Pulsatile Flow in A Helically Coiled Tube-in-Tube Heat Exchanger

Abstract

Heat exchangers have achieved extensive applications in modern days in every field. They have got wide applications in automobile industries, food processing operations, aerospace applications. Among different types of heat exchangers, helical tube heat exchangers have gained much popularity due to their compactness and effectiveness. Helical heat exchngers provide greater surface area for heat exchange for same floor space. In this paper pulsating flow(both parallel and counter flow) is studied in a model of a helical tube-in-tube heat exchanger using ANSYS 15.0. The results are compared with constant flow(both parallel and counter flow) in the same model of the helical tube-in-tube heat exchanger. Then further analysis is done by studying pulsating flow (both parallel and counter flow) in the same model of helical tube-in-tube heat exchanger but by fixing a thin wire on the surface of the inner helical tube of the heat exchanger model. All analysis is done using ANSYS 15.0 for flow time of 60 seconds in each case. The temperature drops for the hotter fluid and temperature rise for the colder fluid is studied for each case and then comparision is done to establish the best configuration of the above. It is observed that the temperature drop for the hot fluid and temperature rise for cold fluid is: Constant velocity flow < Pulsating flow < Pulsating flow