Numerical study of heat transfer of wavy channel supercritical CO2 PCHE with various channel geometries

Abstract

Printed Circuit Heat Exchanger (PCHE) is a widely chosen plate type compact heat exchanger for highpressure application. Increasing performance of printed circuit heat exchanger (PCHE) is very important for improvement of thermal efficiency of supercritical CO2Brayton cycle. The innovation of this paper is using triangular and trapezoidal channels instead of conventional circle channels to improve the performance of wavy printed circuit heat exchangers with sCO2 as working fluid. Due to the turbulent flow, the turbulence model SST k-ω was used, which is a suitable model for the flow near the wall and its separation, and has been used in many similar studies. ANSYS FLUENT 18.2 is used in this paper to solve all the governing equations . In this study, heat transfer performance of a sinusoidal wavy channel PCHE numerically investigated. The effect of channel geometries in different Reynolds number are studied and the results of them are compared to obtain best condition for augmentation in heat transfer rate. Based on the results Trapezoid channel at Reynolds number 13,000 has the best heat transfer rate which is about 48% more than triangular one.

Keywords

• CO2 Brayton cycle
• PCHE
• wavy channel
• CFD