摘 要

氢气浓度探测的应用领域非常广泛，覆盖了工业，航空航天，国防，能源，环保及日常生产等各方面。本文旨在通过测量超声波发射和接受信号的相位差来测量氢气的浓度，论文首先给出待测气体浓度与超声波信号相位差之间的关系，并且依靠此关系式作为实验原理，通过检测相同声程的收发信号的相位差来反映气体浓度。

本论文进行的研究工作主要有以下几个方面：

(1)理解声波在混合气体中的传播规律，完成相关公式的推导；依据此原理成功搭建实验平台，并通过示波器辅助测量收发信号的波形，测量不同氢气浓度下的声波信号的相位差，根据相位差来测量氢气浓度。

(2)在实验方案实施的基础上，分别进行了H2分辨率测试，N2与不同浓度H2线性标定实验，全温度下的不同氢气浓度下的计数值测量试验，根据测得的相同条件下不同浓度的计数值，确定了氢气浓度与计数值之间的线性关系，在此基础上，分析温度对计数值的影响，完成了温度补偿实验，确定了温度补偿系数，根据实验条件，求得了气体浓度的表达式，并分析了实验误差的来源。

(3)根据所得结果，由氢气浓度表达式中各项因子所代表意义，分析每一项对最终结果带来的误差程度，并重点分析了温度对本实验结果的影响，最后对本检测方法与其他气体检测方法进行对比，分析其优劣，并提出了进一步提高测量精度的建议和后续研究方向。

研究结果表明：氢气浓度值和相位差之间有良好的线性关系，只要在温度补偿系数精确的条件下，只要测得了超声波收发信号之间的相位差（即计数值个数），就可以较准确的测得氢气的浓度。

关键词：超声波相位差检测法；气体浓度；线性标定；温度补偿

Abstract

The hydrogen concentration detection applications is very extensive, covering industry, aerospace, defense, energy, environmental protection and daily production. This paper aims at through measurement of ultrasonic transmitting and receiving the signal phase difference to measure the hydrogen concentration, firstly measured the relationship between gas concentration and the ultrasonic signal phase difference, and rely on this as the principle, through detecting the same acoustic path for sending and receiving signal phase difference to reflect the gas concentration.The research work of this paper mainly has the following aspects:

First,understanding of acoustic wave in the mixture of gases in the propagation, the derivation of the formula; based on this principle, to build a successful experimental platform, and through the oscilloscope aided measurement of receiving and sending signal waveform measured under different hydrogen concentrations of acoustic signal phase difference, on the basis of the phase difference to measure the hydrogen concentration.

Second,Implemented in the experimental program based on, respectively, were H2 resolution test, N2 and different concentrations of H2 linear calibration experiments, numerical experiments to measure the temperature of different hydrogen concentrations, according to the measured under identical conditions with different concentrations of count to determine the linear relationship between the hydrogen concentration and the count value, based on. Analysis temperature effects on the count value, completed the temperature compensation experiment, determined the temperature compensation coefficient. According to the experimental conditions, obtained the expressions for the concentration of gas, analyses the sources of experimental error.

Third,On the basis of the results, by the expression of hydrogen concentration in the factor in the meaning, and focuses on the analysis of the influence of temperature on the experimental results, finally is the comparison of this method with other gas detection method, analyzes their advantages and disadvantages, and puts forward the further improve the measurement accuracy of the recommendations and follow-up research direction.

The results show that there is a good linear relation between the hydrogen concentration and phase difference, as long as in precise temperature compensation coefficient conditions, as long as the measured between got ultrasonic transceiver signal phase difference (i.e. count number of values), can be accurately measured the concentration of hydrogen.

Key Words：Ultrasonic phase difference detection；gas concentration；Linear calibration；temperature compensation

目 录

第1章 绪论 1

1.1 高精度的氢气浓度检测 1

1.2 超声波相位差检测法 2

1.3 论文研究内容与章节安排 2

1.3.1 研究的基本内容 2

1.3.2 章节安排 3

第2章 气体的声速理论 4

2.1 气体的浓度与声速 4

2.2 测量气体声速的原理与方案 5

第3章 超声测量氢气浓度实验 10

3.1 实验平台的搭建 10

3.2 实验测量结果与分析 11

3.2.1 测量结果与数据 11

3.2.2 温度对实验测量的影响 15

3.2.3 实验结果误差分析 16

第4章 总结与展望 19

4.1 论文工作总结 19

4.2 对后续工作的展望 19

参考文献 20

致谢 21

第1章 绪论

氢气作为一种在日常生产和生活中应用广泛的气体，自发现以来就受到了人们的重视。如今，无论是在环境保护还是石油化工中都是重要的气体，尤其是现在能源的需求量越来远大，而氢气在未来的可持续发展中有举足轻重的地位，作为新能源，不仅可以再生产，而且燃烧后的产物对环境不会产生影响，应用前景十分可观。近些年来，氢气在航空航天也有广泛的应用^[1]。可以预见，在不久的未来，氢气在燃料领域必将占据一席之地。但是氢气在广泛应用的同时，随之而来的也有许多问题，特别是氢气的安全性方面，我们了解到氢气作为一种小分子气体，在生产，运输，使用过程中，只要稍有疏忽就有可能发生泄漏，因此对生产和应用过程带来很大的安全隐患，当空气中的氢气浓度达到一个临界值时，遇到火苗就会发生剧烈的爆炸，造成后果将会很严重，不仅是生产设备，更是对人员生命安全的挑战。因此我们需要对氢气发生泄漏时进行检测，实时对氢气的浓度进行监测，作出警报^[2]。

1.1 高精度的氢气浓度检测