Mazda to RG- Hydrogen is coming !!!
11-09-2007, 02:03 PM
#77
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Nope not at all. Rotary and piston engines both work fine. Gasoline works fine. Hydrogen doesn't. There's a difference. I'm open to alternative fuels. I'm not against them at all. I embrace them. I'm against crap fuels. Hydrogen is one of them. When someone finds a fuel that gives us the power we have now with less emissions, no dependence on foreign oil, is cheaper, easy to produce, and safe, then I'll embrace it. Too bad nothing is close to that. I am also a fan of electricity. I am not a fan of heavy batteries though.
11-09-2007, 02:07 PM
#78
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The point of hydrogen burning fast should not be a concern as it is just a matter of changing ignition timing. Pound per pound hydrogen kicks gasolines *** as far as energy emitted. Most manufacturers are still using a throttle body in conjunction with thier hydrogen cars becuase they are making hybrid engines that need to run on gasoline also. A true hydrogen vehicle does not use a throttle body. Airflow is free flowing and power is added by controlling the amount of hydrogen allowed to enter the combustion chamber. This is just one of the reasons why the hp numbers are way down. It would be like slapping a throttle body on a deisel and expecting it to run at full efficiency.
You point about throttle bodies is valid. We add oxygenates to fuel in order to keep pollution down...but why not just add, umm...oxygen? In the form of air? It's tricky to do with gasoline, but with small amounts of h2 you can run much leaner than before. H2 has a far wider range of fuel/air ratios for consistent, controllable combustion.
This is all pretty academic though. A far more realistic alternative is a plugin hybrid that can be quick-charged. The only obstacle is batteries that are good enough for 40 miles or so, that would represent a radical cut in gasoline useage and an energy efficiency that no IC engine (or fuel cell) could hope to match. The batteries already exist, only they just aren't cheap yet. And there's all sorts of nano-technology mumbo-jumbo that is poised to make even greater improvements in batteries in the coming years. We already have the distribution network, and we have the excess capacity (well, at night).
Last edited by BaronVonBigmeat; 11-09-2007 at 02:13 PM.
11-09-2007, 02:08 PM
#79
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Nope not at all. Rotary and piston engines both work fine. Gasoline works fine. Hydrogen doesn't. There's a difference. I'm open to alternative fuels. I'm not against them at all. I embrace them. I'm against crap fuels. Hydrogen is one of them. When someone finds a fuel that gives us the power we have now with less emissions, no dependence on foreign oil, is cheaper, easy to produce, and safe, then I'll embrace it. Too bad nothing is close to that. I am also a fan of electricity. I am not a fan of heavy batteries though.
11-09-2007, 02:15 PM
#80
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Pound per pound yes, but volume per volume, no. Take 1 liter of gas/air or h2/air mixture, suck it into a piston, compress it as much as you can get away with, and then ignite it under ideal conditions. The hydrogen will never make as much power as the gasoline engine. That's one of the reasons why the rotary would be preferred as a h2 engine--a 4 rotor would be approx. the same size/weight/power as one of today's gasoline V6's.
11-09-2007, 03:16 PM
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They work good in that manner as hydrogen isn't being used as a burned fuel but rather a source of electrical generation. My complaint with hydrogen is that it's crap as the sole fuel source of an internal combustion engine. As a fuel cell material however it seems quite useful.
11-10-2007, 02:38 AM
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Originally Posted by meatbaron
Pound per pound yes, but volume per volume, no. Take 1 liter of gas/air or h2/air mixture, suck it into a piston, compress it as much as you can get away with, and then ignite it under ideal conditions. The hydrogen will never make as much power as the gasoline engine. That's one of the reasons why the rotary would be preferred as a h2 engine--a 4 rotor would be approx. the same size/weight/power as one of today's gasoline V6's.
When hydrogen is injected in its gas phase (as currently done in with all engines), it displaces so much air and with it oxygen, that there's not enough oxygen left to burn in order to produce lots of power.
Anyway, who cares about hydrogen if one can have this:
www.teslamotors.com (with a small 'emergency' rotary engine one can have a range of 600 miles with an average gasoline consumption of 200 mpg since the car will mostly be driven on pure electric power as most people don't drive more than 50 miles per trip).
