CN114688339A

CN114688339A - Axial-flow type regulating valve with anti-surge function

Info

Publication number: CN114688339A
Application number: CN202011610860.9A
Authority: CN
Inventors: 李科; 黄亮亮; 曾科; 陈凤; 彭文凯
Original assignee: Zigong New Dipper Valve Co ltd
Current assignee: Zigong New Dipper Valve Co ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2022-07-01

Abstract

An axial flow type regulating valve with an anti-surge function comprises a valve body, a flow-limiting piston shaft, a valve rod and an executing device, wherein an inner valve body is arranged in an outer valve body, a shaft sleeve positioning hole is formed in the inner valve body, the flow-limiting piston shaft is transversely connected in the inner valve body, a shaft sleeve is sleeved outside the flow-limiting piston shaft, the shaft sleeve penetrates through the shaft sleeve positioning hole, a cage sleeve is arranged between a flow guide cover and an outlet of the valve body, and the flow-limiting piston can slide along the inner wall of the cage sleeve; the valve rod bearing is arranged in the valve rod bearing positioning hole, and the valve rod is arranged in the valve rod bearing; the flow-limiting piston shaft and the valve rod are both provided with rectangular tooth surfaces, and the rectangular teeth are meshed with each other to realize transmission; the executing device comprises a support and an air cylinder, and the upper end of the valve rod is arranged in the support; the top end of the execution piston rod is connected with an execution piston, the execution piston is positioned in the cylinder, and the bottom end of the execution piston is provided with a spring; the cylinder is communicated with a pneumatic mechanism; the pneumatic mechanism comprises a pneumatic amplifier of a filter pressure reducing valve, a positioner, a quick-release valve and an electromagnetic valve.

Description

Axial-flow type regulating valve with anti-surge function

Technical Field

The invention relates to an axial flow type regulating valve, in particular to an axial flow type regulating valve with an anti-surge function.

Background

The anti-surge valve is mainly arranged on an anti-surge circulating pipeline from an outlet to an inlet of the compressor, is controlled by an anti-surge system of the compressor, and is actuated by a signal (4-20mA) instruction output by the anti-surge system, and needs to be opened quickly (the full-stroke opening time is usually less than 2S, and in emergency, the full-stroke opening time is less than 1S), and is closed slowly (less than or equal to 12S). During the process of starting, stopping and normally adjusting the flow of the compressor unit, the valve performs adjustment action according to the relevant instructions of the control system, so that the phenomenon that the compressor unit surges or more serious consequences are caused because the load is lower than a surge line in the operation process is prevented.

The prior valves are commonly used as straight-stroke single-seat type, sleeve type, high-pressure-difference type and butterfly type regulating valves, when media flows through the valves in the using process, indirect flow exists, the flow direction changes to form noise and turbulent flow, and the problems of small flow capacity, short service life of the valves, large influence of unbalanced force of the media on an actuating mechanism, short action response time and the like exist; meanwhile, the anti-surge valve is generally arranged outdoors, the extreme environmental temperature of partial areas is lower than the allowable temperature of electric accessories such as the electromagnetic valve and the like, and the conventional anti-surge valve electric accessories are not exposed outside, so that the service performance of the product can be influenced or the function of the product can be disabled under extreme conditions.

Disclosure of Invention

In order to solve the above problems, the present invention provides the following solutions:

