Buildings.Controls.OBC.RadiantSystems.Heating
Package with control sequences for radiant heating systems
Information
Package with controllers for radiant heating systems.
Extends from Modelica.Icons.Package (Icon for standard packages).
Package Content
| Name | Description |
|---|---|
 HighMassSupplyTemperature_TRoom
|
Room temperature controller for radiant heating with constant mass flow and variable supply temperature |
 Validation
|
Collection of validation models |
Buildings.Controls.OBC.RadiantSystems.Heating.HighMassSupplyTemperature_TRoom
Room temperature controller for radiant heating with constant mass flow and variable supply temperature
Information
Controller for a radiant heating system.
The controller tracks the room temperature set point TRooSet by
adjusting the supply water temperature set point TSupSet linearly between
TSupSetMin and TSupSetMax
based on the output signal y of the proportional controller.
The pump is either off or operates at full speed, in which case yPum = 1.
The pump control is based on a hysteresis that switches the pump on when the output of the
proportional controller y exceeds 0.2, and the pump is commanded off when the output falls
below 0.1. See figure below for the control charts.
For systems with high thermal mass, this controller should be left configured as a P-controller, which is the default setting. PI-controller likely saturate due to the slow system response.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | TSupSet_max | Maximum heating supply water temperature [K] | |
| Real | TSupSet_min | 293.15 | Minimum heating supply water temperature [K] |
| Control gains | |||
| SimpleController | controllerType | Buildings.Controls.OBC.CDL.T... | Type of controller |
| Real | k | 2 | Gain of controller |
| Real | Ti | 3600 | Time constant of integrator block [s] |
| Real | Td | 0.1 | Time constant of derivative block [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | TRooSet | Set point for room air temperature [K] |
| input RealInput | TRoo | Measured room air temperature [K] |
| output RealOutput | TSupSet | Set point for heating supply water temperature [K] |
| output RealOutput | y | Control signal for heating system from P controller [1] |
| output BooleanOutput | on | Outputs true if the system is demanded on |
| output RealOutput | yPum | Pump speed control signal [1] |
Modelica definition
block HighMassSupplyTemperature_TRoom
"Room temperature controller for radiant heating with constant mass flow and variable supply temperature"
parameter Real TSupSet_max(
final unit="K",
displayUnit="degC") "Maximum heating supply water temperature";
parameter Real TSupSet_min(
final unit="K",
displayUnit="degC") = 293.15 "Minimum heating supply water temperature";
parameter Controls.OBC.CDL.Types.SimpleController controllerType=Buildings.Controls.OBC.CDL.Types.SimpleController.P
"Type of controller";
parameter Real k(
min=100*Buildings.Controls.OBC.CDL.Constants.eps)=2
"Gain of controller";
parameter Real Ti(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)=3600
"Time constant of integrator block";
parameter Real Td(
final quantity="Time",
final unit="s",
min=100*Buildings.Controls.OBC.CDL.Constants.eps)=0.1
"Time constant of derivative block";
Controls.OBC.CDL.Interfaces.RealInput TRooSet(
final unit="K",
displayUnit="degC")
"Set point for room air temperature";
Controls.OBC.CDL.Interfaces.RealInput TRoo(
final unit="K",
displayUnit="degC") "Measured room air temperature";
Controls.OBC.CDL.Interfaces.RealOutput TSupSet(
final unit="K",
displayUnit="degC")
"Set point for heating supply water temperature";
Controls.OBC.CDL.Interfaces.RealOutput y(
final unit="1",
final min=0,
final max=1)
"Control signal for heating system from P controller";
Controls.OBC.CDL.Interfaces.BooleanOutput on
"Outputs true if the system is demanded on";
Controls.OBC.CDL.Interfaces.RealOutput yPum(
final unit="1",
final min=0,
final max=1)
"Pump speed control signal";
Controls.OBC.CDL.Continuous.PID conHea(
final controllerType=controllerType,
final k=k,
final Ti = Ti,
final Td = Td,
final yMax=1,
final yMin=0,
final reverseActing=true) "Controller for heating supply set point signal";
Controls.OBC.CDL.Continuous.Hysteresis hysHea(
uLow=0.1,
uHigh=0.2)
"Hysteresis to switch system on and off";
protected
Controls.OBC.CDL.Continuous.Sources.Constant one(final k=1) "Outputs one";
Controls.OBC.CDL.Continuous.Sources.Constant zero(final k=0) "Outputs zero";
Controls.OBC.CDL.Continuous.Sources.Constant THeaSup_minimum(final k(
final unit="K",
displayUnit="degC") = TSupSet_min)
"Negative value of minimum heating supply water temperature";
Controls.OBC.CDL.Continuous.Sources.Constant THeaSup_maximum(
final k(
final unit="K",
displayUnit="degC") = TSupSet_max) "Maximum heating supply water temperature";
Controls.OBC.CDL.Continuous.Line TSup(
limitBelow=false,
limitAbove=false,
y(final unit="K",
displayUnit="degC")) "Set point for supply water temperature";
CDL.Conversions.BooleanToReal booToRea(
final realFalse=0,
final realTrue=1)
"Pump control signal as a Real number (either 0 or 1)";
equation
connect(conHea.y,hysHea.u);
connect(TRoo, conHea.u_m);
connect(TRooSet, conHea.u_s);
connect(TSup.x1, zero.y);
connect(one.y, TSup.x2);
connect(conHea.y, TSup.u);
connect(TSup.f1, THeaSup_minimum.y);
connect(THeaSup_maximum.y, TSup.f2);
connect(TSup.y, TSupSet);
connect(hysHea.y, on);
connect(conHea.y, y);
connect(booToRea.y, yPum);
connect(booToRea.u, hysHea.y);
end HighMassSupplyTemperature_TRoom;