Centrifugal pump inducer cryogenic visualization device

Abstract

This invention relates to the field of centrifugal pump testing technology, and in particular to a cryogenic visualization device for a centrifugal pump inducer impeller. The device includes a transparent viewing window positioned at the inlet of the centrifugal pump, with the inducer impeller extending into and corresponding to the window. An annular interlayer is formed within the viewing window, and this interlayer is evacuated. A high-speed camera positioned outside the centrifugal pump is positioned corresponding to the viewing window, and the camera captures images of the cavitation phenomenon caused by the inducer impeller through the viewing window. This invention is compact and easy to use, enabling independent study of the inducer impeller as well as visual study of the influence of the impeller on the inducer impeller, providing data support for cavitation research in cryogenic centrifugal pumps.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump testing technology, and in particular to a low-temperature visualization device for a centrifugal pump inducer wheel. Background Technology

[0002] Cryogenic centrifugal pumps are widely used in critical fields such as aerospace propulsion, LNG transportation, and superconducting cooling. Cavitation problems severely affect system stability, efficiency, and service life. Inducer impellers are typically installed before the impeller to improve its anti-cavitation performance, but the inducer impeller itself can also experience cavitation. Currently, international research is focused on constructing numerical models of cavitation that accurately reflect the thermodynamic effects of cryogenic temperatures, and developing matching cryogenic visualization and synchronous measurement experimental techniques.

[0003] Existing low-temperature induction wheel visualization devices generally do not include an impeller, focusing only on the induction wheel and ignoring the interaction between the impeller and the induction wheel under real-world conditions. Due to limitations of traditional high-speed camera technology, observation requires opening a local planar window on the cylindrical surface. To avoid fogging or frost formation on the window, numerous measures are needed, resulting in a complex structure. Furthermore, the influence of the planar window on the internal flow space does not match the actual situation. During operation, the double-layered window needs to be evacuated in real time to achieve vacuum insulation, making operation inconvenient.

[0004] Therefore, there is an urgent need to design a cryogenic visualization device for centrifugal pump inducer wheels to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a low-temperature visualization device for centrifugal pump induced wheel to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a low-temperature visualization device for a centrifugal pump inducer wheel, including a transparent viewing window, the viewing window being disposed at the inlet of the centrifugal pump, and the inducer wheel in the centrifugal pump extending into the viewing window and being disposed corresponding to the viewing window; The window has an annular interlayer, which is evacuated. The viewing window is correspondingly set to a high-speed camera located outside the centrifugal pump. The high-speed camera captures the cavitation phenomenon caused by the inducer wheel through the viewing window.

[0007] Preferably, the window comprises a cylindrical body, and the interlayer is a closed cavity coaxially disposed with the body.

[0008] Preferably, the body is made of a transparent material that is resistant to low temperatures.

[0009] Preferably, the centrifugal pump includes a pump body, a pump cover plate is installed at the rear end of the pump body, a shaft for transmitting power is rotatably connected to the pump cover plate, the shaft extends into the pump body, and the inducer wheel is fixedly installed at the end of the shaft.

[0010] Preferably, the pump body is provided with an impeller, the impeller is driven and sleeved on the shaft, and the impeller is located behind the inducer.

[0011] Preferably, the pump body is provided with an inlet flange in the inlet direction, the viewing window is clamped and fixed between the inlet flange and the pump body, and the inlet flange and the pump body are locked together by a locking assembly.

[0012] Preferably, the locking assembly includes a plurality of axially spaced tie rods, which pass through the inlet flange and are locked to the pump body. The tie rods are arranged around the viewing window, and the high-speed camera visualizes and photographs the fluid in the viewing window through the gaps in the tie rods.

[0013] Preferably, the inlet flange and the pump body are respectively provided with flange stops corresponding to the viewing window, and the two ends of the viewing window abut against the bottom end of the flange stops.

[0014] Preferably, elastic gaskets are provided at both ends of the viewing window, and the two elastic gaskets abut against the pump body and the inlet flange respectively.

[0015] Preferably, during the test, the rotational speed of the shaft is in the range of 8000-10000 rpm.

[0016] Compared with existing technologies, this invention has the following advantages and technical effects: This invention discloses a low-temperature visualization device for a centrifugal pump inducer wheel. A transparent window is set at the inlet of the centrifugal pump, and the inducer wheel of the centrifugal pump extends into the window, forming a corresponding spatial relationship with the window, providing a visual basis for observing the cavitation phenomenon of the inducer wheel. The window has an annular interlayer, which is vacuum-treated to form a vacuum insulation structure, avoiding fogging and frost problems when the low-temperature medium is working, ensuring the clarity of the camera's observation, and eliminating the need for additional real-time defrosting / anti-fogging operations. A high-speed camera is set outside the centrifugal pump, and the camera is arranged correspondingly to the window. By utilizing the cooperation between the transparent window and the external high-speed camera, the cavitation phenomenon of the inducer wheel can be directly captured. The cavitation phenomenon generated during the operation of the inducer wheel can be directly photographed through the transparent window, providing intuitive visual data for the study of cavitation in the low-temperature centrifugal pump inducer wheel, and realizing the visualized monitoring of cavitation in the inducer wheel. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the structure of the cryogenic visualization device for the centrifugal pump inducer wheel of the present invention; Figure 2 This is a schematic diagram of the window structure of the present invention; In the diagram: 1. Inlet flange; 2. Tie rod; 3. Viewing window; 4. Inducer wheel; 5. Elastic gasket; 6. Impeller; 7. Pump outlet; 8. Pump body; 9. Pump cover plate; 10. Shaft; 11. High-speed camera; 12. Jacket. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1 to 2 As shown, this embodiment provides a low-temperature visualization device for a centrifugal pump inducer wheel, including a transparent window 3, which is set at the inlet of the centrifugal pump, and an inducer wheel 4 in the centrifugal pump extends into the window 3 and is set correspondingly to the window 3. A ring-shaped interlayer 12 is provided in window 3, and the interlayer 12 is vacuum-equipped; The viewing window 3 is correspondingly set with a high-speed camera 11 installed outside the centrifugal pump. The high-speed camera 11 captures the cavitation phenomenon caused by the inducer wheel 4 through the viewing window 3.

[0021] This invention discloses a low-temperature visualization device for a centrifugal pump inducer wheel. A transparent window 3 is set at the inlet of the centrifugal pump, and the inducer wheel 4 of the centrifugal pump extends into the window 3, forming a corresponding spatial relationship with the window 3, providing a visual basis for observing the cavitation phenomenon of the inducer wheel 4. The window 3 has an annular interlayer 12, which is vacuum-treated to form a vacuum insulation structure, avoiding fogging and frost problems in the window 3 when the low-temperature medium is working, ensuring the clarity of the camera's observation, and eliminating the need for additional real-time defrosting / anti-fogging operations. A high-speed camera 11 is set outside the centrifugal pump, and the camera is arranged correspondingly to the window 3. By using the cooperation of the transparent window 3 and the external high-speed camera 11, the cavitation phenomenon of the inducer wheel 4 can be directly captured. The cavitation phenomenon generated by the inducer wheel 4 during operation can be directly photographed through the transparent window 3, providing intuitive visual data for the study of cavitation in the low-temperature centrifugal pump inducer wheel 4, and realizing the visualized monitoring of cavitation in the inducer wheel 4.

[0022] Further optimizing the design, the viewing window 3 comprises a cylindrical body, with the interlayer 12 being a closed cavity coaxially arranged with the body. As the core component of this invention, the viewing window 3's body is designed as a hollow cylindrical structure, conforming to the flow channel shape of the centrifugal pump inlet, preventing the fluid from being affected when passing through, ensuring that the fluid flow space around the inducer wheel 4 is consistent with the actual working state, and improving the accuracy of the observed data; the interlayer 12, which is evacuated within the body, is in a closed state, resulting in a more uniform vacuum insulation effect, comprehensively preventing fogging / frost formation on the viewing window 3, while the closed structure allows the vacuum state to be maintained for a long time without additional maintenance.

[0023] The design was further optimized by using a low-temperature resistant transparent material for the main body. The window 3 is made of a low-temperature resistant transparent material. The low-temperature resistant property ensures that the window 3 will not crack or deform due to low temperature in the low-temperature working environment, thereby improving the structural stability and service life of the device. The transparency of the material ensures that the observation and shooting field of the high-speed camera 11 is unobstructed, ensuring the visualization effect.

[0024] In one embodiment of the present invention, the material of the window 3 may be quartz glass, which not only does not shrink and become brittle like ordinary materials, but also becomes more stable in size as the temperature decreases, and even exhibits extremely weak "reverse expansion", making it an ideal material for high-precision measurement and observation in low-temperature environments.

