Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-16-2017, 08:50 AM   #271 (permalink)
EcoModding Lurker
 
ar5boosted's Avatar
 
Join Date: Jun 2017
Location: Sydney
Posts: 62
Thanks: 4
Thanked 17 Times in 15 Posts
Quote:
Originally Posted by teoman View Post
I takes 2.2 MJ to vaporize 1 kg of water.
1 kg of gasoline has about 46MJ of energy.

Havent had a look at all the steam table pressure graphs yet, but purely from an energetic point of view, every unit of water by mass cancels out about 0.05 units of fuel.

Energy is used up to vaporize the water. After that both n2 and h2o compete for the thermal energy and expand.
I have my own observations on Water-Injection, developed from years of continual operation.

Whilst it takes energy to vaporise the water, it was heat energy that the engine was going to throw away anyway.

Adding water will simply convert extra heat that is there and not really wanted into kinetic piston driving energy so that the heat is not flushed out the radiator and muffler as it is on a normal car.

So you can win in fuel efficiency using water-injection.

__________________
2003 Renault Scenic - 30% more power with no loss in fuel economy.
1991 Toyota GT4 - more economical before ST215W engine-swap.
previous: Water-Injected Mitsubishi ~33% improved.
future - probably a Prius
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-16-2017, 09:58 AM   #272 (permalink)
Master EcoModder
 
Join Date: Jan 2017
Location: Istanbul
Posts: 330
Thanks: 24
Thanked 29 Times in 23 Posts
Yes it could be possible to win in fuel efficinecy. But i like to fully understand what is going on. Then i feel that i can tune it so that i can maximise the benefit.

Unfortunately that energy is not useless waste energy. Its function is to heat up the air and make it expand.

But with the water phase change if you can get the same gas pressure but cooler, you have less losses.

For example how much water is ideal?

For 20 units of water to 1 unit of fuel by mass theoretically you are producing steam at ambient pressure. So the engine will not run.

All the academic publications i have read seem to suggest that %20 water to fuel is the most beneficial.

But those are lab tests. And in real world consitions with changing load and rpm ine may need different rates.

If i can understand the theory behind the anectodal evidence i believe i can create the best setup.

Last edited by teoman; 07-16-2017 at 10:27 AM..
  Reply With Quote
Old 07-16-2017, 03:16 PM   #273 (permalink)
Lada Fan
 
Fingie's Avatar
 
Join Date: Jan 2015
Location: Finland
Posts: 642

"The War Wagon" Aka Yevina - '03 Vaz 2111 1.5 8V Injected
90 day: 38.49 mpg (US)
Thanks: 186
Thanked 59 Times in 48 Posts
when it rains heavily or when the air is otherwise moist, my car's MPG improves noticeably. I am curious into this.
__________________
If you don't make any mistakes in your life,
life itself will be a f*ckup.



A V T O V A Z
  Reply With Quote
Old 07-16-2017, 03:56 PM   #274 (permalink)
EcoModding Lurker
 
Join Date: Jan 2011
Location: Hamilton, New Zealand
Posts: 71
Thanks: 1
Thanked 2 Times in 2 Posts
I agree we need to understand what is going on. We could do a before /after test on engine heat rejection, if less heat is going out the radiator or exhaust then we should be able to quantify it too. doing this would be a bit complicated though.
If you consider the combustion chamber temperature, and particularly the valves and piston, in normal operation will be hot enough to make some stream. There was a design once for a steam engine with internal steam generation, cylinder head was heated and a thin gap was created radially in the head that injected water was forced into by the "compression" stroke and turned instantly into steam. I think there could be a bit of this happening.
Of course, the engine is cooled in the process.
  Reply With Quote
Old 07-16-2017, 07:55 PM   #275 (permalink)
EcoModding Lurker
 
ar5boosted's Avatar
 
Join Date: Jun 2017
Location: Sydney
Posts: 62
Thanks: 4
Thanked 17 Times in 15 Posts
Quote:
Originally Posted by George Tyler View Post
If you consider the combustion chamber temperature, and particularly the valves and piston, in normal operation will be hot enough to make some stream..
Inside the combustion chamber it's definitely hot enough to make steam.

You want to make steam as water expands 1800x when it turns to steam.

