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Desenvolvimento e demonstração de funcionamento de um sistema híbrido de geração de energia elétrica, com tecnologia nacional composto por um módulo de células a combustível tipo PEMFC e acumulador chumbo ácido; Hybrid system development and operation for an electric power generation with the brazilian technology composed of a PEMFC fuel cell stack and lead acid battery

Senna, Roque Machado de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/06/2012 PT
Relevância na Pesquisa
68.1271%
Este trabalho apresenta a contribuição obtida no desenvolvimento de um Gerador de Eletricidade Híbrido (HYBRIDGEN), com tecnologia nacional, focado nos sistemas de terceira geração de energia elétrica híbrido, composto por um módulo de células a combustível tipo PEMFC, associado a um acumulador chumbo ácido. Mostra-se também a sua capacidade de operar em modo contínuo, carga com demanda variável e fator de carga inferior a 50%. Foram abordados quatro temas principais. O primeiro refere-se a um estudo para a melhoria da eficácia na conversão de energia em corrente contínua (cc), ao regular o potencial de saída do conversor cc-cc. A energia é proveniente do módulo de célula a combustível de 1 kWe, equipado com sistema térmico de refrigeração e sistema de alimentação de gases, aqui denominados MCC1. Para tal, foi construído o modelo matemático do sistema conversor de corrente contínua (sistema conversor cc-cc), com solução suportada em equações diferenciais algébricas, ensaios no MCC1, bem como em simulação computacional no programa MATLAB7®. O segundo tema refere-se ao desenvolvimento do projeto e montagem do protótipo do HYBRIDGEN devido à inexistência no mercado brasileiro de um equipamento com as características necessárias tanto para a pesquisa...

Sistema de gerenciamento para carga e descarga de baterias (chumbo-ácido) e para busca do ponto de máxima potência gerada em painéis fotovoltaicos empregados em sistemas de geração distribuída; Management system for charging and discharging of batteries (lead acid) and search for the maximum power point generated on photovoltaic panels employed in distributed generation systems

Bastos, Renan Fernandes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/01/2013 PT
Relevância na Pesquisa
78.468423%
O presente trabalho visa o desenvolvimento de um sistema de carga e descarga de baterias de chumbo-ácido para sistemas de geração distribuída acoplada a um conjunto de painéis fotovoltaicos e conectada à rede elétrica. O conjunto de painéis opera de forma a maximizar a energia gerada através de um algoritmo MPPT (Maximum Power Point Tracking) e a rede elétrica opera como rota para o excedente produzido pelos painéis. Para que a bateria possa ser carregada e descarregada com eficiência evitando sobrecargas e descarregamentos profundos, uma metodologia de estimação do estado de carga da bateria é implementada visando um controle mais eficiente (maximizando a vida útil da bateria) e um melhor aproveitamento da energia armazenada. Para o gerenciamento da carga e descarga do banco de baterias é utilizada uma topologia bidirecional (Boost-Buck) com controlador fuzzy P+I para estabilização de corrente ou tensão. Em relação à técnica de controle para o sistema PV, um controlador PI clássico é utilizado para regular a tensão terminal e ponto de máxima potência que é definido por um algoritmo de perturbação e observação (P&O). Para validar os controladores e os modelos teóricos desenvolvidos é construído um protótipo do sistema. São analisados...

Desenvolvimento na indústria de acumulação de energia em baterias chumbo-ácido: processos alternativos de recuperação de chumbo

