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17 Uppsatser om Self-ignition - Sida 1 av 2

Automatisk tändning till modern vedpanna

If you have access to wood, a wood burning boiler is a cheap way to heat your home, but it is certainly not the most convenient option. Wood requires many operations and management, which takes time. One way to reduce this workload is to have a modern boiler with automatic ignition. Enertech/CTC has a desire to create an accessory with automatic ignition to a modern wood burning boiler. Today there is no boiler on the market that can ignite firewood automatically without the introduction of paper and sticks.

H2 För racing

AbstractMotor sports have been around as long as motor vehicles have been. Sports are often seen as costly polluter but in the same time the motor sports have encourages a large part of development, both for vehicles and other industries. Inventions like rear mirror and ABS brakes come from motor sports. One way to once again drive development forward while making motor sports carbon-neutral is to run the race cars on hydrogen. In this thesis, the goal is to convert a spark ignition engine for hydrogen operation.

Utveckling av 22 : -en motkolvs HCCI motor

Environment friendly transports are one of the main topics in the industry and society today.Shell organizes an annual university competition called Shell Eco Marathon. The goal is to buildthe car that consumes the least fuel during a race. KTH participated for the first time in 2006.The engine for this competition, DoubleTwo, has been developed within the school. Theprinciple is a two stroke counter piston HCCI engine with variable compression ratio. HCCIstands for homogenous charge compression ignition.

ESC-analys och studering av knack på en "Diesel Dual Fuel"-motor

A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.

Miljöpåverkansbedömning vid tillverkning av etanol från cellulosabaserade råvaror : ekologisk gård självförsörjande med drivmedel

Fuel produced from renewable resources is of big interest. In this project the difference between a few different renewable materials are compared on the matter of environmental load when ethanol is produced. The renewable materials that are compared are Salix, straw and reed canary-grass (rörflen). The cellulose in the material is cut down to small pieces and then hydrolysed so that the sugar from the cellulose can be fermented into ethanol. Tha amount of ethanols that is studied in this work is the smount of ethanol needed to cultivate 1000 ha. The functional unit in the report is 1000 ha.

Energy efficient storage of biomass at Vattenfall heat and power plants

Storage of biomass is often associated with problems such as heat development, dry matter losses and reduction of fuel quality. The rise in temperature can potentially cause a risk of Self-ignition in the fuel storage. Moreover, emissions from storage piles can cause health problems in the surrounding. The dry matter losses and reduction of fuel quality can have economical effects. The aim of this thesis project is to develop guidelines on how to store large amount of biomass at Vattenfalls heat and power plants in an optimal way.

Abrasiv nötning av polymerer tillverkade genom 3D-skrivning

Volvo Cars in Skövde manufacture and assemble Volvo engines. When attaching the ignition coil to all 4-cylinder engines, a special mounting tool is required. This mounting tool is currently manufactured from injection-molded polyoxymethylene (POM), a thermoplastic. It has been noted that the life span of the tool is shortened as a result of abrasive wear that occurs during the attachment process of the ignition coil.An investigation of the possibility of manufacturing the mounting tool with a 3D-printer is undertaken in cooperation with ÅF, a consultant to Volvo Cars. A literature study is first presented to introduce broader knowledge on the subject.

Hastighets- och positionsinterface för motorer

The environmental requirements and laws on combustion engine emissions are very tough today andthey will become even more stringent in the future. To achieve these requirements there are highdemands on the control systems for these engines. An improved precision in the measurement of anengine's speed and position gives the electronic control system an even better timing when it comes tofuel injection and ignition. This makes the engine more fuel efficient, reducing the emissions. This thesisis part of a collaborative project between Hoerbiger Control Systems and subsidiaries.

Styrutrustning för gnistprovningsapparat

Denna rapport beskriver utvecklingen av en ny styrutrustning för SP´s provning av elektriskaprodukter som sitter i explosionskänslig miljö. Enligt svensk lagstiftning måste produkternauppfylla ATEX-direktivet. SP har en gnistprovningsapparat för provning av elektriskaprodukter. Styrutrustningen till gnistprovningsapparaten har genom åren blivit omodern ochbesvärlig att använda. Den gamla utrustningen är konstruerad på tidigt 80-tal och saknar enkomplett dokumentation.

