燃煤锅炉温度场与高温腐蚀气氛场同步在线检测装置开发及应用

Research and application on synchronous on-line measurement of temperature field and high temperature corrosive atmosphere field in coal-fired boiler

燃煤锅炉主燃区燃烧场的经济性、安全性和环保性对于智慧电厂建设具有重要意义。其中,水冷壁近壁面高温腐蚀H_(2)S和CO气体浓度的实时在线监测尤为重要。为实现燃煤锅炉主燃区温度场和高温腐蚀气氛场的同步测量,基于红外热成像原理,采用Optris-PI1M小型红外热成像仪,基于LabVIEW温度实时采集应用软件,在炉膛的观察口对主燃区温度场进行连续监测。以低成本1.5μm附近的通信波段激光器作为测量高温腐蚀气体H_(2)S和CO的激光光源,并结合波长调制光谱技术和频分复用技术,以实现H_(2)S和CO气体浓度的同步检测。线性度实验表明,其线性拟合相关系数为0.9995。将研制的同步检测仪器对某300 MW四角切圆燃煤锅炉的主燃区的温度场和气氛场进行了现场应用试验。现场测试结果表明,锅炉主燃区温度主要分布范围在1300~1400℃,最高温度达到了1500℃;同时得到了锅炉主燃区的H_(2)S和CO浓度分布,H_(2)S浓度在12~125 mg/m^(3)的范围内波动,而CO浓度主要分布在10%~20%之间,最高可达22%;炉内H_(2)S和CO的浓度呈正相关,氧气浓度保持在1%以下,由于厌氧燃烧会导致两种气体的含量增加,从而造成对水冷壁近壁面的高温腐蚀。

The economic,safety,and environmental implications of the combustion processes within the primary combustion zone of coal-fired boilers are pivotal for the development of intelligent power plants.Among these considerations,real-time online monitoring of H_(2)S and CO gas concentrations,attributed to high-temperature corrosion near the water-cooling wall,holds particular significance.Employing infrared thermal imaging technology and tunable semiconductor laser absorption spectrum measurement technology,we synchronously measure the temperature field and high-temperature corrosion atmosphere field in the primary combustion zone of coal-fired boilers.Utilizing the infrared thermal imaging principle,we developed application software for LabVIEW temperature real-time acquisition,employing the Optris-PI1M small infrared thermal imager.Continuous monitoring of the temperature field in the primary combustion zone was conducted at the furnace observation port.A low-cost communication band laser,operating near 1.5μm,serves as the laser source for high-temperature corrosive gases H_(2)S and CO.Simultaneous monitoring of H_(2)S and CO gas concentrations is achieved through the combination of wavelength modulation spectroscopy and frequency division multiplexing technology,as validated by a linearity experiment with a correlation coefficient of 0.9995.The developed synchronous measuring instrument was employed for field measurements in the main combustion zone of a 300MW tangential coal-burning boiler.Results indicate that the temperature in the boiler predominantly falls within the 1300-1400℃ range,with the highest temperature recorded at 1500℃.H_(2)S concentration fluctuates between 12~125 mg/m^(3),while CO concentration primarily ranges from 10%~20%,peaking at 22%.Positive correlation exists between H_(2)S and CO concentrations,with oxygen levels maintained below 1%.The anaerobic combustion conditions lead to an increase in the concentrations of these gases,resulting in high-temperature corrosion near the water-cooling wall.