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HydroICE Project Developing a Solar-Powered Combustion Engine
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."
While the engine may ideally just vaporize the water with hot oil, the reactions involved would eventually degrade the oil. Additionally, the separations processes are often 50% of the whole system's energy requirements, I just wouldn't see the viability of such a system. Now a heat exchanger for hot oil/water vaporization would wake a lot more sense, but it seems they want to generate a funding buzz with an internal engine spin.
... that Slashdot had been finally invaded by the 'run your ICE-powered device on water' fraudsters who are all over the car forums on the web now. Thankful to find its just a bad description of using steam expansion as part of a power stroke (BMW tested the same theory using steam generated or augmented by the engines cooling system a few years back, although it worked for them they couldnt get the costs of it to be viable)
For the record before anyone does start talking about vehicle water injection, it adds no power per se, all it does is increase implied octane ratings by adding better cooling and detonation control, exactly the same way a well-designed intercooler would but with the added risk that it steam-cleans the oil from the cylinder walls and probably shortens the engine life as a result. Not to mention the effect on the cat and tailpipe from the increased moisture in the exhaust
I have been a user for about 10 years. This ends Feb 2014. The site's been ruined. I'm off. Dice, FU
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/
Because high pressure steam is much harder to manage than the hot oil. High pressure steam lines, boilers, etc. Hot oil is low pressure and can be pumped with a circulating pump.
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.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
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.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
If you use a small amount of oil to flash a relatively large amount of water you would get better efficiency, but you'd need to heat the oil to higher temperatures which brings its own problems. Also separating oil and water is easy, seeing as they don't actually mix.
stirling engines are extremely precise machines
What, their fuel injectors? Old fashioned mechanical carburators?
Yeah I know the guy is trying to get at the wider temp fluctuations in cylinder and piston temp, unless you go uniflow which has whole nother kettle of fish, but its not really much of a problem.
See if you try to crank up the efficiency and power of a trad ICE, eventually you get all manner of predetonation (ping) and trouble keeping crankshaft loads low enough while not letting the valves float and it gets all technical very fast. With a stirling you just crank up the heat until you melt or deform the piston/cylinder. Its more easily understood so its easier to empathize so its "seems" harder, but actually ICE are way more difficult its just we can't talk in uneducated company about the actual challenges. Any moron can understand "it melted" so any moron thinks stirlings are more difficult because they can't even talk about ICE engine optimization.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Yes, they have reinvented the steam engine.
In this case, literally: it runs on stream. (As opposed to many more modern heat engines, which usually use other working fluids).
The innovation seems to be that they have separated the heat absorption from the expansion of the working fluid.
If the best they can do is 15%, it will not be competitive with photovoltaic, ever. This needs tracking and mirrors, and that kind of moving parts just can't beat the production efficiencies of silicon solar cells.
http://www.geoffreylandis.com
Most people think of "solar" or "wind" as renewable, but in fact, burning straw pellets could also work very well as a heat source and be carbon neutral (renewable). The nice thing about an engine like this is that any form of heat could drive it. Separating combustion from from the pressures in the engine also will eliminate NOx and other pollutants. So even if the solar part doesn't work out (or at night), this idea still has potential for carbon-neutral energy from just about any heat source that can heat up the oil.
I'd pay money to see the first run.
"Eve of Destruction", it's not just for old hippies anymore...
seems stupid, though: we have good heat-exchangers that don't require mixing the two fluids. Just coiled metal pipes (add fins if needed) would do the trick.
We've been building liquid sodium/water exchangers for nuke plants for years. There is zero reason to mix the fluids and then add a separator (which is a real pain in the ass given the oil is in a closed cycle.)
...I see a few issues, some fixable, some less so.
First, while removing the boiler from the whole "steam plant" equation really does help the safety side of things, you have to be VERY VERY SURE that your separator removes ALL the water from your exhaust. Why? Because if you have even a tiny bit of water in your oil tank, and your heat it to 700F, it's going to boil and expand... and suddenly your low-pressure oil reservoir systems just turned into a really weak boiler full of oil that's hot enough to burst into flames. Instead of venting superheated invisible steam that can strip flesh from bones in seconds, you're going to be spurting oil around at temperatures that cause spontaneous combustion when meeting atmospheric oxygen. Not sure if that's really a step up.
Second, while oil and water don't mix, they do tend to form a really annoying to work with mayonnaise-like suspension of oil globules in water when mixed together really well. This takes a long time - or a lot of energy - to completely split apart.
