Exploring the advantages of boot-electronically controlled injector in flexible fuel injection strategies for marine diesel engines

An appropriate fuel injection strategy is crucial for enhancing combustion efficiency and lowering emissions in marine diesel engines. In this study, the Boot-Electronically Controlled Injector (Boot-ECI) was developed by refining the Traditional Electronically Controlled Injector (TECI), introducing diverse injection strategies, including injection rate shaping. An analysis using an AMESim model demonstrated the Boot-ECI's superior capabilities in both single and multiple injections, showcasing advantages over the TECI. The Boot-ECI enables strategies such as square, small-quantity, and various boot injections, which can be combined for versatile multiple injections. It features faster needle movement in square injection, reducing needle opening and closing times by 72 μs and 280 μs, respectively, and offering a fuller injection rate shape. The Boot-ECI can achieve boot injections with varying boot proportions. In terms of ensuring the consistency of injection quantity, the boot injection can replace the pilot-main injection prone to fusion. It includes both coarse and fine-tuning mechanisms for injection quantity control, achieving an accuracy level of about 2.3 mm3 at a low lift/high lift ratio of 0.4. The design considerations for the low lift/high lift ratio, including factors such as injection quantity, duration, and rate, are critical for optimizing the Boot-ECI's performance.