Buildings.Fluid.Boilers
Package with boiler models
Information
This package contains components models for boilers.Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
Name | Description |
---|---|
UsersGuide | User's Guide |
BoilerPolynomial | Boiler with efficiency curve described by a polynomial of the control signal and (optional) temperature |
BoilerTable | Boiler with efficiency described by a table with control signal and inlet temperature |
Data | Package containing performance data for boilers |
Examples | Collection of models that illustrate model use and test models |
Validation | Collection of validation models |
BaseClasses | Package with base classes for Buildings.Fluid.Boilers |
Buildings.Fluid.Boilers.BoilerPolynomial
Boiler with efficiency curve described by a polynomial of the control signal and (optional) temperature
Information
This is a model of a boiler whose efficiency is described by a polynomial. See Buildings.Fluid.Boilers.UsersGuide for details.
The parameter effCur determines what polynomial is used to compute the efficiency with the following selections:
Parameter effCur |
Efficiency curve |
Buildings.Fluid.Types.EfficiencyCurves.Constant |
η = a1 |
Buildings.Fluid.Types.EfficiencyCurves.Polynomial |
η = a1 + a2 y + a3 y2 + ... |
Buildings.Fluid.Types.EfficiencyCurves.QuadraticLinear |
η = a1 + a2 y + a3 y2 + (a4 + a5 y + a6 y2) T |
where T is the boiler outlet temperature in Kelvin. For effCur = Buildings.Fluid.Types.EfficiencyCurves.Polynomial, an arbitrary number of polynomial coefficients can be specified.
Extends from Buildings.Fluid.Boilers.BaseClasses.PartialBoiler (Boiler base class with efficiency unspecified).
Parameters
Type | Name | Default | Description |
---|---|---|---|
replaceable package Medium | PartialMedium | Medium in the component | |
Generic | fue | Fuel type | |
Power | Q_flow_nominal | Nominal heating power [W] | |
ThermalConductance | UA | 0.05*Q_flow_nominal/30 | Overall UA value [W/K] |
Efficiency | eta_nominal | if effCur == Buildings.Fluid... | Boiler efficiency at nominal condition [1] |
Efficiency | eta | if effCur == Buildings.Fluid... | Boiler efficiency [1] |
EfficiencyCurves | effCur | Buildings.Fluid.Types.Effici... | Curve used to compute the efficiency |
Real | a[:] | {0.9} | Coefficients for efficiency curve |
Temperature | T_nominal | 353.15 | Temperature used to compute nominal efficiency (only used if efficiency curve depends on temperature) [K] |
Nominal condition | |||
MassFlowRate | m_flow_nominal | Nominal mass flow rate [kg/s] | |
PressureDifference | dp_nominal | Pressure difference [Pa] | |
Assumptions | |||
Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
Advanced | |||
MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
Diagnostics | |||
Boolean | show_T | true | = true, if actual temperature at port is computed |
Flow resistance | |||
Boolean | from_dp | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
Dynamics | |||
Conservation equations | |||
Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Volume | VWat | 1.5E-6*Q_flow_nominal | Water volume of boiler [m3] |
Mass | mDry | 1.5E-3*Q_flow_nominal | Mass of boiler that will be lumped to water heat capacity [kg] |
Initialization | |||
AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
Temperature | T_start | Medium.T_default | Start value of temperature [K] |
MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
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 RealInput | y | Part load ratio |
output RealOutput | T | Temperature of the fluid [K] |
HeatPort_a | heatPort | Heat port, can be used to connect to ambient |
Modelica definition
Buildings.Fluid.Boilers.BoilerTable
Boiler with efficiency described by a table with control signal and inlet temperature
Information
This is a model of a boiler whose efficiency is described by a table with control signal and inlet temperature. See Buildings.Fluid.Boilers.UsersGuide for details.
The efficiency tables are supplied via Buildings.Fluid.Boilers.Data.
Extends from Buildings.Fluid.Boilers.BaseClasses.PartialBoiler (Boiler base class with efficiency unspecified).
Parameters
Type | Name | Default | Description |
---|---|---|---|
replaceable package Medium | PartialMedium | Medium in the component | |
Generic | fue | per.fue | Fuel type |
Power | Q_flow_nominal | per.Q_flow_nominal | Nominal heating power [W] |
ThermalConductance | UA | per.UA | Overall UA value [W/K] |
Efficiency | eta_nominal | per.eta_nominal | Boiler efficiency at nominal condition [1] |
Efficiency | eta | effTab.y | Boiler efficiency [1] |
Generic | per | Records of efficiency curves | |
Nominal condition | |||
MassFlowRate | m_flow_nominal | per.m_flow_nominal | Nominal mass flow rate [kg/s] |
PressureDifference | dp_nominal | per.dp_nominal | Pressure difference [Pa] |
Assumptions | |||
Boolean | allowFlowReversal | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
Advanced | |||
MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
Diagnostics | |||
Boolean | show_T | true | = true, if actual temperature at port is computed |
Flow resistance | |||
Boolean | from_dp | false | = true, use m_flow = f(dp) else dp = f(m_flow) |
Boolean | linearizeFlowResistance | false | = true, use linear relation between m_flow and dp for any flow rate |
Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
Dynamics | |||
Conservation equations | |||
Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Volume | VWat | per.VWat | Water volume of boiler [m3] |
Mass | mDry | per.mDry | Mass of boiler that will be lumped to water heat capacity [kg] |
Initialization | |||
AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
Temperature | T_start | Medium.T_default | Start value of temperature [K] |
MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
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 RealInput | y | Part load ratio |
output RealOutput | T | Temperature of the fluid [K] |
HeatPort_a | heatPort | Heat port, can be used to connect to ambient |