modelMediumColumnDynamic

Vertical shaft with no friction and storage of heat and mass

Extends from IBPSA.Fluid.Interfaces.LumpedVolumeDeclarations.

Information

This model contains a completely mixed fluid volume and models that take into account the pressure difference of a medium column that is at the same temperature as the fluid volume. It can be used to model the pressure difference caused by a stack effect.

Typical use and important parameters

Set the parameter use_HeatTransfer=true to expose a heatPort. This heatPort can be used to add or subtract heat from the volume. This allows, for example, to use this model in conjunction with a model for heat transfer through walls to model a solar chimney that stores heat.

Dynamics

For a steady-state model, use IBPSA.Airflow.Multizone.MediumColumn instead of this model.

In this model, the parameter h must always be positive, and the port port_a must be at the top of the column.

Parameters

Type	Name	Default	Description
Modelica.SIunits.Length	h	3	Height of shaft
Modelica.SIunits.Volume	V		Volume in medium shaft
Nominal condition, used only for steady-state model
Modelica.SIunits.MassFlowRate	m_flow_nominal		Nominal mass flow rate
Assumptions › Heat transfer
Boolean	use_HeatTransfer	false	= true to use the HeatTransfer model

Components

Type	Name	Description
Modelica.Fluid.Interfaces.FluidPort_a	port_a	Fluid connector a (positive design flow direction is from port_a to port_b)
Modelica.Fluid.Interfaces.FluidPort_b	port_b	Fluid connector b (positive design flow direction is from port_a to port_b)
IBPSA.Fluid.MixingVolumes.MixingVolume	vol	Air volume in the shaft
MediumColumn	colTop	Medium column that connects to top port
MediumColumn	colBot	Medium colum that connects to bottom port
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	heatPort	Heat port to exchange energy with the fluid volume

Name	Description
Medium	Medium in the component
HeatTransfer

Revisions

May 1, 2018, by Filip Jorissen:
Removed declaration of allowFlowReversal and changed default density computation such that it assumes a constant pressure. See #877.
October 6, 2014 by Michael Wetter:
Removed assignment of port_?.p.nominal to avoid a warning in OpenModelica because alias sets have different nominal values.
July 31, 2011 by Michael Wetter:
Changed model to use new base class IBPSA.Fluid.Interfaces.LumpedVolumeDeclarations.
May 25, 2011 by Michael Wetter:
Added m_flow_nominal, which is used if component is configured as steady-state.
July 28, 2010 by Michael Wetter:
Released first version.