The following measures can be taken to deal with and prevent LVDT core breakage, coil failure, or aviation plug loosening caused by high-frequency vibration of the 3000TD adjustable door displacement sensor:
1. Troubleshooting and Handling
1.1 Core fracture
-Cause analysis:
-High frequency vibration causes long-term friction between the LVDT core and the inner wall of the coil, ultimately leading to core fracture.
-The anti rotation design of the regulating valve stem is unreasonable, and the rotation angle of the valve stem is too large, resulting in the misalignment and fracture of the LVDT iron core.
-Handling method:
-Replace the broken LVDT iron core or the entire LVDT sensor.
-Check the anti rotation design of the valve stem to ensure that the rotation angle of the valve stem is within a reasonable range.
1.2 Coil malfunction
-Cause analysis:
-High frequency vibration causes LVDT coil wear.
-During LVDT installation, the iron core and coil are not concentric, resulting in wear during operation.
-Handling method:
-Replace the worn LVDT coil or the entire sensor.
-When installing LVDT, ensure that the iron core is concentric with the coil and remains parallel to the valve stem throughout the full stroke range of the regulating valve.
1.3 Loose aviation plug
-Cause analysis:
-High temperature and vibration environments can cause poor or loose contact of aviation plugs.
-Handling method:
-Check and tighten the aviation plug to ensure a secure connection.
-If conditions permit, the aviation plug can be changed to directly solder the leads to avoid poor contact.
2. Preventive measures
2.1 Optimize installation design
-New installation method:
-Adopting a new LVDT installation design scheme, such as installing a guide rod on the LVDT side and two universal joints on the connecting crossbar side, to achieve technical measures of "guidance" and "unloading".
-Install a spring buffer at the nut connection between the valve lead out rod and the LVDT iron core to effectively suppress LVDT fracture.
2.2 Triple redundancy design
-Redundant measurement method:
-Adopting triple redundant measurement method, installing three LVDT displacement sensors to achieve feedback triple redundant control.
-By using reasonable signal sampling to identify and eliminate faulty LVDT signals, the reliability of the system can be improved.
2.3 Daily Maintenance
-Regular inspection:
-Regularly check the fixation of the iron core and bracket to ensure reliable connection.
-Check the fastening of LVDT signal wire terminals to ensure shielding and no wear of the signal wire.
-Measure the coil resistance and insulation of the casing during each shutdown.
3. Precautions for online replacement
-Maintain system stability:
-During the replacement process, it is necessary to maintain system stability and avoid major disturbances.
-Gradually adjust the valve:
-After replacement, gradually adjust the valve command from 0% to 100%, and then from 100% to 0%, and compare the consistency between the valve command and feedback.
-Monitoring process:
-The operation supervisor and thermal supervisor must be present for process monitoring to ensure that the entire process is under control.