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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.
31

Effektivisering av processen inom råkaffelagret på Zoégas / Improved process efficiency at Zoégas raw coffee inventory

Svanström, Elias January 2020 (has links)
Zoégas är ett svenskt kafferosteri i Helsingborg som ingår i den globala Nestlékoncernen. Stora delar av Zoégas produktion är automatiserad förutom deras råvarulager, vilket har många moment och helt saknar automation. Ett av dessa moment är dessutom inte ergonomiskt för de tre operatörerna som arbetar på råkaffelagret och kan orsaka arbetsskador. Nestlékoncernen ställer höga krav på säkerhet och hållbarhet i alla steg från odlare av kaffebönor, via transporter, produktion och förpackning till att deras produkter når hyllorna i våra matvaruaffärer. Zoégas ledning vill därför effektivisera och öka lagerkapaciteten i råvarulagret samt göra det mer säkert att arbeta i. Examensarbetets uppgift har varit att ta fram förslag på åtgärder för att effektivisera processen i råkaffelagret samt öka lagringskapaciteten i densamma samt att minimera riskerna för arbetsskador, där investeringar i förbättringar återbetalar sig inom två år. För att kartlägga nuläget, identifiera och utvärdera förbättringsförslag användes framför allt flödesscheman, Ishikawadiagram för att identifiera orsakssamband, Lean 7+1 slöserier samt återbetalningstid för att se hur snabbt olika förbättringsinvesteringar betalar sig. Interna transporter på råkaffelagret är tidskrävande för operatörerna, vilket beror på de många olika stegen i processen, är ett slöseri som begränsar effektiviteten i lagerhållnings processen samt utgör också onödiga risker för operatörerna då truck används för flera transporter. Golvbärighet och takhöjd visade sig vara de viktigaste fysiska faktorerna som begränsade införandet av mer automatiserade lösningar och ökad Zoégas är ett svenskt kafferosteri i Helsingborg som ingår i den globala Nestlékoncernen. Stora delar av Zoégas produktion är automatiserad förutom deras råvarulager, vilket harmånga moment och helt saknar automation. Ett av dessa moment är dessutom inte ergonomiskt för de tre operatörerna som arbetar på råkaffelagret och kan orsaka arbetsskador. Nestlékoncernen ställer höga krav på säkerhet och hållbarhet i alla steg från odlare av kaffebönor, via transporter, produktion och förpackning till att deras produkter når hyllorna i våra matvaruaffärer. Zoégas ledning vill därför effektivisera och öka lagerkapaciteten i råvarulagret samt göra det mer säkert att arbeta i. Examensarbetets uppgift har varit att ta fram förslag på åtgärder för att effektivisera processen i råkaffelagret samt öka lagringskapaciteten i densamma samt att minimera riskerna för arbetsskador, där investeringar i förbättringar återbetalar sig inom två år. För att kartlägga nuläget, identifiera och utvärdera förbättringsförslag användes framför allt flödesscheman, Ishikawadiagram för att identifiera orsakssamband, Lean 7+1 slöserier samt återbetalningstid för att se hur snabbt olika förbättringsinvesteringar betalar sig. Interna transporter på råkaffelagret är tidskrävande för operatörerna, vilket beror på de många olika stegen i processen, är ett slöseri som begränsar effektiviteten i lagerhållnings processen samt utgör också onödiga risker för operatörerna då truck används för flera transporter. Golvbärighet och takhöjd visade sig vara de viktigaste fysiska faktorerna som begränsade införandet av mer automatiserade lösningar och ökad effektivitet, lagringskapacitet och förbättrad säkerhet för operatörerna. En förstärkning av lagergolvet med ett ramverk i kombination med silos och ett pneumatiskt transportsystem är det lösningsförslag som har möjlighet att skapa ökad effektivitet i lagerprocessen, ökad lagringskapacitet, hållbarhet och säkerhet samt klara av en återbetalningstid av investeringen på mindre än två år. Lösningen har rekommenderats till Zoégas ledning för fortsatt utvärdering. / Zoégas is a Swedish coffee roastery in Helsingborg, which is part of the global Nestlé Group. Large parts of Zoégas’s production is automated except for their inventory of raw material, which has a process that includes many steps and is completely lacking automation. Furthermore, one of these steps in the process is not sufficiently ergonomically designed for the three operators who work in the raw coffee inventory facilities and may cause injuries.  The use of forklifts is also representing a non-neglectable risk. The Nestlé Group policy is to maintain high standards with regard to safety and sustainability in all steps from the coffee bean growers, via transportation, production and packaging until their products reach the shelves of our grocery stores. The objective for the management of Zoégas is to make the process in the raw material inventory more efficient and increase its storing capacity as well as make it safer to work in. The aim of this final exam project was to propose solutions which will make the raw coffee inventory process more efficient, increase the storing capacity and minimize the risk for work related injuries, where the investments related to improvements must have a payback period shorter than two years. In order to map out the current situation, identify and evaluate alternative solutions, flow charts, Ishikawa diagrams for identifying causal links, the Lean 7+1 wastes as well as payback period to see how quickly savings pay off investments through improvements, have been used. Internal transportations are time consuming for the operators, which depends on that there are many steps in the process and therefor represents a waste which limits the efficiency in the inventory process as well represents unnecessary risks for the operators since forklifts are used in a number of the steps.  The floor load capacity and ceiling height were the most significant physical factors which limited the deployment of more automated solutions with increased stock keeping capacity in the current stock keeping facilities for the raw coffee.  Both an entirely automatic stock keeping system, including a silo system and a pneumatic transport system, as well as a completely new bulk container system were evaluated after that other solutions had been disqualified either due to the physical limitations of the stock keeping facilities or due to the fact that such solutions did not solve the main problems such as the need for more efficiency, capacity and a more safe working environment for the operators. A reinforcement of the floor in the stock keeping facility in combination with silos and a pneumatic transport system is a solution that would be contributing to increased efficiency and storing capacity in the raw coffee inventory, sustainability and safety as well as offering a payback period for the investment shorter than two years.  The solution has been recommended to the management of Zoégas to be further studied.
32

