The article presents the results of the experimental studies of the ignition processes of mixed fuels “wood + coal” under conditions corresponding to the furnace spaces of the boiler units of TPPs. It has been established that under conditions of relatively low ambient temperatures, the time characteristics of the ignition process of coal and wood particles in the composition of the mixture differ significantly from the analogous characteristics for the ignition of single particles. It is shown that woody biomass significantly accelerates the ignition of coal, compared to the ignition of homogeneous coal (the delay time is reduced by 20–30%). At the same time, it has been found that coal particles significantly slows down the process of wood ignition (on average by 30%).

The analysis of the distance between particles (d) has shown that d has a significant effect on the ignition performance. It was found that there is a certain “optimal” value of d, at which the ignition delay times are minimal. It is also shown that with an increase in the ambient temperature, the effect of the distance between particles decreases significantly.

Based on the results of the experimental studies, a mathematical model has been developed for the ignition of wood-coal fuel particles, which differs from the known ones by a detailed description of thermophysical and thermochemical processes occurring in the porous structure of fuels and in a small vicinity of these particles. A comparative analysis of theoretical and experimental values of ignition delay times has shown their good agreement. An asymptotic analysis of the ignition time has shown that the entire induction period can be conditionally divided into two stages: fuel heating and direct thermochemical reaction. The fuel heating time takes about 90% of the entire induction period.

本文介绍了在与TPPs锅炉单元的炉膛相对应的条件下“木+煤”混合燃料着火过程的实验研究结果。已经确定的是，在相对较低的环境温度下，混合物中的煤和木材颗粒的着火过程的时间特性与单个颗粒着火的类似特性明显不同。结果表明，与均质煤的点燃相比，木质生物质显着加速了煤的点燃（延迟时间减少了20％至30％）。同时，已经发现煤颗粒显着减慢了木材着火的过程（平均降低了30％）。

对颗粒（d）之间距离的分析表明，d对点火性能有很大影响。发现存在一定的“最佳”值d，在该值处点火延迟时间是最小的。还显示出，随着环境温度的升高，颗粒之间的距离的影响显着降低。

根据实验研究的结果，已经开发了一种用于点燃木煤燃料颗粒的数学模型，该模型与已知模型的不同之处在于，对燃料的多孔结构和燃料中的热物理和热化学过程进行了详细描述。这些粒子的距离很小。对点火延迟时间的理论值和实验值的比较分析表明，它们具有很好的一致性。点火时间的渐近分析表明，整个诱导期可以有条件地分为两个阶段：燃料加热和直接热化学反应。燃料加热时间约占整个诱导期的90％。