Two submersible pumps on guide rails, start, lag, stop and high-level devices, riser check valves and a common force main form this lift station. Adjust wet-well inflow and pump capacity, fail either pump, or corrupt the main level signal, and see how staged control and the independent high-level device respond.
• A real-time 3D view with numbered, clickable parts: wet-well cutaway; submersible pumps and guide rails; start, lag, stop and high-level devices; risers, check valves and force main; alternation and fault annunciator. Scene tools include home view, focus-selected-part, auto-rotate, expand and show/hide labels, and drag-to-orbit with pinch-to-zoom. • Experiment controls: wet-well inflow (8–45 L/s); capacity per available pump (15–25 L/s); pump a failed; pump b failed; main level signal (normal / stuck-low / stuck-high), plus a show flow/process markers toggle, pause/resume, single-step buttons (0.1 s and 1 s), a playback-speed selector and a restart trial action. • Live readouts: actual wet-well level; main level signal; running pumps; combined discharge; lead pump · 0=A, 1=B; overflow volume. A model response curve is drawn beside the 3D view and updates as you change controls. • A Curves & measurements tab with two live charts, the model equations as written in the simulator and snapshot readouts; an Experiments tab with 2 guided presets (lead pump unavailable; lost main level signal) plus a model-verification bench, timestamped event log and copyable trial report. • A Learn & assess tab with 3 lessons (lead/lag is different from simultaneous starts; alternation shares starts; signal faults differ from pump faults), a 2-question knowledge check with reset, and a written model-scope statement.
The lead pump starts at 1.8 m and the lag pump joins only when the level reaches 2.8 m, so the second pump is added when one cannot keep up, rather than starting at the same time. Both stop at 0.7 m. After a normal stop the next cycle selects the other pump as lead, which shares starts between the two.
If the lead pump is unavailable, the other pump takes over as the available lead replacement. Running pumps, combined discharge and the lead-pump indicator are displayed, and the model integrates wet-well level over a 12 m² area with a maximum storage depth of 4 m.
A stuck-low main level signal can prevent the pumps from starting, yet the wet well still fills. An independent high-level device at 3.5 m is modeled separately, so the alarm still activates if the actual level rises, which is the lost-level-signal experiment. A stuck-high signal instead calls pumps to run.
Pump flow is a fixed per-pump approximation, not a parallel-pump curve analysis, and failures of the independent high and low devices themselves are not included. One animation second represents one minute.
Lead/lag adds the second pump only when the level keeps rising to the lag setpoint. Starting both at once would waste energy and increase starts when inflow is modest.
Alternation spreads running hours and starts across both pumps so wear is shared, and it keeps both pumps exercised.
The controller believes the level is low and does not start pumps, but the real level rises. The independent high-level device still detects it and raises the alarm.
No. Each available pump delivers a fixed flow that you choose, so the simulator demonstrates control logic rather than parallel-pump hydraulics.