modelHeatflow_L1

Ideal Heat flow boundary with constant or prescribed power and constant pressure loss

Extends from TransiEnt.Components.Boundaries.Heat.Base.PartialHeatBoundary.

Information

1. Purpose of model

Ideal boundary model with prescribed or constant heat flow and without fluid volume. Pressure loss is constant and given via parameter.

2. Level of detail, physical effects considered, and physical insight

Constant pressureloss, no fluid volume

3. Limits of validity

Not time dependent because lack of volume

4. Interfaces

TransiEnt.Base.Interfaces.Thermal.FluidPortIn (x2)

RealInput (for specification of boundary power)

5. Nomenclature

(no elements)

6. Governing Equations

First law of thermodynamics

7. Remarks for Usage

Heat flow can be limited by T_out_limit if use_T_out_limit==true to model a temperature level of heat source/heat sink

8. Validation

Tested in model TransiEnt.Components.Boundaries.Heat.Check.testHeatflow_L1

Seems that no further testing is necessary because of simplicity of component

9. References

(no remarks)

10. Version History

Model created by Pascal Dubucq (dubucq@tuhh.de) on Mon Aug 18 2014

Model modified by Oliver Schülting (oliver.schuelting@tuhh.de) on Jul 2019

Parameters

TypeNameDefaultDescription
TILMedia.VLEFluidTypes.BaseVLEFluidMedium (from PartialHeatBoundary)simCenter.fluid1Medium model
SI.PowerQ_flow_const100e3Constant heating Power
Booleanuse_Q_flow_intrueUse external Value for Q_flow
Booleanuse_T_out_limitfalseUse limitation of output temperature
SI.Pressurep_dropsimCenter.p_nom[2] - simCenter.p_nom[1]Nominal pressure drop
Booleanchange_signfalseChange sign on input values, false: negative setpoint will produce heat
SI.TemperatureT_out_limit_const273.15 + 100maximum output temperature - if change_sign==true: minimum output temperature
BooleanuseVariableToutlimitfalseDefine limit of output muss flow by input

Connectors

TypeNameDefaultDescription
TransiEnt.Basics.Interfaces.Thermal.FluidPortOutfluidPortOut (from PartialHeatBoundary)
TransiEnt.Basics.Interfaces.Thermal.FluidPortInfluidPortIn (from PartialHeatBoundary)
TransiEnt.Basics.Interfaces.Thermal.HeatFlowRateInQ_flow_prescribedRealInput (for specification of boundary power)
TransiEnt.Basics.Interfaces.General.TemperatureInT_out_limit_prescribed

Components

TypeNameDefaultDescription
TransiEnt.SimCentersimCenter (from PartialHeatBoundary)
Modelica.Units.SI.HeatFlowRateQ_flow_boundary (from PartialHeatBoundary)fluidPortIn.m_flow*(actualStream(fluidPortIn.h_outflow) - actualStream(fluidPortOut.h_outflow))
SI.SpecificEnthalpyh
SI.SpecificEnthalpyh_out_limit