Multifunctional Butterfly Valve for Steam Turbine

Abstract

The present invention relates to a multifunctional butterfly valve for steam turbine, comprising a butterfly valve and a control device; the characteristics are: the control device is composed of a cylinder and a pressure control valve; the pressure control valve adopts a spring-type safety valve, which comprises a control valve body, a valve cover and a pressure setting device, and uses the medium pressure of the butterfly valve inlet channel to control the state of the cylinder through the pressure control valve to automatically control the opening or closing of the butterfly valve, and has the characteristics of small size, simple structure, low cost, etc. The multifunctional butterfly valve is suitable for protecting the safety of equipment on the medium pipeline of the system such as steam turbine, water turbine, pump shaft, etc.

Description

Technical Field

[0001] The present invention belongs to the field of valves, and in particular relates to a butterfly valve, which is applicable to a multifunctional butterfly valve on a gas medium pipeline of a steam turbine system for protecting the safety of equipment. Background Art

[0002] In the medium delivery pipeline of the steam turbine system, in addition to the on / off valves for fluid on / off control, it is also necessary to install fast-closing and slow-closing check valves to prevent the backflow of the medium. At present, hydraulically controlled butterfly valves are widely used in steam turbine systems. Their structure consists of a hydraulic station and a butterfly valve. The hydraulic station controls the opening or closing of the butterfly valve to achieve on / off control and check control of the fluid. Its main disadvantages are complex structure, large product volume, and high manufacturing cost. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a multifunctional butterfly valve for steam turbines which utilizes pipeline medium to automatically control the opening, closing and check functions of the butterfly valve and has a simple structure, a small size and a low manufacturing cost.

[0004] The technical solution of the present invention comprises a butterfly valve and a control device, wherein the butterfly valve comprises a valve body, a butterfly plate and a valve stem; the control device comprises a cylinder and a pressure control valve; the cylinder comprises a cylinder body and a piston, wherein the cylinder body comprises a left cylinder body and a right cylinder body, wherein the piston comprises a left piston and a right piston, wherein the left piston and the right piston are respectively installed in the inner cavities of the left cylinder body and the right cylinder body, wherein the facing planes of the two are fixedly connected by a piston rod, wherein the middle part of the piston rod is connected to the valve stem through a transmission device, and a thrust spring is installed in the rodless cavity of the right cylinder body; the pressure control valve adopts a spring-type safety valve, wherein the spring-type safety valve comprises a control valve body, a valve cover and a pressure setting device. The control valve body inner cavity is connected with the inlet, the control port and the discharge port, the inlet is connected with the valve body inlet channel through a pipeline, the pressure setting device is installed in the valve cover inner cavity, and its structure includes a push rod, a spring and an adjusting nut; the control port is connected with the rodless cavity of the left cylinder body through a pipeline, a valve disc is arranged at the inlet of the control valve body inner cavity, an axial guide hole is arranged between the control valve body inner cavity and the valve cover inner cavity, the discharge port is located on the side wall of the axial guide hole, the lower end of the push rod touches the center of the upper end face of the valve disc, the lower plane of the valve disc is provided with a sealing surface which cooperates with the upper end face of the inlet, and the upper plane of the valve disc is provided with a sealing surface which cooperates with the lower end face of the axial guide hole.

[0005] An axial guide is used between the push rod and the axial guide hole, and an axial flow channel connecting the inner cavity of the control valve body and the discharge port is provided between the matching surfaces of the two; the valve disc is movably embedded in the guide hole between the inner cavity of the control valve body and its inlet, and an axial flow channel is provided between the outer cylindrical surface of the valve disc and the guide hole.

[0006] A guide column is arranged in the axial guide hole, the lower end of the push rod is installed on the center of the upper end surface of the guide column, the push column is installed between the center of the lower end surface of the guide column and the center of the upper end surface of the valve disc, and an axial flow channel connecting the inner cavity of the control valve body and the discharge port is arranged between the outer cylindrical surface of the guide column and the axial guide hole; the valve disc is movably embedded in the guide hole between the inner cavity of the control valve body and its inlet, and an axial flow channel is arranged between the outer cylindrical surface of the valve disc and the guide hole.

[0007] The upper end of the push rod is provided with a valve opening locking device and a valve closing locking device.

