07-20-2017, 04:30 PM
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#31 (permalink)
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Master EcoWalker
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Quote:
Originally Posted by Fingie
i wonder if it'd be more efficient to run a steam engine off the cat, lol  |
Actually, a very small steam turbine would have a better power to weight ratio than any of the other heat harvesting methods, as long as you waste the steam exhaust and keep the water tank small. Any attempt to capture and condense the refuge would make it impractically heavy.
Sad thing is afaik nobody produces very small steam turbines commercially.
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07-23-2017, 02:25 PM
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#32 (permalink)
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Cyborg ECU
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More questions occur to me... will the exhaust gases slow down as they are cooled by any significant power generation being extracted from the exhaust heat? Will that have consequences for fuel economy (back pressure) or emissions?
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See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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07-23-2017, 02:31 PM
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#33 (permalink)
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Master EcoModder
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Yes but no.
The square pipe is the exhaust. Putting extra stuff around it you are insulating it. So it will be hotter in my opinion.
I also think that iany effect will be insignificant.
Tegs are not excellent thermal consuctors.
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07-24-2017, 05:49 AM
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#34 (permalink)
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Master EcoModder
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Quote:
Originally Posted by California98Civic
More questions occur to me... will the exhaust gases slow down as they are cooled by any significant power generation being extracted from the exhaust heat? Will that have consequences for fuel economy (back pressure) or emissions?
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Yes they slow down, but no it does not matter. A cat or a muffler poses many times more restriction than that. |
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07-25-2017, 12:27 AM
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#35 (permalink)
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It's all about Diesel
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Quote:
Originally Posted by California98Civic
More questions occur to me... will the exhaust gases slow down as they are cooled by any significant power generation being extracted from the exhaust heat? Will that have consequences for fuel economy (back pressure) or emissions?
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It doesn't sound so likely to happen, since a TEG built alongside the exhaust would basically harvest the heat that is simply wasted through irradiation from a poorly-insulated exhaust. |
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09-24-2017, 11:59 AM
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#36 (permalink)
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EcoModding Apprentice
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I was thinking you could create a new header for the car that utilizes the concept a propane fridge uses, having it take the heat from the exhaust to vaporize the ammonia then having it condense on the cold side of the peztier module?
By having a container inside the header that the exhaust flows around holding the ammonia, while the outside wall of the exhaust is directly touching the hot side of the peztier I could create more power without added requirements!?!
From what I understand a normal propane fridge only needs around 250 f to properly function??
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09-24-2017, 02:08 PM
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#37 (permalink)
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Master EcoModder
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I would think that anything in the exhaust flow would reduce the efficiency of the engine and probably negate the gains achieved by replacing the alternator.
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09-24-2017, 02:13 PM
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#38 (permalink)
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Master EcoModder
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But peltiers are not in the exhaust flow. And i suppose the ammonia can be used in a jacket around the exhaust so you would not inhibit the exhaust flow.
Besides the peltiers, if the ammonia system is not too heavy the replacing the AC with such a system would be very good for us who run the AC for 6 months.
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09-24-2017, 02:40 PM
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#39 (permalink)
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Master EcoModder
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Quote:
Originally Posted by teoman
But peltiers are not in the exhaust flow.
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Stovie's suggestion, that my reply was addressing, was having a container inside the header that the exhaust flows around. |
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