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PLEH2EREH
26-03-2015, 01:44 AM
This is dealing with R-507, which I believe has a CT of ~160 f. Current discharge pressure is 220 psig with a discharge temperature of 158 f. I believe that is like a 63 f discharge super-heat, which to me seems high. None the less, this is how it has been operating for several months. Does anyone see a problem here, or am I just misunderstanding something? Twin screw / thermosyphon chiller.... slide at 40%, hot gas bp closed.....

PLEH2EREH
26-03-2015, 01:47 AM
Need to add, no I haven't checked the temperature transmitter to verify temp, but the other system (same set up) is operating same just a few degrees lower in discharge temp...

Rob White
26-03-2015, 08:52 AM
This is dealing with R-507, which I believe has a CT of ~160 f. Current discharge pressure is 220 psig with a discharge temperature of 158 f. I believe that is like a 63 f discharge super-heat, which to me seems high. None the less, this is how it has been operating for several months. Does anyone see a problem here, or am I just misunderstanding something? Twin screw / thermosyphon chiller.... slide at 40%, hot gas bp closed.....
.

I work in degC so I had to convert but I think you are confusing critical temp with
the discharge superheat. Discharge temp is the temp of the gas and it is super heated
way above the saturation temp. It is the saturation temp that goes critical if it
touches the critical point.

On my Ph your system is running about 15bar and 30degC condensing temp/pressure
and the discharge superheat is about 70degC. This might be a bit high. When I complete
the graph and follow the compressor compression cycle it is showing high superheat
to the compressor.

I would look at the evap and see if it is set correctly and check the superheat to the
compressor from the suction return. If the suction return is high the compressor discharge
will be high also.

Rob

.

PLEH2EREH
30-03-2015, 10:58 AM
Thanks Rob. It was my bad. Getting old and just forgetting to plug in all the "factors".. Thanks anyway!!