Effect of parallel connection of pumping units on operating costs of pumping station

¹ Department of Usage of water energy and pumping stations, Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, 100000 Kari Niyazi street, 39 Tashkent, Uzbekistan
² Hydromelioration faculty, Tajik agrarian University named after Sh.Shohtemur, 734003 Rudaky avenue 146. Dushanbe, Tajikistan

^* Corresponding author: ikramov-1978@mail.ru

Abstract

In Uzbekistan, as well as in many other countries of the world, pumping units operate in parallel into a common pressure pipeline at some pumping stations of the irrigation system. This was done mainly to save on the capital costs of the pipeline. Analysis and hydraulic calculation of the existing large irrigation pumping stations with pumping units operating in parallel showed that at some of them the conditions of parallel operation of pumping units were impaired. As a result, a negative hydraulic process arises, in the form of self-induced vibrations of the water flow in the pipeline, which leads to various damage and deformation of the pressure pipeline and pipeline supports. The calculations showed that with different modes of pumping units operating together, the power consumption at the Amu-Bukhara-1 and Namangan pumping stations, accounting for one unit increases by 0.72 ... 6.53%, and at the Amu-Bukhara-2 and Amu-Zang-2 pumping stations, this index, on the contrary, decreases by 0.32 ... 1.67%. Therefore, a properly selected operating mode of parallel-connected pumping units will lead to a decrease in operating costs, i.e. decrease in the prime cost of raised water.