Merge pull request #4088 from SenHuang19/issue3538_Air2Air_recovery

Issue3538 air2 air recovery

Buildings/Fluid/HeatExchangers/ThermalWheels/BaseClasses/Validation/VariableSpeedThermalWheels.mo

@@ -4,18 +4,28 @@ model VariableSpeedThermalWheels
   extends Modelica.Icons.Example;
   parameter Buildings.Fluid.HeatExchangers.ThermalWheels.Data.ASHRAE
     perSenWhe(
-    motorEfficiency(uSpe={0.1,0.6,0.8,1}, eta={0.3,0.8,0.85,1}),
+    mSup_flow_nominal=1,
+    mExh_flow_nominal=1,
+    motorEfficiency(uSpe={0.1,0.6,0.8,1},
+    eta={0.3,0.8,0.85,1}),
     haveLatentHeatExchange=false,
     useDefaultMotorEfficiencyCurve=false)
     "Performance record for the sensible heat wheel"
     annotation (Placement(transformation(extent={{-80,74},{-60,94}})));
-  parameter Buildings.Fluid.HeatExchangers.ThermalWheels.Data.ASHRAE perLatWhe(
-    motorEfficiency(uSpe={0.1,0.6,0.8,1}, eta={0.3,0.8,0.85,1}),
+  parameter Buildings.Fluid.HeatExchangers.ThermalWheels.Data.ASHRAE
+    perLatWhe(
+    mSup_flow_nominal=1,
+    mExh_flow_nominal=1,
+    motorEfficiency(uSpe={0.1,0.6,0.8,1},
+    eta={0.3,0.8,0.85,1}),
     haveLatentHeatExchange=true,
     useDefaultMotorEfficiencyCurve=false)
     "Performance record for the enthalpy wheel"
     annotation (Placement(transformation(extent={{-40,74},{-20,94}})));
-  parameter Buildings.Fluid.HeatExchangers.ThermalWheels.Data.ASHRAE perLatWheDefMotCur(
+  parameter Buildings.Fluid.HeatExchangers.ThermalWheels.Data.ASHRAE
+    perLatWheDefMotCur(
+    mSup_flow_nominal=1,
+    mExh_flow_nominal=1,
     haveLatentHeatExchange=true,
     useDefaultMotorEfficiencyCurve=true)
     "Performance record for the enthalpy wheel with default motor dataset"
@@ -24,19 +34,20 @@ model VariableSpeedThermalWheels
     senWhe(per=perSenWhe)
     "Sensible heat wheel"
     annotation (Placement(transformation(extent={{-10,40},{10,60}})));
-
   Modelica.Blocks.Sources.Ramp uSpe(
     duration=1,
     startTime=0,
     offset=0,
     height=1)
     "Speed ratio"
     annotation (Placement(transformation(extent={{-60,-10},{-40,10}})));
-  Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses.SpeedCorrectionLatent latWhe(
+  Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses.SpeedCorrectionLatent
+    latWhe(
     per=perLatWhe)
     "Enthalpy wheel"
     annotation (Placement(transformation(extent={{-10,-10},{10,10}})));
-  Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses.SpeedCorrectionLatent latWheDefMotCur(
+  Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses.SpeedCorrectionLatent
+    latWheDefMotCur(
     per=perLatWheDefMotCur)
     "Enthalpy wheel with default motor curve"
     annotation (Placement(transformation(extent={{-10,-60},{10,-40}})));

Buildings/Fluid/HeatExchangers/ThermalWheels/Data/ASHRAE.mo

@@ -1,5 +1,6 @@
 within Buildings.Fluid.HeatExchangers.ThermalWheels.Data;
 record ASHRAE = Buildings.Fluid.HeatExchangers.ThermalWheels.Data.Generic(
+  final haveVariableSpeed=true,
   senHeatExchangeEffectiveness(
     uSpe={0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1},
     epsCor={0,0.40,0.71,0.83,0.90,0.93,0.96,0.97,0.98,0.99,1}),

Buildings/Fluid/HeatExchangers/ThermalWheels/Data/Generic.mo

@@ -1,37 +1,71 @@
 within Buildings.Fluid.HeatExchangers.ThermalWheels.Data;
-record Generic "Generic data record for variable-speed wheels"
+record Generic "Generic data record for thermal wheels"
   extends Modelica.Icons.Record;
 
