As exhaust emissions regulations are becoming increasingly stringent year by year, higher injection pressure and higher injection precision are required for diesel fuel injection equipment. On the other hand, market fuels tend to diversify. From the viewpoint of global warming prevention in particular, biodiesel fuels are attracting attention as renewable fuel and have been launched in many parts of the world. Moreover it is predicted that the concentration of Fatty Acid Methyl Ester (FAME) in biodiesel fuel will be increased and greater diversity of feedstocks will be used in the future. On the other hand there is a concern about deposit adhesion caused by biodiesel fuel to diesel fuel injection equipment.
This paper clarifies the biodiesel deposit formation mechanism [1],[2],[3] and describes an accelerated re-production test method, which simulates real-world market condition and enables evaluations with a common rail system. Then, it reports that, using the re-production test method, Diamond Like Carbon (DLC) coating was proved effective to prevent deposit adhesion to common rail system.