11-10-2007, 02:19 PM
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Octane isn't as important as flame travel speed. Look at diesel as an example. You can advance it compared to an octane level that would be equal to that of gasoline but it's still not enough to make up for the fact that your fuel burns too fast to be truly useful in an internal combustion engine.
Diesel? The problem with diesel is that it burns too slowly, limiting your revs. Stationary diffusion flames aren't the best for high output because of this, and engines that burn fuel using this kind of mechanism lag noticeably behind engines that burn similar fuel using a traveling flame front in terms of power/displacement. I'm not sure what you were going for with that example...
11-10-2007, 02:24 PM
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Well, a hydrogen powered engine could make more power than a gasoline engine, if it were directly injected in its liquid phase (which would cause all sorts of new problems).
When hydrogen is injected in its gas phase (as currently done in with all engines), it displaces so much air and with it oxygen, that there's not enough oxygen left to burn in order to produce lots of power.
Anyway, who cares about hydrogen if one can have this:
www.teslamotors.com (with a small 'emergency' rotary engine one can have a range of 600 miles with an average gasoline consumption of 200 mpg since the car will mostly be driven on pure electric power as most people don't drive more than 50 miles per trip).
When hydrogen is injected in its gas phase (as currently done in with all engines), it displaces so much air and with it oxygen, that there's not enough oxygen left to burn in order to produce lots of power.
Anyway, who cares about hydrogen if one can have this:
www.teslamotors.com (with a small 'emergency' rotary engine one can have a range of 600 miles with an average gasoline consumption of 200 mpg since the car will mostly be driven on pure electric power as most people don't drive more than 50 miles per trip).
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Last edited by Renesis_8; 09-11-2011 at 01:50 PM.
11-10-2007, 02:43 PM
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The hydrogen is stored as a liquid, but is injected into the intake manifold and so is very likely a gas when it is injested by the cylinder. This means that it has a very high specific volume, as Globi mentioned, and so displaces a lot of the air in the cylinder. Less air = less oxygen = less power. Here's a little more on this specific engine that I found via Google:
Article
Edit:
A bit more searching has yielded this pdf from the DOE's Energy Efficiency and Renewable Energy page:
http://www1.eere.energy.gov/hydrogen...fs/fcm03r0.pdf
It talks about the use of H2 as a fuel for ICEs and goes through some of the benefits and pitfalls of hydrogen usage. The section on Power Output might be good reading for most of us, as would the section on the Combustive Properties of Hydrogen.
Article
Originally Posted by Article
Because hydrogen is combustible in mixtures in air between a broad range of 4% and 75%, and because it burns quickly, a small amount of fuel can generate a high level of efficiency. BMW used this characteristic to run the engine in the Hydrogen 7 quite lean, with lambda ranging from 2 to 4 under partial load. With the lean burn keeping temperatures in the combustion process relatively low, engine-out NOx is also low.
Under full load, the 7 runs under stoichiometric conditions: a complete balance of oxygen and hydrogen (lambda = 1). Under this operating condition, a regular three-way exhaust catalyst handles the NOx. (See NOx map above.)
The Hydrogen 7 has two injection and mixture-formation systems: direct injection for gasoline, and manifold injection for the hydrogen. The manifold injection puts some limitations on the hydrogen charge formation that, combined with the lower energy of hydrogen itself, lowers the energy in the cylinder, compared to gasoline with direct injection.
BMW is considering the possibility of using direct injection for hydrogen as well as gasoline. Rough calculations, according to Korn, indicate that a direct hydrogen injection system could deliver about 20% higher performance.
Under full load, the 7 runs under stoichiometric conditions: a complete balance of oxygen and hydrogen (lambda = 1). Under this operating condition, a regular three-way exhaust catalyst handles the NOx. (See NOx map above.)
The Hydrogen 7 has two injection and mixture-formation systems: direct injection for gasoline, and manifold injection for the hydrogen. The manifold injection puts some limitations on the hydrogen charge formation that, combined with the lower energy of hydrogen itself, lowers the energy in the cylinder, compared to gasoline with direct injection.
