Nuclear/thermal power turbine set fluid excitation numerical calculation method and system based on flow field simulation

Abstract

The invention provides a nuclear / thermal power turbine set fluid excitation numerical calculation method and system based on flow field simulation. The method comprises: according to set structure andoperation conditions, simplifying fluid computational domain, creating a flow channel geometric model comprising two stator blades and three rotor blades; discretizing the surface of the blade by utilizing a structured grid, introducing a discretized fluid calculation domain, setting a phase change model, a turbulence model, a boundary condition and a numerical solution parameter according to different flow working conditions, and solving transient distribution pressure of the surface of the blade under different working conditions through flow field simulation; for the blades adopting three-dimensional hexahedron unit discretization, the transient distribution pressure on the surfaces of the blades is equivalent to fluid excitation suitable for different blade structure units by utilizing an inverse distance weighted interpolation method and an equivalent method based on a virtual work principle; and for the blades adopting the spatial twisted beam units for dispersion, transient distribution pressure on the surfaces of the blades is converted into equivalent fluid excitation of the spatial twisted beam units by utilizing a virtual work principle.

Description

technical field [0001] The disclosure relates to a numerical calculation method and system for fluid excitation of a nuclear / thermal power steam turbine set based on flow field simulation. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. [0003] With the rapid development of large-scale, high-efficiency, and high-parameter rotating machinery such as nuclear / thermal power steam turbines with complex structural characteristics such as long shafts, large flexible blades, and shrouds, the vibration problems induced by fluid excitation on the blade-rotor system have become an issue affecting the unit. One of the key factors for safe and stable operation. Fluid excitation mainly refers to the interaction force between fluid and solids (blades, shafts, etc.) The multi-field coupling excitation force related to multi-variables such as , rotation speed, ...

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Problems solved by technology

At present, due to the limitation of test technology, it is still impossible to directly measure the excitation force borne by the rotating blade of the whole machine scale or use the dynamic inverse problem method to identify the fluid excitation in the complex flow field environment based on the measured data of blade vibration response and system modal characteristics. The deformation coupling nonlinearity between the blade and the elastic shaft and the asymmetric nonlinearity of the airfoil pre-twisted blade are two geometric nonlinearities and the nonlinear coupling effect of the shroud damping induced by fluid excitation. At present, there is no complex solution that can be accurately solved and is convenient for engineering applications. Method of Fluid Excitation Force of Blade-Rotor Structure in Wet Steam Complicated Flow Field

Most of the existing patents on numerical simulation of the flow field only proposed a method for predicting the flow of air or other working fluids in the equipment, and no further research was given to extract the excitation force of the fluid on the fluid or solid, and no Applicable to complex rotor systems; the fluid excitation simplified calculation method proposed in the paper does not consider the influence of multiple variables such as complex rotor structure and operating conditions, and simplifies the non-uniform distributed excitation force generated by the fluid to a uniformly distributed force or in the fluid excitation modeling In the paper, the wet steam is assumed to be an ideal gas, only the wake excitation is considered, and the fluid excitation force in the wet steam environment is ignored

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