Thermal and Hydraulic Performance of an SCO_2 Printed Circuit Heat Exchanger (PCHE) with New Channel Geometry based on a Cosine Curve

摘要

Printed circuit heat exchangers (PCHE) play a critical role in the performance and layout sizing of the new supercritical CO_2 power cycle. The current study aims to predict the thermal and hydraulic performance of the new geometry of sCO_2 PCHE. In this new geometry, conventional zig zag geometry has been replaced with the new channel geometry that is based on the curve of the cosine function. The new geometry has eliminated the recirculation zones that result in regions with low rates of heat transfer. Boundary reinitialization has been achieved by a discontinuous fin structure. Thermal and hydraulic performance of the printed heat exchanger were evaluated using the commercial ANSYS-CFX code. The computational model was validated by using conventional geometry and comparing numerical results with published correlations. Discretization of the computation domain was conducted using ANSYS ICEM-CFD and ANSYS-Mesh. Properties of supercritical carbon dioxide (sCO_2) were computed using an in-house Matlab code that was linked with NIST Refprop. The same code was used to write the properties in the real gas property (rgp) table which was then supplied to ANSYS CFX in rgp file format.