【作者】 沈钧；

【导师】 孙颖； 马双；

【作者基本信息】 哈尔滨商业大学 ， 能源动力， 2023， 硕士

【摘要】 随着当今时代人工智能和大数据等信息技术的高速发展,数据中心作为其不可或缺的基础设施也在高速发展壮大中。随着数据中心耗电量的逐年增加,其向外排放的废热量也在增大,这些废热直接排放会局部堆积,影响着数据中心的空调能效,增加更多能耗。回收数据中心的这些余热的意义不仅在于降低数据中心空调能耗,更是为了将其再利用,响应我国的“双碳政策”,为社会的碳中和做出部分贡献。热管的导热性能十分优秀,重力热管在没有外力驱动的作用下依靠重力便能实现热传导,所以在进行余热回收时也不会增加数据中心的能耗。本文针对数据中心的单机柜设计了一种重力热管余热回收系统,并对其进行了实验研究与模拟研究。首先,设计了数据中心单机柜余热回收的系统。根据热管的特点设计了单机柜箱体和余热回收箱体的结构、尺寸及材质,两者通过热管相连。通过热管对单机柜内的热量进行传导,加热上方余热回收箱内的空气,以此达到机柜内余热回收的目的。在单机柜中采用600W的铸铝加热板作为系统热源。为了增大热管与机柜内空气的换热面积,还在热管表面增设了铜翅片。其次,进行余热回收实验。在实验中设置了不同管径(8mm、10mm、12mm)、不同充液率(10%、20%、30%)和不同管内工质(甲醇、乙醇、水)三个自变量,进行了 27种工况的实验。根据实验数据计算不同工况下热管的当量导热系数,得到传热性能最优的热管是充液率30%、管内工质为甲醇、直径为8mm的热管,其当量导热系数为 3674.3W/(m·K)。再次,对余热回收系统进行了数学建模、网格划分,再将传热性能最优的热管当量导热系数带入到Fluent中进行模拟计算,将模拟数据与实验数据进行对比,验证模拟的准确性。最后,根据建立的数学模型,分别进行了两根、三根、四根热管参与余热回收的模拟研究。模拟了包含单根热管系统在内的共10种热管布置方案,并对模拟结果进行了分析比较,得出了不同数量热管在余热回收系统中的最佳布置方式。两根热管参与导热的最佳布置方式B,其保温箱内的升温速度比单根快21.1%,三根热管参与导热的最佳布置方式D,保温箱内升温速度比单根的快44.1%,四根热管参与导热的最佳布置方式G,其保温箱内升温速度比单根系统快52.5%。更多还原

【Abstract】 With the rapid development of information technology such as artificial intelligence and big data in the current era,data centers as their indispensable infrastructure are also growing at a high speed.As the power consumption of the data centers increases year by year,the waste heat discharged from the data centers also increases.The waste heat of direct discharge will accumulate locally,which will affect the air conditioning energy efficiency and increase energy consumption in the data center.The significance of recycling these waste heat of data centers is not only to reduce the energy consumption of air conditioning,but also to reuse it in response to "China’s’ two-carbon policy"and make some contributions to the carbon neutralization of society.Heat pipes have excellent thermal conductivity.Gravity heat pipes can transfer heat by gravity without external drive,so it will not increase the energy consumption of the data centers when recovering waste heat.In this paper a waste heat recovery system with gravity heat pipes is designed for the single cabinet of data centers,and the experimental and simulation research is carried out.Firstly,a waste heat recovery system of single cabinet is designed.According to the characteristics of heat pipe,the structure,size and material of the single cabinet box and the waste heat recovery box are designed.The two boxes are connected through the heat pipe.Heat pipes are used to conduct the heat of the cabine,which will heat the air in the upper waste heat recovery box in order to recovery the waste heat of the cabinet.The 600W cast aluminum heating plate is used as the system heat source in the single cabinet.In order to increase the heat transfer area between the heat pipe and the air in the cabinet,copper fins are also added on the surface of the heat pipe.Secondly,the waste heat recovery experiments are carried out.Three independent variables of different pipe diameters(8mm,10mm,12mm),different liquid filling rates(10%,20%,30%)and different working medium(methanol,ethanol,water)are set up in the experiments,which are 27 working conditions.According to the experimental data,the equivalent thermal conductivity of heat pipes of different working conditions is calculated,and the optimal heat transfer performance is the heat pipe with liquid filling rate of 30%,tube working medium of methanol,diameter of 8mm.Its equivalent thermal conductivity is 3674.3W/(m·K).Thirdly,mathematical modeling and grid division were carried out for the waste heat recovery system,and then equivalent thermal conductivity of heat pipe with optimal heat transfer performance was brought into Fluent for simulated calculation,and the simulation data was compared with the experimental data to verify the accuracy of the simulation.Finally,according to the established mathematical model,two,three and four heat pipes are simulated to participate in waste heat recovery.A total of 10 heat pipe layout schemes including a single heat pipe system are simulated,and the simulation results are analyzed and compared,and the optimal layout of different number of heat pipes in the waste heat recovery system was obtained.In the waste heat recovery box,the best arrangement of two heat pipes is B,the temperature rise is 21.1%faster than that of a single one;the best arrangement of three heat pipes is D,the temperature rise is 44.1%faster than that of a single one;the best arrangement of four heat pipes is G,the temperature rise is 52.5%faster than that of a single heat pipe.更多还原