Optimum structural design of a heat exchanger for gas-circulation systems

T-type gas-circulation systems are widely used in gas lasers to remove waste heat from the discharge process. The structure of the heat exchanger is a very important factor that affects the performance of a T-type gas-circulation system. To develop a high-performance heat exchanger for such a gas-circulation application, a computational fluid dynamics approach was adopted for this study. A three-dimensional numerical model was established. A detailed study focused on the influence of the shape of the channel and the location of the finned tubes on the performance of the heat exchanger. Based on the heat-transfer characteristics and the flow structure, a novel geometric structure was proposed to reduce the volume of the heat exchanger. Comprehensive simulations to determine the optimum locations for the finned tubes were also conducted. As a result of this optimization, the heat exchanger for a T-type gas-circulation system could be made more compact and its pressure loss penalty decreased by 11.5% even though its heat-transfer ability remained unchanged. In addition, the results of a theoretical analysis and numerical simulation were found to be in good agreement with the results of the experiment, indicating the validity of the results of the research.