Engee documentation

Absolute Pressure & Temperature Sensor (G)

Pressure and temperature sensor.

Pressure & Temperature Difference Sensor (G)

pressure temperature difference sensor (g)

Absolute Pressure & Temperature Sensor (G)

absolute pressure temperature sensor (g)

Description

The Pressure & Temperature Sensor (G) unit is an ideal pressure and temperature sensor for the gas network. There is no mass or energy flow through the sensor.

The Pressure & Temperature Sensor (G) unit operates in two modes depending on the value of the Measurement type parameter:

  • `Absolute' - the unit in Absolute Pressure & Temperature Sensor (G) mode measures absolute values of temperature and pressure. Only one A port is needed to measure absolute values.

  • Difference - unit in Pressure & Temperature Difference Sensor (G) mode measures temperature or pressure differences. In this mode, the unit has two input ports A and B. Measurements are positive when the values on port A are greater than the values on port B.

Temperature measurements are different from pressure measurements because the rate of energy flow depends on the direction of flow. A temperature measurement represents the temperature upstream of the node being measured. For example, if port A of the Pressure & Temperature Sensor (G) unit is connected to a node between pipe 1 and pipe 2, and gas flows from pipe 1 to pipe 2, the temperature measured at port A represents the temperature of the volume of gas in pipe 1. If the gas then reverses direction and flows from pipe 2 into pipe 1, then the temperature measured at port A is the temperature of the volume of gas in pipe 2. If the temperatures of the two gas volumes are different, this will manifest itself as a change in measured temperature when the direction of flow is switched. If two or more streams merge at a node, the temperature measurement at the node represents a weighted average based on perfect mixing of the streams.

Four ports are provided for outputting measurement data:

  • The Pa port outputs absolute pressure.

  • The Pg port outputs overpressure.

  • The P port outputs the differential pressure across the sensor.

  • Port T outputs temperature or temperature difference.

These ports have conditional visibility on the block icon. Use the block parameters to use only those ports required for measurements in a particular model.

Ports

Output

Pa - absolute pressure value, Pa
scalar

Output port for measuring the absolute value of pressure.

Dependencies

To use this port, set Measurement type to Absolute', Pressure to `on, and Pressure type to `Absolute pressure'.

Pg - overpressure, Pa
scalar

Output port for gauge pressure measurement.

Dependencies

To use this port, set Measurement type to Absolute', Pressure to `on, and Pressure type to `Gauge pressure'.

P - pressure difference, Pa
scalar

Output port for pressure difference measurement.

Dependencies

To use this port, set Measurement type to Difference' and Pressure to `on.

T is the temperature value, K
scalar

Output port for temperature measurement.

Dependencies

To use this port, set Temperature to on.

Non-directional

A - gas at sensor inlet
gas

Gas port, corresponds to the sensor inlet.

B - gas at the sensor outlet
gas

Gas port, corresponds to the sensor outlet.

Parameters

Measurement type - selection between absolute and relative measurements
Absolute (By default) | Difference

Select between absolute and relative measurements:

  • Absolute - the sensor measures pressure and temperature on port A. Only one port is needed for absolute measurements. Selecting this option hides port B on the unit icon.

  • Difference - the sensor measures the pressure and/or temperature difference between two points in the model. Selecting this option shows the B port on the block icon.

Pressure - Enable the output port for pressure measurement
On (By default) | Off

Checking this box opens the Pa, Pg or P output port to allow pressure measurement.

Pressure type - selection between absolute and gauge pressure
Absolute pressure (By default) | Gauge pressure.

Select whether the sensor is measuring absolute or gauge pressure:

  • Absolute pressure - the sensor measures absolute pressure at port A. When this option is selected, the Pa port is displayed on the unit icon.

  • Gauge pressure - the sensor measures the gauge pressure on port A. When this option is selected, the Pg port is displayed on the unit icon.

Dependencies

This parameter is used when Pressure is set to on and when Measurement type is set to `Absolute'.

Temperature - Enables the output port for temperature measurement
Off (By default) | On

When this checkbox is selected, the T output port is opened to allow temperature measurement.

Examples