Pump turbine flow monitoring system

Abstract

The invention relates to the technical field of water turbine fluid monitoring, in particular to a pump turbine flow monitoring system which is characterized in that a transparent pipe section is formed on a pump turbine, the outer side of the transparent pipe section is of a plane structure, and water passing holes communicated with the outlet side of a runner of the pump turbine and the inlet side of a draft tube are formed in the transparent pipe section; the system comprises a data acquisition end and an early warning terminal, the data acquisition end comprises PIV and LDV monitoring subsystems arranged on the side face of a transparent pipe section, and the PIV and LDV monitoring subsystems are both connected with the early warning terminal. The transparent pipe section provides a measurement environment with high transparency and small optical distortion for fluid monitoring, optical distortion caused by a complex flow field structure is reduced, loss in the laser transmission process is ensured to be minimum, and through the combined action of the PIV monitoring subsystem and the LDV monitoring subsystem, the monitoring accuracy is improved. The data collected by the LDV monitoring subsystem is used for correcting the data collected by the PIV monitoring subsystem, and the measurement precision and reliability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydroturbine fluid monitoring, and more particularly, to a flow monitoring system for a pump-turbine. Background Art

[0002] With the continuous development of hydroelectric power technology, the pump-turbine, as the core equipment of a pumped-storage power station, has a significant impact on the overall performance of the system in terms of its operating efficiency and stability. However, the internal flow of the pump-turbine is complex, involving various phenomena such as multiphase flow, turbulence, and eddy current. Traditional sensor monitoring methods are difficult to comprehensively and accurately capture these flow characteristics.

[0003] PIV (Particle Image Velocimetry) and LDV (Laser Doppler Velocimetry) are two commonly used measurement techniques in the field of fluid mechanics, both of which are used to measure the velocity field in a fluid. Among them, PIV is a non-contact optical measurement technique. By injecting tracer particles into the flow field, irradiating these particles with a laser, and then using a high-speed camera to capture the images of the particles at two different time points; by analyzing these images, the displacement and velocity of the particles can be calculated, thereby obtaining the instantaneous velocity field information on the entire measurement plane. PIV can provide the overall information of a large-scale flow field, is suitable for the measurement of two-dimensional or three-dimensional velocity fields, and has high spatial resolution and fast response capabilities. However, in some cases, PIV may not be able to achieve extremely high spatial resolution or accuracy. Especially when facing uneven distribution of tracer particles or complex flow field structures, PIV will produce relatively large measurement errors. LDV, on the other hand, is a measurement technique based on the laser Doppler effect, which determines the velocity by measuring the motion of suspended particles in the fluid; LDV usually can only measure the velocity at a single point, so its measurement results are local and it is difficult to obtain the overall information of the flow field.

[0004] Based on this, how to achieve the overall measurement of the flow field when the distribution of tracer particles is uneven or the flow field structure is complex is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0005] The purpose of the present invention is to provide a flow monitoring system for a pump-turbine. By setting a transparent pipe section on the pump-turbine, it provides a measurement environment with high transparency and small optical distortion for the PIV monitoring subsystem and the LDV monitoring subsystem, which helps to reduce the optical distortion caused by the complex flow field structure, ensures the minimum loss of the laser signal during transmission, and then through the combined action of the PIV monitoring subsystem and the LDV monitoring subsystem, uses the data collected by the LDV monitoring subsystem to correct the data collected by the PIV monitoring subsystem, improving the measurement accuracy and reliability, so as to solve the technical problem of how to achieve the overall measurement of the flow field when the distribution of tracer particles is uneven or the flow field structure is complex.

[0006] The present invention is achieved through the following technical solutions: A water pump turbine abnormal flow warning system, a transparent pipe section is formed on the water pump turbine, the outer side of the transparent pipe section is a planar structure, and water passing holes are provided inside the transparent pipe section and are respectively communicated with the outlet side of the runner of the water pump turbine and the inlet side of the draft tube of the water pump turbine;

[0007] The system includes a data acquisition end and a warning terminal. The data acquisition end is composed of a PIV monitoring subsystem and an LDV monitoring subsystem arranged on the side of the transparent pipe section. Both the PIV monitoring subsystem and the LDV monitoring subsystem are communicatively connected to the warning terminal. Among them, the PIV monitoring subsystem is used to obtain first data, and the first data is the global flow state of the internal flow field of the water passing hole. The LDV monitoring subsystem is used to obtain second data, and the second data is the local flow state of the internal flow field of the water passing hole. The warning terminal is configured to receive the first data and the second data and use the second data to correct the first data, and trigger a warning action based on the corrected first data.

