Quote:
Originally Posted by john_bud
Did you read the study closely? They added 20% hydrogen to the combustion mix. That is a HUGH amount of hydrogen. They also added pure 100% hydrogen. The typical home made HHO devices will, on a good day, generate 0.5 to 1.0 liter per minute of total gas. That's H2, O2 and H2O vapor. The hydrogen content of the device effluent stream is about 1/2 by volume with the remainder being the oxygen and heated water vapor. Do the math on an engine to see the volume needed to reach 20%.
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First of all, I said the kits didn't work, and there are many reasons for that, the primary one in my mind being, they can't do anything to lean out the fuel mixture so it dosen't matter how much hydrogen they produce.
Quote:
Originally Posted by john_bud
A typical 2.0L 4 cyl engine on the freeway will run about 2000 rpm. (Makes the math easy) A 4 cycle engine will inhale once per 2 revolutions, so at 2000 rpm's that 1000 inhales. If you are at full throttle, it will inhale 2000 liters of air per minute. 20% of 2000 liters is 400 liters. So, to get the full benefit of hydrogen fumigation, you would need a system that could produce a variable volume of hydrogen up to 400 liters per minute for a 2.0 4 cyl engine. If you make a good "HHO" system it may make 1 liter of gas per minute with 10 amps supplied. (assume it's all H2). To reach the 400 liter of hydrogen the study called for you will need 4000 amps  . |
I don't know if it's wise to assume 100% volumetric efficiency, or that i'll be going down the highway at full throttle. Most of the time i'm way down near 30% throttle, and my car definately dosen't get 100% volumetric efficiency at any throttle, and at any RPM. The goal is not to make a drag car more fuel efficient. Never the less, you are correct in that it would take substantial power to add in 20% hydrogen. That being said, 20% hydrogen lets them massively lean out the AFR while maintaining burn stability. Personally, i'd be trying to target perhaps 5% hydrogen, and an AFR of 16:1 or 17:1.
Quote:
Originally Posted by john_bud
Think about this; How much lag time is there between the peddle getting pressed and the hydrogen being produced? Obviously, you need different amounts of hydrogen when the engine is idling at a stop light compared to accelerating when the light turns green, right? So you really need a system that can fumigate a small amount (5-10 liter hydrogen per minute) at idle then increase to 400 liter per minute as you hit the accelerator without a lag. Then you need the system to be able to stop the fumigation when you let up the peddle (or the engine will continue to rev as you try to coast or stop!! ).
The aspect of matching the volume of hydrogen to the engine throttle opening / rpm / fuel flow is never discussed on the sites that sell the systems. Ever wonder why? |
The same thing happens when you hit the gas peddle on you car with respect to air. There is no magic device that allows the air in the intake manifold to suddenly jump from 5 psi to 14psi (MAP reading). As a result, the AFR dosent' perfectly track at 14.7:1. It wanders. Richens up when you punch the peddle, leans out when you suddenly let off. That's fairly normal, and the same would be acceptable in a hydrogen system.
Also: You could have a hydrogen system that could go from full production to nothing back to full in a milisecond if it was electronic. With ease my friend.