Numerical Investigation of Heat Transfer and Erosion Characteristics of a New Waffle Primary Surface Heat Exchanger

Abstract

In this paper, the heat transfer and pressure loss of a new waffle primary surface heat exchangers (WPSHX) with square, spherical and elliptical primary surface structures are numerically investigated. Meanwhile, the discrete phase model (DPM) coupling with the continuous air is applied to study the erosion problem in the primary surface heat exchanger. It is indicated that the elliptical WPSHX may decrease the air pressure loss with 87.3% at general operating condition and the heat transfer performance will decrease about 30.2% as well. The empirical correlations of the Nusselt number and friction factor are figured out with the form of Dittus-Boelter equation. The numerical result shows that the major erosion issue happens in the front of the heat exchanger due to the direct hit of particles. The elliptical WPSHX, which has much streamline structure, can reduce the erosion rate of the material effectively.