上海某UPS机房空调气流组织优化分析

以上海某数据中心UPS电源柜机房为例,首先在现场测量了UPS电源柜机实际运行工况下的温湿度等参数,然后利用CFD模拟软件建立了物理模型,并对机房内气流组织形式及热工环境进行模拟。通过比较测量数据与模拟结果,验证了物理模型的准确性。最后针对机房存在的实际问题以及未来预期运行的工况,进行了机房的优化改造及多工况模拟,提出了针对该UPS电源柜机房的气流组织优化建议。     

数据机房热区内气流组织的数值模拟及优化

建立数据机房热区内气流流动和传热的物理及数学模型,利用Fluent软件模拟其热区内气流的速度、温度和压力分布,模拟值和实测值相吻合。针对模拟数据机房热区内气流组织的缺点,从节能的角度提出改善方案,再通过Fluent软件模拟分析。研究结果表明：数据机房热区内最佳空调送风风速为3.6 m/s;SUN4900服务器的最佳放置方式是全交错放置且全交错距离为0.3 m。     

上海小型数据中心机房气流组织CFD模拟研究

以上海地区典型的冷热通道隔离封闭式数据机房为例,通过CFD模拟的方法研究小型机房冷通道内气流组织情况,并借助服务器温度方程求出服务器出口温度,分析机房的热环境。最后在不改变送风参数的情况下,通过改变机柜进风口形状大小和加装风扇以实现机房的节能优化。     

IDC机房空调节能改造工程

本文介绍了中国联通唐山分公司高开区IDC(互联网数据中心)机房空调的节能改造工程,根据改造后空调机组耗电量的实测数据,对节能型机房空调与普通型机房空调的能耗进行了对比,证实了改造后机房空调方案具有很好的节能效果,可为相似老旧通信机房的节能改造提供参考.     

基于CFD软件的机房通风系统数值模拟

机房通风及温度分布情况和网络设备的工作稳定性及使用寿命密切相关,结合新办公楼装修和机房组建的实际情况,利用CFD软件Airpak建立的机房通风系统物理模型,分析了采用空调送风和排气扇排风方式进行通风,机房内的速度场及温度场分布特点.结果表明,无论是制冷还是采暖通风的方式和送排风的位置设置对机房空气流通和温度分布都有较大影响,这些结果可以为选择合适的排风系统及风口的设置提供依据,确保所用排风系统满足网络设备的工作要求.     

以节能为核心的绿色数据中心建设探究

大数据时代下信息领域迎来了高速发展的时期,伴随着信息设备高度集成化的趋势,数据中心机房建设必须围绕节能为核心,克服设备的高功率密度问题。更换设备、改变温度、引入云计算等一系列节能技术理念正在不断被尝试,但真正完成新一代绿色数据中心的建设需要从更多角度入手,深入且全面地分析探讨实际案例,走向数据中心可持续发展之路。     

已建成数据中心的温控散热痛点分析及改造策略

随着国家“双碳”政策的提出与实施,对数据中心的节能减排提出了新的要求。受当时社会发展和科技水平的制约,早期建成的数据中心存在设计不合理,空调系统冷量无法得到充分利用等问题。而随着设备扩容、功耗上升,使得空调系统冗余功率下降并将进一步恶化其内部热环境。通过对已建成机房散热痛点问题的分析归纳,认为导致散热问题的主要因素在于送风过程中的冷量损失、气流短路以及机房设备布局的不合理性。针对上述原因,提出了优化机房布局、采用精确送风技术及冷通道封闭技术的改进措施,其优点在于不影响机房连续平稳运行,在不额外增加制冷功耗的前提下,提高机房冷量的利用效率,改善机房热环境。     

绿色数据中心机房空调系统节能与露点温度的关系分析

通过分析空调系统中露点温度相关参数之间的关系,利用焓湿图计算《数据中心设计规范》(GB50174—2017)对于主机房和辅助区内要求的露点温度对应下的相对湿度,为实际机房运维工作中合理设置精密空调除湿、加湿器加湿的相对湿度设置点以及精密空调的回风温度设定点提供参考。将送风温度保持在露点温度之上,一方面可以在很大程度上降低机房加湿、除湿能耗,打造绿色节能数据中心,另一方面可以提高数据中心机房计算机设备的寿命及可靠性,为数据机房安全生产提供强有力的基础环境保障。     

