Tesis sobre el tema "Solar adsorption"
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Schurger, Uwe. "Investigation into solar powered adsorption cooling systems : adsorption technology and system analysis". Thesis, De Montfort University, 2007. http://hdl.handle.net/2086/4122.
Texto completoPapakokkinos, Giorgos. "Computational modeling of adsorption packed bed reactors and solar-driven adsorption cooling systems". Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/672099.
Texto completoLa preocupació mediambiental sobre el canvi climàtic i l'esgotament d'ozó exigeix un canvi de paradigma en la producció de fred. La demanda de refredament mostra una tendència alarmant creixent, així és imperatiu satisfer-la de forma sostenible. Els sistemes de refredament per adsorció (ACS) són un candidat per a un futur sostenible de la producció de fred, ja que poden utilitzar energia solar o calor residual, emprant substàncies amb zero potencial d'esgotament d'ozó i d'escalfament global. L'objectiu d'aquesta tesi és contribuir a la investigació i millora dels ACS, mitjançant el desenvolupament de dos models computacionals - que aborden els ACS des de diferents perspectives - i la seva utilització per a la realització d'estudis numèrics. La primera línia d'investigació se centra en el disseny del reactor d'adsorció, el component més important dels ACS. La seva configuració geomètrica és determinant pel rendiment de sistema. El seu disseny és una tasca crucial, ja que crea una dicotomia entre la potència específica de refrigeració (SCP) i el coeficient de rendiment (COP). Les optimitzacions individuals basades en el SCP i el COP resultarien a configuracions geomètriques completament oposades. S'ha desenvolupat un model computacional per a la simulació de reactors d'adsorció tipus "packed bed", capaç de simular reactors de qualsevol geometria. S'adopta una estratègia multi-timestep, que permet una dràstica reducció del cost computacional de les simulacions. La fiabilitat del model es va avaluar a través de processos de verificació i validació. Dins d'aquesta línia de recerca es van realitzar dos estudis principals. El primer aspira a proporcionar una comparació entre cinc geometries de reactors, motivat per la falta de comparabilitat entre diferents estudis en la literatura. Es simulen tretze casos de cada geometria, variant el gruix de les aletes, la seva longitud i la fracció de volum de sòlid. El segon estudi presenta la investigació d'una geometria sub-explorada previament, el reactor d'adsorció de honeycomb hexagonal. Es realitza un estudi paramètric pel que fa a les tres dimensions que defineixen la geometria, així com per a diverses condicions de funcionament. La segona línia de recerca es dedica a la investigació dels ACS. i en particular, a la seva integració dins d'un sistema tèrmic més ampli, un edifici refredat per energia solar. Aquesta integració no és senzilla a causa de la inèrcia tèrmica i a el funcionament cíclic inherent dels ACS, així com a la dependència d'una font intermitent i d'un sistema auxiliar, amb l'objectiu de prioritzar l'energia solar. S'ha desenvolupat un model numèric utilitzant models 1-d pels reactors i models 0-d per l'evaporador i el condensador. El model es va validar amb resultats experimentals trobats en la literatura. El model es va acoblar amb l'eina d'optimització genèrica GenOpt, permetent així estudis d'optimització. El model ACS es va acoblar amb models de col·lectors solars, emmagatzematge tèrmic i amb un model d'edifici. Aquest últim va ser desenvolupat prèviament al CTTC. Aquest acoblament resulta a una eina de simulació integral per a edificis refredats per energia solar utilitzant adsorció. Es considera un cas d'estudi per a una oficina refredada per energia solar, amb l'objectiu d'investigar el potencial de satisfer la seva demanda de fred utilitzant energia solar. Es proposa una estratègia de control basada en la duració variable del cicle, utilitzant valors optimitzats per a les condicions instantànies. La durada variable d'el cicle permet satisfer la demanda utilitzant una quantitat significativament menor de col·lectors solars o un menor aportació d'energia auxiliar. Les emissions de CO2 evitades es calculen entre 28.1-90.7% respecte a quatre escenaris de sistemes elèctrics de diferent rendiment i intensitat d'emissions de carboni.
Merino, Jose Carlos Alvarez y Kazuo Hatakeyama. "Technology surveillance of the solar refrigeration by absorption/adsorption". Institute of Electrical and Electronics Engineers Inc, 2016. http://hdl.handle.net/10757/622310.
Texto completoIn order to establish networks of cooperation looking for not to duplicate research and even to make use of existing research in a remote form, it is necessary to identify and classify (around the world) the researchers and laboratories, that are researching in the topic of solar refrigeration by absorption/adsorption. The methodology consists in: i) the technology's classification, ii) technological trajectory Identification, iii) a thematic bibliographic review, and iv) patent's analysis. In this way, with the previous determination of keywords, will be identified main authors and their respective institutions. With the same keywords, are determined the licensed patents (in certain span of time). In addition, the analysis of publications, patents, and commercial products give us an opportunity to establish comparisons between prototypes and tests (in several conditions). The larger results implicate the use of actor's network and the remote access to the data and tests, for a collaborative research, overcoming the lack of laboratory resource and accelerating the knowledge acquisition
Revisión por pares
Sinha, Saket. "An energy efficient solar-assisted advanced adsorption chiller system". Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23401.
Texto completoYou, Ying 1962. "A solar adsorption refrigeration system operating at near atmospheric pressure". Monash University, Gippsland School of Engineering, 2001. http://arrow.monash.edu.au/hdl/1959.1/8740.
Texto completoEscobedo, João Francisco. "Refrigeração com uso de energia solar". Universidade de São Paulo, 1987. http://www.teses.usp.br/teses/disponiveis/54/54132/tde-28052009-094024/.
