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Discrete element modelling of packed rock beds for thermal storage applicationsNel, Rick Guillaume 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The increased necessity to obtain power from other sources than conventional
fossil fuels has led to the growing interest in solar power. The problem with
the proposed technology is that it can only provide power during the day
and therefore requires some sort of storage system, if power is to be supplied
throughout the day and night. A number of storage systems exist, but the one
of particular interest for this research, is packed rock beds. Rock beds have the
advantage that if designed right, they have the potential to be one of the most
cost effective means of storing thermal energy for solar power plants. Discrete
Element Models (DEM) of rock beds were therefore developed through both
experimental and numerical procedures, by conducting a series of sensitivity,
calibration and verification studies.
The developed models were then used to study various aspects associated with
rock beds, which were either too impractical, impossible or too expensive to
conduct through actual experimental work. This research focused specifically
on the potential of constructing self-supporting tunnels within the rock beds
in order to improve the air flow uniformity through the bed, while minimizing
the pressure drop. It was observed that if the appropriate steps were followed,
stable self-supporting tunnels could be formed. Valuable information such as
the rock orientations resulting from different packing directions could also be derived from the models and finally, a method to convert the DEM models into
the appropriate format such that it could be imported into a CFD preprocessor
for future CFD studies, was developed. / AFRIKAANSE OPSOMMING: Die verhoogde noodsaaklikheid om energie te verkry uit ander bronne as konvensionele fossielbrandstowwe, het gelei tot die groeiende belangstelling in
sonkrag energie. Die probleem met die voorgestelde tegnologie is dat dit net
energie gedurende die dag kan voorsien en dus word daar ’n stoorstelsel benodig indien energie deur beide die dag en nag voorsien moet word. Tans bestaan
daar wel ’n aantal van hierdie stoorstelsels, maar die een wat van besondere
belang is in hierdie navorsing, is verpakte klip beddens. Klip beddens het die
voordeel dat, indien dit reg ontwerp is, dit oor die potensiaal beskik om een
van die mees koste-doeltreffende middels te wees vir die stoor van termiese
energie vir sonkragstasies. Diskreet Element Modelle (DEM) van die klip beddens is ontwikkel deur gebruik te maak van beide experimentele en numeriese
metodes waartydens ’n reeks sensitiwiteits-, kalibrasie- en verifiëring studies
uitgevoer is.
Die ontwikkelde modelle is gebruik om verskeie aspekte van klip beddens te
ondersoek, wat of te onprakties, onmoontlik of te duur is vanuit ’n eksperimentele oogpunt. Hierdie navorsing het spesifiek gefokus op die potensiaal om
self-ondersteunende tonnels binne in die klip beddens te vorm, ten einde die egaligheid van die lugvloei deur die bed te verbeter, terwyl die drukval geminimeer word. Daar is waargeneem dat stabiele self-ondersteunende tonnels wel
gevorm kon word indien die toepaslike stappe gevolg is. Waardevolle inligting
soos die klip oriëntasies wat as gevolg van die verskillende verpakkings rigtings
onstaan kon ook vanuit die model verkry word. Ten slotte is ’n metode ontwikkel om die DEM modelle na die toepaslike formaat te omskep sodat dit ten
einde gebruik kan word in numeriese vloeidinamika studies.
