Dissertações em Engenharia de Infraestrutura e Desenvolvimento Energético (Mestrado) - PPGINDE/NDAE/Tucuruí

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/9401

Navegar

Agora exibindo 1 - 20 de 22

Acesso aberto (Open Access)
Análise do aproveitamento energético em redes de distribuição de água com a utilização de bombas como turbina (BFT)
(Universidade Federal do Pará, 2022-03-31) SILVA, Victor Renan Barbosa da; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
Climate change has intensified research related to the production of renewable energies around the world. In this sense, the present study intends to contribute to the analysis of the use of Pumps Functioning as Turbine (PAT) to replace Pressure Reducing Valves (PRV), aiming both at the control of pressure in water distribution networks, as well as , consequently, its use for energy generation. The installed PAT must be able to operate under different flow rates due to fluctuations in the water consumption rate, which makes it difficult to select the appropriate pump, therefore, the selection process of PATs to replace PRVs was optimized by combining two selection methods and PAT prediction, Williams (1995) the first method was used to select the appropriate PAT according to height and flow data available in the network, then the method of Rossi et al. (2019) was used to evaluate the characteristic curves of the pump as a turbine, with particular attention to out-of-design operating conditions. Two simulations were performed for the optimization process, considering the PAT with constant speed, applied to a real network that was divided into 3 district measurement areas (DMA). In the first simulation a PAT was added to the network to replace a PRV located at (DMA 3), in the second simulation two PATs were added to the network (DMA 3) to replace the PRVs. The results show, in simulation 2, that the pressure control was better, in addition to the recovery of electrical energy, which was 190.96 kWh/day or 69.70 MWh/year, corresponding to a reduction of 41.74 tons of CO2 not emitted. Thus, the energy recovery was 267% higher compared to simulation 1. In addition, the pressure control also presented satisfactory results, staying within the established standards. Therefore, the combination of Williams' (1995) and Rossi et al. (2019), simplified the work of BFT selection and prediction with significant results and it was possible to conclude that BFTs working at peak consumption hours can adjust the required standard pressure and, in the rest, PRVs can regulate the pressure. In this case, in addition to controlling the pressure continuously, significant renewable energy can be recovered from the WDN
Acesso aberto (Open Access)
Análise do ciclo de vida da cadeia da banana na região do Lago de Tucuruí
(Universidade Federal do Pará, 2018-07-20) PINHEIRO, Joana Cláudia Zandonadi; MESQUITA, Andre Luiz Amarante; http://lattes.cnpq.br/1331279630816662; GOMES, Luiz Moreira; http://lattes.cnpq.br/7074266533007983
This work deals with the analysis of the banana life cycle in the Lake of Tucuruí region, in the State of Pará. The environmental impacts of this product and its production chain are quantified. It is also evaluated the potential of beneficiation, aiming the incentive of its production in the region. Regional banana producers were visited on their properties, where they mapped the life-cycle flows of this product, from planting to sale. The methodology applied in the research involves the Life Cycle Analysis (LCA) tool, which allows the visualization of the environmental and economic contributions of each productive process. This approach makes it possible to focus analysis on reducing environmental impacts and on better processing practices and costs of product processing. The obtained results show that the properties studied have similar emission indices of environmental impacts as others studied in the world and that the stages of the planting until the formation of the fruit have elevated indices of emissions, so that the application of best practices to the processes, so that there is potential reduction of the environmental impacts generated. The LCA methodology used was extremely important to identify the factors that impact the problems of agricultural production. Thus, we can propose improvements in the use of natural resources for the properties studied, seeking conservation and sustainability for future generations.
