Dissertations / Theses on the topic 'Heating – Efficiency – Simulation methods'
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Dowrani, Ali Akbar Gharooni. "Efficiency of air cooler coil defrost methods and the effect of these methods on the refrigeration cycle performance." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316876.
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Partain, Seth Collins. "Fused deposition modeling with localized pre-deposition heating using forced air." Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/partain/PartainS0507.pdf.
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Meng, Yao. "Assessing the effect of new control and payment methods on heating energy consumption and occupant behaviour in Chinese dwellings." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/25749.
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Energy demand reduction has become a global issue involving all countries, including China. As major energy consumers in today s society, the need for buildings to be built and operated more energy efficiently is well recognized. In 1995, the national standard on building energy efficiency in China (JGJ 26-95) was refined and updated to become the new residential Buildings standard (JGJ 26-2010) published in 2010. In the new version, many changes have been made to support the construction of more energy efficient buildings in China. For example, in the new standard, all buildings are highly recommended to install personal control on the heating system, such as by Thermostatic Radiator Valves (TRVs), together with pay for what you use tariffs. Previous practice comprised uncontrolled heating with payment based on floor area. In order to reduce building energy consumption, Chinese government has revised the Chinese building design standard. In the new guide the use of individual room temperature control is highly recommended for new and refurbishment buildings. However, evidence to quantify the extent to which this improvement impact upon on the building energy consumption is currently lacking. This thesis evaluates the impact of updated building design standards on thermal conditions and energy consumption in Chinese residential buildings. In order to evaluate the impact on the building energy consumption, two types of residential buildings have been chosen, one complying with the old Chinese building design standard, while the other complies with the new standard. The study was carried out in seven apartments in each type of building, a total of fourteen apartments and comprised with a longitudinal monitoring of indoor air temperature, outdoor air temperature, window position and energy consumption of each apartment. The impact of the new design standard has been evaluated in relation to a number of aspects, that include building construction, indoor thermal environment, occupant behaviour, thermal comfort and building energy consumption. It is concluded that updating the building design standard has had a positive influence on the building conditions and energy consumption. Furthermore, a thermal comfort survey was carried out in both new and old apartments according to updated standards. The results show that the Predicted Mean Vote (PMV) model has a efficiently adequate predictor of occupants thermal comfort in both type of apartments. Thereby allowing confirmation that the new control refine did not compromise on thermal comfort. The percentage of acceptable of occupants is higher in new apartments compared with the old apartments.
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Widström, Torun. "Enhanced Energy Efficiency and Preservation of Historic Buildings : Methods and Tools for Modeling." Licentiate thesis, KTH, Byggnadsteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102544.
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As the environmental impacts of the energy usage of the world today becomes more and more evident, enhancement of energy performance of the already existing building stock becomes more urgent. Buildings belonging to the cultural heritage are often the ones that are most difficult to deal with in this context. The subject of this thesis is the use of building simulation of historic buildings. The task here is to identify and when necessary develop simulation tools and methods that are suitable for planning of retrofitting strategies in historic buildings, and to identify and analyze what demands such tools and methods would have to fulfill, in what contexts different simulation strategies are suitable, how the demands on the tools might be met and what results and how the results would facilitate the decision making process in the most optimal way. A powerful means to acquire such analyses is the use of whole-building simulation. In the case of historical buildings there are several aspects to take into consideration, determining the choice of simulation tool and method. This thesis includes Investigation of the variability of the demands on simulation tools and methods that the historic buildings pose, and its implication on complexity of the simulation process, and suggestion of a complexity index tool. Investigation of the whole-building simulation process and how it complies with the demands identified, and how the exergy concept can be used, exemplified by a case study. Identification of a need for a tool and method for a large amount of cases not easily covered by abundantly available tools and methods Suggestion of a tool and method to address these cases, and presentation of a case study where the suggested tool and method have been applied, with good agreement between the simulated and measured values. One important feature of the suggested tool is the Very Small Wall-part Method, that includes the assessment of especially damage prone points into the whole-building simulation model, otherwise unable to accommodate these points. Another is the damage risk assessment feature where a mould risk prediction tool is presented.QC20120920
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Vadambacheri, Manian Karthik. "Novel Methods to Improve the Energy Efficiency of Multi-core Synchronization Primitives." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1511858440610247.
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Nilsson, Daniel. "Analysis and simulation of systems for delivery of fuel straw to district heating plants /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5721-1.pdf.
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Ertem-Müller, Senem [Verfasser]. "Numerical Efficiency of Implicit and Explicit Methods with Multigrid for Large Eddy Simulation in Complex Geometries / Senem Ertem-Müller." Aachen : Shaker, 2003. http://d-nb.info/1181602696/34.
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Mason, Kevin Richard. "Development of numerical schemes to improve the efficiency of CFD simulation of high speed viscous aerodynamic flows." Thesis, Swansea University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678434.
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Starke, Martin, Benjamin Beck, Denis Ritz, Frank Will, and Jürgen Weber. "Frequency based efficiency evaluation - from pattern recognition via backwards simulation to purposeful drive design." Technische Universität Dresden, 2020. https://tud.qucosa.de/id/qucosa%3A71072.
