Variable-width diffuser and centrifugal compressor

Abstract

The utility model discloses a variable-width diffuser and a centrifugal compressor. The variable-width diffuser comprises a vaneless diffusion front cover plate, a vaneless diffusion rear cover plate, a driving shaft, a driving ring, a diffusion sliding block and a positioning pin which are correspondingly arranged, and the vaneless diffusion front cover plate and the vaneless diffusion rear cover plate are both arranged on the volute; the driving shaft drives the driving ring to rotate; the diffusion sliding block is arranged at the end, close to the vaneless diffusion rear cover plate, of the vaneless diffusion front cover plate in a sleeving mode, and the positioning pin penetrates through a U-shaped groove of the diffusion sliding block and then is fixedly arranged on the vaneless diffusion front cover plate. The driving ring drives the diffusion sliding block to rotate, and the positioning pin abuts against the inner wall of the U-shaped groove so that the diffusion sliding block can be close to or away from the vaneless diffusion rear cover. According to the centrifugal compressor, the diffusion sliding block is arranged between the vaneless diffusion front cover plate and the vaneless diffusion rear cover plate, the driving shaft and the driving ring are used for driving the diffusion sliding block to be close to or away from the vaneless diffusion rear cover plate, distance adjustment is achieved, the surge pressure ratio can be effectively increased, and the centrifugal compressor can also obtain a larger working condition range.

Description

Technical Field

[0001] This utility model relates to the field of diffusers, and in particular to a variable width diffuser and a centrifugal compressor. Background Technology

[0002] In the field of fluid machinery, a diffuser is defined as a device that converts the kinetic energy of a fluid into pressure energy. Diffusers primarily achieve energy conversion by altering the flow area of ​​the fluid. As fluid flows through a diffuser, the flow area gradually increases, and according to the continuity equation of fluid dynamics, the fluid velocity decreases. Simultaneously, based on Bernoulli's principle, and neglecting changes in potential energy, the fluid pressure increases accordingly.

[0003] In a centrifugal compressor, the diffuser is located on the outlet side of the impeller and is a component between the impeller and the volute. The function of the diffuser is to receive the high-speed fluid flowing at the impeller outlet, effectively convert the fluid's kinetic energy into pressure energy, and then deliver the fluid into the volute.

[0004] Currently, diffusers typically have an optimal operating flow rate. When the actual flow rate deviates from this optimal value, the diffuser's performance will decrease. If the flow rate is too low, it may also cause the fluid to flow too slowly within the diffuser, resulting in unstable phenomena such as backflow, making it difficult to meet the requirements of centrifugal compressors operating under varying conditions. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the above-mentioned defects in the existing centrifugal compressor where the diffuser is difficult to meet the requirements of variable operating conditions, and to provide a variable width diffuser and a centrifugal compressor.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] A variable width diffuser for a centrifugal compressor includes: a vaneless diffuser front cover plate, a vaneless diffuser rear cover plate, a drive shaft, a drive ring, a diffuser slider, and a positioning pin. Both the vaneless diffuser front cover plate and the vaneless diffuser rear cover plate are located within the volute of the centrifugal compressor. The drive ring is sleeved on the end of the vaneless diffuser front cover plate away from the vaneless diffuser rear cover plate. The drive shaft is fixed to the drive ring and drives the drive ring to rotate. The diffuser slider is sleeved on the end of the vaneless diffuser front cover plate near the vaneless diffuser rear cover plate. The diffuser slider has a U-shaped groove, and the positioning pin passes through the U-shaped groove and is fixed to the vaneless diffuser front cover plate. The drive ring is connected to the diffuser slider, and the drive ring drives the diffuser slider to rotate. The positioning pin abuts against the inner wall of the U-shaped groove, causing the diffuser slider to move closer to or further away from the vaneless diffuser rear cover plate.

[0008] In this solution, by adopting the above structure, the diffuser slider is placed between the vaneless diffuser front cover plate and the vaneless diffuser rear cover plate. The drive shaft and drive ring are used to move the diffuser slider closer to or away from the vaneless diffuser rear cover plate, thereby adjusting the distance between the diffuser slider and the vaneless diffuser rear cover plate, which means adjusting the flow channel width. This can effectively improve the surge pressure ratio of the centrifugal compressor, reduce the operating speed of the centrifugal compressor, and obtain a wider operating range.

