Transformation of mercury speciation through the SCR system in power plants

Coal-fired utility boilers are now identified as the largest source of mercury in the United States. There is speculation that the installation of selective catalytic reduction （SCR） system for reduction of NOx can also prompt the oxidation and removal of mercury. In this paper, tests at six full-scale power plants with similar type of the SCR systems are conducted to investigate the effect of the SCR on the transformation of mercury speciation. The results show that the SCR system can achieve more than 70%-80% oxidation of elemental mercury and enhance the mercury removal ability in these units. The oxidation of elemental mercury in the SCR system strongly depends on the coal properties and the operation conditions of the SCR systems. The content of chloride in the coal is the key factor for the oxidization process and the maximum oxidation of elemental mercury is found when chloride content changes from 400 to 600 ppm. The sulfur content is no significant impact on oxidation of elemental mercury.     

16000m~3/h制氧机组噪声治理

制氧机组均有各种类型的空压机、氧压机、氮压机以及透平膨胀机、气体输送管道等高噪声设备,声源多、声级高、分布面广,屏蔽效应复杂,对噪声源强的全面、准确分析以及针对性的隔声、消声、吸声等降噪措施,是治理制氧机组噪声的成功经验。     

有机高分子絮凝剂溶解装置设计及其应用

针对具有高效絮凝性能的有机高分子絮凝剂存在易吸潮、难溶解的不足 ,设计了一种高分子有机絮凝剂的溶解输送装置 ,该装置简单实用 ,易于在污水处理生产中推广应用。将该溶解装置用于炼油污水气浮处理的有机絮凝剂溶解 ,取得良好的效果     

炼油污泥的热化学清洗处理

以广西省某炼化企业污水处理系统的炼油污泥为研究对象,采用热化学法对其进行清洗处理。对比了含油率的测定方法,对8种药剂进行筛选和复配,同时通过正交实验确定清洗工艺参数,并对重金属污染物进行分析。实验结果表明:8种药剂中Na2Si O3的清洗效果最好,而复配药剂(Na OH与Na2Si O3的质量比为1∶5)的清洗效果优于单一Na2Si O3;在清洗温度70℃、搅拌转速350 r/min、搅拌时间30 min、复配药剂质量分数5.0%、液固比3∶1的最佳工艺参数下,单级洗油率为63.6%,三级洗油率为69.4%、残油率为15.6%;清洗前后炼油污泥中Zn,Mn,Cu,Cr等重金属含量均超过GB 15618—1995《土壤环境质量标准》三级标准限值。     

Fault diagnosis of pipeline and pump unit systems using status coupling analysis

Earlier studies on fault diagnosis of the pipeline and pump unit systems (PPU) relied mainly on independent equipment analyses, which usually lead to false alarms because of the loss of information fusion. The aim of this study is to utilize the status coupling relationship to improve fault detection sensitivity and reduce false alarm rate. A real-time status identification of related equipment step is added between capturing abnormal signals and listing out diagnosis results. For example, when the pipeline pressure fluctuation is found abnormal, a status analysis of pump units is performed immediately, if the pump units are proven to be operational normally, then the pipeline leak alarm is acknowledged valid. The logical reasoning algorithm is used to capture abnormal conditions of pipeline pressures. The pump unit faults are captured by combining information from multiple sources. Field applications show that the proposed method significantly improves the PPU fault detection capability on fault detection sensitive and accuracy.     

水解酸化-好氧生物滤池处理炼油废水

以高炉水渣为填料,采用水解酸化-好氧生物滤池处理炼油废水。考察了好氧区气水比、水力停留时间对炼油废水处理效果的影响。实验结果表明：在水力停留时间为6h、温度为20～35℃、废水pH为6～9、好氧区气水比为10：1的条件下,该生物滤池对NH3-N,Ar-OH,COD的总去除率分别为100％,97％,85％,处理后出水水质达到国家《污水综合排放标准》一级标准。     

臭氧/紫外光法处理炼油厂汽提污水的静态实验

用O3／UV法对炼油厂汽提污水中高浓度的COD、Oil、Ar-OH、S^2-进行降解研究,通过控制O3浓度、反应时间,可使各污染物降解达到较高的去除率。近一年的实验表明,与单独用O3法相比,UV使COD、Oil、Ar-OH的降解率,平均分别提高了16％、18％、26％。同时用GX-94测爆仪对反应过程中的尾气进行检测分析,表明O3／UV使废水中各污染物的降解过程是,S^2-类污染物最先被O3／UV氧化降解,其次是含C类有机物的氧化降解,降解的终产物是CO、小分子CH类物质等。本方法也使原废水的可生化性得到显著提高。     

煤油厂外排废水回用于循环水

针对炼油厂外排废水回用时存在的结垢和腐蚀问题,讨论了结垢和阻垢机理,详细介绍了水中Ca2+浓度、碱度、总溶固、悬浮物、浓缩系数五项因素对结垢的影响,并通过实验筛选出5种阻垢剂。其中Rp-88、BC-501阻垢率均在90%以上,与国外同类药剂性能相当。     

MACROSCALE HYDROLOGIC MODELING FOR REGIONAL CLIMATE ASSESSMENT STUDIES IN THE SOUTHEASTERN UMTED STATES1

ABSTRACT: A macroscale hydrologic model is developed for regional climate assessment studies under way in the southeastern United States. The hydrologic modeling strategy is developed to optimize spatial representation of basin characteristics while maximizing computational efficiency. The model employs the “grouped response unit” methodology, which follows the natural drainage pattern of the area. First order streams are delineated and their surface characteristics are tested so that areas with statistically similar characteristics can be combined into larger computational zones for modeling purposes. Hydrologic response units (HRU) are identified within the modeling units and a simple three‐layer water balance model, Soil and Water Assessment Tool (SWAT), is executed for each HRU. The runoff values are then convoluted using a triangular unit hydrograph and routed by Muskingum‐Cunge method. The methodology is shown to produce accurate results relative to other studies, when compared to observations. The model is used to evaluate the potential error in hydrologic assessments when using GCM predictions as climatic input in a rainfall‐runoff dominated environment. In such areas, the results from this study, although limited in temporal and spatial scope, appear to imply that use of GCM climate predictions in short term quantitative analyses studies in rainfall‐runoff dominated environments should proceed with caution.     

Parallel agent-based modeling of spatial opinion diffusion accelerated using graphics processing units

In this article, we describe a parallel agent-based model of spatial opinion diffusion that is driven by graphics processing units (GPUs). Modeling opinion exchange and diffusion across landscapes often involves the simulation of large numbers of geographically located individual decision-makers and a massive number of individual-level interactions. This simulation requires substantial computational power. GPU-enabled computing resources provide a massively parallel processing platform based on a fine-grained shared memory paradigm. This massively parallel processing platform holds considerable promise for meeting the computing requirement of agent-based models of spatial problems. In this article, we focus on the parallelization of an agent-based spatial opinion model using GPU technologies. We discussed key algorithms designed for parallel agent-based opinion modeling: including domain decomposition and mutual exclusion. Experiments conducted to examine computing performance show that GPUs provide a computationally efficient alternative to traditional parallel computing architectures and substantially accelerate agent-based models of large-scale opinion exchange among individual decision makers.