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The efficiency of hydraulic drive systems in mobile machines is influenced by several factors, like the operators’ guidance, weather conditions, material respectively loading properties and primarily the working cycle. This leads to varying operation points, which have to be performed by the drive system. Regarding efficiency analysis, the usage of standardized working cycles gained through measurements or synthetically generated is state of the art. Thereby, only a small extract of the real usage profile is taken into account. This contribution deals with process pattern recognition (PPR) and frequency based efficiency evaluation to gain more precise information and conclusion for the drive design of mobile machines. By the example of an 18 t mobile excavator, the recognition system using Hidden – Markov - Models (HMM) and the efficiency evaluation process by means of backwards simulation of measured operation points will be described.
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Sakellari, Dimitra. "Modelling the dynamics of domestic low-temperature heat pump heating systems for improved performance and thermal comfort : a systems approach." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-269.
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Venturi, Elisa. "Dynamic simulation and analysis of a Passive House case study with direct PV system for heating and domestic hot water production." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16590/.
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Different heating systems for space heating and domestic hot water (DHW) preparation are investigated with respect to their energy efficiency. In particular, a case study of a multi-storey Passive House (called An-der-Lan) is analysed by means of dynamic simulations.
The first part of dynamic simulations focuses on the comparison of the UA and RC models for a simple office located in Rome. This is a case study from the project IEA SHC T56 – System Simulation Models. In particular, attention is put on the influence of the thermal capacity. Assuming the RC model as the reference case, variants of the UA model with different percentages of the thermal capacity are simulated, in order to find out the most similar to the RC model. The same investigation is carried out for the An-der-Lan building. In general, it is not possible to identify the best UA model, because for every considered quantity, the minimum difference between the UA and RC model is got for a different percentage of the thermal mass.
The second part of dynamic simulation focuses on the comparison among different systems for heating and DHW preparation. The realized system is direct electric heating for both space heating and DHW preparation. It is denoted as the reference Case1 and it is compared against alternative solutions. Case2 is based on a central air/water heat pump system for both heating and DHW production. A sensitivity analysis study is conducted. Finally, Case3 and Case4 are a mix of the previous two cases.
Results show that Case2 is the best in terms of electric energy required from the grid, although it is the system with the highest thermal losses. Furthermore, the PV system only in the south façade is not sufficient to cover the energy required in neither of the cases.
Finally, annual, monthly, daily, hourly and 10 minutes balances are compared. Results show the importance of smaller time step in balances between required and produced energy, in order to have more precise results.
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Shi, Hongsen. "Building Energy Efficiency Improvement and Thermal Comfort Diagnosis." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555110595177379.
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Scullin, Michelle E. "Integrating Value Stream Mapping and Simulation." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd898.pdf.
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Carpenter, Nolan A. W. "A study of exergy destruction and methods improving second law efficiency in common production engines using a thorough analysis of engine simulation results." Birmingham, Ala. : University of Alabama at Birmingham, 2009. https://www.mhsl.uab.edu/dt/2009m/carpenter.pdf.
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Hauerhof, E. "The assessment of oil products tanker design methods and technologies to enhance the Energy Efficiency Design Index measure by means of computer simulation and trend analysis." Thesis, City, University of London, 2017. http://openaccess.city.ac.uk/17635/.
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The primary objective of this PhD research is to develop an advanced understanding of the necessary and realistic performance expectations from a full form medium size ship system by means of numerical computer modelling. This includes the minimisation of the harmful environmental signature by increasing its efficiency in compliance with the EEDI requirements while in search of how the EEDI methodology might be enhanced. The investigation has focused on a medium sized products tanker acting as a midpoint of the spectrum of ship sizes within the range of 20,000 – 60,000 DWT of this type. In order to solve such an extensive problem, in the first place, it was important to analyse the energy efficient technology market in a structured manner and then, to identify the most favourable fuel consumption reduction methods that can be associated with the examined ship type. Next, an integrated computer simulation model, involving linked engine, propeller and hull analysis programs, has been developed and calibrated with the model tests and sea trial data. The ship system has been analysed under diverse conditions including various propulsion systems, innovative machinery arrangements, efficiency enhancing hydrodynamic appendages as well as changing weather and load conditions. The evaluation of potential benefits associated with the deployment of innovative technology(s), operation profile(s) or their combination has been made by comparing the designated Energy Efficiency Indicators (EDI), namely, the propulsive efficiency, fuel oil consumption, exhaust emissions footprint and EEDI, respectively associated with the technical, fuel savings, environmental and legal perspectives. In addition, such a comprehensive analysis has also helped to detect a number of uncertainties in the current EEDI formulation while pointing out ways in which it can be improved.
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Tillman, Johan. "En energistudie över Fengerfors bruk : Kartläggning och förslag till effektiviseringsåtgärder hos byggnader av industrikaraktär." Thesis, Karlstads universitet, Fakulteten för teknik- och naturvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-7898.
