Issue3063 District DHW

Buildings/Experimental/DHC/EnergyTransferStations/BaseClasses/PartialDirect.mo

@@ -57,7 +57,7 @@ model PartialDirect
     "Bandwidth around reference signal for on/off controller"
     annotation (Dialog(tab="Advanced"));
 
-  Modelica.Blocks.Interfaces.RealInput TSetDisRet(
+  Modelica.Blocks.Interfaces.RealInput TDisRetSet(
      final unit="K",
      displayUnit="degC")
     "Setpoint for the district return temperature (min for cooling, max for heating)"
@@ -197,7 +197,7 @@ equation
   connect(senTDisSup.T,dTDis. u2)
     annotation (Line(points={{-170,-269},{-172,-269},{-172,-184},{60,-184},{60,-110},
           {78,-110}},                                            color={0,0,127}));
-  connect(TSetDisRet, con.u_s)
+  connect(TDisRetSet, con.u_s)
     annotation (Line(points={{-318,0},{-272,0},{-272,250},{-222,250}},
                                                                      color={0,0,127}));
   connect(senTBuiRet.T, con.u_m)
@@ -224,7 +224,7 @@ cooling network is at or above the minimum specified value. This configuration
 naturally results in a fluctuating building supply tempearture.
 </p>
 <p align=\"center\">
-<img src=\"modelica://Buildings/Resources/Images/Experimental/DHC/EnergyTransferStations/Cooling/Direct.PNG\" alt=\"DC ETS Direct\"/>
+<img src=\"modelica://Buildings/Resources/Images/Experimental/DHC/EnergyTransferStations/Cooling/Direct.png\" alt=\"DC ETS Direct\"/>
 </p>
 <h4>
 Reference

Buildings/Experimental/DHC/EnergyTransferStations/BaseClasses/PartialIndirect.mo

@@ -84,7 +84,7 @@ model PartialIndirect
   parameter Real yMin=0.01
     "Lower limit of output"
     annotation (Dialog(group="PID controller"));
-  Modelica.Blocks.Interfaces.RealInput TSetBuiSup
+  Modelica.Blocks.Interfaces.RealInput TBuiSupSet
     "Setpoint temperature for building supply"
     annotation (Placement(transformation(extent={{-340,-20},{-300,20}})));
   Modelica.Blocks.Interfaces.RealOutput Q_flow(
@@ -201,7 +201,7 @@ equation
     annotation (Line(points={{-26,-193},{-26,-180},{-140,-180},{-140,-240},{-120,
           -240},{-120,-232}},
                           color={0,0,127}));
-  connect(TSetBuiSup, con.u_s)
+  connect(TBuiSupSet, con.u_s)
     annotation (Line(points={{-320,0},{-240,0},{-240,-220},{-132,-220}},
                                                  color={0,0,127}));
   connect(con.y, conVal.y)

Buildings/Experimental/DHC/EnergyTransferStations/Combined/BaseClasses/PartialParallel.mo

@@ -223,9 +223,11 @@ equation
     annotation (Line(points={{282,-60},{290,-60},{290,-40},{320,-40}},
                                                   color={0,0,127}));
   connect(hex.yValIso_actual[1],valIsoCon.y_actual)
-    annotation (Line(points={{-12,-251},{-40,-251},{-40,-113},{-55,-113}},color={0,0,127}));
+    annotation (Line(points={{-12,-251.5},{-40,-251.5},{-40,-113},{-55,-113}},
+                                                                          color={0,0,127}));
   connect(hex.yValIso_actual[2],valIsoEva.y_actual)
-    annotation (Line(points={{-12,-253},{-16,-253},{-16,-240},{40,-240},{40,-113},{55,-113}},color={0,0,127}));
+    annotation (Line(points={{-12,-252.5},{-16,-252.5},{-16,-240},{40,-240},{40,
+          -113},{55,-113}},                                                                  color={0,0,127}));
   connect(valIsoEva.port_b,colAmbWat.port_bDisSup)
     annotation (Line(points={{50,-120},{30,-120},{30,-106},{20,-106}},color={0,127,255}));
   connect(valIsoCon.port_b,colAmbWat.port_aDisSup)

Buildings/Experimental/DHC/EnergyTransferStations/Combined/BaseClasses/package.order

@@ -1 +1,2 @@
+PartialHeatPumpHeatExchanger
 PartialParallel

Buildings/Experimental/DHC/EnergyTransferStations/Combined/ChillerBorefield.mo

@@ -266,9 +266,11 @@ equation
   connect(conSup.yAmb[1],borFie.u)
     annotation (Line(points={{-238,25},{-200,25},{-200,-212},{-82,-212}},color={0,0,127}));
   connect(valIsoCon.y_actual,borFie.yValIso_actual[1])
-    annotation (Line(points={{-55,-113},{-40,-113},{-40,-198},{-90,-198},{-90,-217},{-82,-217}},color={0,0,127}));
+    annotation (Line(points={{-55,-113},{-40,-113},{-40,-198},{-90,-198},{-90,
+          -216.5},{-82,-216.5}},                                                                color={0,0,127}));
   connect(valIsoEva.y_actual,borFie.yValIso_actual[2])
-    annotation (Line(points={{55,-113},{40,-113},{40,-200},{-88,-200},{-88,-215},{-82,-215}},color={0,0,127}));
+    annotation (Line(points={{55,-113},{40,-113},{40,-200},{-88,-200},{-88,
+          -215.5},{-82,-215.5}},                                                             color={0,0,127}));
   connect(borFie.PPum,totPPum.u[3])
     annotation (Line(points={{-58,-216},{250,-216},{250,-62},{258,-62},{258,-60}},color={0,0,127}));
   connect(zerPPum.y,totPPum.u[3])

