A replaceable valve plate type flow pulsation generator

Abstract

This invention discloses a replaceable valve plate type flow pulsation generator, comprising: a device pipe, a rotary valve plate, a rotary shaft, a bearing sleeve, a high-speed motor, and a fixed bracket. The high-speed motor is fixed on the fixed bracket, and its output end is connected to one end of the rotary shaft via a coupling. The other end of the rotary shaft extends into the cylindrical section of the device pipe. A mounting through-hole is provided at the top of the device pipe. Rotary valve plates of different sizes are fitted onto the other end of the rotary shaft through the mounting through-hole, allowing the valve plates to rotate within the device pipe with the rotary shaft. A top sealing cap is fitted into the mounting through-hole. A bearing sleeve is installed on the outer side of the rotary shaft, and rolling bearings are installed between the rotary shaft and the bearing sleeve. A sealing structure is installed between the bearing sleeve and the device pipe. The bottom end of the bearing sleeve is connected to the fixed bracket. This invention solves the problems of existing pulsation generators where the valve plate size is fixed and cannot be replaced, can only generate specific pulsation amplitudes, and cannot guarantee the overall structural reliability at high speeds.

Description

Technical Field

[0001] This invention relates to the field of fluid turbomachinery, and more particularly to a replaceable valve plate type flow pulsation generator. Background Technology

[0002] Multistage centrifugal compressors and axial-centrifugal combined compressors have wide applications in industrial equipment, aero engines and other fields.

[0003] For a typical single-stage compressor, its optimal design point is usually chosen near the maximum speed or where the compressor can generate the maximum pressure rise. When the compressor operates under low flow conditions, its internal flow deteriorates, often leading to compressor stall or even surge. Stall and surge are two typical signs of a compressor entering an unstable state, manifested externally as periodic pulsations in airflow and pressure. Stall is generally divided into low-frequency stall and high-frequency stall. The pulsation amplitudes of these two types of stall are similar and relatively small (less than 10%), but the stall frequencies differ significantly: the pulsation frequency of low-frequency stall is about one-fifth of the compressor speed, while the pulsation frequency of high-frequency stall is about half of the compressor speed. Typical small and medium-sized compressors typically have a maximum speed of 60,000–120,000 rpm, therefore, the corresponding low-frequency stall pulsation frequency is 200Hz–400Hz, and the corresponding high-frequency stall pulsation frequency is 500–1000Hz. Surge causes the airflow to produce a large amplitude, low frequency pulsation, with the pulsation amplitude generally between 10% and 30% and the pulsation frequency generally between 10 Hz and 20 Hz, which is related to the compressor structure.

[0004] The stability of a single-stage compressor has a significant impact on the matching of multi-stage compressors. Ideally, each stage of a multi-stage compressor operates at its optimal design point. However, this is not the case in reality. Most compressors operate at non-design pressure ratios and speeds for at least a certain period, leading to matching problems between compressor stages. In particular, when the preceding stage compressor experiences stall or surge, the mass flow rate of the airflow produces different periodic pulsations, which affect the subsequent stages of the compressor—a problem requiring in-depth research. Directly focusing on multi-stage centrifugal compressors or axial-centrifugal combined compressors is clearly insufficient for a comprehensive and systematic study of this issue. Therefore, a gas flow pulsation generator capable of producing different pulsation frequencies (0-1000Hz) and amplitudes (0-30%) is needed to replace the preceding stage of the multi-stage compressor and simulate the airflow pulsations during stall or surge.

[0005] Currently, existing flow pulsation generators have the following problems:

[0006] 1. In traditional pulsation generators, the valve plate size is fixed and cannot be replaced. It can only generate a specific pulsation amplitude and cannot flexibly achieve changes in pulsation amplitude.

