Tang Xiao-Jun, Li Yu-Jun, Zhu Ling-Jian, Ding Hui, Liu Jun-Hua
State Key Laboratory of Electrical Insulation & Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2011 Nov;31(11):3031-5.
Aimed at the problem that Fourier transform infrared (FTIR) spectral analysis can't be used solely to analyze complex gas mxiture, in which there are many gas compositions, some compositions have same molecular group, and the concentrations of some compositions range greatly, in the present paper, a new spectral analysis method is proposed. For this method, the effects of gas temperature and gas pressure on the analysis result are taken into account, and feature variable extraction, recognition and correction of spectral disorder, robust modeling and multi-layer modeling with neural network (NN) are used to build gas mixture analysis models. At the end of this paper, on-line analysis of five alkane gases is taken as example to test the performance of the analysis method. CH4, C2 H6, Ca3 Ha8, iso-C4 H10 and n-C4 H10 are taken as object gases while iso-C5 H12 and n-C5 H12 are looked as disturbing gases. The comparison results that analysis result curves of FTIR overlap that of gas chromatograph indicate that FTIR can be solely used in on-line and in-situ analysis of multicomponent gas mixture with same molecular group if the analysis method presented in this paper is used.
针对傅里叶变换红外（FTIR）光谱分析不能单独用于分析复杂气体混合物的问题，该复杂气体混合物存在多种气体成分，一些成分具有相同的分子基团，且一些成分的浓度范围差异很大，本文提出了一种新的光谱分析方法。对于该方法，考虑了气体温度和气体压力对分析结果的影响，并采用特征变量提取、光谱紊乱识别与校正、稳健建模以及利用神经网络（NN）进行多层建模来构建气体混合物分析模型。本文最后以五种烷烃气体的在线分析为例来测试该分析方法的性能。将CH4、C2H6、C3H8、异丁烷和正丁烷作为目标气体，而异戊烷和正戊烷作为干扰气体。FTIR分析结果曲线与气相色谱分析结果曲线的对比结果表明，如果采用本文提出的分析方法，FTIR可单独用于具有相同分子基团的多组分气体混合物的在线和原位分析。
