舶用 大型 低速 디젤機關 燃料噴射系統의 시뮬레이션에 關한 硏究

Abstract

It has been a major research to improve the performance and reliability of diesel engine, since internal combustion engine has been invented originally.

However, recently much of these researches are focused on the reduction of exhaust emission for environmental pollution protection with the concerns of the low fuel consumption rate.

The charactristics of fuel injection system have a strong influence on the air-fuel mixing process and engine output, thermal efficiency, durability, noise, and exhaust emissions. The performance and exhaust emission of diesel engine is related to the fuel injection rate and injection pressure, injection duration. Combustion in diesel engine is mainly governed by characteristics of fuel injection.

In this study, a simulation program was developed, which could simulate a fuel injection system for low-speed marine diesel engine. The fuel injection system was composed of fuel injection pump, high pressure pipe and fuel injection valve. The unsteady flow in the high pressure injection pipe was analyzed by the method of characteristics, considering cavitation and variation of fuel density and bulk modulus.

It was assured that the simulation results agree well with experimental results of injection pressure and quantity at the high pressure distributor in fuel injection system for the training ship "M/V Hannara". And the effects of the high pressure pipe length and diameter, plunger diameter, nozzle opening pressure, nozzle hole diameter and maximum needle lift were also investigated utilizing the simulation program developed in this study.