Texto completoA numerical simulation of the adsorption refrigeration cycle was made for zeolite/water and activated carbon(AC-35)/ methanol pairs, to select the pair and the solar collector in the prototype. The fabricated prototype consists of a cylindrical paraolic concentrator with solar trackins, a heat pipe and the refrigeration unit (with the zeolite/water pair). The technical aspects of values, welds and out-gassing are analyzed. The results of the performance tests are presented, discussed and compared with the literature. An analysis of costs is made. In parallel thermopiles were constructed using the evaporation method. These thermopiles were used in the construction of the piranometer and the pirheliometer. The instruments were characterized in terms of: sensitivity, stability with time, linearity, effects of temperature and natural convenction. The results of this characterization are discussed and compared with a model made by Eppley. Finally, in Apendix I, we tested the performance of a flat plate collector using a selective coating of aluminium oxide (developed in IFQSC) as absorber. The Best conditions for obtaining the seletive coating on big size plates are discussed.
Tabassum, Alim Abid. "Solar refrigeration : evaluation of technical options and design of a solar-generator-adsorber for a novel adsorption refrigerator". Thesis, Cranfield University, 1989. http://dspace.lib.cranfield.ac.uk/handle/1826/4213.
Texto completoTabassum, Salim Abid. "Solar refrigeration: evaluation of technical options and design of a solar-generator-adsorber for a novel adsorption refrigerator". Thesis, Cranfield University, 1989. http://hdl.handle.net/1826/4213.
Texto completoAraÃjo, Maria Elieneide. "ValidaÃÃo experimental de um resfriador de Ãgua operando em ciclo de adsorÃÃo com aquecimento solar indireto". Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3400.
Texto completoApresenta a validaÃÃo experimental de um novo refrigerador solar por adsorÃÃo com aquecimento indireto. Os componentes do refrigerador sÃo: adsorvedor, condensador, evaporador e coletor solar. A escolha do par adsorbato / adsorvente, Ãgua e sÃlica gel tipo RD, respectivamente, levou em consideraÃÃo as temperaturas alcanÃadas pelos coletores e disponÃveis para a dessorÃÃo do fluÃdo refrigerante (Ãgua) das cavidades do material adsorvente (sÃlido poroso). Devido à coexistÃncia das etapas de aquecimento e resfriamento no adsorvedor, foi definida uma geometria para este componente capaz de permitir uma melhor dissipaÃÃo de calor no material adsorvente na fase de resfriamento, e a conservaÃÃo de energia tÃrmica durante a fase de aquecimento. Os resultados experimentais comprovaram o funcionamento do refrigerador, visto que foram atingidas temperaturas de 140ÂC na entrada do adsorvedor, 80ÂC no leito adsortivo e de 4,4ÂC no evaporador, possibilitando sua aplicaÃÃo em sistemas de condicionamento de ar
This work presents the experimental validation of a new adsorption solar refrigeration with indirect heating. The components of the refrigerator are: an adsorber, a condenser, an evaporator, and a solar collector. The choice of the adsorbate / adsorbent pair, water and silica gel type RD, respectively, took into consideration the temperatures reached by the solar collectors and available for the desorption of the refrigerant fluid (water) from the cavities of the adsorbent material (a porous solid). Due to the co-existence of the heating and cooling phases in the adsorber, a specific geometry for this component was defined so as to allow a good heat dissipation in the adsorbent material in the cooling phase, and the conservation of thermal energy in the heating phase. The experimental results validate the operation of the refrigerator, as temperature valves of 140ÂC at the inlet of the adsorber, of 80ÂC in the adsorber bed, and of 4,4ÂC in the evaporator were reached, allowing its application in air conditioning systems
Demirocak, Emre Dervis. "Thermodynamic And Economic Analysis Of A Solar Thermal Powered Adsorption Cooling System". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610110/index.pdf.
Texto completomass recovery cycles are presented. Secondly, adsorption characteristics of three adsorbent/adsorbate pairs which are zeolite-water, silica gel-water and activated carbon-methanol are given. Following this, load side (i.e., building) of the system is designed and parameters that should be considered in building design are presented. Then, solar-thermal cooling system design methodology with an emphasis on solar fraction is presented. In addition, system parameters effecting the performance of the adsorption cooling system are analyzed and results are presented. Finally, economic analysis is done in order to understand the economic feasibility of the solar-thermal cooling systems compared to conventional cooling systems. TRNSYS is used for the yearly simulations and an integrated model of the overall system is developed in TRNSYS. Since energy consumption and performance investigations of environment-dependent systems such as building HVAC, refrigeration systems and solar collectors usually require weather information, typical meteorological year (TMY) data for Antalya is also generated in order to be used in the analysis of the system parameters.
Taylan, Onur. "Numerical Modeling And Performance Analysis Of Solar-powered Ideal Adsorption Cooling Systems". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611799/index.pdf.
Texto completoMarcos, Carla Abregú, Abraham Sopla Maslucán, Miguel Cano Lengua y José C. Alvarez. "Co-authors Networks in Adsorption Refrigeration and Air-Conditioning with Solar Energy". Universidad Peruana de Ciencias Aplicadas (UPC), 2021. http://hdl.handle.net/10757/653778.
Texto completoThe refrigeration and air conditioning systems by adsorption with solar energy are a very interesting option to replace the conventional compression systems because they save energy, are noiseless and use non-aggressive ozone layer refrigerants; however, there are scarcities of studies at this topic. The acquisition of knowledge and positioning in research on this topic by new research groups could be facilitated by knowing the context, trends, and collaborations that emerge in the subject. A map of collaborative co-authors between the greatest authors on the subject was drawn up, the same one that is done using Gephi software. From the analysis of these maps, the centrality degree and collaboration between the authors were determined.
