| The emergence of the problem of ozone destruction has forced people to abandon HCFCs and CFCs refrigerants.Currently,with the intensification of the greenhouse effect,people have to limit the use of high GWP refrigerants,such as hydrofluorocarbons(HFCs).In this era,it is urgent to find new kinds of alternative refrigerants.HFE-356 mmz is a hydrofluoroether type substance which has a small GWP value,0 ozone depletion potential,short atmospheric lifetime,non-toxic and harmless to human.It is a kind of environmental friendly working fluids which meet environmental protection requirements.However,the lack of research of corresponding thermophysical paramaters has caused the difficulties in the use of this substance in alternative refrigerants.Based on this situation,this paper mainly studied the thermal properties of HFE-356 mmz,and the main contents are as follows:1.Tested 100 points of HFE-356 mmz gas phase pvT properties,164 points of compressed liquid phase density data and 67 points of vapor pressure data.The deviations between the calculated values and the experimental values are: the average deviation of saturated vapor pressure is 0.059%,and of gas pressure is 0.339%,for liquid density,it is 0.077%;2.The saturated specific heat capacity of HFE-356 mmz was tested,and it was fitted to a cubic polynomial with respect to temperature.The fitting error is within 0.299%.The formula can well reproduce the properties of saturated specific heat capacity;3.Based on statistical thermodynamics,the ideal gas isobaric heat capacity of HFE-356 mmz was obtained through theoretical calculation;4.Based on the experimental and extrapolated data,a special Helmholtz form equation of state was established,which is applicable to the liquid phase,gase phase,and two-phase region.The applicable temperature range is(313.09-448.20)K,and the maximum applicable pressure is 25 MPa.A table of saturation properties of HFE-356 mmz is given. |
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