Acesso aberto (Open Access)
Avaliação de modelo de elemento de pá aplicado a turbinas eólicas com difusores através de análise CFD
(Universidade Federal do Pará, 2023-05-30) BEZERRA, Waldson Melo; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The diffuser effect on free flow turbines shows a possibility of reaching a power coefficient greater than that of a classic turbine, exceeding the Betz limit. The present work evaluated the effect of an Eppler 423 profile diffuser coupled in a horizontal axis wind turbine with a 4-bladed rotor NACA 65(3) 618 profile. Using computational fluid mechanics (CFD, Computational Fluid Dynamics), numerical simulations were performed allowing to obtains more information about the fluid flow and the increase in extracted power for configurations with and without diffuser for the velocity of 7 m/s. Considering the dimensions of the test section, the results obtained in the CFD analyses were validated through experimental results, in which the rotor and diffuser assembly were confined in a wind tunnel. It was observed that coupling the diffuser to the turbine considerably increased the fluid velocity, providing a 37% increase in the initial velocity of the flow. Showed an increase in the power coefficient in the order of 45,45% with the use of the diffuser, for the same flow velocity, 7 m/s. Thus, through the results obtained numerically in this work, it was possible to obtain reliable data for the evaluation of a specified Blade Element Momentum (BEM) model applied to diffuser-augmented wind turbines, which is employed to analyze the same turbine rotor and diffuser designs. Despite the good results of the BEM model, the present study indicates possible improvements for the consistency of the modeling.
Acesso aberto (Open Access)
Cálculo de ar induzido pela queda livre de materiais granulares via CFD
(Universidade Federal do Pará, 2021-12-17) LIMA, Leandro Ferreira Borba; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The proposal of the work consists of presenting an analysis method via ANSYS-Fluent using the DDPM tool (Dense Discrete Phase Model) of the integrated Eulerian multiphase model, a better understanding of the flow of granulated material with the adjacent induced air due to the drag provided by the free-falling particles, which result in the generation and propagation of dust, avoid simulations with materials where particle density and diameters are variable. The use of this analysis tool will make it possible to improve and improve de dusting projects in industries that work with granular materials that emit dust. The simulations carried out were compared with other computational methods and practical experiments, in addition to previous theoretical formulas.
Acesso aberto (Open Access)
Critério do coeficiente de pressão mínimo aplicado ao dimensionamento de bombas axiais: caso de estudo para um túnel de água circulante
(Universidade Federal do Pará, 2022-12-15) RAMALHO, Rodolfo Vitorino Correia; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
An analysis of the pressure coefficient on the suction side of blades is presented as a design criterium for axial-flow pumps. A CFD model is developed and validated from experimental tests available in the literature. The model uses the finite volume method through the commercial software Ansys CFX. In the criterion application step, the X-Foil software is used to determine the lift and drag coefficients of the blade profiles. A case study is presented for the dimensioning of axial-flow pumps for a large recirculation tunnel, to be used for testing vessels, naval structures and hydrokinetic turbines. Special attention is given to pump cavitation conditions. The criterion of the minimum pressure coefficient is then evaluated by the CFD model, showing good performance for the pump.
Acesso aberto (Open Access)
Desenvolvimento de sistema de diagnóstico de falhas em roletes de transportadores de correia
(Universidade Federal do Pará, 2024-03-28) SOARES, João Lucas Lobato; MESQUITA, Alexandre Luiz Amarante; http://lattes.cnpq.br/3605920981600245; https://orcid.org/0000-0001-5605-8381
Belt conveyors are essential equipment in mining industry and require constant monitoring to maintain good reliability. In order to support the belt and the material being conveyed, rollers are components that constantly fail during operation, in which they present faults in bearings and surface wear in the shell as the most common failure modes. Thus, monitoring based on predictive maintenance is essential, and machine learning techniques can be used as an alternative for detecting equipment failures. In diagnostics using machine learning, the feature selection step is important to avoid loss of accuracy in the classification of the equipment's condition. The present study analyzes the performance of the decision tree algorithm and Analysis of Variance (ANOVA) as alternative methods for dimensionality reduction. Initially, the vibration signals were collected on the rollers of a belt conveyor bench and the Wavelet Packet Decomposition (WPD) was applied to the signals to obtain the energy ranges, which were used as features for classification. After the determination of the best features, two approaches were analyzed for the selection of features: one with the application of the method without dimensionality reduction and the other with the application of the decision tree. In addition, different classification algorithms were used: Support Vector Machine (SVM), k-Nearest Neighbor (kNN) and Artificial Neural Network (ANN). As a result, it was found a superior performance of diagnostic accuracy in all techniques with a reduction in the dimensionality of the characteristics selected by the decision tree. In addition, SVM, kNN and ANN showed increases in accuracy ranging among the fault diagnosis models approached.
