Switching to Hydrogen Fuel: Materials & Lubricants Needed

[Lefty1986]

Hi,

any idea , what is the material inside a internal combustion engine need to be change when i change the gasoline fuel into hydrogen fuel.? Also what is the lubricant that will suitable for this hydrogen fuel. thanks

Piston top - what is the suitable material
Cylinder head-
crankcase-
cylinder wall-

also is there any lubricant that is suitable for hydrogen internal combustion engine ? thx

 

[brewnog]

Hydrogen has a really (!) low methane number and as a result is very susceptible to combustion knock. Don't worry about changing the combustion chamber materials, worry about a way to effectively control air fuel ratio and detonation over the range of operating speeds and loads.

Lube oil should be a relatively simple selection, what's the application?

It can be done. Why do you want to do it?

 

[Lefty1986]

Thx for the reply.

ya, i know the knock is there. i need to know what is the material i needed to change ? i m getting interested in getting to know more about the material. for the lubrication do you have any example ? is any normal fully synthetic engine oil can be used?

the internal combustion engine will be the car engine. Plan to use hydrogen as the fuel for petrol car engine. so what is the part that i need to change ?

 

[brewnog]

Why do you want to change 'material'? The materials of the combustion chamber components will have small effect on detonation, but will not cure any issues. By far the biggest concern is controlling the combustion process as I mentioned above. The combustion chamber material is largely irrelevant (at least until you've sorted out the fundamental challenges).

For automotive applications in an SI engine a "standard" lube oil should be adequate (I wouldn't recommend changing it from what you normally use). I'd advise that you analyse samples for the first few thousand miles just to make sure there's nothing nasty going on with the valves, rings or bearings. There is a chance you may suffer hydrogen embrittlement of valves and rings, and possibly pistons, but I would only expect seeing these at significant engine hours. Getting the engine to actually run well is the biggest challenge.

 

[Lefty1986]

no, i am not working to correct the detonation, others will find info about that. i m only dealing with the material part that's why i need to know even though there might be knock problem. can the normal petrol engine cylinder head, wall and piston top withstand the bigger pressure from the hydrogen combustion ?wont it crack ? like when we use normal aspired car and fit in a turbo sometimes the cylinder head will crack. also how to cure the embrittlement problem ? any references or web pages that i can refer to ?

thx brewong for your help.

 

[becoming2000]

To be perfectly honest, a well-tuned turbo or supercharged engine really shouldn't suffer any catastrophic failure until you're pushing the limits way harder than can be used on the street. My supercharged Saleen has been a custom project for years, and is currently running at 15psi. The block should hold up to 30psi. Beyond that, you're really stressing the materials, and if you build the materials strong enough, you'll introduce all new problems. The key is a proper tune. Run too close to stoichiometric ratio, and you're toast. Spark too early, and you're toast. There's a pattern to be seen there.. The moral of my story is that the engine materials can really handle a lot of abuse, and don't really need to be changed. Especially not for the sake of not having to accurately control combustion, because no matter how strong you make it, it'll never be strong enough to withstand detonation with any frequency.

I haven't spent a ton of time researching hydrogen-only engines, but have looked quite a bit into hydrogen supplementation on a gasoline engine. When you switch over to hydrogen only, timing becomes your largest issue. With gasoline, you can normally ignite within 20 degrees of TDC, but with hydrogen, you need to push that spark way later. The number 70 is floating in my head, but don't quote that. To my understanding, the problem is that the expansion rate of hydrogen/oxygen combustion is much higher than that of gas/oxygen. It was explained to me as saying that the gas/air mix gives more of a soft/gradual push compared to the hydrogen, which would be more like smacking the piston with a hammer. I'm sure that's an overexaggeration, but it got the point across to me.. Whether it was right or not though, I can't tell. :) Like I said, the common solution I've seen so far hasn't been to try to contain the intense expansion, but delay it so that the cylinder volume is larger and the expansion is less critical. The average pressure in each cylinder really isn't going to change much no matter what fuel you burn. You can run an ICE on air pressure, if you want to.

The trick is figuring out how long to wait before igniting the mixture so that the pressure created meets the demands of the power desired. You could go higher and have a much stronger motor, but you end up hitting the limits of materials available. If you make it so strong it can handle high pressure, the rotating mass will limit power, and that much mass won't shed heat fast enough no matter how good your cooling system. It's a problem that compounds itself, and you'll chase it forever.

I would really like to see someone experiment with a hydrogen powered rotary engine. Getting the seals to hold up would be tricky, but you don't have reversal like an ICE has, and the design of the engine is much more hydrogen friendly.

I really think you'd have your work cut out for you, trying to harness maximum efficiency in a hydrogen-only engine. There are videos of guys running 2 cycle engines on HHO after modifying the magneto to spark much, much later than gasoline requires. If there are people out there doing it already, do you have links to any of it? I'd really like to see how far people are coming with it.

 

[Lefty1986]

To be perfectly honest, a well-tuned turbo or supercharged engine really shouldn't suffer any catastrophic failure until you're pushing the limits way harder than can be used on the street. My supercharged Saleen has been a custom project for years, and is currently running at 15psi. The block should hold up to 30psi. Beyond that, you're really stressing the materials, and if you build the materials strong enough, you'll introduce all new problems. The key is a proper tune. Run too close to stoichiometric ratio, and you're toast. Spark too early, and you're toast. There's a pattern to be seen there.. The moral of my story is that the engine materials can really handle a lot of abuse, and don't really need to be changed. Especially not for t sakehe of not having to accurately control combustion, because no matter how strong you make it, it'll never be strong enough to withstand detonation with any frequency.

I haven't spent a ton of time researching hydrogen-only engines, but have looked quite a bit into hydrogen supplementation on a gasoline engine. When you switch over to hydrogen only, timing becomes your largest issue. With gasoline, you can normally ignite within 20 degrees of TDC, but with hydrogen, you need to push that spark way later. The number 70 is floating in my head, but don't quote that. To my understanding, the problem is that the expansion rate of hydrogen/oxygen combustion is much higher than that of gas/oxygen. It was explained to me as saying that the gas/air mix gives more of a soft/gradual push compared to the hydrogen, which would be more like smacking the piston with a hammer. I'm sure that's an overexaggeration, but it got the point across to me.. Whether it was right or not though, I can't tell. :) Like I said, the common solution I've seen so far hasn't been to try to contain the intense expansion, but delay it so that the cylinder volume is larger and the expansion is less critical. The average pressure in each cylinder really isn't going to change much no matter what fuel you burn. You can run an ICE on air pressure, if you want to.

The trick is figuring out how long to wait before igniting the mixture so that the pressure created meets the demands of the power desired. You could go higher and have a much stronger motor, but you end up hitting the limits of materials available. If you make it so strong it can handle high pressure, the rotating mass will limit power, and that much mass won't shed heat fast enough no matter how good your cooling system. It's a problem that compounds itself, and you'll chase it forever.

I would really like to see someone experiment with a hydrogen powered rotary engine. Getting the seals to hold up would be tricky, but you don't have reversal like an ICE has, and the design of the engine is much more hydrogen friendly.

I really think you'd have your work cut out for you, trying to harness maximum efficiency in a hydrogen-only engine. There are videos of guys running 2 cycle engines on HHO after modifying the magneto to spark much, much later than gasoline requires. If there are people out there doing it already, do you have links to any of it? I'd really like to see how far people are coming with it.

thx for ur help mate.

the part where you mention about delaying the spark will help to reduce the effect of hammering on the piston head and cylinder wall? thanks

btw, i have come across those HHO gas thingy and one of my friend is experimenting it. but the experiment still on progress.

 

[brewnog]

To my understanding, the problem is that the expansion rate of hydrogen/oxygen combustion is much higher than that of gas/oxygen. It was explained to me as saying that the gas/air mix gives more of a soft/gradual push compared to the hydrogen, which would be more like smacking the piston with a hammer.

As noted in my previous two posts, that's detonation.

The trick is figuring out how long to wait before igniting the mixture so that the pressure created meets the demands of the power desired.

No, the trick is finding a way to prevent detonation through effective mixture preparation and combustion control. Retarding the spark event combats the detonation, because the cylinder pressure peak caused by combustion is moved even further away from that caused by compression. It's a good way to protect your engine, but it certainly doesn't help your goal of efficiency since so much more energy goes straight out of the exhaust. In addition, it's a pretty reactive measure.

The average pressure in each cylinder really isn't going to change much no matter what fuel you burn.

This may be the case, but the peak cylinder pressure can vary dramatically, and this is what causes the damage.

I would really like to see someone experiment with a hydrogen powered rotary engine. Getting the seals to hold up would be tricky, but you don't have reversal like an ICE has, and the design of the engine is much more hydrogen friendly.

Been done, with moderate success:

http://en.wikipedia.org/wiki/Mazda_RX-8_Hydrogen_RE

 

[grnguy]

Since the exhaust is water vapor which could rust everything. I wonder if we can use strong ceramic material like the tiles on the space shuttle or the material we use on ceramic blow torque nozzle?

 

[brewnog]

Since the exhaust is water vapor which could rust everything. I wonder if we can use strong ceramic material like the tiles on the space shuttle or the material we use on ceramic blow torque nozzle?

It's not even an issue. There's a shedload of water vapour in the exhaust using conventional fuels. It's so hot it doesn't even condense under normal conditions.

 

[russ_watters]

Remember, the primary component of hydrocarbons is hydrogen, so when you burn them, you get mostly water -- the rest (ideally) is carbon, so you get carbon dioxide.