PUMP RUNNING AS A TURBINE P045-1
When running as a turbine, the performance of the pump acts very differently than when it was running as a pump:
- The discharge of the pump becomes the inlet of the turbine and the suction becomes the outlet of the turbine.
- The pump impeller will turn in the opposite direction and becomes the runner of the turbine.
- The impeller orientation is the same in both the pump and turbine mode.
- It is difficult to predict actual the turbine performance of a reverse running pump. You really need specific test data on the pump you intend to use as a turbine, if you want predictable results
The following equation can be used to make an estimate:
Some things to consider when you run the pump as a turbine:
- You will have a narrow operating band compared to variable nozzle turbines
- At constant speed, the power developed and efficiency drop to zero at approximately 40% of the hydraulic turbine best efficiency rate of flow.
You will also want to look at:
- Over speed trip controls
- Runaway speed possibility
- The flow rate at runaway speed
- Abrasives and solids in the fluid.
- Torque reversals at start-up and shutdown.