Projeto do gas-path em compressores centrífugos operando com dióxido de carbono em estado supeecritico através do método de curvatura de linha de corrente
Centrifugal compressors are the main type of compressor used in the oil and gas industry. Modern GHG (Greenhouse Gases) mitigating technologies such as the CCS (Carbon Capture and Storage) usually require the compressor to operate with CO2 at the supercritical condition. This work presents a methodology to design the flow path of a centrifugal compressor impeller for future CCS operation on deep Brazilian pre-salt reservoirs. The design process is based on the analysis of the 2D throughflow solution by using a streamline curvature method. The method was modified to use the SW (Span-Wagner) state-of-art EoS (Equation of State) for CO2. A computational code, with a graphical user interface, was developed to facilitate the design process. Automated features expedite the process of data preparation and CAD (Computer Aided Design) model exportation. To avoid the possibility of condensation, three different suction total temperatures were purposed. The impeller’s preliminary 1D sizing was evaluated and some improvements were addressed before starting the flow path design. The software proved its capability to deliver a detailed impeller design required for complex 3D FEM (Finite Element Method) and high fidelity CFD (Computational Fluid Dynamics) analysis. The increment of the suction total temperature showed small impacts on the isentropic efficiencies. At low suction temperatures, however, the phase change can become an issue and further analysis must be conducted to assure a condensation-free operation.