I was already familar with the basics of the ammonia cycle fridge that our Westy's have in it. I was undecided, however, on whether or not it was an Einstein design fridge (yah, that Einstein.) I also didn't understand the improvements that Einstein had done to the ammonia cycle fridge. Now I do. Sometimes it takes the right teacher. It's actually a very cool augmenting of the ammonia cycle. So first to the basics of the ammonia cycle. Ammonia is an interesting substance. If you heat it up, only slightly, it will vaporize and in the process of vaporizing, it will absorb tremendous more amounts of heat. That's the basic principle used in the Dometic fridge and in many other 3 mode fridges. To augment this the heat chamber usually has a constriction on the exit, so that ammonia gets pressurized as it is heated. This enhances effect of the vaporizing of the ammonia liquid. Einstein's enhancement was to put Hydrogen gas in to the cooling chamber. Why? Well, because it lowers the gas pressure. And, as most folks know, liquids will boil at lower temperatures at lower gas pressure. So it means you have to supply less heat to the liquid ammonia in order to vaporize it, and hence you can get even lower cooling temperatures. It is also a very very energy efficient design. There are folks that are investigating the Einstein design once again, using different gasses to see if they can make improvements. |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.