Third, in addition to the previous problems with separating mayonnaise, heat dissipation will be an issue. Internal combustion engines carry a LOT of their waste heat away with exhaust, but in a closed-loop system like the one they're proposing here you need to remove the 85% of the energy you don't convert into work. Steamboats traditionally do this with a condenser that sits in the water, but if you're not near a large body of water, well... let's just say your condensing apparatus is going to be a huge, complicated, and difficult to work with because even if you don't have a high-pressure steam BOILER you're still going to have a high-pressure steam CONDENSER.
You could, of course, run the oil at a cooler temperature... but that drastically cuts back on your efficiency, because your power depends on having a lot of pressure inside the cylinder, and that pressure comes from the steam, and the pressure of the steam depends on the temperature... well, you get the idea. Basic thermodynamics.
So anyway. It's a cute idea, but unless they've got some really amazing tricks to solve the glaring technical fiddly parts I don't think it's going to get very far. I hope I'm wrong... but I don't think I am.
Never underestimate the stupidity inherent in all human beings.
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.
In the near term, for residential power production I think the best method is to use the grid for "storage". The system would need to be able to gracefully shut down and restart without human intervention, though. PV handles that very gracefully and naturally, this would have to be engineered for it.
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Separating oil and water which have been mixed at such a fine level doesn't seem the easiest. While I know it can be done, can it be done in such a manner to maintain any of the heat energy which remains? Or does one just accept that energy as lost?
Wouldn't you just cool it below the vapor temperature of the oil and/or water then separate it as liquids? A lot of the will be lost, but not all. Some of the energy can be recaptured by preheating the liquid water and oil.
They're going to have to cool and return at least the water back to liquid state anyway before it can be injected again for the next cycle.
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.
[Fuck Beta]
o0t!
seems stupid, though: we have good heat-exchangers that don't require mixing the two fluids. Just coiled metal pipes (add fins if needed) would do the trick.
The point of mixing the fluids is that you cannot otherwise impart enough heat to flash boil the water.
Not to mention that it's really hard to do what you're suggesting inside the cylinder
There is zero reason to mix the fluids and then add a separator (which is a real pain in the ass given the oil is in a closed cycle.)
The whole point of their technique is that they create steam inside the strongest part of an engine.
As it turns out, oil and water will try to separate on their own, which makes this a less than complicated issue.
[Fuck Beta]
o0t!
Does the oil eliminate the high pressure steam? Sounds like the steam is still there.
The high pressure steam is only inside the piston chamber. After expanding and pushing the piston, the pressure drops.
seems stupid, though: we have good heat-exchangers that don't require mixing the two fluids. Just coiled metal pipes (add fins if needed) would do the trick.
The point of mixing the fluids is that you cannot otherwise impart enough heat to flash boil the water.
Not to mention that it's really hard to do what you're suggesting inside the cylinder
That is just not true. Look at a steam catapult, or a pressure cooker, or even a classic rail locomotive. You just need a boiler under some pressure.
There is zero reason to mix the fluids and then add a separator (which is a real pain in the ass given the oil is in a closed cycle.)
The whole point of their technique is that they create steam inside the strongest part of an engine.
As it turns out, oil and water will try to separate on their own, which makes this a less than complicated issue.
"Trying to separate" is a lot different from actually separating. Heat a pan of oil to 400 degrees in your kitchen, now dribble water drops onto the oil for a minute or two. Notice how greasy your kitchen tops are getting? Heat transfer == physical motion in liquids == oil in your steam.
How do you plan to separate the stream/oil droplet mixture? Do simple experiment: shake a pint of cooking oil and water together. How long did they take to separate back out? 1 hour to get to 95%? Now try it at high temperatures: you are talking days unless you have a serious refrigeration unit in your engine.
Modern day robotics make precision a non-issue. And with Stirling engines you can use more ceramics in the hot section since it's not exposed to explosive forces or crazy high RPMs like a gas turbine. Plus we can use them for refrigerator compressors without any specialized refrigerant. What they don't presently have is rapid throttle response, much like a regular steam engine, and to get a lot of power, they need to be very large, which is not an issue for stationary applications.
“He’s not deformed, he’s just drunk!”
I don't understand... can you make a car analogy?
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I should think the water won't last long in the oil as its being heated to 700 degrees, the watter should boill off and be recoverable with a condensor.
Only if the water is still steam when it exits the expansion chamber -- which should be easy enough to achieve by balancing the amount of oil and water injected, taking the temperatures of both into consideration.
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