Transcript EnergyPlus Training Part 1

Lecture 18: Template Systems
and Autosizing
Material prepared by GARD Analytics, Inc. and University of Illinois
at Urbana-Champaign under contract to the National Renewable Energy
Laboratory. All material Copyright 2002-2003 U.S.D.O.E. - All rights reserved
Purpose of this Lecture
 Introduce Templates—a time saving feature
 Putting an actual system together in EnergyPlus
(by hand) can be difficult and time consuming
 Templates provide shorthand way of describing
systems
 Introduce Autosizing
 Some components require sizes that the user may
not know immediately
 Autosizing asks EnergyPlus to size these
automatically
2
HVAC System Templates
Template Purpose
Current Templates
Future Templates
Template Concepts
Using HVAC Templates
HVAC Template Structure
Typical HVAC Systems
Template Example Inputs/Results
3
Template Purpose
HVAC system templates provide a
shorthand way of describing selected
standard HVAC system configurations
4
Current Templates
 Zone Thermostat
 Purchased Air
 Four Pipe Fan Coil
 VAV Single Duct w/ Reheat
 Packaged Furnace w/ DX Air Conditioner
5
Current Templates (cont’d)
 Purchased Hot and Chilled Water Supply
Loops
 Single Boiler and Chiller Supply Loops
6
Future Templates
 Constant Volume Dual Duct
 Variable Volume Dual Duct
 VAV w/ Power Induction Unit
 Heat Pumps
 Add automatic autosizing to all templates
 Provide “IDF Segments” for template systems
 Multiple Boiler and Chiller Supply Loops
 Multiple Equipment Condenser Loop
7
Template Concepts
 Beneficial for setting up the loops, branches,
and nodes
 Not as beneficial for fans, pumps, chillers,
coils, etc.,
 The only "automatic" fields are the object
name, node names, and maybe flow rates.
 For autosized templates the defaults are
already specified
8
Template Concepts (NonAutosized)
User assigns a template variable for
each of the remaining fields in the
object for Fans, Coils, Chillers, etc…


Advantage: order-independent keywords to
assign values to
Disadvantage: mapping the variable names
to object fields is messy, and then the user
has to go find the object documentation to
understand what the variables really mean
9
Using HVAC Templates
To describe typical HVAC system
configurations, a combination of system
macro commands is used along with the
required macro variable definitions prior
to each command
10
HVAC Template Structure
Input File.imf
##include HVACTemplates.imf
Regular EnergyPlus objects
RUN PERIOD, 1, 1, 12, 31;
...
HVAC Template commands:
##set1 ZoneName = "RESISTIVE ZONE"
##set1 AvailSched = "FanAndCoilAvailSched"
##set1 HeatSuppAirTemp = 50
##set1 CoolSuppAirTemp = 13
##set1 HeatSuppAirHR = 0.015
##set1 CoolSuppAirHR = 0.010
PurchAirZone[]
...
EP-Launch or RunEplus.bat
EP-Macro.exe
EPMIDF File
Regular EnergyPlus objects
after macro processing
(“Clean IDF file”)
EnergyPlus.exe
EnergyPlus output files
EnergyPlus output files
EnergyPlus output files
11
Typical HVAC Systems
Purchased Air System

ZoneThermostat[ ] (once for each zone)

PurchAirZone[ ] (once for each zone)
Packaged Furnace w/ DX Cooling

ZoneThermostat[ ] (once for each zone)

DirectAirZone[ ] (once for each zone)

UnitaryAirLoop[ ]
12
Typical HVAC Systems (cont’d)
Single-Duct VAV System w/ OA Option

ZoneThermostat[ ] (once for each zone)

VAVZone[ ] (once for each zone)

VAVAirLoop[ ]

ChilledWaterDemand[ ]

HotWaterDemand[ ]
13
Typical HVAC Systems (cont’d)
Single Chiller Supply Plant

ChillerSupply1[ ]

