Coal-fired boiler and hot primary air heat exchange system thereof

The utility model relates to a coal-fired boiler and a hot primary air heat exchange system thereof, and the hot primary air heating system of the coal-fired boiler system comprises an air preheater, a coal pulverizing system, a hot primary air pipeline, a hot primary air bypass pipeline, a heat exchange pipeline and at least one heat pipe, the hot primary air pipeline is communicated between a hot primary air inlet of the air preheater and the pulverizing system, an inlet and an outlet of the hot primary air bypass pipeline are communicated with the hot primary air pipeline at intervals in the gas conveying direction in the hot primary air pipeline, an evaporation section of the heat pipe is located in the hot primary air pipeline, and a condensation section of the heat pipe is located in the heat exchange pipeline. The heat in the hot primary air bypass pipeline is transferred out through the heat pipe, the temperature of hot primary air introduced into the coal pulverizing system can be reduced, mixing of