The work deals with development and assembly of ultrasonic airflow measurement module for measurement of air flowing around photovoltaic panel. This system allows quantification of photovoltaic panel air cooling. The work contains development of sine wave generator, bridge amplifier and receiver with passive band pass filter, amplifier and comparator. It also deals with digital part realization. This digital part is formed by Renesas 78K0R microcontroller on demo board. The last part of this work contains testing of the whole system in aerodynamic tunnel and on photovoltaic panel installation.

This thesis is concerned with the cooling of electronic component. The work focuses on contemporary design of LED signal functions used in modern automotive headlamps and a on new design solution for the DRL function in the headlamp Skoda Octavia, including the use of alternative materials for cooler.

No description available.

There is a need to counteract economic injustice in the world. As an architect, as a creator, it is my responsibility to make the world a better place. I want to help people to help themselves by concentrating their efforts in a constructive way. I desire to create a prototypical solution for a village in an area with high unemployment and desperate poverty as a means to give work to people and to serve as an example for other groups of people wanting to do the same. The site I've chosen to illustrate this concept of self-help housing is a 300 x 500 meter plateau in Tegucigalpa, Honduras. / Master of Architecture

Thesis (MEng) -- Stellenbosch University, 2014. / ENGLISH ABSTRACT: This project investigates aspects of a novel inherently safe nuclear power steam supply system as safety is of paramount importance. The system envisaged has unique features namely: a) a two-phase flow flash-tube type natural circulating primary loop (also the secondary radioactive particle containment); b) a twophase flow thermosyphon heat pipe type heat exchanger secondary loop is used to transfer heat from the primary loop to the steam generators, thereby physically separating the two flow streams from one another; c) a natural convection air cooled condenser for the removal of the reactor’s residual heat; d) a unique core using TRISO type fuel (acting as the primary radioactive particle containment) with life of at least 8.9 years; e) a steel containment vessel acting as a tertiary radioactive product containment; f) a concrete containing structure with air vents to allow air to pass over the main steel containment vessel for cooling purposes in the case of an emergency, and for the removal of parasitic heat during operation. In particular the primary and secondary loops of the proposed system are investigated. This is done by design, construction and testing of a small scale experimental set-up of the primary and secondary loops as well as the development of theoretical models for the two loops. A literature survey focusing on nuclear technology, thermosyphon loops, natural circulating loop instabilities, heat pipes, and two-phase flow modelling is presented to give a brief overview of the technologies as well as tools used in the work undertaken. Observations of the inside flow behaviour of the primary loop experimental set-up were made possible by windows providing many insights into the inner workings, such as plume formation and geysering. The transient response of the secondary heat pipe loop start-up is also investigated. A thermal resistance theoretical model was developed for the secondary loop using heat transfer formulae from theory as well as experimentally semiempirical correlated formula. Different states of operation of the secondary loop were observed during testing with the theoretical model of the condensing regime correlating well, two-phase regime correlating acceptably and liquid regime correlating poorly to experimental results and thus were modelled using an experimentally determined overall heat transfer coefficient. The secondary loop model of the liquid regime is coupled with the primary loop theoretical model to predict the system’s performance. A homogeneous, one-dimensional, simple theoretical model for the primary loop was derived and computer simulated. The results did not compare well with experimental results for single phase flow and failed to