Hydraulic Hybrid Vs. Electric Hybrid

[jason.thompson]

Hydraulic Hybrid
1. 80% brake energy regeneration efficiency
2. Cost of system $2,500
3. Time to install on any vehicle 14 hours
4. 40% fuel economy improvement
5. No possible EMF interference
6. No mining of precious metals
7. Easier to recycle

Electric Hybrid
1. 30% brake energy regeneration efficiency
2. Cost of battery alone (God knows)
3. Still need to create the vehicle which costs energy (disposable vehicles just like cell phones)
4. Same fuel economy improvement
5. Technology and technicians not mature

I would use a battery for smaller things not in the drivetrain. Charge it with waste heat using a Cyclone Steam engine and then use that electricity to power an electrolysis generator to produce hydrogen and oxygen for diesel engine.

[Kiwi_ME]

I think what say's it all is a quote from an article on the EPA / UPS's hydraulic hybrid system.

"Because of the added weight of the tanks used to store pressurized fluid in the system, the best application may be in heavy-duty trucks that inch their way through urban stop-and-go driving."

My somewhat limited engineering experience in hydrostatic system design tells me that overall efficiency is not all that high, but perhaps no worst than the cumulative losses encountered in electric hybrid battery charge/discharge and power conversion steps.

Either system needs computerized controls but the major difference is that the hydraulic system will be far cheaper for high-capacity systems. For a car the size of a Prius hydraulics is unlikely to be a better choice for a number of reasons, persistent oil leaks being only one of them.

[jason.thompson]

Battery Weight. Weight has a dramatic impact on overall transportation efficiency, and even lithium ion battery technologies add significant weight. Toyota’s current battery pack adds 150 pounds to the Prius, the Chevy Volt battery pack is expected to weigh 350 pounds, and Tesla’s battery pack exceeds 1000 pounds. Equivalent storage in carbon fiber tanks weigh 75 pounds.

Is what their site says.

I like creating these dualities to stir the pot. I really have nothing against moving electrons.

[jason.thompson]

Plus I don't see why you would need to go to a complete start or stop.

When you go down a hill charge up the tank when you go up the hill (which usually happens next) let er rip.

Or how about a electric hydraulic hybrid?

[jason.thompson]

Or how about a hydraulic electric hybrid?

And its not a hydrostatic setup. The original transmission is used.

Hydraulic Pump/Motor - The main hydraulic component of a parallel hydraulic hybrid vehicle is a hydraulic pump/motor. The pump/motor is a variable displacement, axial piston type pump. This type of closed circuit pump has been used reliably in various hydraulic applications for many years. Depending on which port is pressurized, the pump/motor can operate in both counter-clockwise and clockwise directions and as a pump or motor with the same efficiency of between 85% and 90% depending on speed. Because of this characteristic, the pump/motor can either add power to the system or be used to pump hydraulic fluid to a high pressure accumulator and store that energy for use in its opposite mode of operation.

An in-line configuration where the pump is added after the engine and torque converter but before the transmission would allow the pump to operate through a greater range of speeds before requiring assistance from the engine. This configuration would also allow the engine to drive the pump and charge the accumulator at very low flow rates. The amount of power that the pump requires from the engine comes from the equation HP = PSI X GPM / 1714, where HP is the horsepower required from the
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engine, PSI is the system pressure in pounds per square inch, GPM is the pump flow rate in gallons per minute, and 1714 is a constant. As mentioned above the pump is a variable displacement type which allows the pump to pump any amount of fluid between zero gallons per minute and its maximum value which is dependent on the physical size of the pump. While the main pump can be made to pump no fluid at all, there is an integrated gear pump within the unit that allows the pump to operate, and keeps it lubricated. This pump has a constant flow rate of .53 gallons per minute at a pressure-relieved pressure of 300 psi. This pump also powers the hydraulic logic controls. If the pump is not pumping any fluid at all, the pump losses can be calculated according to the equation: 300 psi X .53 gpm / 1714 = .092 HP or roughly one tenth of a horsepower. This is a very small amount of power, comparable to a standard alternator or air-conditioning unit used on a vehicle. The advantage of this configuration is that the pump can be made to pump fluid at the optimum rate for the engine’s fuel use maps with the transmission in neutral and the vehicle at a stop. That energy is stored in the accumulator and allows the vehicle to make a full acceleration cycle using the pump only. The accumulator can be charged in the same way while the vehicle is moving, and the system is now behaving very similarly to a series system.
For increased performance, the pump and internal combustion engine can be used simultaneously to

[solarguy]

To me, the biggest difference is the accumulator vs the battery. The accumulator is just a really strong tank (pressure vessel). The energy produced by braking gets stored in the accumulator by compressing nitrogen gas. Nitrogen gas never wears out. It's cheap to "make" by condensing it out of the air. All the opposite is true for current (and virtually any future) battery technology. Definitely wears out, expensive to make, much greater enviro impact to make and to recycle.

The technology wouldn't have to be heavy. Composite high pressure tanks are becoming more common, partly as a consequence of the dumb hydrogen car people. Oooops, did I say that out loud?


Finest regards,

troy

[jason.thompson]

Combine this with an IVT transmission.

A super turbo charged diesel

Biodiesel

Diesel-CNG Hybrid

[jason.thompson]

solarguy perhaps you haven't looked at it like this but you are driving a hydrogen car as we speak. You just have a few carbons attached. Imagine if they crack CNG with steam and then set up a hydrogen system for fuel cells. You will be able to fill up your hydrogen tank and then run it into your diesel engine. Or you could just skip the dance and burn CNG today in your diesel engine. 3 CNG to 1 part biodiesel..

[jason.thompson]

The new diesels are really quite. You can't even tell them from gas maybe more quite cause they don't have to scream to make power.

I'll come out and say that I have a slight bias towards diesels.

[solarguy]

Originally Posted by jason.thompson

solarguy perhaps you haven't looked at it like this but you are driving a hydrogen car as we speak. You just have a few carbons attached. Imagine if they crack CNG with steam and then set up a hydrogen system for fuel cells. You will be able to fill up your hydrogen tank and then run it into your diesel engine. Or you could just skip the dance and burn CNG today in your diesel engine. 3 CNG to 1 part biodiesel..

There are more hydrogen atoms in a gallon of gasoline than in gallon of volume in a compressed hydrogen tank, or in a hydrogen adsorption tank. Hydrogen is a moderately to terribly crummy energy storage device/substance. Why would I want to steam reform natural gas and waste fully half of the energy by the time I'm done putting it through the fuel cell? What do they do with the carbon they liberate from the natural gas when they make hydrogen? Oh yeah, they just release it into the atmosphere. Well, couldn't they sequester it? Mmmmm, yeah. But at an energy cost, and a monetary cost, for a time. The longer you sequester it, the greater the costs. Hydrogen=crummy. Even if we had voluminous cheap green electricity from the electricity fairy, batteries would probably be a more efficient carrier than hydrogen from electrolysis.

Besides, I don't burn (hardly any) diesel in my car. I burn biodiesel made from wvo (waste veggie oil), and hydrogen can't hold a candle to that fuel in terms of EROEI. It's also closer to carbon neutral than steam reformed natural gas. We can't all do that, but I can do that, and I can do it now.

Sorry. Rant mode off. Sorry for the hyjack.

I'll quit now.

troy