[0025] The design is further optimized. The centrifugal pump includes a pump body 8, with a pump cover plate 9 installed at the rear end of the pump body 8. A shaft 10 for transmitting power is rotatably connected to the pump cover plate 9, extending into the pump body 8. An inducer wheel 4 is fixedly installed at the end of the shaft 10. The pump body 8 serves as the main structure of the centrifugal pump. The cover plate is detachably installed at the rear end of the pump body 8, and the shaft 10 is positioned by bearings. The end of the shaft 10 extends into the inner cavity of the pump body 8. The inducer wheel 4 is fixed to the end of the shaft 10 by threads, making the fixing method of the inducer wheel 4 more stable, and its rotation state during operation is consistent with that of an actual centrifugal pump. The cover plate is detachable from the pump body 8 for easy maintenance.

[0026] The design was further optimized by incorporating an impeller 6 within the pump body 8. The impeller 6 is mounted on the shaft 10 and positioned behind the inducer 4. This mounting of the impeller 6 on the shaft 10 and its location at the rear of the inducer 4 ensures that the shaft 10 rotates simultaneously with both the inducer 4 and the impeller 6, mirroring the structure of a real centrifugal pump. This achieves the coordinated operation of the inducer 4 and impeller 6, replicating the actual working combination of the inducer 4 and impeller 6 in a centrifugal pump. This allows for the study of cavitation in the inducer 4 independently, as well as the influence of the impeller 6 on the cavitation of the inducer 4 when both work together. This makes the experimental results more realistic and overcomes the limitations of existing technologies that only study the inducer 4 in isolation. Furthermore, the arrangement of the inducer 4 in front and the impeller 6 behind closely matches the actual fluid flow and pressurization process of a centrifugal pump, making the experimental scenario more authentic.

[0027] In one embodiment of the present invention, the pump body 8 is provided with an upward pump outlet 7, which is correspondingly provided with the impeller 6. When the impeller 6 rotates, the fluid entering the pump body 8 is pressurized and discharged through the upward pump outlet 7, thereby driving the fluid.

[0028] The design is further optimized by installing an inlet flange 1 at the inlet of the pump body 8. The viewing window 3 is clamped and fixed between the inlet flange 1 and the pump body 8, and the inlet flange 1 and the pump body 8 are locked together by a locking assembly. The inlet flange 1 is connected to the inlet of the pump body 8 via the locking assembly, and the viewing window 3 is clamped and fixed between the inlet flange 1 and the pump body 8. This distributes the clamping force across the entire viewing window 3, preventing stress concentration and damage. Installation and disassembly are convenient, and the connection between the viewing window 3 and the pump body 8 and inlet flange 1 provides better sealing, preventing leakage of low-temperature media. It also ensures the stability of the connection structure and facilitates the maintenance and replacement of the viewing window 3.

[0029] In one embodiment of the present invention, the window 3 does not have a flange or a connection hole, which reduces the manufacturing difficulty and the probability of damage during use.

[0030] The design is further optimized by including multiple axially spaced tie rods 2. The tie rods 2 pass through the inlet flange 1 and are locked to the pump body 8. The tie rods 2 surround the viewing window 3. A high-speed camera 11 observes and photographs the fluid within the viewing window 3 through the gaps in the tie rods 2. The multiple tie rods 2 surrounding the viewing window 3, passing through the inlet flange 1 and threaded onto the pump body 8, apply force evenly to the inlet flange 1, clamping the viewing window 3. The circumferentially spaced tie rods 2 ensure uniform force application to the viewing window 3 by the inlet flange 1, resulting in a more even clamping force on the viewing window 3 and preventing damage due to uneven force, thus improving connection stability. The lens of the high-speed camera 11 photographs the viewing window 3 through the gaps in the tie rods 2, providing an unobstructed field of view and ensuring smooth visualization observation.

[0031] In one embodiment of the present invention, the number of pull rods 2 is not less than 4, to ensure the clamping force on the viewing window 3 and to ensure the safety of the test.

[0032] The design was further optimized by installing flange stops on the inlet flange 1 and pump body 8, each corresponding to the viewing window 3. The two ends of the viewing window 3 abut against the bottom of these flange stops. Concave flange stops are provided on the opposite surfaces of the inlet flange 1 and pump body 8, with the diameter of the flange stops matching the outer diameter of the viewing window 3. This provides precise positioning for the viewing window 3, preventing misalignment during installation and ensuring accurate alignment between the inducer wheel 4 and the viewing window 3, thus not affecting observation. Simultaneously, the flange stops ensure precise installation of the viewing window 3, preventing misalignment during installation and preventing the inlet flange 1 from damaging the tilted viewing window 3, thus ensuring installation safety. The abutment structure of the stops can distribute the clamping force on the viewing window 3, further preventing damage and improving the sealing effect between the viewing window 3 and the flange and pump body 8.

