In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SO...In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SOFC),supercritical CO_(2)cycle(S-CO_(2)),and organic Rankine cycle(ORC)is proposed.The clean syngas obtained from sludge gasification is mixed with CH4 and then first utilized by the fuel cell.The exhaust gas from the fuel cell is fully combusted in the afterburning chamber and then enters the bottom cycle system consisting of S-CO_(2)&ORC to generate electricity.To understand the performance of the system,thermodynamic and economic analyses were conducted to examine the project's performance.The thermodynamics as well as the economics of the coupled system were analyzed to arrive at the following conclusions,the power production of the system is 37.34 MW;the exergy efficiency is 55.62%,and the net electrical efficiency is 61.48%.The main exergy destruction is the gasifier and SOFC,accounting for 62.45%of the total exergy destruction.It takes only6.13 years to repay the construction investment in the novel system,and the project obtains a NPV of 17723820USD during 20 years lifetime.The above findings indicate that the new coupled system has a better performance in terms of energy utilization and economy.展开更多
In this paper, an integrated system of solid oxide fuel cell(SOFC) and methane steam reforming for hydrogen production is proposed. The mathematical model of the coupled integrated system is studied by COMSOL and Aspe...In this paper, an integrated system of solid oxide fuel cell(SOFC) and methane steam reforming for hydrogen production is proposed. The mathematical model of the coupled integrated system is studied by COMSOL and Aspen software, and the energy analysis of the integrated system is carried out. The system recovers and reuses the waste heat of the SOFC stack through the heat exchanger, which can realize the cascade efficient use of energy. By adjusting the different reforming temperatures, steam-to-carbon ratio and SOFC operating temperature of methane steam reforming to produce hydrogen, the parameters that have a greater impact on the system are studied. The research results show that as the steam-to-carbon ratio and reformer operating temperature increase, the net output power and efficiency of the system increase. When the fuel cell operating temperature is 800℃, the output power and efficiency of the system reach the maximum values of 899.93 W and 52.52%, respectively. Increasing the operating temperature of SOFC helps to improve the efficiency of fuel cells, but the efficiency of the integrated system of methane steam reforming hydrogen production and SOFC first increases and then decreases. This system can realize the direct coupling between the SOFC reactor subsystem and the methane steam reforming hydrogen production system under optimized conditions, which has reference significance for the actual operating conditions of the coupled system.展开更多
This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an i...This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an integrated BOP （balance of plant）. The ex-situ experiments, without an SOFC stack installed in the system, were fast conducted to investigate the operability of a BOP apparatus. It was found that the BOP possessed high conversion rates for both steam reforming and water gas shift reactions. The total fuel concentration of hydrogen and carbon monoxide from the reformer was around 91.2%. The system validation tests showed that, with the natural gas as fuel, the output power from the stack reached to 1,060 W, while the fuel utilization efficiency and electrical efficiency were 67.16% and 45.0%, respectively. A steady 600-hour system operation test was carried out at an average system temperature of 694℃. Of which, a 36-cell stack was employed for the test. Meanwhile, the current, voltage and output power were 26 A, 32.3 V and 840 W, respectively, and its electrical efficiency was around 33.4%.展开更多
Solid oxide fuel cell (SOFC) has been identified as an effective and clean alternative choice for marine power system.This paper emphasizes on the dynamic modeling of SOFC power system and its performance based upon m...Solid oxide fuel cell (SOFC) has been identified as an effective and clean alternative choice for marine power system.This paper emphasizes on the dynamic modeling of SOFC power system and its performance based upon marine operating circumstance.A SOFC power system model has been provided considering thermodynamic and electrochemical reaction mechanism.Subcomponents of lithium ion battery, power conditioning unit, stack structure and controller are integrated in the model.The dynamic response of the system is identified according to the inertia of its subcomponent and controller.Validation of the whole system simulation at steady state and transit period are presented, concerning the effects of thermo inertia, control strategy and seagoing environment.The simulation results show reasonable accuracy compare with lab test.The models can be used to predict performance of a SOFC power system and identify the system response when part of the component parameter is adjusted.展开更多