[0009] Optionally, the bladeless diffuser front cover has a U-shaped hole, and the variable width diffuser further includes a bolt that passes through the drive ring, the U-shaped hole, and the diffuser slider.

[0010] Optionally, the drive shaft passes through the side of the drive ring.

[0011] Optionally, both the bladeless diffuser front cover and the bladeless diffuser rear cover are bolted to the volute.

[0012] Optionally, the drive shaft is bolted to the drive ring.

[0013] A centrifugal compressor includes a variable width diffuser as described above, the variable width diffuser being disposed in the volute of the centrifugal compressor.

[0014] In this solution, by adopting the above structure and setting a variable width diffuser, the flow channel width can be adjusted, which can effectively improve the compressor surge pressure ratio, reduce the operating speed of the centrifugal compressor, and obtain a wider operating range.

[0015] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this utility model.

[0016] The positive and progressive effects of this utility model are as follows:

[0017] This invention adjusts the distance between the diffuser slider and the bladeless diffuser rear cover plate by placing the diffuser slider between the front cover plate and the rear cover plate of the bladeless diffuser and using a drive shaft and drive ring to move the diffuser slider closer to or away from the rear cover plate of the bladeless diffuser. This adjustment achieves the adjustment of the flow channel width, which can effectively improve the surge pressure ratio of the centrifugal compressor, reduce the operating speed of the centrifugal compressor, and obtain a wider operating range. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the diffuser in a centrifugal compressor according to an embodiment of the present invention.

[0019] Figure 2 for Figure 1 A schematic diagram of a partial cross-section of the diffuser in a centrifugal compressor.

[0020] Explanation of reference numerals in the attached figures:

[0021] Centrifugal compressor 100

[0022] 11-shell

[0023] Impeller 12

[0024] Variable width diffuser 20

[0025] bladeless diffuser front cover 21

[0026] U-shaped hole 211

[0027] 22 bladeless diffuser back cover

[0028] Drive shaft 23

[0029] Drive ring 24

[0030] Diffusion slider 25

[0031] U-shaped groove 251

[0032] Positioning pin 26

[0033] Bolt 27 Detailed Implementation

[0034] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments.

[0035] like Figures 1-2 As shown, this embodiment includes a variable width diffuser 20 and a centrifugal compressor 100. The centrifugal compressor 100 uses the variable width diffuser 20, which is located in the volute 11 of the centrifugal compressor 100. By setting the variable width diffuser 20, the flow channel width can be adjusted, which can effectively improve the surge pressure ratio of the centrifugal compressor 100, reduce the operating speed of the centrifugal compressor 100, and obtain a wider operating range.

[0036] In this example, the variable width diffuser 20 includes: a vaneless diffuser front cover plate 21 and a vaneless diffuser rear cover plate 22, a drive shaft 23, a drive ring 24, a diffuser slider 25, and a positioning pin 26. The vaneless diffuser front cover plate 21 and the vaneless diffuser rear cover plate 22 are both located on the volute 11 of the centrifugal compressor 100. The drive ring 24 is sleeved on the end of the vaneless diffuser front cover plate 21 away from the vaneless diffuser rear cover plate 22. The drive shaft 23 is fixed to the drive ring 24. Used to drive the drive ring 24 to rotate; the diffuser slider 25 is sleeved on one end of the bladeless diffuser front cover plate 21 near the bladeless diffuser rear cover plate 22. The diffuser slider 25 has a U-shaped groove 251. The positioning pin 26 passes through the U-shaped groove 251 and is fixed to the bladeless diffuser front cover plate 21; the drive ring 24 is connected to the diffuser slider 25. The drive ring 24 drives the diffuser slider 25 to rotate. The positioning pin 26 abuts against the inner wall of the U-shaped groove 251 so that the diffuser slider 25 moves closer to or away from the bladeless diffuser rear cover. By placing the diffuser slider 25 between the bladeless diffuser front cover plate 21 and the bladeless diffuser rear cover plate 22, and using the drive shaft 23 and drive ring 24 to drive the diffuser slider 25 to move closer to or away from the bladeless diffuser rear cover plate 22, the distance between the diffuser slider 25 and the bladeless diffuser rear cover plate 22 can be adjusted, which means the flow channel width can be adjusted. This can effectively improve the surge pressure ratio of the centrifugal compressor 100, reduce the operating speed of the centrifugal compressor 100, and obtain a wider operating range.

