【摘要】 将环路热虹吸管与服务器散热相结合,设计并加工出一种用于模拟服务器液冷的循环冷却系统.以HFE-7100作为工质,研究不同加热功率下服务器模拟热启动问题,并探讨不同注液率、汽路绝热段长度(箱体与冷凝器的高度差)对循环系统传热特性的影响.此外还对实验过程中汽路内的流动状态进行了分析.研究结果表明,在低加热功率下(90～120 W),服务器箱体温度会出现先升高后降低随后逐渐平稳的现象,而高加热功率下(≥150 W)则会出现箱体温度先快速升高然后缓慢升高随后逐渐平稳的现象.热启动过程中的现象可以分为3个阶段.第1阶段为过冷至蒸发,第2阶段循环系统初步建立,第3阶段系统循环完全建立.其中第2阶段热启动箱体最高温度会随着加热功率的增加而逐渐降低,系统达到稳定循环的时间会随着加热功率的增加而增加.此外,注液率从65%增加到85%时,系统压差(箱体及储液箱内的压强差)提高34.7%,但是冷凝器效率降低,其出口过冷度会降低47.4%;当汽路绝热段长度从40 cm增加到80 cm时,系统压差提高26.6%,冷凝器效率提升,其出口过冷度提高120.6%.更多还原

【Abstract】 This paper combines loop thermosiphon with server cooling to design and fabricate a circulating cooling system for simulating liquid cooling in servers. HFE-7100 was used as the working fluid to investigate the thermal startup issues of the servers under different heating powers and to explore the effects of varying liquid injection rates and the length of the adiabatic section in the vapor line(the height difference between the enclosure and the condenser) on the heat transfer characteristics of the circulation system. Additionally, the flow state within the vapor line during the experiment was analyzed. The research findings indicate that at low heating powers(90～120 W), the temperature of the simulated server enclosure firstly increases, then decreases, and eventually stabilizes. In contrast, at high heating powers(≥150 W), the enclosure temperature initially rises quickly, then increases slowly, and finally stabilizes. The phenomena observed during the thermal startup process can be divided into three stages:Stage 1(from subcooled to evaporation), Stage 2(initial establishment of the circulation system), and Stage 3(full establishment of the system circulation). In Stage 3, the maximum temperature of the enclosure gradually decreases with increasing heating power, while the time required for the system to reach stable circulation increases with higher heating power. Furthermore, when the liquid injection rate is increased from 65% to 85%, the system pressure differential(the pressure difference between the enclosure and the liquid storage tank) increases by 34.7%, but the efficiency of the condenser is reduced, and the outlet supercooling degree will be reduced by 47.4%. When the length of the adiabatic section of the vapor line is increased from 40 cm to 80 cm, the system pressure differential increases by 26.6%, while the efficiency of the condenser improves, and the outlet supercooling degree is increased by 120.6%.更多还原