CAJ | 학술논문

对自由射流和受限射流乙醇小尺度扩散火焰的燃烧温度及稳燃特性进行了实验研究。结果表明：火焰在静止空气中燃烧会经历淬熄前火焰、稳燃火焰、振荡前火焰、振荡火焰4个不同的状态。受限空间和自由空间下，火焰峰值温度随雷诺数增大均会经历增大，稳定和减小3个阶段，自由空间下，其温度最高可达1300K。尾部烟气温度随雷诺数先增大后保持稳定，其温度最高可达480K。只有当内径小到一定程度，玻璃管壁温才会随雷诺数有较大增加，其温度最高可达370K。随着受限空间内径的减小，火焰的燃烧上限明显降低，且均比自由空间时的低，而燃烧下限几乎均与自由空间时相同。在本实验范围内，热熄火是淬熄的主要因素，而燃料的不完全燃烧则是火焰由稳定燃烧转变为振荡燃烧的主要因素。
대자유사류화수한사류을순소척도확산화염적연소온도급은연특성진행료실험연구。결과표명：화염재정지공기중연소회경력쉬식전화염、은연화염、진탕전화염、진탕화염4개불동적상태。수한공간화자유공간하，화염봉치온도수뢰낙수증대균회경력증대，은정화감소3개계단，자유공간하，기온도최고가체1300K。미부연기온도수뢰낙수선증대후보지은정，기온도최고가체480K。지유당내경소도일정정도，파리관벽온재회수뢰낙수유교대증가，기온도최고가체370K。수착수한공간내경적감소，화염적연소상한명현강저，차균비자유공간시적저，이연소하한궤호균여자유공간시상동。재본실험범위내，열식화시쉬식적주요인소，이연료적불완전연소칙시화염유은정연소전변위진탕연소적주요인소。
The experimental studies were carried out on the combustion temperature and stability of small-scale diffusion flames using ethanol as fuel both for free jet flow and confined jet flow. Results show that there are four conditions for the jet flow flames in the quiescent air, namely the quenching flames, stable combustion flames, quasi-oscillatory flames, and oscillatory flames. As Reynolds numbers increase, the flame peak temperatures increase firstly and then will decrease. For the free jet flow, the flame peak temperatures reach 1300K, and the exhaust gas temperatures increase, then keep stable, and may reach the maximum value of 480K. When using the quartz glass tube with a certain small diameter, the wall temperatures increase quickly with the increasing of Reynolds numbers, and may reach the maximum of 370K. The upper combustion limits of confined flow are all less than that of free flow, but the lower combustion limits are very close. As the inner diameters of the quartz glass tubes decrease, the upper combustion limits decrease sharply. In the present parameter ranges, thermal quenching is the main factor for flame quenching, and the main reason causing the transition from stable flames to oscillatory flames is the fuel incomplete combustion.