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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Návrh otopné soustavy s tepelným čerpadlem vzduch-voda a zdrojem na tuhá paliva pro vytápění rodinného domu / Design of a space heating system with a heat pump air-water and solid fuel source for heating the family house

Španihelová, Kateřina January 2014 (has links)
The aim of this thesis is to design the heating system for the house, including the design and calculating the required quantity of heat for hot water. The specified heat sources are the heat pump air to water and solid fuel boiler. The task was to design the heating system to the fastest possible return on investment. The initial investment in a heat pump is high so it is necessary to design the heating system as efficiently as possible. The thesis contains a complete project of calculating heat loss of the building, the design of heating surfaces and their heat-technical calculation. There is included the design of the pipe system, the calculation of pressure loss and its regulation. The thesis also includes design of safety equipment, temperature regulation and drawings. On the basis of calculated data was processed economic assessment, which determines the return on investment to the heat pump. Compared to the gas condensing boiler the return on investment will ideally be after five years.
22

Náhrada parovodu horkovodem v systému centrálního zásobování teplem teplárny Martinská teplárenská, a.s / Substitution of steam by hot water in heat distribution net

Mužila, Martin January 2014 (has links)
The work is focused on area of exchanging steam distribution net for hot water one, in central distribution net of Martin’s heating plant. The main subject, which talks about pros and cons in this exchange process, is determination of heat losses which are created on heat distribution net during different operating status. These heat losses are calculated and on their basis some conclusions are concluded. Moreover, new heat exchanger is designed for certain conditions and also mathematical model of distribution net is created, which is suitable for checking different operating status. As a result of the work is technic’s and economic’s analysis of this project.
23

Vytápění panelového domu tepelným čerpadlem / Block of Flat heating using heat pump

Šmarda, Milan January 2015 (has links)
Diploma thesis deals with change of heating source for a block of flats with aim to reduce heating costs. Thesis contains calculations of energy requirements of house, including requirements for heating and domestic hot water preparation. Several ways of heating by a heat pump were designed based on the calculated values. Each variant of the designed heating system is compared with current operational costs. Possible cost economies and maximum value of investment costs of the heating system were assessed
24

Vliv zateplení objektu na návrh zdroje tepla / Influence of thermal insulation on the building proposal heat

Šverák, Jakub January 2013 (has links)
This thesis deals with the influence of building insulation to design of the heat source. The theoretical part describes the historici evolution of the construction, insulation origins and basic concepts associated with heat loss calculations. Introduction to the practical part describes possible wals of rating proposal and construction and technical description of the new residential building Cacovická. The main part deals with "Influence of thermal insulation on the building proposal heat" performed in two different variants. Finally work is a comparison of the two variants and evaluation of lower cost options.
25

Návrh vytápění a vzduchotechniky novostavby s nízkými energetickými náklady / Design of heating and ventilation system for the building with low energy costs

Halm, Petr January 2016 (has links)
The thesis is aimed on a proposal from heating sources, heating systems and ventilation of family house. Designing of a house is provided by Keeo4design. This proposal contains a complex of two houses. The first one is used for residential purposes, the other is made up of mostly parking garages. The work focuses on heat loss calculation objects. Subsequently, on a proposal from heating sources, heating systems, ventilation systems and their regulation.
26

Návrh vytápění a vzduchotechniky pro dvoupatrový rodinný dům po rekonstrukci / Design of heating and ventilation system for two-storey family house after renovation

Potočník, Jan January 2016 (has links)
The thesis is focused on the design of the reconstruction of a house built in the 70s of the last century. Part of this work is an introduction with the current state of the object and calculation of the appropriate heat losses. In the next step, renovations containing building insulation, replacement windows and doors, replacement of the heating system and the installation of air conditioning are made. Based on the design of the adjustments are again calculated heat losses and a comparation of energy savings is made. Another part of the proposal focuses in detail on heating system and its regulation. The final chapter deals with the design of the ventilation device using heat recovery. Attachments contain detailed calculations and necessary documentation.
27

Grundisolering för flerbostadshus : Jämförelse av cellglas och cellplast avseende energieffektivisering, ekonomiska aspekter och miljöpåverkan