Acesso aberto (Open Access)
Desenvolvimento de túnel de vento para avaliação de bicos de pulverização no abatimento de poeira
(Universidade Federal do Pará, 2024-12-20) SANTOS, Danilo Silva; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Mining is extremely important economically and socially for the industry, especially iron ore, but along with its benefits, it also has environmental impacts generated in different ways, such as dust. This inconvenience has caused disruptions to mining enterprises, such as production shutdowns and heavy fines, as well as problems for people who work in the companies and surrounding communities, due to health problems associated with inhaling dust and dirt from the environments, making them unhealthy and devalued. Dust control mechanisms have been widely studied and one of these is dust control using spraying of suppressant solutions. Studying the efficiency of spray nozzles has become of great importance and bench tests act as efficient means of understanding the mechanism of dust abatement from minerals. Research has been common to use wind tunnels. Thus, a tunnel was built capable of evaluating 5 different nozzles and their efficiencies in suppressing pellet feed and sinter feed at two speeds and different water pressures. It was concluded that the tunnel is capable, through the methodology used, of evaluating and comparing the best nozzle, demonstrating that it is an important tool in consolidating this knowledge in the Fluid Dynamics and Particulates Laboratory.
Acesso aberto (Open Access)
Desenvolvimento de um túnel para secagem e emissão de minério em condições ambientais controladas
(Universidade Federal do Pará, 2021-12-15) SILVA, Artur José Cunha da; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
A dust emission is present in the various stages of the mineral industry, from extraction in mines to ship loading in ports. Transport in train wagons, storage in stockpiles and handling are three major sources of particulate emissions into the atmosphere. Suspended dust does not only affect the local environment, as the wind transports the particulates and brings disturbances to urban centers close to railway networks and ports. Larger particles are deposited on surfaces, outperforming visual surfaces, and smaller, unresearched particles with a size between 10 and 2.5μm are easily inhaled and lodge in lung tissue, potentially causing irritation or necrosis. Dust emission is enhanced by local atmospheric conditions, which cause the evaporation of surface moisture from the wet ore, breaking the liquid bridges that keep the particles linked together. Aiming at studying the dynamics of drying ore, a drying tunnel was designed and built, comprising a wind tunnel, cooling, heating and humidification equipment that are interconnected by a supervision and control system. The use of the bench for drying studies using sinter feed is known to be satisfactory, as the temperature remained stabilized at the setpoint during the drying time, reflecting the good calibration of the temperature PID controller. Moisture and ore mass were automatically measured using a scale and a capacitive moisture sensor positioned in the test section of the bench. The constant rate and descending rate drying curves only in the lightest weather conditions. The biggest limitations and variations were observed only in the period with decreasing drying rate, showing the influence of environmental conditions on the drying dynamics. Therefore, this work leaves as a contribution the preparation tunnel for future research and an experimental database for the calibration of numerical models and models of mathematical models for prediction prediction.
Acesso aberto (Open Access)
Determinação experimental da vazão de despoeiramento na descarga de carvão coqueificável
(Universidade Federal do Pará, 2021-02-26) CHAVES, Gabriel Guedes; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Dust control mechanisms during industrial processes are often carried out using spray nozzle methods or exhaust systems, equipped with bag filters. The following work aims to develop an experimental method to determine the volume of exhaust in different quantities of materials and different heights of material discharge. A test protocol is presented to design exhaust systems for any material, mass flow and drop height, using an experimental method in which it simulates the material drop in order to evaluate experimental dedust flow rates for an industrial ventilation system. A literature review of the current empirical models of exhaustion volume is presented. The methodology is correlated through the concentration of respirable particles measured by the measurement equipment with the exhaust flow data. The results presented are for coal, comparing existing and suggested correlations with experimental data for three different heights of fall. It is hoped, therefore, to support design engineers in the design of industrial exhaust systems, reducing the damage caused by fine particles in workers and in the population that lives near the polluting source.
