Chiller refrigerant purge question

[Clymber]

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

 

[Cooky]

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

 

[imok2]

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.

 

[Cooky]

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

 

[Centrif]

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.

 

[Keith53]

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.

http://www.redicontrols.com