Buildings.Fluid.Movers.BaseClasses.Characteristics
Functions for fan or pump characteristics
Information
This package implements performance curves for fans and pumps, and records for parameter that can be used with these performance curves.
See the User's Guide for information about these performance curves.
Package Content
Name | Description |
---|---|
efficiency | Flow vs. efficiency characteristics for fan or pump |
efficiency_yMot | Efficiency vs. motor PLR characteristics for fan or pump |
motorEfficiencyCurve | This function generates the generic curve for motor efficiency based on rated motor power |
power | Flow vs. electrical power characteristics for fan or pump |
pressure | Pump or fan head away from the origin without correction for mover flow resistance |
efficiencyParameters | Record for efficiency parameters vs. volumetric flow rate |
efficiencyParameters_yMot | Record for efficiency parameters vs. motor part load ratio |
flowParameters | Record for flow parameters |
flowParametersInternal | Record for flow parameters with prescribed size |
powerParameters | Record for electrical power parameters |
Buildings.Fluid.Movers.BaseClasses.Characteristics.efficiency
Flow vs. efficiency characteristics for fan or pump
Information
This function computes the fan or pump efficiency for given normalized volume flow rate and performance data. The efficiency is
η = s(V̇/rN, d),
where η is the efficiency, rN is the normalized fan speed, V̇ is the volume flow rate, and d are performance data for fan or pump efficiency.
Implementation
The function s(·, ·) is a cubic hermite spline. If the data d define a monotone decreasing sequence, then s(·, d) is a monotone decreasing function.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Type | Name | Default | Description |
---|---|---|---|
efficiencyParameters | per | Efficiency performance data | |
VolumeFlowRate | V_flow | Volumetric flow rate [m3/s] | |
Real | d[:] | Derivatives at support points for spline interpolation | |
Real | r_N | Relative speed [1] | |
Real | delta | Small value for switching implementation around zero speed |
Outputs
Type | Name | Description |
---|---|---|
Real | eta | Efficiency [1] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.efficiency_yMot
Efficiency vs. motor PLR characteristics for fan or pump
Information
This function is similar to Buildings.Fluid.Movers.BaseClasses.Characteristics.efficiency, but takes the motor part load ratio y=Pele ⁄ Pele,nominal instead of volumetric flow rate V̇ as input and does not consider the speed of the mover.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Type | Name | Default | Description |
---|---|---|---|
efficiencyParameters_yMot | per | Efficiency performance data | |
Real | y | Motor part load ratio, y = PEle/PEle_nominal | |
Real | d[:] | Derivatives at support points for spline interpolation |
Outputs
Type | Name | Description |
---|---|---|
Real | eta | Efficiency [1] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.motorEfficiencyCurve
This function generates the generic curve for motor efficiency based on rated motor power
Information
This function generates a generic motor efficiency curve based on the rated motor power input and maximum motor efficiency according to U.S. DOE (2014) (shown below). It returns a constant array if the rated power is unavailable.
References
U.S. DOE (2014). Determining Electric Motor Load and Efficiency. URL: https://www.energy.gov/sites/prod/files/2014/04/f15/10097517.pdf
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Type | Name | Default | Description |
---|---|---|---|
Power | P_nominal | Rated input power of the motor [W] | |
Efficiency | eta_max | Maximum motor efficiency [1] |
Outputs
Type | Name | Description |
---|---|---|
efficiencyParameters_yMot | motorEfficiency_yMot | Motor efficiency vs. motor part load ratio |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.power
Flow vs. electrical power characteristics for fan or pump
Information
This function computes the fan power consumption for given volume flow rate, speed and performance data. The power consumption is
P = rN3 s(V̇/rN, d),
where P is the power consumption, rN is the normalized fan speed, V̇ is the volume flow rate and d are performance data for fan or pump power consumption at rN=1.
Implementation
The function s(·, ·) is a cubic hermite spline. If the data d define a monotone decreasing sequence, then s(·, d) is a monotone decreasing function.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Type | Name | Default | Description |
---|---|---|---|
powerParameters | per | Pressure performance data | |
VolumeFlowRate | V_flow | Volumetric flow rate [m3/s] | |
Real | r_N | Relative speed [1] | |
Real | d[:] | Derivatives at support points for spline interpolation | |
Real | delta | Small value for switching implementation around zero speed |
Outputs
Type | Name | Description |
---|---|---|
Power | P | Power consumption [W] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.pressure
Pump or fan head away from the origin without correction for mover flow resistance
Information
This function computes the fan static pressure raise as a function of volume flow rate and revolution in the form
Δp = rN2 s(V̇/rN, d),
where Δp is the pressure rise, rN is the normalized fan speed, V̇ is the volume flow rate and d are performance data for fan or pump power consumption at rN=1.
