Steam extraction regulating valve and steam extraction regulating valve performance optimization method

Abstract

The steam extraction regulating valve comprises a valve body, a valve cover, a valve cage and a valve element, a first cavity is formed between the valve body and the valve cover, the valve body is provided with a first inlet and a first outlet, the valve cage is arranged in the first cavity, and a first chamber is formed between the outer wall of the valve cage and the inner wall of the first cavity; the first chamber is communicated with the first inlet, a second chamber is formed in the middle of the valve cage and communicated with the first outlet, and a through-flow hole is formed in the side wall of the valve cage. The valve element is arranged in the second chamber, the valve element can slide in the axis direction of the valve cage, the valve element is provided with a first matching surface and a second matching surface which are arranged in the axis direction of the valve element in a spaced mode, and the first matching surface and the second matching surface abut against the inner wall of the valve cage; when the air exhaust adjusting valve is in a closed state, the first matching face and the second matching face are located on the two sides of the through-flow hole in the axis direction of the valve cage respectively. According to the steam extraction regulating valve, the stress performance of the valve trim can be optimized, and the stability of the steam extraction regulating valve is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power units, and in particular relates to a steam extraction regulating valve and a method for optimizing the performance of the steam extraction regulating valve. Background Art

[0002] In recent years, as power technology develops towards high-parameter and large-capacity units, in order to meet the needs of high-efficiency and wide-load operation of units with a single capacity of one million, the feed water temperature of the unit is increased to improve the thermal cycle efficiency and reduce coal consumption, and the #0 high-pressure heater (abbreviated as "0 high-pressure heater") is installed. The inlet steam of the 0 high-pressure heater is taken from the high-pressure cylinder of the steam turbine. The steam pressure is high and needs to be reduced by the high-pressure heater extraction regulating valve before entering the 0 high-pressure heater. The high-pressure heater extraction regulating valve has poor operating conditions and insufficient stability. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides a steam extraction regulating valve, which can optimize the stress performance of valve trim and improve the stability of the steam extraction regulating valve.

[0005] An embodiment of the present invention also provides a method for optimizing the performance of a steam extraction regulating valve.

[0006] The steam extraction regulating valve according to the embodiment of the present invention comprises:

[0007] A valve body and a valve cover connected to each other, wherein a first cavity is formed between the valve body and the valve cover, and the valve body has a first inlet and a first outlet;

[0008] A cage, the cage is arranged in the first cavity, a first chamber is formed between the outer wall of the cage and the inner wall of the first cavity, the first chamber is communicated with the first inlet, a second chamber is formed in the middle of the cage, the second chamber is communicated with the first outlet, and a through hole is provided on the side wall of the cage, the through hole is used to communicate the first chamber with the second chamber;

[0009] A valve core, the valve core is arranged in the second chamber and is slidable along the axial direction of the valve cage, the valve core has a first mating surface and a second mating surface arranged at intervals along the axial direction thereof, and the first mating surface and the second mating surface are both in contact with the inner wall of the valve cage;

[0010] When the air extraction regulating valve is in a closed state, the first mating surface and the second mating surface are respectively located on two sides of the through hole in the axial direction of the valve cage.

[0011] The steam extraction regulating valve of the embodiment of the present invention can optimize the stress performance of the valve trim and improve the stability of the steam extraction regulating valve.

[0012] In some embodiments, the inner wall surface of the valve cage has a third mating surface and a fourth mating surface, and the third mating surface and the fourth mating surface are respectively located on both sides of the flow hole in the axial direction of the valve cage, the first mating surface abuts the third mating surface, and the second mating surface abuts the fourth mating surface.

[0013] In some embodiments, the first mating surface and the second mating surface have a first metallographic structure, the third mating surface and the fourth mating surface have a second metallographic structure, and the first metallographic structure and the second metallographic structure are produced by different heat treatment processes.

[0014] In some embodiments, the inner wall surface of the valve cage includes a first section, a second section, and a third section arranged in sequence along its axial direction, the inner diameters of the second section and the third section are equal, the inner diameter of the first section is smaller than the inner diameters of the second section and the third section, the flow hole is located in the second section, the third mating surface is located in the first section, and the fourth mating surface is located in the third section.

[0015] In some embodiments, there are multiple flow holes, and the multiple flow holes are distributed in the second section, and the flow area of ​​the second section at one end close to the first outlet is smaller than the flow area of ​​the second section at one end away from the first outlet.

[0016] In some embodiments, the through-hole comprises a first hole and a second hole, the first hole is a circular hole, the second hole is a strip-shaped hole, a plurality of the first holes and at least one of the second holes are sequentially arranged along the opening direction of the valve core and form a group of through-hole groups, a plurality of groups of the through-hole groups are sequentially arranged along the circumferential direction of the valve cage, and the first hole is closer to the first outlet than the second hole;

[0017] The first holes between adjacent flow hole groups are staggered in the circumferential direction of the cage.

