Synthetically Aerodynamic Design and Optimization on the Stationary Units of Centrifugal Compressor

The operating efficiency of a centrifugal compressor installed in air-separation plant was lower than the design parameter. In order to analyze the cause, a flow simulation on the whole centrifugal compressor was carried out on a parallel computational platform. The numerical results show that the inefficiency of the compressor was mainly caused by the flow loss in the stationary units. A synthetically aerodynamic redesign and optimization on the stationary units of the centrifugal compressor was performed to improve its polytrophic efficiency. Firstly, radial splitter vanes were appended in the flow passage of suction chamber to balance the flow loss and depress inlet flow distortion. Secondly, the meridian curve of the crossover and return channel was numerically optimized by using a combined neural network and genetic algorithm (GA) approach. Lastly, the b₃/b₂ of the vaneless diffuser was advanced to improve its total pressure recovery coefficient. An experimental measurement was carried out to validate the coupling effect of the improved stationary units to the centrifugal compressor performance. The experimental result shows that 4% advancement of the polytrophic coefficient of the centrifugal compressor has been achieved.