modelHeatPump
Information
This heat pump model does not consider part-load operation (ON/OFF regulation is assumed). The heating power and the heat soure temperature are computed by assuming a linear correlation between their actual and nominal values. The electrical efficiency is computed assuming a constant second-law efficiency, parameter of the model.
The primary fluid is modeled by means of 1-D incompressible fluid flow model (Cell1DimInc), in which a dynamic energy balance and static mass and momentum balances are applied on the fluid. The heat transfer in the primary fluid is modeled with a constant heat transfer coefficient. However, it can be changed to other heat transfer models through the HeatTransfer parameter in the fluid model.
Furthermore, the model includes a Boolean input connector on_off, which defines the operational state of the heat pump. In the equations, the Boolean input is translated to a variable value together with a first order block, which can take into account a start-up time constraint.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Volume | V | 0.005 | Internal volume |
| Modelica.Units.SI.Area | A | 10 | Heat exchange area |
| Real | eta_II | 0.4 | Second law efficiency of the HP |
| Modelica.Units.SI.Time | tau | 60 | Start-up time constant |
| Modelica.Units.SI.Power | Qdot_nom | 10E3 | Nominal heating capacity |
| Modelica.Units.SI.Temperature | Th_nom | 35 + 273.15 | Nominal heat sink temperature |
| Modelica.Units.SI.Temperature | Tc_nom | 273.15 | Nominal heat source temperature |
| Modelica.Units.SI.Mass | M_wall | 69 | Mass of the metal wall between the two fluids |
| Modelica.Units.SI.SpecificHeatCapacity | c_wall | 500 | Specific heat capacity of metal wall |
| Modelica.Units.SI.Temperature | Tmax | 273.15 + 100 | Maximum temperature at the outlet |
| Initialization | |||
| Modelica.Units.SI.Temperature | Th_start | 35 + 273.15 | Start value for the condenser temperature |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.Interfaces.FluidPort_a | InFlow | ||
| Modelica.Fluid.Interfaces.FluidPort_b | OutFlow | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | HeatSource | ||
| Modelica.Blocks.Interfaces.BooleanInput | on_off |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | COP | ||
| Real | COP_nom | ||
| Modelica.Units.SI.Power | Wdot | ||
| Modelica.Units.SI.Power | Wdot_nom | ||
| Modelica.Units.SI.Power | Qdot | ||
| Modelica.Units.SI.Temperature | Th | ||
| Modelica.Units.SI.Power | Wdot_in | ||
| Flows.FluidFlow.Cell1DimInc | fluid | ||
| Interfaces.Heat.HeatPortConverter | heatPortConverter | ||
| Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow | prescribedHeatFlow | ||
| Modelica.Blocks.Continuous.FirstOrder | firstOrder |
Contents
| Name | Description |
|---|---|
 Medium |