Sealing mechanism and water turbine vaneless area pressure pulsation measuring device

Abstract

The utility model discloses a sealing mechanism and a water turbine vaneless area pressure pulsation measuring device, and relates to the technical field of hydro-generators, the sealing mechanism adopts four sealing structures, the risk of water flow permeation is blocked layer by layer, and the occurrence of a top cover flooding accident caused by a sealing problem is effectively avoided; according to the pressure pulsation measuring device for the vaneless area of the water turbine, the sensor shell is directly embedded into the top cover for measurement, a long-distance pipeline leading mode is completely abandoned, and the problems of signal amplitude attenuation and high-frequency component loss caused by pipeline friction and resonance in a traditional method are solved; particularly, 1-2 times of blade frequency characteristic signals generated by dynamic and static interference of the rotating wheel and the guide blades can be accurately captured, and the data authenticity and the analysis reliability are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of hydro-generator technology, and in particular to a sealing mechanism and a pressure pulsation measuring device in the bladeless zone of a hydro-generator. Background Technology

[0002] As the core power equipment of a hydroelectric power generation system, the operational stability of the turbine directly affects the lifespan of the unit and the economic benefits of the power station. Water pressure pulsation is the main cause of turbine vibration. In particular, when mixed-flow and axial-flow fixed-blade turbines operate in high-head, low-load regions deviating from their optimal operating conditions, the low-frequency pressure pulsation generated by the tailrace vortex can not only lead to abnormal unit vibration and runner blade crack propagation, but may also cause major safety hazards such as powerhouse structural resonance.

[0003] The traditional method used in the industry to measure pressure pulsation in the bladeless zone of large mixed-flow hydropower units is to run pipelines from the top cover to the top of the top cover or the turbine chamber, and then install sensors for measurement. However, this technical solution has significant drawbacks—the top cover flooding accident occurs frequently due to sealing problems, and the pressure pulsation signal amplitude is attenuated and high-frequency components are lost due to fluid friction, pipeline resonance and other factors caused by long-distance pipelines. In particular, it may be distorted when capturing the 1-2 times blade frequency characteristics caused by the dynamic and static interference between the impeller and the guide vanes.

[0004] To solve this problem, we urgently need a brand-new sealing mechanism and a pressure pulsation measuring device for the bladeless zone of a water turbine. This sealing mechanism can prevent the occurrence of top cover flooding accidents caused by sealing, and the measuring device can accurately capture the 1-2 times blade frequency characteristic signal generated by the dynamic and static interference between the runner and the guide vane, significantly improving the authenticity of the data and the reliability of the analysis. Utility Model Content

[0005] In view of the problems existing in the prior art, this utility model is proposed.

[0006] The problem this invention aims to solve is how to address the frequent occurrence of top cover flooding accidents due to sealing issues, and the potential distortion in capturing 1-2 times blade frequency characteristics caused by fluid friction, pipeline resonance, and other factors in long-distance pipelines.

[0007] The above-mentioned technical problems are solved by the following technical solution: This utility model proposes a sealing mechanism, a sensor housing, which is embedded in a top cover; one end of the sensor housing embedded in the top cover is connected by a first sealing component, and a second sealing component is provided at the end away from the first sealing component and at the connection between the sensor housing and the top cover; wherein, the first sealing component includes a sensor base disposed in the top cover for mounting the sensor housing, and sealant is filled between the sensor base and the sensor housing to form a first seal; wherein, the second sealing component includes a sealing base disposed on the other side of the top cover and a sealing cap disposed on one side of the sealing base.

[0008] In a preferred embodiment of the sealing mechanism of this utility model: the sealing base is provided with an internal threaded hole, and the sealing cover is connected and fixed to the internal threaded hole by bolts.

[0009] The dual sealing component design, consisting of a first sealing component and a second sealing component, forms a multi-level sealing protection, effectively blocking the risk of water infiltration and ensuring the long-term sealing reliability of the device under high pressure and high vibration environments.

[0010] By filling the gap between the sensor base and the sensor housing with sealant, the first chemical adhesive seal is formed, filling the tiny gaps at the connection, effectively preventing water from seeping in from the installation interface, and at the same time enhancing the vibration resistance between the sensor housing and the sensor base, avoiding loosening of the seal due to mechanical vibration.

