Heat Based Cooling System

There's a good explanation here:Cooling Unit (How it works)

The bad news is that although ammonia is a really good refrigerant, it is very dangerous. The systems operate at high pressures and ammonia is not a benevolent gas to breathe.

I don't understand the second question. You want COLD air going into an engine intake, not hot air.

You could route exhaust heat into the passenger cabin for heat in the winter. Not directly, of course. VW's have no water cooling, so they heat the cabin with hot engine air.

This is called adsorption cooling....yes it could be done, but might not be worth the effort or expense, I don't see a potential for a lot of gain here...

http://en.wikipedia.org/wiki/Absorption_refrigerator

Yes but you would still need electricity,whereas a gas fridge needs none.

Bazzer

A friend of mine has had a propane powered fridge for his off grid cabin for decades and he says it still works great.

There is a variant that is sometimes called the Einstein fridge. I think there is less ammonia in that system and it is sealed so less danger. http://en.wikipedia.org/wiki/Einstein_refrigerator

At various times people work on the Einstein fridge at universities but nothing much happens in the real world. I am sure they could use them right now in India if instead of propane they had concentrated solar as the heat source.

Ammonia is still the best refrigerant. The Space Station recently recharged some 6-10lbs of it into its power system. Since it is outside of the station, the known downside like poisonous - does not apply.

I was thinking of experimenting with some RV LPG fridges using hot oil from the engine instead of exhaust heat. The RV fridges are three-way fridges. They use 12 volts or 120 volts for the heating element, or LPG (small flame) for the heat. Thought I would strip out the electric heating element and replace it with small diameter copper tubing. I haven't stripped one down yet to look at it. Probably won't get to this project until this fall. I already asked about the feasibility of same, but nobody had any input. The LPG flame is so small, I'm pretty certain it would work.

Absorption fridges are low power, by necessity. As long as you can control the heat, it does not matter where it does come from. Good luck.

Thanks for the response. I was trying to find out what temperature was required. I deduced from the tiny LPG flame that not a lot of heat energy was required, I just wasn't sure if there is a "threshold" temperature. I'm pretty sure the hot oil idea is going to work, which means when the generator (engine) is not running, I could also use other heat sources to accomplish the same function (heat the oil), solar collector, wood-burning stove, whatever.

Solar Eagle's system only uses water as the "refrigerant". The cooled water is sprayed over the coil and uses the heat from the liquid being cooled to evaporate the water in a vacuum. The vapor is caught in a desiccant liquid, which is heated to drive off the water so it can be condensed (with tower water as shown) or with air over a coil. The condensed water starts the process again as it is captured by the now-concentrated desiccant.

Several LPG units out there likely use a non-ammonia refrigerant- possibly even the water shown before- because no sane manufacturer is going to put an ammonia system into the hands of amateurs anymore. WAY too much liability.

Take a look at most RVs they have gas,mains or battery powered fridg/freezers.

Bazzer

Gas Fridges were highly efficient for their day, not so much compared to modern HE units though.

As to your second thought, Chysler was famous for their manifold heater on the 2.2 (and others) intake. They formed a water passage on the bottom of the aluminum intake manifold and circulated hot coolant from the engine to heat the intake and air/fuel passing through it. These and the fourway water diverter valves were some of the worst engineering ideas ever....from a I got fix this S@#* perspective. Their value as a fuel saving device for a cold engine was debatable. Their annoying habit of leaking in places not accessible...exemplary.

So, other than trying to get your engine to heat up faster, heating the intake mixture is not necessarily a good idea. The one caveat is if you are going with a full evaporative fuel system. (Pogue carb type) Otherwise most folks are more interested in intercooling as a way to produce more power by providing a denser air/fuel charge.

Thanks for all who commented. One small addition.

My idea is to use it like a second intercooler for the intercooler output so that there is more air (oxygen) pushed into the engine intake. I by no means want to heat the intake for it is not a good idea.

I use ceramic based paints for heat shielding of the whole air intake system to keep it as cool as possible for the steady state operation of the engine. So this is an addition to it.

:-)

I have a 3 way refrigerator out of a motor home that I installed in my kitchen. I have used it for about 16 years. I run it on propane and a 12 volt deep cycle marine battery. The refrigerant is in a sealed system, (anhydrous ammonia) and is not supposed to be tampered with. Anhydrous ammonia can give you instant freezer burns and if inhaled is deadly. Because the system is sealed and has no moving parts they are very reliable if periodic maintenance is performed. About every 6 months or so the orifice for the propane needs to be cleaned. I have also had to replace the ignitor twice and the cicuit board once. About once a week the battery needs charging. The main advantage (for me) is that I dont have to run the generator all the time as I would have to do with a regular refrigerator. The down side is these refrigerators cost a lot more to buy.