Condenser1[ ]
Single Boiler Supply Plant

BoilerSupply1[ ]
14
Template Example Inputs Thermostat
##include HVACTemplates.imf
! Master Zone
##set1 ZoneName
##set1 ZoneCtrlSched
##set1 SnglHeatSPSched
##set1 SnglCoolSPSched
##set1 SnglHtClSPSched
##set1 DualSPHeatSched
##set1 DualSPCoolSched
ZoneThermostat[]
=
=
=
=
=
=
=
! Command to insert template master file
"RESISTIVE ZONE"
! Zone name
"Zone-Control-Type-Sched" ! Cntrl Type Sched
"Heating-Setpoints" ! Single Heat SP Sched
"Cooling-Setpoints" ! Single Cool SP Sched
"None"
! Single Heat/Cool SP Sch
"None"
! Dual SP Heat SP Sched
"None"
! Dual SP Cool SP Sched
! Trigger the zone thermostat macro
15
Template Example Results Thermostat
ZONE CONTROL:THERMOSTATIC,
RESISTIVE ZONE Thermostat,
RESISTIVE ZONE,
Zone-Control-Type-Sched,
Single Heating Setpoint, RESISTIVE ZONE SingleHeatSPSched ,
Single Cooling SetPoint, RESISTIVE ZONE SingleCoolSPSched ;
SINGLE HEATING SETPOINT,
RESISTIVE ZONE SingleHeatSPSched,
Heating-Setpoints;
SINGLE COOLING SETPOINT,
RESISTIVE ZONE SingleCoolSPSched,
Cooling-Setpoints;
16
Template Example Inputs –
Direct Air Zone
##set1 ZoneName
##set1 AvailSched
##set1 ZoneSuppAirFlow
DirectAirZone[]
= "RESISTIVE ZONE"
! Zone name
= "FanAndCoilAvailSched" ! System Avail Sched
= 2.0
! Supply air flow [m3/s]
! Trigger the direct air zone macro
17
Template Example Results –
Direct Air Zone
CONTROLLED ZONE EQUIP CONFIGURATION,
RESISTIVE ZONE,
! zone name
RESISTIVE ZONE Equipment, ! zone equipment list
RESISTIVE ZONE Inlets,
! inlet node list
,
! exhaust node list
RESISTIVE ZONE ZoneNode,
! zone node
RESISTIVE ZONE OutletNode; ! zone outlet node
ZONE EQUIPMENT LIST,
RESISTIVE ZONE Equipment, ! name
DIRECT AIR, RESISTIVE ZONE Direct Air, 1, 1;
NODE LIST,
RESISTIVE ZONE Inlets,
! name
RESISTIVE ZONE AirTermInletNode; ! zone inlet is the direct air
DIRECT AIR,
RESISTIVE ZONE Direct Air, !- Direct Air Name
FanAndCoilAvailSched,
!- Schedule name for on/off schedule
RESISTIVE ZONE AirTermInletNode, !- Zone Supply Air Node Name
2.0;
!- Maximum air flow rate {m3/s}
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HVAC Sizing Options
Component Sizing
Zone Sizing
System Sizing
Plant Sizing
19
Component Sizing
Components are typically autosized
based on specified summer and winter
design days.
Global sizing factor optional

