Advances in solar thermal power plants based on pressurised central receivers and supercritical power cycles

This work addresses the comparative thermo-economic study of different configurations of solar thermal power plants, based on supercritical power cycles and pressurised central receiver systems. For all the cases examined, two innovations are introduced in the solar subsystem, compared to other simi...

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Detalhes bibliográficos
Autores: Guedez Mata, Rafael, Linares Hurtado, José Ignacio, Reyes Belmonte, Miguel Ángel, Montes Pita, María José
Tipo de documento: artigo
Data de publicação:2023
País:España
Recursos:Universidad Nacional de Educación a Distancia
Repositório:e-spacio. Repositorio Institucional de la UNED
Idioma:inglês
OAI Identifier:oai:e-spacio.uned.es:20.500.14468/12402
Acesso em linha:https://hdl.handle.net/20.500.14468/12402
Access Level:Acceso aberto
Palavra-chave:Solar thermal power plant
Microchannel receiver
Radial configuration
Supercritical power cycle
Supercritical fluid
Pressurised gas
Descrição
Resumo:This work addresses the comparative thermo-economic study of different configurations of solar thermal power plants, based on supercritical power cycles and pressurised central receiver systems. For all the cases examined, two innovations are introduced in the solar subsystem, compared to other similar studies. Firstly, the heat transfer fluid in the receiver is either a pressurised gas or a supercritical fluid. Secondly, the receiver is composed of compact structures performing as absorber panels, arranged in a radial configuration. The investigation considers different supercritical CO2 recompression cycles of 50 MWe, including a novel proposal of a directly coupled cycle with heat input downstream of the turbine. Furthermore, the study evaluates different heat transfer fluids in the receiver, specifically CO2, N2, and He, concluding that the former is preferred due to its better thermal performance. The main results show that an increase in the receiver inlet pressure yields to a reduction in its size, favouring the thermal efficiency but penalising the optical efficiency of the solar field. Therefore, optimal working pressures may exist for each configuration, depending on the operating temperature. When comparing the optimal configurations, it is observed that the plant based on the intercooling cycle demonstrates the highest overall efficiency, reaching 32.05%. At last, an economic analysis is conducted to assess the viability of the identified optimal configurations. In this regard, the plant based on the partial-cooling cycle exhibits the lowest levelised cost of electricity at 0.15 $/kWh. This is primarily due to its lower investment cost. The innovative directly coupled cycle follows closely with a cost of 0.17 $/kWh, driven by its high electricity production resulting from its low self-consumption.