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Abstract(s)
A preocupação com as alterações climáticas causadas pelo aquecimento global e pelas emissões de gases de efeito de estufa, originaram restrições legislativas que limitam o uso de gases fluorados com efeito de estufa, pressionando o setor industrial e comercial como supermercados e hipermercados a aderir a outras alternativas mais viáveis não só do ponto de vista económico, mas também do ponto de vista ambiental. A alternativa passa pelo uso de fluidos frigorigéneos naturais, como por exemplo amoníaco, dióxido de carbono e água. Como cada fluido frigorigéneo natural apresenta as suas características, vantagens e desvantagens que as caracterizam, é cada vez mais importante tendo em conta as opções de fluidos naturais que existem no mercado, perceber, qual o que se melhor adequa para o uso de instalações frigoríficas comerciais. Dado que, existem diversos sistemas frigoríficos que usam fluidos frigorigéneos naturais, é importante também perceber quais os sistemas que mais se adequam para um determinado projeto. O presente trabalho tem
como principal objetivo caracterizar os sistemas a CO2 transcríticos, bem como o sistema a amoníaco com distribuição de água glicolada, e perceber através de um caso de estudo prático qual dos sistemas é o mais adequado. Para isso efetuou-se uma descrição dos fluidos frigorigéneos em estudo, sendo apresentadas as suas características, vantagens e desvantagens, bem como os tipos de sistemas em que estes podem ser encontrados e respetiva descrição dos componentes. Assim, será possível para o caso de estudo, escolher
o melhor sistema a CO2 e o melhor sistema a amoníaco com distribuição de água glicolada a utilizar, sendo depois efetuado todo o dimensionamento dos equipamentos bem como a sua implementação no caso de estudo. Para análise e comparação dos sistemas em estudo foram analisados indicadores de performance (KPI), que permitem no final perceber qual o sistema melhor.
Concerns about climate change caused by global warming and greenhouse gas emissions have led to legislative restrictions that limit the use of fluorinated greenhouse gases, pressuring the industrial and commercial sector such as supermarkets and hypermarkets to join other more viable alternatives not only from the economic point of view, but also from the environmental point of view. The alternative is the use of natural refrigerants, such as ammonia, carbon dioxide and water. As each natural refrigerant has its own characteristics, advantages and disadvantages that characterize them, it is increasingly important taking into account the options of natural fluids that exist in the market, to understand, which one is best suited for the use of commercial refrigerating systems. Given that there are several refrigeration systems that use natural refrigerants, it is also important to understand which systems are best suited for a particular project. The main objective of this work is to characterize the transcritical CO2 systems, as well as the ammonia system with glycol water distribution, and to understand through a practical case study which system is the most suitable. To this end, a description of the refrigerants under study was carried out, presenting their characteristics, advantages and disadvantages, as well as the types of systems in which they can be found and the respective description of the components. Thus, for the case study, it will be possible to choose the best CO2 system and the best ammonia system with distribution of glycol water to be used, and then all the equipment sizing will be done, as well as its implementation in the case study. For analysis and comparison of the systems under study, performance indicators (KPI) were analyzed, which allow us to understand wich system is better.
Concerns about climate change caused by global warming and greenhouse gas emissions have led to legislative restrictions that limit the use of fluorinated greenhouse gases, pressuring the industrial and commercial sector such as supermarkets and hypermarkets to join other more viable alternatives not only from the economic point of view, but also from the environmental point of view. The alternative is the use of natural refrigerants, such as ammonia, carbon dioxide and water. As each natural refrigerant has its own characteristics, advantages and disadvantages that characterize them, it is increasingly important taking into account the options of natural fluids that exist in the market, to understand, which one is best suited for the use of commercial refrigerating systems. Given that there are several refrigeration systems that use natural refrigerants, it is also important to understand which systems are best suited for a particular project. The main objective of this work is to characterize the transcritical CO2 systems, as well as the ammonia system with glycol water distribution, and to understand through a practical case study which system is the most suitable. To this end, a description of the refrigerants under study was carried out, presenting their characteristics, advantages and disadvantages, as well as the types of systems in which they can be found and the respective description of the components. Thus, for the case study, it will be possible to choose the best CO2 system and the best ammonia system with distribution of glycol water to be used, and then all the equipment sizing will be done, as well as its implementation in the case study. For analysis and comparison of the systems under study, performance indicators (KPI) were analyzed, which allow us to understand wich system is better.
Description
Trabalho final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica
Keywords
Fluidos naturais CO2 transcrítico Amoníaco Água glicolada Instalações frigoríficas comerciais Eficiência energética Refrigeração Natural fluids Transcritical CO2 Ammonia Glycol water Commercial refrigeration plants Energy efficiency Refrigeration
Citation
ATALAIA, João Miguel Oliveira – Estudo comparativo de instalações frigoríficas comerciais com CO2 transcrítico versus amoníaco e água glicolada. Lisboa: Instituto Superior de Engenharia de Lisboa, 2021. Dissertação de Mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa