低温环境非色散红外气体检测仪温控系统  

Temperature Control System of Non-dispersive Infrared Gas Detector in Low Temperature Environment

作　　者：薄滕飞 李亚飞 李保霖 马卓 郑传涛 王一丁 BO Tengfei;LI Yafei;LI Baolin;MA Zhuo;ZHENG Chuantao;WANG Yiding(State Key Laboratory of Integrated Optoelectronics,College of Electronic Science and Engineering,Jilin University,Changchun 130012,China;Jilin Provincial Engineering Research Center of Infrared Gas Sensing Technique,Changchun 130012,China)

机构地区：[1]吉林大学电子科学与工程学院集成光电子学国家重点联合实验室吉林大学实验区,长春130012 [2]吉林省红外气体传感技术工程研究中心,长春130012

出　　处：《光子学报》2023年第3期295-306,共12页Acta Photonica Sinica

基　　金：国家重点研发计划(No.20213201903);国家自然科学基金(Nos.61960206004,62175087);吉林省科技发展计划(No.20200401059GX);吉林省教育厅科技发展规划项目(No.JJKH20211088KJ);长春市重点研发项目(No.21ZGN24);吉林大学科技创新团队项目(Nos.JLUSTIRT,2021TD-39)。

摘　　要：由于红外热释电探测器在低温环境下易发生温度漂移,导致非分散红外(NDIR)二氧化碳(CO_(2))农业火灾检测仪受低温影响较大。针对上述问题,本文设计了一种应用于-40℃低温环境的探测器温度控制系统。给出了NDIR农业火灾检测仪的原理,探究了热释电探测器温度漂移现象,在此基础上,设计了以STM32F103为核心的温度控制系统。将温度控制系统集成于火灾检测仪中,在-40℃环境温度下,将探测器温度从20℃起始温度控温,稳定在21℃的响应时间为16 s,温度波动的1σ值为0.0126℃,响应时间和稳定性均满足低温环境下的控温需求。在控温条件下,对传感器进行了标定,将气体标定实验得到的吸收通道与参考通道电压信号的一次谐波幅值比和标准气体浓度值进行指数拟合,拟合优度达到了99.852%。利用纯氮气(N_(2))样品,对检测仪进行了25 min的稳定性测试,测得的浓度波动范围为-28.12876×10^(-6)~27.2405×10^(-6)。引入Allan方差进行评估,当积分时间为0.25 s时,检测下限为1.21301×10^(-6);当积分时间为114.75 s时,理论上系统的检测下限可达到4.8225×10^(-7)。实验结果表明,该温度控制系统可以保证火灾检测仪在低温环境下的正常工作。In agricultural harvesting operations,agricultural fires can be induced due to various human or natural factors.Agricultural fires pose a great threat to agricultural production and the safety of life and property,so it is imperative to accurately monitor agricultural fires.At every stage of fire,gas can be produced.So gas sensors have been developed rapidly in the field of fire detection.In case of a fire,the burning of crops will produce a large amount of carbon monoxide(CO)and carbon dioxide(CO2),which will lead to a rapid increase in the concentration of CO and CO_(2)in the air.Real time monitoring of changes in the concentration of CO and CO_(2)can give an alarm.A gas sensor based on Non-Dispersive Infrared(NDIR)has the advantages of high integration and low cost,which is conducive to miniaturization design,on-site detection and commercial promotion.Therefore,many studies on NDIR gas sensors have emerged.However,the reported NDIR sensors only show good performance under laboratory conditions,but often do not perform well in low temperature environments.The main reason is that the internal infrared thermoelectric detector is prone to temperature drift in low temperature environments,and it is difficult to work normally under low temperature conditions.In view of this phenomenon,a small temperature control system is designed for the infrared detector,and is applied to a NDIR CO2detector.Then the detector can be maintained at 21℃in a low temperature environment at-40℃.Finally the purpose of making the sensor work normally under low temperature environment is achieved.Firstly,the detection principle of the infrared gas detector is introduced,and the relationship between harmonic signal and gas volume fraction is determined according to Lambert-Beer law.The system structure of the detector is analyzed,which is mainly composed of an electrical module,an optical module,an upper computer monitoring module and a detector temperature control module.Under a low temperature environment below-20℃,the output signal

关 键 词：火灾检测 气体吸收 温度控制 BUCK电路 牛顿迭代法 增量式PID 

分 类 号：TN21[电子电信—物理电子学]