Detta arbete beskriver hur Herons ångkula fungerar och hur den har byggts. Ånkulan konstruerades för ca 2000 år av Heron. Meningen var att få fram en verkningsgrad eftersom denna var okänd. Verkningsgraden blev aldrig konstaterad. Endast en teoretisk beräkning för verkningsgraden gjordes. Kulan sattes inte i rotation av ångtrycket som byggdes upp när det eldades under denna. Anledningen var troligen att det var för mycket friktion i tätningen som skulle tillföra matarvatten in i kulan. Värmeöverföringen mellan gaslågan och kulkroppen var inte heller den mest optimala. Kulan med tillhörande kringutrustning byggdes under dec-07/jan-08 efter eget tycke och utan någon existerande ritning. Den byggdes för att efterlikna originalet så mycket som möjligt. Dessutom hade en mindre ångkula byggts några år tidigare och denna hade visat sig fungera. Denna något större ångkula fick därför samma utseende. Eftersom ångkulan inte orkade rotera råder det inga tvivel om hur ineffektiv denna tidiga reaktionsmotorn är. Den fick ingen praktisk betydelse för 2000 år sedan, och det har den inte idag heller. En framräknad verkningsgrad finns redovisad och denna blev mycket låg. Det var stimulerandel att bygga Herons ångkula men konstruktionen i sig tillhör inte de mest lyckade. / This work describes how the Herons steam ball was built and how it works. It was constructed by Heron 2000 years ago. The purpose was to determine the efficiency of the steam ball because it was unknown. The efficiency was never determined. It was only theoretically determined by calculations. The steam pressure never gave the steam ball rotation when heat was added underneath the construction. A possible reason was that friction in the sealing for supplying feed water into the steam ball was too high. The heat transfer was also a reason that the construction did not rotate. The steam ball and necessary equipment was fabricated in dec-07/jan-08. It was built without any drawings. The goal was to make it look like the original as much as possible. A smaller steam ball was built some years before. This one did rotate and therefore was the same design given to the bigger one. Because of the lack of rotation there was no doubt if the steam ball was a sucsess or not. It was not used for any real purpose 2000 years ago and this has not changed. A calculated figure of the efficiency was documented in this rapport, and it was very low. It was amusing to design and build the steam ball but the construction was clearly no success.

This thesis presents a study of the cooling process of a solid block performed by a turbulent air flow channel. The study focuses on the turbulent flow and its influence in the heat transfer of the block. The first part of the thesis is an analysis of the different turbulent model and their adaptation on the necessities of this study. Once the turbulent model has been confirmed it makes a study of the behavior of the cooling process by CFD (Computational Fluid Dynamics), and an analysis of the numerical accuracy of this computational study. When the procedure of the study of the cooling process is defined it proposes some different variations in the initial solution to improve this process. The study concentrates in variations of the turbulence and the geometry of the studied block. Finally, the different improving are discussed analyzing parameters as the heat transfer, pressure drop, time consuming or energy consuming.

<p> </p><p>Due to its impact on human health and the nature surrounding us, diesel engine emissions have been significantly reduced over the last two decades. This reduction has been enforced by the legislating organs around the world that gradually have made the manufacturers transform their engines to today’s complex high-tech products. One of the most challenging areas to meet the legislations is transient operation where the inertia in gas-exchange system makes transition from one load to another problematic.</p><p> </p><p>Modern engines have great potential to minimize the problems associated with transient operation. However, their complexity also imposes a great challenge regarding optimization and systematical testing of transient control strategies in an engine test bed could be both expensive and time consuming.</p><p> </p><p>The objective of this project is to facilitate optimization of transient control strategies. This should be done by identifying appropriate measurement methods for evaluation of transients and by providing models that can be used to optimize strategies off-line.</p><p> </p><p>Measurement methods for evaluation of transients have been tested in several experiments, mainly focusing on emission but also regarding e.g. EGR flow. Applicable instruments for transient emission measurements have been identified and used. However, no method to measure soot emissions cycle resolved has yet been found. Other measurements such as EGR flow and temperatures are believed to have significantly decreased accuracy during transients.</p><p> </p><p>A model for prediction of NOx emissions have been used and complemented with a new approach for soot emission predictions that has been developed in this project. The emission models have been shown to be applicable over a wide range of operating conditions with exception for highly premixed combustion. It has also been shown that models developed for steady state conditions can be used for transients operation.</p>

