Loading...

CFD Modeling of PCCI Combustion for early Direct Injection of Diesel Fuel

Ghofrani, Iraj | 2016

764 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48837 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Hosseini, Vahid; Taghizadeh Manzari, Mehrdad
  7. Abstract:
  8. At today’s crowded world, the importance of automobile transportation is obvious for all. Due to energy crisis and air pollution problems, designing and manufacturing high-performance and low emission engines is very important. Because of high efficiency and low fuel consumption, diesel engines have attracted more attention. In addition to the mentioned advantages, diesel engine’s nitrogen oxide and particulate matter emissions are very high. So to limit these pollutants, strict standards was legislated by different countries and nations. Recently in the field of diesel engines emission reduction, low temperature combustion concept is proposed that can reduce nitrogen oxide and particulate matters. Homogeneous charge compression ignition, premixed charge compression ignition and reactivity controlled compression ignition classified in this category.In the present study low temperature combustion based on the reactivity controlled compression ignition was used. Accordingly a light-duty and a heavy-duty diesel engines that uses the concept of reactivity controlled compression ignition, are investigated and the combustion and emission characteristics are studied.Simulation results show that in reactivity controlled compression ignition type engines, the start of the heat release is starts by the high reactive fuel (like diesel) and after releasing enough energy, the energy of the low reactive fuel is released. Because of the staged heat release, the energy of fuel is released softly and in-cylinder temperature doesn’t increase suddenly. So in addition to the energy loss in the engine is reduced, the emission of nitrogen oxides is greatly reduced as well. The result of the study of the light and heavy duty engines shows the reduction of soot and nitrogen oxide at early injection. But IMEP and efficiency is reduced by early injection. Spray angle studies show that when fuel distribution is away from the walls, the fuel mixed well so nitrogen oxide pollutants are reduced. Changing the spray angle doesen’t change IMEP and efficiency due to complete combustion at all spray angles. Usage of EGR decreases in-cylinder temperature and reduced nitrogen oxide, but indicated mean effective pressure is dropped and soot is increased. The high percentage of diesel mass fraction is increase in-cylinder fuel reactivity and causes faster combustion timming so nitrogen production increased. By changing the diesel mass fraction IMEP and efficiency is approximately constant. For the purpose of investigating ambient condition on RCCI engines, the temperature is changed, and the response of the engine was studied. Generally, for better control the reactivity controlled compression ignition engines, combination of the studied parameters is necessary
  9. Keywords:
  10. Emission Reduction ; Nitrogen Oxides ; Soot ; Compression Ignition ; Computational Fluid Dynamics (CFD) ; Diesel Early Injection ; Low Temperature Combustion ; Dual Fuel Combustion ; Diesel Early Injection ; Low Temperature Combustion ; Dual Fuel Combustion

 Digital Object List

 Bookmark

No TOC