Detailed Design and Optimization of the First Stage of an Axial Supercritical CO2 Compressor

Abstract

Advancement in energy storage technology is critical in the transition to increased renewable energy sources. The thermodynamic properties of S-CO2 allow for high thermal efficiency and power density potential in turbomachinery design. Relative to the Steam Rankine and Air Brayton cycles, S-CO2 cycles benefit in performance, size, and cost. As S-CO2 gains acceptance in the industry, research must be conducted to understand the potentials and limitations of this new technology; this is key to the eventual commercial viability of S-CO2 applications. Currently, applications of S-CO2 in turbomachinery are limited to centrifugal design due to the complex fluid properties and flow interactions. Advancements in compressor design now allow for the intelligent navigation of this complex design space. Optimization tools are utilized to evaluate parametrically defined blades in S-CO2 working fluid to explore advanced, high-performance geometries. The first axial S-CO2 compressor is designed using this optimization based methodology. This design is the scaled 9 MW 3 stage version of a larger 100 MW 9 stage compressor that will be used for an energy storage application. The adiabatic efficiency of the first stage design is estimated at 91.6% with 3.14 MW of power at 19,800 rpm. The blade height at the rotor leading edge is 3.28 cm. The first stage of the scaled 9 MW 3 stage compressor will be tested at the University of Notre Dame Turbomachinery Lab; testing of the complete 3 stage machine will follow the single stage testing. Stage one design drawings have been finalized and submitted for manufacturing. The IGV and Stator 1 have been manufactured and received by the University of Notre Dame Turbomachinery Lab for assembly and testing in the Fall of 2022.