ibpsa · mwetter · Oct 12, 2021 · Jul 12, 2021 · Jul 12, 2021 · Jul 12, 2021
diff --git a/IBPSA/Fluid/FixedResistances/Examples/PlugFlowPipe.mo b/IBPSA/Fluid/FixedResistances/Examples/PlugFlowPipe.mo
@@ -17,7 +17,6 @@ model PlugFlowPipe "Simple example of plug flow pipe"
     annotation (Placement(transformation(extent={{82,-10},{62,10}})));
   IBPSA.Fluid.FixedResistances.PlugFlowPipe pip(
     redeclare package Medium = Medium,
-    nPorts=1,
     dh=0.1,
     length=100,
     dIns=0.05,
@@ -56,7 +55,7 @@ equation
     annotation (Line(points={{-20,70},{10,70},{10,10}}, color={191,0,0}));
   connect(Tin.y, sou.T_in)
     annotation (Line(points={{-71,4},{-62,4}}, color={0,0,127}));
-  connect(pip.ports_b[1], senTemOut.port_a)
+  connect(pip.port_b, senTemOut.port_a)
     annotation (Line(points={{20,0},{30,0}}, color={0,127,255}));
   connect(senTemOut.port_b, sin.ports[1])
     annotation (Line(points={{50,0},{62,0}}, color={0,127,255}));

diff --git a/IBPSA/Fluid/FixedResistances/PlugFlowPipe.mo b/IBPSA/Fluid/FixedResistances/PlugFlowPipe.mo
@@ -1,7 +1,7 @@
 within IBPSA.Fluid.FixedResistances;
 model PlugFlowPipe
   "Pipe model using spatialDistribution for temperature delay"
-  extends IBPSA.Fluid.Interfaces.PartialTwoPortVector;
+  extends IBPSA.Fluid.Interfaces.PartialTwoPort;
 
   constant Boolean homotopyInitialization = true "= true, use homotopy method"
     annotation(HideResult=true);
@@ -117,12 +117,12 @@ model PlugFlowPipe
     redeclare final package Medium = Medium,
     final m_flow_nominal=m_flow_nominal,
     final V=if rho_default > 500 then VEqu else VEqu/1000,
-    final nPorts=nPorts + 1,
+    final nPorts=2,
     final T_start=T_start_out,
     final energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
-    final mSenFac = if rho_default > 500 then 1 else 10)
-    "Control volume connected to ports_b. Represents equivalent pipe wall thermal capacity."
-    annotation (Placement(transformation(extent={{60,20},{80,40}})));
+    final mSenFac=if rho_default > 500 then 1 else 10)
+    "Control volume connected to port_b. Represents equivalent pipe wall thermal capacity."
+    annotation (Placement(transformation(extent={{40,20},{60,40}})));
 
 protected
   parameter Modelica.SIunits.HeatCapacity CPip=
@@ -157,19 +157,16 @@ initial equation
     level = AssertionLevel.warning);
 
 equation
-  for i in 1:nPorts loop
-    connect(vol.ports[i + 1], ports_b[i])
-    annotation (Line(points={{70,20},{72,20},{72,6},{72,0},{100,0}},
-        color={0,127,255}));
-  end for;
   connect(cor.heatPort, heatPort)
     annotation (Line(points={{0,10},{0,10},{0,100}}, color={191,0,0}));
 
   connect(cor.port_b, vol.ports[1])
-    annotation (Line(points={{10,0},{70,0},{70,20}}, color={0,127,255}));
+    annotation (Line(points={{10,0},{48,0},{48,20}}, color={0,127,255}));
 
