The Optimization Design Of Three-fluid Heatexchanger Used In Airplane

High power airborne electronic equipment is widely used with the development of aviation technology and the continuously improvement for the overall performance and military combat effectiveness of the plane, which a higher cooling requirement the aircraft environmental control system have been put forward. Traditional air cycle refrigeration system has been difficult to meet the demand of cooling for the airborne electronic equipment, the multi-stream Heat Exchanger with high efficient and compact structure is developed to meet the increasing demands.The selections of choosing the number 65 antifreeze、R134a and air for the heat transfer medium in this paper. The design、performance analysis and optimized design are based on the methods of numerical calculation and experimental simulation. The specific work contents and conclusions are as follows:(1)A calculation method for the Three-Way Flow Exchanger based on the cold and hot fluid taxonomy is deduced. And a design calculation for the three flow heat exchanger of the airborne is done to get the structure parameters to meet the design requirements of the heat exchanger.(2)The design calculation for a given plate-fin heat exchanger is done through the heat exchanger design calculation software ASPEN. The heat transfer effect can be improved and the pressure loss can be reduced by changing the channel arrangement and the fluid pattern. At the same time, the results show that: the counter flow method for the cold and hot fluid has a smaller pressure loss at the air end. And analyze the influence of the relative flow value between the cold and hot fuild on the channel configuration of the heat exchanger. The cross flow with the interval arrangement way for the cold and hot fluid is the best way by taking the heat exchange efficiency and the pressure loss into account.(3)The experiment platform for the three flow heat exchanger performance analysis is done to prove the correctness and feasibility of the design scheme of the airborne heat exchanger. Which shows that: the cooling capacity increase with the cold fluid flow when all the cold fluid is air, but the cooling capacity exceed when the cold fluid flow increased to a certain extent which effect the heat transfer efficiency, and the temperature drop rate decreased for the hot fluid.The results of the study provides technical reference for the practical application of the airborne three flow heat exchanger.