WO2022218166A1

WO2022218166A1 - Axial-flow type flow control valve

Info

Publication number: WO2022218166A1
Application number: PCT/CN2022/084702
Authority: WO
Inventors: 明笛
Original assignee: 南京亿准纳自动化控制技术有限公司
Priority date: 2021-04-13
Filing date: 2022-04-01
Publication date: 2022-10-20

Abstract

An axial-flow type flow control valve, comprising: a valve body (1), a valve core (2), a valve seat (4), and a driving apparatus. The valve core (2) is fixedly provided inside the valve body (1), and an annular fluid channel is formed between the valve core (2) and the valve body (1); the valve seat (4) is tubular and sealingly connected to the inner wall of the valve body (1); the valve body (1), the valve core (2), and the valve seat (4) are coaxially arranged; the driving apparatus is used for driving the valve seat (4) to move in the axial direction of the valve body (1) so as to be connected to or separated from the valve core (2), so as to close or open the flow control valve. By means of the flow control valve, the problems of the instability of the overall contour of a throttling member, flow separation, and increased flow resistance and the like caused by the driving apparatus driving the valve core to move are solved.

Description

Axial Flow Control Valve

technical field

The invention relates to the field of flow control, in particular to an axial flow control valve.

Background technique

The control valve (also known as the regulating valve) is the terminal executive element of the control loop. It plays a very important role in the process control of the process industry, and it is also a long-term technical weakness. The axial flow control valve developed by MMOKVELD as the representative solves the problems of poor maintenance performance, poor reliability and poor durability of traditional angle valves, butterfly valves, spherical valves and sleeve valves.

The axial flow control valve is different from the conventional straight-stroke control valve. It changes the overall flow structure of the conventional straight-stroke control valve, and changes the phenomenon that the conventional straight-stroke control valve throttling part is inconsistent with the flow direction of the medium, so that the energy loss of the medium is less. , The flow capacity is increased by 20% to 50% compared with the conventional straight-stroke control valve. It has the characteristics of low flow resistance coefficient, firmness and durability, low maintenance and high performance. It is widely used in natural gas, crude oil, refined oil and other non-corrosive gases and Adjustment control of liquids. Relevant professional technicians and manufacturers at home and abroad have launched various axial flow control valves, such as US4638832, US2011/0017306A1, WO2019/20153A2, CN210770459U, etc.

The existing axial flow control valves generally have the following problems:

1. The structure of the valve core destroys the rectification effect of the throttling element. The valve core is often placed inside the throttling part, and is connected to a driving device consisting of pneumatic, hydraulic or mechanical racks and pinions. The relative position between the valve seats at the inlet and outlet is used to adjust the flow of the medium. The uncertainty of the valve core position causes the overall shape of the throttle element to be unstable, as well as the uneven transition between the valve core and the throttle element, resulting in flow separation, which increases negative effects such as flow resistance.

2. The drive mechanism of the valve core is often placed in the throttle, which causes the shape of the throttle to be very bulky and heavy, and the hydrodynamic performance is negatively affected. At the same time, in order to connect with the actuator outside the valve body, a sufficiently thick connection channel must be set between the throttle and the pipe wall, which further increases the flow resistance and affects the flow state of the medium in the pipe.

3. The hydrodynamic structure of the throttling part in the valve body has not been fully optimized, and the effect of diversion and drag reduction is not ideal.

4. A "valve cage" coaxial with the valve core is set at the rear of the throttle part and the periphery of the valve core, that is, a number of diversion holes or diversion grooves are opened on the rear wall of the throttle part, and the medium in the pipe flows through the joint. After the flow piece, it flows out from the guide hole or groove that is not covered by the valve core. The medium flow in the pipeline is controlled by controlling the shielding degree of the valve spool to the cage. The design of the cage can reduce noise and vibration to a certain extent, but at the same time, it will increase the flow resistance and increase the pressure loss in the pipeline.

Therefore, it would be desirable to develop a new type of axial flow control valve to at least partially overcome the above-mentioned problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose an axial flow control valve to optimize the flow state of the medium in the control valve and reduce the flow resistance.

