【正文】 , the vaporization cooling control system and so on. Each section of temperature optimized hypothesis and the automatic control in the reheating furnace are the primary controlling goals. The system has used the doublecross limit control principle realization reheating furnace burning automatic control. The system put each section temperature as the adjustment signal， controlled gas regulating valve opening, and guaranteed corresponding gas the quantity which burning needed. At the same time, put gas flow as regulating signal, control opening degree of air regulating valve according to the best burning ratio. After applying doublecross limit control mode, it can reduce the emission of noxious gas. It can also achieve the energy conservation and the environmental protection goal. Besides, it can improve the stability of airfuel ratio and the effect of the furnace temperature controlling in the system. The system applies the Control Logix5000 series programmable controller position distributed control system in American AB Corporation to plete various crafts parameter examination and control and to monitor the puter and to collect the data. So the problem about the heating furnace bustion process is universal high, the billet temperature fluctuation is serious, the precision of temperature control and forth on are solved. Key words： Reheating furnace, double–cross limit, PLC, temperature control 鞍山科技大學本科生畢業(yè)設計 (論文 ) 第 III 頁 目 錄 摘要 ............................................................................................................................................. I 1緒論 ......................................................................................................................................... 1 步進式加熱爐簡介和工藝特點 .................................................................................. 1 加熱爐控制技術應用現(xiàn)狀 ........................................................................................... 1 加熱爐燃燒控制系統(tǒng)研究內容及方法 ....................................................................... 3 2加熱爐的控制系統(tǒng)總體設計 ................................................................................................. 4 鋼坯加熱的工藝過程 ................................................................................................... 4 加熱爐主要檢測項目 ................................................................................................... 5 煤氣與空氣壓力 檢測 ......................................................................................... 6 煤氣流量檢測 ..................................................................................................... 7 爐膛內溫度檢測 ................................................................................................. 7 加熱爐主要 調節(jié) 項目 ................................................................................................... 7 3加熱爐燃燒控制系統(tǒng)設計 ..................................................................................................... 8 加熱爐燃燒控制的理念 ............................................................................................... 8 單交叉限幅控制 ........................................................................................................... 8 雙交叉限幅控制 ........................................................................................................... 9 改進型雙交叉限幅控制 ............................................................................................. 11 本文采用的控制設計 ................................................................................................. 11 4計算機控制系統(tǒng)設計 ........................................................................................................... 13 系統(tǒng)構成和配置 ......................................................................................................... 13 系統(tǒng)功能 ..................................................................................................................... 14 系統(tǒng)軟件介紹 ............................................................................................................. 14 系統(tǒng)軟件梯形圖 ............................................................................................... 15 系統(tǒng)軟件指令介紹 ........................................................................................... 16 系統(tǒng)軟件編程設計 ..................................................................................................... 20 熱電偶溫度控制設計 ....................................................................................... 20 煤氣流量溫度 /壓力補正 .................................................................................. 21 鞍山科技大學本科生畢業(yè)設計 (論文 ) 第 IV 頁 比例積分微分控制器 ....................................................................................... 22 雙交叉限幅控制的軟件編程 ........................................................................... 23 結論 .......................................................................................................................................... 26 致謝 .......................................................................................................................................... 27 參考文獻 .................................................................................................................................. 28 附錄 A（軟件程序） ......................................