bsug energyplus hvac features
Post on 14-Apr-2018
224 Views
Preview:
TRANSCRIPT
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 1/25
Examples of EnergyPlus HVACSimulation Features
Michael Rosenberg, Jian Zhang, Yunzhi Huang
Building Energy Simulation Forum
• November 16, 2011
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 2/25
EnergyPlus – Example HVAC Simulation Features
1. Built in Energy Management System
. x
3. Dedicated Outdoor Air Systems
2
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 3/25
1. Energy Management System in EnergyPlus
Standard control in EnergyPlus
Thermostatic control, flow control, daily andseasonal schedules,
Outdoor temperature reset, economizer control,
Equipment load staging, and daylighting control.yp ca y pre e ne con ro sequences w on y
schedules and set points accessible to the user.
Interactions between components are limited and
are usually hard-coded in the simulation program.
3
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 4/25
Energy Management System in EnergyPlus
Ener mana ement s stem control
EMS in EnergyPlus is a powerful tool to simulatecomplex HVAC system controls
mu a es e ypes o con ro s poss e w e g aenergy management systems used in real buildings
EMS enables control interactions between components
Accesses sensor data initiates control actions
4
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 5/25
Energy Management System in EnergyPlus
EMS
Sensors (to “GET”)
TemperaturesFlow
Metered data
Actuators (to “SET”)-
Schedules
Setpoints (temp, humidity)
owPrograms – E+ Runtime Language (Erl)
Keywords (RUN, SET, IF, ELSEIF, ENDIF…)
5
Operators (+, -, /, …) & Built-in functions (math,
psychrometric,…)
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 6/25
Example of EMS in CBP Project
DOE’s Commercial Building Partnerships (CBP) ProgramPNNL teamed with one of America’s largest retailers to explore energy design
Retrofit project goal: cutting site energy use by 30%Pre/post-renovation metering data available to calibrate simulation
Detailed simulation is required: EnergyPlus 4.0
Location Virginia
Building type Retail
Built 1987
6
Area ~100,000 ft2
No. of stories 1 level
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 7/25
Building HVAC System and Thermal Zoning
Built‐up air handling unit (AHU)
Chilled water cooling
Central system duct furnace
Operates like a single zone VAV system with inputs from main sales floor (Control Zone).
Other areas and zones (Slave Zones) are also served by zone heaters
OAVFD
Control signal from main sales floor conditions
RA
Main office
RTU1
Salon
RTU2Sales floor (Control Zone)
Storage, offices, and other (Slave Zones)
7
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 8/25
Supply Air Flow and Temperature Control
Heating setpoint 70 ºF
Cooling setpoint 75 ºF
Fan speed
Temperature
8
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 9/25
Modeling with EnergyPlus Standard Controls
Zone
Slave
Zone
Control
Zone 1
SlaveZone 2
Zone
ControlZone
Design schematic Model in E+ with standard
control
… …
9
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 10/25
Modeling with EnergyPlus Standard Controls
E+ objects and settings Problems
AirLoo HVAC:OutdoorAirS stem • Slave zones
System
level
become control
zones
• Supply fan stays
Coil:Cooling:Water
Fan:VariableVolume Max 100% Min 30%
Coil:Heating:Gas
at minimum (30%)
at heating mode
• Cannot realize
• Hypothetical central heating coil with zero W capacity
SetpointManager:Warmest
• Strategy: MaximumTemperature
Heating: 34% at
1st stage, 66% at
2nd stage
• Scheduled Minimum Flow Fraction at 30%
• Gas reheat. Duct furnace’s capacity is proportionally
split to terminal reheat coils based on design flow•
• Cannotsynchronize
heating and VAV
damper positions
ThermostatSetpoint:DualSetpoint
• Deadband 70F - 75F for Control Zone• ea an - or ave ones
10
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 11/25
Simulated Controls with EMS
ControlZone
ControlZone
Slave
Zone 1
Slave
Zone 1
Design system Simulated controls in
Zone 2
Zone 2
11
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 12/25
EMS Program Applied
IF Control Zone reheat coil
input, Q SET
Q > = 50% capacity2nd stage heating mode
• Slave Zone reheat coil availability = YES• Slave and Control Zone min damper = 66%
0< Q < 50% Capacity1st stage heating mode
• Slave Zone reheat coil availability = YES
• Slave and Control Zone min damper = 34%
Q = 0
• Slave Zone reheat coil availability = NO
• Slave and Control Zone min damper = 30% Control Zone damper opening fraction
12
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 13/25
Hourly Results of Winter and Summer Daysea ng mo e oo ng mo e
Reheating coil availability andVAV damper positions are
Reheat coils input rate is not’.
limitation
13
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 14/25
Other Examples of Use of EMS
Turn on a relief fan when economizer is in use
Simulate pressure controlIf OA > Min Ventilation Energize relief fan
Reduce cooling temperature setpoint if space humidity
exceeds thresholdoo ng se po n eg.