[0018] In some embodiments, the outer wall surface of the valve core includes an intermediate section located between the first mating surface and the second mating surface, and the inner diameter of the intermediate section is smaller than the inner diameter of the first section;

[0019] And / or, an annular boss is provided on the outer wall surface of the valve core, and the outer wall surface of the boss forms the second matching surface.

[0020] In some embodiments, a valve seat is further included, the valve seat is connected to the valve body, the valve seat has a first sealing surface, the valve core has a second sealing surface, and when the air extraction regulating valve is in a closed state, the first sealing surface and the second sealing surface are in contact with each other;

[0021] The valve core is provided with an anti-impact groove, and the second sealing surface is arranged at the bottom of the anti-impact groove.

[0022] In some embodiments, one end of the valve core close to the valve seat has an expansion section and a guide section, and the expansion section and the guide section are arranged on the side of the second mating surface close to the first outlet, and the guide section is frustum-shaped, and the radial dimension of the expansion section is smaller than the radial dimension of the second mating surface, so that an expansion cavity is formed between the expansion section and the inner wall of the valve cage; the anti-collision groove is located between the expansion section and the guide section.

[0023] And / or, it also includes a valve stem and a pre-start valve core, the pre-start valve core is connected to the valve core, one end of the valve stem is connected to the pre-start valve core, and the other end of the valve stem is slidably matched with the valve cover.

[0024] The method for optimizing the performance of a steam extraction regulating valve according to an embodiment of the present invention is used to manufacture the steam extraction regulating valve described in any one of the above embodiments, and comprises the following steps:

[0025] Establish a mathematical model based on the original control valve to obtain flow field data;

[0026] Obtain the abnormal operation data of the original control valve;

[0027] Based on the flow field data and the abnormal operation data, the structure and assembly relationship of the valve core and the valve cage are determined, a first mating surface and a second mating surface are provided on the valve core, and a third mating surface and a fourth mating surface are provided on the valve cage, so that when the air extraction regulating valve is in a closed state, the first mating surface abuts against the third mating surface, the second mating surface abuts against the fourth mating surface, and the resultant force of the medium acting on the valve core and the valve stem is directed toward the first outlet;

[0028] Based on the flow field data and the abnormal operation data, the structure and assembly relationship of the valve core and the valve seat are determined, a first sealing surface is provided on the valve seat, an anti-collision groove and a second sealing surface are provided on the valve core, and the second sealing surface is arranged at the bottom of the anti-collision groove to prevent the medium from eroding the second sealing surface;

[0029] Based on the flow field data and the abnormal operation data, determining a structure of the flow hole in the valve cage, and making the flow area of ​​one end of the valve cage close to the first outlet smaller than the flow area of ​​one end of the valve cage far from the first outlet;

[0030] Based on the flow field data and the abnormal operation data, the material of the valve trim, the smelting process of at least part of the valve trim, and the heat treatment process of at least part of the valve trim are determined to meet the expansion margin of the valve trim under preset working conditions and the sliding performance between at least part of the valve trim. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a steam extraction regulating valve according to an embodiment of the present invention.

[0032] Figure 2 It is a structural schematic diagram of a steam extraction regulating valve according to another embodiment of the present invention.

[0033] Figure 3 yes Figure 2 Schematic diagram of the enlarged structure of part A in the middle.

[0034] Figure 4 It is a schematic structural diagram of a valve core according to an embodiment of the present invention.

[0035] Figure 5 Schematic diagram of the structure of a valve cage according to an embodiment of the present invention.

[0036] Figure 6 Schematic diagram of the structure of the through-flow hole in an embodiment of the present invention.

[0037] Reference numerals:

[0038] 100. Steam extraction regulating valve;

[0039] 1. valve body; 11. first cavity; 111. first chamber; 112. second chamber; 12. first inlet; 13. first outlet;

[0040] 2. Valve cover;

[0041] 3. Valve cage; 31. Through hole; 32. First hole; 33. Second hole; 34. Through hole group; 35. Third mating surface; 36. Fourth mating surface; 37. First section; 38. Second section; 39. Third section;

[0042] 4. valve core; 41. first matching surface; 42. second matching surface; 43. middle section; 44. boss; 45. second sealing surface; 46. anti-collision groove; 47. expansion section; 48. guide section;

[0043] 51. Valve stem; 52. Pre-start valve core;

[0044] 6. Valve seat; 61. First sealing surface. DETAILED DESCRIPTION

[0045] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0046] The operating conditions of the high-pressure steam extraction regulating valve are: under the load of 1000MW, the medium pressure is: the maximum is lower than 15MPa. The medium temperature is: the maximum is lower than 530℃.

