How to Calculate and Solve for Internal Energy of Steam | Enthalpy
Last Updated on June 6, 2022
The internal energy of steam is illustrated by the image below.
To compute for internal energy of steam, four essential parameter are needed and these parameters are Enthalpy of Wet Steam (h), Specific Volume of Gas (vg), Pressure (P) and J.
The formula for calculating internal energy of steam:
U = h – Pvg / J
Where:
U = Internal Energy of Steam
h = Enthalpy of Wet Steam
vg = Specific Volume of Gas
P = Pressure
Given an example;
Find the internal energy of steam when the enthalpy of wet steam is 20, the specific volume of gas is 14 and the pressure is 8.
This implies that;
h = Enthalpy of Wet Steam = 20
vg = Specific Volume of Gas = 14
P = Pressure = 8
U = h – Pvg / J
U = 20 – 8 x 14 / 1
U = 20 – 112 / 1
U = 20 – 112
U = -92
Therefore, the internal energy of steam is -92J.
Calculating the Enthalpy of Wet Steam when the Internal Energy of Steam, the Specific Volume of Gas and the Pressure is Given.
h = U + Pvg / J
Where:
h = Enthalpy of Wet Steam
U = Internal Energy of Steam
vg = Specific Volume of Gas
P = Pressure
Let’s solve an example;
Given that the internal energy of steam is 28, the specific volume of gas is 12 and the pressure is 8. Find the Enthalpy of wet steam?
This implies that;
U = Internal Energy of Steam = 28
vg = Specific Volume of Gas = 12
P = Pressure = 8
h = U + Pvg / J
h = 28 + 8(12) / 1
h = 28 + 96
h = 124
Therefore, the enthalpy of wet steam is 124J/Kg.
Calculating the Specific Volume of Gas when the Internal Energy of Steam, the Enthalpy of Wet Steam and the Pressure is Given.
vg = h – U / P x J
Where:
vg = Specific Volume of Gas
U = Internal Energy of Steam
h = Enthalpy of Wet Steam
P = Pressure
Let’s solve an example;
Find the specific volume of gas when the internal energy of steam is 10, the enthalpy of wet steam is 20 and the pressure is 4.
This implies that;
U = Internal Energy of Steam = 10
h = Enthalpy of Wet Steam = 20
P = Pressure = 4
vg = h – U / P x J
vg = 20 – 10 / 4 x 1
vg = 10 / 4 x 1
vg = 2.5 x 1
vg = 2.5
Therefore, the specific volume of gas is 2.5J/Kg.
Calculating the Pressure when the Internal Energy of Steam, the Enthalpy of Wet Steam and the Specific Volume of Gas is Given.
P = h – U / vg x J
Where:
P = Pressure
U = Internal Energy of Steam
h = Enthalpy of Wet Steam
vg = Specific Volume of Gas
Let’s solve an example;
Find the pressure when the internal energy of steam is 18, the enthalpy of wet steam is 14 and the specific volume of gas is 6.
This implies that;
U = Internal Energy of Steam = 18
h = Enthalpy of Wet Steam = 14
vg = Specific Volume of Gas = 6
P = h – U / vg x J
P = 14 – 18 / 6 x 1
P = -4 / 6 x 1
p = -0.667 x 1
P = -0.667
Therefore, the pressure is -0.667.
Nickzom Calculator – The Calculator Encyclopedia is capable of calculating the internal energy of steam.
To get the answer and workings of the internal energy of steam 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
Android (Paid) – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator
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Apple (Paid) – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8
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 Internal Energy of Steam under Enthalpy
The screenshot below displays the page or activity to enter your values, to get the answer for the internal energy of steam according to the respective parameter which is the Enthalpy of Wet Steam (h), Specific Volume of Gas (vg), Pressure (P) and J.
Now, enter the values appropriately and accordingly for the parameters as required by the Enthalpy of Wet Steam (h) is 20, Specific Volume of Gas (vg) is 14, Pressure (P) is 8 and J is 1.
Finally, Click on Calculate
As you can see from the screenshot above, Nickzom Calculator– The Calculator Encyclopedia solves for the internal energy of steam and presents the formula, workings and steps too.
