The characteristics of fuel from biomass, coal and some waste materials are lower heat value and different compositions. The lower heat value fuel (LHVF) can be used on power engine such as boiler, gas engine and gas ...The characteristics of fuel from biomass, coal and some waste materials are lower heat value and different compositions. The lower heat value fuel (LHVF) can be used on power engine such as boiler, gas engine and gas turbine. Some laboratory and pilot work have been done, but the work done on micro-gas turbine is still limited. The characteristics of LHVF can cause the operations change of micro-gas turbine designed for nature gas. Some possible adjustment and modification methods were mentioned for the use of LHVF on micro-gas turbine. One kind of representative LHVF was chosen and the operations of micro-gas turbine were analyzed. The temperature field and the non-uniformity scale of temperature distribution of combustor were calculated using FLUENT. The feasibility of different adjustment and modification methods were analyzed according to the efficiency, output power and the non-uniformity scale of temperature distribution.展开更多
The solid oxide fuel cell(SOFC)power system fueled by NH_(3)is considered one of the most promising solutions for achieving ship decarbonization and carbon neutrality.This paper addresses the technical challenges face...The solid oxide fuel cell(SOFC)power system fueled by NH_(3)is considered one of the most promising solutions for achieving ship decarbonization and carbon neutrality.This paper addresses the technical challenges faced by NH_(3)fuel SOFC ship power system,including slow hydrogen(H2)production,low efficiency,and limited space.It introduces an innovative a NH_(3)-integrated reactor for rapid H2 production,establishes a safe and efficient all-electric SOFC all-electric propulsion system adaptable to various sailing conditions.The system is validated using a 2 kW prototype experimental rig.Results show that the SOFC system,designed for a target ship,has a rated power of 96 kW and an electrical efficiency of 60.13%,meeting the requirements for rated cruising conditions.Under identical catalytic scenarios,the designed reactor,with highly efficient heat transfer,measuring 1.1 m in length,can achieve complete NH_(3)decomposition within 2.94 s,representing a 35%reduction in cracking time and a 42%decrease in required cabin space.During high-load voyage conditions,adjusting the circulation ratio(CR)and ammonia-oxygen ratio(A/O)improves system efficiency across a wide operational range.Among these adjustments,altering the A/O ratio proves to be the most efficient strategy.Under this configuration,the system achieves an efficiency of 55.02%at low load and 61.73%at high load,allowing operation across a power range of 20%to 110%.Experimental results indicate that the error for NH_(3)cracking H2 is less than 3%within the range of 570-700℃,which is relevant to typical ship operation scenarios.At 656℃,the NH_(3)cracking H2 rate reaches 100%.Under these conditions,the SOFC produces 2.045 kW of power with an efficiency of approximately 58.66%.The noise level detected is 58.6 dB,while the concentrations of CO_(2),NO,and SO_(2)in the flue gas approach zero.These findings support the transition of the shipping industry to green,clean systems,contributing significantly to future reductions in ocean carbon emissions.展开更多
Micro gas turbine(MGT)is widely used in small-scale distributed power systems because of its low emissions and fuel flexibility.However,the under-utilization of its exhaust heat and the low electric efficiency are the...Micro gas turbine(MGT)is widely used in small-scale distributed power systems because of its low emissions and fuel flexibility.However,the under-utilization of its exhaust heat and the low electric efficiency are the main bottlenecks that restrict its application.Additionally,the flexible switching between the power generated by the MGT and the power grid is also a key factor for keeping the secure operation of a distributed power station.Therefore,this paper conducted some experimental investigations of a 30 kW MGT to provide reference solutions for the above issues.This MGT is located at Shanghai Jiao Tong University(SJTU),which is designed by the Gas Turbine Research Institute of SJTU,and is manufactured by a turbo machinery factory in Chongqing,China.The demonstration prototype is mainly composed of a single stage centrifugal compressor,a radial turbine,a combustor,a high-speed pennanent magnet generator,and a control system.The results show that the MGT can achieve steady operation at a low rotational speed from 10000 r/min to 34000 r/min in the case of using oil lubricated bearings,which can greatly reduce the economic cost compared with the use of air bearings.At the same time,the ignition success rate of combustion chamber(CC)reaches 98%at a low rotational speed,and a wide range of stable combustion area can be obtained,because of the novel design method of combustor by referencing the way applied in an axial flow aero-engine.The MGT generating set can achieve functions,such as starting up,ignition,stable operation,loaded operation,grid-connection and stopping.This system also can realize flexibly switching from the start motor mode to the generator mode,and from grid-connected mode to off^grid mode,because the innovative multi-state switching control system is adopted.The above research work can make our state master independent intellectual property rights of micro gas turbine,rather than continue to be subject to the technological monopoly of the developed states,which can provide theoretical and experimental support for the industrialization of MGT in China.展开更多
