The Naked Scientists

The Naked Scientists Forum

Author Topic: How does a hydrogen fuel cell-powered car work?  (Read 48161 times)

Offline jonbyrd

  • First timers
  • *
  • Posts: 3
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #50 on: 20/06/2008 16:48:42 »
Hi there,

I think this information may help you out

Have you ever heard of HHO fuel that  has got to be the best way to save on gas prices.?
? Imagine the savings. It will cost you about $160, or two tanks of gas to install an HHO

conversion kit

<Hydrogen Car Kit - Save Money and Improve MPG Massively
Hydrogen car kit empowers your car to run on water and avoid oil as fuel. A vehicle however
will not be able to run on water alone. There needs to be a mixture of gasoline and water to
enable it to run smoothly.

Even the Water Fuel Conversion Kits - How Using Water As Fuel Helps Cut Your Gas Consumption

Recently,there is increased awareness among many drivers of a technology that uses plain

water tosupplement the cars' gasoline consumption. Called a water fuel conversion kit, it is

a simpleadd-on to your current car engine that uses your car battery to carry out an

electrolysis on water to produce Hydroxy gas (HHO). This Hydroxy gas is used to supplement

the burning ofgasoline in the car's engine.


Hydrogen generator kit for car can be better than gasoline or oil additives to raise gas
mileage. When you make or do it on your own, you can save money on gas but will save lots
of dollars on the kit and reproduce the system for other automobiles on your own.

saving money should be what everyonr thinks off and I have done this by using all ideas from
my free Ebook -******

I purchased the available eBooks that teach you how to run your car on water and installed

one on my "chevy 350 small block," it's pretty easy.

<******* This reads too much like an advert so I have removed the link. Hope you don't mind. People can send you a personal message if they want the booklet.
Mod>

« Last Edit: 20/06/2008 19:32:42 by sophiecentaur »
 

Offline skeptic

  • Jr. Member
  • **
  • Posts: 38
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #51 on: 21/06/2008 19:50:36 »
Hi there,

I think this information may help you out

Have you ever heard of HHO fuel that  has got to be the best way to save on gas prices.?
? Imagine the savings. It will cost you about $160, or two tanks of gas to install an HHO

conversion kit

<Hydrogen Car Kit - Save Money and Improve MPG Massively
Hydrogen car kit empowers your car to run on water and avoid oil as fuel. A vehicle however
will not be able to run on water alone. There needs to be a mixture of gasoline and water to
enable it to run smoothly.

Even the Water Fuel Conversion Kits - How Using Water As Fuel Helps Cut Your Gas Consumption

Recently,there is increased awareness among many drivers of a technology that uses plain

water tosupplement the cars' gasoline consumption. Called a water fuel conversion kit, it is

a simpleadd-on to your current car engine that uses your car battery to carry out an

electrolysis on water to produce Hydroxy gas (HHO). This Hydroxy gas is used to supplement

the burning ofgasoline in the car's engine.


Hydrogen generator kit for car can be better than gasoline or oil additives to raise gas
mileage. When you make or do it on your own, you can save money on gas but will save lots
of dollars on the kit and reproduce the system for other automobiles on your own.

saving money should be what everyonr thinks off and I have done this by using all ideas from
my free Ebook -******

I purchased the available eBooks that teach you how to run your car on water and installed

one on my "chevy 350 small block," it's pretty easy.

<******* This reads too much like an advert so I have removed the link. Hope you don't mind. People can send you a personal message if they want the booklet.
Mod>



Interesting that this 'scientific miracle' has never been seen publicly. Everyone has a book, CD, or E-book on their website, but nobody in the auto or parts industries can recall ever seeing one.

Oh, by the way, Sophie, you have joined the ranks of the 'Big Oil Conspiracy'(according those who believe there is one) by editing that link.
 

lyner

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #52 on: 22/06/2008 13:10:05 »
Quote
Oh, by the way, Sophie, you have joined the ranks of the 'Big Oil Conspiracy'(according those who believe there is one) by editing that link.
??? I just removed what looked to be an advert.
Of course there is, or has been, a 'Big Oil Conspiracy', just as there are Pharmaceutical, Political and Financial Conspiracies.  But now the Energy system is changing there is money to be made elsewhere and there will probably be a 'Green Conspiracy'.
How can you expect any large organisation not to promote its own interests in any way that it can?
Thanks to the relative freedom of information, conspiracies are often exposed, tho'.

Was I just being dim there and failed to spot a joke?
 

Offline skeptic

  • Jr. Member
  • **
  • Posts: 38
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #53 on: 23/06/2008 05:19:44 »
Quote
Oh, by the way, Sophie, you have joined the ranks of the 'Big Oil Conspiracy'(according those who believe there is one) by editing that link.
??? I just removed what looked to be an advert.
Of course there is, or has been, a 'Big Oil Conspiracy', just as there are Pharmaceutical, Political and Financial Conspiracies.  But now the Energy system is changing there is money to be made elsewhere and there will probably be a 'Green Conspiracy'.
How can you expect any large organisation not to promote its own interests in any way that it can?
Thanks to the relative freedom of information, conspiracies are often exposed, tho'.

Was I just being dim there and failed to spot a joke?

Yes, I made that crack because my friendly librarian has decided that the reason anyone takes the opposing side of this issue is because the oil companies are intentionally suppressing this miracle of physics. She can't accept that it may just be a scam. I think our public librarians are losing brain cells at a faster rate than ever before.
 

lyner

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #54 on: 24/06/2008 23:52:52 »
There's one born every minute.
 

Offline skeptic

  • Jr. Member
  • **
  • Posts: 38
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #55 on: 26/06/2008 02:19:28 »
There's one born every minute.

At the time that phrase was first uttered, the World was somewhere between its first(1825) and second(1929) billion people. They say around 2012 we will top seven billion.
Judging by the acceleration rate, I think we can safely say that there's at least one born every 10 seconds. LOL-Jesoph
« Last Edit: 26/06/2008 02:41:26 by skeptic »
 

lyner

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #56 on: 26/06/2008 09:59:04 »
Yes but that assumes that they are all mugs (Barnum's(?) original quotation referred to mugs, I believe). Your calculation implies that one in six of us is a mug. Let's see - there's you and there's me - not mugs. . .
Now count the conspiracy theorists, on the other hand.
 

Offline skeptic

  • Jr. Member
  • **
  • Posts: 38
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #57 on: 27/06/2008 02:28:38 »
Yes but that assumes that they are all mugs (Barnum's(?) original quotation referred to mugs, I believe). Your calculation implies that one in six of us is a mug. Let's see - there's you and there's me - not mugs. . .
Now count the conspiracy theorists, on the other hand.
It took many centuries to reach one billion, only one century for the next billion, and less than one century for the next five billion.
I meant to imply that all of us, suckers or not, are multiplying 5-6 times faster than when P.T.Barnum(or whoever)said that.

 
 

Offline jonbyrd

  • First timers
  • *
  • Posts: 3
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #58 on: 20/07/2008 14:02:51 »
   
The concept of running water as fuel for cars has been something scientists and researchers have been attempting for quite some time. With the high fuel prices as well as the pollution being an ever-increasing concern, the idea of water grows in the minds of these scientists and researchers. As the process continues for them to successfully create fuel from water the exhausting fact that it just isnít working has them somewhat baffled.

Although many experts claim that water can in fact be used there are those skeptics who believe it is impossible. However, in all fairness water does in fact contain hydrogen and hydrogen of course is a form of gas.
You can avail e-books on water fuel at

mod edit - stop spamming the forum with links - people can ask you by PM if they want to follow your comments up.
« Last Edit: 24/07/2008 14:03:21 by BenV »
 

Offline skeptic

  • Jr. Member
  • **
  • Posts: 38
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #59 on: 22/07/2008 01:19:57 »
   
The concept of running water as fuel for cars has been something scientists and researchers have been attempting for quite some time. With the high fuel prices as well as the pollution being an ever-increasing concern, the idea of water grows in the minds of these scientists and researchers. As the process continues for them to successfully create fuel from water the exhausting fact that it just isnít working has them somewhat baffled.

