Servo system, gas turbine and guide vane adjustment method

Abstract

The application discloses a kind of servo system, gas turbine and guide vane adjustment method, including driver, reversing valve, first pipeline, second pipeline, third pipeline, fourth pipeline, first valve, second valve, fifth pipeline and sixth pipeline, driver includes cylinder and piston, first cavity and second cavity are equipped in cylinder, piston is slidably cooperated between first cavity and second cavity, first pipeline is connected between first cavity and reversing valve, second pipeline is connected between second cavity and reversing valve, third pipeline and fourth pipeline are communicated with reversing valve, first valve is arranged in first pipeline and second pipeline or in third pipeline and fourth pipeline, fifth pipeline is connected between first pipeline and third pipeline, sixth pipeline is connected between second pipeline and fourth pipeline, and second valve is arranged in fifth pipeline and sixth pipeline.The servo system of the application has simple structure, less hidden trouble and good reliability.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, specifically to a servo system for a gas turbine, a gas turbine using the servo system, and a guide vane adjustment method based on the gas turbine. Background Technology

[0002] The compressor is a crucial component of a heavy-duty gas turbine. It is primarily used to supply pressurized air into the combustion chamber of the gas turbine. To meet the operational requirements of different operating conditions, the amount of air supplied by the compressor needs to be adjusted using adjustable guide vanes. However, in related technologies, adjustable guide vanes sometimes fail to close properly during use, resulting in poor reliability, increased gas turbine failure rate, and reduced gas turbine service life. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] In related technologies, adjustable guide vanes are mainly driven by hydraulic servo mechanisms. However, these mechanisms suffer from poor operational stability and cannot fully close in the event of a malfunction, thus reducing their reliability. Furthermore, the hydraulic servo mechanisms in these technologies are complex in structure, prone to interference, and have numerous potential malfunctions, further compromising their operational stability.

[0005] The present invention aims to at least partially solve one of the technical problems in the related art.

[0006] Therefore, this invention proposes a servo system with a simple structure, few potential failures, and high reliability.

[0007] This invention also proposes a gas turbine that utilizes the aforementioned servo system.

[0008] This invention also proposes a guide vane adjustment method based on the above-mentioned gas turbine.

[0009] The servo system of this invention includes: a driver, the driver including a cylinder and a piston, the cylinder having a first chamber and a second chamber, the piston being slidably fitted between the first chamber and the second chamber; a reversing valve, a first pipeline and a second pipeline, the first pipeline connecting the first chamber and the reversing valve, the second pipeline connecting the second chamber and the reversing valve; a third pipeline and a fourth pipeline, the third pipeline and the fourth pipeline being connected to the reversing valve, and one of the third pipeline and the fourth pipeline being able to interact with the first pipeline when the reversing valve is actuated. The pipeline is connected to one of the second pipeline and the third pipeline and the fourth pipeline, and the other of the third pipeline and the fourth pipeline is connected to the other of the first pipeline and the second pipeline; a first valve is disposed between the first pipeline and the second pipeline or between the third pipeline and the fourth pipeline, and the first valve is adapted to isolate the reversing valve and the actuator; a second valve, a fifth pipeline and a sixth pipeline, the fifth pipeline being connected between the first pipeline and the third pipeline, the sixth pipeline being connected between the second pipeline and the fourth pipeline, and the second valve being disposed between the fifth pipeline and the sixth pipeline.

[0010] The servo system of this invention has a simple structure, few potential faults, and high reliability.

[0011] In some embodiments, the servo system includes: a sensor adapted to monitor the displacement of the piston and output a displacement signal; and a control device that receives the displacement signal and opens or closes the directional valve and / or the first valve and / or the second valve when the piston moves to a set position.

[0012] In some embodiments, the servo system includes a frame, and the driver, the reversing valve, the first pipeline, the second pipeline, the third pipeline, the fourth pipeline, the first valve, the second valve, the fifth pipeline, the sixth pipeline, the sensor, and the control device are integrated into the frame.

