电厂烟气脱硫机组改造取消GGH可行性研究分析

介绍了石灰石一石膏湿法烟气脱硫工艺及烟气换热器（简称GGH）在烟气脱硫（简称FGD）工程中的作用,指出安装GGH产生的烟囱腐蚀和增加系统故障等问题。实践证明烟气脱硫工程取消GGH对大气环境无明显影响,并且能产生较大的经济效益。     

煤矿矿井水中SO4^2-的去除方法研究

制备了高效SO4^2-吸附剂,用其对某煤矿矿井水进行了试验,对影响吸附剂吸附效率的各因素进行了研究,结果表明：吸附剂用量1.0 g/L时,去除率达到最高,为93.5%。溶液在酸性范围内吸附剂对SO42-去除率明显大于碱性范围。随着SO4^2-浓度的增加,吸附剂的去除率逐渐降低。试验水温选择为25℃,最佳吸附时间为40 m in,最佳pH为7.0。     

An integrated assessment method of urban drainage system:A case study in Shenzhen City,China

In recent years, the urban drainage system in China is facing the dual pressure of renovation and construction. This requires that the integrated assessment for the planning and operation of the urban drainage system is obligatory. To evaluate the urban drainage system, an integrated assessment methodology based on the analytic hierarchy process (AHP), integrated simulation, and fuzzy assessment is established. This method is a multi-criteria decision adding app roach to the assessment of the urban drainage system comprehensively. Through the integration of the Storm Water Management Model (SWMM), a simple wastewater treatment plant model, and a surface water quality model, an integrated modelling system for the urban drainage system is developed and applied as a key tool for assessment. Using the established method, a case study in Shenzhen City has been implemented to evaluate and compare two urban drainage system reno vation plans, the distributed plan and the centralized plan. Because of the particularity of this case study, the established method is not applied entirely. Considering the water environ mental impact, ecological impact, technological feasibility, and economic cost, the integrated performance of the distri buted plan is better. As shown in this case study, the proposed method is found to be both effective and practical.     

北京燕山石化废水排放特征研究

在调查燕山石化废水排放现状的基础上,采用等标污染负荷法对污染物进行评价.结果表明,燕山石化废水污染物浓度较低,基本可实现达标排放;废水主要污染源是辅助装置及生活污水,废水及污染物排放量最大的是化工一厂和炼油厂;主要污染物外排口是东沙河外排口;首要控制的污染物为COD,与国家“十一五”总量控制指标相同.     

Effects of significant damage of flame gap surfaces in flameproof electrical apparatus on flame gap efficiency

Electrical apparatus for use in the presence of explosive gas atmospheres has to be specially designed to prevent the apparatus from igniting the gas. Flameproof design is one of several options, and one requirement is then that any holes and slits in the enclosure wall be designed to prevent a possible gas explosion inside the enclosure from being transmitted to an explosive gas cloud outside it. Current standards (IEC) require that joint surfaces have a surface roughness of <6.3 μm. Any damaged joint surface has be restored to this quality. The present investigation has demonstrated that flame gap surfaces in flameproof electrical apparatuses can suffer considerable mechanical and corrosive damage before the flame gaps no longer function satisfactorily. In some cases very significant mechanical surface damage in fact improves the gap performance. This indicates that current high costs of repairing and replacing flameproof electrical apparatus in process plants offshore and onshore can be reduced considerably without any increase of the explosion risk.     

