生物质与兰炭掺混燃烧被认为是解决大量碳排放、NOx和SO2等空气污染相关问题的潜在途径。分别通过热重试验和滴管炉试验研究纯兰炭、兰炭与生物质混合物空气分级燃烧特性,分析掺混比对混合燃料着火温度、燃尽温度、结渣特性、沾污特性及燃烧特性指数的影响,确定适宜空气分级燃烧比例、最佳燃烧温度和最佳掺混比。结果表明,掺烧生物质可有效降低混合燃料着火点,其着火点由474℃降至300℃,掺烧生物质后燃尽温度略降低,兰炭掺混生物质燃烧未明显提高燃烧特性指数;兰炭粉掺混生物质燃烧有高灰分沉积倾向,结渣倾向小。相比掺烧前,不同温度掺烧生物质后出口NOx和SO2质量浓度均较低,1200℃出口NOx和SO2质量浓度降幅均较高,分别达87.27%和80.2%。未空气分级时,综合出口NOx等参数得出,适宜生物质质量分数为30%~40%,最佳燃烧温度1200~1300℃。分级燃烧时,生物质质量分数30%的NOx初始排放随温度变化平缓,稳定性好,出口NOx质量浓度最低,均低于125mg/m3。研究结论可为有机固废焚烧处置设备的运行及相关燃烧工况组织调控提供一定技术支持。

The co-combustion of biomass and semi-coke is considered to be a potential way to solve a large number of air pollution-relatedproblems such as carbon emissions, NOx and SO2. The air-staged combustion characteristics of semi-coke, mixture of semi-coke and biomass were studied by thermogravimetric experiment and drop tube furnace experiment respectively. The effects of blending ratio on ignitiontemperature, burnout temperature, slagging characteristics, fouling characteristics and combustion characteristic index of mixed fuel wereanalyzed, and the suitable air-staged combustion ratio, optimal combustion temperature and optimal blending ratio were determined. Theresults show that the ignition point of the mixed fuel is effectively reduced after co-firing biomass, and the ignition point is reduced from474 ℃ to 300 ℃ . The burnout temperature is slightly reduced after co-firing biomass. The combustion characteristic index is not significantly improved by the combustion of carbon mixed biomass. The combustion of biomass mixed with carbon powder has a tendency of highash deposition and a small tendency of slagging. The outlet NOx mass concentration and outlet SO2 mass concentration after co-firing biomass at different temperatures are lower than those before co-firing. Compared with those before co-firing, the mass concentration of outletNOx and SO2at 1 200 ℃ decreases significantly, reaching by 87.27 % and 80.2 % respectively. Based on comprehensive export parameters such as NOx, the optimal biomass mass fraction is 30% ~40%, and the optimal combustion temperature range is 1 200~1 300 ℃ under the condition of no air classification. The initial NOx emission of biomass with a mass fraction of 30% changes gently with temperatureduring staged combustion, showing good stability. The outlet NOx mass concentration is the lowest, all below 125 mg/ m3. The research conclusions can provide some technical support for the equipment operation of organic solid waste incineration disposal and the organizational regulation of related combustion conditions.

0 引言

1 试验

   1.1 热重试验

   1.2 滴管炉试验

   1.3 分析方法

2 结果与讨论

   2.1 热重试验

   2.2 滴管炉试验

3 结论