Although many experts claim that water can in fact be used there are those skeptics who believe it is impossible. However, in all fairness water does in fact contain hydrogen and hydrogen of course is a form of gas.
You can avail e-books on water fuel at

As one of "those skeptics", I must point out that many of us are perfectly willing to accept this theory if we could see a working model. There are endless numbers of "how-to" CDs, books, and E-books, but nobody willing to actually demonstrate that this technology is anything more than a scam publicly. 
« Last Edit: 24/07/2008 14:03:35 by BenV »
 

tech30528

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #60 on: 24/07/2008 14:00:02 »

Interesting that this 'scientific miracle' has never been seen publicly. Everyone has a book, CD, or E-book on their website, but nobody in the auto or parts industries can recall ever seeing one.

 

I have, I have one in my company vehicle now doing testing. I'm a 21 year L1 ASE Master, and know a good deal more than most about how they actually work. While I do plan on making some money building and installing these systems on my customer's vehicles, assuming they actually work (testing still in progress), I'll be making the information publicly available once I've collected enough data. There are a lot of people interested in this even in this area, but no one I've talked to has collected solid performance data, and a few have blown up cells and smoked wiring on their test vehicles. Of course in my own interests I'm not letting out everything I know locally, I don't think there's anything wrong with making some money off the years of work I've put in to understand cars better than most, but I see it as a temporary source of income (there are only so many customers in my area that will want them) and with so many people looking in to it it is only a matter of time before these systems are widespread. That is, assuming they really work. I can tell you this, though, I have noticed a difference in throttle response on my test vehicle, and just this morning passed 100 miles since I installed it. I powered it up after filling my gas tank and recording the mileage, the needle has just dropped down off the full mark. I'm going to run it at least 300 miles before filling it back up so I can get an accurate reading on what the mileage is now.

Oh, and we've got production costs on the cell and everything needed to install it under $100 now, including CPVC, stainless electrodes, tubing and electrical supplies. My suggestion to anyone looking at doing this is to wait. By the time you buy the information and get a test model working, I'll have data, pictures, and installation instructions posted here. You can start from scratch if you like, or you can wait a couple of weeks and build a system that has already been tested and had improvements done. Simple things like installing a drain petcock on the cell so that it's easier to empty it and refill it with fresh water instead of just adding to it and changing your catalyst concentration.
« Last Edit: 24/07/2008 14:10:43 by tech30528 »
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #61 on: 27/07/2008 13:47:35 »
At some point I assume this thread got confused between hydrogen fuel cells and water fuel cells (or electrolysers).

From the original question I would have assumed that it was the fuel cells that input hydrogen and air to give water and electricity to drive an electric motor, that was being asked about. If so this technology, though relatively new, is quite straight-forward. Great if you have an electric car and a hydrogen fueling station just down the road... otherwise hopeless!

Diverging into on-board electrolysers which act to supplement hydrocarbon fuel with oxygen and hydrogen in order to aid burning is a lot more controversial - but far more interesting. There seems to be a lot of these so-called 'hydroboosters' on the internet market at present, though looking at some of them, the gas output must be miniscule. One high profile booster with a few strands of stainless steel wire is almost laughable and must surely be extremely innefficient, yet they make some very wild claims. 

That said, given that it is known that quite a lot of hydrocarbon fuel is unburnt, then anything that improves the burn would surely be better for the environment. It would also seem logical that less fuel wasted would mean more miles per gallon, but as to claims of increasing the mileage 50% or more... well this would surely depend upon how hard your booster was working! 

Immediately this will no doubt allow the 'energy in = energy out' brigade to jump in, telling us that any extra energy provided by the gases will be countered by the alternator having to work harder. But consider this.

If you use an electrolyser that draws 10 amps, this would be no different from driving with your lights on at night, using heated seats or a rear heated window. Does anyone know of a car manufacturer that gives you a mpg of their vehicles for night time driving?

Has anyone ever turned there head lights on at night and felt the power drain from the engine as the horsepower dropped? No? Neither have I.

Sure there will be a drop in horse power the more electrics are used, but I'm not sure anyone would grump about losing a couple of hp if they increased their mpg by 20%.

How does it help burn the hydrocarbon fuel?

