Thermoelectric Tech in the 5

[Ronin]

The Turbosteamer, as its name suggests, uses exhaust heat to boil a fluid which is under high pressure. This fluid then turns into steam, which powers an expansion turbine that generates electrical energy.

The Thermoelectric Generator, meanwhile, uses technology developed by NASA and is essentially a special material that can generate electricity under the Seebeck Effect, where an electrical voltage can be generated between two thermoelectric semiconductors if they have different temperatures.

Currently, the generator produces up to 600 watts of electrical energy but the goal for production is 1,000 watts.

Interestingly, the project is being partially funded by the U.S. Department of Energy together with Michigan-based Amerigon.

But best of all, the components developed have been configured to form a module that can fit into current production cars. So far, a mock-up system has been installed in the BMW 5-Series..

Initial testing using a four-cylinder engine has shown that gas mileage can be improved by around 10 percent on long-distance journeys.

Now, combine this with existing fuel saving technologies such as brake energy recovery, engine stop-start, low rolling resistant tires, and active grille louvers, and we could be seeing improvements as high as 20 to 25 percent.

Look out for a preview at the 2011 Frankfurt Auto Show in just two weeks' time.




http://www.motorauthority.com/news/1...gy-in-5-series

[fundahl]

Funny thing is I came up with a similar idea after finishing my refrigeration classes. Always wondered why nobody took advantage of the waste heat from ICEs.

[Sticky]

Interesting tech that can make a real benefit. Looking forward to what BMW has to show for it at Frankfurt.

[oddjob2021]

Funny thing is I came up with a similar idea after finishing my refrigeration classes. Always wondered why nobody took advantage of the waste heat from ICEs.

cool man, gotta patent ideas like that! i wonder if/when it becomes standard on motors that performance guys will rip it out for flow, or maybe, alter it and use it like a boost such as in KERS on race cars.

[Bimmerdude]

BMW has been developing this for at least 8 years now, I read about it back in 04 for the first time and it wasn't something all that new for BMW then (it was developed somewhat) so I think what we are seeing is technology takes about 10 years to make it to market on some of these complex systems. Makes me wonder if the variable compression Nissan motors or the GM test with a compression ignition gas engine (cruising and idling only).

[DBFIU]

Ive used these thermoelectric conductors before, they are VERY cool and when I was in college I never understood why they were not being used everywhere.

Basically these devices are about the size of a playing card. Two LTCC plates sandwich a germanium - bismuth doped silicon material which acts as the 'in between material, where all the magic happens'. If you apply a voltage to the plates, one side gets hot and the other gets cold. In turn if they experience a temperature gradient (one side exposed to hot and other side is cold) they will generate a voltage.

They do have downsides, that is because we cannot escape the second law of thermodynamics the device is irreversible and ultimately the system will generate net heat. If you're smart, you can actually isolate one side of the plate and shed heat on the other side while the cold side acts as a refrigerator. This is not a completely novel idea, as some of my classmates succeeded in implementing this idea as senior projects. The plates are very power robbing and it is difficult to shed all the heat off of the hot side of the plate.

Anyway, the thermoelectrics have a ton of uses. $#@! I could think of 10 off the top of my head I would love to use them for.

[Sticky]

If you're smart, you can actually isolate one side of the plate and shed heat on the other side while the cold side acts as a refrigerator.

Isn't this what a peltier cooler does?

[DBFIU]

Isn't this what a peltier cooler does?

Yep.

[Sticky]

Yep.

Yay, look at me and my awesome physics knowledge.

[Bimmerdude]

Yeah, I was going to say "these are used everywhere." I learned about all this in high school.

Peltier coolers are great, but expensive and very inefficient. They are used on nuclear subs, etc. heavily because they are solid state (no noise), but I think we haven't seen them in things like engine cooling systems - think about using all that thermal energy we send to the radiator. But I'm not sure they are as long lasting / efficient as needed for that kind of use.

[Sticky]

Peltier coolers are great, but expensive and very inefficient.

Why are they inefficient? They move heat very well.

[DBFIU]

Why are they inefficient? They move heat very well.

they require tons of electrical current to do this...


both sides of the plate are so close together that it is difficult to keep one side cool without having to battle heat trying to conduct its way back into the cold plate. they have to be designed with large heatsinks and insulation to work effectively, otherwise if u turn it on one side will got hot and the other cold. then eventually the net heat created will be positive and the cold side will not be as cold as the hot side is hot, there is a way to quantify what i juat said but that is the overall idea.

[Bimmerdude]

they require tons of electrical current to do this...


both sides of the plate are so close together that it is difficult to keep one side cool without having to battle heat trying to conduct its way back into the cold plate. they have to be designed with large heatsinks and insulation to work effectively, otherwise if u turn it on one side will got hot and the other cold. then eventually the net heat created will be positive and the cold side will not be as cold as the hot side is hot, there is a way to quantify what i juat said but that is the overall idea.

This.

Nuclear subs have practically unlimited power so its no big deal in that application. And the solid state functionality pays huge dividends when you need to be silent.

[Sorena]

Funny thing is I came up with a similar idea after finishing my refrigeration classes. Always wondered why nobody took advantage of the waste heat from ICEs.

once we cooked burgers with exhaust heat, so i can say they stole my idea too.