[0011] In a preferred embodiment of the sealing mechanism of this utility model: the sealing base is provided with an internal threaded hole, and the sealing cover is connected and fixed to the internal threaded hole by bolts;

[0012] In a preferred embodiment of the sealing mechanism of this utility model: a first sealing groove is provided on the side wall of the sensor housing, a first sealing element is provided in the first sealing groove, and the first sealing element contacts the sensor base to form a second seal.

[0013] Dynamic sealing compensation is achieved through sealing components, which can adapt to minute displacements between the sensor housing and the sensor base, block the path of water flow to seep along the surface of the sensor rod, further improve sealing redundancy, and prevent sealing failure caused by water flow pulsation or mechanical vibration.

[0014] In a preferred embodiment of the sealing mechanism of this utility model: a second sealing groove is provided at the bottom of the sealing cover, and a second sealing element is provided in the second sealing groove to form a third seal.

[0015] A reliable sealing barrier is provided by a second seal, reducing the impact of water flow on the internal sealing mechanism.

[0016] In a preferred embodiment of the sealing mechanism of this utility model: a third sealing groove is provided at the bottom of the sealing cover, and a third sealing element is provided in the third sealing groove to form a fourth seal.

[0017] By complementing the second seal, the seepage path is further blocked, the sealing redundancy is enhanced, and the sealing integrity is ensured under extreme operating conditions.

[0018] In a preferred embodiment of the sealing mechanism of this utility model: the second sealing groove is located above the third sealing groove.

[0019] By using sealing layers distributed from top to bottom, the pressure of the sealing mechanism can be gradient-distributed, optimizing sealing efficiency and extending the service life of the seals.

[0020] In a preferred embodiment of the sealing mechanism of this utility model: the cross-section of the second sealing groove is trapezoidal; the cross-section of the third sealing groove is rectangular.

[0021] The trapezoidal structure, through its inclined surface contact design, increases the contact area between the second seal and the groove wall, evenly distributing the sealing pressure and avoiding local stress concentration. At the same time, it enhances the second seal's resistance to compression, preventing deformation or displacement of the seal under the impact of high-pressure water flow.

[0022] The rectangular structure provides a stable vertical support surface, which facilitates the precise positioning and fixing of the third seal, ensuring that the seal maintains stable contact under vibration and reducing sealing gaps caused by assembly tolerances.

[0023] The two types of grooves work together to meet the flexibility and rigidity requirements of the sealing structure, thereby improving the adaptability and reliability of the overall sealing system.

[0024] In a preferred embodiment of the sealing mechanism of this utility model: the sealant is a liquid sealant; the first sealing element is an O-ring; the second sealing element is a copper washer; and the third sealing element is a gasket.

[0025] The liquid sealant's liquid properties allow it to fully fill gaps, forming a seamless sealing layer after curing, effectively blocking micro-leakage paths. The elastic material of the O-ring provides dynamic sealing compensation, maintaining sustained sealing contact pressure. The copper gasket, a highly ductile metal, undergoes controllable deformation under high pressure, forming a rigid barrier against the sealing surface, and is resistant to high temperatures and corrosion. The sealing gasket uses wear-resistant and aging-resistant composite materials (such as graphite or rubber) as the final sealing layer, absorbing residual pressure fluctuations and preventing media penetration. The combination of liquid sealant, elastic ring, metal gasket, and composite gasket forms a three-level sealing gradient of "flexible-rigid-composite," progressively attenuating pressure impacts and blocking different penetration paths, comprehensively improving the reliability and durability of the sealing system.

[0026] In a preferred embodiment of the sealing mechanism of this utility model: a slot is provided on the side wall of the sensor housing for fixing and engaging with the sealing cover.

[0027] The mechanical locking structure of the slot and sealing cover prevents the sensor housing from breaking or falling off due to high-pressure water flow, thus enhancing the overall stability of the device.

