An Impeller Optimization Method for the High Specific Speed Mixed-Flow Reactor Coolant Pump Applied to Marine Nuclear Power

The reactor coolant pump (RCP) is the only rotating equipment in the primary circuit system of a nuclear power plant and the "heart" of the nuclear reactor. The L formula is defined, and the L/h(imp) is introduced to study the influence of impeller blade type on the performance of the RCP. Twenty groups of models are designed, the concept of arc height ratio is proposed from the perspective of h(imp) and L, and the distribution of internal entropy production within the impeller of the RCP under different Ls and h(imps) of the impeller blade type is analyzed. The results show that when himp remains un-changed and L increases, the low-pressure area at the inlet of the impeller expands while the high-pressure area at the outlet decreases under the design flow or large flow conditions. The smoother blade profile reduces the occurrence of secondary flow phenomena and makes the RCP pressure distribution more uniform. Under design flow and large flow conditions, smaller L/h(imp) and higher h(imp) lead to higher efficiency and head performance. However, higher efficiency and lower head performance can be achieved under small flow conditions with larger L/h(imp) and lower h(imp).