Sökresultat:
4465 Uppsatser om Specific energy consumption - Sida 42 av 298
Optisk sortering av matavfall : en jämförelse med en minskning av svinnet
The purpose of this study is to compare the energy related and environmental consequences of implementing optical sorting as a means of waste collection with those of reducing food waste. In addition to studying the possibility of implementing optical sorting in downtown Stockholm, the yielded amounts of energy from waste collection and reduced wastage will be calculated. This is done by way of literature reviews and interviews. The amount of energy that can be generated through optical sorting and biogas production via anaerobic digestion in downtown Stockholm is 29-44 TJ/year, compared to 118 TJ/year saved by completely eliminating food waste. The generated biogas can replace fossil fuels, but the required food waste contributes to increased greenhouse gas emissions as well as reduced bio diversity and eutrophication during the wasted food?s lifecycle.
Termoelektrisk lagring i system med fjärrvärmeproduktion
With increased deployment ofintermittent renewable energy, such aswind and solar power, energy storagebecomes necessary to help reduceproduction peaks. Thermoelectric EnergyStorage is a method still in researchphase, which stores electricity in hotwater at a temperature of 120 ° C. Thisthesis aims to examine whether theThermoelectric Energy Storage would bepossible to integrate into existingpower generation such as a combined heatand power plant, and how the technologypotentially could function in theelectricity market. ThermoelectricEnergy Storage consists of a chargingprocess and a discharging process, bothoperating by the working fluid CO2. Toincrease the efficiency of theThermoelectric Energy Storage, wasteheat from the district heating networkis integrated.A model of the Thermoelectric EnergyStorage has been developed and it wascalculated by thermodynamic propertiesof the working fluid, CO2, in thevarious process steps.
Rökgaskondensering och skrubber till vedeldade villapannor :
This paper deals with the opportunities for the technique of condensation, for wood fired household heaters, on the Swedish market. In this project the condenser is preceded by a scrubber and both energy exchange and separation of unburnt particles have been studied.
The facility studied is connected to a wood stove at 30 kW. The tests would show that the effect from the stove never reached above 16 kW. This might be a result of the low temperature of the water going into the stove, from the condenser. In addition to this the wood was not of highest quality and the stove could have needed some maintenance before the tests.
Analys av systemfaktorers påverkan på tillförlitligheten i distributionsnät
In this master thesis outage statistics covering tree years from two distribution grids are analyzed with the purpose to deduce which factors yield outages. The statistics are extensive therefore allowing in-depth analysis of both customer and system related factors. From this starting point and as a model of explanation energy not supplied is studied as the consequence and the measurement of the inconvenience caused by outages. Different methods for calculating energy not supplied are developed and studied and put in comparison to the method used in Network Performance Assessment Model, which is the Swedish frame work for regulating electricity distribution.Analysis of the outage statistics show a relation between the type category of customer and outages that can be deduced to the variance and the density associated with that customer category. Prioritization of different customer categories is elevated also in this aspect.
Miljöbedömning av olika behandlingsmetoder för organiskt hushållsavfall, slakteriavfall och flytgödsel
Organic material used for biogas production can also undergo other treatments. The emissions and impact from the different treatments are evaluated in this environmental assessment, with a focus on energy and climate. The materials included in the study are organic household waste, slaughterhouse waste and liquid manure. Other than biogas production, the possible treatments for organic household waste and slaughterhouse waste are incineration and composting, and for liquid manure storing and spreading. The analysis is based on data and information from current and relevant literature, and relates to the conditions in the Swedish energy system.
Från alger till biodiesel - Den italienska drömmen?
This project aims to investigate whether algae can be used for biodiesel production in Italy. Algaes are a good option since they are fast growing and do not occupy arable land. The aspects that have been considered are growing, harvesting, which algae strain that is most suitable, extraction of oil, the production of biodiesel and where in Italy this could be possible due to climate. Cost? and energy calculations have been made to investigate if biodiesel produced from algae would be profitable. During the production of biodiesel there are several residues obtained. When the oil has been extracted from the algae, biogas is produced from the residual biomass by anaerobic digestion and then the electricity that can be produced is supplied to the production of biodiesel.
Effekten av olika andelar grovfoder och kraftfoder i foderstaten på mjölkproduktion, välfärd och hälsa hos mjölkkor
Dairy cows transform grass to milk with help from ruminal microorganisms that can digest indigestible fiber in their feed. The digestive system of the cow is adapted to a diet consisting of forage and disorders like acidosis, laminitis and abomasal displacement can occur if the feed contains too much starch. To achieve the highest production possible the cow has to be given a high amount of concentrate or grain as the difference in milk yield is significant, approximately 1000 kg energy corrected milk per cow and year between conventional and organic cows that are fed a lower versus a higher share of forage. If the cow shall be able to eat the same amount of energy from forage as from grain or concentrate the eating- and rumination time gets longer and she might not be able to eat enough, which will result in a lower milk yield and will make it harder for the cow to recover from the negative energy balance that originate from the beginning of the lactation. Fat and in a sense protein content differs also depending on if the cow is given a high or low share of forage..
Utveckling av en ytmonterad fördelningsmätare som underlag för individuell debitering av vattenförbrukning i fastigheter
The master thesis, conducted at Metrima AB, concerns the development of a non-intrusivedistribution meter as a basis for individual tap water billing in apartments.The project is conducted in response to the market interest in individual tap water billing inapartments as an answer to environmental concerns regarding water consumption. Due to thehigh installation cost of traditional water meters, a new method of determining waterconsumption, without having to cut water pipes, is proposed.The proposed method distributes the total water consumption for an apartment complex toindividual apartments according to distribution meters, measuring water run-time, in eachapartment. The water run-time is estimated by measuring the water pipe?s outward vibrationsand temperature changes.A test environment was established and a prototype built, using a tilt- and vibration sensor forvibration sensing and a precision temperature sensor to measure temperature changes. As bothsensors work well in the test environment, further testing was done in 3 apartments for aduration of 5 days.
