Hydrogen assist

[bwilson4web]

Hummm, perhaps we're doing this wrong. When our hydrogen fraud friends show up, we should help them find a nice, low mileage vehicle forum. We should ask them, "What mileage are you getting in what kind of car now?" and answer with our typical values. Then point out we don't really need a hydrogen solution but ". . . those folks over at <gas_guzzlers.net> really need your technology." After all, 20% of 50 MPG would save only a miniscule amount of gas compared to 20% of an 18 MPG vehicle. Heck, an interstate trucker only gets 6-7 MPG and a 20% savings would be huge!

Yes, nothing like helping our visiting hydrogen experts find a forum where their technology would really be appriciated. <GRINS>

Bob Wilson

[dallas2727]

<div class='quotetop'>QUOTE(qbee42 @ Sep 19 2007, 09:43 PM) [snapback]515069[/snapback]</div>

Yes, you are wrong. Every bit of electricity from the alternator is paid for by burning gas, and you don't trade evenly for it. You have to consume more energy than the alternator produces, so it works at a net loss (this is basic thermodynamics). From a fuel efficiency standpoint, you are better off to not make the extra electricity and save the fuel used to make it.

Tom
[/b]

I thought alternators were belt driven, thus at high rpm would produce more electricity. I.E. they are variable output devices. And the belt does not disengage.

Obviously If I plug in a cigarette lighter or spotlight, my engine does not rev up to run the alternater at the optimum rpm to have just enough juice to run any electric devices I may or may not be using at the momemt. Headlights, stereo, etc. All cars are built with headroom to add electric devices.

You guys may be right, but not for the reasons you are stating. And yes, i know the laws of thermodynamics quite well. Lose the education and read the question.

[darelldd]

<div class='quotetop'>QUOTE(dallas2727 @ Sep 20 2007, 09:13 AM) [snapback]515283[/snapback]</div>

I thought alternators were belt driven, thus at high rpm would produce more electricity. I.E. they are variable output devices. And the belt does not disengage.[/b]

Load, and not RPM, is what determines the output. Yes the alternator can output more at higher RPM... but id doesn't until there's a load on it. Electricity isn't "produced" until it is used.

When you plug in your spot light, the engine doesn't need to rev higher... but more load is put on it, and the engine works harder, and burns more fuel to power the alternator that now has a larger load on it. (we're talking about a "normal" gas car here, not the Prius). If you turn the high beams on at idle, you can hear the extra work the engine is doing, and sometimes you can notice a drop in RPM as the engine works harder.

Or to think of it another way... look at the outlets in your home. They sit there doing nothing until you plug a device into one. Then electricity is used/consumed. If you use a 60W bulb, you draw 60W from the outlet. If you use a 100W bulb, you draw 100W from the outlet. Doesn't matter how much energy is being shoved into that outlet until you put a load on it. Until you add a load, no electricity is being "output."

That's about all the education I can afford to lose for one day. Your question was answered before... I think you just missed it. Make more sense now?

[dogfriend]

<div class='quotetop'>QUOTE(dallas2727 @ Sep 20 2007, 09:13 AM) [snapback]515283[/snapback]</div>

I thought alternators were belt driven, thus at high rpm would produce more electricity. I.E. they are variable output devices. And the belt does not disengage.

Obviously If I plug in a cigarette lighter or spotlight, my engine does not rev up to run the alternater at the optimum rpm to have just enough juice to run any electric devices I may or may not be using at the momemt. Headlights, stereo, etc. All cars are built with headroom to add electric devices.

You guys may be right, but not for the reasons you are stating. And yes, i know the laws of thermodynamics quite well. Lose the education and read the question.
[/b]

Part of the headroom is the energy stored in the 12v battery. Also, I believe that the voltage regulator is designed to keep the voltage constant regardless of engine rpm.

There is no doubt that some of the power used to turn the alternator is wasted. Could it be used to generate hydrogen gas?. Possibly, however, the HSD system is probably a better way to go - eliminate the alternator completely and use a DC to DC converter to supply the 12V battery.

I think that the people here who had to suffer through thermodynamics are saying that unless you have extrordinary proof that you can generate more energy with the alternator driven electrolysis than you consume in the process plus related losses, then they are not going to abandon their skepticism.

