Norwegian Journal of development of the International Science No 43/2020
59
TECHNICAL SCIENCES EFFICIENCY IMPROVEMENT METHOD FOR EXPLOITATION OF MACHINE-TRACTOR DIESEL UNIT WITH ELECTRONIC POSITIONAL REGULATION OF FUEL SUPPLY Gabdrafikov F. Doktor of Engineering Sciences,Professor of the Department of Heat-Power Engineering and Physics,Federal State Budgetary Educational Institution of Higher Education (Bashkir State Agrarian University),Ufa Abstract The relevance of this study is due to the low performance of diesel engines of machine-tractor units, with widespread separate type fuel injection systems, on partial and unsteady operating modes. The purpose of this article is to develop methods and technological practices for increasing the efficiency of a diesel engine of a machine-tractor unit with a positional effect on the fuel supply control bodies. The leading method for investigating the problem is to evaluate the interaction process of the regulator-diesel engine system on partial and unsteady operating modes. Results of the research: An information model for the functioning of a diesel engine of a tractor unit in dynamic modes has been developed. It is a combination of technological models and workflows of units, systems and mechanisms of a machine-tractor unit having cause-effect relationships. A mathematical model has been developed for the operation of a machine-tractor unit engine, which makes it possible to determine the patterns of change in the speed limit depending on the disturbances in force: an increase in the cycle fuel supply and the degree of irregularity of the resistance moment. There was established the need to increase the cycle fuel supply relative to the increase in the moment of resistance of a diesel machine-tractor unit on the basis of motor tests on partial and unsteady modes. With the values of the degree of non-uniformity of the moment of resistance 0.20-0.80, the positional electronic regulation will reduce the overspeed by 20 ... 70 min-1, and reduce the transition time by 0.2 ... 1.4 s in partial modes. Reducing the overload of the crankshaft rotational speed and reducing the duration of the engine transitional process contributed to an increase in the efficiency of the diesel engine (the power increase was 13.5%, the effective specific fuel consumption decreased by 23.8%). Keywords: diesel engine of a machine-tractor unit, mathematical model of a diesel engine, electronic regulator, fuel supply system. INTRODUCTION. Machine - tractor units are operated in wide ranges of speed and load modes of operation. In the general balance of working time, almost 50% is due to low-energy-intensive work and, as a result, a considerable part of the time the engines of machine-tractor units operate in partial load modes and low crankshaft rotational speeds, and 90% of time in unsteady load modes [13,14] . Such operating conditions adversely affect the operation of the engine, cause a decrease in the efficiency of the diesel machine-tractor unit and an increase in fuel consumption due to deterioration in the quality of diesel fuel systems, primarily due to the inability of the mechanical regulator of the fuel pump to respond to changes in external conditions (they work well in conditions of nominal and steady state operation). The methodology for improving the performance of diesel engines of machine-tractor units is to improve the fuel supply systems, taking into account the actual conditions of their work and operating conditions [2,13]. For diesel engines of machine-tractor units with a direct-feed fuel system, already well-developed constructively and reliably working in the agricultural conditions of any economic zone, there can be systems with electronic control of fuel feed for load and positional influence on the control body.
Modern microprocessor technologies in automatic control systems make it possible to fully implement the regulation of the fuel injection system and the engine, taking into account the load change as the main disturbing effect [1-7]. Directly operated fuel injection systems for electronic control are divided into systems with discrete and positional effects. In systems with discrete exposure, the output pulse signal directly determines the starting and ending points of fuel injection. The R. Bosch electromagnetic actuator is used in in-line fuel pumps of the type MV and P. It is a precision linear electromagnet installed coaxially with the metering rail of the injection pump. The rail in the direction of reducing the fuel supply is moved by a return spring. The required characteristics of the cycle feed are formed in the electronic unit of the automatic control system based on signals from the crankshaft speed sensors, the position of the fuel pump rail and the control lever of the regulator [13]. A similar microprocessor control system for distribution injection pumps was developed by Lucas CAV and Central Scientific Research Institute of Fuel Systems (CSRIFS). A number of companies have noted a significant simplification of the fuel pump when introducing an electronic injection control system; The Lucas CAV distribution pump (similar to the DSU pump) with elec-
