As a key device influencing the safety and the economy of nuclear power plants simultaneously, the main feed water regulating valve (MFWRV) controls the flow rate flowing to the steam generator. In this work, modal and structural analysis is conducted under different loading conditions to investigate vibration characteristics and mechanical characteristics of MFWRV. The results show that the combination of loading conditions has little effect on the natural frequency and the mode shape of MFWRV. However, it influences the results of structural analysis significantly. Compared with the fixed internal pressure, the variable internal pressure promoted the maximum stress intensity when the valve opening (L/L_max) is smaller than 80%. The maximum deformation when the seismic load is considered is almost three times as large as it when the seismic is not considered. The seismic load always has a positive effect on the maximum gap (g_max) between the valve core and the sleeve. However, the variable internal pressure only has a positive effect on g_max relative to the fixed internal pressure when L/L_max = 40 ~ 90%. Besides, the variable internal pressure has an evident negative effect on the maximum sliding distance (sd_max) between the valve core and the sleeve relative to the fixed internal pressure under the low and the middle valve opening. This work provides a reference for the structural design of the main feed water valve and other similar valves.

作为同时影响核电站安全性和经济性的关键设备，主给水调节阀（MFWRV）控制流向蒸汽发生器的流量。在这项工作中，在不同的载荷条件下进行了模态和结构分析，以研究MFWRV的振动特性和机械特性。结果表明，加载条件的组合对MFWRV的固有频率和振型几乎没有影响。但是，它会显着影响结构分析的结果。与固定的内部压力相比，可变的内部压力会在打开阀门时提高最大应力强度（_最大L / L）小于80％。考虑地震荷载时的最大变形几乎是不考虑地震荷载时的最大变形的三倍。地震载荷始终会对阀芯和衬套之间的最大间隙（g _max）产生积极影响。但是，当L / L _max  = 40〜90％时，可变内部压力相对于固定内部压力只会对g _max产生积极影响。此外，可变的内部压力对最大滑动距离（sd _max）阀芯和衬套之间相对于低和中阀开度下的固定内部压力。这项工作为主给水阀和其他类似阀的结构设计提供了参考。