An online test slide valve and its test method

Abstract

The present invention relates to the field of mechanical technology, and in particular to an online test slide valve, comprising a housing, a slide valve, a valve cover, a bracket, a threaded sleeve, a stud, a rod, and a handle. The center of the housing is machined with an axial hole and an annular cavity. The side of the annular cavity inside the housing is provided with a communicating oil circuit interface, and the oil circuit interface is provided in multiple forms. A valve is installed on one side of the bottom of the housing, a steel ball is provided at the bottom of the housing at the upper end of the valve, a stud is installed inside the housing, and a slide valve is installed at the lower end of the stud inside the housing. In the present invention, the unit can be tested for mechanical tripping without stopping the unit, which is convenient to use. A sealing nut is provided to ensure the sealing between the adjusting screw and the housing. A boss is provided inside the valve cover. The valve cover is embedded and fixed to the housing, which is stable, safe, and reliable. The slide valve is carburized, which is beneficial to improving the fatigue strength of the slide valve, improving the strength, impact toughness, and wear resistance of the slide valve, thereby extending the service life of the slide valve.

Description

Technical Field

[0001] The present invention relates to the field of mechanical technology, in particular to an online test slide valve and a test method thereof. Background Art

[0002] Most of the sliding valves currently available on the market have poor sealing performance during experiments, and the connections between the various components are not safe and reliable enough. In particular, the working efficiency is relatively low when switching oil circuits. Therefore, to address the above problems, an online test sliding valve and its test method are proposed. Summary of the Invention

[0003] The object of the present invention is to provide an online test slide valve and a test method thereof to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] An online test sliding valve comprises a housing, a sliding valve, a valve cover, a bracket, a threaded sleeve, a stud, a rod and a handle. An axial hole and an annular cavity are machined in the center of the housing. The side of the annular cavity inside the housing is provided with a communicating oil circuit interface, and there are multiple oil circuit interfaces. A valve is installed on one side of the bottom of the housing. A steel ball is provided at the upper end of the valve at the bottom of the housing. A stud is installed inside the housing. A sliding valve is installed at the lower end of the stud in the housing. A valve cover is installed at the upper end of the housing. A bracket is installed on one side of the top of the valve cover. The upper end of the sliding valve passes through the middle of the valve cover. The bracket One side of the frame is rotatably connected to one end of the support fork through pins a and pin b, and the front end of the support fork is connected to the bracket through an adjusting screw. A sealing nut is provided at the front end of the adjusting screw on one side of the shell. The left side of the support fork is fixedly connected to the right end of the rod, and a ball button is welded to the left end of the rod. Round steel is installed on one side of the upper and lower ends of the shell. A threaded sleeve is sleeved on the upper end of the stud, and a threaded pin is provided on the threaded sleeve. The support fork is connected to the threaded sleeve through the threaded pin, and the bottom of the threaded sleeve is connected to the sliding valve through an elastic cylindrical pin. The top of the stud is fixedly connected to the handle through a screw a.

[0006] Preferably, the axial hole inside the shell is communicated with the annular cavity inside the shell.

[0007] Preferably, the sliding valve slides up and down on the stud and is connected to the oil circuit.

[0008] Preferably, a sealing ring is installed at the connection between the valve and the housing.

[0009] Preferably, an O-type sealing ring a is provided between the valve cover and the housing, and an O-type sealing ring b is provided between the valve cover and the bracket.

[0010] Preferably, a washer is provided at the connection between the screw a and the handle.

[0011] Preferably, both sides of the valve cover are fixedly connected to the top of the shell by screws b, and the upper ends of both sides of the valve cover are fixedly connected to the bracket by screws c.

