Controlled Heat Exchanger Temperature - GSC (Metric Units)
Controlled Heat Exchanger Temperature - GSC (English Units)
Summary
The objective of this example is to use the GSC module to vary a Three Way Valve percent open to divert heat exchanger flow to maintain a downstream temperature of
Note: This example can only be run if you have a license for the GSC module.
Topics Covered
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Using GSC to control flow splits
Required Knowledge
This example assumes the user has already worked through the Walk-Through Examples section, and has a level of knowledge consistent with the topics covered there. If this is not the case, please review the Walk-Through Examples, beginning with the Beginner - Three Reservoir example. You can also watch the AFT Fathom Quick Start Video Tutorial Series on the AFT website, as it covers the majority of the topics discussed in the Three-Reservoir Model example.
In addition the user should have worked through the Beginner - Heat Transfer in a Pipe - GSC example.
Model Files
This example uses the following files, which are installed in the Examples folder as part of the AFT Fathom installation:
Step 1. Start AFT Fathom
From the Start Menu choose the AFT Fathom 13 folder and select AFT Fathom 13.
To ensure that your results are the same as those presented in this documentation, this example should be run using all default AFT Fathom settings, unless you are specifically instructed to do otherwise.
Step 2. Open the Model
Open the
Step 3. Define the Modules Group
Open Analysis Setup, and navigate to the Modules panel. Check the box next to Activate GSC. The Use option should automatically be selected, making GSC enabled for use.
Step 4. Define the Goal Seek and Control Group
Specify the variables and goals for the model.
Variables Panel
Open the Variables panel in the Goal Seek and Control group. For this example, we will be adding a variable for the Three Way Valve % Open. Click New Variable and enter the following data:
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Apply = Selected
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Object Type = Junction
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Junction Type = Three Way Valve
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Junction Number and Name = J3 (Three Way Valve)
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Variable Parameter = Open Percentage
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Link To = (None)
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Lower Bound = 0
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Upper Bound = 100
Goals Panel
Open the Goals panel in the Goal Seek and Control group in Analysis Setup. Click New Goal for the downstream temperature and define it with the data below:
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Apply = Selected
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Goal Type = Point
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Object Type = Branch
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Goal Parameter = Temperature
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Criteria = =
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Goal Value = 50
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Goal Units = deg. C
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Object ID = J8 (Branch)
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Object Location = Outlet
After entering the data, the Goals panel should appear as shown in Figure 3:
Step 5. Run the Model
Click Run Model on the toolbar or from the Analysis menu. This will open the Solution Progress window. This window allows you to watch as the AFT Fathom solver converges on the answer. Now view the results by clicking the Output button at the bottom of the Solution Progress window.
Step 6. Examine the Output
The results of the GSC module analysis are shown in the General Output section. The GSC Variables tab shows the final value for the variable parameter, as shown in Figure 4. The open percentage required for the Three Way Valve to achieve a temperature of