This thesis provides a basic overview of the ancillary services in a transmission system. It summarizes changes regarding the implementation of European directives SOGL and EBGL. It describes in detail a portfolio of non-frequency ancillary services used in the distribution systems. It evaluates the demand of E.ON distribution system potential for those services in particular locations. Practical part is focused on a potential of reactive power management in this distribution area. It evaluates reactive power flow into transmission system and indicates the most critical substations. This thesis also covers analysis of existing resources in this distribution area and assign their possible potential in reactive power management.

This thesis deals with stochastic water demand modellling in the water supply network. In the opening section, a research is created, where two different approaches to stochastic modelling of water consumption are presented. The practical part describes the creation of a deterministic hydraulic model and its calibration. Generated stochastic water demand patterns with a small time step of 1 minute, are then inserted into this model. Each household is assigned with a unique water demand pattern. Then a hydraulic analysis was done. A comparison of deterministic and stochastic approaches is presented at the end of the thesis. The comparison shows, that small-time step modelling does not have a big impact on the pressure ratios in the water supply network, but has a huge impact on the maximum flows and speeds occurring in links of the hydraulic model.

Fluid flow maldistribution plays a key role in equipment used in process and energy industries, although its evaluation is often underestimated or fully neglected. Uneven flow distribution may cause thermal or mechanical load on the tube bundle, and in extreme scenarios, it can also have an adverse effect on the process efficiency. This thesis aims to find the optimal computational tools for flow distribution prediction suitable for the initial stage of the equipment design process and to identify suitable settings of these tools for their subsequent industrial deployment. The results of simplified analytical models, detailed numerical simulations, and experimental measurements were compared for the dividing header and the U-type distribution system. It was found that the results provided by simplified mathematical models, the solution of which is also significantly less time-consuming compared to detailed CFD simulations, best correspond to the measured experimental values in all modeled configurations. For arrangements with higher lateral resistance coefficient, both computational approaches provide approximately equally accurate results. However, for arrangements with lower lateral resistance coefficient, the deviation of the results obtained by CFD calculations from the experimental data is significantly larger.

This work deals with the deployment of distributed power sources into the electric power grid. The nature of these sources causes that the massive integration may experience problems with power quality in the local context, and also overall reliability of supply in the range of interconnected power systems may be endangered. Work is focused on local voltage quality problems with special emphasis on analysis and design of tools (e.g. reactive power compensation units of power plants or dynamic voltage control by transformers 110/22kV) for voltage control in power distribution systems. These tools should be used as a part of uniform concept of voltage control. The proposed concept is involved.

This Diploma thesis deals with minimum night flows issue. Basic findings about minimum night flows were summarized in the introductory part of thesis. Findings like the minimum night flow components, affecting parameters and used methodologies for assessment of minimal night flows. In the practical part of this thesis was this knowledge applied to real water distribution system in the municipality Hrádek u Sušice. The part of this thesis was also determinate the measurement accuracy of used water meter, which was formerly installed at the outlet in the Hrádek water tank. Measurement errors was determinate for the flow values, that are close to the real measured minimum night flow data in the water distribution system in municipality Hrádek u Sušice.

This diploma thesis introduces the reader to the possible types of electric energy storage technologies, their comparisons and utilization. After its introduction, it follows the description of individual technologies and principles that are currently meaningful and useful in practice. The thesis continues with the part characterizing the ways of using the accumulation in the grid. However, the main points of this thesis include the analysis of the influence of the photovoltaic installation on the specified distribution grid operation at the low voltage level and the analysis of the influence on the grid with connected accumulation. Another important objective was the model for the calculation of steady-state, which was programmed on the basis of the theory supported by the principles of production from intermittent sources and the principle of accumulation function. The outputs of the model in the form of the calculated voltage ratios at the individual supply points and current flows at the distribution transformer point were used to evaluate the analyzes mentioned above. The courses of the calculated parameters are broken down by different scenarios (according to the period, the degree of integration of production and the accumulation or the power output of the production), graphically processed and compared from the point of view of voltage fluctuations and changes in the power (or current) balance of the supply transformer.

En el país es poco común el uso de energías renovables, por ello es importante que se difundan las tecnologías asociadas al uso de este tipo de recursos. La energía geotérmica superficial es un recurso que se puede aprovechar prácticamente en toda la corteza terrestre, no proporciona una cantidad de energía elevada, pero si tiene aplicaciones que reducen la producción de CO2 (por sistemas de calefacción) y el consumo de energía. En la investigación se analizan los sistemas geotérmicos de baja entalpia, específicamente las cimentaciones termoactivas, las cuales consisten en incorporar el intercambiador de calor en la estructura de la cimentación, esto aunado a la bomba de calor y el sistema de distribución constituye un uso importante de la energía geotérmica somera en los sistemas de calefacción de edificaciones. Para desarrollar las cimentaciones termoactivas es necesario realizar estudios previos tales como, estudio de características geotécnicas y térmicas del suelo, hidrogeología y geología. / The use of renewable energies is rare in the country, so it is important that the technologies associated with the use of this type of resources be disseminated. Surface geothermal energy is a resource that can be used practically throughout the earth's crust, it does not provide a high amount of energy but it does have applications that reduce CO2 production (by heating systems) and energy consumption. The research analyzes low enthalpy geothermal systems, specifically thermoactive foundations, which consist of incorporating the heat exchanger in the foundation structure, this together with the heat pump and the distribution system constitutes an important use of shallow geothermal energy in building heating systems. To develop thermoactive foundations it is necessary to carry out previous studies such as a study of the geotechnical and thermal characteristics of the soil, hydrogeology and geology. / Tesis

