| The valve body, valve bonnet, and disc are pressure bearing part of the valve. The lawsand regulations of pressure vessels design should be obeyed when they are calculated. Thestructure of the valve body is relatively complex than the cylindrical, spherical shell, endclosure and other pressure vessels, more factors should be considered when it is calculated.ASME, RCCM and other laws and regulations should be obeyed in the process of design andcalculation of the nuclear level valve. A nuclear level valve is used as an example in this paper,the strength analysis of the valve is researched on the basis of the third volume of ASME.The three-dimensional model of the valve was built by using Solidworks software in thispaper, and then the center of gravity of the valve position and accurate quality were got, at thesame time, the model was simplified properly. According to the needs of the analysis, themodal analysis model and thermal stress analysis model were established. The simple ASMEmaterials database was established when the material of valve parts was edited. In the griddivision part, the grid average length of side setting, local grid size control mesh divisionmethod were discussed, and then reasonable mesh precision was get. In the earthquakeanalysis part, the influence of the modal analysis on valve natural frequency was discussedwhether prestress exist or not, at the same time the natural frequency of prototype gate valveswas get by using analysis software. In the steady state thermal analysis part, the compressivestress and thermal stress of composite stress effect was researched in detail, at the same time,the thermal boundary conditions of the classification of the methods were discussed in detail.In the steady state static analysis part, in accordance with the ASME regulations and therequirements of technical specification, the nuclear level valve design conditions of finiteelement were calculated and analysis, at the same time valve membrane stress, film andbending stress, peak stress, thermal stress and total stress and stress state were considered.And the simulation analysis results of the design was verified by experience formulacalculation method, simulation analysis and the accuracy of calculation the results wereverified. |
