Study On The Methods For System-Level Thermal Management Of Computers

With progress of modern informationization, computer technology is witnessing an ever rapid development. In order to achieve a faster computing speed and larger storage capacity, both the chip manufacturing process and packaging density keeps improving. Although some emerging technologies did play a role in reducing the power consumption of a single micro-device, it often encounters trouble caused by the continuously increased power consumption due to dense integration in large-scale integrated circuits. Therefore, the latest computer technology is still restricted by the serious thermal barrier. In recent years, deviating from focusing on chip-level thermal management alone, system-level solution received an ever higher attention which raised a lot of problems for solving. Aiming to establish new techniques for the computer industry, theoretical or (and) experimental researches on several system-level thermal management methods were performed, which could work well in desktop computers, notebook computers and computer cluster, respectively. Results are as follows:1. Experimental study on thermal management method with independent heat flow path used in high-performance desktop computerThrough the numerical simulation on traditional system-level air-cooled thermal management method with single heat flow path, the limitations on cooling capacity and availability (mainly noise) of such method were analyzed. During the process of components design, the flaws in previous research were fully discussed. Experiments on an actual computer were accomplished, and solutions for the raised problems were proposed. Advantages of the new method over traditional ones were also analyzed.2. Numerical simulation on notebook computer with separated heating elementsThe traditional system-level air-cooled method and method by separating heating elements from the main module proposed before by the present lab were simulated. According to simulation results, the reasons why the latter one was better than the former were discussed in detail, some solutions toward practical application were proposed as well, which provided the initial evidence of the feasibility of the new method.3. Theoretical analysis on the feasibility of rack embedded thermal management methodThrough introducing the exergy loss evaluation model, the rack embedded system-level thermal management method proposed by the author in the patent was analyzed, focusing on its superiority in energy utilization. A simplified numerical model for a partial data center was fabricated and simulated. The exergy losses in both the traditional and new methods were calculated based on the simulation results. Finally, the energy saving potential was quantificationally evaluated to illustrate the practical value of the new method.4. Experimental study on rack embedded thermal management methodTwo experimental prototypes of rack embedded thermal management method with simulated heat source were fabricated and tested. Some new problems emerged in the experiment were analyzed theoretically. Solutions and optimization approaches for these problems were proposed. Amendments on experimental results were conducted using theoretical analysis and numerical simulation because of the differences between prototype and actual computer. The results demonstrated the feasibility and practicality of the new method.