风电、光伏等新能源发电规模持续快速增长，电网负荷峰谷差不断增大，燃煤火电机组调峰运行更加频繁。为研究燃煤机组实际调峰运行中的关键影响因素，开展了8台不同类型机组的调峰试验。通过分析锅炉炉膛负压与火检信号、助燃措施投运状态，确定锅炉在深度调峰运行状态下的稳燃能力，对燃煤机组低负荷运行状态下污染物排放浓度进行分析，分析了机组SCR烟气脱硝装置温度在不同负荷下的变化规律，并研究了抽汽供热机组供热量与调峰能力之间的关系，分析机组供热量对机组调峰运行的影响。结果表明：在燃用煤质与设计煤质接近的情况下，大部分机组在纯凝工况下可达到40%额定容量以下稳定运行的能力，接近机组设计最低稳燃负荷；NOx排放是燃煤火电机组深度调峰运行期间的重要限制因素，SCR脱硝装置运行温度在低负荷下可能降至300 ℃ 以下，严重影响SCR装置正常运行，从而制约机组深度调峰运行；机组供热量较小时有助于提升锅炉低负荷运行能力，但供热量较大时严重影响机组深度调峰，可能会使机组调峰能力下降20%以上。

The scale of new energy power generation such as wind power and photovoltaics continues to grow rapidly,and the peak-to-valley difference of grid load continues to increase,as a result,the peak shaving operation of coal-fired thermal power units has become more frequent. In order to study the key influencing factors in the actual peak-shaving operation of coal-fired units,the peak-shaving test of 8 coal-fired units with different types was carried out. In the test,the stable combustion ability of the boiler under the deep peak regulation operation state was analyzed by measuring the negative pressure of the boiler furnace,the fire detection signal and the state of the combustion-supporting measures. The pollutant emission concentration of the coal-fired unit under the low-load operation state,and the variation law of the temperature of the SCR flue gas denitrification device under different loads was also analyzed. In addition,the relationship between the heat supply of the extraction steam heating unit and the peak regulation capacity was studied,and the effect of unit heat supply on peak shaving performance was analyzed. The results show that when the coal quality is close to the design coal quality,most units can achieve stable operation below 40% of the rated capacity under pure condensing conditions,which is close to the unit′s design minimum stable combustion load;NOx emission has become an important limiting factor during the deep peak-shaving operation of coal-fired power units. The operating temperature of the SCR denitrification device may drop below 300 ℃ under low load,which will seriously affect the normal operation of the SCR device and restrict the deep peak shaving operation of the unit.The small heat supply of the unit will help to improve the low-load operation of the boiler.However,when the heat supply is large,it will seriously affect the deep peak shaving of the unit,which may reduce the peak shaving capacity of the unit by more than 20%.

0 引言

1 试验

   1.1 机组概况

   1.2 试验过程

   1.3 燃用煤质

2 调峰试验结果分析

   2.1 机组调峰能力

   2.2 锅炉稳燃能力分析

   2.3 污染物排放

   2.4 机组供热

3 结论