Comparison of the overall heat transfer coefficient value of double pipe heat exchanger without and with various twisted inserts of different twist ratios

Abstract

Techniques for heat transfer augmentation are relevant to several engineering applications. In recent years, the high cost of energy and material has resulted in an increased effort, aimed at producing more efficient heat exchange equipment. Furthermore, sometimes there is a need for miniaturization of a heat exchanger in specific applications, such as space application, through an augmentation of heat transfer. For this process a double pipe heat exchanger is chosen which is normally used for improving the process of heat exchange between two fluids which are at different temperatures. In an attempt to improve heat exchanger performance in a better way a twisted sheet is inserted into the inner pipe. These types of twisted sheet inserted heat exchangers can be useful in overhead condensers, compression inter stage coolers etc.The main objective of our project is to create turbulence in the hot fluid channel with the help of twisted sheet inserts so that an increase in the heat transfer coefficient can be identified. By conducting experiments, the overall heat transfer coefficient value of double pipe heat exchanger without and with various twisted inserts of different twist ratios will be compared. Keywords - Aluminum twisted tubes, Counter flow, Double pipe heat exchanger, Heat exchangers, Heat transfer co-efficient.