Influência de variáveis arquitetônicas no desempenho energético de hotéis no clima quente e úmido da cidade de Natal/RN

This master thesis aims to assess the influence of the design decisions on the energy building performance of hotels. The research is based on the integration of field study and computer simulation. Firstly, a detailed field study is carried out to identify the characteristics of hotels in Natal, Rio Grande do Norte. The items assessed are occupancies, light and equipment densities, types of air conditioning, total and monthly energy consumption, among others. A second and more comprehensive field study is carried out to identify the range of occurrence of architectural variables, with a larger number of buildings. A base case is modelled in VisualDOE, based on the first field study. Then, a first set of simulations are run to explore the sensitivity of the variables on the energy consumption. The results analyses were the base of a second set of simulations, which combined the most influential variables. The results of 384 models were assessed, and the impacts of design decisions were quantified. The study discusses tendencies and recommendations, as well as the methods advantages and disadvantages

Balanço energético de um forno túnel de cerâmica estrutural convertido de lenha para gás natural

In energy systems, the balance of entrances, exits and losses are fundamental to rationalize the energy consumption, independently of the source (sun, natural gas, wind, water, firewood or oil). This estimate is important so much in the phase of project of the facilities, as in the exploration or operation. In the project phase it indicates the energy needs of the process and the contribution of the energy in the cost of the product and the capacity of storage of the fuel and in the operation phase it allows to evaluate the use of the energy in the process of it burns, showing the weak points that should suffer intervention to improve the efficiency. With this tool, it can be implemented routines of calculation of thermal balances in ovens of it burns of structural ceramic, in way to generate an optimized mathematical model for application in the current and promising structural ceramic brazilian industry. The ceramic oven in study is located in the metropolitan area of Natal (Rio Grande do Norte) and it is a continuous oven of the type wagons tunnel, converted of firewood for natural gas and it produces blocks of red ceramic. The energy balance was applied in the oven tunnel before and after the conversion and made the comparisons of the energy efficiencies (it burns to the firewood and it burns to natural gas), what showed that the gaseous fuel is more efficient when we burn structural ceramic in ovens tunnels. When we burn natural gas, the requested energy is smaller and better used. Tests were accomplished in the burned product that showed the best quality of the burned brick with natural gas. That quality improvement makes possible to accomplish new interventions for the most rational use of the energy in the oven tunnel of the Ceramic in study and in the industries of structural ceramic of the whole Brazil, that need control tools of burning and of quality

Proposta arquitetônica para o Centro de Treinamento dos Servidores do IFRN com base nos fatores de desempenho energético.

In recent years, as part of the expansion process of its activities, the Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte – IFRN (Federal Institute for Education, Science and Technology of the State of Rio Grande do Norte – IFRN) detected the need to hire more employees for the institution. This expansion process, a policy of the Federal Government, together with the increase of human resources, required the construction of an adequate facility in the municipality of São Gonçalo do Amarante-RN, for training and qualification and as a means of better enabling its personnel. Along with this policy, the Federal Government is also deeply concerned that its buildings be environmentally friendly. This study deals with this subject matter, as it develops an architectural design of a public building with an emphasis upon the reduction of energy consumption, through the study of energy performance factors such as defined by Carneiro (1988) and adapted by the author of the present study. It is known that residential, commercial and public buildings represent about 45 % of energy consumption in Brazil. That is why it is necessary to consider the reduction of such consumption in buildings, as well as the role that professionals, especially architects, play in this issue. The most effective participation in this regard in the field of architecture occurs in the design phase. However, the architectural solution proposed here goes beyond the energy performance factors, since it also involves other aspects, such as the definition of the concept, the parti and the spatial solution itself. In this sense, the architectural project of the Centro de Treinamento dos Servidores do IFRN - CTSIFRN (Training Center for IFRN Personnel – CTSFIRN) is particularly fitting as a subject for research at the Professional Master Program at PPGAU/UFRN, which is devoted to research on architecture, design and the environment.