-  connect(cor.port_a, port_a)
-    annotation (Line(points={{-10,0},{-56,0},{-100,0}}, color={0,127,255}));
+  connect(vol.ports[2], port_b) annotation (Line(points={{52,20},{52,20},{52,0},
+          {100,0}}, color={0,127,255}));
+  connect(port_a, cor.port_a)
+    annotation (Line(points={{-100,0},{-10,0}}, color={0,127,255}));
   annotation (
     Line(points={{70,20},{72,20},{72,0},{100,0}}, color={0,127,255}),
     Diagram(coordinateSystem(preserveAspectRatio=false, extent={{-100,-100},{
@@ -215,6 +212,17 @@ d = %dh")}),
     Documentation(revisions="<html>
 <ul>
 <li>
+July 9, 2021, by Baptiste Ravache:<br/>
+Replaced the vectorized outlet port <code>ports_b</code> with
+a single outlet port <code>port_b</code>.<br/>
+This is for
+<a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1494\">IBPSA, #1494</a>.<br/>
+This change is not backward compatible.<br/>
+The previous class definition was moved to
+<a href=\"modelica://IBPSA.Obsolete.Fluid.FixedResistances.PlugFlowPipe\">
+IBPSA.Obsolete.Fluid.FixedResistances.PlugFlowPipe</a>.
+</li>
+<li>
 April 14, 2020, by Michael Wetter:<br/>
 Changed <code>homotopyInitialization</code> to a constant.<br/>
 This is for
@@ -274,8 +282,6 @@ The thermal capacity of the pipe wall is implemented as a mixing volume
 of the fluid in the pipe, of which the thermal capacity
 is equal to that of the pipe wall material.
 In addition, this mixing volume allows the hydraulic separation of subsequent pipes.
-Thanks to the vectorized implementation of the (design) outlet port,
-splits and junctions of pipes can be handled in a numerically efficient way.
 <br/>
 This mixing volume is not present in the
 <a href=\"modelica://IBPSA.Fluid.FixedResistances.BaseClasses.PlugFlowCore\">PlugFlowCore</a> model,
@@ -295,7 +301,7 @@ The boundary temperature is uniform.
 </li>
 <li>
 The thermal inertia of the pipe wall material is lumped on the side of the pipe
-that is connected to <code>ports_b</code>.
+that is connected to <code>port_b</code>.
 </li>
 </ul>
 <h4>References</h4>

diff --git a/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/FlowReversal.mo b/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/FlowReversal.mo
@@ -11,12 +11,11 @@ model FlowReversal
   Sources.Boundary_pT sin(
     redeclare package Medium = Medium,
     nPorts=1,
-    p(displayUnit="Pa") = 101325,
+    p(displayUnit="bar") = 500000,
     T=313.15) "Pressure boundary condition"
     annotation (Placement(transformation(extent={{82,-10},{62,10}})));
   IBPSA.Fluid.FixedResistances.PlugFlowPipe pip(
     redeclare package Medium = Medium,
-    nPorts=1,
     dIns=0.05,
     kIns=0.028,
     cPip=500,
@@ -28,7 +27,7 @@ model FlowReversal
     v_nominal=2,
     T_start_in=293.15,
     T_start_out=293.15) "Pipe"
-    annotation (Placement(transformation(extent={{0,-10},{20,10}})));
+    annotation (Placement(transformation(extent={{2,-10},{22,10}})));
   IBPSA.Fluid.Sources.MassFlowSource_T sou(
     nPorts=1,
     redeclare package Medium = Medium,
@@ -52,14 +51,14 @@ model FlowReversal
     "Temperature sensor"
     annotation (Placement(transformation(extent={{-30,-10},{-10,10}})));
 equation
-  connect(pip.ports_b[1], senTemOut.port_a)
-    annotation (Line(points={{20,0},{30,0}}, color={0,127,255}));
+  connect(pip.port_b, senTemOut.port_a)
+    annotation (Line(points={{22,0},{30,0}}, color={0,127,255}));
   connect(senTemOut.port_b, sin.ports[1])
     annotation (Line(points={{50,0},{62,0}}, color={0,127,255}));
   connect(sou.ports[1], senTemIn.port_a)
     annotation (Line(points={{-40,0},{-30,0}}, color={0,127,255}));
   connect(senTemIn.port_b, pip.port_a)
-    annotation (Line(points={{-10,0},{0,0}}, color={0,127,255}));
+    annotation (Line(points={{-10,0},{2,0}}, color={0,127,255}));
   connect(m_flow.y, sou.m_flow_in)
     annotation (Line(points={{-71,8},{-62,8}}, color={0,0,127}));
   annotation (
@@ -74,6 +73,11 @@ Validation model in which water flows into the pipe and then the flow is reverse
 </html>", revisions="<html>
 <ul>
 <li>
+July 12, 2021, by Baptiste Ravache:<br/>
+Change outlet boundary pressure to avoid negative 
+pressure at the inlet when flow is reversed.
+</li>
+<li>
 October 25, 2017, by Michael Wetter:<br/>
 First implementation.
 </li>

