| dc.description.abstract | Supercritical Carbon Dioxide (sCO2) power cycles are a transformational technology for the energy industry, providing higher thermal efficiency compared to traditional heat-source energy conversion including conventional fossil and alternative energy sources. The novel cycle significantly reduces capital costs due to smaller equipment footprints and design modularity. In addition, it allows for rapid cyclic load and source following to balance solar and wind energy power swings. Recent testing has been performed on a 2.5 MW sCO2 compressor operating near the dome. Compressing CO2 is not novel, but mostly at lower vapor pressures, and also at higher pressure and lower temperatures as a liquid. Compression near the dome is a new interest that has many advantages and challenges. The key advantage is the low head requirement when compressing near the CO2 dome (35cC [95oF] and 8.5 MPa [1,233 psi]). To pressurize from 8.5 MPa (target inlet pressure of power cycle) to 27.0 MPa (3,916 psi), only a single compressor stage is required. This low head requirement means much less power is required to compress and leads to overall increase in thermal efficiency of these various power cycles. This kind of technology could also be used to reduce the power of Enhanced Oil Recovery (EOR) and Carbon Capture Sequestration (CCS) applications.This type of compression also brings many challenges. A compressor for this application pushes many current technology limits, including but not limited to: bearing technologies, sealing technologies, damping, rotordynamics, compact machinery packaging, and high-density high-speed compression. In addition, when compressing near the CO2 dome, there are large swings in density for slight changes in temperature. This is a unique challenge not observed when CO2 is pumped or compressed as a liquid or vapor. Due to these large changes in density, range extension is required to maintain high compression efficiency and controlled mass flow over a range of operating temperatures. This particular compressor will utilize actuated inlet guides vanes (IGVs) and represents the highest density centrifugal compressor reported in the literature with densities over 60% of water. | |
