The invention discloses a device and a method for preventing coking,
pollution and
corrosion on a pipeline wall surface of a boiler heating surface. According to the device, strip-type cavities are formed in the front, middle, two sides and rear of
pipe bundle of the protected boiler heating surface along the
smoke flow direction; holes communicated with the outside are formed in the surfaces of the cavities and serve as nozzles; the cavities are provided with joints; liquid and gas filled through the joints are ejected from the nozzles to form a gas film or liquid film at the peripheries of the cavities; the boiler heating surface
pipe bundles which are sequentially arranged in the rear of the cavities are arranged in acting areas of the gas film and the liquid film for effective isolation and protection; ash particles which directly
impact the surfaces of the cavities are blocked by the gas film or the liquid film, and the ash particles are prevented from directly washing the
pipe bundles of the rear boiler heating surface; the surrounding ash particles are cooled through the gas film, and the adhesiveness of the ash particles is reduced; and moreover, an isolating layer is formed between the boiler heating surface and high-temperature
flue gas through the gas film, the ash particles are prevented from being in direct contact with the boiler heating surface, and the adhesion possibility is reduced.