Research On Enhancing Heat Transfer Performance Of Circular Plate And Shell Oil Cooler

Circular plate and shell heat exchanger not only has compact volume and efficiency heat transfer ability, but also can bear the high pressure of 6 MPa. Therefore, it can be well applied to the lubricating-oil cooler. This article studies on its flow and heat transfer characteristics through experiment and numerical simulation.Through the experiment of circular plate and shell oil cooler and square plate oil cooler,it is found that in the multi-pass circular plate and shell oil cooler, the heat transfer and pressure drop characteristics of the previous pass are better than ones of the next pass; under the same pressure drop, the comprehensive performance of circular plate and shell oil cooler is better than that of square plate oil cooler. In addition,a new separation of heat transfer coefficient is proposed because existing separation methods can't deal with circular plate and shell oil cooler. The error of separating result is less than 5%.Considering high cost of experiments, CFD simulation is used to study the effect of structure parameters of circular corrugation plates and pass structure on flow and heat transfer characteristics. It is found that as corrugation angle ? increasing from 15° to 60°,both of heat transfer coefficient and pressure drop increase. But as corrugation angle ?outnumbers 60°, heat transfer ability keep unchanged,and pressure drop still increases; As ratio of pitch and height increasing, heat transfer ability and pressure drop increase together.The above results are same with existing researches. However, there are some difference: as corrugation angle ? increasing, flow pattern keep zig-zag flow, never changing. When ratio of pitch and height reduces, flow pattern transform from criss-crossing flow to zig-zag flow;corrugation styles nearly have nothing with flow and heat transfer characteristics of circular plate and shell oil cooler. In addition, increasing parallel channel number and Reynolds number will makes flow distribution worse and pressure drop observably increase. It also deteriorates heat transfer ability, but its influence is slight. In the research range, when channels number outnumbers 75, the pressure drop of one-pass circular plate and shell oil cooler is bigger than two-pass one. Therefore, in order to enhance flow and heat transfer characteristics, corrugation angle should be 60°, ratio of pitch and height small, and when Re=20, parallel channels numbers in a pass less than 75.