Design of Gear-type Combustion Stabilizer under Benign Control of Pulverized Coal Combustion Behavior

Abstract

ABSTRACT To achieve a smooth control of the pulverized coal combustion behavior of an aggregate drying pulverized coal burner, a gear-shaped combustion stabilization device was added to the end of primary tuyere of aggregate drying pulverized coal burner. The design problem of gear-shaped combustion stabilization device was solved in this study. By taking the distribution of pulverized coal concentration and internal flow field distribution as the evaluation criteria and using cold- and hot-state simulation experiment methods, the effect of gear-shaped combustion stabilization device on the combustion characteristics of pulverized coal was analyzed in detail, and the stable combustion performance of different numbers of teeth gear-shaped combustion stabilization device was analyzed. The results show that the arrangement of gear-shaped combustion stabilization device is beneficial to ignition, strengthening of ignition, and stable combustion; it enables the pulverized coal jet to achieve “concentration separation,” making the pulverized coal concentration inside the flame higher and the pulverized coal concentration outside the flame lower, thus inhibiting the formation of NOX. The radial dimension of return zone of 24-gear combustion stabilization device is about 0.1–0.4 m, and the axial dimension of return zone is about 0.6–1.2 m. The area with a high concentration above 1.2 kg/m3 is the largest, 0.7 kg/m3. The area of next low-concentration area is also the largest; the size of relative comparison recirculation zone is the largest; the concentration of pulverized coal is the highest; the distribution of pulverized coal is the most uniform; the combustion characteristics are the best; the stability of combustion is the strongest; and it is most suitable for aggregate drying and pulverized coal combustion device.