modelCoolingCoilHumidifyingHeating_ClosedLoop
Extends from Modelica.Icons.Example, Buildings.Applications.DataCenters.ChillerCooled.Equipment.Validation.BaseClasses.PartialAirHandlerControl.
Information
This model demonstrates the use of Buildings.Applications.DataCenters.ChillerCooled.Equipment.CoolingCoilHumidifyingHeating. The valve on the water-side and the electric heater on the air-side is regulated to track a setpoint temperature for the air outlet based on the step changes in the inlet temperature on the waterside. The humidifier on the air-side is manipulated to control the humidity of the air outlet.
To avoid simultenous cooling (by opening the valve on the water side) and heating (by turning on the heater), a built-in controller is used to turn the reheater on and off. The detailed control logic can be found in Buildings.Applications.DataCenters.ChillerCooled.Controls.Reheat. A setting for this example is shown as following:
-
The switch point for the valve position,
yValSwiis set asyValSwi=yValMin + 0.1, and a deadband0.05is used. -
The switch point for the difference between the inlet temperature of
the reheater and the required outlet temperature setpoint,
dTSwiis set to 0, and deaband temperature difference 0.5 Kelvin is used.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.ThermalConductance | UA_nominal | m2_flow_nominal*1006*(T_b2_nominal - T_a2_nominal)/Buildings.Fluid.HeatExchangers.BaseClasses.lmtd(T_a1_nominal, T_b1_nominal, T_a2_nominal, T_b2_nominal) | Thermal conductance at nominal flow for sensible heat, used to compute time constant |
| Real | yValMin | 0.4 | Minimum position of water-side valves |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Applications.DataCenters.ChillerCooled.Equipment.CoolingCoilHumidifyingHeating | ahu | Air handling unit | |
| Modelica.Blocks.Sources.Constant | uFan | Control input for fan | |
| Modelica.Blocks.Sources.Constant | masFraSet | Setpoint mass fraction | |
| Buildings.Controls.Continuous.LimPID | PID | PID controller for the water-side valve in air handling units |
Revisions
-
April 11, 2017, by Yangyang Fu:
First implementation.