露天煤垛内部高温非接触式红外测量方法

目前常采用人工手持测温杆逐个煤垛不定点测量的方法进行露天煤垛温度监测,人工测温法存在重复性差、测量位置有限和工作量大等问题。为实现大范围、全天候、多煤垛在线自动测温,提出了一种非接触式煤垛内部温度红外测量的方法和内部温度分层式计算模型,并设计实现了相应的露天煤垛内部高温红外监测系统。该方法将煤垛分为表层与内层两部分,两层的交界定义为边界面,表层受外界环境的影响,内层则不随外界环境变化。先由红外热像仪采集煤垛的表面温度,结合小型气象站采集得到的天候参数,通过温度校正算法去除天候环境对表面温度的影响,获得煤垛表面的真实温度。然后采用表面热平衡方程由校正后的表面真实温度计算得到边界面温度,再由内层温度与距离的指数关系即可计算得到内部温度值。通过现场实验证实,该方法对内热源温度的计算误差约为10.36%,能够满足工程实际要求,能非接触式直接测量露天煤垛内部温度。

Infrared noncontact internal temperature detection method of opencast coal stack

In temperature measurement methods of opencast coal stack，the artificial temperature measurement is considered as a commonly used method.However，the artificial temperature measurement has some defects，such as low reproducibility，limited measuring positions and heavy workload.In order to overcome these defects，this paper provided a largescale，allweather，multitarget monitoring and effective temperature monitoring method and an internal temperature layered algorithm.Furthermore，an infrared internal temperature detection system was designed and implemented.According to the inner temperature detection method，the coal stack was divided into inner layer and outer layer according to the temperature influence by external environment.The bounding surface was defined as the junction between inner and outer layer of coal stack.The outer layer was varied with environment，and then the inner layer was relatively stable.The surface temperature of coal stack was captured by farinfrared image instrument，and weather conditions were measured by small weather station.The temperature correction algorithm is designed to reduce surface temperature measurement error caused by the atmospheric effect and reflected radiation.Then，the corrected temperature is used as the true surface temperature to calculate internal temperature by layered algorithm.The temperatures of bounding surface is calculated by the heat balance equation of coal stack，and the temperature of inner layer is calculated through exponential relationship between the temperature of bounding surface and the distance from calculated position to the bounding surface.The experimental results of the proposed method indicate that the internal temperature calculation error is 10.36%，and satisfied the temperature detecting practical demand.