M.S.

Design of internal cooling channels for gas turbine blade is critical to system performance. To achieve maximum efficiency, i.e. maximum cooling with minimum coolant usage, intensive research is required to optimize heat transfer enhancement features. The present study aims at experimental and numerical investigation of two heat transfer augmentation techniques for internal cooling, viz. dimple and swirl induced jet impingement. Dimples are suitable candidates for high performance enhancement as they impose a low pressure drop penalty. The present study aims at experimentally measuring heat transfer on all the walls of diamond, triangular, square and cylindrical shaped dimples in a staggered configuration at three flow conditions in a high aspect ratio channel. A thermal-hydraulic performance factor was evaluated to characterize each dimple shape. Numerical simulations were conducted to visualize flow patterns which was correlated with heat transfer distribution. The results were in good agreement with previous studies. Triangular dimples showed the highest overall performance due to lowest pressure drop penalty, but heat transfer was low inside the dimples. In rotating channels, Coriolis Effect and centrifugal buoyancy significantly affect heat transfer distribution. There is a need to develop a cooling geometry that benefits from rotation and provides consistent cooling. A new geometry was derived from a past study, consisting of two channels divided by a wall with angled holes to provide jet impingement from inlet to outlet channel. Liquid crystal technique was used for heat transfer measurements. It was found that at high rotational speeds, heat transfer increased in the inlet channel, while it decreased in the outlet channel. Additional testing at even higher speeds may provide insight into replacing a traditional U-bend channel in a turbine blade. / Master of Science

Yes / The ever-increasing demand for high-processing electronic systems has unequivocally called for improved microprocessor performance. However, increasing microprocessor performance requires increasing power and on-chip power density, both of which are associated with increased heat dissipation. Electronic cooling using fins have been identified as a reliable cooling approach. However, an investigation into the thermal behaviour of fin would help in the design of miniaturized, effective heatsinks for reliable microprocessor cooling. The aim of this paper is to investigates the simultaneous effects of surface roughness, porosity and magnetic field on the performance of a porous micro-fin under a convective-radiative heat transfer mechanism. The developed thermal model considers variable thermal properties according to linear, exponential and power laws, and are solved using Chebychev spectral collocation method. Parametric studies are carried using the numerical solutions to establish the influences of porosity, surface roughness, and magnetic field on the microfin thermal behaviour. Following the results of the simulation, it is established that the thermal efficiency of the micro-fin is significantly affected by the porosity, magnetic field, geometric ratio, nonlinear thermal conductivity parameter, thermogeometric parameter and the surface roughness of the micro-fin. However, the performance of the micro-fin decreases when it operates only in a convective environment. In addition, we establish that the fin efficiency ratio which is the ratio of the efficiency of the rough fin to the efficiency of the smooth fin is found to be greater than unity when the rough and smooth fins of equal geometrical, physical, thermal and material properties are subjected to the same operating condition. The investigation establishes that improved thermal management of electronic systems would be achieved using rough surface fins with porosity under the influences of the magnetic field. / Supported in part by the Tertiary Education Trust Fund of Federal Government of Nigeria, and the European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN- 2016SECRET-722424.

