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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Thermal Characterization And Kinetics Of Diesel, Methanol Route Biodiesel, Canola Oil And Diesel-biodiesel Blends At Different Blending Rates By Tga And Dsc

Topa, Ece Hatice 01 September 2010 (has links) (PDF)
Application of thermogravimetric analysis to the renewable energy sources is a novel study and it has been becoming attractive by the researchers in recent years. In this thesis, thermal and kinetic properties of biodiesel as new energy source, diesel and canola oil have been analyzed by using very popular thermogravimetric analysis methods which are / Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA/DTG). The main aim of the study is to observe the combustion and pyrolysis behaviour of methanol route biodiesel and diesel blends at different blending rates. Additionally, combustion and pyrolysis behaviour of canola oil, the origin of biodiesel have been analysed to observe the transesterification reaction effect on biodiesel. Therefore, biodiesel, diesel, canola oil and blends of diesel and biodiesel at different percentages are exposed to isothermal heating under nitrogen and air atmosphere with a constant heating rate of 5, 10 and 15
202

Rational bioenergy utilisation in energy systems and impacts on CO2emissions

Wahlund, Bertil January 2003 (has links)
<p>The increased concentration of greenhouse gases in theatmosphere, in particular CO<sub>2</sub>, is changing the Earth’s climate. Accordingto the Kyoto protocol, where the international community agreedon binding emission targets, developed countries are committedto reduce their greenhouse gas emissions. The increased use ofbiomass in energy systems is an important strategy to reduce CO<sub>2</sub>emissions. The purpose of this thesis has been toanalyse the opportunities for Sweden to further reduce CO<sub>2</sub>emissions in the energy system, by rationallyutilising woody biomass energy. The characteristics of currentcommercially operating biofuel-based CHP plants in Sweden aresurveyed and systematically presented. A consistent andtransparent comprehensive reference base for system comparisonsis given. Furthermore, the fuel effectiveness and contributionto CO<sub>2</sub>reduction is calculated. The governmentalsubsidies of the CHP plants’investment, expressed as costof specific CO<sub>2</sub>reduction, appears to be low.</p><p>The competitiveness of biomass-fuelled energy production inrelation to fossil-based production with carbon capture isanalysed, showing that the biomass-fuelled systems provide acompetitive option, in terms of cost of electricity andefficiencies. The remaining Swedish woody biofuel potential ofat least 100 PJ/yr is principally available in regions with abiomass surplus. Transportation is therefore required to enableits utilisation in a further national and international market.Refining the biofuel feedstock to pellets, or even furtherrefining to motor fuels (DME, methanol or ethanol) or power,could facilitate this transport. Different options for fuelrefining are studied and compared. The entire fuel chain, fromfuel feedstock to end users, is considered and CO<sub>2</sub>emissions are quantified. Substituting fuelpellets for coal appears to be the most costeffectivealternative and shows the largest CO<sub>2</sub>reduction per energy unit biofuel. Motor fuelsappear more costly and give about half the CO<sub>2</sub>reduction. Transportation of the upgraded biofuelpellets is highly feasible from CO<sub>2</sub>emissions point of view and does not constitute ahindrance for further utilisation, i.e. the pellets can betransported over long distances efficiently with only limitedemissions of CO<sub>2</sub>.</p><p>Bioenergy utilisation has additional features forenvironmental improvement, apart from the CO<sub>2</sub>aspect. Waste heat from biofuel-based CHP can becost-effectively used in conjunction with sewage treatment. Theincoming sewage water to the nitrification process can bepreheated with the waste heat, and thereby substantiallyenhance the nitrification and the reduction of ammoniumnitrogen during the winter season.</p><p><b>Keywords:</b>CO<sub>2</sub>reduction, energy system, biofuel, CHP, refining,fuel pellets, ethanol, methanol, DME, fuel substitution, sewagewater, nitrification.</p>
203

