FUEL INJECTION RETROFIT FOR IMPROVED DIESEL ENGINE PART LOAD PERFORMANCE

A CONVENTIONAL DIESEL FUEL INJECTOR, WHICH CONSISTS OF A CAM ACTUATED PLUNGER AND SPRING LOADED NOZZLE VALVE, IS DESIGNED TO DELIVER RATED SPEED AND FULL LOAD FUEL REQUIREMENTS AT A PRESSURE LEVEL THAT WILL PROVIDE SATISFACTORY ATOMIZATION AND SPRAY PATTERN. AT REDUCED SPEED AND/OR ENGINE LOAD, THE INJECTION PRESSURE, WHICH IS A FUNCTION OF THE QUANTITY, AND PLUNGER SPEED, IS DRAMATICALLY REDUCED FROM RATED CONDITIONS, RESULTING IN POOR ATOMIZATION AND COMBUSTION. THE BKM SERVOJET SYSTEM, CURRENTLY UNDER DEVELOPMENT, EMPLOYS THE ACCUMULATOR PRINCIPLE WITH A TRIGGERED RELEASE. AS A RESULT, THE INJECTION IMPINGEMENT PRESSURE IS INDEPENDENT OF ENGINE SPEED AND WILL ALWAYS BE AT A LEVEL THAT PROVIDES GOOD ATOMIZATION AND AVOIDS THE DRIBBLING AT LOW LOADS THAT CAUSES SMOKE "WET STACKING", AND HIGH FUEL CONSUMPTION. IT IS PROPOSED THAT A TYPICAL DIESEL ENGINE BE SELECTED FOR MODIFICATION OF THE CONVENTIONAL UNIT INJECTOR SYSTEM TO INCORPORATE THE ACCUMULATOR AND HIGH PRESSURE FEATURES OF THE SERVOJET SYSTEM TOGETHER WITH SOME NEW THEORIES TO INJECTION SPRAY PRESENTLY BEING INVESTIGATED. THE PLAN IS TO DESIGN AND MANUFACTURE A SET OF INJECTORS FOR THE RETROFIT, AND TO TEST AT VARIOUS LOADS AND SPEEDS, INCLUDING STARTING AND IDLING, TO MEASURE THE IMPROVEMENT IN FUEL CONSUMPTION, SMOKE AND OTHER OPERATING PARAMETERS.