The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Somchai Wongwises - One of the best experts on this subject based on the ideXlab platform.
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optimum absorber temperature of a once reflecting full conical concentrator of a low temperature differential stirling Engine
Renewable Energy, 2005Co-Authors: Ancha Kongtragool, Somchai WongwisesAbstract:This paper provides a theoretical investigation on the optimum absorber temperature of a once-reflecting full conical concentrator for maximizing overall efficiency of a solar-Powered low temperature differential Stirling Engine. A mathematical model for the overall efficiency of the solar-Powered Stirling Engine is developed. The optimum absorber temperature for maximum overall efficiency for both limiting conditions of maximum possible Engine efficiency and maximum possible Engine Power output is determined. The results indicated that the optimum absorber temperatures calculated from these two limiting cases are not significantly different. For a given concentrated solar intensity, the maximum overall efficiency characterized by the condition of maximum possible Engine Power output is very close to that of the real Engine of 55% Carnot efficiency, approximately.
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investigation on Power output of the gamma configuration low temperature differential stirling Engines
Renewable Energy, 2005Co-Authors: Bancha Kongtragool, Somchai WongwisesAbstract:This paper provides a study on Power output determination of a gamma-configuration, low temperature differential Stirling Engine. The former works on the calculation of Stirling Engine Power output are discussed. Results from this study indicate that the mean pressure Power formula is most appropriate for the calculation of a gamma-configuration, low temperature differential Stirling Engine Power output.
Songcharng Kong - One of the best experts on this subject based on the ideXlab platform.
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combustion and emissions characteristics of compression ignition Engine using dual ammonia diesel fuel
Fuel, 2011Co-Authors: Aaron J Reiter, Songcharng KongAbstract:Abstract This study investigated the combustion and emissions characteristics of a compression-ignition Engine using a dual-fuel approach with ammonia and diesel fuel. Ammonia can be regarded as a hydrogen carrier and used as a fuel, and its combustion does not produce carbon dioxide. In this study, ammonia vapor was introduced into the intake manifold and diesel fuel was injected into the cylinder to initiate combustion. The test Engine was a four-cylinder, turbocharged diesel Engine with slight modifications to the intake manifold for ammonia induction. An ammonia fueling system was developed, and various combinations of ammonia and diesel fuel were successfully tested. One scheme was to use different combinations of ammonia and diesel fuel to achieve a constant Engine Power. The other was to use a small quantity of diesel fuel and vary the amount of ammonia to achieve variable Engine Power. Under the constant Engine Power operation, in order to achieve favorable fuel efficiency, the preferred operation range was to use 40–60% energy provided by diesel fuel in conjunction with 60–40% energy supplied by ammonia. Exhaust carbon monoxide and hydrocarbon emissions using the dual-fuel approach were generally higher than those of using pure diesel fuel to achieve the same Power output, while NOx emissions varied with different fueling combinations. NOx emissions could be reduced if ammonia accounted for less than 40% of the total fuel energy due to the lower combustion temperature resulting in lower thermal NOx. If ammonia accounted for the majority of the fuel energy, NOx emissions increased significantly due to the fuel-bound nitrogen. On the other hand, soot emissions could be reduced significantly if a significant amount of ammonia was used due to the lack of carbon present in the combination of fuels. Despite the overall high ammonia conversion efficiency (nearly 100%), exhaust ammonia emissions ranged from 1000 to 3000 ppmV and further after-treatment will be required due to health concerns. On the other hand, the variable Engine Power operation resulted in relatively poor fuel efficiency and high exhaust ammonia emissions due to the lack of diesel energy to initiate effective combustion of the lean ammonia-air mixture. The in-cylinder pressure history was also analyzed, and results indicated that ignition delay increased with increasing amounts of ammonia due to its high resistance to autoignition. The peak cylinder pressure also decreased because of the lower combustion temperature of ammonia. It is recommended that further combustion optimization using direct ammonia/diesel injection strategies be performed to increase the combustion efficiency and reduce exhaust ammonia emissions.
