A pumped storage unit top cover dynamic stress test system

Abstract

The utility model discloses a kind of pumped storage unit top cover dynamic stress test systems, including three-way strain flower, signal transmission component, protection component, strain acquisition instrument and data storage equipment.Three-way strain flower is arranged in top cover combination gluten board measuring point, is connected strain acquisition instrument by 8-core signal line fixed through fixing piece, protection component contains galvanized steel plate protective cover and sealing glue, ensure that system adapts strong vibration, many oil dirt environment.This system solves the problem of existing technology loose structure, insufficient protection, with the advantage of high test precision, structure stable, applicable to pumped storage unit top cover dynamic stress test.

Description

Technical Field

[0001] This utility model relates to the field of pumped storage unit structure testing technology, and in particular to a dynamic stress testing system for the top cover of a pumped storage unit. Background Technology

[0002] As a core pressure-bearing component, the dynamic stress characteristics of the pumped-storage unit's roof directly affect the unit's operational safety. Existing dynamic stress testing systems suffer from the following problems: loose signal transmission structures that are prone to detachment in high-vibration environments; a lack of targeted protective design, making strain gauges and solder joints susceptible to damage from oil and scratches; and insufficient structural compatibility between system components, resulting in low testing accuracy and impacting unit operational safety. Therefore, a structurally stable and reliably protected dynamic stress testing system for pumped-storage unit roofs is urgently needed. Utility Model Content

[0003] To address the shortcomings of existing technologies, this utility model provides a dynamic stress testing system for the top cover of a pumped storage unit, which solves the problems of loose system structure, insufficient protection, and low accuracy in existing technologies.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A dynamic stress testing system for the top cover of a pumped-storage unit includes a triaxial strain gauge, a signal transmission component, a protective component, a strain acquisition instrument, and a data storage device. The triaxial strain gauge is installed at the measuring points of the stiffeners on two adjacent composite surfaces of the pumped-storage unit's top cover to collect dynamic stress signals. The signal transmission component includes an 8-core signal cable and a fixing component. One end of the 8-core signal cable is connected to the triaxial strain gauge, and the other end is connected to the strain acquisition instrument. The fixing component secures the 8-core signal cable to a non-rotating component. The protective component includes a protective cover covering the connection between the triaxial strain gauge and the 8-core signal cable, and a sealant applied to the signal cable near the measuring points inside the top cover. The strain acquisition instrument is connected to the data storage device to store the collected dynamic stress signals.

[0005] Furthermore, the number of triaxial strain flowers is four, which are respectively arranged in the +Y and -Y directions of the stiffeners on two adjacent composite surfaces of the top cover.

[0006] Furthermore, the fixing components include a strip, a strong adhesive tape, a PE plastic corrugated pipe, and a cover plate; the 8-core signal line runs along the inner pipeline of the top cover, the outer perimeter stairs of the waterwheel room, and the corridor of the waterwheel room, and is fixed to non-rotating parts by the strip and the strong adhesive tape; the 8-core signal line on the ground section is wrapped with a PE plastic corrugated pipe, and a cover plate covers the 8-core signal line at the pedestrian passage.

[0007] Furthermore, the 8-core signal line is divided into 4 groups of 2×2×2×2, with each group of signal lines having a twist pitch of 5-8mm.

[0008] Furthermore, the triaxial strain gauge is attached to the measuring point using 502 quick-drying adhesive, and the adhesive layer thickness of the 502 quick-drying adhesive is 0.05-0.1mm.

[0009] Furthermore, a welding structure is provided at the connection between the three-dimensional strain gauge and the 8-core signal line, and the welding structure is an elliptical solder joint.

[0010] Furthermore, the protective cover is made of galvanized steel plate, with dimensions of 5cm×5cm×1cm, and has a 1cm diameter cable outlet hole on the side. The 8-core signal cable passes through the cable outlet hole, and the protective cover is fixed to the measuring point with strong adhesive.

[0011] Furthermore, it also includes a measurement point pretreatment structure, which is a 5cm×5cm metal surface that has been polished and cleaned.

[0012] Furthermore, the strain acquisition instrument is a SomatXR series data logger with an acquisition rate of 2400Hz; it also includes a cDAQ acquisition device for acquiring guide vane opening signals, the acquisition rate of which is 2000Hz.