<h1>Abstract</h1><p>The future of ethanol is depending on good solutions for the production. ENA energy power plant produces electrical power and district heating by heating biofuel. By building an integrated bioenergy plant surplus steam could be used to produce ethanol as fuel to vehicle.</p><p>This would mean that ethanol is produced renewable energy and the energy for the process derives from the surplus of power.  ENA energy, MDH (the University of Mälardalen) and the energy authority has initiated a research project were different bioenergy combinations integrate with existing power plant.  As a part of the project which size an integrated factory should be to gain the best efficiency for the plant was investigated. Consideration will be taken to the cost of the production in order to be competitive to the price of imported ethanol.</p><p> </p><p> </p><p>Etanolens framtid vilar på bra lösningar för framställning.  I ENA energi kraftverk i Enköping produceras el och fjärrvärme genom eldning av biobränsle.  Genom att bygga ett integrerat bioenergikraftverk där skulle man kunna använda överskottsånga till att framställa etanol som fordonsbränsle. Detta skulle innebära att etanolen framställs med ett förnybart bränsle och energin till framställningen kommer från ett överskott på värme.   ENA energi, MDH och energimyndigheten har initierat ett forskningsprojekt där en bioenergiintegrering skall undersökas.  Som del i detta skall här undersökas vilken storlek en integrerad etanolfabrik skall ha för att nå högsta totala verkningsgrad för verket samt om framställningspriset kan konkurrera med importerad etanol.</p><p> </p>

<p>In order to reduce the discharge of the greenhouse gas CO2, the use of biomass is nowadays promoted as fuel in boilers. Compared to boilers fired with coal and oil the biomass-fired boilers have more complications related to both fouling and corrosion on the heat transfer surfaces. After the combustion, unburned inorganic matter in state of vapour, melts and solid particles are transported in the flue gas and may form deposits on heat transfer surfaces.</p><p>Deposits on the heat transfer surfaces may result in both increasing corrosion and decreasing boiler efficiency as the heat transfer rate to the superheaters and reheaters decrease by deposits.</p><p>In order to understand the process of deposit build-up, the whole combustion and transport process had to be analysed including aspects such as, boiler design, fuel properties and combustion environment, followed by particle transport phenomena and the probability for particles to get stuck on the heat transfer tubes.</p><p>In this thesis numerical simulation of particle trajectories has been conducted as well as measurements of deposits on a special designed deposit probe followed by investigation of on-site measurements of deposit depth on the super-heater tubes in a circulating fluidised bed in Västerås, Sweden.</p><p>Numerical simulations of particle trajectories in the vicinity of two super-heater tubes were conducted in an Eulerian-Lagrangian mode considering the flue gas and ash particles phase. Particle impingements on the tubes were investigated for different particle sizes. The results from the particle trajectory simulations show that particle larger than 10 µm will mainly impinge on the windward side of the first tube but, however also on the sides of the second tube in the flue gas flow direction. In theory as well as from observations and measurements two tubes can merge together by the deposit build-up. Smaller particles are usually more dispersed due to turbulence and thermophorectic forces, resulting in a more even impingement distribution on the whole surface of the tubes.</p><p>Probe measurements reveal that the deposit layer growth rate have a significant temperature and time dependence. After the initial deposit build-up a sintering process occurs and sintering is also proven to be dependent on temperature and exposure time.</p><p>Soot-blowing is the most common method to reduce the effect of deposits on the heat transfer tubes. In the present thesis the soot boiling efficiency is therefore also investigated. The soot-blowing show a strong positive effect on the heat transfer rate in a short time (hours) perspective after a soot-blowing cycle is completed. This positive effect is much weaker when considering a time period of three years. This is an effect of fact that soot-blowing mostly remove the loose part of the deposit material leaving the hard sintered part unaffected.</p><p>The subject of deposit build up on superheater tubes in large scale boilers involves multi-discipline knowledge and historically, the related research is mostly conducted as measurements and experiments on operating plants. Possibly in the future, theoretical simulations will have a bigger part of research on deposit build-up where the calculations are to be calibrated through measurements on real sites plants.</p>