BMW is considering the possibility of using direct injection for hydrogen as well as gasoline. Rough calculations, according to Korn, indicate that a direct hydrogen injection system could deliver about 20% higher performance.
A bit more searching has yielded this pdf from the DOE's Energy Efficiency and Renewable Energy page:
http://www1.eere.energy.gov/hydrogen...fs/fcm03r0.pdf
It talks about the use of H2 as a fuel for ICEs and goes through some of the benefits and pitfalls of hydrogen usage. The section on Power Output might be good reading for most of us, as would the section on the Combustive Properties of Hydrogen.
Last edited by PoorCollegeKid; 11-10-2007 at 02:59 PM.
11-10-2007, 03:48 PM
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Originally Posted by PCK
The hydrogen is stored as a liquid, but is injected into the intake manifold and so is very likely a gas when it is injested by the cylinder. This means that it has a very high specific volume, as Globi mentioned, and so displaces a lot of the air in the cylinder. Less air = less oxygen = less power.
I'd still be curious of how a small amount of hydrogen could speed up the gasoline combustion of the rotary engine (and improve efficiency and performance).
With a flywheel generator (e.g. braking energy) and by using the waste heat of the exhaust it could possibly produce enough hydrogen while driving (high temperature electrolysis) and store it in a little tank to improve the combustion at certain load settings.
http://en.wikipedia.org/wiki/High-te...e_electrolysis
But then again, a pure electrically driven plug-in hybrid with a small rotary engine for increased range (always running at high loads and thus high specific efficiencies) might be more economical and less complex.
11-10-2007, 06:46 PM
#89
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Exactly, that's the point. Hydrogen has an extremely low boiling point of -253 degrees C or -423 degrees F. For the same reason the hydrogen BMW has an empty tank after one week, because it constantly has to release hydrogen. Otherwise the tank filled with cold liquid hydrogen will eventually start to blow up (not a fire explosion). It's like putting a tank filled with water in an oven. Regardless how well it is insulated, it will eventually blow up like a boiler of a steam locomotive, if the boiling water is not gradually released:
I'd still be curious of how a small amount of hydrogen could speed up the gasoline combustion of the rotary engine (and improve efficiency and performance).
With a flywheel generator (e.g. braking energy) and by using the waste heat of the exhaust it could possibly produce enough hydrogen while driving (high temperature electrolysis) and store it in a little tank to improve the combustion at certain load settings.
http://en.wikipedia.org/wiki/High-te...e_electrolysis
But then again, a pure electrically driven plug-in hybrid with a small rotary engine for increased range (always running at high loads and thus high specific efficiencies) might be more economical and less complex.
I'd still be curious of how a small amount of hydrogen could speed up the gasoline combustion of the rotary engine (and improve efficiency and performance).
With a flywheel generator (e.g. braking energy) and by using the waste heat of the exhaust it could possibly produce enough hydrogen while driving (high temperature electrolysis) and store it in a little tank to improve the combustion at certain load settings.
http://en.wikipedia.org/wiki/High-te...e_electrolysis
But then again, a pure electrically driven plug-in hybrid with a small rotary engine for increased range (always running at high loads and thus high specific efficiencies) might be more economical and less complex.
11-10-2007, 07:32 PM
#90
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Popular mechanics did an article on the costs of having a hydrogen infrastructure. At this point in time it'd cost too much money. Until we find some way of producing energy at near zero cost, hydrogen will not be plausible. Actually at this point, simply running a vehicle off of compressed air achieves better results than burning hydrogen and I'm not talking compressed air as in turbos or supers. Basically you put highly compressed air into a cylinder and let it expand and press the pistons down to drive the vehicle. Nice concept, but again not as useful as gasoline.
Now if only JP-4 didn't burn like diesel...I can see it now...
"What's that thing run off?"
"JP-4
"
Didn't someone actually say that once?
Now if only JP-4 didn't burn like diesel...I can see it now...
"What's that thing run off?"
"JP-4
"Didn't someone actually say that once?
11-10-2007, 09:25 PM
#91
I don't care what sub zero scandanavian country it's going to. It's still a crap fuel! You CAN NOT change that!!! Quit trying to make **** poor excuses for justifying crap. It burns too fast to be useful. Propane would be a much better choice if you want to use a gas. If Mazda builds an engine that runs on dog **** and crack and then places the infrastructure in service to allow it, but it makes a fraction of the power that gas does, would you use it too?
