New thermoelectric generator converts vehicle exhaust heat into electricity, boosting fuel efficiency
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Yes, and no. Heat and kinetic energy are fundamentally all just energy. What we call heat is, technically, the kinetic energy of molecules vibrating around.
When exhaust gas passes through a turbocharger, it is both slowed and reduced in pressure, resulting in it being slightly cooler than when it entered. This device is using a different method of getting energy out of the exhaust gas, but it's fundamentally still the kinetic energy of those very energetic exhaust gas molecules bouncing against one side of the thermoelectric generator and giving up their energy into it. I would still expect the exhaust gas to come out of it slightly cooler and slower.
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This type of technology and the concepts of energy conservation and recovery are so damn cool.
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Fools logic. This is a single system imagine the world running systems like this on every device or system, then the amount adds up. Energy recovery is the future. Maximizing what we can produce. Sustainability.
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Gotcha, thanks. It doesn't sound particularly revolutionary as far as energy capture goes, since 40W is probably negligible on today's cars.
NGL though, on an old '75 Honda motorcycle I used to own, an extra 40W would have been amazing. The alternator was too tiny to keep the electronics running and battery charged, and I had to turn the headlight off whenever possible to keep the battery charging.
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What we call heat is, technically, the kinetic energy of molecules vibrating around
I’ve wondered about this. If this is so, and heat is molecules moving back and forth, how do the molecules stop, change direction, and then accelerate in the other direction, stop, change directions again, and go back, over and over and over?
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It even says in the article 40 watts. I’m not going to say this affects literally nothing, but it is not a significant enough amount of power to meaningfully affect the locomotion of a car. It might make more sense in much more scaled up helicopters and planes where fuel economy is a far bigger problem. But thermoelectric has never been a very potent method.
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Wouldn't be powerful enough actually. You're better off having a battery that's in good condition. I've done nearly 100 km with the alternator belt off. It being a diesel, it didn't need to fire sparks though.
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I remember when I first learned about regenerative braking when the first Priuses were coming out. Shit blew my mind.
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We already do this at every steam based power plant in the world (basically everything but hydro, PV, and wind) and it's done much more efficiently. Doing this stuff with tiny gadgets on micro generators like ICE vehicles is a pretty inefficient implementation, especially as it adds weight to already heavy vehicles, decreasing efficiency and safety, and increasing tire and brake wear. The only place I can imagine this being useful is very heavy vehicles that for some reason still have to be using diesel like long haul trucks/busses, diesel freight trains etc and the like. And EVEN then you're looking at major issues with economy. If you increase the weight of a truck by 2 percent to give it a 2% increase in fuel efficiency, you are hurting not helping. 2% comes off of your GCVWR margins and suddenly you need 51 trucks instead of 50 trucks to transport a given load, not only increasing your fuel use by 2% but also increasing vehicle maintenance and tire and brake pollution by 2%
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Your explanation about where the energy comes from with turbochargers sounds wrong to me.
When exhaust gas passes through a turbocharger,
You're skipping a crucial step here. The exhaust gases get pushed through input of the exhaust gas impeller on the turbocharger by the movement of a piston in the engine during the exhaust cycle. This "work" isn't free. Its energy that comes from the other pistons on their combustion cycle. If there is more resistance on the exhaust coming out of the engine (which there is to drive the turbocharger impeller), that energy must be added (robbed) by the energy at the crankshaft that ultimately powers the wheels.
The extra boost of power we experience in an engine from using a turbocharger is that the turbocharger allows more oxygen to be put into the combustion chambers (and the engine puts more fuel in at the same time). The extra energy is from burning - - more fuel in the same period of time than without turbocharging. The fuel is the source of the energy, the turbocharger isn't recovering any energy.
The article is covering technology is actually recovering energy turning heat (thermal energy) back into electricity (electrical energy).
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Molecules interact with each other. Energy is transferred as they bump around. If you were to follow a single molecule it would move around randomly. What we can measure is usually the average of many molecules.
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Show this to any automotive engineer and count how many seconds before they start laughing
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So it’s less of vibrating and more about smashing around into things?
This is easier to envision with a gas: like a chamber of balks all ricocheting like mad. It’s harder to envision for a solid. But I guess a molecule will be up smack against its neighbors, getting repelled, not so much bounding freely?
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Fools logic was meaning this type of technology doesn't have a purpose when it definitely does and that is how your post came off lack of context I guess, it is the internet.
While it won't power the locomotion of the car it will help to power accessories even on a 40w basis even more so over trips and somewhat lengthy drives.
Your post lacked any of your clarifications so it comes off as you simply think this is an ignorant waste of time concept as a whole. Energy recovery is a useful premise.
But making micro machines to do it, or retrofitting old cars with this wouldnt help much but manufacturing newer more effecient vehicles isn't a viable strategy like the guy explains above you. There's other uses besides moving a vehicle. There's other fields and applications this could be used for having nothing to do with configuration. All I was saying was that this tech has viability.
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Even solids are mostly nothing. This is why neutron stars are so dense - there is a lot less nothing between the neutrons, largely due to gravity.
Here's another way to think about it. A gas is like a bunch of balls bouncing around a room, hitting the walls and occasionally each other. A solid is like a ball pit, but the balls are vibrating. There is still a lot of bouncing, but most of themstay together.
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The article opens with saying only 25% of the fuel's energy gets used by the motor, 75% is in the heat of the exhaust. I'll take that as a given. Let's assume a small motor (in this inventions favour) with a nominal power of only 60 kW, running only at half tilt, 30 kW.
That gives us 90 kW in the exhaust heat by the numbers of the article. So the 56 W it captured in the simulation would be 0.046% of the total 120 kW power being converted by burning the fuel, raising the efficiency from 25% to 25.046%.
The headline is so massively overstated it's basically just a lie. If the device was built, not just simulated, and you'd manage to substitute part of the alternator's ouptut with the thermoelectic generator's output, the effect on fuel economy would be below the measurable level.
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Yeah, I do apologize - I'm somewhat simplifying my explanation because when you start going into the full detail, it just brings up more questions.
So yes, like the other comment says, the particles are constantly bouncing into other things.
- If they're bounded in by something - walls of a container, or even just more gas surrounding the specific sample you're looking at - they'll bump into that, and transfer some of their energy to that.
- If they don't have something to bump off of and the particles are free-floating, they'll take off in any given direction. If they only have something to bump off of in a limited number of directions, they'll take off in the other direction. (For instance, in a rocket engine, we make a lot of molecules really, really hot and then surround them with barriers in every direction except the one we want them to zoom out in.)
- In some cases, the molecules have electromagnetic bonds with each other, which take more energy to break than the energy contained in their "bouncing around". So they'll stay stuck, just bouncing off each other, even in a vacuum, (Or at least, until they radiate away their heat via electromagnetic energy... another whole story.)
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You are confusing me with other person. Read the names.
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Nothing to apologize for - thank you for elaborating.
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Oh damn
my bad.
