燃气锅炉掺氢燃烧、排放及运行特性研究
Research on hydrogen-blended combustion, emission and operation characteristics of gas boilers
摘要：
燃气锅炉掺氢燃烧是城镇供热减少碳排放的重要途径,但针对燃气锅炉掺氢燃烧、排放及运行特性的研究较少。本文分析了掺氢比对燃气锅炉各项运行参数的影响,探讨了掺氢天然气的物性参数变化、燃烧与排放特性及锅炉运行优化策略。结果显示:掺氢天然气可显著降低CO2排放,但其物性参数的显著变化需重新调整燃烧参数以维持锅炉效率;掺氢比增大会加速层流火焰传播速度,扩大可燃极限,并提升火焰温度,导致热力型NOx排放量增大(尤其在温度高于1 600 K时);通过调节过量空气系数可抑制NOx生成,但高掺氢比(>50%)时效果减弱;现有研究多聚焦小型家用锅炉(25～28 kW),证实掺氢可提升冷凝效率及节能潜力,但大容量工业锅炉的高掺氢运行数据仍匮乏。
Abstract：
Hydrogen-blended combustion of gas boilers is an important way to reduce carbon emissions in urban heating, but there are few studies on the hydrogen-blended combustion, emission and operation characteristics of gas boilers. This paper analyses the influence of the hydrogen blending ratio on various operation parameters of gas boilers, and discusses the changes in physical parameters, combustion and emission characteristics of the hydrogen-blended natural gas, and boiler operation optimization strategies. The results show that the hydrogen-blended natural gas can significantly reduce CO2emissions, but the significant changes in its physical parameters require re-adjustment of combustion parameters to maintain boiler efficiency. Increasing the hydrogen blending ratio will accelerate the laminar flame propagation speed, expand the flammability limit, and increase the flame temperature, leading to increased thermal NOxemissions (especially when the temperature is higher than 1 600 K). Adjusting the excess air coefficient can suppress NOxgeneration, but its effectiveness diminishes at high hydrogen blending ratios (large than 50%). Current research primarily focuses on small household boilers (25-28 kW), confirming that hydrogen blending can improve condensation efficiency and energy-saving potential. However, the data on high hydrogen blending ratios in large-capacity industrial boilers remain scarce.
Keywords:gas boiler; hydrogen-blended combustion; hydrogen blending ratio; combustion characteristic; emission characteristic; operation characteristic; NOx emission; CO2 emission