本研究利用可程式控制器(PLC)聯結機櫃冷卻系統模糊PID控制方法進行研究,根據設定過熱度值與蒸發器冷媒過熱度之曲線變化,探討如何快速準確及穩定達到蒸發氣過熱度控制目標值,以最佳參數設定值控制此系統最佳化,並搭配主機系統中由壓縮機之變頻控制。本研究節由機櫃降溫曲線,以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。 由實驗結果可知加入模糊PID控制方法可有效快速穩定,進而提升節能效率;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1.36,變冷卻水溫實驗結果得知,可看出在整體系統中PUE值普遍落在1.3~1.4間比定水溫於滿載下之測試時可匹配於更高之負載。各項實驗結果指出本機櫃系統PUE值與美國ASHRAE之300RT 等級之標準PUE值為1.52,與國內機房實際量測PUE平均值為1.9,相較之下優於許多;根據Green Grid協會所訂定之PUE等級區分,依機櫃冷卻系統各項實驗結果看可歸屬於金、銀級(Gold、Silver)1.25~1.67相當高等級,其機櫃冷卻系統之電能使用效率皆優於國內外之案例。
This research aims at the Programmable Logic Controller (PLC) associates with fussy PID control on in-rack cooling system. Utilizing PLC control and monitoring each circuit point, and recording the temperature curve are collected to compute the transfer function of this system, then using the empirical law which is suggested by Z-N rule to compute the simulation control parameter. According to the result of research we can find out that the energy-saving efficiency could be more accurate by joining PID control method. The maximum efficiency, PUE could be 1.36 when the temperature of condenser water is invariable, the PUE value could be 1.3~1.4 when the temperature is variable. 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. Also, according to the classification which set by Green Grid, it may be classified in Gold/Silver Level (1.25~1.67), obviously the efficiency is better than other cases in Taiwan or wherever.