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electronicsuk
02-07-2003, 10:15 PM
I'm pretty much a newbie to refrigeration, and would like to know a little about using propane as a refrigerant. Just a couple of quick questions:
1)At room temperature (let's say 20 deg/c) what is the pressure that propane gas will liquify at?
2)If a system was measured as 150psi high side with ambient temperature @ 20 deg/c ambient, how much would this pressure vary? Let's say that ambient temperatures could go as low as 0 degrees and as high as 30 degrees. How high/low is the system pressure likely to go? Wouldn't want to risk any explosions, especially with hydrocarbons.

Many thanks!

Matthew

Gary
02-07-2003, 10:44 PM
1)At room temperature (let's say 20 deg/c) what is the pressure that propane gas will liquify at?

105.8 psig

But assuming you mean 20C air flowing through the condenser, the SCT (saturated condensing temperature) inside the condenser will be somewhat higher, depending on condenser sizing, refrigerant charge, and airflow, and thus the pressure will be somewhat higher.


2)If a system was measured as 150psi high side with ambient temperature @ 20 deg/c ambient, how much would this pressure vary? Let's say that ambient temperatures could go as low as 0 degrees and as high as 30 degrees. How high/low is the system pressure likely to go? Wouldn't want to risk any explosions, especially with hydrocarbons.


Assuming the system is not grossly overcharged, at 30C ambient, given even minimum airflow through the condenser, the pressure would be unlikely to go much over 200 psig, maybe 225 tops.

On the low end it would pretty much match ambient (0C) at 53.2 psig.

electronicsuk
03-07-2003, 09:37 AM
Thanks Gary, that's exactly what I was after.

Matthew