modelPartialFanCoil4Pipe
Extends from Buildings.DHC.Loads.BaseClasses.PartialTerminalUnit (Partial model for HVAC terminal unit).
Information
This is a simplified partial model of a sensible only four-pipe fan coil unit for heating and cooling. It is intended to be used in conjunction with Buildings.DHC.Loads.BaseClasses.FlowDistribution, and hence it computes the water mass flow rate required to meet the temperature set point.
For the sake of simplicity, a sensible only heat exchanger model is considered.
For the sake of computational performance, a PI controller is used instead of an inverse model of the heat exchanger to assess the required water mass flow rate. Each controller output signal is mapped linearly to the water mass flow rate, from zero to its nominal value. The maximum of the two output signals is mapped linearly to the air mass flow rate, from zero to its nominal value.
The model takes the measured room air temperature as an input (as opposed to the fan inlet temperature) to maintain a valid control loop output in case of zero air flow rate.
The model is partial to allow various connectivity options on the load side: either with fluid ports or with heat ports.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| hexConfiguration | hexConHea | hexConfiguration.CounterFlow | Heating heat exchanger configuration |
| hexConfiguration | hexConCoo | hexConfiguration.CounterFlow | Cooling heat exchanger configuration |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialTerminalUnit) | false | Set to true to allow flow reversal in building distribution system |
| Boolean | allowFlowReversalLoa (from PartialTerminalUnit) | true | Set to true to allow flow reversal on the load side |
| Scaling | |||
| Real | facMul (from PartialTerminalUnit) | 1 | Multiplier factor |
| Real | facMulZon (from PartialTerminalUnit) | 1 | Zone multiplier factor |
| Configuration | |||
| Boolean | have_heaWat (from PartialTerminalUnit) | false | Set to true if the system uses heating water |
| Boolean | have_chiWat (from PartialTerminalUnit) | false | Set to true if the system uses chilled water |
| Boolean | have_chaOve (from PartialTerminalUnit) | false | Set to true if the chilled water based heat exchanger operates in change-over |
| Boolean | have_eleHea (from PartialTerminalUnit) | false | Set to true if the system has electric heating system |
| Boolean | have_eleCoo (from PartialTerminalUnit) | false | Set to true if the system has electric cooling system |
| Boolean | have_heaPor (from PartialTerminalUnit) | false | Set to true for heat ports on the load side |
| Boolean | have_fluPor (from PartialTerminalUnit) | false | Set to true for fluid ports on the load side |
| Boolean | have_TSen (from PartialTerminalUnit) | false | Set to true for measured temperature as an input |
| Boolean | have_QReq_flow (from PartialTerminalUnit) | false | Set to true for required heat flow rate as an input |
| Boolean | have_weaBus (from PartialTerminalUnit) | false | Set to true to use a weather bus |
| Boolean | have_fan (from PartialTerminalUnit) | false | Set to true if fan power is computed |
| Boolean | have_pum (from PartialTerminalUnit) | false | Set to true if pump power is computed |
| Nominal condition | |||
| Modelica.Units.SI.HeatFlowRate | QHea_flow_nominal (from PartialTerminalUnit) | 0 | Nominal heating capacity (>=0) |
| Modelica.Units.SI.HeatFlowRate | QCoo_flow_nominal (from PartialTerminalUnit) | 0 | Nominal cooling capacity (<=0) |
| Modelica.Units.SI.MassFlowRate | mHeaWat_flow_nominal (from PartialTerminalUnit) | 0 | Heating water mass flow rate at nominal conditions |
| Modelica.Units.SI.MassFlowRate | mChiWat_flow_nominal (from PartialTerminalUnit) | 0 | Chilled water mass flow rate at nominal conditions |
| Modelica.Units.SI.MassFlowRate | mLoaHea_flow_nominal (from PartialTerminalUnit) | 0 | Load side mass flow rate at nominal conditions in heating mode |
| Modelica.Units.SI.MassFlowRate | mLoaCoo_flow_nominal (from PartialTerminalUnit) | 0 | Load side mass flow rate at nominal conditions in cooling mode |
| Modelica.Units.SI.Temperature | T_aHeaWat_nominal (from PartialTerminalUnit) | 273.15 + 60 | Heating water inlet temperature at nominal conditions |
| Modelica.Units.SI.Temperature | T_bHeaWat_nominal (from PartialTerminalUnit) | T_aHeaWat_nominal - 22.2 | Heating water outlet temperature at nominal conditions |
| Modelica.Units.SI.Temperature | T_aChiWat_nominal (from PartialTerminalUnit) | 273.15 + 7.2 | Chilled water inlet temperature at nominal conditions |
| Modelica.Units.SI.Temperature | T_bChiWat_nominal (from PartialTerminalUnit) | T_aChiWat_nominal + 5.6 | Chilled water outlet temperature at nominal conditions |
| Modelica.Units.SI.Temperature | T_aLoaHea_nominal (from PartialTerminalUnit) | 273.15 + 21.1 | Load side inlet temperature at nominal conditions in heating mode |
| Modelica.Units.SI.Temperature | T_aLoaCoo_nominal (from PartialTerminalUnit) | 273.15 + 26.7 | Load side inlet temperature at nominal conditions in cooling mode |
| Modelica.Units.SI.MassFraction | w_aLoaCoo_nominal (from PartialTerminalUnit) | 0.011 | Load side inlet humidity ratio at nominal conditions in cooling mode |
Connectors
Components
Revisions
-
February 21, 2020, by Antoine Gautier:
First implementation.