[0013] In some embodiments, the servo system includes: a first throttle and a second throttle, the first throttle being disposed in the first pipeline and adapted to regulate the flow rate of the first pipeline, the second throttle being disposed in the second pipeline and adapted to regulate the flow rate of the second pipeline; and / or, a third throttle and a fourth throttle, the third throttle being disposed in the fifth pipeline and adapted to regulate the flow rate of the fifth pipeline, the fourth throttle being disposed in the sixth pipeline and adapted to regulate the flow rate of the sixth pipeline.

[0014] In some embodiments, the first valve is disposed in the first pipeline and the second pipeline, and the first throttle and the second throttle are located downstream of the first valve.

[0015] In some embodiments, the third pipeline is a liquid inlet pipeline, and the third pipeline is provided with a third valve. The third valve is located upstream of the connection between the fifth pipeline and the third pipeline, and the third valve is adapted to open and close the third pipeline.

[0016] In some embodiments, the third pipeline is provided with a filter located upstream of the connection between the fifth pipeline and the third pipeline, and downstream of the third valve.

[0017] In some embodiments, the fourth pipeline is a return pipeline, and the fourth pipeline is equipped with a one-way valve, which is located downstream of the connection between the sixth pipeline and the fourth pipeline.

[0018] In some embodiments, the reversing valve includes a valve core and a plurality of coils, the plurality of coils being arranged in parallel and the plurality of coils being adapted to drive the valve core to move to achieve reversing switching of the reversing valve.

[0019] In some embodiments, the directional valve is a servo valve and / or the first valve is a solenoid valve and / or the second valve is a solenoid valve.

[0020] The gas turbine of this invention includes a servo system and a compressor. The servo system is the servo system described in any of the above embodiments. The compressor includes guide vanes, which are connected to the piston of the driver.

[0021] The guide vane adjustment method of this invention includes the following steps:

[0022] S1: When the reversing valve fails, the first valve is used to isolate the reversing valve and the second valve is opened;

[0023] S2: Referencing the rotational speed of the gas turbine, intermittently close the second valve to close the guide vanes in stages;

[0024] In some embodiments, step S2 includes the following steps:

[0025] S21: Divide the speed of the gas turbine into multiple speed levels, and divide the closing angle of the guide vanes into multiple closing angles;

[0026] S22: If the speed of the gas turbine drops from the previous higher speed level to the next lower speed level, then the second valve is opened;

[0027] S23: Once the guide vane rotates to the closing angle corresponding to the two speed levels in S22, close the second valve;

[0028] S24: Repeat steps S22 to S23 above until the guide vane is completely closed. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the servo system according to an embodiment of the present invention.

[0030] Figure 2 yes Figure 1 A schematic diagram of the structure of the driver.

[0031] Figure 3 This is a schematic diagram of the overall structure of the servo system according to an embodiment of the present invention.

[0032] Figure label:

[0033] Servo system 100;

[0034] Driver 1; Cylinder 101; Piston 102; First chamber 103; Second chamber 104; Reversing valve 2; First pipeline 3; Second pipeline 4; Third pipeline 5; Fourth pipeline 6; First valve 7; Second valve 8; Fifth pipeline 9; Sixth pipeline 10; Sensor 11; First throttle 12; Second throttle 13; Third throttle 14; Fourth throttle 15; Third valve 16; Filter 17; Check valve 18; Frame 19;

[0035] Guide vane 200. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] like Figures 1 to 3 As shown, the servo system 100 of this embodiment includes a driver 1, a reversing valve 2, a first pipeline 3, a second pipeline 4, a third pipeline 5, a fourth pipeline 6, a first valve 7, a second valve 8, a fifth pipeline 9, and a sixth pipeline 10.

[0038] The actuator 1 includes a cylinder 101 and a piston 102. The cylinder 101 has a first chamber 103 and a second chamber 104, and the piston 102 is slidably engaged between the first chamber 103 and the second chamber 104. Figure 1 and Figure 2 As shown, the actuator 1 can be a hydraulic cylinder. The actuator 1 can include a cylinder body 101 and a piston 102. The piston 102 is assembled inside the cylinder body 101 and is movable along the axial direction of the cylinder body 101. The piston 102 divides the inner cavity of the cylinder body 101 into a first cavity 103 and a second cavity 104. Both the first cavity 103 and the second cavity 104 are movable cavities, and hydraulic fluid can be introduced into both the first cavity 103 and the second cavity 104.

