TCC - Engenharia Mecânica (UACSA)
URI permanente para esta coleçãohttps://arandu.ufrpe.br/handle/123456789/2920
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Resultados da Pesquisa
Item Desenvolvimento de um código computacional para estudo parametrizado da carga térmica de uma câmara frigorífica(2021-03-01) Moreira, José Luciano Batista; Marques, Adriano da Silva; http://lattes.cnpq.br/0104058705628000; http://lattes.cnpq.br/9231432778525972Cold rooms are fundamental equipments for the preservation of perishable foods, guaranteeing the maintenance of the quality of the products in the stages of their processing and distribution. The correct dimensioning of this equipment represents efficiency related to the cooling and freezing performance, as well as the energy efficiency of the system. Thus, this project deals with the development of a computational code on the EES platform (Engineering Equation Solver) to determine the energy consumption of the evaporator unit (thermal load) of a cold room. The cold storage was designed to be installed in the city of Belém do Pará, responsible for storing 5 tons per day of apples and 10 tons per day of pork. The study also presents parameterized results for the thickness of the thermal insulation and the inlet temperature of the products, applying the equations of the thermal load by conduction and the load by the product. The values applied to the parametric variation respect the conditions established by the current technical standards, related to the refrigerated storage of food. It was verified that the discrepancy between the maximum and minimum operation regimes of the cold room, represents a reduction of approximately 20,19% of the energy consumption of the evaporator unit. Thus, it can be concluded that the parameterized study can result in a diagnosis of energy savings for cold storage projects.Item Dimensionamento e seleção de equipamentos de uma câmara frigorífica hipotética destinada ao congelamento de frutos do mar e resfriamento de hortaliças(2021-02-25) Silva, Matheus Silvestre; Marques, Adriano da Silva; http://lattes.cnpq.br/0104058705628000; http://lattes.cnpq.br/7747778014491031Among the industrial applications of refrigeration, the food sector can be highlighted. Using concepts of thermodynamics, heat transfer, fluid mechanics, refrigeration and project management, this work deals with the sizing of a cold room for freezing 5 T/day of fish and cooling 3 T/day of fresh produce. The work started with the definition of the project premises, followed by the collection of storage parameters for each product as instructed by the responsible agencies. From there, the thermal load of the cold room was calculated. The sizing was performed following the methodology of the ASHRAE refrigeration manual. A computational code was developed using the EES (Engineering Equation Solver) platform. Values of 5.26 TR, 7.27 TR and 86.59 TR were obtained for the tomato, carrot, and fish chambers, respectively. The fruit and vegetable chambers were dimensioned at 62.40 m3 in volume each, while the fish chamber was at 112.86 m3 in volume. Thus, two condensing units were selected for the fruit and vegetable chambers, with capacities of 6.13 TR and 7.60 TR respectively, and eight units for the fish chamber with a capacity of 10.82 TR. The project costs were estimated at just over R$ 500.000, which includes: equipment, freight and installation costs.Item Projeto de uma caixa de redução por engrenagens cilíndricas retas para um veículo Baja SAE(2021-12-10) Andrade, Douglas Santana; Farias Filho, João Gutemberg Barbosa de; http://lattes.cnpq.br/0718103459959119; http://lattes.cnpq.br/6243297653363605The system designed by the present work is a gearbox that uses straight cylindrical gears to reduce the rotation speed of the engine and increase the torque transmitted to the wheels. The design is made based on the maximum stresses present in the parts. These tensions will serve as a parameter to choose the materials to make the gears, shafts, keys and select the bearings. The study of the tensions present in the axes is done through the calculation of bending moment and shear force. The gears are designed according to the AGMA standard for cylindrical spur gears. The selection of the bearings is made by comparing the result of the calculation of the theoretical load on the bearing and the parts present in the catalogs. The material to be used as braces is selected by comparing the stress results with the tensile strength limit of each material. Throughout the calculation of the geometry of the parts, it is noticed that it is possible to design the box to be compact and resistant so that it has an easy installation on the vehicle.Item Dimensionamento e seleção de equipamentos para um sistema de acondicionamento e refrigeração de frutas e carnes(2021-02-12) Oliveira, Diêgo Mendes de; Marques, Adriano da Silva; http://lattes.cnpq.br/0104058705628000Refrigeration and air conditioning allow, through the storage method, an extension in the life of alimentary products in places with adverse climates. This work constitutes the design and of a cold room that should be installed in Belém-PA, responsible for the packaging and refrigeration of apple and pork respectively. The project consists in the calculation of the thermal load and the specifications of the equipment necessary for the operation of a cold chamber. In this work, we specified the factors that influenced the development of the project and the equipment’s principle of operation. The designed system uses the steam mechanical compression cooling cycle with the R-404a refrigerant. The cold storage chamber in question