报道了针对液氮温区混合物工质 Ｊ Ｔ节流制冷机的热力循环优化计算。作者以制冷循环的卡诺系数为目标函数， 考虑了压缩机的容积效率及换热器的传热温差损失等实际情况， 采用复合形优化算法， 在给定热力条件下来优化混合物最佳配比和循环最佳运行压力参数。计算结果对实际混合物制冷循环设计有一定指导意义。 A thermodynamic cycle optimization calculation for JT throttling refrigerator for the mixture of liquid nitrogen and temperature is reported. Taking the Carnot coefficient of the refrigeration cycle as the objective function, the author takes the volumetric efficiency of the compressor and heat transfer loss of heat exchanger as an example, and uses the compound optimization algorithm to optimize the optimal ratio of the mixture under given thermal conditions And cycle the best operating pressure parameters. The calculation results have certain guiding significance for the design of refrigeration cycle of the actual mixture.