[0039] The piston 102 may be equipped with two drive rods, one of which is fixed to one side of the piston 102 and the other is fixed to the other side of the piston 102. When the piston 102 moves inside the cylinder 101, the two drive rods will move synchronously with the piston 102. The drive rods can be connected to an external actuator for transmission, and the movement of the actuator can be adjusted by moving the drive rods.

[0040] The reversing valve 2 may have four ports, namely the first port, the second port, the third port, and the fourth port. The first port and the second port may be located on one side of the reversing valve 2, and the third port and the fourth port may be located on the other side of the reversing valve 2. The reversing valve 2 may have a valve core that can move within the reversing valve 2. By moving the valve core, the first port may be connected to the third port, and the second port may be connected to the fourth port; alternatively, the first port may be connected to the fourth port, and the second port may be connected to the third port.

[0041] The first pipe 3 connects the first chamber 103 and the reversing valve 2, and the second pipe 4 connects the second chamber 104 and the reversing valve 2. For example... Figure 1 As shown, one end of the first pipe 3 can be connected to the first port, and the other end of the first pipe 3 is connected to the first cavity 103. One end of the second pipe 4 can be connected to the second port, and the other end of the second pipe 4 is connected to the second cavity 104.

[0042] The third pipeline 5 and the fourth pipeline 6 are connected to the reversing valve 2, and one of the third pipeline 5 and the fourth pipeline 6 can be connected to one of the first pipeline 3 and the second pipeline 4 when the reversing valve 2 is activated, and the other of the third pipeline 5 and the fourth pipeline 6 can be connected to the other of the first pipeline 3 and the second pipeline 4.

[0043] like Figure 1 As shown, the third pipeline 5 can be connected to the third port of the reversing valve 2, and the fourth pipeline 6 can be connected to the fourth port of the reversing valve 2. By the action of the valve core in the reversing valve 2, the third pipeline 5 can be connected to the first pipeline 3, and the fourth pipeline 6 can be connected to the second pipeline 4. Alternatively, the third pipeline 5 can be connected to the second pipeline 4, and the fourth pipeline 6 can be connected to the first pipeline 3.

[0044] The first valve 7 is located in the first pipeline 3 and the second pipeline 4, or in the third pipeline 5 and the fourth pipeline 6. The first valve 7 is suitable for isolating the directional valve 2 and the actuator 1. Figure 1 As shown, the first valve 7 can be installed on the first pipeline 3 and the second pipeline 4. The first valve 7 can simultaneously control the opening and closing of the first pipeline 3 and the second pipeline 4, and play the role of isolating the reversing valve 2.

[0045] In some other embodiments, the first valve 7 can also be provided on the third pipeline 5 and the fourth pipeline 6. In this case, the first valve 7 can control the opening and closing of the third pipeline 5 and the fourth pipeline 6 near the reversing valve 2, thereby also achieving the function of isolating the reversing valve 2.

[0046] The fifth pipe 9 connects between the first pipe 3 and the third pipe 5, and the sixth pipe 10 connects between the second pipe 4 and the fourth pipe 6. The second valve 8 is located between the fifth pipe 9 and the sixth pipe 10. Figure 1 As shown, the hydraulic fluid in the third pipeline 5 can flow directly into the first chamber 103 via the fifth pipeline 9, and the hydraulic fluid in the second chamber 104 can also flow back to the fourth pipeline 6 via the sixth pipeline 10. The second valve 8 can simultaneously control the on / off state of the fifth pipeline 9 and the sixth pipeline 10.

