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If tubes in water supply systems are damaged, the fractures might enlarge unnoticeably, but continuously and become a great leakage in the tube.
Leakage control is to detect this kind of tube fractures. Due to individual facility equipment and means of measurement, it is not possible to offer an off-the-shelf software solution. The comprehensive parameter set of the ProWin® system lets you solve this problem very easily by means of archives, script technology and visualization.
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Sample facility - Task:
- the facility includes three inductive flow meters
- the flow meters are installed on by-pass-tubes next to the main tube
- the total flow rate is to be monitored in a certain period and, if exceeding a defined value, an alarm is set off (auto-mode)
- the measurement is to be done automatically at night (period with low water consumption)
- the time period can be set manually by the user (from ... o´clock till ... o´clock)
- manual starting and stopping of the measurement should be possible at every time
- the measurement procedure is to be initialized and visualized in an user window
- slide valve commands (open/close) are to be checked automatically for correct order and proper execution (command feed-back)
- in addition, quarter-hour-amounts (analog sums) are to be calculated and archived with min- and max-values
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ProWin®-application: The current flow data is indicated in a sub-window. There are input boxes for 4 upper limit values and for start and end time of automatic measurement.
The bypass is shown in a picture. You can choose between automatic and manual measurement by clicking the interlocked buttons. If you choose manual measurement, the start- and stop buttons are released.
After opening properly, the main tube valve is closed. Then the measurement starts ("Messung läuft").
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The three analog instantaneous values are processed to an instantaneous sum by a script. This sum becomes a new PV in the data model of the facility. The script is set to react to every change of one of the values. By setting the PV sum variable and saving in the data model, ProWin® monitors and checks these values for limit violations. The monitoring can be locked by a release PV. |
When violating the limits, a standard alarm is set off:
- flashing and coloured indication of measured value´s PV (state evaluation)
- violation is registered in the operating log and the alarm log
- alarm is indicated in the status bar of the screen
- acoustic signal possible
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Each of the limiting values has been assigned to a coupling PV. The latter are set to "1" in case of violation. They are indicated in a different colour in the dialog window (GW1 to GW4).
You can acknowledge the alarm by clicking a button in the dialog window.
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A trend analysis is available when you would like to trace measured values later or manually (e.g. minute archive).
The measurement is stopped when the time for the automatic measurement is over (end time) or the stop-button is clicked. The main valve opens up again, the bypass valves are closed.
With the data gained (instantaneous values, sums, archived values), a quarter-hour minimum or maximum can be estimated. Other compression grades can be set, such as 2-hour, daily or monthly values. You may log this data or even visualize in a curve graphics (ProWin® standard).
Further user-specific functions with script technology:
By means of scripts, the gained quarter-hour values can be used for further treatment, like for example a quarter-hour limit checks, comparison to a defined number of previous quarter-hour-values, etc. These can be defined in free protocols. |
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