350 MW燃煤机组耦合垃圾回转窑燃烧系统应用研究

Application and research of 350MW coal fired unit coupled with garbage rotary kiln combustion system

双碳目标背景下,国家对碳减排要求不断加强,火电机组作为主要的CO_(2)排放源,通过掺烧生物质、垃圾等绿色能源减少化石类能源的消耗是实现碳减排的有效方式。以某350 MW机组燃煤锅炉耦合垃圾回转窑燃烧系统工程为研究对象,选用废纸板、塑料瓶、湿瓜藤等为原料,在对垃圾回转窑燃烧系统性能测试的基础上,分析了垃圾回转窑燃烧系统投运后对锅炉运行的影响。测试结果表明:借助于高温一次风的助燃作用,垃圾在回转窑中的燃尽性较好,垃圾回转窑燃烧系统热效率为80.90%,对垃圾的能量利用率为32.68%,高于目前国内生活垃圾焚烧发电厂平均22%的能量利用率10.68个百分点,且系统点火、燃烧全过程均不需要燃油助燃,节能效果明显。350 MW工况下锅炉热效率由94.76%降低到94.65%,主要原因为回转窑系统烟气通过热二次风箱进入锅炉参与燃烧,降低了助燃风中的氧浓度,对炉内燃烧有一定的弱化作用,造成飞灰含碳量从0.28%增加到0.56%。回转窑燃烧系统投运后,锅炉总排口二噁英浓度从为0.041 ng TEQ/m^(3)增加到0.053 ng TEQ/m^(3),飞灰浸出液中硒元素含量从0.0116 mg/L增加到0.0185 mg/L,总铬元素含量从1.61 mg/L增加到1.79 mg/L。

In the context of the two-carbon target,the country's requirements for carbon emission reduction have been continuously.strengthened.As the main.source of CO_(2) emissions from thermal power plants,reducing the consumption of fossil energy by burning biomass,garbage and other green energy sources is an effective way.Taking a 350 MW unit coal-fired boiler coupled with garbage rotary kiln combustion system project as the research object,using waste cardboard,plastic bottles and wet melon vines as raw materials,based on the performance test of the garbage rotary kiln combustion system,the influence of the garbage rotary kiln combustion system on the boiler performance was analyzed.The results show that with the aid of the combustion-supporting effect of high-temperature primary air,the waste in the rotary kiln has good burnout performance,the thermal efficiency of the garbage rotary kiln combustion system is 80.90%,and the energy utilization rate of the waste is 32.68%which is about 10.68 percentage points higher than the current domestic waste incineration power plant average of 22%,and the whole process of ignition and combustion of the system does not require fuel combustion,and the energy saving effect is obvious.After the coupling system was put into operation,the thermal efficiency of the boiler was reduced from 94.76%to 94.65%under the 350MW working condition.The main reason was that the flue gas of the coupling system entered the boiler through the hot secondary air box to participate in the combustion,which reduced the oxygen concentration in the combustion air and reduced the combustion in the furnace causing the carbon content of fly ash to increase from 0.28%to 0.56%.After the garbage rotary kiln combustion system was put into operation,the dioxin concentration in the total discharge of the boiler increased from 0.041ng TEQ/m^(3) to 0.053ng TEQ/m^(3),and the selenium content in fly ash increased from 0.0116mg/L to 0.0185mg/L,and the total chromium content increased from 1.61mg/L to 1.79mg/L.