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combustion and emissions characteristics of compression ignition Engine using dual ammonia diesel fuel
Fuel, 2011Co-Authors: Aaron J Reiter, Songcharng KongAbstract:Abstract This study investigated the combustion and emissions characteristics of a compression-ignition Engine using a dual-fuel approach with ammonia and diesel fuel. Ammonia can be regarded as a hydrogen carrier and used as a fuel, and its combustion does not produce carbon dioxide. In this study, ammonia vapor was introduced into the intake manifold and diesel fuel was injected into the cylinder to initiate combustion. The test Engine was a four-cylinder, turbocharged diesel Engine with slight modifications to the intake manifold for ammonia induction. An ammonia fueling system was developed, and various combinations of ammonia and diesel fuel were successfully tested. One scheme was to use different combinations of ammonia and diesel fuel to achieve a constant Engine Power. The other was to use a small quantity of diesel fuel and vary the amount of ammonia to achieve variable Engine Power. Under the constant Engine Power operation, in order to achieve favorable fuel efficiency, the preferred operation range was to use 40–60% energy provided by diesel fuel in conjunction with 60–40% energy supplied by ammonia. Exhaust carbon monoxide and hydrocarbon emissions using the dual-fuel approach were generally higher than those of using pure diesel fuel to achieve the same Power output, while NOx emissions varied with different fueling combinations. NOx emissions could be reduced if ammonia accounted for less than 40% of the total fuel energy due to the lower combustion temperature resulting in lower thermal NOx. If ammonia accounted for the majority of the fuel energy, NOx emissions increased significantly due to the fuel-bound nitrogen. On the other hand, soot emissions could be reduced significantly if a significant amount of ammonia was used due to the lack of carbon present in the combination of fuels. Despite the overall high ammonia conversion efficiency (nearly 100%), exhaust ammonia emissions ranged from 1000 to 3000 ppmV and further after-treatment will be required due to health concerns. On the other hand, the variable Engine Power operation resulted in relatively poor fuel efficiency and high exhaust ammonia emissions due to the lack of diesel energy to initiate effective combustion of the lean ammonia-air mixture. The in-cylinder pressure history was also analyzed, and results indicated that ignition delay increased with increasing amounts of ammonia due to its high resistance to autoignition. The peak cylinder pressure also decreased because of the lower combustion temperature of ammonia. It is recommended that further combustion optimization using direct ammonia/diesel injection strategies be performed to increase the combustion efficiency and reduce exhaust ammonia emissions.
Aaron J Reiter - One of the best experts on this subject based on the ideXlab platform.
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combustion and emissions characteristics of compression ignition Engine using dual ammonia diesel fuel
Fuel, 2011Co-Authors: Aaron J Reiter, Songcharng KongAbstract:Abstract This study investigated the combustion and emissions characteristics of a compression-ignition Engine using a dual-fuel approach with ammonia and diesel fuel. Ammonia can be regarded as a hydrogen carrier and used as a fuel, and its combustion does not produce carbon dioxide. In this study, ammonia vapor was introduced into the intake manifold and diesel fuel was injected into the cylinder to initiate combustion. The test Engine was a four-cylinder, turbocharged diesel Engine with slight modifications to the intake manifold for ammonia induction. An ammonia fueling system was developed, and various combinations of ammonia and diesel fuel were successfully tested. One scheme was to use different combinations of ammonia and diesel fuel to achieve a constant Engine Power. The other was to use a small quantity of diesel fuel and vary the amount of ammonia to achieve variable Engine Power. Under the constant Engine Power operation, in order to achieve favorable fuel efficiency, the preferred operation range was to use 40–60% energy provided by diesel fuel in conjunction with 60–40% energy supplied by ammonia. Exhaust carbon monoxide and hydrocarbon emissions using the dual-fuel approach were generally higher than those of using pure diesel fuel to achieve the same Power output, while NOx emissions varied with different fueling combinations. NOx emissions could be reduced if ammonia accounted for less than 40% of the total fuel energy due to the lower combustion temperature resulting in lower thermal NOx. If ammonia accounted for the majority of the fuel energy, NOx emissions increased significantly due to the fuel-bound nitrogen. On the other hand, soot emissions could be reduced significantly if a significant amount of ammonia was used due to the lack of carbon present in the combination of fuels. Despite the overall high ammonia conversion efficiency (nearly 100%), exhaust ammonia emissions ranged from 1000 to 3000 ppmV and further after-treatment will be required due to health concerns. On the other hand, the variable Engine Power operation resulted in relatively poor fuel efficiency and high exhaust ammonia emissions due to the lack of diesel energy to initiate effective combustion of the lean ammonia-air mixture. The in-cylinder pressure history was also analyzed, and results indicated that ignition delay increased with increasing amounts of ammonia due to its high resistance to autoignition. The peak cylinder pressure also decreased because of the lower combustion temperature of ammonia. It is recommended that further combustion optimization using direct ammonia/diesel injection strategies be performed to increase the combustion efficiency and reduce exhaust ammonia emissions.
