Excess heat storage in ICU automobiles

[Roadam]

I had an idea a few days ago when driving back home. Basically, every IC engine generates about 3 times the usable power as heat. So as the average car is working at average 15 kilowatts when driving along nicely. Given the average drive back home is about half an hour, it uses about say 8 kilowatt hours worth of energy. In that time it also produces about 25 kilowatt hours worth of heat, converted to joules, 90MJ of heat.

 

And 50 liter boiler could store 17 MJ of heat in the water heated to 80°C.

[Roadam]

Oh well, i didnt finish it yet. When I was halfway trough I noticed I had to go someplace.

 

Anyway, I think that if you could make 50 liters of boiling water on your way home, you could heat the house up pretty quickly and also you would have lots of water for a hot shower.

 

Problem is that it would have to be fitted as close to the engine as possible, thats where there is not much place anyway.

 

Any thoughts?

[Moontanman]

I would like to see ICU engines that operate at higher temperatures, this would allow them to operate more efficiently and loose less heat to waste. Your idea has merit, I wonder how much energy would be needed to haul that water with you so you could transfer it to your house. I've seen a car engine used to generate both heat and electricity, the heat was used to make hot water. maybe the excess heat could be used to make electricity by a Stirling type engine? Heat recovery, especially in a stationary setting, could be significant. air cooled engines can be made to work at higher temps but then you have to make them with lower tolerances so they are less efficient. Possibly a ceramic engine that operates at red hot temps could be made with close tolerances? A super charged direct injection two stroke ceramic engine that operates at red hot temps would be a good idea?

[Roadam]

I have seen some firm rework an engine from 120 hp to 750 hp, but that is using very exotic parts such as gold even.

 

As the system would have to sacrifice some internal space of the car aerodynamics wouldnt be affected. Driving at usuall highway speeds even the weight doesnt have much influence. 200 pounds would mean about 3-4% reduction in mileage, not much I say.

 

I was quite enthusiastic about stirling engines at the time, but now I see that while they are theoretically the most efficient, you need some quite expensive materials to resist the temperature. While in the ICE the work is done within the gas and its not needed to pass trough the solid wall as in sterling.

 

As far as I can tell, the most straight forward approach to making ICEs more efficient is making compression ratio bigger. Problem is that this would increase the likeness of preignition or knocking as they say.

 

But back to the point, the engine is surely hotter than 100°C, so it could boil water, exhaust gasses are hot too but I guess if they would be cooled catalyser wouldnt work as well thus increasing pollution.