modelPartialConnection2Pipe

Partial model for connecting an agent to a two-pipe distribution network

Extends from Buildings.DHC.Networks.BaseClasses.PartialConnection2Pipe2Medium (Partial model for connecting an agent to a two-pipe distribution network with two medium declarations).

Information

Partial model to be used for connecting an agent (e.g. an energy transfer station) to a two-pipe distribution network.

Three instances of a replaceable partial model are used to represent the pipes:

One representing the main distribution supply pipe immediately upstream the connection.
Another one representing the main distribution return pipe immediately downstream the connection.
The last one representing both the supply and return lines of the connection. When replacing that model with a pipe model computing the pressure drop, one must double the length so that both the supply and return lines are accounted for.

Type	Name	Default	Description
Boolean	show_entFlo	false	Set to true to output enthalpy flow rate difference
General › Nominal condition
Modelica.Units.SI.MassFlowRate	mDis_flow_nominal (from PartialConnection2Pipe2Medium)		Nominal mass flow rate in the distribution line
Modelica.Units.SI.MassFlowRate	mCon_flow_nominal (from PartialConnection2Pipe2Medium)		Nominal mass flow rate in the connection line
Assumptions
Boolean	allowFlowReversal (from PartialConnection2Pipe2Medium)	false	= true to allow flow reversal, false restricts to design direction (port_a -> port_b)
Dynamics › Equations
Modelica.Fluid.Types.Dynamics	energyDynamics (from PartialConnection2Pipe2Medium)	Modelica.Fluid.Types.Dynamics.FixedInitial	Type of energy balance: dynamic (3 initialization options) or steady state
Dynamics › Nominal condition
Modelica.Units.SI.Time	tau (from PartialConnection2Pipe2Medium)	10	Time constant at nominal flow for dynamic energy and momentum balance

Type	Name	Description
Modelica.Fluid.Interfaces.FluidPort_a	port_aDisSup (from PartialConnection2Pipe2Medium)	Distribution supply inlet port
Modelica.Fluid.Interfaces.FluidPort_b	port_bDisSup (from PartialConnection2Pipe2Medium)	Distribution supply outlet port
Modelica.Fluid.Interfaces.FluidPort_a	port_aDisRet (from PartialConnection2Pipe2Medium)	Distribution return inlet port
Modelica.Fluid.Interfaces.FluidPort_b	port_bDisRet (from PartialConnection2Pipe2Medium)	Distribution return outlet port
Modelica.Fluid.Interfaces.FluidPort_b	port_bCon (from PartialConnection2Pipe2Medium)	Connection supply port
Modelica.Fluid.Interfaces.FluidPort_a	port_aCon (from PartialConnection2Pipe2Medium)	Connection return port
Buildings.Controls.OBC.CDL.Interfaces.RealOutput	mCon_flow	Connection supply mass flow rate
Buildings.Controls.OBC.CDL.Interfaces.RealOutput	dp	Pressure drop accross the connection (measured)
Buildings.Controls.OBC.CDL.Interfaces.RealOutput	dH_flow	Difference in enthalpy flow rate between connection supply and return

Type	Name	Description
Model_pipDisSup	pipDisSup (from PartialConnection2Pipe2Medium)	Distribution supply pipe
Model_pipDisRet	pipDisRet (from PartialConnection2Pipe2Medium)	Distribution return pipe
Buildings.Fluid.FixedResistances.Junction	junConSup (from PartialConnection2Pipe2Medium)	Junction with connection supply
Buildings.Fluid.FixedResistances.Junction	junConRet (from PartialConnection2Pipe2Medium)	Junction with connection return
Model_pipCon	pipCon	Connection pipe
Buildings.Fluid.Sensors.MassFlowRate	senMasFloCon	Connection supply mass flow rate (measured)
Fluid.Sensors.RelativePressure	senRelPre	Relative pressure sensor
DifferenceEnthalpyFlowRate	senDifEntFlo	Difference in enthalpy flow rate

Name	Description
Medium	Medium model
Model_pipCon

March 28, 2022, by Kathryn Hinkelman:
Refactored to extend shared two medium base class.
March 3, 2022, by Michael Wetter:
Removed massDynamics.
This is for issue 1542.
February 21, 2020, by Antoine Gautier:
First implementation.