Simviation Forums

Can someone give the specifications of the BMW new Hydrogen 7 hydrogen tank?

It holds 8 kg liquid hydrogen in 74 l volume. How much does the tank itself weigh?

How much would a bigger hydrogen tank weigh, if you had volume in your car, van, bus, truck etc. for it?

Can someone give the specifications of the BMW new Hydrogen 7 hydrogen tank?

It holds 8 kg liquid hydrogen in 74 l volume. How much does the tank itself weigh?

How much would a bigger hydrogen tank weigh, if you had volume in your car, van, bus, truck etc. for it?

You have got your wires crossed a little here.
BMW Hydrogen 7 comes with both a conventional 74-litre (16.3 Imp gal) gasoline tank and an additional fuel tank taking up approximately 8 kilos or 17.6 lb of liquid hydrogen.
As for the weight, saddled with an undisclosed amount of additional weight, the V-12 is said to deliver its driver to 62 mph in a leisurely 9.5 seconds, regardless of which fuel is being used. Powering the Hydrogen 7 is a 256-hp 6.0-liter V-12 (the same engine in the 760Li makes 438 hp) That

Now I though about this, I have to say, what a totally pointless car this is (and I am driving my 5th BMW).

Who ever thought about this needs to go and have this done to himself http://www.simviation.com/cgi-bin/yabb/ ... 1161961360

You take a 6L V12 and put in the capability to run on Hydrogen to the tune of 125 mile and then give it a further 300 miles of a carbon based fuel  :P
It is so obvious that BMW and the other major car companies are in the pocket of the oil producers other wise we would see that technology in a nice 1.8 or 2.0 litre car doing 500 miles and getting a very good equivalent MPG.


Matt

Hydrogen as a viable fuel alternative has a way to go. It's too expensive to extract, containment during storage is problematic, and the automobile fuel cell is too heavy.
It's a good idea that needs more refinement and it's going to take full government and industrial backing before it can be realized.

BMW Hydrogen 7 comes with a conventional 74-litre (16.3 Imp gal) gasoline tank

Hmm, that surprises me, my earlier ( e38 ) 7 Series has an 85 Litre tank!

Hmm, that surprises me, my earlier ( e38 ) 7 Series has an 85 Litre tank!

My E34 tourer also had an 85 litre tank, my E39 Tourer is down to 70 litres. However of the Hydrogen 7 it is more likely a space question.

Matt

Hydrogen as a viable fuel alternative has a way to go. It's too expensive to extract, containment during storage is problematic, and the automobile fuel cell is too heavy.

Except that BMW Hydrogen 7 does not have a fuel cell. It has an Otto engine, no heavier (except for the second injection system) than a benzine burning Otto engine.

Presumably, hydrogen could also be burnt in a gas turbine?

Except that BMW Hydrogen 7 does not have a fuel cell. It has an Otto engine, no heavier (except for the second injection system) than a benzine burning Otto engine.

Presumably, hydrogen could also be burnt in a gas turbine?

Not quite ready for flight testing  ;D
http://www.ucicl.uci.edu/RESEARCHPROJEC ... Index.aspx

And now to the other extreme.
http://dsc.discovery.com/news/2006/10/1 ... 1010100000

Matt

Hydrogen as a viable fuel alternative has a way to go. It's too expensive to extract, containment during storage is problematic, and the automobile fuel cell is too heavy.

Except that BMW Hydrogen 7 does not have a fuel cell. It has an Otto engine, no heavier (except for the second injection system) than a benzine burning Otto engine.

I was actually refering to all possibilities, not just the BMW. Sorry for the confusion.
Now for a little more about hydrogen as a fuel:

Direct injected diesel engines coupled with hybrid energy accumulation systems will have efficiencies exceeding 55% (source US DOE).
The problem with hydrogen is that it is an energy carrier, and must be produced from other primary energy sources.

Whats the SLPM of hydrogen gas to this new engine?

Whats the SLPM of hydrogen gas to this new engine?

Do you mean "Standard Liters Per Minute" or something else??

Matt

Yer I mean "Standard litres per minute"

Now I understand. The BMW Hydrogen 7 does not have a fuel cell, so SLPM I would think cannot be measured. The car uses a standard petrol engine and used hydrogen in a similar fashion to a LPG converted car. The hydrogen is in liquid form under pressure in a gas tank and then via BMW black magic into gas and then as LPG-ish process injected and burnt.

Matt

Well the hydrogen must go into the cylinders at a 2:1 ratio as....

2H2+O2=2H2O+Energy,...so two hydrogen to one oxygen

so there is always this ratio going in every revolution, so twice as much will be going in at 6000rpm than at 3000rpm.

So if it is possible to find the amount of gas sucked into the cycliders every revolution...lets say it is 1 litre....

(1L*1000rpm)/Two thirds(as the ratio is 2:1)=Lpm at 1000rpm (right?)  

So is it possible to figure out how much gas mixture is in the cylinder for each revolution?

Well the hydrogen must go into the cylinders at a 2:1 ratio as....

2H2+O2=2H2O+Energy,...so two hydrogen to one oxygen

so there is always this ratio going in every revolution, so twice as much will be going in at 6000rpm than at 3000rpm.

So if it is possible to find the amount of gas sucked into the cycliders every revolution...lets say it is 1 litre....

(1L*1000rpm)/Two thirds(as the ratio is 2:1)=Lpm at 1000rpm (right?)  

So is it possible to figure out how much gas mixture is in the cylinder for each revolution?

The tank hold 74 litres and can travel 125 miles (200 km). If the car travels at a constant speed, say the standard 56 mph (100 kph) at say 4000 rpm you should be able to get a basic figure, however bearing in mind it is 04:45 in the last hours of my nightshift, I am not the person to work it out. I would say that I think it is going to be a very low figure. A bit more than if it was petrol.

Matt