[0047] The servo system 100 of this invention includes only a reversing valve 2, a first valve 7, a second valve 8, and corresponding pipelines. The overall structure of the servo system 100 is simple, avoiding the problems of complex structures and potential fault points caused by numerous components in related technologies. This simplifies the structure of the servo system 100 and reduces costs. Furthermore, due to its simple structure and clear oil circuit, it is easy to implement in engineering and also improves the problem of interference during operation.

[0048] In addition, during normal use, the guide vane 200 can be adjusted by the reversing valve 2 and the first valve 7. When the reversing valve 2 is damaged (due to frequent switching, the failure rate is high), the first valve 7 can be used to isolate the reversing valve 2, and then the second valve 8 can be opened. At this time, the hydraulic fluid can be delivered to the driver 1 through the second valve 8, so that the guide vane 200 of the gas turbine can still be closed. This provides double protection, ensures the safety of the heavy-duty gas turbine, and improves the reliability of the guide vane 200 under the control of the servo system 100.

[0049] In some embodiments, the servo system 100 includes a sensor 11 and a control device. The sensor 11 is adapted to monitor the displacement of the piston 102 and output a displacement signal. The control device receives the displacement signal and opens or closes the directional valve 2 and / or the first valve 7 and / or the second valve 8 when the piston 102 moves to a set position.

[0050] like Figure 1 and Figure 3 As shown, sensor 11 can be an LVDT displacement sensor or a magnetostrictive displacement sensor, and the control device can be a PLC control system, or other types of processors. Sensor 11 can monitor the movement of piston 102 in driver 1 and transmit displacement signals to the control device. After receiving the corresponding displacement signals, the control device can coordinate the opening and closing of directional valve 2, first valve 7 and second valve 8.

[0051] For example, when hydraulic fluid is supplied to the actuator 1 through the reversing valve 2 and the first valve 7, when the piston 102 moves to one end of the actuator 1, the container of the first chamber 103 can be considered to be at its maximum and the volume of the second chamber 104 can be considered to be at its minimum. The sensor 11 will detect this position and send a displacement signal to the control device. After receiving the displacement signal, the control device will cut off the current of the reversing valve 2, thereby keeping the piston 102 of the actuator 1 in this position.

[0052] In some embodiments, the servo system 100 includes a frame 19, a driver 1, a reversing valve 2, a first pipeline 3, a second pipeline 4, a third pipeline 5, a fourth pipeline 6, a first valve 7, a second valve 8, a fifth pipeline 9, a sixth pipeline 10, a sensor 11, and a control device integrated into the frame 19.

[0053] like Figure 3 As shown, the frame 19 can be a frame on which components such as the actuator 1 and the reversing valve 2 are assembled. The first pipe 3, the second pipe 4, and other pipes can be independent pipes. It is understood that in some other embodiments, the frame 19 can be a block, and components such as the actuator 1 and the reversing valve 2 can be assembled within the grooves of the frame 19. In this case, the first pipe 3, the second pipe 4, and other pipes can be through holes located within the frame 19.

[0054] In some embodiments, the servo system 100 includes a first throttle 12 and a second throttle 13. The first throttle 12 is disposed in the first pipeline 3 and adapted to regulate the flow rate of the first pipeline 3, and the second throttle 13 is disposed in the second pipeline 4 and adapted to regulate the flow rate of the second pipeline 4.

[0055] like Figure 1 As shown, both the first throttle 12 and the second throttle 13 can be throttle valves. The first throttle 12 can be installed on the first pipeline 3, and the second throttle 13 can be installed on the second pipeline 4. In use, the flow area of ​​the first pipeline 3 can be adjusted by the first throttle 12, and the flow area of ​​the second pipeline 4 can be adjusted by the second throttle 13, thereby controlling the displacement speed of the piston 102 in the actuator 1, and thus adjusting the execution speed of the actuator.

[0056] It is understood that in some other embodiments, the first throttle 12 may be a throttle orifice provided on the first pipeline 3, and the second throttle 13 may be a throttle orifice provided on the second pipeline 4.

[0057] In some embodiments, the servo system 100 may include a third throttle 14 and a fourth throttle 15, wherein the third throttle 14 is disposed in the fifth pipe 9 and adapted to regulate the flow rate of the fifth pipe 9, and the fourth throttle 15 is disposed in the sixth pipe 10 and adapted to regulate the flow rate of the sixth pipe 10. Figure 1 As shown, similar to the first throttle valve 12 and the second throttle valve 13, the third throttle valve 14 and the fourth throttle valve 15 can also be throttle valves. The third throttle valve 14 is installed on the fifth pipe 9, and the fourth throttle valve 15 is installed on the sixth pipe 10. The third throttle valve 14 can adjust the flow area of ​​the fifth pipe 9, and the fourth throttle valve 15 can adjust the flow area of ​​the sixth pipe 10. Thus, when the second valve 8 is used to operate the actuator 1, the displacement speed of the piston 102 in the actuator 1 can be adjusted by the third throttle valve 14 and the fourth throttle valve 15.

[0058] Optionally, such as Figure 1 As shown, the first valve 7 is located in the first pipeline 3 and the second pipeline 4, and the first throttle 12 and the second throttle 13 are located downstream of the first valve 7.

[0059] In some embodiments, the third pipeline 5 is a liquid inlet pipeline, and the third pipeline 5 is provided with a third valve 16. The third valve 16 is located upstream of the connection between the fifth pipeline 9 and the third pipeline 5, and the third valve 16 is adapted to open and close the third pipeline 5. Figure 1 As shown, the third valve 16 can be a shut-off valve, and the third pipeline 5 is mainly used to supply hydraulic fluid into the driver 1. The third pipeline 5 can be cut off through the third valve 16, thereby facilitating the inspection, maintenance and component replacement of the servo system 100.

[0060] In some embodiments, the third pipeline 5 is provided with a filter 17, which is located upstream of the connection between the fifth pipeline 9 and the third pipeline 5, and downstream of the third valve 16. The filter 17 can perform a filtering function, thereby reducing the blockage of the reversing valve 2 and improving the stability of the servo system 100 during operation.

[0061] In some embodiments, the fourth pipeline 6 is a return pipeline, and the fourth pipeline 6 is equipped with a one-way valve 18, which is located downstream of the connection between the sixth pipeline 10 and the fourth pipeline 6. The one-way valve 18 can prevent hydraulic fluid from flowing back into the oil circuit of the servo system 100, improve the stability of operation, and help reduce the failure rate.

[0062] In some embodiments, the reversing valve 2 includes a valve core and multiple coils arranged in parallel, and the multiple coils are adapted to drive the valve core to move, thereby realizing the reversing switching of the reversing valve 2. Two coils may be provided, arranged in parallel. During normal operation of the reversing valve 2, both coils operate simultaneously, with each coil sharing half of the total current. When one coil fails, the other coil can still drive the valve core to move; in this case, the current in that coil becomes the total current. This further improves operational stability and mitigates the problem of frequent failure points.

[0063] It is understood that in some other embodiments, there may be three, four, or more coils, and the multiple coils may be arranged in parallel.

[0064] In some embodiments, the directional valve 2 is a servo valve and / or the first valve 7 is a solenoid valve and / or the second valve 8 is a solenoid valve. For example, the directional valve 2 is a servo valve, and the first valve 7 and the second valve 8 are both solenoid valves. Solenoid valves are reliable in operation, less prone to jamming compared to servo valves, proportional valves, etc., and are also inexpensive.

[0065] In some embodiments, the actuator 1 can be a double-acting hydraulic cylinder with a double rod, that is, the cross-sectional area of ​​the first chamber 103 and the cross-sectional area of ​​the second chamber 104 are the same. This ensures that the driving force is the same when the actuator 1 moves up and down, which helps to improve the stability of the actuator 1 when it moves.

[0066] The gas turbine of an embodiment of the present invention is described below.

[0067] The gas turbine in this embodiment of the invention includes a servo system 100 and a compressor. The servo system 100 can be the servo system 100 described in the above embodiments, such as... Figure 1 As shown, the compressor includes a guide vane 200, which is drivenly connected to the piston 102 of the driver 1. For example, the guide vane 200 can be drivenly connected to the piston 102 of the driver 1 via a connecting mechanism.

[0068] When it is necessary to stop the gas supply to the combustion chamber of the gas turbine, hydraulic fluid can be supplied to the first chamber 103 of the actuator 1 and the hydraulic fluid in the second chamber 104 can be discharged, thereby closing the guide vane 200. When it is necessary to supply compressed air to the combustion chamber, hydraulic fluid can be supplied to the second chamber 104 of the actuator 1 and the hydraulic fluid in the first chamber 103 can be discharged.

[0069] The following describes the method for adjusting the guide vane 200 according to an embodiment of the present invention.

[0070] The guide vane 200 adjustment method of this invention includes the following steps:

[0071] S1: When directional control valve 2 malfunctions, the first valve 7 isolates directional control valve 2 and the second valve 8 is opened. For example, when all coils in directional control valve 2 are damaged, the valve core of directional control valve 2 cannot be driven to move. The first valve 7 can be energized and closed, thereby preventing hydraulic fluid from flowing through directional control valve 2. Then the second valve 8 can be energized and opened, allowing the third pipeline 5 and the fourth pipeline 6 to connect to the first chamber 103 and the second chamber 104 of the actuator 1 via the first valve 7, respectively.

[0072] It should be noted that in this embodiment, the first valve 7 is in the open state when not energized and in the closed state when energized; the second valve 8 is in the closed state when not energized and in the open state when energized.

[0073] S2: Referring to the speed of the gas turbine, the second valve 8 is intermittently closed to close the guide vane 200 in stages. Specifically, since the speed of the gas turbine decreases slowly, the intermittent closure of the second valve 8 can achieve a slow reduction in the compressed air supplied to the compressor, thereby matching the slow decrease in the speed of the gas turbine and avoiding the damage to the gas turbine that could be easily caused by a sudden shutdown of the gas supply.

[0074] In some embodiments, step S2 includes the following steps:

[0075] S21: Divide the speed of the gas turbine into multiple speed levels, and divide the closing angle of the guide vane 200 into multiple closing angles.

[0076] For example, as the speed of a gas turbine gradually decreases, the speed can be divided into a first speed level, a second speed level, and a third speed level. The speed of the first speed level is higher than that of the second speed level, and the speed of the second speed level is higher than that of the third speed level. Each of the first, second, and third speed levels represents a specific speed range.

[0077] The closing angle of the guide vane 200 can be divided into a first closing angle and a second closing angle, wherein the first closing angle is greater than the second closing angle.

[0078] S22: If the speed of the gas turbine decreases from a higher speed level to a lower speed level, then the second valve 8 is opened. For example, when the gas turbine decreases from the first speed level to the second speed level, the second valve 8 can be opened.

[0079] S23: Once the guide vane 200 rotates to the closing angle corresponding to the two speed levels in S22, close the second valve 8. For example, the first closing angle corresponds to the first speed level and the second speed level. When the gas turbine drops to the second speed level, the guide vane 200 can be adjusted to the first closing angle, thereby reducing the gas supply of the compressor. After the guide vane 200 is adjusted to the first closing angle, the second valve 8 can be closed, so that the guide vane 200 can be maintained at the first closing angle.

[0080] When the gas turbine speed drops from the second speed level to the third speed level, the guide vane 200 can be adjusted to the second closing angle, and then the second valve 8 can be closed.

[0081] S24: Repeat steps S22 to S23 above until the guide vane 200 is completely closed. Specifically, continuously repeat steps S22 to S23 above until the speed of the gas turbine drops to zero. At this time, the guide vane 200 is also completely closed, that is, the gas supply of the compressor is also zero.

