基于声谱特征点的多元可激发混合气体检测方法研究

项目名称： 基于声谱特征点的多元可激发混合气体检测方法研究

项目编号： No.61461008

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 张克声

作者单位： 贵州理工学院

项目金额： 50万元

中文摘要： 本项目研究利用多元可激发气体中声弛豫现象进行气体检测的传感方法。首先，将传统上的研究对象由声谱曲线转变为声谱特征点，在无需改变气体腔体压强的条件下，通过两个点频上声测量值合成声谱特征点，再由特征点求解得到弛豫气体有效热容的三要素--外自由度热容、耦合热容、弛豫时间。其次，通过三要素之一的外自由度热容与气体分子浓度和分子几何结构的解析关系，不仅可实现气体浓度的定量检测，还可用于检测气体分子几何结构；利用耦合热容这一要素与气体分子浓度和振动特征频率的解析关系，亦可用于气体浓度的定量检测，同时为定性地判断气体分子成分提供了可能。本研究一方面可简化气体分子弛豫现象的声学传统研究方法，另一方面解决了既有利用声弛豫现象的气体检测方法不能获得声测量值与气体浓度或某一分子特性的解析关系的问题。本项目的预期研究成果可应用于煤层瓦斯气体的实时监测和检测。

中文关键词： 气体声弛豫；声谱特征点；有效热容；气体传感机理；声信号处理

英文摘要： This project studies the sensing method for multi-component excitable gas mixtures based on the acoustic relaxation phenomenon.First, we research on the characteristic points of acoustic spectra curve rather than the whole curve using by traditional way. Without the necessity of varying the ambient pressure, the three elements of effective heat capacity of relaxing gases, i.e. the heat capacity of external degree of freedom (DOF), the coupling heat capaciy and the relaxation time, is obtained from the characteristic points of acoustic spectra, which are synthesized by the two-frequency acoustic measurements. Second, on the one hand, based on the measured heat capacity of external DOF, we can not only quantitatively detect gas concentration,but also determine molecular symmetry. On the other hand, by using the measured coupling heat capacity, gas concentration also can be detected, and a possible way to qualitatively detect gas compostions is proposed based on the vibrational frequencies. Consequently, this project can not only simplify the traditional acoustic method of studying molecular relaxations in excitable gases, but also obtain the analytical relation, which is not be given by the exisiting methods, between acoustic measurements and gas concentration or a molecular feature. The proposed method can be applied for monitoring and detecting mine gas in real-time.

英文关键词： gas acoustic relaxation;characteristic points of acoustic spectra;effective heat capacity;gas sensing mechanism;acoustic singal processing