Ratushnyi O. Increasing head pressure in the centrifugal pump stage by cascade blade modernization of an impeller

In the dissertation presented a new solutionof a scientific problem, consisting in increasing the energy efficiency of the centrifugal pump stage. As away of solving this problem is considered the ability of creation of steps with considerably high pressure at constant geometric dimensions, feed amount and rotational speed. Based on a review of scientific and technical information has been proving the actuality the research topics and formulated its purpose and tasks. The solution of this scientific problem, which is to increase the pressure centrifugal pump stage by combining a variety of ways to influence the geometry of the blade grid of impellers: by using the double blade grid, truncated blade shape modification, the S-shaped blades with a larger angle of outlet. At the appropriate mathematical models to get a picture of flowin the impeller, which allow assessment of distribution of velocities and pressures and determining the geometric parameters that most significantly affect its energy characteristics. The optimum ratio of the basic geometrical parameters which allow increasing the pressure ofthe impeller between 15-30 % with almost the same level of efficiency. The influence of individual geometric parameters of impeller with the modernizing blades on its characteristics, which provided an opportunity to optimize for different parameters based on the methodology of experimental design, is stablished. It determined the range of high-speed ns = 65-95, in which the totality of increasing pressure and the efficiency are optimal. Indicated the possibility of using modernized impellers composed stage without replacing the guide vanes.