【作者】 柴丽娜；

【导师】 刘景植； 李江云；

【作者基本信息】 武汉大学 ， 水利水电工程， 2005， 硕士

【摘要】 20世纪50、60年代以来,我国沿海地区兴建了数百座大型排水泵站,其出水流道多为虹吸式形式。该流道包括上升段、顶部驼峰段及下降段,适用于设有堤防的排水泵站。驼峰顶部高程按略高于出水池最高设计水位确定,可起到挡水作用,其上设有真空破坏阀,采用破坏顶部真空的形式进行断流,其断流措施对水流无阻力,运行可靠。然而,近年来,一方面由于江河水文条件的变化,水位逐年提高,使得超驼峰水位频繁出现;另一方面,随着社会经济的发展,排水区的排水标准有所提高;为了减轻内涝灾害,迫切要求在超驼峰水位下开机排水。此时,必须研究解决超驼峰水位下机组启动和事故停泵等问题,以确保超驼峰水位运行下泵站机组安全。为此,本文建立了一套完整的处理超驼峰状态下泵站运行改造措施。 本文首先对大型排水泵站超驼峰运行的各种断流方式进行了分析和评价,指出了传统断流方式在具体运用中存在的技术难题,提出了在超驼峰状态下,利用压缩空气技术及新型活页式快速闸门独立或联合运用实施机组启动、停机及防止江水倒灌的系列技术措施。从理论上分析了泵系统启动及事故停泵过渡过程中电动机、轴流泵及流道的过渡过程特性,建立了描述其启动及停泵过程的数学模型。通过编程计算,得出泵装置在过渡过程中流量、扬程等参数随时间变化的情况,并以此设计了启动排气装置、压缩空气断流装置、活页式快速闸门装置。同时对单独设有活页式快速闸门的泵站,进行了停机过渡过程分析计算,建立了闸门下落运动的数学模型。最后以湖北嘉鱼余码头泵站为例,进行了压缩空气断流装置在超驼峰水位下实施启动及事故停泵过程的计算,并进行了活页式快速闸门在超驼峰状态下启动及事故停泵的启门及下落过程的计算,为工程设计提供了一套压缩空气装置及活页式快速闸门装置的设计方法。更多还原

【Abstract】 Since 1960’s hundreds of large pumpmg stations for drainage have been built near the rivers and seas in China. These drainage pumping stations often use siphon outlet conduit .They consist of up-segment、 top-hump、down-segment, which are the same with the pumping station with levees. The height of the hump is decided according to the height designing water level of outlet pool and so the hump can prevent the backward flow. There is a vacuum breaker on the top of the hump. It breaks vacuum on the hump and cuts off flow, which cannot resist the current and runs reliably. However in the late years, the pumping stations operate continually over the hump because of the change of the hydrology conditions and the elevation of the water level. On the other hand with the development of economy, the drainage standard of distract is increased and so pumping stations urgently need starting and draining when the water level is over the hump for abating the disaster of internal water logging. So they have to be researched and settled that the pumping station operate on starting and suspending period over the hump for the safety of the pumping stations. Therefore, this paper set up a series of integrated lash-up measure.In this paper all kinds of cut-off flow ways were analyzed and appraised when the large drainage pumping stations operate over the hump. And technical problems of traditional cut-off flow ways in practice are indicated. We come up with a series of new cut-off flow means of using compressed air and a new loose-leaf rapid-gate running alone or together to finish pumping set starting, suspending and preventing the water in the river from backwards flow. A theoretical study was made on the dynamic characteristics of pumping system during the hydraulic transient process of starting and suspending. Mathematical models are presented to express the characteristics based on the systematical analysis of electromotor, axial pump and outlet conduit dynamic characteristics, and numerical calculation methods are promoted. The exhaust equipment, the compressed air cut-off flow system and the new loose-leaf rapid-gate were designed with the results of the transient process. The case which the new loose-leaf rapid-gate operated alone is analyzed and it’s mathematical model is drown during the gate dropping. In the end, according to YuMaTou pumping station in JiaYu county HuBei province, the calculations are done that compressed-air cut-off flow system in the water level over the hump finishes starting and suspending transient process. The calculations are also done for the raising and dropping of the loose-leaf rapid-drop gate when the water level is over the hump. A series way is offered for designing of compressed-air equipment and loose-leaf rapid-drop gate.更多还原