Hytran - 3-step
transient analysis
STEP 1: BUILD
THE PIPE SYSTEM
The screen image
below shows the pipe system to be simulated. It comprises a downstream
pump delivering to an
upstream reservoir.
Horizontal and
vertical scales are selected and the pipe layout simply click-and-dragged
on screen, lengths and
elevations being approximated to the chosen scales. Actual lengths
and elevations can then be defined using the
Data Input Dialog Boxes.
The coloured vertical lines at the pump and high point locations
are user-defined and generate a real-time display
of transients at those locations.
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STEP 2: DEFINE
THE BOUNDARY CONDITIONS
This pallet is used to build
the model and select Boundary Conditions and Control Devices.
The Pencil Tool bottom left is used to drag-and-draw the pipes.
Other items such as the Air Valve (top right) are then drag-and-dropped
onto the pipe in the appropriate position.
The Data Input Tool (bottom center
) is used to enter the appropriate data for each pipe, Boundary
Condition and Control Device.
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STEP 3: RUN
THE REAL TIME TRANSIENTS
The screen image below shows
the result of a 150 second simulation of pump failure.
The Surge Tank at the high point just upstream of the pump plays
an important role in
reducing transient pressures.
The upper and lower dotted lines
show the maximum and minimum HGL transient envelope.
The (almost) horizontal straight line shows the steady state
HGL.
The wavy line shown the instantaneous transient HGL at the time
150.9 seconds (end of run).
Flow directions are shown in the pipe - blue is normal direction,
red is reverse direction.
The insert Window shows the variation of pressure with time at
three selected positions in the pipe, viz:
the pump (blue), high point 1 (red) and high point 2 (green).
Click
here to see a simulation
of this system in real time without the Surge Tank protection.
When you do so, note the much higher maximum transient HGL and
also at high point 2,
the black dots in the pipe indicating column separation.
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