水素アシストディーゼル燃焼の研究: 第1報，水素吸入がディーゼルエンジンの燃焼・排気特性に及ばす影響

摘要

ディーゼルエンジンは熱効率に優れ，CO_2（Carbon rndioxide）削減の有効な手段として注目されているが，rn一方で排気中のスモーク（すす）や，NO_x（Nitrogen rnoxide）が大きな問題となっている．代替動力源にrn関する研究も行われているが，エネルギー密度の観rn点やインフラ面で課題があり，実用化するには時間rnを要すると考えられる．%The present study experimentally investigated the performance and emission characteristics of a diesel engine with hydrogen added to the intake air at late diesel-fuel injection timings. The diesel-fuel injection timing and the hydrogen fraction in the intake mixture were varied while the available heat produced by diesel fuel and hydrogen was kept constant at a certain value. As the hydrogen fraction was increased, NO first deceased, attained minimum, and then increased. The maximum rate of incylinder pressure rise also showed minimum at 10 vol% hydrogen fraction. The indicated thermal efficiency was almost constant or slightly increased with small amount of hydrogen. A combination of hydrogen addition and late diesel fuel injection timing contributed to low temperature combustion, in which NO decreased without the increase in unburned fuel.