而新系統采用了雙CPU、雙電源熱備方式，當其中一套出現問題，另一套半自動投入運行，這樣大大降低了事故率，提高了系統的可靠性。

PLC硬件系統的擴容性顯著提高，設備存貯容量大，所帶外設輸入、輸出點多，有利于被控設備的擴容，為以后工藝系統改造留有充裕的空間。

改造前，平均每月因S5出現故障2次，影響洗煤生產4小時，而新系統運行兩年多來，沒有發生故障。選煤廠小時處理量為1000噸，噸原煤利潤為25元，則的可減少損失120萬元。同時，原S5控制系統采用10臺S5-150APLC裝置，而新系統僅用了2臺PLC系統，控制系統簡單，便于檢修，減少備品備件的庫存量，每年可減少備件投入120萬元，降低了洗煤成本。改造后，精煤批合樓率由93.46%提高到99.85%，精煤回收率提高了0.84%，年創效益300余萬元。

四、集中控制系統技術實路評價

1.操作方式

原系統操作臺上有100多個選擇開關及測量控制儀表，而新系統全部采用了計算機虛擬開關和儀表替代原系統的硬件開發和測量儀表，操作員只需通過鼠標操作就可實現對全廠設備的控制。

2.監測方法

原系統采用硬件發光二極管顯示設備的運行狀況，信息少。新系統采用2臺100英寸背投大屏幕顯示全廠工藝流程及設備的運行狀況，直觀、明了，設備的各種故障報警均能故障定位，縮短了故障的查找和處理時間，且所有故障報警均有記錄。主要設備安裝了閉路電視，實時監控設備運行狀態。

主要生產崗位配置了LD（1800*800）矩陣數碼顯示器屏，操作人員可以及時了解生產情況、工藝參數及洗煤指標，以指導洗煤生產。

3.網絡結構

采用了設備、控制、信息3層網絡結構，建立了選煤廠局域網絡，并配置了8種管理軟件，自動采集生產、技術、成本等各項參數，實現了管—監—控一體化目標。并通過遠程分站了解選煤廠的生產情況，為各級及時掌握和指導洗煤生產創造了條件。

4.工藝參數的調節

新系統采用PLC直接處理各種模擬量輸入、輸出信號，這樣在實現監測、控制、調節時，不需要安裝各種調節器和記錄儀，使工藝參數的調節更加簡便、準確、快捷，并可減少各種干擾，提高了測量系統的穩定性和靈敏度。同時，在生產過程中，操作員只需通過鼠標操作就可以對原煤給料量、密度、濃度、料位、速度等參數進行設定，系統便可將上述參數調整到佳狀態，從而有效地保證了產品質量，提高洗煤效益。

五、VM1D控制系統的特點

CVM1D1可編程控制器系統除了具有一般可編程序控制器系統所具有的可靠性高、柔性好、功能*、使用方便、體積小功耗低等特點之間外，還具有以下特點：

1.PLC設有RS422/485通信接口與上位計算機鏈接主要進行系統管理、狀態監控、信息處理、編輯PLC程序和打印報表的工作。

2.操作系統簡單：工業控制計算機與個人計算機兼容，操作方便，易學。automation, information and specialization. The following is the introduction of the transformation of the centralized control system in Fangezhuang Coal Preparation Plant.

1、 Background of centralized control system transformation

Fangezhuang Coal Preparation Plant is a large coal preparation plant which imported complete sets of equipment from West Germany in 1980s, and put into operation in 1984. The process is flexible and perfect, the equipment processing capacity is large and the automation is high. At that time, it was a large-scale and modern coal preparation plant with advanced technology.

10 S5 computers (programmable controller) are used for production process control to control the start-up of more than 600 equipment in the whole plant, and 16 closed-loop systems are set up according to the process requirements, and the process parameters such as density, depth, flow rate and material level are controlled. In order to facilitate the commａnd and production, the analog panel and alarm device are designed, and the industrial TV monitoring system is also installed in the main posts.

However, with the rapid development of computer, the centralized control system of the coal preparation plant of Fangezhuang mining branch has been backward and can not directly deal with the simulated quantity. The S5 computer machine, as the core of coal preparation plant control, has been eliminated in foreign countries, some plug-ins are seriously aging, some control systems and measuring instruments are unable to use, which causes high accident rate and can not meet the needs of coal