Study on Powder Coke Combustion and Pollution Emission Characteristics of Fluidized Bed Boilers

Abstract

The fluidized reactor is widely used in a number of chemical processes due to its high gas-particle contacting efficiency and excellent performance on solid mixing. An improved numerical framework based on the multiphase particle-in-cell (MP-PIC) method has been developed to simulate the processes of gas–solid flow and chemical reactions in a fluidized bed. Experiments have been carried out with a 3-MW circulating fluidized bed with a height of 24.5 m and a cross section of 1 m2. In order to obtain the relationship between pollutant discharge and operating conditions and to better guide the operation of the power plant, a series of tests and simulations were carried out. The distributions of temperature and gas concentration along the furnace from simulations achieved good accuracy compared with experimental data, indicating that this numerical framework is suitable for solving complex gas–solid flow and reactions in fluidized bed reactors. Through a series of experiments, the factors affecting the concentration of NOx and SOx emissions during the steady-state combustion of the normal temperature of powder coke were obtained, which provided some future guidance for the operation of a power plant burning the same kind of fuel.

Simulation of Two-Phase Flow and Syngas Generation in Biomass Gasifier Based on Two-Fluid Model

“…Loha et al [16] evaluated and compared the Euler-Euler and Euler-Lagrange models for a fluidized bed gasifier. Yang [17,18] used the core-annulus chamber model and the Lagrangian-based MP-PIC method to study the flow and reaction characteristics in a fluidized bed reaction system. Tamer [19] studied a pilot-scale gasifier in an oxygen-enriched environment and analyzed the syngas components under different conditions using a homemade CFD model; through comparison with experimental results, the model was proven to have good prediction ability.…”