Experimental and CFD Analysis of a Helical Coiled Heat Exchanger Using Various Fluids

Abstract

Abstract Shell and Helically coiled heat exchangers enhance the heat transfer rate by increasing surface area and inducing secondary fluid flow. In this paper, the heat transfer rate and effectiveness of a shell and helically coiled heat exchanger using two fluids have been analyzed experimentally and numerically. The majority of previous studies in this regard has been on helically coiled heat exchangers with water as the working fluid. The application of helically coiled heat exchanger in cooling the tube side fluid with a coolant inside the shell has been reported in many studies. There have not been many such studies using other working fluids like water-ethylene glycol inside the tube in a coiled heat exchanger. In this work, a helically coiled tube heat exchanger has been designed and a corresponding 3D computational fluid dynamics (CFD) model has been developed. Assessment has been done on the feasibility of using ethylene glycol-water mixture as a working fluid by conducting an experimental and numerical comparison with water. Two different fluids have been used inside the helical tube, water and water-ethylene glycol (50-50). An experimental set-up has been fabricated for evaluation of thermal properties of the shell and helically coiled heat exchanger. This work analyses the behavior of parameters like heat transfer rate, pressure drop and effectiveness by introducing hot fluid through shell and cold fluid through tube under variable flow rate. Enhancement of heat transfer rate has been observed for ethylene glycol-water mixture at higher mass flow rate. The simulation data is in close agreement with the experimental data.