O₂/H₂O combustion, as a new evolution of oxy-fuel combustion, has gradually gained more attention recently for carbon capture in a coal-fired power plant. The physical and chemical properties of steam e.g. reactivity, thermal capacity, diffusivity, can affect the coal combustion process. In this work, the ignition and volatile combustion characteristics of a single lignite particle were first investigated in a fluidized bed combustor under O₂/H₂O atmosphere. The flame and particle temperatures were measured by a calibrated two-color pyrometry and pre-buried thermocouple, respectively. Results indicated that the volatile flame became smaller and brighter as the oxygen concentration increased. The ignition delay time of particle in dense phase was shorter than that in dilute phase due to its higher heat transfer coefficient. Also, the volatile flame was completely separated from particles (defined as off-flame) in dense phase while the flame lay on the particle surface (defined as on-flame) in dilute phase. The self-heating of fuel particles by on-flame in dilute phase was more obvious than that in dense phase, leading to earlier char combustion. At low oxygen concentration, the flame in the H₂O atmosphere was darker than that in the N₂ atmosphere because the heat capacity of H₂O is higher than that of N₂. With the increase of oxygen concentration, the flame temperature in the O₂/H₂O atmosphere was dramatically enhanced rather than that in the O₂/N₂ atmosphere, where the diffusion rate of oxygen in O₂/N₂ atmosphere became the dominant factor.

O ₂ / H ₂ O燃烧作为含氧燃料燃烧的一种新发展，近来在燃煤电厂的碳捕集中逐渐引起了更多关注。蒸汽的物理和化学特性（例如反应性，热容量，扩散率）会影响煤的燃烧过程。在这项工作中，首先在流化床燃烧器中在O ₂ / H ₂下研究单个褐煤颗粒的着火和挥发性燃烧特性。O气氛。火焰和颗粒温度分别通过校准的双色高温计和预埋热电偶测量。结果表明，随着氧气浓度的增加，挥发性火焰变得更小，更亮。致密相粒子的点火延迟时间短于稀相，这是因为其传热系数较高。同样，挥发性火焰在浓相中与颗粒（定义为熄灭火焰）完全分离，而火焰在稀相中位于颗粒表面（定义为燃烧火焰）。稀相燃烧时燃料颗粒通过自燃产生的自热现象比浓相燃烧时更明显，从而导致较早的炭燃烧。在低氧浓度下，H ₂ O气氛中的火焰比N _2中的火焰更暗H ₂ O的热容量高于N ₂的热容量。随着氧浓度的增加，在将O火焰温度₂ / H ₂ ö气氛中显着增强，而不是在将O ₂ / N ₂气氛下，其中氧的为O的扩散速率₂ / N ₂气氛成为优势因素。