modelCHP_PT1

Simple general CHP model

Extends from AixLib.Obsolete.BaseClasses.ObsoleteModel (Icon for classes that are obsolete and will be removed in later versions).

Information

Overview


Simple model for a electricity driven CHP. using record

Concept

There are two possibilities for parameterization. The first is based on records for CHP characteristics from the FastHVAC.DataBase. In this case the electrical and thermal efficiency of the CHP is a function of return temperature, water mass flow rate and electrical power.

The second possibility is to set the parameters manually (compare: Parameters-Unit properties). In this case the set values are constant.

The electrical and thermal behavior of the CHP is represented by PT1 transfer function. The control strategy is pretended from an external controller. There is an ON/OFF switch for the boiler and also a possibility to control the modulating operation, CHPs electrical capacity. Furthermore a switch counter is implemented.

Example Results

CHP

Parameters

TypeNameDefaultDescription
BooleanselectabletrueCHP record
FastHVAC.Data.CHP.BaseDataDefinitionparamFastHVAC.Data.CHP.Ecopower()Paramter contains data from CHP records
FastHVAC.Media.BaseClasses.MediumSimplemediumFastHVAC.Media.WaterSimple()Standard flow charastics for water (heat capacity, density, thermal conductivity)
RealLHV47300000Lower heating value [J/kg]
Modelica.Units.SI.TemperatureT0Modelica.Units.Conversions.from_degC(20)Initial temperature
Unit properties
Modelica.Units.SI.Efficiencyeta_el0.25CHP's electrical efficiency
Modelica.Units.SI.Efficiencyeta_th0.65CHP's thermal efficiency
Modelica.Units.SI.PowercapP_el1000CHPs electrical capacity

Connectors

TypeNameDefaultDescription
Modelica.Blocks.Interfaces.BooleanInputonOffCHP on/off switch
FastHVAC.Interfaces.EnthalpyPort_benthalpyPort_b
FastHVAC.Interfaces.EnthalpyPort_aenthalpyPort_a
Modelica.Blocks.Interfaces.RealOutput[3]Energy1=W_el 2=Q_th 3=E_fuel
Modelica.Blocks.Interfaces.RealOutput[3]Capacity1=P_el 2=dotQ_th 3=dotE_fuel
Modelica.Blocks.Interfaces.RealInputP_elRelCapacity of electrical power [0 to 1]

Components

TypeNameDefaultDescription
Modelica.Units.SI.Efficiencyeff_totTotal efficiency
Modelica.Units.SI.HeatFlowRateQ_thThermal power
Modelica.Units.SI.MassFlowRatedotm_fuelFuel mass flow rate
Modelica.Units.SI.HeatFlowRatedotE_fuelFuel energy consumption
Modelica.Units.SI.Efficiencyeff_elCHP's electrical efficiency
Modelica.Units.SI.Efficiencyeff_thCHP's thermal efficiency
Modelica.Units.SI.PowerP_elCapacity
RealsigmaNominal power to heat ratio
Modelica.Blocks.Continuous.FirstOrderfirstOrderQ_thdynamic behavior of thermal power output [W]
Modelica.Blocks.Continuous.FirstOrderfirstOrderP_eldynamic behavior of electrical power output [W]
FastHVAC.BaseClasses.WorkingFluidfluidCHP
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlowvarHeatFlow
Modelica.Blocks.Continuous.Integrator[3]integrator
FastHVAC.Components.Controller.SwitchCounterswitchCounter
FastHVAC.Components.Sensors.MassFlowSensormassFlowRate
FastHVAC.Components.Sensors.TemperatureSensorT_flow
FastHVAC.Components.Sensors.TemperatureSensorT_return

Revisions

  • November 28, 2016  Tobias Blacha:
    Moved into AixLib
  • February 09, 2015  Konstantin Finkbeiner:
    Implemented