has a capacity to cool five tonnes of apple (at a temperature of 0 °C) and freeze ten tonnes of pork (at a temperature of -5.5 °C) daily. All calculation of the project, was based on the current technical standards of ASHRAE (American Society of Heating, Refrigerating and AirConditioning Engineers), aiming at equipment that offers safety to its operators, consumers and a good economic condition of operation. For the physical space, the expanded polyurethane was used as insulating material, with a thickness of 100 mm. The results obtained indicate that the largest portion of thermal load involved in the project would be related to the products, reaching 21.77 kW for apples and 137.7kW for pork, which means 97% of the total value of the total thermal load. The results indicate that the projected system should promote a heat removal of 736,7 BTU/h from the internal space, using three evaporators and five condensing units.Item Projeto de dimensionamento e seleção de equipamentos para uma câmara frigorífica de congelamento de carnes e resfriamento de laticínios(2021-01-21) Costa, Mateus de Albuquerque Souza; Marques, Adriano da Silva; http://lattes.cnpq.br/0104058705628000; http://lattes.cnpq.br/4446185927194653The food industry condenses one of the biggest applications of industrial refrigeration, be it in the development, storage or distribution of food. Applying knowledge of refrigeration and heat transfer, the present paper has as objective describe the steps of dimensioning a cold store for a supermarket located in the city of Corumbá - MS, with a freezing demand of 15 T/day of beef and cooling of 5000 L/day of curd. In order for the project to be developed, the storage characteristics of the food under study, such as temperature and storage volume, were initially collected. With this information, the dimensioning of the thermal load of the beef and curd chambers was carried out taking into account the product loads, infiltration, heat transmission, people, lighting and equipment. The entire calculation was developed according to the ASHRAE refrigeration manual and using the Engineering Equation Solver (EES) software. For the meat chamber a total thermal load of 269,562 kcal/h was obtained, while for the curd chamber the calculated load was 32,674 kcal/h. In addition, the product storage shelves and cold rooms were dimensioned and designed in CAD, with 58.86 m2 and 54.94 m2 areas for the meat and curd chambers, respectively. Using the thermal load data, refrigeration equipment was selected by consulting supplier catalogs. To meet the demand of the chambers, 5 evaporator units with a nominal capacity of 61,946 kcal/h were selected to freeze the meat and 1 evaporator with a capacity of 42,009 kcal/h to cool the curds. For the stages of compression and condensation, 9 condensing units were chosen with a cooling power of 32,719 kcal/h for meat and only 1 condensing unit with a capacity of 32,854 kcal/h for curds. The equipment operates with R-404A refrigerant. The costs of the project were estimated at around half a million reais, not including freight and installation, with electrical refrigeration equipment comprising approximately 82% of the total value of the project (511,007.00 reals).Item Avaliação da viabilidade energética e exergética de um sistema de cogeração em uma usina sucroalcooeira no estado de Pernambuco(2021-12-08) Gama Neto, Samuel Bezerra da; Marques, Adriano da Silva; http://lattes.cnpq.br/0104058705628000; http://lattes.cnpq.br/9717090908631600The demand on the consumption of electricity in various sectors and the concerns about the environmental impacts of exploration and use of fossil fuel, has encouraged the study of various alternative energy sources, including wind, photovoltaic, biomass and hydropower. The use of biomass such as sugarcane bagasse in Brazil is a technically viable option that can reduce the emission of greenhouse gases. Thus, the study consists of an energy and exergetic analysis for a simplified configuration of a sugarcane plant, located in the state of Pernambuco, with an electric power generation capacity of 11.8 MWh by burning sugarcane bagasse with 50% of moisture. Thus, for the analysis, equipment data, plant parameters and references found in the literature for similar cases were considered. The analysis of the combustion process in the set of boilers determined the high heat value of 10,299 MJ/kg for a molar mass of 14.26 kg/kmol of bagasse, with the thermal efficiency of the set of boilers being 61.5%. The energy analysis of the generating turbine set and the drive turbine set resulted in 8974 kW and 1980 kW, respectively, for the shaft powers. Through the exergetic analysis it was found that the largest portion of exergy destroyed is in the set of boilers (85.34%), in the condenser (8.59%) and in the set of generation turbines (4.66%). The plant's exergetic efficiency (5%) demonstrates the need for performance improvement projects.Item Dimensionamento de sistema de controle de bombas hidráulicas em processo thermex para redução de fragilidade azul em barras metálicas(2020-10-05) Motta, José Jonathan Sávio de Souza; Souza, Alisson Cocci de; http://lattes.cnpq.br/0526736580480309Steel rebar is one of the most widespread materials in civil construction, where its mechanical properties are governed by international or exclusive technical standards in each country. At the end of the production of hot-rolled rebars, heat treatment takes place by means of cooling, such as Thermex. In this process, heterogeneity in the mechanical properties of the bar can occur, caused by non-uniform cooling throughout the metal part, including the fragility of 500 °F, which