基于WebGIS的城市供水管网系统的设计与实现

介绍了基于WebGIS的城市供水管网信息系统的体系结构、功能组成以及供水管网建模技术.城市供水管网系统主要包括管网建模、查询统计、爆管事故分析、运行状态监控、漏损分析、系统维护等六个方面.城市供水管网建模是进行城市供水系统规划、设计、分析与优化调度的重要支撑技术,充分发挥WebGIS的分布式与可视化地理空间信息分析的优势,结合城市供水管网的管理需求,将WebGIS技术应用到城市供水管网的建模中.该系统可为城市供水部门的高效管理提供决策依据.     

基于SQL信息技术在供水管网漏损事故中的应用

本文在探讨了供水管网漏损多维数据集的创建过程后,通过SQL管理系统对所管辖区内的用户供水信息进行查询,判断该区域管网的漏损情况,以此希望为供水企业提供准确而即时的决策支持。     

边缘AI管网漏损管控系统

1目标和概述 1.1行业所面临的挑战 传统的供水管网漏损治理方法多以人工排查的方式进行,存在的问题主要集中在以下几个方面: (1)传统的管网漏损治理主要采用声波技术进行检漏,这种方法在很长的一段时间内都发挥了显著的成效,但从过程和方式来看,属于被动式的漏损控制方法,对漏水点不能做到及时发现,导致泄漏时间延长和水损增大;...     

基于改进蚁群算法的Hanoi给水管网优化设计

给水管网优化设计是一个多变量的离散优化问题,设计方案直接影响到工程的投资.针对蚁群算法在优化给水管网问题时易陷入局部极小难以寻求最优解的缺陷,提出一种改进蚁群算法,通过蚁群分工机制与优化信息素增加值提高了蚁群算法的全局搜索能力.利用改进蚁群算法对汉诺塔管网进行优化设计,结果表明改进蚁群算法的设计方案在满足工程要求的同时造价最低.通过与其他优化方法相比,提出的改进蚁群算法在给水管网优化问题中具有较好的全局搜索能力.     

基于健康管理的多机器人覆盖控制

装备了传感器的多机器人系统可以在各种场景中完成覆盖搜索任务,例如污染源监测和控制。而传统基于CVT的覆盖控制算法未曾考虑到环境对机器人健康的影响,以及不同健康机器人对覆盖成本的影响。针对上述问题,提出了一种基于健康优化管理的多机器人覆盖控制算法。首先引入多机器人健康优化管理办法,将机器人的健康退化纳入位置优化问题,最大程度地减少机器人的健康损耗,并尽可能地延长不健康机器人的工作寿命;其次引入基于加权维诺的分布式覆盖控制方法,为多机器人提供最优配置的同时最小化代价函数;目标是当机器人执行任务的能力随时间变化时,执行覆盖任务,提供最优配置。最终通过数值仿真和实验验证了所提算法的有效性。     

参数自适应粒子群算法的给水管网优化研究

针对粒子群算法在解决给水管网优化问题时存在容易陷入局部最优的缺点,通过分析粒子的运动轨迹和相似程度,提出一种参数自适应粒子群算法。该算法利用种群粒子与期望粒子之间相似度的大小,动态调整算法参数,平衡算法全局和局部搜索能力,利用分期变异策略增加种群多样性,保证算法收敛于全局最优值。将改进算法用于优化汉诺塔管网和纽约管网2个经典的管网案例,证明算法可以有效应用于给水管网这类组合优化问题。将该算法优化实际的管网改扩建案例,结果表明,所提出的算法具有更好的寻优性能和收敛性能。     

基于改进粒子群算法的油气集输管网拓扑结构优化方法

针对传统方法优化后的油气集输管网拓扑结构误差较高大、人力物力成本较高等问题,提出基于改进粒子群算法的油气集输管网拓扑结构优化方法.分析井口—计量站-联合站的布站程序,计算体积流量等工艺参数;将油汽集输费用最小作为目标函数;在计量站储油能力、中转站加工能力以及各站点位置约束下,构建管网拓扑结构优化模型;调节最优粒子编码顺...     

P_MOEA:一种多目标决策辅助遗传算法用于服务组合QoS优化

在服务组合场景下,SLA约束下的服务组合优选是实现服务质量管理的重要基础之一.服务组合优选既是一个组合优化问题同时也是多目标决策问题,需要高效的算法以支持大规模的候选组合方案集合,同时也需要有效的评价模型来明确定义候选方案的优劣程度,从而为决策者提供支持.现有的服务组合优选方法多基于两种模型定义其优化目标:线性效用函数和Pareto最优.前者需要量化权重配置以定义效用函数,但是对于用户来说精确的量化权重配置是一个非常困难的任务,特别是在涉及到的QoS维度较多时;后者无需权重配置,将Pareto最优的skyline集合作为优化结果返回给用户,然而skyline集合的规模是不可控的,最优结果集的规模会随着问题的规模增大而显著增大,过大的最优结果集显然难以为决策者提供有效参考.针对上述传统方法的不足,在本文中,我们将PROMETHEE方法引入服务组合优选问题,结合Pareto和PROMETHEE两种评价模型,将skyline集合基础上的Top-k PROMETHEE最优方案作为优化目标,提出并实现了一个高效的遗传算法:PMOEA.算法可以针对大规模问题,高效地返回Top-k PROMETHEE最优组合方案集合,从而为进一步的决策提供有效的参考.我们实验验证了算法的效率和有效性.     

