基于WebGIS的灌区水资源管理信息化方法与实现

以西北干旱地区疏勒河灌区为例,提出了将WebGIS应用于灌区水资源管理,构建和设计了系统结构、功能,并对灌区渠系水资源管理数据进行分类,分析了动态访问数据库技术,实现了灌区所需信息的采集、传输、处理与分析的现代化与自动化.     

基于远程无线监控的太阳能和热泵集中供热水系统设计

针对目前集中供热水系统存在的不足,利用太阳能和空气源热泵作为热源,采用GSM网络技术开发设计出基于远程无线监控的集中供热水系统。太阳能为主加热热源,当太阳能加热温度达不到设定温度时,由空气源热泵进行辅助加热。利用GSM网络进行远程无线数据收发,将现场控制设备的状态和故障信息发送给监控中心和设备管理人员、维修维护人员手机,监控中心或设备管理和维修维护人员将现场设备控制指令通过GSM网络发送给现场控制器,控制现场设备运行。系统节能、环保,实现了远程全自动化监控,无人值守,降低了投资运营成本。经实际应用表明,系统性能稳定可靠,效果良好。     

基于B/S与C/S模式相结合的东港灌区信息管理系统

为实现水资源的合理配置,促进节水高效农业的发展,针对东港灌区的实际情况建立了基于B/S与C/S模式相结合的东港灌区信息管理系统,在介绍系统设计及实现的基础上,研究了系统实现的关键技术.系统运行结果表明,该系统可实现灌区管理的自动化、网络化,且操作方便快捷.     

GSM与太阳能技术在高压直流输电接地极在线监测系统中的应用

论述了GSM和太阳能供电技术在高压直流输电换流站接地极监测系统中的应用和具体实现方法.该系统监测单元能够实时检测换流站接地极的入地电流、观测井的水位和温度等数据.实际运行结果说明了GSM和太阳能技术在电力系统远程通信和在线监测中的优越性.     

国际可再生能源新闻

综合类▲全球首个风能和太阳能GSM基站商用日前,摩托罗拉公司宣布在纳米比亚霍马斯行政区的Dordabis村部署了一个风能和太阳能系统,为纳米比亚MTC公司的GSM手机基站供电。这次与MTC Namibia联合进行的试验,旨在支持运营商在纳米比亚乡村地区实现提供语音和数据服务覆盖的战略,同时这也是全球首个此类系统。通过在通信网络中采用可再生能源解决方案,摩托罗拉试验的这一解决方案为运营商提供了一种     

输电线路避雷器动作信息传输监测技术研究

避雷器能够有效避免雷电瞬时电压、浪涌过电压引起的输电装置击穿、输电线路损毁等事故,增强了电力系统的安全性和可靠性。研究从某地区110kV输电线路运行现状出发,设计一种基于GSM网络输电线路的太阳能供电监测装置,针对避雷器计数校验难度大、故障判断准确性差等问题,进行避雷器动作机构的信息电子化改造,使其能够通过GSM网络快速传输雷击计数数据及故障区域信息。     

对节水型灌区建设的几点建议

本文以关中九大灌区为例,就建设节水型灌区要解决的认识、思路、管理、技术环节、资金筹措、服务体系建设等问题作了论述.     

基于GSM的水电厂闸门PLC远程监控系统

利用GSM网络的SMS(ShortMessageService)通讯模块,构建了水电厂闸门远程监控系统的现地控制层与中控层之间的无线数据通讯系统,并采用Wavecom公司生产的SMS通讯模块WMOi3实现了SMS装置与PLC以及工作站之间的数据通讯,为闸门PLC远程监控系统提供了一种新的通讯方式     

车尔臣河灌区2030年灌溉需水量预测

水资源预测对灌区生产发展具有重要作用.分析了车尔臣河灌区基本概况及流域水资源利用现状,根据灌区灌溉制度及渠系用水系数,采用能量平衡法,对灌区2030年灌溉需水量进行了预测,为灌区后续发展和水资源调度提供了重要技术支撑.     

蒲阳站灌溉用水市场的调查与思考

灌区灌溉管理是促进灌溉用水量,提高作物产量的基础工作.灌区内工程管理、用水组织管理以及水费和水价廉政都是管理的中心工作.笔者对所在灌区内灌溉用水现状作了调查,提出自己的几点看法.     

Premixed flame propagating into a narrow channel at a high speed, part 2: Transient behavior of the properties of the flowing gas inside the channel

The behavior of a premixed flame propagating from a chamber into a narrow channel at a high speed was examined using high speed and instantaneous schlieren photography, ion current measurement with electrostatic probes, and temperature measurement with an optical method. From detailed measurements of flames passing through the channel, flame extinguishment in the channel, no matter whether transient or not, was found to occur due to quenching of the reacting gas by rapid turbulent mixing with cold fresh mixture at the downstream of the contraction region and by heat transfer to the cold channel walls. Extinguishment must occur when these heat losses exceed the heat released by the chemical reaction of the flowing mixture.     

基于无线网络的农业灌溉水电管理系统设计与应用

基于我国农业灌溉实际情况,采用无线组网技术提出了一种能满足远程自动抄表、自动计量及实现IC卡身份识别的农业灌溉水电管理系统,介绍了系统数据拓扑方式,阐述了水电控制器、通讯控制器及中心计算机在无线方式下的数据传输模式和实现方法,设计了通讯控制器的硬件电路.试验结果表明,该无线传输网络在一定程度上满足了农业灌溉的需求,有实用性和推广价值.     

