ChE 3211
Design and Build a Heat Exchanger
Sarah Wang
Duane Long
University of Minnesota Duluth
Department of Chemical Engineering
Objectives
• Provide hands-on experience
• Provide an open-ended design problem
• Develop a sense of engineering judgment
Process
•
Prepare a detailed schematic
•
Solve design equations
•
Preliminary uncertainty analysis
•
Generate a Project Proposal
Process
Build your heat exchanger
•
Test your design
•
•
•
Calculate heat transfer parameters
Calculate efficiency and the economic
rating
Prepare full/memo report and oral
presentation
Design Equations
• Energy Balance
q  mh c p Thi  Tho 
• Heat Transfer
q  UATh  Tc 
 UATln mn 
• Overall Heat Transfer
Coefficient
1

UA
1
1

 ...
hi Ai ho Ao
Design Objectives
• Design a safe operating heat exchanger that
meet the guidelines of OSHA and the
Company
• Minimize the cost and size
 Minimize the weight and length
• Length (tube end to tube end)
• Weight (dry weight)
Design Objectives
• Minimize the Cost and
Size to enhance the
Economic Rating
E

L W
  
L W 
100
– Min. Weight and Length
• Effectiveness Factor

Thi  Tho

Thi  Tci
Specifications
Fluid is water
• Tube side temperature change ≥ 20oC and
≤26°C
Stream
Cold
Temperature
(˚C)
15  2
Flow Rate
(L/min)
0.60 ± 0.02
Hot
50  3
0.20 ± 0.02
Room air
21 ± 2
Hot ΔT
21 - 26
Materials
• Only materials locally available
– Schedule 40 PVC with max. dia = 4”
– ¼” Copper tubing
– ¼” Polyethylene tubing
• Connections must accommodate ¼” compression
fittings (Swagelok)
• Use common building materials
Construction
1. Design approved by the planning team
2. Meets the safety requirements of McCracken
Industry, Inc and OSHA.
3. Hand tools will be made available.
4. Dept. will buy materials as specified in the
“Call for Project Proposal” document –
allow us time to get materials.
5. Safety first, sign release form after reading
the Tool Safety information.
Testing
1. Rig available for testing.
2. Your exchanger must be compatible with
the test rig.
3. Make arrangements with Duane to test your
heat exchanger.
4. Carefully gather data.
Project Proposal
1. A Project Proposal shall be submitted in response to the
“Call for Project Proposal”
2. The document “Call for Project Proposal” and information
about the Heat Exchanger Design Project can be found at
http://www.d.umn.edu/~dlong/studentbuildhtexc.html
3. Heat Exchanger Design should include at a minimum:
a.
b.
c.
d.
Diagram of your heat exchanger;
Size of PVC pipe (D x L) you will use for the shell;
Length of copper tubing you will need; and
The type and the number of each type of Swagelok fitting you will
need to build your heat exchanger.
Project Proposal
1. Submission of a Change Order
2. Information is found at the Web address on
the previous slide and click on “Information
required in a Project Proposal Change
Order”
a. Examples when a change order is needed
b. Information to be included in a change order
Due Dates
1. Tuesday Afternoon lab (Section 1)
a. Project Proposal is due for submission to Dr.
Sarah Wang with an electronic copy to Duane
Long by 4:30 PM, Monday, October 29, 2012.
Due Dates
3. Thursday Afternoon lab (Section 2)
a. Project Proposal is due for submission to Dr.
Sarah Wang with an electronic copy to Duane
Long by 4:30 PM, Wednesday, October 31,
2012.
Due Dates
1. If Duane does not receive an electronic
copy, you may have to wait the first day of
the lab until your kit containing the fittings is
made up before you can start building your
heat exchanger.
Good Luck!