Revisión por pares
Yeung, King-ho y 楊景豪. "An optimization model for a solar hybrid water heating and adsorption ice-making system". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29632432.
Texto completoBivona, Santo. "Adsorption Machine & Desiccant Wheel based SOLAR COOLING in a Second Law perspective". Thesis, Università degli Studi di Catania, 2011. http://hdl.handle.net/10761/224.
Texto completoMayor, Louise Charlotte. "The adsorption and charge-transfer dynamics of model dye-sensitised solar cell surfaces". Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/13521/.
Texto completoThoms, Matthew W. "Adsorption at the nanoparticle interface for increased thermal capacity in solar thermal systems". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74946.
Texto completoCataloged from PDF version of thesis.
Includes bibliographical references (p. 86-88).
In concentrated solar power (CSP) systems, high temperature heat transfer fluids (HTFs) are responsible for collecting energy from the sun at the solar receiver and transporting it to the turbine where steam is produced and electricity is generated. Unfortunately, many high temperature HTFs have poor thermal properties that inhibit this process, including specific heat capacities which are half that of water. In an effort to enhance the effective heat capacity of these high temperature HTFs and thus increase the efficiency of the CSP systems, adsorption energy at the liquid-solid interface was investigated as a mechanism for increased thermal capacity. Solid ceramic nanoparticles were dispersed in several molten salts at 1-2% by mass with diameters ranging from 5 nm to 15 nm to provide a significant available surface area for adsorption at the particle-molten salt interface. After successful nanofluid synthesis, differential scanning calorimetry (DSC) was used to measure anomalous deviations from the expected heat capacity and enthalpy of fusion values in the nanofluids. The variation in the sensible and latent heat values was determined to be dependent on the presence of sub-100 nm particles and attributed to a layer of salt that remains adsorbed to the surface of the nanoparticles after the bulk of the salt has melted. The adsorbed salt layer is expected to desorb at a higher temperature, providing an increased effective thermal capacity in the vicinity of this desorption temperature. A thermal analysis technique utilizing DSC was proposed to approximate the thickness of the adsorbed layer at the liquid-solid interface, a value that has previously only been obtained using simulation or transmission electron microscopy. More specifically, the adsorbed layer of LiNO3 on Al2O3 particles was determined to be 5.3-7.1 nm thick, similar to the 1-3 nm layers that have been observed in literature for simple, monatomic fluids. The results provide new insight into the nature of adsorption at the liquid-solid interface in more complex fluid and particle systems that can be harnessed for enhanced thermal capacity in HTFs.
by Matthew W. Thoms.
S.M.
Lefebvre, Dominique. "Thermal Energy Storage Using Adsorption Processes for Solar and Waste Heat Applications: Material Synthesis, Testing and Modeling". Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34173.
Texto completoAl, Hodali Reyad. "Numerical simulation of an agricultural foodstuffs drying unit using solar energy and adsorption process". Doctoral thesis, Universite Libre de Bruxelles, 1997. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212169.
Texto completoLiu, X. "Removal of humic substances from water using solar irradiation and granular activated carbon adsorption". Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/20232/.
Texto completoMengistu, Meron Mulatu. "Study of Solar Cooling Alternatives for Residential Houses in Bahir dar city :". Thesis, KTH, Energiteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-63419.
Texto completoKarki, Bipin. "Experimental and Life Cycle Analysis of a Solar Thermal Adsorption Refrigeration (STAR) Using Ethanol - Activated Carbon". University of Dayton / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1524583058600568.
Texto completoMesta, Murat. "Adsorption Of Aromatic Molecules On Rutile Tio2(110) Surfaces". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610928/index.pdf.
Texto completoJames, Keith Edward. "The Effects of Phosphonic Acids in Dye-Sensitized Solar Cells". PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/2951.
Texto completoBesharat, Zahra. "Adsorption of molecular thin films on metal and metal oxide surfaces". Doctoral thesis, KTH, Materialfysik, MF, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195613.
Texto completoQC 20161107
Alkan, Ufuk. "The effects of solar radiation, adsorption and sedimentation of the population of enteric bacteria in marine waters". Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359000.
Texto completoMilani, Dia. "Modelling framework of solar assisted dehumidification system to generate freshwater from "Thin air"". Thesis, The University of Sydney, 2012. http://hdl.handle.net/2123/13581.
Texto completoVural, Kivilcim Basak. "Adsorption Of Gold Atoms On Anatase Tio2 (100)-1x1 Surface". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610962/index.pdf.
Texto completoVieira, Herbert Melo. "Estudo teórico e experimental de coletor adsortivo". Universidade Federal da Paraíba, 2009. http://tede.biblioteca.ufpb.br:8080/handle/tede/5392.
Texto completoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
This paper presents simple and feasible alternatives that will help improve the performance of a refrigeration system by adsorption, which uses solar energy as a heat source to promote the raising of the temperature of the porous bed, thus occurring, the process of desorption, which is the separation of the adsorbent adsorbato. The studies were made in the modification of the geometry of the absorber plate for triangular tube, which caused an increase in the area provided between the plate and the adsorbent, which were analyzed by a computer program that simulates the cycle of a refrigeration system by adsorption . Another study proposed is the removal of a concentric screen, which aims to promote the flow of radial adsorbato during the processes of sorption, the withdrawal of this screen aims to verify whether the change in the flow of adsorbato of radial to the axial an increase in the concentration of adsorbato the porous bed and if the phenomenon occurs throughout the entire adsorptive column, thus enabling a constructive process of collecting tubular simple plan, this phase of work, is shown through experimental results, verifying the concentration and temperature in two adsorptive columns during the adsorption.
