The research is focused on the ignition of solid fuels in a heated air flow. The experimental conditions correspond closely to solid fuel combustion in coal-fired boiler furnaces. Charcoal, wood, brown and bituminous coals were used as independent solid fuels and as fuel mixture components. The particle sizes of these fuels were less than 40 μm, 40–140 μm, 140–250 μm, 250–375 μm and 375–800 μm. They were ignited under the conditions of radiant-convective heating as they were moving in a heated air flow with a temperature of 500–800 °C and at a velocity of 5 m/s. The ignition delay time was the main investigated characteristic, recorded by a high-speed video camera. The induction period of bituminous coal shortens by 25–35% when 25–50% brown coal or wood in an air-dry state is added. The lowest ignition delay times were established for the fuel mixtures of bituminous coal with dry charcoal. The experimental curves of the ignition delay times of fuels and their mixtures versus the heated air temperature were presented as approximation equations. Based on the conducted research findings, a muffle burner design with a vortex structure of the fuel-air flow was proposed for the fuel oil-free start-up of coal-fired boilers.

该研究的重点是在加热的气流中点燃固体燃料。实验条件与燃煤锅炉炉中的固体燃料燃烧密切对应。木炭、木材、褐煤和烟煤被用作独立的固体燃料和燃料混合物组分。这些燃料的粒径小于 40 μm、40-140 μm、140-250 μm、250-375 μm 和 375-800 μm。它们在辐射对流加热的条件下被点燃，因为它们在温度为 500-800°C 的热空气流中以 5 m/s 的速度移动。点火延迟时间是主要研究特征，由高速摄像机记录。加入25%～50%的褐煤或风干状态的木材后，烟煤的诱导期缩短25%～35%。为烟煤与干木炭的燃料混合物建立了最低点火延迟时间。燃料及其混合物的点火延迟时间与热空气温度的实验曲线以近似方程的形式呈现。根据研究结果，提出了一种燃料-空气流涡流结构的马弗式燃烧器设计，用于燃煤锅炉的无燃油启动。