Modelling of a porous flowing electrolyte layer in a flowing electrolyte direct-methanol fuel cell

The flowing electrolyte-direct methanol fuel cell is a developing technology that may have practical uses in the future. Its main advantage over a direct methanol fuel cell is that it limits methanol crossover using a flowing electrolyte layer. The flowing electrolyte layer (or flowing electrolyte channel) involves an ion-conducting fluid that allows protons to be transported from the anode to the cathode, and flows through a porous material to wash away crossed-over methanol. In this study, the flowing electrolyte layer is modelled as a porous domain in ANSYS CFX. General flow behaviour and the effects of volume flux, channel thickness, and porous material properties are investigated. It is found that the flow has a flattened velocity profile with thin boundary layers that are virtually independent of volume flux and channel thickness. The pressure drop is mainly dependent on the volume flux and the permeability. It is recommended that cell performance could be improved by using a flowing electrolyte channel that is thinner, and selecting a sufficiently high volume flux and a sufficiently permeable porous material to achieve an optimal combination of pressure drop and methanol removal characteristics.     

GSM与太阳能技术在高压直流输电接地极在线监测系统中的应用

论述了GSM和太阳能供电技术在高压直流输电换流站接地极监测系统中的应用和具体实现方法。该系统监测单元能够实时检测换流站接地极的入地电流、观测井的水位和温度等数据。实际运行结果说明了GSM和太阳能技术在电力系统远程通信和在线监测中的优越性。     

大规模小水电并网调度信息采集通信方式及应用

针对利用单一通讯方式无法解决所有小水电的信息传输难题,提出了采用混合通讯方式,即采用运动装置自动传输、VPN通道、GPRS专网和GSM手机短信平台4种通信方式进行小水电信息采集,并将其应用于云南省电网小水电信息采集中。实际运行结果表明,各地调小水电信息采集缺失率仅为2%~3%,较好地解决了小水电信息采集问题,方便调度员及时了解掌握小水电的发电能力和实时发电情况,且该系统投资少、维护成本低。     

边界层理论在三角形长喉道量水槽流量计算中的应用

三角形长喉道量水槽是一种明渠量水设施。目前的流量计算主要是经验公式,经验公式的应用受试验条件的限制较大。本文根据边界层位移厚度和临界水深理论,推导了该量水槽流量的理论设计方法,该方法可以根据渠道的比降、糙率和设计流量灵活的调整量水槽的几何尺寸,喉道底部也可以根据量水范围的要求设计成平底或底部拱起。用文献[1]的实验结果进行了比较,计算与实测值一致。在此基础上,还提出了三种复合三角形断面长喉道量水槽的理论计算方法。     

我国运煤通道现状与优化对策研究

我国煤炭赋存量与经济发展的逆向分布,使得运煤通道的优化成为平衡煤炭供需矛盾的关键。根据供需状况,我国省区可分为:煤炭输出区、煤炭输入区和煤炭后备区。在分析我国铁路、公路、水路和管道等运煤通道现状的基础上,提出应在进一步完善运煤铁路和公路通道的同时,大力提高水路煤炭运输能力,并从长远考虑重视发展煤炭管道运输。     

新型凝结换热表面的研究

提出了一种新型凝结换热表面，报道了该表面及流道的结构、实验研究的系统和工况，得出了表征饱和水蒸气在该类复杂结构流道中流动凝结时所服从的凝结换热规律，并分析了影响流动凝结换热的因素。     

Unified description of size effects of transport properties of liquids flowing in nanochannels

The present work connects transport properties of simple fluids flowing in nanochannels: the diffusion coefficient, the shear viscosity and the thermal conductivity. We used non-equilibrium molecular dynamics (NEMD) simulations of liquid argon flowing in a nanochannel formed by krypton walls, macroscopically equivalent to the planar Poiseuille flow, at constant temperature. All properties approach bulk values as the channel width increases. As the channel width decreases, the transport properties change dramatically: the diffusion coefficient decreases with the channel width, the shear viscosity increases with the channel width and the thermal conductivity increases with the channel width. The novel result of this work is that, if the size effect of one of the transport properties (say the diffusion coefficient) is known, then all the others can be estimated from results that apply to classic fluid mechanics.     

1D modeling of a flowing electrolyte-direct methanol fuel cell

In this study, the performance characteristics of a flowing electrolyte-direct methanol fuel cell (FE-DMFC) and a direct methanol fuel cell (DMFC) are evaluated by computer simulations; and results are compared to experimental data found in the literature. Simulations are carried out to assess the effects of the operating parameters on the output parameters; namely, methanol concentration distribution, cell voltage, power density, and electrical efficiency of the cell. The operating parameters studied include the electrolyte flow rate, flowing electrolyte channel thickness, and methanol concentration at the feed stream. In addition, the effect of the circulation of the flowing electrolyte channel outlet stream on the performance is discussed. The results show that the maximum power densities that could be achieved do not significantly differ between these two fuel cells; however the electrical efficiency could be increased by 57% when FE-DMFC is used instead of DMFC.