The homogeneous phase flow model was established to analyze gravity recirculating evaporators in the condition that four kinds of refrigerants are used respectively. The experimental device of gravity recirculating refrigeration system was set up

and the experimental results were compared with the theoretical calculation results under different working conditions. Taking R404A as an example

when the air temperature in heat insulation decreased from 0 ℃ to -25 ℃

the deviation of the experimental value from the theoretical value of the heat transfer coefficient lowers from 15.91% to 3.01% gradually. The deviation of the experimental value from the theoretical value of the cooling capacity decreases from 14.43% to 2.07%. The lower the air temperature in heat insulation is

the smaller the deviation becomes

which indicates that the running state of the gravity recirculating refrigeration system is in better agreement with the theoretical operating state in lower temperature. This model was used to predict the running states of the four refrigerants. And it shows that comparing with the other three refrigerants

the heat transfer coefficient and cooling capacity of the R407C are the highest when the supplying height is in a relatively low level.