[0047] The inventors have realized that the following problems exist in the operation of the steam extraction regulating valve:

[0048] 1. During the operation of the valve, the valve vibrates greatly and becomes stuck during opening and closing and adjustment; the valve stem rotates; and the valve opens and closes automatically and leaks. After multiple inspections and replacement of spare parts, the results are not good, causing great safety hazards and economic losses to the user.

[0049] 2. The valve vibrates violently, becomes stuck, and the valve stem rotates.

[0050] 3. During the process of opening, closing and adjusting the valve, the valve vibrates violently, makes loud noises and has obvious sticking phenomena.

[0051] 4. Valve stem rotation. When the unit load is high, even if the valve does not move, the valve stem rotates back and forth irregularly.

[0052] 5. The valve adjustment linearity is poor. The valve full stroke adjustment linearity is poor. The valve has a certain adjustment performance only in the small opening section. When the valve opening is greater than 30%, it no longer has the adjustment ability.

[0053] 6. The valve opens and closes automatically. When no valve action signal is given, the valve automatically opens, closes or moves back and forth irregularly.

[0054] 7. The valve is leaking. There is significant leakage along the valve stem.

[0055] Through further analysis, the inventors realized that the main reasons are:

[0056] 1. The valve flow field is uneven and the valve pressure difference is high. Due to the high-pressure area at the inlet and the low-pressure area at the bottom of the valve, the flow field inside the valve is uneven, and turbulence and eddy currents are formed on the non-inlet side of the valve. The valve stem rotates irregularly under the combined action of the inlet medium and the eddy current.

[0057] 2. The force on the valve core is unbalanced and the valve pressure difference is high. Although a balancing hole is set on the upper part of the valve cage, the hole diameter is small and cannot balance the unbalanced force on the valve core. The resultant force on the valve core is unilaterally upward along the flow direction of the inlet medium, and the force is large, resulting in jamming, vibration, and automatic opening of the valve during the opening and closing and adjustment process.

[0058] 3. The clearance between the valve core and the cage is too large. The valve core and the cage only form a matching surface on the upper part of the cage. When the valve is opened, closed and adjusted, the valve core is subjected to a single-sided oblique force, and the valve core and the valve stem form a cantilever structure. The valve core and the valve stem vibrate, causing the valve to vibrate and become stuck. At the same time, the vibration of the valve stem causes the valve stem packing to loosen and the valve to leak.

[0059] 4. The cage structure is not designed properly. When the valve opening is greater than 40%, the valve tends to be fully open and the flow rate increases. At this time, the valve vibration intensifies and the steam medium flow is unstable. The cage flow structure is a full-body strip window with a linear physical flow area. When the opening is small, the valve pressure difference is high; when the opening is large, the valve pressure difference is low; resulting in poor regulation linearity. After the valve opening exceeds 40%, the valve almost loses its regulation performance.

[0060] Based on at least part of the above problems, an embodiment of the present invention provides a steam extraction regulating valve 100, such as Figure 1 - to 6.

[0061] like Figure 1-Figure 5 As shown, specifically, the steam extraction regulating valve 100 according to the embodiment of the present invention comprises a valve body 1 and a valve cover 2 connected to each other, a first cavity 11 is formed between the valve body 1 and the valve cover 2 , and the valve body 1 has a first inlet 12 and a first outlet 13 .

[0062] The steam extraction regulating valve 100 further includes a valve cage 3 and a valve core 4. The valve cage 3 is arranged in the first cavity 11. A first chamber 111 is formed between the outer wall of the valve cage 3 and the inner wall of the first cavity 11. The first chamber 111 is communicated with the first inlet 12. A second chamber 112 is formed in the middle of the valve cage 3. The second chamber 112 is communicated with the first outlet 13. A through hole 31 is provided on the side wall of the valve cage 3. The through hole 31 is used to communicate the first chamber 111 with the second chamber 112. The valve core 4 is arranged in the second chamber 112, and the valve core 4 is slidable along the axial direction of the valve cage 3. The valve core 4 has a first mating surface 41 and a second mating surface 42 arranged at intervals along the axial direction thereof. The first mating surface 41 and the second mating surface 42 are both in contact with the inner wall of the valve cage 3. When the air extraction regulating valve is in a closed state, the first mating surface 41 and the second mating surface 42 are respectively located on both sides of the through hole 31 in the axial direction of the valve cage 3.

[0063] It should be understood that the valve core 4 of the steam extraction regulating valve 100 is in contact with the valve cage 3 through the first mating surface 41 and the second mating surface 42, which increases the rigidity of the valve core 4 and effectively prevents the valve core 4 from oscillating. At the same time, after the first mating surface 41 and the second mating surface 42 are in contact with the valve cage 3, the mating clearance in the corresponding area can be reduced. When the steam extraction regulating valve is in a closed state, the flow hole 31 is located between the first mating surface 41 and the second mating surface 42, which can further prevent oscillations caused by uneven flow field and unstable force on the valve core 4.