The invention provides an axial flow control valve, comprising: a valve body, a valve core, a valve seat and a driving device; the valve body is tubular, the valve core comprises a head, a middle part and a tail which are connected in sequence, the The valve core is fixed in the valve body, and an annular fluid channel is formed between the valve body; the valve seat is tubular, and is sealingly connected to the inner wall of the valve body, the valve body, the valve core and the valve body The valve seat is coaxially arranged; the driving device is arranged on the outside of the valve body, and is used to drive the valve seat to move along the axial direction of the valve body so as to be connected with or separated from the valve core, so that the The flow control valve is closed or open.

Preferably, the valve core comprises a head, a middle and a tail which are connected in sequence;

The valve core is in the shape of a spindle or a droplet, the axial section of the head is arc-shaped or parabolic, and the middle part is a cylinder; or, the axial section of the head is arc-shaped or parabolic The shape of the middle part is a cylinder, and the shape of the tail part is the same as that of the head part.

Preferably, the valve core includes a head, a middle and a tail connected in sequence, the head and the tail are cones, the middle is a cylinder, and the cone angle of the head is greater than or equal to the The taper angle of the tail.

Preferably, the valve seat is close to one end of the valve core, and the inner wall of the valve seat is a smooth curved surface;

When the valve seat is in contact with the valve core, the inner wall of the valve seat is tangent to the outer surface of the valve core.

Preferably, annular sealing rings are respectively provided on the outer peripheries of both ends of the valve seat, so as to be sealingly connected with the inner wall of the valve body.

Preferably, the driving device is provided outside the valve body; the outer periphery of the valve seat is provided with a rack, the driving device includes an actuator and a gear, the actuator is used to drive the gear, and the gear connected with the rack.

Preferably, the outer circumference of the valve seat is provided with a thread, the driving device includes an actuator and a worm, the actuator is used to drive the screw, and the worm is drive-connected with the thread.

Preferably, the driving device is provided outside the valve body; the driving device includes an actuator and a cylinder or a hydraulic cylinder, the actuator is used to drive the piston of the cylinder or the hydraulic cylinder, and the cylinder or The piston rod of the hydraulic cylinder is connected to the outer periphery of the valve seat.

Preferably, the axial flow control valve further includes a plurality of support sheets, the plurality of support sheets are evenly distributed along the circumference of the valve core, one end of the support sheet is connected to the outer circumference of the valve core, and the other end is connected to the outer circumference of the valve core. connected to the inner wall of the valve body.

Preferably, a high-pressure pressure-taking hole and a low-pressure pressure-taking hole are provided on the side wall of the valve body, the high-pressure pressure-taking hole is close to the end of the valve core facing the fluid inlet, and the low-pressure pressure-taking hole is close to the valve the middle of the core;

The flow control valve further comprises a differential pressure flowmeter, the high pressure inlet end and the low pressure inlet section of the differential pressure flowmeter are respectively connected with the high pressure taking hole and the low pressure taking hole to measure the flow;

The driving device is connected with the differential pressure flowmeter, and drives the valve seat to move along the axial direction of the valve body according to the flow measured by the differential pressure flowmeter, thereby realizing closed-loop control.

The beneficial effects of the present invention are:

1. The valve core of the axial flow control valve is fixed, and the valve seat is connected with the driving device. Under the action of the driving device, it is connected or separated from the valve core along the axial movement of the valve body, so that the flow control valve is closed or opened. , which avoids problems such as instability of the overall shape of the throttling member, flow separation, and increased flow resistance caused by the movement of the valve core driven by the drive device in the prior art.

2. The drive device is located outside the valve body, which will not adversely interfere with the flow state of the medium in the pipeline, and is also convenient for daily maintenance and maintenance.

3. The shape of the valve core is optimized to minimize the flow resistance and ensure the rectification effect. When the medium flows through the spool, almost no flow separation occurs, thereby reducing adverse effects such as noise and vibration. When the medium in the pipeline is liquid, the possibility of flash evaporation, cavitation and cavitation can be reduced. The seat shape is optimized to minimize flow resistance and avoid disruption to the overall flow field.

4. The double throttle design of the valve core and valve seat provides great convenience for directly using the control valve itself for accurate flow measurement. Neither the valve core nor the valve seat adopts the valve cage or similar design in the prior art, which will not destroy the linear shape of the axial flow channel in the valve body, thereby avoiding damage to the overall flow field.