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I slutet av 1900-talet började man inse konsekvenserna av att förlita sig på icke förnyelsebara energikällor för uppvärmning. Priserna steg i höjden och man valde ofta att byta ut sin oljepanna mot el vilket för tillfället var en lönsam lösning. I och med prisstegringen som skett det senaste decenniet har betydelsen av energieffektivt byggande framstått som allt mer tydlig. Detta innebär att många äldre byggnader ofta kan ha mycket dåliga värmeisolerade egenskaper eftersom både energipriser och byggnormer var lågt ställda vid tiden för uppförning. Uppdragsgivarna till arbetet är en ideell ekonomisk förening vid namn Not Quite med sin bas i Fengerfors bruk, Åmål. De har framfört att de har problem med för höga uppvärmningskostnader och svårigheter med att hålla önskad inneluftstemperatur i deras lokaler. Objekten som beskrivs är av industrikaraktär och har tidigare tillhört ett pappersbruk som lades ned år 1979. Byggnaderna är numera kulturminnesmärkta. Syftet med arbetet har varit att åt uppdragsgivarna utföra en kartläggning där energianvändning och potentiella effektiviseringsåtgärder relaterat till de aktuella objekten analyseras. Detta för att uppnå tillfredsställande uppvärmning samtidigt som energiförbrukningen om möjligt kan reduceras. Kostnadseffektiviteten för de specifikt föreslagna åtgärdsalternativen skall också analyseras. Målet med arbetet har varit att med hjälp av simulering utföra kartläggningen där energianvändning, dimensionerande värmeeffektbehov samt potentiella effektiviseringsåtgärder analyseras. Åtgärderna bestod i huvudsak av tilläggsisolering, tätning, intermittent drift, värmeåtervinning samt byte av fönster. Kostnadseffektiviteten analyserades genom en livscykelkostnadskalkyl utifrån värmekällorna ved, pellets och luft-/luftvärmepump. Slutsatsen är att föreslagna åtgärdsalternativ reducerar energiförbrukningen i avsevärd omfattning samtidigt som en tillfredsställande inneluftstemperatur erhålls. Objekten har efter att effektiviseringsåtgärderna tillämpats uppnått en energiförbrukning likvärdig med dagens normalbyggnader i Sverige. Livscykelkostnadskalkylen visar att nuvärdet för respektive åtgärdsalternativ i samtliga relevanta ekonomiska framtidsscenarier leder till stora besparingar. Arbetet har också visat att betydelsen av tillfredsställande diskretisering är oerhört signifikativ i denna typ av simulering.In the late 1900s society began to realize the consequences of relying on non-renewable energy sources for heating. Prices were increasing heavily and because of that people often chose to replace their oil boiler with electricity which at the time was a viable option. With the rise in prices that has occurred over the past decade the importance of energy efficient measures seemed increasingly clear. With that said many older buildings often have poor thermal properties since both energy prices and construction standards were considerably lower back then. The client Not Quite is a nonprofit association based in Fengerfors mill, Åmål. They have expressed dissatisfaction over increasing heating costs combined with problems getting the desired thermal comfort related to their premises. The objects described are of industrial nature and has previously been used to a paper mill which closed in 1979. The buildings are now classified as part of a cultural monument. The intention of this dissertation has been to map the energy use and to evaluate appropriate efficiency measures related to the specific objects. This includes getting the demanded thermal comfort in combination with possibly reducing the energy consumption. The cost-effectiveness of proposed efficiency measures will also be evaluated. The objective of this dissertation has been to through the use of simulation identify the energy consumption, required thermal input and potential energy efficiency measures. The efficiency measures consisted mainly of adding insulation, air sealing, intermittent heating, heat recovery and window replacements. Cost-effectiveness was evaluated through a life cycle cost analysis with the different heat sources of wood, pellets and air source heat pumps. The conclusion has been that the proposed efficiency options related to each object reduces energy consumption to a considerable extent, while an adequate heating is achieved. The objects have through these measures obtained just as good energy consumption rates as standard considered buildings in Sweden. The life cycle cost analysis shows us that the present value of the proposed efficiency measures in all economic case scenarios results in great cost savings. It has also been shown that a satisfactory discretization of building elements is very important in this type of simulation.
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Baradar, Mohamadreza. "On the Efficiency and Accuracy of Simulation Methods for Optimal Power System Operation : Convex Optimization Models for Power System Analysis, Optimal Utilization of VSC-type DC Wind Farm Grids and FACTS Devices." Doctoral thesis, KTH, Elektriska energisystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166383.
