Simulation on flow, heat transfer and stress characteristics of large-diameter thick-walled gas cylinders in quenching process under different water spray volumes

Abstract

Cooling strength is one of the important factors affecting microstructure and properties of gas cylinders during quenching process, and reasonable water spray volume can effectively improve the quality of gas cylinders and reduce production costs. To find the optimal water spray parameters, a fluid-solid coupling model with three-phase flow was established in consideration of water-vapor conversion. The inner and outer walls of gas cylinder with the dimensions of d914 mm×38 mm×12000 mm were quenched using multi-nozzle water spray system. The internal pressure, average heat transfer coefficient (have) and stress of the gas cylinder under different water spray volumes during quenching process were studied. Finally, the mathematical model was experimentally verified. The results show that both the internal pressure and have increase along with the increase of spray volume. The internal pressure increases slowly first and then rapidly, but have increases rapidly first and then slowly. To satisfy hardenability of gas cylinders, the minimum spray volume should not be less than 40 m3/(h·m). The results of stress indicate that water spray quenching will not cause deformation of bottle body in the range of water volume from 40 to 290 m3/(h·m).