The Research On Soft Sensing Technology Of NO_x Flow In 125MW Circulating Fluidized Bed Boiler

With the increasing problems of air pollution represented by acid rain and haze,environmental pollution control has gradually become an important aspect of energy production.In coal-fired power plants of China,SNCR denitrification technique is one of the major means to control NO_X pollution for its maturity and extensive use.Further study of SNCR denitration technology,in view of the SNCR denitration variable condition features of operation,the system construction of measurement model,select export NO_x levels can response the dynamic characteristics of input and output data,establish an effective NO_x measurement model.The accurate and rapid measurement of NO_x content is an important way to optimize the control logic and improve denitration efficiency,which is of great reference value to the control and operation of the SCNR denitration device.In this paper,the technology and application of SNCR dedenitration are reviewed,which is based on the research background of the group of circular fluidized bed unit of China source thermoelectric LTD.(hereinafter referred to as"huayuan thermoelectricity").Based on the generalization ability of the model,the generalization is reliable,the calculation speed is fast,and the method of least square support vector machine is used to establish the soft measurement model.Firstly,the similarity function optimization is adopted to remove the redundant data of variables.Aiming at the problem that the precision of the model is difficult to guarantee,a multi-scale least-two-plane model is proposed to achieve the precise measurement.The above modeling method is applied to the measurement of the NO_x content of SNCR denitration system,and the test results show that the measurement accuracy of the soft measurement model is high and the generalization ability is strong.Finally,the measurement model is applied to the actual running site,which is very good to meet the requirements of on-site measurement,and provides effective data support for reducing the environmental pollution and reducing the ammonia escape rate.