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Optimering av last och produktion i Gävles fjärrvärmenät : Reducering av effekttoppar via värmelagring i byggnaderElofsson, Fredrik January 2019 (has links)
District heating is today the most common way of providing a building with heat and hot water in Sweden. It is an environmentally friendly product mostly used with renewable fuel. However, at power peaks most companies use production units that are more expensive and worse for the environment and should therefore be avoided as much as possible. This can be done with a method called load management. When a power peak occurs, the heat supply to buildings connected to the district heating system can be temporarily reduced. The heat energy can later be returned when the heat demand is lower. Thanks to the heat inertia of the buildings, the indoor temperature will not fall within the time frame for the load management. Historical data has been analysed to identify when and why power peaks occur in the district heating network. Power peaks throughout the district heating network have proved difficult to identify. However, for individual consumers clear patterns of power peaks have emerged. These power peaks mainly occur because of large use of hot water but also because of the shifting outdoor temperature. In order to see how the production cost would differ from the actual outcome load management was applied for Gävle's district heating 2018. The load management was calculated manually by identifying the most expensive production unit on an hourly basis. If a cheaper production unit had the potential to deliver higher power the next hour, the production was moved to the cheaper production unit. The process was repeated for each hour during 2018. After carrying out load management for Gävle's district heating network, 1 457 MWh had been shifted to a cheaper production unit. This resulted in a financial saving of 1,0 % of the total production cost. The environmental savings showed a reduction from 6.1 to 5.9 g CO2eq /kWh a total of 197 tonne CO2eq. In the exact same way, a load management was performed for a scenario where Gävle and Sandviken's district heating network were connected. The gain for a load management with Sandviken will be considerably larger, a reduced production cost of 3.6 % is possible. The environmental savings showed a reduction from 8.4 to 7.8 CO2eq /kWh a total of 575 tonne CO2eq. For future efficient load management, buildings should be divided into different classes depending on the building's time constant. User patterns for the entire district heating network have proved difficult to detect. Artificial intelligence can be an option for short-term forecasting of the power output / Fjärrvärme är idag det vanligaste sättet att förse en bostad med värme och tappvarmvatten i Sverige. Fjärrvärmen är ofta en miljövänlig produkt som kan produceras av till exempel biobränsle- och avfallseldade kraftvärmeverk eller spillvärme från industrier. Vid tillfälligt högt effektbehov, effekttoppar, använder sig merparten av bolagen av dyrare produktionsenheter med större miljöpåverkan. Dyrare produktionsenheter bör undvikas i största möjliga mån och i detta syfte används metoden laststyrning. Vid en effekttopp kan värmetillförseln till byggnader sänkas temporärt för att återföras några timmar senare när effektbehovet är lägre. Tack vare värmetrögheten i byggnaderna bör inomhustemperaturen inte sjunka inom tidsramen för laststyrning. Statistik från Gävles fjärrvärmanvändning på timbasis under 2018 har analyserats för att identifiera när och varför effekttoppar sker. Effekttoppar i hela fjärrvärmenätet har visat sig svåra att identifiera. På lokal nivå har däremot tydliga mönster för effekttoppar framkommit. Dessa effekttoppar beror till största del av tappvarmvattenanvändning men även förändringar i utomhustemperaturen. För att se hur produktion och last kunde skiljt sig från det verkliga utfallet tillämpades laststyrning för Gävles fjärrvärmeproduktion 2018. Laststyrningen beräknades manuellt genom att den dyraste produktionsenheten identifierades på timbasis. Om en billigare produktionsenhet hade potential att leverera högre effekt nästkommande timmar försköts produktionen. Därefter upprepades processen för varje timme under 2018. Efter utförd laststyrning för Gävles fjärrvärmenät hade ca 1 457 MWh förskjutits till en billigare produktionsenhet. Det gav en ekonomisk besparing på 1,0 % av Gävles totala produktionskostnad. Den miljömässiga besparingen visade på en sänkning från 6,1 till 5,9 [g CO2ekv /kWh] sammanlagt 197 ton CO2ekv. På samma sätt utfördes en laststyrning för ett scenario där Gävle och Sandvikens fjärrvärmenät sammankopplats. Vinsten för en laststyrning med Sandviken blev betydligt större med en minskad produktionskostnaden på 3,6 %. Den miljömässiga påverkan sjönk från 8,4 till 7,8 g CO2ekv /kWh sammanlagt 575 ton CO2ekv. För en framtida effektiv laststyrning bör byggnader delas in i olika klasser beroende på byggnadens tidskonstant. Användarmönster för hela fjärrvärmenätet har visat sig svårt att identifiera. Artificiell intelligens kan vara ett alternativ i framtiden för att prognostisera effektuttaget
