A Heat Recovery Device using Oscillating Heat Pipe with Circular and Elliptical Tubes

Abstract

In this study, an oscillating heat pipe heat exchanger has been used as a heat recovery device in air ductwork, and the characteristics of the thermal performance of the energy-saving were investigated by using a circular and elliptical cross-sectional tubes. An experimental study was conducted by oscillating heat pipe made from copper with an inner diameter of 3.5 mm for the conventional tube, and the major and minor axis of 4.2 and 2.2 mm for the elliptical tube. The working fluid was water with filling ratio of 50% of the total volume. The experimental data implied that the thermal effectiveness and the energy-saving highly affected by the inlet air temperature and velocity. The proposed model of the oscillating heat pipe heat exchanger possessed the effectiveness of 19.5% at 50 ºC and 0.5 m/s, and the potential energy-saving of 1117 W at 50 ºC and 2 m/s. The comparison results between the elliptical and conventional cross-sectional area of oscillating heat pipe heat exchanger indicated that the energy-saving and effectiveness enhanced by the ratio of 18%, and 14%.