Ocenění a ekonomická návratnost investičního projektu / Assessment and Economic Return on Investment Project

Nyklová, Petra January 2014 (has links)
This work deals with an assessment and economic return on investment project. The theoretical part describes price formats, methods of drawing up an object budget, a payback period, costs and revenues matters and ways of financing construction projects. The practical part of this work focuses on acquiring costs and revenues emerged during the construction implementation and the use of the building. Costs incurred during the implementation will be obtained by means of itemized and general construction budget. Having obtained these values, there will be carried out a profit and loss account, from which a payback period will then be calculated.
33

Optimering av balkonginfästningar : ComBAR glasfiberförstärkt polymerplast som armering i betong / Optimization of balcony-to-facade connections : ComBar a fibreglass reinforced polymer plastic as reinforcement in concrete

Dilanson, Rekar January 2014 (has links)
I samband med EU-direktivs mål att reducera energikonsumtionen med 20 % fram till år 2020 har kraven i Boverkets byggregler skärpts för energianvändningen i Sverige. Dessa krav håller den totala energiförbrukningen i sektorn bostäder och service på jämn nivå trots att det sker en ständig ökning av antalet bostäder.   Syftet med detta arbete är att undersöka om det finns möjlighet till att minimera energiförluster i infästningen mellan inspända balkonger och bjälklaget. Detta utfördes för att ge samtliga aktörer inom byggbranschen en uppfattning om hur stor inverkan en optimering av de oftast försummade detaljerna i ett projekt har.   Glasfiberförstärkta polymerplaster (GFRP) isolerar ca 120 gånger bättre än konstruktionsstål och klarar samtidigt av att ta upp dragkrafter i en betongkonstruktion om de formas som armeringsstänger. Från ett urval har flera GFRP produkter granskats där ComBAR har valts att studeras och kontrolleras som en ersättningsprodukt för stålarmering i balkonginfästningar. ComBAR uppfyller samtliga konstruktionskrav för att fungera som armering i betong och har egenskaper som är att föredra framför stål vilket även gör den användbar i flera andra konstruktionsdelar i en byggnad eller anläggning.   Utförandet av beräkningar och analyser är indelat i tre delar som är analys av byggstatik för att bestämma den erforderlig armering i balkonginfästningen, simulering av energiflöde mellan balkongen och bjälklaget samt ekonomisk kalkyl för att uppskatta avkastningstiden. I den ekonomiska kalkylen knyts resultaten ihop från analysen av byggstatik och beräkning av energiflödet för att sedan kunna avgöra om en investering är lönsam.   Ur resultaten från analysen av byggstatik som består av handberäkningar och simuleringar i beräkningsprogrammen Concrete Beam och FEM-Design kan vi dra slutsatsen att det behövs en armeringsstång mindre av ComBAR än stål för att bära upp balkongen i studien. Ur statisk synpunkt är det lämpligt att använda glasfiberbaserade armeringsstänger i balkonginfästningen. Energiflödesberäkningarna har utförts i programmet Comsol för att erhålla ett noggrant resultat på energiflödet igenom infästningen. Återbetalningstiden på över 100 år för det pris som ComBAR ligger på i dagsläget anses inte vara rimligt och det behövs en halvering av priset innan det kan komma på tal att användas.
34

