Highly efficient centrifugal compressors series development for the turbo-cooling machines

Abstract

BACKGROUND: Currently, there is a growing demand for single-stage centrifugal compressors with a high pressure ratio. Such requirements encourage the use of high-pressure stages with high circumferential speeds u2 300 m/s, which leads to increased levels of Mach number and, as a consequence, pressure losses. Work to improve the efficiency of such steps leads to a reduction in energy consumption and an increase in the cooling capacity of refrigerating machines. AIMS: To develop a series of ten highly efficient high-head model centrifugal compressors with the pressure ratio of c = 2.0. MATERIALS AND METHODS: a complex calculation technique developed by the authors is used to increase the efficiency of the stages of centrifugal compressors. The method consists of sequential execution of 4 stages: gas dynamic calculation, profiling, three-dimensional viscous calculation, multiparametric optimization. RESULTS: a series of the model centrifugal compressors has been designed for the following range of design mode parameters: conditional flow coefficient 0.035 Fr0.12; theoretical head coefficient t.p. =0.74; conditional Mach number 0.93Mu0.96. The estimated isentropic efficiency of the developed centrifugal compressors ranges from 77% to 84%, depending on the flow rate of the stage. CONCLUSIONS: a series of ten highly efficient flow parts of centrifugal compressors have been developed, which can be used in gas-dynamic projects when designing modern centrifugal compressors.