[0064] The valve core 4 and the valve cage 3 are coaxially arranged, and the axial direction of the valve core 4 is the same as the axial direction of the valve cage 3, both of which are in the up-and-down direction as shown in the figure.

[0065] Compared with the solutions in the related art, the embodiment of the present invention can change the assembly relationship between the valve core 4 and the valve cage 3, and can optimize the flow field distribution of the medium in the valve cage 3 and the valve core 4, so that the stability of the valve core 4 is better. The steam extraction regulating valve 100 of the embodiment of the present invention can optimize the stress performance of the valve trim and improve the stability of the steam extraction regulating valve 100.

[0066] like Figure 1 , Figure 4 and Figure 5 As shown, in some embodiments, the inner wall surface of the valve cage 3 has a third mating surface 35 and a fourth mating surface 36, and the third mating surface 35 and the fourth mating surface 36 are respectively located on both sides of the flow hole 31 in the axial direction of the valve cage 3, the first mating surface 41 abuts against the third mating surface 35, and the second mating surface 42 abuts against the fourth mating surface 36.

[0067] That is to say, after the valve core 4 and the valve cage 3 are assembled, the first mating surface 41 of the valve core 4 and the third mating surface 35 of the valve cage 3 abut against each other and can slide relative to each other, and the second mating surface 42 of the valve core 4 and the fourth mating surface 36 of the valve cage 3 abut against each other and can slide relative to each other. While meeting the sliding performance, it is ensured that there is a good abutment effect between the two, reducing the gap between each other, and ensuring the rigidity and structural stability of the valve core 4.

[0068] Furthermore, the first mating surface 41 and the second mating surface 42 have a first metallographic structure, the third mating surface 35 and the fourth mating surface 36 have a second metallographic structure, and the first metallographic structure and the second metallographic structure are produced by different heat treatment processes.

[0069] Different heat treatment processes are used for the mating surfaces of the valve cage 3 and the valve core 4, respectively, so that metallographic structure differences are generated between the first mating surface 41 and the third mating surface 35, and metallographic structure differences are generated between the second mating surface 42 and the fourth mating surface 36. Under high temperature and high pressure conditions, the valve core 4 and the valve cage 3 are prevented from biting and causing jamming, the relative sliding performance of the valve cage 3 and the valve core 4 is improved, and the movement of the valve core 4 is smoother.

[0070] In some embodiments, the inner wall surface of the valve cage 3 includes a first section 37, a second section 38 and a third section 39 arranged in sequence along its axial direction, the inner diameters of the second section 38 and the third section 39 are equal, the inner diameter of the first section 37 is smaller than the inner diameters of the second section 38 and the third section 39, the flow hole 31 is located in the second section 38, the third mating surface 35 is located in the first section 37, and the fourth mating surface 36 is located in the third section 39.

[0071] During the movement of the valve core 4, the first mating surface 41 of the valve core 4 corresponds to the third mating surface 35 on the first section 37, and the second mating surface 42 of the valve core 4 corresponds to the fourth mating surface 36 on the third section 39. Of course, during the opening of the valve core 4, the second mating surface 42 of the valve core 4 will also move to the second section 38 and abut against the wall surface of the second section 38. Therefore, the fourth mating surface 36 can also extend to the second section 38. During the opening and closing of the valve core 4, the first mating surface 41 and the second mating surface 42 of the valve core 4 will always be supported and constrained in the circumferential direction to ensure the structural stability and rigidity of the valve core 4.

[0072] Furthermore, there are multiple through holes 31 distributed in the second section 38 , and the flow area of ​​the second section 38 at one end close to the first outlet 13 is smaller than the flow area of ​​the second section 38 at one end away from the first outlet 13 .

[0073] The flow hole 31 is arranged in the second section 38, so when the valve core 4 is in a closed state, there is no flow hole 31 on the side of the second mating surface 42 close to the first outlet 13, and the force of the medium acting on the valve core 4 is located between the first mating surface 41 and the second mating surface 42, thereby ensuring the force stability of the valve core 4, and based on the first inlet 12 and high pressure and the first outlet 13 low pressure, the force of the valve core 4 and the valve stem 51 is directed toward the first outlet 13, preventing the valve core 4 from malfunctioning, causing the valve to tend to close under the force of the medium, and ensuring that the valve does not leak.

[0074] In the embodiment of the present invention, the flow area of ​​the end of the second section 38 close to the first outlet 13 is smaller than the flow area of ​​the end of the second section 38 away from the first outlet 13. It should be understood that the flow area per unit area of ​​the end of the second section 38 close to the first outlet 13 is smaller than the flow area per unit area of ​​the end of the second section 38 away from the first outlet 13.