Faktorer som bör vägas in vid investering av solceller : Miljöanalys av de vanligaste solcellerna på marknaden

Olsson, Lovisa January 2019 (has links)
Four solar cells dominate the Swedish market today and are divided into two groups; first generation and second generation. The first generation involves of two silicone solar cells called mono-and multicrystalline solar cells. These solar cells were, as the name indicates, first on the market and today receive the highest efficiency. Due to high manufacturing costs, the second generation was developed which became thin film solar cells. The two most common solar cells in that generation are CdTe and CIGS, which account for about 20 percent of the solar cell market today while the first-generation accounts for the remaining 80 percent. Going towards a sustainable future it’s important and clear that both companies, cities and countries are ready meet the challenges. The solar cell technology has gained high confidence to bring in sustainable electricity production. Investors in Sweden experience the lack of a valuation concept from an environmental perspective between the solar cells on the Swedish market. The study has examined how the four different solar cells affect different environmental categories and which materials in the solar cells that are the most critical. By simulating the electricity production for a year with Gothenburg's solar radiation, the amount of electricity that could be used or sent to the grid was obtained. Where the silicon solar cells that have the highest efficiency also received the most electricity per square meter of solar cell. After producing electricity production and electricity consumption, the energy repayment period was calculated. Through LCA, 11 different environmental categories were developed to analyze different areas that are affected by solar cell production. Aquatic ecotoxicity of the marine environment was the environmental category that was most affected by the production for all four solar cell types. From the environmental category Global Warming, the amount of carbon dioxide equivalents was studied and then a payback time was calculated. Solar cells generally have three different phases; manufacture, operating and waste. The use phase is considered to be almost emission-free, the waste phase is relatively new for solar cell technologies. This is because no large waste streams have come than when the first major investments took place only in the nineties. The solar cells need different techniques depending on the type. The strategies should be different as different parts should be recycled and reused as far as possible. Due to the fact that there is unstable waste management, this phase has not been studied but only the manufacturing phase.   A square metered solar cell was analyzed. For photovoltaic production in Europe, multicrystalline solar cell panels pay back the carbon dioxide equivalents after 11.5 years, while monocrystalline solar cell panels pay again after 14.3 years, ie after about half the life. CdTe paid the carbon dioxide equivalents fastest, after 2.2 years, and CIGS after 3.6 years. This means that the thin-film solar cells have the fastest time to get minus emissions. It is not justified to invest in solar cells manufactured in China when operating in Gothenburg, only after studying solar cell production. When the repayment period for carbon dioxide equivalents has been calculated, a Nordic electricity mix has been calculated with, depending on which electricity mix is ​​chosen, it either gives reasons to not invest or to invest in solar cells. It is therefore important to be clear about what use the solar cells will have and which electricity is actually replaced before investors decide whether solar cells are the right energy source to invest in.
35

Techno-Economic Analysis and Optimization of Distributed Energy Systems

Zhang, Jian 10 August 2018 (has links)
As a promising approach for sustainable development, distributed energy systems have receive increasing attention worldwide and have become a key topic explored by researchers in the areas of building energy systems and smart grid. In line with this research trend, this dissertation presents a techno-economic analysis and optimization of distributed energy systems including combined heat and power (CHP), photovoltaics (PV), battery energy storage (BES), and thermal energy storage (TES) for commercial buildings. First, the techno-economic performance of the CHP system is analyzed and evaluated for four building types including hospital, large office, large hotel, and secondary school, located in different U.S. regions. The energy consumption of each building is obtained by EnergyPlus simulation software. The simulation models of CHP system are established for each building type. From the simulation results, the payback period (PBP) of the CHP system in different locations is calculated. The parameters that have an influence on the PBP of the CHP system are analyzed. Second, PV system and integrated PV and BES (PV-BES) system are investigated for several commercial building types, respectively. The effects of the variation in key parameters, such as PV system capacity, capital cost of PV, sell back ratio, battery capacity, and capital cost of battery, on the performance of PV and/or PV-BES system are explored. Finally, subsystems in previous chapters (CHP, PV, and BES) along with TES system are integrated together based on a proposed control strategy to meet the electric and thermal energy demand of commercial buildings (i.e., hospital and large hotel). A multi-objective particle swarm optimization (PSO) is conducted to determine the optimal size of each subsystem with the objective to minimize the payback period and maximize the reduction of carbon dioxide emissions. The results reveal how the key factors affect the performance of distributed energy system and demonstrate the proposed optimization can be effectively utilized to obtain an optimized design of distributed energy systems that can get a tradeoff between the environmental and economic impacts for different buildings.
36

