What criteria do you use to carry out maintenance after the boilers in your plant are shut down? Which maintenance method to use?

Nitrogen should be used for filling; remember to purchase a prefabricated boiler, as it is protected by nitrogen filling during transportation and installation. I’m not very familiar with boiler shutdowns.

For short-term parking, use the water-filled method for protection; for long-term parking, drain the water and use nitrogen filling for protection

(1) Dry anti-corrosion methods: 1) Waste heat drying and vacuum maintenance method (the most commonly used anti-corrosion method at present): During the shutdown for major or minor repairs of the unit, the waste heat drying and vacuum maintenance method can be employed. The sequence is: rapid water drainage from the furnace – evaporation under negative pressure – drying with residual heat. 2) Nitrogen filling method (the boiler is shut down for more than 7 days; this method is not commonly used due to current grid demands and the operating conditions of the units). In this method, nitrogen is introduced into the boiler’s steam and water system, maintaining a certain positive pressure to prevent air from entering. The purity of the nitrogen used is 99% or higher. (II) Wet-type anti-corrosion: 1) Steam heating maintenance 2) Ammonia-hydrazine maintenance