The Heating, Ventilation and Air Conditioning (HVAC) systems are nowadays in almost every new building, develop or improve better control strategies for them is very common, looking to have more energy efficiency and require less input parameters from the user. In this project, new control strategies based in previous theory models has been used with a new approach in order to find a good solution for irregular occupied spaces. In this new approach a feed-forward filter with a fixed preheating time, using an algorithm based on an identified model, calculates how much degrees the temperature room can be decreased and regulate the power of the radiators to do it.The results of this project displays that the chosen model have to be changed but the idea is interesting, because the simulations of the reference building give, with a preheating timeof 2 hours, around 3ºC of temperature reduction during 18 days and savings of 33% of the heat energy needed for the whole month.Considering that buildings and the residential sector currently account for 40 percent of Sweden's energy consumption and around 25 percent of other countries like USA or Spain, and that irregular spaces are more or less a 10% of the governmental, institutional, academic or public buildings, the potential savings are not negligible. The evaluation of this control strategy with its mathematical model as well as its resultsduring the month of January and the behavior of the system along the year have been made with the help of IDA program for simulation of the reference building and its energy system.

The aim of diploma thesis is describes the design of heating in a primary school in Trenčín. In this project are two variants of the heat source. The first variant is heat pump of an air/water of split design and second variant is two gas condensing boilers. The thesis includes hot water preparation. In the experimental part of the thesis is deals with heating output of radiators.

This theses deals with large objects heating issue, more precisely, heating of industrial halls. The theses focuses primarily on the most effective way of heating, given the economical and hygienical functionality of the object. Heating options of the object and selection of the most appropriate one, according to the specified documents, are also mentioned in this work.

The introduction of theoretical part deals history of floor heating. Here is an overview of the technology, which was for centuries used for floor heating. Further included in the introductory part of the aggregate materials used, which are used for floor heating, and used. In the next part of the theoretical introduction we are given the best known ecological heat source. These are mainly heat pumps and solar collectors. The last part is made in the proposal which are important values calculated for the design and seamless use of central heating system.

My diploma thesis deals with heating with the aid of renewable energy sources and thier application in the building of elementary school. This thesis is devided into three parts. The first part is theoretical and is focused on overview of renewable energy sources. It deals with biomass boilers and heat pumps in detail. The second part of this thesis contains comparison of two variants of heat sources and necessary calculations and designs. The first variant is an air-to-water heat pump and the second one is a pellet boiler. The chosen variant is elaborated in detail in the last part. The last part contains technical drawings and technical report.

The aim of the diploma thesis is to design heating and hot water preparation in a complex of buildings consisting of retail space and two residential buildings. Retail space is heated using VRF system and apartment blocks are heated by gas boilers located in the mechanical room in the basement. Gas boilers are connected to heating system and storage water he-ater. The heating surface is created by tabular and tubular heating units. Heat consumption in apartments is measured by calorimeters with remote data collection system. The temperatu-re in each flat is controlled by an electrically powered zone valve.

