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1064 Uppsatser om Heat expansion - Sida 7 av 71
Energieffektivisering genom förvärmning av flis till kokare med sekundärvärme
The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester.The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester.Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected.
Analys av off-design prestanda för ett absorptionskylsystem
This master thesis project at KTH is performed in the Mechanical and Aerospace Engineeringdepartment at University of Florida (UF). The thesis is a small part of a gas turbine researchproject where a vapour absorption refrigeration system (VARS) and a high pressure regenerativeturbine engine (HPRTE) are integrated together. The main objective is to build a computermodel of the VARS. The computer model is supposed to be used to analyse the off-designperformance of the VARS and should also be easy to integrate as a subroutine in a more complexsystem model. To model the VARS some knowledge of the absorbent/refrigerant mixture had tobe well known, in this case a mixture of ammonia and water.
Analys av energianvändningen i kvarteren Carolina och Jenny : en fallstudie
An energy study has been performed on two blocks in an area called Gävle Strand. The buildings are owned by a tenant-owner?s association called brf Carolina and were built by the company Skanska 2008. The builder as well as brf Carolina are pussled by the fact that electricity use is higher than expected while heating is less. Skanska is also very interested in finding out how much heat recovery from stale exhaust air through a geo-thermal heat pump is contributing to the general heating requirement and energy balance in four out of the ten buildings located on the properties.To find possible answers to the higher electricity use a literature survey on user behaviour was conducted.
Optimering av glidlager och utveckling av dess konstruktion
I detta projekt har vi fördjupat oss i en glidlagerkonstruktion som befinner sig i en skruvpress. Skruvpressen kompakterar en okänd massa som är sekretessbelagd. Robustus har ett förslag på överdimensionering av det nuvarande glidlagret. Målet med projektet var att analysera och optimera några glidlager i förhållande till det befintliga glidlagret samt att ta hänsyn till materialval och den miljö som lagret kommer att befinner sig i. Det som analyserna och optimeringen visade var att det befintliga glidlagret hade den bästa geometrin bland alla lösningar men inte det optimala materialet.
Hållbarhetsaspekter på tillvaratagande av spillvärme i borrhålslager- ur ett företags- och samhällsperspektiv
The objective of this study is to examine the sustainability of recovering industrial wasteheat from several heat sources in a foundry constructed in a plant belonging to ITT Waterand Wastewater in Emmaboda, Sweden. A triple bottom line perspective will be appliedto achieve this objective. The triple bottom line approach takes into account ecologicaland social performance in addition to financial performance. The technology forrecovering the waste heat is a Borehole Thermal Energy Storage (BTES) which is aconstruction consisting of 140 vertical boreholes, 150 meters deep with an internal spaceof four meters.The calculated amount of energy for storage is approximately 3800 MWh annually. Ofthis amount 2500 MWh are expected to be utilized, while storage losses accounts for theremaining part.
Kastrering av frisk tik
In this work we have compiled results from various studies concerning medical conditions that may possibly be avoided by castration and the effects that may occur after castration of the healthy bitch. The work is a literature review but it also includes a summary on the age recommendations for castration of the healthy bitch, castration before or after the first heat and the castration method most commonly used of ovariohysterectomy and ovariectomy. The summary is based on a questionnaire answered by personnel from 20 veterinary clinics and animal hospitals evenly distributed throughout Sweden.The summary showed that ovariohysterectomy was the most common method of castration and the recommendation in age ranged from 6-12 months. Regarding castration before or after the first heat 75% of the veterinary clinics and animal hospitals answered that they recommended castration after the first heat. Literature study shows that there are both advantages and disadvantages of castration of the healthy bitch and that it therefore is important that each bitch get a personal and individual evaluation before a decision is taken concerning a castration..
Val av värme- och ytbehandling
Atlas Copco Tools develops and manufactures handheld industrial tools. Heat and surface treatments are used to provide the tools with certain properties. There are no routines for the choice of treatment or for how to specify treatment on drawings. Production documents that are sent for production abroad may not be clear enough. Some treatments are known as trademarks and there are no instructions for how to specify these on drawings and in CAD-models.The purpose of this master thesis work is to create recommendations for the procedure of choosing heat and surface treatment.
Utveckling av lastmodell för Uppsala fjärrvärmenät
The aim of this study was to develop a load prognosis model for Uppsala district heating system to be used as a tool for heat production optimization. The methodwas to build three models for the different customer types; housing, industry andoffices and then scale them for the total system using data from Uppsala districtheating system. The heat load consists of two parts, one that is temperaturedependent and one that is dependent of the social behavior of the customers. Thetemperature part was modelled with an ARX model using an outdoor temperatureprognosis as input signal. The social behavior part was modelled using the mean ofthe social behavior from some days before and additionally by distinguishing betweenweekdays and weekends.