This will give the engine extra torque, so much so it's like adding extra cylinders. You feel it straight away.
__________________
2003 Renault Scenic - 30% more power with no loss in fuel economy.
1991 Toyota GT4 - more economical before ST215W engine-swap.
previous: Water-Injected Mitsubishi ~33% improved.
future - probably a Prius
  Reply With Quote
Old 07-17-2017, 04:04 AM   #276 (permalink)
toc
EcoModding Apprentice
 
Join Date: Jan 2011
Location: Australia
Posts: 167

Sonata97 - '97 Hyundai Sonata GL
90 day: 25.96 mpg (US)

Pulsar - '03 Nissan Pulsar ST
Team Nissan
90 day: 36.09 mpg (US)

Lancer - '04 Mitsubishi Lancer
90 day: 31.11 mpg (US)

Lancer 2.0 - '09 Mitsubishi Lancer
90 day: 27.1 mpg (US)
Thanks: 5
Thanked 12 Times in 11 Posts
Simple approach is to add an injector into the intake after the airflow meter and calculate a pulse width based on current fuel injection pulse width (be it 0.2 times or less)?
Tune the injection time based on real world findings..

Is that a dumb idea?
__________________
  Reply With Quote
Old 07-17-2017, 05:22 AM   #277 (permalink)
EcoModding Lurker
 
ar5boosted's Avatar
 
Join Date: Jun 2017
Location: Sydney
Posts: 62
Thanks: 4
Thanked 17 Times in 15 Posts
Quote:
Originally Posted by toc View Post
Simple approach is to add an injector into the intake after the airflow meter and calculate a pulse width based on current fuel injection pulse width (be it 0.2 times or less)?
Tune the injection time based on real world findings..

Is that a dumb idea?
Sounds ok to me. I've been told by the background neighsayers that the injectors will rust. However, Injectors are cheap and plentiful at the wreckers and I bought one for $3 to test how long it would last but got distracted.

Using spray-nozzles is problematic for various reasons. 'Limiting' is a better description, however that's what I used and could get it to work in a somewhat approximate system.

I based water input at a constant rpm of about 1,100 rpm on my Mitsubishi. Slightly above idle and slightly below accelerating values, but I was satisfied with that.
__________________
2003 Renault Scenic - 30% more power with no loss in fuel economy.
1991 Toyota GT4 - more economical before ST215W engine-swap.
previous: Water-Injected Mitsubishi ~33% improved.
future - probably a Prius
  Reply With Quote
Old 07-17-2017, 11:18 AM   #278 (permalink)
MPGuino Supporter
 
t vago's Avatar
 
Join Date: Oct 2010
Location: Cedar Rapids, IA
Posts: 1,730

The Karen-Mobile - '05 Dodge Magnum SXT
Team Dodge
90 day: 25.65 mpg (US)

Fiat Dakota - '00 Dodge Dakota SLT RWD Quad Cab
90 day: 16.67 mpg (US)

The Red Sled - '01 Dodge Durango SLT 4WD
90 day: 16.96 mpg (US)
Thanks: 767
Thanked 656 Times in 418 Posts
Injectors for E85 should not rust.
__________________
The Fiat Dakota


The Karen-mobile


The Red Sled
  Reply With Quote
Old 07-17-2017, 12:16 PM   #279 (permalink)
Master EcoModder
 
Join Date: Jan 2017
Location: Istanbul
Posts: 330
Thanks: 24
Thanked 29 Times in 23 Posts
Thanks for dropping by tvago.

I have the setup sorted out.

I a using an arduino a canbus shield and an injector.
  Reply With Quote
Old 07-17-2017, 11:17 PM   #280 (permalink)
MPGuino Supporter
 
t vago's Avatar
 
Join Date: Oct 2010
Location: Cedar Rapids, IA
Posts: 1,730

The Karen-Mobile - '05 Dodge Magnum SXT
Team Dodge
90 day: 25.65 mpg (US)

Fiat Dakota - '00 Dodge Dakota SLT RWD Quad Cab
90 day: 16.67 mpg (US)

The Red Sled - '01 Dodge Durango SLT 4WD
90 day: 16.96 mpg (US)
Thanks: 767
Thanked 656 Times in 418 Posts
Quote:
Originally Posted by teoman View Post
Thanks for dropping by tvago.

I have the setup sorted out.

I a using an arduino a canbus shield and an injector.
Good! Have you seen any improvement in fuel economy with your setup?

__________________
The Fiat Dakota


The Karen-mobile


The Red Sled
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com