They aren't going away (hydraulic hybrids)

[user removed]

The vehicle could begin operation with precharged accumulators. Climbing extended grades with something like Pikes Peak as the most extreme example will test any hybrid to the point where it no longer has the capacity to climb that extreme a grade. How much range owuld a Nissan Leaf have climbing Pike's Peak. It might no make it from the bottom to the top. Climbing grades is where you actually can use peak BSFC in any IC engine, going down the other side of that grade is where you may exceed your storage capacity. remember the vehicle is a constant energy drain regardless of the circumstances so that reduces the potential for regeneration downhill.

The power required to climb a grade is fairly easy to calculate. A 7% grade of 1 mile is .07X5280 feet That's 369.6 feet per mile. I have read about coasting for 35 miles coming down the east side of the Rocky Mountains. Most Interstates are 7% grades or less with a few exceptions. Only a car with good aerodynamics will exceed 70 MPG coasting down the vast majority of grades on US roads, so we are talking about very small percentages of grades where there would be regeneration opportunities. I am not saying never just fairly rare and I am sure many here see excetions to that rule daily.

A 2200 pound car needs 28 horsepower to climb a 7% grade, 7 feet and 4 times 550 pounds per foot. That is in addition to the power required for level speed, so lets assume you need 40 HP to climb a 7% grade. You need to size the engine for that to be at best BSFC for the most efficient grade capability. Could you recover all the energy of any grade imaginable? Of course not. What vehicle can do this, and why design one so it covers every extreme. That ios the problem with vehicles today. They have engines sized to cover every extreme, which means their efficiency is 50% of their potential when they are not in extreme circumstances.

That does not exist in the design of Hh vehicles, the engine shuts off when the loads are light, and runs constantly when loads are extreme. As far as emissions, shutting an engine off for short periods of time is already done in hybrids and they seem to pass emissions easily. no change there.

I am breaking up my posts so that my log in doesn't time out.

regards
Mech

[user removed]

I think Ian's post are thoughtful and he seems to be reading the material posted with high levels of comprehension. It will always be "possible" to develop alternative configurations. The question is will they be cost effective? If not then most will never see production on the scale of conventional vehicles. I want a solution that applies to all vehicles, inclusively, not exclusively. If you want to store energy in a battery and use it in an electric motor, you are not excluded from using a HH powertrain, just turn the motor on , without any current regulation, charge the accumulator when it needs it and drive the vehicle normally.

That way those who have the capability to collect energy with solar panels can use that energy to drive their cars. My guess would be that is less than .0001 percent of the vehicle operators in the US, but even that minuscule percentage could use a hydraulic powertrain platform and eliminate the motor controller and achieve higher overall efficiency, especially in the current mostly local high traffic density scenarios in which most BEVs operate.

I posted a long time ago that you could use the same vehicle with interchangeable power modules. One IC and liquid fuel. The other battery electric. Use the first for long distance trips and the second for local operation. As battery technology improved, you would use more of config2 and less of config1 until battery tech became your principle source of energy.

regards
mech

[IamIan]

Originally Posted by jamesqf

Seems like you'd be getting rather Rube Goldbergish, though. Say I have solar panels on my roof, and want to charge my hybrid with them. Pretty easy with electricity, but with an HH you'd have to add something like an extra electric pump to the system, plus plumbing &c.

That is very possible ... depending on the details of a specific setup.

For Solar ... I suspect the PHEV has a significant efficiency , complexity, etc ... edge for the pre-charge side.

For Mechanical RE ... Wind , Water , etc ... It might be possible to design a system that could get comparable performance ... but even there it would not be an easy task.

Of course all the pieces have analogies ... plumbing or wires ... pump or charge controller ... etc... even if they are not all equally analogous.

- - - - - -

Another factor to consider about the source for Plug in options is the utility of the source for other potential loads ... RE that outputs electricity has a multitude of other uses ... RE that outputs pneumatic , or hydraulic pressure storage ... maybe if it were located somewhere that needed such things ... or if the RE would only have the one use , for the vehicle pre-charging.

- - - - - -

Of course sense the vast majority of current RE systems are designed and built for electric output ... that kind of gives anything charging from that electric output a significant head start / lead ... technology , cost, etc ... at least on the pre-charge side.