Payback Information: It's Effect on Home Buyers Regarding Energy Efficiency

Sparti, Steven E. 20 June 2006 (has links) (PDF)
This study was conducted to find out how payback analysis would affect consumer decision making with regards to home energy efficient upgrade packages. Three different home plans were obtained from a local builder and seven different energy efficient packages were created. Using Hot2000 the heating and cooling loads were calculated for each building, with each energy efficient package, in each of the four major cardinal directions. The averages were taken and the payback information was calculated. The payback information included the increased cost of the package, the increase in the mortgage payment, the annual savings from heating and cooling bills, the monthly savings, the positive or negative monthly cash flow, the amount of time and interest saved if the monthly savings were added to the mortgage principle, the number of years required to pay back the original investment, the rate of return and the increased home value. A survey was taken to see how the subjects would react to viewing the payback information. The subjects were individuals looking to buy a home in the next 12 months somewhere along the Wasatch Front area in Utah. Depending on the size of the home the subjects were looking for, the subjects were shown the different packages with their accompanying cost increase and how that would affect the subjects monthly mortgage payment. The subjects then chose the package they would want for their home, based on their knowledge of construction materials, the additional cost, and how it would affect their mortgage. They were then shown the payback information for the home that was chosen and asked if they would change their mind concerning the previous decision. They were then asked what parts of the payback information they found to be most useful. This study shows that payback information is indeed useful and would help builders to attract new customers, increase profits, and provide customers with powerful information that will empower them to make better decisions about home energy efficiency.
37

Analytical Modeling and Optimization of a Thermoelectric Heat Conversion System Operating Betweeen Fluid Streams

Taylor, Stephen H. 13 July 2011 (has links) (PDF)
Analytical, closed-form solutions governing thermoelectric behavior are derived. An analytical model utilizing a thermal circuit is presented involving heat transfer into, through, out of, and around a thermoelectric device. A nondimensionalization of the model is presented. Linear heat transfer theory is applied to the model to obtain a series of closed form equations predicting net power output for the thermoelectric device. Fluid streams flowing through shrouded heat sinks with square pin fins are considered for the thermal pathways to and from the device. Heat transfer and pressure drop are characterized in a manner conducive to an analytical model using previously published experimental results. Experimental data is presented which validates and demonstrates the usefulness of the model in predicting power output for commercially available thermoelectric generators. A specific design for a thermoelectric power harvester is suggested consisting of a pattern of thermoelectric generators. An economic model for calculating payback time is developed. An optimization process is demonstrated that allows for the payback time of such a system to be minimized through optimization of the physical design of the system. It is shown that optimization of the thermal pathways dramatically reduces payback time. Optimized design of a system is discussed in light of theoretical cases with feasible payback times.
38

Environmental Impact Assessment of aPhotovoltaic Power Station in Stockholm / Miljöutvärdering av en fotovoltaisk solcellsanläggning i Stockholm

