Research on annual energy consumption
of packaged air-conditioning units
Research on annual energy consumption
of packaged air-conditioning units
Graduate School of Frontier Sciences
The University of Tokyo
Eiji Hihara, Jianfeng Wang
June 4, 2004 in Yokohama, Japan.
Graduate School of Frontier Sciences
The University of Tokyo
Eiji Hihara, Jianfeng Wang
JRA4048:2001 by JRAIA is used to calculate the annual electrical power consumption
Research Purpose
Research Purpose
z
To examine the reliability of the
To examine the reliability of the
To examine the reliability of the
To examine the reliability of the
JRA standard
JRA standard
JRA standard
JRA standard
・・
・ ・
・
・・
・ ・
・・
・
Assessment of power consumption of packaged air
Assessment of power consumption of packaged air--conditioning unitsconditioning units
Measurement of three subjects (A, B, C)Measurement of three subjects (A, B, C)
Calculation with JRA4048 standard Calculation with JRA4048 standard
Comparison between calculated and measured values Comparison between calculated and measured values
Performance measurements
of three PAC units
Performance measurements
of three PAC units
Subjects of measurement
Subjects of measurement::
Packaged air
Packaged air--conditioning units conditioning units
・・AA・・・・・・ Constant speed Constant speed ((CeilingCeiling--suspended typesuspended type))
<
<Rated cooling capacity 12.5kW, COP=2.63, R22Rated cooling capacity 12.5kW, COP=2.63, R22>>
・
・BB・・・・・・ InverterInverter--equipped equipped ((CeilingCeiling--mounted cassette mounted cassette type
type))
<
<Rated cooling capacity 10.0kW, COP=4.52, R407CRated cooling capacity 10.0kW, COP=4.52, R407C>>
・
・CC・・・・・・InverterInverter--equipped equipped (( CeilingCeiling--mounted cassette mounted cassette
type
Test Purposes
Test Purposes
The reliability of JRA4048:2001
The reliability of JRA4048:2001 「「Method of assessing seasonal Method of assessing seasonal power consumption (
power consumption ( 期間消費電力量算出方法期間消費電力量算出方法))」」
Measurement of running performance under part load and
Measurement of running performance under part load and
intermittent running conditions
intermittent running conditions
Measurement of performance degradation coefficient (
Measurement of performance degradation coefficient (CCDD))
C
C
DD=
=
=
=
=
=
=
=
0.25=const.
0.25=const.
????
????
( ) ( ) ( ) ( )1
/
1
/
c cyc c dry D c cyc c dryCOP
COP
C
Q
Q
−
=
−
JRA standard
Effect of C
D
values:
constant speedEffect of C
D
values:
constant speed0% 20% 40% 60% 80% 100% 120% 140% 160% 180% 200% 220% 240% 0 0.25 0.5 0.75 1 C D Cooling Total Heating
Relative electricity consumption
CD=0.25.
CD=0.25 at 100% of seasonal power consumption
C
CDD=0.25 at 100% of seasonal power consumption=0.25 at 100% of seasonal power consumption
Calculated
Effect of C
D
values:
inverter-installed
Effect of C
D
values:
inverter-installed
0% 20% 40% 60% 80% 100% 120% 140% 160% 180% 200% 220% 240% 0 0.25 0.5 0.75 1 CD Value Cooling Cooling&Heating Heating
CD=0.25 at 100% of seasonal power consumption
C
CDD=0.25 at 100% of seasonal power consumption=0.25 at 100% of seasonal power consumption
When CD<0.25, the decrease of intermittent running efficiency is limited(Save energy)
When C
When CDD<0.25, the decrease of intermittent running efficiency is limite<0.25, the decrease of intermittent running efficiency is limitedd((Save energySave energy))
Calculated
Schematic of Measurement
Schematic of Measurement
Outdoor unit side Outdoor unit sideIndoor unit side Indoor unit side
Test chamber
Air Flow Mechanical
room (2(2F)(2(2F)F)F) Outdoor unit Indoo r unit Monitor Room
Items of measurement
Items of measurement
Standard measurement (Rated)
Minimum capacity measurement
Part load measurement
(30
%
~90%)
【
Change . Ambient temp
】
Standard measurement (Rated)
Minimum capacity measurement
Part load measurement
(30
%
~90%
)
【
Change . Ambient temp
】
Standard measurement (Rated)
Standard measurement (Rated)
Minimum capacity measurement
Minimum capacity measurement
Part load measurement
Part load measurement
(30
(30
%
%
~90%)
~90%)
【
【
Change . Ambient temp
Change . Ambient temp
】
】
Standard measurement (Rated)
Standard measurement (Rated)
Minimum capacity measurement
Minimum capacity measurement
Part load measurement
Part load measurement
(30
(30
%
