隨著火電機組向大容量、高參數發展,機組在起停中需要監控的項目不斷增加。可以設想,如此繁多的輔機、閥門若由電廠運行人員手動操作,是難以完成機組的起停工作的,甚至導致事故的進一步擴大。由此可見,在大中型電廠應普遍進行順序控制。機組順序控制系統的英文全稱是Sequential Control System,簡稱SCS。SCS包括主機的順序控制和機組外圍設備的順序控制。機組主機的順序控制可由可編程序控制器(PLC)實現,也可由集散控制系統實現。
電廠鍋爐是生產中使用最廣泛的設備之一,鍋爐補給水的處理工作對確保電廠安全、經濟運行有著重要意義,它是電廠運行中的一項重要技術基礎工作。目前鍋爐水處理工藝流程設計中最廣泛使用的是離子交換法(化學處理法)和滲透法(物理處理法),傳統的水處理過程中多為繼電器和人工操作,系統故障多,勞動強度大,運行成本高。
本文介紹一種關于化學水處理工藝過程的PLC控制系統的設計,通過闡明了化學水處理的工藝及PLC控制系統各項功能,給出一種詳細的設計方案。
關鍵詞:PLC; 化學水處理; 控制系統
ABSTRACT
With thermal power machine group to High Capacity, high parameter extend, needs for supervisory item of machine group at on-off are increasing without intermission . Imagining,if power plant operator operate so multitudinous auxiliary and valve only by hands, it is so difficult to finish machine team's on-off working, even result in more expanding of accident.We see, therefore,at cleanness defect type power plant should proceed preva lence sequential control.It's full name in english is sequential control system , that of machine group sequence control system ,for short scsScs include mainframe's sequential control and machine group peripheral equipment's sequential control .The sequential control of the machine group mainframe can realize not only by programmable controller(plc)but also by total distributed control system .
It was one of the churn used most widely eqoupment on power plant online,boiler feedwater ' dispose working bore import sense on ensuring security and economical operation of power plant ,though it is one of important supporting technology wrought on power plant in-serviceNow that of boiler water treatment process design most extensively used,it was ion-exchange method(method of chemical treatment)and osmose process(physical treatment law),conventional water curing course much serve as RELAID and manhandle and manhandle,much system malfunction and largelabour intensity .
The text introduce a sort of craft procedural's plc control system design of water treatment in chemical,by illuminating chemical water treatment 'craft and plc control system 'each term function, it present a detailed design scheme .
Keywords:plc; chemical water treatment; control system