modelContinuousCHP
Extends from Base.PartialCHP (Partial model of a large scale CHP plant with characteristics specified by PQ boundaries and PQ-Heat input table).
Information
1. Purpose of model
This model represents the simplest of all large scale CHP models in the library. It allows a quick representation of a CHP plant with three main characteristics:
- Plant's operation limits
- Plant's fuel input requirements based on electricity and heating outputs
- Time delay between the plant's set point values and actual production values
This component extends from the base class TransiEnt.Producer.Combined.LargeScaleCHPpackage.Base.BaseLargeScaleCHP.
2. Level of detail, physical effects considered, and physical insight
(no remarks)
3. Limits of validity
(no remarks)
4. Interfaces
P_set: input for Power in [W]
Q_flow_set: input for heat flow rate in [W]
outlet: FluidPortOut
inlet: FluidPortIn
gasPortIn: RealGasPortIn
eye: Eyeout
epp: choice of power port
5. Nomenclature
(no remarks)
6. Governing Equations
(no remarks)
7. Remarks for Usage
Two things are required for using this component: parametrisation and set-value definition
The parametrisation of this component consists of the following steps:
- C-Value: this corresponds to the power to heat ratio, defined as P_CHP/Q_useful. Common values can be taken from [1]
- PQ-Boundaries: select a record representing the plant's PQ-boundaries as defined in the package: TransiEnt.Producer.Combined.LargeScaleCHPpackage.Base.PQboundariesPackage
- Q_flow_input_PQDiagram: select a text file containing the fuel input matrix as defined in the component: TransiEnt.Distribution.Heat.HeatGridControl.HeatInput_f_PQ
- Q_max: maximum heat flow output (default: value is automatically taken from the PQ-Boundaries)
Cascading CHP-plants:
Via parameter 'quantity' the whole CHP-plant is devided into several cascading CHP-plants which start up after one another. This implementation repeats the characteristic PQ-field several times. In total, the nominal electrical and thermal power add up to the nominal electrical and thermal power the whole CHP-plant. This is a way for a simple representation of several CHP-plants without having to model several instances of a CHP-plant-model.
8. Validation
(no remarks)
9. References
(no remarks)
10. Version History
Ricardo Peniche, 2016
Model modified by Oliver Schülting (oliver.schuelting@tuhh.de) in Nov 2018: added gasPort
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.HeatFlowRate | Q_flow_n_total (from PartialCHP) | Q_flow_n_CHP + Q_flow_n_Peak | |
| Integer | quantity (from PartialCHP) | 1 | |
| Boolean | integrateHeatFlow (from PartialCHP) | false | True if heat flow shall be integrated |
| Boolean | integrateElectricPower (from PartialCHP) | false | True if electric power shall be integrated |
| Boolean | integrateElectricPowerChp (from PartialCHP) | false | True if electric power of the chp shall be integrated |
| SI.Power | P_el_n_single (from PartialCHP) | P_el_n/quantity | |
| SI.Power | Q_flow_n_CHP_single (from PartialCHP) | Q_flow_n_CHP/quantity | |
| Physical Constraints | |||
| TransiEnt.Producer.Combined.LargeScaleCHP.Base.Characteristics.Generic_PQ_Characteristics | PQCharacteristics (from PartialCHP) | TransiEnt.Producer.Combined.LargeScaleCHP.Base.Characteristics.PQ_Characteristics_WW1() | Characteristics of CHP plant |
| Modelica.Units.SI.Power | P_el_n (from PartialCHP) | 300e6 | Installed capacity for investment cost calculation |