[0037] The variable width diffuser 20 can improve the performance of the centrifugal compressor 100 under varying operating conditions, enabling it to achieve a wider operating range. When the centrifugal compressor 100 operates under partial load and high pressure ratio conditions, the characteristic flow rate of the centrifugal compressor 100 will be significantly reduced. When the flow rate is too low, backflow will occur in the flow channel, which is the main cause of stall and surge. However, by reducing the flow channel width through the variable diffuser, the flow velocity of the fluid in the variable diffuser can be increased, eliminating backflow and thus preventing stall and surge. The variable diffuser can effectively improve the compressor surge pressure ratio, and the operating speed of the centrifugal compressor 100 can be reduced to a lower level, thus achieving a wider operating range.

[0038] The bladeless diffuser front cover 21 has a U-shaped hole 211, and the variable width diffuser 20 also includes a bolt 27, which passes through the drive ring 24, the U-shaped hole 211 and the diffuser slider 25.

[0039] The drive shaft 23 passes through the side of the drive ring 24. Both the vaneless diffuser front cover 21 and the vaneless diffuser rear cover 22 are bolted to the volute 11. The drive shaft 23 is bolted to the drive ring 24.

[0040] The structure and installation position of the variable width diffuser 20 are as follows: Figure 1 , 2As shown, a variable width diffuser 20 is composed of a drive shaft 23, a drive ring 24, a vaneless diffuser front cover plate 21, a vaneless diffuser rear cover plate 22, and a diffuser slider 25. In this example, the vaneless diffuser front cover plate 21 and the vaneless diffuser rear cover plate 22 are fixed to the volute 11 by bolts 27. The diffuser slider 25 is fitted into the vaneless diffuser front cover plate 21 and is limited by a locating pin 26. The drive shaft 23 is fixed to the drive ring 24 by bolts 27. The drive ring 24 is connected to the diffuser slider 25 through the U-shaped hole 211 of the vaneless diffuser front cover plate 21 by bolts 27 and then fixed to each other. By rotating the drive shaft 23, the drive ring 24 and the diffuser slider 25 can be rotated. Due to the structural limitation of the U-shaped groove 251 of the diffuser slider 25, the diffuser slider 25 can be axially displaced to expand or shrink the distance between the diffuser slider 25 and the vaneless diffuser rear cover plate 22, thereby achieving the purpose of changing the flow channel width.

[0041] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A variable width diffuser for use in a centrifugal compressor, characterized in that, The variable width diffuser includes: The corresponding bladeless diffuser front cover plate and bladeless diffuser rear cover plate are provided in the volute of the centrifugal compressor. A drive shaft and a drive ring, wherein the drive ring is sleeved on one end of the bladeless diffuser front cover plate away from the bladeless diffuser rear cover plate, and the drive shaft is fixed to the drive ring and is used to drive the drive ring to rotate. A diffuser slider and a positioning pin are provided. The diffuser slider is sleeved on one end of the bladeless diffuser front cover plate near the bladeless diffuser rear cover plate. The diffuser slider has a U-shaped groove. The positioning pin passes through the U-shaped groove and is fixedly installed on the bladeless diffuser front cover plate. The drive ring is connected to the diffuser slider, and the drive ring drives the diffuser slider to rotate. The positioning pin abuts against the inner wall of the U-shaped groove so that the diffuser slider moves closer to or away from the bladeless diffuser back cover.

2. The variable width diffuser as described in claim 1, characterized in that, The bladeless diffuser front cover has a U-shaped hole, and the variable width diffuser also includes bolts that pass through the drive ring, the U-shaped hole, and the diffuser slider.

3. The variable width diffuser as described in claim 1, characterized in that, The drive shaft passes through the side of the drive ring.

4. The variable width diffuser as described in claim 1, characterized in that, Both the bladeless diffuser front cover and the bladeless diffuser rear cover are bolted to the volute.

5. The variable width diffuser as described in claim 1, characterized in that, The drive shaft is bolted to the drive ring.

6. A centrifugal compressor, characterized in that, The centrifugal compressor includes a variable width diffuser as described in any one of claims 1-5, wherein the variable width diffuser is disposed in the volute of the centrifugal compressor.

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