modelModularCHPSystem
Example of the modular CHP power unit model inside a heating circuit
Extends from Modelica.Icons.Example.
Information
An example of the use of modular CHP components combined as a power unit with interfaces to a controller and to the heating circuit.
It allows an impression of the versatile and complex application possibilities of the model by the changeability of many variables of individual components and the detailed investigation capability.
For a better understanding the controller modulates the fuel consumption of the CHP unit. The effects to the thermal output can be visualized by looking at T_Ret and T_Sup.
The return temperature as well as the volume flow in the heating circuit are considered constant in this example.
Caution:
If the prime coolant cirlce of the power unit is using a gasoline medium instead of a liquid fluid, you may need to adjust (raise) the nominal mass flow and pressure drop of the cooling to heating heat exchanger to run the model, because of a background calculation for the nominal flow.
-
April, 2019 by Julian Matthes:
First implementation (see issue #667)
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Unit properties | |||
| AixLib.DataBase.CHP.ModularCHPEngineData.CHPEngDataBaseRecord | CHPEngineModel | DataBase.CHP.ModularCHPEngineData.CHP_Kirsch_L4_12() | CHP engine data for calculations |
| AixLib.Fluid.BoilerCHP.Data.ModularCHP.EngineMaterialData | EngMat | AixLib.Fluid.BoilerCHP.Data.ModularCHP.EngineMaterial_CastIron() | Thermal engine material data for calculations |
| Ambient Parameters | |||
| Modelica.Units.SI.Temperature | T_amb | 293.15 | Default ambient temperature |
| Modelica.Units.SI.AbsolutePressure | p_amb | 101325 | Default ambient pressure |
| Calibration parameters › Fast calibration - Electric power and fuel usage | |||
| Real | s_til | abs((cHP_PowerUnit.cHP_PowerUnit.inductionMachine.s_nominal*(cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_til/cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_nominal) + cHP_PowerUnit.cHP_PowerUnit.inductionMachine.s_nominal*sqrt(abs(((cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_til/cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_nominal)^2) - 1 + 2*cHP_PowerUnit.cHP_PowerUnit.inductionMachine.s_nominal*((cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_til/cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_nominal) - 1))))/(1 - 2*cHP_PowerUnit.cHP_PowerUnit.inductionMachine.s_nominal*((cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_til/cHP_PowerUnit.cHP_PowerUnit.inductionMachine.M_nominal) - 1))) | Tilting slip of electric machine |
| Real | calFac | 0.94 | Calibration factor for electric power output (default=1) |
| Real[:,2] | modTab | [0.0, 0.8; 7200, 0.8; 7200, 0.93; 10800, 0.93; 10800, 0.62; 14400, 0.62; 14400, 0.8; 18000, 0.8; 18000, 0.0] | Table for unit modulation (time = first column; modulation factors = second column) |
| Calibration parameters › Fast calibration - Thermal power output | |||
| Modelica.Units.SI.ThermalConductance | GEngToCoo | 33 | Thermal conductance of engine housing from the cylinder wall to the water cooling channels |
| Modelica.Units.SI.ThermalConductance | GCooExhHex | 400 | Thermal conductance of the coolant heat exchanger at nominal flow |
| Modelica.Units.SI.Thickness | dInn | 0.01 | Typical value for the thickness of the cylinder wall (between combustion chamber and cooling circle) |
| Calibration parameters › Advanced calibration parameters | |||
| Modelica.Units.SI.HeatCapacity | CExhHex | 50000 | Heat capacity of exhaust heat exchanger(default= 4000 J/K) |
| Modelica.Units.SI.Mass | Cal_mEng | 0 | Added engine mass for calibration purposes of the system´s thermal inertia |
| Modelica.Units.SI.Area | A_surExhHea | 100 | Surface for exhaust heat transfer |
| Modelica.Units.SI.MassFlowRate | m_flow_Coo | 0.4 | Nominal mass flow rate of coolant inside the engine cooling circle |
| Modelica.Units.SI.ThermalConductance | GEngToAmb | 2 | Thermal conductance from engine housing to the surrounding air |
| Modelica.Units.SI.ThermalConductance | GAmb | 10 | Constant heat transfer coefficient of engine housing to ambient |
| Modelica.Units.SI.Efficiency | eps | 0.9 | Heat exchanger effectiveness |
| Engine Cooling Circle | |||
| Modelica.Units.SI.Temperature | T_HeaRet | 303.15 | Constant heating circuit return temperature |
| Boolean | VolCon | true | Is volume flow rate control used? |
| Advanced › Latent heat use | |||
| Boolean | ConTec | true | Is condensing technology used and should latent heat be considered? |
| Advanced › Generator heat use | |||
| Boolean | useGenHea | true | Is the thermal loss energy of the elctric machine used? |
| Advanced › Assumptions | |||
| Boolean | allowFlowReversalExhaust | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for exhaust medium |
| Boolean | allowFlowReversalCoolant | true | = false to simplify equations, assuming, but not enforcing, no flow reversal for coolant medium |
| Modelica.Units.SI.MassFlowRate | mExh_flow_small | 0.001 | Small exhaust mass flow rate for regularization of zero flow |
| Modelica.Units.SI.MassFlowRate | mCool_flow_small | 0.005 | Small coolant mass flow rate for regularization of zero flow |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.MassFlowRate | m_flow_HeaCir | if not VolCon then CHPEngineModel.m_floCooNominal else V_flow_HeaCir*senDen.d | Nominal mass flow rate inside the heating circuit |
| Modelica.Units.SI.VolumeFlowRate | V_flow_HeaCir | 0.3/3600 | Nominal volume flow rate inside the heating circuit |
| Modelica.Fluid.Sources.MassFlowSource_T | source | Flow source of heating circuit | |
| Modelica.Fluid.Sources.FixedBoundary | sink | Sink of the heating circuit | |
| Modelica.Blocks.Sources.RealExpression | tempFlowHeating | ||
| AixLib.Fluid.Sensors.DensityTwoPort | senDen | Density sensor for volume and mass flow calculation | |
| Modelica.Blocks.Sources.RealExpression | massFlowHeating | ||
| AixLib.Fluid.BoilerCHP.ModularCHP.ModularCHPIntegrated | cHP_PowerUnit | Model of a CHP unit |
Contents
| Name | Description |
|---|---|
| Medium_Fuel | |
| Medium_Coolant | |
| Medium_HeatingCircuit | |
| Medium_Airprotected | |
| Medium_Exhaustprotected |