烟气排放连续监测系统的烟气参数在线监测技术研究

Research on On-line Monitoring Technology of Flue Gas Parameters for Continuous Monitoring System of Flue Gas Emissions

为实现锅炉燃烧状态监测与优化调整,提出了一种基于LabVIEW的锅炉燃烧状态监测与优化系统。系统采用OPC通信技术,实现对锅炉燃烧运行参数的远程监控和显示。此外,系统应用神经网络预测建模,实现了烟气温度、氧含量、飞灰含碳量和氮氧化物含量的在线软测量,并结合差异进化算法算法,寻求当前运行条件下锅炉的最佳二次风、过燃空气节流开度参数。该系统在600 MW燃煤锅炉上的应用结果表明,该系统通过将OPC标签与烟气温度、氧含量等测量点连接,实现了远程燃烧状态监测,并在机组40%负荷和90%负荷两种工况下进行了燃烧优化试验,发现在40%负荷下进行燃烧优化后,烟气温度、飞灰含碳量和氮氧化物含量分别平均下降了20%、23%和31%,对提高锅炉燃烧效率和降低氮氧化物排放具有重要意义。

In order to realize the monitoring and optimization of boiler combustion state,a LabVIEW-based monitoring and optimization system of boiler combustion state is proposed.The system adopts OPC communication technology to realize remote monitoring and display of boiler combustion operation parameters.In addition,the system applies neural network prediction modeling to realize on-line soft measurement of flue gas temperature,oxygen content,carbon content in fly ash and nitrogen oxide content,and combines the differential evolution algorithm to find the best boiler under the current operating conditions.Throttling opening parameters of secondary air and over-fired air.The application results of the system on a 600 MW coal-fired boiler show that the system realizes remote combustion state monitoring by connecting the OPC label with the measurement points such as flue gas temperature and oxygen content,and can monitor the combustion state at two levels of 40%load and 90%load of the unit.The combustion optimization test was carried out under the working conditions,and it was found that after the combustion optimization was carried out under 40%load,the flue gas temperature,the carbon content of fly ash and the nitrogen oxide content decreased by 20%,23%and 31%on average respectively,which is very important for improving the boiler.Combustion efficiency and reduction of nitrogen oxide emissions are of great significance.