O presente trabalho apresenta alternativas viáveis e simples que venham contribuir para melhorar o desempenho de um sistema de refrigeração por adsorção, que utiliza a energia solar como fonte de calor para promover a elevação da temperatura do leito poroso, ocorrendo assim, o processo de dessorção, que é a separação do adsorbato do adsorvente. Os estudos feitos constituíram na modificação da geometria da placa absorvedora de tubular para triangular, o que ocasionou um aumento na área de contanto entre a placa e o adsorvente, que foram analisadas através de um programa computacional que simula o ciclo de um sistema de refrigeração por adsorção. Outro estudo proposto é a retirada de uma tela concêntrica, que tem como finalidade promover o fluxo radial do adsorbato durante os processos de adsorção/dessorção, a retirada desta tela tem como objetivo verificar se com a modificação do fluxo do adsorbato de radial para axial a um aumento na concentração de adsorbato no leito poroso e se ocorre o fenômeno adsortivo ao longo de toda coluna, possibilitando assim, um processo construtivo do coletor plano tubular mais simples, esta etapa do trabalho, é apresentada através de resultados experimentais, verificando a concentração e temperatura em duas colunas adsortivas durante o período de adsorção.
Das, Saikat. "FUNDAMENTAL STUDIES OF SURFACTANT TEMPLATED METAL OXIDE MATERIALS SYNTHESIS AND TRANSFORMATION FOR ADSORPTION AND ENERGY APPLICATIONS". UKnowledge, 2015. http://uknowledge.uky.edu/cme_etds/48.
Texto completoGhaghazanian, Arash. "System Integration of PV/T Collectors in Solar Cooling Systems". Thesis, Högskolan Dalarna, Energiteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:du-19554.
Texto completoTatsidjodoung, Parfait. "Procédé de stockage d'énergie solaire thermique par adsorption pour le chauffage des bâtiments : modélisation et simulation numérique". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENA012/document.
Texto completoSorption heat storage systems (SHSS) open new perspectives for solar heating of residential buildings. These systems allow long term heat storage (storage is done in the form of chemical potential) and offer high energy densities (up to 230 kWh/m3 of material on average) compared to conventional heat storage systems such as sensible heat storage (which, for the case of water, has an average energy density of approximately 81 kWh/m3 of material for a temperature change of 70 °C) and latent heat storage (nearly reaching energy densities of 90 kWh/m3 of material on average).This thesis aims to study the performance of a sorption solar heat storage system on zeolite 13X, integrated to low-energy building. Mathematical models of coupled heat and mass transfer of various components of the system are developed and validated through experimentation. Numerical dynamic simulations allow to study the functioning of the SHSS in specific conditions, and its design with the results from the parametric sensitivity analysis on its components
Alessandrini, Stefano. "Experimental analysis and dynamic simulation of solar cooling systems". Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/11128.
Texto completoIl continuo aumento della richiesta di energia elettrica e la conseguente crescita dei valori di anidride carbonica nell'atmosfera terrestre crea sempre più la necessità di attuare modifiche sostanziali non solo nei metodi di produzione dei settori energetico e industriale, ma anche nella vita di ogni abitante del pianeta. Questa tesi analizza la possibilità di utilizzare l'energia solare per la produzione di acqua fredda grazie alla contemporaneità tra la disponibilità di energia rinnovabile e la richiesta di raffrescamento durante il periodo estivo. Due diversi impianti sperimentali, dotati di collettori solari a tubi evacuati commerciali e chiller ad adsoprbimento di piccole dimensioni (20 kW), sono stati monitorati ed i primi risultati sperimentali sono presentati in questo studio. Per studiare soluzioni diverse e trovare un design ottimale, un modello di simulazione dinamica è stato creato e testato utilizzando il software commerciale TRNSYS 17.
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Vodianitskaia, Paulo José. "Estudo teórico e experimental de um chiller a adsorção para sistemas de ar condicionado solar". Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/8957.
Texto completoMade available in DSpace on 2017-05-22T14:42:18Z (GMT). No. of bitstreams: 1 arquivo total.pdf: 11672574 bytes, checksum: 5bf89f8b81d381d3a77f4d0f8236dc47 (MD5) Previous issue date: 2016-07-29
Human society in general, and Brazil in particular, face severe scenarios, from restricted energy supply to climate change and other challenges for a sustainable future. Thus renewable energy alternatives offering lower environmental and social impacts such as solar energy are subjects of special interest. The present work refers to this challenging picture. As a way to apply renewable energy, solid adsorption air conditioning favors energy security and contributes to the mitigation of greenhouse gases due to the lower dependency in regard to primary energy. It allows to a reduction on demand peaks, and to a natural adjustment between supply and demand levels. Moreover, the materials used in such systems present low environmental impact, especially the refrigerant fluid: water, abundant in nature and non-toxic. The general objective of this work is the development of an experimental chiller using local technology, resulting in a state-of-the-art performance level. Specific objectives include the development of a representative model for the adsorber, the comparison of adsorption kinetics between two fractions of silica gel, the evaluate how specific heat and mass diffusion influence the chiller performance. The numerical model contributions are related to the use of specific heat of the adsorbed phase, and mass diffusion for cycle characterization. The model resulted representative of the experimental behavior. COP was found to be 0,53 and SCP is 68 W/kg for 2.0 mm beads. These values are comparable or higher to the ones reported in literature for silica gel in loose grains. The use of a crushed silica gel of smaller size (026 mm) resulted in lower level of performance, which is probably due to the reduction of porosity after crushing.
