Hydogen Internal Combustion Engines

[wolliver 1]

ive been doing some research on these, and i got to say they are pretty simple, very similar to todays cobustion engines, and you can get some pretty good power out of them aswell.

just want to know what are all of your thoughts on these?

i know bmw had some 740i's with the HIC engines in them on tour around europe and the states showing what they can do.

[Lucan 196]

Bored? Get a job Wolley....hahaha

[wolliver 1]

lol... got one lined up

[elmarco 56]

From what I understand, yes they can be similar in concept to a normal spark ignition engine but are not always. The induction system is different (obviously), and there has been a load of work around minimising the amount of static electicity involved (apparently static electricity used to ignite the hydrogen and blow the motor apart!). I wonder if there are special coatings for the valves, pistons and bore?

There are loads of sticking points with hydrogen vehicles that are taking years to work through. One is the fuel storage, another is the fuel supply network and production of the hydrogen. Most manufacturers have looked at it as a way to generate power via a fuel cell, although even this is an end goal with natural gas as the interim step.

Mazda getting some really good results using a fairly standard rotary running on hydrogen a few years back and had rotary engined prototypes running around.

Not sure I would be too comfortable having a tank of hydrogen sitting behind the back seat, or refueling it at a gas station though....

[wolliver 1]

yeah the ones ive been researching are pretty much all very similar to normal IC engines. They have had troubles with the hydrogen requiring very little energy to ignite the fuel, so pre-ignition of the fuel befor its ment to ignite is a big problem, ways they have used to prevent this is EGR, water injection and flat, disc shaped combustion chambers.

i know what you mean about the 'not wanting to drive around with a huge tank of hydrogen sitting behind the back seat' but just a thought, if they can do it safely with LPG fueld cars wouldnt it be just as safe for hydrogen? just as long as oxygen is kept out of the fuel lines.

[Docile 64]

is that like the one from top gear? the Honda clarity ?? it has a hydrogen powerplant as a engine... only by product is water from the exhaust... James took it around and range is about the same as a petrol engine, refuelling time same as petrol engine - not like electric cars that needs to be charged 24 hours after a couple of k's, cost of hydrogen about the same as gas.

now if that is the case... what on earth is everyone still riled up on electric cars for??

Honda Clarity

NOW IM SO IN FOR THAT !!..

[elmarco 56]

I read the problem was also ignition of the hydrogen before it even got to the combustion chamber - so blowing manifolds off etc. Might have been some early experiments though. Must have made one hell of a bang, and puckered the dyno operators pants!

Hydrogen is a much smaller molecule and much more difficult to seal effectively - no chance to use standard type seals etc (they all need to be very specific, as do refuelling connections, earth straps etc). It also burns with no flame making it impossible to see (not nice in an accident). I'm guessing they could add an odourant as is done with LPG - maybe it is not necessary as it is lighter than air and rises (as opposed to the opposite with LPG).

The storage pressure required for the tank (to get decent energy density) is around 10-20 times that of your standard LPG BBQ bottle and around 200 degrees C colder so there a few engineering challenges there as well. Nothing insurmountable, but development needed. They can obviously store it relatively safely at the moment - maybe just not at a high performance or high volume production level yet.

Manufacturing H2 is quite energy intensive at the moment as well - making it less effective in combating CO2 etc. However, with new nuclear technology it will allow reactors to run at very high (800+ degrees) and use process heat directly in making hydrogen from water. Just hope like hell one of those doesn't crack off....

I don't think a conventional combustion engine will be the way of the future using hydrogen as it is too inefficient. Still, some pretty cool work going into it and I'd be interested to see one in person!

[elmarco 56]

is that like the one from top gear? the Honda clarity ?? it has a hydrogen powerplant as a engine... only by product is water from the exhaust... James took it around and range is about the same as a petrol engine, refuelling time same as petrol engine - not like electric cars that needs to be charged 24 hours after a couple of k's, cost of hydrogen about the same as gas.

now if that is the case... what on earth is everyone still riled up on electric cars for??

Honda Clarity

NOW IM SO IN FOR THAT !!..

That IS an electric car.... They just use the hydrogen in a fuel cell to make electricity and drive electric motors as opposed to using the hydrogen as a fuel in an internal combustion engine.

[Docile 64]

yeah i know.. but it makes its own power..a big ass alternator !!.. as opposed to battery powered electric cars

[wolliver 1]

BMW have been running hydrogen cars in Germany on public roads for over 35 years , there are refuelling stations - welcome to 1976

they have? wow i did not know that, would be interesting to know how much it is to fill up in comparison to gas over there