Research on annual energy consumption of packaged air-conditioning units

Transcription

1 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.

2 Research Purpose Assessment of power consumption of packaged air-conditioning units JRA4048:2001 by JRAIA is used to calculate the annual electrical power consumption To examine the reliability of the JRA standard Measurement of three subjects (A, B, C) Calculation with JRA4048 standard Comparison between calculated and measured values

3 Performance measurements of three PAC units Subjects of measurement: Packaged air-conditioning units A Constant speed (Ceiling-suspended type) <Rated cooling capacity 12.5kW, COP=2.63, R22> B Inverter-equipped equipped (Ceiling-mounted cassette type) <Rated cooling capacity 10.0kW, COP=4.52, R407C> C Inverter-equipped equipped ( Ceiling-mounted cassette type)

4 Test Purposes The reliability of JRA4048:2001 Method of assessing seasonal power consumption ( 期 間 消 費 電 力 量 算 出 方 法 ) Measurement of running performance under part load and intermittent running conditions Measurement of performance degradation coefficient (C( D ) C D = 1 COP / COP c( cyc) c( dry) 1 Q / Q c( cyc) c( dry) JRA standard C D =0.25=const C D =0.25=const.????

5 Effect of C D values:constant speed C D =0.25 at 100% of seasonal power consumption Relative electricity consumption 240% 220% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% Cooling Total Heating C D CD=0.25. Calculated

6 Effect of C D values: inverter-installed C D =0.25 at 100% of seasonal power consumption 240% 220% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% Cooling Cooling&Heating Heating CD Value Calculated When C D <0.25, the decrease of intermittent running efficiency is limited(save energy)

7 Schematic of Measurement Test chamber Outdoor unit side Indoor unit side Outdoor unit Indoor unit Monitor Room Air Flow Mechanical room (2F)

8 Items of measurement Cooling Standard measurement (Rated) Minimum capacity measurement Part load measurement(30%~90%) Change. Ambient temp Heating Standard measurement (Rated) Minimum capacity measurement Part load measurement(30%~90%) (30%~90% Change. Ambient temp

9 A: Cooling at constant speed Assumed load from a detached house COP C D =0.25 COP(cooling) JRA rated 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 C D =0.18 equivalent %load %load 2.60 Low temp Ambient temp. rated

10 A:Heating at constant speed 4 COP(heating) Rated Part load General load %load Rated CD= Low temp. C D = Ambient Temp.

11 B: Cooling with inverter Assumed load from a detached house(store) COP(cooling) JRA rated, estimated JRA part load, estimated Part load, measured 4.5 Low temp COP C D = Middle(min.)measurement C D =0.61 equivalent 20%load %load Rated Ambient temp.

12 B:Heating with inverter 5 COP(Heating) 4.5 Rated Middle(minimum) Part load General load Rated %Load CD =0.74 C D = %load Low temp Ambient temp.

13 C: Cooling with inverter Assumed load from a detached house (store) COP(cooling) JRA rated, estimated JRA part load, estimated Part load, measured rated COP C D = %load 70% load 90% load %load 4.00 middle(minimum C D =0.42 equivalent Ambient Temp.

14 C:Heating with inverter Rated Part load General load 90%load COP(Heating) Middle(minimum) Rated test %load %load 30%load 3.50 CD=0.51 CD= Low temp Ambient temp.

15 Estimated and measured power consumption 1Capacity power power from specification ( C D =0.25) 2Capacity power power from measurement( C D =0.25) 3Capacity power power from measurement( C D from measurement) C D =0.25???

16 Conclusion The seasonal power consumption calculated using rated C D (=0.25) is obviously different from that obtained using measured C D. It is difficult to predict intermittent performance using continuous performance. The assessment of energy consumption in middle loaded (intermittent) region using JRA standard is NOT reliable. Energy loss is very large for high rotation speed startup of inverter-installed installed units.?-1: More appropriate method of assessing packaged air- conditioning units is necessary?-2: Reference to the annual performance estimation of carbon dioxide heat pumps

17 JRA Standards JIS C 9612:1999 JIS B 8615:1999 JIS B 8616 JRA4048:2001 C D 1 COP / COP 1 COP / COP = = 1 CLF 1 Q / Q c( cyc) c( dry) c( cyc) c( dry) c( cyc) c( dry)

18 16 Cooling Intermittent running Continuous running Rated and measured capacity Accumulated annual load 800 KW 8 6 Load= capacity 600 KWh 4 Accumulated annual power Power for cooling Ambient Temp. Low temp. Rated

19 Capacity Load