Impeller assembly, centrifugal impeller and steam compressor

Abstract

This invention provides an impeller assembly, a centrifugal impeller, and a steam compressor. The impeller assembly includes a hub and multiple blades disposed on the hub. Multiple separation plates are disposed on the sides of the blades, and an airflow channel is formed between adjacent separation plates. The impeller assembly, centrifugal impeller, and steam compressor provided by this invention, by setting multiple separation plates on the blades and forming airflow channels, optimizes the flow characteristics of the airflow in the impeller, effectively reducing friction and flow losses caused by blade boundary layer friction and secondary flow losses, thereby improving the impeller efficiency. Simultaneously, the separation plates also strengthen the blades, enabling them to meet the requirements of a steam compressor. The weight-reducing grooves reduce the weight of the blades while maintaining their strength, thereby increasing the critical speed of the impeller, reducing energy consumption, and ultimately improving blade performance.

Description

Technical Field

[0001] This invention relates to the field of air handling equipment technology, and in particular to an impeller assembly, a centrifugal impeller, and a steam compressor. Background Technology

[0002] As a new generation of refrigerant, water has many advantages, such as being environmentally friendly (ODP=0, GWP<1), having a wide range of raw material sources, low extraction costs, high stability coefficient, and sufficient heat storage during vaporization, which can fully meet the requirements of heat pump air conditioning systems with high environmental protection requirements. However, as a fluid with a low molecular weight, water's large specific volume and high adiabatic index during vaporization also limit the system pressure difference, resulting in characteristics such as small cooling capacity per unit volume and high exhaust temperature. Compressors using water vapor as a new generation of refrigerant also have higher standards compared to compressors using traditional refrigerants. Therefore, how to make the impeller meet the dual requirements of high strength and high performance is an urgent problem to be solved in this field. Summary of the Invention

[0003] To address the technical problem that the impellers of conventional refrigerant compressors in the prior art cannot meet the strength and performance requirements of steam as a refrigerant, an impeller assembly with a separation plate to increase strength and performance, a centrifugal impeller, and a steam compressor are provided.

[0004] An impeller assembly for use in a compressor includes a hub and a plurality of blades disposed on the hub. A plurality of separation plates are disposed on the side of the blades, and an airflow channel is formed between two adjacent separation plates, the airflow channel extending from the center of the hub to the edge of the hub.

[0005] The blade has a first end face located at the edge of the hub and a second end face located at the center of the hub, and one end of the airflow channel faces the first end face and the other end faces the second end face.

[0006] The width of the airflow channel gradually increases along the edge of the hub toward the center of the hub.

[0007] The blade has a windward side, on which a plurality of separation plates are provided; or, the blade has a leeward side, on which a plurality of separation plates are provided.

[0008] The blade has a windward side and a leeward side arranged opposite to each other. The separation plate is provided on both the windward side and the leeward side, and the number of separation plates on the windward side is greater than or equal to the number of separation plates on the leeward side.

[0009] The thickness d of the separation plate is ≤0.5mm; and / or the width h0 of the airflow channel is related to the height h1 of the blade as 0.1h1≤h0≤0.5h1.

[0010] The blade has a fourth end face away from the hub, and at least one weight-reducing groove is provided on the fourth end face.

[0011] The relationship between the width a0 of the weight reduction groove and the thickness a1 of the blade is 0.1a1≤a0≤0.3a1.

[0012] The number of weight-reducing grooves is at least two. Along the length direction of the blade, the minimum distance b0 between the edges of two adjacent weight-reducing grooves is related to the dimension b1 of the weight-reducing groove in the length direction of the blade as 1.5b1≤b0≤3b1.

[0013] Another aspect of the present invention provides a centrifugal impeller, including the impeller assembly described above.

[0014] Another aspect of the present invention provides a steam compressor, including the impeller assembly described above or the centrifugal impeller described above.

[0015] The impeller assembly, centrifugal impeller, and steam compressor provided by this invention have multiple separation plates on the blades to form airflow channels. The flow channels are optimized to optimize the flow characteristics of the airflow in the impeller, effectively reducing friction and flow losses caused by blade boundary layer friction and secondary flow losses, thereby improving the efficiency of the impeller. At the same time, the separation plates can also strengthen the blades, so that the blades can meet the requirements of the steam compressor. The weight reduction groove can reduce the weight of the blades while ensuring the strength of the blades, thereby increasing the critical speed of the impeller, reducing energy consumption, and achieving the effect of improving the performance of the blades. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the impeller assembly provided in an embodiment of the present invention;

[0017] Figure 2 for Figure 1 A partial schematic diagram of point A in the middle;

[0018] Figure 3 A partial schematic diagram of the blade provided in an embodiment of the present invention;

[0019] Figure 4 This is another partial schematic diagram of the blade provided in an embodiment of the present invention;

[0020] In the picture:

[0021] 1. Hub; 2. Blade; 3. Separator plate; 4. Airflow channel; 21. First end face; 22. Second end face; 23. Windward side; 24. Leeward side; 25. Fourth end face; 5. Weight reduction groove. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0023] like Figures 1 to 4 The impeller assembly shown is used in a compressor and includes a hub 1 and multiple blades 2 disposed on the hub 1. Multiple separation plates 3 are disposed on the side of each blade 2, and an airflow channel 4 is formed between adjacent separation plates 3, extending from the center of the hub 1 to its edge. By setting multiple separation plates 3 on the blades 2 and forming airflow channels 4, the flow of gas on the blade surface is optimized according to the flow characteristics of the airflow in the impeller. This effectively reduces friction and flow losses caused by boundary layer friction and secondary flow losses on the blades 2 due to pressure differences (such as the pressure difference between the windward and leeward sides of the blades, and the pressure difference between the hub and the impeller cover), thereby improving the impeller efficiency. Simultaneously, the separation plates 3 also strengthen the blades 2, enabling them to meet the requirements of a steam compressor.