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combustion and emissions characteristics of compression ignition Engine using dual ammonia diesel fuel
Fuel, 2011Co-Authors: Aaron J Reiter, Songcharng KongAbstract:Abstract This study investigated the combustion and emissions characteristics of a compression-ignition Engine using a dual-fuel approach with ammonia and diesel fuel. Ammonia can be regarded as a hydrogen carrier and used as a fuel, and its combustion does not produce carbon dioxide. In this study, ammonia vapor was introduced into the intake manifold and diesel fuel was injected into the cylinder to initiate combustion. The test Engine was a four-cylinder, turbocharged diesel Engine with slight modifications to the intake manifold for ammonia induction. An ammonia fueling system was developed, and various combinations of ammonia and diesel fuel were successfully tested. One scheme was to use different combinations of ammonia and diesel fuel to achieve a constant Engine Power. The other was to use a small quantity of diesel fuel and vary the amount of ammonia to achieve variable Engine Power. Under the constant Engine Power operation, in order to achieve favorable fuel efficiency, the preferred operation range was to use 40–60% energy provided by diesel fuel in conjunction with 60–40% energy supplied by ammonia. Exhaust carbon monoxide and hydrocarbon emissions using the dual-fuel approach were generally higher than those of using pure diesel fuel to achieve the same Power output, while NOx emissions varied with different fueling combinations. NOx emissions could be reduced if ammonia accounted for less than 40% of the total fuel energy due to the lower combustion temperature resulting in lower thermal NOx. If ammonia accounted for the majority of the fuel energy, NOx emissions increased significantly due to the fuel-bound nitrogen. On the other hand, soot emissions could be reduced significantly if a significant amount of ammonia was used due to the lack of carbon present in the combination of fuels. Despite the overall high ammonia conversion efficiency (nearly 100%), exhaust ammonia emissions ranged from 1000 to 3000 ppmV and further after-treatment will be required due to health concerns. On the other hand, the variable Engine Power operation resulted in relatively poor fuel efficiency and high exhaust ammonia emissions due to the lack of diesel energy to initiate effective combustion of the lean ammonia-air mixture. The in-cylinder pressure history was also analyzed, and results indicated that ignition delay increased with increasing amounts of ammonia due to its high resistance to autoignition. The peak cylinder pressure also decreased because of the lower combustion temperature of ammonia. It is recommended that further combustion optimization using direct ammonia/diesel injection strategies be performed to increase the combustion efficiency and reduce exhaust ammonia emissions.
Anthony Mark Phillips - One of the best experts on this subject based on the ideXlab platform.
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Engine Power smoothing energy management strategy for a series hybrid electric vehicle
American Control Conference, 2011Co-Authors: Stefano Di Cairano, Ming L Kuang, Wei Liang, Ilya V. Kolmanovsky, Anthony Mark PhillipsAbstract:Hybrid electric vehicles exploit energy production and energy storage systems to achieve improved fuel economy with respect to conventional Powertrains. In order to maximize such improvements, advanced control strategies are needed for deciding the amount of energy to be produced and stored. In this paper we propose an approach for energy management of a series hybrid electric vehicle (SHEV). This approach focuses on maximizing the pointwise Powertrain efficiency, rather than the overall fuel consumption. For a given Power request the steady state Engine operating point is chosen to maximize the efficiency. A control algorithm regulates the transitions between different operating points, by using the battery to smoothen the Engine transients. Due to the constrained nature of the transient smoothing problem, we implement the control algorithm by model predictive control. Experimental testing on the UDDS cycle shows improved fuel economy with respect to two baseline strategies.
