A differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve

Abstract

The present invention discloses a differential pressure type self - adaptive pressure - limiting and flow - stabilizing valve, which comprises a valve body and a pressure self - adaptive component; the pressure self - adaptive component includes a piston, a pressure - limiting spring, a fixed baffle plate and a movable flow - through pipe; the flow - through pipe and the fixed baffle plate are arranged in the valve body, the flow - through pipe is communicated with the valve inlet of the valve body, the piston is arranged at the inlet end of the flow - through pipe, the pressure - limiting spring is sleeved on the flow - through pipe, and the outlet end of the flow - through pipe is closed; a cone is arranged inside the bottom end of the valve body; the outlet end of the flow - through pipe is closed and is provided with a conical surface seal, the conical surface seal is located inside the cone, a plurality of conical holes are formed in the conical surface seal, a fixed conical surface outlet is formed in the cone, and the fixed conical surface outlet is communicated with the valve outlet of the valve body; a plurality of micropores are formed in the flow - through pipe located inside the cone. The present invention can realize continuous adjustment of the flow rate under various pressure conditions, keep the flow rate within a stable range, and at the same time has the advantages of simple structure, mechanical automatic control, strong adaptability and convenient maintenance.

Description

Technical Field

[0001] The present invention belongs to the technical field of valves, and particularly relates to a differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve. Background Art

[0002] With the rapid development of the power industry, 600MW and 1000MW capacity units in the existing thermal power generating units in China have become the main force of power supply. A large number of instruments are used in the generating units to monitor the water and steam quality of the water and steam system. Under the current spot trading mode of the power grid, when the generating unit is in deep peak shaving of the power grid, the operating load of the unit will fluctuate violently. Taking a 1000MW unit as an example, the load mutation range of the unit is 100 - 800MW. Due to the certain hysteresis of the water and steam system, the steam flow rate, the pressure and flow rate of the feed water become unstable at this time, thus affecting the use effect of the measuring instrument from the sampling point to the measuring point. Usually, the required flow range of the measuring instrument is about 200 - 300 mL / min. Existing regulating valves, pressure stabilizing valves, flow limiting valves and other various products all have many problems such as complex structure, large volume, poor reliability, high price and inconvenient installation. They are particularly not suitable for variable or rapidly changing working conditions. Therefore, a valve that can automatically adjust the flow rate is needed to ensure the measurement accuracy and precision of the measuring instrument and realize the protection of the instrument. Summary of the Invention

[0003] To solve the above problems, the present invention provides a differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve, which can automatically adjust the flow rate, ensure the measurement accuracy and precision of the measuring instrument, and realize the protection of the instrument.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve includes a hollow tubular valve body and a pressure self-adaptive component;

[0006] The pressure self-adaptive component includes a piston, a pressure-limiting spring, a fixed baffle and a movable flow tube;

[0007] The flow tube and the fixed baffle are arranged in the valve body. The flow tube is communicated with the valve inlet of the valve body. The flow tube passes through the fixed baffle. The piston is arranged at the inlet end of the flow tube. The pressure-limiting spring is sleeved on the flow tube. One end of the pressure-limiting spring contacts the piston, and the other end contacts the fixed baffle. The outlet end of the flow tube is closed;

[0008] A cone is arranged inside the bottom end of the valve body;

[0009] The outlet end of the flow tube is closed and is provided with a conical seal. The conical seal is located inside the cone. A plurality of conical holes are opened on the conical seal. A fixed conical outlet is opened on the cone. The fixed conical outlet is communicated with the valve outlet of the valve body; A plurality of micropores are opened on the flow tube located inside the cone.

[0010] Further, an upper valve seat is provided at the top of the valve body, the valve inlet is provided on the upper valve seat, a lower valve seat is provided at the bottom of the valve body, the valve inlet is provided on the upper valve seat, and the valve outlet is provided on the lower valve seat.

[0011] Further, the upper valve seat is threadedly connected to the valve body, and the lower valve seat is threadedly connected to the valve body.

[0012] Further, the cone includes a circular bottom plate, the circular bottom plate is perpendicularly arranged with the flow pipe, and the flow pipe passes through the circular bottom plate. A baffle is provided on the circular bottom plate, and a fixed conical surface is provided on the baffle, and the fixed conical surface matches the conical surface sealing structure.

[0013] Further, a fixed conical surface outlet is formed on the fixed conical surface, and the fixed conical surface outlet is communicated with the valve outlet.

