water injection = Higher Efficiency?

[IamIan]

Originally Posted by t vago

Specific volume of liquid water at 80 C: 0.00103 m^3 / kg
Specific volume of steam at 80 C: 3.40527 m^3 / kg
Expansion ratio at 80 C: 3306.1:1
Vapor pressure of steam at 80 C: 47.4 kPa

So ... no amount of pressure can contain this expansion , 1Pa or 1TPa the expansion is the same ... the gravity of a black hole could not contain this expansion ... traveling at the speed of light the expansion would proceed forward faster than the speed of light ... as long as it is at 80C it always expands the same amount ... and there is always an expansion ... even when 80C is bellow the phase change point of the liquid water ... yeah ... that's doesn't seem right to me.

I think some other factors could have an influence... like a box not big enough for that much expansion.

Originally Posted by t vago

Grow up.

Interesting ... you fabricate a work of fiction ... then try to pass it off as if it were a quote from me ... and when I try to politely point that out ... You ask me to grow up.

Originally Posted by t vago

I never stated that you made that particular statement

wow ... that's interesting denial.

Who were you referring to then with your quote?
To me , it seemed like you were referring to me.

Originally Posted by t vago

You spent an entire post that all but stated that explicit statement

I didn't claim that ... those aren't my words ... that isn't my position.

Originally Posted by t vago

now you appear to be taking offense when I summarize your faulty position within quote marks.

I am taking offense to you fabricating a false quote.

If you think my position is faulty ... fine ... making up fictional quotes is not necessary... it is not appreciated ... and I do take offense to it... even if you see nothing wrong with it.

Originally Posted by t vago

you devoted a novelette to expressing that idea, that steam could somehow be treated as an ideal gas because the ideal gas doesn't perfectly model the behavior of real gases.

I've tried to address this misunderstanding of yours before ... I don't know how else to try and explain it ... so that you don't come back to this same incorrect impression of my position.

Originally Posted by t vago

No, but you are willing to discard over a century of collected real-world data about how water behaves, all because it doesn't jibe with your religious fascination with the ideal gas law.

Incorrect.

Reminder ... you don't know my thoughts , much less my religious beliefs...
As being myself ... I am more qualified about this than you are.

I tried to explain to you my view about the data I think you are referring to ... I am not discarding it ... anymore than I would be discarding the autoignition point of changing the temperature and pressure for a container with air and gasoline in it... anymore than I would be discarding data for hydrogen and oxygen at various temperatures and pressures that also will not always follow the ideal gas law.

- - - - - - - - -

I have my doubts ... but I'll try again to try and explain the difference between my position and what it seems to me is the impression of what my position is what you keep getting.

Weather it is 1700:1 , 1600:1 , or 1500:1 ... The energy that ( for lack of a better descriptor ) 'fueled' that expansion if not spent for the expansion ... because the limited volume of the container prevented it ... will result in greater pressures ... those greater pressures can have other influences ... increased pressures will raise the phase transition point of liquid water ... increased pressures will raise temperatures of compressible materials like gases.

Take the boiling of water on a kitchen stove top for example ... if the container it can expand into is large enough so that the expansion of the steam being phase changed is not restricted by the container , than the steam coming off a open pot of boiling water does not increase in pressure ... if the container however is smaller ... like a pressure cooker ... so that the steam given off does not have enough room to expand ... the result of that lack of sufficient volume for expansion is that the pressure inside goes up ... as the pressure goes up it also has other secondary effects ... the phase change point of the water goes up due to the increased pressure ... because the phase change point has gone up to a higher temperature ... the remaining liquid water can be brought up to higher temperatures than it could have at the lower pressures.... this increase in the phase change temperature happens after or as a result of the increased pressure ... prior to the pressure increasing the water could not increase its' temperature... it was already at the phase transition temperature for the lower pressure... and if the volume of the container does not restrain that expansion ... the pressure will not go up.

