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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.
1

Life cycle sustainability assessment of the electrification of residential heat supply in UK cities

Sims, Roland January 2014 (has links)
The recent revival of urban living in the UK has been stimulated by many different factors, including life style choices and government policies. This has led to a rapid increase in the number of apartments in the UK cities. This increased density living has also brought about various changes in the city infrastructure, including the way energy is supplied to residential buildings. The recent trend of ‘electrification of heat’ represents one of these changes, whereby electricity rather than natural gas is now typically being used for space and water heating as well as for cooking. Further growth in electricity demand has been predicted in the governments Carbon Plan with the increased use of all-electric systems including heat pumps for domestic heat. This will in turn impact the environment since electricity supplied in the UK is predominantly based on fossil fuels and contributes to significant greenhouse gas (GHG) and other emissions. However, greater penetration of renewable sources in the future would be expected to reduce GHGs. This would also help to improve the security of supply through diversification of energy sources. On the other hand, there are concerns that increasing reliance on electricity could lead to fuel poverty for a greater section of society. Thus, it is not immediately clear whether the change from gas to electricity would contribute to the sustainability or otherwise of energy supply in the UK residential sector. Therefore, this research has set out to understand better the implications of the electrification of heat in the urban residential sector by examining the trade-offs between environmental impacts, techno-economic costs and social aspects. This work therefore goes beyond the previous research that has typically focused solely on GHG emissions and energy pay-back times of different energy options. This is also the first time as far as the author is aware that the sustainability of the electrification of heat in cities are analysed in depth. Various tools have been used for these purposes, including life cycle assessment (LCA), indoor air quality monitoring (IAQ), life cycle costing (LCC), social surveys (SS), scenario analysis (SA) and multi-criteria decision analysis (MCDA).Assuming all sustainability aspects considered here to be equally important, the most sustainable option is the district heating system. All-electric heat-providing systems (electric panel, electric storage, and air source heat pumps) have on average 2.5 times higher environmental impacts than gas-based systems (individual gas boiler, solar thermal and gas, district heating and community CHP systems). The techno-economic costs of all-electric systems are 80% that of the district heating system – however, fuel cost and demand changes increase substantially all-electric system cost vulnerability. Gas-based systems are widely accepted and valued - all-electric systems while a ‘good fit’ for particular city homes - have greater social impacts including affordability. If the proposed decarbonisation of electricity generation is realised, the global warming potential from electric heat-providing systems could be reduced to a 1/10th of present emission levels by 2050 increasing electrification of heat sustainability. Therefore, the choice of the most sustainable heat-providing options in the future, including that of the ‘electrification of heat’, will depend on the extent of the decarbonisation of the UK electricity supply and the relative importance placed on sustainability impacts by different stakeholders.
2

Záměna zdroje v lokální výtopně 2,5 MW / Change of heat source in a heating palnt 2.5 MW

Pikola, Jan January 2010 (has links)
The scope of this Master´s thesis is estimation of changing of heat source in a heating plant 2.5 MW. In the present heating plant burns natural gas, placing of the heating plant makes it possible development source of burning biomass. The scope of thesis is establish with regard to developed capital and operational costs, next effects to environment in scene of heat source, measuring and regulation of technological unit, determination of acceptable size of fuel depot and composition of fuel and ashes economy. The results of this Master´s thesis can be used as a basis about determination toward investment.
3

Spojení kondenzačního kotle se solárními kolektory pro zásobování RD tepelnou energií / Condensing boiler with solar collectors for thermal energy supply of residences

Zeman, Radek January 2016 (has links)
This diploma thesis deals with practical design of heat supply of real house in Libhošť, Nový Jičín. Main strategy of heat supply is gas condensation boiler, that replaces current gas boiler, with solar collector. From known house heat loss we determine temperatures of heating water and power of boiler, that heats the house and hot water. System with solar collector is designed to heat hot water in the house. All necessary equations are calculated both for long term measured meteorological data and for data in year 2015. Heat gains and payback periods of investment in solar system are determined from them. Payback periods are calculated given to price of heat that gas boiler produces. Equations and payback period evaluation are made for systems with one to four solar collectors. There is recommendation at the end of thesis, whether the solar system is advantageous, or not.
4

Energie ze zemědělské půdy / Energy from Agricultural Land

Šatra, Jan January 2010 (has links)
Thesis is concerned with relation of usable energy and space as it's widely spread source. For this purpose are introduced not only a few indicators suitable to energy management description, but also principles of environmental assessment thinking are expained, as these help to distinguish the really sustainable ways of deriving energy from space. As examples of energy-from-space extraction are introduced photovoltaics, liquid biofuels and fast growing energy plants. After a brief entry to heat supply problematics, focus is remains on a simple case study: quantifying relationship between local heat demand and local potential production of solid biomass from short rotation coppice. This so far rather hypothetic relation is examined at the municipal level, while Central and South Bohemia regions are the target area. Soil characteristics and population census data (2001) about residental habitats are used.
5

Data Centres as Prosumers: A Techno-Economic Analysis

Sintong, Jeremy Ericsson January 2023 (has links)
Rapid growth of digitalization has urged Data Centres (DC) to be more energy efficient by recovering waste heat from server racks that would otherwise be wasted. This techno-economic study is focused on upgrading low temperature waste heat from typical Air-Cooled DC for District Heating Network (DHN) market in Stockholm region. The methodology is carried out by four system configurations that are experimented with different historical electricity data, impacts of climate change with simulated weather data, and variations in DHN temperature as the heat supply scenario development. The results show that DC configuration with combination of both free-cooling and waste heat recovery can foster techno-economic benefits by reducing cooling consumption by 55.6%, compared to DC configuration with free-cooling only; and further lowering Power Usage Effectiveness (PUE) from 1.95 to 1.52. Lifecycle Operational Expenditure (LCO) has also been used as the economic indicator to represent the maximum initial investment that data centre should accept when deciding to recover the waste heat to the DHN. Moreover, the new technical Key Performance Indicators (KPIs) were introduced to support the decision-making in the supply of recovered waste heat to DHN. The electricity price was further identified to have greater impact than the effect of climate change for the overall techno-economic performance. On one specific hand, heat supply with Price-Limit scenario concluded that 40.18% of available waste heat from DC is not profitable should it be injected to DHN in the case of low electricity price. In the case when the electricity price is high, the amount of waste heat not injected to DHN increases to 58.57%. / <p>The thesis defense presentation was held digitally on Zoom on June 19th 2023 at 09.00 CEST</p>
6