In this paper,the operation perfonnance of three novel kinds of cogeneration systems under design and off-design condition was investigated.The systems are MGT(micro gas turbine)+ORC(organic Rankine cycle)for electric...In this paper,the operation perfonnance of three novel kinds of cogeneration systems under design and off-design condition was investigated.The systems are MGT(micro gas turbine)+ORC(organic Rankine cycle)for electricity demand,MGT+ERC(ejector refrigeration cycle)for electricity and cooling demand,and MGT+ORC+ERC for electricity and cooling demand.The effect of 5 different working fluids on cogeneration systems was studied.The results show that under the design condition,when using R600 in the bottoming cycle,the MGT+ORC system has the lowest total output of 117.1 kW with a thermal efficiency of 0.334,and the MGT+ERC system has the largest total output of 142.6 kW with a thermal efficiency of 0.408.For the MGT+ORC+ERC system,the total output is between the other two systems,which is 129.3 kW with a thermal efficiency of 0.370.For the effect of different working fluids,R123 is the most suitable working fluid for MGT+ORC with the maximum electricity output power and R600 is the most suitable working fluid for MGT+ERC with the maximum cooling capacity,while both R600 and R123 can make MGT+ORC+ERC achieve a good comprehensive performance of refrigeration and electricity.The thermal efficiency of three cogeneration systems can be effectively improved under oredesign condition because the bottoming cycle can compensate for the power decrease of MGT.The results obtained in this paper can provide a reference for the design and operation of the cogeneration system for distributed energy systems(DES).展开更多
文摘The characteristics of fuel from biomass, coal and some waste materials are lower heat value and different compositions. The lower heat value fuel (LHVF) can be used on power engine such as boiler, gas engine and gas turbine. Some laboratory and pilot work have been done, but the work done on micro-gas turbine is still limited. The characteristics of LHVF can cause the operations change of micro-gas turbine designed for nature gas. Some possible adjustment and modification methods were mentioned for the use of LHVF on micro-gas turbine. One kind of representative LHVF was chosen and the operations of micro-gas turbine were analyzed. The temperature field and the non-uniformity scale of temperature distribution of combustor were calculated using FLUENT. The feasibility of different adjustment and modification methods were analyzed according to the efficiency, output power and the non-uniformity scale of temperature distribution.
基金supported by the National Natural Science Foundation of China(Grant No.52176013)the Shanghai Intergovernmental International Cooperation Project,China(No.23160710200)+1 种基金the National Science and Technology Major Project,China(No.J2019-I0012-0012)the UK Royal Society,China(Grant No.IES\R3\213195).
文摘The solid oxide fuel cell(SOFC)power system fueled by NH_(3)is considered one of the most promising solutions for achieving ship decarbonization and carbon neutrality.This paper addresses the technical challenges faced by NH_(3)fuel SOFC ship power system,including slow hydrogen(H2)production,low efficiency,and limited space.It introduces an innovative a NH_(3)-integrated reactor for rapid H2 production,establishes a safe and efficient all-electric SOFC all-electric propulsion system adaptable to various sailing conditions.The system is validated using a 2 kW prototype experimental rig.Results show that the SOFC system,designed for a target ship,has a rated power of 96 kW and an electrical efficiency of 60.13%,meeting the requirements for rated cruising conditions.Under identical catalytic scenarios,the designed reactor,with highly efficient heat transfer,measuring 1.1 m in length,can achieve complete NH_(3)decomposition within 2.94 s,representing a 35%reduction in cracking time and a 42%decrease in required cabin space.During high-load voyage conditions,adjusting the circulation ratio(CR)and ammonia-oxygen ratio(A/O)improves system efficiency across a wide operational range.Among these adjustments,altering the A/O ratio proves to be the most efficient strategy.Under this configuration,the system achieves an efficiency of 55.02%at low load and 61.73%at high load,allowing operation across a power range of 20%to 110%.Experimental results indicate that the error for NH_(3)cracking H2 is less than 3%within the range of 570-700℃,which is relevant to typical ship operation scenarios.At 656℃,the NH_(3)cracking H2 rate reaches 100%.Under these conditions,the SOFC produces 2.045 kW of power with an efficiency of approximately 58.66%.The noise level detected is 58.6 dB,while the concentrations of CO_(2),NO,and SO_(2)in the flue gas approach zero.These findings support the transition of the shipping industry to green,clean systems,contributing significantly to future reductions in ocean carbon emissions.
