以火电厂汽轮机主汽阀、调节阀等空心门杆为研究对象，阐述汽轮机汽阀空心门杆结构，并以两个门杆断裂案例分析门杆断裂的原因，利用ABAQUS仿真软件对空心门杆十字平衡孔不同孔径及不同位置进行仿真。仿真结果表明：发生断裂部位主要集中于空心门杆的十字平衡孔处，断裂原因为材料及加工制造缺陷引起的空心门杆强度不足；十字平衡孔孔径由8 mm缩小至5 mm时，门杆最大应力降低了21%，将原交叉十字平衡孔错位30 mm后，最大应力增加了9%；建议在更换新门杆时可考虑适当缩减平衡孔孔径，采用交叉十字平衡孔结构。

Taking the hollow core valve rods of steam turbine main valve and regulating valve in thermal power plant as the research object, the structure of hollow core valve rod of steam turbine valve was described, and the causes of valve rod fracture were analyzed with two valve rod fracture cases. The ABAQUS software was used to simulate different hole diameters and positions of cross balance hole of hollow core valve rod. The results show that the fracture position is mainly concentrated in the cross balance hole of the hollow core valve rod, and the fracture is mainly due to the insufficient strength of the hollow core valve rod caused by material and manufacturing defects. When the diameter of the cross balance hole is reduced from 8mm to 5mm, the maximum stress of the valve rod is reduced by 21%. The maximum stress increases by 9% after the original cross balance hole is misplaced for 30mm. It is suggested to consider appropriately reducing the diameter of balance hole and adopting cross balance hole structure when replacing new valve rod.

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