--- Water injection VS Steam Injection ---

[dcb]

Yay free
Here, I fixed the link
http://www.engine-expo.com/forum_200...azmi_osman.pdf

[dcb]

Thanks for sharing that, just one initial comment, I do think eventually the O2 tank has to go (and the efficiency/emissions re-evaluated) , or the energy to make/compress the O2 has to be factored into the net efficiency somehow.

[gone-ot]

...anybody know the theoretical efficiency of using separate 02 and gasoline injection (ie: 'contained' rocket combusiton) thus, essentially, a cyclic rocket combustion engine?

[dcb]

not me, I was looking at it as:
If I had to carry the equipment to make sufficient high pressure O2 to feed the engine, what would the efficiency be?

I mean, you talk about pumping losses...

I think you have to look at how it would operate with air (efficiency and emissions) to make any comparison with a road vehicle.

[gone-ot]

...I was thinking two separate "filling stations" (a) one for Hydrogen (H2) or gasoline only, and (b) one for Oxygen (O2) only.

...obviously, would NOT expect them to be co-located for safety reasons (big BOOM)!

[dcb]

ok, but how do you account for the energy that goes into making pure high pressure O2? I doubt that was accounted for in the %70 efficiency figure, correct me if I'm wrong azmio.

But if you had to replace your throttle body and intake valves and air filter with something that could make enough high pressure O2 to keep the engine running, i think you will find that it is much less efficient.

Trick is getting it to work with AIR, I don't think you can expect cars to carry O2 bottles or make their own efficiently.

But without some way to compare the total energy needed, there is no basis for a comparison. The doc mentioned that it was "cheap" to make o2, but that isn't the same.

[gone-ot]

...the "thought analog" that originally came to my mind was: a buzz-bomb (pulse) internal combustion engine.

[Christ]

The thought that came to my mind was:

That boom is going to create a lot of Hydrogen Peroxide antiseptic...

[dcb]

The explosion discussion can probably wait

This sorta reminds me of the 6 stroke. While I think the o2 tank is too inefficient/impractical, I could see a long stroke having time to burn the fuel and still have time for a squirt of water, but this has to have been tried before.

[Azmio]

thanks a lot guys, with regard to the oxygen storage, a lot of my colleagues run natural gas vehicles in Malaysia. The vehicles must be crash tested and the composite tank must be shot at before it is allowed to be used. With the existing composite tank technology, the tank was not punctured even when shot at by an assault rifle. With the recent development of hydrogen composite tank that can withstand a pressure of up to 700 bar. I dont mind driving it even with my 2 kids in. The natural gas tank is even safer than the gasoline tank based on fire statistic. Let's make it safer by having methanol instead of gasoline or diesel.

The oxygen production is also an interesting one as i received many questions in the international conferences. it takes around 0.21 kWh/kg to produce the oxygen. I presented one slide last year to compare the energy balance of conventional diesel vs. oxygen engine. Conventional diesel normally runs lean in the range of 20:1-40:1. At full load, with 20:1 AF ratio, it takes twice the energy to compress the charge until it auto ignite if compared to oxygen engine together with oxygen production. The trick is simple, I utilize the trapped exhaust gas to raise the cylinder temperature with some compression work to ensure that it reaches the auto ignition temperature. The throttling of exhaust gas using variable valve timing and lift is a brilliant one and I have to thank my colleague who helped me out with this.

With oxygen at 200 bar similar to natural gas in the composite tank, I need a gas injector from westport to directly inject the gas at that pressure. The DI technology is already available and Isuzu has been using it few years ago. Furthermore, with oxygen, i just need 1/5 the amount of gas that need to be inducted into the cylinder. What's great about this method, i can inject oxygen, water and fuel at any rate independent of the engine speed and load. There is no vacuum needed in the cylinder to pull the gas in. I presented one paper about the predicted engine performance where full load operation can be done from idle as early as the next firing cycle.

you're right in saying that there is no point in carrying lots of oxygen in gaseous form. However, i mentioned in the paper that oxygen will also be supplied through methanol considering that methanol is an oxygenated fuel. For conventional air engine the AF ratio is 6:1 but for this engine it is 1.2:1. This is almost a 1 to 1 ratio and it’s no longer 14.5:1. I estimated that methanol enables the vehicle to travel to up to 400 km whereas diesel will never reach that far with every combined refilling.

I know that fire is a concern but my research office is stuffed and surrounded with so many dangerous fuels. The trick is simple, keep the temperature far below the auto ignition point so that oxygen and fuel will never ignite even if you mix it together. The metal smelter and metal cutter industry have been using oxygen to lower their fuel consumption by up to 60% and I can gladly said, they never had any accident with the use of pure oxygen.

Good job guys, keep the questions and criticisms coming. The hotter the grilling the better.