5. The support sheet firmly fixes the valve core on the axis of the valve body. In addition, no additional components are installed on the valve core, which can avoid adverse effects on the rectification effect of the valve core.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of the exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein the same reference numerals are generally used in the exemplary embodiments of the present invention. represent the same parts.

Fig. 1 shows a schematic structural diagram of an axial flow flow control valve according to a first exemplary embodiment of the present invention;

FIG. 2 shows a schematic diagram of flow characteristics of the axial flow flow control valve according to the first exemplary embodiment of the present invention;

FIG. 3 shows a schematic structural diagram of an axial flow flow control valve according to a second exemplary embodiment of the present invention;

FIG. 4 shows a schematic structural diagram of an axial flow flow control valve according to a third exemplary embodiment of the present invention;

FIG. 5 shows a schematic structural diagram of an axial flow flow control valve according to a fourth exemplary embodiment of the present invention;

FIG. 6 shows a schematic structural diagram of an axial flow flow control valve according to a fifth exemplary embodiment of the present invention;

7 shows a schematic structural diagram of an axial flow flow control valve according to a sixth exemplary embodiment of the present invention;

8 shows a schematic structural diagram of an axial flow flow control valve according to a seventh exemplary embodiment of the present invention.

Description of reference numbers:

1 valve body, 2 valve core, 3 support plate, 4 valve seat, 5 seal ring, 6a driving gear, 6b follower gear, 7 actuator, 8 worm, 9 hydraulic cylinder, 9a piston, 9b piston rod, 10 pressure taking Orifice, 11 differential pressure flowmeter.

Detailed ways

The present invention will be described in more detail below with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The invention provides an axial flow control valve, comprising: a valve body, a valve core, a valve seat and a driving device; the valve core is fixed in the valve body, and an annular fluid channel is formed between the valve body and the valve body; the valve seat is tubular and sealed Connected to the inner wall of the valve body, the valve body, the valve core and the valve seat are coaxially arranged, and the driving device is used to drive the valve seat to move along the axial direction of the valve body to connect or separate with the valve core, so as to close the flow control valve or open.

The axial flow control valve of the present invention drives the valve seat to move through the driving device, so that the valve seat is connected or separated from the valve core, so that the flow control valve is closed or opened. The problems such as instability of the overall shape of the throttling member, flow separation, and increased flow resistance caused by the drive device driving the movement of the valve core in the prior art are avoided.

Example 1

FIG. 1 shows a schematic structural diagram of an axial flow flow control valve according to a first exemplary embodiment of the present invention. As shown in Figure 1, the axial flow control valve includes: a valve body 1, a valve core 2, a valve seat 4 and a driving device; the valve core 2 is fixed in the valve body 1, and an annular fluid is formed between the valve body 1 and the valve body 1. The valve seat 4 is tubular and is sealingly connected to the inner wall of the valve body 1. The valve body 1, the valve core 2 and the valve seat 4 are coaxially arranged, and the driving device is used to drive the valve seat 4 to move along the axial direction of the valve body 1. In order to connect or separate with the valve core 2, so as to close or open the flow control valve.

The valve seat 4 is driven to move by the driving device, so that the valve seat 4 is connected or separated from the valve core 2, so that the flow control valve is closed or opened. Problems such as instability of the overall shape of the throttling member, flow separation, and increased flow resistance caused by the drive device driving the movement of the valve core 2 in the prior art are avoided.

In this embodiment, the valve core 2 is in the shape of a spindle or a water droplet, and according to the flow direction of the medium (the direction shown by the arrow in FIG. 1 ), it includes a head, a middle and a tail that are connected in sequence, and the axial section of the head is an arc Shaped or parabolic, with a cylinder in the middle. The shape of the valve core 2 is optimized to minimize the flow resistance and ensure the rectification effect. When the medium flows through the valve core 2, almost no flow separation occurs, so that adverse effects such as noise and vibration can be reduced. When the medium in the pipeline is liquid, the possibility of flash evaporation, cavitation and cavitation can be reduced.

The valve seat 4 is close to one end (tail end) of the valve core 2, and the inner wall of the valve seat 4 is a smooth curved surface. When the valve seat 4 is connected to the valve core 2, the inner wall of the valve seat 4 is tangent to the outer surface of the valve core 2, thus Close the control valve. In this embodiment, the axial section of the inner wall of the valve seat 4 is in the shape of a circular arc. According to design requirements, the axial section of the inner wall of the valve seat 4 may also be other smooth curved surfaces. The shape of the valve seat 4 is optimized to minimize flow resistance and avoid damage to the overall flow field.

