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Abstract(s)
Em Portugal, diariamente, milhares de pessoas frequentam ginásios com a finalidade de praticar exercícios físicos. Os utilizadores ingerem alimentos, ou seja, energia, e despendem-na em máquinas de ginásios praticando exercícios físicos, sendo essa energia desperdiçada e com potencial de ser recuperável. Paralelamente, a situação atual do planeta exige que todas as oportunidades de recuperação de energia sejam equacionadas, para que se cumpram as metas estabelecidas pelo acordo de Paris (COP 21), fazendo face às alterações climáticas que já enfrentamos. A nossa sociedade cada vez é mais dependente de energia para o quotidiano, o objetivo desta dissertação consiste em verificar a viabilidade da implementação de um sistema de recuperação da energia cinética dissipada numa máquina de ginásio. O utilizador da máquina de ginásio, ao efetuar o seu exercício físico levanta os pesos e os cabos acionam o gerador incorporado na polia. Por sua vez, o gerador irá transformar a energia mecânica em energia elétrica aos seus terminais. Essa energia elétrica será utilizada como autoconsumo na rede elétrica do ginásio. Uma vez que o potencial gerador não será superior ao consumo instantâneo do ginásio, não existe necessidade de armazenar essa energia elétrica, pois seria mais um custo para incrementar ao sistema. Foi realizada uma visita a uma fábrica de bicicletas elétricas, a Miralago, com a finalidade de conhecer a tecnologia utilizada nesse sistema. Nessa visita, fiquei a conhecer o motor de cubo, que é adequado para substituir numa polia de uma máquina de ginásio atual, de forma a recuperar a energia cinética e convertê-la para energia elétrica. Abordou-se também de uma forma simplificada, quais seriam os custos de implementação do sistema, prevendo quais seriam os equipamentos necessários para que o sistema pudesse através da energia cinética, gerar energia elétrica. Foram efetuadas medições numa máquina de ginásio, de forma a poder quantificar a energia desperdiçada numa máquina real, com um utilizador, onde foi possível medir a velocidade de rotação com recurso a um equipamento de medição denominado de tacómetro. Obteve-se dados de tempo e velocidade de rotação que foram a base do trabalho desenvolvido, tornando possível prever qual a quantidade de energia elétrica produzida e mediante os pressupostos estabelecidos.
Assim verifica-se que a potência média difere entre as duas máquinas estudadas, sendo mais favorável a máquina Puxador Vertical, com uma potência média para duas máquinas de 232 W, considerando 1.413 horas de utilização efetiva, o período de retorno do investimento realizado é cerca de 12 anos. Estes valores foram obtidos, convertendo uma máquina atual, adquirindo peças apenas para adaptar duas máquinas, e poderá tornar-se mais atrativo caso os fabricantes incluam este sistema nas máquinas já comercializadas, produzindo em escala. Devido à máquina elétrica utilizada apenas gerar energia em dois sentidos, foi necessário equipar cada máquina com dois geradores, de forma a captar a energia cinética do movimento ascendente e descendente, aumentando a energia recuperada, mas também o custo no investimento. Caso se encontre uma forma de reduzir o número de geradores de dois para um por máquina, mantendo a energia gerada, o período de retorno do investimento irá diminuir significativamente.