Adsorption av Sb på zeolit / Sb adsorption by zeolite

Lundstedt, Evert January 2007 (has links)
<p>Detta examensarbete är en förundersökning till Glafos undersökning angående rening av glasbrukens processvatten från antimon med zeolit.</p><p>Förundersökningen gick ut på att via experiment ta reda på hur mycket antimon som adsorberas av behandlad (för optimering: dels med NaNO3 och dels med NaCl) och obehandlad zeolit (porstorlek 0.4 nm). pH mättes och ställdes eftersom det har betydelse för adsorptionen, åtminstone vid väldigt lågt pH. När lösningarna hade filtrerats mättes den kvarvarande antimonhalten med atomabsorptionsspektrofotometri. Mätningarna visade att i genomsnitt 53 % av Sb-halten i lösningarna hade adsorberats av zeoliten. Förundersökningen visade att det inte blir någon adsorption då pH är väldigt lågt (under 1). Den visade också att när pH är över 4 verkar det inte ha någon betydelse om zeoliten är behandlad eller inte.</p><p>Zeoliten bör behandlas med NaCl först i en tank med omrörning, sedan blandas i processvattnet (vars pH justerats till pH 4) i en tank eller bassäng och därefter filtreras.</p><p>Tidsfaktorn för hur lång tid det tar för zeoliten att nå jämvikt och temperaturens inverkan bör även undersökas.</p> / <p>The aim of this diploma work is to study the removal of antimony from glassworks process water using zeolites.</p><p>The experimental part of the studies were carried out to find the quantity of antimony adsorbed by the zeolite. The studies included treated (for optimization: partly with NaNO3 and partly with NaCl) and untreated zeolite. The pore size is 0.4 nm. pH was measured and adjusted because it is important for the antimony adsorption. When the solutions were filtrated the content of antimony left was measured with atomic absorption spectrophotometry. The measurements showed an average uptake of antimony by the zeolite of 53 %.The preinvestigation indicates that with a very low pH (below 1) there is no antimony adsorption. It also indicates that with pH above 4 it does not matter if the zeolite are treated or not.</p><p>In further investigations the zeolite should be treated with NaCl in a stirred tank, then be mixed in the process water (pH is set to 4) in a tank or basin and then be filtrated.</p><p>The time to reach equilibrium and the influence of temperature should also be investigated.</p>
204

A study of the phenomenon of bridging of sugarcane bagasse

January 1996 (has links)
This work reports the results of a systematic study of the factors that affect the bridging behaviour of bagasse. It shows that traditional bulk solids theory is inappropriate for predicting bagasse flow mainly because of the impossibility of obtaining a reliable measure of internal friction. It demonstrates the significant influence of fibre length and moisture content on its handling charateristics. Correlations of pertinent bulk properties such as compactibility, tensile strength, surface friction and translation of vertical into horizontal pressure have been developed. These were derived as a result of measurements in equipment that was designed for the purpose. Finally, an empirical model utilising these correlations is proposed by which the likelihood of bridge formation in any piece of bagasse handling equipment can be determined. The validity of the model is assessed by comparison with bridging tests that were performed under controlled conditions. / Thesis (Ph.D.)-University of Natal, 1996
205

Influência da frequência de vibração mecânica sobre o refino de grãos em metais de solda de juntas do aço ASTM A516 Gr.60. / Influence of mechanical vibration frequency on weld metals grain refining of ASTM A516 Gr.60 welded joint.

