Pipework is a large part of the cost of a process plant. Plant designers need to minimize the total cost of this pipework across the lifetime of the plant. The total overall cost is a combination of individual costs related to the:
- pipe material,
- installation,
- maintenance,
- depreciation,
- energy costs for pumping,
- liquid parameters,
- required flowrate,
- pumping efficiencies,
- taxes,
- and more.
The total cost is not a simple linear sum of the individual costs; a more complex relationship is needed.
This application uses the approach described in [1] to find the pipe diameter that minimizes the total lifetime cost. The method involves the iterative solution of an empirical equation using Maple’s fsolve function (the code for the application is in the Startup code region).
Users can choose the pipe material (carbon steel, stainless steel, aluminum or brass), and specify the desired fluid flowrate, fluid viscosity and density. The application then solves the empirical equation (using Maple’s fsolve() function) and returns the economically optimal pipe diameter.
Bear in mind that the empirical parameters used in the application vary as economic conditions change. Those used in this application are correct for 1998 and 2008.
[1]: "Updating the Rules for Pipe Sizing", Durand et al., Chemical Engineering, January 2010