an axial flow type regulating valve with an anti-surge function comprises a valve body, a flow-limiting piston, a valve rod and an executing device, wherein the valve body comprises an inner valve body and an outer valve body, the inner valve body is arranged in the outer valve body, the inner valve body and the outer valve body are fixed by reinforcing ribs, a shaft sleeve positioning hole is formed in the inner valve body, a flow-limiting piston shaft is transversely connected in the inner valve body, a shaft sleeve is sleeved outside the flow-limiting piston shaft, the shaft sleeve penetrates through the shaft sleeve positioning hole, the flow-limiting piston is arranged at one end, close to an outlet of the valve body, of the flow-limiting piston shaft, a cage sleeve is arranged between the inner valve body and the outlet of the valve body, and the flow-limiting piston can slide along the inner wall of the cage sleeve; the inner valve body and the outer valve body are longitudinally provided with valve rod bearing positioning holes from top to bottom, the valve rod bearing is arranged in the valve rod bearing positioning holes, and the valve rod is arranged in the valve rod bearing; the flow-limiting piston shaft and the valve rod are both provided with rectangular tooth surfaces, and the rectangular teeth are meshed with each other to realize transmission; the actuating device comprises a support and an air cylinder, the upper end of the valve rod is arranged in the support, and the top end of the valve rod is driven by an actuating piston rod to move up and down along the support; the top end of the execution piston rod is connected with an execution piston, the execution piston is positioned in the cylinder, and the execution piston moves up and down along the cylinder so as to drive the valve rod to move up and down through the execution piston rod; a pneumatic single spring is arranged between the bottom end of the execution piston and the bottom surface of the cylinder; the cylinder is communicated with a pneumatic mechanism; the pneumatic mechanism comprises a first filtering pressure reducing valve, a second filtering pressure reducing valve, a pneumatic amplifier, a positioner, a quick exhaust valve and an electromagnetic valve; the first filtering pressure reducing valve, the pneumatic amplifier and the quick exhaust valve are sequentially connected in series on the air inlet pipeline from front to back; the air inlet pipeline is also connected with a positioning pipeline in parallel, a second filtering pressure reducing valve and a positioner are sequentially connected on the positioning pipeline in series from front to back, an electromagnetic valve is connected between the positioner and the second filtering pressure reducing valve, and the other end of the electromagnetic valve is communicated with a signal port of the pneumatic amplifier through a pipeline.

Further, the angle between the rectangular teeth on the valve rod and the axis of the valve rod is 30 degrees; the angle between the rectangular teeth on the flow-limiting piston shaft and the axis of the flow-limiting piston shaft is 60 degrees.

Further, a protective box is arranged outside the air cylinder, and a heater is arranged on the protective box.

Furthermore, a needle valve is arranged on an air inlet pipeline at the front end of the first filtering and reducing valve.

Furthermore, a buffer cylinder is arranged outside the lower half part of the execution piston rod, the buffer cylinder is provided with an oil injection valve and a throttle valve, and hydraulic oil is injected between the inner wall of the buffer cylinder and the execution piston rod.

Furthermore, the positioner is located the support and is located the valve rod outward in the cover, and the cooperation has the clamp splice for survey valve rod displacement distance.

Furthermore, a limiting block used for limiting the stroke of the execution piston is arranged at the middle position of the inner wall of the air cylinder, a limiting shaft is arranged at the bottom end of the execution piston, and a limiting barrel corresponding to the limiting shaft is arranged on the bottom surface of the air cylinder.

Further, a sliding bearing used for being connected with a piston rod of the actuator is arranged on the bottom surface of the cylinder.

Furthermore, the bottom of the valve rod bearing is fixed with the bottom end of the outer valve body through a bottom cover and a valve rod bearing fastener.

Further, the shaft sleeve comprises a first shaft sleeve and a second shaft sleeve, the first shaft sleeve is arranged in the shaft sleeve positioning hole, and the second shaft sleeve is fixedly matched with the front end of the first shaft sleeve through a fastener matched with the shaft sleeve pressing ring.

Furthermore, a leak detection valve and a lubricating oil injection hole are arranged at the upper end of the valve body corresponding to the position of the valve rod.

The valve body of the invention is of an axial flow structure, thus avoiding the bad working conditions of large resistance and large power consumption of the fluid of the stop regulating valve or the butterfly regulating valve caused by the tortuous medium channel in the valve body and the formation of noise and turbulence after the flow direction is changed; the medium is gathered to the center after passing through the cage, the flow state is stable, the circulation capacity is strong, the erosion to the valve body can be avoided, the large foreign matters brought by the pipeline upstream can be isolated outside the cage, and the damage to the piston and the valve seat is avoided.