results in a decrease in toughness and ductility in the regions where the heat treatment was more intense, causing loss metal by non-compliant product. An automated system was developed to control the hydraulic pumps of the Thermex process, by means of a programmable logic controller, responsible for controlling the drive to regulate the pressure and water flow at the moment of entry of the bar, seeking to reduce the heat treatment intensity in its portion initial, as it is the part most affected by the blue fragility, where the regulated pressures and flows were dimensioned from results obtained through simulation, using the finite element method in computer software. Through the tensile test of the bars thermally treated by the dimensioned Thermex system, the values of yield limit, strength limit and elongation were obtained. When comparing these mechanical properties with the values obtained from the bar in normal condition and comparing with the reference values of the technical standard, a reduction of metallic loss per non-conforming product was perceived from 2.56% per rolled bar to 0.64%. The best state of properties was found in the test bar where the activation time was 3.4 seconds by the activation signal coming from photocell A3, at a pressure of 7 bar, over the first 12 meters of the bar. With the reduction of the blue fragility effect, we achieved a greater use of the bar, generating financial and environmental benefits, since the rework of the non-compliant portion was reduced, reducing energy and water consumption.Item Revisão teórica do uso de próteses cerâmicas na região femoral(2019-07-10) Vasconcelos Filho, Elenilton Xavier de; Araújo, Vinícius Dantas de; http://lattes.cnpq.br/9752753965948564; http://lattes.cnpq.br/7369646269005456The interaction of metallic biomaterials with the human body living tissue results in a metallic ions liberation by the organism. For a hip prosthesis, larger superficial contact is required, this liberation may even cause carcinogenic effects. It is intended to obtain a alternative material for the titanium alloy (Ti-6Al-4V), currently used in prosthesis, a structural analysis through the finite element method was performed, for comparative purposes, using the Zirconia Toughened Alumina (ZTA) ceramic, considering a human being weighing 60kg on a walk. From a initial geometry, that shows well defined stress concentration points, was verified that the maximum stress present in the prosthesis considering both materials shows very close values, 90MPa to the ZTA and 80MPa to the Ti-6Al-4V. Intending to decrease the maximum stress in the implant a new geometry was made, causing the decrease to 47MPa, in both materials. In this case, can be considered that the ZTA ceramic as good choice for replacement of the Ti-6Al-4V alloy, considering the chemical inertia and some mechanical properties of the ceramic.Item Comparação de desempenho das técnicas de controle PID e por modo deslizante no rastreamento de trajetórias de um sistema dinâmico não linear com motores de hélice(2019-12-12) Silva Júnior, Edivaldo Sebastião da; Medeiros, Philippe Eduardo de; http://lattes.cnpq.br/5594617038786753Currently, control systems are gaining more and more prominence in the scientific environment and in the industrial environment, this wider scope of control systems is mainly due to the theoretical and technological advances in control engineering. This advance involves the solidification of increasingly robust control techniques, especially non-linear control techniques. In view of this fact, this work consists of comparing the PID linear control technique and the non-linear sliding control technique, both techniques being applied in a second order nonlinear dynamic system. The comparison of the PID control and the control by sliding mode, discussed in this work, took place from numerical simulations of the Seesaw Propeller system and also through physical experiment using a real plant of the system. The results presented in this work contain the individual performance of each controller, from a quantitative analysis of its performance, these analyzes were made for both the numerical simulations and the experiments carried out. These results are expressed throughout the work by means of graphs and through the analysis of the mean square error presented by each controller.Item Estudo da influência do fluido de trabalho no desempenho de um ciclo Rankine orgânico através da análise energética(2019-12-12) Anjos, Leidy Catarina Felix dos; Souza, Ronelly José de; http://lattes.cnpq.br/8234458375858794; http://lattes.cnpq.br/3187993447331921Currently, science has sought the reuse of energy in the most diverse ways. Organic RankineCycle (ORC) is already used in various applications in thermal with low and mediumtemperature sources such as waste heat, solar energy, solar concentrators and etc. Thiswork aims the economic analysis of an ORC, based on a master's dissertation, through theinfluence of the variation of working fluids from the perspective of the first law ofthermodynamics. The analysis were done through the Engineering Equation Solver (EES)computer simulator. The studied fluids were: R123, R134a, R227ea, R245fa and R290,where the behavior of the ORC was evaluated by using variations of some parameters as away of evaluation and application viability of the ORC and of the most suitable refrigerator forthe project. The parameters are: pressure ratio (RP), expander inlet temperature (T5),condensing temperature (T2), efficiency, Greek letter “eta” and net power (Ẇₗᵢq). It was found that the fluids that obtained the highest levels of power and efficiency were: R134a, R227ea and R290.