diff --git a/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/PlugFlowAIT.mo b/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/PlugFlowAIT.mo
@@ -60,7 +60,6 @@ model PlugFlowAIT
     kIns=0.024,
     length=115,
     allowFlowReversal=allowFlowReversal,
-    nPorts=2,
     m_flow_nominal=0.3,
     R=1/(2*0.024*Modelica.Constants.pi)*log(0.18/0.0899) + 1/(2*2.4*Modelica.Constants.pi)
         *log(2/0.18),
@@ -69,7 +68,7 @@ model PlugFlowAIT
     rhoPip=8000,
     initDelay=false,
     m_flow_start=0) "Pipe 1"
-    annotation (Placement(transformation(extent={{50,0},{30,20}})));
+    annotation (Placement(transformation(extent={{60,0},{40,20}})));
   PlugFlowPipe pip4(
     dh = 0.0337 - 2*0.0032,
     redeclare package Medium = Medium,
@@ -79,7 +78,6 @@ model PlugFlowAIT
     allowFlowReversal=allowFlowReversal,
     m_flow_nominal=0.3,
     thickness=thickness,
-    nPorts=2,
     R=R80,
     cPip=500,
     rhoPip=8000,
@@ -97,7 +95,6 @@ model PlugFlowAIT
     kIns=0.024,
     dIns=0.045,
     allowFlowReversal=allowFlowReversal,
-    nPorts=2,
     m_flow_nominal=0.3,
     R=1/(2*0.024*Modelica.Constants.pi)*log(0.18/0.0899) + 1/(2*2.4*Modelica.Constants.pi)
         *log(2/0.18),
@@ -114,7 +111,6 @@ model PlugFlowAIT
     dIns=0.045,
     kIns=0.024,
     allowFlowReversal=allowFlowReversal,
-    nPorts=1,
     m_flow_nominal=0.3,
     thickness=thickness,
     dh=0.0337 - 2*0.0032,
@@ -134,7 +130,6 @@ model PlugFlowAIT
     dIns=0.045,
     kIns=0.024,
     allowFlowReversal=allowFlowReversal,
-    nPorts=1,
     m_flow_nominal=0.3,
     thickness=thickness,
     dh=0.0337 - 2*0.0032,
@@ -210,7 +205,6 @@ model PlugFlowAIT
     kIns=0.024,
     length=20,
     allowFlowReversal=allowFlowReversal,
-    nPorts=2,
     m_flow_nominal=0.3,
     R=1/(2*0.024*Modelica.Constants.pi)*log(0.18/0.0899) + 1/(2*2.4*Modelica.Constants.pi)
         *log(2/0.18),
@@ -261,6 +255,36 @@ model PlugFlowAIT
         rotation=180,
         origin={46,56})));
 
