Checking method for feedback abnormity of rotatable guide vane of gas turbine

Abstract

The invention relates to a gas turbine rotatable guide vane feedback abnormity checking method, which is based on a guide vane control principle, points out conditions of single-cylinder alarm, double-cylinder alarm, non-alarm actual angle abnormity and the like, performs classified checking through fault phenomenon analysis, and is comprehensive in analysis, clear in logic and high in accuracy. The reason for feedback abnormity of the rotatable guide vane can be accurately positioned, and the method has important significance for recovering stable operation.

Description

Technical Field

[0001] This invention relates to the field of marine gas turbine technology, and in particular to a method for troubleshooting abnormal feedback from rotatable guide vanes in gas turbines. Background Technology

[0002] Gas turbines, as a type of high-speed rotating power equipment, are widely used in power generation, industrial drives, and marine propulsion. The compressor, as a key component of the gas turbine, has strong nonlinearity, and its performance directly affects the operating efficiency of the gas turbine.

[0003] The inlet guide vanes, serving as stationary blades at the compressor inlet, are controlled by an electric cylinder to change their angle, thereby regulating the amount of air entering the gas turbine. A malfunction in this system often leads to gas turbine shutdown, resulting in personnel and economic losses.

[0004] However, during use, the main faults are abnormal feedback from the rotatable guide vanes of the gas turbine. Therefore, a method is needed to quickly troubleshoot the faults and restore the stable operation of the gas turbine. Summary of the Invention

[0005] This application addresses the shortcomings of the existing production technology by providing a method for troubleshooting abnormal feedback from the rotatable guide vanes of a gas turbine, which can quickly identify faults and restore stable operation of the gas turbine.

[0006] The technical solution adopted in this invention is as follows: A method for troubleshooting abnormal feedback from rotatable guide vanes in gas turbines establishes a linear relationship between the guide vane angle and the extension length of the electric cylinder under normal operating conditions. The investigation was conducted based on the aforementioned linear relationship as the test benchmark. When the rotatable guide vanes of the gas turbine malfunction, the current guide vane angle and the extension length of the electric cylinder are checked to see if they both conform to the aforementioned linear relationship. Based on the non-compliance factors, check the condition of the gas turbine components and adjust them so that the current guide vane angle and electric cylinder extension length conform to the aforementioned linear relationship.

[0007] Suitable for use in applications where two electric cylinders are operating.

[0008] This method is applicable to situations where the feedback anomaly of the rotatable guide vane occurs as follows: Scenario 1: The extension length of cylinder A corresponds to the commanded angle, and the actual angle of the guide vane is correct, but inconsistent with the feedback angle. Scenario 2: The extension length of cylinder A is inconsistent with the commanded angle, but consistent with the feedback angle; simultaneously, the feedback angle of cylinder B is consistent with the command from the GT control system. Scenario 3: The actual angle of the rotatable guide vane lies between the angle corresponding to the extension length of cylinder A and the feedback angle of cylinder B, which is inconsistent with the GT control system command. The extension length of cylinder A is inconsistent with the GT control system command and the feedback angle; however, the GT control system command and feedback are consistent. Scenario 4: The control system issues an alarm indicating an abnormality in the feedback angle and command of cylinders A and B, even though the feedback angles of cylinders A and B are consistent. Scenario 5: The feedback angles and extension lengths of cylinders A and B are consistent with the commands of the GT control system, but the actual angles do not correspond to the commands.

[0009] In scenario one, the angle feedback transmission channel from the guide vane control cabinet to the GT control system should be checked for abnormalities. In scenario two, if the actual angle of the rotatable guide vane is between the feedback angle of cylinder A and cylinder B, then the command channel from the guide vane control cabinet to cylinder A, the cylinder A motor, and factors causing brake lock-up in cylinder A should be investigated. If the actual angle of the rotatable guide vane is consistent with the command of the GT control system, then check for abnormalities in the command channel from the guide vane control cabinet to cylinder A and abnormalities in the cylinder A motor.

[0010] In scenario three, check for abnormalities in the position transmission device inside cylinder A.

[0011] Cylinder A can be either of the two electric cylinders.

[0012] In scenario four, an abnormality was found in the command channel from the GT control system to the guide vane control cabinet.

[0013] In scenario five, check for abnormalities in the mechanical transmission mechanism of the rotatable guide vanes.

[0014] The beneficial effects of this invention are as follows: This application discloses a method for troubleshooting abnormal feedback from rotatable guide vanes in gas turbines. Based on the guide vane control principle, this method identifies situations such as single-cylinder alarm, dual-cylinder alarm, and actual angle abnormality without alarm. Through fault phenomenon analysis, it classifies and troubleshoots the issues. This method is comprehensive and logically clear, and can accurately locate the cause of abnormal feedback from rotatable guide vanes, which is of great significance for restoring stable operation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the measurable part of the electric cylinder used in this application.

[0016] Figure 2 This is a line graph showing the relationship between the extension length of cylinder A and the guide vane angle in this application.

[0017] Figure 3 This is a line graph showing the relationship between the extension length of cylinder B and the guide vane angle in this application.

[0018] Figure 4This is a flowchart for troubleshooting abnormal angles of rotatable guide vanes in gas turbines. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0020] Establish the relationship between the actual guide vane angle and the electric cylinder extension length under all operating conditions of the gas turbine. The electric cylinder extension length is the measurable portion during the troubleshooting process.

[0021] Measure the actual angle of the guide vane and the corresponding extension length of the electric cylinder under all operating conditions. For example... Figure 1 As shown, the corresponding relationships are derived, as shown in Table 1. Based on the aforementioned guide vane angle and electric cylinder extension length, the following relationships are established: Figure 2 and Figure 3 The line graph shown illustrates the linear relationship between the extension length of the electric cylinder and the guide vane angle. Figure 2 The linear relationship for cylinder A is given. Figure 3 The linear relationship of cylinder B is given.

