"The molecules in liquid water are held together by relatively strong hydrogen bonds, and its standard enthalpy change of vaporisation, 40.8 kJ/mol, is more than five times the energy required to heat the same quantity of water from 0 °C to 100 °C (cp = 75.3 JK−1mol−1)."
So my question:
Water vaporizing when it hits the center bolt of the turbo will remove 5 times the heat that water would normally remove when heated a full 212 degrees (by the turbo - although our coolant is heated from say 190 degrees [normal operating temperature] to 255 degrees [65 degree difference with water under pressure so it does not vaporize] during an overheat situation) .... I think I am starting to understand where you are going with this .... bear with me, I am an EE not an ME or CE or fluid dynamics expert
A modern inkjet printer uses a piezo-electric print head to control the size and rate of drops for ink .... I believe it is controllable in picoLiter increments .... very precise control. Could a similar method be employed with water placed very very close to the center bolt of the tubo as posted earlier?
My other question is as follows: The heat pulled from the turbo must go somewhere (removed by the vapor - the CAC would receive the vapor first, then it would be drawn into the engine ....) and ultimately it would end up in the exhaust?
I like round numbers and imperial units, as I am accustomed to it. When water evaporates, energy is absorbed. The endothermic process results in decreases air temp. a pound of water, completely evaporated, consumes 1000 BTU. This is almost unchanged across the pressure spectrum, of 2-3 bar, typical turbo compression.
The turbo takes air at 100 degrees, and compresses it. This compression creates very hot dense air, at 450 degrees, (adiabatic compession). Well above the BP of the water at 2 atm (BP=250 degrees) This is a tremendous evaporation opportunity waiting for a mechanism.
We all know water readily evaporates much more readily past its BP. Heating a pan of water demonstrates that.
Back to evaporation. Taking water at it's boiling point and evaporating it at its boiling point, requires 1000 BTU's for every pound. Compare this to the energy required to heat a pound of water, without evaporating it. 1 btu/lb F. IOW, the energy required to evaporate a pound of water, is exactly equivalent to heating it 1000 degrees (same as what you said Mark), without a state change. Impossible for all practical purposes to do, but that demonstrates the power of evaporation.
The heat energy (BTU's) to do this has to come from somewhere. In the kitchen it is supplied by the burner. In the turbo, it comes from the hot air. That air cools as it trades it's energy for water vapor.
Constraints exist however. In our case, the most water that can be evaporated, is constrained by how much vaporous water that the air can hold, referred to as humidity. 100% RH limits us. Beyond that, you get condensation.
Not sure if I am just confusing you more, but the significance of the state change, from liquid to vapor, is not well understood. This is all nothing new. GE and other manufacturers have been using water 24/7 on many of there electricity producing engines for many years. For fuel savings.
I live in a place where I can survive out of doors in 125 degree heat, if I have a water supply. It is the only way I could do a 2 hour mountain bike ride today, after I post this. It has also saved the lives of many people here, as well as my dog. It is not the quick comfort feeling of cool water on the skin, it is the evaporation over the following 20 minutes that is cooling the skin.
With a water soaked long sleeved shirt, I feel like it is 85 degrees out, when I am riding 12 mph. My water loss is exponentially decreased, and my skin blood supply keeps my brain and internals from boiling. But don't try this if you live in the tropics. It doesn't work.
Compared to what we are looking at in terms of capacity in the turbo-diesel, this is an extremely mild form of evap cooling, .
Air....in the intake tract...is analogous to skin....in the above example.
(it does need mentioning, that most of the energy that evaporates the water from a cotton shirt, goes to lowering the surrounding air temperature, so the effect of cooling the skin is valid, but it is an inefficient use of water, UNLIKE contained evaporation withing the intake tract. All of the water get used for the intended purpose)
At home you can see this. soak a sock in rubbing alcohol (don't use the good scotch) and fit it over your hand. Now stick your hand out the window of a moving vehicle. You may just get mild frostbite. Yet much of the cooling is cooling the air around your hand, a waste. A residential "evaporative cooler" does this exactly. Pass relatively dry air over a wet mat, and you get cooler air in your house, albeit humid.
Back to the TD: as altitude increases, there is reduced humidity typically, making this more effective in the worst conditions for overheat.
If I haven't answered your question please ask it again