modelBoilerPolynomialClosedLoop
Boilers with efficiency specified by polynomial and with open loop control
Extends from Modelica.Icons.Example.
Information
This model illustrates how to use a boiler model with closed loop control. The controller modulates the boiler temperature between 60°C and 80°C. A three-way valve mixes recirculated water with boiler water to regulate the temperature of the volume at a constant temperature of 40°C. There is also a bypass in the boiler loop to ensure circulation when the valve position is such that it only recirculates water from the load. The bypass between valve and pump mixes recirculated water, thereby allowing the valve to work over a larger operating range. The expansion vessel near the boiler is used to set a reference pressure, and it is used to accommodate for the thermal expansion of the water.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Power | Q_flow_nominal | 20000 | Nominal power |
| Modelica.Units.SI.Temperature | dT_nominal | 20 | Nominal temperature difference |
| Modelica.Units.SI.MassFlowRate | m_flow_nominal | Q_flow_nominal/dT_nominal/4200 | Nominal mass flow rate |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.Boilers.BoilerPolynomial | boi | Boiler | |
| Modelica.Blocks.Logical.OnOffController | onOffController | ||
| Modelica.Blocks.Math.BooleanToReal | booleanToReal | ||
| Actuators.Valves.ThreeWayEqualPercentageLinear | val | ||
| Movers.FlowControlled_m_flow | pumLoa | Pump for heating load | |
| Movers.FlowControlled_m_flow | pumBoi | Pump for boiler loop | |
| Modelica.Blocks.Sources.Constant | m_flow_pum | Mass flow rate of pump | |
| Modelica.Blocks.Sources.Constant | TSetBoi | Temperature setpoint for boiler | |
| Controls.Continuous.LimPID | conPID | ||
| Modelica.Blocks.Sources.Constant | TSetHea | Temperature setpoint for heating load | |
| Buildings.Fluid.FixedResistances.Junction | spl | Splitter/mixer | |
| Buildings.Fluid.FixedResistances.Junction | spl1 | Splitter/mixer | |
| Buildings.Fluid.FixedResistances.Junction | spl2 | Splitter/mixer | |
| Buildings.Fluid.FixedResistances.Junction | spl3 | Splitter/mixer | |
| Storage.ExpansionVessel | exp | ||
| Buildings.Fluid.FixedResistances.Junction | spl4 | Splitter/mixer | |
| MixingVolumes.MixingVolume | vol | ||
| Modelica.Thermal.HeatTransfer.Components.ThermalConductor | thermalConductor | ||
| Modelica.Thermal.HeatTransfer.Sources.FixedTemperature | TBou | Fixed temperature boundary condition | |
| Modelica.Blocks.Math.Gain | gain | Multiply the mass flow rate as this circuit has a smaller temperature difference | |
| Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor | TVol | Sensor for volume temperature |
Contents
| Name | Description |
|---|---|
| Medium | Medium model |
Revisions
-
April 9, 2024, by Hongxiang Fu:
SpecifiednominalValuesDefineDefaultPressureCurve=truein the mover component to suppress a warning. This is for #3819. -
March 1, 2016, by Michael Wetter:
Removed parameterdynamicBalance. This is for #484. -
December 22, 2014 by Michael Wetter:
RemovedModelica.Fluid.Systemto address issue #311. -
October 6, 2014, by Michael Wetter:
Corrected wrong value ofm_flow_nominalforspl3. -
March 25, 2014, by Michael Wetter:
Updated model with new expansion vessel. -
March 1, 2013, by Michael Wetter:
Added nominal pressure drop for valve as this parameter no longer has a default value. -
November 1, 2011 by Michael Wetter:
First implementation.