[0013] Furthermore, the data storage device is an operable terminal, and the 8-core signal line forms a wired transmission path with the strain acquisition instrument and the operable terminal.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The grouped tightening design of the signal transmission components and the various types of fasteners, combined with the protective cover and sealant of the protective components, are suitable for environments with strong vibration and high oil content, preventing the system from falling off or being damaged, and ensuring the safe operation of the unit.

[0015] 2. The targeted arrangement of triaxial strain gauges, wired transmission, and quantified bonding and welding standards reduce signal distortion and can accurately capture high-frequency stress during the transition process.

[0016] 3. The thickness of the protective cover is matched with the vibration frequency of the unit. The roughness control of the pre-treatment structure and the planning of the wiring path make the system suitable for the complex working conditions of high-head and large-capacity units. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a diagram showing the location of the measuring points in an embodiment of this utility model. Figure 2 This is a diagram of the three-dimensional strain rosette measurement points according to an embodiment of this utility model; Figure 3 This is an unfolded view of the measuring point protective cover according to an embodiment of this utility model; Figure 4 This is a signal diagram of the top cover + Y strain measurement point collected in an embodiment of the present invention; Figure 5 This is a signal diagram of the top cover-Y strain measurement point collected in an embodiment of the present invention.

[0018] Among them, the top cover 1, the three-dimensional strain gauge 2, the protective cover 3, and the cable outlet 4. Detailed Implementation

[0019] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0020] A dynamic stress testing system for the top cover of a pumped storage unit includes a triaxial strain gauge 2, a signal transmission component, a protection component, a strain acquisition instrument, and a data storage device. The specific structure and connection relationship of each component are as follows: Triaxial strain gauge 2: Four KYOWAKFW-5-350-C1-11L1M2R models from Japan are used, arranged in the +Y and -Y directions of the stiffeners on two adjacent composite surfaces of the top cover 1. Figure 1 As shown, it is used to accurately acquire dynamic stress signals in areas of stress concentration.

[0021] Signal transmission components: 8-core signal cable: divided into 4 groups according to 2×2×2×2, with a twist pitch of 5-8mm in each group to reduce electromagnetic interference; one end is soldered to the triaxial strain gauge 2, and the other end is connected to the strain acquisition instrument; Fasteners include: PVC strip, strong adhesive tape, PE plastic corrugated pipe and cover plate. The signal line runs along the inner pipeline of the top cover 1, the outdoor stairs and corridor of the waterwheel, and is fixed to non-rotating parts by PVC strip and strong adhesive tape. The signal line on the ground section is covered with PE plastic corrugated pipe, and the pedestrian passage is covered with a cover plate to prevent damage from being stepped on.

[0022] Pre-treatment structure of measuring points: a 5cm×5cm metal surface, which is polished with 120-grit coarse sandpaper along a 45° direction with the axis of the unit and 800-grit fine sandpaper along a direction perpendicular to the coarse grinding direction. The surface roughness Ra≤0.8μm. Then, it is cleaned with a lint-free cloth soaked in alcohol until there is no residue, ensuring that the triaxial strain gauge 2 is firmly attached.

[0023] Adhesion Structure: The triaxial strain gauge 2 is adhered to the measuring point using 502 quick-drying adhesive. The adhesive layer thickness is 0.05-0.1mm, and the amount of adhesive applied is calculated using the formula V=A×h×k. Where: A is the strain gauge area, h is the adhesive layer thickness, and k=1.2-1.5. After adhesion, it is cured at 25-30℃ for 20-30 minutes. Figure 2 As shown.

[0024] Soldering structure: The solder joints between the 8-core signal line and the 2 leads of the three-way strain gauge are elliptical with a resistance value ≤0.1Ω. The soldering time is controlled within 3 seconds to ensure stable signal transmission.

[0025] Protective components: Protective cover 3: Made of galvanized steel sheet (5cm×5cm×1cm), with a 1cm diameter cable outlet hole 4 on the side. Figure 3 As shown, it is fixed to the measuring point with strong adhesive, and the thickness is calculated according to the formula δ=K×f², where: K=0.002-0.003, f is the rated vibration frequency of the unit, which is suitable for the vibration environment; Sealant: Applied to signal lines and solder joints near the inner test point of the top cover 1 to prevent personnel from scratching and interfering with the signal.

