双蒸发器冷藏车制冷系统应用R404A的模拟研究

采用分布参数法，对双蒸发器冷藏车制冷系统的空调侧和冷藏侧蒸发器建立了数字模型，开对新型混合制冷剂R404A在空调和冷藏2种工况下的换热和流动情况与R22和R134a进行了模拟分析比较．结果表明，在空调和冷藏工况范围内，R404A在两蒸发器中的换热量仅略小于R134a而明显高于R22，制冷剂侧压降虽然大于R22，但却比R134a小很多．在双蒸发器冷藏车制冷系统中，R404A表现出换热性能好、压降小的特点，兼有了R134a和R22的优点，并能够适用于比R134a更低的冷藏温度。

Simulation of the Dual-Evaporator Refrigerator Cars System Using New Refrigerant R404A

With distributed parameter method,mathematical models of an air conditioning(A/C) evaporator and a refrigeration evaporator in the dual-evaporator refrigerator cars were presented.The simulation analysis and comparison of the heat transfer and flow characteristics of R404A,R22,and R134a were performed under A/C and refrigeration operating conditions.The results show that the cooling capacity of R404A is a little lower than that of R134a but much higher than that of R22,and the pressure drop of R404A is higher than that of R22 but much lower than that of R134a under the both conditions.R404A has good heat transfer and low pressure drop performance,and can be used in lower refrigeration temperature than R134a in the dual-evaporator refrigerator cars system.