This chapter describes technology that ensures reliable pumping of drainage and sewage water during electromechanical and hydro-mechanical transients from blocks of the hydroelectric power stations and pumping stations. As an alternative source of energy, it is proposed to use the energy of the liquid column of the pressure penstock of the stations, and as an auxiliary, to use jet pumps. Transmission of energy to the suction stream is carried out without direct usage of electrical and mechanical energy. During total shutdown of electric power, reliable evacuation of drainage and seepage water and reduction the influence of electromechanical and hydro-mechanical transients on power equipment and pipelines can be ensured with the use of self-regulating jet pumps over a period of several days; this cannot be accomplished by any other pump. The scientific results of the research are recommended to allow efficient use of water and energy resources and to ensure reliable operation of the power equipment of stations, especially in the events of sudden power outages.
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To provide reliable and trouble-free operation of the main equipment and structures of pumping and hydroelectric power stations, auxiliary drainage systems are provided. As an alternative source of energy, it is proposed to use the energy of the liquid column of the pressure penstock of the stations, and as an auxiliary, to use jet pumps. At the same time, taking into account the special significance and importance of the work of the hydroelectric power stations and pumping stations drainage systems, a technology is implemented that ensures reliable pumping of drainage and sewage water from all blocks of the stations and from canals, with efficient hydraulic automation in any combination of hydraulic units’ work.
About 1500 pumping stations and about 50 hydroelectric power stations are operated in the Republic of Uzbekistan, many of which are related to the first and second class of hydraulic facilities, i.e. they are the objects of state importance, and any accidents can lead to catastrophic consequences or significant economic damage.
The pumping stations are among the main electric power consumers in the Republic of Uzbekistan. From about 50,7 billion kWh/year the electricity supplied to consumers in Uzbekistan (http://agro.uz/ru/information/about_agriculture/420/5856, 2019). All of them are now under the jurisdiction of the Ministry of Water Resources of the Republic of Uzbekistan. At these pumping stations about 5000 pump units are established. Their total power is about 3.8 million kW and the general water delivery is about 7000 m3/s.
In Uzbekistan 2.4 million hectares out of total 4.3 million hectares of irrigated lands now are irrigated by means of pumping stations. Annually about 55 billion m3 of irrigating water are pumped. This volume consists of 24 billion m3 pumped by the first lifting, and 31 billion m3 by the subsequent liftings of pumping stations stages.
Such a significant consumption of electricity by pumping stations, gives the problem of energy conservation to them a status of special importance and relevance.
It is possible to judge the large scale of machine irrigation by the following examples: the Karshi pumping stations stage – total delivery is 200 m3/s; height of lifting is 132 m; the area of irrigation is 350 thousand hectares; the Amu-Bukhara pumping stations stage – total delivery is 263 m3/s, height of lifting is 69 m, the area of irrigation is 285 thousand hectares; the Djizak pumping stations stage – total delivery is 138 m3/s; height of lifting is 112 m, the area of irrigation is 110 thousand hectares.
Among the most important auxiliary systems there are drainage systems. The in-depth position of station buildings, the presence of technological leaks, as well as possible damages and accidents, cause the accumulation in stations buildings the amounts of filtration, drainage and sewage water.
As the world experience of operation shows, the overwhelming number of accidents at pumping stations occurs during electromechanical or hydro-mechanical unsteady processes, when the system experiences the greatest dynamic loads.
Most of the stations were built in the 1960s-1980s and the wearing of the auxiliary equipment of the stations is considerable. As practice has shown, centrifugal pumps do not always meet reliability requirements, especially with sudden power outages. A number of flooding of pumping station buildings is known because at that time all auxiliary systems are paralyzed (Khokhlov, Khokhlov & Titova, 2011, 2018).
In rural brunch of economy very actual are ensuring of reliability, continuity, high energy efficiency and flexibility of pumping stations work, as well as their performance under transient conditions. In order to achieve all of the abovementioned parameters in different countries of the world the certain progress has been made where modern pumping equipment is constantly updating and improving. In this regard, the use of high-tech specialized basic and auxiliary power equipment and new efficient and safety operating modes of pumping stations, prolonging the life of the large systems is necessary.