*Yes vapor is boiling.
*I acknowledged not knowing what the heat absorption difference is between water and alcohol.
*Evaporation does make things cooler. When a liquid turns to gas it obsorbs heat. It's primary principle of refrigeration. It's what happens when we sweat.
*Liquids expand dramatically when the turn to gaseous state.
*Put an ounce of water in a tray along side of another tray with an ounce of alcohol in it. The alcohol will vaporize in a fraction of the time the water will. Reason is it vaporizes at much lower temperature than water. Doesn't matter if it aborbs more heat per ounce or not. The faster it vaporizeds the faster it removes heat.
Please study your subject before replying. I'm not the only one saying you are wrong. SkeeterSkeeter is quoting your statements are mine and telling you the same thing I've told you.
Originally Posted by SkeeterSkeeter
My 2 cents, is first lets get damn NASA in here to straiten this all out.
Second, IMHO I think that the pressure would rise as the temperature does. Using the ideal gas law we see that (Pressure * Volume) = (Number of Moles * .021 * Temperature). For us inside a heat pipe we hold Volume, Number of Moles, and of course the constant (R = .021) constant. So this means for a heat pipe Pressure is directly related to Temperature.
But, this still does not take into account the liquid (not a gas obviously) so it does not fall under this ideal gas law.
But, As the liquid evaporates it becomes a gas giving more pressure, raising the temperature (of the GAS!; which has its heat spread to other object like the heat pipe walls) But then as the gas rises it cools again as it gives heat to the walls, lowering the temperature of the gas (hopefully condensing it).
So at some points the temperature may rise with the pressure, but as soon as that extra temperature leaves through the pipe walls the pressure drops back again. So I guess at some points it is normal (at a base pressure; initial filling pressure), but for it to work it has to lower its pressure to have liquid evaporate, then high pressure/ or cold to condense it.
You are quoting what billbartuska said, not what I said. All of the green text are his statements. Please read my original post #48. I said basically the same thing you are saying; that when the liquid vaporizes it expands and increases the pressure in heatpipe.Edited by doyll - 2/27/13 at 5:25am