Design of A Heat Exchanger - Saylor.org

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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.



For the cold fluid, the inlet and outlet temperatures are 90oC and 130oC, respectively.



The area for heat transfer A is 100 m2.



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.



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.



Make sure that you understand “overall heat transfer coefficient U,” “log-mean temperature difference” (LMTD), and t “effectiveness NTU.”



Review different configurations of heat exchangers on pages 107-119 of Lienhard and Lienhard’s A Textbook on Heat Transfer.



Review Example 3.4 on page 120 and Example 7.6 on page 373 in Lienhard and Lienhard’s A Textbook on Heat Transfer.

The Saylor Foundation 1