Modeling and Dynamic Characteristic Analysis of Combustion Process of Biomass Vibrating Grate Furnace

Abstract

In order to explore the combustion characteristics of the biomass vibrating grate furnace and realize the control and optimization of the unit combustion process, the mechanism model of the grate combustion process was established through the analysis of the biomass fuel characteristics and combustion mechanism. Moreover, the dynamic change of the grate fuel amount was studied, and the key parameters such as furnace temperature and flue gas oxygen content were predicted. The influence of periodic vibration of grate on combustion state in furnace was discussed. The results show that the amount of fuel in the grate is related to the current feed rate and fuel burning rate. The fuel has a large storage capacity on the grate, which leads to a large delay between the fuel burning and the current feeding. The predicted values of furnace temperature and flue gas oxygen content can follow the measured values well, and their changes are in accord with the combustion characteristics. The periodic vibration of the grate will cause the periodic change of the combustion state in the furnace. When the grate vibrates, the fuel combustion speed, furnace temperature, furnace pressure will increase, and the oxygen content of the flue gas will be reduced. As the vibration of the grate stops, these parameters return to the steady state level.

Keywords

• thermal power
• biomass direct combustion power generation
• grate furnace
• combustion characteristics
• dynamic characteristics