Acesso aberto (Open Access)
Dimensionamento de soluções acústicas para máquina aplicada à extração de fibras do pseudocaule da bananeira
(Universidade Federal do Pará, 2020-02-28) SILVA, Geanilson Brito da; MESQUITA, Alexandre Luiz Amarante; http://lattes.cnpq.br/3605920981600245; https://orcid.org/0000-0001-5605-8381
The Lake Tucuruí Integration Region (RI) stands out for its banana production in the state of Pará, making it one of the main producers of the fruit. However, the income of farmers in the region with banana production is restricted only to the sale of the fruit, discarding the other parts of the banana tree, which can be used to manufacture products with higher added value. With the use mainly of the fibers of the banana pseudo-stem, several products can be generated, boosting the development of banana cultivation in the region and promoting an increase in employment and income. Aiming at this socioeconomic growth of the RI Lago de Tucuruí, the present work presents, in its first part, an analysis of the fiber extraction machine of the banana pseudo-stem at the Federal University of Pará, Campus de Tucuruí, which will serve the small producers and cooperatives of farmers in the region. In the operation of the machine, it was found that it has noise problems. The sound pressure levels measured around the machine are above the normative limits. Thus, studies were carried out to define acoustic solutions aimed at solving the problem. In the second part, the main focus of this work is to present the acoustic solutions for the fiber extraction machine, including the specification of vibration isolators, replacement of the electric motor fan and dimensioning of the partial enclosure of the machine.
Acesso aberto (Open Access)
Dispersão de energia em um cristal granular hexagonal decorado
(Universidade Federal do Pará, 2024-02-29) RAMOS, Jorde Anthonny Alves; MACHADO, Luis Paulo Silveira; http://lattes.cnpq.br/0702289670734922; https://orcid.org/0000-0003-1587-3632
The decorated hexagonal granular crystal consists of main spherical grains arranged in a two-dimensional hexagonal array, with small spherical grains filling the interstitial spaces. These additional grains barely touch the main grains, increasing the number of contacts per grain. Additionally, all grains are initially at rest, with null velocities. For comparation, we used results from a similiar arrangement without decoration (i.e., without interstitial grains). We investigated the mechanical responses of both granular arrangements to the punctual incidence of an external grain. Our analysis focused on how the mechanical energy is dispersed and mitigated after a single initial impact. The proposed model confirmed the significant role of interstitial grains in the granular crystal. The decorated arrangement demonstrated accelerated behavior of the energy wavefront, both in its mitigation and propagation. In our analysis of energy scattering orientations, we found that the decorated arrangement exhibits greater energy mitigation and reorientation of return energy compared to the undecorated arrangement. Thus, the addition of interstitial grains promoves a greater return of mechanical energy to the external medium of origin. We conclude that with proper decoration, a granular crystal could act as a barrier against strong impacts.
