A method for online monitoring of flange bolt tension and working load

Abstract

The invention provides an online monitoring method for flange bolt tension and working load. A high-precision displacement sensor is installed at the flange joint, and the relative displacement data of the flange is collected and corrected, and the bolt tension and the outer surface of the bolt joint are calculated according to the displacement data. Load, and further calculate the total working load acting on the flange, compare the calculated values ​​with the set thresholds, and give an early warning when the thresholds are exceeded. The present invention can monitor the axial relative displacement of the flange through a high-precision displacement sensor, and carry out online monitoring of bolt tension and flange working load, can realize fully automatic processing, high calculation efficiency, and real-time online monitoring of flange bolt tension and flange work Load changes can avoid equipment damage caused by flange connection bolt failure or excessive flange working load. By rationally arranging the number and position of high-precision sensors, all flange bolt tension and flange working load can be accurately and comprehensively monitored.

Description

technical field [0001] The invention relates to an online monitoring method for flange bolt tension and working load, and belongs to the technical field of flange bolt tension and load monitoring. Background technique [0002] Flange connection refers to the connection of flanges, gaskets and bolts as a detachable structure. Flange connection is extremely common in the current industrial field and plays a very important role. The flange connection structure will be subjected to various alternating loads and impact loads during work. Under the action of alternating tension and compression loads, the thread may be plastically deformed to cause the bolt to loosen, and the tension of the bolt will decrease. If the bolt tension is too small, the connection will be unreliable, which will affect the normal operation of the machine. If the bolt tension is too large, it may cause the bolt to break under the load, thereby weakening the bearing capacity of the connecting node, and in...

AI Technical Summary

Problems solved by technology

[0005] 1) Using ultrasonic technology to monitor bolt tension online, this technology needs to install ultrasonic probes and other monitoring sensors or equipment on each planned monitoring bolt, which has high cost, long preparation time and on-site construction time; for flange bolts, it needs to be disassembled, reinstalled The installation of bolts will cause the friction coefficient to change during the bolt tightening process, which will affect the accuracy of monitoring data; the number of monitoring equipment is large, and the installation is easy to loosen, so the probability of failure is high; the number of bolts that can be monitored is limited, and comprehensive and all-round monitoring cannot be realized

[0006] 2) Use the strain gauge technology to measure the bolt tension. When this technology is applied to field measurement, the first thing to solve is the signal transmission of the strain gauge. Since the gap between the screw and the screw hole is very small, it is very difficult to realize the signal transmission of the strain gauge. At the same time, the connection surface of the flange bolts will slip slightly under the load during the working process, which may cause damage to the resistance strain gauge. Therefore, the reliability of the resistance strain gauge measurement bolt tension is not high, and it is not suitable for field use Engineering Applications

[0007] 3) Use pressure sensor technology to measure bolt tension. Although this method has high measurement accuracy, it destroys the integrity and integrity of the workpiece, and sometimes it cannot be installed due to the limitation of geometric space.

[0008] To sum up, although the existing technology has made a certain contribution to the online monitoring of bolt tension, there are still many deficiencies and cannot meet the needs of many practical engineering applications.

[0009] Regarding the online monitoring technology of flange working load, there are very few technologies available in the market

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