Design and Development of a Trapezoidal Plate Fin Heat Exchanger for the Prediction of Heat Exchanger Effectiveness

Abstract

A trapezoidal plate-fin exchanger has been designed and developed, and an experimental test rig fabricated to test the plate fin heat exchanger. The heat exchanger was constructed in a 5 layer cross-flow arrangement. The length of the trapezoidal fins between the layers were 380mm and its height, thickness, top width and bottom width were 40mm, 0.5mm, 20mm, and 80mm respectively. A hot fluid test has been conducted to determine the thermo- hydraulic performance of the given heat exchanger at different mass flow rates (4.975 kg/s to 9.751 kg/s) at a hot inlet temperature of 369K. The values of the effectiveness obtained were plotted against the corresponding values mass flow rate to compare and evaluate the variation of the results. Thus, the performance of a heat exchanger with trapezoidal fins has been studied experimentally and it has been determined that: the mass flow rate of the fluids is proportional to the temperature drop of the fluids after passing through the exchanger. Also Increase in mass flow rate, increases the effectiveness of the heat exchanger. Improper insulation influenced heat transfers in heat exchanger cores and caused energy imbalance in the heat exchanger. This study suggests that the calculated effectiveness of 0.98 using trapezoidal plate fin heat exchanger result provides benchmark data to evaluate and predicts the performance of a plate-fin heat exchanger with trapezoidal fins for energy recovery application.

Keywords: Heat exchanger development; trapezoidal fin, effectiveness, heat exchanger analysis; hot and cold fluids

DOI: 10.7176/JETP/9-8-03

Publication date: November 30^th 2019