重油催化余热锅炉水处理技术研究与应用

Study and Application of Water Treatment Technology for Heavy Oil Catalysis Exaust-heat Boiler

为了防止重油催化余热锅炉腐蚀和减少锅炉结垢,作为锅外水处理的补充,常对锅炉水质进行补充性锅内加药处理。经对重催锅炉的运行调研发现,锅炉水处理之前常出现炉管泄漏和汽轮机因结晶结垢而停车的现象。分析表明,溶解氧含量高是锅炉系统水侧腐蚀的主要原因;重催锅炉过热蒸汽中夹带Na+和SiO2是造成汽轮机结晶结垢的主要原因。锅炉水处理工业试验效果表明,重催锅炉系统加药前除氧水的溶解氧含量较高(40～50μg/L),加药后已稳定在15μg/L;加药前后汽包的锅炉水pH值变化不大;加药前蒸汽中的Na+、SiO2含量较高,加药后呈下降趋势(小于20μg/L)。锅炉水处理药剂的应用提高了锅炉水浓缩倍数,减少了排污,节约了大量蒸汽。以余热锅炉进水量200t/h计,扣除使用药剂的成本后,一年可节约污水处理费331万元;因增产过热蒸汽,还可增加经济效益1356万元。

To prevent corrosion of heavy oil catalysis exhaust-heat boiler and reduce scaling,technicians usu- ally add chemical dosages to improve the quality of the water in the boiler as a supplement to water treatment outside of the boiler.A survey of the operation of heavy oil catalysis boilers shows that leakage is often detected in the boiler tube and the steam turbine often stops due to crystallization and scaling before water treatment.Analysis shows that the high content of dissolved oxygen is the main cause of waterside corrosion in the boiler system and that Na~ and Si02 contained in the steam gas in the heavy oil catalysis boiler are the main cause of the crystallization and scaling in the steam turbine.Industrial experiments of boiler water treatment show that the content of dissolved oxygen in the deoxygenized w er system was high （40-50μg/L） before the addition of chemical dosages. ater in the heavy After the dosages oil catalysis boilwere applied, the content of dissolved oxygen stabilized at 15μg/L.The pH value of the boiler water in the steam drum did not change dramatically before and after the addition of the dosages.Before the addition of the dosages,the contents of Na~ and SiO2 were high and dropped to below 20μg/L after the use of the dosages.The application of chemical dosages for treating boiler water raised the volume concentration of boiler water,reduced wastewater discharges and saved a large amount of steam.Assuming water is fed to the exhaust-heat boiler at a speed of 200t/h,the costs of using chemical dosages deducted,3.31 million Yuan in sewage treatment fees can be saved annually as a result of the use of chemical dosages.In addition,since more steam gas is produced,revenues could increase by about 13.56 million Yuan per year.