Three-dimensional full-loop numerical simulation of coal and sludge co-combustion in a circulating fluidized bed
Journal article, 2023

The Dense Discrete Phase Model (DDPM) method is used to simulate the co-combustion process of coal and sludge over the full-loop circulating fluidized bed in a three-dimensional (3D) Eulerian-Lagrangian framework. Both heterogeneous (fuel conversion through pyrolysis and char combustion) and homogeneous reactions (e.g. volatile combustion) are considered. Comparison of the predicted pressure profile, flue gas composition and bed temperature with measurements show good agreement and validate the DDPM methodology for accurate description of the gas–solid flow and combustion process over the full-loop circulating fluidized bed. The results of coal and sludge co-combustion are analysed qualitatively and quantitatively in terms of flow characteristics, gas composition, reaction rate profile, and particle combustion characteristics. Due to the lower density and higher volatile content of the sludge, as the coal-to-sludge feeding ratio decreases, the combustion reaction rate is gradually skewed upwards in the furnace, shifting up also the corresponding gas concentration profiles. For the given fuel sizes, the faster devolatilization rate of coal yields a shorter burnout time than that of the sludge particles. Our work provides an intuitive perspective to the fluidized bed community to boost comprehension on the coal and sludge co-combustion in a full-loop circulating fluidized bed.

Full-loop

Co-combustion

Circulating fluidized bed

Simulation

Dense Discrete Phase Model

Author

Wanqiang Wu

Key Lab of Energy Thermal Conversion and Control, Ministry of Education

L. Duan

Key Lab of Energy Thermal Conversion and Control, Ministry of Education

Yuanqiang Duan

Key Lab of Energy Thermal Conversion and Control, Ministry of Education

Lin Li

Key Lab of Energy Thermal Conversion and Control, Ministry of Education

D. Y. Liu

Key Lab of Energy Thermal Conversion and Control, Ministry of Education

David Pallarès

Chalmers, Space, Earth and Environment, Energy Technology

Fuel

0016-2361 (ISSN)

Vol. 337 127235

Subject Categories

Energy Engineering

Chemical Process Engineering

Bioenergy

DOI

10.1016/j.fuel.2022.127235

More information

Latest update

1/5/2023 2