Neither the valve core nor the valve seat of this embodiment adopts the valve cage or similar design in the prior art, which will not destroy the linear shape of the axial flow passage in the valve body, thereby avoiding damage to the overall flow field.

The outer circumferences of both ends of the valve seat 4 are respectively provided with annular sealing rings 5 for sealing connection with the inner wall of the valve body 1 to prevent the medium from leaking from between the valve seat 4 and the inner wall of the valve body 1 .

The axial flow control valve of this embodiment further includes a plurality of support sheets 3, which are evenly distributed along the circumference of the valve core 2, one end of the support sheet 3 is connected to the outer circumference of the valve core 2, and the other end is connected to the valve body 1 inner wall. The support sheet 3 firmly fixes the valve core 2 on the axis of the valve body 1 , other than that, no additional components are installed on the valve core 2 , which can avoid adverse effects on the rectification effect of the valve core 2 .

The valve body 1 is in the shape of a round tube, and both ends can be connected to the medium pipeline through flanges respectively. In particular, a section of pipeline can be used as the valve body 1, the inner diameter of which is the same as that of the controlled medium pipeline. The driving device is provided outside the valve body 1 . The outer circumference of the valve seat 4 is provided with a rack, and the driving device includes an actuator 7 and a gear. The actuator 7 is used to drive the gear, and the gear is connected with the rack, so that the valve seat 4 can be driven to be close to the inner wall of the valve body 1 along the valve body. 1 in order to change the flow area between the valve seat 4 and the valve core 2 and control the flow in the valve body. When it is necessary to reduce the flow of the medium in the pipeline, the gear is driven by the actuator 7 to rotate, and then the valve seat 4 is driven close to the valve core 2 through the rack. At this time, the flow area between the valve seat 4 and the valve core 2 is gradually reduced, and the flow rate in the pipeline also gradually decreased. When the valve seat 4 moves to a specific position, the inner wall of the valve seat 4 is tangent to the outer surface of the tail of the valve core 2 (as shown by the dotted line in Figure 2), at this time the valve is completely closed and the flow in the pipeline is zero. On the contrary, the actuator 7 drives the gear to rotate, and then drives the valve seat 4 to gradually move away from the valve core 2 through the rack. At this time, the flow area between the valve seat 4 and the valve core 2 gradually increases, and the flow in the pipeline also gradually increases until achieve the desired flow. In order to make the valve seat 4 receive even force and move smoothly, more than one set of racks and gears can be evenly distributed on the outer circumference of the valve seat 4, one of which is the driving gear 6a, which is connected to the actuator 7; the other gears are The follower gear 6b is not connected to the actuator 7 .

Due to the above-mentioned structural features, the axial flow control valve of the present embodiment has more ideal flow characteristics compared with the existing axial flow control valve, as shown in Figure 2 (data from the prototype test).

Example 2

FIG. 3 shows a schematic structural diagram of an axial flow flow control valve according to a second exemplary embodiment of the present invention. As shown in FIG. 3 , the only difference between Embodiment 2 and Embodiment 1 is that the outer periphery of the valve seat 4 is provided with threads, the driving device includes an actuator 7 and a worm 8, the actuator 7 is used to drive the screw 8, and the worm 8 is connected to the thread. drive connection. The worm 8 is driven by the actuator 7, thereby driving the valve seat 4 to move along the axial direction of the valve body 1 against the inner wall of the valve body 1, so as to change the flow area between the valve seat 4 and the valve core 2 and control the flow in the pipeline. In order to make the valve seat 4 move evenly and move smoothly, more than one group of worms can be evenly distributed on the outer circumference of the valve seat 4. One of the worms is the active worm and is connected to the actuator 7; the other worms are the follower worms. Not connected to actuator 7.

