Refrigeration Subcommittee
description
Transcript of Refrigeration Subcommittee
July 26, 2014
Refrigeration SubcommitteeProposed Revision of Refrigeration Provisional Data Requirements
Data Collection for demonstration projects
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Demonstration project data collection best practices method
Compressor power (kW) and energy15 minute interval data compressor current
15 minute interval data compressor current
15 minute interval data compressor current
15 minute interval data compressor current
Condenser fan electric power (and pump motor for evaporative-cooled condensers) (kW) and energy
15 minute interval data fan current
15 minute interval data fan current
Display case electric power (kW) and energy
15 minute interval data for lighting and ASH circuits
15 minute interval data for lighting and ASH circuits
Walk-in electric power (kW) and energy
15 minute interval data for motor circuits
15 minute interval data for motor circuits
Outside air temperature Available online / from EMS Available online / from EMS Available online Available online
Suction Pressure (psig)From EMS, 3 day samples pre and post
From EMS, 3 day samples pre and post
Discharge pressureFrom EMS, 3 day samples pre and post
From EMS, 3 day samples pre and post
Outside relative humidity Available online Available online Available online Available online
TMY3 NOAA data for weather site used in DOE2.2r
Available online Available online Available online Available online
Project #1 (FHPC LT/MT) Project #2 FHPC LT/MT)Project #3 (Case LED, ASHC and WI ECM)
Project #4 (Case LED, ASHC and WI ECM)Measurement
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Demonstration project data collection best practices method
Measurement Projects actual measurements
Best Practices from Table 8.1
Compressor power (kW) and energy
o 15 minute interval data compressor current (3-phs). Volts measured once.
o Electric power (kW) measured over timeo Maximum 5-minute interval datao Data collection must use watt meter as compressor efficiency and power factor varies with load on motor.
Condenser fan electric power (and pump motor for evaporative-cooled condensers) (kW) and energy
o 15 minute interval data fan current (3-phs). Volts measured once.
o Same interval as compressor data.o Volts and power factor (3-phs) measured onceo Amps measured over timeasured onceo If there is a VFD or 2-speed fan, watt meter data is needed as motor efficiency and power factor varies with load
Display case electric power (kW) and energy
o 15 minute interval data for lighting and ASH curcuits
o Maximum 15-minute interval datao Volts and power factor (3-phs) measured one timeo Amps measured over time to estimate kWh
Walk-in electric power (kW) and energy
o 15 minute interval data for motor circuits
o Maximum 15-minute interval datao Volts and power factor (3-phs) measured one timeo Amps measured over time to estimate kWh
Outside air temperature o Hourly weather data from Vancouver airport NOAA station
o Drybulb or wetbulb, depending on condenser typeo Shaded to prevent solaro Maximum 30-minute log data, maximum sampling time 1-minuteo Accuracy +/- 1 F
Suction Pressure (psig) o From EMS, 3 day samples pre and post
o Pressure sensor with +/- 2% of FSo Maximum sampling time 5 seconds, maximum 5-minute log data
Discharge pressure o From EMS, 3 day samples pre and post
o Pressure sensor with +/- 1% of FSo Maximum sampling time 5 seconds, maximum 5-minute log data
Outside relative humidityo Hourly weather data from Vancouver airport NOAA station
o Accuracy of +/- 2% RH between 10% and 90%o Maximum sampling time 1-minuteo Maximum log time 30 minutes
TMY3 NOAA data for weather site used in DOE2.2r
o Hourly weather data from Vancouver airport NOAA station o Temperature
o Correlation between site temperatures and weather station data
Project #1
Data Collection and Calibration
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Regression analysis (Best Practices)
Collection Periods:• Pre: 2/27 to 4/22• Post: 4/22 to 7/9
Methodology for regression• Average daily temp from NOAA as independent• Averaged hourly compressor power• Compressor power as dependent• Linear regression
Method for calculating annual savings• Applied linear regression to average daily TMY3
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Regression analysis
Pre measure implementation
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Regression analysis
Post measure implementation
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Regression analysis
Pre measure implementation
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Regression analysis
Post measure implementation
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Best Practice model results
Pre: kWh = 3.4238(Temp) +422.39Post: kWh=-1.486(Temp) + 584.74
kWhPre 221,697Post 184,123Savings 37,573% Savings 17%
Simplest reliable method
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SRM analysis
• Audit data collected (See protocol appendix)
• DOE2 Simulation with TMY3
kWhPre 375,103Post 320,687Savings 54,416% Savings 14.5%
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Calibration adjustments
• Focused on rated compressor power and capacity• Used manufacturer’s selection tool as a guide• Increased capacity and power to adjust baseline and
savings
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SRM Results
kWhPre 229,914Post 192,988Savings 36,926% Savings 16%
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Comparison of BP and SRM
Best Practices Original SRM % BP to SRM Adjusted SRM % BP to SRMPre 221,697 375,103 69% 229,914 4%Post 184,123 320,687 74% 192,988 5%Savings 37,573 54,416 45% 36,926 -2%
©2014 PECI All rights reserved.
