ControlledPumpCentrifugal pump with ideally controlled mass flow rate |
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Diagram
Information
This information is part of the Modelica Standard Library maintained by the Modelica Association.
This model describes a centrifugal pump (or a group of nParallel pumps)
with ideally controlled mass flow rate or pressure.
Nominal values are used to predefine an exemplary pump characteristics and to define the operation of the pump.
The input connectors m_flow_set or p_set can optionally be enabled to provide time varying set points.
Use this model if the pump characteristics is of secondary interest. The actual characteristics can be configured later on for the appropriate rotational speed N. Then the model can be replaced with a Pump with rotational shaft or with a PrescribedPump.
Parameters (33)
| allowFlowReversal |
Value: system.allowFlowReversal Type: Boolean Description: = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
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| energyDynamics |
Value: Types.Dynamics.SteadyState Type: Dynamics Description: Formulation of energy balance |
| massDynamics |
Value: Types.Dynamics.SteadyState Type: Dynamics Description: Formulation of mass balance |
| substanceDynamics |
Value: massDynamics Type: Dynamics Description: Formulation of substance balance |
| traceDynamics |
Value: massDynamics Type: Dynamics Description: Formulation of trace substance balance |
| p_start |
Value: p_b_start Type: AbsolutePressure (Pa) Description: Start value of pressure |
| use_T_start |
Value: true Type: Boolean Description: = true, use T_start, otherwise h_start |
| T_start |
Value: if use_T_start then system.T_start else Medium.temperature_phX(p_start, h_start, X_start) Type: Temperature (K) Description: Start value of temperature |
| h_start |
Value: if use_T_start then Medium.specificEnthalpy_pTX(p_start, T_start, X_start) else Medium.h_default Type: SpecificEnthalpy (J/kg) Description: Start value of specific enthalpy |
| X_start |
Value: Medium.X_default Type: MassFraction[Medium.nX] (kg/kg) Description: Start value of mass fractions m_i/m |
| C_start |
Value: Medium.C_default Type: ExtraProperty[Medium.nC] Description: Start value of trace substances |
| p_a_start |
Value: system.p_start Type: AbsolutePressure (Pa) Description: Guess value for inlet pressure |
| p_b_start |
Value: p_a_start Type: AbsolutePressure (Pa) Description: Guess value for outlet pressure |
| m_flow_start |
Value: system.m_flow_start Type: MassFlowRate (kg/s) Description: Guess value of m_flow = port_a.m_flow |
| V_flow_single_init |
Value: m_flow_start / rho_nominal / nParallel Type: VolumeFlowRate (m³/s) Description: Used for simplified initialization model |
| delta_head_init |
Value: flowCharacteristic(V_flow_single_init * 1.1) - flowCharacteristic(V_flow_single_init) Type: Position (m) Description: Delta head for a 10% increase of flow at the initialization point |
| nParallel |
Value: 1 Type: Integer Description: Number of pumps in parallel |
| N_nominal |
Value: 1500 Type: AngularVelocity_rpm (rev/min) Description: Nominal rotational speed for flow characteristic |
| rho_nominal |
Value: Medium.density_pTX(Medium.p_default, Medium.T_default, Medium.X_default) Type: Density (kg/m³) Description: Nominal fluid density for characteristic |
| use_powerCharacteristic |
Value: false Type: Boolean Description: Use powerCharacteristic (vs. efficiencyCharacteristic) |
| checkValve |
Value: false Type: Boolean Description: = true to prevent reverse flow |
| V |
Value: 0 Type: Volume (m³) Description: Volume inside the pump |
| use_HeatTransfer |
Value: false Type: Boolean Description: = true to use a HeatTransfer model, e.g., for a housing |
| g |
Value: system.g Type: Acceleration (m/s²) |
| show_NPSHa |
Value: false Type: Boolean Description: obsolete -- remove modifier and specify Monitoring for NPSH instead |
| p_a_nominal |
Value: Type: AbsolutePressure (Pa) Description: Nominal inlet pressure for predefined pump characteristics |
| p_b_nominal |
Value: Type: AbsolutePressure (Pa) Description: Nominal outlet pressure, fixed if not control_m_flow and not use_p_set |
| m_flow_nominal |
Value: Type: MassFlowRate (kg/s) Description: Nominal mass flow rate, fixed if control_m_flow and not use_m_flow_set |
| control_m_flow |
Value: true Type: Boolean Description: = false to control outlet pressure port_b.p instead of m_flow |
| use_m_flow_set |
Value: false Type: Boolean Description: = true to use input signal m_flow_set instead of m_flow_nominal |
| use_p_set |
Value: false Type: Boolean Description: = true to use input signal p_set instead of p_b_nominal |
| V_flow_op |
Value: m_flow_nominal / rho_nominal Type: VolumeFlowRate (m³/s) Description: operational volume flow rate according to nominal values |
| head_op |
Value: (p_b_nominal - p_a_nominal) / (rho_nominal * g) Type: Position (m) Description: operational pump head according to nominal values |
Inputs (1)
| fluidVolume |
Default Value: V Type: Volume (m³) Description: Volume |
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Connectors (5)
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port_a |
Type: FluidPort_a Description: Fluid connector a (positive design flow direction is from port_a to port_b) |
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port_b |
Type: FluidPort_b Description: Fluid connector b (positive design flow direction is from port_a to port_b) |
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heatPort |
Type: HeatPort_a |
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m_flow_set |
Type: RealInput Description: Prescribed mass flow rate |
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p_set |
Type: RealInput Description: Prescribed outlet pressure |
Components (4)
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system |
Type: System Description: System properties |
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medium |
Type: BaseProperties |
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heatTransfer |
Type: HeatTransfer |
| monitoring |
Type: Monitoring Description: Monitoring model |
Used in Examples (2)
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Modelica.Fluid.Examples Simple model of a heating system |
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Modelica.Fluid.Examples Demonstrates the parameterization of a pump and a pipe for given nominal values |