Numerical simulation study for double pipe heat exchanger with spiral fins

Abstract The aim of the presented is to investigate the effects of different helical fin pitches (20, 40, and 60 mm) on the performance of helical fins on inner tube outer surface. With an outer tube diameter of 65–75 mm, an inner tube diameter of 25–35 mm, and a length of 400 mm, water was used as the heat exchange fluid. The cold fluid entered the inner tube at a 20 °C temperature, with a Reynolds number ranging from 3,000 to 10,000. The hot fluid flowed through the annular space between the two tubes at a constant rate. The study utilized numerical simulation in ANSYS FLUENT v.21 software. The inner pipe was constructed of aluminum, while the outer pipe was insulated. The numerical results indicated that heat transfer and thermal performance initially increased and then decreased as the pitch of the helical fins increased.