[0008] The valve opening locking device is composed of a valve opening solenoid valve and a valve opening connecting rod. The left end of the valve opening connecting rod is hingedly mounted on the valve cover, the middle part of the valve opening connecting rod is located below the lifting nut fixedly mounted on the top rod, and the right end of the valve opening connecting rod is hingedly connected to the lower end of the driving rod of the valve opening solenoid valve; the valve closing locking device is composed of a valve closing solenoid valve and a valve closing connecting rod. The left end of the valve closing connecting rod is hingedly connected to the lower end of the driving rod of the valve closing solenoid valve, the middle part of the valve closing connecting rod is hingedly mounted on the valve cover, and the right end of the valve closing connecting rod is located directly above the top rod. The valve bodies of the valve closing solenoid valve and the valve bodies of the valve opening solenoid valve are fixed to the valve bodies through mounting plates.

[0009] The transmission device is composed of a shift fork fixed on the upper end of the valve stem and a shift rod vertically fixed on the middle part of the piston rod, and the shift rod is movably nested in the fork opening of the shift fork.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the control device of the butterfly valve is composed of a cylinder and a pressure control valve, and the medium pressure in the inlet channel of the valve body is used to control the state of the cylinder through the pressure control valve to automatically control the opening or closing of the butterfly valve, and it has the characteristics of small size, simple structure, low cost, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the present invention.

[0012] Figure 2 The present invention Figure 1 Schematic diagram of the structure of the middle cylinder.

[0013] 1. Valve body, 2. Butterfly plate, 3. Valve stem, 4. Left cylinder body, 5. Right cylinder body, 6. Left piston, 7. Right piston, 8. Piston rod, 9. Thrust spring, 10. Push rod, 11. Fork, 12. Control valve body, 13. Valve cover, 14. Inlet, 15. Control port, 16. Discharge port, 17. Push rod, 18. Spring, 19. Adjusting nut, 20. Valve disc, 21. Guide column, 22. Push column, 23. Opening solenoid valve, 24. Opening connecting rod, 25. Closing solenoid valve, 26. Closing connecting rod, 27. Lifting nut. DETAILED DESCRIPTION

[0014] like Figure 1The multifunctional butterfly valve for steam turbine shown in the figure comprises a butterfly valve and a control device, wherein the butterfly valve comprises a valve body 1, a butterfly plate 2 and a valve stem 3, and the butterfly valve adopts a three-eccentric structure; the characteristics are as follows: the control device comprises a cylinder and a pressure control valve; the cylinder comprises a cylinder body and a piston, wherein the cylinder body comprises a left cylinder body 4 and a right cylinder body 5, and the piston comprises a left piston 6 and a right piston, wherein the left piston 6 and the right piston 7 are respectively installed in the inner cavity of the left cylinder body 4 and the right cylinder body 5, and the facing planes of the two are fixedly connected by a piston rod 8, so that the left piston 6 and the right piston 7 form a linkage structure The middle part of the piston rod 8 is connected to the valve stem 3 through a transmission device. A thrust spring 9 is installed in the rodless cavity of the right cylinder 5. When there is no pressure in the rodless cavity of the left cylinder 4, the thrust spring 9 pushes the left piston 6 and the right piston 7 to move to the right, and the piston rod 8 drives the valve stem 3 to rotate counterclockwise to close the butterfly plate 2. The pressure control valve adopts a spring-type safety valve, which includes a control valve body 12, a valve cover 13 and a pressure setting device. The valve cover 13 is fixedly installed on the upper end of the valve body 12. The inner cavity of the control valve body 12 is connected to the inlet 14, The control port 15 and the discharge port 16, the inlet 14 are connected with the inlet channel of the valve body 1 through a pipeline. The pressure setting device is installed in the inner cavity of the valve cover 13, and its structure includes a push rod 17, a spring 18 and an adjusting nut 19. The adjusting nut 19 is threadedly matched with the inner screw hole at the center of the upper end of the valve cover 13 by an external thread. The upper end of the push rod 17 passes through the center hole of the adjusting nut 19 and extends to the upper end surface of the adjusting nut 19. The spring 18 is installed between the upper and lower spring seats on the push rod 17, and the lower end of the adjusting nut 19 presses on the upper plane of the upper spring seat. The control port 15 is connected with the rodless cavity of the left cylinder body 4 through a pipeline, a valve flap 20 is arranged at the inlet of the inner cavity of the control valve body 12, an axial guide hole is arranged between the inner cavity of the control valve body 12 and the inner cavity of the valve cover 13, the discharge port 16 is located on the side wall of the axial guide hole and is connected with the axial guide hole, the lower end of the push rod 17 passes through the axial guide hole and touches the center of the upper end face of the valve flap 20, the lower plane of the valve flap 20 is provided with a sealing surface which cooperates with the upper end face of the inlet 14, and the upper plane of the valve flap 20 is provided with a sealing surface which cooperates with the lower end face of the axial guide hole. When the medium pressure of the inlet channel of the valve body 1 is lower than the set pressure of the pressure setting device, the valve disc 20 is pressed and sealed with the sealing surface of the upper end of the inlet 14 by the downward thrust of the push rod 17, and the rodless chamber of the left cylinder 4 is connected with the discharge port 16 through the control port 15, the inner chamber of the control valve body 12, and the axial guide hole. The left piston 6 and the right piston 7 are on the left side under the thrust of the thrust spring 9, and the butterfly plate 2 is in a closed state; when the medium pressure of the inlet channel of the valve body 1 is higher than the set pressure of the pressure setting device, the valve disc 20 moves upward under the action of the medium pressure of the inlet 14, and the sealing surface of the upper plane and the sealing surface of the lower plane of the axial guide hole are sealed with each other, and the inner chamber of the control valve body 12 is separated from the discharge port 16. The medium of the inlet channel of the valve body 1 enters the rodless chamber of the left cylinder 4 through the inlet 14 and the control port 15, pushing the left piston 6 and the right piston 7 to move to the right to overcome the elastic force of the thrust spring 9, and opening the butterfly plate 2, realizing the automatic control of the opening, closing and check function of the butterfly valve by the medium pressure of the inlet channel of the valve body 1.It is particularly suitable for system conditions such as steam turbines, water turbines, and pump stations. When the steam turbines, water turbines, and pump stations are started, the pressure in the inlet channel of valve body 1 rises and the butterfly valve opens automatically. When the steam turbines, water turbines, and pump stations are shut down, the pressure in the inlet channel of valve body 1 is lost and the butterfly valve closes automatically to prevent the backflow of the medium and protect the safety of equipment such as steam turbines, water turbines, and pump stations.

