View Full Version : solar powered absorbtion unit

15-04-2007, 10:32 AM

I have been working on solar thermal for a while and would like know what i am talking about when someone says how do you cool with heat? Can someone send me a scamatic of how to build a lithum bromide cooler using hot water?

Frank the solar guy

15-04-2007, 03:06 PM
Hi therub9,

What you need is absorption refrigeration.
Have a look at : http://www.chpcentermw.org/08-01141_tech.html
Hope this helps.

27-06-2007, 04:58 PM
wht not start with a propane chest freezer? this is adsorption as well but amonia is more benign, (slightly) than li- br. just immerse the heating coil in heat transfer fluid at 150C from a evac tube or trough solar array.

if easy to understand and money no problem silica gel is best. this is a-B-sorption where water vapourizing at lower pressure gets cold. instead of compresing back to liquid, the gel absorbs (just like anti moisture paks), the water, is removed from the chamber and heat is used to dry out the jel.... need two rotating absorbent beds for continous cooling.

The MG Pony
27-06-2007, 05:22 PM
I love ammonia absorption fridges, just using a parabolic reflector targeted to the generator works great, or using a black tube and reflectors to boil water and drive it via steam, both work astoundingly well along with leaving you the option to use combustion eneregy in the event of low light levels.

03-07-2007, 12:31 AM
I am working on a solar design too.. I ended up with a very complicated system which i started to butcher down until a KISS design was achieved. It may not be most efficient by hey solar heat is free and wasted anyway.

At the moment looking for a method to put design in diagram form to present on this forum and seek validation.

In a nutshell it uses two generators and one liquid collection vessels. The generators swap role such that one is absorber and other is generator at any given time. The day cycle is driven by solar heat and night cycle is driven by natural gas. Complete with electronic automation, cooling tower and battery backup.