The Numerical Simulation And Experimental Research On Heat Transfer Performance Of Tube Fin Heat Exchanger

Heat exchanger is widely used in many fields,such as automobile,atomic energy,aerospace,petrochemical and so on.Research and design of tube fin heat exchanger with high efficiency and high performance is an important way to solve the problem of high temperature heat transfer and ensure the normal operation of the equipment,but also an important measure to save energy and reduce consumption.In this paper,the heat transfer performance of the finned tube exchanger for aviation is studied from two aspects of numerical simulation and experiment.By changing the internal structure of heat exchanger unit,improving the fluid disturbance and heat transfer area in heat exchanger,to study the strengthening effect and find an effective way to improve the heat exchange efficiency of tube fin heat exchanger,so as to provide theoretical reference for the design and modification of tube fin heat exchanger Specific research contents and conclusions are as follows:(1)Through the numerical simulation analysis of the flow field characteristics of finned tube heat exchanger before and after optimizing with straight fin undrilling or drilling holes.The research showed that,after optimization,the outlet temperature of traight fin with holes is higher than undrilling holes 0.13 ?,the pressure drop increased by 0.26 Pa,the heat transfer coefficient increased by 0.67%.Although the pressure drop increases after the optimization of the straight finned tube heat exchanger with holes,the flow disturbance is stronger and the heat transfer effect is better.(2)Based on the FLUENT numerical simulation software,the heat transfer performance and resistance characteristics of straight fin tube heat exchangers before or after optimization and corrugated fin tube heat exchangers were studied.Compared to the straight fin without hole,the Nusselt number of the straight fin with holes increased by 0.3%~0.67%,the Nusselt number of the corrugated fin increased by 0.88%~11.38%,the pressure drop is also greatly increased,and the optimized corrugated finned tube heat exchanger has better heat transfer performance.(3)Taking straight finned tube heat exchanger with two rows as the model,the influence of different fin spacing on the straight finned tube heat exchanger without holes and the effect of fin thickness,fin tube outer radius,hole diameters on the heat transfer performance of the finned tube heat exchanger with holes were analyzed in kerosene side.Research shows that the fin spacing has a great influence on the heat transfer coefficient of the straight finned tube heat exchanger without holes,but has little effect on pressure drop.In a certain range,with the increase of fin spacing,the heat transfer coefficient increases.But with the fin spacing continuing to increase,the heat transfer coefficient decreases.For the straight fin with holes,the heat transfer coefficient decreases with the increase of fin thickness,but the degree of reduction is not obvious.And it increases with the increase of the outer radius and the aperture diameter.It can be seen that the fin thickness has little effect on the heat transfer coefficient,but the outer radius of the finned tube and the aperture of the holes have great influence on the heat transfer coefficient.(4)From the experimental aspect to study the heat transfer characteristics of tube fin heat exchanger.The results show that,in the same conditions,the higher the inlet temperature of the hot side hydraulic oil the greater the inlet and outlet temperature difference and the better heat transfer capacity.Properly reducing the length of core can make the total heat transfer rate of heat exchanger decreased,but the temperature drop is large,heat transfer capacity is well,and the flow resistance of hydraulic oil in hot side is greatly reduced,which makes the comprehensive heat transfer effect better.