A novel cooling mechanism based on evaporation of thin liquid films is presented for thermal management of confined heat sources, such as microprocessor hotspots. The underlying idea involves utilization of thin nanoporous membranes for maintaining microscopically thin liquid films by capillary action, while providing a pathway for the vapor generated due to evaporation at the liquid-vapor interface. The vapor generated by evaporation is continuously removed by using a dry sweeping gas keeping the membrane outlet dry. This thesis presents a detailed theoretical, computational and experimental investigation of the heat and mass transfer mechanisms that result in dissipating heat. Performance analysis of this cooling mechanism demonstrates heat fluxes over 600W/cm2 for sufficiently thin membrane and film thicknesses (~1-5µm) and by using air jet impingement for advection of vapor from the membrane surface. Based on the results from this performance analysis, a monolithic micro-fluidic device is designed and fabricated incorporating micro and nanoscale features. This MEMS/NEMS device serves multiple functionalities of hotspot simulation, temperature sensing, and evaporative cooling. Subsequent experimental investigations using this microfluidic device demonstrate heat fluxes in excess of 600W/cm2 at 90 C using water as the evaporating coolant. In order to further enhance the device performance, a comprehensive theoretical and computational analysis of heat and mass transfer at micro and nanoscales is carried out. Since the coolant is confined using a nanoporous membrane, a detailed study of evaporation inside a nanoscale cylindrical pore is performed. The continuum analysis of water confined within a cylindrical nanopore determines the effect of electrostatic interaction and Van der Waals forces in addition to capillarity on the interfacial transport characteristics during evaporation. The detailed analysis demonstrates that the effective thermal resistance offered by the interface is negligible in comparison to the thermal resistance due to the thin film and vapor advection. In order to determine the factors limiting the performance of the MEMS device on a micro-scale, a device-level detailed computational analysis of heat and mass transfer is carried out, which is supported by experimental investigation. Identifying the contribution of various simultaneously occurring cooling mechanisms at different operating conditions, this analysis proposes utilization of hydrophilic membranes for maintaining very thin liquid films and further enhancement in vapor advection at the membrane outlet to achieve higher heat fluxes.

Thesis (PhD (Industrial Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Injection moulding of polymer components is subject to ever increasing demands for improved part quality and production rate. It is widely recognised that the mould cooling strategy employed is crucial to achieving these goals. A brief overview of injection moulding units and different types of injection moulds is given. The modern Additive Manufacturing (AM) technology for processing metal powders such as Direct Metal Laser Sintering (DMLS) and Selective Laser Melting (SLM) offers almost full freedom to the mould designer. Some of these modern manufacturing methods based on metal powders, which are able to produce complex cooling channels are analysed. A drastic change has entered the mould design domain - shifting the paradigm from design for manufacture to manufacture for design. In combination with suitable AM methods the concept of surface cooling moulds can now be efficiently implemented. This study presents a new approach of predicting the minimum cooling time required for the produced part. Different cooling layouts are analysed taking the heat transfer into consideration. The lumped heat capacity method is implemented in this research in order to determine the minimum cooling cycle time required. A new approach was developed to determine the most suitable cooling layout configuration, such as conventional cooling, conformal cooling or surface cooling, required for a moulded part based on its characteristics such as shape complexity, space available for the cooling layout, part quality requirements, production volume, and product life cycle. A mould cooling design process including simulation, reverse engineering and manufacturing of the mould insert was implemented in this study. In order to validate the generic model developed during the course of this research comparative experiments were carried out to determine the difference in performance of injection moulding using conventional or surface cooling methods. The experimental results showed a significant improvement in part quality produced with reduced cycle times using the surface cooling method. / AFRIKAANSE OPSOMMING: ‘Injection Moulding’ van polimeer komponente word al meer gedruk vir verbeterde kwaliteit en vinniger produksie tyd. Dit is orals bekend dat die gietvorm afkoeling strategie ‘n groot rol speel om hierdie twee doelwitte te bereik. Eers word ‘n kort oorslag gegee van ‘Injection Moulding’ eenhede en van verskillende ‘Injection Moulding’ vorms. Die moderne Aditatiewe Vervaardigingstegnologie vir die prosessering van metaal poeiers soos bv. Direkte Metaal Laser Sintering (DMLS) en Selektiewe Laser Smelting (SLM) bied basies volle vryheid ten opsigte van gietvorm ontwerp. Party van die moderne vervaadigings metodes, wat op metaal poeiers gebaseer is, wat komplekse koelings kanale kan produseer word geanaliseer. Die ontwerpers arena het ‘n groot verandering ondergaan deurdat die fokus van ontwerp vir vervaardiging verskuif het na vervaardiging vir ontwerp. In kombinasie met toepaslike aditatiewe vervaardigings metodes kan oppervlak verkoeling nou effektief geïmplementeer word. Hierdie studie bied a nuwe manier om die minimum verkoelings tyd benodig vir ‘n part te voorspel. Verskeie verkoelings uitlegte word geanaliseer waar hitte oordrag in ag geneem word. Die “lumped heat capacity” metode word gebruik om die minimum siklus tyd te bepaal. ‘n Nuwe benadering is ontwikkel om die mees geskikste verkoelings uitleg soos bv. konvensionele verkoeling, konvorme verkoeling of oppervlak verkoeling te bepaal vir ‘n spesifieke part gebaseer op die part se vorm kompleksiteit, spasie beskikbaar vir verkoelings kanale, kwaliteit vereistes en produk lewensiklus. Die volgende is in die studie geïmplementeer: ‘n vorm verkoelings ontwerp proses met simulasie, ‘reverse engineering’ en vervaardiging van die vorm insetsel. Om die generiese model te verifieer gedurende die studie is vergelykende eksperimente uitgevoer om die verskil in prestasie te bepaal tussen die gebruik van konvensionele en oppervlak verkoelings metodes. Die eksperimentele resultate het ‘n beduidende verbetering in part kwaliteit getoon met ‘n verkorte siklus tyd tydens die gebruik van die oppervlag verkoelings metode.