Implementation
The function s(·, ·) is a cubic hermite spline. If the data d define a monotone decreasing sequence, then s(·, d) is a monotone decreasing function.
The function allows rN to be zero.
Extends from Modelica.Icons.Function (Icon for functions).
Inputs
Type | Name | Default | Description |
---|---|---|---|
VolumeFlowRate | V_flow | Volumetric flow rate [m3/s] | |
Real | r_N | Relative revolution, r_N=N/N_nominal [1] | |
Real | d[:] | Derivatives of flow rate vs. pressure at the support points | |
PressureDifference | dpMax | Maximum pressure drop at nominal speed, for regularisation [Pa] | |
VolumeFlowRate | V_flow_max | Maximum flow rate at nominal speed, for regularisation [m3/s] | |
flowParametersInternal | per | Pressure performance data |
Outputs
Type | Name | Description |
---|---|---|
PressureDifference | dp | Pressure raise [Pa] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.efficiencyParameters
Record for efficiency parameters vs. volumetric flow rate
Information
Data record for performance data that describe efficiency
versus volumetric flow rate.
The volume flow rate r_V
must be increasing, i.e.,
V_flow[i] < V_flow[i+1]
.
Both vectors, V_flow
and eta
must have the same size.
Extends from Modelica.Icons.Record (Icon for records).
Parameters
Type | Name | Default | Description |
---|---|---|---|
VolumeFlowRate | V_flow[:] | Volumetric flow rate at user-selected operating points [m3/s] | |
Efficiency | eta[size(V_flow, 1)] | Fan or pump efficiency at these flow rates [1] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.efficiencyParameters_yMot
Record for efficiency parameters vs. motor part load ratio
Information
Data record for performance data that describe efficiency versus part load ratio.
This is used a method to describe the motor efficiency etaMot
.
The PLR y
must be increasing, i.e.,
y[i] < y[i+1]
.
Both vectors, y
and eta
must have the same size.
Extends from Modelica.Icons.Record (Icon for records).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Real | y[:] | Part load ratio, y = PEle/PEle_nominal | |
Efficiency | eta[size(y, 1)] | Fan or pump efficiency at these part load ratios [1] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters
Record for flow parameters
Information
Data record for performance data that describe volume flow rate versus
pressure rise.
The volume flow rate V_flow
must be increasing, i.e.,
V_flow[i] < V_flow[i+1]
.
Both vectors, V_flow
and dp
must have the same size.
Extends from Modelica.Icons.Record (Icon for records).
Parameters
Type | Name | Default | Description |
---|---|---|---|
VolumeFlowRate | V_flow[:] | Volume flow rate at user-selected operating points [m3/s] | |
PressureDifference | dp[size(V_flow, 1)] | Fan or pump total pressure at these flow rates [Pa] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParametersInternal
Record for flow parameters with prescribed size
Information
Data record for performance data that describe volume flow rate versus
pressure rise.
The volume flow rate V_flow
must be increasing, i.e.,
V_flow[i] < V_flow[i+1]
.
Both vectors, V_flow
and dp
must have the same size.
This record is identical to
Buildings.Fluid.Movers.BaseClasses.Characteristics.flowParameters,
except that it takes the size of the array as a parameter. This is required
in Dymola 2014. Otherwise, the array size would need to be computed in
Buildings.Fluid.Movers.BaseClasses.FlowMachineInterface
in the initial algorithm
section, which is not supported.
Extends from Modelica.Icons.Record (Icon for records).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Integer | n | Number of elements in each array | |
VolumeFlowRate | V_flow[n] | Volume flow rate at user-selected operating points [m3/s] | |
PressureDifference | dp[n] | Fan or pump total pressure at these flow rates [Pa] |
Modelica definition
Buildings.Fluid.Movers.BaseClasses.Characteristics.powerParameters
Record for electrical power parameters
Information
Data record for performance data that describe volume flow rate versus
electrical power.
The volume flow rate V_flow
must be increasing, i.e.,
V_flow[i] < V_flow[i+1]
.
Both vectors, V_flow
and P
must have the same size.
Extends from Modelica.Icons.Record (Icon for records).
Parameters
Type | Name | Default | Description |
---|---|---|---|
VolumeFlowRate | V_flow[:] | Volume flow rate at user-selected operating points [m3/s] | |
Power | P[size(V_flow, 1)] | Fan or pump electrical power at these flow rates [W] |