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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.
151

熱泵熱水系統生命週期評估與淨能源分析之整合研究 / Integrated Studies on Life Cycle Assessment and Net Energy Analysis of the Heat Pump Water Heater System

郭乃頊 Unknown Date (has links)
根據歐盟2009 年發布之再生能源指令,定義熱泵系統所擷取之大氣熱能、水熱能以及地熱能為再生能源之選項,熱泵技術不受日夜與天候影響,且具安全、有低耗能、低排碳的優點,可應用在空調、暖氣、熱水等設備,備受歐美日本等先進國家重視,也是歐美各國政府極力推廣的項目之一。本研究針對台灣地區家戶住宅所使用小型空氣源熱泵熱水機組,透過環境資源及能源效率的角度,來探討熱泵熱水系統對於台灣住宅部門的適用性。 在研究方法上,針對國內熱泵個案廠商進行系統盤查分析,並且估算使用運轉過程中所需之能源投入,以計算熱水系統在製造過程與運轉使用過程中之環境影響。選擇生命週期評估軟體SimaPro 7.3做為評估工具,使用Eco-Indicator 95、EPS 2000兩種衝擊評估模式,來以生命週期評估探討熱泵熱水系統對環境之影響。並輔以淨能源分析法中能源投資報酬率與能源回收期,以及估算熱泵熱水系統生命週期CO2排放量,來衡量熱泵熱水系統之能源效率是否具有其效益。並進一步針對不同的再生能源發電比例與提升熱泵能源效率比例,探討不同方案的敏感度分析。 根據本研究分析結果顯示,熱泵熱水系統不管從Eco-indicator 95或EPS 2000衝擊評估模式下,運轉使用階段對環境衝擊較大,主要的衝擊項目為重金屬汙染,是因為熱泵熱水系統運轉所使用的電力消耗所致。使用熱泵熱水系統對環境衝擊程度遠較電熱水系統來得小,雖在Eco-indicator 95之衝擊評估模式下,瓦斯熱水系統較熱泵熱水系統環境衝擊程度較小,但以EPS 2000衝擊評估模式下,熱泵熱水系統對環境是最為友善的熱水系統。以淨效益估算熱泵熱水系統源投資報酬(EROI)值為1.45~5.55,能源回收期約為0.22年至2.16年,表示熱泵熱水系統從生命週期的角度來檢視能源效率是具有效益的。由於目前熱泵熱水系統對環境最大的負擔來源是電力的使用,若未來能提高再生能源發電比例、降低臺灣電能含碳濃度,或者提高熱泵能源生產效率,均能降低熱泵熱水系統對環境的負面影響。 / The purpose of this study is to apply life cycle assessment (LCA) and net energy analysis to explore the environmental impacts of the heat pump water heater in Taiwan. In order to achieve this objective, domestic data inventory was gathered from local heat pump industry in Taiwan through questionnaires including input of energy, product output and waste, etc. The SimaPro7.3 program and two impact assessment methods including Eco-Indicator 95, EPS 2000 were utilized to evaluate the environmental impact of the heat pump water heater. Also, we used net energy analysis such as energy return on investment and energy payback time, and estimated the life-cycle CO2 emissions to see whether if the heat pump water heater has its energy efficiency. In addition, the sensitivity analysis was performed by varying renewable energy generation portfolio and the heat pump energy efficiency ratio. Emprical results of two impact assessment methods (Eco-indicator 95 and EPS 2000) show that the main impact on environment of heat pump water heater is from operation phase. When operating the heat pump water heater, it needs to consume electricity which is generated from fossil fuel and caused the environmental impact. Compared with the electric water heater, the environmental impact degree of heat pump water heater is much smaller. In Eco-indicator 95 method, gas water heater has less influence on the environment than heat pump water heater; however, heat pump water heater is the most environment-friendly system in EPS 2000 method. That is because gas is a kind of nonrenewable resource. From the viewpoint of resource stock, gas indeed influence “Depletion of reserves” of environmental impact. By utilizing net energy analysis, the estimated energy return on investment (EROI) of heat pump water heater is 1.45~5.55, and energy payback time is 0.22~2.16 years. It indicates that heat pump water heater has significant benefit from life-cycle perspective. The main impact to environment by heat pump water heater is essentially derived from electricity input. To mitigation this environmental issue, one can reduce environmental impact by increase the proportion of renewable energy generation, and reducing the electricity CO2 emission. Furthermore, improving the energy efficiency of the heat pump would also helpful.
152

