| National large-scale development of nuclear power requires self-reliance in nuclear technology and home-made manufacture. Our country can already be able to design and manufacture the ordinary nuclear valve at present, but due to the technical difficulties and highly-demanded security, certain key equipments in critical positions such as MSIV are still relying on import. In July 2014, SUFA successfully researched and developed DN800 MSIV and received experts’ approval, and meanwhile, DN1050 MSIV prototype is in research and development.In accordance with the operation of Qinshan nuclear power station, the noise problem of MSIV does exist when in service. To solve this problem, in the paper, in-service MSIV of Qinshan nuclear power station is taken as the base, DN800 MSIV is taken as sample, and Solidworks is taken to establish three-dimensional modeling on DN1050 MSIV flow field. Additionally, numerical simulation is taken to analyze MSIV flow capacity, steady flow field and large eddy simulation with Fluent to further analyze MSIV inner flow field. Finally, by the methods of LES and calculation, the reason for noise, forming location of noise, level of noise are discovered after analysis, and the advices are given on how to reduce noise.After steady flow analysis, we can get flow capacity and steady flow characteristics of the MSIV, and the maximum velocity of MSIV for 84.6m/s. By LES, it shows the transient flow characteristics of MSIV. The MSIV noise level is 75 dB by the analysis of LES and the theoretical calculation.The problem of MSIV noise which is hard to simulate can be solved by the above research, analysis and calculation, and become a research method for it. Provide optimal recommendations on the structure design to avoid the phenomenon of vibration and noise. |