[0008] According to a preferred embodiment, the PIV monitoring subsystem and the LDV monitoring subsystem are respectively arranged on different sides of the transparent pipe section.

[0009] According to a preferred embodiment, the PIV monitoring subsystem is composed of a first laser for generating a sheet light source to illuminate the internal flow field of the water passing hole and a camera for capturing images of tracer particles in the internal flow field of the water passing hole. The first laser is arranged on the first side of the transparent pipe section, and the camera is arranged on the second side of the transparent pipe section perpendicular to the optical path of the first laser.

[0010] According to a preferred embodiment, the LDV monitoring subsystem is composed of a second laser for generating a coherent light beam to irradiate the internal flow field of the water passing hole and a photodetector for capturing the reflected light beam of tracer particles in the internal flow field of the water passing hole. The second laser and the photodetector are arranged on the third side of the transparent pipe section parallel to the optical path of the first laser.

[0011] According to a preferred embodiment, the PIV monitoring subsystem and the LDV monitoring subsystem are arranged on the same three-dimensional moving platform.

[0012] According to a preferred embodiment, the transparent pipe section is made of plexiglass.

[0013] According to a preferred embodiment, an upper flange is connected to the upper end of the transparent pipe section, a lower flange is connected to the lower end of the transparent pipe section, and sealing rings are provided on the inner rings of the upper flange and the lower flange.

[0014] According to a preferred embodiment, a fixing frame is further included. The fixing frame is composed of a fixing upper cover, a fixing lower cover and reinforcing bolts. The fixing upper cover is sleeved on the upper end of the transparent pipe section, the fixing lower cover is sleeved on the lower end of the transparent pipe section, the first end of the reinforcing bolt is connected to the fixing lower cover, and the second end of the reinforcing bolt penetrates through the fixing upper cover and extends to be connected to the runner of the pump-turbine.

[0015] The technical solution of a pump-turbine flow monitoring system provided by the present invention has at least the following advantages and beneficial effects: (1) By arranging a transparent pipe section on the pump-turbine, the present invention provides a measurement environment with high transparency and small optical distortion for the PIV monitoring subsystem and the LDV monitoring subsystem, which helps to reduce the optical distortion caused by the complex flow field structure and ensure the minimum loss of the laser signal during transmission. In addition, the shape design of the transparent pipe section helps to guide the fluid to pass through the monitoring area more smoothly, maintain the original state of the fluid flow, and thus improve the accuracy of the monitoring data. (2) Through the combined action of the PIV monitoring subsystem and the LDV monitoring subsystem, the present invention corrects the data collected by the PIV monitoring subsystem by using the data collected by the LDV monitoring subsystem, combines the advantages of fast response and global measurement of PIV and the accuracy advantage of LDV, provides more detailed fluid velocity data, improves the accuracy and reliability of the overall measurement of the flow field, and provides more comprehensive and accurate data support for fault diagnosis. (3) The present invention reinforces the transparent pipe section through an embedded fixing frame, and uses upper and lower flanges to connect the runner and the draft tube. While achieving the sealing effect, it can more effectively disperse and withstand external pressure or tension, reduce vibration and shaking, protect the transparent pipe section from damage, and improve the strength and stability of the overall structure. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of the pump-turbine flow monitoring system provided in Embodiment 1 of the present invention;

[0017] Figure 2 It is a schematic diagram of the early warning process provided in Embodiment 1 of the present invention;

[0018] Figure 3 It is a schematic structural diagram of the fixing frame provided in Embodiment 3 of the present invention;

[0019] Reference numerals: 1 - first laser, 2 - camera, 3 - pump-turbine, 4 - three-dimensional moving platform, 5 - transparent pipe section, 6 - second laser, 7 - upper cover plate, 8 - reinforcing bolt, 9 - lower cover plate. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0021] Embodiment 1

[0022] Figure 1 It is a schematic structural diagram of a flow anomaly warning system for a pump-turbine provided by an embodiment of the present invention. Refer to Figure 1 As shown, a transparent pipe section 5 is formed on the pump-turbine 3. The outer side of the transparent pipe section 5 is a planar structure, such as a smooth tetrahedron or a smooth hexahedron, etc.; water passing holes are provided inside the transparent pipe section 5 and are respectively communicated with the outlet side of the runner of the pump-turbine 3 and the inlet side of the draft tube of the pump-turbine 3. The upper end of the water passing hole is adapted to the pipe diameter of the outlet side of the runner, and the lower end of the water passing hole is adapted to the pipe diameter of the inlet side of the draft tube. In one embodiment, the pipe diameter of the upper end of the water passing hole is smaller than that of the lower end.