Example 3

FIG. 4 shows a schematic structural diagram of an axial flow flow control valve according to a third exemplary embodiment of the present invention. As shown in FIG. 4 , the only difference between Embodiment 3 and Embodiment 1 is that the driving device includes an actuator 7 and a hydraulic cylinder 9 (or air cylinder), and the actuator 7 is used to drive the piston 9 a of the hydraulic cylinder 9 . The piston rod 9b is connected to the outer periphery of the valve seat 4 . The piston rod 9b is driven by the actuator 7, and then the valve seat 4 is driven to move along the axial direction of the valve body 1 against the inner wall of the valve body 1, so as to change the flow area between the valve seat 4 and the valve core 2 and control the flow in the pipeline. . When it is necessary to reduce the flow of the medium in the pipeline, the piston rod 9b is driven by the actuator 7, and then the valve seat 4 is pushed closer to the valve core 2. At this time, the flow area between the valve seat 4 and the valve core 2 is gradually reduced, and the flow rate in the pipeline is also reduced. gradually decreases. When the valve seat 4 moves to a specific position, the inner wall of the valve seat 4 is tangent to the outer surface of the tail of the valve core 2, and the valve is completely closed at this time, and the flow in the pipeline is zero. On the contrary, the actuator 7 drives the piston rod 9b, and then pushes the valve seat 4 away from the valve core 2 gradually. At this time, the flow area between the valve seat 4 and the valve core 2 gradually increases, and the flow rate in the pipeline also gradually increases until it reaches the desired value. flow required.

Example 4

5 shows a schematic structural diagram of an axial flow flow control valve according to a fourth exemplary embodiment of the present invention. As shown in FIG. 5 , the only difference between Embodiment 4 and Embodiment 1 is that the head and tail of the valve core 2 are cones, the middle is a cylinder, and the cone angle of the head is larger than that of the tail.

Example 5

FIG. 6 shows a schematic structural diagram of an axial flow flow control valve according to a fifth exemplary embodiment of the present invention. As shown in FIG. 6 , the only difference between Embodiment 5 and Embodiment 1 is that the axial section of the head of the valve core 2 is arc-shaped or parabolic, the middle is a cylinder, and the tail has the same shape as the head. This structure can be used when bidirectional flow control is required.

Example 6

FIG. 7 shows a schematic structural diagram of an axial flow flow control valve according to a sixth exemplary embodiment of the present invention. As shown in FIG. 7 , the only difference between Embodiment 6 and Embodiment 1 is that the head and tail of the valve core 2 are cones, the middle is a cylinder, and the cone angle of the head is equal to the cone angle of the tail. This structure can be used when bidirectional flow control is required.

Example 7

8 shows a schematic structural diagram of an axial flow flow control valve according to a seventh exemplary embodiment of the present invention. As shown in Figure 8, the difference between Embodiment 7 and Embodiment 1 is:

The side wall of the valve body 1 is provided with a pressure-taking hole 10, which is a high-pressure pressure-taking hole and a low-pressure pressure-taking hole respectively. The head of the valve core 2 is tangent, and the low pressure pressure taking hole is close to the middle of the valve core.

The flow control valve also includes a differential pressure flowmeter 11, the high pressure inlet end and the low pressure inlet section of the differential pressure flowmeter 11 are respectively connected with the high pressure taking hole and the low pressure taking hole to measure the flow. Specifically, when the medium in the pipeline flows through the valve core 2, due to the rectification effect of the valve core 2, the fluid evenly enters the annular fluid channel formed between the valve core 2 and the valve body 1. The pressure is reduced, creating a standard annular channel flow. Using the pressure difference between the lower pressure in the annular channel and the higher pressure at the head of the valve core 2, the instantaneous flow rate of the fluid in the pipeline is obtained after transmission and calculation by the differential pressure flowmeter 11.

The driving device is connected to the differential pressure flowmeter 11 , and drives the valve seat 4 to move along the axial direction of the valve body 1 according to the flow measured by the differential pressure flowmeter 11 . Specifically, the driving device includes an actuator 7 and gears. The flow measured by the differential pressure flowmeter 11 is transmitted to the actuator 7 as a feedback signal, and the actuator 7 controls the movement of the valve seat 4 according to the flow, so that the pipeline flow and the Closed-loop control between valve seat movements to precisely control the flow of media in the pipeline.

