空调工况下非共沸制冷剂蒸发时的换热特性

为了揭示空调工况下非共沸制冷剂在蒸发器中的换热特性，探明制冷剂和换热流体间温差的沿程变化规律，建立了制冷剂的蒸发换热模型，根据标准的空调工况确定了制冷剂的蒸发物性参数．利用制冷剂状态方程得到蒸发过程中温度与焓的对应关系，计算出制冷剂和换热流体在蒸发过程中的温差．通过归纳沿程位置的温差变化，得到它的变化规律，对大多数非共沸制冷剂，换热温差沿程呈非线性变化，这为合理设计蒸发器提供了一定的理论依据．最后应用上述方法对15种非共沸制冷剂的蒸发特性进行了评价，发现R407C制冷剂换热性能最优．

Heat Exchanging Characters of Non-Azeotropic Refrigerants Evaporating with Air-Conditioning Operation

In order to reveal characters of non-azeotropic refrigerants with evaporating, and the changing rule of temperature difference between refrigerant and heat transfer fluid, a model of refrigerants evaporating was built, and refrigerants situation parameters were decided for the air-conditioning operation. Then the situation equation of refrigerants was applied for computing relationship between temperature and enthalpy, as well as temperature differences between refrigerants and fluids. The results show that temperature differences change nonlinearly with length of heat exchanger. This is helpful to design evaporators in air-conditioner or heat pump units. Finally, the method was used to evaluate evaporating heat exchanging characters of 15 sorts of non-azeotropic refrig- erants, and the R407C is the best.