modelModularAHU
model of a modular air handling unit
Information
This model represnts a central air handling unit. It can be configured in modular way. Depending on the desired functionalities it will inherit a heat recovery system, a heater, a cooler and a humidifier. The type of hmumidifier can be chosen by the user. It will be either steam or adiabatic humidification. Dehumidification is realized by sub-cooling only. Hence, if no cooling and heating is implemented, dehumidification will be disabled.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | humidifying | false | set to true if humidifying is implemented |
| Boolean | cooling | true | set to true if cooling is implemented |
| Boolean | dehumidifying | false | set to true if dehumidification by sub-cooling is implemented |
| Boolean | heating | true | set to true if heating is used |
| Boolean | heatRecovery | true | set to true if heat recovery system is implemented |
| Boolean | usePhiSet | false | set to true if relative humidity is controlled, else absolute humidity is controlled |
| Boolean | limPhiOda | false | set to true if outdoor air humidity is limited to saturation |
| Nominal values | |||
| Modelica.Units.SI.MassFlowRate | m_flow_nominal | nominal mass flow rate in air handling unit | |
| Modelica.Units.SI.PressureDifference | dpHrs_nominal | nominal pressure drop of heat recovery system | |
| Modelica.Units.SI.PressureDifference | dpCoo_nominal | nominal pressure drop of cooler | |
| Modelica.Units.SI.PressureDifference | dpHea_nominal | nominal pressure drop of heater | |
| Modelica.Units.SI.PressureDifference | dpHum_nominal | nominal pressure drop of humidifier | |
| Modelica.Units.SI.PressureDifference | dpFanOda_nominal | nominal pressure increase of outdoor air fan | |
| Modelica.Units.SI.PressureDifference | dpFanEta_nominal | nominal pressure increase of extract air fan | |
| Settings AHU Value | |||
| Real | effHrsOn | 0.8 | efficiency of HRS in the AHU modes when HRS is enabled |
| Real | effHrsOff | 0.2 | taking a little heat transfer into account although HRS is disabled (in case that a HRS is physically installed in the AHU) |
| Fans › Constant Assumptions | |||
| Modelica.Units.SI.Pressure | dpFanOda | 800 | pressure difference over supply fan |
| Modelica.Units.SI.Pressure | dpFanEta | 800 | pressure difference over extract fan |
| Modelica.Units.SI.Efficiency | etaFanOda | 0.7 | efficiency of outdoor air fan |
| Modelica.Units.SI.Efficiency | etaFanEta | 0.7 | efficiency of extract air fan |
| Advanced › Humidifying | |||
| Modelica.Units.SI.Temperature | TWat | 293.15 | water temperature |
| Modelica.Units.SI.Temperature | TSteam | 373.15 | steam temperature |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | VOda_flow | volume flow of outdoor air in m3/s | |
| Modelica.Blocks.Interfaces.RealInput | TOda | Temperature of outdoor air in K | |
| Modelica.Blocks.Interfaces.RealInput | phiOda | relative humidity of outdoor air 0...1] | |
| Modelica.Blocks.Interfaces.RealInput | VEta_flow | volume flow of extract air in m3/s | |
| Modelica.Blocks.Interfaces.RealInput | TEta | Temperature of extract air in K | |
| Modelica.Blocks.Interfaces.RealInput | phiEta | relative humidity of extract air [0...1] | |
| Modelica.Blocks.Interfaces.RealInput | TSupSet | Set value for supply air temperature in K | |
| Modelica.Blocks.Interfaces.RealInput[2] | phiSupSet | set value for supply air relative humidity [Range: 0...1] (Vector: [1] min, [2] max) | |
| Modelica.Blocks.Interfaces.RealOutput | phiSup | supply air relative humidity | |
| Modelica.Blocks.Interfaces.RealOutput | TSup | supply air temperature in K | |
| Modelica.Blocks.Interfaces.RealOutput | QCoo_flow | The absorbed cooling power supplied from a cooling circuit [W] | |
| Modelica.Blocks.Interfaces.RealOutput | QHea_flow | The absorbed heating power supplied from a heating circuit [W] | |
| Modelica.Blocks.Interfaces.RealOutput | Pel | The consumed electrical power supplied from the mains [W] | |
| Modelica.Blocks.Interfaces.RealOutput | QHum_flow | The humidification power supplied from a humidifier [W] |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Components.HeatRecoverySystem | heaRecSys | heat recovery system | |
| Components.FanSimple | fanOda | outdoor air fan | |
| Components.FanSimple | fanEta | extract air fan | |
| Components.Cooler | coo | cooler | |
| humidifier | hum | ||
| Components.Heater | hea | ||
| Controler.ControlerHumidifier | conHum | Controler for Humidifier | |
| Controler.ControlerHeatRecovery | conHeaRecSys | Controler for heat recovery system | |
| Controler.ControlerCooler | conCoo | Controler for cooler |
Contents
| Name | Description |
|---|---|
 humidifier |
Revisions
- April, 2020 by Martin Kremer:
First Implementation. - February, 2025 by Martin Kremer:
Impleted some controler and minor bug fixes.