[0012] A method for testing an online sliding valve comprises the following steps:

[0013] 1) The pressure oil enters the housing from port P, and the slide valve is pushed to the normal operating position under the action of oil pressure. At this time, PA and E1-E2 are the passages. The pressure oil flows to the emergency trip throttle through the test slide valve, and then the quick-close oil flows from the emergency trip throttle through the test slide valve and from the E2 port to the starting regulator and quick-close valve;

[0014] 2) To conduct the test, first slowly press down the ball button, and continue to press the ball button after the displacement is limited. At this time, the slide valve is in position b, PA is still a passage, and E1-E2 is blocked. However, at this time, the central axial hole and radial oil groove of the slide valve connect A and E2. Although the emergency trip valve no longer outputs quick-closing oil to the downstream, the pressure oil bypasses the emergency trip throttle to the starting regulator, so the emergency trip throttle and quick-closing valve remain in normal working condition. Then slowly turn the handle clockwise, and the handle stud pushes the slide valve down to position a, and the corresponding pressure oil The test oil enters the emergency safety device from the center hole of the slide valve through the four semicircular windows of the upper groove and the H oil port, and passes through the pipeline connector from the center hole of the rotor. As the handle is slowly turned, the test oil circuit builds up pressure in a controlled manner. At this time, pay attention to observe the indication of the test oil pressure gauge. When the oil pressure rises to a certain value, although the unit has not increased speed, the emergency safety device hammer is struck out by the centrifugal force of the oil column to trip the emergency trip throttle. At this time, although the emergency trip throttle has been activated, P-E2 is still a passage, so the quick-closing valve is not disturbed and the unit maintains normal operation.

[0015] 3) After the throttle is actuated, immediately rotate the handle in the opposite direction (i.e., return it to position b). Cut off the test oil to reset the emergency trip device. Then, release the ball knob. The spool will automatically move upward under the action of the oil pressure. Due to the hydraulic damping zone between the spool and the valve cover, the upward movement of the spool is delayed. Its reset speed can be controlled by the adjusting screw on the side of the housing. The spool reset time is 10 to 20 seconds. After the ball knob is released, during the spool reset process (from position b to position e), when the spool is in positions c and d, the pressure oil connects with the switch oil and flows through the M port to the emergency trip throttle, causing it to automatically reset. At the conclusion of the test, the system returns to normal operation.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. When the emergency safety device is tested within the operating speed range, the emergency safety device and the throttle are activated, but the state of the quick-closing valve does not change. Therefore, the unit will not interrupt operation. The unit mechanical trip can be tested without stopping the unit, which is convenient for use.

[0018] 2. Use the sealing nut to ensure the sealing between the adjusting screw and the housing.

[0019] 3. The inside of the valve cover is equipped with a boss, and the valve cover and the housing are inlaid and fixed, which is stable, safe and reliable.

[0020] 4. The slide valve is carburized. Carburizing treatment generates compressive internal stress on the surface of the slide valve, which is beneficial to improving the fatigue strength of the slide valve, and improving the strength, impact toughness and wear resistance of the slide valve, thereby extending the service life of the slide valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the overall structure of an online test slide valve and its test method according to the present invention;

[0022] Figure 2 This is a front view of an online test slide valve and a test method thereof in a first working state according to the present invention;

[0023] Figure 3 This is a front view of an online test slide valve and a test method thereof in a second working state of the present invention;

[0024] Figure 4 The figure is a schematic diagram of the internal structure of a shell of an online test slide valve and a test method thereof according to the present invention.

[0025] Figure 5 This is a top view of an online test slide valve and its test method according to the present invention.

[0026] Figure 6 This is a structural diagram of the upper end of an online test slide valve and its test method according to the present invention.

[0027] Figure 7 The present invention discloses an online test slide valve and a test method thereof for a normal operating oil circuit.

[0028] Figure 8 The present invention discloses an on-line test slide valve and a test method thereof, and a test state oil circuit diagram.

