G-type engine has been developed with the improvement of propulsion efficiency, fuel saving and environmentally friendly side which is conducted sea trial since early 2015. But the problems are being caused recently because of low speed and ultra long stroke, characteristics of G-type engine.
This study analysed the difference between S-type engine and G-type engine, tuning method of G-type engine. And discussed the results of sea trial of G-type engine and review of Class rule and solution.
Among the problems of G-type engine, this study focused on the problems related steam production of exhaust gas economizer(EGE) and acceleration performance of main engine in narrow channels, barred speed range(BSR) and so on.
Actual sea trial resulted that the contract condition of steam is dissatisfied as reduced exhaust gas quantity of G-type engine. That can be solved by exhaust gas bypass(EGB) manual mode or economizer energy control(EEC) system. This study confirmed that EGB tuning with EEC would have enabled engine to obtain enough steam production and auxiliary boiler to make additional operation unnecessary.
Also, Actual sea trial resulted that passing time of BSR is delayed as decreased acceleration performace of G-type engine. That can be solved by light running margin(LRM) increase, application of high capacity blower and dynamic limit function(DLF) system. And reviewed that the combination of increased LRM and DLF has feasibility and effectiveness.
DLF is currently under development and need to consider the confirm ation about productive result for problem improvement of G-type engine.