Evaluation of zeotropic refrigerants based on nonlinear relationship between temperature and enthalpy

With the CFCs refrigerants being forbidden and the HCFC refrigerants phased out gradually, more and more zeotropic refrigerants are proposed as substituting (the zeotropic refrigerants commercialized exceeds 20 kinds), such as R401A (R22/R152a/ R124, 53%/13%/34%, wt.), R409A (R22/R124/R142b, 60%/25%/15%, wt.) and R407C(R32/R125/R134a, 23%/25%/52%), those zeotropic refrigerants are being used widely and rapidly. The phase change process of zeotropic refrigerants is quite different from …

Evaluation of zeotropic refrigerants based on nonlinear relationship between temperature and enthalpy

In order to evaluate cycling characters of zeotropic refrigerants in air-conditioning operation, and to reveal distribution rules of temperature difference between refrigerants and heat transfer fluids in condenser and evaporator, theoretical researches were carried out based on nonlinear relationship between temperature and enthalpy in period of refrigerants’ phase change. Firstly, a phase changing model of refrigerants was built, and refrigerants state parameters were decided in the air-conditioning operation. Secondly, the state equation of refrigerants was applied for computing relationship between temperature and enthalpy, else based on some suppositions, temperature differences between 15 sorts of refrigerants and heat-transfer fluids were gotten too. Through concluding those temperature differences changing in condenser and evaporator, some rules were found. Lastly, after calculating and comparing the additive exergy loss among 15 sorts of refrigerants, which resulted from the changing of temperature difference, their cycling characters evaluation were presented.