A computational fluid dynamic method for dense-phase carbon dioxide centrifugal pump

Abstract

As an advanced approach for large-scale low-carbon utilization of fossil energy, the carbon capture, utilization and storage technology is a promising means to achieve the carbon-neutrality target by 2060. Among the most widely used approaches for carbon storage is the enhanced oil recovery technique, for which the centrifugal pump is used to inject high-pressure dense-phase carbon dioxide (CO2) into the stratum. This work focuses on real fluid effects and inter-stage matching deviation from the incompressibility assumption for a dense-phase CO2 centrifugal pump, of which the inlet condition is close to the fluid critical point. With a thermophysical-state table for CO2 based on the thermophysical-property database of the National Institute of Standards and Technology embedded into a computational fluid dynamics solver, a numerical simulation method for compressible dense-phase CO2 pumps is established. The developed method is validated in the 50kW main compressor for a supercritical CO2 cycle and then applied to the simulation of a multistage dense-phase CO2 pump designed for carbon storage. The stage with the most remarkable fluid compressibility is determined, which provides a priori basis for the follow-up design optimization of the pump. This work is of promising application prospect for design of advanced dense-phase fluid machinery.