modelHx1DConst
Extends from BaseUnits.BaseHxConst.
Information
Model Hx1DConst represent the model of a counter-current heat exchanger in which one of the two fluid is a constant heat capacity fluid. It is based on the connection of different sub-components:
- A Flow1Dim component representing the flow of the fluid in one side of the exchanger
- A Flow1DConst component representing the flow of the fluid in the other side of the exchanger
- A MetalWall component representing the thermal energy accumulation in the metal wall
- A CountCurr component that enables the possibility of parallel or countercurrent flow
Modelling options
In the Initialization tab the following options are availabe:
- steadystate_T_sf: if true, the derivative of temperature of the constant heat capacity fluid is set to zero during Initialization
- steadystate_h_wf: if true, the derivative of enthalpy of the working fluid is set to zero during Initialization
- steadystate_T_wall: if true, the derivative of temperature of the metal wall is set to zero during Initialization
Numerical options
The numerical options available for the HxRec1DConst are the one implemented in Cell1Dim. and CellConst.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | N | 5 | Number of nodes for the heat exchanger |
| Integer | Nt | 1 | Number of tubes in parallel |
| Modelica.SIunits.Volume | V_sf | 0.03781 | Volume secondary fluid |
| Modelica.SIunits.Volume | V_wf | 0.03781 | Volume primary fluid |
| Modelica.SIunits.Area | A_sf | 16.18 | Area secondary fluid |
| Modelica.SIunits.Area | A_wf | 16.18 | Area primary fluid |
| Boolean | counterCurrent | true | Swap temperature and flux vector order |
| Modelica.SIunits.Mass | M_wall | 69 | Mass of the metal wall between the two fluids |
| Modelica.SIunits.SpecificHeatCapacity | c_wall | 500 | Specific heat capacity of metal wall |
| Modelica.SIunits.MassFlowRate | Mdotnom_sf | 3 | Nominal flow rate of secondary fluid |
| Modelica.SIunits.MassFlowRate | Mdotnom_wf | 0.2588 | Nominal flow rate of working fluid |
| General › Heat transfer | |||
| Modelica.SIunits.CoefficientOfHeatTransfer | Unom_sf | 369 | Coefficient of heat transfer, secondary fluid |
| Modelica.SIunits.CoefficientOfHeatTransfer | Unom_l | 300 | if HTtype = LiqVap: heat transfer coefficient, liquid zone |
| Modelica.SIunits.CoefficientOfHeatTransfer | Unom_tp | 700 | if HTtype = LiqVap: heat transfer coefficient, two-phase zone |
| Modelica.SIunits.CoefficientOfHeatTransfer | Unom_v | 400 | if HTtype = LiqVap: heat transfer coefficient, vapor zone |
| Initialization | |||
| Modelica.SIunits.Pressure | pstart_wf | 23.57e5 | Nominal inlet pressure of working fluid |
| Modelica.SIunits.Temperature | Tstart_inlet_wf | 334.9 | Initial value of working fluid temperature at the inlet |
| Modelica.SIunits.Temperature | Tstart_outlet_wf | 413.15 | Initial value of working fluid temperature at the outlet |
| Modelica.SIunits.Temperature | Tstart_inlet_sf | 418.15 | Initial value of secondary fluid temperature at the inlet |
| Modelica.SIunits.Temperature | Tstart_outlet_sf | 408.45 | Initial value of secondary fluid temperature at the outlet |
| Initialization › Intialization options | |||
| Boolean | steadystate_T_sf | false | if true, sets the derivative of T_sf (secondary fluids Temperature in each cell) to zero during Initialization |
| Boolean | steadystate_h_wf | false | if true, sets the derivative of h of primary fluid (working fluids enthalpy in each cell) to zero during Initialization |
| Boolean | steadystate_T_wall | false | if true, sets the derivative of T_wall to zero during Initialization |
| Numerical options | |||
| Discretizations | Discretization | ThermoCycle.Functions.Enumerations.Discretizations.centr_diff | Selection of the spatial discretization scheme |
| Boolean | Mdotconst_wf | false | Set to yes to assume constant mass flow rate of primary fluid at each node (easier convergence) |
| Boolean | max_der_wf | false | Set to yes to limit the density derivative of primary fluid during phase transitions |
| Boolean | filter_dMdt_wf | false | Set to yes to filter dMdt of primary fluid with a first-order filter |
| Real | max_drhodt_wf | 100 | Maximum value for the density derivative of primary fluid |
| Modelica.SIunits.Time | TT_wf | 1 | Integration time of the first-order filter |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Interfaces.Fluid.Flange_Cdot | inletSf (from BaseHxConst) | ||
| Interfaces.Fluid.Flange_ex_Cdot | outletSf (from BaseHxConst) | ||
| Interfaces.Fluid.FlangeA | inletWf (from BaseHxConst) | ||
| Interfaces.Fluid.FlangeB | outletWf (from BaseHxConst) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| ThermoCycle.Components.FluidFlow.Pipes.Flow1Dim | WorkingFluid | ||
| Components.HeatFlow.Walls.MetalWall | metalWall | ||
| Components.HeatFlow.Walls.CountCurr | countCurr | ||
| ThermoCycle.Components.FluidFlow.Pipes.Flow1DConst | SecondaryFluid | ||
| SummaryClass | Summary |
Contents
| Name | Description |
|---|---|
 Medium2HeatTransferModel | |
| Medium1HeatTransferModel | |
| SummaryBase | |
| SummaryClass |