[0015] An axial guide is used between the push rod 17 and the axial guide hole, and an axial flow channel connecting the inner cavity of the control valve body 12 and the discharge port 16 is provided between the mating surfaces of the two. The axial flow channel controls the discharge speed of the medium pressure in the rodless cavity of the left cylinder 4, thereby realizing the slow closing function of the butterfly valve; the valve flap 20 is movably embedded in the guide hole between the inner cavity of the control valve body 12 and its inlet 14, so that the valve flap 20 moves up and down in the guide hole, and an axial flow channel is provided between the outer cylindrical surface of the valve flap 20 and the guide hole, so that when the valve flap 20 is opened, the medium of the inlet 14 enters the inner cavity of the control valve body 12 through the axial flow channel.

[0016] A guide column 21 is arranged in the axial guide hole, the lower end of the push rod 17 is mounted on the center of the upper end surface of the guide column 21, and a push column 22 is installed between the center of the lower end surface of the guide column 21 and the center of the upper end surface of the valve disc 20. An axial flow channel connecting the inner cavity of the control valve body 12 and the discharge port 16 is provided between the outer cylindrical surface of the guide column 21 and the axial guide hole; the valve disc 20 is movably embedded in the guide hole between the inner cavity of the control valve body 12 and the inlet 14, and an axial flow channel is provided between the outer cylindrical surface of the valve disc 20 and the guide hole.

[0017] The upper end of the push rod 17 is provided with a valve opening locking device and a valve closing locking device.

[0018] The valve opening locking device is composed of a valve opening solenoid valve 23 and a valve opening connecting rod 24. The left end of the valve opening connecting rod 24 is hingedly mounted on the valve cover 13. The middle part of the valve opening connecting rod 24 is located below the lifting nut 27 fixedly mounted on the push rod 17. The right end of the valve opening connecting rod 24 is hingedly connected to the lower end of the driving rod of the valve opening solenoid valve 23. When the valve opening solenoid valve 23 is energized, the driving rod moves upward to pull up the push rod 17. The medium pressure in the inlet channel of the valve body 1 only needs to be greater than the elastic force of the thrust spring 9 to open the butterfly valve. The valve closing locking device is composed of a valve closing solenoid valve 23 and a push rod 9. The solenoid valve 25 is composed of a valve closing connecting rod 26. The left end of the valve closing connecting rod 26 is hinged to the lower end of the driving rod of the valve closing solenoid valve 25. The middle part of the valve closing connecting rod 26 is hinged and installed on the valve cover 13. The right end of the valve closing connecting rod 26 is located directly above the push rod 17. When the valve closing solenoid valve 25 is energized, its driving rod moves up, the left end of the valve closing connecting rod 26 rises and the right end presses down, pressing the push rod 17 and the valve disc 20 against the inlet 14, preventing the valve disc 20 from opening, locking the butterfly valve in a closed state, protecting the safety of equipment maintenance, and playing the role of a maintenance valve. The valve closing solenoid valve 25 and the valve opening solenoid valve 23 are fixed to the control valve body 12 through a mounting plate. The valve closing solenoid valve 25 and the valve opening solenoid valve 23 can also use manual pull rods.

