modelPump_m_flow
Pump with prescribed mass flow rate
Extends from Buildings.Fluid.Movers.Preconfigured.FlowControlled_m_flow (Fan or pump with ideally controlled mass flow rate as input signal and pre-configured parameters).
Information
This is a steady-state model of a pump with ideally controlled mass flow rate as input signal, and no heat added to the medium.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.Movers.Data.Generic | per (from PartialFlowMachine) | ||
| Boolean | computePowerUsingSimilarityLaws (from PartialFlowMachine) | = true, compute power exactly, using similarity laws. Otherwise approximate. | |
| Boolean | addPowerToMedium (from PartialFlowMachine) | true | Set to false to avoid any power (=heat and flow work) being added to medium (may give simpler equations) |
| Boolean | nominalValuesDefineDefaultPressureCurve (from PartialFlowMachine) | false | Set to true to avoid warning if m_flow_nominal and dp_nominal are used to construct the default pressure curve |
| Modelica.Units.SI.MassFlowRate | constantMassFlowRate (from FlowControlled_m_flow) | m_flow_nominal | Constant pump mass flow rate, used when inputType=Constant |
| Modelica.Units.SI.MassFlowRate | massFlowRates (from FlowControlled_m_flow) | m_flow_nominal*{per.speeds[i]/per.speeds[end] for i in 1:size(per.speeds, 1)} | Vector of mass flow rate set points, used when inputType=Stage |
| Dynamics › Conservation equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics (from LumpedVolumeDeclarations) | Modelica.Fluid.Types.Dynamics.DynamicFreeInitial | Type of energy balance: dynamic (3 initialization options) or steady state |
| Modelica.Fluid.Types.Dynamics | substanceDynamics (from LumpedVolumeDeclarations) | energyDynamics | Type of independent mass fraction balance: dynamic (3 initialization options) or steady state |
| Modelica.Fluid.Types.Dynamics | traceDynamics (from LumpedVolumeDeclarations) | energyDynamics | Type of trace substance balance: dynamic (3 initialization options) or steady state |
| Modelica.Units.SI.Time | tau (from PartialFlowMachine) | 1 | Time constant of fluid volume for nominal flow, used if energy or mass balance is dynamic |
| Advanced › Dynamics | |||
| Modelica.Fluid.Types.Dynamics | massDynamics (from LumpedVolumeDeclarations) | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state, must be steady state if energyDynamics is steady state |
| Initialization | |||
| Medium.AbsolutePressure | p_start (from LumpedVolumeDeclarations) | Medium.p_default | Start value of pressure |
| Medium.Temperature | T_start (from LumpedVolumeDeclarations) | Medium.T_default | Start value of temperature |
| Medium.MassFraction[Medium.nX] | X_start (from LumpedVolumeDeclarations) | Medium.X_default | Start value of mass fractions m_i/m |
| Medium.ExtraProperty[Medium.nC] | C_start (from LumpedVolumeDeclarations) | fill(0, Medium.nC) | Start value of trace substances |
| Medium.ExtraProperty[Medium.nC] | C_nominal (from LumpedVolumeDeclarations) | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Dynamics | |||
| Real | mSenFac (from LumpedVolumeDeclarations) | 1 | Factor for scaling the sensible thermal mass of the volume |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTwoPort) | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| Control | |||
| Buildings.Fluid.Types.InputType | inputType (from PartialFlowMachine) | Buildings.Fluid.Types.InputType.Continuous | Control input type |
| Real | constInput (from PartialFlowMachine) | 0 | Constant input set point |
| Real[:] | stageInputs (from PartialFlowMachine) | Vector of input set points corresponding to stages | |
| Dynamics › Motor speed | |||
| Boolean | use_riseTime (from PartialFlowMachine) | true | Set to true to continuously change motor speed |
| Modelica.Units.SI.Time | riseTime (from PartialFlowMachine) | 30 | Time needed to change motor speed between zero and full speed |
