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Visar resultat 1 - 5 av 257 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Biomass Pre-treatment for the Production of Sustainable Energy : Emissions and Self-ignition

   Författare :Katarina Rupar-Gadd; Mehri Sanati; Evert Ljungström; Växjö universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; terpenes; SPME; biomass; pellets; self-ignition; storage; drying; calorimetry; Chemical engineering; Kemiteknik; Bioteknik; Biotechnology;

   Sammanfattning : Organic emissions with focus on terpenes, from biomass drying and storage were investigated by Solid Phase Microextraction (SPME) and GC-FID and GC-MS. The remaining terpenes in the biomass (Spruce and pine wood chips) after drying were dependant on the drying temperature and drying medium used. LÄS MER

3. 2. On the Impact of Piston Motion and In-Cylinder Charge Composition on Energy Release, Auto Ignition and Emission Formation in Premixed Charge Internal Combustion Engines

   Författare :Ola Stenlåås; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bränslen; sprängämnen; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; Internal Combustion Engine; Emission; SI; Spark Ignition; HCCI; Homogeneous Charge Compression Ignition; zone model; Chemical Kinetic; Engine simulation; Reformed Methanol; Hydrogen; Knock; Auto Ignition; NO; Piston Motion; Nitric Oxide; Premixed Charge;

   Sammanfattning : The results presented in this thesis can be divided into four areas of investigation: Investigation of the effect of new volume-crank angle relations on engine emissions, power and efficiency; investigation of nitrogen oxides effect on auto ignition and knock in SI engines; investigation of premixed SI and HCCI engine operation with the alternative fuels hydrogen and reformed methanol gas (RMG); software development of a detailed chemical kinetics zonal engine model. Model development of the in-house two-zone chemical kinetic code focused on expansion of the Jacobian matrix to allow simulations of variable in-cylinder charge. LÄS MER

4. 3. Experimental Studies of Advanced Ignition Systems for Lean Burn Natural Gas Engines

   Författare :Jessica Dahlström; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ignition system; spark energy; internal combustion engine; engine; spark ignition; natural gas;

   Sammanfattning : One of the greatest challenges for the transport sector today is reducing its environmental impact. This applies especially to the emission aspects, much due to increasingly stringent emissions legislations. LÄS MER

5. 4. Improving the Efficiency of Gas Engines using Pre-chamber Ignition

   Författare :Ashish Shah; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ignition system; high efficiency; pre-chamber ignition; natural gas; Internal combusiton engines;

   Sammanfattning : The aim of this project is to explore and understand the combustion phenomenon in engines operating on gaseous fuels, and develop technologies as an alternative to the present diesel engine technologies for heavy duty applications; which are facing severe challenges like stringent emissions norms, high technology costs and unsustainable fuel supply. The studies presented in this thesis focus on the application of pre-chamber ignition system in heavy duty natural gas engines, as a means to improve fuel efficiency and reduce NOx emissions. LÄS MER

7. 5. Spark Ignition Combustion of Direct Injected Alternative Fuels

   Författare :Lars Christian Riis Johansen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spark ignition; optical diagnostics; internal combustion engine; stratified combustion;

   Sammanfattning : Several technologies and modifications exist to increase the fuel efficiency of passenger vehicles in general and spark ignition engines in particular. Combining a spark ignition engine with an electric drive system in hybrid powertrain and thermodynamic cycle improvements are two such approaches with the potential to greatly reduce fuel consumption. LÄS MER