In dieser Arbeit wird das Verhalten der Störstrahlung großer Prüflinge untersucht mit dem Ziel, vorhandene Standards für Störstrahlungstests wie CISPR 16 zu verbessern. Diese Arbeit sieht als Standardtestumgebung einen reflektierenden, ausgedehnten Grund vor, auf dem sich der Prüfling befindet. Die Strahlung, die dieser aussendet, wird durch die Verteilung der elektrischen Feldstärke auf einer Testhalbkugel oberhalb des Grunds bewertet. Ihr Zentrum befindet sich am Fußpunkt des Prüflings. Eine solche Halbkugel stellt nahezu gleiche Abstände von etwa der Länge des Kugelradius' zwischen dem Prüfling und den auf ihr definierten Meßpunkten her. Da die Halbkugel geschlossen ist, kann auf ihr das gesamte vom Prüfling nach außen gestrahlte Feld nachgewiesen werden. Meßabstände mit in Normen vorgegebenen Längen sind in der Praxis nicht immer einzuhalten, vor allem dann, wenn sich Prüflinge in einer normalen Betriebsumgebung befinden. In beengten Umgebungen ist es hilfreich, Meßabstände zu verkürzen. Hieraus ergibt sich eine kleinere Testhalbkugel, die sich leichter abtasten läßt. Bei kurzen Meßabständen jedoch können Meßsonden in das Nahfeld des Prüflings ragen. Für diesen Fall werden in dieser Arbeit Feldeigenschaften in Prüflingsnähe untersucht. Aus denen ergeben sich Mindestabstände zum Prüfling, jenseits derer sich gemessene Feldstärkewerte zu größeren, in Normen vorgegebenen Abständen extrapolieren lassen. Um die Verteilung der Feldstärke auf einer Testfläche zu beschreiben, wird der Begriff der Halbwertsfläche eingeführt: Die Halbwertsfläche definiert jenen Teil der Testfläche, auf dem die Dichte der abgestrahlten Leistung mindestens die Hälfte ihres Maximums beträgt. Die Halbwertsfläche ergibt sich aus der Richtwirkung des Prüflings als Strahler. Sie ist somit ein Maß für die Wahrscheinlichkeit, auf der Testfläche das Strahlungsmaximum zu finden. Aus der Größe der Halbwertsfläche ergibt sich die nötige Anzahl an gleichmäßig auf der Testfläche verteilten Meßpunkten, um das Strahlungsmaximum mit gegebener Wahrscheinlichkeit zu finden. Wird an den Meßpunkten die Größe der Feldstärke berücksichtigt, läßt sich die Anzahl der Meßpunkte optimieren und das Vertrauen in den Test erhöhen. Als ein erster Schritt zur Entwicklung einer praktikablen Strahlungstestmethode wird die Testdrahtmethode untersucht. Bei dieser Methode wird Strahlung mit einem langen, um den Prüfling herum gespannten Draht erfaßt. Die Strahlung induziert in dem Draht einen Strom, der an den Drahtabschlüssen gemessen werden kann. Weil der Draht i. allg. lang ist, ist er sehr meßempfindlich. Ist er jedoch länger als eine Wellenlänge des abgestrahlten Felds, sind sein Übertragungsfaktor und damit die Meßergebnisse schwer zu bestimmen. Statistische Methoden der Auswertung werden hierzu untersucht. Ein System aus kleinen Meßsonden kann denselben Teil des Prüflings abdecken wie ein Testdraht. Weil als Übertragungsfaktor eines solchen Systems der einer Einzelsonde wirksam ist, lassen sich Ergebnisse aus Messungen mit einem solchen System leichter auswerten. Jedoch ist die Empfindlichkeit kleiner Sonden i. allg. gering. Der Weg zu einer praktischen Anwendung führt somit vorerst in die Richtung herkömmlicher Meßantennen, die in einem beweglichen System geeignete Testflächen abtasten. - (Die Dissertation ist veröffentlicht im Jörg Vogt Verlag, Dresden, Deutschland, http://www.vogtverlag.de, ISBN: 978-3-938860-25-0) / In this work the behavior of radiation emitted by large equipment is investigated. The aim of investigation is to improve existing standardized radiation tests. The radiation from an EUT (equipment under test) placed on reflecting ground is described by the distribution of the electric field strength on a hemispheric test area, which encloses the EUT placed in its center. This kind of area guarantees a nearly equal measurement distance to the EUT from every point defined on it. This distance is defined by the radius of the hemisphere. However, measurement distances according to standards are difficult to realize. Because of practical constraints shorter distances will become useful. This requires a smaller test area, to be scanned more easily. At shorter measurement distances field probes are possibly located in the near field of the EUT. Therefore this work investigates the behavior of the field in the vicinity of the EUT to find an adequate transition point, beyond which, field strength values can be extrapolated to distances instructed by standards with confident results. An important parameter of the field strength distribution is the half-power area. It defines that part of the test area where the radiated power exceeds the half of its maximum. The half-power area is related to the directivity of the EUT, which can be approximated by antenna theory or statistics. If the directivity of the EUT is high, the half-power area is small, and the probability to find the field maximum on the test area is low. The size of the half-power area yields to a least number of observation points, equally distributed on the test area, to find the field maximum with a high level of confidence. If the field strength measured at any observation point is considered, the distance to other observation points can be optimized, and the level of confidence in the test can be increased. As a first step in developing a practicable field scanning method is highlighted: the test wire method. This method establishes a measurement executed by a long wire which covers the EUT. At its terminations current can be measured induced by the radiation. Because the wire is long it is very sensitive. However, if it is longer than one wave length of the radiation, the evaluation of results is difficult because of an uncertain transmission factor. Therefore, some statistic methods are applied to describe the behavior of results and their maxima. Also a system of small probes, e. g. short dipoles, can cover the same part of the EUT as a test wire. The measurement with small probes can be evaluated more easily because of a unique transmission factor. However, their sensitivity is lower.

