Evaluation of Useful Lifetime of Gas Engine Lubrication Oils

Gas engine lubricating oil degrades when it undergoes thermal decomposition by its exposure to high temperature. It is oxidized by air, and it changes the nitrate ester formed by the combustion products of fuel gas mixes. The degradation of the use oil causes about decrease in engine efficiency, the corrosion and the increase of wear for engine troubles. So, it is necessary to change the use oil beforehand at an appropriate period. Generally, gas engine lubricating oil consists of base oil and about ten kinds of additives in proper ratio. But now, degradation of gas engine lubrication can simply be evaluated by such broad guideline, as general analytic index. Therefore, it is difficult to specify the degradation conditions under which to decade the interval of effective oil. In this study, the authors established a method of analysis which can evaluate degradation of base oil and specific additives qualitatively or quantitatively (a method to accurately evaluate the life of lubrication). The authors have revolved the results of their study because it has become now possible to show by an index results and effects of extreme pressure on additives and neutralization additions regardless of the old type used.