This work discusses a preliminary thermodynamic assessment of three different supercritical CO2(sCO2) power cycles applied to a high temperature solar tower system, with maximum temperatures up to 800 °C. The thermal power is transferred from the solar receiver to the power block through KCl-MgCl2molten salts as heat transfer fluid, therefore an indirect cycle configuration is considered assuming a surrounded field as the one of Gemasolar plant. The most promising cycle configuration in terms of solar-to-electric efficiency is selected, optimizing the cycle turbine inlet temperature to achieve the best compromise between cycle and receiver performance: the highest efficiency at design conditions is achieved by the Recompression with Main Compression Intercooling (RMCI) configuration with a solar to electric efficiency of 24.5% and a maximum temperature of 750 °C. The yearly energy yield of the proposed power plant is estimated with a simplified approach and results in the range of 18.4%: the performance decay from design to average yearly conditions is mostly due to the optical and thermal efficiencies reduction (−10.8% and −16.4%, respectively).

Preliminary assessment of sCO2cycles for power generation in CSP solar tower plants

BINOTTI, MARCO;ASTOLFI, MARCO;CAMPANARI, STEFANO;MANZOLINI, GIAMPAOLO;SILVA, PAOLO
2017-01-01

Abstract

This work discusses a preliminary thermodynamic assessment of three different supercritical CO2(sCO2) power cycles applied to a high temperature solar tower system, with maximum temperatures up to 800 °C. The thermal power is transferred from the solar receiver to the power block through KCl-MgCl2molten salts as heat transfer fluid, therefore an indirect cycle configuration is considered assuming a surrounded field as the one of Gemasolar plant. The most promising cycle configuration in terms of solar-to-electric efficiency is selected, optimizing the cycle turbine inlet temperature to achieve the best compromise between cycle and receiver performance: the highest efficiency at design conditions is achieved by the Recompression with Main Compression Intercooling (RMCI) configuration with a solar to electric efficiency of 24.5% and a maximum temperature of 750 °C. The yearly energy yield of the proposed power plant is estimated with a simplified approach and results in the range of 18.4%: the performance decay from design to average yearly conditions is mostly due to the optical and thermal efficiencies reduction (−10.8% and −16.4%, respectively).
High temperature molten salts; KCl-MgCl2; Molten salts receiver; sCO2cycle; Solar tower; Supercritical CO2; Civil and Structural Engineering; Building and Construction; Energy (all); Mechanical Engineering; Management, Monitoring, Policy and Law
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1034196
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