Die Kühlung thermisch hoch belasteter Bauteile wird häufig mit Kühlverfahren realisiert, die auf dem Prinzip des Massetransports durch die Bauteilwand beruhen. Neben der Film- und Transpirationskühlung gehört die Effusionskühlung zu diesen Verfahren und basiert auf einer Reihe oder einem Raster von Bohrungen. Dieser Ansatz ermöglicht sowohl den Abtransport von Wärme aus dem Bauteil als auch die Ausbildung eines schützenden Kühlmittelfilms auf der Bauteiloberfläche. Viele Autoren beschäftigten sich in ihren Arbeiten mit den Auswirkungen der Filmkühlung auf den Wärmeübergang an der Bauteilwand und definierten einen Filmkühlwirkungsgrad, der die Effektivität der Kühlung widerspiegelt. Auch die Freistrahlen aus Effusionskühlbohrungen wurden mit diesen Mitteln untersucht und eine Vielzahl unterschiedlicher Einflussgrößen auf den Filmkühlwirkungsgrad identifiziert. Dazu gehören insbesondere geometrische Bedingungen, wie z.B. der Bohrungswinkel, das Verhältnis von Länge zu Durchmesser der Bohrung und die Austrittsgeometrie der Bohrungen. In späteren Beiträgen analysierten verschiedene Autoren die Einflüsse der Turbulenz sowie der Stoffwerte von Kühlmittel und Hauptströmung. Dabei kamen meist Luft und seltener Kohlendioxid oder Stickstoff als Kühlmittel zum Einsatz. In den letzten Jahren wurde das Verhalten des Kühlmittelstrahls vor allem numerisch untersucht. Dabei beschränkte sich das Berechnungsgebiet oftmals auf das direkte Umfeld der Effusionskühlbohrung und die Identifikation und Beschreibung auftretender Wirbelstrukturen. Der Bereich weiter stromab der Bohrung blieb oft unberücksichtigt. Die vorliegende Arbeit verfolgt den Ansatz, den Kühlmittelstrahl in der Hauptströmung zu beobachten. Das wird durch die Verwendung von Helium und Argon als Kühlmittel möglich, denn diese Gase können in der Luftströmung detektiert werden. Durch eine in zwei Richtungen bewegliche Kombisonde wird Gas aus der Grenzschicht abgesaugt und die Konzentration des Kühlmittels bestimmt. Die so an diskreten Punkten stromab der Effusionskühlbohrung erhaltenen Konzentrations- und Geschwindigkeitsprofile ermöglichen die Verfolgung des Kühlmittelstrahls und dessen Wechselwirkungen mit der Hauptströmung. Für eine vergleichende Analyse der gemessenen Profile entstand ein empirisches Verfahren zur Systematisierung der gesamten Messdaten. Die Definition einer mittleren Kühlmittelkonzentration innerhalb einer zweckmäßig festgelegten Höhe über der Wand und eines normierten Einblasparameters, der das Verhältnis der molaren Massen von Kühlmittel und Hauptströmung berücksichtigt, sind der Kern des empirischen Verfahrens. Für Vergleiche mit der Literatur erfolgte die Berechnung eines Filmkühlwirkungsgrads auf Basis der Massebilanz in der Grenzschicht und der mittleren Kühlmittelkonzentration. Während der Datenauswertung zeigte sich, dass der Bohrungswinkel einen geringen Einfluss auf die mittlere Kühlmittelkonzentration hat und so ein Bohrungswinkel von 30° ein guter Kompromiss zwischen Herstellungsaufwand und Kühlwirkung ist. Kühlmedien mit geringer molarer Masse und hoher spezifischer Wärmekapazität sollten bevorzugt werden, da deren Kühlwirkung hoch, der Einfluss auf die Grenzschicht aber gering ist. / The cooling of thermally heavily loaded components is commonly performed by injecting a mass flow through the component’s wall into the hot flow, which is called Film cooling. The main goal is to form a coolant film to reduce the hot side heat transfer and to absorb thermal energy in order to protect the component’s wall. There are different techniques available called film cooling, transpiration cooling and effusion cooling. By applying transpiration cooling, the cooling fluid is injected through a porous material into the hot gas flow. Unfortunately, these porous materials do not have the physical strength required to work within gas turbines. If the injection is done with a row or a pattern of holes so the cooling film is renewed at certain positions, the cooling technique is called effusion cooling. Film cooling means the