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Recently, significant changes in electric power systems such as rapid developmentof smart grid and electricity market and integration of non-dispatchablesources have added more complexity to the Power Flow Scheduling (PFS) andPower Balancing (PB) models. For instance, non-dispatchable sources introducean increasing level of uncertainty in the electricity market and power system operation.One of the solutions for handling these uncertainties in the power systemoperation is the improvement of system flexibility through a more efficient operationof power systems. On the other hand, efficient operation can be achieved bywell capturing variable behavior of uncertain sources such as wind power sourceswhich in turn demands efficient and robust PFS/PB models. This way, a moreflexible system, capable of efficiently accommodating higher levels of wind powerchanges, can be achieved. All these factors increase a need for PFS/PB models suchas Power Flow (PF) and Optimal Power Flow (OPF) models which can addressthese new challenges in an efficient, reliable, and economic way while supportingthe power system operation and control. In this regard, various solution methodshave been developed for solving different forms of PF/OPF formulation. The difficultyof solving OPF problems increases significantly with increasing network sizeand complexity. One of these complexities is how to model advanced controllable devices such as HVDC grids and Flexible AC Transmission Systems (FACTS) devices.Accurate handling of these complexities has limited the use of OPF in manyreal-world applications mainly because of its associated computational challenges.The main reasons behind computational challenges are nonlinearity and especiallynon-convexity of constraints representing power system and its components. Inthis regard, OPF problems are classified into two main groups. In the first group,researchers adopt Nonlinear programming (NLP) approach to fully represent thenonlinearity of the power system for the sake of accuracy but with the cost of complexityin the model. Computational and theoretical challenges associated withNLP approaches are then used as a motivation towards developing a more simplifiedOPF model, leading to the second group of OPF models known as LinearProgramming (LP) based OPF models. LP approaches are fast, reliable, and especiallyconvex, and therefore guarantee a global optimum to the simplified OPFproblem. The problem of LP approach to OPF is that the LP solution of OPF may not even be a feasible solution of original nonlinear OPF at all. Another issueassociated with LP models is that complex power system devices such as HVDClinks are difficult to be incorporated. These limitations have restricted the applicationof LP approaches for many OPF problems. According to the mentionedadvantages and disadvantages of NLP and LP based OPF models, what we seeks isan OPF model which can have main advantages of both LP OPF models (Efficientnumerical solvers) and full AC OPF models (Results accuracy). In this thesis, wedevelop convex optimization problems which can be adopted as both PF and OPFmodels which are capable of catching the nonlinear nature of power systems asmuch as possible while can be solved by efficient solution methods such as InteriorPoint Methods (IPMs). These OPF models can incorporate HVDC links, windfarm Multi Terminal HVDC (MTDC) grids, and shunt FACTS devices.QC 20150521
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Costa, Herson Vargas da. "Estudo teórico da eficiência de uma usina termelétrica baseado em dados reais." Universidade do Vale do Rio dos Sinos, 2012. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3843.
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CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico
Neste trabalho, foi realizada a simulação do ciclo térmico da Usina Termoelétrica São Jerônimo – UTSJ. A Usina, muito antiga, possui caldeira do tipo grelha. Na mesma Usina foi instalada uma caldeira experimental de leito fluidizado, para funcionar em paralelo com a existente. O trabalho é iniciado com a modelagem de um ciclo de Rankine simples e segue evoluindo até se estabelecer a configuração mais adequada e representativa na tarefa de simular o modo de trabalho da Usina Termelétrica São Jerônimo – UTSJ. Desta forma, foram adotadas as considerações mais convencionais na prática de projeto de centrais termelétricas cujos sistemas térmicos baseiam-se no ciclo de Rankine. As simulações, que se caracterizam pela resolução simultânea das equações que modelam o ciclo e seus componentes, foram efetuadas através de programa IPSE-pro®. As simulações foram aplicadas para a obtenção dos resultados mais importantes na análise de sistemas térmicos, tais como rendimento térmico do ciclo, potência, vazões mássicas do sistema, calor trocado no gerador de vapor e no condensador, entre outros. Por fim, com objetivo de melhorar o rendimento térmico da planta, são apresentadas algumas alternativas ao sistema atual, tais como o aumento de eficiência da caldeira mediante substituição ou a adição de uma caldeira em paralelo à original.
In this work was made the simulation of the thermal cycle of São Jerônimo - UTSJ thermal power plant. The power plant, very old, has a grate boiler. In the same power plant was installed an experimental fluidized bed boiler, workingin parallel with the existing one. The work starts with the modeling of a simple Rankine cycle and evolves up to establish the most suitable and representative configuration to simulate the mode the work of São Jerônimo –UTSJ thermal power plant. Therefore, in this work it was adopted the more conventional considerations in the design practice for thermal power plants whose systems are based on the Rankine cycle. The simulations, which are characterized by the simultaneous solving of equations that model the cycle and its components, were made through the IPSE-pro® software. The simulations were applied to obtain the main results on the analysis of thermal systems such as, thermal efficiency of the cycle, power, system mass flow, heat exchanged in the steam generator and condenser, among others. Finally, in order to improve the thermal efficiency of the plant, some alternatives to the actual system were presented.
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Silva, Josenildo Araujo da. "Simulação de um aquecedor solar de água como etapa do processo de destoxicação da torta de mamona." Universidade Católica de Pernambuco, 2007. http://tede2.unicap.br:8080/handle/tede/921.
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Algorithms have been developed in arder to simulate the water solar heating as a strategy for lowering castor bean pie destoxication costs, among from the biodiesel oil for production extraction processo Diverse procedure, substances solubilization, this residue toxic caracter factor, found in hot water and in some saline solutions, motivated this water heating modeling work, through solar energy, since this procedure type can and low cost to the above-mentioned methods, on account of this, one has used computational smulink/matlab in arder to simulate and to arise favorable conditions for this technique use strategies elaboration. One has, then, analized several situation, departing from a termal heating proposal, since this is a less expensive heat transference formo Of this form an objective function was proposal to create O variable that esteem the behavior of the system and better define the excellent conditions for the considered processo .Among these, the established variable as parameters for the simulated conditions, are presented the results, taking itself in account values of income for the process, existing in literature. One porpuses dynamic models, under complexity different degress, for a water heating process previous evaluation, through solar energy. Temperature variations, in the process diferrent stages, have been simulated, with simulink/matlab aid for the above-mentioned system behaviour analysis one presents computational models. blocks diagrams, correspondent to each one of the elaboration stage. Proposed mathematical models provided important previsions for temperature values, in the above-mentioned system different components, resulting as a work important tool for a next stage which is that one of the optimization.