Well, and I'm only speculating here, but I think that it would be something to do with the much faster flame front of the hydrogen. This might well aid the breakdown of the bigger hydrocarbon molecules, almost like a pre-burn.

I'm currently building a small electrolyser specifically for trialing on my motor, so maybe soon I'll have some actual figures. 

Just out of curiousity Techy, what current does your electrolyser draw?

« Last Edit: 27/07/2008 13:50:02 by Farrah Day »
 

tech30528

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #62 on: 29/07/2008 18:47:19 »
At the current electrolyte level it is pulling about 12.3 amps when active and warmed up.

A couple of things worth noting here:

1) When attached to a vacuum source, the consumption of water from the cell becomes unpredictable, as do the results. As you know, water will boil at a lower temperature under vacuum, the cell also appears to produce considerably more gas under vacuum. It is hard to say if this is splitting the water or just boiling it (big difference), although the reaction stops when the power is cut even with the vacuum source still attached. Still, the boiling may be occuring in conjuction with electrolysis. But it is vastly different, emptying my 16 ounce cell in less than 10 miles. I would not believe that it is all BG production, as that amount of gas would make a huge diffence.

2) With my cell attached to a low vacuum port in order to keep the water useage reasonable, I did notice a slight increase in mileage (from 22mpg to 23mpg, 9.5%) and a slight improvement in throttle response. The mileage difference may very well be attributed to lighter throttle use to maintain speed. If the process we are assuming (more efficient ignition of the gasoline) is happening, the net effect would be basicly a slight advancing of ignition timing which could account for this.

3) I have read several accounts of damage to engines ranging from radiator hoses failing to melted pistons, all of which could be the result of other changes made, such as tampering with oxygen sensor readings and MAP sensor readings. These changes could result in incorrect timing or lean conditions that would cause problems with or without BG. Making adjustments to sensor reading would be fine, if the amount of BG was measured and the changes were to compensate for the effects on the burn specificly, but simply adjusting them without knowing the extent of what the BG is doing could, and has, caused damage.
 

tech30528

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #63 on: 29/07/2008 19:26:03 »
Just adding to the previous post:

I own an auto repair shop, and have a vested interest in making this work, but am not willing to do it at the cost of damaging vehicles. Given my 20+ years in this field, I understand the control systems on today's vehicles much better than most. I have had a scan tool plugged in to my test vehicle, and have observed the following:

1) Oxygen sensor readings with or without BG remain unchanged, as they should. The information collected by the oxygen sensors is used by the computer to adjust mixture by changing the on time of the injectors. The computer will adjust this time to keep the oxygen sensors in range. Post burn oxygen readings are a very good indicator of burn efficiency, and should not be tampered with to obtain artificially lean conditions. This can lead to damage, the severity and how long it will take to present will vary according to how far the information is changed.

2) Injector pulse widths are slightly lower, as are fuel trim numbers (with the cell active). They are in line with the minor change in economy. If you were able to get significant change, the fuel trim numbers would exceed test parameters (25% off of base) and would set codes. These parameters are there to catch problems such as restricted exhaust or vacuum leaks. Once the parameter is exceeded, the computer records a code and readings from the oxygen sensors are ignored as flawed, and the computer reverts back to open loop or programmed fuel delivery and timing, which will decrease fuel economy.

It is my conclusion so far that the first step to making this work as intended would be to determine how much BG is needed for best performance, I.E. the point that the gas stops enhancing the burn and starts to become a fuel source, then being able to provide that percentage across all driving conditions. This would very likely require storing the BG, as changing production amounts based on throttle angle and engine load would be too far delayed to be effective. Short of being able to maintain that balance, finding a lower than optimum amount that would be effective at cruising RPM would give nominal gains, without producing so much as to lean the engine out too much over prolonged idling. Ideally it would be much more effective to reduce the fuel pressure a specified amount and allow the computer to adjust injector on time to compensate for exhaust oxygen levels. By slightly reducing fuel pressure, the computer would hold the injectors open longer to deliver the same amount of fuel, and would have more room to cut it back under optimum conditions, keeping fuel trim adjustments off the "trip" points that would lead to open loop operation.

