Thermodynamic Properties Sensor (2P)

Measure temperature, density, specific enthalpy, specific entropy, and specific volume in two-phase fluid networks

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Libraries:
Simscape / Foundation Library / Two-Phase Fluid / Sensors

Description

The Thermodynamic Properties Sensor (2P) block represents an ideal sensor that measures temperature, density, specific enthalpy, specific entropy, and specific volume in a two-phase fluid network. There is no mass or energy flow through the sensor.

The block measures these thermodynamic properties at the node connected to port A. All measurements are taken with respect to absolute zero.

Examples

Two-Phase Fluid Refrigeration

Models a vapor-compression refrigeration cycle using two-phase fluid components. The compressor drives the R-134a refrigerant through a condenser, an expansion valve, and an evaporator. The hot gas leaving the compressor condenses in the condenser via heat transfer to the environment. The pressure drops as the refrigerant passes through the expansion valve. The drop in pressure lowers the saturation temperature of the refrigerant. This enables it to boil in the evaporator as it absorbs heat from the refrigerator compartment. The refrigerant then returns to the compressor to repeat the cycle. The controller turns the compressor on and off to maintain the refrigerator compartment temperature within a band around the desired temperature.

• Open Model

Ports

Output

T — Temperature measurement, K

physical signal

Physical signal output port for measuring the temperature of two-phase fluid.

Dependencies

To enable this port, select the Temperature check box.

h — Specific enthalpy measurement, kJ/kg

physical signal

Physical signal output port for measuring the specific enthalpy of two-phase fluid.

Dependencies

To enable this port, select the Enthalpy check box.

ρ — Density measurement, kg/m^3

physical signal

Physical signal output port for measuring the density of two-phase fluid.

Dependencies

To enable this port, select the Density check box.

v — Specific volume measurement, m^3/kg

physical signal

Physical signal output port for measuring the specific volume of two-phase fluid.

Dependencies

To enable this port, select the Specific volume check box.

s — Specific entropy measurement, kJ/(kg*K)

physical signal

Physical signal output port for measuring the specific entropy of two-phase fluid.

Dependencies

To enable this port, select the Entropy check box.

Conserving

A — Sensor inlet

two-phase fluid

Two-phase fluid conserving port. Connect this port to the node in the two-phase fluid network where you want to measure the thermodynamic properties. All measurements are taken with respect to absolute zero.

Parameters

Temperature — Control output port visibility for measuring temperature

Off (default) | On

Selecting this check box exposes the output port T, which lets you measure the temperature of two-phase fluid.

Enthalpy — Control output port visibility for measuring specific enthalpy

Off (default) | On

Selecting this check box exposes the output port h, which lets you measure the specific enthalpy of two-phase fluid.

Density — Control output port visibility for measuring density

On (default) | Off

Selecting this check box exposes the output port ρ, which lets you measure the density of two-phase fluid.

Specific volume — Control output port visibility for measuring specific volume

Off (default) | On

Selecting this check box exposes the output port v, which lets you measure the specific volume of two-phase fluid.

Entropy — Control output port visibility for measuring specific entropy

Off (default) | On

Selecting this check box exposes the output port s, which lets you measure the specific entropy of two-phase fluid.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2015b

R2023a: Usability enhancement for two-phase fluid sensors

The Thermodynamic Properties Sensor (2P) block can now also measure density.

The block ports now have conditional visibility on the block icon. You can use the block parameters to expose only the ports that you need for measurements in a particular model.

There is no compatibility impact when you use the Thermodynamic Properties Sensor (2P) block in your models. However, if you use this block in your custom composite components, you need to update the composite component code.

Old Syntax	New Syntax
sensor = foundation.two_phase_fluid.sensors.thermodynamic_sensor;	sensor = foundation.two_phase_fluid.sensors.thermodynamic_sensor(temperature=true, enthalpy=true, specific_volume=true, entropy=true);