injection of fluid through a slot without renewing the film. Many authors analyze the effect of the film or effusion cooling on the wall temperature, the heat transfer coefficient or the cooling effectiveness. Many influencing factors were identified, such as the length to diameter relation, the hole’s alignment, fluid properties as well as turbulence and vortices. Recent works use numerical simulations to investigate the turbulent flow and vortex development in the near field of the injection hole. Due to the complexity of the simulation, the effects far downstream area were not covered by these simulations. This work investigates the behavior of the cooling jet within the boundary layer above the wall. Therefore a foreign gas (Helium, Argon) was injected as coolant into a cross flow and a pitot probe was used to get gas samples out of the boundary layer and the coolant gas fraction was measured. The measured concentration was empirically systematized by comparative data analysis. Therefore, a mean concentration within a certain height above the wall was calculated. Also a normed blowing rate was used to include the molar masses of coolant and cross flow. With this mean concentration a cooling effectiveness is calculated based on a balance model and compared to the results in the literature. As a result of the data evaluation, the hole’s angle was found to have a minor influence on the mean coolant concentration. An angle of about 30° is a good compromise between production effort and cooling efficiency. Also coolant fluids with a low molar mass and high specific heat capacity should be preferred because of their low impact on the boundary layer.

På uppdrag av Sundsvall Energi AB har FVB Sverige AB påbörjat en förstudie kring etableringen av fjärrkyla i Sundsvall. Produktionsmedlen i det planerade nätet kommer att innefatta frikyla från akviferen och en kompressordriven kylmaskin. Det övergripande syftet med projektet har dels varit att ta fram en optimal framledningskurva, samt att ta reda på i vilken utsträckning frikylan kan nyttjas innan kylmaskinen måste användas som spetsproduktionsmedel. Projektet har inledningsvis fokuserat på att undersöka hur klimatet och kylbehovet ser uti Sundsvall. Kylbehovet granskades utifrån sex befintliga byggnader som nyttjar dricksvattenkyld fjärrkyla i Sundsvall. Därefter undersöktes olika typer av klimatsystem för att utröna vad de har för krav på framledningstemperaturen. Det konstaterades att kylbatterier var den komponent som kräver lägst framledningstemperatur, varför kyleffektberäkningar utfördes på dem. Resultatet ur kylbatteriberäkningarna fick motsvara den av fjärrkylenätet avgivna kyleffekten vid varierande utomhustemperatur. Genom att väga den avgivna kyleffekten vid varierande framledningstemperatur mot det erforderliga kyleffektbehovet vid varierande utomhustemperatur kunde framledningskurvan ta form. Akviferen antas hålla en temperatur på omkring 7°C till 9°C året runt, men utgångspunkten i detta projekt har varit att den konstant är 9°C. Under de förutsättningarna har framledningstemperaturen kunnat bestämmas till att vara 11°C under större delen av året, men att den sänks vid en utomhustemperatur på omkring 21°C i varierande grad ned till 6°C vid utomhustemperaturen 25°C. Med hjälp av framledningskurvan kunde därefter frikylans täckningsgrad bedömas. Resultatet visar att om framledningens temperatur höjs med 0,5–1,0°C i distributionsnätet kommer kylmaskinen att behöva vara i drift under 159 timmar per år. Om istället uppvärmningen blir 1,5° eller 2,0°C kommer kylmaskinen behöva vara i drift under 233 timmar respektive 325 timmar. Sammantaget har samtliga av projektets konkreta och verifierbara mål besvarats. / On behalf of Sundsvall Energi AB, FVB Sverige AB has initiated a preliminary study on the establishment of a district cooling system in Sundsvall. The main source for the cooling will be cool water drawn from the aquifer and a compressor chiller. The main purpose of this project has both been to provide the optimal supply temperature