计算流体动力学在模拟气升式环流反应器中的研究进展

计算流体动力学(CFD)是对气升式环流反应器进行数值模拟的重要手段.为此,本文综述了CFD模拟概况及气升环流反应器中流体数值模拟研究进展,总结了目前CFD模拟气升环流反应器存在的问题,并提出了进一步的研究方向.     

多晶硅切割液废液的回收与利用

结合工程实际,介绍了太阳能产业用多晶硅片切割过程中产生的割液废液的处理工艺及回收工艺,并分析了它的投资成本和经济效益。     

低渗透介质中轻非水相流体迁移转化规律

本文利用COMSOL软件建立轻非水相流体（LNAPL）纵向迁移转化模型,采用有限单元法进行求解,预测污染物分布规律,并利用局部分析法进行参数敏感性分析.结果表明,大部分LNAPL会在水面以上聚集形成高的质量分布峰值区域,少部分克服毛细压力向下迁移,在自由相迁移范围内,其溶解相浓度达到或接近饱和溶解度;当顶部污染源消失后,降水会使最大饱和度和浓度出现的深度逐渐下移;多孔介质中的低渗透镜体会使污染物垂向入渗受阻,在其表面聚积形成污染池;渗透系数是控制LNAPL纵向迁移速度及饱和度分布的关键参数.     

Large eddy simulation of plume dispersion behind an aircraft in the take-off phase

The aim of this paper is to provide an investigation, using large eddy simulation, into plume dispersion behind an aircraft in co-flowing take-off conditions. Validation studies of the computational model were presented by Aloysius and Wrobel (Environ Model Softw 24:929–937, 2009) and a study of the flow and dispersion properties of a double-engine aircraft jet was presented by Aloysius et al. (EEC/SEE/2007/001, EUROCONTROL Experimental Centre, ), in which only the engine was modelled. In this paper, the complete geometry of a Boeing 737 is modelled and investigated. The current work represents a contribution towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations will be useful for future improvements of existing dispersion models.     

三相生物流化床处理含油废水的试验研究

我国油田含油废水利用传统的隔油、混凝、过滤（老三套）处理工艺,出水指标达不到国家的二级排放标准。为提高含油废水处理水平,在“老三套”基础上添加了生物处理部分,即三相生物流化床。为强化生物处理,采取了投加漂浮填料和悬浮填料的强化处理措施,出水能达到国家二级排放标准。     

绿色分离技术-超临界流体萃取的应用

介绍了超临界流体的性质及萃取过程,主要介绍了超临界流体萃取技术在医药、食品、环保及分析领域方面的应用。     

超临界CO2螯合萃取金属离子及其影响因素

介绍了一种新型分离技术－－超临界流体螯合萃取技术,讨论了螯合剂、温度、压力、ＰＨ、基质、修饰剂、被萃元素的存在形态等因素对超临界ＣＯ２螯合萃取的影响。     

CX170-1井钻井废水及废钻井液处理技术

CX170-1井位于川西平原,周围良田环绕。文章就川西地区钻井作业现状提出了比较可行的钻井废水及废钻井液无害化处理工艺技术。针对钻井废水,详细介绍了轻度污染废水;严重污染废水和特殊作业废水的处理工艺及处理效果。对于废钻井液,该井主要采用了固化处理。结果表明:经固化处理的废钻井液干结后具有一定强度,失去了水敏性,不再具有返浆性。浸泡实验表明,有害物得到了比较彻底的固定,经检测,各种污染指标大都低于国家一级标准,自然条件下外排的废钻井液不再对环境造成污染。     

改性PVDF中空纤维膜处理压裂返排液研究

针对中空纤维膜应用于水力压裂返排液处理时存在的膜污染严重、通量衰减快、影响处理效率等问题,研究了PVDF固含量、凝固浴温度等因素对PVDF膜性能的影响,通过非溶剂致相分离法制备了PVDF中空纤维膜,并采用表面接枝技术,对PVDF中空纤维膜进行了表面亲水化改性。压裂返排液吸附实验结果表明,表面接枝降低了PVDF的接触角,提高了膜的亲水性。与未接枝改性的PVDF膜相比,亲水改性后的PVDF膜表面吸附的压裂返排液更少。将亲水性中空纤维膜用于页岩气水力压裂返排液的过滤处理,应用结果表明其对压裂返排液中的总铁、SS、浊度、细菌去除率达到90%以上,长时间运行后的通量保持率高,有较好的抗膜污染性。     

Optimization of gas detector placement considering scenario probability and detector reliability in oil refinery installation

Gas detection system is a critical layer of protection in process safety. Leak scenario probability and detector reliability are two key factors in the optimization of gas detector placement. However, they are easily neglected in previous studies, which may lead to an inaccurate evaluation of the optimization solutions. In this study, a stochastic programming (SP) optimization method is proposed considering these two factors. In order to quantitatively represent the probability of leak scenarios, a complete accident scenario set (CASS) is built combining leak sources and wind fields. Then, the computational fluid dynamics (CFD) method is adopted for consequence modeling of gas dispersion. The Markov model is developed to predict the detector reliability. With the objective of minimal cumulative detection time (MCDT), the SP formulation considering scenario probability and detector reliability (MCDT-SPR) is proposed. By introducing the particle swarm optimization (PSO) algorithm, the optimization formulations can be solved. A case study is investigated on a diesel hydrogenation refining unit. Results validate this approach is promising to improve the detection efficiency. This method is more practical and matching with the actual industrial environment, where the leak scenarios and the detector reliability can change dynamically in real process setting.