+  IBPSA.Fluid.FixedResistances.Junction splPip1(
+    redeclare package Medium = Medium,
+    m_flow_nominal={pip1.m_flow_nominal,pip5.m_flow_nominal,pip4.m_flow_nominal},
+    from_dp=true,
+    linearized=true,
+    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
+    dp_nominal(each displayUnit="Pa") = {0,0,0},
+    portFlowDirection_1=if allowFlowReversal then Modelica.Fluid.Types.PortFlowDirection.Bidirectional
+         else Modelica.Fluid.Types.PortFlowDirection.Entering,
+    portFlowDirection_2=if allowFlowReversal then Modelica.Fluid.Types.PortFlowDirection.Bidirectional
+         else Modelica.Fluid.Types.PortFlowDirection.Leaving,
+    portFlowDirection_3=if allowFlowReversal then Modelica.Fluid.Types.PortFlowDirection.Bidirectional
+         else Modelica.Fluid.Types.PortFlowDirection.Leaving)
+    "Splitter coming out of pip1"
+    annotation (Placement(transformation(extent={{30,20},{10,0}})));
+  IBPSA.Fluid.FixedResistances.Junction splPip2(
+    redeclare package Medium = Medium,
+    m_flow_nominal={pip5.m_flow_nominal,pip2.m_flow_nominal,pip3.m_flow_nominal},
+    from_dp=true,
+    linearized=true,
+    energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial,
+    dp_nominal(each displayUnit="Pa") = {0,0,0},
+    portFlowDirection_1=if allowFlowReversal then Modelica.Fluid.Types.PortFlowDirection.Bidirectional
+         else Modelica.Fluid.Types.PortFlowDirection.Entering,
+    portFlowDirection_2=if allowFlowReversal then Modelica.Fluid.Types.PortFlowDirection.Bidirectional
+         else Modelica.Fluid.Types.PortFlowDirection.Leaving,
+    portFlowDirection_3=if allowFlowReversal then Modelica.Fluid.Types.PortFlowDirection.Bidirectional
+         else Modelica.Fluid.Types.PortFlowDirection.Leaving)
+    "Splitter coming out of pip5"
+    annotation (Placement(transformation(extent={{-30,0},{-50,20}})));
 equation
   connect(m_flow_p3.y, Point3.m_flow_in) annotation (Line(
       points={{-62,-110},{-58,-110},{-58,-94}},
@@ -280,12 +304,12 @@ equation
       smooth=Smooth.None));
   connect(DataReader.y[9], prescribedTemperature.T)
     annotation (Line(points={{21,-130},{38,-130}},        color={0,0,127}));
-  connect(pip4.heatPort, pip1.heatPort) annotation (Line(points={{20,40},{20,40},
-          {40,40},{40,20}}, color={191,0,0}));
-  connect(pip1.heatPort, pip0.heatPort) annotation (Line(points={{40,20},{40,26},
+  connect(pip4.heatPort, pip1.heatPort) annotation (Line(points={{20,40},{50,40},
+          {50,20}},         color={191,0,0}));
+  connect(pip1.heatPort, pip0.heatPort) annotation (Line(points={{50,20},{50,26},
           {100,26},{100,-10},{90,-10}},
                                       color={191,0,0}));
-  connect(pip1.heatPort, pip2.heatPort) annotation (Line(points={{40,20},{40,26},
+  connect(pip1.heatPort, pip2.heatPort) annotation (Line(points={{50,20},{50,26},
           {-78,26}},                   color={191,0,0}));
   connect(pip5.heatPort, pip2.heatPort) annotation (Line(points={{-10,20},{-10,26},
           {-78,26}},                       color={191,0,0}));
@@ -316,29 +340,21 @@ equation
   connect(lessThreshold.u, m_flow_p4.y) annotation (Line(points={{93.6,128},{
           100,128},{100,140},{114,140}},
                                color={0,0,127}));
-  connect(pip1.port_a, pip0.ports_b[1])
-    annotation (Line(points={{50,10},{78,10},{78,0}}, color={0,127,255}));
-  connect(pip1.ports_b[1], pip4.port_a)
-    annotation (Line(points={{30,8},{10,8},{10,30}}, color={0,127,255}));
-  connect(pip5.port_a, pip1.ports_b[2])
-    annotation (Line(points={{0,10},{30,10},{30,12}}, color={0,127,255}));
-  connect(pip4.ports_b[1], senTem_p4.port_a)
-    annotation (Line(points={{8,50},{8,70}},        color={0,127,255}));
-  connect(Point5.ports[1], pip4.ports_b[2]) annotation (Line(points={{36,56},{
-          36,56},{12,56},{12,50}}, color={0,127,255}));
-  connect(pip5.ports_b[1], senTemIn_p2.port_b)
-    annotation (Line(points={{-20,8},{-60,8}},          color={0,127,255}));
-  connect(pip3.port_a, pip5.ports_b[2])
-    annotation (Line(points={{-50,-10},{-50,12},{-20,12}},
-                                                         color={0,127,255}));
+  connect(pip1.port_a, pip0.port_b)
+    annotation (Line(points={{60,10},{80,10},{80,0}}, color={0,127,255}));
+  connect(pip4.port_b, senTem_p4.port_a)
+    annotation (Line(points={{10,50},{10,60},{8,60},{8,70}},
+                                                    color={0,127,255}));
+  connect(Point5.ports[1], pip4.port_b) annotation (Line(points={{36,56},{36,56},
+          {10,56},{10,50}},        color={0,127,255}));
   connect(senTemIn_p2.port_a, pip2.port_a)
     annotation (Line(points={{-80,8},{-88,8},{-88,16}},   color={0,127,255}));
-  connect(pip2.ports_b[1], senTem_p2.port_a)
+  connect(pip2.port_b, senTem_p2.port_a)
     annotation (Line(points={{-88,36},{-88,46}},          color={0,127,255}));
-  connect(pip3.ports_b[1], senTem_p3.port_a) annotation (Line(points={{-50,-30},
+  connect(pip3.port_b, senTem_p3.port_a) annotation (Line(points={{-50,-30},
           {-50,-40}},           color={0,127,255}));
-  connect(ExcludedBranch.ports[1], pip0.ports_b[2]) annotation (Line(points={{82,30},
-          {82,0}},                       color={0,127,255}));
+  connect(ExcludedBranch.ports[1], pip0.port_b) annotation (Line(points={{82,30},
+          {82,16},{82,0},{80,0}},        color={0,127,255}));
   connect(switch1.y, Point5.m_flow_in) annotation (Line(points={{109,64},{58,64}},
                             color={0,0,127}));
   connect(m_flow_p4.y, switch1.u3) annotation (Line(points={{114,140},{100,140},
@@ -348,6 +364,18 @@ equation
   connect(lessThreshold.y, switch1.u2) annotation (Line(points={{75.2,128},{66,
           128},{66,104},{140,104},{140,64},{132,64}},
                                                     color={255,0,255}));
+  connect(pip5.port_a, splPip1.port_2)
+    annotation (Line(points={{0,10},{10,10}},color={0,127,255}));
+  connect(pip1.port_b, splPip1.port_1)
+    annotation (Line(points={{40,10},{30,10}}, color={0,127,255}));
+  connect(splPip1.port_3, pip4.port_a) annotation (Line(points={{20,20},{20,24},
+          {10,24},{10,30}}, color={0,127,255}));
+  connect(senTemIn_p2.port_b, splPip2.port_2)
+    annotation (Line(points={{-60,8},{-60,10},{-50,10}}, color={0,127,255}));
+  connect(pip5.port_b, splPip2.port_1)
+    annotation (Line(points={{-20,10},{-30,10}}, color={0,127,255}));
+  connect(pip3.port_a, splPip2.port_3) annotation (Line(points={{-50,-10},{-50,-4},
+          {-40,-4},{-40,0}}, color={0,127,255}));
   annotation (
     experiment(
       StopTime=603900,

