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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.
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