Heat Transfer Enhancement Using Passive Technique

Abstract

Heat exchangers are popularly used in industrial and engineering applications. The design procedure of heat exchangers is quite complicated, as it needs exact analysis of heat transfer rate, efficiency and pressure drop apart from issues such as long-term performance and the economic aspect of the equipment. One of the most important techniques used is passive heat transfer enhancement technique. These techniques when adopted in heat exchanger proved that the overall thermal performance improved significantly. The current work presents computational analysis on a plain tube with and without twisted tape insert at constant wall heat flux. In this work, the validated model predicts heat transfer coefficient for twisted tape of different materials viz. Polyetheretherketone and polytetrafluoroethylene (PEEK and PTFE), respectively. The twisted tape used has a constant twist pitch of 82.5 mm with two different widths (26 and 10 mm) and thickness of 0.487 mm. Pipe with an inner diameter of 27.5 mm is used. Reynolds number varies from 9000 to 14,500. It is observed that there is an enhancement of heat transfer in the range of 75 to 110% for different Reynolds numbers.