14
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 15/25
2. Zone Air Mixing in Energy Plus
ZoneMixing
User defined air transfer Transfers energy from one zone to another (sensible and latent heat
Input parametersSource zone
Receiving zone
Airflow rate – flow per zone, flow/person, flow/area, ACH
Schedule
Delta temperature availability
Outdoor air temperature availability
15
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 16/25
Example of Zone Air Mixing in AEDG
Advanced Energy Design Guides
type and climateIdentifies pathways to 30% and 50% energysavin s
Collaboration of professional organizationsand DOE
Backed by technical support documents(TSDs)
http://www.pnl.gov/main/publications/external/technical_reports/PNNL-19809.pdf
16
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 17/25
Zone Air Mixing – AEDG Quick Service Restaurant
Transfer air from dining room used as MU air for kitchen exhaust
Location Various
Building type Restaurant
Built New Construction
17
Area ~25,000ft2
No. of stories 1 level
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 18/25
Zone Air Mixing – AEDG Quick Service Restaurant
Transfer air from dining room used as MU air for kitchen exhaust
OA2 = 3,120 OA1 = 2,080
Bathroom
Exhaust
-
BX = 400
-
0 0KX = 4,800
TRA = 1,680
RA1SA2 RA2 SA1
Kitchen Dining Area
ZoneMixing,Kitchen_Exhaust_Fan_Mixing, !- Name
Kitchen, !- Zone Name
Hours_of_kitchen_operation, !- Schedule Name
18
Flow/Zone, !- Design Flow Rate Calculation Method
1,680, !- Design Flow Rate {ft3/min}
Dining, !- Source Zone Name0.0; !- Delta Temperature {deltaF}
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 19/25
Zone Air Mixing – AEDG Quick Service Restaurant
ZoneMixing – Not the perfect solutionOnly energy balance is affected – air balance is “left to the user’s discretion”
– –
Dining - Not an issue since equivalent air flow to transfer is relieved through RTU-1.Unless ERV is also included in dining zone, then “dummy” exhaust added.
RTU-1
BathroomExhaust
RTU-2 RTU-1
BathroomExhaust
RTU-2
“Dummy”Exhaust
SP =0SP2 = SP1 x 4,800
3,120
OA2 = 3,120 OA1 = 2,080OA2 = 3,120 OA1 = 2,080
0 0KX= 4,800
BX= 400
TRA= 1,680
RA1SA 2 RA2 SA1
0 0KX=3,120
BX= 400
TRA= 1,680
RA1SA2 RA2 SA1TX= 1,680
Kitchen Dining Area Kitchen Dining Area
19
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 20/25
3. DOAS in EnergyPlus
DOASTwo parallel HVAC systems serving a single zone
Better control of space temperature and humidityBetter control over quantity of OA
Sin le OA su l and exhaust enhance ener recover
20
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 21/25
DOAS in EnergyPlus
Like many simulation programs E+ limit is one HVAC system per zone
Only one “air loop” serving a zone
providing space conditioning (ex. fan coils, heat pumps or radiant panels)
Air loop can be space conditioning system serving multiple zones withzonal DOAS
EnergyPlus Air Loop
21
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 22/25
Example of DOAS in AEDG Medium Office
Location Various
Building type Medium Office
Built New Construction
22
Area ~54,000ft2
No. of stories 3 story
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 23/25
Example of DOAS in AEDG Medium Office
Fan Coil Units Combined with Multi-zone DOAS
DOAS DOAS With Energy Recovery –
OA OA temperature based on OAreset schedule
Fan coil control – thermostat
EA
RA RA
23
Fan Coil an o
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 24/25
Example of DOAS in AEDG MediumOffice
DOAS Temperature Control DOAS Supply Air Reset,
DOAS SAT setpoint, !- Name
Temperature, !- Control Variable60, !- Setpoint at Outdoor Low Temp
50, !- Outdoor Low Tem58
59
60
61
p D e g .
F .
55, !- Setpoint at Outdoor High Temp
60, !- Outdoor High Temp
DOAS Supply Outlet Node; !- Setpoint Node or NodeList Name54
55
56
0 20 40 60 80 100
S A
T e
OA Temp, Deg. F.
Fan Coil ControlThermostatSetpoint:DualSetpoint,
Core_bottom DualSPSched, !- Name 708090
Heating Setpoint Cooling Setpoint
HTGSETP_SCH, !- Heat Setpoint Temp Sched NameCLGSETP_SCH; !- Cool Setpoint TempSched Name
01020304050
1 3 5 7 9 11 13 15 17 19 21 23Weekda
24
7/27/2019 BSUG EnergyPlus HVAC Features
http://slidepdf.com/reader/full/bsug-energyplus-hvac-features 25/25
25
top related