The flow-limiting piston and the flow-limiting piston shaft are of a pressure balance type structure, the left and right movement of the flow-limiting piston is completely not influenced by medium pressure, the valve action only needs to overcome the friction force of a moving part, and the required thrust is small. The central control instruction action can be responded effectively in time.

The shaft sleeve is divided into a first shaft sleeve section and a second shaft sleeve section, the coaxiality, the roundness and the surface quality of an inner hole of the shaft sleeve are better, the flow limiting piston shaft is more stable and reliable when sliding in the shaft sleeve, and the stability and the reliability of the movement of the flow limiting piston are ensured.

The valve rod bearing is arranged in the valve body from the bottom cover, so that online maintenance and replacement are facilitated; the valve rod sealing sleeve and the valve rod bearing are used for respectively positioning two ends of the valve rod, so that the bad phenomena that the moving friction force is increased or the valve rod moves and is blocked and the like due to the fact that the valve rod slightly deflects due to the fact that the upper part and the lower part of the valve rod are not concentric are avoided.

The flow-limiting piston shaft, the shaft sleeve, the valve body, the valve rod sealing sleeve and the bottom cover form a closed meshing cavity, a certain amount (30 percent of volume) of lubricating liquid is injected into the meshing cavity, meshing tooth surfaces and sliding friction pairs can be effectively lubricated, the reliability of a transmission device and the sliding friction pairs can be guaranteed, the service life of the transmission device and the sliding friction pairs can be prolonged, and the action reliability and the service life of the valve can be guaranteed.

The valve body is provided with a leak detection valve and a lubricating liquid injection valve communicated with the meshing cavity, the lubricating liquid injection valve is convenient for injecting lubricating liquid, and the leak detection valve is convenient for detecting the effectiveness of dynamic sealing in the valve.

Pneumatic actuating mechanism is the single spring structure of gas shut type, and the spring action opens the valve, and the single spring atress of installing in the cylinder center is steady, and two planar designs of spring have a slide bearing, even if the spring has rotatory tendency in extrusion or release process, and accessible slip slide bearing eliminates, can avoid the flexible in-process valve stem rotation of spring to avoid damaging drive mechanism meshing tooth.

The actuating mechanism is provided with a hydraulic buffer device, the opening of the hydraulic buffer device is 85-100% when the valve is opened, and the hydraulic buffer device has an anti-impact function within 0-15% of the stroke when the valve is closed, so that impact caused by opening and closing is avoided; the hydraulic oil is sealed in the buffer cylinder, the buffer ring moves up and down to enable the hydraulic oil to form internal circulation in the buffer cylinder, and the valve slow closing time can be adjusted by adjusting the opening degree of a throttle valve arranged on the buffer cylinder according to the requirements of actual use working conditions.

The actuating mechanism is provided with a plurality of quick exhaust valves on the gas path, and the quick exhaust valves can discharge the gas in the cylinder rapidly, realizes the control to the valve opening time, and the gas path entry that the air supply entry got into the cylinder is provided with a needle valve, and the gas flow rate that gets into the cylinder is adjusted according to the air supply condition to make the closing speed of valve satisfy the operating mode demand, avoid present practical application prevent breathing a valve and have the too fast problem of closing the valve. Thereby really realizing the functions of fast opening and slow closing.

The main electrical accessories of the electrical control system are integrated in the heat-insulation control box, the temperature sensor monitors the temperature in the control box, when the temperature in the control box is lower than a set temperature, the heater in the control box is automatically started, so that the temperature in the control box is kept at a normal temperature, and the influence of low temperature on the normal work of the electrical accessories is avoided, thereby ensuring the reliability and the service life of the actuator, and further ensuring the action reliability and the service life of a product.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of gas path control;

FIG. 3 is a schematic view of the machining of the tooth surface of the shaft (valve rod) of the flow-limiting piston;

FIG. 4 is a valve stem configuration view;

FIG. 5 is a front view of the valve stem;

FIG. 6 is a view of a shaft structure of a flow restricting piston;

FIG. 7 is a front view of a restrictor piston shaft;

