electrolysis, HHO intake charge

[jayman]

Originally Posted by qbee42

Many of these devices have you remove or tamper with the oxygen sensor, making the engine run overly lean. That's one way to get a short term boost in fuel economy.

Tom

Correct, and it even works. Just make sure you're handy with overhauling, as pistons and valves don't appear to tolerate it for very long

[jayman]

Originally Posted by dogfriend

If you want to know where we are headed, visit your local WalMart.

Oy, my head hurts just thinking about it. No, haven't had enough to drink to make the head hurt

[jayman]

Originally Posted by qbee42

I gathered that was where you were going. I was just clarifying that water is produced when you burn hydrocarbons.

Correct, as a "real world" gasoline combustion process will yield NOx, CO2, CO, unburnt HC residuals, H2O, trace metals depending on fuel composition and oil consumption, etc. A lot of the dripping you see from a car exhaust system is condensation

That said, I don't think any of us will take seriously a magic little box that can deliver more energy than inputed

[ShellyT]

Despite what the sites trying to sell these generators sound like, the idea isn't to defy physics. It's to make the gasoline engine more efficient. The addition of hydrogen can improve engine efficiency by 30%. It's a question of whether the hydrogen generator set up produces enough gas for a net gain in efficiency.

MIT Plasma Science & Fusion Center: <research<Plasma Technology<research<plasmatron
http://www.psfc.mit.edu/research/pla...DF/dan_cps.pdf

[bbald123]

Originally Posted by ShellyT

Despite what the sites trying to sell these generators sound like, the idea isn't to defy physics. It's to make the gasoline engine more efficient. The addition of hydrogen can improve engine efficiency by 30%. It's a question of whether the hydrogen generator set up produces enough gas for a net gain in efficiency.

MIT Plasma Science & Fusion Center: <research<Plasma Technology<research<plasmatron
http://www.psfc.mit.edu/research/pla...DF/dan_cps.pdf

Okay, since neither cite has ANYthing to do with electrolysis of water and the introduction of the electrolysis products into an essentially stock ICE, what's your point?

[sergio]

Originally Posted by ShellyT

Despite what the sites trying to sell these generators sound like, the idea isn't to defy physics. It's to make the gasoline engine more efficient. The addition of hydrogen can improve engine efficiency by 30%. It's a question of whether the hydrogen generator set up produces enough gas for a net gain in efficiency.

MIT Plasma Science & Fusion Center: <research<Plasma Technology<research<plasmatron
http://www.psfc.mit.edu/research/pla...DF/dan_cps.pdf

Shelly

No one denies that adding Hydrogen can improve engine efficency but the question is : how much energy do you spend to generate such hydrogen ? In my poor knowledge of phisics laws the electrical energy you have to drain from the battery to make electrolysis is higher than total energy supplied by the generated Hydrogen. (You have thermal loss to consider).
It means that the energy balance will be always negative and also that the extrapower you obtain from the ICE is anyway paid with an extra fuel.
You can only have an hypotetical advantage if you use an indipendent hydrogen tank but in this case you simply use an external energy to be considered in the total balance.
But ... anyone is free to have its own dream....

Sergio

[richard schumacher]

Okay, since neither cite has ANYthing to do with electrolysis of water and the introduction of the electrolysis products into an essentially stock ICE, what's your point?

It's relevant because it describes potential benefits of hydrogen injection (increased octane, decreased NOx), but as you noted the hydrogen is derived by onboard reformation of 25% (!) of the fuel and not electrolyzing water. Generating hydrogen at that rate by water electrolysis would require a big electrolysis cell, a bigger generator to power the cell, a water tank or exhaust water-vapor condenser, and of course a higher-compression engine to take advantage of the octane boost.

HHO schemes like the OP's can clean up a dirty engine, but the cheaper way to do that is to get the engine tuned up or repaired.

[bwilson4web]

Hi Shelly,

I think I see your problem:

Originally Posted by ShellyT

. . . The addition of hydrogen can improve engine efficiency by 30%. . . .
http://www.psfc.mit.edu/research/pla...DF/dan_cps.pdf

I believe you took this quote from pp. 25 of the reference but unfortunately you forgot to include all of the text:

Originally Posted by Coalition

• Hydrogen addition provides a large increase in fuel
  octane number.
• High octane fuel allows higher performance engines
  (turbocharging, high compression ratio).
• Engines can be smaller and more efficient.
• Hydrogen addition also facilitates ultralean burn.
• Engine efficiency can be increased by up to 30%.