So that's it so far. First, find out how much BG you need and how much you are making. That means getting your cell right first, baselining your elecrolyte type and concentration so you can duplicate it. Then, assuming your cell can exceed how much you need, back off the electrolyte level to get it low enough to avoid overloading your engine at idle. It won't do you much good to lean your engine out to show big fuel savings if you blow the engine up in the process. There is no doubt that BG does have an effect on how gasoline is burned in the engine, the idea is to make it effective and safe.

 
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #64 on: 29/07/2008 21:02:09 »
I would expect that a lot more evaporation of the water will occur under vacuum and it may be because the vacuum disrupts surface tension - just as wind blowing over a puddle will cause it to evaporate faster than just the heat from the sun.

You may actually then be getting water gas going into the engine. As the heat of the engine will not allow this to condense into liquid water, it will probably pass through the engine and straight out of the exhaust.

I'm curious Techy are you maximising your electrolyser design with floating plates? Or have you simply put 12-14v across a single cell?

I've just built and am currently testing what I call a small figure 8 cell. This cell employs two threaded stainless steel rods of 10mm. Each rod then has 3 concentric ss tubes surrounding it. Each tube greater in diameter than the previous one, with a 2mm gap between each, held in place with laboratory rubber spacers. The large outer tubes are bolted together and hence I get my figure 8. Only the threaded bars at the centre of each set of tubes is physically connected to the supply. This gives me a 2 volt drop across each space from a 12 volt supply and hence maximises my voltage/current ratio to minimise power dissipation from any given current.

The main area I'm concerned with at present is keeping the unit cool enough so that the water does not boil off!  Even 120W will quickly boil the water in a compact electrolyser unless a way of avoiding this is designed into the unit.

I'm obviously very interested as you are experimenting with exactly the same thing as myself. Keep us posted.

Incidentally I'll be testing on an old Land Rover so do not have the problems of fancy electronics and Lamda sensors to content with.
« Last Edit: 29/07/2008 21:04:08 by Farrah Day »
 

tech30528

  • Guest
Re: How does a hydrogen fuel cell-powered car work?
« Reply #65 on: 30/07/2008 15:25:38 »
The cell is very similiar in design to the PowerTube you can see on YouTube, except that it is 13" tall with no bend. Rather than a sight tube, the top section of the generator is clear. I've measured the volume, and have the tube marked at a low point of 12 ounces and a full mark of 16 ounces with a bit of head room above it. A guy is building these locally, we are using it for a baseline model that we will improve as needed. For instance, what do you do when the outside temperature drops below freezing and the vehicle is parked? When a distilled water/ baking soda solution gets down to 32 degrees, the baking soda separates out of the water and it freezes. So at some point we will need to install a sensor and heater to keep the water from freezing and damaging the cell.
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #66 on: 30/07/2008 17:18:43 »
Hi Techy

I'm not a 100% on this, as I've not yet had to put it to the test, but I believe that simply adding regular radiator anti-freeze in winter works. I don't think it reacts or greatly effects electrolysis.

When I spoke of the cell, I was talking about the electrode parts, not the unit as a whole. I was actually wondering about your electrode configuration.

I haven't seen the PowerTube unit, will try to find it.
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
Re: How does a hydrogen fuel cell-powered car work?
« Reply #67 on: 30/07/2008 17:49:42 »
Hi Techy

Just took a look at the PowerTube and to be honest it is a very poor design. Very inefficient.

I'm getting greater gas output from my small figure 8 cell (4" high) from just a couple of amps!

He also states that he's using a PWM, so pulsing the voltage. However, this would seem to be doing nothing to aid gas production, but simply used to control current flow, and so an unnecessary complication. He is drawing 13 amps or more with poor gas production.

All I can say is that if he is improving his fuel economy from that unit, a well designed, efficient unit, will no doubt far exceed expectations!

The PowerTube is relying on just a cathode and an anode, which means that the full power supply is dropped over just two electrodes. It would be better to add floating plates to work the voltage down to around 1.5 - 2 volts per cell. Current through the unit can be set by the electrolyte concentration without having to worry about a PWM. I will simply want a pre-set maximum current flow at all times. An MCB in line will trip in the case of a fault such as an electrical short.

