The Pump Surge Data is accessed from the Pump Surge Data button from the Attribute Browser when a pump is selected. A turbine is represented by the pump element with turbine-specific parameters in a surge model. A wicket gate can be specified for the turbine element to simulate the transients due to wicket gate changes. This dialog box  is used to specify the properties of the pump/turbine which are to be used in a surge analysis. If you intend to have your pump trip or ratchet during the surge analysis it is necessary to specify a Pump File. Select Pump File Provided below, select the appropriate pump file (a Pump File Selector is provided to assist in the pump file selection) from the menu, include the necessary Pump File Settings below and include the trip or ratchet data in the Pump Operation Change Data. The pump's PID control can be taken into account in a surge analysis.

Transients for pumps are initialized by changing the pump speed or designating a pump trip where the rundown speed is calculated. Transients for turbines are initialized by changing the turbine speed, changing the wicket gate opening during the surge analysis. Note that turbine operation is the reverse of pump operation when interpreting surge outputs. The turbine's upstream side is the pump's downstream side, while the turbine's downstream side is the pump's upstream side.



As Pump

The element is modeled as Pump in surge analysis.

As Turbine

The element is modeled as Turbine in surge analysis.

Wicket Gate Associated

When option is checked on, there is a Wicket Gate associated with the turbine; otherwise, there is no Wicket Gate associated with the turbine. The option is enabled only when the element is modeled as Turbine.

Bypass Installed

If this box is checked, this indicates that there is a Bypass line installed for the selected pump. A bypass line is a pipe that goes around the pump from inlet to outlet that functions to reduce transients in the event of a pump trip. This allows flow to bypass the pump when the suction head exceeds the discharge head.

Bypass Resistance

Resistance of the Bypass line.

Check Valve Installed

If this box is checked, then a check valve will be modeled for this device. A Check Valve (CV) prevents flow reversal through the pump.

Check Valve Opening and Closing Time

This is the amount of time in seconds that it takes for the check valve to go either from fully opened to fully closed or the opposite.

Non-Reopen Check Valve

If this box is checked, then the check valve will not open once it has closed. Please note: if the pump is off and starts with the check valve in the closed position, with this option checked, the check valve will not open.

Pump File Provided

If this box is selected, then the Pump File specified in the blank to the right will be used as a basis for modeling the selected pump during a Surge analysis. A Pump File is a table defining head and torque as a function of flow and speed. These are based on experimental data and 8 files are available to use. The Pump Files contain the information about pump performance in both normal and abnormal operating conditions. There is a calculator provided, Pump File Selector, to help you select the most appropriate pump file.

Pump File Settings

  • Rated Head - Rated Head, ft or m. This will override the design head during a surge simulation.

  • Rated Flow - Rated Flow, specified flow unit. This will override the design flow during a surge simulation.

  • Inertia - lb-ft2 or N-m2. The inertia is assumed to be available from the pump manufacturer. If this data is not available, the summation of motor inertia and either fairly old pumps or small, light weight pumps in the  Pump Inertia Calculator can be used to estimate the inertia.

  • Efficiency - % (at rated flow). The efficiency when the pump operates at the rated point.

  • Rated Speed - Rated Speed of the selected pump in revolutions per minute, rpm.

  • Initial Speed Ratio - This is the ratio of the speed that the pump is being operated at (at the start of the simulation) to the rated speed of the pump in RPMs. If the pump is being operated at the rated speed then this number will be 1. Note that the value in this blank must agree with the initial value of a Pump Speed Curve if this data is entered.

Turbine Settings (Settings are Active if "As Turbine" is Selected)

  • Rated Head - Rated Head, ft or m of the turbine. This will override the design head during a surge simulation.

  • Rated Flow - Rated Flow, specified flow unit of the turbine. This will override the design flow during a surge simulation.

  • Inertia - lb-ft2 or N-m2. The inertia is assumed to be available from the turbine manufacturer.

  • Efficiency - % (at rated flow). The efficiency when the turbine operates at the rated point.

  • Rated Speed - Rated Speed of the selected turbine in revolutions per minute, rpm.

  • Initial Speed Ratio - This is the ratio of the speed that the turbine is being operated at (at the start of the simulation) to the rated speed of the pump in RPMs. If the turbine is being operated at the rated speed, then this number will be 1. Note that the value in this blank must agree with the initial value of a Turbine Speed Curve if this data is entered.

PID Control

  • Select Controlling Junction - Click to select a junction that the pump's PID control is based on.

  • Junction ID - The ID of the controlling junction.

  • Target Pressure - The target pressure for the PID controller on the pump.

  • Gain - The proportional term parameter for the PID controller. If left blank or zero, the proportional term is not used.

  • Integral Time - Time for the integral term for the PID controller. If left blank or zero, the proportional term is not used.

  • Differential Time - Time for the differential term for the PID controller. If left blank or zero, the proportional term is not used.

Purge - Use the Purge button to remove existing Data.

Create/Update - Enter new or changed data and exit the dialog box window.

Cancel - Cancels any new or changed data and closes the dialog box window.