Modelica.Fluid.Sensors

Information

Package Sensors consists of idealized sensor components that provide variables of a medium model and/or fluid ports as output signals. These signals can be, e.g., further processed with components of the Modelica.Blocks library. Also more realistic sensor models can be built, by further processing (e.g., by attaching block Modelica.Blocks.FirstOrder to model the time constant of the sensor).

For the thermodynamic state variables temperature, specific enthalpy, specific entropy and density the fluid library provides two different types of sensors: regular one port and two port sensors.

• The regular one port sensors have the advantage of easy introduction and removal from a model, as no connections have to be broken. A potential drawback is that the obtained value jumps as flow reverts.
• The two port sensors offer the advantages of an adjustable regularized step function around zero flow. Moreover the obtained result is restricted to the value flowing into port_a if allowFlowReversal is false.

Modelica.Fluid.Examples.Explanatory.MeasuringTemperature demonstrates the differences between one- and two-port sensor at hand of a simple example.

Package Content

Name	Description
Pressure	Ideal pressure sensor
Density	Ideal one port density sensor
DensityTwoPort	Ideal two port density sensor
Temperature	Ideal one port temperature sensor
TemperatureTwoPort	Ideal two port temperature sensor
SpecificEnthalpy	Ideal one port specific enthalpy sensor
SpecificEnthalpyTwoPort	Ideal two port sensor for the specific enthalpy
SpecificEntropy	Ideal one port specific entropy sensor
SpecificEntropyTwoPort	Ideal two port sensor for the specific entropy
MassFractions	Ideal one port mass fraction sensor
MassFractionsTwoPort	Ideal two port sensor for mass fraction
TraceSubstances	Ideal one port trace substances sensor
TraceSubstancesTwoPort	Ideal two port sensor for trace substance
MassFlowRate	Ideal sensor for mass flow rate
VolumeFlowRate	Ideal sensor for volume flow rate
RelativePressure	Ideal relative pressure sensor
RelativeTemperature	Ideal relative temperature sensor
BaseClasses	Base classes used in the Sensors package (only of interest to build new component models)

Modelica.Fluid.Sensors.Pressure

Information

This component monitors the absolute pressure at its fluid port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port
p	Pressure at port [Pa]

Modelica.Fluid.Sensors.Density

Information

This component monitors the density of the fluid passing its port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port
d	Density in port medium [kg/m3]

Modelica.Fluid.Sensors.DensityTwoPort

Information

This component monitors the density of the fluid flowing from port_a to port_b. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
d	Density of the passing fluid [kg/m3]

Modelica.Fluid.Sensors.Temperature

Information

This component monitors the temperature of the fluid passing its port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port
T	Temperature in port medium [K]

Modelica.Fluid.Sensors.TemperatureTwoPort

Information

This component monitors the temperature of the passing fluid. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
T	Temperature of the passing fluid [K]

Modelica.Fluid.Sensors.SpecificEnthalpy

Information

This component monitors the specific enthalpy of the fluid passing its port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port
h_out	Specific enthalpy in port medium [J/kg]

Modelica.Fluid.Sensors.SpecificEnthalpyTwoPort

Information

This component monitors the specific enthalpy of a passing fluid. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
h_out	Specific enthalpy of the passing fluid [J/kg]

Modelica.Fluid.Sensors.SpecificEntropy

Information

This component monitors the specific entropy of the fluid passing its port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port
s	Specific entropy in port medium [J/(kg.K)]

Modelica.Fluid.Sensors.SpecificEntropyTwoPort

Information

This component monitors the specific entropy of the passing fluid. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
s	Specific entropy of the passing fluid [J/(kg.K)]

Modelica.Fluid.Sensors.MassFractions

Information

This component monitors the mass fraction contained in the fluid passing its port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor
substanceName	Name of mass fraction

Connectors

Name	Description
port
Xi	Mass fraction in port medium

Modelica.Fluid.Sensors.MassFractionsTwoPort

Information

This component monitors the mass fraction of the passing fluid. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
substanceName	Name of mass fraction
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
Xi	Mass fraction in port medium

Modelica.Fluid.Sensors.TraceSubstances

Information

This component monitors the trace substances contained in the fluid passing its port. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor
substanceName	Name of trace substance

Connectors

Name	Description
port
C	Trace substance in port medium

Modelica.Fluid.Sensors.TraceSubstancesTwoPort

Information

This component monitors the trace substance of the passing fluid. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
substanceName	Name of trace substance
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
C	Trace substance of the passing fluid

Modelica.Fluid.Sensors.MassFlowRate

Information

This component monitors the mass flow rate flowing from port_a to port_b. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
m_flow	Mass flow rate from port_a to port_b [kg/s]

Modelica.Fluid.Sensors.VolumeFlowRate

Information

This component monitors the volume flow rate flowing from port_a to port_b. The sensor is ideal, i.e., it does not influence the fluid.

Parameters

Name	Description
replaceable package Medium	Medium in the component
Assumptions
allowFlowReversal	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Advanced
m_flow_nominal	Nominal value of m_flow = port_a.m_flow [kg/s]
m_flow_small	Regularization for bi-directional flow in the region |m_flow| < m_flow_small (m_flow_small > 0 required) [kg/s]

Connectors

Name	Description
port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
V_flow	Volume flow rate from port_a to port_b [m3/s]

Modelica.Fluid.Sensors.RelativePressure

Information

The relative pressure "port_a.p - port_b.p" is determined between the two ports of this component and is provided as output signal. The sensor should be connected in parallel with other equipment, no flow through the sensor is allowed.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port_a
port_b
p_rel	Relative pressure signal [Pa]

Modelica.Fluid.Sensors.RelativeTemperature

Information

The relative temperature "T(port_a) - T(port_b)" is determined between the two ports of this component and is provided as output signal. The sensor should be connected in parallel with other equipment, no flow through the sensor is allowed.

Parameters

Name	Description
replaceable package Medium	Medium in the sensor

Connectors

Name	Description
port_a
port_b
T_rel	Relative temperature signal [K]