Cooling heat transfer and pressure drop of supercritical CO2 in wavy microchannels with consistent and opposite crests and troughs

Abstract

A numerical study on cooling heat transfer and pressure drop of supercritical CO2 in horizontal wavy microchannels with consistent crests and troughs (WMCCT) and wavy microchannels with opposite crests and troughs (WMOCT) was conducted. The aim is to provide reference for optimal design in trans-critical CO2 gas cooler equipment. The influence of the channel structure on heat transfer coefficient, pressure drop, buoyancy effect, flow fields and overall thermal performance was analyzed. WMOCT and WMCCT show great advantages in heat transfer performance, while get slightly larger pressure loss punishment when compared with straight microchannel (SM). It is worthy to note that both heat transfer coefficient and pressure drop increase with increased amplitude or decreased wavelength in both WMOCT and WMCCT, which is particularly evident in WMOCT. Furthermore, the analyses carried out identified an optimal channel structure that could improve the overall thermal performance of microchannel gas coolers.