HEAT TRANSFER ENHANCEMENT BY USING INSERT TWISTED TAPE (A REVIEW)

Mechanical Engineering

Heat transfer enhancement techniques refer to different methods used to increase rate of heat transfer without affecting much the overall performance of the system. These techniques are used in heat exchangers. Some of the applications of heat exchangers are-in process industries, thermal Power plants, air-conditioning equipments, refrigerators, radiators for space vehicles, automobiles etc. These techniques broadly are of three types viz. passive, active and compound techniques. The present paper is a review of the passive enhancement techniques used in the recent past. Twisted tapes play a very important role in heat transfer enhancement of electronic cooling systems, heat exchangers etc. The present work shows the results obtained from experimental investigations of the augmentation of turbulent flow heat transfer in a horizontal tube by means of varying width twisted tape inserts with air as the working fluid. In order to reduce excessive pressure drops associated with full width twisted tape inserts, with less corresponding reduction in heat transfer coefficients, reduced width twisted tapes of widths ranging 12 mm, which are lower than the tube inside diameter of 50 mm are used. Experiments were carried out for plain tube with/without twisted tape insert at constant wall heat flux and different mass flow rates. The twisted tapes are of three different twist ratios (5,5 and 5.8 mm) each with three different widths (12,12 and 12 mm) respectively.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.