Kinetics of motor oil aging in marine diesel engines under continuous and periodic refill to compensate loss

The article considers the balance of the engine oil aging components in the diesel engine lubrication system with the refinement of oil composition caused by the oil product loss. The motor oil aging process has been identified under continuous and periodic oil refill in order to replenish the lubrication system with fresh oil which would compensate the burnt off oil products. There were derived and solved the differential equations of the oil product balance for such aspects of aging as contamination by insoluble impurities and multifunctional additives impact, which helped understand the general regularities and kinetics of the studied process. Novelty of the approach to theoretical description of the process consisted in the fact of filtering the insoluble and colloidal components of mechanical impurities and additives by the purification and burnout means. Cyclic picture of aging allows to analyze the state of the oil aging before and after refill with its periodic refreshment. The dependence is transformed and presented in a form where it is possible to determine the state of the oil at each aging cycle, without examining the intermediate concentrations of impurities and additives. The advantage of the obtained kinetic integral expressions for oil aging is the ability to determine the conditions for a long-term or permanent mode of its use in the lubrication system of a diesel engine. There are given the formulas by which the intensity of filtration and the concentration of additives in fresh oil or the time of their impact are calculated at a given oil loss and provide a pre-rejection mode of using circulating luboil in a diesel engine.