Design and simulation of prechamber with high pressure CNG injector system for single cylinder four stroke engine

• Main Author: Mohd Fadzli, Mat Lazim
• Format: Undergraduates Project Papers
• Language: English
• Published: 2012
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://umpir.ump.edu.my/id/eprint/4921/1/cd7350_66.pdf; http://umpir.ump.edu.my/id/eprint/4921/

This thesis presents an ignition system to improve engines efficiency. The method used in this study is by using a prechamber as a pre-ignition system for the engine, where the prechamber is located at the top of cylinder head. Prechamber is an ignition technology which can improve engines efficiency. Previous research indicates that the prechamber is responsible for engine out emission. In this project, four concepts of prechamber designs are developed with objective to improve the engines efficiency. The design variable is the volume of the prechamber. Solidworks 2010 software was used for designing process while Ansys 12.1 software was used to perform the simulation of the engine with prechamber. The results of maximum in cylinder pressure and temperature from the simulation are used to determine the best prechamber model. Yamaha FZ150i engine has been chosen as the baseline engine for this project. The engine are disassembled for the measurement process and then modelled in solidworks as a computational domain for the simulation process. The engine is simulated at engine speed of 2000 rpm. The simulation process can be divided into two types which are cold flow simulation and combustion simulation. The result from the simulation shows that the prechamber model that have lowest volume give the maximum in cylinder pressure and temperature which are 19.12 bar and 360.425 K for the cold flow simulation while for the combustion simulation the maximum in cylinder pressure and temperature are 47.54 bar and 2620.7384 K. This results shows that when the volume of the prechamber is low, the compression ratio of the engine is kept high. Compression ratio is the main factor that affecting the value of in cylinder pressure and temperature.