Enhancing performance of oblique double layer plate microchannel heat exchanger by computational fluid dynamics: Design and performance optimization

Abstract

This study aims to improve the performance of oblique microchannel heat exchangers by modifying conventional straight microchannel configurations. A simulation model using computational fluid dynamics (CFD) is developed to evaluate the efficiency of the heat exchanger by analyzing design parameters such as microchannel width, primary to secondary channel width ratio, and number of oblique cuts along the microchannel. Coefficient of performance (COP) a forthright metric for assessing the interaction between operating parameters and achieving optimal performance is proposed. Utilizing a width of 0.48 mm, path ratio of 2.06, and oblique ratio of 1.61, significant improvements in heat transfer and performance efficiency are achieved. The optimized design leads to a substantial reduction in fabrication material, potentially using more than half less material than before. The optimized design of the oblique microchannel heat exchanger strikes a balance between hot flue gas temperature and coolant Reynolds Number (Re) in a waste heat recovery system which considering waste flue gas from the most common boiling process in industry. The results indicate a promising improvement in hydrothermal performance of 8.48% compared to the baseline case of straight microchannel design, resulting in cost savings and enhanced economic sustainability. These findings establish the oblique microchannel heat exchanger as a viable solution for waste heat recovery systems, showcasing its potential for efficient energy reutilization.