LVDT (Linear Variable Differential Transformer) connecting structure for low-pressure regulating valve of feed pump turbine

Abstract

The utility model relates to the technical field of turbine speed regulation, in particular to an LVDT (Linear Variable Differential Transformer) connecting structure for a low-pressure regulating valve of a feed pump turbine. The LVDT connecting structure comprises a clamping plate and a connecting plate, the valve rod and the LVDT induction rod are connected through the clamping plate and the connecting plate, all the components are detachably connected, and installation, debugging, maintenance and replacement are convenient. And when a certain part is damaged, the part can be independently disassembled for maintenance or replacement, so that the maintenance cost is reduced. The linear motion of the valve rod is transmitted to the LVDT induction rod through the clamping plate and the connecting plate in sequence, the rod-shaped structure is prevented from being broken as far as possible through the arrangement of the plate-like structure, then transmission of a valve rod motion signal to the LVDT induction rod can be stably and reliably achieved, the accuracy of measuring the position signal of the valve rod by the LVDT is guaranteed, and the accuracy of measuring the position signal of the valve rod is improved. Measurement signal misalignment caused by breakage of a connection structure is avoided, so that stable adjustment of a water feed pump turboset valve is guaranteed, and the safety and stability of operation of a set and a power grid are improved.

Description

Technical Field

[0001] This utility model relates to the field of turbine speed regulation technology, and in particular to an LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine. Background Technology

[0002] As the power grid's peak-shaving intensity is upgraded, the low-pressure regulating valve of the feedwater pump turbine operates frequently. Under the combined action of high-temperature thermal stress and steam flow mechanical stress, high-frequency vibration is generated, which leads to a decrease in valve regulation accuracy, steam valve swaying, and consequently load oscillation.

[0003] Among them, the linear variable differential transformer (LVDT) linkage is a key hub for signal transmission. Once it breaks, it will not only cause the LVDT measurement signal to become inaccurate, but may also cause fluctuations in the valves of the feedwater pump turbine unit, seriously threatening the safe operation of the unit and the power grid, and even causing unplanned shutdown of the unit. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine, which solves the technical problem of easy breakage of the LVDT connecting rod in the prior art.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted by this utility model include:

[0008] This utility model provides an LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine, used to connect the valve stem and the LVDT sensing rod, including a clamping plate and a connecting plate; one end of the clamping plate is detachably connected to the valve stem, and the other end of the clamping plate is detachably connected to the connecting plate; the end of the connecting plate away from the clamping plate is detachably connected to the LVDT sensing rod, so that the linear movement of the valve stem is transmitted to the LVDT sensing rod sequentially through the clamping plate and the connecting plate.

[0009] Preferably, the clamping plate includes a first clamping plate unit and a second clamping plate unit, which are located on both sides of the valve stem and are detachably connected by a first connector; the inner surface of the first clamping plate unit and the second clamping plate unit is an arc-shaped structure, and the arc-shaped structure of the first clamping plate unit and the second clamping plate unit fits against the outer surface of the valve stem; the second clamping plate unit is detachably connected to the connecting plate.

[0010] Preferably, the second clamping plate unit has a positioning groove on the side near the connecting plate, and the side of the connecting plate near the second clamping plate unit matches the positioning groove; the positioning groove has at least one first connecting hole, and the connecting plate has at least one second connecting hole, the first connecting hole and the second connecting hole correspond one-to-one and are connected by the second connector.

[0011] Preferably, the thickness of the first clamping plate unit and the second clamping plate unit is H1, the thickness of the connecting plate is H2, and H1>H2.

[0012] Preferably, both the first connector and the second connector are anti-loosening bolts.

[0013] Preferably, the end of the connecting plate away from the clamping plate has a through hole; the LVDT sensing rod passes through the through hole and is detachably connected to the connecting plate by bolts.

[0014] Preferably, the through hole is a horizontally extending elongated hole.

[0015] Preferably, the bolt is a double-nut anti-loosening bolt; the axial direction of the bolt is parallel to the axis of the valve stem.

[0016] Preferably, the clamping plate is made of stainless steel.

[0017] (III) Beneficial Effects

[0018] The beneficial effects of this utility model are:

[0019] This utility model relates to an LVDT (Low-Pressure Controller) connection structure for a low-pressure regulating valve in a feedwater pump turbine. It includes a clamping plate and a connecting plate, which connect the valve stem and the LVDT sensing rod. All components are detachable, facilitating installation, debugging, maintenance, and replacement. When a component is damaged, it can be disassembled and repaired or replaced individually, reducing maintenance costs. The linear motion of the valve stem is transmitted sequentially to the LVDT sensing rod through the clamping plate and connecting plate. The plate structure avoids the risk of breakage associated with the rod-like structure in existing technologies, thus enabling a more stable and reliable transmission of the valve stem motion signal to the LVDT sensing rod. This ensures the accuracy of the LVDT's measurement of the valve stem position signal and prevents measurement signal inaccuracies caused by connection structure breakage. This, in turn, guarantees stable regulation of the feedwater pump turbine unit valves and improves the safety and stability of the unit and power grid operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the LVDT connection structure connecting the valve stem and the LVDT sensing rod of this utility model;

[0021] Figure 2 for Figure 1 An exploded diagram of the LVDT connection structure.

