利用動態補償優化脫硫系統石灰石漿液pH控制

劉津

摘? 要：西塞山公司2臺330MW機組石灰石漿液供給是由運行人員根據漿液pH濃度值和煙囪入口CEMS二氧化硫的實時監測值來進行操作，當機組工況突變，如果調整不及時會造成脫硫效率的下降，影響環保指標。680MW機組脫硫的石灰石漿液供給，是用實測石灰石漿液pH濃度計算值與pH濃度設定上下限值進行計算比較，來控制石灰石漿液供給電動閥門的開關以達到供漿的目的。該文以脫硫控制邏輯的改造為切入點，針對680MW機組脫硫pH計因只有D漿液循環泵一套漿液測量系統運行時，因測量入口法蘭通徑較窄使其漿液流通性差，造成該出口pH計測量不準，改造方案上利用動態補償優化進行了論述，最后就脫硫pH的節能效果和控制進行了分析。

關鍵詞：動態補償優化? 脫硫pH? 石灰石漿液? 效果分析

中圖分類號：X701.3 ? ? ? ? ? 文獻標識碼：A 文章編號：1672-3791（2020）09（a）-0065-03

Abstract： Limestone slurry supply of two 330MW units of Xisaishan company is operated by operators according to slurry pH value and CEMS sulfur dioxide real-time monitoring value at chimney inlet. If the unit working condition changes suddenly， if the adjustment is not timely， the desulfurization efficiency will be reduced and the environmental protection index will be affected. The limestone slurry supply for desulfurization of 680mw unit is calculated and compared with the calculated value of measured limestone slurry pH concentration and the upper and lower limit value of pH concentration to control the switch of limestone slurry supply electric valve to achieve the purpose of slurry supply. In this paper， the transformation of desulfurization control logic is taken as the breakthrough point. When the desulfurization pH meter of 680mw unit has only one set of slurry measurement system of D slurry circulating pump， the measurement of outlet pH meter is inaccurate due to the narrow diameter of measuring inlet flange. The dynamic compensation optimization is used in the transformation scheme. Finally， the energy-saving effect and control of desulfurization pH are analyzed.

Key Words： Dynamic compensation optimization; Desulfurization pH; Limestone slurry; Effect analysis

1? 改造前漿液供給控制邏輯的問題

西塞山公司2臺330MW機組在多年的運行過程中，石灰石漿液供給是由運行人員根據漿液pH濃度值和煙囪入口CEMS二氧化硫的實時監測值來進行操作。pH濃度值下降，煙囪入口CEMS二氧化硫上升時，啟動供漿泵并打開泵出口電動門;pH濃度值升高，煙囪入口CEMS二氧化硫下降時，停止供漿泵并對供漿管道進行沖洗。

然而通過前文的分析可了解到石灰石漿液pH濃度值的測量穩定性和準確性都不夠高，只能靠運行經驗進行人工控制。當機組工況穩定時運行人員可將脫硫效率控制在合格水平，二氧化硫濃度的變化基本和石灰石漿液pH濃度值的變化呈反比關系;石灰石漿液密度在此期間基本能夠控制在合格范圍內。……