Concentrated solar power (CSP) is a promising alternative to conventional fossil fuel energy for the future electricity generation. Upgrading the power block with a supercritical carbon dioxide (S-CO2) cycle is regarded as a promising approach to achieving better efficiency and lower levelized cost of electricity (LCOE) for the CSP plant. This work performs an optimal design of the S-CO2 cycle based system for the CSP application based on the evaluation of both design-point and off-design performance. The design optimization begins with the selection of the intercooling configuration for the compressors. Then, the exegoeconomic analysis is performed for the CSP plant integrated with the SCO2 cycle based system. Moreover, the superstructure-based optimization is applied to obtain the optimal configuration for the S-CO2 cycle based system. After the design-point optimization, the off-design performance of the S-CO2 cycle based system with different control schemes is investigated. The effect of real-time parametric optimization on the cycle off-design performance is also evaluated. Finally, two case studies under different meteorological conditions are conducted to find the optimum design values for the main compressor (MC) inlet temperature (TMC,in,d) based on cycle annual performance. The results of the design-point study show that the main compression intercooling (MCIC) is the optimal intercooling configuration. The exergoeconomic analysis identifies the interaction between the S-CO2 cycle based system and the TES system during the optimal integration and indicates the cycle hot-end configuration has apparent effects on both the cycle efficiency and LCOE. The S-CO2 cycle based system features an MCIC recompression or partial cooling configuration in the cold end and a simple configuration in the hot end is identified as the optimal design result. The off-design study indicates that the modified configuration of the MC can prevent the hazardous conditions under off-design conditions, which cannot be fully addressed with the basic configuration. The cycle with variable pressure (VP) control mode has an apparent improvement in cycle energetic efficiency (η ̄en,cycle) with real-time parametric optimization, yet at the cost of the reductions in both net output power and temperature differential for thermal input. By contrast, the fixed pressure (FP) control mode with real-time parametric optimization can maintain higher net output power and temperature differential for thermal input, despite the less improvement in η ̄en,cycle. The hybrid between these two pressure control modes is recommended to meet the demands for different operating situations of the CSP plant. The annual performance evaluation shows that the optimum TMC,in,d for the FP subcase and VP subcase,are 32 ◦C and 41 ◦C respectively, in the Delingha case; the TMC,in,d to result in the optimum efficiency is 41 ◦C for both FP and VP subcases in the Daggett case.
Optimal design of supercritical carbon dioxide cycle based system for concentrated solar power application
Optimaler Entwurf eines auf dem überkritischen Kohlendioxid-Kreislauf basierenden Systems für die Anwendung konzentrierter Sonnenenergie
2020
Sonstige
Elektronische Ressource
Englisch
DDC: | 629 |
Marine generator direct cooling system based on supercritical carbon dioxide power cycle
Europäisches Patentamt | 2024
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