Low-temperature section anti-corrosion device of steel pipe type air preheater

The low-temperature section anti-corrosion device of the steel pipe type air preheater comprises a first pipe plate and a second pipe plate, a plurality of air preheater pipes are arranged between the first pipe plate and the second pipe plate at intervals in a matrix mode, and the air preheater pipes are horizontally arranged in the left-right direction; the two ends of the air preheater pipe horizontally extend out of the outer surfaces of the first pipe plate and the second pipe plate correspondingly, and the second pipe plate is connected with the air preheater pipe in a sealed welding mode. The ends, close to the first tube plate, of the multiple air preheater tubes are sleeved with 304 stainless steel outer sleeves, the inner diameter of each 304 stainless steel outer sleeve is larger than the outer diameter of the corresponding air preheater tube, and the 304 stainless steel outer sleeves are connected with the first tube plate in a sealed welding mode. By means of the characteristic that the 304 stain