[0029] In the figure: 1. Housing; 2. Sliding valve; 3. Valve cover; 4. Bracket; 5. Threaded sleeve; 6. Stud; 7. Support fork; 8. Rod; 9. Adjusting screw; 10. Round steel; 11. Ball knob; 12. Handle; 13. Threaded pin; 14. Pin a; 15. Pin b; 16. Screw a; 17. Washer; 18. Screw b; 19. Screw c; 20. O-ring a; 21. O-ring b; 22. Sealing nut; 23. Valve; 24. Steel ball; 25. Elastic cylindrical pin; 26. Sealing ring. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] See also Figure 1-8The present invention provides a technical solution: an online test slide valve, comprising a housing 1, a slide valve 2, a valve cover 3, a bracket 4, a threaded sleeve 5, a stud 6, a rod 8 and a handle 12. The center of the housing 1 is processed with an axial hole and an annular cavity. The axial hole inside the housing 1 is connected to the annular cavity inside the housing 1. The side of the annular cavity inside the housing 1 is provided with a communicating oil circuit interface, and the oil circuit interface is provided with multiple. A valve 23 is installed on one side of the bottom of the housing 1. A sealing ring 26 is installed at the connection between the valve 23 and the housing 1. The setting of the sealing ring 26 strengthens the sealing between the valve 23 and the housing 1. A steel ball 24 is provided at the upper end of the valve 23 at the bottom of the housing 1. The housing 1 A stud 6 is installed inside, and a slide valve 2 is installed at the lower end of the stud 6 in the housing 1. The slide valve 2 slides up and down on the stud 6 and is connected to the oil circuit. The slide valve 2 is carburized. The carburizing treatment causes compressive internal stress to be generated on the surface of the slide valve 2, which is beneficial to improving the fatigue strength of the slide valve 2, improving the strength, impact toughness and wear resistance of the slide valve 2, thereby extending the service life of the slide valve 2. A valve cover 3 is installed on the upper end of the housing 1. Both sides of the valve cover 3 are fixedly connected to the top of the housing 1 by screws b18, which enhances the firmness between the valve cover 3 and the housing 1. The middle part of the inside of the valve cover 3 is in the shape of a boss. The boss is set inside the valve cover 3, and the valve cover 3 is inlaid with the housing 1. Fixed, stable, safe and reliable, the upper ends of both sides of the valve cover 3 are fixedly connected to the bracket 4 by screws c19, strengthening the firmness of the bracket 4, an O-ring a20 is provided between the valve cover 3 and the housing 1, the O-ring a improves the sealing between the housing 1 and the valve cover 3, and an O-ring b21 is provided between the valve cover 3 and the bracket 4, the setting of the O-ring b improves the sealing effect between the valve cover 3 and the bracket 4, one side of the top of the valve cover 3 is equipped with a bracket 4, and the upper end of the stud 6 passes through the middle of the valve cover 3, one side of the bracket 4 is rotatably connected to one end of the support fork 7 by the pin a14 and the pin b15, and the front end of the support fork 7 is adjusted by the adjusting screw 9 It is connected to the bracket 4, and a sealing nut 22 is provided at the front end of the adjusting screw 9 on one side of the shell 1. The setting of the sealing nut 22 ensures the sealing. The left side of the support fork 7 is fixedly connected to the right end of the rod 8, and a ball button 11 is welded to the left end of the rod 8. Round steel 10 is installed on one side of the upper and lower ends of the shell 1. A threaded sleeve 5 is mounted on the upper end of the stud 6, and a threaded pin 13 is provided on the threaded sleeve 5. The bottom of the threaded sleeve 5 is connected to the stud 6 through an elastic cylindrical pin 25. The top of the stud 6 is fixedly connected to the handle 12 by a screw a16. A washer 17 is provided at the connection between the screw a16 and the handle 12 to enhance the firmness between the screw a16 and the handle 12.

[0032] A method for testing an online sliding valve comprises the following steps:

[0033] 1) Pressure oil enters the housing 1 from port P, and the slide valve 2 is pushed to the Figure 1The normal operating position is shown. At this time, PA and E1-E2 are passages. The pressure oil flows to the emergency trip throttle through the test slide valve 2, and then the quick-closing oil flows from the emergency trip throttle through the test slide valve 2 from the E2 interface to the starting regulator and the quick-closing valve.