某大型商业综合体高效制冷机房实施技术路径研究

引入高效制冷机房是暖通空调节能的有效途径。高效制冷机房对设计优化、高效选型、BIM施工、能耗平台监测、调适运维等全流程阶段进行精细化管理,从而实现全生命周期内全负荷工况下机房所有设备的最佳匹配运行。通过分析机房系统能耗,阐述高效机房评价指标,最终得到高效机房实施的技术路径。结果显示：高效制冷机房能效比(EER)达到5.0,比常规制冷机房节能20%以上,节能降碳节能效果显著。     

绿色数据中心空调节能技术研究

通过分析数据中心机房能耗结构,得出空调系统节能是降低数据中心机房PUE值的重点.通过对数据中心机房4种空调节能技术的研究分析,为今后数据中心机房的节能改造和设计提供技术参考.     

Thermal Performance of an Air-Cooled Data Center With Raised-Floor and Non-Raised-Floor Configurations

In this paper, the thermal performances of an air-cooled data center with raised-floor and non-raised-floor configurations are compared with respect to the room and ceiling return strategies. The thermal performance of the data center is evaluated in terms of supply heat index, rack cooling index, total irreversible loss, and the number of racks with at least one server exceeding the maximum recommended and allowable inlet air temperature according to American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) thermal guidelines. The numerical simulations are conducted providing an insight into the flow and temperature distributions, and thus giving a better understanding of the cooling issues. It is found that using a ceiling return strategy for the return of hot exhaust air to the computer room air conditioning units gives a better thermal performance of the data center, for both raised- and non-raised-floor strategy, as compared to the room return. The findings are then extended to a geometrically complex operational data center to improve its cooling effectiveness. The paper also highlights the drawback of using supply heat index alone as a performance metric.     

Rapid prediction of exergy destruction in data centers due to airflow mixing

ABSTRACT

A novel lumped parameter approach is introduced to predict data center exergy destruction due to airflow mixing, resulting in a speedup of several orders of magnitude compared to detailed computational fluid dynamics (CFD) simulations. Both lumped parameter and detailed CFD methods agree within 8.5% for 11 test cases on an example data center. A significant time-saving design strategy is also introduced using two detailed CFD simulations to predict bulk flow parameters, and then applying lumped parameter analysis on flow-independent design parameters. The strategy shows agreement within 0.39% when computer room air conditioner (CRAC) supply temperature is varied from 12–20°C.     

冷热房间之间隔门通风性能的数值分析

应用数值模拟方法,对冷热房间之间隔门通风情况进行了分析。三维模拟区域主要运用稳态湍流和Boussinesq模型进行模拟,并着重对不同隔门高度和外部条件下流动换热情况作了对比研究。研究表明,两个墙壁间的温差及其引起的密度差是形成温度和速度分布的主要原因。隔门使两个房间之间形成对流,右侧高温房间下部有冷气流进入,而左侧低温房间有热气流由上方进入。当隔门高度降低时,零压差线的相对高度不断升高,对流效应减弱。     

Airflow Management in a Contained Cold Aisle Using Active Fan Tiles for Energy Efficient Data-Center Operation

Generally, passive perforated tiles are used in a data center and the supplied airflow rate is underprovisioned; thus, the balance of the server air requirement is met by the hot air in the room, resulting in higher server inlet temperatures. Full provisioning of the supplied airflow rate and containing the cold aisle is expected to minimize the hot air leakage in the cold aisle, resulting in uniform and lower server inlet temperatures. Thus, the supply air temperature can be raised, resulting in energy savings at the chiller plant. Supplying extra air can be achieved using active perforated tiles, having multiple fans installed on them. In this paper, the underprovisioned case using passive tiles and the fully provisioned case using active tiles are investigated for both open and contained aisle conditions. Thermal field measurements suggest lower and uniform server inlet temperatures for the case with contained aisle as compared to open aisle and for the fully provisioned case using active tiles as compared to the underprovisioned case using passive tiles. System-level energy calculations suggests that containing the cold aisle results in lower (improved) power usage effectiveness (PUE); however, use of active tiles does not seem to improve the PUE.     

