宋廷

摘  要：在燃煤电厂实际生产作业过程中，由于会排放出大量的废气，而这些废气中氨气和二氧化氮等有毒气体含量较多。因此需要做好燃煤电厂烟气处理工作。目前燃煤电厂一般会利用烟气脱硝技术来处理烟气，这其中以选择性催化还原法为主，即SCR。而且通过在火电厂中加装SCR装置还能够实现对废气的有效净化，但在实际燃煤电厂烟气脱硝过程中易产生空气预热器堵塞问题，这种情况发生多是由于局部喷氨过量造成大量氨气逃逸，由此而造成空气预热器的冷段部分硫酸氢胺结晶出现堵塞，影响空预器的运行效果。文章从SCR的脱硝原理入手，分析了空预器堵塞原因，并进一步阐述了改善火电厂空预器堵塞的措施。

关键词：火电厂;空预热器;脱销;堵塞;原因;措施

中图分类号：TM621        文献标志码：A 文章编号：2095-2945（2020）15-0130-02

Abstract： In the actual production process of coal-fired power plants， a large number of waste gases will be emitted， and there are more toxic gases such as ammonia and nitrogen dioxide in these exhaust gases. Therefore， it is necessary to do a good job in flue gas treatment in coal-fired power plants. At present， coal-fired power plants generally use flue gas denitrification technology to treat flue gas， in which selective catalytic reduction （SCR） is the main method. Moreover， the waste gas can be effectively purified by adding SCR device in the thermal power plant， but the clogging of the air preheater is easy to occur in the denitrification process of the smoke report in the actual coal-fired power plant， which is mostly due to the escape of a large amount of ammonia gas caused by excessive local ammonia injection， easily leads to the blockage of the crystallization of amine hydrogen sulfate in the cold section of the air preheater， and affects the operation effect of the air preheater. Starting with the denitrification principle of SCR， this paper analyzes the causes of blockage of air preheater， and further expounds the measures to improve the blockage of air preheater in thermal power plant.

Keywords： thermal power plant; air preheater; out of stock; blockage; cause; measure

前言

在火力发电机组实际运营过程中，空预器易出现堵塞现象，这必然会对机组运行的安全性和经济性带来较大的影响。在空预器实际运行过程中，当其烟气压差增大时，一次风压和二次风压会出现规律增大或是减小的情况，一次风机、送风机和引风机电流会有摆动现象发生，由此而导致空预器堵塞。当空预器堵塞情况发生时，会对锅炉运行的经济性和安全性带来较大的影响，同时不罕引起送风机喘振，加剧空预器低温腐蚀，严重时还会造成锅炉限负荷、停炉等。因此针对空预器堵塞问题要做好预防和治理措施，使其保持良好的工作状态，为脱硝机组安全、稳定的运行打下良好的基础。……