Engee documentation

Reservoir (G)

Boundary conditions for a gas network at constant pressure and temperature.

blockType: AcausalFoundation.Gas.Elements.Reservoir

reservoir (g)

Path in the library:

/Physical Modeling/Fundamental/Gas/Elements/Reservoir (G)

Description

Block Reservoir (G) It is an endless reservoir at a fixed pressure and temperature. The tank and its inlet can be at atmospheric or set pressure. Port A corresponds to the entrance to the tank.

The volume of gas inside the tank is considered infinite, so the flow is assumed to be quasi-stationary.

The gas enters and exits the tank at the pressure set for the tank, but its temperature is determined by the direction of gas flow. If the gas enters the tank, its temperature is determined by the incoming gas network, then the tank acts as a heat sink. If the gas comes out of the tank, then its temperature is equal to the temperature of the tank, and the tank acts as a heat source.

This unit also serves as a reference point for measuring pressure and temperature in the gas network. These measurements refer to the pressure and temperature inside the tank, respectively. Connect the tank to the B port of the Pressure unit & Temperature Sensor (G)* to measure the relative pressure and temperature of the node connected to the sensor port A.

Assumptions and limitations

  • The pressure and temperature inside the tank are constant.

  • The gas in the tank is quasi-stationary.

Ports

A — gas inlet-outlet
gas

The gas port corresponds to the entrance to the tank.

Parameters

Reservoir pressure specification — selection of the pressure setting method
Atmospheric pressure (by default) | Specified pressure

Select the pressure setting method:

  • Atmospheric pressure — the atmospheric pressure set by the unit is used Gas Properties (G), connected to the gas network.

  • Specified pressure — the value of the Reservoir pressure parameter is used.

Reservoir pressure — pressure in the tank
101325.0 Pa (by default)

Enter the desired pressure in the tank. This pressure remains constant throughout the simulation time.

Dependencies

Enabled if the Reservoir pressure specification parameter is set to Specified pressure.

Reservoir temperature — temperature in the tank
293.15 K (by default)

Sets the temperature in the tank. This temperature remains constant throughout the simulation time.

Cross-sectional area at port A — area normal to the flow direction at the inlet to the tank
0.01 m2 (by default)

The cross-sectional area of the inlet to the tank in the direction normal to the gas flow path.

Examples