Fluid-Dynamics Analysis and Structural Optimization of a 300 kW MicroGas Turbine Recuperator

Abstract

Computational Fluid Dynamics (CFD) is used here to reduce pressure loss and improve heat exchange efficiency in the recuperator associated with a gas turbine. First, numerical simulations of the high-temperature and low-temperature channels are performed and, the calculated results are compared with experimental data (to verify the reliability of the numerical method). Second, the flow field structure of the low-temperature side channel is critically analyzed, leading to the conclusion that the flow velocity distribution in the low-temperature side channel is uneven, and its resistance is significantly higher than that in the high-temperature side. Therefore, five alternate structural schemes are proposed for the optimization of the low-temperature side. In particular, to reduce the flow velocity in the upper channel, the rib length of each channel at the inlet of the low-temperature side region is adjusted. The performances of the 5 schemes are compared, leading to the identification of the configuration able to guarantee a uniform flow rate and minimize the pressure drop. Finally, the heat transfer performance of the optimized recuperator structure is evaluated, and it is shown that the effectiveness of the recuperator is increased by 1.5%.