Author : Shravani A. Phule and Kundlik V. Mali

In the present study, heat transfer from hot water to cold water by double pipe heat exchanger for plain tube and plain tube with twisted wire brush inserts is experimentally investigated. The experiments were carried out for counter flow configuration with hot water in the inner tube and cold water flowing in the annulus through outer tube. All the experiments were conducted by varying hot water Reynolds number at constant cold water Reynolds number in the laminar flow region. The horizontal double pipe heat exchanger is made from straight copper tube with inner tube and outer tube diameters of 15 and 25 mm, respectively. The twisted wire brush inserts were fabricated by winding a 0.2 mm diameter of the copper wires over a 2 mm diameter two twisted iron core-rods. All the required parameters like inlet and outlet temperature of hot and cold water, flow rates of both hot and cold water were measured using appropriate instruments. Effect of inlet fluid temperature and other relevant parameters on heat transfer characteristics and pressure drop were studied. The convective heat transfer coefficient of double pipe heat exchanger under various operating conditions was determined.

Keywords: Twisted wire brush inserts, double pipe heat exchanger, Heat transfer enhancement