+  parameter Modelica.Units.SI.MassFlowRate mSup_flow_nominal
+    "Nominal supply air mass flow rate"
+    annotation (Dialog(group="Nominal condition"));
+  parameter Modelica.Units.SI.MassFlowRate mExh_flow_nominal
+    "Nominal exhaust air mass flow rate"
+    annotation (Dialog(group="Nominal condition"));
+  parameter Modelica.Units.SI.PressureDifference dpSup_nominal(displayUnit="Pa")=500
+    "Nominal supply air pressure drop across the heat exchanger"
+    annotation (Dialog(group="Nominal condition"));
+  parameter Modelica.Units.SI.PressureDifference dpExh_nominal(displayUnit="Pa")=dpSup_nominal
+    "Nominal exhaust air pressure drop across the heat exchanger"
+    annotation (Dialog(group="Nominal condition"));
   parameter Real P_nominal(final unit="W")=100
-    "Power consumption at the design condition";
+    "Power consumption at the design condition"
+    annotation (Dialog(group="Nominal condition"));
+  parameter Modelica.Units.SI.Efficiency epsSen_nominal(
+    final max=1)=0.8
+    "Nominal sensible heat exchanger effectiveness"
+    annotation (Dialog(group="Nominal condition"));
+  parameter Modelica.Units.SI.Efficiency epsSenPL(
+    final max=1)=0.75
+    "Part load (75% of the nominal supply flow rate) sensible heat exchanger effectiveness"
+    annotation (Dialog(group="Part load effectiveness"));
+  parameter Modelica.Units.SI.Efficiency epsLat_nominal(
+    final max=1)=0.8
+    "Nominal latent heat exchanger effectiveness"
+    annotation (Dialog(group="Nominal condition"),
+    enable=haveLatentHeatExchange);
+  parameter Modelica.Units.SI.Efficiency epsLatPL(
+    final max=1)=0.75
+    "Part load (75% of the nominal supply mass flow rate) latent heat exchanger effectiveness"
+    annotation (Dialog(group="Part load effectiveness"),
+    enable=haveLatentHeatExchange);
   parameter Characteristics.HeatExchangerEffectiveness senHeatExchangeEffectiveness(
     uSpe={0},
     epsCor={0.7})
     "Multiplication factor for sensible heat exchange effectiveness due to wheel speed ratio between 0 and 1"
-    annotation (Dialog(group="Heat exchange effectiveness computation"));
+    annotation (Dialog(group="Heat exchange effectiveness computation",
+    enable=haveVariableSpeed));
   parameter Characteristics.HeatExchangerEffectiveness latHeatExchangeEffectiveness(
     uSpe={0},
     epsCor={0.7})
-    "Multiplication factor for latent heat exchange effectiveness due to wheel speed ratio between 0 and 1" annotation (
-      Dialog(group="Heat exchange effectiveness computation", enable=
-          haveLatentHeatExchange));
+    "Multiplication factor for latent heat exchange effectiveness due to wheel speed ratio between 0 and 1"
+    annotation (Dialog(group="Heat exchange effectiveness computation",
+    enable=haveLatentHeatExchange and haveVariableSpeed));
   parameter Characteristics.MotorEfficiency motorEfficiency(
     uSpe={0},
     eta={0.7})
     "Motor efficiency versus wheel speed ratio"
-    annotation (Dialog(group="Power computation", enable=useDefaultMotorEfficiencyCurve ==
-      false));
+    annotation (Dialog(group="Power computation",
+    enable=haveVariableSpeed));
   final parameter Buildings.Fluid.Movers.BaseClasses.Characteristics.efficiencyParameters_yMot
     motorEfficiency_default=Buildings.Fluid.Movers.BaseClasses.Characteristics.motorEfficiencyCurve(
       P_nominal=P_nominal,
       eta_max=1)
     "Motor efficiency versus default wheel speed ratio"
-    annotation (Dialog(group="Power computation", enable=useDefaultMotorEfficiencyCurve ==
-      true));
-  parameter Boolean haveLatentHeatExchange = true
+    annotation (Dialog(group="Power computation"));
+  parameter Boolean haveLatentHeatExchange=true
    "Set to true to compute latent heat exchange";
-  parameter Boolean useDefaultMotorEfficiencyCurve = true
-   "Set to true to use default motor efficiency curve";
+  parameter Boolean useDefaultMotorEfficiencyCurve=true
+   "Set to true to use default motor efficiency curve"
+    annotation (Dialog(enable=haveVariableSpeed));
+  parameter Boolean haveVariableSpeed=true
+   "Set to true for the heat recovery wheel with a variable speed drive";
 
