lubricant oil in refrigeration system

[Lc_shi]

Dear sirs

I know the importance of lubricant oil in refrigeration system ,the positive is to keep compressor in good state and the negative is to hinder the heat tranfer of heat exchanger due to the oil film.
The oil return is very important in the long pipe refrigeration system. How to manage the oil best in refrigeration system from design to installation ?
Who can offer clues at this issue.
Thanks in advance!

regards
LC

[NoNickName]

It's easy: keep the oil in the compressor as much as possible.

[toprunner]

You keep as high speed as possible in the tubes with respect to the pressure loss. The tricky part is the evaporator.

[Lc_shi]

thanks ,
IT's right to keep the high enough speed but the big pressure loss is not good for the system efficiency.

[Ernie]

You keep as high speed as possible in the tubes with respect to the pressure loss. The tricky part is the evaporator.


i read an article awhile ago which advised to stop adding oil trap's in a suction line on long vertical riser's. i believe it was in an HRAI update/magazine.

would it be to avoid the pressure loss in a trap?

thanks.

[NoNickName]

I assume they suggest to use double risers instead of oil traps. Can you point us to the article, if it is available on line?

[Brian_UK]

Sorry LC, missed your post earlier.

McQuay do a useful piping guide which may be of interest to you...
http://www.mcquay.com/mcquaybiz/literature/lit_systems/AppGuide/AG_31-011_120407.pdf

There is a good range of documents also available...
http://www.mcquay.com/McQuay/DesignSolutions/GreenWayPage3