A humanidade em geral, e o Brasil em particular, enfrentam duros cenários de restrição de energia, mudanças climáticas e outros desafios para um futuro sustentável. Assim, alternativas de energia renovável, de menor impacto ambiental e social, como a energia solar, se tornam objeto de especial interesse. É dentro desse quadro desafiador que se insere o presente trabalho. Como aplicação de energia renovável, a climatização a adsorção se configura como fator de segurança energética e contribui para a mitigação das emissões de gases efeito estufa, ao reduzir a dependência de energia primária. Conduz à redução de picos de demanda, e apresenta um ajuste natural entre demanda e oferta. Além disso, os materiais utilizados são de baixo impacto ambiental, especialmente o refrigerante: a água, abundante na natureza e atóxica. O objetivo geral do presente trabalho é desenvolver um chiller experimental com tecnologia nacional que permita atingir níveis de desempenho comparáveis ao estado da arte. Os objetivos específicos são: desenvolver um modelo representativo para o reator adsortivo, comparar a cinética de adsorção em duas granulometrias de sílica gel, e estudar a influência do calor específico e da difusão de massa. O modelo numérico trouxe como contribuições originais considerar o calor específico da fase adsorvida e a difusão de massa para caracterização do ciclo. O modelo resultou representativo do comportamento verificado experimentalmente. Foram obtidos COP de 0,53 e SCP de 68 W/kg para partículas de adsorvente de 2,0 mm, valores comparáveis ou superiores aos registrados na literatura para sílica gel em grãos soltos. A fração de granulometria menor (0,26 mm) teve desempenho inferior, provavelmente devido à redução de porosidade após britagem.
Wilson, Earle Anthony. "Investigation of renewable, coupled solar-hydrogen fuel generation with thermal management systems suitable for equatorial regions". Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4508.
Texto completoOscarsson, Johan. "Towards Mixed Molecular Layers for Dye-Sensitized Solar Cells : A Photoelectron Spectroscopy Study". Doctoral thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-301164.
Texto completoPeic, Antun. "Mesoporous thin-film materials studied by optical waveguide spectroscopy". Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518293.
Texto completoTelegang, Chekem Cedric. "Matériaux carbonés multifonctionnels à porosité contrôlée à partir des ressources végétales tropicales : application au traitement de l'eau par photocatalyse". Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0026/document.
Texto completoAdsorption/photodegradation dual property of AC-TiO2 composites materials towards biorefractory pollutants is a promising issue for solar water treatment. In this work, AC-TiO2 hybrid materials have been synthesized through 03 novel routes based on the conversion of typical biomasses, abundantly found in the subsaharian African sunny areas. Biomasses pyrolysis derived activated carbon (AC) developed a porous structure which is modified differently according to the method used to fix TiO2 nanoparticules (TiO2-NPs). AC impregnated with a sol containing TiO2-NPs suspension provides the derived composite material (CAT.SX) with TiO2-NPs regularly deposited at the “external surface”, leading to a good coupling of adsorption/photodegradation activities towards phenol elimination in 100 mg.L-1 polluted water, carried out on lab scale experiments. Pore/surface area network is less developed on composites obtained after in situ fixation of TiO2-NPs on TiO2 gel impregnated AC (CAT.GX), or obtained after direct pyrolysis of TiO2-NPs impregnated biomass (CAT.SBX) – which infers lesser decontamination performances for these two latter families of catalysts. Pollutant elimination kinetics curves depicted after recycling of CAT.SX over several running water treatment was simulated with a suitable mathematical model which takes into consideration the dual functionalities of the elaborated material. The established model is a promising attempt for future dimensioning of real solar water treatment plants, operating in sunny areas with the new composite catalysts
Nedjar, Achraf. "Dimensionnement et optimisation d'un système photovoltaïque thermique avec intégration dans le bâtiment pour la production de froid". Electronic Thesis or Diss., CY Cergy Paris Université, 2024. http://www.theses.fr/2024CYUN1285.
Texto completoThis thesis presents a comprehensive study of a hybrid photovoltaic/thermal (PVT) system performance dimensioned for cold production by adsorption. TRNSYS dynamic simulation software was used to simulate the system, considering meteorological conditions in Algiers, northern Algeria. The study takes into account the actual generation of thermal energy by the collectors, as well as the actual variation in performance of the adsorption chiller. The main objective is to dimension and optimize the solar system with thermal energy storage to guarantee stabilized cooling production throughout the year.Prior to this, an extensive literature review was carried out, examining PVT hybrid systems, solar sorption cooling systems, as well as existing research exploring the combination of these two technologies.Secondly, a numerical study of the PVT collector's exchanger geometry determined that the water table geometry offers the best thermal and overall efficiency. In addition, the temperature range of the hot water delivered by collectors with this geometry, notably DualSun manifolds, corresponds to the operating temperatures of adsorption solar chillers.Next, the PVT - Adsorption system components were dimensioned and a mathematical model was developed and validated by published experimental work. A study of the system's performance for cooling needs between 4°C and 8°C revealed that DualSun hybrid collectors offer optimum annual production. Furthermore, the adsorption cooling system is able to meet 36% of year-round demand. The temperature difference between the inside and outside of the cooling enclosure balances cooling supply and demand. It was also noted that thermal efficiency is strongly affected by ambient temperature, whereas electrical efficiency is more sensitive to solar radiation.Analysis of storage system losses showed that these depend, on the one hand, on the temperature difference between the inside and outside of the storage tank, with more significant values during the summer season. On the other hand, losses also depend on the volume of the storage tank, which has been optimized to limit heat exchange with the outside.Economic analysis of the proposed PVT - Adsorption system has revealed its viability under certain key conditions, mainly related to the cost of electricity. Profitability is achieved provided that the cost of electricity exceeds the threshold of 0.08 USD/kWh.The environmental analysis determined the rate of mitigation of greenhouse gas emissions as a function of the conversion factors associated with electricity generation. The system contributes to the mitigation of around 30 tons of carbon dioxide per year.The performance of the PVT - Adsorption system was studied under different climates: Mediterranean, humid subtropical and arid desert. The results showed that the system is more productive in an arid desert climate and more efficient in a Mediterranean climate, which offers better regularity between cooling supply and demand.In sum, the combination of PVT and solar adsorption technologies is therefore proving to be an efficient way of producing cold, and can make a significant contribution to achieving sustainable development goals
Karlsson, Maria. "Quantum Chemical Investigations of Phenol and Larger Aromatic Molecules on TiO2 Surface". Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2715.