   annotation (
   defaultComponentPrefixes = "parameter",
@@ -45,16 +79,20 @@ First implementation.
 </ul>
 </html>", info="<html>
 <p>
-Record containing power and heat exchange parameters for variable-speed thermal wheels.
+Record containing performance-related parameters for thermal wheels.
 </p>
 <p>
 It is used as a template of performance data
-for the variable-speed wheel models in
+for the thermal wheel models in
 <a href=\"modelica://Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses\">
 Buildings.Fluid.HeatExchangers.ThermalWheels.BaseClasses</a>.
 </p>
 <p>
-The record contains four datasets:
+The record contains the parameters, including the nominal mass flow rates, nominal pressure drops, 
+and the heat exchanger effectiveness at part load (75% of the nominal supply flow rate) and at nominal conditions.
+</p>
+<p>
+For the variable-speed thermal wheel (<code>haveVariableSpeed=true</code>), the record also includes the following datasets:
 </p>
 <ul>
 <li>
@@ -86,12 +124,12 @@ corrections versus wheel speed ratio are correction factors that are multiplied
 with the heat exchange effectiveness that the wheel has a full rotational speed.
 </li>
 <li>
-When <code>haveLatentHeatExchange = true</code>,
+When <code>haveLatentHeatExchange=true</code>,
 the dataset of the latent heat exchange effectiveness
 corrections versus wheel speed ratio is enabled,
 </li>
 <li>
-When <code>useDefaultMotorEfficiencyCurve = true</code>,
+When <code>useDefaultMotorEfficiencyCurve=true</code>,
 the motor efficiency versus wheel speed ratio is disabled,
 and the default motor percent full-load
 efficiency versus wheel speed ratio is enabled.

Buildings/Fluid/HeatExchangers/ThermalWheels/Data/package.mo

@@ -1,10 +1,10 @@
 within Buildings.Fluid.HeatExchangers.ThermalWheels;
-package Data "Performance data for variable-speed wheels"
+package Data "Performance data for thermal wheels"
 extends Modelica.Icons.MaterialPropertiesPackage;
 
 annotation (Documentation(info="<html>
 <p>
-This package contains performance data sets for variable-speed thermal wheels.
+This package contains performance data sets for thermal wheels.
 </p>
 </html>"));
 end Data;