That isn't a guarantee it will always be that way ... but that is the way it is now ... and that gives a disadvantage to anything that is trying to buck that trend / system and do it differently ... The utility and diversity of electricity is a elephant in that room ... one I don't think is going away any time soon.

[NeilBlanchard]

I've never had a post time out on me ... Here's what I do when I know I'm going to be a while: I open a second tab on the same web page, click on the New Posts button, and set the auto reload addon tool in my browser to about 5 minutes. Or, you can post it part way through, and then immediately edit it. Also, if I think I may have timed out, I Copy the whole thing to my clipboard before clicking Post - for our friend Justin Case.

In looking at the brochure, I notice that the hydraulic series hybrid needs to have the same engine as the conventional car - and I'm assuming that this is because the accumulators are not able to buffer the energy for a longer time? This brings up the issue of warmup time - the engine must be cycling on and off fairly rapidly - what sort of time frame for this to drive at 55MPH on flat ground in no wind? Does the engine run constantly, or cycle on for 3 minutes and off for 3 minutes - what would be typical?

[Cobb]

Again, we can find more excuses against it than for it. At least the folks at Toyota were successful and are turning a profit at the hybrid thing using batteries and electric motors regardless of their down falls.

[jamesqf]

Originally Posted by Old Mechanic

I have read about coasting for 35 miles coming down the east side of the Rocky Mountains. Most Interstates are 7% grades or less with a few exceptions. Only a car with good aerodynamics will exceed 70 MPG coasting down the vast majority of grades on US roads, so we are talking about very small percentages of grades where there would be regeneration opportunities.

Not all roads are interstates, and mountain roads (or the hilly equivalents east of the Mississippi) are probably less likely than most to be. On the vast majority, your speed is not limited by aerodynamics, but by tire adhesion going around hairpin turns.

Just from my own experience, the top speed of a Honda Insight coming down east of Carson Pass on Calif 88 (steep but fairly straight) is somewhat in excess of 80 mph, with regen. There are a lot of places where you'd want/need to go slower, so I need to brake in addition to using max regen.

That way those who have the capability to collect energy with solar panels can use that energy to drive their cars. My guess would be that is less than .0001 percent of the vehicle operators in the US...

This is a bit chicken/egg, though. As for instance, my monthly power bill runs about $40, which doesn't give me much of an incentive to spend $10-20K on a solar system. But if I had a PHEV that would suit my needs, I would have a much greater incentive to install solar.

[UFO]

Originally Posted by Old Mechanic

The power required to climb a grade is fairly easy to calculate. A 7% grade of 1 mile is .07X5280 feet That's 369.6 feet per mile. I have read about coasting for 35 miles coming down the east side of the Rocky Mountains. Most Interstates are 7% grades or less with a few exceptions. Only a car with good aerodynamics will exceed 70 MPG coasting down the vast majority of grades on US roads, so we are talking about very small percentages of grades where there would be regeneration opportunities. I am not saying never just fairly rare and I am sure many here see excetions to that rule daily.

regards
Mech

I live and drive east and in the Rockies. Even my 4x4 Toyota will easily exceed 70mph coasting down the 7% grades. That's the way I exceed 30mpg driving it to mountain destinations, but those grades are too dangerous to EOC, most of them I must engine brake to control my speed.

[user removed]

Driven Virginia from Willamsburg to Blacksburg to Ashburn in my CVT Insight and averaged 70.2 MPG with an average speed close to 55 MPH. Over 600 miles on that trip. I have been to the west coast, a long time ago and remember coming down the eastern slope of a mountain range where you could see headlights 40 miles away coming down the west slope of another mountain range. I think the speed limit was 80, but that was before the 1973 oil embargo. 1966 Chevy G10 van.

Went west before that in 1959 and saw Alcatraz when it was still operational 1958 Plymouth Custom Suburban Wagon (no interstates).

I have come down the mountian from blacksburg in my VX at 85 drafting a big rig, for close to 3 miles and almost 3k feet drop, dowshifting to slow down. I know the scenarios.

regards
Mech

[user removed]

Once drove straight through from Marathon in the Florida keys to St Louis in 33 hours.
1973 Alfa Romeo GTV 2000. Total mileage driven since 1966 probably 800,000 plus miles.

regards
Mech

[user removed]

Some more GCC stuff.

Green Car Congress: Peugeot to show 2008 HYbrid Air at Geneva show; more detail on operation

regards
Mech