HEAT TRANSFER ENHANCEMENT IN HEAT EXCHANGER USING TANGENTIAL INJECTOR TYPE SWIRL GENERATOR

Abstract

n this work, the effect of heat transfer enhancement of swirl generator with tangential injection of fluid was examined. The five tangential injectors are placed such that they are equidistance along the length of pipe to improve the efficiency of heat transfer in concentric pipe heat exchanger the injectors are designed and placed such that it creates tangential flow in the pipe. The experiment performed for water as working fluid, hot water flowing through inner tube of material mild steel with inner diameter (ID) 16 mm and outer diameter (OD) 21 mm and cold water flowing through annulus space to generate swirling motion. The outer tube of material UPVC (un-plasticized polyvinyl chloride) having ID 35 mm and OD 42 mm. The experiment was performed for different Reynolds number ranging from 2200- 4600 for parallel and counter flow configurations. It is observed from the experimental results that the heat transfer rate increased with increase in Reynolds number. Heat transfer rate was increased about 20 % to 70 % with tangential injector type swirl generator than the heat exchanger without tangential injectors. It was also observed that the maximum heat transfer coefficients (1613 W/ m2K) could be achieved at Reynolds number of 4600 for all (five) nozzles opening with 70 % increase in heat transfer.