WRX Electric turbo

[zigzagz94]

WTF does this have to do with the FR-S? There is no mention of it in that article or is this thread just posted in the wrong section. Unless the OP has some info about that engine finding it's way into the toyobaru twins, I suggest this be moved to the other vehicles section of the forum.

[CarryOne]

From what I understand of electrified drivetrains and reading from this article ( http://jalopnik.com/5855317/will-bmw...-end-turbo-lag), I believe Genomaxter basically explained it. Now some of what I will state is my speculation. Not trying to be disrespectful, but would like to be a little more precise. I am little nitpicky.

At low rpms and off boost, and electric motor will spin the compressor.

More precisely, when car is told to quickly accelerate (ex. 0 mph and stepping on the gas all the way down) while the turbine is at low RPMs and boost is at a negligible psi, the electric motor quickly brings the turbine to required RPMs. This is done until boost is at proper pressure. This is extremely fast compared to a conventional turbo as you do not have to wait for it to spool from the low pressure exhaust. So a sense of lag is removed. At this point, the electric motor is no longer powered by the electrical storage device (e.g. battery, super capacitor, etc) and instead acts like a generator to recharge it. At proper boost levels, the exhaust is now spinning the turbines at high RPMs which in turn spins the generator. After the battery is charged to a certain state of charge, the generator/motor is disengaged from the turbine as Genomaxter stated. This is to increase efficiency.

Some of it is speculation so if I am wrong, please correct me.

[Bristecom]

Yeah, that's what I thought. It's like an anti-lag system without the flames coming out of your exhaust. :P

That's exciting.

And yeah, this thread doesn't belong in the main FR-S forum.

[7thgear]

Originally Posted by Matador

That design makes no sense whatsoever.

so wind turbines and hydro electricity make no sense?


turbo setups as we know it use the force of the exhaust to drive a mechanically connected compressor that sucks in air.

what they have come up with is a way to generate enough electricity from the exhaust system to power an air compressor that feeds the engine.

this way you can mount the compressor anywhere you want and not have to worry about heat (since you're only worried about the heat generated from air compression).

this will mean more efficient exhaust design, more efficient intake design, reduced heat, reduced weight, reduced wear and tear.

awesome.





you guys know what this is, right?

[Matador]

Originally Posted by Genomaxter

I read up on how BMW plans to do an electric turbo and here is what I know from a year ago. You have a regular turbo setup. Everything is piped the same. The difference is the turbo housing has an electric motor built onto it. At low rpms and off boost, and electric motor will spin the compressor. Once pressure builds, a clutch will disengage the motor and let the turbo run normally from the exhaust gasses. That's it.

Toyota has been working on a system like this since 2007 or earlier. I had a whitepaper on this, I have to dig it up.

Originally Posted by 7thgear

so wind turbines and hydro electricity make no sense?


turbo setups as we know it use the force of the exhaust to drive a mechanically connected compressor that sucks in air.

what they have come up with is a way to generate enough electricity from the exhaust system to power an air compressor that feeds the engine.

Don't try to be a condescending ass. I understand exactly what kage described and the principle on which it works. It makes no sense set up as described for **that** application. It would certainly not be very efficient at all.

[7thgear]

Originally Posted by Matador

It would certainly not be very efficient at all.

Certainly? Please explain where your certainty comes from. Do you have access to their patent, are you a subaru engineer?

There was a time steam engines were all the rage you know.. i guess the concept of technological progress eludes you.

The concept is most certainly a step forward, why are you so negative about a possible breakthrough in it's actual application?

[blu_]

It's an interesting concept but the article is riddled with errors so I don't know what to make from it. how is the exhaust heat converted to electricity? is there going to be a steam motor to spin a turbine to charge a battery? I'm not trying to be condescending, I just don't know how you go from heat straight to electricity without an intermediary step.

[7thgear]

Originally Posted by blu_

It's an interesting concept but the article is riddled with errors so I don't know what to make from it. how is the exhaust heat converted to electricity? is there going to be a steam motor to spin a turbine to charge a battery? I'm not trying to be condescending, I just don't know how you go from heat straight to electricity without an intermediary step.

it's not really heat as it is the exhaust gases, a force that currently moves (spins) a turbine

this spinning turbine has a mechanical link to a compressor

but it could be linked to a generator and create electricity, which could then be used to power a compressor.

this hasn't been done because no one figured a way to do it efficiently as far as i'm aware, and i most certainly do not follow any scientific journals and what not.

but perhaps Subaru had a eureka moment, or laid to light some sort of hidden project they kept hush about.. who knows?

