Thermal deformation prediction based on the temperature distribution of the rotor in rotary air-preheater

Thermal deformation of the rotor in the operating rotary air-preheater dramatically decreases the efficiency of air-preheating system. The investigation on the thermal deformation characteristics is of great significance. In this paper, the temperature distribution of the matrix in air-preheater was calculated by using finite difference method, and then the thermal stress induced deformation was calculated by employing finite element method based on the temperature distribution obtained. The effects of operation parameter, inlet gas temperature, and geometry parameters including radius and height of rotor were studied. Good agreement between the numerical results and the measurements was achieved. With the decrease in the axial coordinate, the influence of inlet gas temperature on the temperature distribution decreased, whereas the influence of outlet gas temperature increased gradually. At both hot and cold ends, the droopy deformation increased gradually along the length coordinate. The maximal droopy deformation increased with the inlet gas temperature. The deformation increased with the decrease in height of plate at both hot and cold ends. According to the data obtained, a formula was fitted to evaluate the thermal stress induced deformation, which would provide a reference for the seal system application.