300MW循环流化床锅炉床温床压控制技术

Bed Temperature and Bed Pressure Control Technology of 300 MWe Circulating Fluidized Bed Boiler

文中介绍了基于Alstom技术的300 MW循环流化床锅炉的结构特点,重点讨论了锅炉投煤操作和正常运行过程中床温的控制技术及正常运行过程中床压的控制和翻床的预防与处理方法。运行实践表明:通过调整给煤量和改变油枪出力相配合的方式控制床温以3～5℃/min速率上升,既能保证燃烧工况的平稳过渡,又能保证汽温、汽压等参数的稳定升高;在事故状态下4个外置式换热器均可参与床温、主汽温度的调节,但此时要以牺牲再热汽温为代价;控制翻床的重点在预防。

The structure feature of 300 MW Circulating Fluidized Bed boiler based on Alstom technology is introduced in this paper. Bed temperature and bed pressure are two parameters that should be supervised importantly during the process that the power unit works normally. The paper focuses on the bed temperature control technology during casting coal operation and normal running of the boiler and the bed pressure control technology during the normal operation. The preventing and dealing way in the case of turn-over of bed material are also discussed. Combined with practical experience,the following conclusions can be drawn. Firstly,it can guarantee the combustion situation smooth transition and smoothly ascending of the primary steam temperature and primary steam pressure by controlling the bed temperature ascending under the rate of 3-5℃/min by the means of adjusting coal feeding rate and oil guns contribution. Secondly,all the four external heat exchangers can participate the bed temperature and primary steam temperature adjustment under the urgent situation at the cost of scarifying the second steam temperature. Lastly,it is more important to prevent the occurrence of turn-over of bed material. It is not easy for the bed material turn--over to happen when AP, = 13-14 kPa （correspondingly P3=9- 10 kPa） and AP2〈I.0 kPa under the load of 300 MWe.