To solve the fouling and blocking problem occur in gas-gas heater(GGH) in wet flue gas desulfurization system

a 300 MW coal-fired power unit was taken as the research object to carry out X-ray fluorescence spectroscopy(XRF) analysis and characterization for the fouling products. Combining with the practical operation

the major cause of the GGH blockage was determined. The major factors are the defogger performance

flue gas characteristics

flue structure and soot blowing device's performance. With the help of numerical simulation method

the corresponding GGH anti-blocking optimization measures were proposed. Such as

increasing the blade space of the demister from 38 mm to 26 mm to enhance the droplet collection efficiency

uptilting the horizontal flue duct at outlet of the desulphurization tower by 15° to promote the desulphurization slurry to flow back into the desulphurization tower and improve the distribution of flue gas flow field in the desulphurization system

increasing the blowing pressure of compressed air and reducing the distance between the soot blowing gun and the corrugated plate to realize effective cleaning of the GGH surface and prevent the blocking. After the above anti-blocking optimization measures were implemented

the blockage of the GGH in the wet flue gas process of the unit is effectively alleviated. The result can provide reference and basis for anti-blockage of GGH in wet flue gas desulfurization system.