The Numerical Simulation Of Wet Steam Non-equilibrium Condensation Flow Under The Influence Of Measuring Probe

Steam turbine is one of the core devices for energy conversion in the process of thermal power generation and nuclear power generation.Spontaneous condensation of steam in the low pressure stage of steam turbine not only causes energy loss and blade erosion,but also affects the measurement accuracy of relevant parameters.The model of measuring probe,stator blade runner and moving blade runner are established by using ICEM.The quality of the grid is guaranteed by the method of dividing the grid with structured grid and unstructured grid and density box encryption.Through the euler-euler fluid model,the two-phase flow control equation,the real state equation of wet steam and the turbulence equation suitable for the calculation condition are established,and the two-phase interaction,droplet nucleation and droplet growth are fully considered,so as to ensure that the model can accurately calculate the process of wet steam flow.The simulation data of the nozzle are highly consistent with the experimental data in the literature,and the wake around the flow detachments is also consistent with the theory.The results show that the introduction of the probe has little influence on the temperature and humidity of the wet steam flow,and has great influence on the pressure and velocity of the wet steam.For the probe in this paper,the maximum stress position is basically unchanged in the vibration process,and the maximum stress is far lower than the allowable stress of the material,and no resonance phenomenon occurs.When the probe cantilever beam is about 1.135 m in length,resonance risk is caused.Secondary water droplets introduced by the probe deposit when they touched the inner surface of the blade,and concentrate in the area with the chord length of about 80%-100% and leaf height of about 1m on the inner side of the upper blade.The secondary water droplets formed by trailing edge shedding of stationary blades mainly have four dense deposition areas in the moving blade,which are about 12.5% of the area in the front of the upper blade,the entrance of the lower blade,the inner part of the lower blade in the latter half,and about 28.5% to 48.5% of the area in the outside of the upper blade.