乌兰察布低射气地区及气化区氡浓度分布的多重分形特征研究

发布时间：2018-02-13 05:08

本文关键词： 煤炭地下气化活性炭测氡多重分形时间序列相关性　出处：《太原理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：煤炭地下气化(UCG)是综合性的能源生产技术，可将赋存的不可采和不经济煤炭资源气化成煤气（CH4、CO等），输送到地面供生产生活使用。随着我国能源结构的变化，煤炭地下气化相对以往煤炭开采利用方式在环境效益、资源充分利用率、企业经济效益、施工人员安全性等方面优势明显。目前我国地下气化历经30多年发展，已经逐步由实验室研究朝着工业生产应用方向发展，然而相对于地面煤气化过程，地下煤气化过程中诸多变量的控制和地下炉燃烧状态的监测难以达到有效控制程度。本文以新奥气化采煤技术有限公司申报的国家“863”计划重大研究课题子课题“气化工作面的综合探测技术”为基础，在煤炭气化试验区应用放射性测氡法监测煤炭地下气化过程中的燃烧状态。运用多重分形理论方法对气化试验区氡浓度从时间序列上分析研究了其分布的多重分形特征，研究表明气化区氡浓度分布具有明显的多重分形特征，多重分形参数与气化区温度呈反相关的关系。地表浅部氡浓度随外界因素（气压、气温、湿度）变化而改变，而地表介质种类的不同也是影响氡浓度分布变化的因素，在此基础上在乌兰察布自然状态下的试验区上开展了不同介质不同深度氡浓度分布的多重分形特征研究，从多重分形角度给出了土壤区和玄武岩区活性炭测氡的最佳取样深度，研究表明不同介质的氡浓度分布具有明显的多重分形特征，土壤区和玄武岩区多重分形谱宽度α变化不大，由曲线谱宽度α与曲线α对称可知，，两种介质浅部30cm~40cm深度对称性较好，土壤区以40cm氡浓度的对称性最好，氡浓度分布相对稳定；玄武岩区30cm氡浓度对称性最好，氡浓度分布相对稳定。从多重分形特征上来看，在玄武岩区和土壤区野外测氡时吸附装置的理想埋深深度应在30cm~40cm之间，其中土壤区以40cm效果最佳，而玄武岩区以30cm深度较好。在确定合理取样深度基础上，野外开展工作时，可以科学合理指导野外实地工作。运用多重分形方法研究乌兰察布低射气地区及气化区氡浓度分布的多重分形特征，可以在实际工作时确定合理的取样深度，为气化区燃烧状态的监测提供一种全新的方法。
[Abstract]:The underground coal gasification (UCGG) is a comprehensive energy production technology, which can gasify the unrecoverable and uneconomical coal resources into coal gas, Ch _ 4CO, etc., which can be transported to the ground for production and daily use. With the change of energy structure in China, The underground gasification of coal has obvious advantages in the aspects of environmental benefit, full utilization of resources, economic benefit of enterprises and safety of construction personnel compared with the previous ways of coal mining and utilization. At present, underground gasification in China has been developing for more than 30 years. It has been gradually developed from laboratory research to industrial application. However, compared with the surface coal gasification process, the control of many variables in underground coal gasification process and the monitoring of combustion state in underground coal gasification process are difficult to achieve effective control level. This paper is based on the national "863" project, "Comprehensive Detection Technology of Gasification face", which has been declared by Xinao Gasification Coal Mining Technology Co., Ltd. In the coal gasification test area, the radioactivity radon method is used to monitor the combustion state in the coal underground gasification process. The multifractal distribution of radon concentration in the coal gasification test area is analyzed from the time series by using the multifractal theory. The results show that the radon concentration distribution in gasified area has obvious multifractal characteristics, and the multifractal parameters are inversely correlated with the temperature of gasification area. The concentration of radon changes with the change of external factors (air pressure, air temperature, humidity), and the variety of surface media is also the factor that affects the distribution of radon concentration. On the basis of this, the multifractal characteristics of radon concentration distribution in different media and different depth are studied in the experimental area under the natural condition of Wulanchabu. The optimum sampling depth of radon measurement by activated carbon in soil area and basalt area is given from the point of view of multifractal. The results show that the distribution of radon concentration in different media has obvious multifractal characteristics, and the multifractal spectrum width 伪 in soil and basalt areas has little change. The depth symmetry of the two media is good, the symmetry of radon concentration is the best in the soil area, the distribution of radon concentration is relatively stable, the symmetry of radon concentration is the best in the basalt area, and the radon concentration distribution is relatively stable in the basalt area. The ideal depth of the adsorption device for radon measurement in basalt and soil areas should be between 30 cm and 40 cm, of which 40cm in soil area is the best, and 30cm depth in basalt area is better. On the basis of determining reasonable sampling depth, the optimum depth for field work is 40 cm. The field work can be guided scientifically and reasonably. The multifractal method is used to study the multifractal characteristics of radon concentration distribution in low emission gas area and gasification area of Wulanchabu. The reasonable sampling depth can be determined in practical work, which provides a new method for monitoring combustion state in gasification area.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD84;P631.6

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