核电厂汽轮机房通风系统精细化设计方法

核电厂常规岛汽轮机房通风设计一般采用的计算方法无法确定汽机房内的温度和速度分布,而采用Computational Fluid Dynamics(简称CFD)软件对其室内热环境进行模拟、分析和评价,可以直观地看到汽轮机房各区域温度的情况.同时,CFD方法可以方便地对方案进行反复调整分析以使厂房各点的温度达到设计要求。CFD精细的预测结果,能够为热车间的通风设计提供切实可行的设计策略和方案修正手段．采用CFD的设计方法能够挖掘通风系统的设计亮点,提供了可靠的设计手段。     

EnergyPlus软件在置换通风设计中的应用研究

介绍了EnergyPlus软件中的置换通风模型,采用EnergyPlus辅助某办公室置换通风系统设计,并采用CFD软件模拟了室内温度分布,结果表明,EnergyPlus可以精确地预测置换通风系统负荷,系统设计能满足热舒适要求。     

Computational fluid dynamic investigation of liquid rack cooling in data centres

Relying on thermal air management in a data centre is becoming less effective as heat densities from the Information Technology (IT) equipment continue to rise. Direct liquid cooling is more efficient at transferring the waste heat, but requires liquid loops passing as close as possible to the heat source. A new Computational Fluid Dynamics (CFD) strategy is developed for data centre scenarios where a liquid loop heat exchanger is attached at the rear of server racks (back doors), which can avoid the need to separate the cold and hot air streams in traditional hot/cold aisle arrangements. The effectiveness of additional fans in the back door heat exchangers is investigated using the three-dimensional CFD model of a simplified three-aisle, six-rack data centre configuration.     

A novel approach to the data center hybrid cooling design with containment

Hybrid cooling solutions, which consist of the installation of heat exchangers near IT equipment, aim to eliminate hot spots in data centers containing high-density computer cabinets. In addition, cold aisle containment is often used to reduce hot air recirculation to improve energy efficiency. However, the viability and efficiency of each hybrid cooling strategy with or without containment depend on the IT load and equipment arrangement, and no formal procedure exists for selecting the most efficient strategy for a given application. Therefore, this study provides a computational approach for ranking the performance of different cooling strategies based on their capacity and cooling efficiency. The results of analyses indicate that applying containment is beneficial in (1) lowering the maximum temperature of the air entering the racks as airflow rates are increased, and (2) increasing the uniformity of rack inlet temperatures. However, applying containment also requires additional mechanical work by the computer room air handler (CRAH) fan, which may raise the data center power usage effectiveness (PUE). Application of the computational approach discussed here highlights the use of hybrid cooling to lower PUE by reducing the CRAH fan power.     

热风送风温差对室内环境的影响

为了降低空调系统的能耗,本文以某一典型的空调办公室为研究对象,,采用数值计算软件Fluent模拟冬季室内气流组织的分布状况,对比分析了在相同的热负荷时不同的送风速度和送风温差对室内环境的影响,确定了在既定的热负荷时,在满足规范规定的送风温差的前提下,大温差送风可以提高人体活动区的温度,降低人体活动区的风速,为其他相同或类似房间空调系统的选择和气流组织设计提供参考。     

某地下商场冰蓄冷低温送风系统的模拟与分析

针对地下商场这样的特殊场所,采用冰蓄冷低温送风的具体情况需要进行特殊的研究与探讨。以成都天府广场地下步行街为研究对象,探讨了冰蓄冷低温送风系统送风温度的优化选择问题。根据地下商业建筑负荷特点,主要考虑人员、设备和照明散热引起的传热过程,建立了采用方形散流器变风量系统结合低温送风的空调房间计算模型,对气流组织进行了数值模拟。