Veyron engine loses 2,000 hp to waste heat !
 

I was surprised to see that the Bugatti Veyron engine produced 3,000 horsepower on the dyno, but 2/3 of this is lost to waste heat !
- @ 8:40 in the video

As i watched this video, all i could think of was wow, what a f-ing waste !!

I know using waste heat for increased efficiency is being looked into, but I had no idea ICEs could be this inefficient !

What has been the major hurdle in using waste heat, and why is it taking so long ?

I know it's not this simple, but could steam from some sort of liquid be used on a turbine and then recirculated in an enclosed piping to liquify and create steam again ? Why does this not work ?

dumb question ? :o

( Had to ask )

From the video @ 9:16
Quote " At full load, we could generate enough waste energy to keep 100 homes warm in winter "

( EDIT : And yes it's a Bugatti VEYRON, not Veron )

http://www.youtube.com/watch?v=WUTR4...eature=related

You get about 1/3rd work (ideally) and 2/3rds waste heat. Of course that is considering heating up the atmosphere is a waste, but lets not get into that debate. In reality it's closer to 1/5th work and 4/5th waste heat or even worse.

regards
Mech

I've admired the Veyron since it rolled out. Had no idea it generated that much heat! It even has Titanium con rods and coated pistons. 10 radiators?

I agree, there should be some way to recover some of that energy. I recall in WWII the Wright Cyclone had power-recovery turbines, geared directly to the crankshaft. It gained 150hp per turbine, I think. Found it: 550hp--> http://www.enginehistory.org/Wright/...ompounds.shtml Could be an idea...a working turbine extracts energy, which would cool the exhaust. The W16 is an 8L (487ci), so I don't think it'd get as much as the R3350, but should get something.

Piston aircraft engines typically cruise at 75% power, while automobile engines typically cruise at 5% to 10% power. At 75% power, the exhaust is hot enough to get useful work from. At 10% power, it is not.

Those aircraft engines with the power recovery turbines were notorious for needing a lot of maintenance.

Exhaust heat recovery is the latest thing in large powerplant gas turbines. The best ones are up to 60% efficiency.

1/3 of heat energy transfer to useful work is quite typical maximum efficiency for SI engine. At part throttle is even much, much worse.

I have a resentment of the veyron, simply because 1001 hp just isn't that impressive considering a v16, 4 turbochargers... you can get much more power for much less money.

The Wright Dual-Cyclone R3350 turbo-compound engines with power-recovery turbines were able to "recover" 300 hp above their native 3,000 hp output...that's 10% recovery, but went as high as 450 hp and 20% recovery on some models.

It's kind of confusing how you worded that, Cd. The car nets 1001 metric hp (~987 hp), so you're saying if it were 100% efficient it would put out 3000. Maybe hp isn't the right unit to use when talking about wasted thermal energy. But I'm nit picking :)

The problem is they have to warranty it.

I think steam locomotives waste about 97% of their energy, correct?

I always considered the Veyron too oppulent. Its engine is interesting, but even a pushrod American V8 under 8-litre can provide comparable power and torque figures in a slightly smaller and lighter package...

The whole point of the Veyron is to prove VW could make a 1,001 horsepower car that's actually tractable, easy to drive, streetable, and which won't eat its own guts out after thousands of miles of abuse. Never mind that a new set of Veyron tires and an annual maintenance check could buy you a brand new 1,000 hp crate motor...

The engineering needed to produce 1k ponies is not expensive. the engineering needed to build a car around it that met all of VW's design requirements, however, was insane. Not the least which because the car was designed to fit the body, not the other way around.

I bet the car could be half the cost if they built a supercar first, then built a shell that fit around it, instead.

The reason waste heat is hard to extract is thermodynamics. That waste heat comes out at a much lower temperature, and so it's hard to produce much work from it, especially in a compact package.

BMW's Turbosteamer system is able to recover about 20% of the exhaust stream's heat at lower speeds which is something like a 10% overall increase in efficiency. That's about as much as we can hope for in small engines, a bit over 40% thermal efficiency.

You have to understand that heat energy is much "cheaper" than work (kinetic energy), or electricity, and that it's pretty much not possible to top 60-70% efficiency in a heat engine.

No doubt about it. Anyway, if I had one I'd throw a tuned Chevy LS7 with a twin-turbo layout on it instead of overhaul its stock engine :D

arn't regular engines (in our cars) only 30% efficient, which would mean this Veyron engine is 33% efficient?

And we might remember that, with such a high cost, it could have a more extensive usage of hi-tech ceramic-based materials to reduce internal frictions which lead to all that heat.

Well obviously efficiency depends on speed and load. 33% efficiency at maximum power is *very* high.

At 100% load I know my 1ZZ-FE is most efficient at 3200rpm or so, with a BSFC of 270g/kWh which is about 31% efficiency. Car engines usually have peak BSFC somewhere between 220g/kWh and 250g/kWh. Most of the direct injected engines are peaking around 230g/kWh, which is about 36% thermal efficiency.