SILVA NETO, Jaime Matias da. 17 August 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-17T15:03:40Z No. of bitstreams: 1 JAIME MATIAS DA SILVA NETO- DISSERTAÇÃO (PPGEM) 2018.pdf: 3496418 bytes, checksum: 6c6b6ae8738da4d0e77cbcedcb6bb9d6 (MD5) / Made available in DSpace on 2018-08-17T15:03:40Z (GMT). No. of bitstreams: 1 JAIME MATIAS DA SILVA NETO- DISSERTAÇÃO (PPGEM) 2018.pdf: 3496418 bytes, checksum: 6c6b6ae8738da4d0e77cbcedcb6bb9d6 (MD5) Previous issue date: 2018-02-27 / CNPq / O presente trabalho teve como objetivo avaliar a influência da aplicação de vibração mecânica durante o processo da soldagem sobre o refino de grãos em metais de solda obtidos na soldagem do aço ASTM A516 Gr.60, aplicado em caldeiras e vasos de pressão. Para o tratamento de vibração mecânica foi utilizado o processo VWC (Condicionamento de Soldagem Vibratória), e para a soldagem foram empregados dois tipos de processos: SMAW (Arco Elétrico com Eletrodo Revestido) e GMAW (Soldagem ao arco elétrico com proteção gasosa). Os consumíveis utilizados foram o arame AWS ER 70S-6 com 1,2 mm de diâmetro protegido com CO2 no processo GMAW e o eletrodo AWS E7018 com 2,25 mm de diâmetro no processo SMAW. Foi projetada e desenvolvida uma bancada vibratória para realização dos experimentos. As juntas foram executadas sem e com vibração, submetidas a amplitudes que variaram de 7,2 a 51,2 m/s2 e frequências de 205 a 220 Hz. A vibração promoveu uma melhor distribuição da microestrutura no metal de solda, promovendo um refino de até 113% para uma amplitude de 51,2 m/s2 e frequência de 220 Hz no processo GMAW, em relação a condição sem vibração. Já no processo SMAW a redução chegou a 25% com amplitude de 7,2 m/s2 e frequência de 205 Hz. As reduções nos desvios padrões médios de dureza chegaram a 71% para uma amplitude de 48,9 m/s2 e frequência de 215 Hz, no processo GMAW. Enquanto que no processo SMAW, o desvio padrão médio de microdureza reduziu 27%, com amplitude 7,2 m/s2 e frequência de 205 Hz, em relação a condição sem vibração. / The present work had the objective of evaluating the influence of mechanical vibration during the welding process on grain refining in brazing metals obtained in the welding of steel ASTM A516 Gr.60, applied in boilers and pressure vessels. For the mechanical vibration treatment VWC (Vibration Welding Conditioning) process was used.. , The welds were done using the SMAW (Electric Arc with Coated Electrode) and GMAW (Electric Arc Welding with Gaseous Protection) process. AWS ER 70S-6 wire with 1.2 mm of diameter protected with CO2 in the GMAW process and the electrode E7018 with 2.25 mm of diameter in the process SMAW were used as consumable. A vibratory bed was designed and developed to perform the experiments. The joints were performed without and with vibration, subjected to amplitudes ranging from 7.2 to 51.2 m/s2 and frequencies from 205 to 220 Hz. The vibration promoted a better distribution of the microstructure in the weld metal, promoting a refining of up to 113% for an amplitude of 51.2 m/s2 and a frequency of 220 Hz in the GMAW process, in relation to the condition without vibration. In the SMAW process the reduction reached 25% with amplitude 7.2 m/s2 and frequency of 205 Hz. The reductions in the average hardness standard deviations reached 71% for a range of 48.9 m/s2 and a frequency of 215 Hz, in the GMAW process. Using the SMAW process, the mean standard deviation of microhardness value decreased by 27%, with amplitude 7.2 m/s2 and a frequency of 205 Hz, in relation to the condition without vibration.
206

Modelamento físico de uma panela siderúrgica não cilíndrica agitada com gás

Pereira, Julio Anibal Morales January 2011 (has links)
Utilizando um modelo físico de uma panela siderúrgica agitada com gás, de base elíptica e escala reduzida, foram realizados estudos para verificar a influência de diversas variáveis operacionais na otimização dos processos de mistura, fenômenos de emulsificação, e comportamento da abertura do olho da coluna de bolhas durante a agitação do aço líquido. Para esses estudos foram utilizados água e querosene como simuladores do aço e escória industrial, respectivamente. Os tempos de mistura foram determinados por medidas de condutividade. O escoamento do líquido foi caracterizado por meio da técnica PIV (velocimetria por imagem de partícula) e dispersão de traçador. Ambos experimentos, assim como os fenômenos de emulsificação e abertura do olho da coluna de bolhas, foram registrados por uma câmera de vídeo. Os resultados experimentais mostram que os tempos de mistura diminuem com o aumento da vazão de gás, porém aumentam na presença de uma camada de escória. Das configurações testadas, os menores tempos de mistura foram obtidos para uma adição do traçador (ou liga) no olho da coluna de bolhas e uma posição de injeção de gás a meio raio. Os fenômenos de emulsificação aumentam com o aumento da vazão de gás, com o deslocamento da posição de injeção de gás desde a parede para o centro da panela e com o aumento da camada de escória. A abertura do olho da coluna de bolhas cresce linearmente com o aumento da vazão de gás e diminui com o aumento da camada de escória. As correlações empíricas encontradas na literatura prevêm satisfatoriamente os resultados experimentais do modelo físico. / Utilized gas stirring ladle cold model, elliptic shape and reduced scale, were carried out study for verify effects of operational variables in optimization process mixing, emulsification phenomena, behavior exposed eye of the bubble column or plume and removal inclusions during stirring steel liquid. For these study were utilized water and kerosene how simulators steel and slag industrial. The mixing time was measured by an electrical conductivity method. Fluid flow characterization were realized through PIV (particle image velocimetry) technique and tracer dispersion experiments. This is experiments as well as behavior emulsification and aperture eye of the bubble column or plume were registered by the video recordings. Experimental results show decreases mixing time with increment gas flow rate however, increment in presence of slag layer covered the bath. From the tests configurations, is low mixing time were obtained for location addition tracer (or alloy) in eye of the bubble column or plume and half radius gas position injection. This emulsification phenomena increment considerably with gas flow rate, as gas position injection is moved from the wall ladle to center and increment slag layer thickness. The aperture eye of the bubble column or plume increases linearly with increment gas flow rate and decrease with increment slag layer thickness. Empirical correlations in literature agreement satisfactory the experimental result of physical model.
207

Estudo das perdas térmicas de panelas entre o vazamento no forno elétrico à arco e o transporte para o forno-panela

Bruch, Rafael January 2012 (has links)
A busca de melhoria de produtos siderúrgicos leva uma atenção especial para a área de aciarias. A introdução da metalurgia da panela, e portanto no refino secundário, contribuiu fundamentalmente para o aumento da qualidade do aço produzido. Um dos efeitos foi o aumento do tempo de residência do aço na panela, o que obrigou a utilização de materiais refratários de melhor qualidade. O controle da temperatura do aço líquido ao longo do processo de produção é de fundamental importância para se atingir os requisitos de qualidade e produtividade exigidos atualmente. Com o desenvolvimento de tecnologias siderúrgicas e a busca pela eficiência energética, torna-se necessário o conhecimento e redução das perdas térmicas do aço durante todo o ciclo produtivo. Neste trabalho foram estudadas, em uma aciaria elétrica a arco, as correlações entre as perdas térmicas das panelas através do conhecimento dos tempos de espera e do tempo de transporte das panelas do forno elétrico a arco até o forno-panela, além de comparar a temperatura do revestimento refratário de panelas com e sem isolante refratário. Melhorias no ciclo de panelas foram propostas visando diminuir as perdas térmicas das panelas, otimizar o ciclo de panelas e, consequentemente, reduzir o consumo de energia elétrica do forno-panela, diminuindo os custos envolvidos durante o processo de fabricação do aço. Os resultados apresentaram significância estatística entre o consumo de energia elétrica do fornopanela e as perdas térmicas das panelas. Através dos resultados obtidos observou-se que a minimização do tempo de espera da panela antes de iniciar o vazamento e a diminuição do tempo de transporte da panela até o forno-panela são fundamentais para diminuir as perdas térmicas nas panelas. / The search for improved steel products takes special attention to the melthops. The introduction of ladle metallurgy, and therefore the secondary refining, contributed essentially to increase the quality of steel produced. One effect was to increase the residence time of the steel in the ladle, forcing the use of refractory materials of better quality. Temperature control of liquid steel during the process is of fundamental importance for achieving the requirements of quality and productivity currently required. With the development of technologies and the reach of energetic efficiency, it becomes necessary to reduce the thermal losses during the steel production cycle. In this study the correlations between the thermal losses in the ladles through the knowledge of waiting times and transport times of the ladles to the of the electric arc furnace to the ladle furnace were determined as well as a comparison between temperatures of ladle refractory lining with and without refractory insulation. Improvements in the ladle cycle were proposed to reduce the thermal losses in the ladles and to optimize the ladle cycle and, consequently, to reduce the electric energy in the ladle furnace, reducing the costs involved during the manufacturing process of steel. The results showed statistical significance between the energy consumption in the ladle furnace and heat losses in the ladles. The results obtained showed that minimizing the waiting time of the ladle before the tap and reducing transportation time of the ladle to the ladle furnace are essential to reduce the heat losses in the ladles.
208

Gestão de resíduos perigosos em refinarias de petróleo / Management of hazardous waste oil refineries