基于模拟退火算法的电力系统输电阻塞成本控制

研究了实时电力系统中输电阻塞管理的成本控制问题.针对同时开放发电侧和负荷侧的情形,引入阻塞率因子,建立了新的阻塞费用优化模型.基于minimax思想和模拟退火算法,将实时阻塞管理问题转化为最大输电阻塞时调整费用最小的非线性规划问题,得到了全局最优解.仿真结果表明,改进的优化模型可有效缩减和控制调整费用,所设计的算法简单可行且安全可靠.     

智慧管网算法研究与应用

随着智能信息化的发展,智慧管网在人们的日常生活和城市的发展中的需求越来越大,然而智慧管网算法问题一直是一个难题。针对管网爆管点查找模糊、流量监测数据精度不高和管网成本评估分析困难等问题,根据流向分析与缓冲分析结合的思想,设计一种基于流向的管网爆管分析算法,采用管线管网漏损率和多因素的综合资产评估方法设计了管网评估算法,采用面积比流量、沿线水头损失、水力等效原则和管网水力平差等设计了管网水力计算算法。最后通过乐山市市中区管网数据进行了实验分析,有效地实现了智能化的流量监控、预警提示、爆管点分析、智能规划维修路线以及管网成本评估等功能,达到了智慧管网算法的基本需求。     

物联网形式的供水管网压力控制管理系统

为实现供水网管自来水压力智能控制与远程监控,减少恶劣环境的野外作业,降低水资源的漏损和爆管几率,为科学管理管道自来水提供依据,设计了智能减压阀自来水压力控制管理系统。整个系统由下位机无线智能控制器终端和上位机Web服务器组成。下位机控制器与原先导阀调节接口连接,实时监控阀门压力,通过一种调压控制算法,实时调节出水口压力并使其稳定在目标设定值;上位机Web服务器可以通过GPRS网络接收由控制器终端传来的现场工况状态数据包或下发控制指令。长时间试验运行表明,系统达到了分时段调压、远程调压及上传数据等预期目的。     

无线传感器网络阀门检漏仪表的设计

针对流程工业设备阀门泄漏造成的能源损耗和环境污染等问题,设计了基于ZigBee无线传感器网络的用于检测阀门泄漏的仪表.该无线阀门检漏仪表通过超声波检测、温度检测、压力检测,实现对阀门泄漏在线连续的监控,自动记录和报告阀门泄漏的地点和时间.这样,企业就可以有效地集中资源进行维修,减少泄漏造成的能源浪费和环境污染,最终达到节能减排的效果.     

A microvalve for lab-on-a-chip applications based on electrochemically actuated SU8 cantilevers

Increasing the complexity and functionality of Lab-on-a-Chip devices requires integrated valves for internal flow regulation. The device introduced in this work is an electrochemical SU8 microvalve, featuring a cantilevered structure that seals an adjacent channel under the action of a growing electrolysis bubble. The valve is based on previously reported movable microcantilevers embedded in microchannels. As opposed to membrane valves moving perpendicular to the substrate, the cantilever valve is patterned next to the channel and closes it by moving horizontally, dramatically reducing footprint. Its compact, monolithic and 2D construction reduces assembly problems and results in negligible increase in dead volume (14.5 nl). Besides, its location in the way of the channels avoids the need for auxiliary filling ports or separate working media for actuation. Effective sealing with negligible leakage at 20 kPa has been achieved. The valve also displays passive flow regulation induced by the pressure differential generated across the valve chamber under flow conditions (42-72% flow decrease).     

Proportional directional valve based automatic steering system for tractors

Most automatic steering systems for large tractors are designed with hydraulic systems that run on either constant flow or constant pressure. Such designs are limited in adaptability and applicability. Moreover, their control valves can unload in the neutral position and eventually lead to serious hydraulic leakage over long operation periods. In response to the problems noted above, a multifunctional automatic hydraulic steering circuit is presented. The system design is composed of a 5-way-3- position proportional directional valve, two pilot-controlled check valves, a pressure-compensated directional valve, a pressurecompensated flow regulator valve, a load shuttle valve, and a check valve, among other components. It is adaptable to most open-center systems with constant flow supply and closed-center systems with load feedback. The design maintains the lowest pressure under load feedback and stays at the neutral position during unloading, thus meeting the requirements for steering. The steering controller is based on proportional-integral-derivative (PID) running on a 51-microcontroller-unit master control chip. An experimental platform is developed to establish the basic characteristics of the system subject to stepwise inputs and sinusoidal tracking. Test results show that the system design demonstrates excellent control accuracy, fast response, and negligible leak during long operation periods.     

