Rotor dynamic analysis of nuclear heat transport pump under normal and part void conditions.
A rotor dynamic analysis of a heat transport pump for nuclear power applications is carried out for normal, part void and full operating conditions. The model includes the motor, coupling, pump, casing and external supports with the associated bearings. Predicted forces on the impeller are obtained from scaled test results for somewhat similar impellers. Two types of analysis are considered: (1) vibration response due to synchronous impeller forces under normal operating conditions, (2) response due to nonsynchronous impeller forces for part of full void conditions. Predicted shaft response at the pump bearing is 0.0165 mm (0.00065 in) for the normal case. It is about twelve time this value, 0.0315 mm (0.008 in), for a bearing supply of 7% void and 10% head at an excitation frequency of 300 rpm. Generally, the theoretical results are within a factor of 2 of the available test results. Finally, the predicted results indicate low vibration levels for the design option of a separate full liquid supply to the hydrostatic pump bearing. This is true even with potential unusual system operating conditions which produce large impeller forces at nonsynchronous frequencies. (A)