Chacón Sanhueza, Abel Edmundo
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: 121 f. : il.
POR
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Pós-graduação em Ciência e Tecnologia de Materiais - FC; Este trabalho apresenta o desenvolvimento de dois métodos alternativos para recuperar chumbo. Fusão Alcalina e Eletrohidrometalúrgico. Ambos oferencem a possibilidade de recuperação de outros elementos químicos normalmente perdidos nas escórias. Partindo-se de matérias primas como sucata de baterias chumbo-ácido, resíduos e outras fontes contendo chumbo, a taxa de recuperação foi de 92% a 99% em chumbo com pureza de 99,74%, quando utilizado o método da Fusão Alkalina. Esta taxa foi de 94% em chumbo de 99,99% de pureza, quando empregado o processo Eletrohidrometalúrgico. Cumpre ressaltar que os resíduos gerados por estes métodos são da ordem de 6% a 10% e estão em uma forma química que permite a recuperação de outros metais. Pelo processo convencional (pirometalúrgico), a taxa de recuperação foi de 90% em chumbo com pureza de 98,5% com quantidade de resíduo que chega a 25% do chumbo total produzido e cuja composição obriga o descarte em aterros classe 1. Este trabalho também desenvolve um método para a obtenção de um aditivo que assegura a formação de massas ativas eficientes para placas de baterias chumbo-ácido. O aditivo, à base de sulfato tetrabásico de chumbo (4BS)...

Avaliação do estado de carga de baterias chumbo-acidas por espectroscopia de impedancia eletroquimica; Evaluation of lead-acid batteries state-of-charge by electrochemical impedance spectroscopy

Jose Rocha Andrade da Silva
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/10/2000 PT
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Os acumuladores de energia estacionários devem ser periodicamente avaliados quanto à sua capacidade de carga, visando assegurar que sua energia acumulada poderá ser prontamente utilizada, quando das falhas do sistema de alimentação convencional. Normalmente, essas avaliações são realizadas através dos testes de capacidade, que apresentam como principais desvantagens, o fato do banco de baterias permanecer indisponível, durante a realização do teste, e o desperdício da energia acumulada nas baterias. Neste trabalho á avaliada a potencialidade do método de espectroscopia de impedância eletroquímica como ferramenta na determinação do estado-de-carga de baterias chumbo-ácidas, através da análise das relações dos seus parâmetros eletroquímicos e sua quantidade de carga armazenada; Stationary lead-acid batteries must have their charge capacity periodically evaluated in order to assure that they are ready to supply energy during conventional supplier faults. Normally, these evaluations are conduct by capacity tests, which present these main disadvantages: batteries remain unavailable while tests are conducted and total energy accumulated in batteries is dissipate during the tests. In this work electrochemical impedance spectroscopy is evaluated as a tool to assess the lead....

Overcoming the schlieren effect in flow injection spectrophotometry by introduction of large sample volumes: determination of chloride in the electrolyte of lead-acid batteries

Rocha,Fábio R.P.; Nóbrega,Joaquim A.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1997 EN
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77.82549%
A flow injection spectrophotometric system is proposed for determining chloride in lead-acid battery electrolyte by using the displacement reaction between mercury(II) thiocyanate and chloride in a medium containing iron(III). The employment of a large sample volume was effective to avoid refractive index gradients in the central part of the sample zone. Sulfate interference was studied and the correlation between the chemical equilibria involved and the transient signals was used to develop a strategy for chloride quantification. Samples containing from 2.2 to 3.7 mol L-1 of sulfuric acid can be determined by using the same analytical curve, without matrix interference or any previous treatment. The detection limit and the relative standard deviation were estimated in 0.37 mg Cl- L-1 (99.7% confidence level) and 1.6% (n = 10), respectively. The sampling rate was 45 h-1. Recoveries between 95.9 and 108% were obtained for additions of chloride (2.00 to 8.00 mg L-1) in the samples.

A longitudinal study of the relation of lead in blood to lead in air concentrations among battery workers.

Hodgkins, D G; Robins, T G; Hinkamp, D L; Schork, M A; Krebs, W H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1992 EN
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The relation between lead in air (PbA) and lead in blood (PbB), concentrations was investigated among 44 workers in five major operations in a United States high volume, lead acid battery plant. The study covered a 30 month period in which workers received frequent PbA and PbB determinations, workers remained in a single job, and PbA concentrations averaged below the US Occupational Safety and Health Administration (OSHA) permissible exposure limit of 50 micrograms/m3. In both univariate and multivariable linear regressions, longitudinal analyses averaging PbA concentrations over the 30 month study period appeared superior to cross sectional analyses using only six month PbA averages to model PbB concentrations. The covariate adjusted coefficient (alpha value) for PbA (mu/m3) in models of PbB (micrograms/100 g) was 1.14. This figure is strikingly higher than that reported in previous studies in the lead acid battery industry in all of which PbA concentrations were substantially higher than in the current study. Plausible explanations for the difference in alpha values include non-linearity of the PbA-PbB curve, a higher fraction of large size particulate associated with higher PbA concentrations, survivor bias among workers exposed to higher PbA concentrations...