Sizing factor typically >1.0

Sizing factor can be any value >0

Default 1.0
SIZING PARAMETERS,
1.2;
!- sizing factor
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Zone Sizing
 Calculates required supply air volume to
maintain zone setpoints
 Computes maximum cooling load, heating
load and air flow for systems sizing and sizing
zone components
 Only controlled zones are included in zone
sizing calculations
 OA flow per person based on total number of
people for all PEOPLE statements in zone
(schedule values are not applied)
21
Zone Sizing (cont’d)
ZONE SIZING,
ZONE ONE,
14.,
50.,
0.009,
0.004,
flow/person,
0.00944,
0.0,
0.0,
design day,
0,
design day,
0;
!!!!!!!!!!!!!!!-
Name of a zone
Zone cooling design supply air temperature {C}
Zone heating design supply air temperature {C}
Zone cooling design supply air humidity ratio
{kg-H20/kg-air}
Zone heating design supply air humidity ratio
{kg-H2O/kg-air}
Outside air method
Outside air flow per person {m3/s}
Outside air flow {m3/s}
Zone sizing factor
Cooling design air flow method
Cooling design air flow rate {m3/s}
Heating design air flow method
Heating design air flow rate {m3/s}
22
System Sizing
 Calculates design air flow rates and heating
and cooling capacities based on specified
supply air conditions and zone sizing results
 Must use zone sizing objects to force hard
sizes (will not read component sizes)
 Only controlled zones are included in system
sizing calculations
23
System Sizing (cont’d)
SYSTEM SIZING,
Unitary System,
sensible,
0.0,
1.0,
0.0,
13.0,
50.0,
noncoincident,
no,
no,
0.008,
0.008,
design day,
0,
design day,
0;
!!!!!!!!!!!!!!!!!!-
name of an AIR PRIMARY LOOP object
type of load to size on
Design (min) outside air volume flow rate {m3/s}
minimum system air flow ratio
Preheat design set temperature {C}
Central cooling design supply air temperature {C}
Central heating design supply air temperature {C}
Sizing Option
Cooling 100% Outside Air
Heating 100% Outside Air
Central cooling design supply air hum. ratio
{kg-H2O/kg-air}
Central heating design supply air hum. ratio
{kg-H2O/kg-air}
cooling design air flow method
cooling design air flow rate {m3/s}
heating design air flow method
heating design air flow rate {m3/s}
24
Auto-Sizing
Generate sizing report files (.zsz, .ssz)
Outside air options
Supply-side equipment sizing
Size and “go” runs with computed sizes
Uses all design days and selects max size
25
Auto-Sizing Calculation
A “Purchased Air” simulation is
performed for each zone using user
specified Design Day weather


Purchased Air: hot or cold air supplied
directly to a zone at a fixed temperature
and with infinitely variable air flow.
The Purchased Air simulation yields zone
design air flow rates.
26
Auto-Sizing Calculation
(cont’d)
The zone design air flow rates are
summed to give central air handler
coincident or non-coincident design flow
rates.
User specified design supply
temperatures and the design weather
conditions are used to calculate zone
and system design heating and cooling
capacities.
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Auto-Sizing Calculation
(cont’d)
Coil UAs and other component inputs
are obtained by iterating the component
models to meet the design outlet
conditions
Coil water flow rates are summed to
obtain plant loop hot and chilled water
flow rates
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Auto-Sizing Input
Run Control
At least 2 design days
Special day schedules for sizing
Zone Sizing, System Sizing and Plant
Sizing
Indicate with “Autosize” the inputs to be
auto-sized
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Zone Sizing
Name of Zone
Design cooling supply air temperature
Design heating supply air temperature
Design cooling supply air humidity ratio
Design heating supply air humidity ratio
30
Zone Sizing (cont’d)
Outside air method
Outside air flow per person
Outside air flow
Zone sizing factor
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Zone Sizing (cont’d)
Cooling design air flow method
Cooling design air flow rate
Heating design air flow method
Heating design air flow rate
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Zone Sizing - Example
ZONE SIZING,
SPACE1-1,
14.,
50.,
0.009,
0.004,
FLOW/PERSON,
0.00944,
0.0,
0.0,
design day,
0,
design day,
0;
!!!!!!!!!!!!!-
Name of a zone
Zone cooling design supply air temperature {C}
Zone heating design supply air temperature {C}
Zone cooling design supply air humidity ratio
Zone heating design supply air humidity ratio
outside air method
outside air flow per person {m3/s}
outside air flow {m3/s}
zone sizing factor
cooling design air flow method
cooling design air flow rate {m3/s}
heating design air flow method
heating design air flow rate {m3/s}
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System Sizing
Name of an AIR PRIMARY LOOP
Type of load to size on