[0075] For example, the aperture of the flow hole 31 at the end of the second section 38 close to the first outlet 13 is small, and the aperture of the flow hole 31 at the end of the second section 38 away from the first outlet 13 is large. Under the premise that the spacing distance of the flow holes 31 is constant, the flow area at the end of the second section 38 close to the first outlet 13 is smaller than the flow area at the end of the second section 38 away from the first outlet 13.

[0076] For example, Figure 6As shown, the flow hole 31 includes a first hole 32 and a second hole 33, the first hole 32 is a circular hole, and the second hole 33 is a strip hole. Multiple first holes 32 and at least one second hole 33 are arranged in sequence along the opening direction of the valve core 4 and form a group of flow hole groups 34. Multiple groups of flow hole groups 34 are arranged in sequence along the circumferential direction of the valve cage 3, and the first hole 32 is close to the first outlet 13 relative to the second hole 33; the first holes 32 between adjacent flow hole groups 34 are staggered in the circumferential direction of the valve cage 3.

[0077] By optimizing the flow hole 31, the flow through the lower part of the cage 3 (the end close to the first outlet 13) can adopt a small hole structure, and the diameter of the flow through hole 31 in the upper part of the cage 3 (the end away from the first outlet 13) gradually increases and adopts a strip hole. When the valve is opened at a small degree, the unbalanced force on the valve core 4 can be reduced, and the valve can be prevented from opening automatically; at the same time, when the valve is opened at a small degree, the valve pressure difference is the highest, and as the valve opens, the pressure difference gradually decreases. The diameter of the flow through hole of the cage 3 is gradually increased from bottom to top, which can ensure that the valve adjustment performance is well linear, and the flow capacity of the valve opening above 75% is not lower than the flow capacity of the original valve.

[0078] The first holes 32 between adjacent flow hole groups 34 in the embodiment of the present invention are staggered in the circumferential direction of the valve cage 3, which can make the valve regulation performance more linear and make the total flow area change more smoothly when the valve core 4 is opened.

[0079] Optionally, the apertures of the multiple first holes 32 in each flow hole group 34 may be the same, or may gradually increase along the opening direction of the valve core 4, and the number of first holes 32 in different flow hole groups 34 may be the same or different. For example, in two adjacent flow hole groups 34, the number of first holes 32 in one flow hole group 34 is three and the number of second holes 33 is one, and the number of first holes 32 in the other flow hole group 34 is two and the number of second holes 33 is one.

[0080] Furthermore, in the medium flow direction of the first inlet 12 , the first inlet 12 of the embodiment of the present invention is arranged opposite to the flow hole 31 , which can optimize the direction of the force of the medium acting on the valve core and improve the stability of the valve core.

[0081] like Figure 4As shown, in some embodiments, the outer wall surface of the valve core 4 includes an intermediate section 43 located between the first mating surface 41 and the second mating surface 42, and the inner diameter of the intermediate section 43 is smaller than the inner diameter of the first section 37. That is, in the axial direction of the valve core 4, the intermediate section 43 is located between the first mating surface 41 and the second mating surface 42, and there is a certain gap between the intermediate section 43 and the inner wall surface of the cage 3, thereby forming a chamber that can accommodate the medium. Since the gap between the intermediate section 43 and the second section 38 and the third section 39 of the cage 3 is larger than the gap between the intermediate section 43 and the first section 37 of the cage 3, at this time, the force of the medium acting on the valve core 4 can be directed toward the first outlet 13, so that the valve core 4 tends to be closed.

[0082] Furthermore, an annular boss 44 is provided on the outer wall of the valve core 4, and the outer wall of the boss 44 forms a second mating surface 42. The boss 44 and the outer wall of the valve core 4 can form a step surface, and the step surface serves as a force bearing surface of the medium acting on the valve core 4, so that the force of the valve core 4 can be directed toward the first outlet 13.

[0083] Through accurate calculation and design of the internal dimensions of the valve, the axial force of the valve core 4 and the valve stem 51 is always downward under the action of the medium, ensuring that the pre-start valve seal and the main seal are tightly closed. When the power supply, control power supply or control signal suddenly disappears, the valve still tends to close under the action of the medium force, ensuring that the valve does not leak, providing the valve with "three-break" protection to ensure that no malfunction occurs.

[0084] The second mating surface 42 on the boss 44 abuts against the wall surfaces of the second section 38 and the third section 39 of the cage 3 to form a throttling section, thereby reducing the amount of medium passing through when the valve core 4 is at a slight opening.

