电站锅炉燃气脉冲除灰过程研究

A Study of Gas Pulsation-based Ash Removal Process in Utility Boilers

中国电站锅炉燃用大量的未经洗选的劣质煤 ,导致严重的锅炉积灰。积灰不仅使锅炉热效率下降 ,而且堵塞烟气通道 ,影响了锅炉的正常运行。燃气脉冲除灰技术是中国科学院力学研究所燃烧实验室开发的 ,并在 30多台大型电站锅炉应用 ,取得了很好的效果。本文工作研究了该项技术中燃烧室结构和燃料对火焰传播和压力脉冲的影响 ;用压力传感器测量燃气脉冲在出口外流场中的压力分布 ,观察燃气脉冲的作用强度和作用范围 ;用振动传感器测量积灰板的振动 ,以及在不同空间位置振动加速度的变化情况 ,由此推论了除灰作用的机理。

The burning of huge amount of inferior-quality unwashed coals in Chinese utility boilers has led to serious boiler ash-deposit and related fouling problems. The latter can result in a reduction of boiler thermal efficiency and cause the clogging of the boiler rear flue pass, thus affecting the normal operation of the boiler. The gas pulsation-based ash removal technology was developed by the combustion lab of a Mechanics Research Institute under the Chinese Academy of Sciences. Its use on 30-plus large-sized utility boilers has proved to be very effective. In the present paper the study results of the above-cited technology are reported. They cover a variety of aspects. These include the influence of furnace configuration and fuel on the flame propagation and pressure pulses, the measurement by the use of pressure sensors of the gas pulse pressure distribution at the outlet flow field, and the observation of gas pulse intensity and its action range. In addition, also touched upon were the vibration measurement of ash deposit plate with the help of a vibration sensor and the variation of vibration accelerations at various spatial locations. From the above one can readily gain a better understanding of the mechanism of the gas pulsation-based ash removal action.