The Study Of Heat And Mass Transfer Performance In Vertical High-Speed Spray Chamber

Compared with traditional sprinkler chamber,high-speed sprinkler chamber has more advantages,such as small area and large air handling capacity.Although the highspeed sprinkler chamber has been proposed for a long time,the following problems still exist in the current research: research on the law of water droplet movement in vertical high-speed sprinkler chamber is not comprehensive;the theoretical basis for the structural design of vertical high-speed sprinkler chamber still has some defects;research on heat and moisture exchange performance of vertical high-speed sprinkler is not perfect;the theoretical basis of optimization scheme for vertical high-speed sprinkler chamber is not yet perfect.To address the above issues,based on the software of MATLAB,the movement law of water droplets in vertical high-speed sprinkler chamber and the performance of air-water heat and mass Transfer are studied by numerical calculation,it provides theoretical basis for rational design of vertical high-speed sprinkler chamber structure and optimization of heat and moisture exchange process in the future.Firstly,based on a single water drop,the effects of initial velocity,air velocity,diameter of water drop and spray angle on the two-dimensional motion of water drop were studied,orthogonal experiments were designed and carried out to explore the significant effects of different factors on the total time,total distance and maximum horizontal displacement of water droplets,the optimum combination of parameters is obtained by taking the longest movement time,the longest total distance and the shortest maximum horizontal displacement of water droplets in the vertical high-speed sprinkler chamber as the optimization principle.Secondly,based on the entransy dissipation theory and the principles of energy conservation,momentum conservation and mass conservation,the mathematical model of the two-dimensional motion equation of water droplets coupled with the differential equation of air-water heat-moisture exchange is numerically calculated,the effects of air velocity,water-air ratio,water droplet velocity,water droplet diameter,tower height,spray angle and air relative humidity on heat and moisture exchange performance of highspeed sprinkler chamber were investigated,the results show that the higher the air velocity,the larger the water-air ratio,the smaller the water droplet velocity,the higher the relative humidity of the air,the moderate tower height and spray angle,and the better the heat-moisture exchange performance of the vertical high-speed sprinkler chamber.Finally,the influence of wet air on heat and moisture exchange with water is analyzed when wet air approaches saturation along isothermal,isoenthalpy and isohumid line respectively,the higher the air humidity is,the better the performance evaluation index of heat and moisture exchange is,orthogonal experiments were designed and carried out to explore the significant effects of tower height,water droplet velocity,water droplet diameter,air velocity,air relative humidity,air initial temperature and water-gas ratio on total heat exchange,the entransy-dissipation-based thermal resistance and total heat exchange efficiency,the optimum combination of parameters is obtained by taking heat transfer,total heat exchange and the entransy-dissipation-based thermal resistance as test indexes,to provide theoretical basis for improving the performance of vertical highspeed sprinkler chamber and the design of optimization scheme.