modelInjectionThreeWay
Extends from BaseClasses.PartialActivePrimary (Partial model of active primary network).
Information
This model represents a heating system where the configuration Buildings.Fluid.HydronicConfigurations.ActiveNetworks.InjectionThreeWay serves as the interface between a constant flow primary circuit at constant supply temperature and a constant flow secondary circuit at variable supply temperature. The secondary supply temperature is reset with an open loop, representing for instance a reset logic based on the outdoor air temperature. Two identical terminal units are served by the secondary circuit. Each terminal unit has its own hourly load profile.
The primary side of the injection circuit is balanced at design conditions
if kSizBal=1.
Selecting a lower value of the parameter kSizBal illustrates
the operation with an oversized balancing valve, yielding
a lower pressure drop.
One can observe the degraded ΔT (plot #6) and elevated mass flow rate
(plot #7) in the primary circuit.
However, the operation of the consumer circuit is not disturbed:
the set point and the loads are met.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.HydronicConfigurations.Types.Control | typ (from PartialActivePrimary) | Buildings.Fluid.HydronicConfigurations.Types.Control.Heating | Load type |
| Integer | nTer (from PartialActivePrimary) | 2 | Number of terminal units |
| Real | kSizPum (from PartialActivePrimary) | 1.0 | Pump oversizing coefficient |
| Modelica.Units.SI.Pressure | p_min (from PartialActivePrimary) | 200000 | Circuit minimum pressure |
| Modelica.Units.SI.Temperature | TLiqEnt_nominal (from PartialActivePrimary) | 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 (from PartialActivePrimary) | TLiqEnt_nominal + (if typ == Buildings.Fluid.HydronicConfigurations.Types.Control.Heating then -10 else +5) | Liquid leaving temperature at design conditions |
| Modelica.Units.SI.Temperature | TLiqEntChg_nominal (from PartialActivePrimary) | 60 + 273.15 | Liquid entering temperature in change-over mode |
| Modelica.Units.SI.Temperature | TLiqSup_nominal (from PartialActivePrimary) | TLiqEnt_nominal | Liquid primary supply temperature at design conditions |
| Modelica.Units.SI.Temperature | TLiqSupChg_nominal (from PartialActivePrimary) | TLiqEntChg_nominal | Liquid primary supply temperature in change-over mode |
| Nominal condition | |||
| Modelica.Units.SI.MassFlowRate | mTer_flow_nominal (from PartialActivePrimary) | 1 | Terminal unit mass flow rate at design conditions |
| Modelica.Units.SI.MassFlowRate | m1_flow_nominal (from PartialActivePrimary) | m2_flow_nominal | Mass flow rate in primary branch at design conditions |
| Modelica.Units.SI.MassFlowRate | m2_flow_nominal (from PartialActivePrimary) | nTer*mTer_flow_nominal | Mass flow rate in consumer circuit at design conditions |
| Modelica.Units.SI.PressureDifference | dpTer_nominal (from PartialActivePrimary) | 3E4 | Terminal unit pressure drop at design conditions |
| Modelica.Units.SI.PressureDifference | dpPip_nominal (from PartialActivePrimary) | 0.5E4 | Pipe section pressure drop at design conditions |
| Modelica.Units.SI.PressureDifference | dpPum_nominal (from PartialActivePrimary) | Pump head at design conditions | |
| Modelica.Units.SI.MassFlowRate | mPum_flow_nominal (from PartialActivePrimary) | m1_flow_nominal | Primary pump mass flow rate at design conditions |
| Dynamics › Conservation equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics (from PartialActivePrimary) | Modelica.Fluid.Types.Dynamics.FixedInitial | Type of energy balance: dynamic (3 initialization options) or steady state |
| Configuration | |||
| Real | kSizBal | 0.5 | Sizing factor for primary balancing valve (1 means balanced) |
Components
Revisions
-
June 30, 2022, by Antoine Gautier:
First implementation.