Simulation Study on the Stabilization Control Performance of Low-Calorific-Value Waste Combustion in Waste Incinerators

To address the instability of low-calorific-value waste incineration processes and suppress the generation of toxic dioxins, this study examines a 600 t/day waste incineration furnace as a case study. Numerical simulations of the incineration process were conducted by using bed calculation software FLIC and Fluent. A waste incineration cleanliness index was defined, and the impact of the reduced calorific value of the incoming waste on the temperature distribution within the incineration furnace was explored. The effectiveness of biomass steady combustion was compared to that of natural gas steady combustion, leading to the development of a control model for biomass steady combustion of low-calorific-value waste. The results indicate that a decrease in the calorific value of incoming waste reduces the cleanliness index; when the calorific value is 4739 kJ/kg, the cleanliness index drops to 0.96. The residence time of flue gas in the high-temperature zone of the first flue duct is less than 2 s, which is insufficient to effectively suppress dioxin formation. Therefore, steady combustion control measures are necessary. Both biomass and natural gas steady combustion can effectively increase the temperature of the incineration furnace; however, biomass, as a carbon-free energy source, significantly reduces carbon emissions compared with natural gas. A biomass-mixed control model for steady combustion of low-calorific-value waste was constructed and validated, achieving precise residence times in the high-temperature zones of 2.18 and 2.11 s, both exceeding 2 s, thereby achieving the desired control effect.