FIG. 8 is a schematic view of the valve body structure

In the figure: 1. a valve body; 2. pressing a ring; 3. a flow conductor; 4. a valve stem bearing; 5. a support; 6. a clamping block; 7. hydraulic oil; 8. an oil filling valve; 9. a throttle valve; 10. a sliding bearing; 11. a limiting cylinder; 12. a limiting block; 13. a limiting shaft; 14. a spring; 15. a cylinder; 16. an actuator piston; 17. a cushion cylinder; 18. an actuating piston rod; 19. a valve stem; 20. a valve rod sealing sleeve; 21. a first shaft sleeve; 22. a second shaft sleeve; 23. a cage sleeve; 24. a flow restricting piston shaft; 25. a shaft sleeve compression ring; 26. locking the nut; 27. a flow restricting piston; 28. a seal ring; 29. a fastener; 30. a bottom cover; 31. a valve stem bearing fastener; 32. a positioner; 33. a limit switch; 34. an explosion-proof junction box; 35. an electromagnetic valve; 36. an air intake duct; 37. a second pressure reducing valve; 38. a heater; 39. a needle valve; 40. a first pressure reducing valve; 41. starting an amplifier; 42. a protective box; 43. a quick discharge valve; 44. a temperature sensor; 45. a leak detection valve; 46. a lubricating fluid injection valve; 15.1. a top cover; 15.2. a lower cover; 17.1. an inner cylinder; 17.2. a buffer ring; 1.1. an outer valve body; 1.2. an inner valve body; 1.3. reinforcing ribs; 1.4. a valve rod bearing positioning hole; 1.5. valve housing locating hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. In the following description, certain specific details are set forth in order to provide a thorough understanding of the present invention. Rather, the invention will be implemented without these specific details, i.e., those skilled in the art will more effectively describe the nature of their work to others skilled in the art using the description and presentation herein. Furthermore, it should be noted that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the scope of the actual protection. All the raw materials used in the following examples are commercially available products.

Example one

As shown in fig. 1-8, an axial flow type regulating valve with anti-surge function comprises a valve body 1, a flow-limiting piston 27, a valve rod 19 and an executing device, wherein the valve body 1 comprises an inner valve body 1.1 and an outer valve body 1.2, the inner valve body 1.2 is arranged in the outer valve body 1.1, the inner valve body 1.2 and the outer valve body 1.1 are fixed by a reinforcing rib 1.3, a shaft sleeve positioning hole 1.5 is arranged in the inner valve body 1.2, a flow-limiting piston shaft 24 is transversely connected in the inner valve body 1.2, a shaft sleeve is sleeved outside the flow-limiting piston shaft 24, the shaft sleeve penetrates through the shaft sleeve positioning hole 1.5, the flow-limiting piston 27 is arranged at one end of the flow-limiting piston shaft 24 close to an outlet of the valve body 1, a cage sleeve 23 is arranged between the inner valve body 1.2 and the outlet of the valve body 1, and the flow-limiting piston 27 can slide along the inner wall of the cage sleeve 23; the inner valve body 1.2 and the outer valve body 1.1 are longitudinally provided with valve rod bearing positioning holes 1.4 from top to bottom, the valve rod bearing 4 is arranged in the valve rod bearing positioning hole 1.4, and the valve rod 19 is arranged in the valve rod bearing 4; the flow-limiting piston shaft 24 and the valve rod 19 are both provided with rectangular tooth surfaces, and the rectangular teeth are meshed with each other to realize transmission; the executing device comprises a support 5 and an air cylinder 15, the upper end of the valve rod 19 is arranged in the support 5, and the top end of the valve rod 19 is driven by an executing piston rod 18 to move up and down along the support 5; the top end of the execution piston rod 18 is connected with an execution piston 16, the execution piston 16 is positioned in the cylinder 15, and the execution piston 16 moves up and down along the cylinder 15 so as to drive the valve rod 19 to move up and down through the execution piston rod 18; a pneumatic single spring 14 is arranged between the bottom end of the execution piston 16 and the bottom surface of the cylinder 15; the cylinder 15 is communicated with a pneumatic mechanism; the pneumatic mechanism comprises a first filtering pressure reducing valve 40, a second filtering pressure reducing valve 37, a pneumatic amplifier 41, a positioner 32, a quick-release valve 43 and an electromagnetic valve 35; the first filtering and reducing valve 40, the pneumatic amplifier 41 and the quick exhaust valve 43 are sequentially connected in series on the air inlet pipeline 36 from front to back; the quick exhaust valve 43 is fixed on the top cover 15.1 of the cylinder 15, the air inlet pipeline 36 is also connected in parallel with a positioning pipeline, the positioning pipeline is sequentially connected in series with a second filtering pressure reducing valve 37 and a positioner 32 from front to back, an electromagnetic valve 35 is connected between the positioner 32 and the second filtering pressure reducing valve 37, and the other end of the electromagnetic valve 35 is communicated with a signal port of the pneumatic amplifier 41 through a pipeline.

