为实时监测煤矿井下高温热源.及时发现矿井火灾并报警.分析了矿井红外热成像远距离测温误差.提出了矿井红外热成像远距离精确测温方法.并通过了试验验证.建立了热成像仪接收的单波辐射照度与图像灰度之间的函数关系.得到了热成像仪的辐射测温公式,通过对矿井空气中主要成分的体积分数和红外吸收强度的分析.确立了影响矿井红外热成像远距离测温精度的环境参数.分析了辐射路径中水蒸气.CO2.SO2和CH4吸收.粉尘散射对红外测温精度的影响,结合测量环境条件.对矿井空气透过率进行实时修正.并根据水蒸气.CO2.SO2.CH4的吸收衰减和粉尘的散射衰减.构建了矿井空气总透过率与辐射测温距离的衰减模型,结合热成像仪的辐射测温公式.热成像仪接收的单波辐射照度与图像灰度之间的函数关系和矿井气体和粉尘的衰减模型.提出了红外热成像的远距离精确测温方法.并进行了试验验证.结果表明:提出的精确测温方法测得的物体温度比辐射温度更接近于物体真实温度,目标表面温度变化对测温精度的影响较小.测温路径中的辐射衰减对测温精度影响较大,随着测温距离的增大.红外辐射的总透过率逐渐减小,在35 m测温处.热成像仪自带算法测得的平均相对误差为12.22%.精确测温方法测得的平均相对误差为2.85%.温度测量误差大幅下降.

In order to monitor the high-temperature heat sources underground in coal mines in real time.detect mine fires and give an alarm.this paper analyzed the error of long-distance temperature measurement of mine infrared thermal imaging.and proposed a long-distance accurate temperature measurement of mine infrared thermal imaging.which has passed the test verification. First.the functional relationship between the single-wave radiation illuminance received by thermal imager and the image gray level is established.and the radiation temperature measurement formula of the thermal imager is obtained. Secondly.through the analysis of the concentration and absorption intensity of the main components in the mine air.the environmental parameters that affect the accuracy of long-distance temperature measurement of mine infrared thermal imaging are confirmed. In addition.the influences of water vapor.CO2.CH4 and SO2 absorption and dust scattering in the radiation path on the accuracy of infrared temperature measurement are analyzed. Thirdly.the mine air permeability is corrected in real time in combination with the on-site environmental conditions. According to the absorption attenuation of water vapor.CO2.CH4 and SO2.and the scattering attenuation of dust.the attenuation model of the total mine air permeability and the radiation temperature measurement distance was constructed. Finally.combining the radiation temperature measurement formula of the thermal imager.the functional relationship between the single-wave radiation illuminance and the image gray level.and the attenuation model of mine gas and dust.a long-distance accurate temperature measurement method for infrared thermal imaging is proposed and verified by experiments. The experimental results show that the temperature of the object measured by the proposed method is closer to the true temperature of the object. The temperature change of the target surface has little effect on the temperature measurement accuracy.but the radiation attenuation in the temperature measurement path has a greater impact on the temperature measurement accuracy. As the temperature measurement distance increases.the total transmittance of infrared radiation gradually decreases. At a temperature measurement of 35 m.the average relative error measured by the thermal imager's own algorithm is 12.22%.the average relative error measured by the precise temperature measurement method is 2.85%.and the temperature measurement error is greatly reduced.

1 红外热成像辐射测温原理

2 矿井气体及粉尘对红外热成像远距离测温的影响

   2.1 水蒸气的吸收衰减

   2.2 CO2的吸收衰减

   2.3 CH4.SO2的吸收衰减

   2.4 粉尘微粒的散射衰减

   2.5 矿井空气总透过率及透过率参数修正

3 矿井红外热成像远距离精确测温方法

4 试验验证与分析

   4.1 目标物表面温度变化对温度测量的影响

   4.2 目标物距离变化对温度测量的影响

   4.3 煤炭燃烧远距离测温结果比较

5 结论