A method was proposed to solve the problem of oil sludge treatment environmentally by sending the pretreated oil sludge into a 330 MW pulverized coal boiler co-firing with coal. The combustion characteristics of the oil sludge were studied by thermogravimetric analysis

and it was proved to be easy to ignite with a high calorific value close to coal

which could improve the boiler's low-load stable combustion ability. Numerical simulation results showed that the combustion center shifted downward slightly after the oil sludge was sent into the boiler

while the NOx content decreased. The experimental results proved that the minimum stable combustion load rate can be 20.00% by the benefit of oil sludge co-firing. The temperature at the coal-burner layer increased by 30～50 ℃ and the carbon content of the fly ash decreased from 4.79% to 3.80%. The fire detection analog signal of the coal burner was found to be more stable which validated the positive effect of the oil sludge co-firing at low load condition. The boiler efficiency increased by 0.23 percentage point which reduced the net coal consumption rate by 0.7 g/(k W·h). Moreover

about 3.7 t/h coal was saved at 120 MW load. The method was verified to have a significant energy-saving effect.