跨临界制冷循环中二氧化碳在毛细管内的流动仿真  

Simulation on flow of carbon dioxide in capillary tubes in a transcritical refrigeration cycle

作　　者：曹小林[1] 陈惠[1] 冯明坤[1] 廖胜明[1] 

机构地区：[1]中南大学能源与科学工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2010年第4期1604-1608,共5页Journal of Central South University:Science and Technology

基　　金：国家高技术研究发展计划("863"计划)项目(2007AA05Z225)

摘　　要：根据跨临界制冷循环中二氧化碳在毛细管内流动过程中的状态变化,毛细管划分为超临界气体区、液体区和两相区。针对各分区建立均相数学模型并进行模拟计算。研究结果表明:毛细管内的流动主要是超临界气体区和液体区的流动,两相区的长度短,而且两相区中制冷剂的干度增加快;随着入口温度的升高,超临界气相区长度逐渐增加,而液相区长度缩短,直至接近于0 m,而两相区的长度虽然有一个先增加后缩短的变化过程,但变化幅度小,几乎不变;当其他参数固定时,毛细管总长度随入口压力成比例增长,而与入口温度成反比例增长;此外,当内径或质量流量改变时,毛细管长度变化明显。The flow of carbon dioxide in capillary tubes in a trans-critical cycle was divided into three regions,i.e.,supercritical gas region,liquid region and two-phase region,according to its state change.Homogenous flow mathematical models were established for this three regions,the flow of carbon dioxide was simulated with these models.The results show that the flow of carbon dioxide in capillary is mainly single phase flow and the length of two-phase flow is short,and the quality of carbon dioxide in the two-phase region increases rapidly;when the inlet temperature increases,the length of supercritical gas flow increases and the length of liquid flow decreases,even to 0 m,and the length of two-phase flow changes in a small range,the total length of capillary tube needed is nearly proportional to inlet pressure and approximately inverse proportional to inlet temperature when other parameters are fixed.The change of capillary length needed is remarkable when inner diameter or mass flow rate is changed.

关 键 词：制冷 二氧化碳 跨临界制冷循环 毛细管 

分 类 号：TK124[动力工程及工程热物理—工程热物理]