[0082] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0083] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0084] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0085] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0086] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0087] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A servo system, characterized in that, include: A driver, the driver including a cylinder and a piston, the cylinder having a first chamber and a second chamber, the piston being slidably engaged between the first chamber and the second chamber; A reversing valve, a first pipeline, and a second pipeline, wherein the first pipeline connects the first chamber and the reversing valve, and the second pipeline connects the second chamber and the reversing valve; The third and fourth pipelines are connected to the reversing valve, and one of the third and fourth pipelines can be connected to one of the first and second pipelines when the reversing valve is activated, while the other of the third and fourth pipelines is connected to the other of the first and second pipelines. A first valve is disposed in the first pipeline and the second pipeline or in the third pipeline and the fourth pipeline, and the first valve is adapted to isolate the reversing valve and the actuator; The system comprises a second valve, a fifth pipeline, and a sixth pipeline. The fifth pipeline connects the first pipeline and the third pipeline, and the sixth pipeline connects the second pipeline and the fourth pipeline. The second valve is located on the fifth pipeline and the sixth pipeline.

2. The servo system according to claim 1, characterized in that, include: A sensor, the sensor being adapted to monitor the displacement of the piston and output a displacement signal; A control device that receives the displacement signal and opens or closes the directional valve and / or the first valve and / or the second valve when the piston moves to a set position.

3. The servo system according to claim 2, characterized in that, The device includes a frame, and the driver, the reversing valve, the first pipeline, the second pipeline, the third pipeline, the fourth pipeline, the first valve, the second valve, the fifth pipeline, the sixth pipeline, the sensor, and the control device are integrated into the frame.

4. The servo system according to claim 1, characterized in that, include: A first throttle and a second throttle, wherein the first throttle is disposed in the first pipeline and is adapted to regulate the flow rate of the first pipeline, and the second throttle is disposed in the second pipeline and is adapted to regulate the flow rate of the second pipeline; And / or, a third throttle and a fourth throttle, the third throttle being disposed in the fifth pipeline and adapted to regulate the flow rate of the fifth pipeline, and the fourth throttle being disposed in the sixth pipeline and adapted to regulate the flow rate of the sixth pipeline.

5. The servo system according to claim 4, characterized in that, The first valve is located in the first pipeline and the second pipeline, and the first throttle and the second throttle are located downstream of the first valve.

6. The servo system according to claim 1, characterized in that, The third pipeline is a liquid inlet pipeline, and the third pipeline is equipped with a third valve. The third valve is located upstream of the connection between the fifth pipeline and the third pipeline, and the third valve is adapted to open and close the third pipeline.

7. The servo system according to claim 6, characterized in that, The third pipeline is equipped with a filter, which is located upstream of the connection between the fifth pipeline and the third pipeline, and downstream of the third valve.

8. The servo system according to claim 1, characterized in that, The fourth pipeline is a return pipeline, and the fourth pipeline is equipped with a one-way valve, which is located downstream of the connection between the sixth pipeline and the fourth pipeline.

9. The servo system according to claim 1, characterized in that, The reversing valve includes a valve core and multiple coils, which are arranged in parallel and are adapted to drive the valve core to move to achieve reversing switching of the reversing valve.

10. The servo system according to any one of claims 1-9, characterized in that, The reversing valve is a servo valve and / or the first valve is a solenoid valve and / or the second valve is a solenoid valve.

11. A gas turbine, characterized in that, The device includes a servo system and a compressor, wherein the servo system is the servo system according to any one of claims 1-10, and the compressor includes guide vanes that are connected to the piston drive of the driver.

12. A method for adjusting the guide vanes of a gas turbine according to claim 11, characterized in that, Includes the following steps: S1: When the reversing valve fails, the first valve is used to isolate the reversing valve and the second valve is opened; S2: Referencing the rotational speed of the gas turbine, intermittently close the second valve to close the guide vanes in stages.

13. The guide vane adjustment method according to claim 12, characterized in that, Step S2 includes the following steps: S21: Divide the speed of the gas turbine into multiple speed levels, and divide the closing angle of the guide vanes into multiple closing angles; S22: If the speed of the gas turbine drops from the previous higher speed level to the next lower speed level, then the second valve is opened; S23: Once the guide vane rotates to the closing angle corresponding to the two speed levels in S22, close the second valve; S24: Repeat steps S22 to S23 above until the guide vane is completely closed.

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