Acesso aberto (Open Access)
Estabilidade da geração de energia em usinas hidrelétricas com turbinas Francis reversíveis: estudo de caso UHE Tucuruí
(Universidade Federal do Pará, 2023-10-16) MADUREIRA, Angelo Torres; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Reversible hydroelectric power plant projects have been consolidated on the international energy scene since the 1970s and are increasingly common as a solution in ancillary services for integration with intermittent energy sources (FEI) during peak hours. In Brazil, the large hydroelectric generation base allowed this need to be postponed for a long period. HPP Tucuruí, the last hydroelectric plant in the Tocantins River cascade, is a landmark in national engineering. Equipped with two powerhouses with an installed capacity of 8,535 MW, it has been largely responsible for regulating the FEI in Brazil, especially wind farms in the northeast region. Its Francis turbines at Powerhouse 1 have a nominal power of 350 MW each, maximum flows of 600 m3/s, Francis rotors with a diameter of 8.15m and 12 blades and a specific speed of 86.9 rpm.m3/4 are machines of considerable capacity and has been widely used by the ONS for power regulation. However, the model used for load dispatch shows clear signs of exhaustion, when comparing the growth in the accumulation of electromechanical damage in the generating units. One possibility of mitigating the severity of damage and increasing generation stability is the partial conversion of generating units to TR (Reversible Turbine) operating in hydraulic short circuit, with the aim of stabilizing dispatched power and consequently reducing the frequency of starts and stops. . This work presents the development of a methodology to predict the hydromechanical behavior of Francis turbines converted into reversible turbines in hydroelectric plants. A one-dimensional mathematical model based on the application of the Euler equation for the turbine and pump modes is preliminarily used. The triangle of speeds at the rotor inlet and outlet is formed, for a preliminary analysis of the flow in the Francis rotor. Characteristic curves of flow, torque and power of reversible turbines are produced, based on statistical correlations of existing machines, obtained from the literature. In the end, the hydro energy model is validated and a case study is presented at HPP Tucuruí. The results indicate the technical feasibility of operating stability with a reduction in starts and stops of unconverted generating units. In the dimensionless curves generated, it was not possible to obtain the optimal performance condition in pump mode, with the adoption of the same existing Francis rotor. Therefore, modifications to the mechanical and electrical design of the generating units must be carried out to achieve more stable and safe operation. The use of reversible turbines in this work is not intended to increase energy storage, but rather for the purpose of stability of machine operation and reduction of electromechanical damage, which for this purpose is technically viable.
Acesso aberto (Open Access)
Experimento em escala de emissão de poeira no processo de empilhamento
(Universidade Federal do Pará, 2022-03-25) CASTRO, Maycon Magalhães; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662; MACHADO, Luis Paulo Silveira; http://lattes.cnpq.br/0702289670734922; https://orcid.org/0000-0003-1587-3632
Dust emission can lead to health problems, explosion risk, material segregation and environmental pollution. Therefore, it is necessary to understand the parameters related to dust generation to improve particulate emission control techniques. Dust reduction based on spray spraying is the main method to prevent and control dust emission in ore stacking. Dust suppression techniques at conveyor belt transfer points can be subdivided into material spraying and trapping of fugitive particles. To analyze the parameters associated with dust generation during ore stacking, a scaled conveyor bench was developed for dust suppression tests via water spray. This installation is equipped with spray nozzles whose relative location on the belt can be adjusted and the speed of the conveyor can also be controlled. The spray jet is provided by a set of spray module and flow divider, allowing the variation of the system pressure and with the possibility of using suppressors, which can increase the efficiency of particle capture. Dust suppression performance is analyzed by monitoring strategic points with the highest dust emission. The results of this investigation show that dust generation increased as the drop height increased, it was observed that the region close to the pile emits a higher concentration of dust, due to the impact of the material flow on the stacking surface, in compared to the front region of the flow. The results after using the spray on the belt showed that the highest drop height (1600 mm) emitted the highest concentration of particles (3192.72 μg/m3) after spraying, on the material, the dust concentration reduced by about almost 70%, showing the efficiency of spray humidification. It was also observed that PF has a higher critical humidity than that of SF, as well as that it emits a higher concentration (1116.52 μg/m3) compared to Sinter feed (848.14 μg/m3), making it evident that by as it is a material with a smaller granulometry, the pellet feed tends to emit a higher concentration of particulates when handled.