Influência de variáveis arquitetônicas no desempenho energético de hotéis no clima quente e úmido da cidade de Natal/RN

This master thesis aims to assess the influence of the design decisions on the energy building performance of hotels. The research is based on the integration of field study and computer simulation. Firstly, a detailed field study is carried out to identify the characteristics of hotels in Natal, Rio Grande do Norte. The items assessed are occupancies, light and equipment densities, types of air conditioning, total and monthly energy consumption, among others. A second and more comprehensive field study is carried out to identify the range of occurrence of architectural variables, with a larger number of buildings. A base case is modelled in VisualDOE, based on the first field study. Then, a first set of simulations are run to explore the sensitivity of the variables on the energy consumption. The results analyses were the base of a second set of simulations, which combined the most influential variables. The results of 384 models were assessed, and the impacts of design decisions were quantified. The study discusses tendencies and recommendations, as well as the methods advantages and disadvantages

A influência de decisões arquitetônicas na eficiência energética do Campus vol. 1/UFRN

Building design is an effective way to achieve HVAC energy consumption reduction. However, this potentiality is often neglected by architects due to the lack of references to support design decisions. This works intends to propose architectural design guidelines for energy efficiency and thermal performance of Campus/UFRN buildings. These guidelines are based on computer simulations results using the software DesignBuilder. The definition of simulation models has begun with envelope variables, partially done after a field study of thirteen buildings at UFRN/Campus. This field study indicated some basic envelope patterns that were applied in simulation models. Occupation variables were identified with temperature and energy consumption monitoring procedures and a verification of illumination and equipment power, both developed at the Campus/UFRN administration building. Three simulation models were proposed according to different design phases and decisions. The first model represents early design decisions, simulating the combination of different types of geometry with three levels of envelope thermal performance. The second model, still as a part of early design phase, analyses thermal changes between circulation halls lateral and central and office rooms, as well as the heat fluxes and monthly temperatures in each circulation hall. The third model analyses the influence of middle-design and detail design decisions on energy consumption and thermal performance. In this model, different solutions of roofs, shading devices, walls and external colors were simulated. The results of all simulation models suggest a high influence of thermal loads due to the incidence of solar radiation on windows and surfaces, which highlights the importance of window shading devices, office room orientation and absorptance of roof and walls surfaces

Simulação computacional como ferramenta de auxílio ao projeto: aplicação em edifícios naturalmente ventilados no clima de Natal/RN

Natural air ventilation is the most import passive strategy to provide thermal comfort in hot and humid climates and a significant low energy strategy. However, the natural ventilated building requires more attention with the architectural design than a conventional building with air conditioning systems, and the results are less reliable. Therefore, this thesis focuses on softwares and methods to predict the natural ventilation performance from the point of view of the architect, with limited resource and knowledge of fluid mechanics. A typical prefabricated building was modelled due to its simplified geometry, low cost and occurrence at the local campus. Firstly, the study emphasized the use of computational fluid dynamics (CFD) software, to simulate the air flow outside and inside the building. A series of approaches were developed to make the simulations possible, compromising the results fidelity. Secondly, the results of CFD simulations were used as the input of an energy tool, to simulate the thermal performance under different rates of air renew. Thirdly, the results of temperature were assessed in terms of thermal comfort. Complementary simulations were carried out to detail the analyses. The results show the potentialities of these tools. However the discussions concerning the simplifications of the approaches, the limitations of the tools and the level of knowledge of the average architect are the major contribution of this study

Síntese e caracterização de NiO-CGO para anodo e eletrólitos sólidos e base de Céria para SOFC

