The effects of fin height, fin-tube contact thickness and louver length on the performance of a compact fin-and-tube heat exchanger

In this paper, the effects of fin height, louver length and fin-tube contact thickness on the amount of heat transfer and pressure drop in a compact louvered fin-and-tube heat exchanger were studied experimentally and numerically using the 𝜀 -𝑁𝑇𝑈 method.The effects of fintube contact thickness (with the variations of this thickness being more than or less than fin thickness variation) and fin height and also the relationship between Louvre length and fin height were examined.To validate the modeling, first, the numerical model was compared with an experimental prototype, and a good agreement was observed between the experimental and numerical results.The modeling results indicate that the increase in the fin-tube contact thickness, until the contact thickness becomes equal to fin thickness, leads to the improvement of heat exchanger performance; but beyond that, it is ineffective.Also, heat exchanger performance improves with the increase of louver length at a fixed fin height.According to the results, the minimum Louvre length should be 1.0 mm less than the fin height.An analytical equation relating Louvre length to fin height has been obtained, which agrees with model results by up to 98%.