Das Auftreten von Braunwasser in Trinkwasserverteilungsnetzen ist eine Beeinträchtigung der Trinkwasserqualität, die durch mobilisierte partikuläre Ablagerungen verursacht wird. Die Partikel gelangen durch verschiedene Prozesse, wie z. B. der Korrosion metallischer Leitungen und den Eintrag am Wasserwerk, kontinuierlich in sehr geringen Massenströmen in das Rohrnetz. Durch die Akkumulation der Partikel an Rohroberflächen können sich Ablagerungsmengen bilden, die bei ansteigenden Strömungsgeschwindigkeiten resuspendiert werden und zu unerwünschten Braunwassererscheinungen führen. Die vorliegende Arbeit behandelt die experimentelle Untersuchung des Transportes von Partikeln, die für Trinkwassernetze typisch sind, in Rohrströmungen. Es werden Einflussfaktoren identifiziert, die für den Partikeltransport von Bedeutung sind. Ein neu entwickeltes dynamisches Modell beschreibt den Transport von Partikeln und die Ablagerungsbildung in Rohrströmungen und vermaschten Rohrnetzen. Das Modell wurde in einer Anwendersoftware implementiert und an einem Trinkwasserverteilungsnetz für das Nachvollziehen der beobachteten Ablagerungsbildung eingesetzt. Im Vergleich zu bestehenden dynamischen Modellen werden partikelbezogene Prozesse unter Berücksichtigung der für trinkwasserbürtige Partikel und Ablagerungen typischen Eigenschaften mathematisch genauer beschrieben. Stationäre und dynamische Ereignisse bezüglich Wasserqualität und Ablagerungsbildung können jetzt durch die Berücksichtung zahlreicher zeitabhängiger Einflussfaktoren nachvollzogen werden. / The occurrence of discoloured water in drinking water distribution systems is a disturbance of the water quality, which is induced by mobilised particulate deposits. Different processes result in the continuous entry of small mass flow rates of particles into the piping, for instance the corrosion of metallic pipes as well as the entry at the water works outlet. By the accumulation of these particles, significant amounts of deposits can be formed and at higher flow rates be resuspended, which leads to unwanted events with discoloured water. This study examines the experimental investigation of the transport of particles, which are typical for drinking water distribution systems, in pipe flow. Influencing factors are identified, which are of importance for the particle transport. With a newly developed model, the transport of particles and the deposit formation in pipe flow and in piping is described. The model is implemented into a software application and deployed at a drinking water distribution system to understand the observed deposit formation. In comparison with existent dynamic water quality models, particle-related processes are described mathematically in more details, under consideration of characteristics typical for particles and deposits in drinking water distribution systems. Hence, observed steady-state and dynamic events can be followed using several influencing time-dependent factors.

No description available.

Nowadays individuals spend more than 85% of their total time in indoor environments, mainly at home and work. Thereby, the quality of the indoor environment plays a substantial role in human health and wellness. The four basic factors that define the perception of the indoor environment, through the senses, are the thermal comfort, the indoor air quality, the acoustical quality and the visual or lighting quality. A standard level of the above factors is ensured by the building envelope and the services systems. At the same time, the bearing structure provides the necessary resistance and durability to the construction in order to sustain the various loads without breaking down. Inevitably, over the years, all structures’ robustness declines and their functionality state degrades. For that reason, intensive provision should be given to assure the users’ safety and well-being. The objective of this study is to assess the current indoor air quality, the thermal comfort and the damages at four publicly owned buildings located in Athens, Greece. The evaluation was done through the facilities management contribution, a questionnaire survey and a technical visit – inspection where measurements were taken. Special focus was also put on the Sick Building Syndrome (SBS) and its effects. The results indicated that at 3 out of 4 buildings mainly suffer from unpleasant odors and lack of fresh air intake. Therefore, the installation of mechanical ventilation systems (air handling units, outdoor air processing units) combined with an effective air distribution system (confluent jet ventilation system) is suggested. Substantial building damages were detected at the cultural center (floorings, door/window openings, fungi) and specific proposals for restoration are made. Despite the existence of indicators of an unhealthy indoor environment, a direct correlation between the exposure to various pollutants and the SBS symptoms, cannot be established. The optimization of the research methodologies and the institution of new building design protocols is essential in order to overcome the SBS effects. On the whole, the questionnaire achieved to fulfil the objectives of the survey. It was comprehensible by the respondents while the outcome of the questionnaire and the inspection were consistent to each other. The questionnaire and the checklists are practical tools that could be used as a guide for future investigation in similar fields. Except for technical surveys and questionnaires, many suggestions for future maintenance of the buildings are provided aiming to retain their functionality. These proposals concern the services systems, the building envelope as well as the bearing structure of the buildings.