[miscrms]

The load dependent nature of your alternator can be anecdotally seen in several places, particularly in older cars. On my old saab 900, every time the electric fans kick on there is a significant drop in the rpm, before the idle control gets a hold of things and recovers. Another is jump starting a car. Particularly when you are jump starting a bigger car from a smaller one, the resistance created by the huge sudden load placed on the alternator can even stall the car. This is the reason a lot of older instructions for jump starting say to be in the running vehicle holding the accelerator down part way before starting the dead car. This is pretty much how our regen system works too, the more current you pull from the generator the more mechanical resistance you create. More mechanical resistance requires more fuel to be burned to maintain rpm otherwise you slow down (just like driving up a hill).

In this case the electrolysis of water into H2 is only about 50% efficient. So right off the bat, it takes twice as much power to make the H2 as you get back by burning it. It just goes down hill from there as you add in all of the other non-idealities of the system (tuning, friction ect). Is it possible it makes the fuel combust more efficiently? Maybe, but I doubt it. Modern fuel injected vehicles do a very good job of completely combusting all their fuel, hence their vastly improved emissions. If anything, adding another fuel into the mix will probably throw off your air/fuel ratio and decrease efficiency / increase emissions.

This idea of hydrogen injection isn't a bad idea, if you have an energy efficient source of Hydrogen. Thats the tricky part So far Iceland with their vast 24/7 geothermal power source are about the only ones to make this look feasible.

I saw an interesting interview somewhere with one of the "test families" driving a fuel cell vehicle for one of the major manufacturers. The company had installed a large (~10kW, or enough to run your whole house I seem to recall) solar system to run a hydrogen generation station to power this family's car. The station put out enough Hydrogen for them to fill the tank once a week, and get about 120 miles of use. The same solar system could easily run a factory EV 80-100 miles per day. A 10kW system in the Southwest puts out about 44.3kWh per day on average. An EV1 NimH had about 26.4kWh of battery capacity.

Wish I could remember where I saw that story....

Rob

[darelldd]

<div class='quotetop'>QUOTE(Rob Smith @ Sep 20 2007, 03:56 PM) [snapback]515495[/snapback]</div>

I saw an interesting interview somewhere with one of the "test families" driving a fuel cell vehicle for one of the major manufacturers. The company had installed a large (~10kW, or enough to run your whole house I seem to recall) solar system to run a hydrogen generation station to power this family's car. The station put out enough Hydrogen for them to fill the tank once a week, and get about 120 miles of use. The same solar system could easily run a factory EV 80-100 miles per day. A 10kW system in the Southwest puts out about 44.3kWh per day on average. An EV1 NimH had about 26.4kWh of battery capacity.
[/b]

I've got your story right here! I have a 2.5kW solar system, and it provides all the energy for our EV to the tune of 1000 miles/month... and there is even left-over for the house. Ain't gonna happen with making H2, that's for certain.

[alanh]

Alternators generate power by moving a coil through a magnetic field. In modern automotive alternators, the field is generated by electromagnets. The voltage regulator controls the field current. If the car's voltage sags, the VR applies more field current, which increases the output of the alternator. Since there's no free lunch, this also increases the drag on the belt and engine.

Using this scheme, the VR can control the output of the alternator so that it's exactly enough.

The Prius' motor-generator and inverter is more complex, of course.

[qbee42]

<div class='quotetop'>QUOTE(dallas2727 @ Sep 20 2007, 12:13 PM) [snapback]515283[/snapback]</div>

You guys may be right, but not for the reasons you are stating. And yes, i know the laws of thermodynamics quite well. Lose the education and read the question.
[/b]

Your reply is patronizing to the point of being annoying. My first knee-jerk reaction is to say "Lose the attitude and read the answer", but that's not going to help you understand the physics behind electrical generation. This is a short explanation of the important points:

1) When an alternator spins, it generates a voltage across its output terminals. It takes no power to generate this voltage, except for the frictional losses in the alternator and belt, and some minor internal losses due to being non-ideal. The reason it takes no power is because there is no load. A load will draw some current, which is measured in Amps. When you add a load, the power required to drive the alternator is the product of the voltage and current: Required Power = Volts X Amps. From this equation it is easy to see that the power will be zero if either the voltage or amperage is zero.