[0022] [Explanation of Labels in the Attached Image]

[0023] 1: LVDT connection structure; 11: clamping plate; 111: first clamping plate unit; 112: second clamping plate unit; 113: first connector; 12: connecting plate; 121: through hole; 13: second connector; 14: bolt; 2: valve stem; 3: LVDT sensing rod. Detailed Implementation

[0024] To better explain and facilitate understanding of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown in the figure, this utility model provides an LVDT connection structure 1 for a low-pressure regulating valve of a feedwater pump turbine, used to connect a valve stem 2 and an LVDT sensing rod 3. The LVDT connection structure 1 includes a clamping plate 11 and a connecting plate 12. One end of the clamping plate 11 is detachably connected to the valve stem 2, and the other end of the clamping plate 11 is detachably connected to the connecting plate 12. The end of the connecting plate 12 away from the clamping plate 11 is detachably connected to the LVDT sensing rod 3, so that the linear motion of the valve stem 2 is transmitted sequentially through the clamping plate 11 and the connecting plate 12 to the LVDT sensing rod 3, thereby causing the LVDT sensing rod 3 to move linearly up and down along with the valve stem 2. Since all components are detachably connected, installation, debugging, maintenance, and replacement are convenient. When a component is damaged, it can be disassembled and repaired or replaced individually, reducing maintenance costs.

[0026] The linear motion of valve stem 2 is transmitted sequentially through clamp plate 11 and connecting plate 12 to LVDT sensing rod 3. By setting up a plate-like structure, the breakage of the rod structure is avoided as much as possible, so that the transmission of the valve stem 2 motion signal to LVDT sensing rod 3 can be realized more stably and reliably. This ensures the accuracy of LVDT measurement of valve stem 2 position signal and avoids measurement signal inaccuracy caused by connection structure breakage. This ensures the stable regulation of the feedwater pump turbine unit valve and improves the safety and stability of the unit and power grid operation.

[0027] The clamping plate 11 is made of stainless steel. Stainless steel has excellent high-temperature resistance and corrosion resistance. In the working environment of the feedwater pump turbine, the clamping plate 11 is exposed to high-temperature steam and corrosive media. Using stainless steel ensures that the clamping plate 11 can work stably for a long time in such harsh environments, is not easily damaged, and extends the service life of the clamping plate 11. This, in turn, ensures the stability and reliability of the LVDT connection structure 1, ensures the accurate transmission of LVDT measurement signals, and guarantees the safe and stable operation of the feedwater pump turbine unit.

[0028] like Figure 2As shown, the clamping plate 11 includes a first clamping plate unit 111 and a second clamping plate unit 112. The first clamping plate unit 111 and the second clamping plate unit 112 are located on both sides of the valve stem 2, respectively, allowing for flexible adjustment and installation according to the size of the valve stem 2, thus providing strong adaptability. Furthermore, the first clamping plate unit 111 and the second clamping plate unit 112 are detachably connected by a first connector 113, facilitating the maintenance or replacement of the clamping plate 11 components on the valve stem 2.

[0029] The inner surfaces of the first clamping plate unit 111 and the second clamping plate unit 112 are arc-shaped. These arc-shaped structures fit snugly against the outer surface of the valve stem 2, allowing for a better grip on the valve stem 2. This increases the contact area between the clamping plate 11 and the valve stem 2, improving the stability and reliability of the connection. This enables the movement of the valve stem 2 to be more accurately transmitted to the clamping plate 11, and then to the LVDT sensing rod 3, further improving the accuracy of the measurement signal. The second clamping plate unit 112 is detachably connected to the connecting plate 12. This also facilitates the assembly and disassembly of the entire connection structure, making maintenance and repair easier.

[0030] like Figure 2 As shown, the second clamping plate unit 112 has a positioning groove on the side near the connecting plate 12. The side of the connecting plate 12 near the second clamping plate unit 112 matches the positioning groove, thereby enabling quick and accurate determination of the relative position between the connecting plate 12 and the second clamping plate unit 112 during installation, improving installation efficiency and accuracy. The positioning groove has at least one first connecting hole, and the connecting plate 12 has at least one second connecting hole. The first connecting hole and the second connecting hole correspond one-to-one and are connected by the second connecting member 13. This enhances the robustness of the connection between the connecting plate 12 and the second clamping plate unit 112, ensuring that no relative displacement occurs between the connecting plate 12 and the second clamping plate unit 112 during the movement of the valve stem 2, thus ensuring that the movement signal of the valve stem 2 can be stably and accurately transmitted to the LVDT sensing rod 3. In this embodiment, there are two first connecting holes and two second connecting holes, but three or four can be provided depending on the actual situation.

