Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 40 users online :: 3 registered, 0 hidden and 37 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Quick advanced question about a psi question

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: dapallox1 » Wed Mar 19, 2008 3:25 pm

Ragnarok wrote:A gallon is 4.5 litres, so it would last 4.5 times as long.

However, I do have to express my doubts that an engine could be run on only 5 litres of HHO gas a minute.

Thinking it through 5 litres of Hydrogen gas at 10 psig will only release 30 kJ of energy when burnt.
A 220 hp engine has a power output of 3.6 times that a second.
Input requirements are going to be at least twice that.

Judging by that, your consumption is going to be at least about 450 times your prediction. This means that to run a 220 hp engine, the tanks will last about 14 seconds (assuming lentamentalisk's estimates were correct)

Sorry to tell you this, but your idea really isn't a viable option. I've worked on lots of weird engine designs, and other than the ones which use liquid fuels with low fuel/air ratios, the consumption is a killer.


This is where I found out that it would take 5 liters per min: http://hydropowercar.com/forum_viewtopic.php?8.493

That will explain everything. And before anyone says "running a car on hydrogen is impossible", go to google and see for your self. Never be closed minded.
  • 0

Current Project: 4" Tee Piston Valve
User avatar
dapallox1
Sergeant
Sergeant
 
Posts: 83
Joined: Thu Oct 11, 2007 11:01 am
Location: Senatobia, MS
Reputation: 0

Unread postAuthor: DYI » Wed Mar 19, 2008 4:23 pm

To run a 200 HP auto engine at full speed on nothing but HHO you would need 20 X 5.46 or 109.2 liters per minute!


Looks like you might need to read a bit more carefully before you say you can run a 220HP engine on 5L/minute hydrogen. Ragnarok's numbers look a lot more valid, and I can see a bunch of mistakes in the post on Hydropower as well.

It is possible to run a car on hydrogen, but on board electrolysis is rather wasteful of energy, as it consumes about 2x as much energy as burning the gases it creates. If you want to run a vehicle, you'll need liquid fuels, such as gasoline, propane, or even liquid hydrogen if you want to create a real headache in building a containment vessel.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: psycix » Wed Mar 19, 2008 5:39 pm

@DYI

True,
Makny people think that running a car on water (or hydrogen) means free energy.
It isnt, its just a form of storing and later useing energy.

Water --Electrolysis-> Hydrogen+oxygen --Burning--> water
Electrolysis adds energy
Buring it frees it again.

Due to efficiency losses and some law of thermodynamics you will NEVER gain more energy, always lose.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: Ragnarok » Wed Mar 19, 2008 8:10 pm

I have to admit a small mess-up. My consumptions were based on pure hydrogen. Consumption of HHO gas is therefore 50% higher than on pure hydrogen.

DYI wrote:but on board electrolysis is rather wasteful of energy, as it consumes about 2x as much energy as burning the gases it creates.

I'd agree. I have to ask the OP where the energy for the electrolysis is supposed to come from - A battery bank?
Then much higher efficiency would be had from running an electric motor directly from this, and perhaps rigging up regenerative braking.

Then it might be reasonable to hope to hit efficiencies of around 80%, rather than the 20% or less that is likely by the convoluted route of hydrolysis cells.

If you're really set on a combustion engine, use a fuel that's stored as a liquid.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: Lentamentalisk » Wed Mar 19, 2008 8:54 pm

http://www.instructables.com/id/Run-You ... da-Cans-a/
this is an instructables written by a friend of a friend of mine, who ran his car off of aluminum cans and lye, but he used insanely huge volumes of H<sub>2</sub> gas, and the Al+H<sub>2</sub>->AlO<sub>2</sub>+H<sub>2</sub>+heat is way faster, and doesnt require a battery or anything. In fact, it is an exothermic reaction so it speeds up as it goes, and the excess heat can be used to do what ever the hell you want with.

Edit: in my previous message I said it would last 22 min, given the 5L per minute. Though that 5L/min figure has been disputed, assuming it is correct, the tank should actually last ~100 minutes, because I forgot to convert gallons to liters. In the future try to give all of your data in the same measuring system, preferably metric, so as not to confuse everyone.
  • 0

Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
Lentamentalisk
Brigadier General
Brigadier General
 
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.
Reputation: 0

Unread postAuthor: dapallox1 » Wed Mar 19, 2008 9:12 pm

Well, thanks for the positive feedback guys. I really do appreciate it. How could I store Hydrogen as a liquid?

@Ragnarok

Yeah, HHO Cells are ran off of the battery and triggered off of the ignition switch, or separate switch. It is only ran off of one battery when using it WITH gasoline. But if it was ran off of JUST hydrogen, I would use a few extra batteries to generate HHO faster.
  • 0

Current Project: 4" Tee Piston Valve
User avatar
dapallox1
Sergeant
Sergeant
 
Posts: 83
Joined: Thu Oct 11, 2007 11:01 am
Location: Senatobia, MS
Reputation: 0

Unread postAuthor: Lentamentalisk » Wed Mar 19, 2008 9:29 pm

dapallox1 wrote: How could I store Hydrogen as a liquid?

either compress it to insane pressures, or get it hell of fu<king cold.
I cant find a single phase diagram anywhere on the net, but basically it is not possible to do with out half a million dollars
  • 0

Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
Lentamentalisk
Brigadier General
Brigadier General
 
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: dapallox1 » Wed Mar 19, 2008 9:51 pm

lol, liquid hydrogen freezes at "Freezing Point @ 1 atm: -434.5°F (-259.2°C, 14oK)"

http://www-safety.deas.harvard.edu/serv ... rogen.html

Well, you all have answered a lot of my questions. Thanks a lot.
  • 0

Current Project: 4" Tee Piston Valve
User avatar
dapallox1
Sergeant
Sergeant
 
Posts: 83
Joined: Thu Oct 11, 2007 11:01 am
Location: Senatobia, MS
Reputation: 0

Unread postAuthor: psycix » Thu Mar 20, 2008 9:38 am

dapallox1 wrote:lol, liquid hydrogen freezes at "Freezing Point @ 1 atm: -434.5°F (-259.2°C, 14oK)"

http://www-safety.deas.harvard.edu/serv ... rogen.html

Well, you all have answered a lot of my questions. Thanks a lot.


Soooo, lets power up that old freezer and crank up that voltage a bit :roll:

Or imagine a modified beertender made to tap out pure liquid hydrogen :D
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Previous

Return to Pneumatic Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot]

Reputation System ©'