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Authors
Abstract(s)
A refrigeração está presente em quase todas as áreas que integram a sociedade, quer de uma forma
simples, como é o caso dos pequenos eletrodomésticos, quer de uma forma mais complexa, como
os grandes entrepostos de pescado. Num mercado cada vez mais competitivo e exigente, surge a
necessidade de aperfeiçoar todos os componentes do ciclo de refrigeração, sendo o compressor
uma peça fulcral no desempenho do ciclo, incindindo sobre este componente que os principais
objetivos deste trabalho.
Tendo em conta as diversas alterações à utilização dos fluidos frigorigéneos decorrentes da
aplicação do Regulamento nº 514/2014 do Parlamento Europeu, neste trabalho é proposto um
algoritmo que permite através de alguns parâmetros de entrada estimar o desempenho do
compressor, num determinado regime de trabalho.
Numa primeira fase foi desenvolvido um modelo termodinâmico para o compressor de frio, tendo
por base as equações inerentes ao processo de compressão de vapor saturado e que identificam o
ciclo frigorífico. Foi ainda realizada uma análise de sensibilidade que possibilitou a definição do
modelo para o compressor ideal de refrigeração, sendo o objetivo o cálculo do desempenho que
caracteriza o comportamento do compressor, de modo a fazer uma comparação direta entre um
modelo real do fabricante e o respetivo modelo teórico equivalente, para diferentes tipos de
compressores alternativos e para diferentes regimes de aplicação.
Tendo em conta as diretivas europeias e a consequente renovação dos fluidos frigorigéneos imposta
pelo Parlamento Europeu, foi posteriormente realizada numa segunda fase, uma previsão do
desempenho dos compressores estudados para novos fluidos frigorigéneos em relação ao trabalho
de compressão, à capacidade frigorífica e ao COP. Na análise efetuada comprovou-se que a
utilização de fluidos com um menor PAG (Potencial de Aquecimento Global), é bastante benéfica
para o meio ambiente e que o seu impacto no desempenho do compressor pode até ser positivo.
Refrigeration is regularly present in our daily lives, either in a simple way, like the small refrigerator we have at home, or in a more complex way, such as the cold warehouses where there are some large refrigeration equipment. In an increasingly competitive and more demanding market, it is necessary the improvement of all the components of the refrigeration cycle. As the compressor is a key part in the performance of the cycle, it was the component studied within this work. Taking into account the current concept of industry 4.0 and the constant changes in refrigerants that have occurred in recent years due to Regulation nº 514/2014 of the European Parliament, a theoretical algorithm was developed that allows, through some input parameters, predict the performance of the compressor, as well as the impact of each parameter introduced on its behavior. Firstly, a realistic and thermodynamic model was created based on the equations that are inherent to the compression process and that represent the refrigeration cycle. A sensitivity analysis was also carried out that allowed the definition of the theoretical model for the ideal refrigeration compressor, being the objective the calculation of the performance that characterizes the behavior of the compressor in order to make a direct comparison of a real model of the manufacturer as the equivalent theoretical model, for different types of compressors alternative and different applicationregimes. Taking into account European directives and a consequent renewal of refrigerant fluids imposed by the European Parliament, it was carried out in a second phase, a forecast of the performance of the compressors studied for new refrigerants in relation to the compression work, the cooling capacity and the COP. In the analysis carried out it was proved that the use of fluids with a lower PAG, is quite beneficial for the environment and that its impact on the performance of the compressor can even be positive.
Refrigeration is regularly present in our daily lives, either in a simple way, like the small refrigerator we have at home, or in a more complex way, such as the cold warehouses where there are some large refrigeration equipment. In an increasingly competitive and more demanding market, it is necessary the improvement of all the components of the refrigeration cycle. As the compressor is a key part in the performance of the cycle, it was the component studied within this work. Taking into account the current concept of industry 4.0 and the constant changes in refrigerants that have occurred in recent years due to Regulation nº 514/2014 of the European Parliament, a theoretical algorithm was developed that allows, through some input parameters, predict the performance of the compressor, as well as the impact of each parameter introduced on its behavior. Firstly, a realistic and thermodynamic model was created based on the equations that are inherent to the compression process and that represent the refrigeration cycle. A sensitivity analysis was also carried out that allowed the definition of the theoretical model for the ideal refrigeration compressor, being the objective the calculation of the performance that characterizes the behavior of the compressor in order to make a direct comparison of a real model of the manufacturer as the equivalent theoretical model, for different types of compressors alternative and different applicationregimes. Taking into account European directives and a consequent renewal of refrigerant fluids imposed by the European Parliament, it was carried out in a second phase, a forecast of the performance of the compressors studied for new refrigerants in relation to the compression work, the cooling capacity and the COP. In the analysis carried out it was proved that the use of fluids with a lower PAG, is quite beneficial for the environment and that its impact on the performance of the compressor can even be positive.
Description
Trabalho final de mestrado para obtenção do grau de Mestre em Engenharia Mecânica
Keywords
Compressor Algoritmo teórico Indústria 4.0 Fluido frigorigéneo PAG Theoretical algorithm Industry 4.0 Working fluid GWP
Citation
NUNES, Henrique Martins – Algoritmo do modelo teórico para o compressor ideal de refrigeração. Lisboa: Instituto Superior de Engenharia de Lisboa, 2021. Dissertação de Mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa