How do I get water vapor fraction and pressure?

AI Thread Summary
To determine the vapor fraction and pressure of water in a thermochemical heat storage device after removing a specific mass of water, one can use steam tables that correlate temperature and pressure with vapor properties. The simulation requires knowledge of the initial conditions, including temperature (50°C - 500°C) and pressure (1-20 atm). By applying the principles of thermodynamics, particularly the relationship between pressure, force, and area, one can estimate the changes in vapor state as water is removed. Empirical functions or comprehensive tables for vapor fraction are sought to facilitate accurate modeling in Matlab. Accessing established steam tables in thermodynamic literature is recommended for precise calculations.
jason_85
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Hi Guys,

I'm building a numerical Matlab simulation of a thermochemical heat storage device (using zeolites), and need to update the state of water vapor in the device at every time step. My question is, if I have an empty space with water in it, with temperature, pressure, density, etc. all known, how can I get the vapor fraction and pressure of that same boiler after removing x kilograms of water from it (and not replacing it with anything)?

The temperature range is about 50°C - 500°C and pressure should be between 1-20atm.

Ideally, I would love to get an empirical function for Vapor fraction of water - or at least a comprehensive table I can index in my simulation, so far I haven't been able to find anything myself.

Help would be greatly appreciated!
 
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jason_85 said:
Hi Guys,

I'm building a numerical Matlab simulation of a thermochemical heat storage device (using zeolites), and need to update the state of water vapor in the device at every time step. My question is, if I have an empty space with water in it, with temperature, pressure, density, etc. all known, how can I get the vapor fraction and pressure of that same boiler after removing x kilograms of water from it (and not replacing it with anything)?

The temperature range is about 50°C - 500°C and pressure should be between 1-20atm.

Ideally, I would love to get an empirical function for Vapor fraction of water - or at least a comprehensive table I can index in my simulation, so far I haven't been able to find anything myself.

Help would be greatly appreciated!



I don't really know the answer but maybe I can kind of give you some hints.

pressuve= force/area
force= Newton
if you are going to multuply you kilograms by 9.81m/s2(squered)= gravity, you are going to get Newtons.

if you are going to get rid of watter you are going to increase steam space (area).
so maybe using this somehow u can determin pressure differential.

Forse= Newton= kg x gravity.
from there you can maybe determin how mutch steam you got. that all will be under constant temperature.
I just started 4th class power engineering so I am not really sure what I am talking about.
when I will finish first year I will help out more.
 
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how can I get the vapor fraction
by using steam table you can know the pressure on water and its corresponding temperature and amount of vapor generated.
you can find steam table on most thermodydamic books.
 
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