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Old Guy
21-10-2010, 03:39 AM
How do you calculate or determine the theoretical discharge temperature of an ammonia screw compressor?
Peter_1
22-10-2010, 08:04 AM
Drawing the cycle in a log p/h
ice wombat
22-10-2010, 11:40 AM
Many manufaturers sw give also the discharge temperature so you can compare it with the p-h diagram

iw
Sandro Baptista
22-10-2010, 12:04 PM
Must have in mind that the cooled oil decrease the discharge temperature of the superheated refrigerant.
desA
22-10-2010, 12:49 PM
^ That's a very interesting point.

Do you perhaps have any observed information on this effect?
Quality
22-10-2010, 07:12 PM
Must have in mind that the cooled oil decrease the discharge temperature of the superheated refrigerant.

Screw Compressor only I think

could be wrong though
Peter_1
23-10-2010, 05:03 PM
Must have in mind that the cooled oil decrease the discharge temperature of the superheated refrigerant.
Very true, oil is there to lubricate the screws, provide a gastight seal between them and...to cool down the discharge gases.
Reason why the oil needs to be cooled before it can be reused.
RANGER1
24-10-2010, 10:57 AM
Most manufacturers have either tables or a programe that can determine it .

Some things that affect it are ,

Oil temp into comp, oil cooler designed temp , amount of oil going into compressor , pressures of system , suction superheat , screw condition , type or brand of machine .

I would suggest between 60-85 deg C
A booster usually approx 10 deg C lower than high stage .