Korea Hydro Nuclear Power Co., Ltd.

Hee Seung Chang

Chi Yong Park

Young Sheop Park

Dae Woong Kim

Ji In Kim

Byoung Oh Lee

Yang Seok Kim

Jong Seog Kim

Hyoung Kyun Kim

Bum Nyun Kim

Nam Woo Choi

You Soo Shin

Yong Hoon Park

Ju Hyung Kang

Method for diagnosing a pneumatic control valve by using a positioner model includes: establishing relational expression for outputting valve stem displacement according to control pressure, the relational expression including parameters for the characteristics of a positioner, an actuator, and a valve, determining initial parameter value by adjusting the values of the parameters until the difference between a measured value for a normal operation of the pneumatic control valve and output value obtained by the relational expression is smaller than predetermined error limit, determining diagnostic parameter value by adjusting the values of the parameters until the difference between a measured value for a diagnostic operation of the pneumatic control valve and an output value obtained by the relational expression is smaller than a predetermined error limit, and comparing the initial parameter value and the diagnostic parameter value so as to determine whether the pneumatic control valve has abnormality.

Method and apparatus for diagnosing pneumatic control valve by using positioner model

System for diagnosing pneumatic control valve online include a sensor set having sensors, attached to a pneumatic control valve, for measuring the state of the pneumatic control valve, a smart data analyzer for processing sensor signal acquired in real time from the sensor set and generating pneumatic control valve state information for online automatic diagnosis of the pneumatic control valve, a data server for transmitting, to an online analysis server, the pneumatic control valve state information received in real time from the smart data analyzer and storing the pneumatic control valve state information for predetermined time period, the online diagnostic server for, by comparing the pneumatic control valve state information with pre-stored normal state data of the pneumatic control valve, determining whether the pneumatic control valve is in abnormal state and generating diagnostic information, and a client computer for displaying the diagnostic information received from the online diagnostic server.

System and method for diagnosing pneumatic control valve online

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Daejeon, South Korea

Hee Seung Chang