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Engine Power smoothing energy management strategy for a series hybrid electric vehicle
American Control Conference, 2011Co-Authors: Stefano Di Cairano, Ming L Kuang, Wei Liang, Ilya V. Kolmanovsky, Anthony Mark PhillipsAbstract:Hybrid electric vehicles exploit energy production and energy storage systems to achieve improved fuel economy with respect to conventional Powertrains. In order to maximize such improvements, advanced control strategies are needed for deciding the amount of energy to be produced and stored. In this paper we propose an approach for energy management of a series hybrid electric vehicle (SHEV). This approach focuses on maximizing the pointwise Powertrain efficiency, rather than the overall fuel consumption. For a given Power request the steady state Engine operating point is chosen to maximize the efficiency. A control algorithm regulates the transitions between different operating points, by using the battery to smoothen the Engine transients. Due to the constrained nature of the transient smoothing problem, we implement the control algorithm by model predictive control. Experimental testing on the UDDS cycle shows improved fuel economy with respect to two baseline strategies.
Ming L Kuang - One of the best experts on this subject based on the ideXlab platform.
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Engine Power smoothing energy management strategy for a series hybrid electric vehicle
American Control Conference, 2011Co-Authors: Stefano Di Cairano, Ming L Kuang, Wei Liang, Ilya V. Kolmanovsky, Anthony Mark PhillipsAbstract:Hybrid electric vehicles exploit energy production and energy storage systems to achieve improved fuel economy with respect to conventional Powertrains. In order to maximize such improvements, advanced control strategies are needed for deciding the amount of energy to be produced and stored. In this paper we propose an approach for energy management of a series hybrid electric vehicle (SHEV). This approach focuses on maximizing the pointwise Powertrain efficiency, rather than the overall fuel consumption. For a given Power request the steady state Engine operating point is chosen to maximize the efficiency. A control algorithm regulates the transitions between different operating points, by using the battery to smoothen the Engine transients. Due to the constrained nature of the transient smoothing problem, we implement the control algorithm by model predictive control. Experimental testing on the UDDS cycle shows improved fuel economy with respect to two baseline strategies.
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Engine Power smoothing energy management strategy for a series hybrid electric vehicle
American Control Conference, 2011Co-Authors: Stefano Di Cairano, Ming L Kuang, Wei Liang, Ilya V. Kolmanovsky, Anthony Mark PhillipsAbstract:Hybrid electric vehicles exploit energy production and energy storage systems to achieve improved fuel economy with respect to conventional Powertrains. In order to maximize such improvements, advanced control strategies are needed for deciding the amount of energy to be produced and stored. In this paper we propose an approach for energy management of a series hybrid electric vehicle (SHEV). This approach focuses on maximizing the pointwise Powertrain efficiency, rather than the overall fuel consumption. For a given Power request the steady state Engine operating point is chosen to maximize the efficiency. A control algorithm regulates the transitions between different operating points, by using the battery to smoothen the Engine transients. Due to the constrained nature of the transient smoothing problem, we implement the control algorithm by model predictive control. Experimental testing on the UDDS cycle shows improved fuel economy with respect to two baseline strategies.
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fuzzy gain scheduling proportional integral control for improving Engine Power and speed behavior in a hybrid electric vehicle
IEEE Transactions on Vehicular Technology, 2009Co-Authors: Fazal Urrahman Syed, Shunsuke Okubo, Ming L Kuang, Matthew D Smith, Hao YingAbstract:With the increased emphasis on improving fuel economy and reducing emissions, hybrid electric vehicles (HEVs) have emerged as very strong candidates to achieve these goals. The Power-split hybrid system, which is a complex hybrid Powertrain, exhibits great potential to improve fuel economy by determining the most efficient regions for Engine operation and thereby high-voltage (HV) battery operation to achieve overall vehicle efficiency optimization. To control and maintain the actual HV battery Power, a sophisticated control system is essential, which controls Engine Power and thereby Engine speed to achieve the desired HV battery maintenance Power. Conventional approaches use proportional-integral (PI) control systems to control the actual HV battery Power in Power-split HEV, which can sometimes result in either overshoots of Engine speed and Power or degraded response and settling times due to the nonlinearity of the Power-split hybrid system. We have developed a novel approach to intelligently controlling Engine Power and speed behavior in a Power-split HEV using the fuzzy control paradigm for better performances. To the best of our knowledge, this is the first reported use of the fuzzy control method to control Engine Power and speed of a Power-split HEV in the applied automotive field. Our approach uses fuzzy gain scheduling to determine appropriate gains for the PI controller based on the system's operating conditions. The improvements include elimination of the overshoots as well as approximate 50% faster response and settling times in comparison with the conventional linear PI control approach. The improved performances are demonstrated through simulations and field experiments using a ford escape hybrid vehicle.