Influence of main operating parameters on the incineration characteristics of municipal solid waste (MSW)

Abstract

To study the influence of the main operating parameters on the incineration characteristics of municipal solid waste (MSW), a 375 t/d mechanical grate incinerator is selected as the research object, and the effects of primary air temperature, secondary air arrangement, and grate speed on the MSW incineration process are simulated, and experimental tests are carried out under different primary air temperature and grate speed conditions. The results show that the relative errors between the measured and simulated values of the incinerator outlet O2 content and the measurement point temperature are within ±5% for all test conditions. When the primary air temperature increases from 423 K to 503 K, the position where the MSW incineration ends moves 3.32 m towards the front of the grate, and the moisture evaporation and fixed carbon combustion rates also increase, but the maximum volatile release rate and the optimal incineration condition of the MSW occur at the primary air temperature of 483 K. The increase in grate speed delays the incineration process of MSW and decreases the moisture evaporation rate and fixed carbon combustion rate, but it worsens the incineration effect of MSW. When the grate speed increases from 6.94 m/h to 13.88 m/h, the MSW incineration process is delayed by 3.20 m, and the moisture evaporation and fixed carbon combustion rates decrease by 43 kg·m−2·h−1 and 9 kg·m−2·h−1, respectively. To achieve the optimal operating conditions, the secondary air volume ratio of the front and rear arches is 1.59:1, the secondary air direction of the front arch is 40° and 60°, and that of the rear arch is 0° for the primary air temperature of 463 K and 483 K, respectively. This study can provide useful insights for optimizing the design and operation of mechanical grate incinerators.