[0085] like Figure 2 and Figure 3 As shown, in some embodiments, the steam extraction regulating valve 100 also includes a valve seat 6, which is connected to the valve body 1, and the valve seat 6 has a first sealing surface 61, and the valve core 4 has a second sealing surface 45. When the steam extraction regulating valve is in a closed state, the first sealing surface 61 and the second sealing surface 45 abut against each other; an anti-collision groove 46 is provided on the valve core 4, and the second sealing surface 45 is arranged at the bottom of the anti-collision groove 46.

[0086] Since the pressure difference before and after the valve is large, an anti-scouring groove 46 is designed on the valve core 4 to prevent the medium from scouring the second sealing surface 45 when the valve is slightly opened, which can significantly increase the service life of the sealing pair.

[0087] Furthermore, the end of the valve core 4 close to the valve seat 6 has an expansion section 47 and a guide section 48, and the expansion section 47 and the guide section 48 are arranged on the side of the second mating surface 42 close to the first outlet 13, and the guide section 48 is frustum-shaped, and the radial dimension of the expansion section 47 is smaller than the radial dimension of the second mating surface 42, so that an expansion cavity is formed between the expansion section 47 and the inner wall of the valve cage 3; the anti-collision groove 46 is located between the expansion section 47 and the guide section 48.

[0088] When the valve is closed, the guide section 48 can guide the valve core 4 to be precisely aligned with the valve seat 6, ensuring that the sealing surfaces of the valve core 4 and the valve seat 6 are tightly fitted without leakage. When the valve core 4 is slightly opened, the medium first passes through the outer wall surface of the boss 44 (i.e., the second matching surface 42), and then passes through the expansion cavity of the expansion section 47. At this time, due to the setting of the anti-scouring groove 46, the medium will not scour the second sealing surface 45. Finally, the medium flows out through the first outlet 13. The expansion section 47 can further optimize the flow rate and flow rate of the medium. The boss 44 can reduce the flow rate of the medium. When the expansion cavity can provide a larger space for the medium to flow, the expansion section 47 can increase the circulation space and reduce the flow rate, optimize the medium flow effect in this area, and increase the service life of the first sealing surface 61 and the second sealing surface 45 in this area.

[0089] like Figure 1 and Figure 2 As shown, in some embodiments, the steam extraction regulating valve 100 further includes a valve stem 51 and a pre-start valve core 52, the pre-start valve core 52 is connected to the valve core 4, one end of the valve stem 51 is connected to the pre-start valve core 52, and the other end of the valve stem 51 is slidably matched with the valve cover 2. Specifically, the valve core 4 has an inner cavity, which is communicated with the first cavity 11, the pre-start valve core 52 is slidably arranged in the valve core 4, an elastic member is arranged between the pre-start valve core 52 and the valve core 4, the valve stem 51 is connected to the pre-start valve core 52, and the elastic member is a spring.

[0090] When the valve stem 51 moves, the pre-start valve core 52 moves first, so that the pressure difference before and after the valve core 4 is reduced, which facilitates the smooth opening of the valve core 4.

[0091] The method for optimizing the performance of the steam extraction regulating valve 100 according to the embodiment of the present invention is used to manufacture the steam extraction regulating valve 100 according to any one of the above embodiments, and comprises the following steps:

[0092] A mathematical model is established based on the original regulating valve to obtain flow field data. The mathematical model can be a flow field model, which simulates the flow field conditions in the valve body 1 and analyzes the medium flow field in the regulating valve to obtain flow field data, thereby facilitating further analysis of the force of the medium acting on the valve trim.

[0093] The abnormal operation data of the original regulating valve is obtained. The abnormal operation data includes but is not limited to vibration, jamming, rotation of the valve stem 51, poor linearity of valve opening adjustment, automatic opening and closing, leakage and other problems. The cause of the abnormality is analyzed based on the above abnormal data.

[0094] Based on the flow field data and abnormal operation data, the structure and assembly relationship of the valve core 4 and the valve cage 3 are determined, and a first mating surface 41 and a second mating surface 42 are set on the valve core 4, and a third mating surface 35 and a fourth mating surface 36 are set on the valve cage 3, so that when the air exhaust regulating valve is in a closed state, the first mating surface 41 abuts against the third mating surface 35, the second mating surface 42 abuts against the fourth mating surface 36, and the resultant force of the medium acting on the valve core 4 and the valve stem 51 is toward the first outlet 13.

[0095] By optimizing the structures of the valve core 4 and the valve cage 3, both axial ends of the valve core 4 are in contact with the valve cage 3 to improve its rigidity and stability, and by providing structures such as a boss 44 and an intermediate section 43 on the valve core 4, the force of the medium acting on the valve core 4 and the valve stem 51 is directed toward the first outlet 13 to prevent the valve from opening automatically.