Auxiliary Heater for Natural Gas Trucks

Karlgren Johansson, Mikael, Leong, Kevin January 2017 (has links)
As alternative fuels are becoming more common, technologies need to adjust to them. Natural gas is one of the alternative fuels that has grown during the latest years in the transport sector. Natural gas consists of around 97 % methane and is the cleanest fossil fuel. The use of natural gas can make it easier to transition to biogas as it has equivalent properties. Today Scania CV AB's trucks fuelled by natural gas are using auxiliary cabin heaters driven by diesel. This means that the natural gas trucks have two fuels on-board the truck. The goal of this project is to find a concept to eliminate the diesel fuel and replace it with an auxiliary cabin heater driven by another energy source. It will improve the heating solution and make it superior from an environmental perspective. The result of the project lead to a short-term solution with an auxiliary heater fuelled by natural gas. A long-term solution is to have a cooperation with a manufacturer to develop a better natural gas auxiliary heater that fulfils more of the requirements in the technical specification. An experiment plan is devised to test parameters out of reach of the project.
153

Účinnost zdrojů a nepřímotopný ohřev teplé vody / Boiler efficiency and indirect heating of hot water

Matůšů, Ondřej January 2019 (has links)
This diploma thesis deals with efficiency of heat sources and indirect heating of hot water. First part of this thesis is about heating of hot water, particulary indirect heating of hot water and it is all summarized in theoretical knowledge section. Second part deals with central heating and indirect heating of hot water in four floor flat house. The heat source for this object is cascade of two gas condensing boilers. In this building there are mostly used panel radiators. In the last, third part, I experimentaly deal with operational efficiency of heating sources with heating of hot water.
154

Tepelná čerpadla vzduch-voda / Air - water heat pumps

Illichman, Petr January 2022 (has links)
The topic of my diploma thesis is air-water heat pumps. The diploma thesis contains three parts. In the first part I describe the theory of air-water heat pumps. In the second part I consider two variants of heating, hot water heating and pool water heating using air-water heat pumps in the family house, Révova. The third experimental part is focused on observation of operational process and calculation of heat factors of air-water heat pump while in the heating model. The calculated heating factors are then compared to the heating factors from the manufacturer's graph.
155

Sustainable Construction Practices of Intentional Communities: a Pilot Investigation in Loudoun County, Virginia and Frederick County, Maryland

Shedd, Jason Lee 11 August 2012 (has links)
This project investigated the sustainability of homes within three intentional communities. Semi-structured interview and photographic walkthroughs examined the variability of architectural and technological approaches toward sustainability. These include: passive solar design, green roofs, radiant flooring, composting toilets, ground assist heat pumps, solar water heaters, multiamily units and modular construction. It was hypothesized that variation in sustainable construction is related to socioeconomic status and that economics would be a constraint. This project investigated whether communities were transmitting their practices to wider society, if individuals were copying vernacular architecture and if architectural practices followed individual beliefs regarding sustainability. It was found that the Internet is the main method of conveying these practices; that variability was tied less to individual beliefs than to the communities’ institutional documents; and that copying vernacular architecture was for aesthetics not sustainability. Intentional communities are good models for sustainable development, but knowledge transmission is limited.
156

Development of Resistor-based Silver and Zinc Devices using Novel Applications of Inkjet Printing

Radwan, Abdulaziz (Aziz) N. 27 January 2023 (has links)
No description available.
157

Modeling The Temperature of a Calorimeter at Clab : Considering a Thermodynamic Model of The Temperature Evolution of The Calorimeter System 251

Ekman, Johannes January 2021 (has links)
It is important to know the heat generated due to nuclear decay in the final repository for spent nuclear fuel. In Sweden, the heating powers generated in spent nuclear fuels are currently measured in the calorimeter System 251 at the Clab facility, Oskarshamn. In order to better measure, and increase understanding, of the temperature measurements in the calorimeter, a simple thermodynamic model of its temperature evolution was developed. The model was described as a system of ordinary differential equations, which were solved, and the solution was applied to calibration measurements of the calorimeter. How precise the model is, how its parameters affect the model, et cetera, are addressed. How the temperature evolution of the system changes as the values of parameters in the model are changed is addressed. The mass correction of the calorimeter could be estimated from this model, which validated the established mass correction of the calorimeter. How the measurement results from the calorimeter would be affected if the volume of the calorimeter was changed was also considered. Additionally, gamma radiation escape from the calorimeter without being detected as heat in the calorimeter. The gamma escape energy fraction was estimated by SERPENT simulations of the calorimeter, as a function of the initial photon energy. The gamma escape was also estimated for different values of the radius of System 251.

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