煤质硫含量紫外差分吸收测量方法研究

Research on Measurement Method for Sulfur Content in Coal Based on Ultraviolet Differential Optical Absorption

快速准确地测定煤质硫含量,可为企业、环境监督部门提供重要的技术依据。国内外已有多种煤质硫含量分析仪器,但或多或少存在令操作人员不满意的地方。提出一种基于紫外(UV)差分吸收光谱(DOAS)的煤质硫含量测量方法。针对分子数分数测量范围宽、光程短等问题,在传统算法的基础上,提出基于有限脉冲响应(FIR)滤波和四阶多项式非线性补偿的改进DOAS算法。搭建了实验测量系统,对5种标准煤样进行了实验研究。结果表明,测量系统的下限为0.014%,能够去除烟尘和背景气体的影响,降低系统的维护量,单次测量时间在4min左右,测量系统的重复性满足国家标准的要求。

Determining sulfur content in coal rapidly and accurately can provide technical basis for the enterprises and environmental monitoring departments. A novel method for measuring sulfur content in coal based on ultraviolet （UV） differential optical absorption spectroscopy （DOAS） is put forward. Compared with atmosphere monitoring, the UV DOAS used in the sulfur content measurement in coal encounters with the problems that the concentration range of S02 is wider and the optical path length of the gas cell is shorter. In order to solve the problems, an improved DOAS algorithm based on finite impulse response （FIR） filter and nonlinear compensation is proposed on the basis of the traditional algorithm. An experimental system is designed and built, on which five kinds of standard coals are experimentally tested. Results show that the lower detection limit of the system is 0. 014 % and the influence of the dust and background gas on S02 concentration measurement can be reduced. The repeatability of the measurement system meets the national standards of China. The system has the advantages of low maintenance and short measurement duration （4 min）.