[0028] Another objective of this utility model is to provide a pressure pulsation measuring device for the bladeless zone of a water turbine, including the aforementioned sealing mechanism, a sensor body disposed within the sensor housing, a cable disposed on one side of the sensor body, and a long rod disposed on the other side of the sensor body.

[0029] By connecting the long rod to the sensor body to form an integrated structure, it can directly contact the measured medium, eliminating the need for water diversion through pipelines. The cable connects directly to the sensor body, avoiding the risk of signal interference or water leakage introduced by external adapters. It can withstand deep water, high pressure, and corrosive environments, ensuring the stability and long-term reliability of signal transmission.

[0030] In a preferred embodiment of the pressure pulsation measuring device for the bladeless zone of the water turbine described in this utility model: the cable is a wear-resistant, water-resistant, and high / low temperature resistant cable.

[0031] Wear-resistant, water-resistant, and high / low temperature resistant cables withstand deep-sea, high-pressure, and corrosive environments, ensuring the stability and long-term reliability of signal transmission.

[0032] The beneficial effects of this utility model are as follows:

[0033] The sealing mechanism of this utility model adopts a four-seal structure, which blocks the risk of water seepage layer by layer, effectively avoiding the occurrence of flooding accidents of the top cover due to sealing problems;

[0034] The pressure pulsation measuring device for the bladeless zone of the turbine of this utility model measures the pressure by directly embedding the sensor housing into the top cover, completely eliminating the need for long-distance pipeline connection. This avoids the signal amplitude attenuation and high-frequency component loss caused by pipeline friction and resonance in traditional methods. In particular, it can accurately capture the 1-2 times blade frequency characteristic signal generated by the dynamic and static interference between the runner and the guide vane, significantly improving the authenticity of the data and the reliability of the analysis.

[0035] The pressure pulsation measuring device for the bladeless zone of this utility model uses a cable to directly connect to the sensor body, avoiding the risk of signal interference or water leakage introduced by external adapters. It can withstand deep water pressure and corrosive environments, ensuring the stability and long-term reliability of signal transmission. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments of this utility model will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this utility model, and are not intended to limit the utility model.

[0037] Figure 1 A schematic diagram of the overall structure of the pressure pulsation measuring device in the bladeless zone of a water turbine is shown.

[0038] Figure 2 A schematic diagram of the first sealing component of the sealing mechanism is shown;

[0039] Figure 3 A schematic diagram of the second sealing assembly structure of the sealing mechanism is shown;

[0040] Figure 4 A schematic diagram of the overall structure of the sensor housing is shown. Detailed Implementation

[0041] To enable those skilled in the art to better understand this utility model, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0042] The terminology used in this invention refers to those general terms currently widely used in the art in consideration of the functionality of this invention; however, these terms may vary according to the intent, precedent, or new technology of those skilled in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of this invention. Therefore, the terminology used in this specification should not be construed as simple names, but rather based on the meaning of the terms and the overall description of this invention.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0045] Example 1, referring to Figure 1-3 This is the first embodiment of the present invention. This embodiment provides a sealing mechanism, in which a sensor housing 1 is embedded in a top cover 2. One end of the sensor housing 1 embedded in the top cover 2 is connected by a first sealing component, and a second sealing component is provided at the end away from the first sealing component and at the connection between the sensor housing 1 and the top cover 2. The first sealing component includes a sensor base 3 disposed in the top cover 2 for mounting the sensor housing 1, and sealant is filled between the sensor base 3 and the sensor housing 1 to form a first seal. The second sealing component includes a sealing base 4 disposed on the other side of the top cover 2 and a sealing cap 5 disposed on one side of the sealing base 4.

[0046] It should be noted that mounting holes are machined at the corresponding positions of +X, -X, +Y, and -Y directions on the flow surface 21 of the top cover 2, and the sensor base 3 is fixed to the mounting holes by welding; the sensor base 3 is provided with an internal thread hole, and the outer wall of the sensor housing 1 is provided with an external thread corresponding to the internal thread hole, which is connected to the internal thread hole of the sensor base 3 through the external thread, and the connection is filled with liquid sealant.

[0047] The sealing base 4 is fixed to the top cover 2 by welding. The sealing base 4 is provided with an internal threaded hole. The sealing gland 5 is connected and fixed to the internal threaded hole by bolts 6.

[0048] In summary, the dual sealing component design of the first and second sealing components forms a multi-level sealing protection, effectively blocking the risk of water infiltration and ensuring the long-term sealing reliability of the device under high pressure and high vibration environments.

[0049] By filling the gap between the sensor base 3 and the sensor housing 1 with liquid sealant, the first chemical adhesive seal is formed, filling the tiny gap at the connection, effectively preventing water from seeping in from the installation interface, and at the same time enhancing the vibration resistance between the sensor housing 1 and the sensor base 3, avoiding loosening of the seal due to mechanical vibration.

[0050] Furthermore, a first sealing groove 14 is provided on the side wall of the sensor housing 1, and a first sealing element 141 is provided in the first sealing groove 14, and the first sealing element 141 contacts the sensor base 3.

[0051] It should be noted that the first sealing element 141 uses an "O" ring or gasket. The "O" ring or gasket is interference-fitted with the end face of the sealing base 4 to provide an elastic soft seal and compensate for gap changes caused by manufacturing tolerances and vibration.

[0052] Furthermore, a second sealing groove 51 is provided at the bottom of the sealing gland 5, and a second sealing element 511 is provided in the second sealing groove 51 to form a third seal.

[0053] Furthermore, a third sealing groove 52 is provided at the bottom of the sealing gland 5, and a third sealing element 521 is provided in the third sealing groove 52 to form a fourth seal;

[0054] Furthermore, the second sealing groove 51 is located above the third sealing groove 52;

[0055] Furthermore, the cross-section of the second sealing groove 51 is trapezoidal; the cross-section of the third sealing groove 52 is rectangular.

[0056] Furthermore, the sealant is a liquid sealant; the first sealing element 141 is an O-ring; the second sealing element 511 is a copper washer; and the third sealing element 521 is a gasket.

[0057] It should be noted that the trapezoidal structure, through the inclined surface contact design, increases the contact area between the second seal 511 and the groove wall, evenly distributes the sealing pressure, avoids local stress concentration, and at the same time enhances the compression resistance of the second seal 511, preventing the seal from deforming or shifting under the impact of high-pressure water flow.

[0058] The rectangular structure provides a stable vertical support surface, which facilitates the precise positioning and fixation of the third seal 521, ensuring that the third seal 521 maintains stable contact in a vibration environment and reducing sealing gaps caused by assembly tolerances.

[0059] The second sealing element 511 can be a copper gasket or a gasket made of other metal materials. The third sealing element 521 uses an O-ring or a gasket. The copper gasket, as the third rigid seal, utilizes the plastic deformation capability of the metal material to adapt to the high-pressure environment, providing a reliable initial sealing barrier and reducing the direct impact of water flow on the internal flexible sealing mechanism. The fourth flexible seal complements the third rigid seal, compensating for the assembly tolerance or micro-vibration gap between the sealing gland 5 and the sensor through elastic deformation, completely blocking the leakage path and ensuring the sealing integrity under extreme working conditions.

[0060] Example 2, refer to Figure 3This is the second embodiment of the present invention, which differs from the first two embodiments in that:

[0061] The side wall of the sensor housing 1 is provided with a slot 15 for fixing with the sealing cover 5;

[0062] The mechanical locking structure between the slot 15 and the sealing cover 5 prevents the sensor housing 1 from breaking or falling off due to high-pressure water flow impact, thus enhancing the overall stability of the device.

[0063] It should be noted that the card slot is a ring-shaped card slot 15.

[0064] This utility model adopts a four-seal structure to block the risk of water seepage layer by layer, effectively preventing the top cover from being flooded.

[0065] Example 3, referring to Figure 1-4 This is the third embodiment of the present invention, which differs from the previous two embodiments in that: the present invention provides a pressure pulsation measuring device for the bladeless zone of a water turbine, including a sealing mechanism, and further including a sensor body 12 disposed in a sensor housing 1, a cable 11 disposed on one side of the sensor body 12, and a long rod 13 disposed on the other side of the sensor body 12, the long rod 13 being in direct contact with the measured medium.

