近年來網路資料中心(IDC)機房的發展迅速,因此需要更多的空間來存放資訊設備(IT),由於現今機房空調皆屬於大範圍冷卻,加上伺服器排列密度集高,冷熱通道概念不足,儘管環境溫度確實能達到設定範圍,但實際於IT設備的散熱效果往往有限,因此熱量不易排出,如此持續降低空調溫度往往造成過度的能源消耗。 本研究將開發一套資料中心機櫃冷卻系統,負載部份將使用電子式加熱器來取代IT設備之發熱量,兩機台並列後並可達到自體循環散熱效果,其主要針對IT設備做重點式散熱:其次將控制程式撰寫於可程式控制器(PLC)內部來控制冷媒迴路與系統監控;也紀錄機櫃降溫曲線利用系統辨識求出系統之轉移函數,及使用Z-N所建議之經驗法則計算出模擬控制參數。 實驗過程中則以定冷卻水溫、調變負載與變冷卻水溫等三組條件來進行實驗,在不同負載匹配下,調整壓縮機頻率及調變風散轉速找出機櫃之操控範圍,並使用電源使用效率指標PUE,對應於不同負載匹配時之最佳操作點,因可得到此機櫃冷卻系統之最佳操作曲線,使系統運行於適合之頻率與風機轉速下來達到省電之效果,即可達到節能源之目標。 由定冷卻水溫實驗結果得知,在滿載操作時可得到最佳PUE值為1.47,並與國內機房實際量測平均PUE值1.9與美國ASHRAE 300RT等級之標準PUE值為1.5相較之下,其機櫃冷卻系統之電能使用效率皆優於國內外之案例。
In recent years, the Internet data center (IDC) of the rapid development of the computer room, so need more space to store Information Technology (IT) equipment. As a result of the computer room air conditioners in cooling are large-scale in today’s, coupled with the server set with a high density, the concept of cold and hot channels inadequate, despite the ambient temperature range will be able to achieve the set point. And the actual IT equipment in the cooling effect is often limited so difficult to emit heat, continuing to reduce air-conditioning temperature often results in excessive energy consumption. This study will develop a set of data center cooling rack, the electronic-type heater used in the rack as IT equipment heat generation. The two machines, IT rack and cooling rack, side by side can be reached after the cooling effect from the systemic circulation. The cooling rack functions as spot and closed loop cooling effect on the server rack. The control program was wrote in the Programmable Logic Controller (PLC) to control the internal cooling circuit and system monitoring; also to record rack cooling profile. According to the cooling profile obtained, the parameters of analog control can be calculated through the system identification method, transfer function, and the Z-N rule. The optimum operation condition and the maximum energy efficiency, PUE, of the cooling system were verified through a series of testing conditions including constant condenser cooling water temperature, variable heat load and variable condenser cooling water temperature. The maximum energy efficiency, PUE, is 1.47 under full load and the condenser cooling water temperature per ARI 550/590. This maximum energy efficiency PUE is much better than the average PUE 1.9 of the surveyed data in Taiwan and also better than the PUE 1.5 of design per ASHRAE 90.1-2007.