Warm Air Intake With Steam

[teoman]

I did a bit more coding, and i have my setup frequency function written.

Some one who knows better, t_vago? Could you double check my frequency code?

I wanted the PWM to be as slow as possible because first, I do not want to wear out the injector, secondly, the slower it moves, the dead-time (time between exciting the coil in the injector and the physical movement of the orifice blocking element, plunger?) becomes less of a concern.

I had previously calculated the max frequencies of my injectors, and at 2000 rpm it was 16Hz.

void setPWMFrequency() {

//SETUP PWM FREQUENCY (or it is too fast for the injector) (DONE)
//https://arduino-info.wikispaces.com/Arduino-PWM-Frequency

// INVESTIGATE IF YOU CAN GET IT EVEN SLOWER (DONE)
//https://www.arduino.cc/en/Tutorial/SecretsOfArduinoPWM


//PHASE CORRECT PWM
TCCR2A = _BV(COM2A1) | _BV(COM2B1) | _BV(WGM20);
//TCCR2B = _BV(CS22);


//SET PWM FREQUENCY TO 30/2 HZ ~ 15HZ
TCCR2B = TCCR2B & B11111000 | B00000111;
// OCR2A = 180;
// OCR2B = 50;
}

[teoman]

Well, the phase correct PWM did not really work. So i will be using 30Hz, which is not at all bad.

With the canbus shield attached some of the pins on the arduino do not work. But i found some that do. I will later investigate why this is so, but not at this moment, want to get this thing it to the car as quickly as possible.

The injector gets really hot after a short time of operation, so it would be a good idea on my part to implement some sort of mechanism to check if there is water flow to the injector to cool it.

[teoman]

Cleaning the injector now. Placed it in some vinegar and I am pulsing it.
Later today i will test the system with an ECU simulator.

[teoman]

Originally Posted by cRiPpLe_rOoStEr

Raising the steam temperature to the auto ignition points would be too risky.

Doing a bit of calculation, i have come to the conclusion that with my setup, i cannot get it to reach a temperature that is even close to the auto ignition temperature.

As my system is basically open to the intake (vacuum) it is not possible for me to raise the temperature of the steam above 100 deg C. For that i would need ti increase pressure, otherwise it is close to impossible to exceed the boiling temp of water.

[teoman]

Hnm...

Contradictory research that says fuel consumption at 30 deg c intake air temperature is higher than that at 20 degrees C.

https://www.researchgate.net/publica...asoline_engine

[cRiPpLe_rOoStEr]

When the air density remains the same in spite of the temperature differences, it would need more fuel to cool down in order to avoid pre-ignition. Quite predictable.

[teoman]

But the air would be less dense.

[teoman]

Found another article that claims 6.44 decrease in fuel consumption.

The obtained results have been compared with conventional gasoline engine in terms of performance and NO, CO, CO2, HC emissions. The results of theoretical combustion model agree with experimental data quite well. In the experimental results, it is seen that the engine torque and the effective power increase up to 4.65% at 3200 rpm, specific fuel consumption reduces up to 6.44% at 2000 rpm. There is 40% average reduction in NO emissions at 2800 rpm and it is 31.5% in HC emissions at 2000 rpm.

The effects of electronic controlled steam injection on spark ignition engine

It is a paid publication that I have not bought.

[Occasionally6]

Have you considered the proportion of the exhaust gas that is steam? Altering the EGR flow rate by intercepting the signal or using a stand alone PWM controller would surely be easier than doing what you are now.

If you want to isolate the effect of steam from also adding in CO2 and N2O with exhaust gas, then using the EGR valve with an external source of steam (better than adding steam to the exhaust gas) still seems more sensible than jumping straight into replacing it with another system entirely.

Re. "supercharging" and liquid phase injection of LPG, maybe look for information on steam ejectors for insight on how that might work. The fluids and temperatures are different but the principle is the same.

Among other applications, steam ejectors have been used in air conditioning systems where a ready source of steam is available. One example was in passenger carriages on railway trains with steam driven engines.

[teoman]

Hi, thanks for the comment you are correct that maybe manipulating egr would be easier and could accomplish the same thing.


I first wanted to do water injection. Then i had a look at the benefits of warm air intakes. So for this project my initial idea was to just create a very controllable warm air intake.

I am good with code and electronics, so the injection and the algorithm was very easy to implement for me.

I am not a huge fan of egr as it ads a lot of soot to the engine, and mine has managed to block itself which i will have to address at some point.


I may manipulate the egr aswell at some point if i find it beneficial (to limit water consumption or if the exhaust gasses have some mpg benefit).

Oh and i am not adding steam to the egr. I just thought that the egr mechanism is well enough engineered that it reaches all cylinders. So my steam will also reach all cylinders if introduction point is the same.