[0031] In this embodiment, the thickness of the first clamping plate unit 111 and the second clamping plate unit 112 is H1, and the thickness of the connecting plate 12 is H2, where H1 > H2. This arrangement allows the clamping plate 11 to withstand greater stress. Because the clamping plate 11 is directly connected to the valve stem 2, the valve stem 2 is subjected to various complex stresses during operation, such as high-temperature thermal stress and steam flow mechanical stress. The thicker clamping plate 11 can better disperse the stress, ensuring the strength and stability of the connection structure and avoiding damage to the connection structure due to insufficient strength of the clamping plate 11, thereby ensuring the accurate transmission of LVDT measurement signals.

[0032] Meanwhile, since the thread at the end of the LVDT sensing rod 3 is relatively short, the reliability of the end connection of the LVDT sensing rod 3 is improved by setting the thickness of the connecting plate 12 to be less than the thickness of the first clamping unit 111 and the second clamping unit 112. In this embodiment, the thickness of the first clamping unit 111 and the second clamping unit 112 is 15mm, and the thickness of the connecting plate 12 is 5mm. This improves both the rigidity of the clamping plate 11 and the reliability of the connection of the LVDT sensing rod 3.

[0033] In this embodiment, both the first connector 113 and the second connector 12 are anti-loosening bolts. The anti-loosening bolts can effectively prevent the loosening of the clamping plate 11 itself, the clamping plate 11 and the connecting plate 12 due to vibration and other reasons during the operation of the feedwater pump turbine.

[0034] Preferably, the end of the connecting plate 12 away from the clamping plate 11 is provided with a through hole 121. The LVDT sensing rod 3 passes through the through hole 121 and is detachably connected to the connecting plate 12 via bolts 14. The through hole 121 is a horizontally extending elongated hole, providing the LVDT sensing rod 3 with a certain amount of horizontal movement space. During the operation of the feedwater pump turbine, the LVDT sensing rod 3 may experience some displacement due to thermal expansion and contraction. The elongated hole allows the LVDT sensing rod 3 to move freely within a certain range, avoiding additional stress caused by restriction of the LVDT sensing rod 3, thereby protecting the LVDT sensing rod 3 and the connecting structure, improving the reliability and stability of the entire system, and not affecting the transmission of the valve stem 2's motion signal to the LVDT sensing rod 3. The bolts 14 are double-nut anti-loosening bolts, with the axis of the bolts 14 parallel to the axis of the valve stem 2. This enhances the anti-loosening effect of the bolt 14 connection, preventing the bolts 14 from loosening during the operation of the feedwater pump turbine, and ensuring the firmness of the connection between the LVDT sensing rod 3 and the connecting plate 12.

[0035] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0037] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine, used to connect the valve stem (2) and the LVDT sensing rod (3), characterized in that, Includes a clamping plate (11) and a connecting plate (12); One end of the clamping plate (11) is detachably connected to the valve stem (2), and the other end of the clamping plate (11) is detachably connected to the connecting plate (12); The end of the connecting plate (12) away from the clamping plate (11) is detachably connected to the LVDT sensing rod (3) so that the linear motion of the valve stem (2) is transmitted to the LVDT sensing rod (3) in sequence through the clamping plate (11) and the connecting plate (12).

2. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 1, characterized in that: The clamping plate (11) includes a first clamping plate unit (111) and a second clamping plate unit (112), the first clamping plate unit (111) and the second clamping plate unit (112) are located on both sides of the valve stem (2) respectively, and are detachably connected by a first connector (113); The inner surface portions of the first clamping plate unit (111) and the second clamping plate unit (112) are arc-shaped structures, and the arc-shaped structures of the first clamping plate unit (111) and the second clamping plate unit (112) are in contact with the outer surface of the valve stem (2); The second clamping plate unit (112) is detachably connected to the connecting plate (12).

3. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 2, characterized in that: The second clamping plate unit (112) is provided with a positioning groove on the side near the connecting plate (12), and the side of the connecting plate (12) near the second clamping plate unit (112) matches the positioning groove; The positioning groove is provided with at least one first connecting hole, and the connecting plate (12) is provided with at least one second connecting hole. The first connecting hole and the second connecting hole correspond one-to-one and are connected by the second connecting member (13).

4. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 2, characterized in that: The thickness of the first clamping plate unit (111) and the second clamping plate unit (112) is H1, and the thickness of the connecting plate (12) is H2, and H1>H2.

5. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 3, characterized in that: Both the first connector (113) and the second connector (13) are anti-loosening bolts.

6. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 1, characterized in that: The connecting plate (12) has a through hole (121) at one end away from the clamping plate (11); The LVDT sensing rod (3) passes through the through hole (121) and is detachably connected to the connecting plate (12) by bolts (14).

7. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 6, characterized in that: The through hole (121) is a horizontally extending elongated hole.

8. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 6, characterized in that: The bolt (14) is a double-nut anti-loosening bolt; The axial direction of the bolt (14) is parallel to the axis of the valve stem (2).

9. The LVDT connection structure for a low-pressure regulating valve of a feedwater pump turbine as described in claim 1, characterized in that: The clamp (11) is made of stainless steel.

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