The manuscript presents the results of a numerical study of a centrifugal contra rotating blade system based on a low-speed impeller (ns = 65). They were carried out to assess the possibility of using a contra rotating blade mesh operating in conjunction with a standard centrifugal impeller as a method of intensifying the transmission of energy to a fluid. The designs of the systems under consideration and their pressure and energy characteristics are presented.

The article is devoted to a pilot study of the reverse-bladed pump. The characteristics of the reverse bladed pump are the identical parameters on flow, the head, power, energy efficiency on direct and the return operating modes (at rotation of a rotor of the pump both in one and to the opposite side). The model reversible axial pump with two impeller versions was tested on an experimental bench. The impellers were distinguished by the shape of the profile in the blade sections. The model reversible pump was structurally a reversible axial impeller placed in a cylindrical chamber. Studies were carried out at different angles of rotation of the impeller blades. The power characteristics of tested versions of the pump (impeller) at the design and under loading (unstable operation) modes are given. Low efficiency of the tested versions of the reversible pump compared to the conventional axial pumps is noted, primarily due to the strong influence of the secondary gradients of the pressure factor. The second reason is the profile separation of the flow from the blade surface, to which the tested reverse pump screens are predisposed.

The article is devoted to studying the contra-rotating stages with different impellers and blade discs. Determining the reduction of volumetric losses by modeling the contra-rotating stages in the software package ANSYS CFX. The work aimed to create and study the flow and characteristics: semi-open, closed impellers, and blade discs. As a result of the work, the following contra-rotating stages were determined and compared: the semi-opened impeller with the semi-opened blade disc; the closed impeller with the closed blade disc; the semi-opened impeller with the closed blade disc; the closed impeller with the semi-opened blade disc. As a result of research, fluid flows in contra-rotating stages and their characteristics in the form of pressure and efficiency were obtained. According to the obtained data, the expediency of using contra-rotating stages as a working body of the pump is written.

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.