Simulation Study And Optimization Design Of An Open-hole Elliptical Louvered Fin Heat Exchange

Parallel flow heat exchanger is an important part of automobile air conditioning to ensure the comfort of automobile interior.Because of its advantages of small volume,compact structure and high efficiency,the design of parallel flow heat exchanger is more suitable for the requirements of small volume of automobile air conditioning and is widely used.Most scholars at home and abroad use theoretical and scientific models to study louver fins,optimize the structure of fins to give full play to the best effect of louver fins,and meet the requirements of strengthening the overall comprehensive performance of parallel flow heat exchangers.In this paper,based on the louver fins in parallel flow heat exchangers,a new type of elliptical louver fins with open holes is designed and proposed.The heat exchange performance and flow performance of the heat exchanger are analyzed by numerical simulation and simulation data.The main research contents are as follows :(1)After simplifying the model of louvered fins,the grid independence of conventional louvered fins was verified by software simulation analysis,and the temperature,velocity and pressure changes of the model under five different conditions were compared and analyzed.Comparing the heat transfer factor and resistance factor of the simulation results with the experimental results,it can be seen that the maximum error of the heat transfer factor is less than 10 %,the maximum error of the resistance factor is less than 12 %,and the error is within the allowable range.Therefore,the model simulation is reasonable and meets the engineering requirements.(2)The simulation results of conventional louvered fins and open-hole elliptical louvered fins are compared and analyzed.The simulation results show that the flow resistance and heat transfer performance of open-hole elliptical louvered fins are better than those of conventional louvered fins.The heat transfer factor of open-hole elliptical louvered fins is about 12 % ～ 26.4 %higher than that of conventional louvered fins.The resistance factor decreased by about 17.5 %～ 26.8 %,and the comprehensive evaluation factor increased by about 8.2 % ～ 18.9 %.(3)The fin structure of the open-hole elliptical louver is further optimized,and the optimized model is numerically simulated.In the Reynolds number range of 344 ～ 650,the shape of the open hole,the radius of the circular hole R,the spacing of the holes D and the arrangement of the holes of the open-hole elliptical louver are changed.The influence of different parameter structures on the heat transfer performance of the fin is analyzed.The results show that when the circular hole,the radius of the circular hole R = 0.2mm,the spacing of the circular holes D=2mm,and the arrangement is up and down(S-shaped),the open-hole elliptical louver has the best comprehensive performance.According to the range analysis of orthogonal test,the primary and secondary factors affecting the better comprehensive performance of openhole elliptical shutter fins are from large to small: hole shape,hole spacing,arrangement mode and hole radius.