蒸发器中非共沸混合工质的换热特性

为了阐明非共沸混合工质在制冷、空调系统蒸发器中的换热过程,以及混合工质蒸发时的温度滑移现象为工程实际带来的某些特殊性,运用传热及热力学原理进行了相应的理论分析,发现非共沸混合工质的蒸发过程中蒸发介质存在极限流量的现象,并得到此类工质在可用能角度相比纯工质具有节能效果的结论(一般情况下,相对可用能损失减少40%～55%),最后将理论分析结论应用于几种常用的混合工质上,如R407c、R405a和R414b,并预测了这些工质在实际使用中的极限流量和可用能损失情况.

Heat Transfer Characters of Non-azeotropic Mixtures in Evaporator

In order to know heat transfer characters of non-azeotropic mixtures in the evaporator of air conditioner or heat pump systems, and to understand special function of temperature gliding in engineering, the theoretical analysis was carried out using heat transfer and thermodynamics theories. The results show that the non-azeotropic mixtures had less energy loss than single fluids. In addition, it is found that the maximum evaporation medium flow rate occurred in heat transfer process. Finally, the maximum evaporation medium flow rates and energy loss were predicted for some popular non-azeotropic mixtures including R407c, R405a, and R414b.