[0096] Based on the flow field data and abnormal operation data, the structure and assembly relationship of the valve core 4 and the valve seat 6 are determined, a first sealing surface 61 is set on the valve seat 6, an anti-impact groove 46 and a second sealing surface 45 are set on the valve core 4, and the second sealing surface 45 is arranged at the bottom of the anti-impact groove 46 to prevent the medium from eroding the second sealing surface 45.

[0097] The anti-impact groove 46 can prevent the medium from directly impacting the second sealing surface 45. The arrangement of the boss 44, the expansion section 47 and the guide section 48 can adjust the medium flow rate and flow rate when the valve core 4 is slightly opened, thereby increasing the service life of the sealing pair. At the same time, it can also ensure the alignment of the valve core 4 and the valve seat 6, and ensure the effective alignment and contact between the first sealing surface 61 and the second sealing surface 45.

[0098] Based on the flow field data and the abnormal operation data, the structure of the flow hole 31 in the cage 3 is determined, and the flow area of ​​the end of the cage 3 close to the first outlet 13 is made smaller than the flow area of ​​the end of the cage 3 far from the first outlet 13 .

[0099] The design of the flow hole 31 in the embodiment of the present invention can realize linear adjustment of the valve full stroke, reduce the unbalanced force on the valve core 4, and prevent the valve from opening automatically, thereby improving the flow capacity of the valve. At the same time, the valve actuator opening and the high-pressure heating system control logic can be re-coupled to ensure its effect in practical applications.

[0100] Based on the flow field data and abnormal operation data, the material of the valve trim, the smelting process of at least part of the valve trim, and the heat treatment process of at least part of the valve trim are determined to meet the expansion margin of the valve trim under preset operating conditions and the sliding performance between at least part of the valve trim.

[0101] In view of the special working conditions of the valve, a targeted material heat treatment plan is required, and the optimal heat treatment process is formulated for different parts and materials to bring out the best performance of the material and ensure the long-term safe and stable operation of the equipment. Materials with excellent cavitation resistance and fatigue resistance are selected to meet the performance margin under long-term high-pressure working conditions.

[0102] For example, components such as the valve body 1, valve seat 6, valve cage 3 and valve core 4 are smelted in a vacuum furnace to remove gases and impurities in the metal, accurately control the chemical composition of the alloy, and improve the quality of the metal and the alloy; components such as the valve body 1, valve seat 6, valve cage 3 and valve core 4 are smelted in an electroslag remelting process to effectively ensure that the content of beneficial alloy elements is not lower than the standard value and the impurity elements are not higher than the standard value.

[0103] The embodiments of the present invention optimize and upgrade the materials, thereby greatly improving the material's anti-cavitation and anti-oxidation capabilities under normal working conditions, thereby ensuring that at least one overhaul cycle does not cause abnormal valve movement due to material fatigue or oxidation.

[0104] The embodiment of the present invention can also redesign and process all static sealing elements in the valve, so that the sealing elements are evenly stressed and deformed uniformly through the bolt force of the valve cover 2, thereby ensuring that there is no leakage inside or outside the valve.

[0105] Furthermore, the sealing surface in the embodiment of the present invention is made of high temperature resistant alloy surfacing and heat treated to ensure that the mechanical properties of the alloy sealing surface are better. The sealing pressure ratio of the valve core 4 sealing surface can also be designed according to the temperature, pressure and other parameters required by the working conditions to ensure that the valve still has excellent sealing performance when the temperature, pressure and other parameters change.

[0106] Furthermore, the straightness of the valve stem 51 in the embodiment of the present invention is ≤0.03 mm.

[0107] Furthermore, the sealing line between the valve core 4 and the valve seat 6 in the embodiment of the present invention is continuous, uninterrupted and 100% in contact.

[0108] Furthermore, the exhaust regulating valve in the embodiment of the present invention is tightly closed without leakage, and the leakage level reaches ANSIB16.104 V level or above.

[0109] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0110] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0111] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0112] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0113] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0114] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A steam extraction regulating valve, characterized in that: include: A valve body and a valve cover connected to each other, wherein a first cavity is formed between the valve body and the valve cover, and the valve body has a first inlet and a first outlet; A cage, the cage is arranged in the first cavity, a first chamber is formed between the outer wall of the cage and the inner wall of the first cavity, the first chamber is communicated with the first inlet, a second chamber is formed in the middle of the cage, the second chamber is communicated with the first outlet, and a through hole is provided on the side wall of the cage, the through hole is used to communicate the first chamber with the second chamber; A valve core, the valve core is arranged in the second chamber and is slidable along the axial direction of the valve cage, the valve core has a first mating surface and a second mating surface arranged at intervals along the axial direction thereof, and the first mating surface and the second mating surface are both in contact with the inner wall of the valve cage; When the air extraction regulating valve is in a closed state, the first mating surface and the second mating surface are respectively located on two sides of the through hole in the axial direction of the valve cage.