%
~90%
~90%
)
)
【
【
Change . Ambient temp
Change . Ambient temp
】
】
Cooling
Cooling
Heating
A: Cooling at constant speed
Assumed load from a detached house
A: Cooling at constant speed
Assumed load from a detached house
COP(cooling) 2.65 2.44 2.71 2.60 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 4 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Ambient temp.℃ COP
JRArated CD=0.25 and data from catalogue, estimated
JRA rated CD=0.25 and part load data from measurement, estimated CD and Part load, measured
rated Low temp. 50%load 20%load CD=0.18 equivalent CD=0.25
A:Heating at constant speed
A:Heating at constant speed
COP(heating) 2.67 3.11 2.92 0 0.5 1 1.5 2 2.5 3 3.5 4 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Ambient Temp.℃ Rated Part load General load Low temp. Rated 50%load CD=0.11 CD=0.25
B: Cooling with inverter
Assumed load from a detached house(store)
B: Cooling with inverter
Assumed load from a detached house(store)
COP(cooling) 3.14 2.89 3.32 2.61 4.22 2 2.5 3 3.5 4 4.5 5 5.5 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Ambient temp.℃ COP
JRA rated, estimated JRA part load, estimated Part load, measured
20%load 50%load Low temp. Rated Middle(min.)measurement CD=0.61 equivalent CD=0.25
B:Heating with inverter
B:Heating with inverter
COP(Heating) 1.58 3.26 2.84 3.92 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Ambient temp.℃ Rated Part load General load 20%load Low temp Rated 50%Load Middle(minimum) CD=0.74 CD=0.25
C: Cooling with inverter
Assumed load from a detached house (store)
C: Cooling with inverter
Assumed load from a detached house (store)
COP(cooling) 4.32 4.39 4.29 4.00 4.02 4.43 0.00 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Ambient Temp.℃ COP
JRA rated, estimated JRA part load, estimated Part load, measured
30%load 50%load middle(minimum rated 70% load 90% load CD=0.42 equivalent CD=0.25
C:Heating with inverter
C:Heating with inverter
COP(Heating) 2.37 2.82 3.50 2.25 3.55 3.15 4.42 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Ambient temp.℃ Rated Part load General load 30%load Low temp Rated test 50%load Middle(minimum) CD=0.51 90%load 70%load CD=0.25 CD=0.25
Estimated and measured power consumption
Estimated and measured power consumption
①
①CapacityCapacity・・power from specification ( Cpower from specification ( CD ==0.250.25))
②
②CapacityCapacity・・power from measurementpower from measurement(( CCD ==0.250.25))
③
③CapacityCapacity・・power from measurementpower from measurement(( CCD from measurementfrom measurement))
Conclusion
Conclusion
z
zThe seasonal power consumption calculated using rated The seasonal power consumption calculated using rated C
CDD(=0.25) is obviously different from that obtained using (=0.25) is obviously different from that obtained using measured C
measured CD.D.
z
zIt is difficult to predict intermittent performance using It is difficult to predict intermittent performance using continuous performance.
continuous performance.
z
zThe assessment of energy consumption in middle loaded The assessment of energy consumption in middle loaded (intermittent) region using JRA standard is NOT reliable. (intermittent) region using JRA standard is NOT reliable.
z
zEnergy loss is very large for high rotation speed startup of Energy loss is very large for high rotation speed startup of inverter
inverter--installed units. installed units.
?
?--1: 1: More appropriate method of assessing packaged airMore appropriate method of assessing packaged air- -conditioning units is necessary
conditioning units is necessary…… ?
?--2: Reference to the annual performance estimation of 2: Reference to the annual performance estimation of carbon dioxide heat pumps
JRA Standards
JRA Standards
• JIS C 9612:1999
• JIS B 8615:1999
• JIS B 8616
• JRA4048:2001
• JIS C 9612:1999
• JIS B 8615:1999
• JIS B 8616
• JRA4048:2001
( ) ( ) ( ) ( ) ( ) ( )1
/
1
/
1
1
/
c cyc c dry c cyc c dry D
c cyc c dry
COP
COP
COP
COP
C
CLF
Q
Q
−
−
=
=
Cooling 0 2 4 6 8 10 12 14 16 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Ambient Temp.℃ KW 0 200 400 600 800 1000 1200 1400 KWh Rated Rated Low temp. Load= capacity Accumulated annual load
Accumulated annual power
Power for cooling
Rated and
measured capacity Intermittent running
Load
Load
Capacity