蜗壳结构对高温熔盐泵转子运行稳定性的影响

为了研究蜗壳结构对熔盐泵输送高温介质时转子运行稳定性的影响,设计了相同运行工况条件下的单蜗壳、双蜗壳双出液管结构的2种熔盐泵.利用ANSYS 软件对2种蜗壳结构熔盐泵的内部流场进行了非定常数值模拟,并分析了转子部件上的温度分布;将流场和温度场的计算结果同时加载到转子部件上,进行叶轮和轴上的流热固耦合分析,探讨了2种结构熔盐泵转子部件的应力、变形量和模态.结果表明:双蜗壳结构可以减小叶片表面的压力载荷,提高叶轮表面压力分布的对称性;单蜗壳熔盐泵叶轮和轴的最大变形量较大;而且单蜗壳熔盐泵转子部件在不同旋转角度下最大变形量变化较大,相比于单蜗壳熔盐泵转子的等效应力,双蜗壳熔盐泵叶轮的最大等效应力较大,但双蜗壳熔盐泵泵轴的最大等效应力较小;2种蜗壳结构流场条件下,转子部件运行时均满足结构强度要求.

Influence of volute structure on rotor operational stability in high-temperature centrifugal molten-salt pump

Two centrifugal molten salt pumps with single- and double-volute were designed under the same operating condition. Then, transient flow fields within two pumps were simulated and the tempe-rature distribution in the rotor was analyzed by using ANSYS to clarify the influence of volute structure on operational stability when the pumps transporting high-temperature molten salt. The stress, defor-mation and vibration mode were analyzed by employing fluid-thermal-structure coupling method after the calculated flow and temperature fields had been simultaneously applied to the rotor. The results indicate that the pressure load on blades is relieved and the axis-symmetry of the pressure distribution is improved within the double volute. The maximum deformation in the impeller and shaft is relatively large but also depends on shaft rotational angle significantly within the single-volute. Compared with the single-volute, the maximum equivalent stress in the impeller in the double-volute is larger, ho-wever, the maximum equivalent stress in the shaft is at a lower level. The rotor can meet the requirements of structural strength in the flow fields with two volutes under normal operating conditions.