Simulation of the characteristics and performance of a graphite segmented annular seal under high-speed and high-temperature working conditions

Segmented annular seals are an important part of the sealing technology of rotating mechanical power equipment. At present, there is a lack of research on the characteristics and performance of segmented annular seals under high working condition parameters (high speed and high temperature). Therefore, a fluid-solid-thermal coupling numerical analysis model of a segmented annular seal under high-speed and high-temperature conditions was established. The influence of working condition parameters (rotational speed, temperature and sealing pressure difference) on the performance of the segmented annular seal was analyzed, and the accuracy of the model was verified by experiments. The results indicate that the stress distribution in the main sealing surface of the sealing ring is relatively uniform, with the maximum stress occurring at the lap joint. Only slight deformations occur on the sealing surface, and the strain at the lip edge and the lap joint is considerable. The overall temperature distribution in the sealing ring is relatively uniform, with a significant temperature rise at the main sealing surface. The viscosity of the fluid film medium on the main sealing surface remains constant, and the medium density is a maximum at the inlet. The leakage of the segmented annular seal decreases slightly with increasing rotational speed and temperature, and increases significantly with increasing sealing pressure difference, confirming that the leakage is greatly affected by the sealing pressure difference. There is mixed lubrication on the main sealing surface of the sealing ring. There is no obvious wear on the secondary sealing surface of the graphite ring both before and after operation, whereas the wear of the main sealing surface is more severe.