Thermal wheels #3554

JayHuLBL · 2023-10-09T23:35:10Z

This closes #3538.

Issue3538 air2air recovery

mwetter · 2023-10-25T13:49:24Z

@JayHuLBL : What are the next steps, and who needs to act on them?

JayHuLBL · 2023-10-25T20:33:37Z

@mwetter The PR will be ready for your review when CI test passed.

One questions however is about the base class Buildings.Fluid.HeatExchangers.AirToAirHeatRecovery.BaseClasses.HeatExchagerWithInputEffectiveness. The class is similar as Buildings.Fluid.MassExchangers.ConstantEffectiveness, with the difference that the effectiveness espS and espL are inputs rather than parameter. Is it a good choice to duplicate the class and change the effectiveness to be inputs (as implemented here.)?
Or making the changes in Buildings.Fluid.MassExchangers.ConstantEffectiveness so that the effectiveness could be conditional inputs. But in this case, the class name ConstantEffectiveness will need to be changed.

mwetter · 2023-10-26T22:22:06Z

I think HeatExchagerWithInputEffectiveness is fine as I don't see an elegant way to change the effectiveness to be a conditional input, and remove the parameter if the input is enabled.

mwetter

I did a quick review and it is clear that this model is not yet ready for a final review. Please see comments and review first the code; afterwards I am happy to do a last review.

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/BaseClasses/Effectiveness.mo

mwetter · 2023-10-26T22:26:49Z

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/BaseClasses/Effectiveness.mo

+  vRat = v_ave/v_sup_nom,
+</pre>
+<p>
+where <code>v_ave</code> is the average volumetric air flow rate,


See how we otherwise refer to volume or mass flow rates. (Moreover, if you were to use mass flow rate, then the sensor would be simpler, and the result would in my opinion not change much if at all).

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/BaseClasses/Effectiveness.mo

...Exchangers/AirToAirHeatRecovery/BaseClasses/Validation/HeatExchagerWithInputEffectiveness.mo

mwetter · 2023-10-26T22:36:06Z

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/Examples/BypassDamper.mo

+    m1_flow(start=5),
+    m2_flow(start=5),


Why are there start attribute set?

mwetter · 2023-10-26T22:38:20Z

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/Examples/BypassDamper.mo

+    dp1_nominal=100,
+    dp2_nominal=100,


Is that realistic for a wheel? I think more common are around 300 Pa.

@SenHuang19 In class Examples.WheelWithBypassDamper and Examples.WheelWithVariableSpeed, the dp1_nominal and dp2_nominal are still set to be 100. Is it typical?

mwetter · 2023-10-26T22:38:39Z

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/Examples/BypassDamper.mo

+    epsL_heat_nominal=0.7,
+    epsL_heat_partload=0.6) "Wheel"
+    annotation (Placement(transformation(extent={{6,-4},{26,16}})));
+  Modelica.Blocks.Sources.Ramp DamPos(


Naming convention.

mwetter · 2023-10-26T22:38:48Z

Buildings/Fluid/HeatExchangers/AirToAirHeatRecovery/Examples/BypassDamper.mo

+  inner Modelica.Fluid.System system
+    "Ambient environment"


Why is this needed?

JayHuLBL · 2024-04-17T22:21:05Z

@mwetter It's ready for your review.

mwetter · 2024-04-23T21:53:11Z

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

+  epsSenPL = Buildings.Utilities.Math.Functions.regStep(TSup-TExh, epsSenCooPL, epsSenHeaPL, 1e-5);
+  epsSen_nominal = Buildings.Utilities.Math.Functions.regStep(TSup-TExh, epsSenCoo_nominal, epsSenHea_nominal, 1e-5);
+  epsLatPL = Buildings.Utilities.Math.Functions.regStep(TSup-TExh, epsLatCooPL, epsLatHeaPL, 1e-5);
+  epsLat_nominal = Buildings.Utilities.Math.Functions.regStep(TSup-TExh, epsLatCoo_nominal, epsLatHea_nominal, 1e-5);


These 4 calls to regStep should be changed: There should only be one call to regStep as the first argument is always the same.
In many configurations, the parameters for the efficiency are the same, in which case no regStep (or weighting of the two values) is needed.

I changed these calls.

