AUTOMATION OF MEASUREMENTS OF ENGINE HEAT CONSUMPTION IN THE LUBRICATION AND COOLING SYSTEMS

Abstract

The paper presents the results of an intermediate stage of the study of heat transfer processes in high-speed diesel engines of the automotive tractor type at transient load discharge-load-injection modes, which are characteristic of this type of diesel engines. In such modes, as evidenced by the results of calculations of the thermal stress state of combustion chamber parts, in particular pistons, exhaust valves of the gas distribution mechanism, significant tensile and compressive stresses are observed compared to operation at steady-state conditions. This is the reason for the occurrence of defects in the form of cracks on the heat exchange surfaces of these parts, which limits the service life of automotive tractor engines. For a more detailed study of transient processes, as the main approach, it is proposed to use the well-known method of heat balance tests of a high-speed diesel engine, but with the involvement of automated processing of measurement results in digital form at steady-state and transient modes. It is proposed to focus on heat consumption, which is a component of the heat balance in the lubrication and cooling system. Without the use of automated information processing directly at the time of transient load shedding and load shedding, it is impossible to obtain such information on cooling and lubrication systems. Recording of transient heat transfer processes makes it possible to track the influence of engine operating parameters, the dynamics of the transient process depending on its duration, the initial and final steady-state modes between which the transition is being studied. In general, this way, it is possible to assess the adaptability of cooling and lubrication systems to heat dissipation during sudden changes in load, to avoid, or at least limit, the growth of thermal stresses. The publication presents a possible variant of the schematic solution of such a system for automated processing of the results of heat balance tests with the maximum use of equipment that is mass-produced and has already been used previously in heat balance tests.