I only say all this, because if you only currently at the design stage, it would be better to take these things into consideration now, rather than have to redesign later.

 
 

tech30528

  • Guest
How does a hydrogen fuel cell-powered car work?
« Reply #68 on: 31/07/2008 17:07:26 »
We are looking in to a better design, I just got off the phone with a friend who is building cells. The guy I got mine from is very likely making a few buscks on empty promises, and it will eventually catch up to him.

I volume tested the cell this morning, and was only getting 8-9 ounces of gas production per minute, which according to what I have read is not nearly enough. Also, this cell is still running with baking soda, which I've been told will break down and be consumed in the process, which appears to be correct based on the drop in amperage on the cell over time. So we are going to a bigger cell, and switching to KOH. Size of cell is not really an issue right now, since my test vehicle is an old minivan. So we can build a pretty big box and scale back production by adding less electrolyte. Testing this morning with the cell loaded up on electrolyte and pulling close to 20 amp to see how much gas we could get out of it, it was at 185 degrees with the hood open. I would be concerned that running at that level with the hood closed we would be boiling the water instead of electrolysising it. So puttint the cell somwhere besides in the engine compartment seems like a good idea.

So, how much is your cell producing, and is it on a car yet?
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
How does a hydrogen fuel cell-powered car work?
« Reply #69 on: 31/07/2008 19:05:44 »
My unit is not on the car yet as I'm still testing and working through a few issues.  Rather than collecting the gas, I've been timing the bubble production through my bubbler. This may seem a little odd, but the bubble count per minute gives me a good idea of efficiencies without having to continuously fill up a container - a bit time consuming. I'll do a contolled measurement later if I get the chance. It might however be better to work in volume rather than weight (I'm not sure why you refered to ounces). I'll be using millilitres.

Top of my list is how to prevent the water boiling off - how to cool the unit.

Second is, do I make it bigger and reduce the electrolyte concentration?

Though I'm struggling to find info on this subject, I figure that there must be some trade-off in efficiency when adding more and more electrolyte to provide any given current. I feel that if I can achieve my 10 amp current flow by careful cell design, thereby minimising the amount of electrolyte I need, then I will achieve greater efficiency.

I mean, in theory a couple of stainless steel nails could give off a considerable amount of gas if the electrolyte level was taken to it's maximum, but I'm sure this must come at a cost.

A compact unit like the PowerTube is easier to locate, but the small volume of water will obviously heat up much quicker than a larger unit that can dissipate heat more efficiently. I think I have enough room under the front wing of my Land Rover to be able to mount a unit there. I can then duct air around the unit as I drive. I'm also considering fitting aluminium fins to further help.

Under the bonnet is not an option for me as its simply too hot.  I've seen some of these tiny electrolysers that are built in a pickle jar, placed under bonnets, but as they are so inefficient (and only drawing around 1 - 2 amps), it's not so much of an issue.

I have decided that 10 amps is what I'm looking for, which obviously dissipates 120W at 12v.  Anymore than this and I feel that cooling will be a constant issue. Also, this level of current should pose no longterm problem to my alternator, even with lights, etc on.

The important thing for me is to get maximum gas for my power. This is where cell design is critical and two electrodes (Powertube) simply won't cut it.

I see that the PowerTube guy is selling his units for $50 on ebay. Actually I guess that 50 dollars isn't a bad price for the components and as he also puts it together - he's certainly not going to get rich from them. That said, it is quite clear that he has no background in science and would seem to be lacking even a basic understanding, as he claims that they're powered from free energy that the car otherwise wastes!! (Aaawww, if Sophie heard him say that..  ;). Fixing his unit to the front of the car is probably the only way to keep the unit cool. Furthermore, as I mentioned above the PWM unit is not only pointless, but also wastes power whilst being pointless! There will be a lot of people having a lot of problems with this unit when they fit it under a hot bonnet and it melts - I wouldn't want to be manning the phone in the complaints office! 

Back soon!
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
How does a hydrogen fuel cell-powered car work?
« Reply #70 on: 31/07/2008 19:54:51 »
OK Techy

Just looked at my measuring jug and I take it that you were measuring in fluid ounces.

Right, I just addded fresh tap water to my electrolyser and doped her up with sodium sulphate.

