Research Of Air Heat-moisture Treatment And Nozzle Flow Simulation For The Target Type Impinging Stream Air Washer

Heat and moisture treatment equipment is called air washer where the air and water are directly contacted. Using this method of direct contact air and droplet which is atomized by water at different temperature can achieve a variety of air-heat and wet process and has the ability of cleaning air at the same time .The key equipment of air washer is nozzle, spraying water is atomizated, and the contact area of water and air are increased with it. The major technical indicators of determine the performance are different diameter, water spray and fog effects under the different water pressure. Target type impinging stream nozzle has been practically applied with the advantages of smooth flow path, hardly accumulated dirty stuff, larger atomization area of nozzles, convenient maintenance and management ect。This paper mainly researches heat and moisture process for target type impinging stream nozzle in air washer,and atomization mechanism is deeply discussed and relevant model is established. Heat and mass exchange mechanism of researching impinging stream air washer has been researched and it offers us a mathematical model and systematically and completely summarizing efficiency of target type nozzle of various performance parameters and formulas or curve by using the methods of the integrate of mathematical analysis, experimental test, MATLAB data regression software and FLUENT simulation software. Study on distribution of internal and external flow field for the nozzle is to enable the nozzle can to being widely used in practical engineering. So the main contents are as follows:(1) Heat and mass exchange mechanism of target type impinging stream nozzle with air has been researchedThe technology of impinging stream and the atomization mechanism of impinging stream nozzle is analyzed, and the difference and relationship between impinging stream nozzle and other nozzle is discussed on the basic theory of heat and mass exchange by using heat transfer and boundary layer theory overall heat transfer efficiency, general heat exchange efficiency theory and empirical formula for thermal performance of spray chamber have been given,which laid a theoretical foundation for subsequent analysis and data regression test.(2) Heat and mass exchange in air washer and impinging stream washer model are estiblished.Exact solution of the state of air and water in each section has been obtained by using the methods of heat and mass exchange model basic equation of heat in washer and functional analysis. Four groups analytical solutions are achieved through linear differential model equations. Export parameters and the efficiency formula of impinging stream air washer are obtained on the basic equation model with an additional condition assumption and the correctness and rationality are verified through a calculated example.(3) Target type impinging stream nozzle of water spary under different working conditions in the air washer and the efficiency of heat and moisture exchange and its affected factors are mainly studied .First, the general situation of laboratory bench transformation in the air washer and experimental testing procedures and data reduction are introduced. The water quantity of target type impinging stream nozzle under different pressure is listed and multiple regression in water quantity is taken by using the MATLAB software. Second, the best combination scheme is taken through the four experimental factors of using orthogonal experimental design to the effect efficiency and the significant factors are found out by using variance analysis and F-test. Third, the influences of thermal wet exchange efficiency in various factors about the target type impinging stream nozzle in detail are researched. Last, the multiple regression equation of the general heat efficiency is established and the three-dimensional graphics of the efficiency is drawn with the MATLAB software .(4) The simulation research for the inside and outside flow field distribution of target type impinging stream nozzleFirst, it is stated that FLUENT is a common software which provide us a wealth of physical models and numerical methods, with powerful front and back treatment features, simulating complex flow, heat transfer and other issues. When construction of the nozzle geometry, using GAMBIT pretreatment software produced to grid and determined Nozzle boundary conditions of outlet. After determining its convergence and using SIMPLE algorithm to give the simulation graphics and making a study on results of simulation .The issue not only has theoretical significance, but also important practical value and application prospect.