modelMultiLayerThermalDelta
multi layers of heat exchanger
Extends from AixLib.Fluid.Interfaces.PartialTwoPortInterface (Partial model with two ports and declaration of quantities that are used by many models), AixLib.Fluid.Interfaces.LumpedVolumeDeclarations (Declarations for lumped volumes).
Information
Overview
Model of the multi layers of heat exchanger. From the water flow is the convective and radiative heat output calculated.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Mass | M_Radiator | Mass of radiator | |
| calcT.Temp | calc_dT | Select calculation method of excess temperature | |
| Modelica.Units.SI.Volume | Vol_Water | Water volume inside layer | |
| Real | s_eff | Type[1] | Radiative coefficient |
| Real | Q_dot_nom_i | Nominal power of single layer | |
| Real | dT_nom | Nominal access temperature | |
| Real | delta_nom | Nominal Radiation temperature | |
| Modelica.Units.SI.Emissivity | eps | Emissivity | |
| Modelica.Units.SI.Area | A | Area of radiator layer | |
| Modelica.Units.SI.Length | d | Thickness of radiator wall | |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTwoPort) | true | = false to simplify equations, assuming, but not enforcing, no flow reversal |
| Nominal condition | |||
| Modelica.Units.SI.MassFlowRate | m_flow_nominal (from PartialTwoPortInterface) | Nominal mass flow rate | |
| Advanced | |||
| Modelica.Units.SI.MassFlowRate | m_flow_small (from PartialTwoPortInterface) | 1E-4*abs(m_flow_nominal) | Small mass flow rate for regularization of zero flow |
| Advanced › Diagnostics | |||
| Boolean | show_T (from PartialTwoPortInterface) | false | = true, if actual temperature at port is computed |
| Dynamics › Conservation equations | |||
| Modelica.Fluid.Types.Dynamics | energyDynamics (from LumpedVolumeDeclarations) | Modelica.Fluid.Types.Dynamics.DynamicFreeInitial | Type of energy balance: dynamic (3 initialization options) or steady state |
| Modelica.Fluid.Types.Dynamics | substanceDynamics (from LumpedVolumeDeclarations) | energyDynamics | Type of independent mass fraction balance: dynamic (3 initialization options) or steady state |
| Modelica.Fluid.Types.Dynamics | traceDynamics (from LumpedVolumeDeclarations) | energyDynamics | Type of trace substance balance: dynamic (3 initialization options) or steady state |
| Advanced › Dynamics | |||
| Modelica.Fluid.Types.Dynamics | massDynamics (from LumpedVolumeDeclarations) | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state, must be steady state if energyDynamics is steady state |
| Initialization | |||
| Medium.AbsolutePressure | p_start (from LumpedVolumeDeclarations) | Medium.p_default | Start value of pressure |
| Medium.Temperature | T_start (from LumpedVolumeDeclarations) | Medium.T_default | Start value of temperature |
| Medium.MassFraction[Medium.nX] | X_start (from LumpedVolumeDeclarations) | Medium.X_default | Start value of mass fractions m_i/m |
| Medium.ExtraProperty[Medium.nC] | C_start (from LumpedVolumeDeclarations) | fill(0, Medium.nC) | Start value of trace substances |
| Medium.ExtraProperty[Medium.nC] | C_nominal (from LumpedVolumeDeclarations) | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
| Dynamics | |||
| Real | mSenFac (from LumpedVolumeDeclarations) | 1 | Factor for scaling the sensible thermal mass of the volume |
| Geometry and Material › Geometry | |||
| AixLib.Fluid.HeatExchangers.Radiators.BaseClasses.RadiatorTypes.RadiatorType | Type | Type of radiator | |
| Real | n | Radiator exponent | |
| Modelica.Units.SI.Length | length | Length of radiator, in m | |
| Geometry and Material › Material | |||
| Modelica.Units.SI.Density | DensitySteel | DensitySteel | Specific density of steel, in kg/m3 |
| Modelica.Units.SI.SpecificHeatCapacity | CapacitySteel | CapacitySteel | Specific heat capacity of steel, in J/kgK |
| Modelica.Units.SI.ThermalConductivity | LambdaSteel | LambdaSteel | Thermal conductivity of steel, in W/mK |
| Initialization › Solid material | |||
| Modelica.Fluid.Types.Dynamics | initDynamicsWall | Modelica.Fluid.Types.Dynamics.DynamicFreeInitial | Like energyDynamics, but SteadyState leeds to same behavior as DynamicFreeInitial |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | port_a (from PartialTwoPort) | Fluid connector a (positive design flow direction is from port_a to port_b) | |
| Modelica.Fluid.Interfaces.FluidPort_b | port_b (from PartialTwoPort) | Fluid connector b (positive design flow direction is from port_a to port_b) | |
| AixLib.Utilities.Interfaces.RadPort | radiative | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | convective |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.MassFlowRate | m_flow (from PartialTwoPortInterface) | port_a.m_flow | Mass flow rate from port_a to port_b (m_flow > 0 is design flow direction) |
| Modelica.Units.SI.PressureDifference | dp (from PartialTwoPortInterface) | port_a.p - port_b.p | Pressure difference between port_a and port_b |
| Medium.ThermodynamicState | sta_a (from PartialTwoPortInterface) | if allowFlowReversal then Medium.setState_phX(port_a.p, noEvent(actualStream(port_a.h_outflow)), noEvent(actualStream(port_a.Xi_outflow))) else Medium.setState_phX(port_a.p, noEvent(inStream(port_a.h_outflow)), noEvent(inStream(port_a.Xi_outflow))) | Medium properties in port_a |
| Medium.ThermodynamicState | sta_b (from PartialTwoPortInterface) | if allowFlowReversal then Medium.setState_phX(port_b.p, noEvent(actualStream(port_b.h_outflow)), noEvent(actualStream(port_b.Xi_outflow))) else Medium.setState_phX(port_b.p, noEvent(port_b.h_outflow), noEvent(port_b.Xi_outflow)) | Medium properties in port_b |
| Utilities.HeatTransfer.HeatToRad | twoStar_RadEx | ||
| AixLib.Fluid.HeatExchangers.Radiators.BaseClasses.HeatConvRadiator | heatConv_Radiator | ||
| AixLib.Fluid.HeatExchangers.Radiators.BaseClasses.RadiatorWall | radiator_wall | ||
| AixLib.Fluid.MixingVolumes.MixingVolume | Volume |
Revisions
-
October, 2016 by Peter Remmen:
Transfer to AixLib. -
October 7, 2013 by Ole Odendahl:
Added documentation and formatted appropriately