高扬程泵站水锤计算分析及防护措施研究

发布时间：2018-06-15 15:44

本文选题：高扬程 + 断流弥合水锤　；参考：《宁夏大学》2017年硕士论文

【摘要】：随着城市建设的快速发展和人民生活水平的日益提高,长距离大型输水工程越来越多,随之而来的工程爆管问题引起越来越多工程人员的注意。高扬程多起伏有压输水管道中易发生水柱分离与断流弥合水锤,并造成严重的水锤危害。因此,高扬程多起伏输水管道系统水锤防护问题,作为输水管道安全运行的重要课题之一,是很有必要进行深入研究的。本文首先介绍了水锤基本理论和现有的水锤计算特征线方程法,在此基础上分析了气液两相瞬变流,并对管道中气泡形成的主要原因、气液两相瞬变流的常用数学模型等进行了深入研究。建立了事故停泵水锤计算数学模型,利用计算机进行模拟计算。结合海原新区水源泵站改造工程,对设计单位提出三种管线方案:①原管线方案;②原管线在桩号K3+800m处设转换池方案;③在原管线两道深沟处修建管桥抬高管线高程方案。通过对这三种管线布置方案进行事故停泵水锤计算分析,得出如下结论:(1)在最高点设转换池,对事故停泵水锤的消除和改善没有明显效果,而且增加高位转换池会造成水泵扬程的浪费、投资及维护费用的增加;(2)采用抬高管路部分低点高程,不能消除水柱断裂现象,而且修建管桥的投资非常大;(3)对三种管线布置方案事故停泵水锤分析计算,最终确定为原管线方案。通过对不同运行工况下事故停泵水锤计算,确定出事故停泵两阶段关闭蝶阀最优操作程序;同时提供了事故停泵各断面最大、最小压力变化过程线及相关数据,为泵站的管线设计提供了可靠的数据;(4)通过对该泵站水锤计算结果表明,采用两阶段关闭蝶阀及沿管线局部高点设置进、排气补气阀,可有效控制事故停泵时机组倒转转速、倒泄流量。同时,可有效消除由于事故停泵产生的水柱断裂现象。综合分析认为该泵站有效的防护措施:当事故停泵时,在泵出口采用两阶段关闭蝶阀调节;在管道局部高点设置进、排气补气阀;在确定管道压力等级时,在管道易出现水柱断裂的管段,适当考虑在200m左右范围内增加相应的压力,可使此类高扬程输水管道的防护取得良好效果。
[Abstract]:With the rapid development of urban construction and the improvement of people's living standard, there are more and more long-distance large-scale water conveyance projects. The separation of water column and closure of water hammer are easy to occur in high lift multi-undulating and pressurized water conveyance pipeline, which causes serious harm to water hammer. Therefore, as one of the most important issues in the safe operation of water conveyance pipeline, it is necessary to study the problem of water hammer protection in high lift and multi-fluctuation pipeline system. In this paper, the basic theory of water hammer and the existing characteristic line equation method of water hammer calculation are introduced in this paper. On this basis, the gas-liquid two-phase transient flow is analyzed, and the main reasons for the formation of bubbles in the pipeline are analyzed. The mathematical models of gas-liquid two-phase transient flow are studied in detail. The mathematical model of water hammer calculation is established, and the computer is used to simulate the water hammer. Combined with the reconstruction project of water source pump station in Haiyuan New area, three kinds of pipeline schemes: 1 original pipeline scheme and 2 original pipeline plan are put forward for the design unit. The transfer pool scheme is set up at the position of pile number K3800m and the original pipe bridge elevation scheme is built at the two deep ditches of the original pipeline. Through the calculation and analysis of the three pipeline layout schemes, the following conclusions are drawn: (1) setting up a transfer pool at the highest point has no obvious effect on the elimination and improvement of the accident stop pump water hammer. Moreover, the increase of the high position transfer pool will cause waste of the pump head, the increase of investment and maintenance costs, and the adoption of raising part of the low point elevation of the pipeline will not eliminate the phenomenon of water column breakage. Moreover, the investment in the construction of the pipe bridge is very large. The analysis and calculation of the water hammer caused by the accident of three pipeline layout schemes are finally determined as the original pipeline scheme. Through the calculation of water hammer under different operating conditions, the optimal operation procedure of the two stage closure butterfly valve is determined, and the maximum and minimum pressure variation process line and relevant data are provided for each section of the accident stop pump. This paper provides reliable data for the pipeline design of the pumping station. The calculation results of water hammer in the pump station show that adopting the two-stage closing butterfly valve and setting the intake valve along the local high point of the pipeline and the exhaust filling valve can effectively control the turning speed of the unit when the pump is stopped in an accident. Reverse discharge. At the same time, it can effectively eliminate the water column fracture caused by the accident pump stop. The comprehensive analysis shows that the effective protective measures for the pump station are: when the pump is stopped in an accident, the two-stage shutoff butterfly valve is adopted at the pump outlet, the intake valve is installed at the local high point of the pipeline, and the exhaust gas filling valve is installed; when determining the pressure grade of the pipeline, In the section where water column fracture is easy to occur in the pipeline, appropriate consideration should be given to increasing the corresponding pressure within the range of 200 m or so, which can make the protection of this kind of high head water conveyance pipeline obtain good results.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU991.39

【参考文献】