Application of Monte Carlo method in reliability analysis for
common rail injection system
1.Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.Wuxi Fuel Injection Equipment Research Institute, FAW, Wuxi, Jiangsu 214063, China
Abstract:To realize quantitative analysis of structural reliability in the process of common rail injection system (CRS) development, a ″leakageshutting″ failure model was established, and a structural reliability investigation was demonstrated based on Monte Carlo (MC) method. The model related to the fuel delivery limitation in restrictor and the fuel distribution in common rail injector, and the latter included fuel injection, fuel dynamic leakage and fuel clearance leakage of commandpiston matching parts and nozzle needle matching parts. The parameters of random variables in model were obtained by statistical result of product sampling test. The calculation precision and feasibility of MC direct sampling method were compared with those of MC important sampling method. The results show that the calculation result of failure rate is 7.97×10-5 by MC important sampling method. The failure rate is mainly influenced by several variables of limitation value of restrictor and working clearances of the two pairs of matching parts. The failure rate sensitiveness to working clearance standard deviation of nozzle needle matching parts is 3.1 times than that of commandpiston matching parts. MC important sampling method is appropriate for CRS reliability analysis.