Vaporization
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The vaporization of liquefied gas absorbs heat, which can lower the ambient temperature to below 0 degrees. At this point, will the vaporized gas liquefy again due to the cold? After the liquefied gas vaporizes and reaches a certain pressure, if the gas continues to expand and the pressure drops, will heat still be absorbed at that point, even to the point of lowering the ambient temperature below 0 degrees? Could there be a master to give guidance! Very confused; it’s best to have experience in handling liquefied gases on-site!
I’m not sure if a counterfeit version of the explanation can make things clear: lol It’s better to set certain conditions for your question first; equilibrium between the gas phase and the liquid phase requires such conditions. For a saturated fluid, its phase change is influenced by changes in external conditions, representing a state of equilibrium to a certain extent. Changes in pressure or temperature can cause changes in the phase state. Oh, there is another factor here as well: \"heat\" cannot be ignored; it is the absorption or release of heat that enables phase changes.
Taking a liquefied gas leak as an example, there is equilibrium when no leak occurs; once a leak happens, the vaporization of the liquefied gas absorbs heat, causing the ambient temperature to drop. Will the liquid that has already vaporized condense? For gas buffer tanks, it is necessary to adjust the pressure for reduction; if the pressure is lowered from 10 kilograms to 1 kilogram, does the gas still need to absorb heat?
Expansion always absorbs heat. This includes expansion from the liquid phase to the gas phase, and expansion as pressure decreases from high to low in the gas phase. For example, the vaporization of liquid nitrogen absorbs heat, and the process of releasing nitrogen gas under 15 Mpa in a bottle also absorbs heat; however, if this process occurs slowly, it may not be noticeable
Study the gas-liquid equilibrium of water and water vapor, and you’ll understand. Below the critical temperature, the spontaneous vaporization of a liquid indicates that the partial pressure of the gas phase is lower than the saturated vapor pressure. When saturation is reached, liquefaction and vaporization of the gas occur in equilibrium; with no changes in the surroundings and no external work applied, this state remains unchanged.
Basically, when a high-pressure liquid leaks out, it absorbs heat, causing the pressure to drop and the liquid to turn into a gas. If it is to return from a gaseous state to a liquid state, compression is required (compression generates high temperatures, and heat must also be removed). ------------------------------------------------------------- Will the absorption of heat drop to 0°C? The answer is yes; propylene that leaks out will freeze...
Gas-liquid equilibrium, energy conservation – it’s better to read more books on these topics rather than get stuck on them.
Generally, liquefied gases have very low vaporization temperatures, often well below zero degrees. Although the absorption of heat during vaporization causes the ambient temperature to drop to below zero, this temperature is not sufficient for the vaporized gas to condense back into a liquid. There’s generally no need to worry about this, but there is still a slight issue: as the ambient temperature drops due to heat absorption, frost can form on the vaporizer, which can affect its efficiency. Therefore, it’s best to clean the vaporizer.
I think you’re overcomplicating things here; that’s not the key point. If that were the case, gases could be condensed at zero degrees, but that’s unlikely. Only a very small portion would be condensed, right? Water vapor has a significant impact, I guess
It will not vaporize as long as it reaches the liquefaction temperature.