diff --git a/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/PlugFlowULg.mo b/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/PlugFlowULg.mo
@@ -94,7 +94,6 @@ model PlugFlowULg "Validation against data from Université de Liège"
     T_start_in=T_start_in,
     R=((1/(2*pipe.kIns)*log((0.0603/2 + pipe.dIns)/(0.0603/2))) + 1/(5*(0.0603
          + 2*pipe.dIns)))/Modelica.Constants.pi,
-    nPorts=1,
     initDelay=true,
     m_flow_start=pipeDataULg.m_flowIni,
     cPip=500,
@@ -149,7 +148,7 @@ equation
           0}},                                  color={0,127,255}));
   connect(senTem_out.port_a, senEntOut.port_b)
     annotation (Line(points={{-160,0},{-140,0}},       color={0,127,255}));
-  connect(senEntOut.port_a, pipe.ports_b[1])
+  connect(senEntOut.port_a, pipe.port_b)
     annotation (Line(points={{-120,0},{-100,0}},       color={0,127,255}));
   connect(pipe.port_a, senEntIn.port_b)
     annotation (Line(points={{-80,0},{-62,0}}, color={0,127,255}));

diff --git a/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/TransportWaterAir.mo b/IBPSA/Fluid/FixedResistances/Validation/PlugFlowPipes/TransportWaterAir.mo
@@ -22,7 +22,6 @@ model TransportWaterAir
     annotation (Placement(transformation(extent={{82,16},{62,36}})));
   IBPSA.Fluid.FixedResistances.PlugFlowPipe pip(
     redeclare package Medium = MediumW,
-    nPorts=1,
     dIns=0.05,
     kIns=0.028,
     m_flow_nominal=1,
@@ -62,7 +61,6 @@ model TransportWaterAir
     "Pressure boundary condition"
     annotation (Placement(transformation(extent={{80,-80},{60,-60}})));
   PlugFlowPipe duc(
-    nPorts=1,
     dIns=0.05,
     kIns=0.028,
     m_flow_nominal=1,
@@ -112,7 +110,7 @@ equation
   connect(Tin.y, sou.T_in)
     annotation (Line(points={{-71,30},{-62,30}},
                                                color={0,0,127}));
-  connect(pip.ports_b[1], senTemOutW.port_a)
+  connect(pip.port_b, senTemOutW.port_a)
     annotation (Line(points={{20,26},{30,26}}, color={0,127,255}));
   connect(senTemOutW.port_b, sin.ports[1])
     annotation (Line(points={{50,26},{62,26}}, color={0,127,255}));
@@ -122,7 +120,7 @@ equation
   connect(senTemIn.port_b, pip.port_a)
     annotation (Line(points={{-10,26},{0,26}},
                                              color={0,127,255}));
-  connect(duc.ports_b[1],senTemOutA. port_a)
+  connect(duc.port_b,senTemOutA. port_a)
     annotation (Line(points={{18,-70},{28,-70}}, color={0,127,255}));
   connect(senTemOutA.port_b, sin1.ports[1])
     annotation (Line(points={{48,-70},{60,-70}}, color={0,127,255}));