Raouz, Khalid January 2017 (has links)
The paper at hand presents the environmental impact analysis of a photovoltaic (PV) power station sited in Stockholm, Sweden, using life cycle assessment (LCA). The LCA considers the primary energy return on investment and global warming potential of the PV-station, including; resource extraction, manufacturing, transportation, operation and maintenance, and decommissioning. Other environmental impact indicators are also presented, such as; the eutrophication, acidification, human toxicity, and ozone depletion potentials. The results show that the most critical phase of the lifecycle is the upgrade from metallurgical to solar grade silicon due to the high consumption of energy. The emissions results are compared to the emissions factors used for calculations in Sweden in accordance with the Swedish Energy agency and the European Commission’s directive for emissions calculations. The results for the other environmental indicators showed inconsistencies compared to existing studies, something that is according to the IEA’s guideline for PV-systems LCA caused by data scarcity and the indicators lacking consensus within the PV LCA-community. The studied PV-station is expected to reach energy neutrality after 2,4 years and offset annual GHG emissions of up to18 ton of CO 2 equivalents. / Studien tillhands presenterar miljöutvärderingen av en fotovoltaisk solcellsanläggning i Stockholm. Detta utfördes med hjälp av livscykelanalysverktyget. Analysen använder energiåterbetalningstiden och den globala uppvärmningspotentialen som indikatorer på anläggningens miljöinverkan. Både återbetalningstiden och den globala uppvärmningspotentialen beräknas för gruvarbetet, transporten, drift och underhåll samt avveckling och bortskaffning av anläggningen. Överföringsförluster beräknas också över anläggningens livscykel. Andra indikatorer som beräknas i denna studie är potentialen för försurning, övergödning, ozonnedbrytning och humantoxicitet. Dessa beräknas endast för modulens tillverkningskedja. Studiens resultat visar att den mest kritiska processen under solcellsanläggningens livscykel är kiselmetallens omvandling till solkisel, detta med avseende på energiförbrukningen och utsläpp av växthusgaser. Anläggningens globala uppvärmningspotential uttrycks i växthusgasutsläpp och jämförs med den nordiska elmixens utsläppsfaktor. Jämförelsen görs enligt dem gällande EU-direktiven. Resultaten för dem andraindikatorerna har visat på väsentliga avvikelser jämfört med tidigare studier. Detta beror enligt det internationella energirådet på databrist och på att dessa indikatorer saknar stöd inomLCA samfundet. Solcellsanläggningen beräknas bli energineutral efter 2,4 år samt eutralisera utsläpp på upp till 18 ton koldioxidekvivalenta per år.
39

Climate customized techno-economic analysis of geothermal technology and the road to net-zero energy residential buildings

Neves, Rebecca Ann 07 August 2020 (has links)
Individual and societal desires for fossiluel independence are an increasingly popular goal. This research investigates residential geothermal space heating and cooling as a viable technical and financial alternative. The road to net-zero energy is then assessed, weighing the benefits and detriments to the consumer. First, the template for location-specific geothermal space heating and cooling is developed through a pilot analysis of a home in Memphis, Tennessee. A methodical process of soil investigation, prototype home characteristics, and financial incentives is designed. Expanding upon existing studies, accurate soil data is extracted from beneath the foundation of a specific address, rather than region-wide soil averages. This high level of precision allows the owner of a specific address to preview realistic results and develop truthful expectations. Payback period and system lifetimes savings are calculated using two methods. Second, the framework developed through the Memphis, Tennessee pilot home is used to investigate 11 additional cities across the continental United States. The increase in breadth uses a representative city from its respective climate zone. While each city within a single climate zone will vary from the representative city, a general climate performance can be determined. With each location’s soil properties and heating and cooling demands, the borefield design and heat pump system capacity is customized and applied for analysis. Using human interest surveys from previous energy projects, a climate is ultimately classified as viable or nonviable for geothermal heating and cooling. Finally, the increasingly popular net-zero energy building concept is explored through a complementary solar photovoltaic (PV) array to the geothermal system. An array capacity is sized and priced to offset the total facility energy use in each climate’s representative city. Once determined, the payback and lifetime savings values are calculated and the GHP + PV system results are compared to a baseline + PV system. From this, a system type is identified as the more viable option for each of the 12 climate zones. The final touch on this research is the introduction of the human perceptions toward environmentally friendly renewable energy in general and how it affects a consumer’s ultimate decision.
40

SCREENING METHODOLOGY FOR PRIORITIZING ENERGY CONSERVATION MEASURES FOR OFFICE BUILDING STOCKS

Perry, Heather Lynn 10 1900 (has links)
<p>As energy costs continue to escalate and awareness spreads with regard to the importance of sustainability, interest in reducing energy consumption of buildings is growing. For managers of large stocks of office buildings, the task of selecting building improvement projects is most challenging. A multitude of energy conservation measures (ECMs) are available from which to select, however financial resources are limited and in high demand. Thus, ECMs must be known to be effective and prioritized so as to provide the highest benefit for the financial resources available.</p> <p>The aim of this study is to provide a screening methodology for the evaluation and prioritization of ECMs for implementation in a stock of buildings that exhibit varying characteristics and locations. Prioritization of ECMs is based on predicted energy consumption savings and financial analysis. Building stocks are reduced to a manageable set by applying archetype classification. Energy consumption predictions for representative buildings from each archetype are obtained through use of a mathematical model. Twelve ECMs pertaining to improvements in the building envelope, HVAC, and electrical systems are considered and ranked based on present value over the short, mid, and long terms.</p> / Master of Applied Science (MASc)

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