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供水管网优化调度的目标是运用数据采集、优化决策支持和调度执行等信息化技术,安全可靠地将符合流量、压力和水质要求的水供应给用户.供水管网优化调度决策支持系统包括供水系统的模拟、用水量预测、优化调度决策和运行状态评估.该决策支持系统包括宏观水力模型、微观水力模型、水质模型、考虑供水经济性和水质安全性的多目标优化决策模型.采用单目标优化决策模型与多目标评估体系相结合的方法来考虑供水经济性和水质安全性,开发了供水管网优化调度决策系统,并进行了实践应用. 相似文献
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城市供水管网管理中GIS技术应用是借助地理信息系统技术,收集和整理供水管网的相关信息,对其存储、处理和分析,并建立有效的数据管理系统,通过GIS的空间分析、模型分析,为管网规划设计、建设施工、各种运行状态下的优化调度以及事故抢修提供决策依据,使管理更加科学规范。 相似文献
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当供水管网中发生启停泵、快速关阀等事件时,延时时段模拟(即准稳态模型)不能准确预测系统的瞬时动态变化,而需要采用更为准确复杂的瞬变流动态模型。为明确多种动态模型之间的差异,探讨和分析了供水管网动态模型的分类、模型理论以及在管网运行管理中的应用。结果表明,准稳态模型适用于水力状态缓慢变化的情况;弹性水锤模型可准确模拟系统的瞬时动态特性,包括流体惯性和系统弹性(即流体可压缩性和管壁弹性);刚性水柱模型只考虑了流体的惯性作用,可作为前两者的过渡。在实际应用中,3种动态模型应结合水力状态变化情况和模拟准确性需求合理选用,为供水管网系统提供更精细的运行管理方式。 相似文献
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针对我国目前供水管网管理自动化水平较低的现状,提出以管网SCADA系统为切入点,运用Delphi7可视化开发工具,建立供水管网模拟与综合管理系统。在介绍了国内外相关软件开发现状的基础上,对系统进行了整体的结构设计,并阐述了主要功能的开发过程。该系统不仅能够进行管网的建模、优化设计和信息管理,而且能够在实时模拟管网运行状态的基础上,对爆管等突发性事故进行检测与判别,为管网的优化调度及应急处理提供决策帮助。 相似文献
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介绍了供水管网的微观模型和常用的宏观模型,并分析了各模型的优缺点及其适用范围.最后,以西安市供水管网的宏观模型建立为例,验证了供水管网数学模型仿真的实用性. 相似文献
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根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。 相似文献
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The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects. 相似文献
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In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment. 相似文献
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V. K. Konovalov O. V. Yashkin V. V. Ermakov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(2):105-109
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.
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Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008). 相似文献
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Peter B. Bayley 《河流研究与利用》1991,6(2):75-86
The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed. 相似文献
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简述天湖水电站投运以来各种故障的表现形式,分析其原因,提出了相应的处理方法及措施,并对合理利用国内外设备提出建议。 相似文献