1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T Series L TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 6 (12/2014) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT ITU-T L.1300 Supplement on a validation test
2、of a data centre cooling method using renewable energy in a cold region ITU-T L-series Recommendations Supplement 6 L series Supplement 6 (12/2014) i Supplement 6 to ITU-T L-series Recommendations ITUT L.1300 Supplement on a validation test of a data centre cooling method using renewable energy in a
3、 cold region Summary Supplement 6 to the ITU-T L series refers to the best practices defined in Recommendation ITU-T L.1300. More precisely, the Supplement first provides a background, purpose and overview of the validation test of a data centre cooling method using renewable energy. Then, test resu
4、lts of such a cooling method are reported together with predictions of future yearly energy consumption. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T L Suppl. 6 2014-12-19 5 11.1002/1000/12434 Keywords Best practice, climate change (CC), data centre, energy efficient, inf
5、ormation and communication technology (ICT). _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii L series Supplement 6 (12/2014) FOREWORD
6、The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying tech
7、nical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which,
8、 in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IE
9、C. NOTE In this publication, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this publication is voluntary. However, the publication may contain certain mandatory provisions (to ensure, e.g
10、., interoperability or applicability) and compliance with the publication is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not sugge
11、st that compliance with the publication is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this publication may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, va
12、lidity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the publication development process. As of the date of approval of this publication, ITU had not received notice of intellectual property, protected by patents, which may be required
13、 to implement this publication. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No part of this publication may be reproduced, by
14、any means whatsoever, without the prior written permission of ITU. L series Supplement 6 (12/2014) iii Table of Contents Page 1 Scope . 1 2 Definitions 1 3 Abbreviations and acronyms 1 4 Conventions 1 5 Background and purpose of the test 1 6 Overview of the test 1 6.1 Specifications of the test faci
15、lity 1 6.2 Overview of the air conditioning system 2 6.3 Measurement items . 3 7 Test results 5 7.1 Outdoor air cooling test results . 5 7.2 Snow and ice cooling test results 7 8 Prediction of annual energy consumption 10 8.1 Annual energy consumption estimation method 10 8.2 Estimation of annual en
16、ergy consumption of the test facility 12 8.3 Calculation of energy consumption of the model data centre 13 9 Conclusion 18 Bibliography. 19 L series Supplement 6 (12/2014) 1 Supplement 6 to ITU-T L-series Recommendations ITU-T L.1300 Supplement on a validation test of a data centre cooling method us
17、ing renewable energy in a cold region 1 Scope This Supplement describes a validation test of a data centre cooling method using renewable energy in a cold region based on b-ITU-T L.1300. The scope of this Supplement includes: a background, purpose and overview of the validation test of a data centre
18、 cooling method using renewable energy test result of a data centre cooling method using renewable energy prediction of annual energy consumption 2 Definitions None. 3 Abbreviations and acronyms This Supplement uses the following abbreviations and acronyms: AHU Air Handling Unit CDP Cooling Water Pu
19、mp CT Cooling Tower OA Outdoor Air PUE Power Usage Effectiveness RA Return Air SA Supply Air 4 Conventions None. 5 Background and purpose of the test The test was conducted by the Ministry of Internal Affairs and Communications of Japan in the fiscal year 2009 as part of a promotion project for the
20、realization of a low-carbon society utilizing information and communication technology (ICT). The purpose of the test is to verify the usefulness of outdoor air cooling, and snow and ice cooling, to make effective use of the characteristics of cold regions in order to reduce power consumption for da