Further, the angle between the rectangular teeth on the valve rod 19 and the axis of the valve rod 19 is 30 degrees; the angle of the rectangular teeth on the restrictor piston shaft 24 to the axis of the restrictor piston shaft 24 is 60 °.

Further, a protective box 42 is arranged outside the cylinder 15, and the protective box 42 is provided with the heater 38.

Further, a needle valve 39 is provided on an intake pipe at the front end of the first filtering and pressure reducing valve 40.

Furthermore, a buffer cylinder 17 is arranged outside the lower half part of the execution piston rod 18, the buffer cylinder 17 is provided with an oil injection valve 8 and a throttle valve 9, and hydraulic oil 7 is injected between the inner wall of the buffer cylinder 17 and the execution piston rod 18.

Further, the positioner 32 is located in the bracket 5 and sleeved outside the valve rod 19, and is matched with the clamping block 6 for measuring the displacement distance of the valve rod 19.

Furthermore, a limiting block 12 for limiting the stroke of the actuating piston 16 is arranged at the middle position of the inner wall of the cylinder 15, a limiting shaft 13 is arranged at the bottom end of the actuating piston 16, and a limiting cylinder 11 corresponding to the limiting shaft 13 is arranged at the bottom surface of the cylinder 15.

Furthermore, the bottom surface of the cylinder 15 is provided with a sliding bearing 10 for connecting an actuator piston rod 18, and the top end of the valve rod 19 is also sleeved with a buffer ring 17.2.

Further, the bottom of the valve rod bearing 4 is fixed with the bottom end of the outer valve body 1.1 through a bottom cover 30 and a valve rod bearing fastener 31.

Further, the shaft sleeve comprises a first shaft sleeve 21 and a second shaft sleeve 22, the first shaft sleeve 21 is arranged in the shaft sleeve positioning hole 1.5, and the second shaft sleeve 22 is fixedly matched with the front end of the first shaft sleeve 21 through a fastener 29 and a shaft sleeve pressing ring 25.

Further, a leak detection valve 45 and a lubricating oil injection hole 46 are provided at the upper end of the valve body 1 at positions corresponding to the valve rod 19.

The valve body 1 of the invention is of an axial flow type structure, thus avoiding the bad working conditions of large resistance and large power consumption of the fluid of the stop regulating valve or the butterfly regulating valve caused by the tortuous medium channel in the valve body and the formation of noise and turbulent flow after the flow direction is changed; the medium is gathered to the center after passing through the cage sleeve 23, the flow state is stable, the circulation capacity is strong, the erosion to the valve body 1 can be avoided, the large foreign matters brought by the pipeline upstream can be isolated outside the cage sleeve 23, and the damage to the piston and the valve seat is avoided.

The flow-limiting piston 27 and the flow-limiting piston shaft 24 are of a pressure balance type structure, the left and right movement of the flow-limiting piston is completely not influenced by the pressure of a medium, the valve action only needs to overcome the friction force of a moving part, and the required thrust is small. The central control instruction action can be responded effectively in time.

