板式气冷器中超临界CO2侧表面换热系数研究OA北大核心CSTPCD

In order to study the effect of the factors leading to the occurrence of the maximum surface heat transfer coefficient h on the supercritical CO2 side in plate gas coolers and the effect of shifting this maximum point on the average heat transfer coefficient,a MATLAB-based distributed parameter analysis method for heat exchangers was employed to investigate the distribution pattern of the surface heat transfer coefficient h along the plates of the gas cooler,and examine the dominant factors contributing to the appearance of h's maximum values,as well as the effects of changing plate dimensions and flow rates on moving the maximum point and its effect on the average heat transfer coefficient.The simulation results indicate that the pseudocritical temperature plays a decisive role in the occurrence of h's maximum values in the plate gas coolers;the maximum Cp at a given pressure increases with pressure,but the pseudocritical temperature gradually decreases;Reducing the size of the plates or increasing the mass flow rate can increase the average heat transfer coefficient,and correspondingly,the heat transfer rate will also increase.Moreover,the increases in heat transfer rate brought by the increased mass flow rate are respectively 12.72%,12.79%,11.75%across three different conditions,although the pressure drop will also increase.However,when the maximum value of h is maintained around 6 170 W/(m2·K)or 5 120 W/(m2·K),shifting the maximum value point does not significantly increase the average heat transfer coefficient,and the corresponding heat transfer rate will also decrease.