of the cooling network at different outdoor temperatures, and to find out to what extent the cool water from the aquifer can be used by itself as the cooling source. The project was initially focused on examining the climate and cooling demand in Sundsvall. The cooling demand was examined on the basis of six existing buildings that uses freshwater district cooling, and different types of climatesystems were then examined to ascertain what their requirements for the supply temperature are. Cooling coil batteries were found to be the component that requires the lowest supply temperature; therefore, the cooling power calculations were relied on them. The outcome of the cooling coil battery calculations was presumed to correspond to the cooling power of the network itself. By comparing the cooling power of the coil batteries at different supply temperatures and the cooling demand at different outdoor temperatures the main supply temperature for the district cooling network took shape. The aquifer is expected to maintain a temperature of approximately 7°C to 9°C, but in this project the temperature is set to exactly 9°C. On those premises the supply temperature of the cooling network could be set to 11°C for most of the year, but with a reduction of the supply temperature at outdoor temperatures around 21°C. Subsequently the supply temperature is reduced to 6°C at the outdoor temperature 25°C. Via the supply temperature curve, the aquifer cooling coverage ratio could be assessed. The result shows that if the supply temperature is raised between 0,5°C and 1,0°C in the distribution network the compressor chiller will have to be in operation for 159 hours per year. If instead the supply temperature is raised 1,5°C or 2,0°C, the compressor chiller must be in operation for 233 hours and 325 hours, respectively. In summary, all the goals and targets of the project have been completed.

Atualmente, o processamento de dados é uma operação vital para os negócios de qualquer companhia, indústria ou prestador de serviços. Entretanto, os servidores em operação, dissipam energia térmica, aquecendo o ambiente, podendo ocasionar problemas operacionais, como funcionamento inadequado, paradas operacionais e até incêndios. Por isso, é necessário um sistema de condicionamento de ar para controlar de temperatura e umidade ambiental, entretanto o consumo de energia elétrica deste sistema aumenta o custo operacional da instalação, sendo necessário minimizá-lo. Baseado neste fato, esta tese avalia a aplicação de 2 tipos de sistemas de resfriamento solar, absorção térmica solar e fotovoltaico, para reduzir o consumo do tradicional sistema elétrico com unidades de resfriamento elétricas operadas por compressão de vapor, apresentando economias, disponibilidade diária e vantagens em uma sala de missão crítica localiza genericamente, em São Paulo, Abu Dhabi, Los Angeles e Nova York. Além disto, analisa a contribuição de sistemas de resfriamento natural e seus efeitos sobre carga e consumo. As densidades de carga propostas foram de 0,5 kW?m-², 1,0 kW?m-², 2,0 kW?m-², 4,0 kW?m-² e 8,0 kW/m. Os índices locais de irradiação e temperaturas anuais baseiam-se nos dados apresentados no banco de dados da ASHRAE para as localidades. Os resultados, válidos para um ano típico e são comparados com (1) Sala de missão crítica acionada por um sistema convencional, (2) combinação de métodos de resfriamento solar, (3) combinação de técnicas solares e resfriamento natural. Por meio de estimativas anuais, calculando as contribuições dos métodos de resfriamento solar e natural, concluiu- maioria dos casos o método de absorção solar apresenta maiores vantagens de economia de energia e retorno de investimento que o método fotovoltaico, especialmente quando associado ao resfriamento natural indireto. Ao final, conclui-se que a utilização de resfriamento solar, pode atingir a 50% de economia na conta de energia e um TIR de 25%. Quando associado a sistemas de resfriamento natural, a economia pode atingir valores de 68% de economia e um TIR de 