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As we all know, the otto-cycle engine is only about 25% efficient. Where is the other 75% of the energy created going if it isn't going to the wheels? HEAT! Anyway, part of this heat is tranferred into engine coolant, most into exhaust, and some into the engine oil. We have baked a steam powered turbo
where the water is vaporized using exhaust temperatures, but what about the same design harnessing the heat tranferred into the oil supply. Either by a system of pipes in the oil pan, or something (small design aspects haven't been totally worked out). Anyway, use this energy to vaporize water and power a turbo. This system could work in conjunction with the steam turbo powered by the exhaust manifold. This is just an idea. I haven't done any real research on oil temps, but anyone has been burned doing a hot car oil change can attest to oil temps coming out of an engine. Anyway, let the baking begin.
(?) BMW Turbo Steamer
http://www.gizmag.com/go/4936/
BMW has a simlar concept car [discontinuuity, May 02 2006]
[link]
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By that logic, regular turbochargers make cars less efficient even though they can lead to better and more complete combustion. If i am wrong on this please correct me. |
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I beleive a rule of reliability is: more parts = less reliabiliy. As I look under the hood of my car, I see that no one is too concerned about more parts. For the sake of energy efficiency, reclaiming lost heat to do useful work is a noble pursuit. |
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supposing size and weight was no problem you could possible pipe the heat into a cooler area outside the engine creating a pressure difference making... WIND! put in a small wind turbine to harness the wind making electricity. from here we can get really crazy and make it so the extra electricity is beamed to the nearest electric substation via microwave. if every car in america did that we would be in fine shape for our energy needs. just give the infrastructure and technology 50 years to catch up. |
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The only downside is that oil actually does it's job better at certain temperatures. Cooling it too much could cause a loss of efficiency. |
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I still think the original idea is best. Using the existing water jacket as a boiler and the exhaust manifold to add further heat would be the simplest way. It would require a different pump to supply higher pressure and maybe one-way valves to make sure the steam went to the turbine, not the boiler. A condensor/reservoir downstream of the turbine would supply the pump. As for reliability and efficiency, I don't see any downsides. This idea is not merely adding parts, it's adding a whole new system. It would produce more power from a given amount of fuel, the very definition of increased efficiency. While each extra part is a part that can break, that doesn't automatically make the whole thing less reliable. Cars are already hideously complex machines with thousands of parts, switching to a different water pump and a different type of turbocharger wouldn't really change the reliability of the overall system. |
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There lies the problem with the ICE, its efficient operating temperatures. To cold and it's not efficient, too warm and it's not either. I still think though that the pursuit of a exhaust-manifold heat powered turbine is a valuable idea. The only problem is finding out how to effectively vaporize the steam to produce enough pressure to power a turbine. If it is one loop then all of the water in the loop will become equally warmed if one part of the pipe is heated. Then we end up with a pipe full of steam that doesn't want to go anywhere. I have a problem, also, with using the engine coolant because of the pressure drop that would be needed to allow for the coolant to vaporize. |
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I've been trying to find info about steam turbines. Turns out they've been in use for quite a long time, somewhere in the neighborhood of a century. I can't find any info about what sort of pressures and temps we'd need to run what is basically an air compressor. |
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I'm thinking there would have to be check valves between the pump and the steam nozzle to prevent backflow. The check valves would also maintain the pressure in the water jacket. There's also the fact that the pressure of the system would have to be much higher than the 15-16 PSI in a standard car. That means that even with a large pressure drop, you'd have enough pressure in the block to prevent cavitation. |
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You could use a seperate system to provide the water, it's just not as elegant a solution. You already have a pump, boiler, and reservoir/condensor on the engine, why not use them? Don't forget, the radiator will still be there to cool the condensed steam enough to allow it to be an effective coolant for the engine again. Also, you couldn't let just anybody own one of these. The coolant would have to be distilled, mineral-free water. Not only is this the best coolant, the lack of minerals eliminates the risk of deposits that could ruin the turbine. There would be no "topping off" of the reservoir with a garden hose. |
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True contaminates would quickly destroy the system, however engine bearings are just as delicate as this system would be. If it were created, it would have to be idiot proof and if it were sealed it could produce a low maintenance, long life system. If the exhaust went through a boiler system, similar to a steam engine's boiler, the majority of the exhaust temperature would be transfered to the water, which would go to a turbine, similar to nuclear power production processes. the exhaust blade on the turbo would have to be converted to a two or three stage progressive turbine design. Down sides to this design are added weight with the water, and the exhaust would suffer excessive resistance. The more resistance, the more potential energy that would be transfered to the water, the less resistance, the more wasted heat energy out the tail pipe. Possibly submerged headers with cooling fins could boil ample amounts of water to turn a turbine, to create power to drive a turbo. On second thought doesnt a turbo already operate on all those principles, but is simpler? Maybe those thousands of engineeres responsible for the millions of cars with turbos knew what they were doing, and thats why millions of cars have similar turbo systems without this complex "add-a-system"stuff were all talking about here. |
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i had a similar idea to this harnessing the heat wasted to run a turbine, hoo hum great minds and all that, must be a reason noone has admitted to doing this or used it in practice.
as to the oil that would be a problem for the oil manufacturers |
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I'd use the steam to power accesories like the alternator and A/C rather than as a turbo, after all waiting for 5-20 minutes to get full power out of you engine because the turbo wouldn't have steam yet would be a pain and anyone idling long enough to warm it up would lose any advantages they had gained, however the steam system could keep working till the engine cooled down and so boost the battery with the alternator for a few minutes after shutdown. the only problem I see here is condensors are big, BTW i'm not an engineer but I am a steam propulsion mechanic (naval) |
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