Experimental And Numerical Study On Thermal Contact Resistance Of Finned Tube Heat Exchanger

Finned tube heat exchanger is one of the widely used heat exchangers.Secondary flange finned tube heat exchanger with advances of convenient manufacturing,easy mass production,and low unit cost advantages,it is widely used in a series of heat exchange facilities such as air coolers and so on.However,the secondary flanging fin tube heat exchanger cannot eliminate the thermal contact resistance between the finned tube and the tube,which is severely weakened the heat exchange performance of the finned tube heat exchanger.So the research of thermal contact resistance is necessary.In this paper,the thermal contact resistance of secondary flange finned tube heat exchanger and its influence are studied by means of experimental and numerical simulation.The main contents of the full text are as follows:1)Summarizing the research methods and achievements of the heat exchangers at the present stage.Introducing the several indicators for judgement the economical efficiency of the heat exchangers.Presenting the current research cases and related results for the thermal contact resistance of the heat exchangers.The manufacturing process and problems of secondary flanged fins are presented.And also introducing the papers' research ideas and the main content of the paper.2)An experimental plant for a fin-tube heat exchanger was designed and constructed through relevant technical specifications,and a total of nine different secondary finned tube heat exchangers were experimentally studied;The experimental results were analyzed and evaluated in four groups: different manufacturing technologies group,different fin pitches group,different slice angle group,and different fin thickness group.This part provides experimental data support for subsequent research work3)Through the comparison of experimental data and CFD simulation data,a set of methods for calculating the thermal contact resistance between the finned tube and the fin of the fin-tube heat exchanger was designed,and thermal contact resistance of total nine different types were calculated.It is found that there is a certain relationship between the thermal contact resistance and the fin-tube heat exchanger's fin pitches,fin thickness,slice angle and manufacturing technologies.This study provides support for the subsequent study of the heat transfer effect of the thermal contact resistance of the fin-tube heat exchanger.4)Based on the calculation results of thermal contact resistance,the heat transfer process of nine typical fins was simulated.The heat transfer effect of thermal contact resistance of finned tube heat exchangers was studied.This research method puts forward a new idea for the optimization of finned tube heat exchangers.5)The specific reasons for the change of thermal contact resistance in finned tube heat exchangers were studied.The relationship between thermal contact resistance and contact pressure was demonstrated through theoretical methods.Through the analysis of nine typical fins,the correctness of the research results of the thermal contact resistance in the third part was verified.Through the research content of this article,we can see that the core content of this paper proposes an algorithm for the thermal contact resistance of the finned tube heat exchanger,and subsequent research work is based on this algorithm.Based on this algorithm,this paper proposes a research method that considers the heat transfer performance of the heat exchanger under the effect of thermal contact resistance.The conclusion obtained by this method provides guidance for the improvement and optimization of the finned tube heat exchanger core group.Therefore,this paper has a strong engineering practice and a wide range of application prospects in the field of finned tube heat exchangers.