基金the National Natural Science Foundation of China(Grant No.51806137)Shanghai Sailing Program(Grant No.20QA1404700).
文摘Micro gas turbine(MGT)is widely used in small-scale distributed power systems because of its low emissions and fuel flexibility.However,the under-utilization of its exhaust heat and the low electric efficiency are the main bottlenecks that restrict its application.Additionally,the flexible switching between the power generated by the MGT and the power grid is also a key factor for keeping the secure operation of a distributed power station.Therefore,this paper conducted some experimental investigations of a 30 kW MGT to provide reference solutions for the above issues.This MGT is located at Shanghai Jiao Tong University(SJTU),which is designed by the Gas Turbine Research Institute of SJTU,and is manufactured by a turbo machinery factory in Chongqing,China.The demonstration prototype is mainly composed of a single stage centrifugal compressor,a radial turbine,a combustor,a high-speed pennanent magnet generator,and a control system.The results show that the MGT can achieve steady operation at a low rotational speed from 10000 r/min to 34000 r/min in the case of using oil lubricated bearings,which can greatly reduce the economic cost compared with the use of air bearings.At the same time,the ignition success rate of combustion chamber(CC)reaches 98%at a low rotational speed,and a wide range of stable combustion area can be obtained,because of the novel design method of combustor by referencing the way applied in an axial flow aero-engine.The MGT generating set can achieve functions,such as starting up,ignition,stable operation,loaded operation,grid-connection and stopping.This system also can realize flexibly switching from the start motor mode to the generator mode,and from grid-connected mode to off^grid mode,because the innovative multi-state switching control system is adopted.The above research work can make our state master independent intellectual property rights of micro gas turbine,rather than continue to be subject to the technological monopoly of the developed states,which can provide theoretical and experimental support for the industrialization of MGT in China.
文摘In this paper,the operation perfonnance of three novel kinds of cogeneration systems under design and off-design condition was investigated.The systems are MGT(micro gas turbine)+ORC(organic Rankine cycle)for electricity demand,MGT+ERC(ejector refrigeration cycle)for electricity and cooling demand,and MGT+ORC+ERC for electricity and cooling demand.The effect of 5 different working fluids on cogeneration systems was studied.The results show that under the design condition,when using R600 in the bottoming cycle,the MGT+ORC system has the lowest total output of 117.1 kW with a thermal efficiency of 0.334,and the MGT+ERC system has the largest total output of 142.6 kW with a thermal efficiency of 0.408.For the MGT+ORC+ERC system,the total output is between the other two systems,which is 129.3 kW with a thermal efficiency of 0.370.For the effect of different working fluids,R123 is the most suitable working fluid for MGT+ORC with the maximum electricity output power and R600 is the most suitable working fluid for MGT+ERC with the maximum cooling capacity,while both R600 and R123 can make MGT+ORC+ERC achieve a good comprehensive performance of refrigeration and electricity.The thermal efficiency of three cogeneration systems can be effectively improved under oredesign condition because the bottoming cycle can compensate for the power decrease of MGT.The results obtained in this paper can provide a reference for the design and operation of the cogeneration system for distributed energy systems(DES).
基金the National Natural Science Foundation of China (Grant No.51376123)Shanghai Sailing Program (Grant No.17YF1409800)China's Post-Doctoral Science Fund (No.2017M611561).