[0007] 2. The pulsation frequency generated by the pulsation generator is controlled by the motor speed. The pulsation frequency in the range of 0-1000Hz requires the motor to provide a speed of at least tens of thousands of revolutions per minute. Using a high-speed motor places high demands on the stability of the rotating system and the centering of the generator. Existing pulsation generators cannot guarantee the reliability of the overall structure at high speeds. Summary of the Invention

[0008] This invention provides a replaceable valve plate type airflow pulsation generator to overcome the problems of existing pulsation generators where the valve plate size is fixed and cannot be replaced, can only generate specific pulsation amplitudes, and cannot guarantee the reliability of the overall structure at high speeds.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] A replaceable valve plate type flow pulsation generator includes: a device pipe, a top sealing cover, a rotary valve plate, a rotary shaft, a high-speed motor, and a fixed bracket. The high-speed motor is fixed on the fixed bracket, and the output end of the high-speed motor is connected to one end of the rotary shaft via a coupling. The other end of the rotary shaft extends into the cylindrical section of the device pipe. A mounting through hole is provided at the top of the device pipe. The rotary valve plate is sleeved on the other end of the rotary shaft through the mounting through hole. The rotary valve plate can rotate with the rotary shaft inside the device pipe. The top sealing cover is fitted with the mounting through hole. A bearing sleeve is installed on the outside of the rotary shaft. A rolling bearing is installed between the rotary shaft and the bearing sleeve. A sealing structure is installed between the top end of the bearing sleeve and the device pipe. The bottom end of the bearing sleeve is connected to the fixed bracket.

[0011] Furthermore, the rotary valve plate includes a rotating body and a blade structure connected to the rotating body. The blade structure is a semi-circular structure and the plane containing adjacent blade structures has an included angle of 90°. The blade structure and the rotating body adopt an arc transition, and the blade structure gradually shrinks from the connection end with the rotating body to the distal end.

[0012] Furthermore, the rotating shaft has a stepped structure.

[0013] Furthermore, the sealing structure employs a labyrinth seal.

[0014] Furthermore, the bottom of the device pipe is provided with a circular groove structure, the top of the bearing sleeve is provided with a sealing installation groove adapted to the sealing structure, the top of the bearing sleeve is connected to the circular groove structure, and the sealing structure is installed between the circular groove structure and the sealing installation groove.

[0015] Furthermore, the bottom end of the top sealing cover is provided with a hole that mates with the shaft end of the rotating shaft.

[0016] Beneficial Effects: This invention provides a replaceable valve plate type flow pulsation generator. By adjusting the speed of a high-speed motor to control the speed of a rotating shaft, and thus the speed of a rotating valve plate, it simulates mass flow pulsations of different frequencies. By replacing the rotating valve plates with different sizes, the effective flow area within the device's pipeline exhibits periodic fluctuations of varying amplitudes, thereby simulating mass flow pulsations of different amplitudes. One end of the rotating shaft is connected to the high-speed motor via a coupling, while the other end is suspended within the device's pipeline, forming a cantilever structure. It is sealed and positioned using rolling bearings, bearing sleeves, and a sealing structure. This avoids alignment issues of the rotating shaft during processing or installation, further improving the overall stability of the device and ensuring stable operation at high speeds. 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 description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0019] Figure 2 This is a schematic diagram of the device pipeline structure of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0020] Figure 3 for Figure 2 Cross-sectional view of AA in the middle;

[0021] Figure 4 This is a front view sectional view of the sealing structure of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0022] Figure 5 This is a top view of the sealing structure of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0023] Figure 6 This is a schematic diagram of the bearing sleeve structure of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0024] Figure 7 for Figure 6 Sectional view of AA in the middle;

[0025] Figure 8 This is a top view of the bearing sleeve of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0026] Figure 9 This is a top view of the rotating valve plate of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0027] Figure 10 This is a cross-sectional view of the main view of a replaceable valve plate type flow pulsation generator of different sizes disclosed in this invention;

[0028] Figure 11 This is a first-view view of the rotating valve plate of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0029] Figure 12 This is a second-view view of the rotating valve plate of a replaceable valve plate type flow pulsation generator disclosed in this invention;

[0030] Figure 13 This is a diagram showing the mass flow pulsation characteristics of a replaceable valve plate type flow pulsation generator with rotary valve plates of sizes (DN50, DN55, DN60 and DN65) at a rotational speed of 300 RPM.

