300MW中储式制粉系统燃煤机组低负荷运行研究

随着国内新能源机组装机容量增加,西南地区也相继开始进行煤电机组低负荷运行的尝试。对重庆某300 MW中储式制粉系统机组开展了30%、35%、40%额定负荷三个负荷段下的低负荷不投油稳燃试验。结果表明,三个负荷工况下锅炉能保证稳燃,转向室烟气温度没有明显下降趋势,SCR入口烟温能满足脱硝要求;试验过程中未投运磨煤机,因此避免了三次风对低负荷稳燃的干扰,但这种干扰在长期低负荷运行的过程中客观存在;随着负荷下降,锅炉效率变化不大,但汽机热耗率、发电煤耗及供电煤耗明显上升,严重影响机组的发电效率。对中储式制粉系统低负荷不投油稳燃运行工作的开展具有一定意义。

Research on a 300 MW Unit with Medium Storage Pulverizing System Under Low Load

With the increase of the installed capacity of new energy units,southwest China has also begun to carry out the low load operation of coal power units. Test was carried out on a 300 MW medium-storage pulverizing system unit in Chongqing under the rated loads of 30%,35% and 40%. The test showed that the boiler could ensure stable combustion under three load conditions,the temperature of the flue gas did not decline significantly,and the smoke temperature at the entrance of SCR could meet the requirements of denitrification. The coal mill was not put into operation during the test,so the interference of the third wind to the stable combustion of low load was avoided. With the decrease of load,boiler efficiency changes little,but heat consumption rate of steam turbine,power generation coal consumption and power supply coal consumption significantly increased,seriously affecting the power generation efficiency of the unit. It is significant for the operation of medium storage pulverizing system with low load and steady combustion without oil injection.