- - - - -

The difference between what I am claiming and what it seems you keep getting the impression of what I am claiming ... is that I am not pretending it is just the ideal gas law as some kind of theory of everything ... The ideal gas law does not itself show the effects of pressure on the phase transition temperature of the liquid water ... and those effects and others do have real world effects ... and they should be considered and accounted for ... just because I talk about one of those influences does not mean I am discarding all other influences that will effect the system.

I doubt that explanation will make it any more clear than previous attempts ... but oh well.

[drmiller100]

vago is confusing, as he knows just enough to confuse, but not enough to explain.

if we take water, and put it in a container. Then we remove all the air one way or the other.

If we know the temperature, we know the pressure. Optionally, if we know the pressure, we know the temperature.

This is true for many liquids in specific ranges - freon comes to mind. with two pressure gauges, you can see the different pressures on an AC unit.

What gets confusing is what happens when there are other substances in the mix.

and, to further confuse it, the temperature/pressure thing ONLY works within a narrow band for each substance, or the gasses start acting like ideal gasses, only there are lots of exceptions.

again, vago is pretty good about finding problems with stupid little things..... but he isn't quite good enough to actually do the math to find opportunities for improvement.

and the BIG issue you have circled around, which vago doesn't want to discuss, is the fact steam really DOES act like an ideal gas, until the temp drops to 600ish.

from there, no one is exactly sure what happens - does the steam maintain pressures as the volume increases as the piston goes down????

[t vago]

Originally Posted by IamIan

So ... no amount of pressure can contain this expansion , 1Pa or 1TPa the expansion is the same ... the gravity of a black hole could not contain this expansion ... traveling at the speed of light the expansion would proceed forward faster than the speed of light ... as long as it is at 80C it always expands the same amount ... and there is always an expansion ... even when 80C is bellow the phase change point of the liquid water ... yeah ... that's doesn't seem right to me.

In other words... you have no clue about what humidity is? You do not know anything about the law of partial pressures? You admit to not knowing how gases behave in a mixture? Is this what you're saying?

You gave a specific temperature for saturated steam. You never specified anything else. I quickly gave you the data for which you were so eagerly hoping to prove the steam tables to be wrong.

Originally Posted by IamIan

I think some other factors could have an influence... like a box not big enough for that much expansion.

You're apparently saying there is no box in the world that's big enough to contain both liquid water and water vapor at 80 C. Did I read that right?

Originally Posted by IamIan

Interesting ... you fabricate a work of fiction ... then try to pass it off as if it were a quote from me ... and when I try to politely point that out ... You ask me to grow up.

So you did not actually say this?

Originally Posted by IamIan

Technically no gas 100% follows the ideal gas law ... because no gas is actually 100% ideal... but the basic principle of the relationships shown in the ideal gas law do still apply ... even to saturated steam.

Or can you tell me the substantial difference between that statement you made above, and this one?

"since no gas exactly follows the ideal gas law, we can still treat steam as an ideal gas"

Give me an explanation that substantially differentiates what you said and what I put in quotes. Show me the substance whereby you can justify your being offended. Include in your explanation that I explicitly stated you did not actually say the words that I arranged and placed in quotes, both in the post you responded to, and in this very post.

And while you're at it, grow a thicker skin. (In other words, grow up).

Originally Posted by IamIan

wow ... that's interesting denial.

Who were you referring to then with your quote?
To me , it seemed like you were referring to me.

What are you, some sort of politician now?

Originally Posted by IamIan

I didn't claim that ... those aren't my words ... that isn't my position.

Really? You didn't actually state this?

Originally Posted by IamIan

Technically no gas 100% follows the ideal gas law ... because no gas is actually 100% ideal... but the basic principle of the relationships shown in the ideal gas law do still apply ... even to saturated steam.

Originally Posted by IamIan

I am taking offense to you fabricating a false quote.

If you think my position is faulty ... fine ... making up fictional quotes is not necessary... it is not appreciated ... and I do take offense to it... even if you see nothing wrong with it.

You also have faulty reading comprehension skills. I have explicitly stated that you did not actually say the phrase I put in quotes, both in that other post that you responded to, and this here post.

That you take offense to being paraphrased is rather remarkable.

It's called paraphrasing.

Originally Posted by IamIan

Incorrect.

Reminder ... you don't know my thoughts , much less my religious beliefs...
As being myself ... I am more qualified about this than you are.

It would help your position immensely, if you actually knew about what you were talking about. For instance, whether you knew what the definition of saturated steam was.

Originally Posted by IamIan

I have my doubts ... but I'll try again to try and explain the difference between my position and what it seems to me is the impression of what my position is what you keep getting.

Weather it is 1700:1 , 1600:1 , or 1500:1 ... The energy that ( for lack of a better descriptor ) 'fueled' that expansion if not spent for the expansion ... because the limited volume of the container prevented it ... will result in greater pressures ... those greater pressures can have other influences ... increased pressures will raise the phase transition point of liquid water ... increased pressures will raise temperatures of compressible materials like gases.

Give me the definition of saturated steam.

Originally Posted by IamIan

Take the boiling of water on a kitchen stove top for example ...

Okay. You're adding heat to a container containing both liquid water and saturated steam at a given temperature. So what?

Originally Posted by IamIan

if the container it can expand into is large enough so that the expansion of the steam being phase changed is not restricted by the container , than the steam coming off a open pot of boiling water does not increase in pressure

Saturated steam at a given temperature has a given pressure.

Conversely, saturated steam at a given pressure has a given temperature.

Otherwise, it's not saturated steam.

What is so hard to understand?

Originally Posted by IamIan

... if the container however is smaller ... like a pressure cooker ... so that the steam given off does not have enough room to expand ... the result of that lack of sufficient volume for expansion is that the pressure inside goes up

Your example still has saturated steam, since there is still liquid water present. So what?

Originally Posted by IamIan

... as the pressure goes up it also has other secondary effects ... the phase change point of the water goes up due to the increased pressure ... because the phase change point has gone up to a higher temperature ... the remaining liquid water can be brought up to higher temperatures than it could have at the lower pressures.... this increase in the phase change temperature happens after or as a result of the increased pressure ... prior to the pressure increasing the water could not increase its' temperature... it was already at the phase transition temperature for the lower pressure... and if the volume of the container does not restrain that expansion ... the pressure will not go up.

And at the end of the day, in your vessel containing both liquid and water vapor, if there's still liquid water present, then there's still saturated steam present! It doesn't matter what the temperature is (as long as it's below 373 C). It doesn't matter what the pressure is (as long as it's below about 22 MPa).

Tell me something: What is your definition of saturated steam?

Originally Posted by IamIan

The difference between what I am claiming and what it seems you keep getting the impression of what I am claiming ... is that I am not pretending it is just the ideal gas law as some kind of theory of everything

I'm going to keep beating you over the head with this:

Originally Posted by IamIan

Technically no gas 100% follows the ideal gas law ... because no gas is actually 100% ideal... but the basic principle of the relationships shown in the ideal gas law do still apply ... even to saturated steam.

Steam mostly does not follow the ideal gas law, and saturated steam definitely does not follow the ideal gas law. If you were to take saturated steam in a constant volume at 100 C, raise the temperature of that steam to 120 C, and then try to use the ideal gas law to guess the new pressure, then you'd definitely get a wrong answer.

[bazman]

Holy thread derailing Batman! I tried to wade my pea brain through this thread and this is what I have picked up:

1 - Water injection is great for in cylinder cooling. I know this because I run it and it was worth an instant 45rwhp at 6lb boost in my current ride running 10.7:1 on pump gas. Also, in a previous ride I ran 18lb boost on pump gas with 24 degrees timing... simply impossible without water on that 9:1 motor.

