Lubricant composition for gas engine

Abstract

The invention relates to a lubricant composition for a gas engine. The lubricant composition contains: by mass, less than or equal to 0.08% of phosphorus and less than or equal to 0.8% of sulfate ash. The lubricant composition comprises A) a composite antioxidant comprising at least ingredients of 1, an alkylated diphenylamine antioxidant, 2, a thiophenolic ester antioxidant and 3, an unessential phenolic thioether antioxidant, B) a dispersant, C) one or more sulfurized alkaline earth metal alkyl phenolate cleaning agents, D) at least one zinc dialkyl dithiophosphate, E) one or more ashless friction modifiers, F) one or more metal deactivators and G) a main amount of lubricating base oil. The lubricant composition for a gas engine adopts optimized combination of the multiple ashless antioxidants, is blended with the appropriate clearing agent and the dispersant, has a synergistic effect of the additives, can satisfy high-temperature antioxidation requirements of lubricating oil for a gas engine, and has excellent piston cleanliness, high / low-temperature wear resistance and a good viscosity increasing control capacity.

Description

technical field [0001] The invention relates to a lubricating oil composition, in particular to a low-phosphorus and low-ash lubricating oil composition for a gas engine. Background technique [0002] The low emission, low fuel cost and reasonable fuel resource allocation characteristics of compressed natural gas make it increasingly valued as a vehicle engine fuel in the world, and promote the development of compressed natural gas vehicles at home and abroad, and its technology development is also becoming more and more mature. Compressed natural gas / gasoline dual-fuel vehicles refitted from gasoline vehicles are widely welcomed in large and medium-sized cities, and their development prospects are very bright. However, the original gasoline engine lubricating oil used in this type of vehicles has problems such as high carbon deposits, large sludge, and shortened oil change intervals. The engine is prone to many problems such as early wear and short overhaul mileage. In ter...

AI Technical Summary

Problems solved by technology

However, the original gasoline engine lubricating oil for this type of vehicle has problems such as high carbon deposits, large sludge, and shortened oil change intervals, and the engine is prone to many problems such as early wear and short overhaul mileage.

In terms of performance, ordinary gasoline engine lubricating oil does not meet the requirements for lubricating oil of CNG / gasoline dual-purpose fuel engines. Compressed natural gas / gasoline dual-purpose fuel engines use natural gas when the combustion chamber temperature is high and the exhaust temperature is high, so Ordinary gasoline engine lubricating oil is difficult to meet the anti-oxidation performance requirements of the engine at high temperature, and its high-ash additives are easy to form hard deposits on the surface of engine components, resulting in increased carbon deposits, valve burning, etc.

[0003] Zinc dialkyldithiophosphate (ZDDP) is a phosphorus-containing multi-effect additive with excellent anti-oxidation, anti-wear and anti-corrosion properties. It is an antioxidant component in lubricating oil formulations for internal combustion engines. It will enter the catalytic converter through exhaust gas recirculation or blow-by process, and accumulate on the active metal site, poisoning the catalyst, thereby reducing the catalyst efficiency and shortening its service life, so the use of phosphorus-containing additives as lubricating oil components is restricted by specifications and standards

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