Research On Fluid-thermal-structural Coupling Of Mechanical Seals In Reactor Coolant Pumps In Nuclear Power Station

A kind of hydrostatic mechanical seal with convergent gap used in reactor coolant pump in nuclear power station is introduced. When working normally, complete fluid film can be formed between the seal rings. As a result, the leakage rate through the gap is strictly controlled within a certain range. Meanwhile, the fluid film can provide lubrication and cooling for the friction pair, which guarantee that the seal rings can work for long without abrasion.A theoretical analysis model is developed for the flow field in the seal gap. Using the finite element method, under a certain closing force, the effect of sealing surface structure parameters on sealing performance is analyzed and the optimization of structure parameters is carried. Results show that the transition radius and cone angle have significant effect on the sealing performance.Based on the FEM method and by using the software ANSYS, the flow field,temperature distribution, elastic deformation and thermal deformation of seal components is got. The fluid-thermal-structural coupling is achieved by automatic iterative between the flow field calculation and the seal component calculation. This model allows for the effect of contact, preload and thermal conduction between seal components, and can accurately reflect the interaction between the fluid and seal components.The effect of sealing surface structure parameters; the preload and rotation speed; the pressure and temperature on sealing performance is analyzed, which can provide theoretical reference and foundation for the design of structural and operational parameters for hydrostatic seals.