modelOneFloor_OneZone

Closed-loop model with 1 zone in 1 floor

Extends from Modelica.Icons.Example.

Information

This is a model of a building that has multiple thermal zones on each floor, and an HVAC system on each floor.

The HVAC system is a variable air volume (VAV) system with economizer and a heating and cooling coil in the air handler unit (AHU). There is also a reheat coil and an air damper in each zone inlet branch. Each floor has one VAV AHU system. The figure below shows the schematic diagram of the HVAC system

The control sequence regulates the supply fan speed to ensure a prescribed pressure rise of 850 Pa when the supply fan runs during operation modes occupied, unoccupied night set back, unoccupied warm-up, and unoccupied pre-cool. The heating coil valve, outside air damper, and cooling coil valve are modulated in sequence to maintain the supply air temperature set point. The economizer control ensures the following functions: minimum outside air requirement, and supply air cooling, see Buildings.Examples.VAVReheat.BaseClasses.Controls.Economizer. The controller of the terminal units tracks the room air temperature set point based on a "single maximum" logic, see Buildings.Examples.VAVReheat.BaseClasses.Controls.RoomVAV.

There is also a finite state machine that transitions the mode of operation of the HVAC system between the modes occupied, unoccupied off, unoccupied night set back, unoccupied warm-up, and unoccupied pre-cool. Local loop control is implemented using proportional and proportional-integral controllers, while the supervisory control is implemented using a finite state machine.

The thermal room model computes transient heat conduction through walls, floors, and ceilings and long-wave radiative heat exchange between surfaces. The convective heat transfer coefficient is computed based on the temperature difference between the surface and the room air. There is also a layer-by-layer short-wave radiation, long-wave radiation, convection, and conduction heat transfer model for the windows. The model is similar to the Window 5 model and described in TARCOG 2006.

Each thermal zone can have air flow from the HVAC system, through leakages of the building envelope.

References

ASHRAE. Sequences of Operation for Common HVAC Systems. ASHRAE, Atlanta, GA, 2006.

Deru M., K. Field, D. Studer, K. Benne, B. Griffith, P. Torcellini, M. Halverson, D. Winiarski, B. Liu, M. Rosenberg, J. Huang, M. Yazdanian, and D. Crawley. DOE commercial building research benchmarks for commercial buildings. Technical report, U.S. Department of Energy, Energy Efficiency and Renewable Energy, Office of Building Technologies, Washington, DC, 2009.

TARCOG 2006: Carli, Inc., TARCOG: Mathematical models for calculation of thermal performance of glazing systems with our without shading devices, Technical Report, Oct. 17, 2006.

Parameters

Type	Name	Default	Description
Integer	nZon	1	Number of zones per floor
Integer	nFlo	1	Number of floors
Modelica.Units.SI.PressureDifference	dP_pre	850	Prescribed pressure difference
Modelica.Units.SI.Volume[nZon,nFlo]	VRoo	{{682.7 for j in 1:nFlo} for i in 1:nZon}	Room volume
Modelica.Units.SI.MassFlowRate[nZon,nFlo]	m_flow_nominal_each	7convVRoo[:, :]	Nominal flow rate to each zone
Modelica.Units.SI.MassFlowRate	m_flow_nominal	nZon(7conv)68*2.7	Nominal system flow rate
Real	conv	1.2/3600	Conversion factor for nominal mass flow rate