[0034] 2) To test, first slowly press down the ball button 11, and continue to press the ball button 11 after the displacement is limited. At this time, the slide valve 2 is in Figure 8 In the middle b position, PA is still a passage, and E1-E2 is blocked. However, at this time, the central axial hole and radial oil groove of slide valve 2 connect A and E2. Although the emergency trip valve no longer outputs quick-closing oil to the downstream, the pressure oil bypasses the emergency trip throttle to the starting regulator, so the emergency trip throttle and quick-closing valve remain in normal working condition. Then slowly turn the handle 12 clockwise, and the stud of the handle 12 pushes the slide valve 2 down to position a, and the corresponding pressure oil is connected to the H oil port from the center hole of the slide valve 2 through the 4 semicircular windows of the upper groove, so that the test oil enters the emergency safety device from the center hole of the rotor through the pipeline connector. As the handle 12 is slowly turned, the test oil oil circuit builds up pressure in a controlled manner. At this time, pay attention to observe the indication of the test oil pressure gauge. When the oil pressure rises to a certain value (see notes), although the unit has not increased speed, the emergency safety device hammer is struck out by the centrifugal force of the oil column, causing the emergency shut-off throttle to trip. The tripping of the emergency shut-off throttle is used as the basis for judging whether the emergency safety device hammer is struck. At this time, although the emergency shut-off throttle has been activated, P-E2 is still a passage, so the quick-closing valve is not disturbed and the unit maintains normal operation.

[0035] 3) After the throttle is actuated, immediately rotate the handle 12 in the opposite direction, i.e., return it to position b. This will cut off the test oil and reset the emergency trip device. Then, release the ball knob 11. Spool valve 2 will automatically move upward under the action of the oil pressure. Due to the hydraulic damping area between spool valve 2 and valve cover 3, the upward movement of spool valve 2 is delayed. Its reset speed can be controlled by the adjusting screw 9 on the side of housing 1. The reset time of spool valve 2 is 10 to 20 seconds. After the handle 12 is released, during the reset process of spool valve 2, that is, from position b to position e, when spool valve 2 is in positions c and d, the pressure oil connects with the switch oil and flows through the M interface to the emergency trip throttle, causing it to automatically reset. At the end of the test, the system returns to normal operation.

[0036] Working principle: Emergency safety device test slide valve;

[0037] The function of the test slide valve is to check whether the emergency safety device is operating normally during the normal operation of the turbine without increasing the operating speed or interrupting the operation.

[0038] Normally, when the emergency safety device is operating, the emergency trip throttle trips, causing the quick-close valve to close and the unit to shut down. However, in units equipped with an emergency safety device tester slide valve, when the emergency safety device is tested within the operating speed range, the emergency safety device and the trip throttle will operate, but the quick-close valve will not change, so the unit will not be interrupted. After the test is completed and the test slide valve is reset, if the unit overspeeds and the emergency safety device is activated, the throttle will trip and the quick-close valve will close, causing the unit to shut down in an emergency, just as in the case without the test slide valve.

[0039] Operation process: Figure 7 This is the oil circuit diagram of the test slide valve during normal operation of the unit. Figure 1 The pressure oil enters the housing 1 from the port P, and the slide valve 2 is pushed to the Figure 1 The normal operating position is shown. At this time, PA and E1-E2 are passages. The pressure oil flows to the emergency trip throttle through the test slide valve 2, and then the quick-closing oil flows from the emergency trip throttle through the test slide valve 2 from the E2 interface to the starting regulator and the quick-closing valve.

[0040] When testing, first slowly press down the ball button 11, and continue to press the ball button 11 after the displacement is limited. At this time, the slide valve 2 is in Figure 8 In the middle b position, PA is still a passage, and E1-E2 is blocked. However, at this time, the central axial hole and radial oil groove of slide valve 2 connect A and E2. Although the emergency trip valve no longer outputs quick-closing oil to the downstream, the pressure oil bypasses the emergency trip throttle to the starting regulator, so the emergency trip throttle and quick-closing valve remain in normal working condition. Then slowly turn the handle 12 clockwise, and the stud of the handle 12 pushes the slide valve 2 down to position a, and the corresponding pressure oil is connected to the H oil port from the center hole of the slide valve 2 through the 4 semicircular windows of the upper groove, so that the test oil enters the emergency safety device from the center hole of the rotor through the pipeline connector. As the handle 12 is slowly turned, the test oil oil circuit builds up pressure in a controlled manner. At this time, pay attention to observe the indication of the test oil pressure gauge. When the oil pressure rises to a certain value (see notes), although the unit has not increased speed, the emergency safety device hammer is struck out by the centrifugal force of the oil column, causing the emergency shut-off throttle to trip. The tripping of the emergency shut-off throttle is used as the basis for judging whether the emergency safety device hammer is struck. At this time, although the emergency shut-off throttle has been activated, P-E2 is still a passage, so the quick-closing valve is not disturbed and the unit maintains normal operation.

