Online detection method for external characteristics of in-service pneumatic stop valve based on pulse excitation

Abstract

The invention discloses an online detection method for external characteristics of an in-service pneumatic stop valve based on pulse excitation, and belongs to the field of functional safety detection and evaluation. According to the invention, an external characteristic detection method based on pulse excitation is used for carrying out external characteristic online detection on the in-service pneumatic stop valve, a control system sends current pulse excitation to an electromagnetic valve of the pneumatic stop valve so as to enable the electromagnetic valve to be repeatedly powered on and powered off, a valve rod of an executing mechanism is driven to repeatedly rotate by a small amplitude, the rotation angle of the valve is regulated and controlled by adjusting the duration time of the low-level pulse width within the allowable range of equipment, the output characteristic of the maximum angular displacement is detected, and online detection of the external characteristics of the in-service pneumatic stop valve is achieved. The problem of external characteristic online detection of the in-service pneumatic stop valve without a partial stroke test function is solved, the situation that normal production is affected by too large rotation amplitude of the valve rod in the detection process is avoided, and a basis is provided for evaluating the functional safety integrity of the pneumatic stop valve of a safety instrument system in a safety life cycle.

Description

technical field [0001] The invention relates to an online detection method for the external characteristics of an in-service pneumatic globe valve based on pulse excitation, and belongs to the field of functional safety detection and evaluation. Background technique [0002] Safety instrumented systems are widely used in the petrochemical process industry. Correctly performing their corresponding safety functions when dangerous situations occur in industrial systems play an important role in the safe operation of the production process. As the final actuator in the safety instrumented system, the pneumatic shut-off valve will perform an emergency cut-off when it detects a situation that may cause a safety accident in the production device, so that the production equipment can be stopped safely or the production equipment will be automatically transferred to the preset safe production state. To ensure the safety of personnel, equipment and the surrounding environment of the f...

AI Technical Summary

Problems solved by technology

[0003] The production equipment in petrochemical enterprises runs uninterruptedly for a long time. Since the external characteristics of the pneumatic globe valve cannot be detected by the off-line test method in the normal production process, the hidden dangers of its own faults cannot be discovered in time, which reduces the safety of the system.

In the actual production at this stage, most of the pneumatic globe valves only have test data related to functional safety integrity and SIL certification evaluation provided by the manufacturer before they are put into use. Once the pneumatic globe valve is put into use, it is impossible to know whether it is in use. In the event of functional failure, the pneumatic globe valve can only be detected offline by stopping production or disassembled after switching the bypass. In order to ensure the functional safety integrity of the pneumatic globe valve in its life cycle, it is urgent to propose an in-service pneumatic globe valve On-line detection method for external characteristics of the valve, providing a basis for evaluating the functional safety integrity of safety instrumented system pneumatic globe valves in the safety life cycle

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