capture the onset of two-phase flow. The assumptions of one dimensional model with a unidirectional flow, a hydrostatic pressure problem, a constant volumetric flow rate and the inability of the implementation of the code to handle expansion are noted as some of the flaws in the theoretical model. The following recommendations are made: a more advanced design of the pressuriser should be incorporated into the experiment; the secondary loop’s theoretical model should be characterised under a broader set of operating conditions; the computer program can be used as the basis for further research and implementation of alternative solution algorithms and models. / AFRIKKANSE OPSOMMING: Hierdie projek ondersoek aspekte van ’n ongewone, essensieel veilige kernkrag stoomtoevoer-stelsel, omdat veiligheid van kardinale belang is. Die stelsel wat voorgestel is, het unieke eienskappe, naamlik: a) ’n twee-fasevloei flits-buistipe natuurlik sirkulerende primêre lus (wat ook die sekondêre inperking van radioaktiewe materiaal bevat); b) ’n twee-fasevloei termo-heweleffek sekondêre lus hitte-pyp hitte-uitruiler word gebruik om die hitte vanaf die primêre lus oor te dra na die stoomkragopwekkers en daardeur word die twee strome se vloei fisies geskei van mekaar; c) ’n natuurlike konveksie lugverkoelde kondensor word gebruik vir die verwydering van die reaktors se oortollige hitte; d) ’n unieke kern gebruik TRISO-tipe brandstof (wat as die primêre inperking van radioaktiewe materiaal optree) met ’n lewe van minstens 8.9 jaar; e) ’n inperkingshouer van staal wat optree as ’n tersiêre radioaktiewe produkhouer; f) ’n betonstruktuur met lugventilasie om toe te laat dat lug oor die hoof staalhouer vloei vir verkoeling in ’n noodgeval, en vir die verwydering van parasitiese hitte tydens werking. Hoofsaaklik word die primêre en sekondêre lusse van die voorgestelde stelsel ondersoek. Dit word gedoen deur die ontwerp, konstruksie en die toets van ’n eksperimentele opstelling van die primêre en sekondêre lusse op klein skaal, sowel as die ontwikkeling van teoretiese modelle vir die twee lusse. ’n Literatuurstudie wat fokus op kerntegnologie, termo-heweleffeklusse, natuurlik sirkulerende lus instabiliteit, hitte-pype, en twee-fase vloeimodellering word aangebied om ’n kort oorsig te gee van die tegnologie, sowel as gereedskap gebruik in die werk wat onderneem is. Om die interne vloeigedrag van die primêre lus se eksperimentele opstelling waar te neem, word daar gebruik gemaak van vensters wat dien as ’n manier om die innerlike werking van die proses soos pluimvorming en die kook van die water in die warmwaterkolom te toon. Die oorgangsreaksie van die sekondêre hittepyplus aanvangs is ook ondersoek. ’n Teoretiese termiese weerstandmodel is ontwikkel vir die sekondêre lus met behulp van hitte-oordragformules waarvoor hitte-oordragteorie gebruik is, wat met eksperimentele semi-empiriese formules gekorreleer is. Verskillende toestande van die sekondêre lus se werking is waargeneem gedurende die toetse. Die teoretiese model het goed met die kondensasiestaat gekorreleer, terwyl by die twee-fasewerkswyse aanvaarbare korrellasies aangetref is en die uiteindelike vloeitoestand swakker gekorrelleer het met eksperimentele resultate en dus gemodelleer is met behulp van die NTU-effektiwiteitsmetode. Die sekondêre lusmodel van die vloeistoftoestand is gekoppel met die primêre lus teoretiese model om die werking van die stelsels te voorspel. ’n Homogene een-dimensionele eenvoudige teoretiese model van die primêre lus is afgelei en ’n rekenaar simulasie is uitgevoer. Die resultate vergelyk nie goed met die eksperimentele resultate vir enkelfasevloei en kon nie die aanvang van twee-fasevloei beskryf nie. Die aannemings van ’n een-dimensionele model met eenrigting vloei, ’n hidrostatiese druk probleem, ’n konstant volumetries vloeitempo en die onvermoë van die implementering van die kode om uitbreiding te hanteer is bekend as ’n paar van die foute in die teoretiese model. Die volgende aanbevelings word gemaak: ’n meer gevorderde ontwerp van drukreëlaar moet in die eksperiment ingesluit word; die sekondêre lus se teoretiese model moet gekenmerk word onder ’n wyer stel bedryfsomstandighede, en die rekenaar program kan gebruik word as die basis vir verdere navorsing en die implementering van alternatiewe algoritmes en modelle.

