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Abstract

Content

Introduction

In modern technology, hydraulic machines are widely used – machines that communicate hydraulic energy (pumps) to a fluid flow, or use hydraulic energy (engines).

Pumps are one of the most common types of hydraulic machines. They are used for various purposes, ranging from water supply of the population and enterprises and ending with the supply of fuel in rocket engines.

The pressure may decrease: 1) from an increase in the relative flow velocity in the wheel, 2) during the formation of vortices and separation of the flow from the rear side of the blades, 3) due to the high suction height of the pump, low barometric pressure and increase in the temperature of the pumped liquid on the wheel and on the design of the blade.

1. Theme urgency

Centrifugal pumps are used in almost all sectors of the economy. They are used in thermal power plants, in jet engines of rockets, when pumping water from ship holds, in the mining industry, on suckling shells, for water supply to factories and processing plants, in the mining industry, in metallurgy, for locks on canals.

In the chemical industry, special pumps are used for pumping corrosive and flammable liquids, as well as in technology for mixing and dosing.

There are many different ways to create backwater for high – speed centrifugal pumps. One of the ways to ensure non-cavitation pump operation is the use of booster hydraulic elevators.

Having a number of significant advantages over other booster devices, hydraulic elevators have a relatively low efficiency, which is determined by the design and operating parameters. In this work, the definition of rational parameters of a booster hydraulic elevator for a high-speed centrifugal pump operating under mine drainage conditions has been carried out.

2. Goal and tasks of the research

Centrifugal pumps have found a wide range of applications in various industries. As is known, each of these areas has its own conditions for operation – both favorable and unfavorable for certain types of machines.

Consider the examples of the operation of centrifugal pumps in terms of technological processes.

Centrifugal pumps in the mining industry for mine drainage have found wide application. At the mines, the depth at which the coal is excavated is constantly increasing, and the daily flow increases during operation, which affects the normal operation of the centrifugal pump. It turns out that mine pumping pumps work with a variable suction height, which leads to cavitation.

3. Objective

The establishment of the basic laws of the water jet pump workflow and the development of a method for determining the geometric shape of the flow path, which increases its efficiency.

Conclusion

The actual scientific and technical problem has been solved – the rational parameters of the booster hydraulic elevator have been determined, ensuring the cavitation-free operation of a high – speed centrifugal pump. It is shown that the feed rate of the hydraulic elevator should be as large as possible to reduce power consumption.

The main results and conclusions of the work are as follows:
1) based on the analysis of the working conditions of centrifugal pumps in industry, assessing the values ​​of backwaters ensuring their cavitation-free operation, and the way it was created, the expediency of using water – jet pumps (hydraulic elevators) for this purpose, working in conjunction with pumps, was justified;
2) based on the analysis of the results of experimental studies of a hydraulic elevator, the possibility of using them to determine rational geometric and operating parameters of a booster hydraulic elevator working in conjunction with a high-speed shaft centrifugal pump has been substantiated;
3) the geometric parameters of a booster hydraulic elevator with a module m = 73 were calculated for the central pump – 300–700; its dimensionless and pressure characteristics were calculated; the pump’s operating mode and power on its shaft were determined; a 3D model of hydraulic elevator was developed to identify the optimal geometry of the flow section using CAD – systems – Kompas and Solid Works module Flow Simulation. The need for these studies is due to the fact that for the development of the hydraulic elevator under study, experimental data obtained for the hydraulic elevator of another module were used.
4) the use of a booster hydraulic elevator reduces the capital cost of drainage by 23%, but leads to an over–expenditure of electricity for pumping the annual inflow, compared to the baseline, by 8%.

References

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