Mechanical Engineering Exam > Mechanical Engineering Questions > A sample of steam from a boiler drum at 3 MP...
Start Learning for Free
A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.
Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 bar
hf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 bar
Correct answer is '0.95'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Most Upvoted Answer
A sample of steam from a boiler drum at 3 MPa is put through a thrott...
To solve this problem, we can use the First Law of Thermodynamics for a throttling process. The equation is:
h1 + V1^2/2 + gz1 + q - w = h2 + V2^2/2 + gz2
where:
h1 = enthalpy at state 1 (initial state in the boiler drum)
V1 = velocity at state 1 (initial state in the boiler drum)
g = acceleration due to gravity
z1 = elevation at state 1 (initial state in the boiler drum)
q = heat transfer
w = work transfer (usually negligible for throttling process)
h2 = enthalpy at state 2 (final state in the throttling calorimeter)
V2 = velocity at state 2 (final state in the throttling calorimeter)
z2 = elevation at state 2 (final state in the throttling calorimeter)
Since the velocity and elevation do not change in a throttling process, we can simplify the equation to:
h1 + q = h2
Given:
P1 = 3 MPa
P2 = 0.1 MPa
T2 = 120°C = 393.15 K
hf = 2676.2 kJ/kg
To find the quality (x) of the sample, we need to determine the enthalpy at state 1 (h1) and state 2 (h2). We can use the steam tables or a steam property calculator to find these values.
For state 1:
Using the steam tables or calculator at 3 MPa, we find:
h1 = 2786.2 kJ/kg (approximately)
For state 2:
Using the steam tables or calculator at 0.1 MPa and 120°C, we find:
h2 = 2676.2 kJ/kg (given)
Now, we can substitute these values into the simplified equation:
2786.2 kJ/kg + q = 2676.2 kJ/kg
Solving for q:
q = 2676.2 kJ/kg - 2786.2 kJ/kg
q = -110 kJ/kg
Since q is negative, it indicates that heat is being transferred out of the system. This means the sample is not saturated steam, but rather a mixture of liquid and vapor.
To find the quality (x), we can use the equation:
x = (h1 - hf) / (hfg)
Where:
hfg = hg - hf
Using the steam tables or calculator at 3 MPa, we find:
hg = 2836.7 kJ/kg (approximately)
Substituting the values into the equation:
x = (2786.2 kJ/kg - 2676.2 kJ/kg) / (2836.7 kJ/kg - 2676.2 kJ/kg)
x = 110 / 160.5
x ≈ 0.685
Therefore, the quality of the sample taken from the boiler is approximately 0.685.
h1 + V1^2/2 + gz1 + q - w = h2 + V2^2/2 + gz2
where:
h1 = enthalpy at state 1 (initial state in the boiler drum)
V1 = velocity at state 1 (initial state in the boiler drum)
g = acceleration due to gravity
z1 = elevation at state 1 (initial state in the boiler drum)
q = heat transfer
w = work transfer (usually negligible for throttling process)
h2 = enthalpy at state 2 (final state in the throttling calorimeter)
V2 = velocity at state 2 (final state in the throttling calorimeter)
z2 = elevation at state 2 (final state in the throttling calorimeter)
Since the velocity and elevation do not change in a throttling process, we can simplify the equation to:
h1 + q = h2
Given:
P1 = 3 MPa
P2 = 0.1 MPa
T2 = 120°C = 393.15 K
hf = 2676.2 kJ/kg
To find the quality (x) of the sample, we need to determine the enthalpy at state 1 (h1) and state 2 (h2). We can use the steam tables or a steam property calculator to find these values.
For state 1:
Using the steam tables or calculator at 3 MPa, we find:
h1 = 2786.2 kJ/kg (approximately)
For state 2:
Using the steam tables or calculator at 0.1 MPa and 120°C, we find:
h2 = 2676.2 kJ/kg (given)
Now, we can substitute these values into the simplified equation:
2786.2 kJ/kg + q = 2676.2 kJ/kg
Solving for q:
q = 2676.2 kJ/kg - 2786.2 kJ/kg
q = -110 kJ/kg
Since q is negative, it indicates that heat is being transferred out of the system. This means the sample is not saturated steam, but rather a mixture of liquid and vapor.
To find the quality (x), we can use the equation:
x = (h1 - hf) / (hfg)
Where:
hfg = hg - hf
Using the steam tables or calculator at 3 MPa, we find:
hg = 2836.7 kJ/kg (approximately)
Substituting the values into the equation:
x = (2786.2 kJ/kg - 2676.2 kJ/kg) / (2836.7 kJ/kg - 2676.2 kJ/kg)
x = 110 / 160.5
x ≈ 0.685
Therefore, the quality of the sample taken from the boiler is approximately 0.685.
Free Test
FREE
| Start Free Test |
Community Answer
A sample of steam from a boiler drum at 3 MPa is put through a thrott...
P1 = 3MPa = 30bar
p2 = 0.1MPa = 1 bar
t2 = 120°C
h2 = 2676.2 + 20/50(2776.4 - 2676.2)
= 2716.3 kJ/kg
∴ h1 = h2
∴ h1 = 2716.3 at 30bar
If dryness fraction is
∴h1 = hg1 + xhfg1
Attention Mechanical Engineering Students!
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.
|
Explore Courses for Mechanical Engineering exam
|
|
Similar Mechanical Engineering Doubts
Top Courses for Mechanical EngineeringView all
A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer?
Question Description
A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer?.
A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer?.
Solutions for A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering.
Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
Here you can find the meaning of A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer?, a detailed solution for A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? has been provided alongside types of A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A sample of steam from a boiler drum at 3 MPa is put through a throttling calorimeter in which the pressure and temperature are found to be 0.1 MPa, 120° C. Find the quality of the sample taken from the boiler.Take hf = 2676.2 kJ/kg & hg = 2776.4 kJ/kg corresponding to 1 barhf = 1008.4 kJ/kg & ht = 1793.9 kJ/kg corresponding to 30 barCorrect answer is '0.95'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
|
|
Explore Courses for Mechanical Engineering exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup