HydroICE Project Developing a Solar-Powered Combustion Engine 144
cylonlover writes "OK, first things first – stop picturing a car with solar panels connected to its engine. What Missouri-based inventors Matt Bellue and Ben Cooper are working on is something a little different than that. They want to take an internal combustion engine, and run it on water and solar-heated oil instead of gasoline. That engine could then be hooked up to a generator, to provide clean electricity. While that may sound a little iffy to some, Bellue and Cooper have already built a small-scale prototype."
There is a FAQ here: (Score:5, Informative)
The last comment at the bottom of the article is a post by one of the project team, linking to a FAQ written in response to the comments.
http://hydroice.wordpress.com/ [wordpress.com]
Re:Why bother with the oil? (Score:5, Informative)
It's not being burned, it's only being used as a heat carrier. Seems to me it would be more efficient to just heat the water directly, and use it in a steam turbine. What am I missing here?
The hydraulics. I can't be bothered to crack open a steam table at this time of day, but a substantial sized tank of stored 500F water is going to be ridiculously thick walled and heavy... 500F oil can be more or less unpressurized.
Reading the article I'm not sure what "oil" they're using. Cheap canola oil isn't going to like 500F however asphalt isn't going to like being piped around at room temp.
The journalist articles don't detail it, but stereotypically there is a huge insulated front end tank being heated by panels so you can run the engine at midnight. Usually its a couple orders of magnitude cheaper to redesign the system to not require operation at midnight, but thats a higher level system failure.
Re:Not Combustion (Score:3, Informative)
I just read TFA, and what is described is in no way a combustion engine. Nothing is combusted.
They seem to carefully avoid mentioning it, but most oils when preheated to 700 degrees F (holy cow) and atomized in air will burn pretty well. Probably the water addition is to prevent the cylinder walls from melting, or more likely prevent them from looking like a well seasoned cast iron pan (which would have serious issues WRT cylinder rings)
diesel's autoignition point (not flash point, you're already mechanically atomizing the vapor) is only like 400 degrees F.
diesel has a somewhat lower autoignition point than gasoline, but gasoline has a much lower flash point than diesel, weird but true.
Re:Not Combustion (Score:4, Informative)
They seem to carefully avoid mentioning it, but most oils when preheated to 700 degrees F (holy cow) and atomized in air will burn pretty well. Probably the water addition is to prevent the cylinder walls from melting, or more likely prevent them from looking like a well seasoned cast iron pan (which would have serious issues WRT cylinder rings)
I don't think you read the article carefully enough.
1. hot oil + water = instant steam
2. steam pushes the piston down
3. the oil + steam get recycled
4. GO TO 1
The only input is solar energy to heat the oil.
The rest of the system works on a closed loop.
Re:Reinventing the steam engine (Score:4, Informative)
Not really. You could turn photovoltaic power into heat energy (with a resistor), and use it to heat up a molten salt, but the efficiency losses and the cost of turning this back into electrical power is absurd.
Re:Why not use a Stirling engine? (Score:1, Informative)
stirling engines are extremely precise machines
What, their fuel injectors? Old fashioned mechanical carburators?
A Stirling engine [wikipedia.org] is *not* what you find inside any typical car. A Stirling engine is an external combustion engine (the heat source is provided from outside the engine) rather than the internal combustion engines (Otto cycle [wikipedia.org] for gasoline cars and Diesel cycle [wikipedia.org] for diesel vehicles) typically used. A Stirling engine has neither fuel injectors nor carburators - as an external combustion engine, it doesn't need to get fuel into the cylinders.