To ensure safe and economical operation of the boiler and avoid slagging problem occurred at bottom of the platen superheater

the acoustic temperature measurement system was used to monitor the temperature field of the cross section of the bottom of platen superheater in real time. Based on this system

the influence of the main operating parameters

such as operating oxygen content

separated over-fired air(SOFA) flow rate

secondary air flow rate and primary air velocity

on the temperature field of the cross section of platen superheater was analyzed. The results show that

under different load conditions

the cross-sectional temperature of the bottom of platen superheater increased firstly and then decreased with the increase of operating oxygen content

and increased with the primary air velocity. Under low load conditions

as the opening of the secondary air damper increased

the temperature at the bottom of the corresponding side screen decreased. Under medium and low load conditions

the cross-sectional temperature of the bottom of platen superheater increased with the closing of the burn-out damper opening

while at high load it showed the opposite trend. According to the analysis results

after operation optimization and adjustment under 300 MW load conditions

the deviation of the flue gas temperature at the bottom of platen superheater was improved

and the maximum flue gas temperature at the bottom of platen superheater reduced by 37 ℃

from 1 401 ℃ to 1 364 ℃

which reduced the risk of slagging at the bottom of platen superheater

and the boiler thermal efficiency increased by 0.53 percentage points. The research provides reference for the safe and economic operation of utility boilers.