Research on the resistance characteristics of supercritical CO2 in microchannels
LIU Shouchun
CHEN Fuling
Abstract：To reveal the flow resistance mechanism of supercritical CO2 in the rectangular microchannels of the printed circuit board heat exchanger(PCHE),a resistance characteristic test study is conducted under high heat flux conditions in rectangular microchannel with a hydraulic diameter of 0.16 mm.The influence laws of mass flow rate,heat flux density and system pressure on the friction pressure drop and acceleration pressure drop are systematically investigated using the control variable method.Combined with the changes in physical parameters near the wall and in the main flow region,the intrinsic mechanism of resistance variation is revealed.The results show that the friction factor of supercritical CO2 has a peak characteristic before the pseudo-critical enthalpy value.High heat flux is prone to cause heat transfer deterioration.At this time,the mass flow rate is the main factor affecting the friction pressure drop in the channel.The change in system pressure has a weak influence on the friction pressure drop in the channel,and the change in heat flux density only affects the friction pressure drop in the low enthalpy region.Resistance variation is closely related to the fluid heat transfer characteristics.While conducting the structural design,it is necessary to take into account the changes in fluid heat transfer performance.
Keywords：printed circuit board heat exchangersupercritical CO2rectangular microchannelflow resistance
Publication Date：2026-02-25
Online Publishing Date：2026-03-31(First online date of this platform, not the publication date of the document)
Pages：6( 49-54 )