Research On Reliability Test Method Of Shaft Seal Reactor Coolant Pump In Million Kilowatts Nuclear Power Plants

The small-sample,long-life and complex structure characteristics of the shaft seal reactor coolant pump(RCP)in 1000 MW Nuclear Power Plants make it difficult to carry out reliability test.The normal reliability test method has been unable to meet the needs of RCP.In order to reduce the test cost,it is necessary to study the reliability test method of RCP.Based on the principle of reliability test,a reliability test method suitable for complex electromechanical equipment was proposed and applied to the RCP reliability test.It attempted to carry out a long-term component test combined with a short-term machine test to achieve the purpose of verifying the reliability of RCP.A reliability test method for complex electromechanical equipment was proposed.Based on the reliability test principles and test types,the reliability test characteristics of complex electromechanical equipment were analyzed,and the equipment reliability was related to the probabilities of fatal failure modes.Then the reliability test scheme was determined: using component test to verify the probabilities of components fatal primary failure modes,using logic analysis of support conditions to verify the probabilities of components fatal secondary failure modes and command failure modes,using machine test to verify the probabilities of interfaces fatal failure modes.The corresponding test procedure consists of three steps was developed.This test method was applied to the RCP reliability test.Firstly,the function and structure of RCP were analyzed to define the components and interfaces.Then the fatal failure modes of RCP were determined through FMECA,and the reliability model of RCP was established based on them.The mission profile and the environmental profile of RCP were analyzed,and each mission process and its influence on the reliability were sorted out.These studies established the basis of RCP reliability test.Then the components test method of RCP was studied.The methods for determining the test object and the test profile were studied.Taking the water-lubricated bearing as an example,its test scheme was designed in detail,and its reliability evaluation method based on linear wear was studied.Finally,the machine test method of RCP was studied.On the basis of clarifying the purpose of machine test,the test profile and test time were designed while the design process of the number of start-stop tests and continuous running test time was discussed.The machine test plan was obtained and the reliability evaluation of RCP was proposed by establishing a reliability evaluation model.The reliability test method of RCP can provide a reference for the small-sample and long-life complex electromechanical equipment.