Experimental Study For Enhancement Of Nanoparticles On Gas-liquid Mass Transfer

The gas-liquid mass transfer process exists in a variety of chemical process.Taking the thermal power enterprise as an example,the desulfurization and denitrification process and wet electrostatic precipitator are all based on the gas-liquid mass transfer between flue gas and absorption liquid.Therefore improving the efficiency of gas-liquid mass transfer is of great significance for reducing the energy consumption and reducing pollutant emissions.As a means of strengthening gas and liquid mass transfer,the enhancement of gas and liquid mass transfer by nanoparticle in recent years has attracted attention and been studied by relevant scholars.However,previous studies were mainly based on macroscopic experiments to obtain the macroscopic effect of nanoparticle enhanced absorption and lack of sufficient understanding of the micro characteristics of nanoparticles in the absorption process,which affected the in-depth study of gas-liquid mass transfer process.In this paper,the microcosmic state of nanoparticles in the gas-liquid mass transfer of the evaporation process was studied through microcosmic experiments,the mass transfer rate of droplet evaporation and the enhanced mass transfer effect of nanoparticles were calculated and analyzed by digital image processing technology:Firstly,the platform structure of reflection fluorescence microscope used in this microcosmic experiment was introduced.The experimental image MATLAB data processing for the micro motion observation of gas-liquid mass transfer enhanced by nanoparticles was emphatically analyzed and the validity of the process was verified by an example of experimental image.Besides,the experimental study on the mass transfer process of deionized water droplet evaporation enhanced by nanoparticle was carried out in this paper based the above experimental system.The change of the microcosmic velocity of the nanoparticles and the particle content in the gas-liquid mass transfer interface layer with the time are obtained through data processing and the effect of three main factors(solid content,diameter and particle type)on the microcosmic state of particles at the interface,which would influence the mass transfer enhancement of nanofluids,were also analyzed.Finally,the profile parameters in the evaporation process of the droplets were measured by the contact angle measuring instrument under the same environmental condition.These would be used to calculate the droplet volume at different time nodes based on geometric theory in order to characterize the effect of nanoparticles on the gas and liquid mass transfer rate.And the microcosmic mechanism of nanoparticle enhancement on the gas-liquid mass transfer is analyzed combined with micro state observation of nanoparticles.