Sensible, latent or total
Design (min.) outside air volumetric
flow rate
Minimum system air flow ratio
34
System Sizing (cont’d)
Preheat design set temperature
Central cooling/heating design supply
air temperature
Sizing Option

Coincident or non-coincident
35
Plant Sizing
Design loop exit temperature
Design loop delta T
Name of a PLANT LOOP or CONDENSER
LOOP
Loop type – heat, cool, condenser
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Run Control - example
RUN CONTROL,
Yes, ! zone sizing
Yes, ! system sizing
Yes, ! plant sizing
No,
! design day full simulation
Yes; ! weather file full simulation
Note: design days used here just to size
37
Sizing Schedules Example - 1
SCHEDULE,
Clg-SetP-Sch,
Temperature,
Clg-SetP-WSch,
1,
1,
12,
31;
!- Name
!- ScheduleType
!- Name of WEEKSCHEDULE 1
!- Start Month 1
!- Start Day 1
!- End Month 1
!- End Day 1
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Sizing Schedules Example - 2
WEEKSCHEDULE,
Clg-SetP-Wsch,
Clg-SetP-DSch-We,
Clg-SetP-DSch-Wd,
:
Clg-SetP-DSch-Wd,
Clg-SetP-DSch-We,
Clg-SetP-DSch-We,
Clg-SetP-DSch-SumDes,
Clg-SetP-DSch-HighLimit,
Clg-SetP-DSch-Wd,
Clg-SetP-DSch-Wd;
!- Name
!- Sunday DAYSCHEDULE Name
!- Monday DAYSCHEDULE Name
!- Friday DAYSCHEDULE Name
!- Saturday DAYSCHEDULE Name
!- Holiday DAYSCHEDULE Name
!- SummerDesignDay DAYSCHEDULE Name
!- WinterDesignDay DAYSCHEDULE Name
!- CustomDay1 DAYSCHEDULE Name
!- CustomDay2 DAYSCHEDULE Name
39
Sizing Schedules Example - 3
DAYSCHEDULE,
Clg-SetP-DSch-SumDes,
Temperature,
23.9, 23.9, 23.9, 23.9, 23.9,
23.9, 23.9, 23.9, 23.9, 23.9,
23.9, 23.9, 23.9, 23.9, 23.9,
23.9, 23.9, 23.9, 23.9, 23.9,
23.9,
23.9,
23.9,
23.9;
No setback for autosizing - will cause
oversizing to meet setback recovery
within one timestep
40
What Inputs can
be Auto-sized?
Indicated in IDD file
FAN:SIMPLE:VariableVolume,
…..
N3 , \field Max Flow Rate
\units m3/s
\Autosizeable
…..
41
Asking for Auto-sizing
In the IDF file:
FAN:SIMPLE:VariableVolume,
Supply Fan 1, !Fan Name
FanAvailSched, !Fan Schedule
0.7,
!Fan Efficiency
600.0,
!Delta Pressure [N/M2]
Autosize,
!Max Vol Flow Rate [m3/S]
Autosize,
!Min Vol Flow Rate [m3/S]
0.9,
!motor efficiency
1.0,
!motor in air stream fraction
0.35071223,
!Fan Coeff 1 Coeff's for Inlet Vane Dampers
0.30850535,
!Fan Coeff 2
-0.54137364,
!Fan Coeff 3
0.87198823,
!Fan Coeff 4
0.000,
!Fan Coeff 5
Main Heating Coil 1 Outlet Node, !Outlet Node
VAV Sys 1 Outlet Node;
!Inlet Node
42
Summary
 Templates are a time saving feature that:
 Provides a shorthand way of describing systems
 Assists in the process of putting together
EnergyPlus input
 Autosizing helps the user:
 Determine the size of equipment needed based on
the building description, thermal loads, etc.
 Avoids the need to provide a size for some
equipment which may not be of interest but is still
needed as input for EnergyPlus
43