Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

Automated System for Controlling the Operation of the Shaking Elements of Electrodes in Combination with Dry Removal of Ash from Electric Filter Hopper

An automated system for controlling the operation of shaking elements of electrodes (aeroridges) is suggested, which cleans the electrodes of the electric filter synchronously with the system of pneumatic removal of ash. Relationships for calculating the design parameters of the system depending on the modes of pneumatic transportation and dependences of the parameters of the fluidized layer of the removed ash on the structural variants of aeroridges are presented.     

气力输灰及粉煤灰综合利用方案探讨

研究了国内外电厂干式除灰技术和粉煤灰综合利用的现状,结合华电能源牡丹江第二发电厂的实际,对#7炉电除尘器气力输灰方案进行了探讨,对粉煤灰综合利用及经济效益进行了分析,指出了气力输灰系统应注意的一些问题。     

基于稳定输送流场的正压浓相气力输灰系统研究及应用

分析了大型火电机组气力输灰系统高能耗、输灰管道磨损严重的原因,根据气一固两相流的流动特性与其稳定输送流场的关系,设计了新型多泵制正压浓相型气力输灰系统。对该系统在600MW机组上进行了试验研究,试验结果表明,该系统可节能降耗并减少管道的磨损。     

锅炉气力输灰系统堵管原因及预防措施

以周口隆达发电公司浓相气力输灰系统为例，针对出现输灰系统的耗气量降低的问题提出了气力输灰系统的改进和优化方法，分析了在运行过程中发生堵管的原因并提出预防措施及处理方法；     

气动浮体坝在河道整治中的应用研究

为解决拦河建坝造成的水位壅高与泥沙淤积问题，笔者在万载县布城水水系连通及水环境综合整治工程中采用了气动浮体坝。本文介绍了气动浮体坝的工作原理，并从启闭方式、工程运行、后期运维、工程投资等方面与卧倒式升降坝方案进行了比选。结果表明：气动浮体坝利用浮力启闭，更符合生态治河、低碳治河的理念；坝体运行方便，通过排气即可全部卧倒，对行洪安全基本没有影响，避免了泥沙淤积造成的后期运行管护难题，是河道生态整治中低水头壅水建筑物的可选方案。     

某灰渣库渗漏原因分析及除险加固 渗控措施研究

基于有限元求解渗流场的基本原理,建立了某灰渣库三维渗流场的计算模型,计算分析了原设计方案下的渗流场,论证了左右坝肩异常渗漏的原因,给出了除险加固的渗控设计方案。在此基础上分析了除险加固后以及二次加高后的渗流场分布特征。计算结果和除险加固的运行结果表明,给出的除险加固防渗设计方案正确合理,可供类似的工程除险加固设计及运行管理参考     

闸坝调控下重污染河流污染物迁移规律研究

以沙颍河槐店闸为研究对象,构建了闸坝调控作用下二维水动力-污染物迁移模型,根据试验获取的数据对模型进行率定和检验。结果表明:闸坝的存在对河流水环境系统具有一定负面影响,但是合理的闸坝调控能够改善河流水质,减小突发性水污染事故发生的概率;该模型可以有效地模拟计算闸坝调控作用下污染物的迁移过程。     

Formation of mineral deposits in hydraulic ash removal systems

Selection of design schemes for the water supply (straight through, or circulating) of hydraulic ash-removal (HAR) systems for thermal electric power plants (TPP) is examined as a function of the character of mineralization of the water in a specific system. Causes are outlined for the formation of mineral deposits on equipment of the HAR system, which transports ash slurries of different types of solid fuels. The cause of the high rate of seasonal growth formation in the circulating HAR systems of TPP burning fuel with highly alkaline ash slurries is established experimentally in an example of a shale electric power plant. Measures are developed for rapid slow-down of the rate of growth formation in these systems. Measures are proposed for prevention of growth formation for other types of ash slurries. __________ Translated from élektricheskie Stantsii, No. 5, pp. 41–47, May, 2006.     