[0026] Acquisition and storage equipment: The strain acquisition instrument adopts the German HBM SomatXR series with an acquisition rate of 2400Hz; the data storage device is a laptop or tablet; the guide vane opening signal is connected through the National Instruments cDAQ acquisition device with an acquisition rate of 2000Hz, realizing synchronous recording of stress and operating conditions.

[0027] The following is an example of a test case of Unit 4 of a pumped storage power station: Triaxial strain flower 2 press Figure 1 Four measuring points are arranged in the +Y / -Y direction of the top cover 1 composite rib plate.

[0028] The 8-core signal cable is grouped with a twist pitch of 6mm and fixed along the inner conduit of the top cover. The ground section is covered with a Φ20mm PE corrugated pipe, and the pedestrian passage is protected by a 5mm thick steel plate cover.

[0029] The thickness of the protective cover 3 is calculated based on the rated frequency of the unit, 50Hz. The side cable outlet hole 4 is sealed with sealant after the wire is passed through.

[0030] During system operation, the strain acquisition instrument and the cDAQ device acquire data synchronously. The data stored on the laptop shows that the strain in the 1+Y / -Y direction of the top cover increases with the guide vane opening from 0 to 50 seconds, and then tends to stabilize after 50 seconds. Figure 4 , 5 As shown, the signal has no obvious noise, verifying the effectiveness of the system.

[0031] Finally, it should be noted that 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 or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A pumped storage unit top cover dynamic stress testing system, characterized in that, The system includes a triaxial strain gauge, a signal transmission component, a protective component, a strain acquisition instrument, and a data storage device. The triaxial strain gauge is installed at the measuring points of the stiffening ribs on two adjacent composite surfaces of the pumped storage unit's top cover to collect dynamic stress signals. The signal transmission component includes an 8-core signal cable and a fixing component. One end of the 8-core signal cable is connected to the triaxial strain gauge, and the other end is connected to the strain acquisition instrument. The fixing component secures the 8-core signal cable to a non-rotating component. The protective component includes a protective cover covering the connection between the triaxial strain gauge and the 8-core signal cable, and sealant applied to the signal cable near the measuring points inside the top cover. The strain acquisition instrument is connected to the data storage device to store the collected dynamic stress signals.

2. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The number of triaxial strain flowers is four, which are respectively arranged in the +Y and -Y directions of the stiffeners on two adjacent composite surfaces of the top cover.

3. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The fasteners include a strip, a strong adhesive tape, a PE plastic corrugated pipe, and a cover plate; the 8-core signal line runs along the inner pipeline of the top cover, the outer perimeter stairs of the waterwheel room, and the corridor of the waterwheel room, and is fixed to non-rotating parts by the strip and the strong adhesive tape; the 8-core signal line on the ground section is wrapped with a PE plastic corrugated pipe, and a cover plate covers the 8-core signal line at the pedestrian passage.

4. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The 8-core signal cable is divided into 4 groups of 2×2×2×2, and the twist pitch of each group of signal cables is 5-8mm.

5. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The triaxial strain gauge is attached to the measuring point using 502 quick-drying adhesive, and the adhesive layer thickness of the 502 quick-drying adhesive is 0.05-0.1mm.

6. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The connection between the triaxial strain gauge and the 8-core signal line is provided with a welding structure, which is an elliptical solder joint.

7. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The protective cover is made of galvanized steel plate and measures 5cm×5cm×1cm. It has a 1cm diameter cable outlet hole on the side, through which the 8-core signal cable passes. The protective cover is fixed to the measuring point with strong adhesive.

8. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein It also includes a measuring point pretreatment structure, which is a 5cm×5cm metal surface that has been polished and cleaned.

9. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The strain acquisition instrument is a SomatXR series data logger with an acquisition rate of 2400Hz; it also includes a cDAQ acquisition device for acquiring guide vane opening signals, with an acquisition rate of 2000Hz.

10. A top cover dynamic stress testing system for a pumped storage unit according to claim 1, wherein The data storage device is an operable terminal, and the 8-core signal line forms a wired transmission path with the strain acquisition instrument and the operable terminal.

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