Performance Evaluation of Coiled Spring Wound Compact Heat Exchanger

A compact heat exchanger performs better under the same conditions as a traditional heat exchanger with less size, weight, and cost. In this study, a compact heat exchanger is prepared by coiling a copper spring of 19 gauge on a circular copper tube. Due to this wounding of spring the inner wire of the spring will touch the tubes of heat exchanger which will disturb the viscous sub layer of the fluid flow and hence resistance to heat transfer will decrease. The outer wire of the spring will act as fins and hence surface area of compact heat exchanger will increase which results in increase in heat transfer. The entire assembly of copper spring attached to copper tube is inserted in a PVC pipe. The temperatures at the inlet and outlet of heat exchanger are measured with calibrated thermocouple. The pressure drop at the inlet outlet is also measured. It is observed that the effectiveness of compact heat exchanger is increased by 2.1 times while the overall heat transfer coefficient is increased by 2.69 times of regular heat exchanger.