Buildings.Obsolete.DistrictHeatingCooling.SubStations
Heating and cooling substations
Information
This package contains component and system models for district heating and cooling substations.Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 Cooling
|
Cooling substation |
 Heating
|
Heating substation |
 VaporCompression
|
Package with substations that have a vapor compression engine for heating or cooling |
 Validation
|
Package with models for validation |
 BaseClasses
|
Package with base classes for substations |
Buildings.Obsolete.DistrictHeatingCooling.SubStations.Cooling
Cooling substation
Information
Substation that adds a prescribed heat flow rate
to the water that flows through it.
The substation has a built-in pump that draws as
much water as needed to maintain the temperature difference
dTHex.
Extends from Buildings.Obsolete.DistrictHeatingCooling.SubStations.BaseClasses.HeatingOrCooling (Base class for heating or cooling substation).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| HeatFlowRate | Q_flow_nominal | Nominal heat flow rate added to medium (Q_flow_nominal <= 0) [W] | |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | -Q_flow_nominal/cp_default/d... | Nominal mass flow rate [kg/s] |
| Design parameter | |||
| Pressure | dp_nominal | 30000 | Pressure difference at nominal flow rate [Pa] |
| TemperatureDifference | dTHex | 4 | Temperature difference over the heat exchanger (positive) [K] |
| Advanced | |||
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Flow resistance | |||
| Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Time | tau | 30 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a | Fluid connector a (positive design flow direction is from port_a to port_b) |
| FluidPort_b | port_b | Fluid connector b (positive design flow direction is from port_a to port_b) |
| output RealOutput | PPum | Electrical power consumed by pump [W] |
| input RealInput | Q_flow | Heat flow rate extracted from system (Q_flow ≤ 0) [W] |
Modelica definition
model Cooling "Cooling substation"
extends Buildings.Obsolete.DistrictHeatingCooling.SubStations.BaseClasses.HeatingOrCooling
(
final m_flow_nominal = -Q_flow_nominal/cp_default/dTHex,
mPum_flow(final k=-1/(cp_default*dTHex)));
parameter Modelica.Units.SI.TemperatureDifference dTHex(
min=0.5,
displayUnit="K") = 4
"Temperature difference over the heat exchanger (positive)";
parameter Modelica.Units.SI.HeatFlowRate Q_flow_nominal(max=0)
"Nominal heat flow rate added to medium (Q_flow_nominal <= 0)";
Modelica.Blocks.Interfaces.RealInput Q_flow(
max=0,
final unit="W") "Heat flow rate extracted from system (Q_flow ≤ 0)";
equation
connect(Q_flow, mPum_flow.u);
connect(Q_flow, hex.u);
end Cooling;
Buildings.Obsolete.DistrictHeatingCooling.SubStations.Heating
Heating substation
Information
Substation that removes a prescribed heat flow rate
from the water that flows through it.
The substation has a built-in pump that draws as
much water as needed to maintain the temperature difference
dTHex.
Extends from Buildings.Obsolete.DistrictHeatingCooling.SubStations.BaseClasses.HeatingOrCooling (Base class for heating or cooling substation).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| HeatFlowRate | Q_flow_nominal | Nominal heat flow rate added to medium (Q_flow_nominal > 0) [W] | |
| Nominal condition | |||
| MassFlowRate | m_flow_nominal | -Q_flow_nominal/cp_default/d... | Nominal mass flow rate [kg/s] |
| Design parameter | |||
| Pressure | dp_nominal | 30000 | Pressure difference at nominal flow rate [Pa] |
| TemperatureDifference | dTHex | -4 | Temperature difference over the heat exchanger (negative) [K] |
| Advanced | |||
| MassFlowRate | m_flow_small | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow [kg/s] |
| Diagnostics | |||
| Boolean | show_T | false | = true, if actual temperature at port is computed |
| Flow resistance | |||
| Real | deltaM | 0.1 | Fraction of nominal flow rate where flow transitions to laminar |
| Dynamics | |||
| Time | tau | 30 | Time constant at nominal flow (if energyDynamics <> SteadyState) [s] |
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
Connectors
| Type | Name | Description |
|---|---|---|
| FluidPort_a | port_a | Fluid connector a (positive design flow direction is from port_a to port_b) |
| FluidPort_b | port_b | Fluid connector b (positive design flow direction is from port_a to port_b) |
| output RealOutput | PPum | Electrical power consumed by pump [W] |
| input RealInput | Q_flow | Heat flow rate extracted from system (Q_flow >= 0) [W] |
Modelica definition
model Heating "Heating substation"
extends Buildings.Obsolete.DistrictHeatingCooling.SubStations.BaseClasses.HeatingOrCooling
(
final m_flow_nominal = -Q_flow_nominal/cp_default/dTHex,
mPum_flow(final k=-1/(cp_default*dTHex)));
parameter Modelica.Units.SI.TemperatureDifference dTHex(
max=-0.5,
displayUnit="K") = -4
"Temperature difference over the heat exchanger (negative)";
parameter Modelica.Units.SI.HeatFlowRate Q_flow_nominal(min=0)
"Nominal heat flow rate added to medium (Q_flow_nominal > 0)";
Modelica.Blocks.Interfaces.RealInput Q_flow(
min=0,
final unit="W") "Heat flow rate extracted from system (Q_flow >= 0)";
equation
connect(Q_flow, mPum_flow.u);
connect(Q_flow, hex.u);
end Heating;