Numerical Simulation On New Synergistic Device Of Desulfurization And Dedusting

Promoting clean coal power is the current trend in the coal power industry.The integrated desulfurization and dust removal technology program is widely used in ultra-low emission projects of coal-fired power plants.The desulfurization and dust removal efficiency synergist installed in the program increases the resistance of the desulfurization system.To get better efficiency of desulfurization and dust removal with a small increase in resistance,this article optimizes the structure of the synergistic component and conducts related numerical simulation studies.In this paper,for the integrated scheme of desulfurization and dedusting an improved new type of rotary coupling device is proposed,and the geometric model of the new type of rotary coupling device is built.Numerical simulation of flue gas flow in the new rotary coupling device and the effect of sulfur dioxide removal in the device was carried out.The inlet velocity and SO₂ concentration of the flue gas were used as variables,the pressure drop at the inlet and outlet of the device and the SO₂removal rate were concerned as Investigation index to analyze the numerical simulation results under different working conditions,in order to determining the proper structure rotary coupling device for different work conditions.The results show that:（1）The blade inclination angle is an important parameter that affects the pressure drop and internal pressure distribution of the flue gas inlet and outlet of the device.（2）Compared with the blade pitch angle of the inner ring,the change of the blade pitch angle of the outer ring has a greater influence on the pressure distribution,flow field distribution and SO₂ concentration distribution of the device.When the angle between the inner and outer ring blades is the same as the horizontal plane,the SO₂ removal rate of the device with opposite blade rotation is higher.（3）The flue gas velocity at the inlet of the device is a key parameter that affects the mass transfer and turbulence in the device.The higher the flue gas velocity at the inlet,the greater the turbulent energy in the device and the higher the gas-liquid mass transfer efficiency.In order to model the high-efficiency tube-bundle demister involved in the integrated desulfurization and dust-removal scheme,the dust removal effects of the first-level and second-level tube-bundle demisters were numerically simulated.The particle size distribution and dust removal effect at the outlet of the tube-bundle dust collector and demister were analyzed under different flue gas velocity and dust concentration.The results show that:（1）For the secondary tube bundle demister,the inclination of the first secondary blade is the key parameter that affects the pressure drop and dust inertia collection rate of the device.（2）Selecting the second-stage blade inclination angle smaller than that of the first-stage blade can make the dust more trapped.（3）The smaller the particle size of the dust,the less likely it is to be trapped by inertia.