结霜翅片管换热器热质传递分析  

ANALYSIS OF THE HEAT AND MASS TRANSFER OF FROSTING FINNED TUBE HEAT EXCHANGERS

作　　者：刘凤珍[1] 陈焕新[1] 屈高林[1] 欧阳海生 

机构地区：[1]中南大学制冷与空调研究所,长沙410075 [2]深圳麦克维尔空调有限公司,深圳518031

出　　处：《低温工程》2004年第1期52-55,共4页Cryogenics

摘　　要：低温工况下翅片管换热器的结霜是一个复杂的热质传递过程。从能量的角度出发,由换热器的对数平均温差(LMTD)引出对数平均焓差(LMED),改进了传统的基于对数平均温差(LMTD)的结霜翅片管换热器传热、传质模型,并通过实验研究了影响翅片管换热器结霜及能量传递系数(E_0)的主要因素。结果表明,能量传递系数(E_0)更准确地反映了结霜工况下换热器的热质交换情况,可以作为系统在霜运行及实时化霜的重要性能参数。Frosting of finned tube heat exchangers is a complex process of heat and mass transfer under low temperature conditions. The logarithmic mean enthalpy difference ( LMED ) and heat and mass transfer coefficient (E0) are put forward to analyze the energy transfer during frosting. The traditional model of heat and mass transfer based on logarithmic mean temperature difference( LMTD) is improved on. The experimental studies of the effects on frosting and energy transfer coefficient (E0) of finned tube heat exchangers are conducted in this paper. The results demonstrate that energy transfer coefficient ( E0 ) based on logarithmic mean enthalpy difference( LMED) exactly indicate the heat and mass transfer of frosting finned tube heat exchangers. It is an important performance parameter of frosting operation and real-time defrosting of the system.

关 键 词：结霜现象 翅片管换热器 热质传递 对数平均焓差 对数平均温差 

分 类 号：TK172[动力工程及工程热物理—热能工程] TK124