21、ta centre cooling. 6 Overview of the test 6.1 Specifications of the test facility Figure 1 shows the layout of the test facility. In the “server room“ a cold aisle was formed by a total of six racks consisting of two 3-rack rows placed face-to-face. The server room was surrounded by panelling and pr
22、ovided with floor supply air conditioning. Simulated servers with built-in heaters with a total power rating of 24 kW were installed in the server room. 2 L series Supplement 6 (12/2014) Figure 1 Layout of the test facility 6.2 Overview of the air conditioning system In the test, air conditioning co
23、nditions were adjusted so as to keep supply air temperature (SA) at 18C 2C, return air (RA) temperature at 24C 2C, and return air humidity at 45% 10%. The air conditioning system has the three modes described below. Figure 2 illustrates each air conditioning mode. Mode 1 Conventional air conditionin
24、g: ordinary heat source. Mode 2 - Outdoor air (OA) cooling: OA and RA are mixed together by the air handling unit (AHU), and the mixed air is humidified to achieve the target SA temperature and humidity. Mode 3 Snow and ice cooling: water that has had its temperature raised by heat exchange is sent
25、to the snow storage facility where it is chilled by snow and stored in the chilled water tank. Then, the water is chilled down by the heat exchange unit and sent to the AHUs snow and ice cooling coils. The SA temperature is kept constant by controlling the flow rate of chilled water to be sent to th
26、e coils by means of a three-way valve. L series Supplement 6 (12/2014) 3 Figure 2 Image of each cooling mode 6.3 Measurement items The following items were measured: (1) Temperature of chilled water and cooling water C (2) Flow rate of chilled water and cooling water L/min (3) Temperature and humidi
27、ty of supply and return air C, % (4) Airflow rate (duct air velocity) m3/h (5) Power consumption of equipment kW Figure 3 shows the air conditioning heat source diagram and measuring points. Table 1 shows the specifications of the air conditioning equipment. 4 L series Supplement 6 (12/2014) Figure
28、3 Air conditioning heat source diagram and measurement points Table 1 Specifications of air conditioning equipment No. Name AHU-1 Air handling unit CDP-1 Cooling water pump (for chiller) CT-1 Water cooling tower HEX-1 Heat exchanger (for snow cooling) P-1 Chilled water pump (for chilled water) P-2 C
29、hilled water pump (for chilled water for snow cooling) P-3 Chilled water pump (for snow cooling tank circulation) R-1 Water chilling unit T-1 Settling tank (for snow cooling) T-2 Chilled water tank (for snow cooling) L series Supplement 6 (12/2014) 5 7 Test results 7.1 Outdoor air cooling test resul
30、ts Figure 4 shows the outdoor air temperature. Figure 5 shows the air temperature and air conditioning heat load. The air conditioning heat load was calculated as follows: Air conditioning heat load W= Q m3/h (T-SA C T-RA C) 1.2 kg/m3 1.006 kJ/kgC/3.6 where: Q: airflow rate m3/h; T-SA: supply air te
31、mperature C; T-RA: return air temperature C. Outdoor air temperature fluctuated between 0C and 8C. The SA temperature was around 18C, and the RA temperature was 25C to 26C. Thus, the SA and RA temperatures were kept within their target ranges. These results indicate that air temperature can be contr
32、olled to stay within the specified range by damper operation without relying on heat source (chiller) operation. The air conditioning heat load was overestimated (33.6 kW) compared with the amount of heat generated by the servers (24 kW). The reason for this is thought to be that air velocity measur
33、ement is prone to error, and measurements tended to be too large in the test. Figure 4 Outdoor air temperature and absolute humidity 6 L series Supplement 6 (12/2014) Figure 5 Air (SA, RA, OA) temperature and heat energy To evaluate the state of outdoor air cooling operation, Figure 6 shows changes
34、in air temperature and airflow rate during a particular period. As shown, as outdoor air temperature falls, the RA flow rate increases, and the SA temperature is kept constant by changing the RA/OA ratio. Figure 7 shows absolute humidity and the humidification rate during the same period. The absolu
35、te humidity of outdoor air was as low as about 0.002 kg/kgDA. By mixing outdoor air with the RA, however, absolute temperature rose to about 0.007 kg/kgDA and, through further humidification, reached about 0.008 kg/kgDA. This has shown that the required humidification rate is now high if OA and RA a
