Heat Transfer Analysis on the Tube Type Heat Exchanger with Fin Pitch Variations

Abstract

A heat exchanger is a device usually used to dissipate the heat generated during the mechanical processes. To improve the performance of the heat exchanger, a lot of research has been conducted including the addition of fins on the outer surface. This experimental study examines the heat transfer process on the outer surface of the heat exchanger. The heat exchanger was made of galvanized pipes with an inner and outer diameter of 20 mm and 22 mm. The heat exchanger has a pass length of 30 cm, the spacing between the tube of 6 cm and a total length of 6 m. The spiral fin made of an aluminum plate is mounted to the outer surface of the tube pipe of the heat exchanger. It has a thickness of 0.3 mm. The fin pitch of the heat exchangers was varied to 3 cm, 5 cm, and 7 cm. The heat exchanger was fed with hot water at a constant temperature of 80 °C and a flow rate of 0.4 L/s. While, the ambient air was blown at the outer surface of the heat exchanger at three different speeds namely 2.4 m/s, 2.8 m/s, and 3.4 m/s. It is found that the highest convective heat transfer rate and convective heat transfer coefficient are yielded by the heat exchanger with a fin pitch of 3 cm namely, 6607.2 W and 235.8 W/m2K, respectively.