|
Dew point.
Stuff does not really have a "tendency to stay in the state it is in." There are many variables here, such as the temperature of the air and how saturated it already is (e.g. humid vs. dry air). But just feeding a hot gas into a cooler one does not mean the hot gas will have a tendency to stay a gas.
True to a point…none the less once in a vapor state some action is needed to cause a change into another state.
If you look at a tea kettle with boiling water you see white "smoke" coming out of the top. Steam is completely transparent just like air. What you see are water droplets formed from the steam cooling in air.
Steam IS the “smoke” true fully vapor would be transparent, fully in a full vapor state. My idea of a system would be feeding hot vapor directly into the intake allowing very little time to cool down.
The same will apply to gasoline, especially since some of gasoline's contents need to reach about 200° C in order to boil, which is 100° C more than water. The question is what is the dew point of gasoine in air. Surely it varies, but I don't see air holding nearly 7% of it's mass in liquids that boil up to 200° C at ambient temperatures.
Granted most modern ICEs are running dry intake manifolds so perhaps some testing may be needed to insure no liquid drop out happens.
I believe we would be talking a conversion temperatures of around 500/600C. With a cool down system to lower it to 200C.
That all sounds good and all but I feel is overly optomistic. We already have engines that run on completely vaporized fuels such as hydrogen, propane and natural gas, and none of those work at zero timing advance since they run better with advanced timing. There is no reason vaporized gasoline would work any differently. I would think gasoline would be even worse because it has a lower octane which, long story short, means you end up with a slower burn or it will detonate, and detonation means ¡adiós motor!
[B]Well: Gasoline Gallon Equivalents
Fuel Type Unit of Measure BTUs/Unit Gallon Equivalent
Gasoline (regular) gallon 114,100 1.00 gallon
Diesel #2 gallon 129,500 0.88 gallons
Biodiesel (B100) gallon 118,300 0.96 gallons
Biodiesel (B20) gallon 127,250 0.90 gallons
Compressed Natural Gas (CNG) cubic foot 900 126.67 cu. ft.
Liquid Natural Gas (LNG) gallon 75,000 1.52 gallons
Propane (LPG) gallon 84,300 1.35 gallons
Ethanol (E100) gallon 76,100 1.50 gallons
Ethanol (E85) gallon 81,800 1.39 gallons
Methanol (M100) gallon 56,800 2.01 gallons
Methanol (M85) gallon 65,400 1.74 gallons
Gasoline has the most bang for your buck. Vapor gasoline It also has a high vapor density, which means it produces a lot of vapor compared to other combustible liquids.
The flash point of a volatile material is the lowest temperature needed to evaporate enough fluid to form a combustible concentration of gas. Gasoline has a flash point of -45°F and an auto-ignition temperature of 536°F.
Burning gasoline vapor can cause an explosion.
When you boil a liquid it can expand well over a thousand times it's original volume, and many times even far more. A voluminous gaseous fuel displaces a lot more of air that can get into the engine than a liquid fuel does. You can't just make gasoline 1,600 times or more it's original volume and expect to get the same amount of air into the engine without adding super or turbocharging. Simply put, gaseous fuel means less air and fuel will get into the engine.
This also doesn't take into account that feeding 200° C boiled gasoline vapors into the air is going to increase the air's own temperature causing it to expand before getting into the cylinder, which means even less air will enter the engine.
A ICE is a fairly effect air pump, there is a large amount of air being drawn in, gasoline vapor at say 200C is already working in a 100C engine compartment. I don’t think it will cause any problem in a few seconds as it is fed into the engine.
There will always be left over fuel in the exhaust even if you vaporized all the gasoline. The same happens with other gaseous fuel engines.
Why? Because of quench.
The flame stops burning when it gets to a certain distance near the combustion chamber, the valves, the piston and the cylinder walls. At this point the flame is too close to the metal which, even at temperatures of up to 200° C or more is too cold to let it burn. It ends up sucking the heat out of the flame where the flame gets close enough and leaves a thin layer of unburned air and fuel vapor along the edges of all the metal parts.
The reason small droplets can burn is that the flame that propagates throughout the combustion chamber is around 1,500° C, plenty hot to vaporize any liquid fuel droplets that are small enough. Not that there isn't some potential benefit of reducing them to the point they are completely vaporize, but modern gasoline engines already burn up to 90% of the fuel (or more) in the combustion process. And most of that 10% (or less) of fuel that isn't burned up in the combustion chamber is from quench which is still a problem in gaseous fuel engines.
On the other hand IF the claims are true and gasoline vapor explodes then it “burn” cycle may be too short to allow quenching…it might combust too fast for that action.
Interesting talk.
All things to be looked into.
Rich
|