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The work provided is a continuation the development of research work on the process of pumping high-viscosity liquids and is aimed at creating a universal technique of recalculating the performance curves of dynamic small-sized pumps from water to high-viscosity liquid. The practical need to develop such a technique became relevant after obtaining different results when using existing methods of predicting performance curves for hydrodynamic oil well pumps. The expediency of carrying out studies aimed at clarifying the scope of the technique for calculating the work parameters of a well oil centrifugal pump, which is being developed, is substantiated, and more thorough analysis of the structure of conversion coefficients taking into account the scale factor and flow regime in the hydraulic flow parts of the studied pumps.

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The article is devoted to the research of the torque-flow pump operating process. Its work is closely connected to the formation and stable functioning of the toroidal vortex. The theoretical bases of the formation of a toroidal vortex and the process of energy transfer in a torque-flow pump are considered in the research (vane and vortex components of the operating process). The fact of the presence of some additional hydraulic losses due to the mismatch of the location of the toroidal vortex center and the impeller blade edges has been established. The urgency of the paper is increasing the efficiency of torque-flow pump by improving its flowing part. The upgrade of the pump consists of the theoretical justification and practical implementation of the reduction of these additional hydraulic losses. In this aspect, the location of the impeller blade edge is aligned with the toroidal vortex center. The research was performed by conducting a numerical investigation. The calculations of a high specific speed torque-flow pump of three different design configurations of the impeller blades were performed. Practically confirmed increasing of the head (by 3.2 m) and efficiency (by 7-8%) of the pump with the second design of the impeller blades.

Due to a simple design and hydraulic passage that is the least susceptible to clogging, torque flow pumps (TFP) of Turo type are the most common pumps used for pumping various hydraulic mixtures. These pumps are referred to vortex pumps, operation of which is accompanied by energy loss and vortex formation resulting in low economic efficiency. Since the TFP is a vortex hydraulic machine, the ratio of the fluid velocity in the free pump passage to the impeller rotational speed ωfluid /ω is an indicator of the TFP efficiency. The higher the value of ωfluid , the more efficient the pump is. The mechanism of the energy transfer in the TFP is caused by both blade and vortex operating process, or a combined operating process. The efficiency of the pump can be improved by increasing the portion of blade operating process. The aim of the study is to improve the efficiency of the TFP of Turo type by modifying the impeller design, to obtain a basic equation of the TFP with a new impeller which has several extended blades, and to study the influence of the impeller geometry on the pump performance experimentally. The study was carried out by analytical and experimental methods. The equation describing the head dependence on the hydraulic passage dimensions of the pump with a new impeller was obtained analytically. This equation can be used to clarify the methodological recommendations for designing the pump. The energy balance in the TFP was analyzed. During the testing on a test rig, the characteristics of the pump were obtained, which confirmed the advantages of using the modified impeller with extended blades resulting in increase of the portion of the blade operating process.

Purpose. Evaluation of the effect of changing the width of the impeller blades on the characteristics of a torque-flow pump. Searching for the optimal blade extension into the free chamber of the pump. A torque-flow pump of the “Turo” type SVN 500/32 was chosen as the subject of the research work. Methodology. A number of numerical experiments were conducted to determine the flow structure in the flowing part of a torque-flow pump. The width of the impeller blade was chosen as a variable. Numerical experiments were carried out using the ANSYS CFX software package. The integral parameters of the researched pump were determined in order to build the integral characteristics. Findings. The structure of the general flow and toroidal vortex was studied and analyzed in the torque-flow pump. A flow model was built in a torque-flow pumps with basic and modernized design. A relationship between the parameters of the pump and the change in the impeller blade width was found. The width of the impeller blade was changed in the range from min = -20 to max = +100 mm. Originality. The paper researched the effect of additional hydraulic losses caused by the mismatch between the center of the toroidal vortex and the edges of the impeller blades on the integral characteristics of the torque-flow pump. Practical value. A significant increase in the operating parameters of the “Turo” type torque-flow pump was achieved with the help of modernization of the impeller design. This allows expanding the range of the pump’s operation. At the same time, it is not required to replace such expensive elements as the pump casing.

The reliability of pumping units at nuclear power plants (NPPs) is critical in terms of their energy efficiency and safety. Remarkably, WWER-1000 reactors at Ukrainian NPPs are equipped with outdated pumping units that have already served their full-service life. This fact leads to an urgent need to develop a new, more efficient pump. In the article, a promising pump, ACNA 600-35, was developed. It was designed to increase the energy efficiency of pumps TX 800/70/8-K-2E, applied at the holding pool and the industrial circuit of the nuclear reactor. Since these pumps should be imported from the monopoly suppliers, this affects both the energy efficiency of pumping equipment and the energy independence of Eastern Europe. The proposed pump ACNA 600-35 is characterized by an increased efficiency of up to 0.12–0.13 compared with the TX 800/70/8-K-2E pump. In general, the life cycle cost of the proposed pump is 15–20% lower than for the analog TX 800/70/8-K-2E. The design of the developed pump ACNA 600-35 and the related pumping unit based on its production at industrial facilities allows for further development of the industrial and fuel-energy complex, increasing the state’s energy independence and employment. According to expert estimates, the average economic effect from supplying the developed pump can reach 10 mln USD/year.

Developing ways to increase centrifugal pumps’ pressure and power characteristics is a critical problem in up-to-date engineering. There are many ways to resolve it, but each has advantages and flaws. The presented article aimed to ensure higher energy efficiency indicators by using a counter-rotating pumping stage with trimming. During the research, the comprehensive approach was based on CFD modeling and the Moore–Penrose pseudoinverse approach for overestimated systems. According to the obtained data, pumps with a counter-rotating stage allowed the pressure head to be significantly increased compared with the standard design of the flow part. Notably, for pumping units CPS 180/1900 with a basic stage, the pressure head of 127 m was reached. However, when using a counter-rotating stage, the pressure head could be increased up to 270 m, which was 2.1 times higher. Therefore, to ensure unchanged characteristics when using centrifugal pumps with the counter-rotating stage, the weight and size indicators can be significantly reduced compared to the traditional design scheme. The proposed numerical and analytical approaches allow estimating the highest pressure and energy characteristics values.