Energianvändning i serverhallar: energiflöden och kylning
This thesis examines different methods for the cooling of data centers. Several means of cooling with the refrigeration cycle have been studied, as well as the feasibility of using free cooling in different parts of Sweden. In addition, the possibilities of transferring excess heat to a nearby district heating system were investigated. It was found that in all investigated cases except two, the data center could be cooled solely with free cooling for at least 300 days a year when only the outside air temperature was considered as a constraining factor. The limit was then set to 20 °C.The vast majority of all district heating systems in Sweden get little to none of their heat from other excess heat sources.
Vitvarueffektivisering med hjälp av värmelagring : Simuleringsstudie kring energiförsörjning av vitvaror med hjälp av värmepump & ackumulatortank
The constant need of energy is something that affects us all no matter our current situation. Whether we are driving our car to work, taking the elevator or using the oven to cook dinner we end up relying on energy. Our whole society is continuously striving to achieve a higher grade of efficiency and the process of supplying ourselves with energy is no exception. The importance of appliances in our everyday life cannot be exaggerated and thus the importance of their high efficiency.Efficiency is already a keyword in the appliance industry with labels, stars and numbers helping us choosing the most suitable option for the task ahead. No matter how efficient appliances often use pure electricity as their energy source.
Resurseffektiv livsmedelsproduktion : Tillämpning av industriell symbios för ökad resurseffektivitet inom den svenska tomatodlingsbranschen
Industries with energy costs as a large proportion of their total costs are greatly affected by the instruments deployed to cope with the Swedish climate and energy policy goals. With energy costs representing more than 30 % of the total costs, tomato cultivators are one of the affected industries. In order to remain competitive with other countries, a more resource- and cost-efficient cultivation of tomatoes in greenhouses is desirable in Sweden. Based on the concept of industrial symbiosis, this study investigates the prerequisites for a resource-efficient production of locally grown tomatoes in Sweden through the utilization of low grade industrial waste heat. The study is based on the foundry industry as the supplier of waste heat.To investigate the environmental, technical and economic potential of the exchange of waste heat, a comparative life cycle assessment, an inventory of the supply of industrial waste heat in Sweden, a compilation of potential technologies for the recovery of low grade industrial waste heat for heating greenhouses and a comparative life-cycle cost calculation were carried out.
Islamiskt bankväsende : en kvalitativ studie om internationaliseringsprocessen för islamiska banker
The first official Islamic bank was established in 1975. The characteristic of an Islamic bank is that the bank is based on an interest free system. The interest free system is a requirement for an Islamic bank. The Islamic bank system is based on Sharia laws which are laws that are followed by Muslims and it is based on the text from the Quran. The Islamic Banks had a rapid expansion between 1993 and 2003, the expansion was about 23 percent and since 2003 have the expansion been about 20 percent.
Expansion av sökfrågor med Svenskt OrdNät som termkälla
The purpose of this Masters thesis is to examine the performance of queries that are expanded by synonyms and hyponyms from Svenskt OrdNät, the Swedish version of the Princeton WordNet. Four different types of queries were constructed: a baseline query S1, the baseline query expanded with synonyms S2, the baseline query expanded with hyponyms S3 and finally the baseline query expanded with the synonyms and hyponyms used in S2 and S3. The terms for expansion were picked by hand. The queries were executed in the Query Performance Analyser QPA, a tool used in IR education and in experimental IR research for analysing and comparing the performance of individual queries. 20 topics from the test collection GP_HDINF were chosen for the experiment.
Lågtempererad fjärrvärme i Umeå
People in today?s society are becoming more and more aware of how important it is to use energy as efficiently as possible. This is clearly noticeable by an increase in home produced heat with e.g. solar panels or heat pumps heating systems. These changing customer demands forces district heating technology to be redesigned, which is why there is an ongoing research regarding the next generation of district heating - low temperature district heating (LTDH).
En fallstudie om expansion på Gavle Marknadskommunikation
Syfte:Denna studie fokuserar på ett företag, Gavle Marknadskommunikation. Syftet med uppsatsen är att undersöka hur och varför företaget expanderade till flera nya regioner. Då företaget senare gick i konkurs och därefter nybildades så ämnar jag undersöka om expansionen hade någonting med konkursen att göra. Detta för att kunna utreda vilka risker som togs i samband med expansionen, samt ge exempel på vad man bör tänka på när man skall expandera sin verksamhet. Dessutom skall jag utreda vad som kunde ha gjorts för att förhindra konkursen..