使用于松木生物质颗粒作为燃料,结合先进的自预热燃烧技术,实现燃料在炉膛内的流态化燃烧。通过千瓦级预热燃烧试验平台,对木本生物质颗粒在不同预热温度下的预热改性进行了全面深入的探索。使用BET、SEM扫描电镜与拉曼光谱带对比的方法对高温生物质半焦的比表面积、总孔容积、氮气等温吸附脱附特性、颗粒表明形态等关键物性参数进行检测和分析。分析结果显示,随着预热温度的升高,氮气吸附量明显增加,说明改性后的生物质半焦具有更多的孔隙结构。结合碳微晶结构分析,松木生物质颗粒在高加热速率下解聚脱挥发导致大分子碳链断裂产生小分子挥发物从而改善反应活性。在燃烧特性方面,改性后的高温生物质半焦可在下行燃烧室内迅速实现稳定燃烧,且燃烧效率高达99%以上。在NOx排放上,所有实验工况均将燃烧温度控制在1100℃以下避免产生热力型NOx。预热后松木生物质颗粒的NOx排放浓度并未随预热温度的单调变化而增减。842℃时,NOx排放质量浓度达到峰值,随后开始下降。在试验温度范围内,当预热温度设定为705℃时,NOx排放质量浓度达到最低值,即97.79mg/m3。综上,为确保松木生物质预热燃烧后具有较低的NOx排放和高燃烧效率,推荐的最佳预热温度为705℃。

fluidized combustion within the furnace. The preheating modifications of woody biomass particles under different preheating temperatureswere examined using a kilowatt level preheating combustion test rig. BET, SEM scanning electron microscopy and Raman spectralband comparison methods were employed to detect and analyze the specific surface area, total pore volume, nitrogen isothermal adsorptionand desorption characteristics, particle morphology and other key physical property parameters of high temperature biomass semi-coke.The findings indicate that an increase in preheating temperature results in a noticeable rise in nitrogen adsorption amount, suggesting thatthe modified biomass semi-coke possesses a more developed pore structure. The depolymerization and devolatilization of pine biomass particles at high heating rates, combined with the analysis of carbon microcrystalline structure, result in the disruption of macromolecular carbon chains and the generation of small molecular volatiles, thereby enhancing reactivity. The modified high - temperature biomasssemi-coke exhibits rapid attainment of stable combustion within the descending combustion chamber, with a remarkable combustion efficiency reaching 99% in terms of its combustion characteristics. In terms of NO emissions, the combustion temperature is maintained at1 100 ℃ under all experimental conditions to prevent the formation of thermal NO. It is noteworthy that the concentration of NO emissions from pine biomass particles does not exhibit a linear relationship with preheating temperature. Specifically, at 842 ℃ , the concentration of NO emissions peaks and then begins to decrease. Within the range of test temperatures, when the preheating temperature is set at705 ℃ , the concentration of NO emissions reaches its lowest value, namely 97.79 mg/ m. In conclusion, for ensuring low NO emissionsand high combustion efficiency in pine biomass after preheating combustion, this study recommends an optimal preheating temperature of705 ℃ .

0 引言

1 试验

   1.1 试验装置

   1.2 数据采集与取样分析

   1.3 试验原料

   1.4 试验工况

2 试验结果及分析

   2.1 预热特性

   2.2 燃烧特性

   2.3 NOx排放特性

3 结论