Buildings/Fluid/HeatExchangers/ThermalWheels/Latent/SpeedControlled.mo

JayHuLBL · 2024-04-24T21:09:51Z

@SenHuang19 Would you please address the comments?

mwetter · 2024-04-24T22:42:17Z

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

+  Modelica.Blocks.Sources.RealExpression VSup_flow(
+    final y(final unit="m3/s")=hex.port_a1.m_flow/
+        Medium1.density(state=Medium1.setState_phX(
+        p=hex.port_a1.p,
+        h=hex.port_a1.h_outflow,
+        X=hex.port_a1.Xi_outflow)))
+    "Supply air volume flow rate"
+    annotation (Placement(transformation(extent={{-160,30},{-140,50}})));
+  Modelica.Blocks.Sources.RealExpression VExh_flow(
+    final y(final unit="m3/s")=hex.port_a2.m_flow/
+        Medium2.density(state=Medium2.setState_phX(


All efficiency calculations must be based on mass flow rate.

mwetter · 2024-04-24T22:44:19Z

Buildings/Fluid/HeatExchangers/ThermalWheels/Latent/BypassDampers.mo

+  Buildings.Fluid.Actuators.Dampers.Exponential bypDamSup(
+    redeclare package Medium = Medium1,
+    final m_flow_nominal=m1_flow_nominal,
+    final dpDamper_nominal=dp1_nominal)
+    "Supply air bypass damper"
+    annotation (Placement(transformation(extent={{-60,70},{-40,90}})));
+  Buildings.Fluid.Actuators.Dampers.Exponential damSup(
+    redeclare package Medium = Medium1,
+    final m_flow_nominal=m1_flow_nominal,
+    final dpDamper_nominal=dp1_nominal)
+    "Supply air damper"
+    annotation (Placement(transformation(
+        extent={{-10,-10},{10,10}},rotation=0,origin={-50,40})));
+  Buildings.Fluid.Actuators.Dampers.Exponential damExh(
+    redeclare package Medium = Medium2,
+    final m_flow_nominal=m2_flow_nominal,
+    final dpDamper_nominal=dp2_nominal)


It is unreasonable -- and wrong -- to set the damper pressure drops to the same value as the heat exchanger pressure drop, which is by default 500 Pa.

SenHuang19 · 2024-04-25T00:31:03Z

@SenHuang19 Would you please address the comments?

Sure, will do.

SenHuang19 · 2024-05-13T03:40:38Z

Update the revision history for Thermal wheels #3554 (comment)
Specify the definition of 75% part load for Thermal wheels #3554 (comment)
Replace the volumetric flow rates with mass flow rates for Thermal wheels #3554 (comment)
Replace the RealExpression blocks with mass flow meters
Only one medium object is needed
Wrong pressure values for the damper for Thermal wheels #3554 (comment)

SenHuang19 · 2024-05-13T20:38:40Z

Change the way to define the wheel energy efficiency for #3554 (comment)

Current Implementation

The sensible and latent heat exchange effectiveness under a lower speed ratio = the speed ratio * the sensible and latent heat exchange effectiveness under the full speed
The power of the wheel under a lower speed ratio = the rated power * the speed ratio/motor efficiency

Literature Review

EnergyPlus

The sensible and latent heat exchange effectiveness under a lower speed ratio = the speed ratio * the sensible and latent heat exchange effectiveness under the full speed source_code
The power of the wheel under a lower speed ratio = the rated power source_code

ASHRAE Handbook

The sensible and latent heat exchange effectiveness under a lower speed ratio is described in the following figure (source)
No description regarding the power of the wheel under a lower speed ratio

Manufacturing Data

The sensible and latent heat exchange effectiveness under a lower speed ratio is sometimes provided (source)
No description regarding the power of the wheel under a lower speed ratio
The power-related information includes 1) rated power, 2)rated RPM, 3) wheel weight, and 4) wheel radius (source)

Proposed calculation

Parameters

Rated power (W)
Rated RPM (rad/s)
Wheel weight (kg)
Wheel radius (m)
Rated motor efficiency (default = 0.8)
Motor efficiency under lower speed ratios (Table 1)
Sensible and latent heat exchange effectiveness under lower speed ratios (Table 2 and 3)
Boolean for using the default motor efficiency curve
Boolean for using the default effectiveness curves

Preflight

Rated torque = rated power * 9549 / rated RPM * rated motor efficiency
Inertia moment = wheel weight * wheel radius * wheel radius

Calculation

Actual wheel power = (static torque + dynamic torque) * angular velocity/motor efficiency
Dynamic torque = inertia moment * der(angular velocity)
Static torque = 0.5 * inertia moment * angular velocity * angular velocity
Motor efficiency = f1(speed ratio), f1() is from Table 1 or default DOE curve
Sensible heat exchange effectiveness = f2(speed ratio, sensible heat exchange effectiveness at full speed), f2() is from Table 2 or default ASHRAE curve
Latent heat exchange effectiveness = f3(speed ratio, latent heat exchange effectiveness at full speed), f3() is from Table 3 or default ASHRAE curve

Assert

Static torque + dynamic torque < rated torque

@mwetter and @JayHuLBL could you please take a look at the proposed change?