<p>Heat and power stations are often in need of optimizations. A simulation model is a tool for findingways to optimize the plant. The scope of this diploma work is to develop a simulation model ofBoiler 5 at Mälarenergi AB. Boiler 5 is a circulated fluidized bed boiler that was taken into service inyear 2001. Among the included parts in the boiler are cyclone, convection part andINTREX-chambers. The software that was used for the simulation was SimTech’s IPSEpro. IPSEprois a heat and mass balance software for steady state calculations. The program comes with a set ofmodules in a library called APP_lib which contains modules such as preaheaters, pump, boiler andturbine stages. The user can however design own modules in the Model Development Kit, since thelibrary code is open source. The development of the simulation model started with an updating of anold model from year 2003. Values provided from Foster Wheeler where then used to make the modelcalculate in a right way. Thereafter some calculations of the super heaters’ heat transfer coefficientswere made. The coefficients were then translated into IPSEpro’s own programming language ModelDescription Language, and were put into the model’s modules. The results were compared with realvalues from the plant’s system. It showed that the calculated values needed more investigations to bemore accurate. The conclusion was that the final model needs more equations to describe the plant in amore realistic way.</p>

<p>This diploma work covers an investigation over the heat - and hot water systems of the</p><p>tenant-owner's association, Bogården. The heat - and hot water needs of Bogården are</p><p>satisfied by both district heating as well as three heat pumps. Implemented investigation</p><p>shows that the heat pumps are not used in a profitable way. Apart from that, the reserve</p><p>possibilities are small. There is also a risk of the growth of Legionella bacterium in the</p><p>hot water system.</p><p>Since the heat pumps are already installed, HSB-Gävleborg (responsible for Bogården)</p><p>has a wish to investigate possible proposed actions for optimization of existing plant.</p><p>After completed investigation, a new proposed action is presented. The new proposed</p><p>action goes on intercepting the hot water production and using the heat pumps to only</p><p>heat production during the heating season. Why the hot water production should be</p><p>intercepted, is just in order to eliminate the risk of Legionella. Besides, the new proposal</p><p>is going to bring about a reserve of 1,534,000 SEK during a twenty-year period. This is</p><p>approximately twice as much as what the existing plant may bring during the same</p><p>period.</p><p>During the work's review, it also has been established that heat - and hot water systems</p><p>are error regulated. Since the diploma work does not cover that piece it is instead</p><p>informed as proposals subject to further investigation.</p>

