二氧化碳超临界流体的管内对流换热研究

RESEARCH ON HEAT TRANSFER TO SUPERCRITICAL CARBON DIOXIDE IN TUBE FLOW

随着自然工质ＣＯ２研究的进一步发展，系统中气体冷却器的换热问题越来越受到人们的重视，这是因为高的换热效率是提高系统ＣＯＰ的重要因素．本文首先阐明了超临界流体换热研究的处理原则和分类方法，并重新定义了ＣＯ２临界区范围．利用修改的 ＢＷＲ方程计算得出了 ＣＯ２临界区的物性变化规律，并分析了获得超临界换热关联式的理论求解方法．最后，建立了超临界ＣＯ２管内冷却过程的数学模型，为求解其换热规律提供了方法和依据．

With the further investigations of carbon dioxide as a refrigerant, heat transfer in the gas cooler has been paid more and more attention as it is a pivotal to improve COP of the system. This paper describes the commonly treating principles and classified methods on heat transfer of supercritical fluids, and redefined the critical range of carbon dioxide. By the calculation with modified BWR equation, the rules of CO2 thermophysical properties has been drawn. Moreover, the theoretical methods to obtain heat transfer corrections has been presented. Finally, authors established the mathematics model on a horizontal tube at the cooling process for supercritical carbon dioxide, and proposed the approach to study heat transfer of this process.