循环流化床锅炉脉冲风帽的流化特性研究OA

[Objectives]When large-scale circulating fluidized bed(CFB)boilers are involved in deep peak regulation,the fluidization quality inside the furnace deteriorates.To enhance the fluidization effect of particles in CFB boilers during peak regulation,the concept of pulse-type hood is proposed.[Methods]By adding a Helmholtz oscillation chamber to the inlet pipe of the hood,the outlet airflow exhibits pulse variations at certain frequencies,thereby forming the designed pulse-type hood.Based on a visualized test platform,cold-state tests on a single pulse-type hood are conducted.By analyzing the time-domain and frequency-domain variations of pressure at different positions of the hood,the pulse characteristics are obtained.The resistance characteristics are determined by examining the pressure drop between the inlet and outlet of the hood.The fluidization characteristics are obtained by analyzing the disturbance range and the gas-solid flow of particles around the hood.[Results]The pulse frequency predominantly concentrates within the 18 to 24 Hz range,and the pulse intensity remains notable even at loads below 40%.The pressure drop at both ends of the pulse-type hood increases with increasing load,reaching 2.2 kPa at full load.Compared with bell-type hood,at 40%,70%,and 100%loads,the pulse-type hood increases the disturbance range of particles by 8.0%,11.1%,and 15.7%,respectively,while reducing the accumulation height of large particles by 2.1%,2.5%,and 2.9%,respectively.[Conclusions]The integration of a Helmholtz oscillation chamber allows the pulse airflow to be generated at the hood outlet,enhancing gas-solid contact.This increases the disturbance to the bed particles,reduces the accumulation height of large particles,and significantly improves the fluidization quality of the particles.