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[en] TRANSPORT COEFFICIENTS OF ICE SLURRY IN PLATE HEAT EXCHANGER / [pt] COEFICIENTES DE TRANSPORTE DA PASTA DE GELO EM UM TROCADOR DE CALOR DE PLACASHUGO GUILLERMO JIMENEZ PACHECO 14 January 2004 (has links)
[pt] O uso da pasta de gelo começou recentemente a ser aplicado
em sistemas de refrigeração e condicionamento de ar. Como
principais vantagens deste fluido, podem ser citados: a
possibilidade de armazenar calor latente do gelo e a
possibilidade de ser bombeado como a água fria. Assim, o
pasta de gelo pode ser usado para o armazenamento térmico
no lugar da água fria ou do gelo, desde que, até
determinadas concentrações, possa ser bombeado através dos
trocadores de calor. Para que esta tecnologia seja aceita
extensamente, informações de engenharia são requeridas nas
características de transporte nos equipamentos de troca de
calor. Um dispositivo experimental foi desenvolvido para
estudar os coeficientes de transporte do pasta de gelo em
um trocador de calor de placas, utilizando água como carga
térmica a resfriar. Foram investigadas várias situações para
diferentes frações iniciais e vazões do pasta de gelo. As
condições de entrada da carga térmica, foram mantidas
constantes. São monitoradas a temperatura, a queda de
pressão, a fração do gelo sólido e a vazão do pasta de gelo
no trocador de calor, assim como a vazão e a de temperatura
na parte da carga térmica. Os resultados mostram que o
coeficiente global de troca de calor aumenta com aumento da
fração inicial do gelo. A capacidade do resfriamento do
trocador de calor aumenta consideravelmente, em relação da
água, quando a pasta de gelo, é utilizada como fluido
secundário. Finalmente, a queda de pressão aumenta com o
aumento da fração inicial de gelo. / [en] The use of the ice slurry is recently applied in the
refrigeration and air conditioning systems. Advantages such
as the possibility to store latent heat on ice and the
possibility of being pumped as cold water can be
considered. Ice slurries can be used both for cold storage
in place of chilled water or ice and as a secondary
refrigerant since, up to certain concentrations, they can
be pumped directly through distribution pipeworks and heat
exchangers. For ice slurries to become more widely
accepted, however, more engineering information is
required on fluid flow and heat transfer characteristics.
An experimental device was developed to study the transport
properties of the ice slurry in plate heat exchangers.
Several situations were investigated for different initial
fractions and flows of ice slurry. The conditions of the
thermal load (pure water), had been kept constant. The
temperature field, the pressure loss, the initial fraction
and the flow of ice slurry are monitored in the heat
exchanger, beyond the flow and the temperature field is
monitored in the part of the thermal load. The overall heat
transfer coefficient, increases in function of the initial
ice fraction. The capacity cooling of the heat exchanger
increases with the use of ice slurry when compared to pure
water. Finally can be showed that the loss of pressure
increases for higher initial ice fraction.
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Simulação e avaliação de um sistema de aquecimento solar de água utilizando balanço energético / Simulation and evaluation of a system of solar water heating using energy balanceMedeiros, Maurício 17 February 2012 (has links)
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Previous issue date: 2012-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work was developed at the State University of West of Paraná UNIOESTE, campus de Cascavel and was aimed at developing a computer program to simulate and scale, optimally, a system of solar water heating. To determine the efficiency
parameters of the system were installed three solar collectors of 1.05 m2 each, brand Pro Sol, coupled to a thermal reservoir of 200 liters, containing electrical resistances auxiliary 2000 W. The system works by using thermosyphon, and was installed in a
metal bracket fixed to the ground, oriented to the north at an angle of 35 degrees from the horizontal. We collected hourly data of solar radiation and water temperatures, and evaluated two scenarios. In the first scenario, it was considered
system utilization auxiliary heating controlled by a thermostat, which linked and hang up the electrical resistances as the temperature of water in boiler oscillated around of temperature of consumption (40 º C). In the second scenario, it was considered the system to power auxiliary heating only in timetables of water consumption, when the water temperature in boiler was lower than the temperature of consumption.
