【摘要】 针对某厂燃用烟煤的1025t/h锅炉低负荷稳燃能力差,相邻燃烧器之间流场容易干扰的问题,进行了实验室冷态试验及工业试验研究,并将下层8只燃烧器改造为中心给粉燃烧器。结果表明:在外二次风叶片角度为35o时,中心给粉燃烧器有合适的中心回流区,既能防止相邻燃烧器的相互干扰,还能保证煤粉的及时着火和稳定燃烧,而双调风燃烧器在正常运行条件下没有回流区。与双调风燃烧器相比,沿射流方向的燃烧器中心区域,中心给粉燃烧器的烟气温度和升温速率较高,O2和NOx浓度较低;靠近侧墙水冷壁区域,中心给粉燃烧器的O2浓度较高,烟气温度较低。下层8只燃烧器改造后,锅炉热效率提高了1.03%,NOx排放量降低了13.74%,锅炉可以在110MW电额定负荷下不投油稳定运行。更多还原

【Abstract】 An opposite-wall-fired 1 025 t/h boiler burning bituminous coal have the following problems: no stable flame at low load and appearing interference easily between adjacent burners. To solve these problems, small scale cold flow experiments and full-scale industrial experiments were both performed. Eight enhanced ignition-dual register(EI-DR) burners in the bottom row of the furnace were retrofitted to centrally fuel rich(CFR) swirl burners. The results show that with the outer secondary air vane at 35o, the central recirculation zone of CFR burner can prevent the adjacent jets flows from interfering with each other, and be advantageous for the coal ignition and flame stability. However, for the EI-DR burner, no central recirculation zone is formed at the rated condition. Compared to that with the EI-DR burners, along the jet direction in the central region of the burner, the gas temperature with the CFR burner is higher and has a faster rising rate. The mean concentrations of O2 and NOx are lower. In the region near the side wall, the mean O2 concentration is higher and the gas temperature is lower. After the eight burners in the bottom row being retrofitted, the thermal efficiency of the boiler increases by 1.03%, the NOx emission decreases by 13.74% and the boiler operates stably rated at rating load 110 MW without auxiliary fuel oil.更多还原