Three-dimensional internal and external finned tube integrated air preheater and processing method thereof

The invention discloses a three-dimensional internal and external finned tube integrated air preheater and a smoke processing method thereof. The three-dimensional internal and external finned tube integrated air preheater comprises a vertical case, the upper end and the lower end of the case are provided with flue ports including an flue inlet and a flue outlet respectively; the inside of the case close to the flue ports is provided with tube plates to close the case and separate the inside and the flue ports; a plurality of three-dimensional internal and external finned tubes are welded to the tube plates at the upper end and the lower end in an expanded mode and fixed inside the case; the orifices of the three-dimensional internal and external finned tubes are arranged inside the flue ports; one side of the case is provided with an air inlet, and the other side of the case is provided with an air outlet. The three-dimensional internal and external finned tube integrated air preheater integrates an air preheater and a GGH (gas-gas heater) into a whole, thereby reducing equipment investment, saving equipment space, achieving integration and solving the problems of low heat exchange efficiency, heat transfer surface acid corrosion, scale formation, clogging and the like of existing devices. Most of preheated high-temperature air is applied to combustion of a boiler, the other part of the high-temperature air is mixed with purified flue gas flowing out of a desulfurizing tower, and the temperature of the mixed purified flue gas can be up to environment protecting emission standard.