并联水库群共同供水任务分配规则研究

对于并联供水水库群,通过共同用户相互联系,不仅要参照每个成员水库的状态特征确定供水决策,还要根据每个成员水库的状态特征合理分配共同供水任务。针对跨流域水库群共同供水任务的分配问题,为制定科学、有效合理、均衡公平的共同供水任务的水库间分配规则,寻求并联水库群共同调度规则的最优性运行策略,通过拟定合理的平衡曲线的方式,确定并联水库群共同供水任务的分配比例,指示各库在不同调度时段的蓄水最佳分配策略,并以不同拐点和斜率描述平衡曲线的分段性,表征汛期、非汛期各水库蓄水量及供水量的变化,以缺水率最小及弃水量最小为目标函数建立优化模型对分配规则进行修正,最后采用基于免疫进化的粒子群算法率定平衡曲线的决策变量突变点及斜率,最终得到相对优秀的供水规则。以滦河流域下游水库群为研究对象,结果表明,该方法能有效地实现调度目标,合理划分共同供水任务,提高水库群共同供水任务的计算效率;拟定合理平衡曲线对并联水库群共同供水任务进行分配,其库群系统供水量较补偿调节增加约5%,弃水量减少10%左右,与动态规划得到的最大供水量、年均弃水量及保证率接近,水库间供水任务分配比例与其兴利库容的比值接近,并且成员水库有较大的供水能力和较高的成员水库蓄水率同步性,在一定程度上反应平衡曲线的合理性及优越性。

黄河可供水量分配方案的制度评价

流域水量不同分配模式对相关利益群体的损益影响较大,因此在制度设计中必须考虑流域各省(区)的个体理性因素。运用博弈论和制度分析理论,将流域水资源配置概化为不完全信息动态博弈问题。构建了黄河水资源配置博弈均衡模型,计算结果表明,现有黄河可供水量分配方案缺乏实施效率,不是流域各省(区)用水主体能够自主接受且自我实施的制度选择。

基于模拟-优化模式的供水水库群联合调度规则研究

提出了基于模拟-优化模式的混联供水水库群联合优化调度规则求解框架。首先,通过构建虚拟聚合水库,编制联合调度图,以做出水库群对各用水户的供水方案;其次,通过优化成员水库供水任务分配因子,并结合供水水库群常规调度规则,实现共同供水任务在水库间的优化分配。采用改进粒子群算法(NSPSO)对观音阁-葠窝-汤河水库群联合供水调度模型决策变量(联合调度图调度线位置和成员水库供水任务分配因子)进行多目标优化,分析联合供水调度过程中目标之间的竞争关系,检验联合调度规则的合理性与有效性以及NSPSO算法的优化效率。

有外调水源的库群联合供水调度研究

针对有外调水源的库群联合供水调度中共同供水任务分水方法存在的不足,结合大伙房—英那河—碧流河水库联合供水的工程实例,建立了有外调水源的库群联合供水并行调节模型,并对库群联合供水常规分水方法进行了改进,提出了一种附加调节系数的动态分水方法,即以成员水库可供水量占总可供水量的比例为基数,在其前附加一个以水库蓄满率为决策变量的调节系数,通过调节系数对共同供水任务进行"二次分配"。与常规分水方法相比,此方法供水任务分配更合理,调度结果更优,可为大伙房—英那河—碧流河水库联合供水工程提供决策参考。

城市多源式供水管网调度节能的主要途径

广州市自来水公司属多水源的供水系统,属下有6间水厂和28个加压站,供水管网约有5100多公里。供水调度优化的问题也同样有待调度决策系统进一步发展和完善,并依托用户信息管理系统的开发和供水管网动态模型的建立而逐步优化。文章从优化管网平均压力和各水厂的供水量,建设加压站等方面论述了城市多源式供水管网调度节能的主要途径。

调节阀在南水北调河南受水区配套工程的应用

南水北调中线配套工程输水系统具有线路长、流量大、分支多、运行调节复杂的工程特点。根据输水系统水力过渡过程仿真计算分析,为满足各用水点压力、流量的要求,在供水管线末端设置调节阀。结合PLC控制设备,根据流量信号实现PID闭环调节的基本要求,同时根据配套供水调度需求及末端水厂处理能力、需水量,通过软件编程,响应总运行调度,实现流量分配、调度、调节与保护功能。目前南水北调中线配套工程部分输水系统已按照既定目标成功通水运行。

贵阳市水资源承载状态时空特征研究

水资源承载力的研究源于日益突出的缺水危机,基于文献对水资源承载力及其承载对象的研究,认为人类经济活动的季节性是影响水资源承载状态的主要因素之一。参考月蓄水量动态变化确定研究区的水资源供给量的季节变化规律。利用不同特征经济区的经济增长率和人们生产活动的季节性模数确定水资源承载对象的季节性变化规律,探讨水资源承载状态时空变化的量化方法,建立了基于水资源供给与经济活动规模互动的水资源承载状态评价模型。研究认为云岩、南明两城区水资源承载状态的季节变化较大,在枯水季节容易发生水资源超载而引发的水危机;而修文、息烽等县水资源承载状态的季节性变化较小,在枯水季节的超载程度较轻。研究将为区域可持续能力建设提供有益的参考。

Optimal Dispatching of Large-scale Water Supply System

This paper deals with the use of optimal control techniques in large-scale water distribution networks. According to the network characteristics and actual state of the water supply system in China, the implicit model, which may be solved by utilizing the hierarchical optimization method, is established. In special, based on the analyses of the water supply system containing variable-speed pumps, a software tool has been developed successfully. The application of this model to the city of Shenyang (China) is compared to experiential strategy. The results of this study show that the developed model is a very promising optimization method to control the large-scale water supply systems.