低热水泥胶凝体系水化热计算研究

为了评价几种传统水化热计算方法对低热水泥的适用性,进而提出低热水泥胶凝体系水化热的计算公式,采用直接法测定了不同掺量粉煤灰、矿渣条件下的低热水泥胶凝体系7 d水化热,对比应用矿物成分法、折算公式法、数值拟合法算得相应结果,调整各模型参数并对其计算精度进行评价分析。研究结果表明:矿物成分法仅能计算特征龄期下水泥水化热,算得结果与试验数值差距较大;折算公式法用于计算单一掺合料下胶凝材料7 d水化热时所得结果准确度较高;数值拟合法适用于单掺、复掺不同掺量矿物掺合料的低热水泥胶凝体系,该体系下粉煤灰、矿渣的最终水化热分别为126.6 J/g和172.4 J/g。研究成果可为大体积混凝土的绝热温升计算提供基础数据参考。     

静态应变测试系统在向家坝水电站地弄荷载试验中的应用

采用应变片法现场测试结构实际承载能力在工程上已得到广泛的应用.文中通过静态应变测试系统配合沉降观测、挠度观测介绍了向家坝地弄荷载试验情况和最后成果,为向家坝料场堆场地弄的安全运行提供了可靠依据.     

气力提升系统管道压力实验研究

在实际应用中,受环境作业影响,气力提升不可避免地采用弯曲管道。有鉴于此,该文采用数据采集测试系统通过压力传感器对三种不同提升管内压力进行实验研究,探讨其局部弯曲位置对气力提升性能的影响,分析管内的压力波动特征,进而阐明其中流型的变化机理及规律。实验结果表明:气力提升性能受运行参数和结构参数的影响显著;管内压力时域图因气流量和淹没率变化而显著改变,在弹状流时呈现明显的低频、大幅振荡特征;且存在压力变化转折点;由时域图和压力分析可知管内流型发生两次转变;C型提升系统率先进入弹状流,故管道局部弯曲位置应在进气口之下为宜。     

基于BIM的轨道交通项目管理框架体系研究与实践

传统的地铁工程建设过程中,往往会存在信息丢失、专业繁多、沟通困难、生产效率低下等问题,不仅严重影响了工程的建设进度,也给后期的地铁运维管理带来了极大困难。而BIM技术的物联网、大数据等信息化手段的应用,正成为解决这一问题的有效途径。针对武汉市轨道交通建设,以三阳路越江隧道BIM应用为例,通过市场调研、数据分析、系统开发等,研究了轨道交通项目的BIM项目管理框架体系,分层分专业建立了颗粒度高、精细化程度高、现场匹配度高的BIM模型,以满足三维可视化运维管理需求。结合全系统的综合感知能力,建立了各运维管理模块间的逻辑关联,开发了基于BIM的智能运维监测管理平台,实现对设备设施运行状态的三维智能监测展示。研究结果为武汉市轨道交通工程BIM技术的规范化应用奠定了基础,最终在创建的多方协同管理平台上,实现了项目三维可视化的全生命周期过程管理,有效提升了整个工程的项目管理水平。     

关于南方燃煤电厂干贮灰场运行管理的探讨

燃煤电厂的灰渣在没有完全综合利用的情况下,需要对其进行合理堆放,加强运行维护管理,文章从技术、管理、环境保护、观测项目等四方面对干贮灰场的运行管理进行讨论。     

内含氧化镁水泥混凝土自生体积变形问题探讨

 根据室内混凝土自生体积变形试验结果,归纳了内含氧化镁水泥混凝土自生体积变化规律。内含氧化镁水泥混凝土自生体积变形与配合比参数有关,较大水胶比有利于氧化镁的较快水化,粉煤灰对混凝土变形有抑制作用,内含氧化镁水泥适用于强度等级较低的重力坝混凝土。高强度等级混凝土可采用低氧化镁水泥外掺轻烧氧化镁来改善补偿收缩性能。当氧化镁含量在4%左右时,混凝土自生体积变形在2 a左右即趋于稳定,不会影响结构的安全性。     

Effects of pulsed flows on nuisance periphyton growths in rivers: a mesocosm study

