Review of Heat Transfer Parameters using internal t hreaded pipe fitted with inserts of different materials

Abstract

Many heat transfer enhanced techniques have simultaneously been de veloped for the improvement of energy consumption, material saving, size reduction and pumping power reduction. Screw tape inserts in tubes are a typical technique that offer s a higher heat transfer increase and, at the same time, only a mild pressure drop penalty. This study investi gates the heat transfer characteristics of a horizontal tube-in-tube heat exchanger having internal threaded pip e with Screw tape inserts of different materials i.e. Mild steel screw tape and Aluminum sc rew tape inserted in the inner tube. Heat transfer, flow friction characteristics in a threaded tube fitted with sc rew tape, using oil as working fluid are investigated experimentally. Influences of the changing mate rial i.e M.S screw tape and Aluminum screw tape arrangements are also described. The experiments ar e conducted using the tapes with same twist ratios and pitch over a Reynolds number range less than 2,000 in a heat exchanger.