modelHPHeatingAir2Air
Information
Hypothesis and equations
This is an air/air 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 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
Four parameter choices are possible: WARNING! Be sure to replace the default setting options that are not used because they may be used to simulate the default configuration
- Indication of nominal heating capacity (COP default of about 4.2), HP performances are adapted to the nominal power defined by the user
- 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
- Indication of the nominal point and the regression coeff, this expert parameterization allows to define the C1, C2, D1 and D2 coefficients by a method external to the model (finer regression on more operating points for example)
Although the need to ensure the replacement of default values to use the default configuration, it is possible for advanced users to modify the HP performance curve using the mode 3 or 4, then go in mode 1 or 2 to modulate the HP power from performances defined above.
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 with TIL - Hubert Blervaque, Sila Filfli 05/2012
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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 (2012)
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Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Choice of parameterization method | |||
| Integer | Choix | 1 | |
| Parameterization choice 1 | |||
| Modelica.Units.SI.Power | Qnom | 1380.87 | Nominal heating power in Enom temperature conditions |
| Real | COPnom | 4.18468 | Nominal coefficient of performance in Enom temperature conditions |
| Parameterization choice 2 | |||
| Real[4] | Enom | {7, 20, 329.982, 1380.87} | Nominal manufacturer data: {Text(°C), ToutputHP(°C), Electric power consumed (W), Supplied heat (W)} |
| Real[4] | E1 | {-7, 23, 260.174, 921.479} | Manufacturer data: {Text(°C), ToutputHP(°C), Electric power consumed (W), Supplied heat (W)} |
| Real[4] | E2 | {14, 17, 365.383, 1690.44} | Manufacturer data: {Text(°C), ToutputHP(°C), Electric power consumed (W), Supplied heat (W)} |
| Other parameters | |||
| 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 air temperature (K) | |
| Modelica.Blocks.Interfaces.RealInput | T_int | Indoor air 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 |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | COPt | HP coefficient of performance at time t | |
| Boolean | v |
Revisions
Hubert Blervaque - novembre 2013 : MAJ de la description des paramètres