Study on the influence of circumferential shape on the performance of cross wavy primary surface heat exchanger channel

Abstract

The primary surface heat exchanger can be described as a compact and highly efficient heat exchanger. In contrast, the cross wavy primary surface heat exchangers are suitable for microturbines. Based on the study of circular cross wavy channel, this study innovatively proposed the triangular cross wavy channel to improve the fluid flow conditions and the rectangular cross wavy channel to increase the overall heat exchange of the channel. The applicability domain of the three types of channels is summarized by numerical simulation. The circular cross wavy channels have the smallest irreversible loss, the triangular cross wavy channels have the highest efficiency and the rectangular channels have the largest total heat transfer. Moreover, the correlations of Nusselt number and friction factor are proposed. The correlations for the Nusselt number and friction coefficient have been validated, and the average absolute errors are 2.71 % and 7.85 % respectively. The results show that the correlation formulas can effectively predict the resistance and heat transfer performance of the cross wavy heat exchange channel.