.AixLib.Fluid.HeatExchangers.HeatingRod

Information

Model for a heating rod.

This model adds heat in the amount of Q_flow = u Q_flow_nominal to the medium. The input signal u and the nominal heat flow rate Q_flow_nominal can be positive or negative. A positive value of Q_flow means heating, and negative means cooling.

The outlet conditions at port_a are not affected by this model, other than for a possible pressure difference due to flow friction.

Optionally, this model can have a flow resistance. Set dp_nominal = 0 to disable the flow friction calculation.

For a model that uses as an input the fluid temperature leaving at port_b, use AixLib.Fluid.HeatExchangers.PrescribedOutlet

As output, the electrical energy required to supply Q_flow is calculated using the efficiency which is a parameter of the model.

Lastly, the number of times the heating rod switches on may be used as an output.

Limitations

This model does not affect the humidity of the air. Therefore, if used to cool air below the dew point temperature, the water mass fraction will not change.

Validation

The model has been validated against the analytical solution in the example AixLib.Fluid.HeatExchangers.Validation.HeaterCooler_u.

Revisions

• May 5, 2021, by Fabian Wuellhorst:
  Added model.
  This is for AixLib, #1092.