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99 Uppsatser om Combustion - Sida 2 av 7

Optimering av sotningsfrekvens i biobränsleeldad CFB-panna : panna 5, Mälarenergi AB, Västerås

During the past 30 years the fuels for energy production in heating and power plants have changed. Fossil fuels have decreased in usage whereas bio fuels in Sweden have increased with 60% since the 1970's. Different fuels affects Combustion and the release of various substances and particles into the flue gas. This is caused by the diverse components and chemical structures of fossil fuels and bio fuels. When the flue gas leave the Combustion chamber and enters the path to the chimney particles in the gas are being transported out of the Combustion chamber.

Optimization of Burner Kiln 7, Cementa Slite

In this report focus is put on the Combustion process at a cement plant. Combustion is the heart of the cement making process and absolutely crucial to have under full control and well optimized. The fuel is put into the process through a burner pipe and this burner pipe is modified to reach a more efficient Combustion. The primary target is to enable burning of heterogeneous alternative fuels and increase the production level. Other positive effects from this type of optimization is lowered specific fuel consumption and lowered CO2 emissions. A redundant burner is chosen for the project and overall the project steps are the following: 1. Installing a Jet air nozzle ring in a way so it can move both axially and radially due to temperature changes. 2.

Förbättrad förbränningsstabilitet i EBK för turbofläktmotor RM12 genom förändrad motorreglering : Improved afterburner combustion stability for turbofan engine RM12 by modified engine control

The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased noise level from the engine when the afterburner is in use. The noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable Combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero.

Design av försöksanläggning för trycksatt rökgasrening vid oxy-fuelförbränning

Reducing the CO2-pollution, resulting from the Combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the Combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

Konstruktion av anordning för att undersöka förslitning av syrebärarpartiklar för kemcyklisk förbränning

The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping Combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.

Reglerstrategi för fria ventiler : ? Utveckling av en fyrtakts förbränningsmodell för att prediktera optimala ventilinställningar

As emission legislations across the world continuously pushes engine development forward,engineers constantly need to come up with and implement fuel saving technologies. During thelast decade, variable cam phasing has become a popular solution to increase gas exchangeefficiency. This configuration is typically mechanically constrained by camshaft limitations, anda solution to circumvent this problem would be to use a different valve actuation principle.One example of this is to use pressurized air controlled by electrical solenoids. Such a systemhas been developed byCargine Engineering and this provides the starting point for this work. Tobe able to operate the valvetrain on an actual engine, a control system is needed.

Utveckling av en Multi-Zonsmodell för NOx Bildning i Diesel Motorer

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal Combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel Combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

Gourmetmat för alla!

Vårt mål med projektet var att göra en webbapplikation åt Gourmet Grön och deras nya produktserie. Applikationen innehåller information om produkterna och hur de används samt vilka fördelear dessa ger..

Teknisk och ekonomisk analys av en bränslekonvertering vid SIA TallOils pelletsfabrik :

At SIA TallOil's pellets factory in Latvia wood shavings and saw dust are dried with flue gases from a gas burner. TallOil wants to replace the gas with a biofuel that is available at the pellet plant. The reason for this is the unstable gas market in Europe in combination with the fact that TallOil wants to improve its profile as supplier of renewable bio fuels. In this project the technical and economical possibilities for a fuel conversion to ether bark powder, wood shavings or wood powder have been investigated. These fuels should be burned in one of the following applications: TPS BioSwirl, VTS Multifuel burner or Saxlunds bio fuel Combustion plant Due to the fact that the fuel alternatives available are relatively common except for bark powder, the work has mainly been focused on bark powder.

Gourmetmat för alla!

Vårt mål med projektet var att göra en webbapplikation åt Gourmet Grön och deras nya produktserie. Applikationen innehåller information om produkterna och hur de används samt vilka fördelear dessa ger..

Är det möjligt att använda SCR-rening av rökgaserna vid inblandning av avfall i biobränslet?

Waste appears to be a low-cost fuel compared to biofuel. This Masters thesis was conducted for Vattenfall Utveckling AB and deals with how waste in the fuel affects the performance of a SCR-catalyst. Different mechanisms of deactivation were surveyed, focusing on the poisoning mechanism. A literature study was carried out, which was used as a reference when analysing the results.Small samples (9x2x2 cm, 64 pieces) cut out from a full-scale unused honeycomb catalyst were exposed up to 1500h in two different Combustion plants, Johannes in Gävle (co-Combustion) and Högdalen in Stockholm (waste-Combustion). The activity was measured mainly at 300°C but also at 250, 350, 375 and 400°C.

Uppgradering av biogas med aska från trädbränslen

The Swedish production of biogas was 1,5 TWh 2011. About half of the production was used as vehicle fuels. The cost for upgrading biogas depends on the size of the biogas plant and its gas production. If the gas flow is low the cost will be high. However, further development of existing upgrading technologies or development of new ones, have good potential to decrease the upgrading cost for small scale biogas plants.

Variationer av klor, svavel och aska i havrekärna : odlingsfaktorernas inverkan på havrens bränsleegenskaper

The increasing oil prices during the last years have made it profitable to use cereal grains as a fuel. When compared with wood, cereals contain higher amounts of Cl, S and ash. The Cl and S content makes the gases from cereal Combustion more corrosive than gases from wood Combustion. The goal of this master thesis was to find out the variation of Cl, S and ash content for oat grain grown under different conditions. Oats was chosen because in Sweden it's considered as the cereal with the best fuel qualities.

Förbränning av pellets framställda av defibrerad granråvara :

Fuel pellets are in Sweden mainly produced from sawdust and cutter shavings. Before the pelletising process the raw material is dried to attain consistent moisture content and ground up in a hammer mill. In the densification process (pelletising) the ground material is forced through holes in a rotating die. This heats up the wood particles which cause them to soften and self bond. After the process the pellets are cooled, sieved and bagged. The milling process creates a wide range of particle sizes.

Analys och förbättring av en mätenhet för laddning av elfordon

Reducing the CO2-pollution, resulting from the Combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the Combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

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