流体管道水锤抑制的时间尺度变换控制

在流体管道运行中,打开的阀门突然关闭会造成管道内部流体对阀门及管壁的巨大压力冲击,这种现象叫做水锤效应,严重威胁流体管道的健康运行.基于此,本文研究了阀门关闭过程中抑制水锤效应的最优边界控制问题.水锤模型由一组非线性时空演化方程描述,本文首先通过半离散方法得到一个有限维模型.然后,采用分段一次线性控制变量参数化方法及灵敏度分析方法,结合时间尺度变换方法,推导其梯度形式.最后,结合非线性优化求解器,完成边界最优控制设计.仿真结果显示时间尺度变换方法能够更有效地抑制水锤效应.考虑到实际工程中的控制量为阀门相对开度,在得到阀门处的流量和压力的最优变化过程后,本文给出了阀门相对开度随时间的演化关系.     

Leakage diagnosis with a contamination mitigation control framework using a graph theory based model

This work proposes an operational management approach for water distribution networks (WDNs) that can detect and localize leakages while also mitigating contamination resulting from these leaks. The primary emphasis of this work is the development of a contamination mitigation control scheme. A leak typically leads to a drop in network pressure that increases the risk of contamination. A leakage localization algorithm is responsible for detecting and localizing the leakage in the WDN. When a leak is detected in the network the contamination mitigation control is activated. The flow and pressure settings of the pumps are regulated by the contamination mitigation control in an optimal manner to minimize the risk of contamination. The entire framework is tested on the Smart Water Infrastructure Laboratory situated at Aalborg University, Denmark and a large-scale benchmark water network, which is part of a city network, L-town.     

Dynamically adaptive networks for integrating optimal pressure management and self-cleaning controls

This paper investigates the problem of integrating optimal pressure management and self-cleaning controls in dynamically adaptive water distribution networks. We review existing single-objective valve placement and control problems for minimizing average zone pressure (AZP) and maximizing self-cleaning capacity (SCC). Since AZP and SCC are conflicting objectives, we formulate a bi-objective design-for-control problem where locations and operational settings of pressure control and automatic flushing valves are jointly optimized. We approximate Pareto fronts using the weighted sum scalarization method, which uses a previously developed convex heuristic to solve the sequence of parametrized single-objective problems. The resulting Pareto fronts suggest that significant improvements in SCC can be achieved for minimal trade-offs in AZP performance. Moreover, we demonstrate that a hierarchical design strategy is capable of yielding good quality solutions to both objectives. This hierarchical design considers pressure control valves first placed for the primary AZP objective, followed by automatic flushing valves placed to augment SCC conditions. In addition, we investigate an adaptive control scheme for dynamically transitioning between AZP and SCC controls. We demonstrate these control challenges on case networks with both interconnected and branched topology.     

Optimal Valve Closure Operations for Pressure Suppression in Fluid Transport Pipelines

When a valve is suddenly closed in fluid transport pipelines, a pressure surge or shock is created along the pipeline due to the momentum change. This phenomenon, called hydraulic shock, can cause major damage to the pipelines. In this paper, we introduce a hyperbolic partial differential equation (PDE) system to describe the fluid flow in the pipeline and propose an optimal boundary control problem for pressure suppression during the valve closure. The boundary control in this system is related to the valve actuation located at the pipeline terminus through a valve closing model. To solve this optimal boundary control problem, we use the method of lines and orthogonal collocation to obtain a spatial-temporal discretization model based on the original pipeline transmission PDE system. Then, the optimal boundary control problem is reduced to a nonlinear programming (NLP) problem that can be solved using nonlinear optimization techniques such as sequential quadratic programming (SQP). Finally, we conclude the paper with simulation results demonstrating that the full parameterization (FP) method eliminates pressure shock effectively and costs less computation time compared with the control vector parameterization (CVP) method.      

660MW超临界燃煤机组低压旁路阀频繁内漏处理方法探索研究

本文以某公司2×660MW超临界燃煤机组低压旁路阀频繁内漏（德国西门子原装进口产品）为例,经多次解体发现阀座与阀芯的密封面损坏,主要原因是由于杂质、异物等金属硬物卡涩所致,而系统复杂致锅炉侧死角异物难于彻底吹扫干净,一直严重影响机组安全经济运行。通过对低压旁路阀入口加装滤网、阀门研磨处理、减压孔扩孔、更换阀门、旁路阀阀芯改造等几种方案综合对比优缺点,最后确定对阀芯改造并进行可行性分析,实施效果明显,有效防止了阀芯与阀座密封面损伤,彻底解决了低压旁路阀频繁内漏问题,确保了机组运行安全经济性,无疑对具有类似问题的火电机组解决方案有一定的参考意义。     

基于PLC的天然气高中压站的智能监控系统研制

介绍了融现代电子技术和微机控制技术为一体的PLC系统在燃气供应系统中的应用，通过压力传感器测量管道燃气的进出口压力、流量计测得燃气流量，并通过PLC的程序转换和输出控制减压阀、增压阀和泄压阀，实现了燃气供应系统的流量控制和远程压力调节。