基于混合气体分子复合弛豫模型的一氧化碳浓度检测算法

研究了声波通过混合气体时，复合弛豫声吸收和声速与气体各成分浓度和声频率之间的依赖关系.以一氧化碳气体、水蒸气、氮气和氧气的混合气体为例，分别建立了弛豫声吸收和声速与气体浓度的三维模型，以及弛豫声吸收与声频率的二维模型.完成了通过测量弛豫声吸收和声速计算一氧化碳气体浓度的算法推导，提出了一种依据弛豫声吸收和声速检测气体浓度的简化算法.仿真实验结果不仅证明了算法的理论可行性，还给出了算法的最佳适用声频率范围，并估计了将算法应用于实验的误差原因，证明了算法具有实际可行性. 关键词： 气体浓度声学检测 一氧化碳浓度检测 复合弛豫声吸收 声速

An acoustic gas concentration measurement algorithm for carbon monoxide in mixtures based on molecular multi-relaxation model

In this paper，we disclose the relations between multi-relaxation absorption and the acoustic parameters when ultrasound propagates in gas mixtures，such as the relation between concentrations of constituents and acoustic frequencies. In the meantime，the dependence of acoustic velocity on the same parameters is discussed. Based on the sample consisting of carbon monoxide，water vapor，nitrogen and oxygen，we establish the three dimensional model for the relation between concentrations of mixture constituents and relaxation absorption and acoustic velocity，respectively. Further more，we give the two dimensional dependence between relaxation absorption and acoustic frequency. We propose a simplified algorithm to calculate the carbon monoxide concentration by measuring the relaxation absorption and acoustic velocity. Simulation results proved the feasibility of this method and showed the appropriate range of acoustic frequency. The origins of errors arising in the application of the method are indicated in this paper.