Numerical modeling of peat burning processes in a vortex furnace with countercurrent swirl flows

Thermal Science

Redko Igor¹  Pavlovskiiy Serhii²  Redko Oleksandr²  Norchak Volodymyr²  Redko Andriy²  Burda Yurii²  Dzhyoiev Rafael³ 

[1] Department of Heat Engineering, Kiev National University of Civil Engineering and Architecture, Kiev, Ukraine;Department of Heat, Gas Supply, Ventilation and Using Thermal Second Energy Resources, Khar-kov National University of Civil Engineering and Architecture, Kharkov, Ukraine;Public Corporation “City Gas Supply of Kharkov”, Kharkov, Ukraine;

关键词: combustion processes;    numerical modeling;    peat;    vortex furnace;    countercurrent swirl flows;   

DOI  :  10.2298/TSCI190305158R

来源: DOAJ

【 摘 要 】

The paper presents the process of peat burning in a swirl furnace with counter-current swirl flows and the results of a numerical study. The cyclone-vortex technology of solid fuel combustion allows the furnace volume of a boiler unit, its dimensions and weight to be reduced. The aim of the work is a numerical study of the combustion of pulverized peat in a cylindrical vortex furnace with counter-current swirl flows. The results of computer simulation of the combustion of pulverized peat with a moisture content of 40%, an ash content of 6%, and a higher heat of combustion QpH = 12.3 MJ/kg are presented. The results of the influence of the design parameters of the furnace and heat load (from 100-15%) are given as well. When the heat load is reduced to 15%, the entrainment of unburnt particles increases. The cooled and adiabatic furnace is studied. A significant entrainment of unburned particles is observed in a cooled furnace. The fields of temperature distribution, gas velocity, and particle trajectory in the volume and at the outlet of the furnace are determined. The 3-D temperature distribution in the furnace volume indicates the combustion of peat particles at temperatures (1300-1450°C). Values of the tangential velocity of a swirl flow near the furnace outlet reach 150-370 m/s, which ensures the efficiency of separation of fuel particles and a reduction in heat loss due to mechanical underburning (up to 0.06%). The results of a numerical study show that the diameter of peat particles affects the combustion process, namely coke of particles with an initial diameter from 25-250 μm burns out by 96%, and particles with a diameter of about 1000 μm are carried away from the furnace and do not burn. The furnace provides a complete combustion of dust particles of peat by 99.8% and volatiles by 100%.

【 授权许可】

Unknown