Based on the discussion on 5/21/2024, the followings are the required changes:

The wheel power = rated power * rated efficiency * speed ratio / motor efficiency = rated power * rated efficiency * (rated efficiency/motor efficiency)
Sensible/latent heat exchange effectiveness = sensible/latent effectiveness correction at part speed ratios* sensible heat exchange effectiveness at full speed
Create records for the (rated efficiency/motor efficiency) and sensible/latent effectiveness correction at part speed ratios, respectively
Modify the ASHRAE data record so that the heat exchanger effectiveness equal to 0 when the speed ratio is 0
Move the above implementation to Buildings.Fluid.HeatExchangers.BaseClasses
Duplicate theBuildings.Fluid.Movers.BaseClasses.Characteristics.efficiencyParameters_yMot to Buildings.Fluid.HeatExchangers.BaseClasses.VariableSpeedWheel.BaseClasses.Characteristics

SenHuang19 · 2024-05-13T20:40:43Z

Add realistic examples

Add a control loop to the wheel
Change the zone controller from on-off to PI
Making the mass flow rate of the air through the wheel equals 0 for some times during the simulation period

SenHuang19 · 2024-06-13T02:23:28Z

Based on the discussion on 6/12/2024.

Modify the layout of the connection lines in the icons so that they don't lay on top of other lines, and are aligned with the grid
Change the Buildings.Fluid.HeatExchangers.BaseClasses.VariableSpeedWheel into Buildings.Fluid.HeatExchangers.BaseClasses.VariableSpeedThermalWheels

mwetter · 2024-06-13T20:44:13Z

@SenHuang19 : Note that it should be plural not singular, e.g., VariableSpeedThermalWheels as the models are also in the package ThermalWheels (plural).

Also, the first and last bullet are the same. What needs to be corrected is the layout of the connection lines so that they don't lay on top of other lines, and are aligned with the grid.

SenHuang19 · 2024-06-14T02:02:40Z

@SenHuang19 : Note that it should be plural not singular, e.g., VariableSpeedThermalWheels as the models are also in the package ThermalWheels (plural).

Also, the first and last bullet are the same. What needs to be corrected is the layout of the connection lines so that they don't lay on top of other lines, and are aligned with the grid.

@mwetter thank you so much for your clarification. I have updated the task list.

SenHuang19 · 2024-09-18T15:51:58Z

Updates are made in #3909, which is ready for Jianjun's review.

Huang and others added 12 commits September 28, 2023 17:24

first implementation

3685a5b

enhance the example by adding one use case

12eb4b8

cleanup

07dbf26

update the model doc

b149ee5

improve model doc

c85a367

update the release note

0501e4c

Merge pull request #3541 from SenHuang19/issue3538_Air2Air_recovery

bd60f25

Issue3538 air2air recovery

merged master

aa48571

renamed example model, removed obsolete example

1d1107a

removed Modelica.Fluid.System

dc5a245

reverted changes, changed example models name

7d6d0e0

fixed html syntax, corrected release note

ea482fd

JayHuLBL added 2 commits October 25, 2023 12:10

renamed model

e2cc156

merged master

9ad06bf

mwetter requested changes Oct 26, 2023

View reviewed changes

Huang added 12 commits November 1, 2023 15:41

fix typos

6aa884a

change parameter names and replace if with approximation

80aa7ed

reimplement the wheels with different controls

3b4bddb

fixing naming and icon

d0a6f99

Merge branch 'master' into issue3538_Air2Air_recovery

1280ac1

model clean up

6291751

model doc update and clean up

4bfe833

fix issues in examples

0c47509

diagram and info updated

e7720a1

model doc enhance

fce7045

fix typos

13e1010

merge the changes from the forked repo

1e772d6

improved text

3cbc5a1

Merge branch 'master' into issue3538_Air2Air_recovery

d5549c9

mwetter reviewed Apr 23, 2024

View reviewed changes

mwetter added 4 commits April 23, 2024 15:14

Improved implementation to avoid non-needed call to regStep

fcff2bf

Revised implementation and documentation

5f85b77

Improved implementation to avoid non-needed call to regStep

b7c4161

Updated comment

526249d

mwetter reviewed Apr 24, 2024

View reviewed changes

Buildings/Fluid/HeatExchangers/ThermalWheels/Latent/SpeedControlled.mo Show resolved Hide resolved

mwetter added 2 commits April 24, 2024 09:43

Changed graphical layout

292edbf

Added icons

ddc8734

mwetter added 6 commits April 24, 2024 14:37

Updated icon

234038d

Removed connector to itself

15d5370

Updated release notes

0fa5da9

Corrected html

dfbe906

Restricted ratio of flow rates

c973468

Removed assertion that would trigger each time the fan switches off

40b5d7c

mwetter changed the title ~~Issue3538 air2 air recovery~~ Thermal wheels Apr 24, 2024

mwetter requested changes Apr 24, 2024

View reviewed changes

SenHuang19 mentioned this pull request Jun 22, 2024

Issue3538 thermal wheel #3909

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9 tasks

SenHuang19 mentioned this pull request Sep 18, 2024

Issue3711 desiccant dehumidifier #3748

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Thermal wheels #3554

Thermal wheels #3554

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Thermal wheels #3554

Are you sure you want to change the base?

Thermal wheels #3554

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Current Implementation

Literature Review

Proposed calculation

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