NUMERICAL STUDY OF THE INFLUENCE OF DESIGN PARAMETERS ON HEAT TRANSFER IN A HELICALLY COILED HEAT EXCHANGER

Abstract

Heat exchangers play an important role in the industries comprising heat transfer applications like power plants, refi neries, etc. Enhancing the heat transfer coeffi cient can be achieved by increasing the area of heat transfer per unit volume. This could be achieved by considering a helically coiled tube as a heat exchanger. The present paper investigates the eff ect of different design parameters like the tube diameter, pitch circle diameter, and pitch of the coil on heat transfer in a helical heat exchanger. A helically coiled heat exchanger was simulated for constant wall temperature boundary conditions. It was observed that the Nusselt number, heat transfer coeffi cients, and pressure drop were signifi cantly aff ected by the change in the tube diameter and pitch circle diameter of the coil. For a mass fl ow rate of 0.05 kg/s, the average Nusselt number decreases by 8.8% when the pitch circle diameter is changed from 30 to 150 mm. When the tube diameter is increased from 8 to12 mm, the Nusselt number was decreased by 62%. The infl uence of coil pitch on the heat transfer was not that signifi cant.