.TAeZoSysPro.FluidDynamics.Components.Machines.BaseClasses.PartialPump

Information

This is the base model for pumps strongly inspired from the PartialPump of Modelica Standard Library (MSL).

The pump model is based on the theory of kinematic similarity: the pump characteristics are given for nominal operating conditions (rotational speed and fluid density), and then adapted to actual operating condition, according to the similarity equations.

Pump characteristics

The nominal hydraulic characteristic (head vs. volume flow rate) is given by the replaceable function flowCharacteristic.

The pump energy balance can be specified in two alternative ways:

• use_powerCharacteristic = false (default option): the replaceable function efficiencyCharacteristic (efficiency vs. volume flow rate in nominal conditions) is used to determine the efficiency, and then the power consumption. The default is a constant efficiency of 0.8.
• use_powerCharacteristic = true: the replaceable function powerCharacteristic (power consumption vs. volume flow rate in nominal conditions) is used to determine the power consumption, and then the efficiency. Use powerCharacteristic to specify a non-zero power consumption for zero flow rate.

Several functions are provided in the package PumpCharacteristics of the TAeZoSysPro library or the MSL to specify the characteristics as a function of some operating points at nominal conditions.

Depending on the value of the checkValve parameter, the model either supports reverse flow conditions, or includes a built-in check valve to avoid flow reversal.

Dynamics options

The pump dynamic is quasistatic. No mass or energy are stored.

Heat transfer

The pump is adiabatic.

Diagnostics of Cavitation

The replaceable Monitoring submodel can be configured to PumpMonitoringNPSH, in order to compute the Net Positive Suction Head available and check for cavitation, provided a two-phase medium model is used (see Advanced tab).

Contents

Name	Description
Medium
flowCharacteristic	Head vs. V_flow characteristic at nominal speed and density
powerCharacteristic	Power consumption vs. V_flow at nominal speed and density
efficiencyCharacteristic	Efficiency vs. V_flow at nominal speed and density

Revisions

• 8 Jan 2013 by Rüdiger Franke:
  moved NPSH diagnostics from PartialPump to replaceable sub-model PumpMonitoring.PumpMonitoringNPSH (see ticket #646)
• Dec 2008 by Rüdiger Franke:
  
  • Replaced simplified mass and energy balances with rigorous formulation (base class PartialLumpedVolume)
  • Introduced optional HeatTransfer model defining Qb_flow
  • Enabled events when the checkValve is operating to support the opening of a discrete valve before port_a
• 31 Oct 2005 by Francesco Casella:
  Model added to the Fluid library