Solar process heat in the food industry : methodological analysis and design of a sustainable process heat supply system in a brewery and a dairy

Müller, Holger January 2016 (has links)
The food industry is a large consumer of industrial energy. A very large portion of this energy is needed in the form of thermal energy at medium to low temperatures. Fossil fuels remain the dominant sources of this energy. This combination provides various possibilities to reduce energy consumption and CO2 emissions with heat recovery, but also with the integration of solar process heat. Energy efficiency must provide the context, or background, of such considerations, and is therefore a very important aspect of them. It is a complex task to design an efficient heat supply with a variety of energy sources. An analysis of standards for energy audits, guides for energy efficiency and guides for solar process heat integration confirms that complexity. However, no available methodology considers all the necessary steps. These must range from analysis of the existing heat supply to the redesign of an efficient heat supply system. The focus must be on heat sources with waste heat and on solar process heat that might be used to complement the conventional sources. The design of a process heat system is mainly the task of design engineers in engineering offices. Specific tools and measures are needed to support these experts. However, the companies of the food industry sector employ their own energy engineers for energy issues. These people are actually the decision makers responsible for the configuration of the company energy supply systems, who also possess knowledge of the processes in their industry subsector. The expertise of the energy engineers varies within a broad range and is also connected to their area of responsibility. Therefore, it is important to consider these energy engineers when developing a methodology. The development of the methodology proposed herein consists first of the configuration of the tools and measures, which were assigned to four elements and functions. Second, the methodology so developed was applied at two companies in cooperation with their energy engineers, in detailed case studies. The feedback from the energy engineers is therefore a main objective and provides a background for evaluation of the usability of the methodology. It demonstrates the expertise required of the energy engineers, for the application of the tools and measures provided. Moreover, the development and application of the methodology involving real companies demonstrates the necessity of getting feedback from energy engineers. That finding is very important, and has been insufficiently considered in previous guides or methodologies. It is proposed that further work be aimed at providing additional case studies to extend the use of this methodology to other parts of the food industry.
7

Teplárenské sítě / Piping systems for district heating

Malach, Tomáš January 2018 (has links)
In the first part of master thesis is presented general introduction to district heating system (DHS) and hydraulic calculation for DHS. The next part deals with analysis operation of DHS and the pressure diagram for certain time interval. Subsequently, the thermohydraulic characteristics for the hydraulic main branch (comparing manual calculation with software calculation) and also the selected thermal and hydraulic characteristics for the whole DHS are shown. The last part is focused on the determination of the amount of heat supplied based on the ultrasonic flowmeter and the temperature probes. Subsequently, the computer simulation is also carried out, aiming at approximating the real heat supply from heat source to solved thermal network in winter.
8

Absorpční oběhy v teplárenství / Absorption cycle in the heating industry

Pleva, Ondřej January 2019 (has links)
Goal of this thesis is to introduce technology of absorption heat pumps in various modifications. Technical design draft is created for chosen modification (single stage unit water-LiBr) and based on given parameters calculated in computing software EES (engineering equation solver) and process is explained step-by-step. Following part of thesis contains reference design draft of heat plant and this design is used to demonstrate several different options of applying absorption heat pump including version capable of providing also cooling. Those options are compared with each other from technological and economical stand point.
9

Energetický posudek a průkaz energetické náročnosti budovy / Energy assessment and certificate of energy performance of buildings

Bidmonová, Renata January 2020 (has links)
The aim of the diploma thesis is to evaluate the energy assessment and elaboration of energy performance certificates of the building. The building is an apartment building in Vítkov. The theoretical part deals with centralized heat supply. The calculation part contains a more detailed description of individual relationships and calculation procedures that are used to process energy performance certificates of the building. Furthermore, proposals for measures to improve the energy performance of buildings. In this part there is also a proposal of individual equipment of the new boiler room and thermographic measurement. In the project part there is an energy assessment assessing the building in two variants with individual heat sources. The evaluation is carried out from an energy, economic and environmental aspect.
10

SAKO Brno - vyvedení tepelného výkonu do CZT / SAKO Brno - heat output in CHP

Mazák, Tomáš January 2014 (has links)
The purpose of this thesis is to design a solution thermal power outlet of incinerator in hot water for the supply this town of heat. First and foremost are described problems landfill society and their implications on the environment. Next some alternatives of the waste and the burning in incinerators are described too. The thesis describes the history of the first incineration plant in the Czech Republic and its subsequent upgrading of the economical and environmentally friendly waste recovery and modernization of flue gas cleaning. Contribution of the work is then proposed as amendments to equipment and wiring for use of steam for the conversion heat output into hot water. This is essentially a calculation of steam water heaters at the end of the expansion of the steam and the related adjustments to the turbine blading. At the conclusion outlines the basic economic calculation and comparison of profits and investment associated with this implementation compared to implementation, which is now projected. It is a calculation of investment efficiency and its possible repayment due to higher profits from the sale of energy. This work serves only as a basis work for future technical realization and it outlines the appropriateness of this alteration.

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