Hydrogen is terribly inefficient. You can't make anywhere near the power of other fuels with it and it takes far more of it to go the same distance. All while being weaker. It's a pain in the butt to store too. If the only thing it's got going in it's favor is emissions, that's not close to enough. That's not worth it. Car emissions are not heating up the planet anyways.
Back to hugging your tree...
Hydrogen is terribly inefficient. You can't make anywhere near the power of other fuels with it and it takes far more of it to go the same distance. All while being weaker. It's a pain in the butt to store too. If the only thing it's got going in it's favor is emissions, that's not close to enough. That's not worth it. Car emissions are not heating up the planet anyways.
Back to hugging your tree...
what makes it seem sooo attractive is the lovely thought that is forced into everyone's mind that its only byproduct is water. Thats why it's getting promoted. Propane? it is still a hydrocarbon thus releasing carbon dioxide. That is the reason why that is not popular, hell, thats why natural gas isn't popular either.
11-10-2007, 11:36 PM
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11-11-2007, 12:00 AM
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11-11-2007, 12:28 PM
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I am about to get flamed probably, but...as technology evolves isn't there a chance that a hydrogen motor will become more efficient and produce more power. After all take a look at gas engines of years ago. All of those muscle cars of the past that people like to remember through rose colored glasses did not make much horsepower. Gas engines have continued to improve, couldn't hydrogen. Even if it takes a new motor designs.
11-11-2007, 12:39 PM
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CO2 isnt harmful, but NOx is toxic!
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Last edited by Renesis_8; 09-11-2011 at 01:50 PM.
11-11-2007, 01:42 PM
#98
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I am about to get flamed probably, but...as technology evolves isn't there a chance that a hydrogen motor will become more efficient and produce more power. After all take a look at gas engines of years ago. All of those muscle cars of the past that people like to remember through rose colored glasses did not make much horsepower. Gas engines have continued to improve, couldn't hydrogen. Even if it takes a new motor designs.
As far as muscle cars go though......when did they ever not make much horsepower?
11-11-2007, 02:19 PM
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Dave,
Of course the performance of hydrogen cars can be further improved. But I just doubt hydrogen cars will ever play a major role on the world-market.
If one can easily double the efficiency of a gasoline or diesel engine with or without hybrid and even much further increase it, with a plug-in hybrid, why would hydrogen be a viable alternative?
Hydrogen distribution is not there.
Hydrogen efficiency is not there.
Hydrogen storage is not there.
Hydrogen fuel costs are not there.
Hydrogen engines are not really there.
Gasoline, Diesel and Electricity distribution is there.
Electric efficiency is there.
Gasoline and Diesel storage is there.
Gasoline, Diesel and Electricity costs are there (fuel, engine and motor).
VW already sold a 78 mpg diesel car (Lupo) without hybrid. So reaching 100 mpg with a hybrid doesn't sound like a technical stretch. A plug in hybrid could easily double that and would probably still be considerably less costly than a hydrogen fuel cell car.
And once high performance batteries are developed, we might not even see cars with internal combustion engines anymore.
Of course the performance of hydrogen cars can be further improved. But I just doubt hydrogen cars will ever play a major role on the world-market.
If one can easily double the efficiency of a gasoline or diesel engine with or without hybrid and even much further increase it, with a plug-in hybrid, why would hydrogen be a viable alternative?
Hydrogen distribution is not there.
Hydrogen efficiency is not there.
Hydrogen storage is not there.
Hydrogen fuel costs are not there.
Hydrogen engines are not really there.
Gasoline, Diesel and Electricity distribution is there.
Electric efficiency is there.
Gasoline and Diesel storage is there.
Gasoline, Diesel and Electricity costs are there (fuel, engine and motor).
VW already sold a 78 mpg diesel car (Lupo) without hybrid. So reaching 100 mpg with a hybrid doesn't sound like a technical stretch. A plug in hybrid could easily double that and would probably still be considerably less costly than a hydrogen fuel cell car.
And once high performance batteries are developed, we might not even see cars with internal combustion engines anymore.