Components

Type	Name	Description
Buildings.Examples.ScalableBenchmarks.BuildingVAV.BaseClasses.VAVBranch[nZon,nFlo]	vavTer	Supply branch of VAV system
Buildings.Examples.ScalableBenchmarks.BuildingVAV.ThermalZones.MultiZone	buiZon	Multizone model with scalable number of zones
Buildings.Fluid.Movers.FlowControlled_dp[nFlo]	fan	Supply air fan
Buildings.Fluid.HeatExchangers.DryCoilEffectivenessNTU[nFlo]	hex	Heating coil
Fluid.HeatExchangers.WetCoilEffectivenessNTU[nFlo]	cooCoi	Cooling coil
Buildings.Fluid.FixedResistances.PressureDrop[nFlo]	fil	Filter
Buildings.Fluid.Sources.Boundary_pT[nFlo]	sinHea	Sink for heating coil
Buildings.Fluid.Sources.Boundary_pT[nFlo]	souHea	Source for heating coil
Buildings.Fluid.Sources.Boundary_pT[nFlo]	sinCoo	Sink for cooling coil
Buildings.Fluid.Sources.Boundary_pT[nFlo]	souCoo	Source for cooling coil
Buildings.Fluid.Sources.Outside[nFlo]	amb	Ambient conditions
Buildings.Fluid.Actuators.Dampers.MixingBox[nFlo]	eco	Economizer
Buildings.Fluid.Sensors.TemperatureTwoPort[nFlo]	TMix	Mixed air temperature sensor
Buildings.Fluid.Sensors.VolumeFlowRate[nFlo]	senSupFlo	Sensor for supply fan flow rate
Buildings.Fluid.Sensors.TemperatureTwoPort[nFlo]	TRet	Return air temperature sensor
Buildings.Fluid.Sensors.VolumeFlowRate[nFlo]	senRetFlo	Sensor for return fan flow rate
Buildings.Fluid.Movers.Preconfigured.SpeedControlled_y[nFlo]	fanRet	Return air fan
Buildings.Fluid.Actuators.Valves.TwoWayLinear[nFlo]	valHea	Heating coil valve
Buildings.Fluid.Actuators.Valves.TwoWayLinear[nFlo]	valCoo	Cooling coil valve
Buildings.Fluid.Sensors.VolumeFlowRate[nFlo]	VOut1	Outside air volume flow rate
Buildings.Fluid.Sensors.TemperatureTwoPort[nFlo]	TCoiHeaOut	Heating coil outlet temperature
Buildings.Fluid.Sensors.TemperatureTwoPort[nFlo]	TSup	Supply air temperature sensor
Buildings.Examples.VAVReheat.BaseClasses.Controls.ModeSelector[nFlo]	modeSelector	Finite State Machine for the operational modes
Buildings.Examples.VAVReheat.BaseClasses.Controls.Economizer[nFlo]	conEco	Controller for economizer
Buildings.BoundaryConditions.WeatherData.ReaderTMY3	weaDat
Buildings.BoundaryConditions.WeatherData.Bus	weaBus	Weather Data Bus
Modelica.Blocks.Routing.RealPassThrough	TOut	Outdoor temperature
Buildings.Utilities.Math.Average[nFlo]	ave	Compute average of room temperatures
Buildings.Utilities.Math.Min[nFlo]	min1	Computes lowest room temperature
Buildings.Examples.VAVReheat.BaseClasses.Controls.FanVFD[nFlo]	conFanRet	Controller for fan
Buildings.Examples.ScalableBenchmarks.BuildingVAV.BaseClasses.ControlBus[nFlo]	controlBus	Control bus for each floor
Buildings.Examples.ScalableBenchmarks.BuildingVAV.BaseClasses.HeatSetpoint	TSetHea	Heating setpoint
Buildings.Examples.ScalableBenchmarks.BuildingVAV.BaseClasses.CoolSetpoint	TSetCoo1	Cooling setpoint
Buildings.Controls.SetPoints.OccupancySchedule	occSch	Occupancy schedule
Buildings.Examples.ScalableBenchmarks.BuildingVAV.BaseClasses.FanOnOffWithDP[nFlo]	fan_dP_On_Off	controller outputs fan on or off
VAVReheat.BaseClasses.Controls.SupplyAirTemperature[nFlo]	conTSup	Supply air temperature controller
VAVReheat.BaseClasses.Controls.SupplyAirTemperatureSetpoint[nFlo]	TAirSupSet	Supply air temperature set point

Name	Description
MediumA
MediumW	Medium model for water

Revisions

March 4, 2024, by Michael Wetter:
Corrected wrong use of displayUnit attribute.
April 27, 2023, by Michael Wetter:
Reformulated assignment of m_flow_each to avoid in Dymola 2023x the error "Incompatible number of dimensions for variable and its definition equation".
This is for issue #3360.
August 22, 2022, by Hongxiang Fu:
Replaced fanRet[] with a preconfigured fan model. This is for issue #2668.
June 17, 2022, by Hongxiang Fu:
Changed fan[].m_flow_nominal from 10 to 0.1.
This is for issue #3067.
June 30, 2021, by Antoine Gautier:
Changed cooling coil model. This is for issue #2549.
February 25, 2021, by Baptiste Ravache:
Inverse the sign of hex[nFlo].Q_flow_nominal to respect the heat flow convention.
October 27, 2020, by Antoine Gautier:
Refactored the model for compatibility with the updated control of supply air temperature. This is for #2024.
October 24, 2017, by Michael Wetter:
Updated model for new fan controller that takes the on/off signal as an input.
June 6, 2017, by Jianjun Hu:
First implementation.