Efficient turbomachinery layout design and performance comparison of supercritical CO2 cycles for high-temperature concentrated solar power plants under peak-shaving scenarios

Abstract

The supercritical CO2 (S–CO2) cycle with high operating temperature for the next-generation concentrated solar power (CSP) technology are constructed. The turbomachinery layouts are designed and operating parameters are optimized to efficiently and flexibly respond to part-load operating conditions. The thermodynamic performance advantages of CSP plant based on S–CO2 cycle with high temperature and optimized turbomachinery layout under peak-shaving scenarios are clearly indicated. Results show that compared with the cycle with split shaft layout, the optimization of cycle turbomachinery layout can improve the part-load efficiencies of the cycle by 0.47%–2.33 %. The cycle connecting the turbine and main compressor is recommended to be adopted for deep peak-shaving scenarios, and its efficiency at 30 % rated load is only reduced to 86.3 % of the rated value. While the cycle connecting the turbine and re-compressor maintains superior efficiency performance when the load exceeds 60 % of the rated value. Furthermore, the increase of operating temperature to 750 °C and optimization of cycle turbomachinery layout can improve the efficiency of CSP plant to 21.60 % under PV-CSP peak-shaving scenarios, which is 0.55 % higher than that of the system based on cycle with split shaft layout and 2.18 % higher than that of the conventional CSP plant with 550 °C operating temperature.