The influence of un-lean CNG injection to the material strength of the single cylinder dual fuel diesel engine

Strengthening marine pollution (MARPOL) Regulations 13 which bring technical code of TIER III affect many strategic ways to deal with. The code of TIER III multiply more than three times than TIER II as predecessor. It is not so easy to comply with. There are only three methods to fulfill the new standard, first, is using gas as fuel, second, de-rating of the power output, and third is install SCR (Selective Catalytic Converter) unit. This research work is deal with the first method, use CNG (Compressed Natural Gas) as fuel for diesel engine in the form technique called as dual fuel system. Established dual fuel diesel engine is a very expensive choice. It is possible to develop dual fuel engine from conventional diesel engine. This paper investigates the possibility in developing un-lean CNG injection refer to the influence of the combustion pressure to the material strength. The results show that the impact strength resulted by in-cylinder combustion is less than half compared with the permitted strength. It is a big chance to push the gas/air stoichiometric to un-lean condition. This small scale modelling works by using a single cylinder engine can make big contribution in the development of bigger size marine diesel engine in occupy gas fuel safely.