Development of a mini-channel evaporator model using R1234yf as working fluid

A simulation model of the mini-channel evaporator using R1234yf as working fluid is developed in the present study. The finite element conception is employed, and the effectiveness-NTU method is used to calculate the heat transfer rate. For the two-phase heat transfer of the refrigerant, six correlations are compared in the developed model. The calculated and experimental data of six different samples with R1234yf were compared under typical working conditions of an automotive air conditioning system. The developed model using Kandlikarʹs correlation to calculate for the two-phase heat transfer coefficient of R1234yf can obtain the highest precision. The distribution of the local two-phase heat transfer coefficients in the evaporator is studied using the developed model. Under the same conditions, R1234yf has a lower two-phase heat transfer coefficient than R134a. In high quality region, the heat transfer coefficients of both refrigerants decrease with the increasing of the refrigerant quality.