Texto completoAdsorption of organic molecules at a surface of titanium dioxide (101) anatase is studied using quantum-chemical density functional theory. Anatase can be used in solar cells. For the clean anatase surface the band gap is so large that only UV-light can excite electrons. Different groups with conjugated systems are attached to obtain a more suitable band gap.
Phenol was attached in different positions to a cluster of anatase and geometry optimized using the B3LYP-functional. The geometry that was energetically most favorable was used to put in phenylmethanol, phenylethanol, naphthol, 2-phenanthrol, 1-pyrol and 2-perylol. To give a more realistic model of phenol at anatase, a study of a two- dimensional periodic anatase surface was also made.
Molecular orbitals were calculated to study the overlap between HOMO and LUMO orbitals. The calculation shows that phenol will remain as a molecule and will not dissociate. The band gap gets smaller when molecules are attached at the cluster and with 2-perylol it reaches the energy of visible light.
The molecular orbitals for HOMO, LUMO and LUMO of the adsorbed molecule were investigated. HOMO was localized at the molecule, LUMO at the cluster and LUMO of the adsorbed molecule move closer to the energy of LUMO when the number of rings increases.
Su, Lingcheng. "Soil contamination and plant uptake of metal pollutants released from Cu(In, Ga)Se₂ thin film solar panel and remediation using adsorbent derived from mineral waste material". HKBU Institutional Repository, 2018. https://repository.hkbu.edu.hk/etd_oa/552.
Texto completoCavalcanti, Vladyr Yuri Soares de Lima. "Simulação computacional de um tomógrafo capacitivo elétrico paralelo aplicado ao processo adsortivo". Universidade Federal da Paraíba, 2009. http://tede.biblioteca.ufpb.br:8080/handle/tede/5391.
Texto completoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This thesis aims to computationally simulate the electronic transducer for a parallel electrical capacitance tomography, can generate a voltage level used for image reconstruction of the adsorption phenomenon occurred in the adsorptive bed. This simulation was performed using a computer program like SPICE (Simulation Program with Integrated Circuit Emphasis) for the purpose of defining the parameters for its construction, dedicated to the application of the adsorptive bed bench in a glass case studies of the adsorptive process. This technique uses capacitive sensors coupled to an electronic transducer that will generate a voltage signal associated with the distribution of dielectric permittivity of the medium. The simulation is developed to simulate the main circuit, a differentiator, fitted with high frequency OPA 2690. The simulated model is a simple circuit with a transmitter and a receiver. The results show the technical feasibility of the project being proposed for future work to implement a prototype of the electronic transducer of electrical capacitance tomography applied to the study of the adsorption process.
Esta dissertação tem como objetivo simular computacionalmente o transdutor eletrônico para um tomógrafo capacitivo elétrico paralelo capaz de gerar um nível de tensão utilizado para a reconstrução da imagem do fenômeno de adsorção ocorrido no leito adsortivo. Esta simulação foi realizada em um programa computacional do tipo SPICE (Programa de Simulação com Ênfase em Circuito Integrado) com a finalidade de definir os parâmetros para a sua construção, voltado para a aplicação no leito adsortivo de uma bancada em vidro para estudos do processo adsortivo. Esta técnica utiliza sensores capacitivos acoplados a um transdutor eletrônico que vão gerar um sinal de tensão associado à distribuição da permissividade dielétrica do meio. A simulação desenvolvida consiste em simular o circuito principal, um diferenciador, montado com OPA 2690 de alta freqüência. Simulou-se de um modelo de circuito simples, com um transmissor e um receptor. Os resultados apresentados mostram a viabilidade técnica do projeto, sendo proposto para trabalhos futuros a implementação de um protótipo do transdutor eletrônico do tomógrafo capacitivo elétrico aplicado ao estudo do processo de adsorção.
Ghani, Fatemeh. "Nucleation and growth of unsubstituted metal phthalocyanine films from solution on planar substrates". Phd thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2013/6469/.
