Study On The Performance And Internal Flow In A Mixed Flow Nuclearreactor Coolant Pump Model

Mixed-flow nuclear reactor coolant pump(nuclear main pump for short) with spherical or similar spherical casing, which is to ensure the safety of run time. Unlike regular volute or space guide vane, nuclear main pump has a complex internal flow structure and more hydraulic loss. In order to control its flow loss, it is a key point to make a knowledge of internal flow structure and matching performance of different parts. Apart from hydraulic performance between spherical casing and guide vane,analysis of flow structure on characteristic planes and developing some performance optimized methods, which are based on a nuclear main pump model from own project team. Study works and conclusions are as following:1. Mixed flow impeller and radial guide vane structure size under the design parameters are obtained by similar conversion. And matching a spherical casing, which makes up the important part of nuclear main pump2. Comparing hydraulic performances of different positions between guide vane and spherical casing and analyzing their hydraulic loss, which is to get a position with high performance. Conclusions are following: the lowest hydraulic loss is got as length between casing outlet and guide vane comes to 1/4 of guide vane outlet width; the whole loss is lowest as guide vane outlet is located in axial symmetry plane of spherical casing.3. Complex internal flow is more located near outlet pipe of spherical casing and down-flow of guide vane. Analyzing flow structure information on characteristic planes can simplify its three-dimension internal flow.4. Numerical simulation and mathematical statistic is used to calculate liquid volume with out-flow velocity, conclusions are following: structure of spherical casing mainly influences nearby flow area and leads to an asymmetric flow structure in guide vane.5. On the basis of the unsteady numerical calculation, energy analysis and mathematical statistics method,which is used to compare hydraulic performance and the internal flow field structure of different matching relationship between hydraulic parts in mixed-flow nuclear main pump. Compared with conventional mixed flow pump,comes to a conclusion: only increasing or decreasing numbers of guide vane has little effect on flow field near outlet pipe; spherical casing located eccentric with pump axis can improve flow structure of this field.