VolumeFlowControllerHeatStorage

Use

The volume flow controller for heat storage systems controls the volume flow of the pumps before the heat storage dependent on heat power demand and the actual storage temperature. This model is an older version of the volume flow controller heat, only use this model due to legacy reasons.

Parameters and Connectors

The storage temperature thus needs to be defined using an actual temperature ▶TAct of a specific heat medium layer. Additionally, the necessary volume flow output ▶qvRef is used as a reference input for the heating systems pump.

The other required inputs are the reference temperature to be controlled ▶TRef and the flow and return temperature ▶TFlow of the storage tank at the location of the corresponding pump to be controlled.

To limit the maximum heat output QHeatMax that can be applied to the corresponding pipe of the thermal accumulator, this must be defined and the material properties of the fluid in the thermal accumulator (specific heat capacity cpMed and density rhoMed) must also be specified.

To control the volume flow, the lower temperature difference at which the pump is deactivated deltaTup, the upper temperature difference at which the pump runs at maximum power deltaTlow and the maximum volume flow of the pump qvMax are required.

Model Background

Volume Flow Control Hysteresis

The reference heat power input is controlled via a reference volume flow ▶qvRef to the storage and the associated difference between flow and return temperature ▶TFlow (see the picture below).

• If (▶TAct-▶TRef )< T, then ▶qvRef is maximum.

• If (▶TAct-▶TRef )> T, then ▶qvRef is 0.

• Between the temperature boundaries ▶qvRef is linearly interpolated.