High oil temperature in wet screw system

[desaipt2003]

Hi all,

We had a R134a system with wet screw(WCV 255 13050) of Howden make. Recently we had a maintenance on system including refrigerant recovery, system pressure test, compressor replacement, charging back etc.

After start up of system, we are facing problem of high oil temperature in oil manifold, system is getting tripped on "OIL MANIFOLD TEMP HIGH-HIGH" after 1.5-2 hours of operation. Package supplier suggested to add R134a in the system as we were not getting desired low temperature of refrigerant at outlet of evaporator. Due to shortage of R134a, it was getting superheated inevaporator. R134a added in steps till refrugerant temperature at outlet of evaporator reached -24 C. Still we are getting trouble of high oil temperature. oil cooler is working fine and is not fouled on cooling water side.

What are probable reason of oil temperature rise? Can anybody suggest remedial actions or check points to overcome the problem?

Thanks in advance:)

[US Iceman]

The first questions that come to mind are:



Did you have this problem before?
What is the suction superheat at the compressor?
What type of evaporator is it (flooded chiller or DX air-cooling coils)?
Do you have a 3-way oil temperature control valve?
Is the discharge temperature higher after the service work than what it was before the service work?
Since you have a water-cooled oil cooler, what are the supply and return water temperatures?
Do you have good water flow?

Typically, high oil injection temperature is the end result of insufficient oil cooling or higher than design suction temperatures.

[2400martin]

1 do you have a 3 way valve in the compressor pack.
2 was the old compressor also a WCV or a WRV 9 the WRV has little holes in the slidevalve for cooling between teh rotors.3 send me you condition i can make a selection and check this

[Magoo]

Water cooled oil cooler, have you tried venting water side headres, air locks in water side effectively reduce cooling of oil. Did you clean water tubes during service.