恒压供水在长距离输水工程中应用与研究

发布时间：2019-06-08 11:01

【摘要】：未来科技城供水工程的主要任务是改造马池口水源地水源井现状,沿百葛路及顺沙路新建输水管线至未来科技城北侧新建调蓄水厂,并采用合理的水资源配置方案,从而为未来科技城提供可靠的水源保证。未来科技城供水工程是保证供水安全,支撑未来科技城发展的需要。工程选取15眼水源井作为地下水水源,最大供水规模及水厂调蓄量均为4万方每天。各水源井通过现状D线、C线输水总管连接至新建管线,新建输水管线总长28.08km,其中DN900球墨铸铁管3.95km,DN800球墨铸铁管24.13km,自西向东,由高至低铺设至未来科技城水厂前池,为水厂提供稳定水源。水厂布置在未来科技城西北角,厂内设置八台供水泵,六用两备,水厂出口设置测压点,根据泵站出口压力信号,采用变频恒压供水方式向科技城内用户提供生活用水。本论文结合未来科技城供水工程设计实例,就恒压供水方式对整个供水系统的影响等关键问题进行了较为系统的研究,分析供水系统中各个参数对系统的影响,研究类似工程中的水泵、变频与调流阀的联合控制等问题。对水泵进行调速性能曲线拟定,通过对各水泵并联曲线拟合,通过作图法求出调速比,对整个输水系统建立模型,进行输水系统过度过程计算及分析;对低流量工况下,工频与变频对系统的影响进行了对比。简要阐述了输水系统中封闭管道流体数学模型的原理及分析过程。本文通过理论分析、数值计算等,提出了未来科技城供水工程过渡过程计算的分析结果,为长距离输水工程设计及运行管理提供了科学依据及技术支撑。主要研究结论如下:(1)对于水源地高于水厂,在流量较低的工况,会产生管路的脱流现象,应设置在管线末端设置调流阀避免脱流现象的发生,同时针对不同工况,对调流阀进行特性曲线拟定。(2)对于多个水源井同时向输水管路供水的工况,水源井深井泵应配置变频器,通过调速运行恒压供水减小对整个输水管路的影响。(3)对于多个水源井同时向输水管路供水的工况,在启泵与停泵的过程中,应逐一进行水泵的启停,并应有相应的间隔时间。(4)提出了输水系统及水厂的调试运行方案。
[Abstract]:The main task of the water supply project in the future science and technology city is to transform the present situation of the water source well in the Marchikou water source area, build a new water pipeline along Baige Road and Shunsha Road to build a new water transfer and storage plant on the north side of the future science and technology city, and adopt a reasonable water resources allocation scheme. So as to provide a reliable water source guarantee for the future science and technology city. The future water supply project of science and technology city is to ensure the safety of water supply and support the development of science and technology city in the future. Fifteen water source wells are selected as groundwater sources, and the maximum water supply scale and water plant storage capacity are 40,000 square per day. Each water source well is connected to the new pipeline through the present D line, the C line water main pipe is connected to the new pipeline, the total length of the newly built water pipeline is 28.08km, in which DN900 nodular cast iron pipe is 3.95km, DN800 nodular cast iron pipe is 24.13km, from west to east, From high to low laying to the future science and technology city water plant front pool, for the water plant to provide a stable water source. The water plant is arranged in the northwest corner of the future science and technology city, and eight water supply pumps are set up in the plant, and the pressure measuring points are set up at the outlet of the water plant. According to the outlet pressure signal of the pumping station, the water supply mode of frequency conversion and constant pressure is adopted to provide domestic water to the users in the science and technology city. Based on the design example of water supply project in science and technology city in the future, this paper makes a systematic study on the influence of constant pressure water supply mode on the whole water supply system, and analyzes the influence of each parameter in the water supply system on the system. The combined control of pump, frequency conversion and current regulating valve in similar projects is studied. The speed regulation performance curve of the pump is drawn up, and the speed regulation ratio is obtained by fitting the parallel curve of each pump, and the model of the whole water transmission system is established, and the excessive process of the water transmission system is calculated and analyzed. The influence of power frequency and frequency conversion on the system is compared under the condition of low flow rate. The principle and analysis process of closed pipeline fluid mathematical model in water transmission system are briefly described. Through theoretical analysis and numerical calculation, this paper puts forward the analysis results of the transition process of water supply project in science and technology city in the future, which provides scientific basis and technical support for the design and operation management of long distance water transmission project. The main conclusions are as follows: (1) for the condition that the water source is higher than the water plant, the drain phenomenon of the pipeline will occur in the condition of low flow rate, and the flow regulating valve should be set at the end of the pipeline to avoid the occurrence of the deflow phenomenon, and at the same time, according to different working conditions, Draw up the characteristic curve of the regulating valve. (2) for the condition that multiple water source wells supply water to the pipeline at the same time, the deep well pump of the water source well should be equipped with frequency converter. The influence of constant pressure water supply on the whole water transmission pipeline is reduced by speed regulation operation. (3) for the condition that multiple water source wells supply water to the pipeline at the same time, the starting and stopping of the pump should be carried out one by one in the process of starting and stopping the pump. There should be a corresponding interval. (4) the commissioning and operation scheme of the water transmission system and the water plant is put forward.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU991

【相似文献】