[0019] The transmission device is composed of a shift fork 11 fixed to the upper end of the valve stem 3 and a shift rod 10 vertically fixed to the middle of the piston rod 8. The shift rod 10 is movably nested in the fork of the shift fork 11. Figure 2 When the piston rod 8 moves left and right, the valve stem 3 is driven to rotate 90 degrees through the fork 11.

Claims

1. A multifunctional butterfly valve for a steam turbine, comprising a butterfly valve and a control device, wherein the butterfly valve comprises a valve body (1), a butterfly plate (2) and a valve stem (3); wherein: The control device is composed of a cylinder and a pressure control valve; the cylinder comprises a cylinder body and a piston, the cylinder body comprises a left cylinder body (4) and a right cylinder body (5), the piston comprises a left piston (6) and a right piston (7), the left piston (6) and the right piston (7) are respectively installed in the inner cavity of the left cylinder body (4) and the right cylinder body (5), the facing planes of the two are fixedly connected by a piston rod (8), the middle part of the piston rod (8) is connected to the valve stem (3) through a transmission device, and a thrust spring (9) is installed in the rodless cavity of the right cylinder body (5); the pressure control valve adopts a spring-type safety valve, which comprises a control valve body (12), a valve cover (13) and a pressure setting device, the inner cavity of the control valve body (12) is connected to an inlet (14), a control port (15) and a discharge port (16), and the inlet (14) is connected to the control port (15) through a pipeline. The inlet channel of the valve body (1) is connected, and the pressure setting device is installed in the inner cavity of the valve cover (13), and its structure includes a push rod (17), a spring (18) and an adjusting nut (19); the control port (15) is connected to the rodless cavity of the left cylinder body (4) through a pipeline, a valve disc (20) is arranged at the inlet (14) of the inner cavity of the control valve body (12), an axial guide hole is arranged between the inner cavity of the control valve body (12) and the inner cavity of the valve cover (13), the discharge port (16) is located on the side wall of the axial guide hole and is connected to the axial guide hole, the lower end of the push rod (17) passes through the axial guide hole and contacts the center of the upper end face of the valve disc (20), the lower plane of the valve disc (20) is provided with a sealing surface that cooperates with the upper end face of the inlet (14), and the upper plane of the valve disc (20) is provided with a sealing surface that cooperates with the lower end face of the axial guide hole; An axial guide is provided between the push rod (17) and the axial guide hole, and an axial flow passage connecting the inner cavity of the control valve body (12) and the discharge port (16) is provided between the mating surfaces of the two; the valve disc (20) is movably embedded in the guide hole between the inner cavity of the control valve body (12) and its inlet (14), and an axial flow passage is provided between the outer cylindrical surface of the valve disc (20) and the guide hole; The upper end of the push rod (17) is provided with a valve opening locking device and a valve closing locking device; The valve opening locking device is composed of a valve opening solenoid valve (23) and a valve opening connecting rod (24), the left end of the valve opening connecting rod (24) is hingedly mounted on the valve cover (13), the middle part of the valve opening connecting rod (24) is located below a lifting nut (27) fixedly mounted on the push rod (17), and the right end of the valve opening connecting rod (24) is hingedly connected to the lower end of the driving rod of the valve opening solenoid valve (23); the valve closing locking device is composed of a valve closing solenoid valve (25) and a valve closing connecting rod (26), the left end of the valve closing connecting rod (26) is hingedly connected to the lower end of the driving rod of the valve closing solenoid valve (25), the middle part of the valve closing connecting rod (26) is hingedly mounted on the valve cover (13), the right end of the valve closing connecting rod (26) is located directly above the push rod (17), and the valve closing solenoid valve (25) and the valve opening solenoid valve (23) are fixed to the valve body (1) through a mounting plate; The transmission device is composed of a shift fork (11) fixed to the upper end of the valve stem (3) and a shift rod (10) vertically fixed to the middle of the piston rod (8), and the shift rod (10) is movably nested in the fork opening of the shift fork (11).

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