Elektronisk motorstyrning för ottomotorer

The combustion engines in today?s vehicles are getting more and more advanced and there are increasing demands on that the engines should operate during optimal conditions. Examples of internal combustion engine parameters which may be carefully controlled are the rate between fuel and air, that this gas mixture is homogenous enough and that it is ignited at the correct moment. Moreover, the requirements of these parameters vary depending on, among other, engine speed and load. To meet these requirements in all occurring operation conditions, it is required that many subsystems work together.

Marktillstånd och borbrist på åkermark planterad med gran i Västerbottens län :

This study was made on former agricultural areas that had been planted with spruce or pine, in the county of Västerbotten. The goal of the project was to investigate suspected deficiency of boron in these areas. Several objects have been reported for possible deficiency and some of these have the characteristic symptoms of boron-deficiency. The hypotheses are that 1) Boron deficiency is present at several of the investigated objects. 2) Planting of forest on cultivated postglacial sediments leads to a successive podzolisation with a decreasing content of organic matter in the mineral soil, due to decomposition, and a decreasing pH in the soil, even on locations that have been added lime. To be able to confirm or reject the hypotheses a number of tests were performed.

Utveckling av kyl- och smörjsystem för ekobilen Agilis HCCI motor

Every year, KTH participates in the Shell Eco Marathon, a competition whose goal is to design a vehicle that can go as far as possible using only the equivalent energy of one liter of petrol fuel. This year, one of KTH?s contributions to this race is the Agilis prototype; a car powered by a uniquely configured HCCI-engine developed at the university. The engine is dependent of several subsystems in order to work properly, among other, systems for cooling and lubrication.Combustion engines are in need of a cooling system that reduces the heat developed during the combustion. In general, two main types of cooling systems are employed; either air cooling, where the outside of the cylinder is exposed to a flow of the surrounding air, ore water cooling, where water flows in tubes around the engine, and the heat are transferred by the water to the surrounding air through a heat exchanger.The purpose of the lubrication system is to prevent the friction that builds up in the interference between moving parts in the engine.

Modellering av flisstack

Bioenergi är en stor industri i Sverige och står för en betydande del av energiomsättningen. Bioenergi i form av flis förvaras runt om i landet på hög i väntan på förbränning. Då högarna läggs upp startar olika processer som värmer upp stacken, ofta till temperaturer på 50°C under det första dygnet. En vanlig ansats i litteraturen är att denna temperaturstegring beror på aerob nedbrytning. Arbetet ämnar undersöka om denna uppvärmning endast beror av mikrobiella aktiviteter.

Direct-EGR tillämpat på HCCI

The Homogeneous Charge Compression Ignition (HCCI) engine is promising in terms of lowNOx, low particulates and high efficiency. Due to its homogeneous charge, where thecombustion starts almost simultaneously from a number of points in the combustion chamber,only lean mixtures are possible to burn because of the resulting rapid combustion, which is muchfaster than the combustion in an SI-engine or a diesel engine. When richer mixtures are used thecombustion will start earlier and also be more violent.To phase the combustion later and lower the combustion speed, external cooled EGR can beused. The EGR-system used in this thesis uses a divided exhaust channel where one channel andits corresponding valve are used only for transporting EGR back to the intake system.Consequently the EGR-valve is connected to the intake pressure. This system is called Direct-EGR (D-EGR).Engine tests verified that the CA50 indeed is phased later when cooled EGR is used.

Optisk undersökning av dieselsprayer från en höghastighetsroterande insprutare

There have been changes in Earth?s climate system on both global and regional scale since the pre-industrial era and some of these changes are due to human activities such as the combustion of fossil fuels. This calls for the development of engines with a higher efficiency and less harmful emissions. One interesting concept is the Homogeneous Charge Compression Ignition (HCCI) engine, which has the advantages of potentially low emissions combined with high efficiency. However, HCCI with diesel fuel requires a relatively long fuel/air mixing time to ensure a "homogenous" charge.

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