2) Given the above, let's look at the case of a car driving down the road, but not using any electricity. The alternator is spinning, so there is an output voltage, but no current is being drawn. The power equation looks like this: Power = Volts X Amps = Volts X 0 = 0. No power is being used, other than the losses. This makes sense when we realize that the alternator is doing no work. It's just sitting there spinning like a fan, but not really doing anything.

3) Now let's add a load. The driver switches on a radio that draws one Amp. The power equation now looks like this: Power = Volts X Amps = Volts X 1. If the system voltage is 12, then the required power is 12V X 1A = 12 W, or twelve Watts of power.

4) The driver now switches on the fan, which draws another Amp. The power equation now looks like this:
Power = Volts X Amps = Volts X (1+1)Amps. If we again assume 12 Volts, the required power is now 24 W. When we doubled the load, we doubled the amount of power needed to drive the alternator. This is true in the general case: the power required to drive the alternator is directly proportional to the load.

5) So far we have assumed a constant voltage from the alternator. This is where it gets a little interesting. The voltage developed by an alternator is directly related to the magnetic field cutting the windings inside the alternator. For a given magnetic field, the faster the alternator spins the higher the developed voltage. With a fixed field, the lights of our car would get brighter as we sped up, and dimmer when we slowed down. Likewise with the fan motor and windshield wipers. Most electrical and electronic devices are designed to operate over a narrow range of voltages. On cars the range is approximately 11 to 13.8 Volts. We need some method of controlling the output voltage of the alternator. Enter the Voltage Regulator. The voltage regulator is an electronic or electromechanical device that controls the magnetic field of the alternator. The voltage regulator monitors the system voltage and adjusts the current flowing through the field windings of the alternator. Increasing the current through the field windings increases the field, and therefore increases the output voltage of the alternator. Decreasing the field current has the opposite effect. The voltage regulator does its level best to keep the output voltage at 13.8 Volts.

6) Note that the voltage regulator has no bearing on the relationship of required power and load. They are directly related with or without a voltage regulator.

Hope this helps,
Tom

[stumpy_c]

Ugh - I can't believe there are people out there silly enough to buy in to the "water powered" car BS. It is thermo at its most basic level. It amounts to perpetual motion. You'll find both in the thermo 101 text glossary under the heading "Uhh...no, moron."

Regarding the hydrogen for better fuel economy thing...

Even if your alternator produced more electricity than it needed (which it does not), electrolysis to get hydrogen out of water is so terribly inneficient that you would come out far ahead by simply directing the excess enerrgy into the nimh battery for use by the electric motor (assuming we're talking about using this on a hybrid vehicle). On a non-hybrid the added friction loss the alternator would create by having to produce the extra elctricity for electrolysis would besuch that you would actually LOSE efficiency (energy can only be lost).

[patsparks]

Hey everyone, it's time to wake up now, time to come back to reality, time to stop dreaming.
Was "convicted for fraud" invisible in my last post.
It's all crap.
Alternators are regulated devices, they put out what is asked of them. Have you ever found an electric radiator to dump excess power from the electrical system? No me either. In a regulator the power to the rotor is controlled which controls the output of the stator windings. An alternator can achieve maximum output at about 1/3 of it's maximum revs. The best example I have had of the alternator output and therefore load on the engine automatically adjusting to demand is when jump starting a car. when you make the last connection of the jumper leads you can hear the extra load on the engine of the slave car as it strains the alternator to charge the flat battery. When the car with the flat battery starts you often hear the alternator of that car whistle as it struggles with the demand of the flat battery.

If you push electricity through anything it will give off some heat, using electricity to separate hydrogen from oxygen in water will give off some heat or lost energy.

The only way this form of hydrogen injection could help efficiency is if it can make the petrol burn more completely, the problem here is modern engines are very good at burning almost all the fuel leaving very little to gain.

Here is my idea you can have for free. A coating of industrial diamonds over the piston crown, combustion chamber of the cylinder head and valve heads would reduce heat transfer to the cooling system improving efficiency. This process is relatively cheap and easy. Diamond coating is used on plough tips to reduce wear.