An increase in fuel octane number only works if the engine is designed to use that higher octane. Extensive testing with our Prius, Atkinson cycle, engines has shown that our engines are unable, completely incapable of deriving any significant benefit from higher octane. In fact, it takes full throttle application while going up a hill to see a modest, ~1-2% impact but only at the highest power settings:


It is all but impossible to turbocharge or increase the compression ratio of our Prius engine because two control computers, the engine and hybrid ECU completely manage engine operation. We do not have the source code, much less anything beyond a rudimentary understanding of the sophisticated control laws manage the engine. One Australian did put a turbocharger on his NHW10 but last I heard, it is no longer working and the advantages he described did not seen proportional to the expense.

"Engines can be smaller and more efficient" only works if the engine is designed from the ground up to use these systems. The mechanics and control laws have to work together with the designed fuel system. Changing the fuel does not magically change the engine. Changing the engine takes tools, parts, and a lot of applied time.


"Hydrogen addition also facilities ultralean burn" is certainly true IF the engine control computer will support it and you don't 'burn out' the catalytic converter. Our Prius has to properly warm-up and keep the catalytic converter in an optimum temperature range to handle combustion by-products ... including NO_{x} by-products. But this has to be part of the engine control laws, the software that runs in the engine control computer. This is driven by the two O_{2} sensors as well as the air mass flow sensor and throttle position. To simply dump a bunch of hydrogen or for that matter, any combustible fuel into the intake does not change the control laws. Using diesel fuel does not make a gas car into a diesel:


"Engine efficiency can be increased by up to 30%" does not address the impressive efficiencies already achieved by the Atkinson cycle. What this means is for an ordinary Otto cycle, after doing all of the engine mechanical and control law changes, you can come up with a completely new engine that begins to approach what our Atkinson cycle engine already accomplished. But there comes a limit to the thermal dynamic efficiency improvement and after a while, changing the fuel has no further effect (from Wiki):


I know this "hydrogen" stuff sounds wonderful but it has to be matched by serious changes in the engine mechanics. Otherwise, it provides absolutely no benefit.

Now if you really think you can do better, then by all means, buy a Prius, preferably used, and install your "hydrogen" system of choice with an "ON/OFF" switch. That way you can run controlled tests to prove it works. But a better approach is to buy a $600-1,200, Honda generator and apply your system to that small, standalone unit. Make the standalone generators more efficient and you'll really have something:


If you really want to flog another "hydrogen" fool system, feel free but you might start by first getting the facts and data straight including an understanding of your own sources. It also helps if you begin to study the Prius systems and master these terms:

• Atkinson cycle - what makes our engines an Atkinson cycle?
• engine ECU - what are the inputs and outputs of the ECU and control laws?
• hybrid vehicle ECU - what are the inputs and outputs of this ECU?
• power split device - how does the power split device work and who controls MG1?
• mixture trim - how does mixture trim work?
• catalytic converter - what are the O_{2} sensor signals and what happens when their signals do not match the expected waveform?

Study: get a Prius to experiment with and come back with your lab results and folks will be more interested in your experiments. But to badly parrot part of someone else's work, lifting their content out of context, this is the wrong way to 'help' us.

Bob Wilson

ps. Over the top?

[keydiver]

Originally Posted by qbee42

Independent dynamometer testing would be a good start.

Tom

Device promises to save 60% at the pump | West Palm Beach, Boca Raton, Treasure Coast local news, weather, live radar, investigative from Newschannel 5 | WPTV.com
Click on the video too. I also would sure like to know if this stuff is snake oil, as I have several friends pressing me to research it because they would like to go together for a group buy. As to the O2 sensor issue, there seems to be some differences of opinion depending which HHO generator website you look at. If the device really does lean the AFR, the closedloop operation of the ECU will just richen it back up until you're back where you started from. I don't see much wrong with a leaner AFR, other than slightly increased NOX, as I've always felt the 14.7:1 figure to be rather arbitrary. I write special code for some turbo cars that allows a 16.5:1 leanburn AFR while at light cruise conditions, and it works just fine. But, I certainly wouldn't want to see someone put the engine under heavy load conditions at that AFR.

[jayman]

Originally Posted by bwilson4web

ps. Over the top?

Not in the least. It's obvious that you're not mean and cranky like I am, and you have a far nicer and even way patiently explaining things. Just thinking about this snake oil bulls*** makes me want to turn into a Tasmanian Devil