Texto completoIn den vergangenen Jahren wurden kosteneffiziente nasschemische Beschichtungsverfahren für die Herstellung organischer Dünnfilme für verschiedene opto-elektronische Anwendungen entdeckt und weiterentwickelt. Unter anderem wurden Phthalocyanin-Moleküle in photoaktiven Schichten für die Herstellung von Solarzellen intensiv erforscht. Aufgrund der kleinen bzw. unbekannten Löslichkeit wurden Phthalocyanin-Schichten durch Aufdampfverfahren im Vakuum hergestellt. Des Weiteren wurde die Löslichkeit durch chemische Synthese erhöht, was aber die Eigenschaften von Pc beeinträchtigte. In dieser Arbeit wurde die Löslichkeit, optische Absorption und Stabilität von 8 verschiedenen unsubstituierten Metall-Phthalocyaninen in 28 verschiedenen Lösungsmitteln quantitativ gemessen. Wegen ausreichender Löslichkeit, Stabilität und Anwendbarkeit in organischen Solarzellen wurde Kupferphthalocyanin (CuPc) in Trifluoressigsäure (TFA) für weitere Untersuchungen ausgewählt. Durch die Rotationsbeschichtung von CuPc aus TFA Lösung wurde ein dünner Film aus der verdampfenden Lösung auf dem Substrat platziert. Nach dem Verdampfen des Lösungsmittels, die Nanobändern aus CuPc bedecken das Substrat. Die Nanobänder haben eine Dicke von etwa ~ 1 nm (typische Dimension eines CuPc-Molekül) und variierender Breite und Länge, je nach Menge des Materials. Solche Nanobändern können durch Rotationsbeschichtung oder auch durch andere Nassbeschichtungsverfahren, wie Tauchbeschichtung, erzeugt werden. Ähnliche Fibrillen-Strukturen entstehen durch Nassbeschichtung von anderen Metall-Phthalocyaninen, wie Eisen- und Magnesium-Phthalocyanin, aus TFA-Lösung sowie auf anderen Substraten, wie Glas oder Indium Zinnoxid. Materialeigenschaften von aufgebrachten CuPc aus TFA Lösung und CuPc in der Lösung wurden ausführlich mit Röntgenbeugung, Spektroskopie- und Mikroskopie Methoden untersucht. Es wird gezeigt, dass die Nanobänder nicht in der Lösung, sondern durch Verdampfen des Lösungsmittels und der Übersättigung der Lösung entstehen. Die Rasterkraftmikroskopie wurde dazu verwendet, um die Morphologie des getrockneten Films bei unterschiedlicher Konzentration zu studieren. Der Mechanismus der Entstehung der Nanobändern wurde im Detail studiert. Gemäß der Keimbildung und Wachstumstheorie wurde die Entstehung der CuPc Nanobänder aus einer übersättigt Lösung diskutiert. Die Form der Nanobändern wurde unter Berücksichtigung der Wechselwirkung zwischen den Molekülen und dem Substrat diskutiert. Die nassverarbeitete CuPc-Dünnschicht wurde als Donorschicht in organischen Doppelschicht Solarzellen mit C60-Molekül, als Akzeptor eingesetzt. Die Effizienz der Energieumwandlung einer solchen Zelle wurde entsprechend den Schichtdicken der CuPc Schicht untersucht.
Saulich, Sven. "Generic design and investigation of solar cooling systems". Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/13627.
Texto completoRibeiro, Enrique. "Composites Charbon-Actif/TiO2 pour des applications solaires Activated-Carbon/TiO2 composites preparation: An original grafting by milling approach for solar water treatment applications TiO2 grafted Activated Carbon elaboration by milling: composition effect on sorption and photocatalytic properties Experimental and theoretical coupled approaches for the analysis of radiative transfer in photoreactors containing particulate media : case study of TiO2 powders for photocatalytic reactions AC/TiO2 granular photocatalysts optical properties : material composition effect on the radiative transfer in a photoreactor". Thesis, Perpignan, 2020. http://www.theses.fr/2020PERP0016.
Texto completoThe use of bifunctional adsorbent/photocatalyst composite is a solution of great interest for the solar removal of persistent pollutants from wastewaters. This work investigates the mechanosynthesis as an original approach for the preparation of Activated-Carbon/TiO2 composites . First, the feasibility of the preparation approach was validated. The method appeared relevant to produce homogeneous AC/TiO2 granular composites with controlled structural properties. The control of the preparation parameters led to both AC and TiO2 sorption and photo-oxidation functional properties preservation within the composite structure. Secondly, the preparation method ability in creating compositionally-varied AC/TiO2 composites, exhibiting different functional properties. This second part allowed us to show the adaptability of the AC/TiO2 preparation for a wide range of water treatment applications. The radiative properties of these materials - which are essential to know in order to consider their integration within a photoreactor - have been determined by a theoretical approach coupled with experimental measurements. It was thus possible to model and simulate the radiative transfer within a simple geometry photoreactor containing these materials
Gondre, Damien. "Numerical modeling and analysis of heat and mass transfers in an adsorption heat storage tank : Influences of material properties, operating conditions and system design on storage performances". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI022/document.
Texto completoThe development of energy storage solutions is a key challenge to enable the energy transition from fossil resources to renewable energies. The need to store energy actually comes from a dissociation between energy sources and energy demand. Storing energy meets two principal expectations: have energy available where and when it is required. Low temperature heat, for dwellings and offices heating, represents a high share of overall energy consumption (i.e. about 35 %). The development of heat storage solutions is then of great importance for energy management, especially in the context of the growing part of renewable energies. Adsorption heat storage appears to be the best trade off among available storage technologies in terms of heat storage density and performances over several cycles. Then, this PhD thesis focuses on adsorption heat storage and addresses the enhancement of storage performances and system integration. The approach developed to address these issues is numerical. Then, a model of an adsorption heat storage tank is developed, and validated using experimental data. The influence of material thermophysical properties on output power but also on storage density and system autonomy is investigated. This analysis enables a selection of particularly influencing material properties and a better understanding of heat and mass transfers. The influence of operating conditions is also underlined. It shows the importance of inlet humidity on both storage capacity and outlet power and the great influence of discharge flowrate on outlet power. Finally, it is shown heat storage capacity depends on the storage tank volume, while outlet power depends on cross section area and system autonomy on bed length. Besides, the conversion efficiency from absorbed energy (charge) to released energy (discharge) is 70 %. But during the charging process, about 60 % of incoming heat is not absorbed by the material and directly released. The overall conversion efficiency from energy provided to energy released is as low as 25 %. This demonstrates that an adsorption heat storage system cannot be thought of as a self-standing component but must be integrated into the building systems and control strategy. A clever use of heat losses for heating applications (in winter) or inlet fluid preheating (in summer) enhances global performances. Using available solar heat for system preheating is an interesting option since a part is instantly retrieved at the outlet of the storage tank and can be used for direct heating. Another part is stored as sensible heat and can be retrieved a few hours later. At least, it has the advantage of turning the adsorption storage tank into a combined sensible-adsorption storage tank that offers short-term and long-term storage solutions. Then, it may differ avoidable discharges of the sorption potential and increase the overall autonomy (or coverage fraction), in addition to optimizing chances of partial system recharge
Rerhrhaye, Amal. "Contribution à l'étude de divers couples frigorigènes : Application à la réfrigération solaire photothermique". Nancy 1, 1986. http://www.theses.fr/1986NAN10093.
