In a processing plant, waste heat is to be recovered from a hot oil stream into a cold water stream using a parallel-flow heat exchanger with 0.75 effectiveness. The hot oil enters the heat exchanger at 285 °C with a mass flow rate of 25.0 kg/min while the cold water flows into the heat exchanger at 35 °C with a mass flow rate of 48 kg/min. The specific heat capacities of the oil and the water are 2.2 kl/kg.K and 4.2 ku/kg.K, respectively. The convective heat transfer coefficient on the oil side of the heat exchanger is 58 W/m2.K and that on the water side is 102 w/m².K. Neglect any thermal resistance at the heat transfer wall separating the oil and water streams in the heat exchanger. (a) Calculate the outlet temperatures of the oil and cold water streams in the heat exchanger. (b) Find the number of transfer units (N) of the heat exchanger. (c) Determine the heat transfer area required for the heat exchanger. It is given that for a parallel flow heat exchanger, the effectiveness (e) and the Number of Transfer Units (N) are related by the expression, 1-e-N(1+D) E = [1+ D] where D =- (mc)min (me)max UA N = - (me)min A = heat transfer area, U = overall heat transfer coefficient, m = mass flow rate and c = specific heat capacity.
In a processing plant, waste heat is to be recovered from a hot oil stream into a cold water stream using a parallel-flow heat exchanger with 0.75 effectiveness. The hot oil enters the heat exchanger at 285 °C with a mass flow rate of 25.0 kg/min while the cold water flows into the heat exchanger at 35 °C with a mass flow rate of 48 kg/min. The specific heat capacities of the oil and the water are 2.2 kl/kg.K and 4.2 ku/kg.K, respectively. The convective heat transfer coefficient on the oil side of the heat exchanger is 58 W/m2.K and that on the water side is 102 w/m².K. Neglect any thermal resistance at the heat transfer wall separating the oil and water streams in the heat exchanger. (a) Calculate the outlet temperatures of the oil and cold water streams in the heat exchanger. (b) Find the number of transfer units (N) of the heat exchanger. (c) Determine the heat transfer area required for the heat exchanger. It is given that for a parallel flow heat exchanger, the effectiveness (e) and the Number of Transfer Units (N) are related by the expression, 1-e-N(1+D) E = [1+ D] where D =- (mc)min (me)max UA N = - (me)min A = heat transfer area, U = overall heat transfer coefficient, m = mass flow rate and c = specific heat capacity.
Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
8th Edition
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Kreith, Frank; Manglik, Raj M.
Chapter7: Forced Convection Inside Tubes And Ducts
Section: Chapter Questions
Problem 7.49P
Related questions
Concept explainers
Heat Exchangers
Heat exchangers are the types of equipment that are primarily employed to transfer the thermal energy from one fluid to another, provided that one of the fluids should be at a higher thermal energy content than the other fluid.
Heat Exchanger
The heat exchanger is a combination of two words ''Heat'' and ''Exchanger''. It is a mechanical device that is used to exchange heat energy between two fluids.
Question
![In a processing plant, waste heat is to be recovered from a hot oil stream into a cold
water stream using a parallel-flow heat exchanger with 0.75 effectiveness. The hot oil
enters the heat exchanger at 285 °C with a mass flow rate of 25.0 kg/min while the
cold water flows into the heat exchanger at 35 °C with a mass flow rate of 48 kg/min.
The specific heat capacities of the oil and the water are 2.2 kJ/kg.K and 4.2 kl/kg.K,
respectively. The convective heat transfer coefficient on the oil side of the heat
exchanger is 58 W/m?.K and that on the water side is 102 w/m².K. Neglect any
thermal resistance at the heat transfer wall separating the oil and water streams in
the heat exchanger.
(a) Calculate the outlet temperatures of the oil and cold water streams in the heat
exchanger.
(b) Find the number of transfer units (N) of the heat exchanger.
(c) Determine the heat transfer area required for the heat exchanger.
It is given that for a parallel flow heat exchanger, the effectiveness (e) and the
Number of Transfer Units (N) are related by the expression,
1-e-N(1+D)
E = -
[1 + D]
(mc)min
(mc)max
UA
N =
(me)min
A = heat transfer area, U = overall heat transfer
where D =
coefficient, m = mass flow rate andc = specific heat capacity.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fcae0633b-c53e-472a-9f14-874267a390a4%2Fd9cbe4f4-e441-486c-96f9-349ce727fe17%2Ft09vdl_processed.jpeg&w=3840&q=75)
Transcribed Image Text:In a processing plant, waste heat is to be recovered from a hot oil stream into a cold
water stream using a parallel-flow heat exchanger with 0.75 effectiveness. The hot oil
enters the heat exchanger at 285 °C with a mass flow rate of 25.0 kg/min while the
cold water flows into the heat exchanger at 35 °C with a mass flow rate of 48 kg/min.
The specific heat capacities of the oil and the water are 2.2 kJ/kg.K and 4.2 kl/kg.K,
respectively. The convective heat transfer coefficient on the oil side of the heat
exchanger is 58 W/m?.K and that on the water side is 102 w/m².K. Neglect any
thermal resistance at the heat transfer wall separating the oil and water streams in
the heat exchanger.
(a) Calculate the outlet temperatures of the oil and cold water streams in the heat
exchanger.
(b) Find the number of transfer units (N) of the heat exchanger.
(c) Determine the heat transfer area required for the heat exchanger.
It is given that for a parallel flow heat exchanger, the effectiveness (e) and the
Number of Transfer Units (N) are related by the expression,
1-e-N(1+D)
E = -
[1 + D]
(mc)min
(mc)max
UA
N =
(me)min
A = heat transfer area, U = overall heat transfer
where D =
coefficient, m = mass flow rate andc = specific heat capacity.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps with 3 images
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi…
Mechanical Engineering
ISBN:
9781305387102
Author:
Kreith, Frank; Manglik, Raj M.
Publisher:
Cengage Learning
Refrigeration and Air Conditioning Technology (Mi…
Mechanical Engineering
ISBN:
9781305578296
Author:
John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:
Cengage Learning
Principles of Heat Transfer (Activate Learning wi…
Mechanical Engineering
ISBN:
9781305387102
Author:
Kreith, Frank; Manglik, Raj M.
Publisher:
Cengage Learning
Refrigeration and Air Conditioning Technology (Mi…
Mechanical Engineering
ISBN:
9781305578296
Author:
John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:
Cengage Learning