铜铝复合母线(TLF bus bar)是一种新型铜包铝结构的复合导体材料,此材料既保持了铜母线(copper bus bar)表面抗氧化能力强的特点,又具有铝资源多,质量轻,价格低的优点,是替代铜母线的极佳材料。本文实验研究了相同电流规格下的铜母线及...铜铝复合母线(TLF bus bar)是一种新型铜包铝结构的复合导体材料,此材料既保持了铜母线(copper bus bar)表面抗氧化能力强的特点,又具有铝资源多,质量轻,价格低的优点,是替代铜母线的极佳材料。本文实验研究了相同电流规格下的铜母线及铜铝复合母线温升与截面积的关系,分析了低压成套设备中铜铝复合母线替换铜母线的技术参数。结果表明:铜铝复合母线宽度增加20%或厚度增加33%即可有效取代铜母线。展开更多
In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat ...In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat to electricity and the fuel heat sink increase in recooling cycle are experimentally investigated for fuel conversion rate and components of gas cracked fuel products at different fuel temperatures.The results indicate that the total fuel heat sink(i.e.,physical+chemical+recooling) of a recooling cycle is obviously higher than the heat sink of fuel itself,and the maximum heat sink increment is as high as 0.4 MJ/kg throughout the recooling cycle.Furthermore,the cracked fuel mixture has a significant capacity of doing work.The thermodynamic power generation scheme,which adopts the cracked fuel gas mixture as the working fluid,is a potential power generation cycle,and the maximum specific power generation is about 500 kW/kg.Turbine-pump scheme using cracked fuel gas mixture is also a potential fuel feeding cycle.展开更多
Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation...Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.展开更多
This paper discusses thermo-conductive plastic finned tube radiators used in water saving type powerstations. First, the development of thermo-conductive plastics is introduced. Second, in order todetermine the ration...This paper discusses thermo-conductive plastic finned tube radiators used in water saving type powerstations. First, the development of thermo-conductive plastics is introduced. Second, in order todetermine the rational geometric dimensions of thermo-conductive plastic finned tubes, an objectivefunction which takes the minimum volume of the consumed material for making finned tubes as an ob-ject is introduced. On the basis of the function, the economy comparison between thermaxonductiveplastic finned tubes and metal finned tubes is conducted.展开更多
文摘铜铝复合母线(TLF bus bar)是一种新型铜包铝结构的复合导体材料,此材料既保持了铜母线(copper bus bar)表面抗氧化能力强的特点,又具有铝资源多,质量轻,价格低的优点,是替代铜母线的极佳材料。本文实验研究了相同电流规格下的铜母线及铜铝复合母线温升与截面积的关系,分析了低压成套设备中铜铝复合母线替换铜母线的技术参数。结果表明:铜铝复合母线宽度增加20%或厚度增加33%即可有效取代铜母线。
基金supported by the Key Program of the National Natural Science Foundation of China (Grant No. 51076035)
文摘In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat to electricity and the fuel heat sink increase in recooling cycle are experimentally investigated for fuel conversion rate and components of gas cracked fuel products at different fuel temperatures.The results indicate that the total fuel heat sink(i.e.,physical+chemical+recooling) of a recooling cycle is obviously higher than the heat sink of fuel itself,and the maximum heat sink increment is as high as 0.4 MJ/kg throughout the recooling cycle.Furthermore,the cracked fuel mixture has a significant capacity of doing work.The thermodynamic power generation scheme,which adopts the cracked fuel gas mixture as the working fluid,is a potential power generation cycle,and the maximum specific power generation is about 500 kW/kg.Turbine-pump scheme using cracked fuel gas mixture is also a potential fuel feeding cycle.
基金supported by the sponsors of the Energy Efficiency and Heat Pumps Consortium and Modeling and Optimization Consortium at the Center for Environmental Energy Engineering(CEEE)of the University of Maryland and Heat Transfer Technologies LLC for manufacturing the heat exchanger prototype
文摘Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.
文摘This paper discusses thermo-conductive plastic finned tube radiators used in water saving type powerstations. First, the development of thermo-conductive plastics is introduced. Second, in order todetermine the rational geometric dimensions of thermo-conductive plastic finned tubes, an objectivefunction which takes the minimum volume of the consumed material for making finned tubes as an ob-ject is introduced. On the basis of the function, the economy comparison between thermaxonductiveplastic finned tubes and metal finned tubes is conducted.