[0023] It should be noted that by setting the transparent pipe section 5 on the pump-turbine 3, the present invention provides a measurement environment with high transparency and small optical distortion for the PIV monitoring subsystem and the LDV monitoring subsystem, which helps to reduce the optical distortion caused by the complex flow field structure and ensure the minimum loss of the laser signal during transmission; in addition, the shape design of the transparent pipe section 5 helps to guide the fluid to pass through the monitoring area more smoothly, maintain the original state of the fluid flow, and thus improve the accuracy of the monitoring data.

[0024] Furthermore, the system includes a data acquisition end and a warning terminal. The data acquisition end is composed of a PIV monitoring subsystem and an LDV monitoring subsystem arranged on the side of the transparent pipe section 5; both the PIV monitoring subsystem and the LDV monitoring subsystem are communicatively connected to the warning terminal and are used to upload and analyze the acquired data; among them, refer to Figure 2As shown, the PIV monitoring subsystem is used to obtain first data, which is the global flow state of the internal flow field of the water passage hole; the LDV monitoring subsystem is used to obtain second data, which is the local flow state of the internal flow field of the water passage hole; the warning terminal is configured to receive the first data and the second data and use the second data to correct the first data. For example, according to the local area flow field state revealed by the second data, the corresponding part of the global area flow field state is updated and corrected to obtain a new global area flow field state, which can have the high precision of LDV measurement to reduce the error of PIV measurement; further, based on the corrected first data, a warning action is triggered. For example, the corrected first data is judged according to a preset flow velocity threshold. When the fluid flow velocity in the flow field revealed by the first data is higher than the preset flow velocity threshold, a warning action is triggered. The warning action includes but is not limited to triggering an alarm such as a buzzer or sending a prompt message, etc., and no specific limitation is made here.

[0025] It should be noted that through the combined action of the PIV monitoring subsystem and the LDV monitoring subsystem, the present invention uses the data collected by the LDV monitoring subsystem to correct the data collected by the PIV monitoring subsystem, combining the advantages of fast response and global measurement of PIV and the precision advantage of LDV, providing more detailed fluid flow velocity data, improving the precision and reliability of the overall measurement of the flow field, and providing more comprehensive and accurate data support for fault diagnosis.

[0026] Embodiment 2

[0027] Based on the technical solution provided in Embodiment 1, the present invention embodiment describes the layout of the PIV monitoring subsystem and the LDV monitoring subsystem:

[0028] In this embodiment, the PIV monitoring subsystem and the LDV monitoring subsystem are respectively arranged on different sides of the transparent pipe section 5. In a preferred implementation manner, the PIV monitoring subsystem is composed of a first laser 1 for generating a sheet light source to illuminate the internal flow field of the water passage hole and a camera 2 for capturing the image of the tracer particles in the internal flow field of the water passage hole. The first laser 1 is arranged on the first side of the transparent pipe section 5, and the camera 2 is arranged on the second side of the transparent pipe section 5 perpendicular to the optical path of the first laser 1 to capture the flow field image under the illumination of the sheet light source. The LDV monitoring subsystem is composed of a second laser 6 for generating a coherent light beam to irradiate the internal flow field of the water passage hole and a photodetector for capturing the reflected light beam of the tracer particles in the internal flow field of the water passage hole. The second laser 6 and the photodetector are arranged on the third side of the transparent pipe section 5 parallel to the optical path of the first laser 1.

[0029] Further, the PIV monitoring subsystem and the LDV monitoring subsystem are integrated on the same three-dimensional mobile platform 4. The PIV monitoring subsystem and the LDV monitoring subsystem are carried by the three-dimensional mobile platform 4 to rotate along the transparent pipe section 5 for acquisition, so as to acquire flow field information in multiple orientations. The specific acquisition method is not elaborated here.

[0030] Embodiment 3

[0031] Based on the technical solution provided in Embodiment 2, the present invention embodiment further describes the installation of the transparent pipe section 5:

[0032] In this embodiment, the transparent pipe section 5 is made of plexiglass material, such as acrylic material, and can achieve a light transmittance of more than 92%. This light transmittance can ensure the minimum loss of laser signals during transmission.