The direct use of natural gas makes the Solid Oxide Fuel Cell (SOFC) potentially more competitive with the current energy conversions technologies. The Intermediate Temperature SOFC (IT-SOFC) offer several advantages over the High Temperature SOFC (HT-SOFC), which includes better thermal compatibility among components, fast start with lower energy consumption, manufacture and operation cost reduction. The CeO2 based materials are alternatives to the Yttria Stabilized Zirconia (YSZ) to application in SOFC, as they have higher ionic conductivity and less ohmic losses comparing to YSZ, and they can operate at lower temperatures (500-800°C). Ceria has been doped with a variety of cations, although, the Gd3+ has the ionic radius closest to the ideal one to form solid solution. These electrolytes based in ceria require special electrodes with a higher performance and chemical and termomechanical compatibility. In this work compounds of gadolinia-doped ceria, Ce1-xGdxO2-δ (x = 0,1; 0,2 and 0,3), used as electrolytes, were synthesized by polymeric precursors method, Pechini, as well as the composite material NiO - Ce0,9Gd0,1O1,95, used as anode, also attained by oxide mixture method, mixturing the powders of the both phases calcinated already. The materials were characterized by X ray diffraction, dilatometry and scanning electronic microscopy. The refinement of the diffraction data indicated that all the Ce1-xGdxO2-δ powders were crystallized in a unique cubic phase with fluorite structure, and the composite synthesized by Pechini method produced smaller crystallite size in comparison with the same material attained by oxide mixture method. All the produced powders had nanometric characteristics. The composite produced by Pechini method has microstructural characteristics that can increase the triple phase boundaries (TPB) in the anode, improving the cell efficiency, as well as reducing the mass transport mechanism effect that provokes anode degradation

Análise da recuperação em reservatório de gás com baixa permeabilidade (TIGHT GAS) através do fraturamento hidráulico

With the increasing of energetic consumption in the worldwile, conventional reservoirs, known by their easy exploration and exploitation, are not being enough to satisfy this demand, what has made necessary exploring unconventional reservoirs. This kind of exploration demands developing more advanced technologies to make possible to exploit those hydrocarbons. Tight gas is an example of this kind of unconventional reservoir. It refers to sandstone fields with low porosity, around 8%, and permeabilities between 0.1 and 0.0001 mD, which accumulates considerable amounts of natural gas. That natural gas can only be extracted by applying hydraulic fracturing, aiming at stimulating the reservoir, by creating a preferential way through the reservoir to the well, changing and making easier the flow of fluids, thus increasing the productivity of those reservoirs. Therefore, the objective of this thesis is analyzing the recovery factor of a reservoir by applying hydraulic fracturing. All the studies were performed through simulations using the IMEX software, by CMG (Computer Modelling Group), in it 2012.10 version

Implementação do algoritmo (RTM) para processamento sísmico em arquiteturas não convencionais

With the growth of energy consumption worldwide, conventional reservoirs, the reservoirs called "easy exploration and production" are not meeting the global energy demand. This has led many researchers to develop projects that will address these needs, companies in the oil sector has invested in techniques that helping in locating and drilling wells. One of the techniques employed in oil exploration process is the reverse time migration (RTM), in English, Reverse Time Migration, which is a method of seismic imaging that produces excellent image of the subsurface. It is algorithm based in calculation on the wave equation. RTM is considered one of the most advanced seismic imaging techniques. The economic value of the oil reserves that require RTM to be localized is very high, this means that the development of these algorithms becomes a competitive differentiator for companies seismic processing. But, it requires great computational power, that it still somehow harms its practical success. The objective of this work is to explore the implementation of this algorithm in unconventional architectures, specifically GPUs using the CUDA by making an analysis of the difficulties in developing the same, as well as the performance of the algorithm in the sequential and parallel version

Projeto, construção e análise de um prototipo vibracional em escala de bancada aplicável ao tratamento de água de produção de petróleo bruto, mediante inovadora operação híbrida de adsorção e auto-flotação

A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity

Aplicação da tecnologia eletroquímica como alternativa para a remoção de corante têxteis em efluentes sintéticos e reais utilizando anodos de platina e diamante