Using a large regulated Farnell PSU I have just drawn exactly 10 amps through my small figure 8 cell.

Result: 500ml in 49 seconds (approx. 17.5 fluid ounces) and bear in mind that I'm only drawing 10A - half the current you were.

I think this illustrates nicely just how important design is in relation to efficiency. And I'm sure I can improve on this as my figure 8 cell was initially just an experimental design and so fairly unusual.
 

tech30528

  • Guest
How does a hydrogen fuel cell-powered car work?
« Reply #71 on: 31/07/2008 23:59:09 »
Very nice. Thanks for the info. From what I have seen, (I"m assuming your Rover is a V-8) you will need to produce about four times what you are to be really effective. As for the heat issue, I think the heat is important to the process to a certain extent, and that cooling the unit may reduce the amount of gas produced. I've observed that when the unit is first started up, it is producing less gas and pulling less current, both increase as the temperture rises. One design I've looked at uses stacked stainless plates with power and ground attached every 5 to 6 plates, allowing a gradual voltage drop across each plate, and is reported to produce less heat. I"m cosidering one of these type units or using a step down transformer to reduce voltage and increase amperage.

One reason I'm looking at going with a fairly large generator is that it should stay cooler by way of larger liquid mass, and make testing easier by keeping electrolyte concentrations more stable. One advantage to using more electrode area is lower concentrations of electrolyte, reducing the need to filter out contaminants with a bubbler, and less electrode corrosion. One advantage I can see here is that many vans and pickups here are designed with two battery trays in case the vehicle will run a diesel or other equipment that requires two batteries. So if the cell was the size of a car battery, there would be a convienient place to put it assuming is could produce the needed volume with lower electrolyte concentration and lower operating temperature.

Clearly your figure eight design is better that the single plate/ stacked washer electrode design in head to head comparison. I agree that efficiency is key, as well as operating temperature. I'm glad to see someone else is going after this objectively, I think between us (and hopefully other who will join in) we can come up with workable solutions. That is, assuming there is one, and I think there is.

Oh, and you'll just have to forgive my standard measurements. I agree metric is easier to work with, but here most liduids and liquid containers are in quarts and gallons. I'll have to pick up a scale for measuring KOH soon, I'll try to post numbers in metric to avoid confusion.
 

Offline Farrah Day

  • Jr. Member
  • **
  • Posts: 45
    • View Profile
How does a hydrogen fuel cell-powered car work?
« Reply #72 on: 01/08/2008 01:19:26 »
My Land Rover is a V6, but I assume that you understand that an electrolyser will never make enough gas to run and ICE. The best I can hope for is it to act as a booster and improve the mpg and by what degree I would guess depends on how much gas I can produce.

The thing is, a poorly designed electrolyser will make the alternator work harder than it has to in achieving a any given gas output.

Electrolysers are more efficient when running hot, but regulating the temperature is going to always pose a problem, as even at low power, in a confined space the unit is likely to eventually start simmering. I'd rather err on the cool side than it boiling off. If anything a temp sensor to cut-off power supply just before the unit starts boiling would be advisable, but surface water will start to evapourate more readily well before the bulk of it boils.

Quote
One design I've looked at uses stacked stainless plates with power and ground attached every 5 to 6 plates, allowing a gradual voltage drop across each plate, and is reported to produce less heat. I"m cosidering one of these type units or using a step down transformer to reduce voltage and increase amperage.

The key is to tailor you're design to fit the applied voltage. If you're using a 12V car battery then ideally you want a 1.5 volt drop across each individual set of plates. So you would want the ground 0v on the cathode (plate 1), with 7 floating plates in between, and finaly the 12v +ve attached to the anode (plate 9).  The potential difference (voltage drop) across each two plates is always 1.5 volts, and from ground to 12v +ve, relative to ground, reads:

plate 1 (cathode) 0v, plate 2 = 1.5v, plate 3 = 3v, plate 4 = 4.5v, plate 5 = 6v, plate 6 = 7.5v, plate 7 = 9v, plate 8 = 10.5v, and plate 9 (anode) = 12v.