The relationship among the working temperature,pressure and current density of a Solid oxide fuel cell(SOFC)and its output power and efficiency are analyzed in the framework of a theoretical model able to provide,amon...The relationship among the working temperature,pressure and current density of a Solid oxide fuel cell(SOFC)and its output power and efficiency are analyzed in the framework of a theoretical model able to provide,among other things,the volt ampere characteristic curve.In particular,following the principle of temperature matching and cascade utilization,we consider a gas turbine(GT)and a LiBr absorption chiller to recycle the high-grade exhaust heat produced by the considered SOFC.This distributed total energy system is set up with the intent to meet typical needs of buildings for cooling,heating and power(CCHP).The total power generated by the considered SOFC and gas turbine is about 222 kW and the total power generation efficiency by low heat value of fuel(LHV)is 63.7%.In the CCHP system,the high temperature exhaust of GT is further used to drive LiBr absorption unit,which can produce about 34.8 kW cooling capacity or 84.5 kW of heat(the total energy utilization 78.03%).展开更多
In order to employ the waste heat effectively,a novel three-stage integrated system based upon a solid oxide fuel cell(SOFC),an alkali metal thermoelectric converter(AMTEC)and thermally regenerative electrochemical cy...In order to employ the waste heat effectively,a novel three-stage integrated system based upon a solid oxide fuel cell(SOFC),an alkali metal thermoelectric converter(AMTEC)and thermally regenerative electrochemical cycles(TRECs)is put forward.Considering the main electrochemically and thermodynamically irreversible losses,the power output and the efficiency of the subsystems and the integrated system are compared,and optimally operating regions for the current density,the power output,and the efficiency of the integrated system are explored.Calculations demonstrate that the maximum power density of the considered system is up to 7466 W/m2,which allows 18%and 74%higher than that of the conventional SOFC-AMTEC device and the stand-alone fuel cell model,respectively.It is proved that the considered system is an efficient approach to boost energy efficiency.Moreover,the influence of several significant parameters on the comprehensive performance of the integrated system is expounded in detail,including the electrolyte thickness of the SOFC,the leakage resistance of the SOFC,and the area ratio between the SOFC electrode and the AMTEC subsystem.展开更多
Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in ...Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in Aspen plus.Key operating parameters,such as steam to fuel ratio,stack temperature,reformer temperature,air flow rate,and air preheating temperature,were analyzed.Optimization was conducted based on the simulation results.Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency,but it might decrease the gross system efficiency.Higher stack and reformer temperatures contribute to the electrical efficiency,and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750℃and 700℃,respectively.The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency,the recommended value is around 600℃under the reference condition.展开更多
This paper shows the development of solid oxide fuel cell （SOFC） technology at the Institute of Nuclear Energy Research. In the development, fabrication processes for planar anode-supported-cell （ASC） by conventio...This paper shows the development of solid oxide fuel cell （SOFC） technology at the Institute of Nuclear Energy Research. In the development, fabrication processes for planar anode-supported-cell （ASC） by conventional methods and metal-supported-cell （MSC） by atmospheric plasma spraying are well established. Procedures and techniques for stacking and cell/stack performance tests are continuously improved to enhance the quality and reliability. Innovative nano-structured catalysts, in which reduced Pt and CeOz particles dispersed onto the A120~ carriers can effectively prevent the migration and coalescence of the metal crystallites, are thermal stable and possess a conversion ratio higher than 95% for reforming of natural gas. A non-premixed after-burner/reformer is designed and fabricated, and it has passed the prerequisite functional tests. Layouts including stacks, components of BOP, power conditioning and control as well as gases and water supply, are designated for a 1-kW SOFC power system. In compliance with system requirements, operating modes, data acquisition, power conditioning, instrumentations, and control logics have been identified and settled. After successive system validation tests, two modules of 18-cell stacks are allocated into the SOFC system. Test results indicate a thermal self-sustaining system on natural gas is achieved with a power output of around 760 watts.展开更多
基金supported by the National Nature Science Fund of China(No.52276006)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51821004)。
文摘In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively,a coupled system based on sewage sludge gasifier(SSG),solid oxide fuel cells(SOFC),supercritical CO_(2)cycle(S-CO_(2)),and organic Rankine cycle(ORC)is proposed.The clean syngas obtained from sludge gasification is mixed with CH4 and then first utilized by the fuel cell.The exhaust gas from the fuel cell is fully combusted in the afterburning chamber and then enters the bottom cycle system consisting of S-CO_(2)&ORC to generate electricity.To understand the performance of the system,thermodynamic and economic analyses were conducted to examine the project's performance.The thermodynamics as well as the economics of the coupled system were analyzed to arrive at the following conclusions,the power production of the system is 37.34 MW;the exergy efficiency is 55.62%,and the net electrical efficiency is 61.48%.The main exergy destruction is the gasifier and SOFC,accounting for 62.45%of the total exergy destruction.It takes only6.13 years to repay the construction investment in the novel system,and the project obtains a NPV of 17723820USD during 20 years lifetime.The above findings indicate that the new coupled system has a better performance in terms of energy utilization and economy.
基金supported by the National Natural Science Foundation of China(Grant No.51866001)Initial Research Funds for the Hainan Universities(KYQD(ZR)1841)。
文摘In this paper, an integrated system of solid oxide fuel cell(SOFC) and methane steam reforming for hydrogen production is proposed. The mathematical model of the coupled integrated system is studied by COMSOL and Aspen software, and the energy analysis of the integrated system is carried out. The system recovers and reuses the waste heat of the SOFC stack through the heat exchanger, which can realize the cascade efficient use of energy. By adjusting the different reforming temperatures, steam-to-carbon ratio and SOFC operating temperature of methane steam reforming to produce hydrogen, the parameters that have a greater impact on the system are studied. The research results show that as the steam-to-carbon ratio and reformer operating temperature increase, the net output power and efficiency of the system increase. When the fuel cell operating temperature is 800℃, the output power and efficiency of the system reach the maximum values of 899.93 W and 52.52%, respectively. Increasing the operating temperature of SOFC helps to improve the efficiency of fuel cells, but the efficiency of the integrated system of methane steam reforming hydrogen production and SOFC first increases and then decreases. This system can realize the direct coupling between the SOFC reactor subsystem and the methane steam reforming hydrogen production system under optimized conditions, which has reference significance for the actual operating conditions of the coupled system.
文摘This research presents the results of system validation tests for an SOFC power system. In the study, the system was heated up without electric device, i.e., the fuel providing the required thermal energy through an integrated BOP （balance of plant）. The ex-situ experiments, without an SOFC stack installed in the system, were fast conducted to investigate the operability of a BOP apparatus. It was found that the BOP possessed high conversion rates for both steam reforming and water gas shift reactions. The total fuel concentration of hydrogen and carbon monoxide from the reformer was around 91.2%. The system validation tests showed that, with the natural gas as fuel, the output power from the stack reached to 1,060 W, while the fuel utilization efficiency and electrical efficiency were 67.16% and 45.0%, respectively. A steady 600-hour system operation test was carried out at an average system temperature of 694℃. Of which, a 36-cell stack was employed for the test. Meanwhile, the current, voltage and output power were 26 A, 32.3 V and 840 W, respectively, and its electrical efficiency was around 33.4%.
文摘Solid oxide fuel cell (SOFC) has been identified as an effective and clean alternative choice for marine power system.This paper emphasizes on the dynamic modeling of SOFC power system and its performance based upon marine operating circumstance.A SOFC power system model has been provided considering thermodynamic and electrochemical reaction mechanism.Subcomponents of lithium ion battery, power conditioning unit, stack structure and controller are integrated in the model.The dynamic response of the system is identified according to the inertia of its subcomponent and controller.Validation of the whole system simulation at steady state and transit period are presented, concerning the effects of thermo inertia, control strategy and seagoing environment.The simulation results show reasonable accuracy compare with lab test.The models can be used to predict performance of a SOFC power system and identify the system response when part of the component parameter is adjusted.
