Design of a Compact Dry Cooler With an Aluminum Heat Exchanger Core for a Supercritical CO2 Power Cycle Is Evaluated for a Concentrating Solar Power Application

Abstract

As the supercritical CO2 power cycle develops and the component technologies mature, there is still a need to reduce the associated costs to maintain a competitive levelized cost of electricity (LCOE) in order to enter the market. When considering concentrating solar power (CSP) coupled with an sCO2 power block and sensible thermal storage, the technology presents a clean source for utility-scale power generation to support baseload or peak-load electrical demand. However, the LCOE of the technology is still considered high and should be reduced to better compete in the market; 2030 targets are 5¢/kWh for dispatchable baseload solar plants and 10¢/kWh for peaker plants, as set by the U.S. Department of Energy. In response to this need, this study is targeting improvements in the power cycle pre-cooler to reduce power block contribution to LCOE. This paper details the high-level findings of a large sensitivity study for design point selection, compact dry cooler design, expected year-round performance for the cooler and power cycle, and the predicted LCOE for a 30-year plant life. It was found that an aluminum heat exchanger core can suitably meet the pressure and temperature requirements for an sCO2 recompression Brayton cycle. The dry cooler assembly was found to have improved heat transfer performance, allowing for increased cycle efficiencies and a reduced plant LCOE. When coupled with a centrifugal blower and compact transition duct, the dry cooler assembly was able to reduce the installation footprint by over 50%.