Partial Least Squares Regression Model to Predict Water Quality in Urban Water Distribution Systems

The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality.Partial least squares(PLS) regression model,in which the turbidity and Fe are regarded as control objectives,is used to establish the statistical model.The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data.The percentages of absolute relative error(below 15%,20%,30%) are 44.4%,66.7%,100%(turbidity) and 33.3%,44.4%,77.8%(Fe) on the 4th sampling point;77.8%,88.9%,88.9%(turbidity) and 44.4%,55.6%,66.7%(Fe) on the 5th sampling point.

Assessment on reliability of water quality in water distribution systems

Water leaving the treatment works is usually of a high quality but its properties change during the transportation stage. Increasing awareness of the quality of the service provided within the water industry today and assessing the reliability of the water quality in a distribution system has become a major significance for decision on system operation based on water quality in distribution networks. Using together a water age model, a chlorine decay model and a model of acceptable maximum water age can assess the reliability of the water quality in a distribution system. First, the nodal water age values in a certain complex distribution system can be calculated by the water age model. Then, the acceptable maximum water age value in the distribution system is obtained based on the chlorine decay model. The nodes at which the water age values are below the maximum value are regarded as reliable nodes. Finally, the reliability index on the percentile weighted by the nodal demands reflects the reliability of the water quality in the distribution system. The approach has been applied in a real water distribution network. The contour plot based on the water age values determines a surface of the reliability of the water quality. At any time, this surface is used to locate high water age but poor reliability areas, which identify parts of the network that may be of poor water quality. As a result, the contour water age provides a valuable aid for a straight insight into the water quality in the distribution system.

Water Resources Development and Water Utilization in the Gavkhuni River Basin, Iran

Analysis of water supplies and demand over the past 50 years in the Gavkhuni River Basin（GRB） indicate that despite large investments in water resources development the basin remains just as vulnerable to drought as it always has been. During the period of analysis two transbasin diversions and a storage reservoir have been constructed which have more or less doubled the annual supply to water to the basin. But with each water resource development extractive capacity for irrigation, urban and industrial use has increased by the same amount, so that all new water is allocated as soon as it is available. The most recent developments, since 1980, have actually increased vulnerability to drought because extractive capacity is greater than average flow into the basin. Whenever demand exceeds supply all water is extracted from the basin and the tail end dries up. During the past 50 years flows into the salt pan at the downstream end of the basin have been negligible for more than half the time. Prospects for the future are bleak because once the current phase of water resources development is completed no further water supplies are likely, but demand continues to rise at a steady rate. Ultimately agriculture will have to concede water to urban, industrial and environmental demands.

Electrocatalytic hydrogen evolution from water at low overpotentials with cobalt complexes supported by redox-active bipyridyl-NHC donors

Three cobalt complexes bearing tunable,redox-active bipyridyl N-heterocyclic carbene(NHC)-based ligands have been studied for electrocatalytic hydrogen evolution from aqueous solutions.The effect of structural modifications to the ligand framework is investigated across the catalyst series,which includes a non-macrocyclic derivative(1-Co)and 16-(2-Co)and 15-(3-Co)membered macrocycles.A structure-activity relationship is demonstrated,in which the macrocyclic complexes have greater activity compared to their non-macrocyclic counterpart with the most rigid catalyst,supported by the 15-membered macrocycle,performing best overall.Indeed,3-Co catalyzes H2 evolution from aqueous pH 4 acetate buffer with a Faradaic efficiency of 97%at a low overpotential of 330 mV.Mechanistic studies are consistent with formation of a cobalt-hydride species that is subsequently protonated to evolve H2 via a heterolytic pathway.

有外调水源的库群联合供水调度方法的改进

针对有外调水源的库群联合供水调度常规方法存在的不足,在调水规则和共同供水任务分配方面进行了改进。在调水规则方面,提出了一种调水过程控制的双调水控制线法,该方法在调度图中引入上下两条调水控制线,两线之间形成一个调水启闭的"缓冲区",有效克服了单调水控制线法调水启闭频次过多的缺陷,易于实际应用。在成员水库共同供水任务分配方面,提出了一种附加调节系数的动态分水方法,通过与成员水库蓄水状态相关的调节系数对共同供水任务进行"二次分配",与常规分水方法相比,供水任务分配更加合理,有效降低了供水成本。在大连市供水系统中的应用实例,验证了改进方法的有效性与合理性。