Heat Transfer in a heat exchanger.

  • Thread starter de312
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  • #1
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So this concept is confusing me.

You have a 20GPM, 150Degree F, 40PSIG water coming in to a heat exchanger through a 1" diameter pipe.

Chilled water is available for cooling from a 6" diameter line at 40 Degrees F, With a pressure of 110PSIG and a flow of 270GPM.

The original solution needs to be cooled from 150 degrees to 80 degrees exiting in a 1.5" line.

  1. The external vessel of the exchanger needs to be 316 stainless steel, any piping or tubing may be of any appropiate material as long as it is schedule 40.
  2. What would be the overall heat transfer coefficient. What would be the hoop stress with a safety factor of 2.0.
  3. Estimate chilled water flow requirements.
  4. What would be the size of the shell, and how many tubes and their size would be required to properly cool the liquid.

This is confusing me ~.~
 

Answers and Replies

  • #2
8
0
So this concept is confusing me.

You have a 20GPM, 150Degree F, 40PSIG water coming in to a heat exchanger through a 1" diameter pipe.

Chilled water is available for cooling from a 6" diameter line at 40 Degrees F, With a pressure of 110PSIG and a flow of 270GPM.

The original solution needs to be cooled from 150 degrees to 80 degrees exiting in a 1.5" line.

  1. The external vessel of the exchanger needs to be 316 stainless steel, any piping or tubing may be of any appropiate material as long as it is schedule 40.
  2. What would be the overall heat transfer coefficient. What would be the hoop stress with a safety factor of 2.0.
  3. Estimate chilled water flow requirements.
  4. What would be the size of the shell, and how many tubes and their size would be required to properly cool the liquid.

This is confusing me ~.~
 
  • #3
8
0
So this concept is confusing me.

You have a 20GPM, 150Degree F, 40PSIG water coming in to a heat exchanger through a 1" diameter pipe.

Chilled water is available for cooling from a 6" diameter line at 40 Degrees F, With a pressure of 110PSIG and a flow of 270GPM.

The original solution needs to be cooled from 150 degrees to 80 degrees exiting in a 1.5" line.

  1. The external vessel of the exchanger needs to be 316 stainless steel, any piping or tubing may be of any appropiate material as long as it is schedule 40.
  2. What would be the overall heat transfer coefficient. What would be the hoop stress with a safety factor of 2.0.
  3. Estimate chilled water flow requirements.
  4. What would be the size of the shell, and how many tubes and their size would be required to properly cool the liquid.

This is confusing me ~.~
 
  • #4
688
1
I would first ask which questions do you understand and which ones are confusing?

Much can be said about these topics - good to know where to start.
 
  • #5
8
0
I wanted to try and clarify this. If it is just a double tube simple heat exchanger like this shown here.

http://i56.tinypic.com/34znmti.png

*What is the calculation to calculate the heat transfer coefficient.
*How much surface area would be required between the two pipes for the solution to cool from 150 degrees to 80 degrees.
 
  • #6
8
0
I wanted to try and clarify this. If it is just a double tube simple heat exchanger like this shown here.

http://i56.tinypic.com/34znmti.png

*What is the calculation to calculate the heat transfer coefficient.
*How much surface area would be required between the two pipes for the solution to cool from 150 degrees to 80 degrees.
 
  • #7
8
0
I wanted to try and clarify this. If it is just a double tube simple heat exchanger like this shown here.

http://i56.tinypic.com/34znmti.png

*What is the calculation to calculate the heat transfer coefficient.
*How much surface area would be required between the two pipes for the solution to cool from 150 degrees to 80 degrees.
 
  • #8
rock.freak667
Homework Helper
6,223
31
For the value of U, I believe you need to use the fact that

[tex] \frac{1}{U} = \frac{1}{h_o} + \frac{1}{h_i}[/tex]

where ho is the outer heat transfer coefficient and hi is the inner heat transfer coefficient.

so essentially

[tex] \frac{1}{U} = \frac{1}{h_{cold}} + \frac{1}{h_{hot}}[/tex]

yes it is just like that in your diagram. You would need to look up how pressure and diameter relates to stress for the hoop stress.

For the chilled water requirements, you will just need a simple heat balance on the system.
 
  • #9
DaveC426913
Gold Member
20,010
3,280
Please do not duplicate posts.
 
  • #10
berkeman
Mentor
60,560
10,870
So this concept is confusing me.

You have a 20GPM, 150Degree F, 40PSIG water coming in to a heat exchanger through a 1" diameter pipe.

Chilled water is available for cooling from a 6" diameter line at 40 Degrees F, With a pressure of 110PSIG and a flow of 270GPM.

The original solution needs to be cooled from 150 degrees to 80 degrees exiting in a 1.5" line.

  1. The external vessel of the exchanger needs to be 316 stainless steel, any piping or tubing may be of any appropiate material as long as it is schedule 40.
  2. What would be the overall heat transfer coefficient. What would be the hoop stress with a safety factor of 2.0.
  3. Estimate chilled water flow requirements.
  4. What would be the size of the shell, and how many tubes and their size would be required to properly cool the liquid.

This is confusing me ~.~

Multiple threads merged. Please do not multiple/duplicate post again on the PF.
 

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