Buildings.Fluid.AirFilters
Package with models of air filters
Information
This package contains component models for air filters.
Extends from Modelica.Icons.Package (Icon for standard packages).
Package Content
| Name | Description |
|---|---|
 Empirical
|
Empirical air filter model |
 Data
|
Performance data for air filters |
 Examples
|
Package with example models |
| Validation
|
Collection of models that illustrate model use and test models |
 BaseClasses
|
Package with base classes for Buildings.Fluid.AirFilters |
Buildings.Fluid.AirFilters.Empirical
Empirical air filter model
Information
Component that empirically models the performance of air filters, focusing on key factors such as contamination and pressure drop, without requiring geometric data.
The model uses as parameters performance characteristics
that describe how the filter works under various conditions.
The performance of the air filter is characterized by a performance dataset per
(see
Buildings.Fluid.AirFilters.Data.Generic), which contains key parameters that
define the filter:
-
Contaminant Names: The array
per.namCondefines the type of contaminants that can be captured by the filter. -
Nominal Conditions: They include the nominal pressure drop
dp_nominaland the nominal mass flow ratem_flow_nominalof the clean filter. They also include the maximum total mass of contaminantsmCon_maxthat the filter can hold. -
Resistance Coefficient: The parameter
per.bdescribes how the pressure drop of the filter increases as the contaminants accumulate over time. See Buildings.Fluid.AirFilters.BaseClasses.FlowCoefficientCorrection for more information. -
Filtration Efficiency Curves: The array
per.filEffParcontains the filtration efficiency curves. Each curve defines the efficiencies for capturing each contaminant that is defined inper.namCon. See Buildings.Fluid.AirFilters.BaseClasses.FiltrationEfficiency for more information.
The input boolean flag, uRep, indicates that the filter has been replaced
and thus reset the mass accumulation to the initial status, i.e.,
when uRep changes from false to true, the
mass of the captured contaminants is reset to per.mCon_start.
Warnings will be written when,
-
the captured contaminant mass exceeds the
mCon_max, or -
the
extraPropertiesNamesin the medium model does not contain all the contaminants specified in theper.namCon.
References
- CONTAM User Guide and Program Documentation Version 3.4
- Qiang Li ta al., (2022). Experimental study on the synthetic dust loading characteristics of air filters. Separation and Purification Technology 284 (2022), 120209.
Extends from Buildings.Fluid.Interfaces.PartialTwoPort (Partial component with two ports).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Generic | per | Performance dataset | |
| Assumptions | |||
| Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a | Fluid connector a (positive design flow direction is from port_a to port_b) |
| FluidPort_b | port_b | Fluid connector b (positive design flow direction is from port_a to port_b) |
| input BooleanInput | uRep | True: replace the filter and reset the accumulation |
| output BooleanOutput | yRep | True if the filter is full and should be replaced |
| output RealOutput | rat | Relative mass of the contaminant captured by the filter, which is the total captured contaminant mass divided by the filter's maximum contaminant capacity [1] |
| output RealOutput | eps[nConSub] | Filtration efficiency [1] |
Modelica definition
model Empirical "Empirical air filter model"
extends Buildings.Fluid.Interfaces.PartialTwoPort;
parameter Buildings.Fluid.AirFilters.Data.Generic per
"Performance dataset";
Buildings.Controls.OBC.CDL.Interfaces.BooleanInput uRep
"True: replace the filter and reset the accumulation";
Buildings.Controls.OBC.CDL.Interfaces.BooleanOutput yRep
"True if the filter is full and should be replaced";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput rat(
final unit="1",
final min=0)
"Relative mass of the contaminant captured by the filter, which is the total captured contaminant mass divided by the filter's maximum contaminant capacity";
Buildings.Controls.OBC.CDL.Interfaces.RealOutput eps[nConSub](
each final unit="1",
each final min=0,
each final max=1)
"Filtration efficiency";
Buildings.Fluid.AirFilters.BaseClasses.MassAccumulation masAcc(
final mCon_max=per.mCon_max,
final mCon_start=per.mCon_start,
final nConSub=nConSub) "Contaminant accumulation";
protected
parameter Integer nConSub = size(per.namCon,1)
"Total types of contaminant substances";
Buildings.Fluid.AirFilters.BaseClasses.PressureDropWithVaryingFlowCoefficient
res(
redeclare package Medium = Medium,
final m_flow_nominal=per.m_flow_nominal,
final show_T=false,
final forceErrorControlOnFlow=false,
final useDefaultProperties=true,
final dp_turbulent=0.3*per.dp_nominal,
final m=per.m,
final dp_nominal=per.dp_nominal)
"Pressure resistance";
Buildings.Fluid.AirFilters.BaseClasses.MassTransfer masTra(
redeclare package Medium = Medium,
final namCon=per.namCon)
"Contaminant removal";
Buildings.Fluid.AirFilters.BaseClasses.FiltrationEfficiency filEff(
final mCon_max=per.mCon_max,
final namCon=per.namCon,
final filEffPar=per.filEffPar)
"Filtration efficiency";
Buildings.Fluid.AirFilters.BaseClasses.FlowCoefficientCorrection floCor(
final b=per.b)
"Flow coefficient correction";
equation
connect(masAcc.mCon,filEff. mCon);
connect(masAcc.uRep,uRep);
connect(filEff.rat,floCor. rat);
connect(floCor.y, res.dpCor);
connect(masTra.mCon_flow, masAcc.mCon_flow);
connect(filEff.y, eps);
connect(masTra.eps,filEff. y);
connect(masAcc.yRep, yRep);
connect(port_a, masTra.port_a);
connect(masTra.port_b, res.port_a);
connect(res.port_b, port_b);
connect(filEff.rat, rat);
end Empirical;