Thermodynamic properties of R134a

[Engineer_M]

Hi,

I apologize in advance for asking such a basic question here. I haven't referenced this in a while...
Lets suppose I have R134a in a container at 150 psig at room temperature. If I were to increase the temperature to 100 F, would my new pressure then be 150 +123.58 psig?

The table I'm referencing is

https://www.engineeringtoolbox.com/r134a-properties-d_1682.html

Thanks!

 

[hacksaw]

Short answer, no. You need to consult the gas tables for refrigerants. Ton's of sources via a simple search...

 

[Latexman]

If you have R134a in a partially full container at 150 psig at room temperature, there is something else besides R134a in the container. Pure R134a at room temperature is 60-70 psig only.

Good Luck,
Latexman

 

[IRstuff]

Unless it was under pressure to start with, since a refill canister would need to have liquefied freon under pressure, and that pressure needs to be high enough to overcome whatever pressure is in the system being refilled.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Engineer_M]

Hi,

Yes the cylinder would have GN2 at 150 to keep the refrigerant pressurized. In that case, if the temperature is increased, is my assessment correct?

 

[Compositepro]

The pressure will be equal to the vapor pressure of R134a plus the partial pressure of N2. The partial pressure of N2 will be what it was at the original conditions plus a little thermal expansion. You are neglecting to subtract the initial vapor pressure of R134a in order to know what the initial partial pressure of N2 was.

 

[Latexman]

R-134a Calculator

If RT = 70 F, R-134a vapor pressure = 85.5 psia. 150 + 14.7 = 164.7 psia total pressure. 164.7 - 85.5 = 79.2 psia nitrogen partial pressure.

@ 100 F, R-134a vapor pressure = 138.2 psia
@ 100 F N2 pressure = 79.2 x (100+460)/(70+460) = 83.7 psia
@ 100 F Total pressure = 222 psia

Good Luck,
Latexman