36、re mixed together. Figure 8 shows the power consumption of the servers and the air conditioning equipment. The power consumption of a server rack averaged 24.0 kWh. The power consumption required to lower the temperature of the servers was 2.4 kWh during outdoor air cooling and 16.1 kWh during conve
37、ntional air conditioning. This is because outdoor air cooling requires only AHUs built-in fans. Thus, it has been shown that outdoor air cooling is highly energy efficient. Figure 6 Air temperature and airflow rate L series Supplement 6 (12/2014) 7 Figure 7 Absolute humidity of air and the humidific
38、ation rate Figure 8 Power consumption of servers and air conditioning equipment 7.2 Snow and ice cooling test results Figure 9 shows the chilled water flow rate and the air conditioning heat load in the case where snowmelt water is used. Figure 10 shows air temperature during snow and ice cooling. T
39、he air conditioning heat load is calculated as follows: Air conditioning heat load W = V L/min (AHU return water temperature C AHU supply water temperature C) 4 200 kJ/m3C 60/3.6/1000 where: V: chilled water flow rate L/min. The amount of heat load removed was about 25 to 27 kW, which was sufficient
40、ly large. As shown in Figure 10, the SA temperature was kept constant at about 18C. This indicates that the flow rate at the snow and ice cooling coil inlet was effectively controlled by a three-way valve. Figure 11 shows the relative humidity of air and the humidification rate. Relative humidity fl
41、uctuated between 38 and 45%, and the amplitude of fluctuation remained constant and stayed within the target range. 8 L series Supplement 6 (12/2014) To evaluate the state of snow and ice cooling operation, Figure 12 shows the temperature of air and the temperature of chilled water used for snow and
42、 ice cooling during a particular period. The temperature difference between the water supplied to and the water returned from the snow storage facility was about 5C; more or less kept constant regardless of temperature fluctuations. In the test, as the temperature of chilled water from the pile of s
43、now rose, the flow rate at the snow and ice cooling coil inlet increased under the control of the three-way valve so that temperature rose and the amount of heat required was kept constant. Figure 13 shows the power consumption of the servers and the air conditioning equipment. The power consumption
44、 of a server rack averaged 23.9 kWh, and the power consumption for snow and ice cooling averaged 5.5 kWh. The power consumption for air conditioning was small because no heat source was used, indicating high energy efficiency. Figure 9 Chilled water flow rate in snow and ice cooling Figure 10 Air te
45、mperature in snow and ice cooling L series Supplement 6 (12/2014) 9 Figure 11 Relative humidity of air and the humidification rate Figure 12 Air temperature in snow and ice cooling 10 L series Supplement 6 (12/2014) Figure 13 Power consumption of servers and air conditioning equipment (snow and ice
46、cooling) Table 2 shows the 10-day power consumption for outdoor air cooling and snow and ice cooling. The percentage reduction from the power consumption for conventional air conditioning is 85.3% for outdoor air cooling and 68.7% for snow and ice cooling, both of which are significantly high. Table
47、 2 10-day power consumption Power consumption （ kWh） Outdoor air cooling Conventional air conditioning Percentage reduction (%) Outdoor air cooling period 566.4 3 864 85.3 Snow and ice cooling Conventional air conditioning Percentage reduction (%) Snow and ice cooling period 1 308 4 176 68.7 8 Predi
48、ction of annual energy consumption 8.1 Annual energy consumption estimation method Figure 14 shows a psychometric chart showing plots of Sapporo weather data used to predict annual energy consumption. The test results have confirmed that outdoor air cooling is feasible even in midwinter. It is thoug
49、ht that the period during which outdoor air cooling can be done is determined by the ranges of temperature and humidity in which the supply air temperature can be controlled so that it is kept within the target range. Table 3 shows the estimated time during which outdoor air cooling can be done. Under the conditions assumed in this study, outdoor air cooling can be done during 6 267 hours