| Modelica.Units.SI.HeatFlowRate | Q_flow_n_CHP (from PartialCHP) | PQCharacteristics.PQboundaries[end, 1]/PQCharacteristics.k_Q_flow | Maximum possible heat flow according to PQ diagram |
| Modelica.Units.SI.HeatFlowRate | Q_flow_n_Peak (from PartialCHP) | 0 | Additional thermal capacity (e.g. peak load heaters) |
| Boolean | useConstantEfficiencies (from PartialCHP) | false | True, constant efficiency over load |
| SI.Efficiency | eta_el_const (from PartialCHP) | 0.4 | Constant efficiency used if useConstantEfficiencies=true |
| SI.Efficiency | eta_th_const (from PartialCHP) | 0.5 | Constant efficiency used if useConstantEfficiencies=true |
| SI.Efficiency | eta_peakload (from PartialCHP) | 0.98 | Constant efficiency of peak load heater annotation |
| Boolean | useConstantSigma (from PartialCHP) | false | True, use constant power to heat ration (sigma) instead of PQ characteristics |
| Real | sigma (from PartialCHP) | 0.3 | Power to heat ration used only if useConstantSigma=true |
| Real | P_grad_max_star | 0.03/60 | Fraction of nominal power per second (12% per minute) |
| SI.Time | T_steamGenerator | 0.5*(0.632/P_grad_max_star) | Time constant of steam generator (overrides value of P_grad_max_star) |
| SI.Time | T_turboGenerator | 60 | Time constant of turbo generator |
| SI.Time | T_heatingCondenser | 40 | Time constant of heating condenser |
| Advanced › Initialization | |||
| SI.ActivePower | P_el_init (from PartialCHP) | P_el_n | Initial or guess value of output (= state) |
| SI.HeatFlowRate | Q_flow_init (from PartialCHP) | Q_flow_n_total | Initial or guess value of output (= state) |
| Boolean | useEfficiencyForInit (from PartialCHP) | false | True, set efficiency; False set steam generator power at init |
| SI.HeatFlowRate | Q_flow_SG_init (from PartialCHP) | Q_flow_init + P_el_init | Initial or guess value of output (= state) of steam generator |
| Real | eta_el_init (from PartialCHP) | 0.4 | Thermal efficiency used at init time |
| SI.Temperature | T_feed_init | 120 + 273.15 | Start temperature of feed water |
| Statistics | |||
| TransiEnt.Basics.Types.TypeOfResource | typeOfResource (from PartialCHP) | TransiEnt.Basics.Types.TypeOfResource.Cogeneration | Type of energy resource for global model statistics |
| TransiEnt.Basics.Types.TypeOfPrimaryEnergyCarrier | typeOfPrimaryEnergyCarrier (from PartialCHP) | TransiEnt.Basics.Types.TypeOfPrimaryEnergyCarrier.BlackCoal | Type of primary energy carrier for co2 emissions global statistics |
| TransiEnt.Basics.Types.TypeOfPrimaryEnergyCarrierHeat | typeOfPrimaryEnergyCarrierHeat (from PartialCHP) | TransiEnt.Basics.Types.TypeOfPrimaryEnergyCarrierHeat.BlackCoal | Type of primary energy carrier for heat for co2 emissions global statistics |
| TransiEnt.Basics.Types.TypeOfCO2AllocationMethod | typeOfCO2AllocationMethod (from PartialCHP) | 1 | Type of allocation method |
| Heating condenser parameters | |||
| TILMedia.VLEFluidTypes.BaseVLEFluid | medium (from PartialCHP) | simCenter.fluid1 | Medium to be used |
| Modelica.Units.SI.Pressure | p_nom | 1e5 | Nominal pressure |
| SI.MassFlowRate | m_flow_nom | 10 | Nominal mass flow rate |
| SI.SpecificEnthalpy | h_nom | 1e5 | Nominal specific enthalpy |
| SI.SpecificEnthalpy | h_start | TILMedia.Internals.VLEFluidConfigurations.FullyMixtureCompatible.VLEFluidFunctions.specificEnthalpy_pTxi(medium, p_nom, T_feed_init) | Start value of sytsem specific enthalpy |
| Fundamental Definitions | |||
| Boolean | useGasPort | false | Choose if gas port is used or not |
| TILMedia.VLEFluidTypes.BaseVLEFluid | medium_gas | simCenter.gasModel1 | Gas Medium to be used - only if useGasPort==true |