재제조 디젤 엔진의 수소 가스 첨가에 따른 NOx 배출 특성 평가

Engine remanufacturing is a whole process of making an old, worn out engine into an almost new engine through disassembling, cleaning, examining, adjusting and reassembling. Engine remanufacturing could save production cost and prevent CO2 emission, but it hardly satisfies the new exhaust gas regulation. Especially in diesel engines, we need various investigations on reducing NOx emission. This research took NOx reducing technology using hydrogen burning (reaction). Addition of hydrogen (using PEME) could reduce NOx emission because it creates fast flame spread that helps decreasing high temperature area of a cylinder. Condition of the experiment was engine load of 25%, 50%, 75%, and 100% each, and engine speed of 1200 RPM, 1600 RPM, 2000 RPM, 2400 RPM, and 2800 RPM. In this experiment we compared each condition focusing on different features of NOx emission. As a result, adding slight amount of hydrogen to intake valve made it tiny worse NOx emission at low engine load. And at middle engine load, hydrogen addition was effective in reducing NOx emission. Finally, at high engine load, we found it hydrogen addition is not effective in reducing NOx emission.