煤质技术2024，Vol.39Issue(4)：85-91,7.DOI:10.3969/j.issn.1007-7677.2024.04.012
煤中氮元素分析仪改造及性能验证研究
Study on the modification and performance verification of nitrogen element analyzer for coal
摘要
Abstract
To replace helium with cheaper argon,which has a thermal conductivity coefficient close to that of nitro-gen,as the carrier gas for measuring nitrogen content in coal,modifications were made to the CHN628 elemental an-alyzer and its thermal conductivity cell sensitivity was enhanced.The modified instrument employed argon as the carri-er gas with optimized parameters,including a baseline delay time of 10 s,a minimum analysis time of 120 s,a com-parison level of 1％,an equilibrium time of 30 s,a filling pressure of 150 mmHg,and an argon flow rate of 320 mL/min.Under these conditions,the nitrogen content in coal samples was measured with a smooth analytical curve.A certified coal reference material with a nitrogen content range encompassing that of routine test samples was selected to calibrate the curve,yielding a correlation coefficient(r)of 0.998,meeting the requirement for linearity.The limit of detection and limit of quantification were determined to be 0.06％and 0.15％,respective-ly,using the blank sample method,satisfying the method's requirements.A statistical comparison was conducted be-tween the two methods of using argon or helium as the carrier gas to measure nitrogen content in coal,inclu-ding measurements of the certified coal reference material GBW 11107p.F-tests and t-tests indicated that using argon as the carrier gas to measure nitrogen content in coal met the precision and accuracy requirements of the national standard GB/T 30733-2014 for intermediate precision,short-term precision,and accuracy.Therefore,the modi-fied equipment can be used to determine nitrogen content in coal.Furthermore,the adoption of argon in this method,with its stable market supply and low price,can help reduce testing costs.关键词
煤中氮/热导池/精密度/准确度/检出限/标定曲线/F检验/t检验Key words
nitrogen in coal/thermal conductivity cell/precision/accuracy/limit of detection/calibration curve/F-test/t-test分类
化学工程引用本文复制引用
王建,殷志源,孙天宇,竺浩玮,沈玉双,吴碧海,张晓丹,鲍莉彬..煤中氮元素分析仪改造及性能验证研究[J].煤质技术,2024,39(4):85-91,7.基金项目
浙江省能源集团有限公司科技资助项目(ZNKJ-2018-064) （ZNKJ-2018-064）
