INVESTIGATION OF THE ENERGY CHARACTERISTICS OF CENTRIFUGAL PUMPS

A hydraulic device that is used to suck up liquid, move it under pressure or pump it, is called a pump. As a rule, any movement of a liquid by similar aggregates is carried out due to the transfer of potential or kinetic energy to it. Depending on the technical indicators, different types of pumps are used. At the same time, they differ in efficiency, power, volumes of fluid pumped per unit time, maximum head and resulting pressure. The most used group of pumps are vane pumps. Their distinctive feature is the impeller rotating in a fixed housing, equipped with blades. Depending on the warehouse of the impeller and the conditions for moving fluid through it, vane pumps are divided into centrifugal and vortex. With a centrifugal pump, liquid is supplied due to the centrifugal force that appears when the impeller rotates. She is carried away by the blades and, under the action of centrifugal force, moves from the middle of the wheel to the edges along the blades. The blades of the impellers are bent in the direction of rotation backwards. The number of blades is usually from 6 to 8 pieces. But special pumps for impure liquids, in order to increase the cross section of the channels in the wheel, are installed with a smaller number of blades from 2 to 4 pieces. Centrifugal pumps are usually installed above the liquid level in the receiving tank, so they must be filled before use. The pump is filled with a check valve on the suction line through the filling funnel until the gas is completely expelled from the suction pipeline and the pump housing. In the absence of a check valve, for filling, air is forced out of the pump housing with the valve closed by a special vacuum pump. The same is done when filling large pumps. Centrifugal pumps are characterized by a rather high efficiency, compactness and durability of use. Based on the numerical modeling of hydrodynamic processes, a substantiation of adjustment of the design of the working wheels of centrifugal pumps is given. Mathematical modeling of the fluid flow in the running part of the centrifugal pump is performed. The results of the CFD calculation are analyzed, after which an experimental work wheel is created, and its tests are carried out. There is a process of comparing a serial and experimental pump. Keywords: Centrifugal pumps, numerical modeling, mathematical model, energy characteristics, hydrodynamic processes, dynamic characteristics, power engineering, working wheel, working fluid, working wheel vanes.