When the flow rate measured by the differential pressure flowmeter 11 is greater than the required flow rate, it is necessary to reduce the flow rate of the medium in the pipeline, drive the gear to rotate through the actuator 7, and then drive the valve seat 4 to approach the valve core 2 through the rack. At this time, the valve seat 4 and the The flow area between the valve cores 2 is gradually reduced, and the flow in the pipeline is gradually reduced until the required flow is reached. Conversely, when the flow rate measured by the differential pressure flowmeter 11 is less than the preset flow rate, it is necessary to increase the flow rate of the medium in the pipeline, and the actuator 7 drives the gear to rotate, and then drives the valve seat 4 to gradually move away from the valve core 2 through the rack. The flow area between the valve seat 4 and the valve core 2 gradually increases, and the flow rate in the pipeline also gradually increases until the required flow rate is reached.

The axial flow flow control valve of this embodiment integrates flow measurement and control, and can realize a closed-loop control valve with medium flow as a feedback signal.

Various embodiments of the present invention have been described above, and the foregoing descriptions are exemplary, not exhaustive, and not limiting of the disclosed embodiments. Numerous modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

An axial flow control valve, characterized in that it comprises: a valve body, a valve core, a valve seat and a driving device; the valve body is tubular, the valve core is fixed in the valve body, and includes a valve body connected in sequence. At the head, the middle and the tail, an annular fluid channel is formed between the valve core and the valve body; the valve seat is tubular and is sealingly connected to the inner wall of the valve body, the valve body, the valve core and The valve seat is coaxially arranged; the driving device is arranged on the outside of the valve body, and is used for driving the valve seat to move along the axial direction of the valve body so as to be connected with or separated from the valve core, so that the The flow control valve is closed or open.
The axial flow control valve according to claim 1, characterized in that, the valve core is in the shape of a spindle or a droplet, the axial section of the head is in the shape of an arc or a parabola, and the middle part is a cylinder Or, the axial section of the head is circular arc or parabola, the middle is a cylinder, and the tail has the same shape as the head.
The axial flow control valve according to claim 1, wherein the head and the tail are cones, the middle part is a cylinder, and the cone angle of the head is greater than or equal to the The taper angle of the tail.
The axial flow control valve according to claim 1, wherein the valve seat is close to one end of the valve core, and the inner wall of the valve seat is a smooth curved surface;

When the valve seat is in contact with the valve core, the inner wall of the valve seat is tangent to the outer surface of the valve core.
The axial flow control valve according to claim 4, wherein the axial section of the inner wall of the valve seat is in the shape of an arc.
The axial flow control valve according to claim 1, wherein the outer circumferences of both ends of the valve seat are respectively provided with annular sealing rings, so as to be sealed with the inner wall of the valve body.
The axial flow control valve according to claim 1, wherein a rack is provided on the outer periphery of the valve seat, the driving device comprises an actuator and a gear, the actuator is used to drive the gear, and the The gear is drivingly connected with the rack.
The axial flow control valve according to claim 1, characterized in that, the outer periphery of the valve seat is provided with a thread, the driving device comprises an actuator and a worm, the actuator is used to drive the screw, the The worm is in driving connection with the thread.
The axial flow flow control valve according to claim 1, wherein the driving device comprises an actuator and a cylinder or a hydraulic cylinder, the actuator is used to drive the piston of the cylinder or the hydraulic cylinder, the The piston rod of the air cylinder or the hydraulic cylinder is connected to the outer periphery of the valve seat.
The axial flow control valve according to claim 1, further comprising a plurality of support sheets, the plurality of support sheets are evenly distributed along the circumference of the valve core, and one end of the support sheet is connected to the The outer circumference of the valve core and the other end are connected to the inner wall of the valve body.
The axial-flow flow control valve according to claim 1, wherein a high-pressure pressure-taking hole and a low-pressure pressure-taking hole are arranged on the side wall of the valve body, and the high-pressure pressure-taking hole faces toward the valve core. One end of the fluid inlet, the low-pressure pressure taking hole is close to the middle of the valve core;

The flow control valve further comprises a differential pressure flowmeter, the high pressure inlet end and the low pressure inlet section of the differential pressure flowmeter are respectively connected with the high pressure taking hole and the low pressure taking hole to measure the flow;

The driving device is connected with the differential pressure flowmeter, and drives the valve seat to move along the axial direction of the valve body according to the flow measured by the differential pressure flowmeter, thereby realizing closed-loop control.