Acesso aberto (Open Access)
Partidas e paradas em usinas hidrelétricas: atendimento ao ONS e custos operacionais
(Universidade Federal do Pará, 2023-12-19) MACHADO, Jucileia Cruz; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Hydroelectric plants (UHEs) connected to the National Interconnected System (SIN) have their operation under the rules of the National System Operator (ONS), which generate operational conditions that are often not suitable for the generating units, whether due to low efficiency or limit conditions. operation that affect maintenance, such as wear and cavitation. This work investigates the short-term dispatch process, a one-day horizon, for a large hydroelectric plant that is part of the national interconnected system (SIN). The Tucuruí hydroelectric plant was used as a base and case study, where data on generation, hydrology and the number of starts and stops of the installation were mapped, as well as the influence on costs associated with the number of intervention requests. A strategy is proposed to minimize the number of starts and stops, using the change of operating points of the generating units on the hill curve, observing the drop height, power and yield points possible to meet the system demand, without having to the need for successive starts and stops. The result of this investigation, for the year analyzed, obtained a reduction, for one operating day (24h), of around 26% in changes in status (starting and stopping) of the generating units, proving that it is possible to make adjustments at the points of operation of generating units, within the limits permitted by operational restrictions, with a focus on reducing starts and stops.
Acesso aberto (Open Access)
Predição de bombas funcionando como turbinas em toda a faixa de operação: estudo de caso de uma rede de distribuição de água
(Universidade Federal do Pará, 2021-06-18) GAIA, Juliana Garcia; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Nowadays, the importance of reducing energy costs and/or obtaining alternative forms of generation has increased more and more. In this context, pumps working as turbines (BFT) emerge as a sustainable alternative for energy generation taking advantage of the hydraulic potential of a location. However, the adversity found is related to the BFT operating range in turbine mode. This work aims to theoretically determine the operating range of pumps working as turbines of pumps selected to work as pressure reducing valves (PRV) in the water supply system (SAA) of Vila Permanente, in Tucuruí. Three experimental studies were evaluated and the methods of Sharma & Williams (1995), Yang et al. (2012) and Alatorre-Frenk (1994) to achieve the PATs head (Ht) and flow (Qt) prediction results in turbine mode at the best efficiency point (BEP); after that, the method developed by Rossi (2019) was applied, which works outside the entire operating range of the BFT, combined with the methods in the BEP to obtain the characteristic curves Q x H (flow x head) and Q x η ( flow x efficiency) of the BFT in turbine mode; and finally, the results obtained through the methods were compared with the results of experimental studies, so that the best combination of methods was selected. Then, with the height and flow values of the pressure points in the SAA of Vila Permanente, centrifugal pumps were selected to work as turbines, applying the best combination of method and then obtaining the characteristic curves Q x H (flow x head) and Q x η (flow x efficiency) of the BFT in turbine mode, in order to reveal various points where the BFT can operate; in addition to energy recovery calculations with values in KW per day, month and year. In water supply systems, energy costs are excessive and it is common to use pressure reducing valves at points where this reduction is necessary to ensure the right circumstances for the transport of water in the pipeline. In this way, it is understood that there is a waste of energy that could be used in the system itself.
Acesso aberto (Open Access)
Procedimentos experimentais para avaliação da emissão de poeira em manuseio de minério
(Universidade Federal do Pará, 2018-11-29) SANTOS JUNIOR, Ronaldo Menezes dos; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The generation of dust during the handling and transportation of bulk causes a series of problems, such as the erected air and loss of valuable material. Due to the risk associated with inhalation of dust, several control mechanisms have been adopted. The use of water is a viable option to inhibit the generation of dust, although the use of chemical suppressants is in some cases more appropriate. However, standards and methods for characterizing the generation of particulates are not very consolidated in the literature, for the proper selection of the control mechanism. Therefore, this study aimed to develop test methodologies to evaluate the emission of minerals particulate. The emission of particulate during transport was evaluated in a test bench developed by adapting an existing wind tunnel, using a wagon model and air speeds of 40 km/h and 70 km/h, for different iron ore moisture values. Results show that the increase in flow speed increases the loss of material mass contained inside the wagon model and the increase in material moisture significantly reduces the loss of mass, being enhanced with the use of dust suppressants applied to the material surface. To simulate material handling, a bench was developed using the dust tower technique concept, which allows dust generation tests during material discharge. In the results obtained, it is also verified that the increase in material moisture significantly reduces the emission of particulates, being more evident for materials that have a higher percentage of fines. The influence of suppressants was also evaluated, and among the tested reagents Fe2(SO4)3 showed the best result for the pellet feed milled, greatly reducing the emission of particulates in relation to the use of water only. For pellets, Ca(OH)2 showed the best results without curing time and CaCl2 for the condition with curing time of 2 hours. Therefore, the results show that the benches and experimental procedures developed, presented satisfactory and coherent results, which are reliable for the characterization of the emission of particulates from different materials.
