Experimental Study And Numerical Simulation On Surface Performance Of Plate-fin Heat Exchanger

Recent studies have concentrated on the development of high-performance compact heat exchangers to reduce energy consumption as well as material cost. Compact heat exchangers are generally characterized by extended surfaces with large surface area/volume ratios that are often configured in either plate-fin or tube-fin arrangements. In a plate-fin exchanger, which finds diverse applications (such as petrochemical engineering, energy and power, aviation, mechanical engineering, and so on.), a variety of augmented surfaces are used: plain fins, wavy fins, serrated fins, perforated fins, pin fins and louvered fins. The performance of a plate-fin heat exchanger is subjected to its fins'surface characteristics. However, being lack of our own fin surfaces performance curves, the thermal design error of the plate-fin heat exchanger made in China is quite large by using the general curves from Japan. Therefore, to obtain fin surface performance curves through experiments and find out the law of the heat-transfer and fluid-flow in the fluid pass based on numerical simulation is a significative and important study, which is just the objective of this paper. The main contributions of the paper are as follows: (1) An indraft heat transfer wind tunnel has been optimized designed based on CFD. And a wind-tunnel testing system for the performance test of the plate-fin heat exchanger has been set up, including air system,steamy system and measuring system. (2) A series of experiments have been carried out on three types of fins. The basic heat-transfer and fluid-friction characteristics of the plate-fin heat exchanger surfaces have been obtained. Comparison of surfaces performance between China and other two countries, America and Japan has been made. The experimental results indicate that the fins show similar pressure drop, and the heat transfer performance of our fins are close to American's. It means that the manufacturing levels of our own have been caught up with the advanced foreign levels. The performance curves of Re-j, Re-f are valuable for designing our plate-fin heat exchangers. (3) The gas flow field in a single pass is simulated with CFD software FLUENT. The effects of fins configuration parameters and operational conditions upon pressure drop and heat transfer performance have been analyzed. The results indicate that the friction and heat transfer are significantly affected by fin height, fin pitch and so on. The serrated fins and wavy fins show better performance in terms of heat transfer than the plain fins. (4) The engineering application of plate-fin heat exchangers has been discussed. A patent product has been designed for saving waste heat in a gas or oil boiler system, from the usage of which, much benefits has been got including economy, environments protection and energy sources saving.