Multi-Objective Optimization of Response Characteristics for High Power Common Rail Injector

High pressure common rail system (HRCRS) is regarded as the most promising fuel injection system. As the key element of the HPCRS, the performance of the electronically controlled common rail injector (ECCRI) determines the working ability of the diesel engines. Excellent response characteristic is an important guarantee for the ECCRI to realize ideal injection rate, which means a lot to the combustion quality for the diesel engines. In an effort to investigate the response characteristics of the ECCRI, a simulation model for high power ECCRI was presented in this article. And 8 crucial structural parameters about the response characteristics were selected as the research factors. Based on Central Composite Design of Experiment and Response Surface Method, the prediction models between the opening response time (ORT) and the closing response time (CRT) of the ECCRI and the crucial parameters were established. And the optimization solution sets (Pareto frontier) of the ORT and the CRT were obtained through Genetic Algorithm. The point which is closest to the origin on the Pareto frontier were considered as the best result. The calculation results under the best structure parameters show that the ORT of the ECCRI is increased by just 1.42%, but the CRT of the ECCRI is reduced by 27.27%. As a result, the total response time is reduced by 19.90%. The response characteristics of the ECCRI are improved apparently after optimization. The results of this article have theoretical guiding significance for the optimal design of ECCRI.