A Multi-Point Sensor Based on Optical Fiber for the Measurement of Electrolyte Density in Lead-Acid Batteries

Cao-Paz, Ana M.; Marcos-Acevedo, Jorge; del Río-Vázquez, Alfredo; Martínez-Peñalver, Carlos; Lago-Ferreiro, Alfonso; Nogueiras-Meléndez, Andrés A.; Doval-Gandoy, Jesús
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 25/03/2010 EN
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This article describes a multi-point optical fiber-based sensor for the measurement of electrolyte density in lead-acid batteries. It is known that the battery charging process creates stratification, due to the different densities of sulphuric acid and water. In order to study this process, density measurements should be obtained at different depths. The sensor we describe in this paper, unlike traditional sensors, consists of several measurement points, allowing density measurements at different depths inside the battery. The obtained set of measurements helps in determining the charge (SoC) and state of health (SoH) of the battery.

Effects of Delta-Aminolevulinic Acid Dehydratase Polymorphisms on Susceptibility to Lead in Han Subjects from Southwestern China

Yang, Yuelin; Wu, Jin; Sun, Pin
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
EN
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This study is to determine the distribution of the delta-aminolevulinic acid dehydratase (ALAD) polymorphism among Han subjects of the Chinese population and to study whether the polymorphism in the ALAD gene modifies the toxicity of lead in lead-exposed workers. For this purpose we conducted a cross-sectional study on 156 Chinese workers who were exposed to lead in lead-acid battery and electric-flex manufacturing plants. The authors found that the allele frequencies of ALAD1 and ALAD2 were 0.9679 and 0.0321, respectively. Workers with the ALAD 1-1 genotype were associated with higher blood lead levels than those with the ALAD 1-2 genotype. Blood and urine lead levels were much higher in storage battery workers than in cable workers. The self-conscious symptom survey showed that the incidences of debilitation, amnesia and dreaminess were much higher in those had more than five years of tenure or contact with lead on the job within the ALAD 1-1 genotype subgroup. Laboratory examinations showed that serum iron and zinc levels in workers’ with the ALAD 1-2 genotype were higher than those with the ALAD 1-1 genotype, especially in storage-battery workers. Correlation analysis indicated that the blood lead level negatively correlated with serum calcium...

Health hazards of China’s lead-acid battery industry: a review of its market drivers, production processes, and health impacts

van der Kuijp, Tsering Jan; Huang, Lei; Cherry, Christopher R
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 03/08/2013 EN
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Despite China’s leaded gasoline phase out in 2000, the continued high rates of lead poisoning found in children’s blood lead levels reflect the need for identifying and controlling other sources of lead pollution. From 2001 to 2007, 24% of children in China studied (N = 94,778) were lead poisoned with levels exceeding 100 μg/L. These levels stand well above the global average of 16%. These trends reveal that China still faces significant public health challenges, with millions of children currently at risk of lead poisoning. The unprecedented growth of China’s lead-acid battery industry from the electric bike, automotive, and photovoltaic industries may explain these persistently high levels, as China remains the world’s leading producer, refiner, and consumer of both lead and lead-acid batteries.

