Analysis And Research On Diagnostic Testing Technology Of AES-91 Nuclear Power Unit Electric Gate Valve

Electric gate valves are common valves in nuclear safety system and important primary circuit system, these valves participate in the normal operation of the nuclear power station and the important functions of emergency situations, whose equipment reliability affects the safe and stable operation of nuclear power plant unit. As far as possible to improve the reliability of Tianwan Nuclear Power Station electric valves, the diagnosis and testing technology of electric gate valve is introduced in this paper. This paper introduces the basic situation of Tianwan Nuclear Power Station electric valves firstly, and in accordance with the development of the industry, the history of electric valve diagnosis testing technology in domestic and foreign is described. Based on the two preventive maintenance work of inspection and overhaul which is promoting on those valves,the defects of current equipment management and the original intention of this research are put forward. Referring to standard system for diagnosis and testing of common electric gate valves in the industry, the various types of force of the electric gate valve is analyzed in the opening and closing process. Thus, based on the summary of the various types of empirical parameters, the mathematical model of the mechanical analysis for the diagnostic test system of the electric valve is established. The mathematical model of the mechanical analysis for the electric gate valve is established in the case of design and manufacture by referring to the Russian valve manufacturing industry standard. Taking a type of Russian manufacturing electric gate valve as an example which is used in Tianwan Nuclear Power Station on-site installation, various type of characteristic parameters of electric gate valve are gathered through the numerous field test. This paper focuses on comparing the collecting parameters and the standard calculating by the two kinds of mathematical model. Meanwhile, the stress of the valve stem is analyzed and discussed Combined with the characteristics of electric gate valves produced by Russia and the actual working conditions. In combination with practical calculation and theoretical calculation, the selection of relevant key factors of electric gate valve is proposed. Analysis of the above foundation, this paper also depicts the control characteristics and requirements of Tianwan Nuclear Power Station electricgate valves, and a set of diagnostic test standard system is studied finally suitable for this type of electric gate valve. The standard system is established on the accurate theoretical calculation model and the field engineering practice, has high reliability and availability of the scene which has smoothly passed the overhaul of Tianwan Nuclear Power Station site verification many times.