134%. Para tal deverá ser observado a carga aplicada, o valor de investimento e a curva característica da unidade de resfriamento que irá complementar a carga. / Nowadays, data processing is a fundamental operation for modern business such as banks, technology companies, and factories, among others. However, computers dissipate non-negligible amounts of heat and as the operating temperature increases, these machines cannot operate properly or, under extreme conditions, can come to a stop by overheating. Consequently, it is necessary air conditioning systems to keep the proper operating temperature as well as the room temperature itself. On the other hand, a data center air conditioning system drains a large amount of electrical energy in the installation. Based on this, this thesis evaluates two types of solar cooling system, an absorption thermal system, and a photovoltaic system, to support the traditional electric chiller system showing the energy saving, advantage over conventional cooling and day availability for this system. In addition, it analyzed free cooling system contribution and his effects on consumption. A case study is analyzed in a generic data center located in the city of São Paulo, Abu Dhabi, Los Angeles, and New York. At first, the electrical power density simulated by the computers is 0.5 kW/m², 1.0 kW/m² 2.0 kW/m², 4.0 kW/m² and 8 kW/m², that would occur in half loads or in high loads computer installations. Local solar irradiation and temperature indexes are based on the ASHRAE database. The results are valid for a typical year and are compared to (1) a conventional data center; (2) the event combination of solar cooling; (3) the event combination of solar cooling and free cooling. In conclusion, the energy savings, payback and internal rate of return for 10 years are presented. In the main cases, the solar absorption takes advantage than photovoltaic cooling, However, It must be observed the load replicated and the influence on the work curve of the chiller and the beginning investment. In conclusion, the solar cooling, especially solar absorption can achieve great advantage to installation, resulting in 50% on savings in the electric bill a return internal rate for 10 years of 25%. When it is associated with free cooling this savings can achieve 68% and return rate of 134%.

Com base em um modelo fenomenológico e a partir de dados experimentais obtidos numa planta piloto, foi obtida uma correlação entre o desempenho de uma torre de resfriamento em função das principais variáveis de processo: fluxos mássicos do gás e da água pela torre, e temperatura de entrada da água. Os resultados apresentaram boa consistência, comparados com os da literatura. A metodologia desenvolvida pode, com relativa facilidade, ser aplicada para torres de resfriamento industriais, pois se baseia em medidas de variáveis, factíveis em termos práticos. Efetuou-se também um estudo paralelo com base em modelagem e simulações matemáticas do comportamento de uma torre de resfriamento de água em condições severas, com temperatura da água de alimentação superior a 50°C. Constatou-se que o coeficiente de transporte de massa na torre de resfriamento aparentemente não é afetado. / Cooling towers are widely used in many industrial and utility plants and its thermal performance is of vital importance. In the present work, using a phenomenological model and by experiments carried on over a pilot installation, the mass transfer coefficient dependence of air and water flow rates and inlet cooling water temperature is determined. The approach proposed may be useful in addition for characterization of industrial cooling towers since it depends on temperature and flow rate measurement usually available in typical plants. A parallel study concerning high mass transfer rate theory is accomplished. Through mathematical modeling and simulations based on this study no influence is detected on the mass transfer coefficient in the cooling tower, operating under harsh conditions with inlet water temperature up to 90°C.

