Abstract: The main steam temperature of the mechanical grate waste incinerator varied greatly during the initial period of operation (within 6 months). And the problem was analyzed from two aspects: by comparing with coal-fired boiler, it was found that the overall heat transfer temperature-pressure of superheater of waste heat boiler was smaller; and through the comparison of thermal calculation data of waste heat boiler in operation for 5 days and 6 months, it was found that the change of the heat transfer temperature-pressure of superheater was the main influencing factor of heat absorption of superheater. It was concluded that the large change range of the flue gas temperature at superheater inlet of waste heat boiler was the main influencing factor of the large change of heat transfer from superheater. The operation data showed that the inlet flue gas temperature of superheater during the initial period of operation could be increased by more than 100 ℃, the overall heat absorption of superheater increased by more than 60%, and the main steam temperature increased by more than 65 ℃. Finally, the feasible suggestions to reduce the change range of superheater inlet flue gas temperature and ensure the safe operation of superheater were put forward.

Key words: waste heat boiler of waste incineration, superheater, initial period of operation, inlet flue gas temperature, heat absorption