[quik1987]

What happened to this?

[azian_advanced]

Originally Posted by denkigrve

I'm sort of wondering the same thing. I think because it's still exhaust driven, just uses the exhaust to charge a generator vs spin a fan.

the definition of a turbo is by having a turbine wheel extract mechanical energy from the flow of the working fluid (ie. exhaust gases). i'm not sure how heat is being converted into electricity (usually it is done the other way around) but it sounds like there is no turbine. the way i see it, this is more of an electric motor powering a compressor wheel. i'm not sure if you could call that a supercharger though...

[denkigrve]

Originally Posted by azian_advanced

the definition of a turbo is by having a turbine wheel extract mechanical energy from the flow of the working fluid (ie. exhaust gases). i'm not sure how heat is being converted into electricity (usually it is done the other way around) but it sounds like there is no turbine. the way i see it, this is more of an electric motor powering a compressor wheel. i'm not sure if you could call that a supercharger though...

Yeah it's really interesting to me since this is being advertised as a "turbo" in terms of the scope of the project, yet functionality sounds more like a supercharger. From what I've read the system would trap the heat generated by the exhaust rather than rely on it for pressure to generate the electricity needed to spin the turbine, thus removing the reliance and lag created by requiring the turbine to function purely from exhaust gases.

So I'm picturing something that traps heat, and then provides enough power to spin a turbine to provide the same type of boost a turbo would provide, only through electricity. But that sounds like a super charger.

My head hurts right now... I'll let people with science degrees hash this part out, I just think it's cool they're trying to innovate in this space.

[serialk11r]

A turbo doesn't do any heat conversion, it only picks up pressure left in the exhaust. Specifically on an Otto cycle gasoline engine, you have a little bit of extra pressure left in the cylinder when the exhaust valve opens, and this little burst of exhaust gas flow is where the energy is, and what a turbo aims to capture. This is why you can get more boost pressure than backpressure.

A regular turbocharger relies 100% on the exhaust gas stream to power the compressor, so it has a lot of backpressure designed into it so that it spools up more quickly among other things, however this saps power from the engine as you probably know. When you separate this turbocharger unit into a supercharger and a turbo-generator, you no longer care what the turbine is doing relative to the supercharger, so it can be more optimized to collect the otherwise wasted blowdown energy. Also might I mention the turbine's speed is very important to how efficiently it operates.

A side benefit is that the primary reason the exhaust is so loud without a muffler is because of the rush of high pressure gas out into the exhaust system with every exhaust valve opening event, if you have a turbine in the way capturing this energy, your noise is automatically reduced significantly.

Might I also mention that arguably the optimal method of controlling this stuff is electrically, and to be creating large amounts of power from the turbine in the form of electricity would require a substantial electrical power storage system, and a way to use all that electricity, perhaps an electric motor of some sort Might I mention another thing rumored is that Subaru has developed a proprietary hybrid system...

[Dimman]

Originally Posted by quik1987

What happened to this?

BRZ STI...



Heh...

[Calum]

wow, omg...

Please fellas, please look up turbine blades. Heat is very much so used in the process of converting the energy in the working fluid into mechanical energy. That mechanical energy is then used to turn something, in this case it'll be an electrical motor and/or a centrifugal compressor.

From what I've seen of these types of designs most companies working on it are trying to incorporate an electrical motor into the tradition "turbo" so that the motor can be used to drive the compressor when the exhaust gases can't. And when the exhaust gases have enough energy to drive the turbo too fast, the motor will then be used in a regenerative cycle to generate electricity.

The biggest hurdle is trying to spin a motor fast enough, while making sufficient torque to drive the compressor with only 14 volts. There have been petitions for quite a while to move to 48v electrical systems in cars, this is one reason why. I'd speculate that turbo manufacturers are working on larger, slower moving/hopefully more energy efficient compressors, but I haven't seen much about that. With the advent of capacitors larger enough to start a car, I'm surprised they haven't side stepped the voltage regulations by making a small voltage quadrupler to run in concert with the regen turbo.

The steam plant I used to work on had steam entering the turbine at ~800 def F/600 PSIG and leaving, after being condensed, at 96 deg F/1 PSIA. Due to the relatively low pressure in that system, the blades were designed to get most of it's energy from heat, roughly 60:40. That plant generated 21,000 shaft HP at 108 RPM.