Developing the automatic system for the multi-point fumigation of air charge in the diesel engine

Introduction. The study deals with enhancement of an automotive diesel engine duty cycle through fumigating air charge by the certain dose (10-20 %) of hydrocarbon activator (alcohol, gasoline, kerosene, biodiesel, etc.). This is a relevant problem in engineering. In spite of its effectiveness, this method has not yet been widely applied to machinery. The existing mechanical devices for fumigating air charge do not provide the exact dosage of activator and its timely supply in a diesel engine at different operating modes. Materials and Methods. The solution for this problem may be the development of an automatic system for the multi-point fumigation of air charge. This device performs the injection of activator into the diesel engine intake manifold branches with the help of electromagnetic injectors managed by the electronic control unit. The system should provide the injectors operation by the algorithm for the cylinders firing order and calculate the injection duration for the adjusted activator dose. For the programming of the Electronic Control Unit, the injection duration of the exact activator dose was theoretically calculated. The algorithm of electromagnetic injectors operation was substantiated (for D-243 tractor diesel engine by the example). Results. To implement the multi-point fumigation of air charge, it was determined that depending on the activator dose and the engine speed and load mode, the cyclic dose of activator amounts may be from 1 mg per cycle to 13 mg per cycle, while the activator injection duration is from 0.27 ms to 3.5 ms. For the practical realization of the multi-point fumigation of air charge for D-243 diesel engine of MTZ-82.1 tractor the automatic system was designed. The system consists of an activator tank, filter, electric pump, rail, pressure regulator, electromagnetic injectors, electronic control unit, fuel consumption sensor, and sensor of phase and crankshaft speed. Conclusions. The device solves the problem of the automatic fumigation of air charge at the intake stroke and helps to improve power, fuel economy and environmental indicators of the automotive diesel engines.