Acesso aberto (Open Access)
Projeto e fabricação de extrusora monorrosca com matriz de extrusão filamentar
(Universidade Federal do Pará, 2024-10-25) RODRIGUES, Rodimilson Coelho; EL BANNA, Wassim Raja; http://lattes.cnpq.br/2005046563115507; HTTPS://ORCID.ORG/0000-0001-5085-4352; NASCIMENTO, Walber Alexandre do; http://lattes.cnpq.br/8022410578951099; https://orcid.org/0000-0002-2699-3982
Large industrial establishments are always looking for increasingly sophisticated technologies to monitor manufacturing processes. This work aims to design and build a laboratory single-screw extruder and its extrusion die for processing polymers and polymer composites, in addition to enabling studies in the area of mechanical recycling of polymers. The first stage of the work involved choosing the type of extruder to be manufactured. The second stage consisted of dimensioning and designing the equipment using Solidworks software. In the third stage, the types of materials and mechanical and electrical components for assembling the extruder were selected. In the fourth stage, the manufacturing processes of the extruder and assembly of the mechanical and electrical components were carried out. In the fifth stage, the equipment was validated, where temperature and mass flow tests were performed, in addition to mechanical and electrical tests in the processing of a thermoplastic polymer, which, in this case, was polypropylene (PP). The last stage consisted of simulating a die with a cylindrical profile, aiming to study the characteristics of the polymer melt flow and define how the die structure should be adjusted to obtain the desired diameter. After designing the die in Solidworks software, a simulation was performed in Ansys software. In this case, the rheological behavior of the melt as it passed through the die was studied through the simulation, analyzing in which part of it the high and/or low shear rates are observed when the polymer flows through it. The drag flow and pressure flow were then extracted from the simulation parameters, which led to the calculation of the operating point and operating pressure for the die. It was also possible to calculate the mass flow rate and the velocity drop at the die wall, in addition to optimizing the die profile for the circular shape and desired diameter.
Acesso aberto (Open Access)
Proposta de metodologia para diagnóstico de falha em rolamentos de baixa velocidade
(Universidade Federal do Pará, 2024-04-19) COSTA, Thiago Barroso; MESQUITA, Alexandre Luiz Amarante; http://lattes.cnpq.br/3605920981600245; https://orcid.org/0000-0001-5605-8381
Monitoring low-speed bearings with vibration analysis is more challenging due to the low energy level of the vibration signal that carries the failure data, making it more susceptible to interference from other sources, impairing the interpretation of information. Thus, an alternative is to calculate signal predictors that may be sensitive to pattern changes relative to failure onset and progression. Hence, the present work extracted different types of features, among them two nonlinear features and eleven extracted from the signal in the time domain. Those features were ranked and selected based on their sensibility to class differentiation, which was estimated using the t-Welch statistic value. Among them is the Largest Lyapunov Exponent, which, in this work, had a modification in one of its calculation steps, improving its sensitivity in some cases. In addition, the influence of the vibration signal window size on the class separability of the indicators was evaluated (which is a scarce content in low-speed bearing monitoring literature). After feature selection, the data were subjected to a linear transformation through PCA (Principal Component Analysis), aiming to reduce the data dimensionality to three dimensions and to minimize the redundancy effects of highly correlated features. In sequence, the data represented in the space of principal components were projected on a Hotelling T2 statistic control chart. The chart allowed the detection and rejection of potential outliers, which consisted of points above a limit line estimated based on F statistic distribution. Finally, binary and multiclass Support Vector Machine classification models were trained with experimental data acquired from normal conditions and three levels of incipient fault in bearing. The models performed well, mainly the binary model with test data obtained from belt conveyor pulley bearings in industrial operation.
