modelHPHeatingAir2Water
Information
Air/water heat pump with fixed speed compressor - polynomial model adapted to variable time step
Hypothesis and equations
This is an air/water heat pump with on/off (intermittently controlled) operation (fixed speed) for the heating mode only.
The model is minimalist in terms of parameters to inform and is based on an empirical approach to determining the power in steady state according to indoor and outdoor temperatures conditions. The transitional regime is modelled using a time constant for the power supplied.
The start regulation is determined by the input Boolean "u" : TRUE the HP must be in operation and FALSE the HP must be stopped.
The HP operates in all or nothing. Start and stop phases are given by the associated control system. To protect the machine, it is common that minimum on and off times are defined (DtminOn and DtminOff), they intervene in internal control of the machine.
Bibliography
none
Instructions for use
Two parameter choices are possible:
- Indication of nominal power and COP (warning, a too large a gap of these values with those by default could result in unreliable modelling of a real machine)
- Indication of 3 operating points, the empirical model approach requires three operating points which delimit the model temperature range
Known limits / Use precautions
For empirical approach, pay special attention to the choice of operating temperatures range.
Degradation related to icing/de-icing is rather grossly given without dynamic (10% degradation of the power supplied for outside temperatures below 2°C).
Not suitable for variable speed.
Validations
Validated model according to air/air HP with TIL - Hubert Blervaque, Sila Filfli 02/2013
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Licensed by EDF under a 3-clause BSD-license
Copyright © EDF 2009 - 2023
BuildSysPro version 3.6.0
Author : Hubert BLERVAQUE, Sila FILFLI, EDF (2013)
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Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Choice of parameterization method | |||
| Integer | Choix | 1 | |
| Parameterization choice 1 | |||
| Modelica.Units.SI.Power | Qnom | 6490 | Nominal heating power in Enom temperature conditions |
| Real | COPnom | 4.3 | Nominal coefficient of performance in Enom temperature conditions |
| Parameterization choice 2 | |||
| Real[4] | Enom | {2, 45, 1800, 4950} | Nominal manufacturer data: {Text(°C), ToutputHP(°C), Electric power consumed (W), Supplied heat (W)} |
| Real[4] | E1 | {-15, 55, 1980, 2480} | Manufacturer data: {Text(°C), ToutputHP(°C), Electric power consumed (W), Supplied heat (W)} |
| Real[4] | E2 | {20, 25, 1690, 7750} | Manufacturer data: {Text(°C), ToutputHP(°C), Electric power consumed (W), Supplied heat (W)} |
| Other parameters | |||
| Modelica.Units.SI.MassFlowRate | MegRat | 0.1 | Nominal water flow inside |
| Integer | PumpOperation | 1 | Water pump operation |
| Modelica.Units.SI.Power | QfanextRat | 0 | Outdoor fan power, if QfanextRat included in Qa then choose 0 |
| Real | Cdegi | 0.9 | Degradation coefficient due to icing: 10% of the defrosting time below 2°C |
| Modelica.Units.SI.Time | TauOn | 120 | Switch-on time constant [GAR 2002] |
| Real | alpha | 0.01 | Percentage of standby power (Eco Design Draft report of Task 4: 1, 2 or 3% according to Henderson2000 work) |
| Modelica.Units.SI.Time | dtminOn | 360 | Minimum operating time |
| Modelica.Units.SI.Time | dtminOff | 360 | Minimum stop time before restarting |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | Qfour | Supplied heating power (W) | |
| Modelica.Blocks.Interfaces.RealInput | T_ext | Outdoor temperature (K) | |
| Modelica.Blocks.Interfaces.RealOutput | Qelec | Consumed electric power (W) | |
| Modelica.Blocks.Interfaces.BooleanInput | u | Value of proportional band on setpoint temperature | |
| Modelica.Blocks.Interfaces.BooleanInput | SaisonChauffe | ||
| Modelica.Blocks.Interfaces.RealInput[2] | WaterIn | Vector containing 1- the input fluid temperarture (K), 2- the input fluid flow rate (kg/s) | |
| Modelica.Blocks.Interfaces.RealOutput[2] | WaterOut | Vector containing 1- the output fluid temperarture (K), 2- the output fluid flow rate (kg/s) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | NbCyclePAC | ||
| Boolean | v |
Revisions
Benoît Charrier 05/2015 : Suppression des connecteurs T & m_flow.
Hubert BLERVAQUE (externe) 03/2021 (on version 3.4.0): adding a parametrization option on the water pump operation, see "PumpOperation"