[0022] Cylinder A: y = -0.893447 x + 82.282447 Cylinder B: y = -0.899702 x + 82.367687 Where x is the actual angle of the guide vane and y is the extension length of the electric cylinder (unit: mm).

[0023] Table 1. Correspondence between the angle of the rotatable guide vane and the extension length of the electric cylinder.

[0024] Case 1: The gas turbine control system issued an alarm indicating an abnormality in the feedback angle and command of cylinder B.

[0025] During steady-state operation, the control system of a certain gas turbine issues an alarm indicating an abnormality in the feedback angle and command of cylinder B.

[0026] Querying the operating data, the gas turbine control system's control command for the rotatable guide vanes is 15.0°, and the actual angle of the rotatable guide vanes is also 15°. Cylinder A's feedback is 15.0°, and cylinder B's feedback is 11°. The extension length of cylinder B is 68.9, which corresponds to the length at 15 degrees (y = -0.899702 x + 82.367687 = -0.899702). (15 + 82.367687 = 68.9). This indicates an abnormality in the angle feedback transmission channel from the guide vane control cabinet to the GT control system. Troubleshooting revealed a loose connection in the B cylinder feedback angle cable connector. Resolving this issue cleared the alarm.

[0027] Case 2: The gas turbine control system issued an alarm indicating an abnormality in the feedback angle and command of cylinder A.

[0028] When a gas turbine is operating under varying conditions, the control system issues an alarm indicating an abnormality in the feedback angle and command of cylinder A.

[0029] Querying the operating data, the gas turbine control system's control command for the rotatable guide vanes is 27.0°, the actual angle of the rotatable guide vanes is 24°, the feedback from cylinder A is 22°, and the feedback from cylinder B is 27°. The extension length of cylinder A, 62.6, is inconsistent with the commanded angle of 27.0° and the feedback angle of 22° (y=-0.893447). (22 + 82.282447 = 62.6) is consistent.

[0030] The fault occurred because the feedback from cylinder A did not match the command, causing it to perform the function of cylinder B. However, after cylinder A malfunctioned, it did not move with cylinder B, indicating that cylinder A was experiencing brake lock-up. An investigation was conducted into abnormalities in the command channel from the guide vane control cabinet to cylinder A, as well as abnormalities in the cylinder A motor and the factors causing the brake lock-up. It was discovered that there was vibration in the command and power cable from the guide vane control cabinet to cylinder A; a loss of power to the power cable would cause braking. After tightening the power cable, cylinder A returned to normal operation, and the fault was eliminated.

[0031] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine, characterized in that: Establish a linear relationship between the guide vane angle and the electric cylinder extension length of the gas turbine under normal operating conditions. The investigation was conducted based on the aforementioned linear relationship as the test benchmark. When the rotatable guide vanes of the gas turbine malfunction, the current guide vane angle and the extension length of the electric cylinder are checked to see if they both conform to the aforementioned linear relationship. Based on the non-compliance factors, check the condition of the gas turbine components and adjust them so that the current guide vane angle and electric cylinder extension length conform to the aforementioned linear relationship.

2. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 1, characterized in that: Suitable for use in applications where two electric cylinders are operating.

3. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 2, characterized in that: This method is applicable to situations where the feedback anomaly of the rotatable guide vane occurs as follows: Scenario 1: The extension length of cylinder A corresponds to the commanded angle, but the actual angle of the guide vane is correct, which is inconsistent with the feedback angle. Scenario 2: The extension length of cylinder A is inconsistent with the commanded angle, but consistent with the feedback angle; simultaneously, the feedback angle of cylinder B is consistent with the command from the GT control system. Scenario 3: The actual angle of the rotatable guide vane lies between the angle corresponding to the extension length of cylinder A and the feedback angle of cylinder B, which is inconsistent with the GT control system command. The extension length of cylinder A is inconsistent with the GT control system command and the feedback angle; however, the GT control system command and feedback are consistent. Scenario 4: The control system issues an alarm indicating an abnormality in the feedback angle and command of cylinder A; the feedback angles of cylinders A and B are consistent. Scenario 5: The feedback angles and extension lengths of cylinders A and B are consistent with the commands of the GT control system, but the actual angles do not correspond to the commands.

4. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 3, characterized in that: In scenario one, the abnormality of the angle feedback transmission channel from the guide vane control cabinet to the GT control system should be investigated.

5. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 3, characterized in that: In scenario two, if the actual angle of the rotatable guide vane is between the feedback angle of cylinder A and the feedback angle of cylinder B, then investigate for abnormalities in the command channel from the guide vane control cabinet to cylinder A, abnormalities in the cylinder A motor, and factors causing brake lock-up in cylinder A. If the actual angle of the rotatable guide vane is consistent with the command of the GT control system, then check for abnormalities in the command channel from the guide vane control cabinet to cylinder A and abnormalities in the cylinder A motor.

6. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 3, characterized in that: In scenario three, check for abnormalities in the position transmission device inside cylinder A.

7. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 3, characterized in that: In scenario four, an abnormality was found in the command channel from the GT control system to the guide vane control cabinet.

8. The method for troubleshooting feedback anomalies in the rotatable guide vanes of a gas turbine as described in any one of claims 4, 5, 6, and 7, characterized in that: Cylinder A can be either of the two electric cylinders.

9. The method for troubleshooting abnormal feedback from rotatable guide vanes in a gas turbine as described in claim 3, characterized in that: In scenario five, check for abnormalities in the mechanical transmission mechanism of the rotatable guide vanes.

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