modelLoadTwoWayValve
Model of a load on a hydronic circuit with flow rate modulation by a two-way valve
Extends from Buildings.Fluid.Interfaces.PartialTwoPortInterface.
Information
This model represents a thermal load on a hydronic circuit, composed of Buildings.Templates.Components.Loads.Load and a two-way valve component that is used to modulate the flow rate through the load component.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.HydronicConfigurations.Types.Control | typ | Load type | |
| Modelica.Units.SI.MassFlowRate | mLiq_flow_nominal | 1 | Liquid mass flow rate at design conditions |
| Modelica.Units.SI.PressureDifference | dpTer_nominal | 3E4 | Liquid pressure drop across terminal unit at design conditions |
| Modelica.Units.SI.MassFlowRate | mAir_flow_nominal | abs(Q_flow_nominal)/10/1015 | Air mass flow rate at design conditions |
| Modelica.Units.SI.Temperature | TAirEnt_nominal | if typ == Buildings.Fluid.HydronicConfigurations.Types.Control.Heating then 20 + 273.15 else 26 + 273.15 | Air entering temperature at design conditions |
| Modelica.Units.SI.MassFraction | phiAirEnt_nominal | 0.5 | Air entering relative humidity at design conditions |
| Modelica.Units.SI.Temperature | TLiqEnt_nominal | if typ == Buildings.Fluid.HydronicConfigurations.Types.Control.Heating then 60 + 273.15 else 7 + 273.15 | Liquid entering temperature at design conditions |
| Modelica.Units.SI.Temperature | TLiqLvg_nominal | TLiqEnt_nominal + (if typ == Buildings.Fluid.HydronicConfigurations.Types.Control.Heating then -10 else +5) | Liquid leaving temperature at design conditions |
| Modelica.Units.SI.HeatFlowRate | Q_flow_nominal | (MediumLiq.specificEnthalpy_pTX(MediumLiq.p_default, TLiqEnt_nominal, X = MediumLiq.X_default) - MediumLiq.specificEnthalpy_pTX(MediumLiq.p_default, TLiqLvg_nominal, X = MediumLiq.X_default))*mLiq_flow_nominal | Transmitted heat flow rate at design conditions |
| Real | u_min | 0.1 | Minimum fan speed |
| Control valve | |||
| Modelica.Units.SI.PressureDifference | dpValve_nominal | dpTer_nominal | Control valve pressure drop at design conditions |
| Balancing valves | |||
| Modelica.Units.SI.PressureDifference | dpBal1_nominal | 0 | Balancing valve pressure drop at design conditions |
| Valve controller | |||
| Buildings.Controls.OBC.CDL.Types.SimpleController | controllerType | Buildings.Controls.OBC.CDL.Types.SimpleController.PI | Type of controller |
| Real | k | 0.1 | Gain of controller |
| Real | Ti | 10 | Time constant of integrator block |
| Real | Td | 0.1 | Time constant of derivative block |
| Dynamics › Conservation equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamics.FixedInitial | Type of energy balance: dynamic (3 initialization options) or steady state |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Controls.OBC.CDL.Interfaces.RealInput | u | Fraction of design load | |
| Buildings.Controls.OBC.CDL.Interfaces.BooleanInput | u1 | System enable | |
| Buildings.Templates.Components.Loads.Load | loa | Load | |
| Buildings.Fluid.HydronicConfigurations.ActiveNetworks.Throttle | con | Throttle circuit connection | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yLoa_actual | Actual load fraction met | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | Q_flow | Total heat flow rate transferred to the load | |
| Buildings.Controls.OBC.CDL.Interfaces.RealOutput | yVal_actual | Valve position feedback |
Contents
| Name | Description |
|---|---|
| MediumAir | Medium model for air |
| MediumLiq | Medium model for liquid (CHW or HHW) |
Revisions
-
December 8, 2025, by Antoine Gautier:
First implementation.