Alexandria Engineering Journal (Aug 2022)
Computational analysis of influence of particle size, oxygen concertation, and furnace temperature on the ignition characteristics of pulverized high ash and high moisture coal particle
Abstract
Energy is a critical component in any given region's growth. India has the world's fourth-largest coal reserves. Therefore, energy generation from coal-based power plants is still a significant source of power in the country. However, the performance of Indian coals is poor compared to foreign coals such as South African, Indonesian, and US coals due to the high ash and moisture content. Seventy percent of country electricity need is still dependent on coal power even with known negative environmental consequences such as the production of CO2 & greenhouse gases, and air pollution caused by SOx, NOx, coal sludge, coal dust, and by-products of coal combustion. In this work, effect of coal types, particle sizes, and furnace temperatures on the ignition delay time of pulverized coal particle is investigated. In the current study, the ignition delay time of four Indian coals (IS1, IS2, IS3, and IS4), two Indonesian coals (IAS1 and IAS2), and one South African coal (SA1) were examined for particle sizes ranging from 35 to 115 µm, furnace temperature ranging from 1000 to 1700 K, and oxygen concentrations ranging from 12 to 20% in gas. Furthermore, ignition delay analysis of different coal mixtures (Indian and foreign coals mixtures) has also been studied. Numerical analysis of ignition delay time has been performed using MATLAB. Results show that the ignition delay time of coal particles increases with a decrease in furnace temperature and an increase in particle size. Results also show that the Indian coals have a larger ignition delay time than other considered coals, and ignition characteristics of Indian coals can be enhanced by mixing with high-grade ones. An increase in oxygen concentration also reduces the ignition delay time of the coals.
