Heat Exchanger Calculations and Design with Excel Spreadsheet Templates

Equations and Parameters

The heat exchanger design equation, Q = U A ΔTlm, can be used to determine the required heat transfer area, A, for a heat exchanger. The heat transfer area can be calculated after values have been determined or estimated for the required heat transfer rate, Q; the overall heat transfer coefficient, U, and the log mean temperature difference for the heat exchanger, ΔTlm, based on the values of several input parameters. Excel spreadsheet templates for calculating the heat transfer area needed for a heat exchanger are presented and discussed in the next section.

For more details about preliminary heat exchanger design, the parameters involved, and example heat exchanger calculations, see the articles: "Preliminary Heat Exchanger Design Example" and "Fundamentals of Heat Exchanger Theory and Design."

Excel Template – Page 1: Calculation of Heat Transfer Area The Excel spreadsheet template shown at the left will calculate the heat transfer area required for a heat exchanger after values for several parameters have been input. The parameters that need input values are the mass flow rate, specific heat, inlet temperature and outlet temperature of one of the fluids; the heat capacity, inlet temperature and outlet temperature of the second fluid; and an estimated value for the overall heat transfer coefficient. After values are entered for those parameters the Excel formulas in the spreadsheet will calculate the heat transfer rate, the log mean temperature difference, the required heat transfer area, and the needed mass flow rate for the second fluid.

Column C has cells for entry of several parameter values. Column I contains the Excel formulas to calculate the parameters noted above. This example spreadsheet shows calculations in U.S. units, however an S.I. version and a U.S. version are available for download just below.

Excel Template – Page 2: Number of Tubes for a Shell and Tube Heat Exchanger The Excel spreadsheet template at the right is for shell and tube heat exchanger design. This spreadsheet calculates the number of tubes needed for a specified tube length and diameter. In the spreadsheet templates that can be downloaded below, this page 2 and page 1 from the previous section are both included as part of the same Excel template. Thus the heat exchange area calculated on page 1 can be used for the page 2 calculations.

This example spreadsheet shows calculations in U.S. units, however an S.I. version and a U.S. version are both available for download just below.

For more background information about the different types of shell and tube heat exchangers, see the article: "Types of Shell and Tube Heat Exchangers."

Excel Template- Alternate Page 2 Length of Pipe for a Double Pipe Heat Exchanger The Excel spreadsheet template at the left is for double pipe heat exchanger design. This spreadsheet This example spreadsheet shows calculations in U.S. units, however an S.I. version and a U.S. version are both available for download just below.

For more background information about double pipe heat exchangers, see the article: "Double Pipe Heat Exchanger Design."

References and Image Credits

References for Further Information:

1. Bengtson, H., Fundamentals of Heat Exchangers, an online, continuing education course for PDH credit.

2. Kuppan, T., Heat Exchanger Design Handbook, CRC Press, 2000.

3. Kakac, S. and Liu, H., Heat Exchangers: Selection, Rating and Thermal Design, CRC Press, 2002.

Image Credits:

1. Shell and Tube Heat Exchanger – Grand Kartech heat exchangers

2. Double Pipe Heat Exchanger – China Commodity Net

This post is part of the series: Heat Exchanger Design

Heat exchanger design includes estimation of the heat transfer area needed for known or estimated heat transfer rate, overall heat transfer coefficient and log mean temperature difference. The tube or pipe diameters and length also need to be determined, as well as the pressure drop.