Estimation of fuel efficiency of automobile and tractor diesel engines, operating with the shutdown of part of the cylinders

The analysis of previously performed studies to determine the fuel efficiency of automobile and tractor engines when a part of the cylinders is disconnected is carried out. This is done by stopping the fuel supply to them with simultaneous disconnection of the gas distribution mechanism for the same cylinders or without affecting the gas distribution organs in partial operating modes. It is shown that if the cylinder shut-off system for engines with forced ignition is used in serial engines, then additional research is required for diesels, since the results of experimental studies given in the literature are contradictory. The previously proposed methods are based on the use of experimental characteristics, empirical dependencies, and other experimental data that are valid only for specific diesels and their operating modes. In addition, the assessment of fuel efficiency is mainly performed by calculation without experimental confirmation. Therefore, the results of computational studies presented in some papers differ qualitatively from the results of experimental studies presented in other papers. A method based on generalized experimental data is proposed that allows the load characteristics of a full-size diesel engine to calculate its indicator and effective indicators when the fuel supply to some cylinders is stopped. The results of experimental and computational studies of changes in the fuel efficiency of a 4CH10,5/12 diesel engine in partial modes when a part of the cylinders is switched off are presented. At the same time, several options are considered - by stopping the fuel supply and closing the intake and exhaust valves, as well as without any impact on the organs of the gas distribution mechanism. It is shown that the improvement of the fuel economy of the 4CH10,5/12 diesel engine when a part of the cylinders is disconnected with the intake and exhaust valves closed is due to the absence of pump losses in the disconnected cylinders.

cylinder, shutdown, fuel efficiency, partial modes, excess air, indicator and mechanical efficiency factors