ibpsa · mwetter · May 21, 2024 · May 15, 2024 · May 16, 2024 · May 17, 2024
diff --git a/IBPSA/Fluid/SolarCollectors/ASHRAE93.mo b/IBPSA/Fluid/SolarCollectors/ASHRAE93.mo
@@ -0,0 +1,209 @@
+within IBPSA.Fluid.SolarCollectors;
+model ASHRAE93 "Model of a solar thermal collector according to the ASHRAE Standard 93"
+  extends IBPSA.Fluid.SolarCollectors.BaseClasses.PartialSolarCollector(
+    redeclare IBPSA.Fluid.SolarCollectors.Data.GenericASHRAE93 per);
+
+  BaseClasses.ASHRAESolarGain solGai(
+    redeclare package Medium = Medium,
+    final nSeg=nSeg,
+    final til=til,
+    final incAngDat=per.incAngDat,
+    final incAngModDat=per.incAngModDat,
+    final y_intercept=per.y_intercept,
+    final use_shaCoe_in=use_shaCoe_in,
+    final shaCoe=shaCoe,
+    final A_c=ATot_internal)
+    "Identifies heat gained from the sun using the ASHRAE Standard 93 calculations"
+             annotation (Placement(transformation(extent={{-20,40},{0,60}})));
+
+  BaseClasses.ASHRAEHeatLoss heaLos(
+    redeclare package Medium = Medium,
+    final nSeg=nSeg,
+    final slope=per.slope,
+    final A_c=ATot_internal)
+    "Calculates the heat lost to the surroundings using the ASHRAE Standard 93 calculations"
+        annotation (Placement(transformation(extent={{-20,10},{0,30}})));
+
+equation
+  // Make sure the model is only used with the ASHRAE ratings data, and slope < 0
+  assert(per.slope < 0,
+    "In " + getInstanceName() + ": The heat loss coefficient from the ASHRAE ratings data must be strictly negative. Obtained slope = " + String(per.slope));
+
+  connect(weaBus.TDryBul, heaLos.TEnv) annotation (Line(
+      points={{-99.95,80.05},{-90,80.05},{-90,26},{-22,26}},
+      color={255,204,51},
+      thickness=0.5,
+      smooth=Smooth.None), Text(
+      textString="%first",
+      index=-1,
+      extent={{-6,3},{-6,3}}));
+  connect(HDirTil.inc, solGai.incAng)    annotation (Line(
+      points={{-59,46},{-50,46},{-50,48},{-22,48}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(HDirTil.H, solGai.HDirTil)    annotation (Line(
+      points={{-59,50},{-50,50},{-50,52},{-22,52}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(HDifTilIso.HGroDifTil, solGai.HGroDifTil) annotation (Line(
+      points={{-59,74},{-40,74},{-40,55},{-22,55}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(HDifTilIso.HSkyDifTil, solGai.HSkyDifTil) annotation (Line(
+      points={{-59,86},{-30,86},{-30,58},{-22,58}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(shaCoe_in, solGai.shaCoe_in) annotation (Line(
+      points={{-120,40},{-40,40},{-40,45},{-22,45}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(solGai.QSol_flow, QGai.Q_flow) annotation (Line(
+      points={{1,50},{50,50}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(temSen.T, heaLos.TFlu) annotation (Line(
+      points={{-11,-20},{-30,-20},{-30,14},{-22,14}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(temSen.T, solGai.TFlu) annotation (Line(
+      points={{-11,-20},{-30,-20},{-30,42},{-22,42}},
+      color={0,0,127},
+      smooth=Smooth.None));
+  connect(heaLos.QLos_flow, QLos.Q_flow) annotation (Line(
+      points={{1,20},{50,20}},
+      color={0,0,127},
+      smooth=Smooth.None));
+annotation (
+    Icon(coordinateSystem(preserveAspectRatio=false, extent={{-100,-100},{100,
+            100}}),
+         graphics={
+        Rectangle(
+          extent={{-84,100},{84,-100}},
+          lineColor={27,0,55},
+          fillColor={26,0,55},
+          fillPattern=FillPattern.Solid),
+        Line(
+          points={{-100,0},{-76,0},{-76,-90},{66,-90},{66,-60},{-64,-60},{-64,
+              -30},{66,-30},{66,0},{-64,0},{-64,28},{66,28},{66,60},{-64,60},{
+              -64,86},{78,86},{78,0},{98,0},{100,0}},
+          color={0,128,255},
+          thickness=1,
+          smooth=Smooth.None),
+        Ellipse(
+          extent={{-24,26},{28,-26}},
+          lineColor={255,255,0},
+          fillColor={255,255,0},
+          fillPattern=FillPattern.Solid),
+        Line(
+          points={{-6,-6},{8,8}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1,
+          origin={-24,30},
+          rotation=90),
+        Line(
+          points={{-50,0},{-30,0}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1),
+        Line(
+          points={{-36,-40},{-20,-24}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1),
+        Line(
+          points={{-10,0},{10,0}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1,
+          origin={2,-40},
+          rotation=90),
+        Line(
+          points={{-8,-8},{6,6}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1,
+          origin={30,-30},
+          rotation=90),
+        Line(
+          points={{32,0},{52,0}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1),
+        Line(
+          points={{-8,-8},{6,6}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1,
+          origin={28,32},
+          rotation=180),
+        Line(
+          points={{-10,0},{10,0}},
+          color={255,255,0},
+          smooth=Smooth.None,
+          thickness=1,
+          origin={0,40},
+          rotation=90)}),
+  defaultComponentName="solCol",
+  Documentation(info="<html>
+<p>
+This component models a solar thermal collector according to the ASHRAE93
+test standard.