Diversos procedimentos têm sido utilizados para destoxicação da torta de mamona. Entre esses a solubilização das substâncias responsáveis pelo caráter tóxico desse resíduo, ricina e ricinina, em água quente e/ou soluções salinas aquecidas. Foram desenvolvidos algo ritmos para simular o aquecimento solar da água como estratégia para baixar custos no processo de destoxicação da torta de mamona, originária do processo de produção de biodiesel. Para isto foi utilizada a ferramenta computacional Simulink/MATLAB@. Foram então analisadas várias situações com base na proposta de aquecimento direto, por se tratar de uma forma de transferência de calor menos dispendiosa. São propostos modelos dinâmicos em diferentes graus de complexidade para uma avaliação prévia do processo de aquecimento da água por meio de energia solar. Apresentam-se os diagramas de blocos dos modelos computacionais, correspondentes a cada uma das etapas de elaboração. Os modelos matemáticos propostos proporcionaram importantes previsões para valores de temperatura nas diferentes fases de elaboração. apresentando-se como importante ferramenta de trabalho para uma próxima etapa que é a de validação experimental do modelo final.
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Doležal, Lukáš. "Provozní účinnosti zdrojů tepla." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392150.
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The topic of this diploma thesis is the operational efficiency of heat sources. The work had several goals. The first was to determine the efficiency of the wood boiler according to available calculation methods and to compare the methods among them. The second was to determine the difference in the performance of the flue gas analyzer and the real calculation. Further, to determine the efficiency of a boiler firing different wood species - spruce and hornbeam based on their properties and elemental composition. Experimental measurement of various operating states of effectiveness took place in an older two-generation family house, which was also the subject of the project part. Due to lack of project documentation, it was necessary to focus and plot the object. Afterwards, the building was thermally inspected and the design of the heating system and the reconstruction of the whole heating system was carried out. The project was developed in two variants for two different heat sources - a heat pump and a solid fuel boiler for heating and water preparation. The thesis deals with the technical report, the conceptual solution of the related professions, the evaluation of the heat source variants and the project documentation.
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Botha, C. P. "Simulation of a building heating, ventilating and air-conditioning system." Diss., 2001. http://hdl.handle.net/2263/26002.
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Simulation is one of the oldest and also among the most important tools available to engineers. In the building Heating, Ventilating and Air-Conditioning (HVAC) community the availability and/or functionality of simulation tools is limited and it is difficult to determine whether the simulation models accurately represent reality. The purpose of this study was to accurately verify one such a simulation model and then to extend the study to two unique applications. Comprehensive structural, comfort and energy audits were performed to construct a suitable simulation model with the aid of the control simulation package: QUICK Control. The model was then verified against measured building data to ensure an accurate representation of the actual dynamic building response. For the first application various control retrofits were evaluated and the highest potential for energy saving was found. Thereafter the model was implemented to investigate the change in indoor air conditions due to failure of HVAC equipment. Heating, ventilating and air-conditioning in buildings consume a significant portion of the available electrical energy in South Africa. Of this energy up to 30% can be saved by improving the HVAC systems currently installed in the buildings. This could result in savings of up to R400 million. For the building used in this study it was found that up to 66% of the HVAC system’s electrical energy consumption could be saved with a payback period of only 9 months. These savings could be achieved by implementing a setback control strategy with an improved time management procedure. Predicting the impact of failing equipment is a difficult task because of the integrated dynamic effect every HVAC component has on the next. With the aid of a comprehensive integrated simulation model the implications of failing can be determined and necessary assessments and precautions can be taken. The results of this study showed that the air-conditioning system under investigation was approximately 100% over designed. Failure of up to 50% was allowable in the cooling equipment before any noticeable impact could be observed in the indoor climate. With further failure the required comfort conditions could not be sustained. Dissertation (MSc (Mechanical Engineering))--University of Pretoria, 2006.
Mechanical and Aeronautical Engineering
unrestricted
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Schneyer, Carolyn Dianarose. "Simulation of energy use in residential water heating systems." Thesis, 2011. http://hdl.handle.net/1828/3526.
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Current federal and provincial efficiency standards for residential water heating are based solely on the tested efficiency of individual water heating devices. Additional energy expended or saved as the water cycles through the home is not taken into account. This research, co-funded by British Columbia’s Ministry of Energy, Mines and Petroleum Resources (MEMPR), is a first step toward the Province’s goal of developing a new energy efficiency standard for water heating systems in new construction. This groundbreaking new standard would employ a “systems” approach, establishing guidelines for new construction based on the total energy used for water heating within the building envelope
The research team has developed a Simulink computer model which, using a one-minute time-step, simulates 24-hour cycles of water heating in a single-family home. The objectives of this thesis are to use that model to simulate a variety of water heating technology combinations, and to devise methods of utilizing the resulting data to evaluate water heating systems as a whole and to quantify each system’s relative energy impact.
A metric has been developed to evaluate the efficiency of the system: the system energy factor (SEF) is the ratio of energy used directly to heat water over the amount of energy drawn from conventional fuel sources. The CO2 impact of that energy draw is also considered.
Data is generated for cities in three different climates around BC: Kamloops, Victoria and Williams Lake. Electric and gas-fired tank water heaters of various sizes and efficiencies are simulated, along with less traditional energy-saving technologies such as solar-assisted pre-heat and waste water heat recovery components. A total of 7,488 six-day simulations are run, each representing a unique combination of technology, load size, location and season.
The resulting data is presented from a variety of angles, including the relative impacts of water heater rating, additional technology type, location and season on the SEF of the system. The interplay between SEF and carbon dioxide production is also examined. These two factors are proposed as the basis for devising performance tiers by which to rank water heating systems. Two proposals are made regarding how these tiers might be organized based on the data presented here, though any tiers will have to be re-evaluated pending data on a wider range of technology combinations.
A brief financial analysis is also offered, exploring the potential payback period for various technology combinations in each location. Given current equipment and energy costs, the financial savings garnered by the increase in energy efficiency are not, in most cases, found to be sufficient to justify the expense to the homeowner from a purely fiscal perspective. Additional changes would need to take place to ensure the financial viability of these technologies before large-scale adoption of systems-based standards could be employed.Graduate
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Arndt, D. C. "Integrated dynamic simulation of large thermal systems." Thesis, 2001. http://hdl.handle.net/2263/26065.
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Studies concluded that more that 10% of all energy consumed in the world is expended by building air-conditioning systems. Energy efficiency in building and HVAC (Heating, Ventilating and Air-conditioning) design is therefore exceptionally important. A cost¬-effective way to improve the energy efficiency of a HV AC system, without compromising indoor comfort, is by implementing better control. System energy cost savings of up to 50% can be realised by optimising the system operating control strategies with direct payback periods of less than a year. However, when changing the operating strategy of a system it is often difficult to predict the resulting changes in system energy consumption and indoor comfort. To achieve these predictions, a dynamic simulation tool, which can efficiently and accurately simulate the building with the HV AC and control system in an integrated fashion, is required. Extensions to the integrated tool QUICKcontrol is therefore proposed to suite the needs of the energy service contractor. QUICKcontrol still has many shortcomings in the availability of component models for certain equipment commonly used in building systems today. New dynamic component models were therefore derived in this study. The accuracy and applicability of integrated building and natural ventilation modelling is illustrated in animal housing facilities. The predicted results obtained during this study were satisfactory to use these models with confidence in this type of building applications. The applicability of building, HV AC system and control simulations was illustrated in conference facilities. The results obtained show the value of integrated building and system simulation in the evaluation of energy cost saving inventions in commercial buildings. The mining and industrial sectors in South Africa consume about 40% of ESKOM's total electrical energy production. Mines alone use nearly 20% of the electricity provided by ESKOM. Ventilation and cooling (VC) systems are responsible for approximately 25% or R750 million of this energy. It will therefore be beneficial if the mines can be more energy clever in order to reduce their VC operating costs. The use of an extended integrated building and system simulation tool was therefore realised to investigate the potential for energy cost savings in mine VC applications. To extend QUICKcontrol for the simulation of other large thermal systems found in mining and industrial applications, new component models and simulations procedures were developed. Two case studies were performed with the extended tool to illustrate its applicability in thermal systems other than building systems. The potential for Demand Side Management (DSM) on a surface cooling plant and an underground clear water-pumping system was investigated. Satisfactory results were obtained during the two investigations to utilise this extended tool with confidence in practice. With more extensions to the tool it should be possible to investigate the potential for energy cost saving on any other thermal industrial applications.Thesis (PhD (Mechanical Engineering))--University of Pretoria, 2007.
Mechanical and Aeronautical Engineering
unrestricted
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Borgohain, Nisha. "From Archaic To contemporary : Energy Efficient Adaptive Reuse of Historic Building." 2019. https://scholarworks.umass.edu/masters_theses_2/820.
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Over recent decades, the global focus on climate change and on conservation of resources has brought about a paradigm shift in the adaptive reuse of old and historic buildings. Adaptive reuse is now seen as a key factor in the conservation of land and environment, preservation of cultural identity, and reduction of urban sprawl. Increasingly, engineers, architects, and urban planners are making concerted efforts to realize the reuse potential of existing and outdated structures. Therefore, those involved in building design have studied the viability of adaptive reuse and generally favor the repurposing of old/historic buildings to suit new patterns of occupancy and use without disturbing the environment or increasing carbon footprints. Redesign and reconstruction through refurbishment, remodeling, renewal, repair and retrofitting is carried out to meet new requirements and provide performance that was not in the original design.
Buildings are one of the largest energy users in the United States.[1] In total, buildings used around 40 percent of energy in 2015, which accounts for the largest share among forms of energy consumption. Many of the buildings are not energy efficient but do have historic value; while giving them a new purpose, their historic legacy can also be preserved. There are many challenges like program modification feasibility, structural issues and energy efficiency which need to be addressed during pre-construction and can be addressed by careful planning and innovative techniques. To understand the various challenges involving adaptive reuse, this study employs the Clark Hall at the University of Massachusetts to test the efficacy of design and performance interventions. Clark Hall was originally used for science classes and botany research and later was converted into painting studios. Presently the building structure is still intact, provides enough room for program modification, and has significant reuse potential. Therefore, Clark Hall is a suitable candidate for adaptive reuse as an academic office building that satisfies contemporary building standards and meets the growing demand for office space.