Akhras, Samir, Arab, Mustafa, Yasin, Ahmed January 2023 (has links)
Purpose: This project compares two foundation insulation materials: cellular plastic and cellular glass. Currently, cellular plastic is the most used material for foundation insulation. While cellular glass is not widely utilized. Its disadvantage lies in its higher cost, which makes contractors prefer the cheaper alternative, cellular plastic. Cellular glass exhibits exceptional properties, including its notable attributes of high load-bearing capacity and superior moisture resistance. The aim of this study is to demonstrate how material savings can be achieved by using cellular glass instead of cellular plastic in the load-bearing parts of the foundation. In addition to cost savings, the study also includes the analysis of carbon dioxide emissions during the production of these materials and specific heat losses through the material. Method: To facilitate understanding of the study, two different buildings were visualized: a two-story building and a seven-story building. The choice of different building sizes aimed to investigate how different loads on foundation insulation affect insulation material costs, carbon dioxide emissions, and the heating requirements of the buildings. Revit and AutoCAD were used for modelling and visualization. Flixo and manual calculations were employed for energy calculations, while manual calculations were used for structural calculations. One Click LCA Software was used to determine the carbon dioxide emissions for the different foundation insulation scenarios. Results: The study suggests that for buildings with lighter loads, cellular plastic is a cost-effective choice, while a hybrid insulation approach combining cellular glass and cellular plastic is the best option considering environmental factors. However, for buildings with higher loads, cellular glass outperforms cellular plastic both in terms of economics and the environment. Nonetheless, a combination of cellular glass and cellular plastic remains the most favourable choice among the three scenarios, as energy losses are approximately the same due to the similar thermal conductivity values of these materials. Conclusion: Hybrid insulation proves to be the most advantageous option in terms of both the environment and economics for both types of buildings studied: the two-story residential building and the seven-story residential building. By using cellular glass F for the load-bearing structures and cellular plastic EPS S60 for the ground slab, effective insulation is achieved. The use of cellular glass F results in material savings, such as cellular plastic XPS 700, which has half the load-bearing capacity of cellular glass F. Additionally, reducing the use of extra concrete for load-bearing foundation constructions decreases the load on the foundation insulation material.
28

Förbättra allmänhetens engagemang i energibesparingsåtgärder i byggnader : Värmekamerans hjälp till villaägarnas förståelse och upptäckt av energiförluster

Andersson, Alva, Leppänen, Natalie January 2021 (has links)
Purpose: this degree project investigates the homeowner’s knowledge about their energy use and the impact of using visualisation tools such as thermal imaging to enhance public engagement in energy conservation in building. Additionally, the study try to increase the understanding of how people's behavior affects the energy use in buildings. The method: the presented study is based on 12 participants who own a single-family house in central Sweden. Participation in this study involved responding to two questionnaires and conducting a thermography inspection. A methodology developed to replace a standard thermography inspection with a DIY themography survey. The study identified and filled the gap in the literature, by allowing house owners to carry out the thermographing inspection of their own buildings, free of charge and by themselves. The participants took part of a developed educational material that helps in increasing energy awareness and includes explanations about how to interpret the thermal images and provides suggestions for possible conservation measures. Finally, a data analyse carried out based on questionnairs, thermal images and communications with the house owners. The results: cold bridges are the most common cause of heat loss in the inspected single-family houses. Householders with older buildings who have long term plan to live in their building are willing to implement measures, while participants with newer buildings do not consider it as necessary. The infrared camera has been an effective tool for visualization of heat loss and attract attention. Many participants are surprised over the results. Conclusion: the study confirms that the infrared camera is an effective tool for heat loss visualization and can be used for enhancing public engagement in energy conservation in building. Thanks to this visualization, Swedish homeowners have gained an increased interest in energy-efficient measures such as additional insulation, window replacement and sun protection. The study has increased the general awareness and knowledge regarding energy efficiency in buildings.
29

Optimierung der Nutzung von industrieller Abwärme durch mehrperiodische Wärmeintegration unter Berücksichtigung von thermischen Energiespeichern und Wärmeverlusten