Carlos Eduardo Soares Canejo Pineiro da Cunha 18 March 2009 (has links)
Diferentes etapas do refino do petróleo resultam na geração de resíduos oleosos que possuem em sua composição substancias que imprimem periculosidade aos mesmos, que, caso venham a contaminar o solo, podem impactar a biota da área, atingir os lençóis freáticos, rios e lagos da região, agredindo diretamente ou indiretamente a saúde humanae gerando custos ambientais, sociais e monetários muito altos. O objetivo do presente trabalho foi avaliar a gestão dos resíduos sólidos perigosos gerados na atividade de refinarias de petróleo no Brasil, descrevendo processos, caracterizando a geração dos mesmos em cada etapa do refino e avaliando técnicas de tratamento e de destinação final. Ao longo do texto, foram abordados conceitos de gestão ambiental e de logística reversa, com o objetivo de ressaltar benefícios ambientais e sócio- econômicos advindos de umatravés do processo de gestão. Sobre a gestão dos resíduos, são apreciados os conceitos básicos desta, compondo-se uma abordagem prática e simplificada, sendo avaliadas estratégias de minimização de resíduos com base nos 3Rs, algumas metodologias de tratamento e a utilização de aterros industriais como local de destinação final para os resíduos. Para a estruturação da dissertação proposta, foi executada uma revisão bibliográfica, além da construção de uma linha de coesão entre os objetos estudados. Conclui-se que atualmente não existe metodologia de gestão tão eficiente que seja totalmente sustentável, nem gestão que possa ser baseada em apenas uma prática ou metodologia. A integração de conceitos e práticas, incluindo programas de minimização de resíduos, logística reversa, tratamento e destinação final faz-se necessária para uma gestão mais eficiente dos resíduos oleosos. Porém, deve-se destacar as novas oportunidades gerenciais associadas à logística reversa, bem como a necessidade de utilização dos aterros industriais em alguma etapa da gestão, assim como a atual tendência à adoção do co-processamento como metodologia de tratamento que apresenta a melhor relação custo x benefício para a gestão dos resíduos perigosos gerados nas refinarias de petróleo. / Different stages of the petroleum refining generate oil wastes that have hazardous substances. When oil waste contaminates the soil it may cause impacts on living resources, reaching groundwater, rivers and lakes in the region, affecting directly or indirectly the human health, with environmental, social and economic costs that can be very high. The objective of this study was to assess the management of hazardous solid wastes generated at petroleum refineries, describing processes and characterizing the way these wastes are generated in different stages of the refining process. The study also included assessment of treatment options and final disposal strategies. Principles of environmental management and reverse logistics were addressed with the objective of highlighting the environmental and socio-economic benefits added by a suitable management scheme. The basic concepts related to solid waste management are discussed in a practical and simplified language, and the minimization strategies are evaluated based on 3Rs principle. Treatment methodologies and the relevance of utilizing industrial landfills as final disposal solution are presented. Besides the literature survey, the construction of a red thread connecting the issues is presented. It was concluded that currently, there is no management scheme for oil waste efficient enough to be considered sustainable, neither management option that can be based on a single technology or methodology. An integration of concepts and different practices including waste minimization, reverse logistics, treatment and final disposal is needed in order to achieve a more efficient oil waste management. However, it is worth to highlight new managerial opportunities related to reverse logistics, as well as the need to make use of industrial landfills in some point of the process and the current trend of co- processing as the option that presents the best cost-benefit for management of oil hazardous wastes generated by petroleum refineries.
209

Retrofit of heat exchanger networks of a petroleum refinery crude unit (CDU) using pinch analysis

Mammen, John Joe January 2014 (has links)
Thesis submitted in fulfilment of the requirements for the degree of Master of Technology: Chemical Engineering, In the Faculty of Engineering, Cape Peninsula University of Technology 2014 / Energy efficiency has become an important feature in the design of process plants due to the rising cost of energy and the more stringent environmental regulations being implemented worldwide. In South Africa as in other African countries, most of the chemical plants were built during the era of cheap energy with little emphasis placed on energy efficiency due to the abundance of cheap utility sources such as coal and crude oil. In most of these plants, there exists significant potential for substantial process heat recovery by conceptual integration of the plant’s heat exchangers. Pinch Technology (PT) has been demonstrated to be a simple and very effective technique for heat integration and process optimization. This study applies the PT approach to retrofit the heat exchangers network of the Crude Distillation Unit (CDU), of a complex petroleum refinery with the aim to reduce utilities requirement and the associated gaseous pollutants emission. This objective is accomplished by firstly conducting an energy audit of the unit to scope for potential energy saving. The existing Heat Exchanger Network (HEN) was re-designed using the remaining problem analysis (RPA) to achieve improved process energy recovery while making maximum use of the existing exchangers. The aim is to maintain the existing plant topology as much as possible. This network was later relaxed trading heat recovery with number of heat transfer unit so as to optimize the capital cost. These were implemented in AspenPlus v7.2 environment. The cost implications of the retrofitted and evolved networks including the capital and operating costs were determined on a 5 years payback time basis. The Problem Table (PT) analysis revealed that the minimum utilities requirements are 75 MW and 55 MW for the hot and cold utilities respectively. Compared to the existing utilities requirements of 103 MW for hot utility and 83 MW for cold utility, this represent a potential savings of about 26 % and 33 % savings for the hot and cold utilities respectively. The target utilities usage in the re-designed network after applying Remaining Problem Analysis (RPA) was found to be 55 MW for the cold utility and 75 MW for hot utility. The relaxed HEN required a cold utility of 62.5 MW and hot utility of 81 MW. From the total cost estimation, it was found that, although an energy saving of 34% can be achieved by the re-designed network before relaxation, the capital cost, US$ 1670000 is significantly higher than for the existing network (about US$ 980000). The final relaxed network gave an energy saving of 34% and with total cost of US$ 1100000. It was recommended from the study after cost comparisons of the four different networks (the original network, the MER network, the relaxed network and a grass-root design) that the best network for the retrofit purpose was the relaxed HEN, because there is no major shift in deviation from the topology of the original network. From the analysis it was found that a 34% saving in energy cost could be achieved from this retrofit. The Total Annual Cost (TAC) for this network gives credence to the fact that this retrofit which applied the rules of pinch analysis can bring about real saving in energy usage.
210

Use of high efficient motors for DSM in South Africa's petroleum refineries

Mithamo, Peter Ng'ang'a January 2012 (has links)
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2012. / Electric motors consume over 60% of the world's generated electricity. In South Africa approximately 65% of the energy generated is consumed by electric motors (Niekerk, 2009). About 95% of motors in use in South Africa are Standard-Efficient Motors (SE-motors) that operate at an average efficiency of 84% to 90%, depending on the size of the motor and the load driven by them. High-Efficient motors (HE-motor) run at an efficiency of 2% to 8% higher than that of SE-motors. In recent years, a drive to replace SE-motors with HE-motors has been promoted for the purpose of Demand Side Management (DSM). The rationale of using HE-motors as a tool of DSM is to harness a small difference in operating efficiency per motor, which can result in a huge reduction in electricity consumption, depending on the number of HE-motors that will replace SE-motors. Reducing the demand for electricity is the key driving factor for DSM in South Africa, so as to relieve the already stressed power generation capacity. Other consequential factors of DSM are to reduce the amount of pollutant gases emitted into the atmosphere. To the electricity users DSM will be a great incentive, as reduced consumption of electricity will decrease the amount of money spent on electricity. Much has been written on the ability of HE-motors to reduce electricity consumption, cost of electricity and global pollution. ESKOM has even demonstrated the faith they have in these motors by giving rebates to motor users who are willing to exchange their existing SE-motors with new HE-motors. The rebates are paid by ESKOM through a newly established DSM program. However, it must be mentioned that savings through HE-motors is not a perfect guarantee. HE-motors have inherent design limitations that may inhibit the saving of energy. To achieve higher efficiency, HE-motors are designed to operate on a smaller slip that consequently increases their speed compared to that of SE-motors (Cheek et al., 1995). Higher rotor speed impacts energy saving abilities of HE-motors when they are used to drive fans, pumps and compressors, normally referred to as centrifugal loads. An increase in speed results in a proportional increase in flow. Power consumed by a motor goes up as a cube of the speed, and the flow rate increases linearly with speed. Motor loads in the petrochemical industry are generally centrifugal, and that is why this thesis focuses on refineries.

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