Thank you [email protected]
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Demonstration project data collection simplest reliable method
Compressor power (kW) and energy15 minute interval data compressor current
15 minute interval data compressor current
15 minute interval data compressor current
15 minute interval data compressor current
Condenser fan electric power (and pump motor for evaporative-cooled condensers) (kW) and energy
15 minute interval data fan current
15 minute interval data fan current
Display case electric power (kW) and energy
15 minute interval data for lighting and ASH circuits
15 minute interval data for lighting and ASH circuits
Walk-in electric power (kW) and energy
15 minute interval data for motor circuits
15 minute interval data for motor circuits
Project #1 (FHPC LT/MT) Project #2 FHPC LT/MT)Project #3 (Case LED, ASHC and WI ECM)
Project #4 (Case LED, ASHC and WI ECM)Measurement
Remove what was not used for model, a
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Revisions: Table 8.1 Provisional Data Collection
Best Practice Method
Requirement
Measurement of electrical energy use of each compressor.
Electric power (kW) measured over time
Determining compressor capacity using compressor performance data (kW/ton)
Maximum 5-minute interval data
Data collection must use watt meter as compressor effi ciency and power factor varies with load on motor.
Same interval as compressor data.
Volts and power factor (3-phs) measured once
Amps measured over time
If there is a VFD or 2-speed fan, watt meter data is needed as motor effi ciency and power factor varies with load
Maximum 15-minute interval data
Volts and power factor (3-phs) measured one time Amps measured over time to estimate kWh.
Maximum 15-minute interval data
Volts and power factor (3-phs) measured one time Amps measured over time to estimate kWh.
Walk-in electric power (kW) and energy
Measurement of fan, l ights, and defrost
Diagnostic
Regression Input for walkin-specific load measures. For all other measures, provides insight as regression input where available
Condenser fan electric power (and pump motor for evaporative-cooled condensers) (kW) and energy
Measurement of electrical energy use of condenser fans and pumps.
Diagnostic
Regression Input for system measures. For all other measures, provides insight as regression input where available
Display case electric power (kW) and energy
Measurement of fan, l ight, defrost, and ASH electrical energy use
Diagnostic
Regression Input for case-specific load measures. For all other measures, provides insight as regression input where available
Measurement UseCandidate Simplified Method Requirement
Description
Compressor power (kW) and energy Diagnostic
Regression Input for system measures. For all other measures, provides insight as regression input where available
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Revisions: 8.1 Provisional Data Collection
Drybulb or wetbulb, depending on condenser type
Shaded to prevent solar Maximum 30-minute log data, maximum sampling time 1-minute Accuracy +/- 1 F Maximum 15-minute interval data (for electric and gas use) Electric energy (kWh)
Data collection must use watt meter as compressor effi ciency and power factor varies with load on motor.
Gas energy (cu ft and energy content from utility) Can use whole building gas meter if other uses of gas are identified as being constant (e.g. water heating).
Pressure sensor with +/- 2% of FS
Maximum sampling time 5 seconds maximum 5-minute log data
Discharge pressure Pressure sensor with +/- 1% of FS
(psig) Maximum sampling time 5 seconds maximum 5-minute log data
Accuracy of +/- 2% RH between 10% and 90% Maximum sampling time 1-minute
Maximum log time 30 minutes
Determining compressor capacity using compressor performance data (need kW/ton)
To test that compressor performance data is correct and same load
Provides insight as regression input where available
Outside relative humidityEvaporative cooled condensers performance regression
Diagnostic for applicable measures (Evap cond)
Provides insight as regression input where available
HVAC end-use (kWh) and ThermsEnergy savings for measures with interactive effects
DiagnosticRegression Input for applicable measures
Suction Pressure (psig)Determining compressor capacity using compressor performance data (need kW/ton)
To test that compressor performance data is correct and same load
Provides insight as regression input where available
Outside air temperature Variable in regression model, diagnostics on condenser energy use
Diagnostic Regression input
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Revisions: 8.1 Provisional Data Collection
Maximum 15-minute log data, maximum sampling time 1-minute Drybulb Temperature Accuracy +/- 1 F Accuracy of +/- 2% RH between 10% and 90% Maximum log time 15 minutes, maximum sampling time 1 minute
Local real-time data for the measurement period:
Temperature
Temperature, Relative Humidity, For refrigeration
Correlation between site temperatures and weather station data
Local solar cloud cover for HVAC loads.Calculator diagnostics For a sample of display cases and walk-insCalculator diagnosticsA trend log per l ine-up. One time line-up checked for consistency in temp
Indoor temperature (store and next to walk-ins)
Infiltration of the cases acting with the indoor air. Also indicates what HVAC setpoints are and when it is operating
Yes, for measures that change infiltration
Yes, for measures that change infiltration
Indoor humidity (store and next to walk-ins)
Infiltration of the cases acting with the indoor air
Yes, for measures that change infiltration
Yes, for measures that change infiltration
TMY3 NOAA data for weather site used in DOE2.2r
Yes Yes
Door open time (display case and walk-in)
Not required but provides insight if available
Not required but provides insight if available
Provides diagnostics on walk-in load and display case load
Display case and walk-in air temperature
Not required but provides insight if available
Not required but provides insight if available
Provides diagnostics on walk-in load and display case load
Calibration: Model parameter examples
Compressors Rated power Rated refrigerant flow Evaporator superheat Return gas temperature COP curves
Loads Fixture infiltration Light, fan, and ASH absorbed into fixtures Sales space humidity levels
Calibration: Keyword adjustments
Calibrated model results
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Data Collection
Individual compressor data
Next Steps
• Recommendations on approach, documentation• Review next projects as available