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Advisor(s)
Abstract(s)
Os últimos anos têm-se caracterizado por uma crescente preocupação com as alterações
climáticas e proteção do meio ambiente. As normas e os regulamentos são cada vez mais
rigorosos sobre as emissões de gases de efeito estufa (GEE) e utilização de
hidrofluorocarbonetos (HFC’s). O Regulamento F-gas (2014), aplicado aos gases
fluorados com efeito de estufa, impõe restrições de uso dos HFC’s de 21% até ao final de
2030, (com base nos níveis de 2015). No Protocolo de Quioto (1997), a União Europeia
assumiu o compromisso de reduzir 80 a 95% as emissões de GEE antes de 2050 (com
base nos níveis de 1990). Estes fatores impulsionam o mercado da refrigeração, a
desenvolver soluções com novas tecnologias, energeticamente mais eficientes e com
menor impacto no meio ambiente.
Este trabalho foi realizado no âmbito de um estágio de natureza profissional na empresa
Rase, S.A., como tal, foi possível o contacto com uma situação real. O caso de estudo
deste trabalho remete a uma das instalações de refrigeração implementadas pela empresa,
num supermercado. No setor da distribuição alimentar, destaca-se a utilização de uma
solução, designada por “sistema híbrido”, que consiste num sistema em cascata, que
utiliza dois fluidos frigorigéneos distintos. Pretendeu-se analisar esta nova solução e
verificar a sua viabilidade, usando R134a/R744, comparando com a solução tradicional
existente no supermercado a R404A. Numa primeira fase, fez-se o revamping da
instalação de refrigeração que se encontra implementada e operacional no supermercado
em estudo. Conhecendo a tipificação da instalação existente, selecionaram-se os
componentes principais da nova instalação e calculou-se a capacidade frigorífica total dos
compressores do novo sistema de refrigeração, de forma a responder às necessidades
frigoríficas da instalação existente (96 kW e 41,5 kW, para responder às necessidades de
média e baixa temperatura, respetivamente). A análise comparada das duas soluções
quanto ao impacto ambiental, foi possível através do cálculo do parâmetro climático
TEWI. Relativamente à eficiência energética, foi necessária uma instalação
implementada e operacional para ter uma referência-modelo da nova instalação. Assim,
conseguiu-se uma previsão quanto aos dados dos consumos de energia elétrica.
Recent years have seen concerns about climate change and environmental protection increasing. Standards and regulations are becoming stricter and stricter with regard to greenhouse gases (GHG) and the use of hydrofluorocarbons (HFCs). The F-gas Regulation (2014) for fluorinated greenhouse gases imposes restrictions on the use of HFCs, aimed at reducing them by 21% by the end of 2030 (based on levels in 2015). In the Kyoto Protocol (1997), the European Union undertook to reduce GHG emissions by 80 to 95% by 2050 (based on levels in 1990). These factors encouraged the refrigeration market to develop solutions using new technology that are more energy efficient and have less of an impact on the environment. The work described in this thesis was carried out in the context of a professional internship at Rase, S.A. and, as such, it was possible to experience a real-life situation. The case study for this thesis is one of the company’s refrigeration installations in a supermarket. Of note in the food distribution sector is the use of what is called a “hybrid system” solution. This solution consists of a cascade system that uses two different refrigerants. The aim was to analyse this new solution, which uses R134a/R744, and ascertain its viability, comparing it to the traditional solution used in the supermarket, R404A. First of all, the refrigeration installation used in the supermarket being studied was revamped. Based on the existing installation, the main components of the new installation were selected and the total refrigeration capacity of the compressors in the new refrigeration system was calculated, so that the refrigeration needs met by the existing installation could be duplicated (96 kW and 41.16 kW, to meet medium and low temperature needs, respectively). It was possible to make a comparative analysis of the two solutions as to their environmental impact by calculating the TEWI climate parameter. With regard to energy efficiency, it was necessary to have an installation implemented and operational in order to provide a reference model for the new installation, which made it possible to predict electricity consumption.
Recent years have seen concerns about climate change and environmental protection increasing. Standards and regulations are becoming stricter and stricter with regard to greenhouse gases (GHG) and the use of hydrofluorocarbons (HFCs). The F-gas Regulation (2014) for fluorinated greenhouse gases imposes restrictions on the use of HFCs, aimed at reducing them by 21% by the end of 2030 (based on levels in 2015). In the Kyoto Protocol (1997), the European Union undertook to reduce GHG emissions by 80 to 95% by 2050 (based on levels in 1990). These factors encouraged the refrigeration market to develop solutions using new technology that are more energy efficient and have less of an impact on the environment. The work described in this thesis was carried out in the context of a professional internship at Rase, S.A. and, as such, it was possible to experience a real-life situation. The case study for this thesis is one of the company’s refrigeration installations in a supermarket. Of note in the food distribution sector is the use of what is called a “hybrid system” solution. This solution consists of a cascade system that uses two different refrigerants. The aim was to analyse this new solution, which uses R134a/R744, and ascertain its viability, comparing it to the traditional solution used in the supermarket, R404A. First of all, the refrigeration installation used in the supermarket being studied was revamped. Based on the existing installation, the main components of the new installation were selected and the total refrigeration capacity of the compressors in the new refrigeration system was calculated, so that the refrigeration needs met by the existing installation could be duplicated (96 kW and 41.16 kW, to meet medium and low temperature needs, respectively). It was possible to make a comparative analysis of the two solutions as to their environmental impact by calculating the TEWI climate parameter. With regard to energy efficiency, it was necessary to have an installation implemented and operational in order to provide a reference model for the new installation, which made it possible to predict electricity consumption.
Description
Trabalho final de mestrado para obtenção do grau de mestre em Engenharia Mecânica
Keywords
Refrigeração comercial Commercial refrigeration Sistema tradicional a R404A Traditional R404A system Sistema em cascata a R134a/R744 R134a/R744 cascade system Impacto ambiental Environmental impact Eficiência energética Energy efficiency
Citation
MARTINS, Sara Ramos Andrade da Silva - "Revamping" de instalação frigorífica com aplicação de tecnologia avançada. Lisboa: Instituto Superior de Engenharia de Lisboa, 2017. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa