Optimisation and numerical study of forced convection heat transfer design for glass tempered cooling grille

Abstract

Conventional glass tempering equipment suffers from uneven cooling and low energy efficiency in its design and operation, which highlights the limitations of existing production technologies. There is relatively little previous work describing the heat transfer properties of tempered glass in actual production. In this study, a combination of numerical simulation and experimental testing is used to optimise the design of cooling air grille in glass tempering equipment. Firstly, the variation characteristics of glass surface temperature with cooling time in the physical tempering process were experimentally investigated. Subsequently, the structural design and optimisation of the air deflector plate in the cooling air grille are carried out. Finally, a coupled flow-thermal-solid numerical model of the cooling air grille is constructed based on the experimental conditions, and the effects of the four air pressure plate structures on the heat transfer efficiency and temperature uniformity in the quenching process are explored. The results demonstrated that the designed rectangular plate performs better than the conventional plate. Compared with the traditional plate, the designed rectangular plate can reduce the base temperature of the glass by 4.21 K, increase the heat transfer coefficient by 5.03 %, and increase the heat transfer rate by 2.13 %. In addition, the glass surface temperature inhomogeneity is reduced by 7.32 % by the rectangular plate. The proposed design offers an appropriate resolution for industrial applications. It also provides a solid foundation for advancements in tempered glass quality.