METHOD OF DETERMINATION OF PROPENSITY OF MOTOR OILS FOR DIESEL ENGINES TO FORMATION OF LOW-TEMPERATURE DEPOSITS

摘要

FIELD: measurement.;SUBSTANCE: invention relates to a method of determining propensity of engine oils for diesel engines to form low-temperature deposits, including a cyclic operation of an engine with a liquid cooling system for a given length of time, supply of exhaust gases to crankcase of engine and determination of amount of deposits M_dep on inner surface of rotor barrel of centrifugal oil filter, rotor rotation speed of which is set, characterized in that the number of engine operation cycles is set equal to not less than 10, duration of each working cycle is 7.5 hours, during which two stages are performed, separated by a time interval of 1.5 hours by stopping the engine for forced air supply at rate of 10 l/min into engine crankcase, each cycle stage consists of idling mode for 0.3 hour and full load mode – 2.5 hours, creating at idling speed crankshaft rotation 1,200 rpm, and at full load mode – 2,000 rpm, while maintaining temperature of analyzed oil in crankcase in these modes 70 °C and 90 °C and temperature of cooling liquid 60 °C and 85 °C respectively, and propensity of motor oils to form low-temperature deposits is additionally estimated from the difference in values of the alkali number before and after 10 cycles, and with M_dep≥240 g on centrifugal oil filter and change in alkali number ΔAN≥5, engine oil is referred to group G and is considered to be prone to formation of low-temperature deposits.;EFFECT: method is developed, which enables to evaluate motor oils for diesel engines by their tendency to formation of low-temperature deposits with high accuracy and reliability, which can be implemented for military equipment on available Russian equipment.;1 cl, 1 tbl, 2 ex