Numerical calculation of internal flow characteristics of small modular reactors coolant pump
LI Tianbin1, GUO Xi′an2, LONG Yun2*
1. Shanghai Electric-KSB Nuclear Pumps and Valves Co., Ltd., Shanghai 201306, China; 2. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Abstract：To study the internal flow of small modular reactor(SMR)coolant pumps under different working conditions, a combination method of computational fluid dynamics(CFD)numerical simulation and experimental validation was used. Four operating conditions(0.6Qd, 0.8Qd, 1.0Qd and 1.2Qd)were specifically selected for internal flow analysis. Three-dimensional streamlines were used to represent the flow inside the pump under different conditions. In addition, typical outlet center sections were selected to compare and investigate the internal flow structures and their variations under different flow rates through velocity streamlines, velocity distribution contour maps and vorticity distribution contour maps. Finally, the pressure and velocity distribution contour maps of the channel turning surface between the impeller and diffuser and the blade pressure load curves of the impeller and diffuser were analyzed to elucidate the flow distribution and energy conversion mechanisms within the impeller and diffuser. The results show that under the design flow rate, the internal streamline of the SMR coolant pumps is smooth and stable, and the pressure load on the pressure surface and suction surface of the blades is more stable. Under the partial flow rate of 0.6Qd and 0.8Qd, the high-pressure area on the impeller increases. Under the operation of the flow rate of 1.2Qd, the pressure distribution of the impeller increases significantly. The consistency between the experimental results and the numerical calculation results further confirms the accuracy of the computational model. This research not only comprehensively elucidates the flow characteristics inside SMR primary pumps, but also provides important theoretical basis and practical guidance for their design and development.
