Experimental characteristic simulation for two-stage pipeline centrifugal compressor

International Conference on Compressors and their Systems 2019

Borovkov, A.I.^1 ; Voinov, I.B.^1 ; Galerkin, Yu.B.^2 ; Drozdov, A.A.^2 ; Soldatova, K.V.^2

Engineering Centre Centre of Computer-Aided Engineering Peter, Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, Saint Petersburg

195251, Russia^1

RandD Laboratory Gas Dynamics of Turbo Machines Peter, Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, Saint Petersburg

195251, Russia^2

关键词: Characteristic configurations;    Characteristics of pressures;    Compressor characteristics;    Dynamic characteristics;    Experimental characteristics;    Physical experiments;    Simulation methodology;    Tangential directions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/604/1/012052/pdf
DOI  :  10.1088/1757-899X/604/1/012052

来源: IOP

【 摘 要 】

Up to now, the design methods for centrifugal compressors have been based on results of physical experiments. The possibility of correct CFD calculation of centrifugal compressors gas-dynamic characteristics could fundamentally change the situation. Gas-dynamic projects will become more reliable, cheaper, and the performance of compressors will be improved. However, the problem has not been solved yet. The experience of various authors shows that CFD calculations in many cases do not align well with experimentally obtained data. The aim of this paper is to check whether the commercial CFD software is capable of simulating centrifugal compressor characteristics using a 16 MW pipeline two-stage compressor as an example. The calculated characteristics of pressure ratio, efficiency and head coefficient are compared with characteristics measured using the manufacturer test bench on air. The calculations are performed in two ways: in the first case the flow in the impeller-stator gaps is taken into consideration, and in the second one it is not. In the first case, we do not take into account friction losses of the outer surfaces of impeller shrouds and leakage through labyrinth seals. The interface "STAGE" averages the parameters of flow at the impeller outlet and vaneless diffuser inlet. The flow leaving the impeller is averaged in tangential direction. This way of calculation excludes the mixing process of high and low-energy flow zones at the exit of the impeller. The calculated characteristic configurations are similar to the experimental ones, but they are shifted to the area of higher flow rates, and the difference in pressure ratio is out of the limits acceptable for engineering and research. Calculations that take into consideration gap losses underestimate the maximum efficiency by up to 2.5%. The characteristics calculated without gap losses are closer to the experimental characteristics. However, it is hardly possible to use this circumstance as a recommendation for the simulation methodology. The problem needs further investigation.