Blood Lead Levels and Health Problems of Lead Acid Battery Workers in Bangladesh

Ahmad, Sk. Akhtar; Khan, Manzurul Haque; Khandker, Salamat; Sarwar, A. F. M.; Yasmin, Nahid; Faruquee, M. H.; Yasmin, Rabeya
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 25/02/2014 EN
Relevância na Pesquisa
68.3049%
Introduction. Use of lead acid battery (LAB) in Bangladesh has risen with sharp rise of motor vehicles. As result, manufacture of LAB is increasing. Most of the lead used by these industries comes from recycling of LAB. Workers in LAB industry are at risk of exposure lead and thus development of lead toxicity. Objective. The objective of this study was to measure the blood lead concentration and to assess the magnitude of health problems attributable to lead toxicity among the LAB manufacturing workers. Methods. A cross-sectional study was conducted among the workers of LAB manufacturing industries located in Dhaka city. Result. Mean blood lead level (BLL) among the workers was found to be high. They were found to be suffering from a number of illnesses attributable to lead toxicity. The common illnesses were frequent headache, numbness of the limbs, colic pain, nausea, tremor, and lead line on the gum. High BLL was also found to be related to hypertension and anemia of the workers. Conclusion. High BLL and illnesses attributable to lead toxicity were prevalent amongst workers of the LAB manufacturing industries, and this requires attention especially in terms of occupational hygiene and safety.

New generation submarine battery electrodes using a tin-lead grid alloy.

Swansson, Brenton Travis
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2015
Relevância na Pesquisa
68.46592%
The life of lead-acid batteries is typically governed by corrosion of the positive grid. The grid experiences highly oxidising environments which, in turn, corrodes the grid material. However, the resulting corrosion layer is essential to create an electrically conductive bond between the grid and active material. Additionally, alloying elements are necessary to allow low-cost production techniques to be used. The selection of grid material is therefore a compromise between function, life and ease-of-manufacture. Tubular plate lead-acid batteries have historically used antimonial-lead alloys as the grid alloy. These alloys impart mechanical strength within a die-cast grid and provide a suitably conductive oxide within the corrosion layer. The use of tin in many lead alloy blends has resulted in a beneficial effect on the corrosion rate of these alloys. Tin-lead alloys are used in thin plate lead-acid batteries. However there is no published data on their use for grids of tubular plates in deep-cycling applications. A simple binary, low-tin lead alloy has been tested and found to exhibit a significantly lower corrosion rate during periods of heavy cycling when compared to a traditional low-antimony based alloy. However, it was shown that under severe over-charge conditions...

Battery Characterization and Optimization for use in Plug-in Hybrid Electric Vehicles: Hardware-in-the-loop duty cycle testing

CAMPBELL, ROBERT
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
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Plug-in hybrid electric vehicles (PHEV) with all-electric range (AER) combine battery driven electric motors with traditional internal combustion engines in order to reduce emissions emitted to the atmosphere, especially during short, repetitive driving cycles such as commuting to work. A PHEV utilizes grid energy to recharge the electrical energy storage device for use in the AER operation. This study focuses on battery systems as the electrical energy storage device and evaluates commercially available technologies for PHEV through scaled hardware-in-loop (HIL) testing. This project has three main goals: determine the state of technology for PHEV batteries through an extensive literature review, characterize commercially available batteries including simulated HIL response to a real-world PHEV simulation model, and finally, develop a tool to aid in choosing battery types for different vehicle styles (a battery decision matrix). The five different battery types tested are as follows: A123 Lithium Iron Phosphate (LiFePO4) Li-Ion, Genesis Pure Lead-Tin lead acid, generic absorbed glass mat (AGM) valve regulated lead acid (VRLA), SAFT Nickel-Metal Hydride (NiMH) and SAFT Nickel-Cadmium (NiCd). The batteries were characterized in terms of capacity and maximum power as well as tested on an individually scaled real-world duty cycle derived from a model developed by the University of Manitoba and the University of Winnipeg. When comparing the results of the characterization testing with the literature review and manufacturers’ data it was found that there are discrepancies between the batteries tested and the manufacturers’ specifications for mass and capacity. Furthermore...

Evaluation of lead exposure in workers at a lead-acid battery factory in Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N).

