| As the country's emphasis on the ecological environment,the optimization of energy structure was put forward higher request,green renewable energy was honored and especially the nuclear power as green energy to improve the energy structure of our country.The localization rate of some essential equipment of nuclear power plant is still relatively low,so it is urgent to solve the key technology that restricts the localization of equipment.Reactor main coolant pump is as the heart of nuclear power plant and its long-term safe and reliable operation plays a vital role in the safe operation of the whole plant.This thesis was based on the hydraulic parts numerical simulation of the main coolant pump in a 300 MW pressurised water reactor nuclear power plant and studied under the condition of the impeller blade inlet angle was reduced by 10 degrees,the flow velocity field,the pressure field,the fluid streamline distribution,the velocity vector distribution,the all channel numerical simulation analysis of the flow channel in the impeller,the guide vane and the pump casing.Based on the hydraulic parts numerical simulation of reference main coolant pump,found the improvement direction of the target pump hydraulic characteristic and combined with model test to determine the final hydraulic performance optimization results.Introduced the theoretical basis of numerical simulation analysis,including conservation of mass,conservation of momentum and conservation of energy.On the basis of reference pump impeller blade structure improvement,and did numerical analysis to of the new blades.Based on the analysis results showed,the new performance of the corresponding parameter values than the required value had a certain margin.Among them,the numerical efficiency and the head of the target impeller increased by 0.6% and 22% the reference pump impeller respectively.The numerical efficiency of the full flow channel was 84.64% at design condition of the hydraulic component of the target pump,and the corresponding head is 71.72 m.In view of the main pump hydraulic component model,did the model test to the optimized design of hydraulic components in accordance with the corresponding standards,which included the efficiency of hydraulic model test and cavitation test and pressure pulsation test,at the same time,in accordance with the test results,calculated the target pump hydraulic performance.At the same time,the results of the target pump calculated by the model test results were compared with the full-channel hydraulic performance of the numerical simulation and get the conclusions as following:(1)The results of the main pump hydraulic components by numerical simulation and the results of prototype pump hydraulic performance by the model pump test results conversion were similar,including the efficiency of the design condition point error was 1.65%,and the head error was 10.33%.(2)The calculation method of computational fluid dynamics software is reliable and can simulate the general rule of hydraulic performance of hydraulic components of main pump.(3)The hydraulic components which were designed in this paper had good anticavitation performance,and the pressure pulsation is gentle at the design point.This paper set up a method which is changing the single element that was impeller blade inlet angle and improve the hydraulic performance by the structure optimization design,the optimized blade settling angle improved the pressure distribution near the hub inlet low pressure area,and the blade suction surface low pressure area near the rim of the inlet side,ensured uniform inlet pressure gradient change,improved pump cavitation resistance;the research method used in this paper is suitable for the existing hydraulic components on the basis of reference to optimization of design,also have certain reference significance such as performance optimization design of turbine. |
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