Analysis of Existing Design and Optimization of Fin Geometry for Intercooler in Reciprocating Air Compressor

Abstract

Compressed air is a basic requirement for any industry to carry out different kinds of operations. The reciprocating air compressor is used in the process industry such as automobile, oil and gas, mining and HVAC, etc. The efficiency and running cost of a compressor are important economic factors for cost-effectiveness. In a multi-stage reciprocating air compressor, intercooling of air is required to enhance the efficiency of the compressor. An intercooler is a heat exchanger located between two stages of compression. The finned tube air-to-air intercooler is used to cool the pressurized air from the previous stage of compression which becomes hotter. An intercooler makes the air cooler by rejecting the heat with the help of a finned tube arrangement and it is an elective way to reduce the work requirement in the next stage of compression. The present study undertakes an analysis of the existing in geometry and configuration to optimize the thermal performance of the intercooler. A mathematical study of the fin tube arrangement is undertaken for a given temperature drop of air in the intercooler and it was found that the present design is 65% over design. Furthermore, fin order to and the optimal design arrangement of the in system, staggered and inline 2D arrangements were studied and simulations were done in which the staggered finned tube arrangement had the maximum temperature drop. For 2D analysis, the analytical and ANSYS Fluent results were compared and the variation was found to be around 6.4%. Furthermore, three different 3D finned tube geometry with different cross-sections were simulated to and the optimum shape of the fin considering the thermal aspect. The 3D simulation of fin tube arrangement was done in ANSYS Fluent and validated with the experimental data for which the variation was found around 9.49%. In the numerical analysis, the trapezoidal fin profile gave the maximum temperature drop and the triangular fin gave minimum temperature drop.