Coefficients were calculated heat loss in the solar collector and storage tank, the heat removal factor of solar collector and the overall efficiency of the heating system installed. These calculated parameters and other data collected were used in
software developed for simulation and design in order to satisfactorily meet the needs of hot water consumption, and minimize the total installation costs and energy consumption. Finally, these system costs solar heating were compared to costs of an electric shower conventional. The results obtained were as follows: coefficient of heat loss in the solar collector (5,45 Wm-2ºC-1), coefficient of heat loss in the thermal
reservoir (5,34 Wm-2ºC-1), removal factor heat of the solar collector (0.78) and overall system efficiency (31%). The times of return on capital invested in the solar heating system (compared to a conventional electric shower), for the two scenarios of use, were, respectively, 11.45 years and 7.81 years. / Este trabalho foi desenvolvido na Universidade Estadual do Oeste do Paraná UNIOESTE, campus de Cascavel, e teve por objetivo principal o desenvolvimento de um programa computacional para simular e dimensionar, de forma otimizada, um sistema de aquecimento solar de água. Para determinar os parâmetros de eficiência do sistema, foram instalados três coletores solares de 1,05 m2 cada, da marca Pro Sol, acoplados a um reservatório térmico de 200 litros, contendo resistências elétricas auxiliares de 2000 W. O sistema utilizado funciona por termossifão, e foi
instalado em um suporte metálico fixado ao solo, com orientação para o norte, num ângulo de 35º em relação à horizontal. Foram coletados dados horários de radiação solar e temperaturas da água, e avaliados dois cenários. No primeiro cenário, considerou-se a utilização do sistema de aquecimento auxiliar controlado por um termostato, que ligava e desligava as resistências elétricas conforme a temperatura da água no boiler oscilava em torno da temperatura de consumo (40ºC). No segundo cenário, considerou-se o acionamento do sistema de aquecimento auxiliar somente nos horários de consumo de água, quando a temperatura da água no boiler estivesse menor que a temperatura de consumo. Foram calculados os coeficientes
de perda de calor no coletor solar e no reservatório térmico, o fator de remoção de calor no coletor solar e a eficiência global do sistema de aquecimento instalado.
Esses parâmetros calculados, e os demais dados coletados, foram utilizados no software desenvolvido para simulação e dimensionamento, de maneira a atender satisfatoriamente às necessidades de consumo de água quente, e minimizar os
custos totais de instalação e consumo de energia elétrica. Por fim, esses custos do sistema de aquecimento solar foram comparados aos custos de um chuveiro elétrico convencional. Os resultados obtidos foram os seguintes: coeficiente de perda de calor no coletor solar (5,45 Wm-2ºC-1), coeficiente de perda de calor no reservatório térmico (5,34 Wm-2ºC-1), fator de emoção de calor do coletor solar (0,78) e eficiência global do sistema (31%). Os tempos de retorno do capital investido no sistema de
aquecimento solar (em comparação a um chuveiro elétrico convencional), para os dois cenários de utilização, foram de, respectivamente, 11,38 anos e 5,73 anos.
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Membrane Stratified Solar PondsSchober, Benjamin January 2010 (has links)
<p>This project deals with the potential of membrane stratified solar ponds which consist of two water layers, where one is a salt solution here, and a separating translucent membrane. An experimental pond was set up to study the thermal behaviour of such collector systems. The input is mainly solar radiation, sometimes when the ambient temperatures are higher than the pond temperatures also heat from the environment is transferred into the pond.</p><p>The measured temperatures of the pond, the ambient temperature, the global radiation and wind speed were the basis data for thermal calculations which showed that the pond was working well as a solar collector and thermal storage system all in one. Heat was not extracted from the pond however, only the losses to the environment were studied.</p><p>It was found out that the pond temperatures were higher than the ambient temperature over the whole measurement period of 12 days, and insulation and pollution problems as well as future prospects and suggestions for further studies are discussed at the end of this paper.</p>
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Membrane Stratified Solar PondsSchober, Benjamin January 2010 (has links)
This project deals with the potential of membrane stratified solar ponds which consist of two water layers, where one is a salt solution here, and a separating translucent membrane. An experimental pond was set up to study the thermal behaviour of such collector systems. The input is mainly solar radiation, sometimes when the ambient temperatures are higher than the pond temperatures also heat from the environment is transferred into the pond. The measured temperatures of the pond, the ambient temperature, the global radiation and wind speed were the basis data for thermal calculations which showed that the pond was working well as a solar collector and thermal storage system all in one. Heat was not extracted from the pond however, only the losses to the environment were studied. It was found out that the pond temperatures were higher than the ambient temperature over the whole measurement period of 12 days, and insulation and pollution problems as well as future prospects and suggestions for further studies are discussed at the end of this paper.
