The Saylor Foundation 1. Assignment 2: Heat Exchanger Design. Instructions: In
this assignment, you are asked to assist in the design process of a.
Assignment 2: Heat Exchanger Design
Instructions: In this assignment, you are asked to assist in the design process of a heat exchanger by evaluating two different designs: parallel-flow versus counter flow. Design Parameters: The design parameters of the heat exchanger are: •
For the hot fluid, the inlet and outlet temperatures are 220oC and 165oC, respectively.
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For the cold fluid, the inlet and outlet temperatures are 90oC and 130oC, respectively.
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The area for heat transfer A is 100 m2.
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The heat transfer coefficient is 100 W/(K.m2)
Questions: Answer the following questions in developing your design. •
Should you use a parallel-flow heat exchanger or a counter flow heat exchanger? Explain the choice you made and how the heat exchanger you chose fits into the design parameters.
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Calculate the overall heat transfer rate for the design that you choose.
Preparation for the assignment: •
Review “Chapter 3: Heat Exchanger Design” in Lienhard and Lienhard’s A Textbook on Heat Transfer.
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Make sure that you understand “overall heat transfer coefficient U,” “log-mean temperature difference” (LMTD), and t “effectiveness NTU.”
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Review different configurations of heat exchangers on pages 107-119 of Lienhard and Lienhard’s A Textbook on Heat Transfer.
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Review Example 3.4 on page 120 and Example 7.6 on page 373 in Lienhard and Lienhard’s A Textbook on Heat Transfer.
