以R407C为工质的翅片式蒸发器结霜过程模拟

翅片式蒸发器的结霜特性对于空气热源热泵的冬季运行十分关键。随着 对HCFCs替代的展开，一些非共沸制冷剂被建议为替代品。同现在使用的纯工质相比，这些非共沸制冷剂的温度滑移使和沿流动方向制冷剂的温度分布更加不均匀。在本文中，作者建立了翅片式蒸发器的分布参数模型，用以模拟结霜过程。传热与流动被认为是准稳态的。文中探讨了数值算法，并以某蒸发器为例进行了模拟。计算表明，结霜过程中空气量的改变明显，整个结霜过程存在一转折点，经过这点后流量急剧下降。R407C在蒸发过程中的温度滑移对霜层在蒸发器上的分布有重要影响。

STUDY ON FROSTING CHARACTERISTICS OF A FINNED EVAPORATOR USING R407C AS REFRIGERANT

The frosting characteristics of the evaporator are of key importance to the running of an air source heat pump in winter As the phase-out of HCFCs is in process, some non-azeotropic refrigerant mixtures are introduced into use Compared with pure refrigerant, these mixtures have temperature glides that make the temperature distribution of the refrigerant more uneven along the heat exchanger In this paper, the distributed parameter model of a finned evaporator is established to simulate the frosting process Quasi-steady heat transfer and refrigerant flow are assumed Numerical algorithm is discussed and simulation is carried out with a sample evaporator It is found that the change in the flow rate of the air is obvious and there is a turning point from which the flow rate goes down quickly The temperature glide of R407C during evaporation has an important impact on the distribution of frost on the evaporator