The shaft sleeve is divided into a first shaft sleeve 21 and a second shaft sleeve 22, the coaxiality, the roundness and the surface quality of an inner hole of the shaft sleeve are better, the current-limiting piston shaft 24 is more stable and reliable when sliding in the shaft sleeve, and the stability and the reliability of the motion of the current-limiting piston 27 are ensured.

The valve rod bearing 4 is arranged in the valve body 1 from the bottom cover, so that online maintenance and replacement are facilitated; the valve rod sealing sleeve 20 and the valve rod bearing 4 are used for respectively positioning two ends of the valve rod 19, so that the bad phenomena that the movement friction force is increased or the valve rod 19 moves and is blocked and the like due to the fact that the valve rod 19 slightly deflects due to the fact that the upper part and the lower part of the valve rod are not concentric are avoided.

The flow-limiting piston shaft 24, the shaft sleeve, the valve body 1, the valve rod 19, the valve rod sealing sleeve 20 and the bottom cover 30 form a closed meshing cavity, a certain amount (30 percent of volume) of lubricating liquid is injected into the meshing cavity, meshing tooth surfaces and sliding friction pairs can be effectively lubricated, the reliability of a transmission device and the sliding friction pairs can be guaranteed, the service life of the transmission device and the sliding friction pairs can be prolonged, and therefore the action reliability and the service life of the valve can be guaranteed.

Be equipped with leak detection valve 45 and lubricated liquid filling valve 49 intercommunication meshing chamber on the valve body, lubricated liquid is convenient for pour into to lubricated liquid filling valve 49, and leak detection valve 45 is convenient for detect valve internal dynamic seal's validity.

The pneumatic actuator is of an air-closed single-spring structure, the spring 14 acts on an open valve, the single spring 14 arranged at the center of the air cylinder 15 is stressed stably, two planes of the spring 14 are provided with sliding bearings, even if the spring 14 has a rotating tendency in the extrusion or release process, the sliding bearings 10 can eliminate the rotating tendency, the valve rod 19 can be prevented from rotating in the expansion and contraction process of the spring 14, and therefore the meshing teeth of the transmission mechanism are prevented from being damaged.

The actuating mechanism is provided with a hydraulic buffer device, the opening of the hydraulic buffer device is 85-100% when the valve is opened, and the hydraulic buffer device has an anti-impact function within 0-15% of the stroke when the valve is closed, so that impact caused by opening and closing is avoided; the hydraulic oil is sealed in the buffer cylinder 17, the buffer ring 17.2 moves up and down to enable the hydraulic oil to form internal circulation in the buffer cylinder 17, and the slow closing time of the valve can be adjusted by adjusting the opening of the throttle valve 9 arranged on the buffer cylinder 17 according to the requirements of actual use working conditions.

The air path of the actuating mechanism is provided with a plurality of quick exhaust valves 43, the quick exhaust valves 43 can rapidly exhaust the air in the air cylinder 15, the control of the valve opening time is realized, the air path inlet of the air source inlet entering the air cylinder 15 is provided with a needle valve 39, the flow rate of the air entering the air cylinder is adjusted according to the condition of the air source, so that the closing speed of the valve meets the working condition requirement, and the problem that the anti-surge valve in practical application is too fast in valve closing is avoided. Thereby really realizing the functions of fast opening and slow closing.

The main electrical accessories of the electrical control system are integrated in the heat-insulation control box, the temperature sensor 44 monitors the temperature in the control box, and when the temperature in the control box is lower than the set temperature, the heater 38 in the control box is automatically started, so that the temperature in the control box is kept at the normal temperature, and the influence of low temperature on the normal work of the electrical accessories is avoided, thereby ensuring the reliability and the service life of the actuator, and further ensuring the action reliability and the service life of the product.

The technical solutions provided by the embodiments of the present invention are described in detail above, and the principles and embodiments of the present invention are explained herein by using specific examples, and the descriptions of the embodiments above are only used to help understanding the principles of the embodiments of the present invention; meanwhile, for those skilled in the art, there may be variations in the embodiments, specific implementations and application ranges according to the present invention, and in summary, the present disclosure should not be construed as limiting the present invention.

