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为了研究雾化特性对喷雾燃烧点火过程的影响,用马尔文激光粒度分析仪等雾化测量系统,对离心喷嘴流量、喷雾锥角、周向不均匀度、液滴索太尔平均直径(SMD)、液滴尺寸分布指数(N)等雾化特性进行了测量;采用高速摄影机和热电偶测温系统,记录了燃烧室内点火过程和燃烧室出口温度变化历程,揭示了初始火焰形成及火焰传播过程,探讨了喷嘴雾化特性对燃烧室初始火焰形成、火焰发展、出口温升开始时间、最大温升时间以及温升率等点火过程和点火性能的影响规律。研究结果表明:随着供油压力的提高,离心喷嘴的燃油流量呈现二次曲线增加,SMD逐渐减小,N值呈现先下降后上升的趋势。在点火油气比为0.0078~0.0125时,随着供油压力的提高,初始火焰变长,火焰的发展先沿着靠近燃烧室上壁面部分向下游发展,再向燃烧室中下部分发展,火焰亮度增强,燃烧室出口温升开始时间缩短,最高温升时间增大,温升率提高,最大温度值上升。在相同的点火油气比下,距离燃烧室上壁面1/4燃烧室高度处热电偶(TC-1)温升值和温升率最高,温升开始时间最低;距离燃烧室上壁面3/4燃烧室高度处热电偶(TC-3)温升值和温升率最低,温升开始时间最高。
In order to study the influence of atomization characteristics on the ignition process of spray combustion, the atomization measurement system of Malvern laser particle size analyzer was used to measure the flow rate of spray nozzle, spray cone angle, circumferential unevenness, ) And droplet size distribution index (N) were measured. The high temperature camera and thermocouple temperature measurement system were used to record the ignition process and the exit temperature of the combustion chamber. The initial flame formation and flame propagation The influence of nozzle atomization characteristics on the ignition process and ignition performance of the combustion chamber, such as initial flame formation, flame development, start time of outlet temperature rise, maximum temperature rise time and temperature rise rate, was discussed. The results show that with the increase of the oil supply pressure, the fuel flow rate of the centrifugal nozzle shows a quadratic curve increase, the SMD decreases gradually, and the N value first decreases and then increases. When the gas-oil ratio is 0.0078 ~ 0.0125, the initial flame becomes longer with the increase of the pressure of oil supply. The development of the flame first develops along the wall near the upper part of the combustion chamber to the lower part and then proceeds to the lower part of the combustion chamber. The flame brightness Enhanced, the combustion chamber outlet temperature start time is shortened, the maximum temperature rise time increases, the temperature rise rate increases, the maximum temperature value increases. At the same ignition gas-oil ratio, the temperature rise value and the temperature rise rate of the TC-1 at the height of one-fourth of the combustion chamber from the upper wall of the combustion chamber are the highest, and the temperature start time is the lowest; Room temperature thermocouple (TC-3) the temperature rise and the lowest rate of temperature rise, the highest temperature rise time.