具有陶瓷涂层的火焰筒壁温和热流计算

NUMERICAL METHOD FOR CALCULATING WALL TEMPERATURE AND HEAT FLOW OF FLAME TUBE WITH CERAMIC COATING

对具有陶瓷隔热涂层的气膜冷却式火焰筒壁面温度和热流提出一种计算方法。在分别建立陶瓷涂层和金属壁面热平衡方程的基础上,给出两者之间的导热耦合关系,使计算模型更加符合实际传热过程。计算过程中始终考虑到金属壁面的轴向导热。通过算例研究了陶瓷涂层对气膜冷却式火焰筒壁面温度和热流的影响。有涂层时壁面温度低于无涂层时壁面温度,但它们的变化规律相似。燃气温度越高陶瓷涂层的隔热效果越好。

This paper provides a new method suitable for calculating wall temperature and heat flow of ceramic-coated flame tube. The effect of ceramic coating on wall temperature and heat flow of film-cooled flame tube is investigated. Compared with previous literature, two important improvments of this paper are: (1) Heat-transfer analyses for ceramic coating and metal wall are made respectively, in which both axial conduction and radial conduction in the flame tube wall are considered simultaneously. The heat balance equations, which consider practical conditions as much as possible, are established. The conduction coupling relationship between ceramic coating and metal wall is provided. (2)A new method of solution and calculation procedure are given.The heat balance equation of ceramic coating is solved by using dichotomic method. The metal wall temperature is calculated by applying Convection-Conduction-Radiation Coupled Iterative Method.. By calculating the ceramic coating temperature and the metal wall temperature alternatively, the conduction coupling between them is accomplished.