Inner protection plate fixing device of waste heat boiler flue

The utility model relates to the technical field of fixing of inner protective plates of waste heat boiler flues, in particular to an inner protective plate fixing device of a waste heat boiler flue. An outer protection layer, a heat preservation layer and an inner protection layer are sequentially arranged in the waste heat boiler flue, the inner protection layer is formed by lap joint of a plurality of inner protection plates, supporting bolts are welded to the outer protection layer and sequentially penetrate through the heat preservation layer and the two inner protection plates to be connected with nuts, and at least three supporting bolts are arranged at the lap joint of every two adjacent inner protection plates. Wherein a fixing plate is arranged at the supporting bolt on the central axis of the inner protection plate, one end of the fixing plate is located at the top of the upper inner protection plate and connected with the supporting bolt, and the other end of the fixing plate is connected with the