×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Chiller refrigerant purge question

Chiller refrigerant purge question

Chiller refrigerant purge question

(OP)
On a self-contained liquid chiller system, I am specifying a combination filter/drier in the refrigerant circuit.  With this in place, do I need to monitor the # of purge cycles in the control system as a secondary check, or is the purge method not used in the presence of a filter/drier?
TIA,
Brad

RE: Chiller refrigerant purge question

Brad,

If this is an absorption chiller, you could monitor the purge cycle with a PLC.  If it's an electric vapour compression chiller you don't need to purge non-condensables from the refrigerant circuit.

Regards,

Cooky

RE: Chiller refrigerant purge question

Brad,
Since 1990, all manufacturers of low-pressure chillers offer purges capable of operating when the chiller is idle or in standby. ASHRAE Guideline 3-1996 encourages designers to specify purges with "the capability of operating while the chiller is idle." Use of such purges can virtually eliminate refrigerant emissions caused by "air-bound" chillers and they come wth counters and alarms if too many purges are occuring.


 

RE: Chiller refrigerant purge question

I found this article......

http://www.trane.com/commercial/library/ashrae/en_27-02.pdf

which explains the ASHRE Guideline imok2 mentions.  I think a purge system would only be necessary for a large chiller operating at low suction pressure, or if the chiller is likely to operate with suction pressures below atmospheric pressure.

Bleacher: If your chiller is operating at standard chilled water temperatures, I don't think you need the purge system.

Cooky

RE: Chiller refrigerant purge question

Any liquid chiller which uses R-123 (or R-11 in older systems) needs a purge system.  Both of the above mentioned refrigerants operate with sub-atmospheric pressure in the compressor suction. Both Trane and York manufacture such chillers and both have purge units as standard equipment on their products.  The presence of air ..the most common non-condensable in a low pressure vapor compression chiller system can have negative effect on heat transfer and performasnce in the affected chiller.  Additionally air in the system can react with the refrigerants and oils to form a mild acidic condition within the chiller.  Corrosion of internal parts would be the end result.  A good purge system is very worthwhile.

RE: Chiller refrigerant purge question

Redi-Controls makes a very reliable automatic purge unit for both high and low pressure machines. It meets all the very latest standards.

You can get them portable or for fixed install. Self installation is very simple and straight forward.

It's the same unit York sells for their chillers. Mine is 10 years old and has been very reliable.

www.redicontrols.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources