为分析煤粉炉掺烧生物质气对耦合锅炉运行性能的影响，基于660 MWe燃煤锅炉和30 t/h生物质气化炉，搭建生物质气化耦合燃煤锅炉系统模型。在额定工况下，选取松木、木屑、污泥3种生物质，研究气化过程；并将最佳气化条件下得到的生物质气引入锅炉进行混合燃烧，研究不同生物质气对锅炉运行及燃烧产物的影响规律。结果表明，生物质气化热效率在最佳空燃比下均可达90%以上。与纯煤燃烧工况相比，耦合工况的炉膛燃烧温度均有所下降，最高下降9.43 ℃；生物质气掺烧使锅炉效率略下降，而耦合系统的生物质利用效率均可达84%以上；且耦合燃烧减少了CO2排放量，其中松木气掺烧时CO2减排量最大，为2.62×105 t/a。耦合系统中NOx生成量与炉膛燃烧温度和生物质气中CH4含量明显相关，其中木屑气耦合燃烧生成的NOx质量浓度下降最多，为167.16 mg/m3；而SOx生成与生物质成分密切相关，其中松木气耦合燃烧生成的SOx质量浓度最低，相比纯煤燃烧下降330.22 mg/m3（标况下）。

In order to analyze the influence of a pulverized coal furnace co-firing with biomass gas on the operation performance of the coupled boiler,a biomass gasification coupled coal-fired boiler system model was built based on a 660 MWe coal-fired boiler and a 30 t/h biomass gasifier. At rated working conditions,three types of biomass,namely pine wood,wood chips,and sludge,were selected for gasification process research. The biomass gases obtained on the optimal gasification condition were fed into the boiler for mixed combustion,the influence law on boiler operation and combustion products generation from different biomass gases co-firing was researched. The results show that the gasification heat efficiency of biomass can reach more than 90% at the best air-fuel ratio. Compared to the pure coal combustion conditions,the furnace combustion temperature of the coupled system decreases,with a highest drop value of 9.43 ℃. The combustion mixed with biomass gas makes the boiler efficiency slightly decrease,but the biomass utilization efficiency of the coupled boiler system can still reach 84% above. In addition,the multi-fuel combustion can reduce CO2 emissions,and the CO2 cut from co-combustion with pine-gas is the largest of all three material,with the value of 2.62×105 t/a. The amount of NOx reduced in the coupled system is significantly related to the furnace combustion temperature and the CH4 concentration in biomass gas,with a maximum drop value of 167.16 mg/m3 from blending a wood chip gas. The SOx mass concentration is relevant to the composition of biomass gas and the lowest value is from co-firing a pine gas,with a drop value of 330.22 mg/m3,compared to the pure coal combustion.

0 引言

1 生物质气化与燃煤锅炉耦合过程分析与模拟

   1.1 耦合系统性能指标

   1.2 耦合系统燃烧产物的生成机理

   1.3 耦合燃烧过程模拟

2 结果分析

   2.1 生物质气化性能

   2.2 生物质气耦合燃煤锅炉运行性能

   2.3 生物质气耦合燃煤锅炉产物

3 结论