In order to evaluate the vibration safety of the central full partition wall of the world's first lignite-fired 700 MW high-efficiency ultra-supercritical CFB boiler

a three-dimensional non-constant hydrodynamic model of the boiler is constructed

and the distribution of the gas-solid flow field within the furnace chamber is simulated. Furthermore

the pressure distribution and its fluctuation law of the gas-solid flow acting on the surface of the central full diaphragm wall within the furnace are solved. The vibration signals of the furnace wall of a supercritical 350 MW CFB boiler with a similar furnace structure are measured and analyzed spectrally to assess the frequency of pressure fluctuations in the furnace. The dynamic stress on the central diaphragm wall under fluctuating pressure in the furnace is calculated using the pressure fluctuations in the furnace obtained from simulation calculations and experimental tests as the excitation. The results demonstrate that the dynamic stress level of the central full diaphragm wall is below the permissible stress of the material

indicating that the central full diaphragm wall is safe.