engine heat

[oldskoolZ]

I read somewhere that 70% of the energy produced by the engine is lost through heat. I dont know how accurate thats is or if that applys to every engine. Im really big on efficiency, heating my house cooling it, anything. But anyway but I came up with idea to get around this. The problem with cooling the engine is you cant have the cylinder walls cold, the heat of the combustion will constantly be trying to heat it...not good for efficiency. Soo what if you took an engine block and bored it out as much as safely possible. Then machine 2 tubes (for lack of a better term) for each cylinder. One thin one out of a super heat conducting material, the other as thick as possible out of a super heat insulating material, like NASA type stuff lol. Have the thin one inside the thick one inside the block...thaaatway the cylinder wall could be super super hot (which is good) and anything that didnt need to be hot wouldnt be, like the rest of the block. And keep the factory cooling system. Sorry for the long post but thanks for reading.

 

MacZ

[Tony D]

That would be 'Ceramics' and the search term is 'Adibiatic'...

 

Ceramic engines run with little to no coolant whatsoever, and heat lost is mainly through radiation from exposed surfaces.

 

Diesels are more suitable for this application since they use the heat of compression for ignition, so an adibiatic engine would ignite diesels efficiently, whereas the upper detonation limit for gasoline would quickly be reached.

[Pop N Wood]

There is more to it than just insulating the engine. Your approach will just cause detonation.

 

You need to give the hot gasses time to expand to convert the maximum amount of heat energy into mechanical energy. Marine diesels can hit 50% efficiency. But they only turn at like 100 RPM and have bores and cylinders so large they effectively build the ship around the engine. They are also designed to run at full throttle all the time. Running an engine at part throttle is part of what kills the efficiency.

[roger.svoboda]

You have omitted the energy loss out the exhaust. Any heat leaving the engine at more than ambient temp is a loss. If my memory serves from college about 30% (maybe more) goes out the exhaust. Marine Diesels actually in some of the newer designs run at more than 50%. But they capture the stack heat with waste heat boilers and use engine coolant for a variety of services requiring heat. Every bit of heat you can use before throwing it out raises your efficiency. In winter your car's efficiency goes up because instead of heating the atmosphere you heat the interior thus using waste heat for a productive use.

[oldskoolZ]

O shoot knock, I never thought of that:icon11:. Ok well, I guess theres really no way around it: you have an explosion which makes heat, you have metal all around the explosion which absorbs the heat. Which is good to a certain degree, but bad after that. "cooling" really is just taking the heat away and putting it somewhere else. If only there was a way to on the subnuclear level slow the down the molicules vibration haha.