高产热密度数据机房冷却技术研究

发布时间：2018-06-02 03:36

本文选题：高产热密度 + 数据机房　；参考：《清华大学》2012年博士论文

【摘要】：随着信息产业的快速发展，全社会对各类高性能数据机房的需求越来越大。以刀片式服务器为代表的高性能IT设备的广泛应用已经使得标准42U机柜的容量从早年的不足1kW跃升到10~20kW，大型数据中心单位面积IT设备发热量高达1~3kW，如此高的产热密度使空调能耗大幅上升，目前已占机房总用电量的40%左右，不仅增加机房运营成本，制约机房升级扩容，还直接影响着未来绿色数据机房的发展。如何有效降低机房空调能耗已成为亟待解决的问题。基于此，本文从机房传热过程的本质入手，从传热动力损失角度重新审视和分析机房传热过程，开展以下研究：对机房传热过程本质的研究。指出机房排热的核心任务是在给定的散热量和可用的传热动力（机房室内外温差）下，通过减少各换热环节的温差消耗，用高温冷源完成热量从室内到室外的搬运，并结合实测数据给出机房实际传热过程的的温度分布，指出室内冷热空气混合对机房传热性能有重要的影响。对机房传热过程分析方法的研究。对于给定传热温差求最大热流的优化问题，分别用传统热力学方法（熵产，火用损失）和热学方法（火积耗散）分析，结果表明热学原理（也称热质理论）适合研究机房传热过程，用火积耗散表征传热动力损失，指出机房排热的核心任务是减少传热火积损失，结合实测数据分析了机房传热过程中由温差传热、冷热流体混合、流量不匹配等因素引起的火积耗散，并分析了在不同工况下投入体系的压缩功以及在不同结构的换热网络中流体流量的变化对体系传热火积耗散的影响。分布式冷却技术研究。基于传热火积损失最小原则提出机房分布式冷却方案，通过与传统集中式冷却流程对比，指出分布式冷却在消除冷热空气混合、改善传热过程匹配性、减少火积耗散以及改善机房热环境、降低排热能耗等方面的优势，在此基础上提出了内置多级分离式热管的内冷型机柜以及冷却塔与多级冷机串联运行的大温差冷水系统，，消除冷热空气混合；通过自然冷却和机械制冷联合运行并连续调节供冷能力，有效延长自然冷却时间，提高机房排热效率。工程应用。对北京市某数据机房空调系统节能改造，通过对全年不同工况下改造前后空调性能对比测试，采用分布式冷却系统后，机房空调系统全年综合能效从2.6提高到5.7，机房年均PUE值从1.6降低到1.35，证明了热学原理和分布式冷却技术在高产热密度数据机房的适用性，为今后的推广应用积累了经验。
[Abstract]:With the rapid development of information industry, the demand of all kinds of high-performance data rooms is increasing. The extensive application of high-performance IT equipment, represented by blade servers, has made the capacity of the standard 42U cabinet jump from insufficient 1kW in the early years to 102kW, and the heat output of IT equipment per unit area of large data center is as high as 1kW, so high as heat production. The density increases the energy consumption of air conditioning. At present, it accounts for about 40% of the total electricity consumption of the computer room, which not only increases the operating cost of the computer room, restricts the upgrading and expansion of the computer room, but also directly affects the development of the green data room in the future. How to reduce energy consumption effectively has become an urgent problem. Based on this, this paper starts with the nature of the heat transfer process in the computer room, and reexamines and analyzes the heat transfer process in the computer room from the point of view of heat transfer power loss, and carries out the following research: Study on the nature of heat transfer process in engine room. It is pointed out that the core task of heat discharge in computer room is to complete the heat transfer from indoor to outdoor by reducing the consumption of temperature difference in each heat exchange link under the given heat dissipation and available heat transfer power (room and outdoor temperature difference). Combined with the measured data, the temperature distribution of the actual heat transfer process in the computer room is given, and it is pointed out that the mixing of indoor cold and hot air has an important effect on the heat transfer performance of the engine room. The analysis method of heat transfer process in machine room is studied. For the optimization of the maximum heat flux for a given heat transfer temperature difference, the traditional thermodynamic method (entropy production, exergy loss) and the thermal method (exergy dissipation) are used to analyze the problem, respectively. The results show that the thermal principle (also called heat and mass theory) is suitable for the study of heat transfer process in computer room, and the heat transfer dynamic loss is characterized by fire accumulation dissipation. It is pointed out that the core task of heat transfer in engine room is to reduce the loss of heat transfer heat accumulation. Combined with the measured data, the fire accumulation and dissipation caused by temperature difference heat transfer, cold and hot fluid mixing, flow mismatch and other factors in the heat transfer process of the machine room are analyzed. The influence of the compression power of the system and the flow rate of the fluid in the heat transfer network under different working conditions on the heat transfer and dissipation of the heat transfer system is analyzed. Research on distributed cooling Technology. Based on the principle of minimum loss of heat transfer product, a distributed cooling scheme for machine room is proposed. By comparing with the traditional centralized cooling process, it is pointed out that distributed cooling can eliminate the mixing of cold and hot air and improve the matching of heat transfer process. On the basis of the advantages of reducing fire deposition and dissipation, improving the thermal environment of the machine room and reducing the energy consumption of heat exhaust, the inner cooling cabinet with built-in multi-stage separate heat pipe and the large temperature difference cooling water system running in series between the cooling tower and the multi-stage cooler are put forward. It can effectively prolong the natural cooling time and improve the heat discharge efficiency of the engine room by the combination of natural cooling and mechanical refrigeration and continuous adjustment of cooling capacity. Engineering application. Through the comparison and test of air conditioning performance before and after retrofitting in a data room in Beijing, after adopting distributed cooling system, The comprehensive energy efficiency of the air-conditioning system in the engine room is improved from 2.6 to 5.7, and the average annual PUE value of the engine room is reduced from 1.6 to 1.35, which proves the applicability of the thermal theory and the distributed cooling technology in the high-yield heat density data room, and accumulates the experience for the future popularization and application.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：TU83;TP308

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