The condensate is purified by using activated carbon filtration or ion exchange, recirculated, and then the vapour, which is produced by the hightemperature heat exchange (preferably at 100-100~) between the condensate and the reforming gas is fed back to the reformer. Furthermore the thermal energy excess can be used for room heating.
03/01208 Chaurasia,
Regenerative fuel cell with chemical reactions P. B. L. et crl. Ener,q
Conwr.vion and Management.
2003. 44.
(4), 611-628.
The function of fuel cells largely depends upon catalytic electrodes, which accomplish a chemical reaction to convert fuel into electric energy. For this purpose, a study has been conducted on different catalysts prepared from various precursors and tested in the fuel cells for power generation under identical conditions. A new precursor has been identified to prepare the catalysts, giving encouraging results. The activity of composite catalysts (ruthenium and platinum) was found more pronounced, and it was observed that a fuel cell with catalytic electrodes having composite catalysts (Ru 2.5 +Pt 2.5 wt%) at the anode and (Ru 5.0 + Pt 2.5 wt%) at the cathode has yielded the best performance in the present fuel cells. The short circuit current and open circuit voltage were found to be 49.63 mA and 91.05 my, respectively, from the fuel cell having electrodes of surface area 4 cm-. The flow rate of hydrogen during the performance study was kept at 100 ml/min (anode) and a diluted mixture of acetone and 2-propanol at 1 ml/min (cathode). The application of such fuel cells in solar energy utilization has a bright future for generation of power through a solar thermal cell (a new concept) and is entirely different from the photovoltaic system, which is a costly affair and has limited efficiency. 03/01207
Start-up analysis for automotive PEM fuel cell
systems De Francesco, M. and Arato, E. Jourwl q/ Power Sourcvs, 2002, IOX, (l-2), 41-52. The development of fuel cell cars can play an important role in resolving transport problems, due to the high environmental compatibility and high efficiency of this kind of vehicle. Among the different types of fuel cells, proton-exchange membrane fuel cells (PEMFCs) are considered the best solution for automotive applications at the moment. In this work, constructive criteria are discussed with the aim of obtaining a power generation module adaptable to a wide range of cars. A particular problem in accomplishing the overall project is represented by the definition of the compressor system for air feeding. In this work, the design approach to the problem will be delineated: some options are reviewed and the best solution is analysed. The
03/01198 Genetic algorithms applied to turbine extraction optimization of a pressurized-water reactor Sacco, W. F et al. Applied Energy, 2002, 73. (3S4), 217-222. In this work, the use of a genetic algorithm (GA) is proposed for the determination of the optimal fraction of mass flow rate to be extracted from each stage of the turbines of a typical pressurized-water reactor (PWR) secondary side, in order to increase cycle efficiency. Here, some preliminary results obtained in a case study were shown in which the PEPSE” system was used as simulation tool.
Loadability of power systems with steady-state and dynamic security constraints
03/01199
Gan. D. CI ul. International Journal of Electricul Power & Energy S~.s~enrs. 2003, 25. (2). 91-96. Estimating loadability of a generation and transmission system is of practical importance in power system operations and planning. This paper presents a new formulation for the problem using mathematical programming theory. Both steady-state and dynamic security are taken into account in the proposed formulation. The difference between the proposed formulation and existing ones is that dynamic security is handled by an integration method. Using the new formulation, an iterative solution procedure is developed to solve the corresponding mathematical programming problem numerically. The method normally yields a slightly conservative estimate on the loadability of a generation/transmission system. Simulation results of a test power system are provided. 03/01200 Mechanical strength of porous nickel plates containing lithium and their performance as the cathode for MCFC
Kim, S. er cl/. Journal ofPower Sources, 2002, 110, (I), 80-85. To improve the mechanical properties of MCFC cathode materials, pre-lithiated porous nickel plates containing l-5 mol% of lithium were fabricated by the tape casting method, and the microstructures, mechanical properties, and performance was examined. The microstructure and pore distribution was not changed until the lithum content reached 3 mol%. The sample containing 5 mol% of lithium had patch structure on the skeleton and a smaller volume of primary pores. XRD analysis showed that lithium-containing porous nickel plates can easily form solid solutions without any undesirable byproducts after the oxidation. Both the bending strength and Young’s modulus of the porous plates increased with the increase of lithium content. The average bending strengths of the samples containing 1, 3, and 5 mol% of lithium were 1.29, 1.33, and 1.49 kgf/mm’ which were 2.9, 3.0, and 3.4 times higher than that of pure porous nickel plate. The Young’s modulus increased up to 1.35 kgf/mm in the case of the 5 mol% lithium containing sample that is 5.4 times higher than that of pure porous nickel plate. The OCV of single cells using pre-lithiated cathodes were between 1.065 and 1.067 V, and comparable cell performance was obtained for 500 h of single cell operation.
Metallceria water-gas shift catalysts for automotive polymer electrolyte fuel cell systems
03/01201
et crl. Preprints Di~~i.siwrof’Furl Chemistry,
Myers, D.
of Symposia
American 2002, 47, (2). 671-672.
Chemical
Society.
In order to produce a Ha rich fuel gas for polymer electrolyte membrane fuel cells for mobile application from gasoline or methanol, these fuels had to be reformed and the CO had to be eliminated by the water-gas shift reaction. Catalyst supports were prepared from ceria and ceria with small amounts of Gd, Sm, Zr, Y, and Pr, and the sp. surface of these materials was detected before loading with 10.14-1.0% Pt and activation. The prepared catalysts were tested on their water-gas shift activity with two simulated reformate feeds of low (1.02%) and high (10%) dry CO content. The water-gas shift activity of all doped ceria catalyst supports was higher than that of pure ceria, and the support with the composition Ceo.sZr~.L72Pr0.DZs01.99 was the highest due to its high sp. surface. The water-gas shift reaction rate was independent of the CO concentration from 1.0-10 mol% CO, while at lower CO concentrations the 1% Pt doped catalyst activity was comparable to the commercial Cu/ZnO catalysts.
