基于连续排放监测数据的水泥工业NOx达标判定方法研究

现行大气污染物排放标准中的达标判定多以手工监测数据为基础，为研究制定基于连续排放监测系统(Continuous Emissions Monitoring System，CEMS)监测数据的达标判定方法，以我国水泥工业2017年957条生产线排放NO_x的CEMS监测数据为基础，根据数据有效性原则筛选出553条生产线的CEMS监测数据作为研究对象，分析研究我国水泥工业排放NO_x的小时浓度(CEMS监测数据)、日均浓度的统计特点，通过变化因子比值法和曲线拟合法建立小时浓度与日均浓度限值之间的关系. 结果表明:①筛选出的553条水泥生产线的NO_x小时浓度对数值与累积频率正态值的相关系数均大于等于0.6. ②NO_x小时浓度与日均浓度限值之间存在关联，曲线拟合法和变化因子比值法得出二者之间的倍数关系无显著差异. ③当要求90%的生产线达标时，NO_x小时浓度限值为日均浓度限值的1.5倍；当要求95%的生产线达标时，NO_x小时浓度限值为日均浓度限值的1.6倍；当要求99%的生产线达标时，NO_x小时浓度限值为日均浓度限值的1.7倍. 研究显示，基于水泥生产线排放的NO_x小时浓度(CEMS监测数据)的统计分析，通过变化因子比值法和曲线拟合法可以确定小时浓度、日均浓度定量比例关系，建立基于CEMS监测数据的达标判定方法. 

Assessment Method of Compliance with NOx Emission Limits of Cement Industry Based on CEMS Data

The current assessment of compliance with air pollutant emission limits is based on manual monitoring data. In order to study and formulate emission limit assessment methods based on the monitoring data of the continuous emissions monitoring system (CEMS), 553 production lines are selected as the research object according to the principle of data effectiveness from 957 production lines in China's cement industry in 2017. The statistical characteristics of hourly concentration and daily average concentration of NO_x in flue gas discharged by cement industry are analyzed and studied on CEMS monitoring data. The relationship between hourly concentration and daily average concentration limit is established by variability factor ratio method and curve fitting method. The results show that: (1) The correlation coefficients between the logarithm of hourly concentration and the normalization value of cumulative frequency of NO_x emission of 553 cement production lines are greater than or equal to 0.6. (2) There is a correlation between the NO_x hourly concentration and the daily average concentration limit, and the multiple relationship obtained by the curve fitting method is slightly higher than that obtained by the variability factor ratio method. (3) If 90% of the production lines are required to meet the limits, the hourly limits can be set to 1.5 times the daily average concentration limits. If 95% of the production lines are required to meet the limits, the hourly limits can be set to 1.6 times the daily average concentration limits. If 99% of the production lines are required to meet the limits, the hourly limits can be set to 1.7 times the daily average concentration limits. The research shows that based on the statistical analysis of CEMS monitoring data of NO_x emission from cement production lines, the quantitative proportional relationship between hourly concentration and daily average concentration can be determined by variation factor ratio method and curve fitting method, and the assessment of compliance with emission limits can be established based on CEMS monitoring data.