modelPositivePump
Possitive desplacement pump with volumetric flow proportional to speed
Extends from PumpBase.
Information
It extends the the PumpBase model. The following parameters are defined:
- n0: The nominal rotational speed
- q0: The nomimal volumetric flow at the nominal rotational speed
- r: The fixed efficiency. The equation Efficiency=r is applied.
- qLeak: The pump expected volumetric leak at pLeak differential pressure.
- pLeak: The differential pressure at which the qLeak is induced.
The variable Qleak is defined, with the equation for its calculation: Qleak= qLeak*Pdiff/pLeak. So the leak is proportional to the differential pressure, in both directions.
Finally the equation Qunit=q0*N/n0-Qleak is applied. You can reverse the flow of the pump by giving a negative value to the rotational speed.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Ports links | |||
| Boolean | useElevDifference (from TwoFluidPorts) | true | introduces, or not, an equation for the ports elevation. Use only in one connector |
| FreeFluids.Types.ElevationOption | elevCalcMethod (from TwoFluidPorts) | FreeFluids.Types.ElevationOption.differential | if useElevDifference==true, selects the equation to use: differential, or absolute for PortB |
| Modelica.Units.SI.Length | elevDifference (from TwoFluidPorts) | 0.0 | used only if previously selected. Positive if PortB higher than PortA |
| Modelica.Units.SI.Length | portBelevation (from TwoFluidPorts) | 0.0 | used only if previously selected. |
| Boolean | calcEnthalpyDifference (from TwoFluidPorts) | true | if true, will calculate the enthalpy difference between ports. Use only in one connector |
| Boolean | passComposition (from TwoFluidPorts) | true | if true, the equation PortA.X=PortB.X will be activated |
| Flow | |||
| Boolean | forceSpeed (from PumpBase) | false | if true, the internal, or external, speed will be applied |
| Boolean | useExternalSpeed (from PumpBase) | false | If true, the connector speed will be used |
| Modelica.Units.SI.Frequency | fixedSpeed (from PumpBase) | 2900.0/60.0 | internally fixed speed for the pump |
| Integer | numParallelUnits (from PumpBase) | 1 | |
| Boolean | directFlow (from PumpBase) | true | if false, reverse flow |
| Modelica.Units.SI.Frequency | n0 | nominal rotational speed (1/s) | |
| Modelica.Units.SI.VolumeFlowRate | q0 | individual pump flow at nominal speed | |
| Modelica.Units.SI.VolumeFlowRate | qLeak | 0 | individual leak flow at given differential pressure |
| Medium.AbsolutePressure | pLeak | 1e-3 | differential pressure at which the leak is referenced |
| Fraction | r | 0.7 | fixed pump efficiency |
| User phys. prop. | |||
| Modelica.Units.SI.Density | rho (from PumpBase) | 0 | fixed average density to use in calculations |
Connectors
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.SpecificEnthalpy | Hdiff (from TwoFluidPorts) | specific enthalpy difference: Port B - Port A | |
| Modelica.Units.SI.PressureDifference | Pdiff (from TwoFluidPorts) | pressure difference: Port B - Port A | |
| Modelica.Units.SI.Frequency | N (from PumpBase) | Rotational speed in 1/s | |
| Real | Efficiency (from PumpBase) | efficiency | |
| Modelica.Units.SI.Power | Wabs (from PumpBase) | total absorbed power | |
| Modelica.Units.SI.SpecificEnergy | SE (from PumpBase) | ||
| Modelica.Units.SI.VolumeFlowRate | Qunit (from PumpBase) | ||
| Modelica.Units.SI.VolumeFlowRate | Qtotal (from PumpBase) | ||
| Medium.ThermodynamicState | State (from PumpBase) | ||
| Modelica.Units.SI.Density | Rho (from PumpBase) | ||
| Medium.Temperature | T (from PumpBase) | Temperature at PortA | |
| Modelica.Units.SI.Height | Dh (from PumpBase) | differential pressure as liquid height | |
| Modelica.Units.SI.VolumeFlowRate | Qleak |