Method and system for generation of electric power using sludge digestion gas
03/01202
Su, Q L’Iul. Jpn. Kokai Tokkyo Koho JP 2002 275,482 (Cl. ClOL3/00), 25 Sep 2002. Appl. 2001/77,301. (In Japanese) Digestion gas, obtained by methanation of biomass and organic waste, is purified by removal of CO* and preferably HaS by contacting with an alkaline adsorbent solution and then used for power generation. The alkaline adsorbent solution is regenerated, by using waste gas from power generation, and recirculated. Power generation may be carried out using fuel cells, gas turbines, or gas engines. 03/01203
supply
Holladay,
228
Microfuel processor for use in a miniature power J. D. (‘I rrl. Journul of Power Sources, 2002, 108, (l-2)
Fuel and Energy Abstracts
July 2003
21-27.
A microscale fuel reformer for use with a miniature fuel cell has been built and operated at efficiencies that make them attractive for use as a miniature power supply for microelectronics. The fuel reformer and the results of initial tests are discussed. The fuel processor assembly consists of two vapourizeripreheaters, a heat exchanger, a combustor. and a steam reformer. Methanol was identified as a good candidate for use in the microscale reformer. A proprietary catalyst was developed to reform methanol. The catalyst was able to process a methanol water mixture (1:l by weight) into a hydrogen-rich stream composed of 7374 ~01% H2, 25-26 ~01% COz, and 0.6-1.2 ~01% CO on H dry basis. Almost 3 mols of hydrogen per mol of methanol reacted, which approached the theoretical maximum. An integrated fuel processor that used proprietary catalyst in the reformer and catalytic combustion to provide the heat was designed and built. The reformer and combustor were each less than 5 mm in volume. When 100 mW, of hydrogen was produced, a thermal efficiency of 9%, or an estimated 4.5% net efficiency (including a hypothetical fuel cell), was achieved.
03/01204 Modelling multiple FACTS devices into multimachine power systems and applications Wang,
H. F. hternationul
Systems,
Journal 2003. 25, (3), 227-237.
of’ Electrircrl
Powtv
& Ener,yv
This paper presents a systematic approach to derive the dynamic model of a multi-machine power system installed with multiple FACTS devices, including SVCs, TCSCs, TCPSs, STATCOMs and UPFCs. The derivation of the model is demonstrated comprehensively for a general n-machine power system. Based on the approach to model the multimachine power system with multiple FACTS devices installed. two study cases of applications are presented in the paper. They are: (1) the multi-agent co-ordination of the secondary voltage control of SVC and STATCOM and (2) the investigation into the dynamic interactions between STATCOM and UPFC control. Study results are demonstrated by example power systems.
03lO1205 Procedure for the recovery of excess water from reforming gases in fuel cells B. et al. Ger. Offen. DE IO. I 12,604 (Cl. CO1 83150). I9 Sep Uckermann 2002, Appl.’ 10.112.604. (In German) This procedure recovers excess water from a reforming gas manufactured in a reformer by condensation of the vapour excess, whereby an optimum of electric energy is produced by the fuel cell. The condensate is purified by using activated carbon filtration or ion exchange, recirculated, and then the vapour, which is produced by the hightemperature heat exchange (preferably at 100-100~) between the condensate and the reforming gas is fed back to the reformer. Furthermore the thermal energy excess can be used for room heating.
03/01208 Chaurasia,
Regenerative fuel cell with chemical reactions P. B. L. et crl. Ener,q
Conwr.vion and Management.
2003. 44.
(4), 611-628.
The function of fuel cells largely depends upon catalytic electrodes, which accomplish a chemical reaction to convert fuel into electric energy. For this purpose, a study has been conducted on different catalysts prepared from various precursors and tested in the fuel cells for power generation under identical conditions. A new precursor has been identified to prepare the catalysts, giving encouraging results. The activity of composite catalysts (ruthenium and platinum) was found more pronounced, and it was observed that a fuel cell with catalytic electrodes having composite catalysts (Ru 2.5 +Pt 2.5 wt%) at the anode and (Ru 5.0 + Pt 2.5 wt%) at the cathode has yielded the best performance in the present fuel cells. The short circuit current and open circuit voltage were found to be 49.63 mA and 91.05 my, respectively, from the fuel cell having electrodes of surface area 4 cm-. The flow rate of hydrogen during the performance study was kept at 100 ml/min (anode) and a diluted mixture of acetone and 2-propanol at 1 ml/min (cathode). The application of such fuel cells in solar energy utilization has a bright future for generation of power through a solar thermal cell (a new concept) and is entirely different from the photovoltaic system, which is a costly affair and has limited efficiency. 03/01207
Start-up analysis for automotive PEM fuel cell
systems De Francesco, M. and Arato, E. Jourwl q/ Power Sourcvs, 2002, IOX, (l-2), 41-52. The development of fuel cell cars can play an important role in resolving transport problems, due to the high environmental compatibility and high efficiency of this kind of vehicle. Among the different types of fuel cells, proton-exchange membrane fuel cells (PEMFCs) are considered the best solution for automotive applications at the moment. In this work, constructive criteria are discussed with the aim of obtaining a power generation module adaptable to a wide range of cars. A particular problem in accomplishing the overall project is represented by the definition of the compressor system for air feeding. In this work, the design approach to the problem will be delineated: some options are reviewed and the best solution is analysed. The