Retrofit existing R22 flooded plant

[cristovaol]

Hi everyone
I have a large two stage flooded R22 refrigeration plant ( about 5.000 Kg of refrigerant) with two separators -30ºC and -10ºC. Refrigerant is pumped by Witt pumps to the cold rooms. Compressors are Mycom screw units.
I need some ideas to change refrigerant, Amonia is for the moment not an alternative, because evaporators are coper/aluminium.
Kind regards

[NoNickName]

Is lubricant naphtenic mineral oil?

[cookster]

Hi everyone
I have a large two stage flooded R22 refrigeration plant ( about 5.000 Kg of refrigerant) with two separators -30ºC and -10ºC. Refrigerant is pumped by Witt pumps to the cold rooms. Compressors are Mycom screw units.
I need some ideas to change refrigerant, Amonia is for the moment not an alternative, because evaporators are coper/aluminium.
Kind regards

r422d is a replacement were using on packs

[lloydjosang]

I have a similar issue with pump recirculated R-22 on factory trawlers.

One of our customers is considering the switch to ammonia but their condensers are cupro-nickel, and although almost all of the piping is steel I am sure there will be things that are forgotten which will bring up emergencies down the road...

If anyone has experience with this it would be much appreciated. I have looked into R-422D but my concern is losing effectiveness as R-422D is not an azeotropic gas. It's a bit hard to justify removing and recharging 7,000Lbs, (3,180Kg) of refrigerant every time they have leaks...

[penguinkiller]

Iceon website for infomation:

R417a for DX
R422d for water chillers

you may actually see an increase in efficiency!!

[lloydjosang]

I can't find the website for iceon. Can you post it here?

[NoNickName]

IT's actually ISCEON

http://refrigerants.dupont.com/Suva/en_US/products/newblends/index.html

All drop in gases are actually worse than R22, and will cause widespread leakages and gasket failures.

[TXiceman]

If your high side has sufficient design pressure, you will find that R-507 is your best choice for a replacement. It is not a drop in and will require checking all gasket/o-ring materials as well as a good lube oil flush.

I stay away from all of the 400 series for anything but the smaller DX equipment.

Another good refrigerant provided the compressors are compatible would be R-290, propane.

Ken

[BobTheBull]

This is out of my league, as I do not do refrigeration, but in researching R22 alternatives, I have run across R290 (porpane) which is the closest to R22 in thermodynamic properties and compatible with mineral oils; does not mean it is a "drop in" replacement.

Among the things I picked up, it is a very good replacement for flooded systems. Obviously with the proper safety precautions. It is being used for this in a number of places. I have also seen references to it's use in Europe for regrigerators. I can't point you to any specific source of information, but perhaps someone else can.

[TXiceman]

Using R-290, propane, brings in a while new set of concerns. First you need to check if the insurance carrier has any problems with using R290. The electrical classification and ventilation for the engine room will need to be reviewed. The PSV exhaust need to be reviewed.

Mineral oils can be used with propane, but you will have fewer problems a good synthetic oil.

With the screw compressors, the oil system may require extensive redesign. Generally a screw on propane will have a lot less oil cooler load and some use no or reduced injection oil to help keep the discharge temperature up. Oil recovery will need to be reviewed.

A propane conversion can be done, but you need a good consultant that is well versed in propane systems.

Ken