Development of a novel common-rail type Dimethyl ether (DME) injector

A novel common-rail type DME injector has been proposed by State Key Laboratory of Engines. The injector employs impact principle to enlarge its electromagnetic force, and thus has no plunger matching parts. The sealing and wear problems brought by plunger can be avoided when the injector injects DME. In addition, oil return is absent from the injector which can be directly driven by 24 V. In order to validate the feasibility of the proposed design and investigate the influence of structure parameters on injector performance, a simulation model is established based on Flowmaster coupled Maxwell. An optimized injector prototype is made in accordance with the simulation results. Our experiment shows that the working principle of the injector is effective, and that its performance can meet the requirements of DME fueled engines. Moreover, the novel injector has the advantages of back-pressure insensitive injection quantity and an opening response that is not affected by common-rail pressure.