Retrofit and Experimental Evaluation of a Conventional Marine Diesel Engine for Dual Fuel Diesel-Methanol Operation

Strict emission laws and energy security concerns have resulted in a variety of alternative ideas applicable to internal combustion engines.In this work, a conventional four-stroke six-cylinder marine diesel engine was retrofitted for diesel-methanol dual fuel operation and a number of experimental studies were conducted to evaluate the combustion, performance, and emission characteristics.The retrofit effort involves the mounting of six methanol injectors on custom-made injector ports, installed before the cylinder head air intake port and after the intercooler.The methanol injection is controlled via a separate ECU, which works in parallel with the original one.Initial tests were carried out after the retrofit, to verify the successful dual fuel operation.The results indicate the success of the retrofit process since the engine thermal efficiency was retained or improved in some cases and NOx emissions were greatly reduced.