創新指標用於網路資料中心機櫃能源使用效率最佳化分析

Abstract

本研究將以三種指標（RCI、RHCI以及Equipment Overheat）搭配計算流體力學套裝軟體FLUENT與實驗分析機房熱流場，並以改造機房設計做為降低耗電量的思維，提出針對機房設計所需的參考標準。本研究分為三個主題，在第一個主題，本研究將結合兩種網路機房的冷卻溫標，RCIHI以及RCI¬LO並使用流體力學套裝軟體FLUENT分析機房熱流場。我們使用RCI來評價機房的機能，在這個部分，首先會進行參考情況的模擬分析而後將會進行參數分析。第二個主題將會發展一套新的冷卻溫標，機櫃濕度冷卻溫標（RHCI），它將用於補助RCI的盲點，可在不同的熱環境或是地區內進行標準化並且無偏差的比較。最後一個主題是實驗量測面對冷通道的機櫃溫度分佈。所量測的結果將會與相對應的模擬作比較。 本研究發現，若減少穿孔板的配置比率，不僅可增加RCI，但同時也增加噴射流效應。若提高CRAC的流量，亦可增加RCI以及噴流效應的影響。若CRAC流量提升至1.5倍可解決10kW的機櫃上端處熱蓄積問題。再另一方面，歸納RCI，RHCI，和設備過熱度的實驗分析結果，我們可以定義RCIHI的水準等級如下：0~35%是過熱範圍，35%~85%是容許溫度範圍，而85~100%是理想範圍。氣候條件的影響已經被RCHI完善的考慮，過熱危害的影響也在設備過熱度內被討論，並且系統能耗也將用PUE考慮之。最後，這些既存於RCI的問題將會被妥善的改進，並且提出幾個建議給網路資料中心的設計者。

This study employs three indices (RCI, RHCI, and Equipment Overheat) combined with the fluid dynamics software FLUENT and experiments to analyze the thermal-and-flow fields in an IDC. It supports the reconstruction of an IDC room to reduce power consumption, and proposes standards for energy-saving design. This study consists of three research topics. In the first topic, the study employs the fluid dynamics software FLUENT to analyze the thermal-and-flow fields in an IDC combined with two Rack Cooling Indices, RCIHI and RCILO, which the RCI is used to justify the design performance and evaluate the specifications for a new IDC. In this part, a reference case was simulated and analyzed first. Then it is followed by the parametric studies. The second topic applies a new tool, Rack Humidity Cooling Index (RHCI) to compensate the shortcoming of RCI. It allows the standardized and unbiased comparisons between different thermal environments and areas. Finally, the last topic carries out the experiments to measure the temperature distributions on the rack surfaces facing the cold aisle. The measured data are compared with the numerical correspondent ones. In this study, it is found lower perforated tiles ratios increase not only RCI but also jet flow effects. Higher volume flow rate of CRACs also increases RCI and jet flow effects. Increasing volume flow rate of CRACs up to 1.5 times of the original one can resolve the heat problems above the 10-kW racks. Besides, the experimental results with RCI, RHCI, and Equipment Overheat also lead to a new RCIHI rating range as follows: 0~35% is the overheated range, 35~85% the permitted temperature range, and 85%~100% the ideal range. The influence of climate should be taken into consideration for RCHI, and the effect of overheat can be take into account for Equipment Overheat, and the influence of power system efficiency should be taken into consideration for PUE. Finally, it can fix those problems to improve RCI effectively, and several suggestions are proposed for IDC designers.