Mechanical Engineering Exam > Mechanical Engineering Questions > In a counter-flow heat exchanger, water is he...
Start Learning for Free
In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is
[2007]
- a)0.104
- b)0.022
- c)10.4
- d)21.84
Correct answer is option 'D'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
In a counter-flow heat exchanger, water is heated at the rate of 1.5 k...
Heat exchanger is a counterflow type.
= 21.83 m2.
= 21.83 m2.
Most Upvoted Answer
In a counter-flow heat exchanger, water is heated at the rate of 1.5 k...
°C to 80°C by hot air flowing at a rate of 2 kg/s. The specific heat capacity of water is 4.18 kJ/kg°C. Calculate the heat transfer rate in the heat exchanger.
To calculate the heat transfer rate in the heat exchanger, we can use the formula:
Q = m * c * ΔT
Where:
Q = heat transfer rate (in kW)
m = mass flow rate (in kg/s)
c = specific heat capacity (in kJ/kg°C)
ΔT = change in temperature (in °C)
Given:
m_water = 1.5 kg/s (mass flow rate of water)
c_water = 4.18 kJ/kg°C (specific heat capacity of water)
ΔT_water = (80 - 40) °C = 40 °C (change in temperature of water)
m_air = 2 kg/s (mass flow rate of air)
c_air = ? (specific heat capacity of air)
ΔT_air = ? (change in temperature of air)
Since we know the mass flow rate and change in temperature of the water, we can calculate the heat transfer rate for water:
Q_water = m_water * c_water * ΔT_water
Q_water = 1.5 kg/s * 4.18 kJ/kg°C * 40°C
Q_water = 250.8 kJ/s = 250.8 kW
Next, we need to determine the change in temperature of the air. Since it is being heated, the change in temperature of the air will be the same as the change in temperature of the water:
ΔT_air = ΔT_water = 40 °C
Now, we can calculate the heat transfer rate for air using the same formula:
Q_air = m_air * c_air * ΔT_air
250.8 kW = 2 kg/s * c_air * 40°C
c_air = 250.8 kW / (2 kg/s * 40°C)
c_air = 3.135 kJ/kg°C
Therefore, the heat transfer rate in the counter-flow heat exchanger is 250.8 kW.
To calculate the heat transfer rate in the heat exchanger, we can use the formula:
Q = m * c * ΔT
Where:
Q = heat transfer rate (in kW)
m = mass flow rate (in kg/s)
c = specific heat capacity (in kJ/kg°C)
ΔT = change in temperature (in °C)
Given:
m_water = 1.5 kg/s (mass flow rate of water)
c_water = 4.18 kJ/kg°C (specific heat capacity of water)
ΔT_water = (80 - 40) °C = 40 °C (change in temperature of water)
m_air = 2 kg/s (mass flow rate of air)
c_air = ? (specific heat capacity of air)
ΔT_air = ? (change in temperature of air)
Since we know the mass flow rate and change in temperature of the water, we can calculate the heat transfer rate for water:
Q_water = m_water * c_water * ΔT_water
Q_water = 1.5 kg/s * 4.18 kJ/kg°C * 40°C
Q_water = 250.8 kJ/s = 250.8 kW
Next, we need to determine the change in temperature of the air. Since it is being heated, the change in temperature of the air will be the same as the change in temperature of the water:
ΔT_air = ΔT_water = 40 °C
Now, we can calculate the heat transfer rate for air using the same formula:
Q_air = m_air * c_air * ΔT_air
250.8 kW = 2 kg/s * c_air * 40°C
c_air = 250.8 kW / (2 kg/s * 40°C)
c_air = 3.135 kJ/kg°C
Therefore, the heat transfer rate in the counter-flow heat exchanger is 250.8 kW.
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
In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer?
Question Description
In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. 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 In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. 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 In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer?.
In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. 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 In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. 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 In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer?.
Solutions for In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. 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 In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer?, a detailed solution for In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer? has been provided alongside types of In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice In a counter-flow heat exchanger, water is heated at the rate of 1.5 kg/s from 40°C to 80°C by an oil entering at 120°C and leaving at 60°C. The specific heats of water and oil are 4.2 kJ/ kgK and 2 kJ/kgK, respectively. The overall heat transfer coefficient is 400 W/m2K.The required heat transfer surface area (in m2) is[2007]a)0.104b)0.022c)10.4d)21.84Correct answer is option 'D'. 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