SCR出口NOX稀释法分区混合测量系统的开发与应用

针对目前燃煤电厂SCR脱硝出口单点CEMS系统测量数据代表性差的问题,该文开展SCR出口NOX稀释法分区混合测量系统的开发,并对其中关键的恒流稀释取样技术进行实验分析。结果表明实验所用的文丘里出入口压差为0.3 MPa时,其喉部产生的负压最低,满足音速小孔的恒流条件,能够实现恒流稀释取样。将该稀释法分区混合测量系统进行现场应用,现场运行效果表明该系统的测量数据准确可靠,能够有效指导脱硝系统合理控制,节省喷氨量,为电厂带来一定的经济效益。

In view of the poor representativeness of the measurement data of the single-point CEMS system at the SCR denitrification outlet of coal-fired power plants,this paper develops a zoning hybrid measurement system for NOx dilution method at the SCR outlet,and conducts experimental analysis on the key constant-flow dilution sampling technology:The results show that when the pressure difference between the inlet and outlet of the venturi used in the experiment is 0.3 MPa,the negative pressure generated by the throat is the lowest,which meets the constant flow condition of the sonic orifice,and can realize constant-flow dilution sampling.The dilution method zoning mixed measurement system was applied on site.The field operation results showed that the measurement data of the system were accurate and reliable,which could effectively guide the reasonable control of the denitrification system,save ammonia injection,and bring certain economic benefits to the power plant.