As transformers are not 100% efficient you will only waste energy taking that route and it is not necessary if you use the correct plate configuration. Using the plate configuration above really is the best way to make the most of your given supply voltage.

To further up the efficiency of my figure 8 cell, I really need to add another 2 outer ss tubes as I'm only effectively using 7, so my voltage drop across each pair of tubes is 2v. But then it was originally just a test cell. 

The most inefficient designs will only have an anode and a cathode, with the full 12 volts drop across just these two electrodes. And don't confuse multiple plates for floating plates.

It doesn't matter what design of electrolyser you use, power dissipated (heat) will always be dictated by the current x the voltage (IxV). You might have a well designed 9 plate electrolyser dissipating exactly the same as a two electrode unit, let's say 150 watts, the difference being that the 9 plate electrolyser will be producing a lot more gas! 8 x more to be exact!!
« Last Edit: 01/08/2008 01:22:22 by Farrah Day »
 

Offline that mad man

  • Hero Member
  • *****
  • Posts: 724
    • View Profile
    • My music
How does a hydrogen fuel cell-powered car work?
« Reply #73 on: 01/08/2008 17:03:25 »
 

tech30528

  • Guest
How does a hydrogen fuel cell-powered car work?
« Reply #74 on: 03/08/2008 20:23:55 »
My Land Rover is a V6, but I assume that you understand that an electrolyser will never make enough gas to run and ICE. The best I can hope for is it to act as a booster and improve the mpg and by what degree I would guess depends on how much gas I can produce.

The thing is, a poorly designed electrolyser will make the alternator work harder than it has to in achieving a any given gas output.

Electrolysers are more efficient when running hot, but regulating the temperature is going to always pose a problem, as even at low power, in a confined space the unit is likely to eventually start simmering. I'd rather err on the cool side than it boiling off. If anything a temp sensor to cut-off power supply just before the unit starts boiling would be advisable, but surface water will start to evapourate more readily well before the bulk of it boils.

Quote
One design I've looked at uses stacked stainless plates with power and ground attached every 5 to 6 plates, allowing a gradual voltage drop across each plate, and is reported to produce less heat. I"m cosidering one of these type units or using a step down transformer to reduce voltage and increase amperage.

The key is to tailor you're design to fit the applied voltage. If you're using a 12V car battery then ideally you want a 1.5 volt drop across each individual set of plates. So you would want the ground 0v on the cathode (plate 1), with 7 floating plates in between, and finaly the 12v +ve attached to the anode (plate 9).  The potential difference (voltage drop) across each two plates is always 1.5 volts, and from ground to 12v +ve, relative to ground, reads:

plate 1 (cathode) 0v, plate 2 = 1.5v, plate 3 = 3v, plate 4 = 4.5v, plate 5 = 6v, plate 6 = 7.5v, plate 7 = 9v, plate 8 = 10.5v, and plate 9 (anode) = 12v.

As transformers are not 100% efficient you will only waste energy taking that route and it is not necessary if you use the correct plate configuration. Using the plate configuration above really is the best way to make the most of your given supply voltage.

To further up the efficiency of my figure 8 cell, I really need to add another 2 outer ss tubes as I'm only effectively using 7, so my voltage drop across each pair of tubes is 2v. But then it was originally just a test cell. 

The most inefficient designs will only have an anode and a cathode, with the full 12 volts drop across just these two electrodes. And don't confuse multiple plates for floating plates.

It doesn't matter what design of electrolyser you use, power dissipated (heat) will always be dictated by the current x the voltage (IxV). You might have a well designed 9 plate electrolyser dissipating exactly the same as a two electrode unit, let's say 150 watts, the difference being that the 9 plate electrolyser will be producing a lot more gas! 8 x more to be exact!!

That's basicly what we are looking at this point. Except for 1.5 volts per plate you will have to add one. A fulling charged battery is 12.6 volts, but your alternator runs in the mid 13's, almost 14 1/2 volts at peak.From what I have read so far the most efficient splitting voltage per plate  is 1.24 to 1.47 volts. We'll look in to it.
 

The Naked Scientists Forum

How does a hydrogen fuel cell-powered car work?
« Reply #74 on: 03/08/2008 20:23:55 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums