Correlation Research Between Guide Vane Axial Position And Performance In Reactor Coolant Pump

Reactor coolant pump which is specified Class I pump, called the heart of the nuclear power plant is the only high-speed rotating device in the primary circuit. As the key to control the coolant circulation system of nuclear power plant, reactor coolant pump must be of long-term safe and reliable operation in high temperature, high pressure and strong radiation corrosion environment. Although at present our country has introduced the Westinghouse AP1000 technology, but due to the research on the basic theory of reactor coolant pump is not mature enough, the independent design of reactor coolant pump and the structure optimization of flow components still exist many technical difficulties.This study chooses self-designed AP1000 reactor coolant pump model pump as the research object, using numerical simulation method to analyze the three-dimensional internal flow characteristics of reactor coolant pump, the effect of reactor coolant pump guide vane axial position on performance and pressure pulsation, and the effect of match characteristic between guide vane axial position and tongue filleting radius of annular casing on performance and characteristics of the flow field, the main research contents and conclusions are as follows:1. Internal flow characteristics analysis of reactor coolant pump. The three dimensional turbulent flow numerical calculation in AP1000 reactor coolant pump model pump is simulated under different conditions, the head and efficiency are obtained, by comparing that with the test results to verify the reliability of numerical calculation methods, and the internal flow characteristics analysis in reactor coolant pump show that the pump hydraulic performance is good. On the basis of this, the monitoring points are set up in the impeller, guide vane and casing, and the pressure fluctuation characteristics of the unsteady state under the design conditions are analyzed by the unsteady numerical simulation.2. The effect of guide vane axial position on the performance of reactor coolant pump. From steady simulation to study the effect of guide vane axial position on external characteristic, the energy conversion characteristic and internal flow field of impeller, guide vane and casing. The results show that the hydraulic performance of model pump is the best, and the length of cantilever shaft is shorter,when the axial relative distance between guide vane and casing is 89 mm. Under small flow rate conditions reducing that axial relative distance, makes the efficiency of pump and impeller both increase, the loss of casing reduce, but also the loss of guide vane increase. Under high flow rate conditions reducing that axial relative distance, makes the efficiency of pump and impeller both decrease, but the loss of guide vane and casing both increase. From the unsteady simulation to study the effect of guide vane axial position on pressure pulsation characteristics in casing, the results show that guide vane axial position mainly affects pressure pulsation amplitude in casing. When the guide vane outlet center plane coincides with the axis of the pumping chamber outlet, it can effectively reduce the pressure pulsation across the tongue and the outlet.3. The effect of match characteristic between guide vane axial position and tongue filleting radius of annular casing on the performance of reactor coolant pump. From steady simulation to study the effect of match characteristic between guide vane axial position and tongue filleting radius on the performance of pump and as well as performance and internal flow field of the flow components at three flow rates:0.8Qd, 1.0Qd and 1.2Qd. Under the small flow rate condition, the head and efficiency of different matching combination model change complexly, with the increase of the flow rate, the head and efficiency with the increase of tongue filleting radius show the similar variation trend at three kinds of guide vane axial position, and guide vane axial position has more greater impact on efficiency of pump. There is an optimal tongue filleting radius matching when guide vane is in a certain axial position, and reasonable matching can effectively improve the performance of model pump.