Möhren, Simon 04 September 2023 (has links)
Zur Reduzierung von Treibhausgasemissionen und Energiekosten in der Industrie kann die Steigerung der Energieeffizienz durch Nutzung der verfügbaren Abwärme einen wichtigen Beitrag leisten. Mit den Methoden der Wärmeintegration kann das Abwärmepotenzial quantifiziert und systematisch Maßnahmen zur Nutzung von Abwärme identifiziert werden. Durch die mathematische Optimierung des Wärmetransports von Wärmequellen hin zu Wärmesenken kann ein Wärmeübertrager Netzwerk gebildet werden. Hierbei können je nach Formulierung der Zielfunktion des Optimierungsproblems der benötigte Energiebedarf, die Kosten oder Treibhausgasemissionen minimiert werden. In dieser Arbeit wird ein Ansatz für mehrperiodische Optimierungsprobleme weiterentwickelt und um die Einbindung von sensiblen und latenten thermischen Energiespeichern erweitert. Die Berücksichtigung des Phasenwechsels erfolgt mit Hilfe einer intervallweise linearen Funktion der Speichertemperatur. Durch Einführen von Binärvariablen erfolgt eine Berücksichtigung des jeweils relevanten Intervalls. Darüber hinaus wird eine Methode zur Berücksichtigung von Wärmeverlusten der Rohrleitungen vorgestellt. Die entwickelten Methoden werden in einem Fallbeispiel aus der Textilindustrie angewendet und im Rahmen von Sensitivitätsanalysen ausgewählte Einflussfaktoren untersucht. / Increasing the energy efficiency by using available waste heat can make an important contribution to reducing greenhouse gas emissions and energy costs in the industry. Heat integration methods can be used to quantify the waste heat potential and systematically identify measures for waste heat utilization. By mathematically optimizing the heat transport from heat sources to heat sinks, a heat exchanger network can be designed. Depending on the formulation of the objective function of the optimization problem, the required energy demand, costs or greenhouse gas emissions can be minimized. In this work, an approach for multiperiod optimization problems is further developed and extended to include sensible and latent thermal energy storage. The phase change is considered by an interval linear function of the storage temperature. By introducing binary variables, the relevant interval is taken into account. Furthermore, a method for including heat losses of pipelines is presented. The developed methods are applied in a case study from the textile industry and selected influencing factors are investigated within the scope of sensitivity analyses.
30

Soot modelling in flames and Large-Eddy Simulation of thermo-acoustic instabilities / Modélisation des suies dans des flammes et Simulation aux Grandes Échelles des instabilités thermo-acoustiques

Hernández Vera, Ignacio 14 December 2011 (has links)
Dans la première partie de cette thèse de doctorat une méthodologie est présentée qui permet de prédire les niveaux de suies produits dans des flammes laminaires monodimensionnelles, ou un modèle semi-empirique de suies est utilisé en combinaison avec une chimie complexe et un solveur radiatif détaillé. La méthodologie est appliquée au calcul de suies dans une série de flammes de diffusion à contre-courant d'éthylène/air. Plusieurs modèles d'oxydation de suies sont testés et les constantes du modèle sont ajustées afin de retrouver un meilleur accord avec les expériences. L'effet des pertes thermiques radiatives sur la formation de suies et la structure des flammes est évalué. Finalement, la performance du modèle de suies est évalué sur des flammes prémélangées monodimensionnelles, ou une expression alternative du terme de croissance de surface est proposée pour reproduire les résultats expérimentaux. Dans la deuxième partie de cette thèse, des outils de Simulation aux Grandes Échelles (SGE) et d'analyse acoustique sont appliqués à la prédiction des oscillations de cycle limite (OCL) d'une instabilité thermo-acoustique qui apparaît dans un brûleur académique partiellement prémélangé de méthane/air à pression atmosphérique. La SGE prédit bien l'apparition et le développement des OCL est un bon accord est trouvé entre simulations et expériences en termes d'amplitude et fréquence des OCL. La simulation permet de révéler certains aspects clés responsables du comportement instable de la flamme. Ensuite, une analyse préliminaire de la quantification des incertitudes est fait, ou l'effet des paramètres tels que l'impédance des entrées, le degré de raffinement du maillage ou les pertes thermiques sur les caractéristiques des OCL est évalué. Aussi, la SGE prédit bien la dépendance de la stabilité de la flamme du point d'opération et de la géométrie du brûleur / In the first part of the present PhD. thesis a methodology is presented that allows to predict the soot produced in one-dimensional academic flames, where a semi-empirical soot model is used in combination with a complex chemistry and a detailed radiation solver. The methodology is applied to the computation of soot in a set of ethylene/air counterflow diffusion flames. Several oxidation models are tested and the constants of the model were adjusted to retrieve the experimental results. Also, the effect of radiative losses on soot formation and the flame structure is evaluated. Finally, the performance of the soot model is evaluated on 1D premixed flames, where an alternative expression for the surface growth term is proposed to better reproduce the experimental findings. In the second part of the thesis, Large-Eddy Simulation (LES) and acoustic analysis tools are applied to the prediction of limit cycle oscillations (LCO) of a thermo-acoustic instability appearing in a partially premixed methane/air academic burner operating at atmospheric pressure. The LES captures well the appearance and development of the LCO and a good agreement is found between simulations and experiments in terms of amplitude and frequency of the LCO. Some light is shed on the mechanisms leading to the existence of such instability. Then, a preliminar uncertainty quantification (UQ) analysis is performed, where the effect on the features of the LCO of several computational parameters such as the inlets impedances, mesh refinement or heat losses is assessed. Also, the LES captures well the flame stability behaviour dependence on the operating point and the burner geometry

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