Through this project, an attempt has been made to explore and understand the complexities and challenges as well as the various possible ways to change the function of Clark Hall from a defunct structure to a modern energy efficient and environmentally sustainable academic office building with measures for energy conservation through contemporary innovative design approaches.
The research work begins with a background study of the building’s history and its different purposes, along with three precedent studies of contemporary and innovative design examples. It also identifies relevant local, federal, and state building and zoning regulations and incorporates existing energy-saving technologies and materials appropriate to Clark Hall. Keeping in mind the financial viability of project, an attempt has been made to control and bring down the operating and the maintenance costs by carrying out extensive energy modelling and simulations to support these recommendations.
In conclusion, the final outcome of my project is a design plan for the adaptive reuse of Clark Hall as a new energy efficient and environmentally sustainable office building for the benefit and the use of University of Massachusetts Amherst that mitigates costs and improves design utility and aesthetics, while preserving its historic value.
[1] According to the U.S. Energy Information Administration, “in 2017, about 39% of total U.S. energy consumption was consumed by the residential and commercial sectors.” https://www.eia.gov/tools/faqs/faq.php?id=86&t=1. October 2018.
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Lohmann, Victor Augusto. "Analysis of the influence of Trombe walls on the thermal behavior of Light Steel Frame Construction." Master's thesis, 2020. http://hdl.handle.net/10316/90169.
Full textAbstract:
Dissertação de Mestrado em Eficiência Acústica e Energética para uma Construção Sustentável apresentada à Faculdade de Ciências e TecnologiaEm termos de eficiência energética, o setor da construção tem um grande potencial de melhoria, visto que 40% de toda a energia produzida é consumida por edifícios na Europa, e o setor segue em expansão. Este grande potencial chama a atenção para estratégias passivas para se alcançar o conforto térmico interior. A energia solar é relevante devido a radiação gratuita que vem do sol, sendo uma alternativa sustentável aos sistemas de aquecimento à base de combustíveis fósseis. A parede de Trombe é um dispositivo solar passivo que pode estar presente na envolvente exterior dos edifícios, para acumular calor solar e auxiliar na ventilação, aquecimento e até arrefecimento dos ambientes interiores. O dispositivo pode reduzir o consumo de energia de um edifício em até 30%. Em relação a sistemas construtivos, a construção leve em aço (LSF) vem atraindo atenção globalmente. Porém, o sistema LSF apresenta alguns desafios, especialmente quanto ao seu comportamento térmico. Estratégias passivas são uma boa alternativa para mitigar estes desafios. Assim, este trabalho tem o objetivo de estudar os impactos de ganhos solares indiretos em construções leves em aço, através de uma parede de Trombe, visando melhorar o seu comportamento térmico e reduzir consumos energéticos. A pesquisa foi conduzida em dois módulos experimentais em LSF construídos no campus da Universidade de Coimbra. Os módulos experimentais são compartimentos cúbicos idênticos, onde a única diferença é a presença de uma parede de Trombe na fachada sul de um deles. Foram realizadas medições para se registar o comportamento térmico dos módulos em LSF. Um modelo destes módulos foi criado no software DesignBuilder, comumente utilizado para análises térmicas e energéticas de edifícios. Concluiu-se que a parede de Trombe traz benefícios para construções em LSF em termos de conforto térmico e eficiência energética, porém é necessário projetar-se medidas de controle para evitar sobreaquecimento no verão e perdas de calor durante a noite.
In terms of energy efficiency, the construction sector has a great potential for improvement, since 40% of all energy produced is consumed by buildings in Europe, and the sector is constantly expanding. This high potential has drawn attention to the passive strategies for achieving indoor thermal comfort. Solar energy is relevant due to the cost-free radiation that comes from the sun, being a sustainable alternative to heating systems that run on fossil fuels. A Trombe wall is a passive solar device that can be present in a building’s external wall system to accumulate solar heat and aid in the ventilation, heating and even cooling of the interior space. The device can reduce the energy consumption of a building up to 30%. Regarding construction systems, the Light Steel-Framed (LSF) has been attracting attention worldwide. However, LSF construction also presents some challenges, especially related to its thermal behavior. Passive strategies are a good choice to mitigate the thermal challenges present on LSF construction. Thus, this dissertation has the objective to study the impacts of indirectly gains from solar energy in LSF construction through a Trombe wall, aiming to improve its thermal behavior and reduce energy consumption. The research was conducted on two LSF modules constructed in the University of Coimbra`s campus. Those experimental modules are identical cubic compartments, the only difference being the presence of a water Trombe wall in the south façade of one of them. Measurements were conducted in order to register the thermal behavior of the LSF modules. A model of these LSF modules will be created on the software DesignBuilder, commonly used for thermal and energy performance analyses of buildings. It was concluded that the Trombe wall is beneficial for LSF buildings in terms of thermal comfort and energy efficiency, but it is necessary to design solutions to avoid overheating during the summer and heat losses during the night.
