根据热力学第二定律，提出采用多目标优化方法对飞机环境控制系统进行最小熵产分析. 选取起飞、加速爬升和高空超音速巡航为设计点，以系统熵产最小为目标函数建立优化模型，并进行了优化计算，分析了热交换器流比、引气流量、涡轮和压气机压力比在不同飞行阶段对系统熵产的影响. 为克服在不同飞行阶段使系统熵产减小对设计变量的要求不一致的问题，将各设计点系统熵产最小作为不同目标函数建立多目标优化模型，并应用NSGA-Ⅱ算法进行优化计算得到了非劣最优解集，在此基础上进行方案决策. 仿真结果验证了方法的有效性.

 Based on the second law of thermodynamics, minimum entropy generation analysis of aircraft environmental control is conducted using the multi-objective optimization method. To design takeoff, climb and supersonic cruise, and take entropy generation minimum as the objective function, an optimization model is established. In the optimization computation, influences of flow ratio of heat exchanger, mass flow of bleed air, pressure ratio of compressor and turbine on system entropy generation during different flight phases are analyzed. To overcome the conflict between design variables during different phases, a multi-objective optimization model is established with minimum entropy generations as different objective functions at the
design points. The Pareto optimal set is obtained using the NSGA-II algorithm, leading to an optimal scheme. Simulation shows validity of the proposed method.