[0014] Further, when the pressure at the valve inlet is greater than the pressure value of the pressure-limiting spring, the piston squeezes the pressure-limiting spring, and by pushing the flow pipe to press the conical surface to the fixed conical surface, the number of conical holes through which the liquid can flow decreases, and the flow rate at the valve outlet becomes smaller.

[0015] Further, when the pressure at the valve inlet is equal to the fixed pressure value of the pressure-limiting spring, the pressure-limiting spring does not act, and the number of conical holes through which the liquid can flow remains constant, and the flow rate at the valve outlet remains unchanged.

[0016] Further, when the pressure at the valve inlet is lower than the fixed pressure value of the pressure-limiting spring, the pressure-limiting spring pushes the piston in the opposite direction, and the number of conical holes through which the liquid can flow increases, and the flow rate at the valve outlet becomes larger.

[0017] Further, the piston is made of stainless steel.

[0018] Further, the sealing conical surface is made of a polymer elastic membrane.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] By providing a conical surface seal that matches the cone, the flow tube can move, compress the pressure-limiting spring, and drive the conical surface seal to move. When the conical surface seal fits with the cone, the number of conical holes in the flow channel of the fluid is reduced, thereby adjusting the fluid flow rate. This steady flow valve has a simple structure and is convenient to use. In the case of sharp changes in the inlet pressure and flow rate, the pressure self-adaptive component can automatically adjust the number of conical holes in the conical surface seal according to the pressure difference between the valve inlet and the pressure-limiting spring, and the pressure difference range is (0 to ±3 MPa), so as to continuously control the flow rate and keep the flow rate at the valve outlet stable within (260 ± 20) mL, thereby realizing continuous control of the flow rate and keeping the outlet flow rate stable within a certain range, so as to meet the requirements of various measuring instruments for the flow rate; secondly, it has strong adaptability and a wide application range. The flowing fluid can be a gas or a liquid. By replacing the pressure-limiting spring and switching the types of membrane holes in the sealing conical surface, different scenarios can be applied; the pressure-limiting steady flow valve of the present invention does not require an additional electric component and is purely mechanically automatically controlled, which is simple and convenient to maintain.

[0021] Further, Brief Description of the Drawings

[0022] Figure 1 is a structural schematic diagram of a differential pressure type self-adaptive pressure-limiting steady flow valve of the present invention;

[0023] Figure 2 is a structural schematic diagram of the pressure self-adaptive component of the present invention;

[0024] Figure 3 is a sectional view of the conical surface seal of the present invention;

[0025] Figure 4 is a sectional view of the fixed conical surface of the present invention.

[0026] Description of the Reference Numerals:

[0027] 1. Upper valve seat; 2. Valve body; 3. Lower valve seat; 4. Piston; 5. Pressure-limiting spring; 6. Conical surface seal; 7. Conical holes; 8. Fixed conical surface; 9. Valve outlet; 10. Fixed baffle; 11. Positioning pin; 12. Micropores; 13. Valve inlet; 14. Flow tube; 15. Spring placement cavity; 16. Fixed conical surface outlet; 17. Conical surface seal cavity. Detailed Embodiment

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments.

[0029] As Figure 1 , Figure 2 , Figure 3 and Figure 4As shown in the figure, a differential pressure type self - adapting pressure - limiting and flow - stabilizing valve of the present invention includes an upper valve seat 1, a hollow tubular valve body 2, a pressure self - adapting component, and a lower valve seat 3.

[0030] The upper valve seat 1 is arranged at the top end of the valve body 2 and is in communication with the valve body 2, and the upper valve seat 1 and the valve body 2 are connected by threads; the lower valve seat 3 is arranged at the bottom end of the valve body 2, and the lower valve seat 3 and the valve body 2 are also connected by threads. A valve inlet 13 is arranged on the upper valve seat 1, and a valve outlet 9 is arranged on the lower valve seat 3.

[0031] As Figure 2 shown, the pressure self - adapting component includes a piston 4, a flow - through pipe 14, a pressure - limiting spring 5, a conical seal 6, and a fixed baffle 10.

[0032] Among them, the flow - through pipe 14 is arranged inside the valve body 2 and is arranged along the length direction of the valve body 2. The inlet end of the flow - through pipe 14 is provided with a piston 4, and a fixed baffle 10 is also arranged on the flow - through pipe 14. Specifically, the flow - through pipe 14 passes through the fixed baffle 10. The piston 4 contacts the inner wall of the valve body 2, and the fixed baffle 10 contacts the inner wall of the valve body 2. The cavity formed among the piston 4, the fixed baffle 10, and the valve body 2 is a pressure - limiting spring placement cavity 15. The pressure - limiting spring 5 is sleeved on the flow - through pipe 14, one end contacts the piston 4, and the other end contacts the fixed baffle 10. The piston 4 moves along the inner wall of the valve body 2, thereby pushing the flow - through pipe 14 in the direction of the valve outlet 9, and the outlet end of the flow - through pipe 14 is closed.