In Portugal, thousands of people go to gyms every day for the purpose of practicing physical exercises. Users ingest food, that is energy, and spend it on gymnasium machines practicing physical exercises, being this energy wasted and has potential to be recoverable. At the same time, the current situation of the planet requires that all opportunities for energy recovery be addressed, so that they can be fulfilled as goals defined by the Paris agreement (COP 21), combating the climate changes we have already faced. As our society is increasingly dependent on energy for everyday life, the aim of this dissertation is to verify the feasibility of implementing a kinetic energy recovery system dissipated in a gym machine. The user, when exercising, lifts the weights and the cables drive the generator incorporated in the pulley. The generator will transform the mechanical energy into electrical energy to its terminals. This electric energy will be used as self-consumption in the electrical network of the gym. Since the potential generator will not exceed the instant consumption of the gym, there is no need to store this electric energy, as it would be a cost to increase the system. A visit to a factory of electric bicycles, Miralago, was carried out in order to know the technology used in this system. On that visit, I got to know the hub motor, which is suitable for replacing on a pulley of a current gym machine, in order to recover the kinetic energy and convert it to electric power. It was also addressed in a simplified way, what would be the costs of implementing the system, predicting what equipment would be necessary for the system to be able to generate electricity through kinetic energy. Measurements were carried out on a gym machine in order to quantify the energy wasted on an actual machine with a user, where it was possible to measure the speed of rotation using a metering equipment called a tachometer. It was obtained data of time and speed of rotation that were the basis of the work developed, making it possible to predict the amount of electric energy produced and the established assumptions. Thus, it is verified that the average power differs between the two machines studied, being more favorable the Vertical Handle machine, with an average power for two machines of 232 W, considering 1.413 hours of effective use, the payback period is about of 12 years. These values were obtained by converting a current machine, acquiring parts only to adapt two machines, and could become more attractive if the manufacturers include this system in the already commercialized machines, producing in scale. Due to the electric machine used only to generate energy in two directions, it was necessary to equip each machine with two generators, in order to capture the kinetic energy of the up and down movement, increasing the recovered energy but also increasing the investment cost. If a way is found to reduce the number of generators from two to one per machine, keeping the energy generated, the payback period of the investment will decrease significantly.
In Portugal, thousands of people go to gyms every day for the purpose of practicing physical exercises. Users ingest food, that is energy, and spend it on gymnasium machines practicing physical exercises, being this energy wasted and has potential to be recoverable. At the same time, the current situation of the planet requires that all opportunities for energy recovery be addressed, so that they can be fulfilled as goals defined by the Paris agreement (COP 21), combating the climate changes we have already faced. As our society is increasingly dependent on energy for everyday life, the aim of this dissertation is to verify the feasibility of implementing a kinetic energy recovery system dissipated in a gym machine. The user, when exercising, lifts the weights and the cables drive the generator incorporated in the pulley. The generator will transform the mechanical energy into electrical energy to its terminals. This electric energy will be used as self-consumption in the electrical network of the gym. Since the potential generator will not exceed the instant consumption of the gym, there is no need to store this electric energy, as it would be a cost to increase the system. A visit to a factory of electric bicycles, Miralago, was carried out in order to know the technology used in this system. On that visit, I got to know the hub motor, which is suitable for replacing on a pulley of a current gym machine, in order to recover the kinetic energy and convert it to electric power. It was also addressed in a simplified way, what would be the costs of implementing the system, predicting what equipment would be necessary for the system to be able to generate electricity through kinetic energy. Measurements were carried out on a gym machine in order to quantify the energy wasted on an actual machine with a user, where it was possible to measure the speed of rotation using a metering equipment called a tachometer. It was obtained data of time and speed of rotation that were the basis of the work developed, making it possible to predict the amount of electric energy produced and the established assumptions. Thus, it is verified that the average power differs between the two machines studied, being more favorable the Vertical Handle machine, with an average power for two machines of 232 W, considering 1.413 hours of effective use, the payback period is about of 12 years. These values were obtained by converting a current machine, acquiring parts only to adapt two machines, and could become more attractive if the manufacturers include this system in the already commercialized machines, producing in scale. Due to the electric machine used only to generate energy in two directions, it was necessary to equip each machine with two generators, in order to capture the kinetic energy of the up and down movement, increasing the recovered energy but also increasing the investment cost. If a way is found to reduce the number of generators from two to one per machine, keeping the energy generated, the payback period of the investment will decrease significantly.
Description
Dissertação para obtenção do grau de mestre em Engenharia Mecânica
Keywords
Exercício físico Physical exercise Geração de energia elétrica Electric power generation Recuperação de energia cinética Kinetic energy recovery Autoconsumo Self-consumption Energia renovável Renewable energy
Citation
LOURENÇO, André Filipe Fialho - Estudo da geração de energia elétrica proveniente da utilização de uma máquina de ginásio. Lisboa: Instituto Superior de Engenharia de Lisboa, 2018. Dissertação de mestrado.
Publisher
Instituto Superior de Engenharia de Lisboa