Buildings.Experimental.DHC.Networks
Package of models for district energy network
Information
This package contains models for elements that form the district network.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 Connection2Pipe
|
Model for connecting an agent to a two-pipe distribution network, using fixed resistance pipe model |
 Controls
|
Package of control blocks for distribution systems |
 Distribution2Pipe
|
Model of a two-pipe distribution network, using fixed resistance pipe model |
 Combined
|
Package of models for DHC distribution networks |
 BaseClasses
|
Package with base classes that are used by multiple models |
Buildings.Experimental.DHC.Networks.Connection2Pipe
Model for connecting an agent to a two-pipe distribution network, using fixed resistance pipe model
Information
This is a model of a connection with a two-pipe distribution network using as pipe model a fixed hydraulic resistance with no heat loss .
Extends from Buildings.Experimental.DHC.Networks.BaseClasses.PartialConnection2Pipe (Partial model for connecting an agent to a two-pipe distribution network).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium model | |
| replaceable model Model_pipDis | Fluid.FixedResistances.Press... | ||
| replaceable model Model_pipCon | Fluid.FixedResistances.Lossl... | ||
| Boolean | show_entFlo | false | Set to true to output enthalpy flow rate difference |
| PressureDifference | dpDis_nominal | Pressure drop in distribution line (supply only, not counting return line) [Pa] | |
| Nominal condition | |||
| MassFlowRate | mDis_flow_nominal | Nominal mass flow rate in the distribution line [kg/s] | |
| MassFlowRate | mCon_flow_nominal | Nominal mass flow rate in the connection line [kg/s] | |
| Assumptions | |||
| Boolean | allowFlowReversal | false | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Dynamics | |||
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Nominal condition | |||
| Time | tau | 10 | Time constant at nominal flow for dynamic energy and momentum balance [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| replaceable model Model_pipDis | ||
| replaceable model Model_pipCon | ||
| FluidPort_a | port_aDisSup | Distribution supply inlet port |
| FluidPort_b | port_bDisSup | Distribution supply outlet port |
| FluidPort_a | port_aDisRet | Distribution return inlet port |
| FluidPort_b | port_bDisRet | Distribution return outlet port |
| FluidPort_b | port_bCon | Connection supply port |
| FluidPort_a | port_aCon | Connection return port |
| output RealOutput | mCon_flow | Connection supply mass flow rate [kg/s] |
| output RealOutput | dp | Pressure drop accross the connection (measured) [Pa] |
| output RealOutput | dH_flow | Difference in enthalpy flow rate between connection supply and return [W] |
Modelica definition
model Connection2Pipe
"Model for connecting an agent to a two-pipe distribution network, using fixed resistance pipe model"
extends Buildings.Experimental.DHC.Networks.BaseClasses.PartialConnection2Pipe
(
redeclare model Model_pipDis=Fluid.FixedResistances.PressureDrop (
final dp_nominal=dpDis_nominal),
redeclare model Model_pipCon=Fluid.FixedResistances.LosslessPipe);
parameter Modelica.Units.SI.PressureDifference dpDis_nominal
"Pressure drop in distribution line (supply only, not counting return line)";
end Connection2Pipe;
Buildings.Experimental.DHC.Networks.Distribution2Pipe
Model of a two-pipe distribution network, using fixed resistance pipe model
Information
This is a model of a two-pipe distribution network using
- a connection model with fixed hydraulic resistance with no heat loss as a pipe model, and
- a dummy pipe model with no hydraulic resistance and no heat loss for the end of the distribution line (after the last connection).
Extends from Buildings.Experimental.DHC.Networks.BaseClasses.PartialDistribution2Pipe (Partial model for two-pipe distribution network).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium model | |
| Integer | nCon | Number of connections | |
| replaceable model Model_pipDis | Fluid.FixedResistances.Lossl... | Model for distribution pipe | |
| Integer | iConDpSen | nCon | Index of the connection where the pressure drop is measured |
| Boolean | show_entFlo | false | Set to true to output enthalpy flow rate difference at each connection |
| Nominal condition | |||
| MassFlowRate | mDis_flow_nominal | Nominal mass flow rate in the distribution line before the first connection [kg/s] | |
| MassFlowRate | mCon_flow_nominal[nCon] | Nominal mass flow rate in each connection line [kg/s] | |
| MassFlowRate | mEnd_flow_nominal | mDis_flow_nominal - sum(mCon... | Nominal mass flow rate in the end of the distribution line [kg/s] |
| MassFlowRate | mDisCon_flow_nominal[nCon] | cat(1, {mDis_flow_nominal}, ... | Nominal mass flow rate in the distribution line before each connection [kg/s] |
| PressureDifference | dpDis_nominal[nCon] | Pressure drop in distribution line (supply only, not counting return line) [Pa] | |
| Assumptions | |||
| Boolean | allowFlowReversal | false | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Dynamics | |||
| Conservation equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Nominal condition | |||
| Time | tau | 10 | Time constant at nominal flow for dynamic energy and momentum balance [s] |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPorts_a | ports_aCon[nCon] | Connection return ports |
| FluidPorts_b | ports_bCon[nCon] | Connection supply ports |
| FluidPort_a | port_aDisSup | Distribution supply inlet port |
| FluidPort_b | port_bDisSup | Distribution supply outlet port |
| replaceable model Model_pipDis | Model for distribution pipe | |
| FluidPort_b | port_bDisRet | Distribution return outlet port |
| FluidPort_a | port_aDisRet | Distribution return inlet port |
| output RealOutput | dp | Pressure difference at given location (measured) [Pa] |
| output RealOutput | dH_flow[nCon] | Difference in enthalpy flow rate between connection supply and return [W] |
| output RealOutput | mCon_flow[nCon] | Connection supply mass flow rate (measured) [kg/s] |
Modelica definition
model Distribution2Pipe
"Model of a two-pipe distribution network, using fixed resistance pipe model"
extends Buildings.Experimental.DHC.Networks.BaseClasses.PartialDistribution2Pipe
(
redeclare Connection2Pipe con[nCon](
final dpDis_nominal=dpDis_nominal),
redeclare model Model_pipDis=Fluid.FixedResistances.LosslessPipe);
parameter Modelica.Units.SI.PressureDifference dpDis_nominal[nCon]
"Pressure drop in distribution line (supply only, not counting return line)";
end Distribution2Pipe;