In this work, electrochemical technology was used to treat synthetic wastewater containing Methyl Red (MR) and Blue Novacron (BN) by anodic oxidation using anodes platinum (Pt) and real samples of textile effluents using DDB anodes and platinum (Pt). The removal of color from the galvanostatic electrolysis of synthetic wastewater MR and BN, and the actual sample has been observed under different conditions (different current densities and temperature variation). The investigation of these parameters was performed in order to establish the best conditions for removal of color and chemical oxygen demand (BOD). According to the results obtained in this study, the electrochemical oxidation processes suitable for the degradation process of color and COD in wastewater containing such textile dyes, because the electrocatalytic properties of Pt and BDD anodes consumption energy during the electrochemical oxidation of synthetic solutions AN and MR and real sample, mainly depend on the operating parameters of operation, for example, the synthetic sample of MR, energy consumption rose from 42,00kWhm-3 in 40 mAcm-2 and 25 C to 17,50 kWhm-3 in 40mAcm-2 and 40 C, from the BN went 17,83 kWhm-3 in 40mAcm and 40°C to 14,04 kWhm- 3 in 40mAcm-2 and 40 C (data estimated by the volume of treated effluent). These results clearly indicate the applicability of electrochemical treatment for removing dyes from synthetic solutions and real industrial effluents

Secagem de resíduo de goiaba em secador convectivo de bandejas: modelagem matemática e análise do processo

Actually, Brazil is one of the larger fruit producer worldwide, with most of its production being consumed in nature way or either as juice or pulp. It is important to highlig ht in the fruit productive chain there are a lot lose due mainly to climate reasons, as well as storage, transportation, season, market, etc. It is known that in the pulp and fruit processing industy a yield of 50% (in mass) is usually obtained, with the other part discarded as waste. However, since most this waste has a high nutrient content it can be used to generate added - value products. In this case, drying plays an important role as an alternative process in order to improve these wastes generated by the fruit industry. However, despite the advantage of using this technique in order to improve such wastes, issues as a higher power demand as well as the thermal efficiency limitation should be addressed. Therefore, the control of the main variables in t his drying process is quite important in order to obtain operational conditions to produce a final product with the target specification as well as with a lower power cost. M athematical models can be applied to this process as a tool in order to optimize t he best conditions. The main aim of this work was to evaluate the drying behaviour of a guava industrial pulp waste using a batch system with a convective - tray dryer both experimentally and using mathematical modeling. In the experimental study , the dryin g carried out using a group of trays as well as the power consume were assayed as response to the effects of operational conditions (temperature, drying air flow rate and solid mass). Obtained results allowed observing the most significant variables in the process. On the other hand, the phenomenological mathematical model was validated and allowed to follow the moisture profile as well as the temperature in the solid and gas phases in every tray. Simulation results showed the most favorable procedure to o btain the minimum processing time as well as the lower power demand.

Estudo do tratamento sequencial (adsorção e eletro-oxidação) para remediação de efluente sintético contaminado com BTX

This paper proposed the study of the treatment of a synthetic wastewater contaminated with BTX by electro-oxidation batch with the anode of Ti/PbO2, and the adsorption of BTX using expanded perlite as adsorbent material, and to evaluate the best operating conditions both methods in order to perform a sequential treatment (adsorption and electro-oxidation) and achieve greater efficiency in the removal of the compounds. The operating conditions were measured: temperature, current density and applied amount of the adsorbent material, by UV-VIS analysis and Demand Chemical oxygen demand (COD). According to the experimental results, the electro-oxidative treatment was efficient in the degradation of the compounds BTX (benzene, toluene and xylenes) in synthetic sewage due to the electrochemical properties of the anode of Ti/PbO2. The applied current density and temperature promoted increased efficiency of COD removal, reaching obtain percentages greater than 70%. In the adsorption process, the temperature increase was not a factor in the removal of organic matter, while the increase in the amount of adsorbent material led to an increase in the percentage removal, obtaining 66.30% using 2 g of adsorbent. The selected operating conditions of both treatments performed separately take into account the removal efficiency of organic matter, and the low energy consumption and operating costs, so the sequential treatment were satisfactory reaching 87.26% of COD removal using adsorption as a pretreatment. Quantification of BTX through the analysis of gas chromatography at the end of the treatments also confirmed the removal efficiency of organic compounds, giving outstanding advantages to sequential treatment.

