Modeling of the Flue Gas Condensation for the PM2.5 Removal Efficiency of a Integrated Technology

Abstract

A combined pseudo-homogeneous and fractal geometry model was developed to simulate the process of a integrated technology. The technology was proposed to replace heat pipes and WFGD, which is based on the theory that liquid membrane and droplets grow in size by vapor heterogeneous condensation with they acting as nucleation centers and then the grown droplets are removed efficiently by using integrated diverse combinations of condenser pipes and a highly efficient scrubber. The model has been approached useful for both analyzing results and aiding in design of the technology by conducting a twodimensional steady-state model by means of infinitesimal analysis, incorporating with the models of whole fine particles absorption efficiency of a regularly arranged liquid membrane and droplets column group, and the models of geometric classifications for liquid and solid based on the fractal dimension identified by different structural of radius of gyration of liquid-solid interface transition zone. The predicted values were also compared with the experimental results, and they are in excellent agreement. The results showed that: When the fractal dimension d f is 0.3, the calculation result is the most closer to actual experiment parameter. The PM 2.5 diffusion volume flux value V w ranges from 22 and 45 mm/s. List of SymbolsAbbreviations R e Reynolds number of flow gas P r Prandtl number of flow gas S c Schmidt number of water vapor S h Sherwood number F Fanning friction factor K th Thermophoretic coefficient ∇T Temperature gradient of the fluid symbols K th Thermophoresis coefficient C Constant number, C = 0.75, or, C = 0.5 α, γ , p, q Fractal ratio (%) β Blockage, % ε fiber porosity (%) r Circular radius of heat exchange tube (m) W j The width of a single liquid dropletss column (m) r f , The vertical axle line distance of two droplets (m) l Characteristic length of channel (m) d Qualitative dimension size of the channel (m) D f Diameter of PM 2.5 separation of droplets (m) δ Thickness of the temperature boundary layer (m) δ t Vapor concentration boundary layer (m) δ c PM 2.5 concentration boundary layer, respectively (m) δ p Boundary layer thickness of PM 2.5 concentration (m) k Flow gas thermal conductivity [w/(m k)] k w Convective mass transfer coefficient of water vapor (m/s) u Particulate axial velocity (m/s) u j Average air velocity corresponding with W j (m/s) 123 Arab J Sci Eng V w Vapor diffusion volume flux of boundary layer (m/s) V d Particulate migration velocity (m/s) v th Thermophoretic velocity, respectively (m/s) v θ Horizontal direction of gas flow velocity (m/s) v r Perpendicular direction of gas flow velocity (m/s) v d Dust particle velocity (m/s) v p Droplets velocity (m/s) υ g Gas kinematic viscosity (m 2 /s) μ g PM 2.5 dynamic viscosity (m 2 /s) D M Virtual membrane mass transfer coefficient (m 2 /s) D p PM 2.5 diffusion coefficient (m 2 /s) D w Water vapor-air diffusion coefficient, respectively (m 2 /s) n w Water vapor condensation mass flux (kg/(m 2 s)) c p Mass concentration of PM 2.5 compone...

Prediction of SO2 removal efficiency for ammonia-based wet flue gas desulfurization in a packed tower

“…Sulfur dioxide (SO 2 ) discharged from thermal power plants is a significant pollutant in the atmosphere, which has a severe harm to human health and the environment [1][2][3]. Many countries have set strict emission standards to reduce sulfur dioxide emissions and various desulfurization methods came into being [4][5][6].…”