Atualmente, o processamento de dados é uma operação vital para os negócios de qualquer companhia, indústria ou prestador de serviços. Entretanto, os servidores em operação, dissipam energia térmica, aquecendo o ambiente, podendo ocasionar problemas operacionais, como funcionamento inadequado, paradas operacionais e até incêndios. Por isso, é necessário um sistema de condicionamento de ar para controlar de temperatura e umidade ambiental, entretanto o consumo de energia elétrica deste sistema aumenta o custo operacional da instalação, sendo necessário minimizá-lo. Baseado neste fato, esta tese avalia a aplicação de 2 tipos de sistemas de resfriamento solar, absorção térmica solar e fotovoltaico, para reduzir o consumo do tradicional sistema elétrico com unidades de resfriamento elétricas operadas por compressão de vapor, apresentando economias, disponibilidade diária e vantagens em uma sala de missão crítica localiza genericamente, em São Paulo, Abu Dhabi, Los Angeles e Nova York. Além disto, analisa a contribuição de sistemas de resfriamento natural e seus efeitos sobre carga e consumo. As densidades de carga propostas foram de 0,5 kW?m-², 1,0 kW?m-², 2,0 kW?m-², 4,0 kW?m-² e 8,0 kW/m. Os índices locais de irradiação e temperaturas anuais baseiam-se nos dados apresentados no banco de dados da ASHRAE para as localidades. Os resultados, válidos para um ano típico e são comparados com (1) Sala de missão crítica acionada por um sistema convencional, (2) combinação de métodos de resfriamento solar, (3) combinação de técnicas solares e resfriamento natural. Por meio de estimativas anuais, calculando as contribuições dos métodos de resfriamento solar e natural, concluiu- maioria dos casos o método de absorção solar apresenta maiores vantagens de economia de energia e retorno de investimento que o método fotovoltaico, especialmente quando associado ao resfriamento natural indireto. Ao final, conclui-se que a utilização de resfriamento solar, pode atingir a 50% de economia na conta de energia e um TIR de 25%. Quando associado a sistemas de resfriamento natural, a economia pode atingir valores de 68% de economia e um TIR de 134%. Para tal deverá ser observado a carga aplicada, o valor de investimento e a curva característica da unidade de resfriamento que irá complementar a carga. / Nowadays, data processing is a fundamental operation for modern business such as banks, technology companies, and factories, among others. However, computers dissipate non-negligible amounts of heat and as the operating temperature increases, these machines cannot operate properly or, under extreme conditions, can come to a stop by overheating. Consequently, it is necessary air conditioning systems to keep the proper operating temperature as well as the room temperature itself. On the other hand, a data center air conditioning system drains a large amount of electrical energy in the installation. Based on this, this thesis evaluates two types of solar cooling system, an absorption thermal system, and a photovoltaic system, to support the traditional electric chiller system showing the energy saving, advantage over conventional cooling and day availability for this system. In addition, it analyzed free cooling system contribution and his effects on consumption. A case study is analyzed in a generic data center located in the city of São Paulo, Abu Dhabi, Los Angeles, and New York. At first, the electrical power density simulated by the computers is 0.5 kW/m², 1.0 kW/m² 2.0 kW/m², 4.0 kW/m² and 8 kW/m², that would occur in half loads or in high loads computer installations. Local solar irradiation and temperature indexes are based on the ASHRAE database. The results are valid for a typical year and are compared to (1) a conventional data center; (2) the event combination of solar cooling; (3) the event combination of solar cooling and free cooling. In conclusion, the energy savings, payback and internal rate of return for 10 years are presented. In the main cases, the solar absorption takes advantage than photovoltaic cooling, However, It must be observed the load replicated and the influence on the work curve of the chiller and the beginning investment. In conclusion, the solar cooling, especially solar absorption can achieve great advantage to installation, resulting in 50% on savings in the electric bill a return internal rate for 10 years of 25%. When it is associated with free cooling this savings can achieve 68% and return rate of 134%.