Chemical Engineering Exam > Chemical Engineering Questions > For evaporators and condensers, for the given...
Start Learning for Free
For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow is
- a)Does not depend on counter flow
- b)Smaller than counter flow
- c)Greater than counter flow
- d)Equal to counter flow
Correct answer is option 'D'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
For evaporators and condensers, for the given conditions, the logarith...
The temperature of one of the fluid remains constant during the flow passage.
Most Upvoted Answer
For evaporators and condensers, for the given conditions, the logarith...
Logarithmic Mean Temperature Difference (LMTD)
The logarithmic mean temperature difference (LMTD) is a key parameter used in the design and analysis of heat exchangers, particularly evaporators and condensers. It represents the average temperature difference between the hot and cold fluids over the length of the heat exchanger.
Parallel Flow and Counter Flow
In a parallel flow heat exchanger, the two fluids flow in the same direction, entering at the same end and exiting at the other end. On the other hand, in a counter flow heat exchanger, the two fluids flow in opposite directions, entering at opposite ends and exiting at the same end.
Calculation of LMTD
The LMTD is calculated using the formula:
LMTD = (ΔT1 - ΔT2) / ln(ΔT1 / ΔT2)
where ΔT1 is the temperature difference at one end of the heat exchanger and ΔT2 is the temperature difference at the other end.
Comparison between LMTD in Parallel Flow and Counter Flow
In parallel flow, the temperature difference remains constant throughout the length of the heat exchanger, as the two fluids are moving in the same direction. Therefore, ΔT1 and ΔT2 are equal, resulting in a logarithmic mean temperature difference of zero.
On the other hand, in counter flow, the temperature difference changes along the length of the heat exchanger. Initially, the temperature difference is high, but it decreases as the hot and cold fluids approach each other. As a result, ΔT1 is greater than ΔT2, leading to a positive LMTD.
Conclusion
From the above discussion, it is clear that the logarithmic mean temperature difference for parallel flow is zero, while for counter flow it is positive. Therefore, the correct answer is option 'D', which states that the LMTD for parallel flow is equal to counter flow.
The logarithmic mean temperature difference (LMTD) is a key parameter used in the design and analysis of heat exchangers, particularly evaporators and condensers. It represents the average temperature difference between the hot and cold fluids over the length of the heat exchanger.
Parallel Flow and Counter Flow
In a parallel flow heat exchanger, the two fluids flow in the same direction, entering at the same end and exiting at the other end. On the other hand, in a counter flow heat exchanger, the two fluids flow in opposite directions, entering at opposite ends and exiting at the same end.
Calculation of LMTD
The LMTD is calculated using the formula:
LMTD = (ΔT1 - ΔT2) / ln(ΔT1 / ΔT2)
where ΔT1 is the temperature difference at one end of the heat exchanger and ΔT2 is the temperature difference at the other end.
Comparison between LMTD in Parallel Flow and Counter Flow
In parallel flow, the temperature difference remains constant throughout the length of the heat exchanger, as the two fluids are moving in the same direction. Therefore, ΔT1 and ΔT2 are equal, resulting in a logarithmic mean temperature difference of zero.
On the other hand, in counter flow, the temperature difference changes along the length of the heat exchanger. Initially, the temperature difference is high, but it decreases as the hot and cold fluids approach each other. As a result, ΔT1 is greater than ΔT2, leading to a positive LMTD.
Conclusion
From the above discussion, it is clear that the logarithmic mean temperature difference for parallel flow is zero, while for counter flow it is positive. Therefore, the correct answer is option 'D', which states that the LMTD for parallel flow is equal to counter flow.
|
Explore Courses for Chemical Engineering exam
|
|
For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer?
Question Description
For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? for Chemical Engineering 2024 is part of Chemical Engineering preparation. The Question and answers have been prepared according to the Chemical Engineering exam syllabus. Information about For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Chemical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer?.
For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? for Chemical Engineering 2024 is part of Chemical Engineering preparation. The Question and answers have been prepared according to the Chemical Engineering exam syllabus. Information about For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Chemical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer?.
Solutions for For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Chemical Engineering.
Download more important topics, notes, lectures and mock test series for Chemical Engineering Exam by signing up for free.
Here you can find the meaning of For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference for parallel flow isa)Does not depend on counter flowb)Smaller than counter flowc)Greater than counter flowd)Equal to counter flowCorrect answer is option 'D'. Can you explain this answer? tests, examples and also practice Chemical Engineering tests.
|
|
Explore Courses for Chemical Engineering exam
|
|
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