Rivers regulated by dams are typically characterized by altered biotic communities and habitat structure in downstream reaches. In the Jackson River (Alleghany Co., VA), a relatively constant flow regime below Gathright Dam and anthropogenic nutrient loading have apparently contributed to nuisance levels of periphyton (>300 mg chlorophyll a m^?2). These nuisance growths cause low dissolved oxygen concentrations in the water column and altered benthic habitats in the Jackson River. The use of periodic pulsed flows has been suggested as a restoration practice that could potentially reduce periphyton biomass. We investigated the effects of increased flow on periphyton chlorophyll a (chl a), ash‐free dry mass (AFDM), % organic matter (%OM) using streamside channels in which periphyton‐colonized tiles were subjected to near‐bed velocities ranging from 20 (control) to 240 cm s^?1. Analysis of variance (ANOVA) and regression were used to examine periphyton responses to velocity treatments. There was a significant decrease in chl a and AFDM, and significant increase in %OM in velocity treatments of 150, 180 and 240 cm s^?1 (p < 0.001), but not in lower velocity channels. Regression analyses showed a significant positive relationship with %OM (r² = 0.88) and significant negative relationship with chl a (r² = 0.77) and AFDM (r² = 0.63). Algal taxa were dominated by Cladophora glomerata, Melosira varians and Pleurosira laevis. There was a significant positive relationship between treatment velocity and % C. glomerata (p = 0.007, r² = 0.87) as diatoms were differentially removed with increasing treatment velocity. Our results demonstrate that pulsed flows can reduce periphyton standing crops in the Jackson River, but the discharge required to achieve this reduction would probably need to produce near‐bed velocities >100 cm s^?1. Further study is needed to establish specific flow targets and evaluate the direct and indirect effects of pulsed flows on ecological conditions in the Jackson River. Copyright © 2009 John Wiley & Sons, Ltd.     

Slagging properties of coals and allowance for them in the analysis of the possibility of using out-of-design fuel

It is shown that out-of-design coal should be used only after computational analysis of slagging of the boiler. The use of ash fusibility as a criterion for the analysis should be avoided because this property does not reflect the slagging properties of coal to an acceptable degree. Parameters characterizing the properties more appropriately are presented. It is shown that slagging of an actual furnace depends on many factors and the condition that “the thermal stresses should be lower than the limiting value” is insufficient. An algorithm for the analysis is suggested on the basis of the slagging conditions arising upon transition from one kind of fuel to another with allowance for the actual slagging situation. __________ Translated from élektricheskie Stantsii, No. 3, March 2006, pp. 18–23.     

东坪水电站粉煤灰混凝土的抗渗性试验与应用

本试验采用添加粉煤灰和膨胀剂的双掺技术制备抗渗混凝土，试验中并分析了粉煤灰的性能，比较了不同掺量的粉煤灰对混凝土抗渗性能的影响。试验结果表明，普通硅酸盐水泥掺用膨胀剂和粉煤灰配制的混凝土其抗渗性能提高，且操作简易、施工方便、成本经济，具有较高的经济效益和环保效益，在工程施工应用中取得了较好的效果。     

Vergleich von Verfahren zur Rückgewinnung von Phosphor aus Abwasser und Klärschlamm

Phosphorus (P) is a vital but limited resource. Though Austria has no P deposits, municipal wastewater offers a potential but largely overlooked source of phosphorus. Over the last several years, numerous technologies have been developed for recovering P from various streams at a wastewater treatment plant. This work uses an approach developed by the authors to assess these technologies on the basis of technical, ecological and economic criteria, providing a basis that legislators and political decision-makers can orient a future, optimized P management system on. The study shows that e.g. technologies for recovering P from process water are already available, and that under the right circumstances they can be used to affordably deliver a high-purity, plant-available end product; however, the potential for P recovery is relatively low. In order to arrive at maximal utilization of the phosphorus from wastewater, the future focus should be on recovery from sewage sludge ash. In this regard, mixing with low-phosphorus ash should be avoided. At this time, however, the necessary structures like e.g. monoincineration plants still need to be expanded. Which technology/ technologies will ultimately be used for the treatment of sewage sludge ash depends e.g. on considerations of affordability, heavy metal elimination, and the plant-availability of the P recovered. The advantages of a strategy based on “monocombustion” of sewage sludge are on the one hand the option of using further P-rich material flows (e.g. meat and bone meal) and on the other, the freedom to store the ash for future recovery (creating an Austrian “phosphate mine”).     

气力提升管内气泡形变的实验研究

气泡的形变作为气力提升装置的主要影响因素,其形变规律直接影响气力提升装置的提升性能。为此,该文中运用高速摄像仪拍摄了气液两相流流场结构,基于图像处理获取了气泡运动过程中的形状参数,通过气泡匹配技术得到了气泡的运动速度。实验结果表明,改变运行参数会引起气泡碰撞和融合发生机率的变化,进而影响到气泡初始生成体积;气泡运动速度的周期性变化会改变气泡的直径和变形,进而改变管内流型,最终导致气力提升装置的提升性能发生变化。