液氮发动机循环分析

新型零排放液氮发动机存在朗肯循环和布雷顿循环两种做功循环方式,为了了解两种循环方式对液氮发动机匹配设计的要求,基于有限时间热力学理论,对比了两种循环对液氮发动机输出功率的影响,研究了液氮发动机在变温热源和恒温冷源之间朗肯循环和布雷顿循环的性能,着重分析了导热率对循环性能及输出功率的影响,为液氮发动机换热器的匹配提供依据.得出换热器的热导率和热容率的匹配决定朗肯循环的最佳循环功率,而与朗肯循环相比布雷顿循环能更好的实现发动机的功率特性的结论.

Analysis of cycle of liquid nitrogen engine

The comparison of output power between two kinds of new zero pollution liquid nitrogen engine cycle modes, Rankine cycle and Branton cycle, was made based on the finite time thermodynamic theory. Under the circumstance of variable temperature heat source and the constant low temperature,the research was made on liquid nitrogen engine performance of two cycle modes, and the effect of heat conductivity on cycle performance and output power was analyzed. The results indicate that the matching of work medium and exchanger heat conductivity decide the best power of Rankine cycle, but the Branton cycle can make the engine better power performance than former one.