modelgeothermalFieldController
Controls the heat exchange with a heat or cold source by setting two valves
Information
This is a model of a controller, which manipulates the opening of two valves. If the measured temperature drops below the lower thrshold, the first valve is fully closed and the second valve is fully opened. The opposite constellation applies if the temperature exceeds the higher threshold. To avoid zero mass flow rates, the opening is only close 0. Additionally, a delay can be set so that the valves do not react simultaneously (opened valve is closed first). It can be used in AixLib.Fluid.Examples.GeothermalHeatPump.Components.GeothermalHeatPump.
- May 24, 2017, by Alexander Kümpel:
Delay improved. - May 19, 2017, by Marc Baranski:
First implementation.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Temperature | temperature_low | 273.15 + 40 | Lower temperature threshold for hysteresis |
| Modelica.Units.SI.Temperature | temperature_high | 273.15 + 45 | Upper temperature threshold for hysteresis |
| Boolean | warmSide | true | true = hysteresis with negation = for warm side |
| Modelica.Units.SI.Time | delayTime | 10 | Time delay between opening of valve 1 and 2 |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | temperature | Temperature of the controlled flow | |
| Modelica.Blocks.Interfaces.RealOutput | valveOpening1 | Actuator position (0: closed, 1: open) | |
| Modelica.Blocks.Interfaces.RealOutput | valveOpening2 | Actuator position (0: closed, 1: open) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Logical.Switch | switch | Switches between fully opened and fully closed | |
| Modelica.Blocks.Nonlinear.FixedDelay | fixedDelay | Delay that prevents that both valves react simultaneously | |
| Modelica.Blocks.Math.Add | add | If one valve is fully openend, the other one must be fully closed | |
| Modelica.Blocks.Logical.Hysteresis | hysteresis | Checks if the temperature is too high or too low | |
| Modelica.Blocks.Sources.Constant | approxFullyClosed | Used for closing a valve almost fully | |
| Modelica.Blocks.Sources.Constant | approxFullyOpened | Used for opening a valve almost fully | |
| Modelica.Blocks.Logical.Switch | switch1 | Switches between delayed and direct opening | |
| Modelica.Blocks.Logical.Switch | switch2 | Switches between delayed and direct opening | |
| Modelica.Blocks.Nonlinear.FixedDelay | fixedDelay1 | Delay that prevents that both valves react simultaneously | |
| Modelica.Blocks.Sources.Constant | fullOpening | Used for opening a valve fully |