modelDetailedHouse7
Extends from DetailedHouse6 (Extension of DetailedHouse5 that adds a heating system).
Information
This step adds a controller that disables the heat pump when the supply water temperature exceeds 45°C. The simple controller has a large impact on the heat pump's COP.
Required models
- IDEAS.Fluid.Sensors.TemperatureTwoPort
- Modelica.Blocks.Logical.Hysteresis
- Modelica.Blocks.Math.BooleanToReal
Connection instructions
The temperature sensor in the storage tank serves as an input to the hysteresis controller. The controller is configured such that it switches to a false signal below 45°C and to true above 50°C.
The output of the hysteresis controller is thus true when the tank temperature is high enough and false
otherwise. This Boolean signal has to be converted in a real control signal that can be accepted by the heat
pump model using the BooleanToReal block. The heat pump already has a control signal.
Since blocks cannot be removed from an extension of a model, the heat pump model input type is set to
enable_variable_speed=true. This configuration allows the model to accept any real signal while ignoring
connections to the other control signal.
Reference result
The figure below shows the operative zone temperature recZon.TSensor, the heat pump condenser temperatureheaPum.con.T
and the radiator heat flow rate rad.Q_flow in the north-oriented zone with (red) and without (blue) hysteresis control.
We see that the supply temperature is indeed reduced significantly.
This causes the zone temperature to be slightly lower, up to about 0.2°C.
However, the COP increases to around 4-5 and the electrical energy use decreases from 28.1 kWh to 17.4 kWh.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Length | l (from DetailedHouse5) | 8 | Zone length |
| Modelica.Units.SI.Length | w (from DetailedHouse5) | 4 | Zone width |
| Modelica.Units.SI.Length | h (from DetailedHouse5) | 2.8 | Zone height |