Abstract
The examinations of NOx reduction are investigated on 3 cylinder test engine that has same dimensions as the commercial engines for marine use except number of cylinders, in order to comply with IMO Regulation No.13 only with modifications of engine design factors without using special devices such as SCR, EGR, emulsion fuel injection and so on.
The test contents followings; verified number of injection holes of fuel atomizers, retarded fuel injection timming, increase of compression ratio and charged air pressure, reduced overlap period of exhaust and inlet valve opening, retarded inlet valve closing timming and adoption of fuel pump planger with retarded fuel injection timming in low loads.
We have accomplished reductions by half of NOx E3 value and it seems there is good prospect of satisfying IMO Regulation No. 13 on commercial engines, in combination of constant combustion pressures with the tested design factors without deterioration of smoke, exhaust gas temperatures and fuel oil consumptions.
