压电谐振式煤矿瓦斯传感器探头设计与研制

发布时间：2018-07-12 15:41

  本文选题：甲烷 + 吸附材料　； 参考：《西安科技大学》2013年硕士论文

【摘要】：我国是一个煤炭生产大国，煤炭储量居世界第三。然而，在煤炭开采过程中，矿难事故频繁发生，其中瓦斯灾难事故是危害最大、死亡比例最高的重大事故之一。矿井瓦斯的监测与治理一直是煤炭行业安全管理工作的重中之重。鉴于目前矿井普遍使用的催化燃烧式瓦斯检测存在零漂及稳定性欠佳等缺点，本文提出利用压电谐振原理设计制作甲烷传感器敏感探头，以吸附材料作为甲烷气体的载体，利用压电振子谐振频率对自身重量的敏感性尝试设计制作传感器敏感探头，，围绕该敏感探头相关的吸附材料、谐振体设计、性能分析等方面做了系统研究，完成了吸附材料的制备与表征、振动体的有限元分析及设计制作、敏感探头的加工组装及其性能分析等工作。 作为同活性炭和沸石相对比的吸附材料,分别以硝酸锌、氯化锌和硫酸锌为原料，采用低温水热法制备出了三种以锌离子为金属骨架结构的配合物。对上述配合物进行了XRD、红外光谱、差热-热重及扫描电镜测试分析。XRD分析结果表明，制备的三种金属骨架配合物晶体为单一的纯相，不含其他杂质，结合红外测试结果推测结构为Zn(NH3)2BDC。差热-热重分析表明，三种配合物可以在温度低于200℃使用，骨架结构不坍塌。通过SEM观测发现，以硝酸锌制备的金属配合物结晶效果最好，为针状晶粒，适用于作甲烷气体的载体；以氯化锌、硫酸锌制备的金属配合物结晶为颗粒状； 以PZT8压电陶瓷作为激振材料，磷青铜为振动本体材料，利用有限元方法进行了模态分析，在分析结果的基础上筛选无模态混叠的模型进行三种气敏探头设计并进行加工、组装与测试。实际阻抗谱测试结果表明，有限元分析结果很好地指导了振动体的设计，其分析结果可信； 分别以活性炭、5A型沸石分子筛、MOF金属有机骨架配合3种不同的谐振体，构成9种传感器敏感探头；利用TH2818型自动元件分析仪、搭建阻抗频率特性测试平台，在甲烷浓度为0%-7.6%之间分别对9种传感器敏感探头进行阻抗频谱测试。通过对不同敏感探头在不同甲烷浓度下的阻抗谱谐振峰偏移量（敏感探头输入-输出曲线）、灵敏度与线性度的对比分析，表明以5A型沸石分子筛为吸附材料与3#谐振头搭配得到的探头对甲烷浓度有较好的灵敏度和线性，可作为甲烷传感器敏感探头。
[Abstract]:Our country is a big country of coal production, coal reserves ranks third in the world. However, in the process of coal mining, mine accidents occur frequently, among which the gas disaster is one of the most harmful and the highest proportion of deaths. Mine gas monitoring and control has been the most important work of coal industry safety management. In view of the shortcomings such as zero drift and poor stability in the catalytic combustion gas detection commonly used in mines at present, this paper presents the design and manufacture of a methane sensor sensitive probe based on piezoelectric resonance principle, in which the adsorbed material is used as the carrier of methane gas. Based on the sensitivity of the resonant frequency of piezoelectric vibrator to its own weight, the sensor sensitive probe is designed and fabricated. The related adsorption materials, resonant body design and performance analysis of the sensor are systematically studied. The preparation and characterization of the adsorption material, the finite element analysis and design of the vibrator, the processing and assembly of the sensitive probe and the performance analysis were completed. As adsorption materials compared with activated carbon and zeolite, zinc nitrate, zinc chloride and zinc sulfate were used as raw materials to prepare three complexes with zinc ion as metal skeleton structure by low temperature hydrothermal method. The results of XRD, IR, DTA, SEM and XRD analysis showed that the crystal of the three metal skeleton complexes was a single pure phase without other impurities. The structure of Zn (NH _ 3) _ 2BDC was deduced from the results of IR. Differential thermogravimetric analysis (DTA) shows that the three complexes can be used at temperatures below 200 鈩

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