Study On The Mechanism And Influencing Factors Of Gas-Liquid Mixed Snowmaking

With the development of science and technology,snow and skiing have become popular in the winter,and more and more skiing sites are located in different places.The mechanism of snow-making process has attracted many scholars'attention.This paper mainly studies the influence of different factors on snow-making process from three parts including the theoretical basis,experimental research and simulation analysis.The theoretical basis is to analyze the heat and mass transfer process of single water droplet evaporating and freezing into snow crystal in cold air,and to establish the relationship between the maximum critical diameter of water droplet and ambient temperature and relative humidity.The experimental research is to study and analyze the influence of ambient temperature,gas-liquid mixing ratio and water temperature on snow density through the experimental system of snow maker.And finally the simulation analysis to study and analyze the heat transfer of single water droplet through COMSOL.The mass transfer process is simulated by multi-physical field,and the effects of environmental temperature,relative humidity,droplet diameter,initial droplet temperature and wind speed on the transformation time of water droplets into snow crystals are analyzed.The study found that:1.As the ambient temperature increases,the snow density value increases rapidly.When the gas-liquid mixture ratio is 0.06 and the ambient temperature is lower than 1.1?,snow with a density of about 300 kg/m~3 can be produced.When the gas-liquid mixture ratio is 0.06,due to the high ambient temperature and large water droplets,the snow produced is slush snow,which loses its use value.2.When the ambient temperature is-1.8?,-0.5?,1.1? and 3.0?,the gas-liquid mixing ratio is 0.2,0.2,0.25 and 0.25,and snowfall distance of 7 m,respectively,the minimum density of snow,and the minimum value is:131.2 kg/m~3,129.9kg/m~3,133.3 kg/m~3,141.2 kg/m~3.The results show that low density snowmaking can still be achieved at higher ambient temperatures with smaler droplet sizes.3.When the snowfall distance is the same,the snow density becomes smaller and smaller as the gas-liquid mixing ratio increases.At four different ambient temperatures,the snow density values showed a downward trend,and the downward trend was most obvious at T_a=-0.5?.4.The water temperature causes small impact on snow density.As water temperature increases,there's no significant change,demonstrating a wave variation,which is consistent with simulating results.5.The results of COMSOL simulation show that the initial diameter of water droplets has a greater influence on the freezing time,and the initial temperature of water droplets has less influence.The maximum initial temperature(12?)and the minimum initial temperature(4?).The freezing time differs by less than 0.03s;from the external environmental factors,the ambient temperature and relative humidity have a greater influence on the freezing time of water droplets,and the influence of wind speed is small.The maximum wind speed(10m/s)and minimum wind speed(2m/s)in the model.The freezing time differs by less than 0.02 s.Therefore,the influence of ambient temperature and relative humidity should be considered when making snow.