Claims

1. The utility model provides an axial-flow type governing valve with anti-surge function, includes valve body, current-limiting piston axle, valve rod and final controlling element, its characterized in that: the valve body comprises an inner valve body and an outer valve body, the inner valve body is arranged in the outer valve body, a shaft sleeve positioning hole is formed in the inner valve body, a flow-limiting piston shaft is transversely connected in the inner valve body, a shaft sleeve is sleeved outside the flow-limiting piston shaft, the shaft sleeve penetrates through the shaft sleeve positioning hole, one end, close to an outlet of the valve body, of the flow-limiting piston shaft is provided with a flow-limiting piston, a cage sleeve is arranged between the flow guide cover and the outlet of the valve body, and the flow-limiting piston can slide along the inner wall of the cage sleeve; the inner valve body and the outer valve body are longitudinally provided with valve rod bearing positioning holes from top to bottom, the valve rod bearing is arranged in the valve rod bearing positioning holes, and the valve rod is arranged in the valve rod bearing; the flow-limiting piston shaft and the valve rod are both provided with rectangular tooth surfaces, and the rectangular teeth are meshed with each other to realize transmission; the actuating device comprises a support and an air cylinder, the upper end of the valve rod is arranged in the support, and the top end of the valve rod is driven by an actuating piston rod to move up and down along the support; the top end of the execution piston rod is connected with an execution piston, the execution piston is positioned in the cylinder, and the execution piston moves up and down along the cylinder so as to drive the valve rod to move up and down through the execution piston rod; a pneumatic single spring is arranged between the bottom end of the execution piston and the bottom surface of the cylinder; the cylinder is communicated with a pneumatic mechanism; the pneumatic mechanism comprises a first filtering pressure reducing valve, a second filtering pressure reducing valve, a pneumatic amplifier, a positioner, a quick exhaust valve and an electromagnetic valve; the first filtering pressure reducing valve, the pneumatic amplifier and the quick exhaust valve are sequentially connected in series on the air inlet pipeline from front to back; the air inlet pipeline is also connected with a positioning pipeline in parallel, a second filtering pressure reducing valve and a positioner are sequentially connected on the positioning pipeline in series from front to back, an electromagnetic valve is connected between the positioner and the second filtering pressure reducing valve, and the other end of the electromagnetic valve is communicated with a signal port of the pneumatic amplifier through a pipeline.

2. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: the angle between the rectangular teeth on the valve rod and the axis of the valve rod is 30 degrees; the angle between the rectangular teeth on the flow-limiting piston shaft and the axis of the flow-limiting piston shaft is 60 degrees.

3. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: a protective box is arranged outside the air cylinder, and a heater is arranged on the protective box.

4. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: a needle valve is arranged on the air inlet pipeline at the front end of the first filtering and reducing valve.

5. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: and a buffer cylinder is arranged outside the lower half part of the execution piston rod, the buffer cylinder is provided with an oil injection valve and a throttle valve, and hydraulic oil is injected between the inner wall of the buffer cylinder and the execution piston rod.

6. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: the positioner is positioned in the support and sleeved outside the valve rod and used for measuring the displacement distance of the valve rod.

7. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: the middle position of the inner wall of the cylinder is provided with a limiting block for limiting the stroke of the execution piston, the bottom end of the execution piston is provided with a limiting shaft, and the bottom surface of the cylinder is provided with a limiting barrel corresponding to the limiting shaft.

8. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: and the bottom surface of the cylinder is provided with a sliding bearing used for connecting an actuator piston rod.

9. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: the bottom of the valve rod bearing is fixed with the bottom end of the outer valve body through a bottom cover and a fastening piece.

10. An axial flow regulator valve having an anti-surge function as claimed in claim 1, wherein: the shaft sleeve comprises a first shaft sleeve and a second shaft sleeve, the first shaft sleeve is arranged in the shaft sleeve positioning hole, and the second shaft sleeve is fixedly matched with the front end of the first shaft sleeve through a fastener.