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Optimal predictive control of thermal storage in hollow core ventilated slab systemsRen, Mei Juan January 1997 (has links)
The energy crisis together with greater environmental awareness, has increased interest in the construction of low energy buildings. Fabric thermal storage systems provide a promising approach for reducing building energy use and cost, and consequently, the emission of environmental pollutants. Hollow core ventilated slab systems are a form of fabric thermal storage system that, through the coupling of the ventilation air with the mass of the slab, are effective in utilizing the building fabric as a thermal store. However, the benefit of such systems can only be realized through the effective control of the thermal storage. This thesis investigates an optimum control strategy for the hollow core ventilated slab systems, that reduces the energy cost of the system without prejudicing the building occupants thermal comfort. The controller uses the predicted ambient temperature and solar radiation, together with a model of the building, to predict the energy costs of the system and the thermal comfort conditions in the occupied space. The optimum control strategy is identified by exercising the model with a numerical optimization method, such that the energy costs are minimized without violating the building occupant's thermal comfort. The thesis describes the use of an Auto Regressive Moving Average model to predict the ambient conditions for the next 24 hours. A building dynamic lumped parameter thermal network model, is also described, together with its validation. The implementation of a Genetic Algorithm search method for optimizing the control strategy is described, and its performance in finding an optimum solution analysed. The characteristics of the optimum schedule of control setpoints are investigated for each season, from which a simplified time-stage control strategy is derived. The effects of weather prediction errors on the optimum control strategy are investigated and the performance of the optimum controller is analysed and compared to a conventional rule-based control strategy. The on-line implementation of the optimal predictive controller would require the accurate estimation of parameters for modelling the building, which could form part of future work.
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[en] INTELLIGENT STRATEGY FOR WATER HEATING BY SOLAR ENERGY / [pt] ESTRATÉGIA INTELIGENTE DE AQUECIMENTO POR ENERGIA SOLARPEDRO MARCONDES MONTALEONE 23 November 2018 (has links)
[pt] Esta dissertação analisa aspectos da utilização da energia solar para aquecimento de água. Dois são os aspectos abordados: O primeiro é quanto à utilização de valores médios mensais ou diários de temperatura e insolação utilizados por diversos métodos de dimensionamento ou simulação de sistemas de aquecimento solar, e o segundo é a utilização de múltiplos tanques de armazenamento de água quente ao invés de um único reservatório de maior volume. Assim, este estudo tem como objetivo formular, simular e analisar diferentes cenários de configurações de sistemas de aquecimento solar de água, variando-se o número de reservatórios térmicos para um mesmo volume total do sistema. Tem-se por finalidade atender um mesmo padrão de consumo de água quente, condicionado a um mesmo perfil climático, visando otimizar a contribuição da energia solar ao sistema e consequentemente minimizar o consumo de energia auxiliar elétrica. / [en] This dissertation examines aspects of the use of solar energy for water heating. Two aspects are handled: The first is regarding the use of average monthly or daily values of temperature and insolation used by different scaling methods or simulation of solar water heating systems, and the second is the use of multiple hot water storage tanks instead of a single larger volume reservoir of water. Thus, this study aims to formulate, simulate and analyze different configurations of solar water heating systems scenarios, varying the number of thermal reservoirs for the same total volume of the system. It intends to satisfy the same standard of hot water consumption, under same climatic conditions to optimize the contribution of solar energy to the system and consequently minimize the consumption of electric auxiliary energy.
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SELF-SUFFICIENT OFF-GRID ENERGY SYSTEM FOR A ROWHOUSE USING PHOTOVOLTAIC PANELS COMBINED WITH HYDROGEN SYSTEM : Master thesis in energy systemMaxamhud, Mahamed, Shanshal, Arkam January 2020 (has links)
It is known that Sweden is categorised by being one of the regions that experience low solar radiation because it is located in the northern hemisphere that has a low potential of solar radiation during the colder seasons. The government of Sweden aim to promote a more sustainable future by applying more renewable initiative in the energy sector. One of the initiatives is by applying more renewable energy where PV panels will play a greater role in our society and in the energy sector. However, the produced energy from the PV panels is unpredictable due to changes in radiation throughout the day. One great way to tackle this issue is by combining PV panels with different energy storage system. This thesis evaluates an off-grid rowhouse in Eskilstuna Sweden where the PV panels are combined with a heat pump, thermal storage tank, including batteries and hydrogen system. The yearly electrical demand is met by utilizing PV panels, battery system for short term usage and hydrogen system for long-term usage during the colder seasons. The yearly thermal demand is met by the thermal storage tank. The thermal storage tank is charged by heat losses from the hydrogen system and thermal energy from heat pump.The calculations were simulated in Excel and MATLAB where OPTI-CE is composed with different components in the energy system. Furthermore, the off-grid household was evaluated from an economic outlook with respect to today’s market including the potential price decrease in 2030.The results indicated that the selected household is technically practicable to produce enough energy. The PV panels produces 13 560 kWh annually where the total electrical demand reaches 6 125 kWh yearly (including required electricity for the heat pump). The annual energy demand in terms of electricity and thermal heat reaches 12 500 kWh which is covered by the simulated energy system. The overproduction is stored in the batteries and hydrogen storage for later use. The back-up diesel generator does not need to operate, indicating that energy system supplies enough energy for the off-grid household. The thermal storage tank stores enough thermal energy regarding to the thermal load and stores most of the heat during the summer when there are high heat losses due to the charge of the hydrogen system. The simulated energy system has a life cycle cost reaching approximately k$318 with a total lifetime of 25 years. A similar off-grid system has the potential to reduce the life cycle cost to k$195 if the energy system is built in 2030 with a similar lifespan. The reduction occurs due to the potential price reduction for different components utilized in the energy system.
