パイロット噴射と組み合わせたアフター噴射のスモーク低減効果

Abstract

This study aims at obtaining the after-injection strategy to reduce smoke emissions in a diesel engine, where after injection is employed in combination with pilot injection. The experiments were performed using a single-cylinder diesel engine under various conditions of pilot and after injection at a fixed load. The results show that small after-injection quantity with short interval offers reduced smoke emission. Larger pilot-injection quantity provides larger smoke reduction from the level in the case without after injection. The smoke-reduction effect is scarcely affected by pilot-injection timing in the case of a larger pilot-injection quantity. These tendencies are explained with attention to the interaction between main-spray flame and after-injection spray.

単気筒ディーゼル機関を用いて，パイロット噴射量や時期を変えながらアフター噴射条件を変化させて実験を行い，その結果を，アフター噴射を行わない場合と比較し，メイン噴霧火炎とアフター噴霧の干渉を考慮した考察を加えることにより，アフター噴射による黒煙低減効果が得られる条件について検討を行った．