Energy and Exergy Performance Analysis of a Counter-Flow Secondary System in an Economical Mini Water Chiller

Mini water chillers are small-capacity cooling systems widely used in laboratory applications and light industries due to their ability to maintain stable temperatures with relatively low power consumption. Nevertheless, the thermal efficiency of these systems can be further improved through optimization of fluid flow configurations in the secondary loop. This study investigates the effect of a counter-flow heat exchanger configuration on the energy and exergy performance of an economical mini water chiller secondary system. The research employs both theoretical and experimental approaches by measuring inlet and outlet fluid temperatures, mass flow rates, and electrical power consumption. Energy analysis is applied to determine the coefficient of performance (COP), while exergy analysis is used to evaluate exergy efficiency (ηₑₓ) and the rate of exergy destruction (Ėd). The results indicate that the counter-flow configuration enhances the system COP by approximately 8–12% compared to a parallel-flow model. In addition, overall exergy efficiency increases by up to 9%, with the most significant reduction in exergy destruction occurring in the secondary heat exchanger. These findings demonstrate that the implementation of a counter-flow model is effective in improving both energy performance and exergy quality in energy-efficient mini cooling systems.