工程科学与技术 (Nov 2024)
Mechanism Analysis of Face Annular Groove Cooling and Heat Transfer in High-speed Deep Spiral-groove Mechanical Seals
Abstract
High viscous heat generation and high-temperature rise of the end face, in the end, clearance are significant and common issues in mechanical seals operating at high speeds. The grooves on the seal face substantially influence fluid heat transfer in the cross-scale clearance. Researchers have determined that the temperature rise of the seal end face can be significantly reduced by incorporating an annular groove on the inner diameter side of the seal ring. This study develops thermohydrodynamic (THD) lubrication models of a deep annular groove-deep spiral groove compound end configuration (ASG) and a classical deep spiral groove end configuration (SG) using ANSYS Fluent to further examine its heat transfer process and cooling mechanisms. In these turbulent computational models, the heat transfer process of the annular groove is compared and analyzed, its cooling mechanisms are revealed, and the impacts of its geometric parameters on the mechanical seal performance and cooling effect are explored. The results indicate that the viscous shear heat of the fluid in the annular groove area decreases considerably due to the large film thickness and minimal shear effect, which effectively reduces the temperature of the lubricating liquid film and the seal face. The cooling effect of the annular groove can be enhanced by up to 15 K with the appropriate increase in groove depth and width, resulting in a temperature rise decrease of about 33%. Furthermore, the cooling effect of the annular groove reduces the fluid viscosity loss, enhancing the bearing and tribological performance of the deep annular groove-deep spiral groove compound end configuration (ASG) compared to the classical deep spiral groove end configuration (SG). The annular groove also increases the radial pressure gradient on the inner radial side of the sealing ring, which leads to a higher seal leakage rate, and the leakage fluid removes more viscous heat per unit time. Additionally, the presence of the annular groove increases the convective heat transfer area of the high-temperature fluid on the inner diameter side and the static ring, aiding in cooling. These structural modifications and the inclusion of an annular groove effectively reduce the temperature rise of the lubrication film and sealing face, which holds significant engineering importance for high-speed mechanical seals.
