Welcome to One Minute Series of shell and tube heat exchangers.
Is it possible to design, check or simulate shell and tube heat exchangers in one minute? Surely it is.
Aspen Exchanger Design and Rating (EDR) program is widely used to design, check or simulate shell and tube heat exchangers in the oil and gas industry. It is extremely powerful. However, being powerful also means being complicated.
A user friendly program was written by Guofu Chen to guide process engineers to design, check or simulate shell and tube heat exchangers in one minute. EDR program takes the input from the Excel interface, runs the thermal engine and returns the results back to Excel.
This tool has three different operating modes: Design, Check and Simulate. Design means sizing a heat exchanger from scratch with process requirement and minimum geometry information. In design mode, engineers normally specify the tube diameter, thickness, tube pitch and pattern. Checking mode is used to check if the geometries can meet the process requirement. It answers if the heat exchanger is undersized or over sized and by how much. Simulation mode is used to answer the shell side and tube side outlet temperatures. Both checking mode and simulation mode needs to fully define heat exchangers geometries.
Let's take a closer look at the tool.
The first case is to design a heat exchanger from scratch. We first define this is a NEN type of heat exchangers, using low fin tube and double segment baffles. Then we input the process information, such as flow, pressure and temperature. Finally we specify what kind of tubes and arrangement we will be using.
Let's run the program.
As you can see, this design is over sized by 23%. Why? Because we force the program to at least have 20% over surface.
Once we are satisfied with the design, we are going to check if this exchanger can satisfy the process requirement. As you can see, we fully specify the geometries in the checking mode. Let's run the checking mode. As you can see, it says the heat exchanger is over surfaced by about 22%, which is very close to the design mode.
You might ask, this geometries can definitely meet the process requirement, since it has about 22% margin. but how likely this heat exchanger is going to perform in the real life? Good question. This leads us to the simulation mode. You might notice, the outlet temperature is not specified in the simulation mode. Let's run the calculation. The tube side temperature is changed to 171.1 F from 173.5 F. The duty is changed to 162 million btu/hr from 159 million btu/hr and the surface margin now is 0.
With this tool, do you think you can design, check or simulate Shell and Tube Heat Exchangers in one minute? You surely can.
Thanks for watching this video, it is brought to you by Guofu Chen. More interesting topics can be found at showcase.guofuchen.com.
For those who can't see the embedded video in this blog, please watch this video on youtube.com at http://youtu.be/m0O7qB_beZc
