MULINBUMP-HCCI复合燃烧放热特征及其对排放和热效率的影响

Characteristics of MULINBUMP-HCCI Compound Combustion and It's Effect on Emissions and Thermo-Efficiency

提出了基于多脉冲喷射和BUMP燃烧室的MULINBUMP HCCI复合燃烧技术。发动机试验和CFD数值模拟研究表明,多脉冲喷射参数,特别是多脉冲喷射定时可以控制预混合气的形成,从而控制燃烧放热率。具有分布式放热率的工作过程的热效率与直喷式柴油机相当,但同时改善了NOx和碳烟排放。在不采用废气再循环的条件下,NOx排放在较低负荷时只有11×10-6,高负荷时也不超过250×10-6。碳烟排放始终小于0 5BSU。

MULINBUMP-HCCI compound combustion technology was developed based on the combustion strategies of combination of controlled premixed charge compression ignition (CPCCI) and lean diffusion combustion (LDC). The results of engine experiments and CFD simulation showed that premixed mixture preparation could be controlled by setting parameters of multi-pulse injection at a certain engine operation condition, especially, by setting the timing of multi-injection. Sequentially, the phase and rate of heat release could be controlled. A MULINBUMP working cycle with dispersed heat release revealed that its thermo-efficiency was proximately as high as a conventional diesel cycle with an advanced injection timing of 8°CA BTDC. However, the emissions of NO_x and soot were simultaneously reduced in the MULINBUMP cycle. The NO_x emission was only 11×10^(-6) at lower engine load and less than 250×10^(-6) at high load. The soot emission was less than 0.5 BSU.