How to Calculate and Solve for Work of Evapouration (wet steam) | Enthalpy
Last Updated on May 27, 2022
The work of evapouration(wet steam) is illustrated by the image below.
To compute for work of evapouration, three essential parameters are needed and these parameters are Specific Volume of Dry Gas (vg), Specific Volume of Wet Steam (vf), Pressure of Gas (P) and Dryness Fraction(x).
The formula for calculating work of evapouration:
WE = Px(vg – Vf)
Where:
WE = Work of Evapouration (Wet Steam)
vg = Specific Volume of Dry Gas
vf = Specific Volume of Wet Steam
P = Pressure of Gas
x = Dryness Fraction
Given an example;
Find the work of evapouration when the specific volume of dry gas is 12, the specific volume of wet steam is 0, the pressure of gas is 5 and the dryness fraction is 8.
This implies that;
vg = Specific Volume of Dry Gas = 12
vf = Specific Volume of Wet Steam = 0
P = Pressure of Gas = 5
x = Dryness Fraction = 8
WE = Px(vg – Vf)
WE = 5 x 8 x (12 – 0)
WE = 5 x 8 x 12
WE = 480
Therefore, the work of evapouration is 480J.
Calculating the Specific Volume of Dry Gas when the Work of Evapouration, the Specific Volume of Wet Steam and the Pressure of Gas is Given.
vg = WE / Px + vf
Where:
vg = Specific Volume of Dry Gas
WE = Work of Evapouration
vf = Specific Volume of Wet Steam
P = Pressure of Gas
x = Dryness Fraction
Given an example;
With work of evapouration as 40, the specific volume of wet steam as 0, the pressure of gas as 10 and the dryness fraction as 2. Find the specific volume of dry gas?
This implies that;
WE = Work of Evapouration = 40
vf = Specific Volume of Wet Steam = 0
P = Pressure of Gas = 10
x = Dryness Fraction = 2
vg = WE / Px + vf
vg = 40 / 10(2) + 0
vg = 40 / 20 + 0
vg = 2
Therefore, the specific volume of dry gas is 2.
Calculating the Pressure of Gas when the Work of Evapouration, the Specific Volume of Dry Gas and the Specific Volume of Wet Steam is Given.
P = WE / x(vg – vf)
Where:
P = Pressure of Gas
WE = Work of Evapouration
vg = Specific Volume of Dry Gas
vf = Specific Volume of Wet Steam
x = Dryness Fraction
Given an example;
Find the pressure of gas when the work of evapouration is 60, the specific volume of dry gas is 15, the specific volume of wet steam is 0 and the dryness fraction is 3.
This implies that;
WE = Work of Evapouration = 60
vg = Specific Volume of Dry Gas = 15
vf = Specific Volume of Wet Steam = 0
x = Dryness Fraction = 3
P = WE / x(vg – vf)
P = 60 / 3(15 – 0)
P = 60 / 45
P = 1.33
Therefore, the pressure of gas is 1.33.
Calculating the Dryness Fraction when the Work of Evapouration, the Specific Volume of Dry Gas, the Specific Volume of Wet Steam and the Pressure of Gas is Given.
x = WE / P(vg – vf)
Where:
x = Dryness Fraction
WE = Work of Evapouration (Wet Steam)
vg = Specific Volume of Dry Gas
vf = Specific Volume of Wet Steam
P = Pressure of Gas
Given an example;
Find the dryness fraction when the work of evapouration is 40, the specific volume of dry gas is 12, the specific volume of wet steam is 0 and the pressure of gas is 3.
This implies that;
WE = Work of Evapouration (Wet Steam) = 40
vg = Specific Volume of Dry Gas = 12
vf = Specific Volume of Wet Steam = 0
P = Pressure of Gas = 3
x = WE / P(vg – vf)
x = 40 / 3(12 – 0)
x = 40 / 36
x = 1.11
Therefore, the dryness fraction is 1.11.
Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the work of evapouration.
To get the answer and workings of the work of evapouration using the Nickzom Calculator – The Calculator Encyclopedia. First, you need to obtain the app.
You can get this app via any of these means:
Web – https://www.nickzom.org/calculator-plus
To get access to the professional version via web, you need to register and subscribe to have utter access to all functionalities.
You can also try the demo version via https://www.nickzom.org/calculator
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Once, you have obtained the calculator encyclopedia app, proceed to the Calculator Map, then click on Materials and Metallurgical under Engineering.
Now, Click on Chemical Reaction Thermodynamics under Materials and Metallurgical
Now, Click on Enthalpy under Chemical Reaction Thermodynamics
Now, Click on Work of Evapouration(wet steam) under Enthalpy
The screenshot below displays the page or activity to enter your values, to get the answer for the work of evapouration according to the respective parameter which is the Specific Volume of Dry Gas (vg), Specific Volume of Wet Steam (vf), Pressure of Gas (P) and Dryness Fraction (x).
Now, enter the values appropriately and accordingly for the parameters as required by the Specific Volume of Dry Gas (vg) is 12, Specific Volume of Wet Steam (vf) is 0, Pressure of Gas (P) is 5 and Dryness Fraction (x) is 8.
Finally, Click on Calculate
As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the work of evapouration and presents the formula, workings and steps too.