On the performance of a vertical helical coil heat exchanger. Numerical model and experimental validation

A numerical model was developed in order to predict the heat transfer process and pressure drop in a vertical helical coil heat exchanger (HCHE) located inside a fluid storage tank in which water is used as inner and outer fluid. Natural convection was considered as boundary condition for the HCHE outer surface. The model was validated with experimental data obtained from an own facility with two HCHEs tested under several operating conditions. The model developed was used to evaluate the main HCHE representative geometrical parameter's influence on the overall heat transfer coefficient and pressure drop. The results show that by increasing the tube diameter causes an increase of the Nusselt number and a larger heat transfer rate to pressure drop ratio is obtained.