Avaliação do tratamento eletroquímico (direto e indireto) como alternativa de degradação do corante azul de metileno

Textile industry has been a cause of environmental pollution, mainly due to the generation of large volumes of waste containing high organic loading and intense color. In this context, this study evaluated the electrochemical degradation of synthetic effluents from textile industry containing Methylene Blue (AM) dye, using Ti/IrO2-Ta2O5 and Ti/Pt anodes, by direct and indirect (active chlorine) electrooxidation. We evaluated the influence of applied current density (20, 40 and 60 mA/cm2 ), and the presence of different concentrations of electrolyte (NaCl and Na2SO4), as well as the neutral and alkaline pH media. The electrochemical treatment was conducted in a continuous flow reactor, in which the electrolysis time of the AM 100 ppm was 6 hours. The performance of electrochemical process was evaluated by UV-vis spectrophotometry, chemical oxygen demand (COD) and total organic carbon (TOC). The results showed that with increasing current density, it was possible to obtain 100 % of color removal at Ti/IrO2-Ta2O5 and Ti/Pt electrodes. Regarding the color removal efficiency, increasing the concentration of electrolyte promotes a higher percentage of removal using 0,02 M Na2SO4 and 0,017 M NaCl. Concerning to the aqueous medium, the best color removal results were obtained in alkaline medium using Ti/Pt. In terms of organic matter, 86 % was achieved in neutral pH medium for Ti/Pt; while a 30 % in an alkaline medium. To understand the electrochemical behavior due to the oxygen evolution reaction, polarization curves were registered, determining that the presence of NaCl in the solution favored the production of active chlorine species. The best results in energy consumption and cost were obtained by applying lower current density (20 mA/cm2 ) in 6 hours of electrolysis.

Aplicação e otimização de métodos eletroquímicos combinados para remoção e determinação de cromo hexavalente em efluentes simulados

Hexavalent chromium is a heavy metal present in various industrial effluents, and depending on its concentration may cause irreparable damage to the environment and to humans. Facing this surrounding context, this study aimed on the application of electrochemical methods to determine and remove the hexavalent chromium (Cr6+) in simulated wastewater. To determine was applied to cathodic stripping voltammetry (CSV) using ultra trace graphite electrodes ultra trace (work), Ag/AgCl (reference) and platinum (counter electrode), the samples were complexed with 1,5- diphenylcarbazide and then subjected to analysis. The removal of Cr6+ was applied electrocoagulation process (EC) using Fe and Al electrodes. The variables that constituted the factorial design 24, applied to optimizing the EC process, were: current density (5 and 10 mA.cm-2), temperature (25 and 60 ºC), concentration (50 and 100 ppm) and agitation rate (400 and 600 RPM). Through the preliminary test it was possible the adequacy of applying the CSV for determining of Cr6+, removed during the EC process. The Fe and Al electrodes as anodes sacrifice showed satisfactory results in the EC process, however Fe favored complete removal in 30 min, whereas with Al occurred at 240 min. In the application of factorial design 24 and analysis of Response Surface Methodology was possible to optimize the EC process for removal of Cr6+ in H2SO4 solution (0.5 mol.L-1), in which the temperature, with positive effect, was the variable that presented higher statistical significance compared with other variables and interactions, while in optimizing the EC process for removal of Cr6+ in NaCl solution (0.1 mol.L-1) the current density, with positive effect, and concentration, with a negative effect were the variables that had greater statistical significance with greater statistical significance compared with other variables and interactions. The utilization of electrolytes supports NaCl and Na2SO4 showed no significant differences, however NaCl resulted in rapid improvement in Cr6+ removal kinetics and increasing the NaCl concentration provided an increase in conductivity of the solution, resulting in lower energy consumption. The wear of the electrodes evaluated in all the process of EC showed that the Al in H2SO4 solution (0.5 mol.L-1), undergoes during the process of anodization CE, then the experimental mass loss is less than the theoretical mass loss, however, the Fe in the same medium showed a loss of mass greater experimental estimated theoretically. This fact is due to a spontaneous reaction of Fe with H2SO4, and when the reaction medium was the NaCl and Na2SO4 loss experimental mass approached the theoretical mass loss. Furthermore, it was observed the energy consumption of all processes involved in this study had a low operating cost, thus enabling the application of the EC process for treating industrial effluents. The results were satisfactory, it was achieved complete removal of Cr6+ in all processes used in this study.