Abstract:
Acoustic excitation has a good application prospect for thermal power plants, which can effectively improve the combustion efficiency of pulverized coal. In this paper, the model of pulverized coal combustion enhanced by acoustic excitation is adopted. The Arrhenius dynamic reaction rate is solved by establishing a two-dimensional numerical calculation model of pulverized coal combustion. The reaction model adopts the finite rate/vortex dissipation model. The temperature field in combustion area is analyzed under different ratios of air inlet speed to coal powder inlet speed (
U0/
U1), different sound pressure levels (135-165 dB) and different acoustic frequencies (50-5 000 Hz). Numerical results show that, this method can effectively characterize the strengthening effect of sound waves on combustion. For
U0/
U1= 1.39, when the coal powder is affected by the 50 Hz high-intensity sound pressure level of 165 dB, the acoustic wave has the best disturbance effect on the flow field, the temperature in the combustion area is the highest, and the enhanced combustion effect is the best.