Kim, Y; Harada, K; Ohmori, S; Lee, B K; Miura, H; Ueda, A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1995 EN
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OBJECTIVE--To evaluate lead exposure among lead-acid battery workers in Korea, to evaluate in more detail the erythrocyte pyrimidine 5'-nucleotidase (P5N) test for lead exposure, and to evaluate the abnormal accumulation of erythrocyte pyrimidine nucleotides in the battery workers. METHODS--Activity of P5N and other biological variables were examined in 66 exposed workers in a lead-acid battery factory and in 26 non-exposed workers in Korea. RESULTS--At the factory the time-weighted average of 13 (72%) of 18 air samples for lead exceeded 0.05 (range 0.012-0.468) mg/m3. Blood lead concentration (PbB) in 39 of the 66 exposed workers was above 40 micrograms/dl, and the mean (SD) PbB in the exposed group was 45.7 (15.7) micrograms/dl. Compared with the nonexposed group, free erythrocyte protoporphyrin in the exposed group was significantly increased, whereas erythrocyte P5N activity and activity of erythrocyte delta-aminolevulinic acid dehydratase (ALAD) were significantly inhibited. Erythrocyte P5N activity had valid correlation biologically with PbB and with other biological variables, such as ALAD activity. In 28 exposed workers, the concentration of erythrocyte pyrimidine nucleotides (uridine 5'-diphosphate-glucose and cytidine 5'-triphosphate) correlated inversely with P5N activity and positively with PbB. CONCLUSIONS--These findings show that the depression of erythrocyte P5N activity by lead exposure results in the accumulation of erythrocyte pyrimidine nucleotides. In general...

Relativity and the lead-acid battery

Ahuja, Rajeev; Blomqvist, Andreas; Larsson, Peter; Pyykkö, Pekka; Zaleski-Ejgierd, Patryk
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/08/2010
Relevância na Pesquisa
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The energies of the solid reactants in the lead-acid battery are calculated ab initio using two different basis sets at non-relativistic, scalar relativistic, and fully relativistic levels, and using several exchange-correlation potentials. The average calculated standard voltage is 2.13 V, compared with the experimental value of 2.11 V. All calculations agree in that 1.7-1.8 V of this standard voltage arise from relativistic effects, mainly from PbO2 but also from PbSO4.

Condition Based Maintenance of Lead Acid Batteries and Environmental Responsibility

Kristoffersen, Asgeir
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project Formato: 471976 bytes; application/pdf
EN_US
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Condition Based Maintenance of Lead Acid Batteries and Environmental Responsibility By Asgeir Kristoffersen May 2010 The increase in demand for electrical energy is putting pressure on outdated utility infrastructures and services at the same time that advances in business operations are requiring stable and sufficient sources of power for sensitive operations. A key component of the electrical grid is energy storage and lead acid batteries remain the most cost effective solution. The efficient and prudent use of lead is at best difficult at a time that lead acid batteries are being called upon to provide backup power for critical power applications. This study seeks to use lead acid batteries efficiently thereby reducing the amount of lead acid in our environment. The research consisted of a case study of US electrical power substations, an integral part of the power grid. The case analysis compared traditional maintenance practices of lead acid batteries versus the use of battery condition monitoring. There is a strong business case to be made for investing in condition monitoring to manage the battery assets within power substations. This will ensure that the batteries will function when required. The case study demonstrated that once condition monitoring was installed the number of preventative maintenance visits to a remote site was reduced by 85% with a commensurate reduction in the number of medium duty trucks on the nation’s roads. The avoided CO2 emissions presented a compelling argument for condition monitoring. Condition monitoring and the resultant condition based maintenance will drive infrastructure reliability higher and result in the more efficient use of lead acid batteries with the added benefit of CO2 reductions. There are hundreds of other applications for this technology and with strong management buy-in it is possible to overcome the resistance to change from traditional maintenance practices.

Lead-Acid battery storage

Sequeira,César A.C.; Pedro,Mário R.
Fonte: Sociedade Portuguesa de Materiais Publicador: Sociedade Portuguesa de Materiais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
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Lead-acid batteries are a prime form of chemical storage that we regard as holding most promise for large-scale energy storage applications. This paper includes a few pertinent comments on these rechargeable systems in their present stages of research and development.

