摘要
为了获得较低的低温环境,通过建立能量方程及辅助软件EES(Engineering Equation Solver)的编程,分析了R1234yf/R744和R134a/R744两种复叠式制冷系统的蒸发温度、冷凝温度、冷凝蒸发传热温差对系统性能的影响。结果表明:R134a/R744系统的COP略高于R1234yf/R744,R1234yf相对于R134a具有优良的环保特性,因此,在复叠系统中,R1234yf/R744可代替R134a/R744制取低温。
In order to obtain a low temperature environment,two kinds of cascade refrigeration systems with R1234 yf/R744 and R134 a/R744 were analyzed for evaporation temperature,condensation temperature and condensation evaporation by establishing the energy equation and the auxiliary software EES( Engineering Equation Solver). The results show that the COP of R134 a/R744 system is slightly higher than that of R1234 yf/R744,and R1234 yf has excellent environmental characteristics compared with R134 a. Therefore,in the cascade system,R1234 yf/R744 can replace R134 a/R744 to produce low temperature.
引文
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