A Study on Soot Formation in Premixed Constant-Volume Combustion at High Pressures

高壓下의 定積 豫混合氣燃燒에 있어서 煤煙생成에 關한 硏究

The effect of pressure on soot formation in premixed propane-air combustion is investigated at high pressures over the pressure range of 1 to 5 MPa by using a specially designed constant volume combustion bomb. The combustiom chamber of disk type with eight spark plugs located on the circumference at an interval of 45deg is 100mm in diameter by 14mm thick. The end gases are compressed to high pressures by the eight converging flames. The soot volume fraction in the chamber center during the final stage of combustion at the highest pressure is measured by the in-situ laser extinction technique, and the burnt gas temperature during the same period is measured by the two-color method. It is found that the soot yield rises with 50 to 100% for the respective equivalence ratio range of 1.9-2.2 at an interval of 0.1 when the combustion pressure is increased from 1 to 5 MPa, and that the turbulent flames decrease in the soot yield as compared with the laminar flames because the burnt gas temperatures increase with the drop of heat loss.

본 연구에서는 고압하의 분무연소에 있어서 매연생성에 대한 기초적 자료를 얻기 위해 난류 확산화염의 복잡한 디이젤 분무연소를 예혼합기에 의한 단순한 연소에 서 모델링 될 수 있는 특수 정적연소 장치를 제작했다. 이러한 정적 연소용기내의 프로판-공기 예혼합기연소를 대상으로, 주로 압력이 매연생성에 미치는 영향을 2색법 에 의한 연소가스온도측정과 더불어 4MPa까지의 넓은 압력범위에 걸쳐 조사했다.