Texto completoVieira, Herbert Melo. "Estudo experimental e teórico de um resfriador de água por adsorção usando energia solar". Universidade Federal da Paraíba, 2013. http://tede.biblioteca.ufpb.br:8080/handle/tede/5350.
Texto completoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The respective thesis aims to develop a cooling system that uses an adsorptive chiller for cooling water and subsequent use of this cold water for air conditioning environment, theoretically and experimentally verifying the performance of adsorption refrigeration system, these devices have several advantages, among them, the use of clean energy such as solar. Brazil is a country with high rates of stroke, with an average capacity 16-20 MJ / year / h, so it becomes quite conducive to harnessing this energy, and to be contributing to the reduction of fossil fuel consumption and reduction of harmful gases to the environment. The proposed system consists of flat solar collectors, which are used to convert solar energy into thermal, being last transferred to a heat transfer fluid that circulates through the collector which is then stored in a boiler, or a thermal fluid, to be used whenever required for heating the bed adsorptive a chiller, which is composed of bed adsorptive the finned annular ducts involved with the adsorbent (silica gel). Many studies have been developed with the aim of increasing the performance of these systems, these studies have focused primarily on increasing the mass transfer and heat of adsorption beds and using systems which run continuously through the use of two adsorption beds which work in different phases. Experimental studies in porous beds featuring different configurations were performed, observing thus which present higher rates adsorbent, and subsequently applied this setting in the construction of the porous bed adsorptive chiller. A computational model was developed theoretically allowing you to check your system's performance.
O respectivo trabalho de tese visa desenvolver um sistema de refrigeração que utiliza um chiller adsortivo para resfriamento de água e posterior uso desta água fria para climatização de ambiente, verificando teoricamente e experimentalmente o desempenho do sistema de refrigeração por adsorção, estes dispositivos apresentam várias vantagens, entre elas, o uso de energia limpa, como a solar. O Brasil é um país que apresenta grande índice de insolação, com uma capacidade média de 16 a 20 MJ/ano/h, desta forma torna-se bastante propício o aproveitamento desta energia, além de estar contribuindo para a redução do consumo de combustíveis fósseis e redução de gases nocivos ao meio-ambiente. O sistema proposto é composto por coletores solares planos, que são usados para converter a energia solar em térmica, sendo está última transferida para um fluido térmico que circula pelo coletor que posteriormente é armazenado em um boiler, podendo este fluido térmico, ser usado sempre que necessário para o aquecimento do leito adsortivo de um chiller, sendo este leito adsortivo composto por dutos aletados na forma anular envolvidos com o adsorvente (sílica gel). Muitos trabalhos vem sendo desenvolvidos com o intuito de aumentar o desempenho destes sistemas, estes estudos estão concentrados basicamente no aumento da transferência de massa e calor dos leitos adsortivos e utilização de sistemas que funcione continuamente através do uso de dois leitos adsortivos que trabalham em fases diferentes. Ensaios experimentais com leitos porosos apresentando configurações diferentes foram realizados, observando deste modo, qual apresentaria maiores taxas adsortivas, sendo posteriormente aplicada esta configuração na construção do leito poroso do chiller adsortivo. Um modelo computacional foi desenvolvido permitindo verificar teoricamente o desempenho do sistema.
Ranwaha, Tshifhiwa Steven. "Density functional theory study of adsorption of cronconate dyes on TiO2 Anatase (010) and (100) surfaces". 2018. http://hdl.handle.net/11602/1359.
Texto completoDepartment of Physics
Currently the dye sensitized solar cells have attracted more attention due to their low cost, transparency and flexibility. These types of solar cells use the dye molecule adsorbed on TiO2 semiconductor in Nano architecture with the role of absorbing photons, in recent research attempts are being made to shifts the absorption spectral of TiO2 to visible and near infrared–region of solar spectrum to achieve maximum photo absorption which yields to an increase in the efficiency of the dye sensitized solar cells. In the current study, density functional theory (DFT) was used to model two croconate dyes (CR1 and CR2), one with an electron donating methyl group (CR1) and the other with an electron –withdrawing caboxyl group (CR2). The geometric, electronic and optical properties of these dyes were compared. The adsorption behaviour of the two dyes on (010 and 100) anatase TiO2 surfaces were investigated in this study by employing first principle calculation based on DFT using a plane-wave pseudo potential method. The generalized gradient approximation (GGA) was used in the scheme of Perdew-Burke Ernzerhof to describe the exchange -correlation function as implemented in the CASTEP package in Material Studio of BIOVIA. The adsorption results shows a spontaneous electron injection followed by efficient regeneration of the oxidized dye molecules by the electrolyte and strong binding ability of CR2 to the TiO2 surface, but also shows a comparable binding strength of CR1. The results of this study will help in the design of high efficient dye for DSSCs.
NRF
Wang, Ji. "Study on Accumulated Performance of a Solar Thermal Powered Adsorption Refrigeration System". Thesis, 2019. http://hdl.handle.net/2440/120966.
Texto completoThesis (MPhil) -- University of Adelaide, School of Mechanical Engineering, 2019
"Research and Development of a Small - Scale Adsorption Cooling System". Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.14333.
Texto completoDissertation/Thesis
Ph.D. Mechanical Engineering 2011