Dans les pays de l’Afrique sub-saharienne, la situation énergétique, le fort taux d’accroissement des aires urbaines, l’inadaptation des techniques de construction et le climat offrent un grand potentiel pour la démarche bioclimatique et la construction durable notamment sur le plan énergétique. Cependant ce potentiel est faiblement exploré. Pour ce faire, cela passe par une bonne connaissance du comportement des bâtiments et par leur adaptation au contexte climatique. Dans le cadre de notre contribution à cette problématique, une étude sur le comportement thermique des bâtiments est initiée grâce à la simulation. En effet la simulation des performances énergétiques du bâtiment devient de plus en plus incontournable dans les processus de conception et d’analyse des bâtiments à travers le monde. Dans ce travail les outils de simulation des performances énergétiques ainsi que les outils d’optimisation sont utilisés pour mener des investigations sur un bâtiment type construit en matériaux conventionnels au Burkina Faso suivant deux principales approches. Dans la première approche le modèle numérique du bâtiment est confronté aux mesures issues de l’expérimentation sur le bâtiment réel. Une méthodologie de calibration basée sur l’analyse de sensibilité et l’optimisation des paramètres a été appliquée pour la comparaison des résultats. Cela a permis de caler le modèle et des études diagnostiques sont réalisées. Dans la seconde approche, des investigations sur des solutions d’amélioration des performances du bâtiment sont réalisées à travers l’application de la simulation dynamique comme outils d’aide à la conception. Les techniques d’interopérabilité et d’optimisation sont utilisées pour implémenter les solutions de refroidissement passif dont les impacts sur le bâtiment étudié sont évalués. Enfin dans ce travail, des techniques d’analyse du bâtiment et des critères de performance sont utilisées pour caractériser et formuler des recommandations sur la conception des bâtiments dans notre contexte climatique. / In sub-Saharan African countries, the energy context, the high urban growth, inadequate construction techniques and climate offer great potential for bio-climatic approach and sustainable construction particularly on the energy level. However, this potential and the use of passive cooling techniques are weakly explored. To do so, it requires a good knowledge of building’s behaviour and their adaptation to the climatic context. As part of our contribution to this issue, a study on the thermal behaviour of buildings is initiated by numerical simulation. Indeed the building’s energy performance simulation tools are becoming more essential in the building’s design processes and analysis. Investigations are conducted on a building built with typical materials in Burkina Faso by following two main approaches. In the first approach a model of the building is faced with measurements from field experiments on the building. A calibration methodology based on the sensitivity analysis and optimization has been applied for the comparison of results. This helped to calibrate the model and diagnostic studies are performed.In the second approach, investigations on methods which can help to improve the building performance are realized through the application building performance simulation as a design aid tool. Interoperability and optimization techniques are used to deal with passive cooling techniques and their impacts on the building thermal behaviour are assessed. Finally in this work analysis techniques and performance criteria are used to characterize and make recommendations on building designs for the tropical climate context.

<p>Nowadays, office buildings often have large temperature variations during the day and building envelope acts as an energy storing mass and damp these effects and so Offices need more cooling because of internal heat sources. But we know that cooling is more expensive than heating and it uses the very good quality of energy sources (exergy). Controlled Active Mass (CAM) is new approach to absorb radiant heating and acts as a passive cooling device. It has direct cooling effect and reduces the peak load. CAM is a new cooling system design with applying the low energy sources and operates at water temperature close to room temperature and increase the efficiency of heat pumps and other systems.</p><p>In this project, we calculated the transient heat transfer analysis for CAM in a very well insulated test room with façade wall, Internal heat generators (such as Manikin, Computer simulator & lighting) and ventilation.</p><p>Then Polished (shiny) CAM constructed from Aluminum sheets with 0.003 m thickness. It is cube shape with 0.6 m length. This size of CAM is according to 2.5 times larger than human body volume and initial water temperature assumed near half of human body temperature. Then in order to more radiation damping (absorption) by CAM, it painted black (also based on color analysis in heat transfer calculation).</p><p>Some velocity and temperature measurement have been carried out on both polished CAM and black CAM, after visualization by smoke and Infrared Camera. And more cases tested to see the effect of façade wall, IHG’s and ventilation inlet temperature. Thermal comfort measurement also have been done for finding PMV, PPD and temperature equivalent for a seated person which is doing an office job with normal closing.</p><p>At the end results discussed which includes the effect of CAM in room, differences between polished CAM and black CAM and effect of main heat sources on both CAM types (Polished / Black).</p>