No / New representations and efficient calculation methods are derived for the problem of propagation from an infinite regularly spaced array of coherent line sources above a homogeneous impedance plane, and for the Green's function for sound propagation in the canyon formed by two infinitely high, parallel rigid or sound soft walls and an impedance ground surface. The infinite sum of source contributions is replaced by a finite sum and the remainder is expressed as a Laplace-type integral. A pole subtraction technique is used to remove poles in the integrand which lie near the path of integration, obtaining a smooth integrand, more suitable for numerical integration, and a specific numerical integration method is proposed. Numerical experiments show highly accurate results across the frequency spectrum for a range of ground surface types. It is expected that the methods proposed will prove useful in boundary element modeling of noise propagation in canyon streets and in ducts, and for problems of scattering by periodic surfaces.

The high complexity of vehicle front-end design, arising from considerations of aerodynamics, safety and styling, causes the airflow velocity profile at the radiator face to be highly distorted, leading to potentially reduced airflow volume for heat dissipation. A flow visualisation study showed that the bumper bar significantly influenced the cooling airflow, leading to three-dimensional vortices in its wake and generating an area of relatively low velocity across at least one third of the radiator core. Since repeatability and accuracy of on-road testing are prejudiced by weather conditions, wind-tunnel testing is often preferred to solve cooling airflow problems. However, there are constraints that limit the accuracy of reproducing on-road cooling performance from wind-tunnel simulations. These constraints included inability to simulate atmospheric conditions, limited tunnel test section sizes (blockage effects) and lack of ground effect simulations. The work presented in this thesis involved use of on-road and wind-tunnel tests to investigate the effects of most common constraints present in wind tunnels on accuracy of the simulations of engine cooling performance and radiator airflow profiles. To aid this investigation, an experimental technique for quantifying radiator airflow velocity distribution and an analytical model for predicting the heat dissipation rate of a radiator were developed. A four-hole dynamic pressure probe (TFI Cobra probe) was also used to document flow fields in proximity to a section of radiator core in a wind tunnel in order to investigate the effect of airflow maldistribution on radiator heat-transfer performance. In order to cope with the inability to simulate ambient temperature, the technique of Specific Dissipation (SD) was used, which had previously been shown to overcome this problem.

Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-12-22T12:14:15Z No. of bitstreams: 0 / Made available in DSpace on 2016-12-22T12:14:15Z (GMT). No. of bitstreams: 0 / A irradiação de alimentos é um meio de preservação de alimentos onde se utiliza uma técnica de processamento que expõe os alimentos a uma radiação ionizante controlada de alta energia. O tratamento realizado com o uso das radiações ionizantes em alimentos tem muitas aplicações tecnologicamente e tecnicamente viáveis incluindo a capacidade de melhorar a segurança microbiológica, reduzir os níveis de bactérias patogénicas, inibir a germinação de tubérculos, aplicação fitossanitária, conservar alimentos armazenados ou a estabilidade de armazenamento e também é utilizada para aumentar a vida de prateleira de determinados produtos devido à redução da contaminação por microrganismos. Em função do aumento do comércio internacional de alimentos e das crescentes exigências regulatórias dos mercados consumidores, cada vez mais países importadores e exportadores têm demonstrando interesse na irradiação de alimentos e desenvolvido pesquisas na aplicação prática desta tecnologia e de métodos de detecção do tratamento. Inúmeras pesquisas foram realizadas mundialmente, resultando em eficientes protocolos para identificar quais alimentos foram ou não irradiados. Até então, o \"mito\" que alimentos irradiados não poderiam ser detectados e que não eram formados quaisquer produtos únicos da radiação foi substituído pelo conhecimento que muitas mudanças podem ocorrer nos alimentos irradiados e essas mudanças poderiam ser utilizadas como ferramentas para identificar essa tecnologia. O processamento por radiação resulta em formações de padrões característicos de hidrocarbonetos saturados, aldeídos, metil e etil ésteres e 2-alcilciclobutanonas, dependendo da composição do ácido graxo do lipídio que compõe o alimento. Com isso a proposta do trabalho foi levantar dados para comparar os efeitos das diferentes doses de radiação gama e de elétrons em alimentos que possuem gordura para verificar as possíveis alterações decorrentes do uso da irradiação, como a presença de 2-Alcilciclobutanonas e também, mostrar os principais equipamentos utilizados para a irradiação de alimentos e suas categorias, com o objetivo de informar o publico em geral. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP