View Full Version : R718 as refrigerant

06-04-2006, 07:44 AM
Hi sirs
I randomly found an article for R718 water chiller. It's an interesting topic. R718 is H2o. Use water to produce chilled water. Very good. Who know this machine? Is it available for practical use? welcome input:)


06-04-2006, 07:55 AM
dear sir
would you provide us with more detales
please send internet site of the company who produce this kind of chiller

06-04-2006, 09:20 AM
Hi Lc_shi

have a look here http://www.refrigeration-engineer.com/forums/showthread.php?t=2619

06-04-2006, 09:54 AM

You are thinking of a Lithium Bromide / Water Absorption chiller. They've been around for most of the last century, and are still made. They tend to be very large capacity, and can capitalise on large quantities of waste heat.
By today's criteria they have a poor efficiency profile, because of thier high reliance on direct-fired carbon fuels, but still installed. Usually they are around 1 - 1. 5mW (3-4000TR).
I worked on a few in the 70s. The smallest one I ever commissioned was a Japanese Carrier 16JB that was considered a table-top model at 100 TR, (about 350 kW).
LiBro is the absorbent and water is the refrigerant. The system is kept at a vacuum to promote evaporation temperatures in the order of 5 Celsius.

The other variant of the absorption process is a slightly different technique; it uses water and ammonia. In this case the ammonia is the refrigerant and water is the absorbent.

vapir oxygen (http://www.vaporshop.com/oxygen-vaporizer.html)

06-04-2006, 11:30 AM
Not quite. R718 can be used in a phase change chiller as the refrigerant, bu evaporating and compressing water vapour exacty as any other refrigerant.

Applications are in the range of high evaporation temperature (+20/35°C).
Considerations must be applied for the high expansion ratio after evaporation and low exponent, that would lead to use turbine compressors (high flow, low compression ratio).
Liquid separation is also an issue.

Johnny Rod
06-04-2006, 11:57 AM

Not sure about what you saw, LC but in principle water would be great, it's a lot like ammonia i.e. high latent heat, large amount of vapour for the liquid volume.

03-05-2006, 09:06 PM
There are developments of compression chillers using water as refrigerant. Several machines have been in the field test in the recent years. (Megawatt class, I guess). However, the compressor is very special and expensive. Therefore, economics is an issue.

Carlo Hansen
07-05-2006, 12:25 PM
Just went back from technical shool.R178 as refrigerant is
a very interesting problem. Here in Denmark LEGO has buildt
a system with water vapour compressor, they use this to
cool down diff. machinery.
Here in Denmark ther has been started a project to develop
water vapour compressors.

By the way a have a PDF file 1.8 Mb. 260 pages concerning
water vapour compressors, so if anyone is interested just
mail to me.

Best regards
Carlo Hansen

Carlo Hansen
07-05-2006, 12:50 PM
Hi again

Just forget to set in this link.


Best regards
Carlo Hansen

07-05-2006, 04:24 PM
[ Will be geatful,if you can mail me the PDF file 1.8 Mb. 260 pages concerning water vapour compressors, I am interested.
Myemail :dhaliwals@gmail.com:
Best regards

08-05-2006, 01:43 AM
I think you can download it by the link:)