[0031] Figure 14 This is a diagram showing the mass flow pulsation characteristics of a replaceable valve plate type flow pulsation generator with rotary valve plates of sizes (DN50, DN55, DN60 and DN65) at a rotational speed of 4000 RPM.

[0032] Figure 15 This is a diagram showing the mass flow rate pulsation characteristics of a replaceable valve plate type flow pulsation generator with rotating valve plates of sizes (DN50, DN55, DN60 and DN65) at a rotation speed of 10000 RPM.

[0033] In the diagram: 1. Device piping; 11. Circular groove structure; 2. Top sealing cover; 21. Shaft end mating hole; 3. Rotary valve plate; 31. Rotating body; 32. Blade structure; 321. First blade; 4. Rotating shaft; 5. Bearing sleeve; 51. Sealing mounting groove; 6. Sealing structure; 7. Rolling bearing; 8. Coupling; 9. High-speed motor; 10. Fixed bracket. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0035] This embodiment provides a replaceable valve plate type flow pulsation generator, such as Figure 1 As shown, the device includes: a pipe 1, a top sealing cover 2, a rotary valve plate 3, a rotary shaft 4, a high-speed motor 9, and a fixed bracket 10. The high-speed motor 9 is fixed at the center of the fixed bracket 10, and the output end of the high-speed motor 9 is connected to one end of the rotary shaft 4 via a coupling 8. The other end of the rotary shaft 4 extends into the cylindrical section of the pipe 1. Figures 2 to 3 As shown, the outer profile of the pipe body of the device pipe 1 is rectangular, and the inner flow section is circular. A mounting through hole is provided at the top of the device pipe 1. This mounting through hole is rectangular. The rotary valve plate 3 is sleeved on the other end of the rotating shaft 4 through the mounting through hole and fixed to the rotating shaft 4 with a fastening nut. The rotary valve plate 3 can rotate with the rotating shaft 4 inside the device pipe 1. The top sealing cover 2 is fitted with the mounting through hole to achieve pipe sealing. The bottom end of the top sealing cover 2 has a shaft end fitting hole 21 for the rotating shaft 4. The top sealing cover 2 is fixedly connected to the device pipe 1 with bolts. The rotary valve plate 3 can be replaced by removing the top sealing cover 2 through the rectangular through hole at the upper end of the device pipe 1. The bearing sleeve 5 is installed on the outer side of the rotating shaft 4. Figures 6 to 8 As shown, the bearing sleeve 5 has two rolling bearings 7 installed inside, one above the other. These rolling bearings 7 are used for positioning the rotating shaft 4. The top of the bearing sleeve 5 has an installation groove. A sealing structure 6 is installed between the top of the bearing sleeve 5 and the device pipe 1. The sealing structure 6 is located within the installation groove and presses the rolling bearings 7 tightly into the bearing sleeve 5. The bottom of the bearing sleeve 5 is circumferentially fixed to the fixed bracket 10 by several double-ended bolts 12. The device pipe 1, through the pre-tightening force during installation and its own weight, tightly engages with the bearing sleeve 5, ensuring the robustness of the device connection.

