热电厂雷电灾害案例分析与防护对策

雷电灾害是造成电力供应中断的主要自然灾害之一。通过对某热电厂的一次雷击事故的具体分析,认为一般热电厂的高大烟囱、冷却塔、露天的大型变电设备、金属油罐及管道等构筑物较易遭受直接雷击,而与热电厂连接的多条架空电力电缆更容易将广袤的大地上发生的雷击形成的线路雷击过电压引入厂区电力设施。发电厂担负着为社会提供电力供应的重要任务,因此,应加强对热电厂系统的雷电灾害研究,提出高效合理的防护对策,减少雷击造成的损失,保证电力供应安全。     

通过英特网进行基于虚拟现实的矿山安全模拟培训

良好的人员素质和有效的救护策略是矿山灾害处理过程中最关键的要素。在矿山生产过程中完全避免伤害是很难做到的 ,甚至在救护过程中 ,突发事件也时有发生。应用目前计算机技术及信息网络技术相结合的系统综合手段 ,通过英特网采用基于虚拟现实的方法 ,对矿山人员进行模拟培训具有逼真、有效、经济、快速的特点和重要的实用价值。这种培训方式是减少矿山事故率和死亡率的很好手段 ,并且能使各大矿井之间互相学习 ,扬长避短     

Trace metal element pollution of soil and water resources caused by small-scale metallic ore mining activities: a case study from a sphalerite mine in North China

Trace metal element contamination in mining areas is always a huge environmental challenge for the global mining industry. In this study, an abandoned sphalerite mine near the Yanshan Mountains was selected as subject to evaluate the soil and water contamination caused by small-scale mining. The results show that (1) Pearson correlation matrix and principal component analysis (PCA) results reveal that Zn, Cu, Cd, and Pb were greatly affected by the operation of mines, especially mineral tailings. The contents of trace metal elements decrease with the increase of the distance from the mining area. Zinc, Pb, and Cd were discovered in almost all soil samples, and Zn accounted for about 80% of pollution of the topsoil. (2) The trace element pollution levels in the topsoil of the three villages were ranked as follows: Cd?>?Cu?>?Pb~Zn. The potential ecological risk of farmland around the mine ranges from lower to higher, with Cd being the most harmful. (3) Human health risk assessment results show that trace elements in the mining area pose obvious non-carcinogenic health risks to children while the risks to adults are not equally obvious. The carcinogenic risk of Cd and Cr is within a safe range and does not pose an obvious cancer risk to the population.

     

基于氨逃逸监测的变比值脱硝控制系统研究

针对选择性催化还原脱硝工艺中被普遍关注的脱硝效果、氨水损耗以及系统控制精度等问题,结合氨逃逸监测系统和变比值控制方案,设计了一套新型变参数-变比值脱硝综合控制系统,改进了原有脱硝控制系统中典型的多回路PID控制方案。在分析了传统脱硝工艺以及典型PID控制方案后,研究了氨逃逸监测系统与变比值控制策略相融合的可行性,设计出了控制系统框图,并将设计的方案投入实际工程中,系统运行结果验证了该方案的有效性和经济性。