Integração da energia solar térmica por concentradores do tipo calha parabólica com uma usina termelétrica operando em ciclo combinado
Carregando...
Data
2023-03-01
Autores
Botamede, Bernardo Bergantini
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
A energia solar térmica é atualmente usada para a geração de energia como uma fonte confiável e livre de carbono em muitos países. Infelizmente, não existe este tipo de projeto comercial em operação no Brasil, embora se verifique um grande potencial solar. Nesse contexto, uma estratégia de transição é o desenvolvimento de uma usina solar híbrida que possa ser aplicada nas atuais usinas termelétricas. Desta forma, o presente trabalho investiga algumas alternativas de layout para o acoplamento de uma usina solar térmica com uma usina em operação de ciclo combinado (ciclo Brayton e Rankine) localizada na região centro-oeste do Brasil. Um sistema com coletor solar de calha parabólica foi selecionado para este estudo, considerando óleo sintético e sal fundido como fluidos de transferência de calor (HTF) na planta solar e água como fluido de trabalho no ciclo de potência. A modelagem termodinâmica e os modelos matemáticos foram desenvolvidos no software de código aberto OpenModelica. A modelagem termodinâmica da configuração atual da usina termelétrica foi validada através de dados operacionais reais cedidos por empresa privada. A usina solar térmica com concentrador solar com armazenamento térmico foi modelada e validada através do software de referência System Advisor Model (SAM) do National Renewable Energy Laboratory (NREL). Uma proposta de acoplamento da usina solar com armazenamento térmico foi feita através da caldeira de recuperação de calor (HRSG), considerando seis layouts com óleo sintético e seis layouts com sal fundido como fluido de trabalho na planta solar, nos quais a usina solar é usada para pré-aquecer a água, evaporar o vapor, superaquecer o vapor ou em uma combinação destes processos em paralelo com a caldeira. Dados horários de um ano meteorológico típico (TMY) foram utilizados como dados de entrada para cada simulação. Os resultados mostraram que os layouts que utilizam a energia solar para superaquecimento do vapor saturado apresentaram o melhor desempenho termodinâmico, com eficiência de conversão da energia solar para a elétrica de até 32,3%, e aumento de 1,5% na potência bruta média diária da turbina a vapor, em condições nominais de irradiação solar (DNI). Em uma base anual, a planta híbrida com o campo solar de 13.080 m² tem o potencial de evitar o consumo de combustível fóssil em até 34.410 MMBtu, representando até 1.997 ton CO2 de redução de emissões e até US$ 458.682,00 de economia de custos de combustível.
Solar Thermal Energy is currently used for power generation as a reliable carbon-free source in many countries. Unfortunately, there is no such commercial project under operation in Brazil, although large solar potential is identified. In this context, a transition strategy is to develop a hybrid solar plant which can be applied in current thermoelectric power plants. Therefore, the present work investigates some layout alternatives for coupling solar thermal plant with an operational plant base on combined cycle (Brayton and Rankine cycle) located in Brazil. A parabolic trough collector was selected for this study, as the most consolidated concentrated solar power (CSP) technology, considering either synthetic oil or solar salt as heat transfer fluid (HTF) and water as power block working fluid. Thermodynamic modeling and additional mathematical models were developed on the open-source software OpenModelica. The thermodynamic modeling of the current power plant model was validated through real operating data, provided by private company. The solar thermal plant with solar concentrator with thermal storage was modeled and validated using the reference software System Advisor Model (SAM) from National Renewable Energy Laboratory (NREL). A proposal for a combined solar power plant with thermal storage was made through the Heat Recovery Steam Generator (HRSG), considering six layouts with synthetic oil and six layouts with molten salt as working fluid in the solar field, where the solar plant is used either to preheat water, to evaporate steam, to superheat steam, or a combination of these processes in parallel with the HRSG. Hourly data from a Typical Meteorological Year (TMY) was used as input on each simulation. The results showed that layoutsusing solar energy to superheat the saturated steam presented the best thermodynamic performance, with an efficiency of conversion from solar to electric energy up to 32.3%, and an increase of 1.5% in the average steam turbine gross power, under nominal solar irradiation conditions (DNI). On an annual basis, the hybrid plant with the 13,080 m² solar field has the potential to avoid up to 34,410 MMBtu fossil fuel consumption, representing 1,997 ton CO2 of emissions reduction and up to US$ 458,682.52 in fuel cost savings.
Solar Thermal Energy is currently used for power generation as a reliable carbon-free source in many countries. Unfortunately, there is no such commercial project under operation in Brazil, although large solar potential is identified. In this context, a transition strategy is to develop a hybrid solar plant which can be applied in current thermoelectric power plants. Therefore, the present work investigates some layout alternatives for coupling solar thermal plant with an operational plant base on combined cycle (Brayton and Rankine cycle) located in Brazil. A parabolic trough collector was selected for this study, as the most consolidated concentrated solar power (CSP) technology, considering either synthetic oil or solar salt as heat transfer fluid (HTF) and water as power block working fluid. Thermodynamic modeling and additional mathematical models were developed on the open-source software OpenModelica. The thermodynamic modeling of the current power plant model was validated through real operating data, provided by private company. The solar thermal plant with solar concentrator with thermal storage was modeled and validated using the reference software System Advisor Model (SAM) from National Renewable Energy Laboratory (NREL). A proposal for a combined solar power plant with thermal storage was made through the Heat Recovery Steam Generator (HRSG), considering six layouts with synthetic oil and six layouts with molten salt as working fluid in the solar field, where the solar plant is used either to preheat water, to evaporate steam, to superheat steam, or a combination of these processes in parallel with the HRSG. Hourly data from a Typical Meteorological Year (TMY) was used as input on each simulation. The results showed that layoutsusing solar energy to superheat the saturated steam presented the best thermodynamic performance, with an efficiency of conversion from solar to electric energy up to 32.3%, and an increase of 1.5% in the average steam turbine gross power, under nominal solar irradiation conditions (DNI). On an annual basis, the hybrid plant with the 13,080 m² solar field has the potential to avoid up to 34,410 MMBtu fossil fuel consumption, representing 1,997 ton CO2 of emissions reduction and up to US$ 458,682.52 in fuel cost savings.
Descrição
Palavras-chave
Modelagem termodinâmica, Energia solar concentrada, Coletor de calha parabólica, Planta termelétrica, Ciclo combinado integrado a solar, Open Modelica, Thermodynamic modeling, Concentrated solar power, Parabolic trough collector, Integrated solar combined cycle, Power Plant