Buildings/Fluid/HeatExchangers/ThermalWheels/Latent/BaseClasses/Effectiveness.mo

@@ -2,39 +2,22 @@ within Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.BaseClasses;
 model Effectiveness
   "Model for calculating the heat exchange effectiveness"
   extends Modelica.Blocks.Icons.Block;
-  parameter Modelica.Units.SI.Efficiency epsSenCoo_nominal(final max=1)
-    "Nominal sensible heat exchanger effectiveness at the cooling mode";
-  parameter Modelica.Units.SI.Efficiency epsLatCoo_nominal(final max=1)
-    "Nominal latent heat exchanger effectiveness at the cooling mode";
-  parameter Modelica.Units.SI.Efficiency epsSenCooPL(final max=1)
-    "Part load (75% of the nominal supply flow rate) sensible heat exchanger effectiveness at the cooling mode";
-  parameter Modelica.Units.SI.Efficiency epsLatCooPL(final max=1)
-    "Part load (75% of the nominal supply flow rate) latent heat exchanger effectiveness at the cooling mode";
-  parameter Modelica.Units.SI.Efficiency epsSenHea_nominal(final max=1)
-    "Nominal sensible heat exchanger effectiveness at the heating mode";
-  parameter Modelica.Units.SI.Efficiency epsLatHea_nominal(final max=1)
-    "Nominal latent heat exchanger effectiveness at the heating mode";
-  parameter Modelica.Units.SI.Efficiency epsSenHeaPL(final max=1)
-    "Part load (75% of the nominal supply flow rate) sensible heat exchanger effectiveness at the heating mode";
-  parameter Modelica.Units.SI.Efficiency epsLatHeaPL(final max=1)
-    "Part load (75% of the nominal supply flow rate) latent heat exchanger effectiveness at the heating mode";
+  parameter Modelica.Units.SI.Efficiency epsSen_nominal(final max=1)
+    "Nominal sensible heat exchanger effectiveness";
+  parameter Modelica.Units.SI.Efficiency epsLat_nominal(final max=1)
+    "Nominal latent heat exchanger effectiveness";
+  parameter Modelica.Units.SI.Efficiency epsSenPL(final max=1)
+    "Part load (75% of the nominal supply flow rate) sensible heat exchanger effectiveness";
+  parameter Modelica.Units.SI.Efficiency epsLatPL(final max=1)
+    "Part load (75% of the nominal supply flow rate) latent heat exchanger effectiveness";
   parameter Modelica.Units.SI.MassFlowRate mSup_flow_nominal
     "Nominal supply air mass flow rate";
-
-  Buildings.Controls.OBC.CDL.Interfaces.RealInput TSup(
-    final unit="K")
-    "Supply air temperature"
-    annotation (Placement(transformation(extent={{-140,-60},{-100,-20}})));
-  Buildings.Controls.OBC.CDL.Interfaces.RealInput TExh(
-    final unit="K")
-    "Exhaust air temperature"
-    annotation (Placement(transformation(extent={{-140,-100},{-100,-60}})));
   Buildings.Controls.OBC.CDL.Interfaces.RealInput mSup_flow(final unit="kg/s")
     "Supply air mass flow rate"
-    annotation (Placement(transformation(extent={{-140,60},{-100,100}})));
+    annotation (Placement(transformation(extent={{-140,40},{-100,80}})));
   Buildings.Controls.OBC.CDL.Interfaces.RealInput mExh_flow(final unit="kg/s")
     "Exhaust air mass flow rate"
-    annotation (Placement(transformation(extent={{-140,20},{-100,60}})));
+    annotation (Placement(transformation(extent={{-140,-80},{-100,-40}})));
   Buildings.Controls.OBC.CDL.Interfaces.RealOutput epsSen(final unit="1")
     "Sensible heat exchanger effectiveness"
     annotation (Placement(transformation(extent={{100,30},{140,70}}),
@@ -45,58 +28,28 @@ model Effectiveness
         iconTransformation(extent={{100,-70},{140,-30}})));
 
 protected
-  parameter Boolean equSen_nominal = abs(epsSenCoo_nominal-epsSenHea_nominal) < Modelica.Constants.eps
-     "true if the sensible cooling and heating efficiencies at nominal conditions are equal";
-  parameter Boolean equSenPL = abs(epsSenCooPL-epsSenHeaPL) < Modelica.Constants.eps
-     "true if the sensible cooling and heating efficiencies at part load conditions are equal";
-  parameter Boolean equLat_nominal = abs(epsLatCoo_nominal-epsLatHea_nominal) < Modelica.Constants.eps
-     "true if the latent cooling and heating efficiencies at nominal conditions are equal";
-  parameter Boolean equLatPL = abs(epsLatCooPL-epsLatHeaPL) < Modelica.Constants.eps
-     "true if the latent cooling and heating efficiencies at part load conditions are equal";
-  Real fraCoo(
-   final min=0,
-   final max=1,
-   final unit="1") "Fraction of efficiency contribution from cooling parameters (used for regularization)";
-
   Real rat
     "Ratio of the average operating air flow rate to the nominal supply air flow rate";
   Real ratRes
     "Ratio of the average operating air flow rate to the nominal supply air flow rate, restricted to valid domain";
-  Modelica.Units.SI.Efficiency epsSenPL
-    "Part load sensible heat exchanger effectiveness used for calculation";
-  Modelica.Units.SI.Efficiency epsSen_nominal
-    "Nominal sensible heat exchanger effectiveness used for calculation";
-  Modelica.Units.SI.Efficiency epsLatPL
-    "Part load latent heat exchanger effectiveness used for calculation";
-  Modelica.Units.SI.Efficiency epsLat_nominal
-    "Nominal latent heat exchanger effectiveness used for calculation";
 
 equation
+  // Calculate the average volumetric air flow and flow rate ratio.
+  rat=(mSup_flow+mExh_flow)/2/mSup_flow_nominal;
   // Check if the air flows are too unbalanced, unless rat < 0.05, in which case
   // the system is likely off or transitioning to on or off.
-  assert(rat < 0.05 or (mSup_flow - 2*mExh_flow <= 1e-5 and mExh_flow - 2*mSup_flow <= 1e-5),
+  assert(rat<0.05 or (mSup_flow-2*mExh_flow<1e-5 and mExh_flow-2*mSup_flow<1e-5),
     "In " + getInstanceName() + ": The ratio of the supply flow rate to the exhaust flow rate should be in the range of [0.5, 2] when flow rates are non-zero.",
     level=AssertionLevel.warning);
-  // Calculate the average volumetric air flow and flow rate ratio.
-  rat = (mSup_flow+mExh_flow)/2/mSup_flow_nominal;
-  // Switch between cooling and heating modes based on the difference between the supply air temperature and the exhaust air temperature
-  fraCoo = if (equSen_nominal and equSenPL and equLat_nominal and equLatPL) then 0.5 else Buildings.Utilities.Math.Functions.regStep(TSup-TExh, 1, 0, 1e-5);
-
-  epsSenPL = if equSenPL then epsSenCooPL else fraCoo*epsSenCooPL + (1-fraCoo) * epsSenHeaPL;
-  epsSen_nominal = if equSen_nominal then epsSenCoo_nominal else fraCoo*epsSenCoo_nominal + (1-fraCoo) * epsSenHea_nominal;
-
-  epsLatPL = if equLatPL then epsLatCooPL else fraCoo*epsLatCooPL + (1-fraCoo) * epsLatHeaPL;
-  epsLat_nominal = if equLat_nominal then epsLatCoo_nominal else fraCoo*epsLatCoo_nominal + (1-fraCoo) * epsLatHea_nominal;
-
   // Calculate effectiveness
-  ratRes = Buildings.Utilities.Math.Functions.smoothLimit(x=rat, l=0.5, u=1.3, deltaX=0.01);
-  epsSen = (epsSenPL + (epsSen_nominal - epsSenPL)*(ratRes - 0.75)/0.25);
-  epsLat = (epsLatPL + (epsLat_nominal - epsLatPL)*(ratRes - 0.75)/0.25);
-  assert(epsSen >= 0 and epsSen < 1,
+  ratRes=Buildings.Utilities.Math.Functions.smoothLimit(x=rat, l=0.5, u=1.3, deltaX=0.01);
+  epsSen=(epsSenPL+(epsSen_nominal-epsSenPL)*(ratRes-0.75)/0.25);
+  epsLat=(epsLatPL+(epsLat_nominal-epsLatPL)*(ratRes-0.75)/0.25);
+  assert(epsSen>=0 and epsSen<1,
     "In " + getInstanceName() + ": The sensible heat exchange effectiveness epsSen = " + String(epsSen) + ". It should be in the range of [0, 1].
     Check if the part load (75% of the nominal supply flow rate) or nominal sensible heat exchanger effectiveness is too high or too low.",
     level=AssertionLevel.error);
-  assert(epsLat >= 0 and epsLat < 1,
+  assert(epsLat>=0 and epsLat<1,
     "In " + getInstanceName() + ": The latent heat exchange effectiveness epsLat = " + String(epsLat) + ". It should be in the range of [0, 1],
     Check if the part load (75% of the nominal supply flow rate) or nominal latent heat exchanger effectiveness is too high or too low.",
     level=AssertionLevel.error);
@@ -140,15 +93,6 @@ for the sensible heat transfer when <code>rat</code> is 1 and 0.75, respectively
 <code>epsLat_nominal</code> and <code>epsLatPL</code> are the effectiveness
 for the latent heat transfer when <code>Rat</code> is 1 and 0.75, respectively.
 </p>
-<p>
-The parameters <code>epsSen_nominal</code>, <code>epsSenPL</code>, <code>epsLat_nominal</code>, and
-<code>epsLatPL</code> have different values depending on if the wheel is in
-the cooling or heating mode.
-If the supply air temperature is greater than the exhaust air
-temperature, the exchanger is considered to operate under
-the cooling mode;
-Otherwise, it operates under the heating mode.
-</p>
 <P>
 <b>Note:</b>
 The value of the <code>rat</code> is suggested to be between <i>0.5</i> and <i>1.3</i> during normal operation