<p>Drying laundry has become a huge consuming factor of energy in residential areas through drying machines as tumble dryers and cabinet dryers. In USA the increasing use of drying machines in households increased from 40% during the 1970 to 80% in the 1990, which correspond to a usage of approximately 76 million drying machines.</p><p>The European market for drying cabinets is not huge. It is mainly Scandinavia that is using cabinet dryers for drying laundry these days. Nowadays cabinet dryers that use hoses to evacuate humid air out the building are developed in the market. Asko Cylinda AB has developed a new condenser cabinet dryer out of a regular cabinet dryer. With the new condenser cabinet dryer no hoses are required because the drying process take place in a closed recirculation system. Several openings at the back of the condenser cabinet dryer make it possible to dry laundry horizontal in different sections.</p><p>In this thesis the condenser cabinet dryer has been studied in a simulation program that is called Comsol MultiPhysics. A 2-dimensonal model was created where the airflow patterns and temperature distribution in the dryer was simulated. On the basis from the basic model of the dryer several modifications was created to attain knowledge of which modifications contributes to an improved airflow pattern.</p><p>The temperature distribution in the condenser cabinet dryer is uneven in the sections according to the simulations the air distribution is good in section 2 and 3 in the basic model. The factor that has the largest impact on the air distribution is the air stream that flows up at the back inside the cabinet, the air stream restrains a part of the hot air jet from the openings at the back. Case 1.1 is the modification that created the best airflow profile, which contributed to an even temperature distribution. In the modification the textiles were used to cover up the space at the back of the cabinet to eliminate the air stream to flow up between the textile and the openings. The effect transport between the textile and the air increased with 50 % at several sections when the modification was carried out according to case 1.1.</p><p>This study is a good basis for further studies in simulation of airflow and temperature distribution in the condenser cabinet dryer. The next step in the study is to create a 3-dimensional model of the cabinet. With this study the 3-D model could be accomplished easier by using parameters from the 2-D model as data on the boundaries. By doing so the system could be delimited, this would reduce the use of computer capacity.</p> / <p>Torkning av kläder har med tiden utvecklats till att bli en stor faktor av energiförbrukning i bostadsområden genom maskiner som bl. a. torktumlare och torkskåp. I USA ökade användningen av torkmaskiner i hushåll från 40% under 1970 till 80% i 1990, vilket motsvarar en användning av ca 76 miljoner torkmaskiner.</p><p>Marknaden för torkskåp är inte stor i Europa. Det är främst Norden som använder torkskåp för torkning av kläder. I dagsläget tillverkas s.k. avluftarskåp, d.v.s. det krävs en slang ut ur huset för att evakuera den fuktiga luften. Asko Cylinda AB har på senare tid utvecklat ett nytt kondensorskåp av ett sådant avluftarskåp. Med det nya kondensorskåpet behövs det inte någon evakueringsslang ut ur huset eftersom torkningen sker i ett recirkulerande system. Gälarna i bakkanten av torkskåpet möjliggör plantorkning eftersom luften skickas in i flera sektioner.</p><p>I uppsatsen har kondensorskåpet studerats i ett simuleringsprogram som kallas Comsol MultiPhysics. En 2-dimensionell modell skapades där bl.a. luftströmningsbilden och temperaturfördelningen i skåpet simulerades. Utifrån grundmodellen skapades ett antal modifieringar på kondensorskåpet för att erhålla kunskap om vilka modifieringar som ger bättre luftflödesbilder.</p><p>Temperaturfördelningen i kondensorskåpet är ojämn enligt simuleringarna då luftdistributionen är bäst i sektion 2 och 3 i grundmodellen. Faktorn som har störst påverkan på luftströmningsprofilen är den uppströmmande luften vid baksidan av skåpet, luften bromsar upp den varma luftstrålen ut från gälarna. Fall 1.1 är modifieringen som skapa den bästa luftströmningsprofilen vilket bidrog med en jämnare temperatur-fördelning. I modifieringen användes textilerna för att täppa igen ytorna vid baksidan av kondensorskåpet för att eliminera uppströmmande luft framför gälarna. Effekttransporten mellan textilen och luften ökade med upp till 50 % på flera sektioner då grunduppställningen modifierades enligt fall 1.1.</p><p>Studien i denna rapport är ett bra underlag för fortsatta studier inom simulering av luftströmningen och temperaturfördelningen i kondensorskåpet. Nästa steg i studien är att konstruera en 3-dimensionell modell av skåpet. Med hjälp av den här studien kan en 3-D modell underlättas genom att använda parametrar från 2-D modellen som indata på randvillkor. Genom det kan systemet avgränsas för att minimera 3-D modellens konsumtion av dataminne.</p>