[0041] After the throttle is actuated, the handle 12 should be immediately rotated counterclockwise, i.e., returned to position b. This will cut off the test oil and reset the emergency trip device. The ball knob 11 should then be released, and the spool valve 2 will automatically move upward under the action of the oil pressure. Due to the hydraulic damping zone between the spool valve 2 and the valve cover 3, the upward movement of the spool valve 2 is delayed. Its reset speed can be controlled by the adjusting screw 9 on the side of the housing 1. The reset time of the spool valve 2 is 10 to 20 seconds. During the reset process of the spool valve 2 after the handle 12 is released, i.e., from position b to position e, when the spool valve 2 is in positions c and d, the pressure oil connects with the switch oil and flows through the M interface to the emergency trip throttle, causing it to automatically reset. At the end of the test, the system returns to normal operation.

[0042] When the steam turbine is equipped with an emergency safety device test slide valve, in order to ensure that the quick-closing valve can open normally, an auxiliary slide valve must be used and the throttle orifice plate in the emergency shut-off throttle must be removed.

[0043] Note: The oil pressure measured by the fly hammer during the test is a reference value, not a specified value. The oil pressure values measured at different speeds within the operating range will vary. Therefore, the test should be conducted at the same speed whenever possible. If the test oil pressures are consistent between two consecutive tests, the emergency device is functioning properly. For the first test after the unit is commissioned, the factory test data (see the product certificate) can be used as a reference, or a new benchmark can be established through separate measurements.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An online test slide valve, characterized by: The invention comprises a housing (1), a sliding valve (2), a valve cover (3), a bracket (4), a threaded sleeve (5), a stud (6), a rod (8) and a handle (12), wherein the center of the housing (1) is processed with an axial hole and an annular cavity, the side of the annular cavity inside the housing (1) is provided with a communicating oil circuit interface, and the oil circuit interface is provided with multiple, a valve (23) is installed on one side of the bottom of the housing (1), a steel ball (24) is provided at the upper end of the valve (23) at the bottom of the housing (1), a stud (6) is installed inside the housing (1), a sliding valve (2) is installed at the lower end of the stud (6) in the housing (1), the sliding valve (2) is carburized, a valve cover (3) is installed on the upper end of the housing (1), and the middle part of the inside of the valve cover (3) is convex, a bracket (4) is provided on one side of the top of the valve cover (3), and the sliding valve (2) is provided with a plurality of screw terminals. The upper end passes through the middle of the valve cover (3), and one side of the bracket (4) is rotatably connected to one end of the support fork (7) through a pin a (14) and a pin b (15). A sealing nut (22) is provided at the front end of the adjusting screw (9) on one side of the housing (1). The left side of the support fork (7) is fixedly connected to the right end of the rod (8), and a ball button (11) is welded to the left end of the rod (8). Round steel (10) is installed on one side of the upper and lower ends of the housing (1). The upper end of the stud (6) is covered with a threaded sleeve (5), and a threaded pin (13) is provided on the threaded sleeve (5). The support fork (7) is connected to the threaded sleeve (5) through the threaded pin (13). The bottom of the threaded sleeve (5) is connected to the slide valve (2) through an elastic cylindrical pin (25). The top of the stud (6) is fixedly connected to the handle (12) through a screw a (16); The axial hole inside the housing (1) is in communication with the annular cavity inside the housing (1); The slide valve (2) slides up and down along with the stud (6) and is connected to different oil circuits.

2. The online test slide valve according to claim 1, characterized in that: A sealing ring (26) is installed at the connection between the valve (23) and the housing (1).

3. The online test slide valve according to claim 1, characterized in that: An O-type sealing ring a (20) is provided between the valve cover (3) and the housing (1), and an O-type sealing ring b (21) is provided between the valve cover (3) and the stud (6).

4. The online test slide valve according to claim 1, characterized in that: A washer (17) is provided at the connection between the screw a (16) and the handle (12).

5. The online test slide valve according to claim 1, characterized in that: Both sides of the valve cover (3) are fixedly connected to the top of the housing (1) via screws b (18), and both upper ends of the valve cover (3) are fixedly connected to the bracket (4) via screws c (19).

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