[0066] It should be noted that the sensor used in the measuring device has a cable 11 at the top, which uses mature technology for submersible hydraulic sensors; the sensor body 12 in the middle uses mature technology for diffused silicon piezoresistive sensors, with a measurement frequency range of 0Hz-1000Hz and timely and sensitive response; and a long rod 13 at the bottom, which is an integral structure with the sensor body 12 and can directly contact the measured medium, eliminating the need for water diversion through pipelines. The total length is 220mm.

[0067] The cable 11 connects directly to the sensor body 12, avoiding signal interference or water leakage risks introduced by external adapters. It withstands deep-water, high-pressure, and corrosive environments, ensuring the stability and long-term reliability of signal transmission. It is important to note that the cable 11 is a wear-resistant, water-resistant, and high / low-temperature resistant cable.

[0068] This invention measures by directly embedding the sensor housing 1 into the top cover 2, completely eliminating the need for long-distance pipeline connection. This avoids the signal amplitude attenuation and high-frequency component loss caused by pipeline friction and resonance in traditional methods. In particular, it can accurately capture the 1-2 times blade frequency characteristic signal generated by the dynamic and static interference between the impeller and the guide vane, significantly improving the authenticity of the data and the reliability of the analysis.

[0069] This utility model uses a cable 11 to directly connect to the sensor 12, avoiding the risk of signal interference or water seepage introduced by external adapters, and is resistant to deep water, high pressure and corrosive environment, ensuring the stability and long-term reliability of signal transmission.

[0070] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways, as long as they do not depart from the scope of this utility model.

[0071] Importantly, the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A sealing mechanism, characterized by: include, The sensor housing (1) is embedded in the top cover (2); One end of the sensor housing (1) is embedded in the top cover (2) and connected by a first sealing component. A second sealing component is provided at the end away from the first sealing component and at the connection between the sensor housing (1) and the top cover (2). The first sealing assembly includes a sensor base (3) disposed inside the top cover (2) and used for mounting the sensor housing (1), and the space between the sensor base (3) and the sensor housing (1) is filled with sealant. The second sealing assembly includes a sealing base (4) disposed on the other side of the top cover (2) and a sealing gland (5) disposed on one side of the sealing base (4).

2. The sealing mechanism according to claim 1, characterized in that: The sealing base (4) is provided with an internal threaded hole, and the sealing cover (5) is connected and fixed to the internal threaded hole by bolts (6).

3. The sealing mechanism according to claim 1, characterized in that: The sensor housing (1) has a first sealing groove (14) on its side wall, and a first sealing element (141) is provided in the first sealing groove (14). The first sealing element (141) is in contact with the sensor base (3).

4. The sealing mechanism according to claim 3, characterized in that: The bottom of the sealing cap (5) is provided with a second sealing groove (51), and a second sealing element (511) is provided in the second sealing groove (51).

5. The sealing mechanism according to claim 4, characterized in that: The bottom of the sealing cap (5) is provided with a third sealing groove (52), and a third sealing element (521) is provided in the third sealing groove (52).

6. The sealing mechanism according to claim 5, characterized in that: The second sealing groove (51) is located above the third sealing groove (52).

7. The sealing mechanism according to claim 6, characterized in that: The second sealing groove (51) has a trapezoidal cross-section; the third sealing groove (52) has a rectangular cross-section.

8. The sealing mechanism according to claim 7, characterized in that: The sealant is a liquid sealant; the first sealing element (141) is an O-ring; the second sealing element (511) is a copper gasket; and the third sealing element (521) is a gasket.

9. The sealing mechanism according to any one of claims 1-8, characterized in that: The sensor housing (1) has a slot (15) on its side wall for fixing and engaging with the sealing cover (5).

10. A device for measuring pressure pulsations in the bladeless zone of a hydraulic turbine, characterized by: Including the sealing mechanism as described in any one of claims 1 to 8, further comprising: A sensor body (12) is disposed inside the sensor housing (1), a long rod (13) is disposed on one side of the sensor body (12), and a cable (11) is disposed on the other side of the sensor body (12) and extends outside the sensor housing (1).

Images