While biomass utilization for energy conversion in the industrialized nations is being largely developed, highly efficient and environmentally friendly, many tropical countries still use biomass at low efficiencies and high emission levels. The main reasons for these gaps are both political and technological: the energy markets are different, the Gross National Product (GDP) differs widely, and the feedstock differs in form and conversion behaviour. By implementing newer technologies adapted for tropical biomass feedstock, there would be a large potential in these countries for increased energy services since access to modern energy still is an essential step for improving the GDP for a country. Two dominant and tropically placed industries available for energy improvements are the cane sugar and palm-oil industries, which both produce an abundant amount of biomass residues. One step towards enhanced utilization of the residues, which would not require large investment costs in the power plant section nor in the processes of these industries, would be to install a pelletizing unit in the industry area to make fuel out of the excess residues for sale to the nearby villages. The pellets could be used both for cooking/heating and for small-scale power generation in a gasification-IC engine plant. The overall objective of this study is to experimentally evaluate the biomass residues in pellet form from the cane sugar and palm oil industries during conversion to useful energy in small-scale systems. The thesis is built upon five publications which include experimental analysis on flaming pyrolysis and rapid heating of pellets (paper I), pyrolysis in oxygen-free atmosphere and slow heating with subsequent steam gasification (paper II), global pelletizing data such as relative energy consumption, temperature levels, particle size and moisture content for successful pelletizing process (paper III), downdraft gasification evaluation including reactor temperature distribution, gas composition, cold-gas efficiency and packed-bed mechanics (paper IV) and a numerical model including the overall system efficiency for residue-to-electric power based in a small-scale gasifier system (paper V).The single-pellet studies revealed that pyrolysis in reducing atmosphere is to prefer compared to flaming pyrolysis in oxidizing environment with regards to the char quality. The studies also showed favourable thermochemical and mechanical behaviour for smaller size pellets (Ø6- Ø8mm) compared to larger size ones (Ø12 mm). Therefore, a downdraft gasifier of closed constricted type was designed for real gasification tests of the residue pellets of sizes Ø6- Ø8mm. These tests showed that all the studied pellet sorts could be used in one and the same gasifier, resulting in different reactor temperature distributions and gas compositions with lower heating values in the range of 4.1-5.4 MJ/m3n dry gas. The reactor bed dynamics showed to be dependent both on the fuel reactivity and the size, with less pressure drop for larger size pellets with lower reactivity. The pelletizing process itself revealed that the selected residues all needed higher moisture content and smaller particle size than recommended for wood for successful pelletizing. The relative electric energy consumption was lower when producing larger size pellets Ø8 mm than smaller ones (Ø6 mm) of same material. For untreated wet empty-fruit bunch (EFB) a stand-alone power plant with integrated EFB pre-treatment and gasification could generate 380 kWh of net electricity per ton of EFB at a “well-to-wheel” efficiency of 15%. / QC 20100712

Abstract The future of ethanol is depending on good solutions for the production. ENA energy power plant produces electrical power and district heating by heating biofuel. By building an integrated bioenergy plant surplus steam could be used to produce ethanol as fuel to vehicle. This would mean that ethanol is produced renewable energy and the energy for the process derives from the surplus of power.  ENA energy, MDH (the University of Mälardalen) and the energy authority has initiated a research project were different bioenergy combinations integrate with existing power plant.  As a part of the project which size an integrated factory should be to gain the best efficiency for the plant was investigated. Consideration will be taken to the cost of the production in order to be competitive to the price of imported ethanol.     Etanolens framtid vilar på bra lösningar för framställning.  I ENA energi kraftverk i Enköping produceras el och fjärrvärme genom eldning av biobränsle.  Genom att bygga ett integrerat bioenergikraftverk där skulle man kunna använda överskottsånga till att framställa etanol som fordonsbränsle. Detta skulle innebära att etanolen framställs med ett förnybart bränsle och energin till framställningen kommer från ett överskott på värme.   ENA energi, MDH och energimyndigheten har initierat ett forskningsprojekt där en bioenergiintegrering skall undersökas.  Som del i detta skall här undersökas vilken storlek en integrerad etanolfabrik skall ha för att nå högsta totala verkningsgrad för verket samt om framställningspriset kan konkurrera med importerad etanol.