Buildings/Experimental/DHC/EnergyTransferStations/Combined/HeatPumpHeatExchangerDHWTank.mo

@@ -0,0 +1,164 @@
+within Buildings.Experimental.DHC.EnergyTransferStations.Combined;
+model HeatPumpHeatExchangerDHWTank
+  "Model of a substation with heat pump for heating, heat pump with storage tank for domestic hot water, and compressor-less cooling"
+  extends
+    Buildings.Experimental.DHC.EnergyTransferStations.Combined.BaseClasses.PartialHeatPumpHeatExchanger(
+    volMix_b(nPorts=4),
+    volMix_a(nPorts=4));
+  Buildings.Fluid.Sources.Boundary_pT souDCW(
+    redeclare final package Medium = MediumBui,
+    use_T_in=true,
+    nPorts=1)  if have_hotWat "Source for domestic cold water"
+                                 annotation (Placement(
+      transformation(
+      extent={{10,-10},{-10,10}},
+      rotation=180,
+      origin={-52,-56})));
+  Buildings.Experimental.DHC.EnergyTransferStations.Combined.Subsystems.HeatPumpDHWTank proHotWat(
+    redeclare final package Medium1 = MediumBui,
+    redeclare final package Medium2 = MediumSer,
+    final COP_nominal=COPHotWat_nominal,
+    TCon_nominal=THotWatSup_nominal,
+    TEva_nominal=TDisWatMin - dT_nominal,
+    QHotWat_flow_nominal=QHotWat_flow_nominal,
+    dT_nominal=dT_nominal,
+    final allowFlowReversal1=allowFlowReversalBui,
+    final allowFlowReversal2=allowFlowReversalSer,
+    dp1_nominal=6000,
+    dp2_nominal=6000,
+    datWatHea=datWatHea) if have_hotWat
+    "Subsystem for hot water production"
+    annotation (Placement(transformation(extent={{30,24},{50,44}})));
+  parameter Buildings.Experimental.DHC.Loads.HotWater.Data.GenericDomesticHotWaterWithHeatExchanger
+    datWatHea "Performance data"
+    annotation (Placement(transformation(extent={{36,48},{48,60}})));
+  Buildings.Experimental.DHC.Loads.HotWater.ThermostaticMixingValve theMixVal(
+    redeclare package Medium = MediumBui,
+    mMix_flow_nominal=QHotWat_flow_nominal/cpBui_default/(THotWatSup_nominal - TColWat_nominal))
+     if have_hotWat
+     "Thermostatic mixing valve"
+    annotation (Placement(transformation(extent={{-20,50},{-40,72}})));
+  Buildings.Experimental.DHC.EnergyTransferStations.BaseClasses.Junction dcwSpl(
+      redeclare final package Medium = MediumBui, final m_flow_nominal=
+        datWatHea.mDom_flow_nominal*{1,-1,-1})
+                                             "Splitter for domestic cold water"
+    annotation (Placement(transformation(
+        extent={{-10,-10},{10,10}},
+        rotation=90,
+        origin={-10,0})));
+  Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter gai(
+    k=1/QHotWat_flow_nominal) if have_hotWat
+    annotation (Placement(transformation(extent={{-80,50},{-60,70}})));
+equation
+
+  connect(proHotWat.port_b2, volMix_b.ports[4])
+    annotation (Line(points={{30,28},{28,28},{28,0},{260,0},{260,-360}},
+                                                           color={0,127,255}));
+  connect(proHotWat.PHea, PHeaTot.u[2]) annotation (Line(points={{52,37},{66,37},
+          {66,38},{268,38},{268,80.5}},
+        color={0,0,127}));
+  connect(proHotWat.PPum, PPumHeaTot.u[2]) annotation (Line(points={{52,34},{
+          176,34},{176,420.5},{188,420.5}},
+                                    color={0,0,127}));
+  connect(proHotWat.mEva_flow, masFloHeaTot.u[2]) annotation (Line(points={{52,31},
+          {68,31},{68,30},{256,30},{256,-139.5},{268,-139.5}},
+                                                           color={0,0,127}));
+  connect(proHotWat.mEva_flow, masFloHea.u2) annotation (Line(points={{52,31},{
+          58,31},{58,-242},{-6,-242},{-6,-252}},
+                                              color={0,0,127}));
+  connect(proHotWat.port_a2, volMix_a.ports[4]) annotation (Line(points={{50,28},
+          {54,28},{54,20},{-260,20},{-260,-360}},             color={0,127,255}));
+  connect(souDCW.ports[1], dcwSpl.port_1) annotation (Line(points={{-42,-56},{
+          -10,-56},{-10,-10}},color={0,127,255}));
+  connect(dcwSpl.port_3, proHotWat.port_a1)
+    annotation (Line(points={{0,-6.66134e-16},{10,-6.66134e-16},{10,40},{30,40}},
+                                                           color={0,127,255}));