[0033] Further optimization involves installing elastic gaskets 5 at both ends of the viewing window 3, with the two elastic gaskets 5 respectively abutting against the pump body 8 and the inlet flange 1. The annular elastic gaskets 5 at both ends of the viewing window 3 act as a buffer, absorbing the compressive force generated when the pull rod 2 is tightened, completely preventing damage to the viewing window 3 due to rigid clamping and protecting its structure. Simultaneously, the sealing effect of the elastic gaskets 5 further enhances the sealing performance between the viewing window 3 and the pump body 8 and the inlet flange 1, preventing leakage of cryogenic media.

[0034] The design was further optimized, and during the test, the rotational speed range of shaft 10 was 8000-10000 rpm.

[0035] Working principle: Before operation, wrap the centrifugal pump with an insulation layer and expose the viewing window 3 for easy observation; fill the centrifugal pump with low-temperature medium and connect the pipeline circuit between the centrifugal pump and the low-temperature medium container; then fix and adjust the high-speed camera 11 so that the lens of the high-speed camera 11 avoids the pull rod 2 and is aimed at the viewing window 3.

[0036] After the centrifugal pump motor is powered on and started, the inducer wheel 4 and impeller 6 and shaft 10 run under the drive of the motor, and at the same time the high-speed camera 11 is turned on to take pictures.

[0037] The cryogenic medium enters the inducer 4 from inside the inlet flange 1. After being pressurized by the inducer 4, it enters the impeller 6 and is further pressurized by the impeller 6 before being discharged from the pump outlet 7. When the pressure of the cryogenic medium entering the inducer 4 is lower than the saturated vapor pressure of the medium, cavitation occurs. The cavitation phenomenon is captured by the high-speed camera 11 outside the viewing window 3.

[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A centrifugal pump inducer cryogenic visualization apparatus, characterized by: The centrifugal pump includes a transparent window (3) which is located at the inlet of the centrifugal pump. The induced wheel (4) in the centrifugal pump extends into the window (3) and is correspondingly positioned to the window (3). The window (3) has an annular interlayer (12) which is evacuated. The viewing window (3) is correspondingly set with a high-speed camera (11) located outside the centrifugal pump. The high-speed camera (11) takes pictures of the cavitation phenomenon caused by the inducer wheel (4) through the viewing window (3).

2. The centrifugal pump inducer cryogenic visualization apparatus of claim 1, wherein: The window (3) includes a cylindrical body, and the interlayer (12) is a closed cavity coaxially arranged with the body.

3. The centrifugal pump inducer cryogenic visualization apparatus of claim 2, wherein: The main body is made of a transparent material that is resistant to low temperatures.

4. The centrifugal pump inducer cryogenic visualization apparatus of claim 1, wherein: The centrifugal pump includes a pump body (8), a pump cover plate (9) is installed at the rear end of the pump body (8), and a shaft (10) for transmitting power is rotatably connected to the pump cover plate (9). The shaft (10) extends into the pump body (8), and the inducer wheel (4) is fixedly installed at the end of the shaft (10).

5. The centrifugal pump inducer cryogenic visualization apparatus of claim 4, wherein: An impeller (6) is provided in the pump body (8), and the impeller (6) is driven and sleeved on the shaft (10). The impeller (6) is located behind the inducer wheel (4).

6. The centrifugal pump inducer cryogenic visualization apparatus of claim 4, wherein: The pump body (8) is provided with an inlet flange (1) in the inlet direction. The window (3) is clamped and fixed between the inlet flange (1) and the pump body (8). The inlet flange (1) and the pump body (8) are locked together by a locking assembly.

7. The centrifugal pump inducer cryogenic visualization apparatus of claim 6, wherein: The locking assembly includes multiple axially spaced tie rods (2), which pass through the inlet flange (1) and are locked to the pump body (8). The tie rods (2) are arranged around the viewing window (3). The high-speed camera (11) visualizes and photographs the fluid in the viewing window (3) through the gaps in the tie rods (2).

8. The centrifugal pump inducer cryogenic visualization apparatus of claim 6, wherein: The inlet flange (1) and the pump body (8) are respectively provided with flange stops corresponding to the viewing window (3), and the two ends of the viewing window (3) respectively abut against the bottom end of the flange stop.

9. The centrifugal pump inducer cryogenic visualization apparatus of claim 6, wherein: The two ends of the viewing window (3) are respectively provided with elastic gaskets (5), and the two elastic gaskets (5) abut against the pump body (8) and the inlet flange (1) respectively.

10. The centrifugal pump inducer cryogenic visualization apparatus of claim 4, wherein: During the test, the rotational speed of the shaft (10) was 8000-10000 rpm.

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