Is it possible to calculate water/steam temperature and pressure in closed container with formulas?

I am quite noob, with physics. If we boil water in closed container, it will perform steam. Is it possible to calculate if water is 200 celcius, how much steam we generate in certain point and how much pressure it will generate to container? Is there a (simplified) formula which could be used?

Also will the process halt, after certain pressure is gained or will the process continue until container break?

Why I ask, is that I would like to put this to game, but simplified, yet quite believable. And if you can, explain it to me like I would be five, thanks, with example something like:

If we assume that there was 10L water and 10L air in closed container, is it possible to calculate how much energy we put in system, that it will be 200 C water and how much we have steam, how much is pressure and temperature (is it 200)?

Or could you point me out where to read this without having 11th physics degree?

  • 1
    $\begingroup$ Working out a full answer is beyond me but the second question is not to hard to address. The pressure and temperature will keep rising. If you keep increasing pressure and temperature, you will transition through the critical point(674K, 220 bar) of water, after which you can no longer differentiate liquid and gaseous phase. You also enter at very high temperatures(T>3000K) a point, where the water molecules dissociate to Hydrogen and Oxygen. And if you go to really crazy temperatures you should end up with plasma (T>10000K). Limiting the range for allowed values might be a good idea. $\endgroup$
    – Hans Wurst
    Feb 14 at 10:18
  • $\begingroup$ If you heat the contents to 200 C (and stop adding heat), the system will reach equilibrium. You can accurately determine the amount of heat that was added, the pressure in the container, and the amount of water that converted from liquid to vapor. But it is not described by a simple formula, and you will have to study thermodynamics to understand how this is done. $\endgroup$ Feb 14 at 13:02
  • $\begingroup$ For your game, what are your input variables for your calculation? In other words, you must know certain things in order to do a calculation. What are those known values? $\endgroup$ Feb 14 at 19:04
  • $\begingroup$ For my game, the closed container contains water X amount, and air Y amount. Pressure is at start 1 atm. Liquid is a certain temp T, and then I would like to apply heat on water, and measure how much pressure is in container, how much temp is water, and how much temp is steam. Thats it. (and I was planning to kinda ignore starting air). But container is not full. $\endgroup$
    – raPHPid
    Feb 14 at 19:24

When water is heated in a closed container, its temperature rises and as some of that water evaporates into the container, the pressure inside that container goes up. How much pressure you get depends on the temperature of the container and on the physical details of the behavior of water in equilibrium with steam.

There is a graphic tool called a Mollier diagram for water-steam which is a chart with a bunch of curves on it which capture all those details and their dependence on pressure and temperature. The answers to questions like yours can be conveniently read right off the chart with a straightedge. Engineers use that chart routinely to solve problems like this.


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