Trace Gas Source (MA)

Addition or removal of impurity gases.

blockType: AcausalFoundation.MoistAir.MoistureTraceGasSources.TraceGas

Controlled Trace Gas Source (MA)

Path in the library:

/Physical Modeling/Fundamental/Moist Air/Moisture & Trace Gas Sources/Controlled Trace Gas Source (MA)

Trace Gas Source (MA)

Path in the library:

/Physical Modeling/Fundamental/Moist Air/Moisture & Trace Gas Sources/Trace Gas Source (MA)

Description

The Trace Gas Source (MA) unit is a permanent source or absorber of impurity gas for a connected humid air network.

A positive or negative mass flow rate of the impurity gas results in an increase or decrease of the impurity gas level.

The energy associated with the addition or removal of the impurity gas is equal to:

where

- is the impurity gas mass flow rate set by the parameter Trace gas mass flow rate;
- specific enthalpy of the admixture gas;
- is the temperature of the added impurity gas, given by the input scalar signal at the T port. The block uses this value to estimate the specific enthalpy of the added impurity gas only. The specific enthalpy of the removed impurity gas is determined from the temperature of the connected humid air network;
- is the temperature at port S, which is equal to the temperature of the connected humid air network.

Port S is the humid air source port. Connect this port to the S port of the humid air final volume unit to add or remove impurity gas using the unit Controlled Trace Gas Source (MA).

Ports

Conserving

# S — addition or removal of impurity gas
`moist air

Details

Wet air source port. Connect this port to the S port of the wet air final volume unit to add or remove impurity gas using the unit Controlled Trace Gas Source (MA).

Program usage name

source_port

Input

# M — mass flow rate, kg/s
scalar

Details

An input port that determines the mass flow rate of the impurity gas through the source.

Dependencies

To use this port, select the Controlled source checkbox.

Data types	`Float64`.
Complex numbers support	No

# T — temperature, K
scalar

Details

An input port that determines the temperature of the impurity gas.

Dependencies

To use this port, select the Controlled source checkbox.

Data types	`Float64`.
Complex numbers support	No

Parameters

# Controlled source — whether the flow rate and temperature of the impurity gas are set by the input signal

Details

Determines how the flow rate and temperature of the impurity gas will be set:

If checked, the flow rate and temperature of the impurity gas are set via the M and T input ports.
If unchecked, the constant flow rate and temperature of the sample gas are set via the parameters Rate of added trace gas and Added trace gas temperature specification respectively.

Default value	`—`
Program usage name	`controlled`
Evaluatable	No

# Rate of added trace gas — constant mass flow rate through the source
kg/s | N*s/m | N/(m/s) | lbf/(ft/s) | lbf/(in/s)

Details

Mass flow rate of the impurity gas through the source.

A positive value adds impurity gas to the connected humid air network. A negative value removes impurity gas from this network.

Dependencies

To use this parameter, uncheck Controlled source.

Units	`kg/s` \| `N*s/m` \| `N/(m/s)` \| `lbf/(ft/s)` \| `lbf/(in/s)`
Default value	`0.0 kg/s`
Program usage name	`trace_gas_mass_flow`
Evaluatable	Yes

# Added trace gas temperature specification — method for setting the impurity gas temperature
Atmospheric temperature | Specified temperature

Details

Selection of the impurity gas temperature setting method:

Atmospheric temperature - the atmospheric temperature set by the unit Moist Air Properties (MA), connected to the circuit, is used.
Specified temperature - the value is set with the parameters Temperature of added trace gas.

Dependencies

To use this parameter, uncheck Controlled source.

Values	`Atmospheric temperature` \| `Specified temperature`
Default value	`Atmospheric temperature`
Program usage name	`temperature_type`
Evaluatable	No

Details

The temperature of the impurity gas. This temperature remains constant during the simulation. The unit only uses this value to estimate the specific enthalpy of the added impurity gas. The specific enthalpy of the removed impurity gas is determined based on the temperature of the connected humid air network.

Dependencies

To use this parameter, set the parameters Added trace gas temperature specification to . Specified temperature.

Units	`K` \| `degC` \| `degF` \| `degR` \| `deltaK` \| `deltadegC` \| `deltadegF` \| `deltadegR`
Default value	`293.15 K`
Program usage name	`trace_gas_temperature`
Evaluatable	Yes