火电厂石灰石湿法脱硫系统吸收塔浆液致盲分析处理

Analysis and Treatment of Absorption Tower Slurry Blindingin Limestone Wet Desulfurization System of Thermal Power Plant

巡检司电厂锅炉采用哈尔滨电气集团哈尔滨锅炉厂有限责任公司法国ALSTOM公司技术设计生产的HG-1025/17.5-L.HM37型CFB锅炉。巡检司电厂2×300 MW机组采用石灰石-石膏湿法脱硫工艺进行脱硫,脱硫装置采用“一炉一塔”方案,即每台机组1套脱硫系统,脱硫效率不低于97.6%,年等效利用小时数不低于5500 h。石灰石浆液致盲,表现为石灰石溶解困难,无法正常电离,吸收塔pH值下降,脱硫效率无法保证,石膏中石灰石含量上升,脱水困难,真空偏高,吸收塔浆液CaCO3含量超出正常值。主要对巡检司电厂2×300 MW机组石灰石湿法脱硫在高负荷运行期间吸收塔石灰石反应致盲现象进行分析,并围绕如何保障吸收塔脱硫效率,提高吸收塔浆液品质,避免发生环保事件,制定预防措施。

The boiler of Xunjiansi power plant adopts HG-1025/17.5-L.HM37 CFB boiler.The 2×300 MW unit adopts a limestone gypsum wet desulfurization process for desulfurization.The desulfurization device adopts the"one furnace,one tower"scheme,which means each unit has one desulfurization system,with a desulfurization efficiency of no less than 97.6%and an annual equivalent utilization hour of no less than 5500 hours.Blindness caused by limestone slurry is characterized by difficulty in limestone dissolution,inability to ionize normally,decreased pH value of absorption tower,inability to ensure desulfurization efficiency,increased limestone content in gypsum,difficulty in dehydration,high vacuum,and CaCO3 content in the absorption tower slurry exceeding normal values.This paper mainly analyzes the blind phenomenon caused by limestone reaction in absorption tower during high load operation of 2×300 MW unit's limestone wet desulfurization,and formulates preventive measures around how to ensure the desulfurization efficiency of absorption tower,improve the slurry quality of absorption tower,and avoid environmental incidents.