Study On Numerical Simulation Of Finned Tube Heat Exchanger

Heat exchanger is an important part of many industrial applications,fin tube heat exchanger is a kind of compact heat exchanger widely used in the field of air conditioning engineering.In order to make full use of energy and save energy,it is necessary to study the technology of strengthening heat exchange to further improve the heat exchange characteristics of its heat exchanger.The air side heat resistance accounts for 70% to 90% of the total heat resistance of the heat exchanger,so in order to improve the overall heat transfer performance of the heat exchanger,it is necessary to conduct in-depth research on the technology of strengthening the air side heat transfer performance.In this paper,the heat transfer and flow characteristics of plain fin,herringbone wave fin,plain fin with vortex generator and herringbone wave fin tube heat exchanger are studied by CFD numerical simulation technology.Firstly,the corresponding mathematical model and three-dimensional geometric model are established,the appropriate fin element is selected as the calculation domain,and the calculation domain is adaptively meshed to verify its grid independence,and the accuracy of the model is determined by comparing the experimental results with the simulation results.Then,the friction factor(f),Colburn factor(j),and efficiency index(j/ f)of various structural parameters(fin spacing,tube spacing,fin thickness,wave height,angle of attack,vortex generator type,etc.)under different Reynolds numbers under dry conditions are obtained by numerical simulation,and the corresponding flow field diagram,velocity,temperature and pressure distribution diagram are obtained to understand the strengthening heat exchange mechanism of different fins.The results show that: for plain fin and herringbone wave fin tube heat exchanger,the tube spacing and tube arrangement have a great influence on its heat transfer and flow characteristics,the fin thickness and fin spacing have a little influence on it,and the elliptical tube has a high efficiency index(j/ f)and a good comprehensive heat transfer performance;Compared with flat fin,herringbone corrugated fin has higher Colburn factor(j),so it has better heat transfer characteristics;Compared with other fins in this paper,the fin tube heat exchanger with vortex generator has higher heat transfer efficiency all the time;The fin tube heat exchanger equipped with vortex generator V1 has better heat transfer enhancement effect at a larger angle of attack,The fin tube heat exchanger equipped with vortex generator V3 has better heat transfer enhancement effect at a smaller angle of attack.