Quote:
Originally Posted by LittleBlackDuck
That is a bit of an extrapolation that I would be reluctant to make. I doubt that the carburetor was operating consistently near stoichiometric AFR, and even if it was, then I am interested in the reasoning that extends the benefits to lean burn given that the stoichiometric ratio for HHO is 2:1 and petrol 14.7:1. To extend into lean burn territory there needs to be an alternate reaction pathway or a synergistic / catalytic reaction phenomenon.
Simon
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The carburetor , by their report, was adjusted to stoichiometric at each test point. They made an addition of HHO of up to 0.45% by volume.
In other threads I have put forth the reasoning behind the ability of a very small amount of HHO to accelerate the combustion via a theory I call "railroading" the side reactions that occur in the thermochemical mess that is the chemistry of combustion. Are you familiar with the basic science behind combustion chemistry? Radical production? Radical interaction? Are you aware of the great number of chemical pathways that occur during combustion of even the simplest of hydrocarbons?
I only ask the above because other forum members have derided my "basic science" simply because they don't have the background to discuss the topic. If you are not familiar with the above science of combustion, understand that it is taught at most engineering schools in the upper and graduate course levels, but it is a basic science.
By accelerating combustion, even by a few degrees of crank rotation, you can save several percent of lost thermal energy at stoichiometric fuel mixes. At lean burn, crank lead at ignition might be in the area of 45 to 60 degrees at cruise. That is a lot of wasted pressure before top-dead-center working against power production. You ask if I am just making this up? No, I have tested it on a 1990 Daihatsu Charade with the CB90 engine which has a relatively "lazy" combustion chamber comprised of a hemispherical head and straight shot intake passages. Running at 22:1 AFR resulted in missed ignition cycles and a COV ( co-efficient of variability ) well above the 5% rule of thumb for a good running engine. The engine could barely run at 24:1 AFR. It must be pointed out that engines designed to run in lean burn, such as the Honda engines, can run up to this point with reasonable COV, but the CB90 could not. Now, the addition of some HHO via an alternator powered electrolysis cell results in a smooth running engine up to 28:1 AFR. That was the limit of the Innovate Wideband O2 sensor we were using. You ask if I did ABA testing? Sure, turn off the HHO generator at 28:1 AFR and the engine cannot run.
Combustion progresses from the production of active radicals, but, if you seed the mixture with H2 and O2 ( of which some of the electrolysis product is O3 ) you can have a mixture rich in radicals BEFORE ignition if enough energy is present in the combustion mix to dissociate the diatomic H2 and ozone.