2 - Water injection does not help economy.... regardless of compression or tune - at LIGHT THROTTLE. It obviously will help a high comp motor under load but that is nothing to do with mpg at cruise.

Point 2 above bums me out because I was hoping that water injected under lean burn at cruise would enable me to run leaner than I can now. I'm on the limit now on pump gas and what I am getting from this thread is that water won't help me push the envelope further.

In that case I'll run plasma ignition which will help make more power at a leaner mix therefore enable more mpg at cruise... plus at WOT it is worth about 8-10hp according to David Vizard tests on an otherwise optimized motor. This will mean mpg goes up but spark plugs will need replacing every oil change so economy + 1; cost of servicing - 1 haha.

Re the water - have I got it right?

I might try heating the fuel and having an ECU by-pass under throttle so cool fuel flows under power and hot fuel at cruise. IN the past I've found hot fuel makes a massive difference to emissions (seen 0% readings on 5 gas analysers for CO and HCC on several cars running heated fuel) and helps mpg if the tune can be adjusted to suit. Some cars will not adjust the tune and the O2 sensor sticks its ugly beak in... so I may remove the O2 sensors and tune around that.

Anyone else run heated fuel and optimized the tune for it? Without ecu control we used to find great results at first but over time the engine would revert slowly back to stock mpg. My theory is ECU control would fix that regression back but I've been wrong many times over many things :-) nothing to with water I know but if water does not work then we might as well talk about something that might lol

[drmiller100]

Originally Posted by t vago

Steam mostly does not follow the ideal gas law, and saturated steam definitely does not follow the ideal gas law. .

saturated does indeed follow ideal gas laws at higher temps.

Therefore, you are wrong.

[drmiller100]

I think water can help mpg at light throttle. I'm trying to understand the math to identify the opportunity.

No one has come along yet who is a good enough engineer to help us out.

[oil pan 4]

You are correct.
No one has come up with a way in theory or practice to inject water on a gasoline engine at light load and increase fuel economy.
You found the only way to use water to increase fuel economy on a gasser, you put together a high compression engine setup like what you have, drive it around normally, with no water injection at light load and use water or water alcohol to increase driveability under high load.

The only other way water might be used to increase fuel ecomomy is to use steam in place of or in addition to EGR.
As far as I can tell no one here is about to do that.

[oil pan 4]

Using ideal gas law for steam is wrong.
Doesn't matter if it works, still wrong.

[Frank Lee]

Originally Posted by oil pan 4

You are correct.
No one has come up with a way in theory or practice to inject water on a gasoline engine at light load and increase fuel economy.
You found the only way to use water to increase fuel economy on a gasser, you put together a high compression engine setup like what you have, drive it around normally, with no water injection at light load and use water or water alcohol to increase driveability under high load.

The only other way water might be used to increase fuel ecomomy is to use steam in place of or in addition to EGR.
As far as I can tell no one here is about to do that.

I think I said something like that about a dozen pages ago.

[t vago]

Originally Posted by drmiller100

saturated does indeed follow ideal gas laws at higher temps.

At temperatures between 75 C and 373 C, saturated steam does not follow the ideal gas law. At temperatures above 373 C, there is no such thing.

Originally Posted by drmiller100

Therefore, you are wrong.

You're so cute when you try to sound all knowledgeable, and stuff.

Originally Posted by drmiller100

You are an idiot. I bet you are an engineer.

Originally Posted by drmiller100

I'm sorry engineers are taught to point out flaws and all the negatives in everything they see.

I'm sorry engineers are trained to copy the previous guy's work, and to never think outside the box.

I'm sorry my existence, thought processes, attitudes, attempts, and comments piss off educated degreed engineers to no end.

I'm sorry I have created many successful projects despite the best advice from oh so many engineers.

I'm sorry engineers can count the trees in a forest, but miss the importance of the raging forest fire on the horizon.

Originally Posted by drmiller100

No one has come along yet who is a good enough engineer to help us out.

And no engineer in their right mind will ever help you out. At least, not here on this board.