Acesso aberto (Open Access)
Protótipo para análise técnico-econômica de bombas funcionando como turbinas em redes de distribuição de água
(Universidade Federal do Pará, 2025-02-27) VIANA, Ingrid Luna Baia; SOUZA, Davi Edson Sales e; http://lattes.cnpq.br/6130270007673176; HTTPS://ORCID.ORG/0000-0001-9632-5667; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
The growing need for sustainable solutions in water distribution networks requires technologies that optimize energy efficiency and reduce operating costs. However, choosing the best alternative for implementing Pumps Operating as Turbines (BFTs) is challenging due to the multiple technical and economic criteria involved. Therefore, this study proposes a decision support model, employing multicriteria techniques and computer programming to assist in selecting the most viable alternative within different scenarios. The analysis focuses on the technical-economic feasibility of BFTs in Water Distribution Networks (RDAs), using the TOPSIS method, where data will be evaluated and classified by similarity to ideal conditions. Implemented in Python, the system ensures calculation accuracy, with a graphical interface called FliessEnergy, hosted by Vercel, with a responsive and scalable layout, providing an optimized user experience. Practical application with real RDA data demonstrated its effectiveness in prioritizing the most advantageous alternatives. The results indicated that Scenario 1 presented the best configuration for implementing BFTs, while Scenario 5 was the least favorable alternative. This classification of alternatives helps managers make decisions, taking into account both the proximity to the best conditions and the distance from the worst. To assess the reliability and consistency of the codes, PyTOPS, free software that allows several simulations with changes in the weights of the criteria, was used. A total of 500 simulations were performed, resulting in reduced variability between the scenarios, which reinforces the robustness of the model and its ability to generate consistent classifications even with small changes in the parameters. The model proved consistent and reliable, offering a useful instrument for evaluating the implementation of BFTs in RDAs. It is expected that, with future improvements and integration of databases, this solution can contribute significantly to strategic decisions in the sanitation sector in Brazil.
Acesso aberto (Open Access)
Resíduos de gesso na construção civil: uma análise bibliométrica na base de dados eletrônica Web of Science
(Universidade Federal do Pará, 2021-11-05) FREITAS, Pablo Virgolino; ISHIHARA, Júnior Hiroyuki; http://lattes.cnpq.br/3498874642887006; https://orcid.org/0000-0002-0081-7913
The construction sector stands out for the exploitation of natural resources and for the production of residues that, in the vast majority, are improperly discarded in nature, generating serious negative consequences for the environment. Aiming to minimize the harm caused by the poor disposal of Construction and Demolition Waste - CDW, as well as to develop alternative ways to replace natural raw material by recycled waste, many studies have been carried out. Among the materials that have high recycling potential is gypsum, whose residues are already being used as a binder, additives in Portland cement, soil correction, among other forms of recycling. Therefore, this study aims to analyze Brazilian and international scientific publications dealing with the reuse of plaster in civil construction, performing a bibliometric mapping in the Web of Science electronic database. The mapping was carried out through exploratory research related to the reuse of gypsum waste in several scientific articles. Words and expressions that had the highest frequency of occurrence in published articles were collected. The search in the database resulted in 89 articles, of which 42 contained information on the recycling of gypsum waste in civil construction. The selected articles belong to authors from 19 countries, the most representative being Brazil, with 13 articles. Through the VOSviewer software, network maps were elaborated, through which it is demonstrated how authors and scientific institutions relate in relation to the recycling of plaster waste. The results of the articles studied here compose a portfolio through which effective methods of reusing this waste can be verified, thus facilitating the search by third parties for this type of information. What can help in the formulation of public mechanisms that help to improve solid waste management in Brazil, because, through the social network Instagram, this information will be made available in order to reach an audience that goes beyond academic borders.