Design and development of an ammonia slip detection device and system for flue gas denitration equipment

Abstract An NH3 slip detection device and system were designed and developed. The system includes sampling, absorption, detection, dosing, cleaning, and control components. The problems accompanying low NH3 slip, easy adsorption and instability, can be effectively overcome by the developed device. Furthermore, an online accurate measurement of NH3 slip was realized. Meanwhile, the online calibration function of the device addresses the drawbacks of existing online NH3 slip monitoring devices. The reliability and stability of the detection data were improved, whereas the sampling time, flow rate, gas concentration, and pH, which affect the NH3 measurement results, were experimentally investigated. The main sampling parameters were optimized by orthogonal experiments, and the measurement error of the detection device was obtained according to experimental results. A correction model for measured values was then established, which further improved the accuracy of the measured data. The device has the advantages of high efficiency, stability, high accuracy, online calibration ability, and high integration compared with existing NH3 slip detection devices for denitration systems. The developed device can be utilized for online detection of NH3 slip in the denitration equipment of coal-fired power plants.