Numerical study of the influence of design parameters on heat transfer in a helically coiled heat exchanger

Heat exchangers play an important role in the industries comprising heat transfer applications like power plants, refineries, etc. Enhancing the heat transfer coefficient 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 effect 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 coefficients, and pressure drop were significantly affected by the change in the tube diameter and pitch circle diameter of the coil. For a mass flow 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 to 12 mm, the Nusselt number was decreased by 62%. The influence of coil pitch on the heat transfer was not that significant.