Study On Spray Cooling For Tempered Of Plate Glass

Compared with chemical tempering and other traditional physical tempering methods,spray tempered glass has a series of advantages,such as low energy consumption,low noise and low cost.But the technology has yet to develop,so it is necessary to study the spray quenching and tempering process of plate glass.In this paper,the spray quenching and tempering process of plate glass is taken as the research object.The principle experimental research is carried out by setting up a small size glass spray cooling experimental bench,and using Fluent software to simulate the spray cooling process.Coupling flow-heat-stress calculation in glass spray cooling process using Workbench platform.The influence of spray cooling factors on the degree of glass tempering and the distribution of temperature and stress is analyzed.The main work includes the following:A small size glass spray cooling experimental bench was established to prove the feasibility of spray cooling glass.The number of pieces of tempered glass was used to judge the degree of glass tempering under different factors,and the energy consumption of spray cooling and tradition air cooling are compared.The experimental results show that reducing the spray distance,increasing the spray mass flow rate,pressure,and glass thickness can significantly improve the tempering effect of the glass;Spray cooling will save 73.7% of energy consumption compared to traditional air cooling.Due to the limitation of experimental methods,in order to carry out a detailed study on the heat transfer process and glass temperature characteristics of the glass surface during spray cooling.According to the experimental conditions,a mathematical model of spray cooling was established based on Fluent software.The hot surface heat transfer model used wall-jet model and wall-film to realize the heat transfer mechanism transition of the hot surface from film boiling,transition boiling to nuclear boiling and non-boiling.And the spray cooling characteristics were studied,and the cooling process of high-temperature glass and the non-uniformity of temperature distribution on the glass surface were analyzed.Finally,the influence of spray distance,mass flow,pressure,and glass thickness on the spray cooling of glass are analyzed.The results show that reducing the spray distance,increasing the spray mass flow rate,pressure and glass thickness will increase the heat exchange efficiency of the glass,the cooling rate of the glass,the temperature difference between the inside and the outside of the glass,and make it easier for the glass to form a larger temperature gradient,so the compressive stress on the glass surface is increased,and the degree of glass tempering is enhanced;Increasing the spray mass flow rate and reducing the spray pressure will improve the temperature uniformity of the glass.In order to study the stress distribution of tempered glass,the Workbench platform was used to calculate the flow-heat-stress in the spray cooling process,and the simulation calculation of spray cooling was realized.The results show that the stress distribution in the thickness direction of the tempered glass approximately meets the parabolic equation in the quadratic curve.It has the characteristics of uniform and symmetrical distribution,and there is a neutral layer,and the stress is zero.The thickness of glass has a greater influence on the tempering stress,while the influence of spray distance and spray mass flow on the tempering stress is relatively small.