oil cooling problem

[chichi]

Dear All,

I started one screw compressor that is designed in condition -10 C as evaporating temp. and +35 as condensing temp. also this compressor is designed with fixed Vi
The pressure of liquid seperator (suction press) was 7 bar(a) in start.
The compressor worked at partial load (about 10% capacity) about 5min. after that high discharge temp. alarm turned up.
I think inner pressure of compessor at oil input of compressor has extra pressure rather discharge press. so oil circulation not been did correctly.
Please advise if you have idea

[RANGER1]

chichi ,

If compressor is differential oil feed it may cause this due to low oil flow, because little pressure difference between suction & discharge .

If lubricated and oil injection cooling by oil pump it should work fine .

Either load machine up or restrict suction valve on machine to achieve bigger pressure difference until plant settles down .

[chichi]

thanks a lot for your kind advice

[chichi]

chichi ,

If compressor is differential oil feed it may cause this due to low oil flow, because little pressure difference between suction & discharge .

If lubricated and oil injection cooling by oil pump it should work fine .

Either load machine up or restrict suction valve on machine to achieve bigger pressure difference until plant settles down .

thanks a lot for your kind advice

[Josip]

Hi, chichi

Dear All,

I started one screw compressor that is designed in condition -10 C as evaporating temp. and +35 as condensing temp. also this compressor is designed with fixed Vi
The pressure of liquid seperator (suction press) was 7 bar(a) in start.
The compressor worked at partial load (about 10% capacity) about 5min. after that high discharge temp. alarm turned up.
I think inner pressure of compessor at oil input of compressor has extra pressure rather discharge press. so oil circulation not been did correctly.
Please advise if you have idea

sometimes at very low partial load you can have a high oil temp .... RANGER1 gave you a good suggestion ... the best is to increase capacity a little to achieve more refrigerant to flow through compressor in your case suction gas had a very high temperature and flow was reduced - right way to get high oil temp ....(take care not to come to high discharge pressure)

Best regards, Josip