Lead-acid battery evolution axis

Pedro,Mário R.; Sequeira,César A.C.
Fonte: Sociedade Portuguesa de Materiais Publicador: Sociedade Portuguesa de Materiais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2007 EN
Relevância na Pesquisa
78.70997%
The recent environmental requirements had compelled the automobile and energy production industries to look for new solutions. The hybrid and electric vehicles and the photovoltaic and wind systems are examples of this research. Thus, it became necessary to find energy storage systems (ESSs) for these new applications. This study is developed in this direction, taking as starting-point the most common SAE: the lead-acid (LAB). Subsequently, alternatives to LAB were studied. The work focused in two points: electrodes and their components. The solutions implicate the total or partial substitution of the lead electrodes by polymers, ceramic or fiber glass, being almost ready to commercialization bipolar batteries with ceramic base that announce the double of specific energy. These ceramics can also be added to the positive paste. The negative paste has been less investigated than the other. As alternative, the Li-ion battery is close to reach its development peak and his mineral reserves are an order of magnitude lower than the ones of lead/nickel. The nickel is used in the hybrid vehicles NiMH batteries, also constituted by other elements that limit their production and increase the battery cost. ZEBRA Battery is a valid option, although it requires working with temperatures above 200ºC. The ultra battery...

Electrochemical oxidation of phenol using a flow-through micro-porous lead dioxide/lead cell

Ferg,Ernst E.; Gouws,Shawn; Pongoma,Basanda
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
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The electrochemical oxidation of phenol to benzoquinone followed by the reduction to hydroquinone and catechol was demonstrated by constructing a three-dimensional porous micro-flow cell from lead dioxide and lead. The electrodes were made by using the principles of curing and formation of lead oxide material that are common in the construction of the electrodes used in lead-acid batteries. This resulted in highly porous electrodes that can allow the reactant solution to flow through them in series, without the risk of having the products being oxidized again at the anode that usually occurs in a simple undivided cell. In this study, a 50 mM solution of phenol in a 60 % acetonitrile and water mixture was used that contained 2 % sulphuric acid. The reactant solution would flow through the anode porous material oxidizing the phenol to benzoquinone. The benzoquinone in solution would then flow through the cathode porous material and reduce to catechol and hydroquinone. The study showed that almost all of the phenol could be converted in one continuous flow process in using a relatively low cost electrochemical micro-flow cell that can be easily scaled up to accommodate larger volumes and concentrations by using electrode manufacturing principles used in the lead-acid battery industry.

The use of an experimental design approach to investigate the interactions of additives used in the making of the negative plate in lead-acid batteries

Ferg,Ernst E.; Snyders,Charmelle
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
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When a conventional starting, lighting and ignition (SLI) lead acid battery is exposed to a high rate partial state of charge (HRPSoC) cycling, it would experience a build-up of irreversible PbSO4 on the negative plate, resulting in capacity loss and electrode damage. The addition of certain graphites to the negative paste mix has proven to be successful in reducing this effect. This study looked at using statistical design of experimental (DoE) principles to observe interactions between two graphite types and a nanocarbon together with other additives, such as BaSO4 and Vanisperse, to a negative paste mixture. The response factors considered were in relation to their effect on the battery's cold cranking ability (CCA) at -18 °C, the HRPSoC and its active material utilization. Typical flooded nominal 8 Ah test cells were assembled in a reverse ratio build,with three positive and two negative plates, with three types of added carbons (flake graphite, natural graphite and nanocarbon) added to the negative paste mixture at a two-level design. The study showed the usefulness of a statistical DoE approach in the effective use of additives that are included to the negative plate paste mixture, where there are interactions between the amounts of added carbon...

A specification of a flywheel battery for a rural South African village

Okou,Richard; Sebitosi,Adoniya Ben; Pillay,Pragasen
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
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48.333364%
The strong growth rates in the installed capacities of renewable energy technologies that have been posted in recent years demonstrate their capacity in the mitigation of green house gas emissions and climate change. The majority of these growths, however, have been realised in grid connected first world programs and do not require provision for energy storage. Most African rural areas are still far from the grid. Many upcoming developments such as cellular network repeater stations and health clinics must be operated from independent off grid PV installations. The intermittence of the resources dictates that reliable energy storage must be provided. The lead acid battery is currently the only available option but has well documented maintenance and disposal problems. The flywheel battery is an old technology that is re-emerging with a strong promise and could address the shortcomings of the lead acid battery. In this paper, a case study of a rural South African village load is depicted. Using a real utility database a possible specification for an electromechanical battery is derived. The authors further highlight the areas that will need future developments.