[0033] To further improve the performance such as the stability of the transparent pipe section 5, in this embodiment, an upper flange is connected to the upper end of the transparent pipe section 5, a lower flange is connected to the lower end of the transparent pipe section 5, and sealing rings are provided on the inner circles of the upper flange and the lower flange. Further, as shown in Figure 3 shown, a fixing frame is further included. The fixing frame is composed of a fixing upper cover, a fixing lower cover, and a reinforcing bolt 8. The fixing upper cover is sleeved on the upper end of the transparent pipe section 5, the fixing lower cover is sleeved on the lower end of the transparent pipe section 5, the first end of the reinforcing bolt 8 is connected to the fixing lower cover, and the second end of the reinforcing bolt 8 penetrates through the fixing upper cover and extends to be connected to the runner of the pump-turbine 3.

[0034] It should be noted that the present invention strengthens the transparent pipe section 5 through an embedded fixing frame, and connects the runner and the draft tube with upper and lower flanges. While achieving a sealing effect, it can more disperse and withstand external pressure or tension, reduce vibration and shaking, protect the transparent pipe section 5 from damage, and improve the strength and stability of the overall structure.

[0035] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A water pump turbine flow abnormality warning system, characterized in that: A transparent pipe section (5) is formed on the water pump turbine (3), the outer side of the transparent pipe section (5) is a plane structure, and the inside of the transparent pipe section (5) is provided with water holes respectively connected to the outlet side of the water pump turbine (3) runner and the inlet side of the water pump turbine (3) tail water pipe; The system comprises a data acquisition terminal and an early warning terminal, wherein the data acquisition terminal is composed of a PIV monitoring subsystem and an LDV monitoring subsystem arranged on the side of a transparent pipe section (5), and the PIV monitoring subsystem and the LDV monitoring subsystem are both connected to the early warning terminal in communication, wherein the PIV monitoring subsystem is used to obtain first data, the first data being the global flow state of the flow field inside the water hole, and the LDV monitoring subsystem is used to obtain second data, the second data being the local flow state of the flow field inside the water hole, and the early warning terminal is configured to receive the first data and the second data and use the second data to correct the first data, and trigger an early warning action based on the corrected first data.

2. The pump-turbine flow abnormality warning system according to claim 1, characterized in that: The PIV monitoring subsystem and the LDV monitoring subsystem are respectively arranged on different sides of the transparent pipe section (5).

3. The pump-turbine flow abnormality warning system according to claim 2, characterized in that: The PIV monitoring subsystem is composed of a first laser (1) for generating a light sheet to illuminate the flow field inside the water hole, and a camera (2) for capturing images of tracer particles in the flow field inside the water hole. The first laser (1) is arranged on a first side of the transparent pipe segment (5), and the camera (2) is arranged on a second side of the transparent pipe segment (5) perpendicular to the optical path of the first laser (1).

4. The pump-turbine flow abnormality warning system according to claim 3, characterized in that: The LDV monitoring subsystem is composed of a second laser (6) for generating a coherent light beam to illuminate the internal flow field of the water hole and a photoelectric detector for capturing the light beam reflected by the tracer particles in the internal flow field of the water hole. The second laser (6) and the photoelectric detector are arranged on the third side of the transparent tube section (5) parallel to the optical path of the first laser (1).

5. The pump-turbine flow abnormality warning system according to claim 4, characterized in that: The PIV monitoring subsystem and the LDV monitoring subsystem are arranged on the same three-dimensional mobile platform (4).

6. The pump-turbine flow abnormality warning system according to any one of claims 1 to 5, characterized in that: The transparent tube section (5) is made of organic glass.

7. The pump-turbine flow abnormality warning system according to claim 6, characterized in that: The upper end of the transparent tube section (5) is connected to an upper flange, and the lower end of the transparent tube section (5) is connected to a lower flange. The inner rings of the upper flange and the lower flange are both provided with sealing rings.

8. The pump-turbine flow abnormality warning system according to claim 7, characterized in that: It also includes a fixing frame, which is composed of a fixing upper cover, a fixing lower cover and a reinforcing bolt (8), the fixing upper cover is sleeved on the upper end of the transparent pipe section (5), the fixing lower cover is sleeved on the lower end of the transparent pipe section (5), the first end of the reinforcing bolt (8) is connected to the fixing lower cover, and the second end of the reinforcing bolt (8) passes through the fixing upper cover and extends to be connected to the runner of the water pump turbine (3).

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