[0033] A cone is arranged inside the bottom end of the valve body 2, and a conical seal 6 is arranged inside the cone. The cone includes a circular bottom plate, and the circular bottom plate is perpendicular to the flow - through pipe 14. The flow - through pipe 14 passes through the circular bottom plate. A baffle is arranged on the circular bottom plate, and a fixed conical surface 8 is arranged on the baffle. A plurality of conical holes 7 are arranged on the conical seal 6, and the fixed conical surface 8 is fixed by a positioning pin 11.

[0034] Refer to Figure 4 , a fixed conical surface outlet 16 is arranged on the fixed conical surface 8, the fixed conical surface outlet 16 is in communication with the valve outlet 9, the diameter of the fixed conical surface outlet 16 is smaller than the diameter of the valve outlet 9, and the diameter of the flow - through pipe 14 is smaller than the diameter of the fixed conical surface outlet 16.

[0035] The conical surface seal 6 matches the structure of the fixed conical surface 8. Specifically, the conical surface seal 6 and the fixed conical surface 8 have the same center line in the direction of fluid outflow. The conical surface seal 6 moves closely along the fluid direction against the fixed conical surface 8. As the moving distance increases, the fitting surface of the two increases, the number of conical holes 7 decreases, and the fluid flow rate becomes smaller. When the conical surface seal 6 moves to the maximum position, the conical surface seal 6 and the fixed conical surface 8 are completely fitted, and only a small number of conical holes 7 are left in the conical surface seal 6 for the fluid to flow out from the fixed conical surface outlet 16. Conversely, when the conical surface seal 6 moves against the fluid direction, the number of conical holes 7 increases and the flow rate increases.

[0036] When the conical surface seal 6 and the fixed conical surface 8 are completely fitted, there are still some conical holes 7 near the flow pipe 14 on the conical surface seal 6 that are connected to the fixed conical surface outlet 16.

[0037] The cavity formed by the conical surface seal 6 and the circular bottom plate is the conical surface seal cavity 17. A number of micropores 12 (with a pore diameter generally of 10 - 500 μm) are provided on the side wall of the flow pipe 14 located in the conical surface seal cavity 17, that is, all the micropores 12 are located within the conical surface seal cavity 17.

[0038] Through the pressure difference between the valve inlet 13 and the pressure limiting spring 5, the pressure limiting spring 5 pushes the flow pipe 14 to drive the conical surface seal 6 to act, controls the number of conical holes 7, realizes the automatic continuous adjustment of the flow rate, and keeps the flow rate at the valve outlet 9 stable at 260 ± 20 mL.

[0039] When the pressure at the valve inlet 13 is greater than the pressure value of the pressure limiting spring 5, the pressure difference is defined as positive (+). The piston 4 squeezes the pressure limiting spring 5, and by pushing the flow pipe 14, presses the conical surface seal 6 against the fixed conical surface 8. At this time, the number of conical holes 7 through which the liquid can flow decreases, and the flow rate at the valve outlet 9 becomes smaller;

[0040] When the pressure at the valve inlet 13 is equal to the fixed pressure value of the pressure limiting spring 5, the pressure difference is defined as 0, and the pressure limiting spring 5 does not act. At this time, the number of conical holes 7 through which the liquid can flow remains constant, and the flow rate at the valve outlet 9 remains unchanged;

[0041] When the pressure at the valve inlet 13 is lower than the fixed pressure value of the pressure limiting spring 5, the pressure difference is defined as negative (-). The pressure limiting spring 5 pushes the piston 4 back to the original position, and the number of conical holes 7 through which the liquid can flow increases, and the flow rate at the valve outlet 9 becomes larger.

[0042] The material of the piston 4 is stainless steel, and wear-resistant rubber is embedded on the outer edge. The sealing conical surface 6 is a polymer elastic membrane, and the polymer elastic membrane is preferably a microporous membrane, a porous membrane, a fiber membrane or a composite membrane.

[0043] By increasing the pressure at the valve inlet 13 so that the pressure at the valve inlet 13 ≥ the pressure of the pressure limiting spring, for the result of the change of the flow rate at the valve outlet 9 with the pressure difference, see Table 1.

