The Research On The Thermodynamic Optimization Of The Environmental Control System Of Aircraft

In this paper, we make a intensive study based on the design of environmental control system (ECS) of the thermodynamic optimization of the Three-wheel air cycle environmental control system which incorporates features of the high pressure water separation, in order to get the smaller irreversible loss in the system by optimizing the size of heat exchanger and analyzing the entropy generation. The main work includes: at first, we make the calculations of the ECS,and build the model of entropy generation which is caused by heat transfer, friction and pressure change in the ECS; Secondly, we make the calculations of the heat exchanger design and the ECS entropy generation when the geometric size of heat exchanger is adjusted; at the same time, we program the SUMT method to make sure the best geometric size of heat exchanger and the best entropy generation number of the ECS when the design condition is fixed. The results show that the irreversible loss of the system is different when the geometric size is changed and we can make the optimization to heat exchangers in the system; next, when the design condition vary, it is shown that the relation between the entropy generation number, the optimized geometric features with the extern parameters; At last, we analyze the reason that the entropy generation rise and vary in the system in different design conditions, and discuss the problems which need to be pay attention to when we optimize the ECS, and get many useful conclusions.Although all the conclusions are based on the Three-wheel air cycle environmental control system which incorporates features of the high pressure water separation, we could apply the method in this paper for other systems by changing the model, and it can also provide the guidance for designing and optimizing ECS.