Lugova S. Hydrodynamic Features of Designing Replaceable Flow Parts during Development of Unified Series of Centrifugal Pumps

The thesis work presents the research results of working process in the flow part of multistage centrifugal pump. The approach to pumping equipment modernization has been systematized by using replaceable flow part with the allowance for hydrodynamic features of the working process. A diagram has been substantiated for development of unified series of pumps with replaceable flow parts which per-mits to minimize the number of replaceable components. Analysis of variation of flow structure and physical nature of hydraulic losses in the flow part of multistage centrifugal pump intermediate stage is the basic content of the work. Transition criteria between the replaceable flow parts have been determined and a diagram for development of dimensional series of pumps with replaceable flow parts is proposed. Based on numerical study analysis of the working process in the flow part of centrifugal pump intermediate stage, a mathematical model of hydraulic losses in diffuser components is proposed and along with its application a mathematical model is de-fined more precisely for power distribution in the components of centrifugal pump intermediate stage. Key words: centrifugal pump, replaceable flow part, impeller, diffuser, mathematical model of losses, power character-istics, efficiency.