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[en] EXPERIMENTAL STUDY OF SUPERCOOLING WATER IN CYLINDRICAL CAPSULES APPLIED TO THE THERMAL STORAGE / [pt] ESTUDO EXPERIMENTAL DO SUPER-RESFRIAMENTO DA ÁGUA EM CÁPSULAS CILÍNDRICASJUAN JOSE MILON GUZMAN 11 November 2004 (has links)
[pt] Um dispositivo experimental foi desenvolvido para o estudo
do super-resfriamento da água em cápsulas cilíndricas
visando sua utilização em processos de termo-acumulação. A
bancada experimental é constituída basicamente por: seção
de teste, sistema de resfriamento, sistema de visualização
e sistema de aquisição e armazenamento de dados. A
temperatura do fluido externo, ou fluido de transferência
(FT), uma solução aquosa de álcool a 50% por volume, foi
mantida fixa por um banho de temperatura controlada
durante cada teste. O trabalho foi dividido em quatro
etapas. A primeira trata do estudo estatístico do super-
resfriamento e nucleação, onde foram utilizadas 4 cápsulas
de materiais distintos (alumínio, bronze, PVC e acrílico)
de 45 mm de diâmetro, com diferentes temperaturas do FT. A
segunda etapa investiga a Taxa de Resfriamento, parâmetro
que quantifica a queda da temperatura e influencia
fortemente o superresfriamento e a nucleação. Na terceira
etapa, foi estudada a influência da rugosidade da parede
interna da cápsula. Nesta etapa, quatro diferentes
cápsulas de alumínio, com diferentes rugosidades, foram
utilizadas. Finalmente, na quarta etapa, foram realizadas
visualizações do processo de nucleação para posterior
processamento e melhor entendimento do fenômeno. Os
resultados obtidos indicam que o material da cápsula
(condutividade e rugosidade) e a temperatura do FT têm
grande influência nos fenômenos de super-resfriamento e
nucleação da água em cápsulas cilíndricas, afetando,
fortemente, o processo de mudança de fase. / [en] An experimental device was developed to investigate the
supercooling phenomenon in water inside cylindrical
capsules used for cold storage process. The experimental
device is formed by the test section, the cooling system,
the visualization system and the data acquisition and
storage system. The temperature of the transfer fluid
(TF), a water-alcohol mixture (50% volume), is controlled
by a constant temperature bath (CTB). The work was divided
in four stages. The first is the statistical study of the
supercooling and nucleation phenomena, where four capsules
of 45 mm diameter made with different materials (aluminum,
brass, PVC and acrylic) had been used, with different
temperatures of the FT. The second stage studies the
Cooling Rate, a parameter related to the supercooling and
nucleation phenomena. In the third stage, the influence of
the superficial roughness of the internal wall was
investigated. Four aluminum capsules, with different
roughness, were used. Finally, in the fourth stage,
visualizations of the nucleation process had carried out,
for posterior processing and analysis. The results
indicate that the material of the capsule (conductivity
and roughness) and the temperature of the TF have a
considerable influence in the supercooling and nucleation
phenomena of the water inside cylindrical capsules,
strongly affecting the phase change process.
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