Lateral pressure fluctuation occurs in large scale circulating fluidized bed(CFB) boilers operating at lower load. In order to analyze the mechanism and influencing factors of lateral pressure fluctuation

a cold bubbling bed test rig with lateral disturbance was built up. In this device

the speed regulating motor and linkage mechanism drive the body of the fluidized bed to generate lateral periodic motion

which makes the gas-solid two-phase flow system generate lateral fluctuation under the forced state. The characteristics of bed pressure fluctuation at different disturbance frequencies and fluidization wind speeds were explored. The experimental results show that

when the gas velocity is 0.72 m/s and with no lateral disturbance

the bed pressure and wind box pressure have the same fluctuation frequency. With the increase of disturbing frequency

the bed pressure fluctuation amplitude increases significantly. But when the disturbing frequency is higher than 1.13 Hz

the bed pressure fluctuation amplitude shows a downward trend

indicating this disturbing frequency equals the natural frequency of lateral bed pressure fluctuation in gas-solid flow system

and the bed pressure fluctuation amplitude reaches the maximum value. The experimental results agrees well with the natural frequency mechanism model. When the wind speed is lower than the minimum fluidized wind speed

the pressure fluctuation characteristics on both sides of the bed are obviously different due to the poor uniformity of wind distribution. The research results have certain reference value for the design of air distribution system and primary air volume control of CFB boilers.