【作者】 谷红伟；

【导师】 许文海；

【作者基本信息】 大连海事大学 ， 通信与信息系统， 2014， 博士

【摘要】 储煤场的安全监管尤其是露天煤垛的存储安全监管是堆场管理的重要工作,关系着国家能源储备和财产安全。本文针对储煤场安全监管中急需解决的多煤垛在线实时温度监测问题,基于红外成像测温技术,展开了可适用于大型储煤场的露天煤垛温度监测方法的研究。论文所进行的主要研究内容如下：根据对储煤场堆垛布局以及煤垛测温方法等实际情况的分析,提出了露天煤垛温度监测方法。该方法通过自行设计研制的无盲区二维转台,由转台搭载可自动调焦的红外热像仪,实现了多煤垛在线温度监测；可通过对影响红外测温的因素进行有效去除,获得较为准确的表面温度；可通过对煤垛表面的实时监测,掌握同一煤垛不同时段的温度变化情况,分析煤垛温度发展趋势,对有自燃隐患煤垛进行预警。根据所提出的露天煤垛温度监测方法,还设计实现了相应的温度监测系统。经实验验证,所提出的方法和系统满足工程实际需求。根据露天煤垛成像测温过程,采用对影响煤垛测温精度的主要因素,如成像系统空间效应、大气辐射传输效应和反射辐射效应等进行校正的方法,有效去除了各测温精度影响项,获得了较为准确的煤垛表面实际温度。实验结果表明,该方法对煤垛表面温度的测温误差由校正前的15%减小到校正后的1%。通过在露天煤垛中预埋圆形恒温面源,进行了浅层(<1.0m)热源煤垛有源温度场内部分布规律的研究。研究结果表明非稳态情况下,有热源部位煤垛表面温度随圆形面热源加热时间的延长而升高,且热扩散面积逐渐扩大,最终达到稳态。不同深度热源引起的有热源部位与无热源部位平均温度之间的温差均表现出一致的升高规律,先快速上升,再缓慢增加,最后达到稳定。由此提出,对于浅层内热源,可通过对煤垛表面温度的连续监测,分析表面温度的温升程度,制定危险等级,对内热源危险程度进行判决,以对存在自燃隐患的露天煤垛进行预警。根据对稳态情况下煤垛有源温度场与表面温度分布规律的实验研究,得出当有源温度场达到稳态时,煤垛表面存在不同面积的等温区,基本与圆形面热源的热扩散规律相符,预埋位置中心温度最高,沿中心向外温度逐渐降低。且距离煤垛表面较浅的位置,煤体温度随外界环境昼夜变化,但当距离表面一定深度后,煤体温度与热源距离之间符合指数增长函数分布。由此,本文提出了露天煤垛有源温度场的温度分层模型,将煤垛从表面向内分为受外界环境影响的表层和不受外界影响的内层,表层与内层的交界为边界层。采用经典的表面热平衡方程计算表层至边界层的温度,再由边界层温度与热源距离的指数增长函数计算浅层热源的温度。为储煤场自燃隐患煤垛的温度分析提供了新的途径。本文的研究对于克服传统人工测温的弊端,实现大型储煤场多煤垛在线温度监测,提高储煤场的堆场安全管理水平,保障煤炭输运和存储安全,保护国家煤炭能源安全等具有重要的现实意义和实用价值。更多还原

【Abstract】 Safety supervision of coal storage yard is an important work of the yard management. In present, the yard intelligent automation management focuses on studying of storage supervision of coal stockpiles, establishing safety supervision network. The online temperature monitoring is a key and important problem in safety supervision of coal storage yard. Based on the infared imaging temperature measurement technique, focusd on the temperature monitory of open coal stockpile, the following contents are the major research works in this thesis:Accoring to the analysis of the effective method of temperature measurement and the layout of open coal stockpiles in coal storage yard, an online temperature monitory method of open coal stockpile is proposed. And a temperature monitory system is designed and realized. Two-dimensional turntable is home-made, and tightly fixed upon a high-mast near the monitored coal stockpiles. The horizontal angle of turntable is widely, which guarantees the infrared imager detection around the high-mast in every horizontal angel.The designed online temperature monitoring system is used to automatically and synchronously monitor the surface temperature of one or more coal stockpiles, collect the meteorological data in the time of infrared image acquisition, calculate the atmospheric radiation transmission and the accurate surface temperature.Through the data query functions of database, the open coal stockpile surface temperatures of the same coal in different time or the different coals at the same time can be acquisited and analyzed. According to the comprehensive analysis of temperatures of multi-coal stockpiles, the staff can find the spontaneous combustion coal stockpile and process the dangerous coal stockpile. Through the field test, the proposed temperature monitoring method and designed system can meet the practical requirement.A temperature correction method is proposed for calculating the accurate surface temperature of coal stockpile. The temperature correction algorithm is proposed to reduce the affect of weather condition to temperature measurement accuracy. And the temperature correction algorithms composed of infrared imager spatial effect correction, atmospheric radiation transmission correction, and reflect radiation correction. The surface temperature of the coal stockpile in the infrared image can be acquired by calculated these three correction using parameters such as weather condition, geographic coordinates and infrared imaging acquisition time. Compared to the surface temperature before correcting, the temperature after correcting is basically same as the actual temperature, and the average measurement error is reduced to1%. The experimental results show that the temperature correction method is an effective method to calculate the accurate surface temperature of coal stockpile.In the end, summary of the whole work and the future work are made.In order to investigate the inner temperature distribution law, an experimental coal postion with pre-buried artificial heat source was build. The experimental results shown that, as the the heating time prolonged, the surface temperature of coal location with pre-buried circular heating source increased. And the thermal diffusion area enlarged. The average temperature of coal position with pre-buried artificial heat source increased fastly, then the growth rate slowed down, finally, the temperature achieved stable. And the normal coal postion has the same rising laws.According to the experimental results, an internal heat source monitoring method is proposed. Through continuous monitoring surface temperature of open coal stockpile, and the surface temperature rising rate can be calculated. The degree of spontaneous combustion is decied according to the temperature rising rate of coal stockpile. Once the rising rate exceeds the dangerous degree, the high temperature warning can be reported.Research results shown that the internal temperatures of coal will rise with the increase of the circular heat source heating time. The temperatures of shallow coal diurnal varied with the external environment, and the temperatures of deep level and distance conform to the exponential growth function distribution. According to the experimental results, an internal heat source temperarture stracification model is proposed. The coal stack was divided into inner layer and outer layer according to the temperature influence by external environment. The bounding surface is defined as the junction between inner and outer layer of coal stack. The outer layer is varied with environment, and then the inner layer is relatively stable. 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.In this thesis, a temperature monitoring method of open coal stockpile is proposed, which can overcome the defects of traditional manual temperature and practical apply in coal storage yard. This research is important to improve the safety management level of coal storage yard and protect the coal energy security.更多还原