Deep deformations of the upper stream of a low-pressure reservoir

Abstract

The article presents the results of the analysis of the deep deformations of the Amu Darya riverbed in the upper reaches of the low-pressure reservoir. The analysis of the combined transverse profiles of the riverbed in different sections of the upper reaches of the Takhiatash reservoir showed that the coastal zones are most intensively silted up. At the same time, the core zone with the highest flow rates is very weakly declared. The height of the silting layer along the length of the upper stream increases in the direction of the dam. The silting area extends upstream for a length 2-3 times longer than the length of the soundings section, which is 17.5 km. To ensure the normal operation of the hydraulic system, it is recommended that conditions should be created for a normal and stable approach of the flow to the hydraulic system, which should be ensured by maneuvering the shield holes. To do this, it is necessary to create conditions for the erosion of the left-bank spillway by increasing the water flow through the extreme left-bank discharge holes. Flushing of the upper left-bank section of the river should continue until the optimal width of the leading channel is reached, which provides the main flow of the stream in front of the structure. It is proved that the formation and development of sediment deposits on the right bank between sections 8-10 leads to a change in the flow correction and creates conditions for the formation of shoals in front of the regulator of the Kizketken channel, which can complicate the operation of the water intake zone. Therefore, it is necessary to take measures to prevent the development of the right-bank channel, and the development of the channel should go from the main channel. As shown by monitoring operating mode Takhiatash waterworks, in the Takhiatash district waterworks intensive processes the channel formation, which has a strong influence on the operational mode of the dam, especially in the operation of the water intakes flushing of sediments, skip flood costs through the shields of the dam and the stability of structures.

Increasing efficiency of flow energy damping with lateral water intake

“…When installing the model, the width of the tunnel tray was maintained using templates installed in pairs along its entire length [15][16][17][18][19][20][21][22].…”

“…However, under certain conditions, this space is either insufficient to accommodate the outlet channel or completely absent. Therefore a large amount of excavation has to be performed [10][11][12][13][14].…”

Influence of hydroabrasive wear of impeller blades on head of centrifugal pump

“…When testing soil pumps [13][14][15][16], it was found that parts made of electrocorundum on an epoxy-phenol-formaldehyde binder, compared with parts made of wear-resistant cast iron, increased the service life of pumps by 3-8 times. But the use of wear-resistant polymeric materials for the manufacture and coating of pump parts has not been widely used in practice due to the following reasons [17,18]: 1) polymer compositions do not provide satisfactory wear resistance at high flow rates; 2) the rough surface of polymer coatings creates additional hydraulic resistance and degrades hydraulic efficiency; 3) the quality of polymer coatings is highly dependent on strict adherence to the application technology.…”

Theoretical models and dependences for calculating intensity of hydroabrasive wear of pump working parts

“…The analysis of the considered schemes in figure 1 and figure 2 shows that from the impact of centrifugal and inertial forces in the interblade channel of the impeller of the axial and centrifugal pumps, separation and redistribution of solid particles in the flow occur. As a result, in centrifugal pumps at the tip of the blade and axial pumps in the end gap of the impeller, the local concentration of solid particles increases compared to the average, which should be considered when determining the wear rate of these elements [18][19][20][21][22][23][24].…”