Multi - Physical Field Analysis Of Nuclear Main Pump Seal

In this paper, the hydrostatic mechanical seal which has a convergent gap of NuclearReactor Coolant Pump (NRCP) is studied. In actual operating conditions, a dielectric film,so-called the seal leakage source, with micron level can be formed between the rotor and stator,usually, to control it, we can get a perfect performance of controlling the mechanical sealleakage. Meanwhile, the dielectric film can provide lubrication and cooling for the seal pair,which guarantee that the seal rings can operate for a long time without wear and has a goodstability.By using the theory of hydrodynamics, the calculation model of seal leakage is establishedfor the Nuclear Reactor Coolant Pump, and the computation formula of the leakage model isestablished in consideration of liquid pressure and centrifugal force, then, studied the geometryand operating parameters effect on the leakage. Studies have shown that theseal face angle and turning radius have significant influence on the sealing performance, andthe seal leakage is impeded by the centrifugal force.Based on the basic theory of hydrodynamics and heat transfer, the continuityequation, momentum equation, energy equation and temperature viscosity equation of NuclearReactor Coolant Pump’s hydrostatic mechanical seal as well as their corresponding boundaryconditions have been analysed. Based on the Hamilton’s principle, the heat flux potentialprinciple of minimum effect and two-way fluid-solid couple, the numerical analysis model ofNRCP mechanical seal fluid-solid-heat coupling field has been established.The simulation method, based on the previous two-way fluid-solid coupling, which, torealize the multi physical field coupling analysis in the ANSYS Workbench platform, adoptedcommand processing to structure analysis and changed the cell structure, input and output, sothat it can receive the loads of pressure and temperature from CFX analysis, meanwhile, sentthe structure analysis of displacement and heat flow to CFX analysis. The NRCP mechanicalseal components as the research object, which carries on the fluid-solid-heat coupling analysis,and studies the pressure distribution between the sealing gap, the sealing ring stressdistribution, temperature distribution and displacement. In this paper, using the fluid-solid-heatcoupling model allows for the effect of preload and thermal conduction between the sealcomponents, and can accurately reflect the interaction between the fluid and seal components.