In order to understand the key parameters and operating experience on fully burning and high proportion blend burning high-alkali coal in boiler with slag-tap furnace

long-term engineering tests were conducted based on a 300 MW boiler with slag-tap furnace in a power plant. An analysis was conducted on the possible combustion organization

nitrogen oxide control

slag flow

and ash deposition issues. Modifications were made to the combustion system

thermal modification system

and slag flow system. So long-term operational data and key parameter records were conducted

after fully burning and high proportion blending burning of 300 000 tons of high-alkali coal

all operating parameters of the boiler were normal. Based on recent operations and comprehensive tests

the optimized boiler with slag-tap furnace in a specific power plant demonstrates strong adaptability to high-alkali coal. Within the control range of coal ash components with w(Al_2O_3)25%

w(Fe_2O_3)15%

12%1.7

acid/alkali ratio0.5

the normal operation of the boiler can be ensured without obvious ash deposition. Burning high-alkali coal can effectively reduce the inlet flue gas temperature of the first-level heating surface to below the design value

effectively avoiding the occurrence of slagging on the first-level heating surface of the boiler

and the generation of nitrogen oxides is also reduced by more than 30% compared with using the original design coal.