Numerical Simulation And Experimental Study On Gas-Liquid Two-Phase Flow Of Wet Electrostatic Precipitator

This thesis adopted the mathematical model of gas-liquid two-phase flow, mainly studied gas-liquid two-phase flow of the horizontal wet electrostatic precipitator. Firstly, it analyzed the force situation of the mist particle in the internal flows of the wet electrostatic precipitator. It also discussed the influence of many forces on the particle movement. Secondly, it made the numerical simulation to the gas continuous phase based on the Euler method. A time-averaged Reynolds equation was established by Euler method, and the normal two-equation mode was introduced to close the equations. Finally, relative movement of the spray particle was described based on Lagrangian jet model.The main results by numerical simulation are: Air distribution plate played an important role in adjusting the air flow distribution. By changing the number and the location of distribution boards, the air flow became even. And two pieces of boards with 40% open porosity were installed. One piece was at the middle section of the bell, and the other one was at junction of the horn mouth and the box. Velocity of the electric field in this ESP had effect on the uniformity of air flow inside. The greater the wind speed, the poorer the uniformity of air distribution, and the best field wind speed was 1.0 m/s. The experiment showed that, the numerical simulation method was correct for different distribution board's case, and provided uniform gas flow for the gas-liquid two-phase flow simulation. Wet ESP was operated with mist spray and the effect of mist on the air flow speed and the motion vector could not be neglected. Compared with single-phase flow state, gas-liquid two-phase flow simulation results were worse, therefore adding mist in the simulation could reflect the true air flow conditions in wet electrostatic precipitator. Dispersed phase flow model was adopted to simulate the mist particles, and the states of the nozzle parameter were adjusted. The results showed that when the nozzle was operated under the pressure of 0.4 MPa, the internal gas-liquid two-phase of the wet ESP went well.