Oil injection.

[Noori]

Hello far the all
I read the following statement in catalogue for air cooled chillier using screw compressor and I did not understand it.
( Oil injection is used to get high COP at high condensing pressures.)
Thanks alot for the all.

[US Iceman]

Oil injection is provided on most screw compressors to improve their pumping efficiency. The injected helps to seal the rotor tips to the inside of the compressor housing. And, since a lot of oil is injected into the compression process this also helps to lower the discharge gas temperatures.

Since the oil is absorbing a part of the heat of compression the oil must be cooled before it is re-injeted back into the compressor.

This has nothing to do with air cooled condensing or any other form of condensing. It is required only to improve the compressor performance.

[Noori]

Dear US ICeman
Thanks so much for the nice answer, I feeled that your information is very good in this subject so please send me a document or a link so that I can increase my information in this field since I found my self in need for such information.
Best regard.
Engineer Noori.