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Mota, Raúl Alves. "Caracterização energética e estudo de medidas de melhoria para um Hotel nZEB." Master's thesis, 2015. http://hdl.handle.net/10316/38920.
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Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.No contexto atual em que a eficiência energética dos edifícios é um tópico de importância crescente, a caracterização adequada das formas de uso de energia nos hotéis é fundamental para se conseguir uma crescente utilização racional da energia. O conforto proporcionado pelas unidades hoteleiras é essencial para o seu desenvolvimento. Como tal, a hotelaria é um sector onde o uso da energia tem especial relevo nos custos totais da atividade. Neste contexto, as ferramentas de simulação computacional disponíveis, como o TRNSYS têm grandes potencialidades associadas e podem assumir um papel relevante na avaliação e otimização do desempenho energético de edifícios. O presente trabalho tem como objetivo a realização de uma análise ao comportamento do sistema de AQS do Hotel TRYP Coimbra, recorrendo ao TRNSYS. Decidiu-se focar o estudo no sistema de AQS, dado que é um dos sistemas que impõe um consumo de energia apreciável, e que, neste caso de estudo apresentava algumas dificuldades ao nível da otimização de funcionamento. Na análise do sistema de AQS estudaram-se, mais concretamente, algumas medidas de possível melhoria do sistema, tais como a alteração dos setpoints dos depósitos, dos coletores solares térmicos e das caldeiras, de forma a racionalizar os consumos de energia e potenciar ao máximo a utilização de energia renovável (coletores solares térmicos). Os resultados das simulações das diversas possibilidades de melhoria definidas, mostraram que é expectável conseguirem-se poupanças de energia de cerca de 19%.
In the current context, in which the energy efficiency of buildings is a topic of growing importance, the proper characterization of the forms of energy use in hotels is critical to achieve an increasing rational use of energy. The comfort provided by the hotel units is essential for their development. As such, the hotels are a sector where energy use has special importance in the total costs of the activity. In this context, the computer simulation tools available, such as TRNSYS have great potential associated and can play a relevant role in the evaluation and optimization of the energy performance of buildings. This paper aims to conduct an analysis of the behavior of the water heating system present in Hotel Tryp Coimbra, using the TRNSYS. It was decided to focus the study on the water weating system, since it is one of the systems that requires a considerable energy consumption, and in this case study presented some difficulties with operation optimization. In the analysis of water heating system were studied, specifically, some measures that can improve the system, such as changing the setpoints of the deposits, solar thermal collectors and the boiler in order to rationalize energy consumption and enhance the most the use of renewable energy (solar thermal collectors). The simulation results of the various defined possibilities of improvement, have shown that it is expected to achieve energy savings of about 19%. Keywords , , ,
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Khatib, Akram Ghassan. "Evaluation of performance of an air handling unit using wireless monitoring system and modeling." Thesis, 2014. http://hdl.handle.net/1805/5943.
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Indiana University-Purdue University Indianapolis (IUPUI)Heating, ventilation, and air conditioning (HVAC) is the technology responsible to maintain temperature levels and air quality in buildings to certain standards. In a commercial setting, HVAC systems accounted for more than 50% of the total energy cost of the building in 2013 [13]. New control methods are always being worked on to improve the effectiveness and efficiency of the system. These control systems include model predictive control (MPC), evolutionary algorithm (EA), evolutionary programming (EP), and proportional-integral-derivative (PID) controllers. Such control tools are used on new HVAC system to ensure the ultimate efficiency and ensure the comfort of occupants. However, there is a need for a system that can monitor the energy performance of the HVAC system and ensure that it is operating in its optimal operation and controlled as expected. In this thesis, an air handling unit (AHU) of an HVAC system was modeled to analyze its performance using real data collected from an operating AHU using a wireless monitoring system. The purpose was to monitor the AHU's performance, analyze its key parameters to identify flaws, and evaluate the energy waste. This system will provide the maintenance personnel to key information to them to act for increasing energy efficiency. The mechanical model was experimentally validated first. Them a baseline operating condition was established. Finally, the system under extreme weather conditions was evaluated. The AHU's subsystem performance, the energy consumption and the potential wastes were monitored and quantified. The developed system was able to constantly monitor the system and report to the maintenance personnel the information they need. I can be used to identify energy savings opportunities due to controls malfunction. Implementation of this system will provide the system's key performance indicators, offer feedback for adjustment of control strategies, and identify the potential savings. To further verify the capabilities of the model, a case study was performed on an air handling unit on campus for a three month monitoring period. According to the mechanical model, a total of 63,455 kWh can be potentially saved on the unit by adjusting controls. In addition the mechanical model was able to identify other energy savings opportunities due to set point changes that may result in a total of 77,141 kWh.
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Barešová, Lenka. "Využití zážitkové pedagogiky a dramatické výchovy ve výuce zeměpisu na střední škole." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-310384.
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The main objective of the thesies is to compare a frontal teaching method and teaching by simulation. Two comparable groups of students were taught the same topic by the two methods. The topic was focused on an uneven world development. Following assumptions were set. Simulation is a more attractive teaching form, therefore it can help to raise the motivation of students. Frontal method is capable of transmitting more information. Simulation, however, can have bigger impact on students' values. The impact of simulation has a long-term impact in comparison to frontal teaching. These assumptions were confirmed by qualitative and quantitative methods.