fridge compressor

[adavid]

is it theoretically possible to replace the fridge compressor with a heat source (as in a gas or propane fridge) without changing the freon gas to ammonia/hydrogen?

[Clanad]

No, since the principle by which the compressor achieves cooling is entirely different than that used in cooling through the propane or natural gas powered fridge. The water/ammonia solution is essential for the gas powered device to work...

[adavid]

you clearly have experience in this field but perhaps I failed to get across what I really meant. I am not looking to substitute freon into a gas heated unit, rather I am seeking to use a compressor driven freon unit in which the compression stage (pressurising and therefore heating) is replaced by a heat source stage (not gas) thereby heating and pressurising. I think that should be possible provided a non-return valve arrangement prevents reverse flow.

[Clanad]

OK... I see your idea more clearly now... however there are still critical drwabcks, as I see it. The first is that the compression of the freon to a very specific level to achieve turning the gaseous state of the freon into a liquid state would be difiicult to achieve by only heating it with an external flame (not impossible, but certainly difiicult). The freon (in gas form) is compressed in the compressor which turns it into a liquid and adds heat, from there it goes to the condensor which cools the liquid to near room temp, from the condensor the liquid runs to a metering device, then into the evaporator, the liquid referigerant boils inside the evaporator and turns back into a vapor , from there the vapor is returned to the compressor via the low side suction line. All of this process, as I've already stated, would be difficult to achieve without a compressor. I think this is evident from the completely different principleeutilized by the propane powered fridge...

[adavid]

Thanks for your input. The external heat source would not be a flame, rather a hot chamber which the piping passes through. How the chamber becomes hot is another story. It's encouraging to know that you see it as difficult but not impossible. I have a number of ideas to overcome the difficulties but I wanted to know if anybody had any experience trying this approach.