R125/R600a混合工质蒸发器结构优化

Evaporator Structure Optimization of R125/R600a Binary Refrigerant Blends

为提高换热效率,从传热和压降的耦合角度出发,针对R125/R600a混合工质蒸发器建立了结构优化的理论数学模型,分析了管径、蒸发温度对管长优化结果的影响,并对理论模型进行验证。结果发现,R125/R600a混合工质蒸发器存在一最优管长,且最优长度随管径的增大而增加;随着蒸发温度的增大最优管长也呈现增大趋势。由此可见,小管径的蒸发器最优管长更短,结构更为紧凑,制造成本更低,而换热效率更高,同时制冷剂的流动摩擦阻力也会更小。研究结果对空调、冰箱、热泵系统的工质选用及运行工况的选择具有借鉴作用。

In order to improve energy utilization efficiency,this paper attempts to establish a tube structure optimization model for R125 / R600 a based on the coupling of heat transfer and pressure drop. The effects of evaporating temperature,tube diameter on the optimal tube length have been analyzed,and the theoretical model is verified. The results show that,for the smaller tube diameter evaporator,the optimal tube length is smaller,the structure is more compact,the heat transfer efficiency is higher,the weight is lighter,and flow resistance of both the refrigerant side and the cooling medium side are smaller. The optimal tube length increases with the increasing of evaporating temperature. Considering the impact of evaporating temperature, the optimal tube length has important practical significance of condenser structural optimization in air conditioners,refrigerators and heat pump systems（ in different operating conditions）.