Ingocar hydraulic hybrid - Fuel Economy, Hypermiling, EcoModding News and Forum

basjoos · 02-26-2010, 04:41 PM

We've had some discussions about hydraulic hybrids recently. Here's one they are working to put into production.

Valentin Technologies, Inc. - The 170MPG Car

roflwaffle · 02-26-2010, 04:56 PM

I'm not seeing how they're going to get 170mpg on the NEDC cycle when a Prius only pulls ~75mpg. There's only a ~400lb difference in weight, and they both have regen.

RobertSmalls · 02-26-2010, 05:56 PM

Well, there's a few things going on here that allow them to claim 170mpg. This is not yet a car, it's just a design exercise. As far as I can tell, they haven't yet expressed an intention to build a prototype or a mule.

They claim a 48% engine efficiency, instead of the Prius' 37%. The engine is just large enough to maintain 60mph @ 6% grade. The biggest advantage of a hybrid is that you're able to carry around just enough gasoline engine to do the job. Unfortunately, the Prius dropped the ball on this one with its 1.8L engine. The Ingocar will have an advantage here, but I wouldn't count on 48% efficiency until they build a prototype.

"An air drag of 0.22 is used in the calculation of fuel consumption." That's achievable, and Toyota could have done the same with the Prius. They chose to settle for 0.25, for various reasons including aesthetics, convention, and usability.

"a weight of 2,200 lb has been used in the calculation" which seems extremely optimistic to me. I think 2800lbs is more like it for a modern car. Accordingly, they'd need to up-size the engine.

Here's a pdf with a few more technical details than the website: http://www.valentintechnologies.com/...-Car-05-07.pdf

roflwaffle · 02-27-2010, 01:40 AM

The absolute best for passenger cars I'm aware of was the engine in the Insight/3L Lupo at ~40+% BTE. 48% is better than maximum efficiency for a non-road diesel, and those have no emissions equipment. They're assuming they can see marine diesel efficiency in a car. Crazy talk IMO. Even if they could, 2+x's the mileage implies they're using a car w/ roughly 50% of the weight/CdA, which is what, ~1450+lbs? There's no way. I don't think going in new directions is a bad idea, but at least keep it within the realm of the possible.

NeilBlanchard · 02-27-2010, 03:12 PM

The rear roof line doesn't appear to drop down enough to get the low drag they are assuming.

user removed · 02-27-2010, 07:40 PM

Efficiency

50% peak.

Other free piston designs have theoretical efficiencies approaching 59%.

Direct combustion to hydraulic pressure.

You will see 60% in the next 10 years.

Valentin has been working on this for a long time, paid $75k for a full page ad in the New York Times about 15 years ago.

The INNAS BMW conversion doubled the vehicles mileage overall, and that was a diesel BMW that was fairly efficient to begin with.

The lean burn Insight was supposed to approach 48%.

Recharging the accumulator allows peak engine efficiency always.

Posted links on previous threads.

regards
Mech

roflwaffle · 02-27-2010, 11:52 PM

So they went to all the trouble of testing the engine, but they didn't even provide their actual testing procedure/data? Even a short video would have been enough. 48% efficiency is low speed marine diesel territory, and impressive claims require substantial data.

P.S. The Insight may have been supposed to reach 48%, but it only hit ~40% according to it's BSFC map

RobertSmalls · 02-28-2010, 12:32 AM

Quote:

Originally Posted by roflwaffle

P.S. The Insight may have been supposed to reach 48%, but it only hit ~40% according to it's BSFC map

The BSFC map in the Wiki is for the CVT variant, which doesn't do lean burn. There's a BSFC map for the 5mt here: http://ecomodder.com/forum/showthrea...iki-12355.html
but it doesn't appear to have lean burn either.

Somewhere near the bottom of my Insight to-do list is to buy some dyno time and try to measure lean burn BSFC.

captainslug · 02-28-2010, 02:52 PM

It's also NOT a hybrid. A hydrostatic drive system is a type of transmission. Albeit an extremely efficient one, but that doesn't make it a hybrid because it's only propelled by a single energy source: the diesel engine.

Having a method of storing the hydraulic pressure is no different than having it stored in a flywheel.

RobertSmalls · 02-28-2010, 03:35 PM

No, it's a series hybrid. The fact that the hydraulic accumulator stores energy, instead of just transmitting it, is the difference between a hydrostatic transmission and a hydraulic hybrid. If you had a flywheel that could spin independently of the engine, you'd have a kinetic hybrid.

Anyway, it behaves like a hybrid: peak power greater than the engine's output allows the engine to be downsized. Kinetic energy is recovered during braking and used later. The engine runs only when required.