[0044] Table 1 Results of the flow rate at the valve outlet varying with the pressure difference

[0045]

[0046]

[0047] By reducing the pressure at the valve inlet 13 such that the pressure at the valve inlet 13 ≤ the pressure of the pressure-limiting spring, for the results of the flow rate at the valve outlet 9 varying with the pressure difference, see Table 2.

[0048] Table 2 Measured data of the flow rate at the valve outlet varying with the pressure difference

[0049] Pressure difference / MPa Valve outlet flow rate / (mL / min) 0 279.8 -0.2 276.4 -0.58 272.4 -1.45 268.8 -2.02 263.3 -2.45 257.9 -2.89 244.7

[0050] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A differential pressure type self - adapting pressure - limiting and flow - stabilizing valve, characterized in that, It includes a hollow tubular valve body (2) and a pressure self - adapting component; The pressure self - adapting component includes a piston (4), a pressure - limiting spring (5), a fixed baffle (10), and a movable flow - through pipe (14); The flow - through pipe (14) and the fixed baffle (10) are arranged inside the valve body (2). The flow - through pipe (14) is communicated with the valve inlet (13) of the valve body (2). The flow - through pipe (14) passes through the fixed baffle (10). The piston (4) is arranged at the inlet end of the flow - through pipe (14). The pressure - limiting spring (5) is sleeved on the flow - through pipe (14). One end of the pressure - limiting spring (5) contacts the piston (4), and the other end contacts the fixed baffle (10). The outlet end of the flow - through pipe (14) is closed; A cone is arranged inside the bottom end of the valve body (2); The outlet end of the flow - through pipe (14) is closed and is provided with a conical seal (6). The conical seal (6) is located inside the cone. A number of conical holes (7) are formed on the conical seal (6). A fixed conical outlet (16) is formed on the cone. The fixed conical outlet (16) is communicated with the valve outlet (9) of the valve body (2). A number of micropores (12) are formed on the flow - through pipe (14) located inside the cone; The cone includes a circular bottom plate. The circular bottom plate is perpendicular to the flow - through pipe (14), and the flow - through pipe (14) passes through the circular bottom plate. A baffle is arranged on the circular bottom plate, and a fixed conical surface (8) is arranged on the baffle. The fixed conical surface (8) matches the structure of the conical seal (6); When the pressure at the valve inlet (13) is greater than the pressure value of the pressure - limiting spring (5), the piston (4) squeezes the pressure - limiting spring (5), and by pushing the flow - through pipe (14) to press the conical seal (6) against the fixed conical surface (8), the number of conical holes (7) through which liquid can flow decreases, and the flow rate at the valve outlet (9) becomes smaller.

2. The differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve according to claim 1, wherein An upper valve seat (1) is arranged at the top end of the valve body (2). The valve inlet (13) is arranged on the upper valve seat (1). A lower valve seat (3) is arranged at the bottom end of the valve body (2). The valve inlet (13) is arranged on the upper valve seat (1), and the valve outlet (9) is arranged on the lower valve seat (3).

3. The differential pressure type self-adaptive pressure limiting and flow stabilizing valve according to claim 2, wherein, The upper valve seat (1) is connected to the valve body (2) by threads, and the lower valve seat (3) is connected to the valve body (2) by threads.

4. The differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve according to claim 1, wherein A fixed conical outlet (16) is formed on the fixed conical surface (8), and the fixed conical outlet (16) is communicated with the valve outlet (9).

5. The differential pressure type self - adapting pressure - limiting and flow - stabilizing valve according to claim 1, wherein, When the pressure at the valve inlet (13) is equal to the fixed pressure value of the pressure - limiting spring (5), the pressure - limiting spring (5) does not act, and the number of conical holes (7) through which liquid can flow remains constant, and the flow rate at the valve outlet (9) remains unchanged.

6. The differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve according to claim 1, wherein When the pressure at the valve inlet (13) is lower than the fixed pressure value of the pressure - limiting spring (5), the pressure - limiting spring (5) pushes the piston (4) in the opposite direction, the number of conical holes (7) through which liquid can flow increases, and the flow rate at the valve outlet (9) becomes larger.

7. The differential pressure type self-adaptive pressure limiting and flow stabilizing valve according to claim 1, wherein The material of the piston (4) is stainless steel.

8. The differential pressure type self-adaptive pressure-limiting and flow-stabilizing valve according to claim 1, wherein The material of the conical seal (6) is a polymer elastic membrane.

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