Research on the performance difference between single wavy channel and full-flow wavy channel of cross wavy recuperator

Abstract

Due to the excellent heat transfer performance of the cross wavy heat exchanger, it is widely used as a micro gas turbine recuperator. At present, scholars have extensively studied the thermodynamic performance of its single channel, but there is a lack of research on its full-flow channel. In this paper, a three-dimensional model of cross wavy full-flow channel is established, and the thermodynamic performance is studied by numerical simulation. The accuracy of the numerical simulation method is verified by experiment. It is found that compared with the single channel model, the Nu of the full-flow channel model varies from -13.51 % to 6.76 % under all working conditions. The variation range of f is 0.89 % to 10.27 %. The sudden expansion and contraction of the inlet and outlet channels cause a sudden change in the thermodynamic performance of the adjacent wavy channels. In addition, the Nu of the air channel decreases continuously along the flow direction, and f increases continuously, while the gas channel is opposite. The reasons for the change of thermodynamic performance are analyzed by vorticity and temperature gradient distribution. Finally, the correlation formula of Nu and f in the full-flow channel with adjacent channels of inlet and outlet is summarized.