中国典型流域有机磷酸酯的污染特征与风险评估

有机磷酸酯（OPEs）作为溴代阻燃剂的替代品,在生产生活中被广泛使用,其环境污染和毒性效应受到广泛关注.梳理中国七大典型流域水体中OPEs的含量水平和分布特征,计算中国成人、青少年和儿童的OPEs日均饮水暴露量,对其健康风险进行评估,并通过蒙特卡洛模拟方法评价了结果的可靠性.检索整理了12种OPEs对水生生物的毒性效应浓度,构建物种敏感度分布（SSD）曲线,对生态风险进行评估.结果表明,低等暴露水平下,七大流域ΣOPEs的第5百分位浓度为52.61 ng·L^-1;中等暴露水平下,七大流域ΣOPEs的中位浓度为499.74 ng·L^-1,磷酸三氯乙酯（TCEP）、磷酸三乙酯（TEP）和磷酸三（1,3-二氯-2-丙基）酯（TDCP）为主要污染物;高等暴露水平下,七大流域ΣOPEs的第95百分位浓度为1904.4 ng·L^-1,是其中等暴露水平的3.8倍,长江流域的ΣOPEs浓度最高.健康风险评估表明,不同人群通过饮用水暴露于OPEs的非致癌风险均在可接受范围内.磷酸三甲酯（TMP）、磷酸三异丁酯（TiBP）和TCEP是致癌风险的主要贡献者.生态风险评估结果表明,TCEP在高等暴露水平下存在中等生态风险;磷酸三正丁酯（TnBP）在中等暴露水平下存在中等生态风险,在高等暴露水平下,有较高生态风险;磷酸三苯酯（TPhP）在低中高3种暴露水平下的风险商均大于1,有较高生态风险,需要重点关注.     

毛细管柱气相色谱法测定环境空气中1,2-二氯乙烷

采用毛细管柱气相色谱法测定环境空气中的1,2-二氯乙烷,用活性碳吸附,二硫化碳解析,FID检测器分析.方法在0 mg/L～311mg/L范围内线性良好,当采样体积为20 L时,最低检出质量浓度为0.006 mg/m3,标准溶液平行测定的RSD≤2.2%,加标回收率为98.4%～101%.     

基于Adam优化深度神经网络快速确定瓦斯抽采半径*

为解决煤矿瓦斯有效抽采半径难以快速准确确定的问题,采用基于Adam算法优化DNN（深度神经网络）方法来预测瓦斯抽采半径。查阅文献共收集已得到验证的970组数据集,每组数据选取煤层瓦斯初始渗透率、钻孔直径、抽采时间、地应力、煤层初始瓦斯压力作为预测模型的5个特征量,有效抽采半径作为目标输出值。接着预测模型进行不断学习和训练,最终训练得到1个最优的瓦斯有效抽采半径预测模型。利用训练好的最优预测模型结合Python语言开发出计算有效抽采半径的软件,并使用该软件在四季春煤矿和鹤煤六矿进行有效抽采半径预测的工程实例研究,验证该软件预测抽采半径的实用性和准确性。研究结果表明:通过使用开发的软件,可快速且较准确地计算出矿井瓦斯有效抽采半径,可为暂不具备现场测试条件的矿井抽采设计提供一定的参考依据。     

A study on the obstacle-induced variation of the gas explosion characteristics

A study on the variation of the gas explosion characteristics caused by the built-in obstacles was conducted in enclosed/vented gas explosion vessels. It has been well known that the obstacles in pipes and long ducts would accelerate the flame propagation, and cause the transition from deflagration to detonation. In this study, the explosion characteristics and the flame behavior of vented explosions and constant-volume explosions were investigated. Experiments were carried out in a 270-liter and 36-liter hexahedron vessels filled with LPG–air mixture. The explosion characteristics of the gas mixture were determined by using a strain-responding pressure transducer. The flame behavior was recorded by using a high-speed video camera. The shape and the size of the obstacle, and the gas concentration, were adjusted in the experiments.

It can be seen from the experimental results that, instead of being accelerated, the flame propagation inside the explosion vessel is decelerated by the plate obstacles fixed at the bottom of the vessel. Also, the characteristics of the enclosed explosion are not so affected by the built-in obstacles as those of the vented explosion are. It is believed that the eddy-induced turbulence behind the obstacle decelerates the flame propagation.