摘要
甲烷气体泄漏会导致火灾爆炸事故的发生,恶劣的环境条件(如低温和浸水)会影响甲烷泄漏的精准检测。该研究系统分析了浸水和低温-浸水复杂条件下催化燃烧式甲烷探测器的响应特性及其影响机制。研究结果表明:浸水会显著降低甲烷探测器的灵敏度,浸水后探测器报警浓度增长90.3%。相比于室温浸水,低温-浸水使报警浓度降低23.3%,响应时间的重复性能提升,平均标准差降低65.16%。浸水后传感器表面的水膜会阻碍甲烷气体进入传感器内部,使得传感器内甲烷含量降低;浸水还会导致催化剂的比表面积降低和催化剂水中毒,减少了甲烷气体的吸附位点,因此浸水后探测器需要更高浓度的甲烷才能触发报警状态。低温环境下探测器铂丝加热器电阻变化更为显著,吸收较少的催化燃烧反应热就能达到报警所需的电阻变化量,降低了探测器报警所需的甲烷浓度,因此低温环境有效减弱了浸水对探测器的不利影响。该文为进一步研究低温-浸水复杂条件对甲烷探测器性能的影响提供了实验依据,有利于提高甲烷泄漏的精准检测。
[Objective]Fires and explosions caused by gas leaks result in serious casualties and property damage.Therefore,the precise detection of gas leaks is crucial.The primary component of natural gas is methane,and gas leak detection aims to accurately detect methane gas.However,methane detectors may face interference from adverse environmental factors during the gas leak detection process,affecting the performance of the detectors.[Methods]This study systematically analyzed the influence of water immersion and the complex conditions of low-temperature immersion on the response characteristics of catalytic combustion methane detectors.The catalytic combustion methane detector was initially immersed for 15–180 mins.The detectors alarm concentration and response time were then tested to evaluate the impact of immersion on the alarm performance and response speed of the catalytic combustion methane detector.Subsequently,tests were conducted on the alarm concentration and response time of the catalytic combustion methane detector immersed for 15 and 30 min at environmental temperatures of 30,15,and 0°C.Furthermore,an analysis was conducted on the reasons for the impacts of low temperature and water immersion on the catalytic combustion detector,considering factors such as resistance,absolute humidity,moisture content,and catalyst-specific surface area.[Results]The results revealed that immersion significantly reduced the sensitivity of the methane detector,with a 90.3%increase in the alarm concentration after immersion.The time required for the display values of the detector to reach 90%of the baseline value increased by 115 min.Compared with room-temperature immersion,low-temperature immersion resulted in a 23.3%decrease in the alarm concentration.The time required for the display values of the detector to reach 90%of the baseline value increased by 55 min,but the repeatability of the response time improved,with an average standard deviation reduced by 65.16%.After immersion treatment,a thin film of water formed on the surface of the sensor,impeding the entry of methane gas into the sensors interior and decreasing the internal methane concentration.Additionally,water immersion reduced the catalysts specific surface area and led to catalyst poisoning,thereby diminishing the available adsorption sites for methane.Therefore,this increase in methane concentration was required for the detector to reach the alarm state.Moreover,the platinum wire heater of the detector showed more significant resistance changes at low temperatures,requiring less heat from the catalytic combustion reactions to achieve the necessary resistance change for triggering the alarm,thereby reducing the required methane concentration for the detectors alarm.The absolute humidity of the testing environment decreased by 92.9%at low temperatures,reducing the impact of environmental humidity on the detector.Therefore,the low-temperature environment effectively mitigates the adverse effects of immersion on the detector.[Conclusions]This study examined the variations in the response characteristics of catalytic combustion methane detectors under low temperature and water immersion conditions.This study also analyzed the reasons for the impacts of low-temperature and immersion environments,thereby providing experimental evidence for addressing the impact of complex low-temperature immersion conditions on methane detector performance.The results are beneficial for enhancing the accurate detection of methane leaks.
作者
何庆
聂士斌
张红
刘小勇
郭贤
徐良骥
HE Qing;NIE Shibin;ZHANG Hong;LIU Xiaoyong;GUO Xian;XU Liangji(School of Safety Science and Engineering,Anhui University of Science and Technology,Huainan 232001,China;Institute of Energy,Hefei Comprehensive National Science Center(Anhui Energy Laboratory),Hefei 230000,China;School of Public Security and Emergency Management,Anhui University of Science and Technology,Hefei 231131,China;Hefei Institute for Public Safety Research,Tsinghua University,Hefei 230601,China)
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第6期965-974,共10页
Journal of Tsinghua University(Science and Technology)
基金
安徽高校协同创新项目(GXXT-2022-018,2023g07020001)
国家自然科学基金项目(52204194)
安徽省自然科学基金项目(2208085QE148)
安徽省高等学校科学研究项目(KJ2021A0460)。
关键词
甲烷泄漏
甲烷探测器
低温-浸水复杂条件
报警浓度
响应时间
methane gas leakage
methane detector
complex conditions of low-temperature and water immersion
alarm concentration
response time
