Research On Structure Optimization And Atomization Performance Of Swirl Nozzle For Snow-maker

Outdoor snow-maker is the main production equipment of snowmaking technology,how to improve the snow production performance and increase the scope of application is the key technical problems that the domestic snowmaker urgent need to solve.Swirl nozzle is the core component of the outdoor snow machine,it’s atomization performance determines the critical environmental parameters that the snow machine generates snow,affecting the snow quality and quantity,is the key to decide the application of snowmaker that adapt to different climate zones.Therefore,optimizing the design of swirl atomization nozzle structure and exploring the atomization performance under multiple working conditions have important guiding significance for the upgrade of snow making machine.The main research and findings of this paper are as follows:1)According to the flow characteristics of the swirl nozzle,numerical model of nozzle atomization was built based on VOF multiphase flow and RNG k-ε turbulence equation;Meanwhile,nozzle atomization experimental platform was built;The atomization Regulation of the basic nozzle was investigated.In both the experimental and simulation studies,the same boundary conditions were set to investigate the effect of nozzle’s inlet pressure variation to the atomization performance.With the increase of nozzle’s inlet pressure,it was found that the nozzle’s atomization flow rate increased linearly,but that the atomization cone angle remained hardly unchanged,and the error between the experiments and simulations were less than 10%.Experiments found that the nozzle’s atomization particle size and inlet pressure is inversely proportional.Analysis of the simulation results finds that with the increase of inlet pressure,the nozzle outlet fluid average velocity rose significantly,the exit film thickness hardly did not change,and the decrease in atomization particle size in the experiment is explained by the increase of outlet fluid velocity.2)Based on the established atomization model,the effect of wall roughness on the atomization effect was investigated.Under the condition that the nozzle’s inlet pressure of 1.4MPa,the nozzle wall finish for▽₁,▽₂,▽₄,▽₅,▽₆,▽₁₀,▽₁₁,▽₁₄ were substituted into the numerical model.The study found:With the decrease of wall finish,the air vortex and atomization cone angle decreased.The atomization flow rate increases,with a maximum improvement of 22.5%.Considering only the change in atomization flow indicators,the rougher the wall,the greater the nozzle atomization flow value,which is a guideline for the design of large flow snow-maker.3)The influence law of structure parameters on atomization effect has been explored,the basic nozzle was optimized from the nozzle shell and the core structure,complete the optimization of the swirl atomization nozzle modification.For the nozzle shell structure,the nozzle diameter of 1.7 mm,1.9 mm,2.1 mm,2.3 mm,2.5 mm and flat section lengths of 0.6 mm,0.8 mm,1.0 mm,1.2 mm,1.4 mm were modified.For the nozzle’s core structure,the depth of the spiral section of the core structure was 1.5 mm,1.7 mm,1.9 mm,2.1 mm,2.3 mm.The atomization effect of the nozzle with the above structure modification is studied:the change of outlet diameter has the most obvious effect on atomizing flow rate and atomizing cone Angle,with the increase of outlet diameter,the nozzle atomizing flow rate increases,and the maximum can be increased by 69.2%,but the atomizing particle size will increase;The change of the length of the flat and straight section has no significant effect on atomization flow rate,atomization cone angle and atomization particle size;The change of rotation core depth has a better effect on atomization particle size.With the increase of rotation core depth,atomization particle size of nozzle decreases.For the outdoor snow-maker,increasing the nozzle outlet diameter is conducive to improving the snow making amount,and increasing the core depth is conducive to improving the snow quality.