2. The steam extraction regulating valve according to claim 1, characterized in that: The inner wall surface of the valve cage has a third mating surface and a fourth mating surface, and the third mating surface and the fourth mating surface are respectively located on both sides of the flow hole in the axial direction of the valve cage, the first mating surface abuts against the third mating surface, and the second mating surface abuts against the fourth mating surface.

3. The steam extraction regulating valve according to claim 2, characterized in that: The first mating surface and the second mating surface have a first metallographic structure, the third mating surface and the fourth mating surface have a second metallographic structure, and the first metallographic structure and the second metallographic structure are produced by different heat treatment processes.

4. The steam extraction regulating valve according to claim 2, characterized in that: The inner wall surface of the valve cage includes a first section, a second section and a third section arranged in sequence along its axial direction, the inner diameters of the second section and the third section are equal, the inner diameter of the first section is smaller than the inner diameters of the second section and the third section, the flow hole is located in the second section, the third mating surface is located in the first section, and the fourth mating surface is located in the third section.

5. The steam extraction regulating valve according to claim 4, characterized in that: There are multiple through-holes, which are distributed in the second section, and the flow area of ​​the second section at one end close to the first outlet is smaller than the flow area of ​​the second section at one end far from the first outlet.

6. The steam extraction regulating valve according to claim 5, characterized in that: The through-flow hole comprises a first hole and a second hole, the first hole is a circular hole, the second hole is a strip-shaped hole, a plurality of the first holes and at least one of the second holes are sequentially arranged along the opening direction of the valve core and form a group of through-flow hole groups, a plurality of groups of the through-flow hole groups are sequentially arranged along the circumferential direction of the valve cage, and the first hole is closer to the first outlet than the second hole; The first holes between adjacent flow hole groups are staggered in the circumferential direction of the cage.

7. The steam extraction regulating valve according to claim 4, characterized in that: The outer wall surface of the valve core includes an intermediate section located between the first matching surface and the second matching surface, and the inner diameter of the intermediate section is smaller than the inner diameter of the first section; And / or, an annular boss is provided on the outer wall surface of the valve core, and the outer wall surface of the boss forms the second matching surface.

8. The steam extraction regulating valve according to claim 1, characterized in that: It also includes a valve seat, the valve seat is connected to the valve body, the valve seat has a first sealing surface, the valve core has a second sealing surface, and when the air extraction regulating valve is in a closed state, the first sealing surface and the second sealing surface are in contact with each other; The valve core is provided with an anti-impact groove, and the second sealing surface is arranged at the bottom of the anti-impact groove.

9. The steam extraction regulating valve according to claim 8, characterized in that: The end of the valve core close to the valve seat has an expansion section and a guide section, the expansion section and the guide section are arranged on the side of the second matching surface close to the first outlet, the guide section is in a frustum shape, and the radial dimension of the expansion section is smaller than the radial dimension of the second matching surface, so that an expansion cavity is formed between the expansion section and the inner wall of the valve cage; the anti-collision groove is located between the expansion section and the guide section; And / or, it also includes a valve stem and a pre-start valve core, the pre-start valve core is connected to the valve core, one end of the valve stem is connected to the pre-start valve core, and the other end of the valve stem is slidably matched with the valve cover.

10. A method for optimizing the performance of a steam extraction regulating valve, used for manufacturing the steam extraction regulating valve according to any one of claims 1 to 9, characterized in that: The following steps are involved: Establish a mathematical model based on the original control valve to obtain flow field data; Obtain the abnormal operation data of the original control valve; Based on the flow field data and the abnormal operation data, the structure and assembly relationship of the valve core and the valve cage are determined, a first mating surface and a second mating surface are provided on the valve core, and a third mating surface and a fourth mating surface are provided on the valve cage, so that when the air extraction regulating valve is in a closed state, the first mating surface abuts against the third mating surface, the second mating surface abuts against the fourth mating surface, and the resultant force of the medium acting on the valve core and the valve stem is directed toward the first outlet; Based on the flow field data and the abnormal operation data, the structure and assembly relationship of the valve core and the valve seat are determined, a first sealing surface is provided on the valve seat, an anti-collision groove and a second sealing surface are provided on the valve core, and the second sealing surface is arranged at the bottom of the anti-collision groove to prevent the medium from eroding the second sealing surface; Based on the flow field data and the abnormal operation data, determining a structure of the flow hole in the valve cage, and making the flow area of ​​one end of the valve cage close to the first outlet smaller than the flow area of ​​one end of the valve cage far from the first outlet; Based on the flow field data and the abnormal operation data, the material of the valve trim, the smelting process of at least part of the valve trim, and the heat treatment process of at least part of the valve trim are determined to meet the expansion margin of the valve trim under preset working conditions and the sliding performance between at least part of the valve trim.

Images