[0036] In the specific implementation process, the device pipeline 1 is connected to the preset experimental pipeline, the high-speed motor 9 is started, and the rotation of the rotating shaft 4 is controlled by adjusting the speed of the high-speed motor 9. The rotation of the rotating shaft 4 controls the rotation speed of the rotating valve plate 3, so that the flow area of ​​the gas inside the device 1 changes periodically, thereby causing the generated flow rate to change periodically. That is, by adjusting the speed of the high-speed motor 9, the rotation speed of the rotating shaft 4 is controlled, and then the rotation speed of the rotating valve plate 3 is controlled, thus simulating mass flow pulsations of different frequencies. By replacing the rotating valve plate 3 with different sizes, the effective flow area inside the device pipeline 1 exhibits periodic fluctuations of different amplitudes, thereby simulating mass flow pulsations of different amplitudes. One end of the rotating shaft 4 is connected to the high-speed motor 9 through the coupling 8, and the other end of the rotating shaft 4 is suspended inside the device pipeline 1, that is, it is made into a cantilever structure. It is sealed and positioned by the rolling bearing 7, the bearing sleeve 5, and the sealing structure 6. This avoids the centering problem of the rotating shaft 4 during processing or installation, further improving the stability of the overall structure of the device, thus ensuring stable operation at high speeds. Furthermore, the rotating shaft 4, rolling bearing 7, bearing sleeve 5, and sealing structure 6 can be integrated into a single structure and made independent of the device pipeline 1, meaning that the rotating shaft 4 and the device pipeline 1 are separate. Therefore, during the installation of the device pipeline 1 and subsequent experiments, the influence of the form and position tolerances, machining errors, or experimental disturbances and vibrations of the device pipeline 1 on the integrated structure can be minimized.

[0037] In a specific embodiment, such as Figures 9 to 10 As shown, the rotary valve plate 3 includes a rotating body 31 and a blade structure 32 connected to the rotating body 31. The blade structure 32 is a semi-circular structure with an included angle of 90° between adjacent blade structures 32. The blade structure 32 and the rotating body 31 are connected by an arc-shaped transition, and the blade structure 32 gradually tapers from the connection end with the rotating body 31 to the distal end. The center of the circle containing the rotary valve plate 3 coincides with the radial axis of the device pipe 1, as shown. Figures 11 to 12 As shown, when the first blade 321 is parallel to the radial direction of the device pipe 1, the corresponding flow area of ​​the device pipe 1 is the minimum flow area. When the first blade 321 forms a 45° angle with the radial direction of the device pipe 1, the corresponding flow area of ​​the device pipe 1 is the maximum flow area. The rotating body 31 is sleeved on the rotating shaft 4 and fastened with bolts. The rotating shaft 4 rotates to drive the rotating body 31 to rotate, thereby realizing the periodic change of the flow area in the device pipe 1. The included angle between the two sides of the blade of the blade structure 32, i.e., the blade tilt angle, is 2.5° to prevent the blade structure from being damaged due to excessive force at the root of the blade structure 32 during the experiment, thus ensuring the integrity of the rotating valve plate 3. This reduces the axial stress of the rotating valve plate 3 on the rotating shaft 4 during the rotation of the rotating valve plate 3, ensuring the stability of the structure operation.

[0038] In a specific embodiment, the rotating shaft 4 has a stepped structure and is installed perpendicular to the device pipe 1, which reduces the axial stress on the rotating shaft 4 during movement. The stepped structure enhances the reliability and tightness of the connection, preventing gaps or relative slippage between the rotating shaft 4 and the connecting body after loading. The connection between the rotating shaft 4 and the rotating valve plate 3 can be provided with a threaded structure, and a matching thread is provided inside the rotating body 31 of the rotating valve plate 3; or the connection between the rotating shaft 4 and the rotating valve plate 3 can be provided as a square shaft, a triangular structure, or other polyhedral structure, and a matching structural shape is provided inside the rotating body 31 to improve the tight connection between the rotating shaft 4 and the rotating valve plate 3, so as to prevent the rotating valve plate 3 from rotating relative to the rotating shaft 4, which would cause inaccurate experimental results in the later stages of the device.

[0039] In a specific embodiment, such as Figures 4 to 5 As shown, the sealing structure 6 employs a labyrinth seal. The sealing structure 6 offers advantages such as excellent sealing performance under high-speed conditions, no lubrication required, no friction, and long service life. Furthermore, it boasts high machining precision and is suitable for sealing high-temperature, high-pressure, high-speed, and large-size sealing components, reducing flow fluctuation losses during experiments and resulting in more accurate experimental results.

[0040] In a specific embodiment, the bottom of the device pipe 1 is provided with a circular groove structure 11, and the top of the bearing sleeve 5 is provided with a sealing mounting groove 51 adapted to the sealing structure 6. The top of the bearing sleeve 5 is connected to the circular groove structure 11, and the sealing structure 6 is installed between the circular groove structure 11 and the sealing mounting groove 51 and fixed to the bearing sleeve 5 by several screws, which improves the tightness of the connection between the devices and provides a guarantee for the stable operation of the devices.