基金supported by the doctoral research initiation fund of Linyi University(Grant No.:204-40618051,Zhang,B.,http://www.lyu.edu.cn/).
文摘The relationship among the working temperature,pressure and current density of a Solid oxide fuel cell(SOFC)and its output power and efficiency are analyzed in the framework of a theoretical model able to provide,among other things,the volt ampere characteristic curve.In particular,following the principle of temperature matching and cascade utilization,we consider a gas turbine(GT)and a LiBr absorption chiller to recycle the high-grade exhaust heat produced by the considered SOFC.This distributed total energy system is set up with the intent to meet typical needs of buildings for cooling,heating and power(CCHP).The total power generated by the considered SOFC and gas turbine is about 222 kW and the total power generation efficiency by low heat value of fuel(LHV)is 63.7%.In the CCHP system,the high temperature exhaust of GT is further used to drive LiBr absorption unit,which can produce about 34.8 kW cooling capacity or 84.5 kW of heat(the total energy utilization 78.03%).
文摘In order to employ the waste heat effectively,a novel three-stage integrated system based upon a solid oxide fuel cell(SOFC),an alkali metal thermoelectric converter(AMTEC)and thermally regenerative electrochemical cycles(TRECs)is put forward.Considering the main electrochemically and thermodynamically irreversible losses,the power output and the efficiency of the subsystems and the integrated system are compared,and optimally operating regions for the current density,the power output,and the efficiency of the integrated system are explored.Calculations demonstrate that the maximum power density of the considered system is up to 7466 W/m2,which allows 18%and 74%higher than that of the conventional SOFC-AMTEC device and the stand-alone fuel cell model,respectively.It is proved that the considered system is an efficient approach to boost energy efficiency.Moreover,the influence of several significant parameters on the comprehensive performance of the integrated system is expounded in detail,including the electrolyte thickness of the SOFC,the leakage resistance of the SOFC,and the area ratio between the SOFC electrode and the AMTEC subsystem.
基金the National Key R&D Program of China(2017YFB0601903).
文摘Solid oxide fuel cell combined with heat and power(SOFC-CHP)system is a distributed power generation system with low pollution and high efficiency.In this paper,a 10 kW SOFC-CHP system model using syngas was built in Aspen plus.Key operating parameters,such as steam to fuel ratio,stack temperature,reformer temperature,air flow rate,and air preheating temperature,were analyzed.Optimization was conducted based on the simulation results.Results suggest that higher steam to fuel ratio is beneficial to the electrical efficiency,but it might decrease the gross system efficiency.Higher stack and reformer temperatures contribute to the electrical efficiency,and the optimal operating temperatures of stack and reformer when considering the stack degradation are 750℃and 700℃,respectively.The air preheating temperature barely affects the electrical efficiency but affects the thermal efficiency and the gross system efficiency,the recommended value is around 600℃under the reference condition.
文摘This paper shows the development of solid oxide fuel cell （SOFC） technology at the Institute of Nuclear Energy Research. In the development, fabrication processes for planar anode-supported-cell （ASC） by conventional methods and metal-supported-cell （MSC） by atmospheric plasma spraying are well established. Procedures and techniques for stacking and cell/stack performance tests are continuously improved to enhance the quality and reliability. Innovative nano-structured catalysts, in which reduced Pt and CeOz particles dispersed onto the A120~ carriers can effectively prevent the migration and coalescence of the metal crystallites, are thermal stable and possess a conversion ratio higher than 95% for reforming of natural gas. A non-premixed after-burner/reformer is designed and fabricated, and it has passed the prerequisite functional tests. Layouts including stacks, components of BOP, power conditioning and control as well as gases and water supply, are designated for a 1-kW SOFC power system. In compliance with system requirements, operating modes, data acquisition, power conditioning, instrumentations, and control logics have been identified and settled. After successive system validation tests, two modules of 18-cell stacks are allocated into the SOFC system. Test results indicate a thermal self-sustaining system on natural gas is achieved with a power output of around 760 watts.