| Modelica.Blocks.Types.Init | init (from PartialFlowMachine) | Modelica.Blocks.Types.Init.InitialOutput | Type of initialization (no init/steady state/initial state/initial output) |
| Modelica.Units.SI.MassFlowRate | m_flow_start (from FlowControlled_m_flow) | 0 | Initial value of mass flow rate |
| Advanced | |||
| Modelica.Units.SI.MassFlowRate | m_flow_small (from PartialFlowMachine) | 1E-4*abs(_m_flow_nominal) | Small mass flow rate for regularization of zero flow |
| Modelica.Units.SI.Pressure | dpMax (from FlowControlled_m_flow) | 2*max(eff.per.pressure.dp) | Maximum pressure allowed to operate the model, if exceeded, the simulation stops with an error |
| Advanced › Diagnostics | |||
| Boolean | show_T (from PartialFlowMachine) | false | = true, if actual temperature at port is computed |
| Nominal condition | |||
| Modelica.Units.SI.MassFlowRate | m_flow_nominal (from FlowControlled_m_flow) | Nominal mass flow rate | |
| Modelica.Units.SI.PressureDifference | dp_nominal (from FlowControlled_m_flow) | if rho_default < 500 then 500 else 10000 | Nominal pressure raise, used for default pressure curve if not specified in record per |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_a (from PartialTwoPort) | Fluid connector a (positive design flow direction is from port_a to port_b) | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_b (from PartialTwoPort) | Fluid connector b (positive design flow direction is from port_a to port_b) | |
| Modelica.Blocks.Interfaces.IntegerInput | stage (from PartialFlowMachine) | Stage input signal for the pressure head | |
| Modelica.Blocks.Interfaces.RealOutput | y_actual (from PartialFlowMachine) | Actual normalised fan or pump speed that is used for computations | |
| Modelica.Blocks.Interfaces.RealOutput | P (from PartialFlowMachine) | Electrical power consumed | |
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort (from PartialFlowMachine) | Heat dissipation to environment | |
| Modelica.Blocks.Interfaces.RealInput | m_flow_in (from FlowControlled_m_flow) | Prescribed mass flow rate | |
| Modelica.Blocks.Interfaces.RealOutput | m_flow_actual (from FlowControlled_m_flow) | Actual mass flow rate |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.VolumeFlowRate | VMachine_flow (from PartialFlowMachine) | eff.V_flow | Volume flow rate |
| Modelica.Units.SI.PressureDifference | dpMachine (from PartialFlowMachine) | -preSou.dp | Pressure difference |
| Real | eta (from PartialFlowMachine) | eff.eta | Global efficiency |
| Real | etaHyd (from PartialFlowMachine) | eff.etaHyd | Hydraulic efficiency |
| Real | etaMot (from PartialFlowMachine) | eff.etaMot | Motor efficiency |
| Modelica.Units.SI.MassFlowRate | m_flow (from PartialFlowMachine) | port_a.m_flow | Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) |
| Modelica.Units.SI.PressureDifference | dp (from PartialFlowMachine) | port_a.p - port_b.p | Pressure difference between port_a and port_b |
| Medium.ThermodynamicState | sta_a (from PartialFlowMachine) | if allowFlowReversal then Medium.setState_phX(port_a.p, noEvent(actualStream(port_a.h_outflow)), noEvent(actualStream(port_a.Xi_outflow))) else Medium.setState_phX(port_a.p, noEvent(inStream(port_a.h_outflow)), noEvent(inStream(port_a.Xi_outflow))) | Medium properties in port_a |
| Medium.ThermodynamicState | sta_b (from PartialFlowMachine) | if allowFlowReversal then Medium.setState_phX(port_b.p, noEvent(actualStream(port_b.h_outflow)), noEvent(actualStream(port_b.Xi_outflow))) else Medium.setState_phX(port_b.p, noEvent(port_b.h_outflow), noEvent(port_b.Xi_outflow)) | Medium properties in port_b |
Revisions
-
December 12, 2023, by Ettore Zanetti:
Changed to preconfigured pump model, This is for issue 3431. -
July 31, 2020, by Antoine Gautier:
First implementation.