+  connect(dcwSpl.port_2, theMixVal.port_col) annotation (Line(points={{-10,10},
+          {-10,52.2},{-20,52.2}}, color={0,127,255}));
+  connect(proHotWat.port_b1, theMixVal.port_hot) annotation (Line(points={{50,40},
+          {60,40},{60,80},{0,80},{0,56.6},{-20,56.6}},
+                                           color={0,127,255}));
+  connect(souDCW.T_in, TColWat) annotation (Line(points={{-64,-60},{-156,-60},{
+          -156,-80},{-320,-80}}, color={0,0,127}));
+  connect(THotWatSupSet, theMixVal.TMixSet) annotation (Line(points={{-320,-40},
+          {-32,-40},{-32,32},{-6,32},{-6,64},{-14,64},{-14,63.2},{-19,63.2}},
+                                                            color={0,0,127}));
+  connect(QReqHotWat_flow, gai.u) annotation (Line(points={{-320,-120},{-288,-120},
+          {-288,60},{-82,60}},
+                         color={0,0,127}));
+  connect(gai.y, theMixVal.yMixSet) annotation (Line(points={{-58,60},{-48,60},
+          {-48,78},{-6,78},{-6,70},{-12,70},{-12,69.8},{-19,69.8}},
+                                                  color={0,0,127}));
+  connect(enaSHW.y, proHotWat.uEna) annotation (Line(points={{-118,80},{-108,80},
+          {-108,43},{28,43}}, color={255,0,255}));
+  annotation (
+  Documentation(info="<html>
+<p>
+This model uses the base energy transfer station defined in
+<a href=\"modelica://Buildings.Experimental.DHC.EnergyTransferStations.Combined.BaseClasses.PartialHeatPumpHeatExchanger\">
+Buildings.Experimental.DHC.EnergyTransferStations.Combined.BaseClasses.PartialHeatPumpHeatExchanger</a>.
+</p>
+<h4>Domestic Hot Water</h4>
+<p>
+Domestic hot water is produced using a dedicated water-to-water heat pump
+with storage tank.
+</p>
+<p>
+Heating is enabled based on the input signal <code>uSHW</code>
+which is held for <i>15</i> minutes, meaning that,
+when enabled, the mode remains active for at least <i>15</i> minutes and,
+when disabled, the mode cannot be enabled again for at least <i>15</i> minutes.
+The enable signal should be computed externally based
+on a schedule (to lock out the system during off-hours), ideally in conjunction
+with the number of requests or any other signal representative of the load.
+</p>
+<p>
+When enabled,
+</p>
+<ul>
+<li>
+The heat pump and the evaporator and condenser hydronics are controlled
+based on the principles described in
+<a href=\"modelica://Buildings.Experimental.DHC.EnergyTransferStations.Combined.Subsystems.HeatPumpDHWTank\">
+Buildings.Experimental.DHC.EnergyTransferStations.Combined.Subsystems.HeatPumpDHWTank</a>.
+</li>
+<li>
+The mass flow rate of water leaving the domestic hot water heat exchanger is computed based on the domestic hot water
+heating load (input <code>QReqHotWat_flow</code>) combined with the operation of a thermostatic
+mixing valve used to mix down the temperature of hot water leaving the domestic hot water heat exchanger
+to the temperature distributed to fixtures (parameter <code>THotWatSup_nominal</code>)
+using domestic cold water at the cold water temperature (input <code>TColWat</code>).
+The desired water flow rate leaving the thermostatic mixing valve
+is determined according to the following equation:
+<p align=\"center\" style=\"font-style:italic;\">
+<code>QReqHotWat_flow</code> = m&#775; cp (<code>THotWatSup_nominal</code> - <code>TColWat</code>)
+</p>
+</li>
+</ul>
+</html>",
+  revisions="<html>
+<ul>
+<li>
+September 13, 2023, by David Blum:<br/>
+First implementation, extended from partial base class.
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3063\">
+issue 3063</a>.
+</li>
+</ul>
+</html>"), Icon(graphics={
+        Rectangle(
+          extent={{-70,36},{-68,26}},
+          lineColor={0,0,255},
+          pattern=LinePattern.None,
+          fillColor={175,175,175},
+          fillPattern=FillPattern.Solid),
+        Rectangle(
+          extent={{-1.5,5.5},{1.5,-5.5}},
+          lineColor={0,0,255},
+          pattern=LinePattern.None,
+          fillColor={175,175,175},
+          fillPattern=FillPattern.Solid,
+          origin={-13.5,26.5},
+          rotation=90)}));
+end HeatPumpHeatExchangerDHWTank;