TEMPERATURE-FIELD THERMAL STRESS IN TUBE AND ITS ACCESSORIES OF POWER-BOILER

摘要

Due to the structure's specialties, the heat-absorption distribution on the panel-style heated surface of power boiler isn't uniform. There is a temperature-grade in the structure. Ordinary, it's difficult to evaluate the safety of the heated surface with a specific temperature grade. Furthermore, the differential equations of temperature field and stress field are very troublesome to solve on the complicated temperature and structure boundary conditions. The non-uniform temperature field existed in panel-style heated parts of Power Boiler gives rise to the second stress in the structure. What about the temperature field under which the structure is safe? In this paper, the temperature fields of fin-tube-wall and other heated parts are considered. By the thermal-elastic mechanics method associated with a reasonable assumption and the Author's understanding to ASME's definition about secondary stress, the limit of temperature-differential is gained. It's useful in the design of power boiler.