[0041] This device provides a replaceable valve plate type flow pulsation generator, employing a high-speed motor. The rotational speed of the valve plate is controlled by adjusting the motor speed, thereby simulating mass flow pulsations of different frequencies. By replacing the rotary valve plates with different sizes, the effective flow area within the device's pipeline exhibits periodic fluctuations of varying amplitudes, thus simulating mass flow pulsations of different amplitudes. Figures 13 to 15 The figure shows the mass flow rate pulsation characteristics of rotary valve plates 3 of different sizes (DN50, DN55, DN60, and DN65) at rotational speeds of 300 RPM, 4000 RPM, and 10000 RPM. The measurement method for the mass flow rate pulsation characteristics obtained in this application is prior art and is not an inventive point of this application; therefore, it will not be described further.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A replaceable valve plate type flow pulsation generator, characterized in that, include: The device includes a pipe (1), a top sealing cap (2), a rotary valve plate (3), a rotating shaft (4), a high-speed motor (9), and a fixed bracket (10). The rotary valve plate (3) includes a rotating body (31) and a blade structure (32) connected to the rotating body (31). The blade structure (32) is a semi-circular structure with an included angle of 90° between adjacent blade structures (32). The blade structure (32) and the rotating body (31) are connected by an arc transition, and the blade structure (32) gradually tapers from the connection end with the rotating body (31) to the far end. An included angle is provided between the two sides of the blade of the blade structure (32) to prevent damage to the blade structure, i.e., the blade tilt angle is 2.5°. The high-speed motor (9) is fixed on the fixed bracket (10), and the high-speed motor (9) has a semi-circular structure with an included angle of 90° between adjacent blades. The output end is connected to one end of the rotating shaft (4) via a coupling (8). The other end of the rotating shaft (4) extends into the cylindrical part of the device pipe (1) to form a cantilever structure. The top of the device pipe (1) is provided with an installation through hole. The rotating valve plate (3) is sleeved on the other end of the rotating shaft (4) through the installation through hole. The rotating valve plate (3) can rotate with the rotating shaft (4) in the device pipe (1). The top sealing cover (2) is installed in conjunction with the installation through hole. A bearing sleeve (5) is installed on the outside of the rotating shaft (4). A rolling bearing (7) is installed between the rotating shaft (4) and the bearing sleeve (5). A sealing structure (6) is installed between the top end of the bearing sleeve (5) and the device pipe (1). The bottom end of the bearing sleeve (5) is connected to the fixed bracket (10). The rotating shaft (4) is a stepped structure used to reduce the axial stress during movement, and is installed perpendicular to the device pipe (1). The connection between the rotating shaft (4) and the rotating valve plate (3) can be provided with a threaded structure, and a matching thread is provided inside the rotating body (31) of the rotating valve plate (3); or the connection between the rotating shaft (4) and the rotating valve plate (3) can be provided with a square shaft, a triangular structure or other polyhedral structure, and a matching structural shape is provided inside the rotating body (31) to improve the tight connection between the rotating shaft (4) and the rotating valve plate (3).

2. The replaceable valve plate type flow pulsation generator according to claim 1, characterized in that, The sealing structure (6) adopts a labyrinth seal.

3. The replaceable valve plate type flow pulsation generator according to claim 1, characterized in that, The bottom of the device pipe (1) is provided with a circular groove structure (11), and the top of the bearing sleeve (5) is provided with a sealing installation groove (51) adapted to the sealing structure (6). The top of the bearing sleeve (5) is adapted to the circular groove structure (11), and the sealing structure (6) is installed between the circular groove structure (11) and the sealing installation groove (51).

4. The replaceable valve plate type flow pulsation generator according to claim 1, characterized in that, The bottom end of the top sealing cover (2) is provided with a shaft end fitting hole (21) for the rotating shaft (4).

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