Hållbara städer ? bidrar IT? En undersökning huruvida kommuner använder IT för att uppnå en hållbar utveckling
Environmental issues and sustainable development is a high priority in today?s society and has received substantial attention lately. In the inaugural speech it is expressed that the goal for the IT?politics is a sustainable information society for everyone, which can be achieved by using IT to support sustainable growth. The Ministry of Enterprise, Energy and Communications has developed a document which outlines three specific proposals on what the government should focus on during a three?year period (2008?2010) that with the use of IT will contribute to a sustainable society.
Effekten av frukostens glykemiska index på energiintag hos barn och ungdomar
Sahlgrenska Academyat University of GothenburgDepartment of Internal Medicine and Clinical NutritionTitle: The effect of the glycemic index of breakfasts in energy intake inchildren and adolescentsAuthor: Charlotte Olofsson, Cornelia Johansson and Maria NordbeckSupervisor: Fredrik BertzExaminer: Ingrid LarssonProgramme: Dietician study programme, 180/240 ECTSType of paper: Examination paper, 15 hpDate: May 16, 2013Background: The glycemic index (GI) and it´s effect on energy intake is a debated subject.Research has been done whether food with lower GI decreases hunger and lowers energyintake, which could be an effective tool to prevent overweight in children and adolescents.Breakfast eating is successful for maintaining a healthy weight and it´s therefore interesting tosee if the quality of the carbohydrates matters.Objective: To evaluate the scientific evidence regarding the effect of GI of breakfasts inchildren?s and adolescents energy intake.Search strategy: To find relevant articles, a systematic literature search was made in thedatabases PubMed, Scopus and Cochrane. Search terms that were used were: breakfast,breakfast quality, children, glycemic index, energy intake, obesity.Selection criteria: Randomized controlled trials and cohort trials, breakfast eatingindividuals, children and adolescents under 18 years old, reported glycemic index. Outcomemeasurements: Energy intake.Data collection and analysis: Six original articles met the inclusion criteria and werereviewed by the SBU audit template for randomized and controlled studies. There after onearticle was excluded because of very low quality of the study.
Automatiskt avvägningssystem för obemannad undervattensfarkost
This master thesis work was done at Saab Underwater Systems AB, a company at the cutting edge of underwater technology. Here torpedoes and other underwater vehicles are developed and manufactured. The major customers are navies of different countries, mostly the Swedish navy. The aim of this master thesis is to develop, construct and evaluate an automatic Trim System for Unmanned Underwater Vehicles. The task of the system is to change the position of the centre of mass and the vehicle?s total mass or volume.
Integrering av gamification i reklam : utmaningar, möjligheter och problem
In this study, we have explored a new area called ?gamification? ? a word and concept that was first introduced on the Internet autumn 2010. Gamification concerns integrating game design, with emphasis on game mechanics and game dynamics, into non-gaming contexts ? such as marketing. At its basic definition, it concerns the process of transforming all kinds of activities into games.
Studie av energianvändningen på Spira förskola: En jämförande studie av faktiskt och simulerad energianvändning samt en parameterstudie av ingående data vid simuleringar av energianvändning
I detta arbete har den faktiska och simulerade energianvändningen på Spira förskola i Luleå undersökts. Den faktiska specifika normalårskorrigerade energianvändningen fastställdes till 121,4 kWh/kvm år. Vid projektering av förskolan uppskattades den specifika energianvändningen med hjälp av simuleringsprogrammet VIP-Energy till 78,5 kWh/m2 år. Därmed översteg den verkliga användningen den simulerade med 54,6 %.En parameterstudie av indata till simuleringsprogramet har också genomförts med avsikt att fastställa den totala förändringen i energianvändning då indata ändras. Följande parametrar har studerats;?Drifttid hos ventilationssystemet?Horisontvinkel?Inomhustemperatur?Klimatzonen?Kvot mellan till- och frånluft?Luftomsättning för ventilationssystemet?Solreflektion från omgivande mark?Temperaturverkningsgrad?Vindhastighet?Vridning av byggnadenNyckeltal som kan användas för att snabbt uppskatta påverkan på den totala energianvändningen har också sammanställts för majoriteten av de studerade parametrarna.
Värmeöverföring i bergvärmesystem : En numerisk analys av den ringformade koaxiala borrhålsvärmeväxlaren
The borehole heat exchangers of today suffer from poor thermal and hydrodynamic performance. The purpose of this thesis is to improve the performance of ground source heat pump systems and thermal energy storages by increasing the energy efficiency of the borehole heat exchangers. For this reason, the annular coaxial borehole heat exchanger (CBHE) has been analyzed. This type of heat exchanger is interesting in terms of both thermal and hydrodynamic performance. A model has been set up in the program Comsol Multiphysics in order to investigate the heat transfer characteristics along the borehole.
Beräkning av värmeförluster och energieffektivisering av elbussar
The ?civilized? world is in need of fossil fuel in order to function. Hybricon AB is a company in Umeå that is developing a technology that hopefully can reduce parts of this need. They are currently testing their two electrical busses (with Hybrid backup) in city traffic on the roads of Umeå in cooperation with the county of Umeå. The busses are originally diesel-busses, but the diesel motor has been replaced with two electrical hub-motors with a power of 145 kW each that are powered by batteries.The batteries are charged at the end station after each route. In case the batteries should run low on capacity during driving, they can be recharged by the so called genset.