+</p>
+
+<h4>References</h4>
+<p>
+ASHRAE 93-2010 -- Methods of Testing to Determine the Thermal Performance of
+Solar Collectors (ANSI approved).
+</p>
+<p>
+<a href=\"https://energyplus.net/assets/nrel_custom/pdfs/pdfs_v23.2.0/EngineeringReference.pdf\">
+EnergyPlus 23.2.0 Engineering Reference</a>.
+</p>
+</html>", revisions="<html>
+<ul>
+<li>
+February 28, 2024, by Jelger Jansen:<br/>
+Refactor model.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3604\">Buildings, #3604</a>.
+</li>
+<li>
+December 11, 2023, by Michael Wetter:<br/>
+Corrected implementation of pressure drop calculation for the situation where the collectors are in parallel,
+e.g., if <code>sysConfig == IBPSA.Fluid.SolarCollectors.Types.SystemConfiguration.Parallel</code>.<br/>
+Changed assignment of <code>computeFlowResistance</code> to <code>final</code> based on
+<code>dp_nominal</code>.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3597\">Buildings, #3597</a>.
+</li>
+<li>
+September 16, 2021, by Michael Wetter:<br/>
+Changed <code>lat</code> from being a parameter to an input from weather bus.<br/>
+This is for
+<a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1477\">IBPSA, #1477</a>.
+</li>
+<li>
+December 17, 2017, by Michael Wetter:<br/>
+Revised computation of heat loss.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/1100\">
+issue 1100</a>.
+</li>
+<li>
+November 21, 2017, by Michael Wetter:<br/>
+Corrected error in heat loss calculations that did not scale correctly with <code>nPanels</code>.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/1073\">issue 1073</a>.
+</li>
+<li>
+October 18, 2013, by Michael Wetter:<br/>
+Removed duplicate connection.
+</li>
+<li>
+January 4, 2013, by Peter Grant:<br/>
+First implementation.
+</li>
+</ul>
+</html>"));
+end ASHRAE93;
diff --git a/IBPSA/Fluid/SolarCollectors/BaseClasses/ASHRAEHeatLoss.mo b/IBPSA/Fluid/SolarCollectors/BaseClasses/ASHRAEHeatLoss.mo
@@ -0,0 +1,87 @@
+within IBPSA.Fluid.SolarCollectors.BaseClasses;
+block ASHRAEHeatLoss
+  "Calculate the heat loss of a solar collector per ASHRAE standard 93"
+  extends IBPSA.Fluid.SolarCollectors.BaseClasses.PartialHeatLoss(
+    QLos_internal = -slope * A_c/nSeg * {dT[i] for i in 1:nSeg});
+
+  parameter Modelica.Units.SI.CoefficientOfHeatTransfer slope(final max=0)
+    "Slope from ratings data";
+
+annotation (
+defaultComponentName="heaLos",
+Documentation(info="<html>
+<p>
+This component computes the heat loss from the solar thermal collector to the
+environment.
+It is designed for use with ratings data collected in accordance with
+ASHRAE Standard 93.
+A negative heat loss indicates that heat is being lost to the environment.
+</p>
+
+<h4> Model description </h4>
+<p>
+This model calculates the heat loss to the ambient, for each segment
+<i>i &isin; {1, ..., n<sub>seg</sub>}</i> where <i>n<sub>seg</sub></i> is
+the number of segments, as
+</p>
+<p align=\"center\" style=\"font-style:italic;\">
+Q<sub>los,i</sub> = -slope A<sub>c</sub> &frasl; n<sub>seg</sub>
+  (T<sub>env</sub>-T<sub>flu,i</sub>)
+</p>
+<p>
+where
+<i>slope &lt; 0</i> is the slope for the heat loss as specified in the ratings
+data, <i>A<sub>c</sub></i> is the collector area, <i>T<sub>env</sub></i> is
+the environment temperature, and <i>T<sub>flu,i</sub></i> is the
+fluid temperature in segment <i>i &isin; {1, ..., n<sub>seg</sub>}</i>.
+</p>
+<p>
+This model reduces the heat loss rate to <i>0</i> when the fluid temperature
+is within <i>1</i> Kelvin of the minimum temperature of the medium model.
+The calculation is performed using the
+<a href=\"modelica://IBPSA.Utilities.Math.Functions.smoothHeaviside\">
+IBPSA.Utilities.Math.Functions.smoothHeaviside</a> function.
+</p>
+
+<h4>Implementation</h4>
+<p>
+ASHRAE uses the collector fluid inlet temperature to compute the heat loss
+(see Duffie and Beckmann, p. 293).
+However, unless the environment temperature which was present during the
+collector rating is known, which is not the case, one cannot compute a
+log mean temperature difference that would improve the <i>UA</i> calculation.
+Hence, this model is using the fluid temperature of each segment
+to compute the heat loss to the environment.
+</p>
+
+<h4>References</h4>
+<p>
+ASHRAE 93-2010 -- Methods of Testing to Determine the Thermal Performance of Solar
+Collectors (ANSI approved).
+</p>
+<p>
+J.A. Duffie and W.A. Beckman 2006, Solar Engineering of Thermal Processes (3rd Edition),
+John Wiley &amp; Sons, Inc.
+</p>
+</html>", revisions="<html>
+<ul>
+<li>
+February 15, 2024, by Jelger Jansen:<br/>
+Refactor model.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3604\">Buildings, #3604</a>.
+</li>
+<li>
+December 17, 2017, by Michael Wetter:<br/>
+Revised computation of heat loss.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/1100\">
+issue 1100</a>.
+</li>
+<li>
+Jan 16, 2012, by Peter Grant:<br/>
+First implementation
+</li>
+</ul>
+</html>"));
+end ASHRAEHeatLoss;