The Research Of Diesel Engineering Oil On-line Monitoring Technology

Lube oil is considered as the "blood" of the diesel engine, which has the function of lubrication, cooling, cleaning, sealing and corrosion resisting, etc. The varieties of contaminations in the lube oil are related to the running conditions of diesel engine to a certain degree and contain lots of tribology status information of the friction couple surface of diesel engine. Consequently, the lubrication status and running conditions of diesel engine can be effectively assessed by analysis towards the physical and chemical properties and the wear debris.In this paper, in order to solve the diesel engine lubrication and wear condition online monitoring issues, by studying the oil line monitoring technology that base on capacitance method and electromagnetic induction method, establish a diesel engine lubricants online monitoring system. The system can monitor oil degree of pollution and online ferromagnetic particle concentration, quantity and size distribution online, and through the ignition of the diesel engine performance verification test bench. The main conclusions obtained are as follows:The capacitive sensor that based on the dielectric constant can be sensitive to monitor the oil water, ethylene glycol, carbon, and an acid changes; When the temperature rises, ethylene glycol, carbon and measured acid value becomes large; When the water content is low, the temperature rise measured value becomes large, when the water content is high, the temperature rises, the measured value becomes smaller.Inductive sensor of ferromagnetic particles can accurately monitor the number and the size distribution and density of ferromagnetic particles in lube oil.This paper established the method to judge the leakage of cooling system and abnormal wear. When the pollution levels have increased sharply at a short period of time in lube oil by the capacitive sensor, the cooling system is compromised of diesel engine. When the number of big size particles increased or the density of particles increased sharply in the lube oil by inductive sensor of ferromagnetic particles, the diesel engine take placed abnormal wear.This paper established the diesel engine test bench. It can simulate the conditions at different speed and load. The results of on-line monitoring of lubricating condition in a period of adjustment of diesel engine shows that as the running-in time extended, the pollution degree of oil and the density of ferromagnetic particles increased slowly.