In today’s increasingly energy conscious society, the methods of providing thermal comfort to humans are constantly under scrutiny. Depending on the climate, and the comfort requirements of the occupants, buildings can be designed to heat and cool occupants with passive methods, as well as mechanical methods. In the subtropics, where buildings often need to be heated in the winter and cooled in the summer, a synthesis of these two methods would be ideal. However, there is a disconnect between the integration of passive cooling and mechanical air conditioning, in subtropical architecture. A study of user attitudes, based out of Australia, found that, “Central control of temperatures has been used to cut demand by preventing users from altering thermostats and other parts of the building for microclimate control. In particular, windows are sealed to prevent tampering.”1 Reliance on air conditioning has the everyday person convinced that if we save energy in the right places, we can use air conditioning as much as we like. The same study goes on to state, “Air-conditioning has been assumed to replace the need for climate design features in buildings creating poor thermal design and high energy use.”2 This can be most clearly seen in our public buildings. Fully conditioned buildings pump cool air into sealed envelopes, adjusting the thermostat to regulate thermal comfort year-round, often in a climate in which mechanical air conditioning is needed only four months of the year, and during the warmest hours of the day. Inversely, ventilated buildings provide passive cooling in a climate in which the temperature and humidity are often too high for thermal comfort during the same four months of the year. In his book Natural Ventilation in Buildings, Francis Allard points out that the global energy efficiency movement, begun in the early 1990s, has now emerged as a concept that incorporates active air conditioning and sitespecific climate design of buildings into one holistic approach.3 However, these buildings exist in more dry and temperate climates, and do not fully apply to the subtropics as cooling models. A model is needed for subtropical architecture allowing a building to reach both ends of the spectrum; from natural ventilation, through mechanical ventilation, to mechanical air conditioning. The goal of this thesis is to design a hybrid model for subtropical architecture which maximizes the use of natural and mechanical ventilation, and minimizes the use of mechanical air conditioning. The vehicle for this explanation is the design of an educational facility. Research of thermal comfort needs for occupants in the subtropics was accompanied with observation studies. This research was compared with case study, site and program analysis. The analysis was supplemented by a handbook of passive and mechanical cooling which was compiled to aid in establishing cooling strategies for the design process. The implementation of the research and analysis was brought to a conclusion that successfully achieved the goals of this thesis. By using passive methods to lower the temperature of the air surrounding the classroom buildings, the incoming air used to cool the occupants reached temperatures low enough to be considered comfortable inside the classrooms.

Nowadays, office buildings often have large temperature variations during the day and building envelope acts as an energy storing mass and damp these effects and so Offices need more cooling because of internal heat sources. But we know that cooling is more expensive than heating and it uses the very good quality of energy sources (exergy). Controlled Active Mass (CAM) is new approach to absorb radiant heating and acts as a passive cooling device. It has direct cooling effect and reduces the peak load. CAM is a new cooling system design with applying the low energy sources and operates at water temperature close to room temperature and increase the efficiency of heat pumps and other systems. In this project, we calculated the transient heat transfer analysis for CAM in a very well insulated test room with façade wall, Internal heat generators (such as Manikin, Computer simulator &amp; lighting) and ventilation. Then Polished (shiny) CAM constructed from Aluminum sheets with 0.003 m thickness. It is cube shape with 0.6 m length. This size of CAM is according to 2.5 times larger than human body volume and initial water temperature assumed near half of human body temperature. Then in order to more radiation damping (absorption) by CAM, it painted black (also based on color analysis in heat transfer calculation). Some velocity and temperature measurement have been carried out on both polished CAM and black CAM, after visualization by smoke and Infrared Camera. And more cases tested to see the effect of façade wall, IHG’s and ventilation inlet temperature. Thermal comfort measurement also have been done for finding PMV, PPD and temperature equivalent for a seated person which is doing an office job with normal closing. At the end results discussed which includes the effect of CAM in room, differences between polished CAM and black CAM and effect of main heat sources on both CAM types (Polished / Black).

No description available.