Study On The Design Methodology Of Swirl Nozzle For Nuclear Reactor Pressurizer

Pressurizer is one of the most important components in reactor coolant system of nuclear power plant.The main function of pressurizer is to regulate the pressure in the reactor coolant system by either cooling the steam or heating the saturated water in its upper zone..When the pressure in the reactor coolant system increases,it will spray cool water to decrease its temperature and pressure through atomizing the reactor coolant with swirl spray head in pressurizer.Swirl nozzle is the key part of pressurizer with swirl structure,it is characterized by huge flow rate and low pressure drop,and its atomization performance decides the quality of pressure control of the reactor coolant system.To enhance the independent design level of both pressurizer ad cooling system,it's neccessary to study on the atomization performance of swirl nozzle for nuclear reactor pressurizer.Aimed on improving the atomization performance of swirl nozzle,systemly the structure design methodology of nuclear reactor pressurizer was studied in three aspects including theory design,numerical simulation and test confirm in this thesis.Through designing the swirl nozzle structure in theory,especially studying the influence of different structures on internal and exterior flow field of swirl nozzles,the primary structure parameters of swirl nozzle were confirmed.Then,through numerical stimulating on the fluid flow and pressure drop of the swirl nozzle,the atomization performance of the nozzle was analyzed.On this based,the typical swirl nozzle was designed and tested,which included spray angle and flow as well as pressure drop tests,and the applicability of the computational fluid dynamics(CFD)method was varified when it was applied in swirl nozzle design.Finally,the design method of swirl nozzle with deep grove of swirl core for nuclear reactor pressurizer was put forward.Through this studying,the correlation between the structure parameters of swirl nozzle and atomization performance was achieved.It is helpful to realize the independent design of pressruzier's swirl nozzle and even to present the design methodology of pressurizer's swirl nozzle with our own characteristic.