[0024] Optionally, the blade 2 has a first end face 21 located at the edge of the hub 1 and a second end face 22 located at the center of the hub 1, and one end of the airflow channel 4 is located on the first end face 21, while the other end faces the second end face 22. That is, one end of the airflow channel 4 is flush with the first end face 21, and the other end is flush with the second end face 22. Increasing the length of the airflow channel 4 as much as possible enhances its guiding effect on the airflow passing over the surface of the blade 2, thereby increasing the working efficiency of the impeller assembly.

[0025] Secondary flow refers to the gas flow along the width of blade 2. Since the impeller assembly works in conjunction with the wheel cover, a low-pressure zone is generated on the wheel cover side and a high-pressure zone on the hub 1 side during operation. The airflow is generated by the pressure difference between the high-pressure and low-pressure zones, resulting in secondary flow, which ultimately reduces the impeller assembly's driving effect on the gas.

[0026] When the separation plate 3 is set and the airflow channel 4 is formed, the separation plate 3 is exactly set in the flow direction of the secondary flow, so as to block the secondary flow and guide the airflow flowing over the surface of the blade 2, so that the airflow flowing over the surface of the blade 2 flows as far as possible towards the center of the hub, thereby increasing the air volume of the impeller assembly, effectively reducing the flow loss inside the impeller assembly and reducing the friction loss with the blade 2.

[0027] As the height of the blade 2 gradually increases along the direction from the first end face 21 to the second end face 22, if the width of the airflow channel 4 remains constant, the distance between the side of the blade 2 and the adjacent separation plate 3 will become larger and larger, resulting in the blade 2's strength not being guaranteed in this part, causing uneven strength of the blade 2. At the same time, the airflow in this part is not restricted, causing uneven stress on this surface of the blade 2, ultimately affecting the reliability of the blade 2. Therefore, the width of the airflow channel 4 is gradually increased along the direction from the first end face 21 to the second end face 22 to make the strength of the blade 2 and the force exerted by the airflow uniform, ensuring the strength and performance of the blade 2.

[0028] During the operation of the impeller, the blade 2 rotates in one direction. The airflow compresses the side of the blade 2 to form the windward side 23 of the blade 2, while the side of the blade 2 opposite to the windward side 23 forms the leeward side 24.

[0029] In one embodiment, the blade 2 has a windward surface 23, on which a plurality of separation plates 3 are provided. The separation plates 3 and the airflow channel 4 are used to reduce the secondary flow that may be generated on the windward surface 23, effectively reducing the internal flow loss and the friction loss with the blade 2.

[0030] In another embodiment, the blade 2 has a leeward surface 24, on which a plurality of separation plates 3 are disposed. The separation plates 3 and the airflow channels 4 are used to reduce the secondary flow that may be generated on the leeward surface 24, effectively reducing the internal flow loss and the friction loss with the blade 2.

[0031] In another embodiment, the blade 2 has a windward side 23 and a leeward side 24 arranged opposite to each other. Since the airflow pressure is high and the gas velocity is low at the windward side 23, while the airflow pressure is low and the gas velocity is high at the leeward side 24, secondary flow is more likely to occur at the leeward side 24. Therefore, when designing according to the airflow characteristics, the airflow pressure is high at the windward side 23 and its pressure gradient is dense. Therefore, the airflow channels 4 on the windward side 23 should be more densely distributed. On the other hand, the airflow pressure is low at the leeward side and its pressure gradient is dispersed. Therefore, the airflow channels 4 on the leeward side 24 should be sparse. Therefore, when the separation plate 3 is provided on both the windward side 23 and the leeward side 24, the number of separation plates 3 on the windward side 23 is greater than or equal to the number of separation plates 3 on the leeward side 24.

[0032] Optional, such as Figure 3 As shown, the thickness d of the separation plate 3 is ≤ 0.5 mm. This is to avoid the separation plate 3 being too thick and affecting the normal operation of the blade 2. The thickness of the separation plate 3 refers to the dimension of the separation plate 3 protruding from the side corresponding to the blade 2.

[0033] Optional, such as Figure 3 As shown, the relationship between the width h0 of the airflow channel 4 and the height h1 of the blade 2 is 0.1h1≤h0≤0.5h1. Specifically, the width of the airflow channel 4 gradually increases, with a minimum value not less than 0.1h1 and a maximum value not greater than 0.5h1. This reduces the influence of secondary flow while ensuring the airflow channel 4's effect on the airflow on the blade 2.

[0034] Taking the impeller assembly of this application as an example, simulation was conducted by adjusting the ratio of h0 to h1, and the simulation results are as follows:

[0035] h0 Volumetric flow rate (m³ / s) Pressure (kPa) 0.05h1 1.456 0.4685 0.1h1 1.48 0.4682 0.25h1 1.493 0.4683 0.5h1 1.488 0.4679 0.75h1 1.465 0.4668 h1 1.423 0.4602

[0036] Simulation results show that the output pressure of the impeller assembly remains relatively constant during the change of h0. However, the volumetric flow rate reaches its maximum value when h0 is 0.25h1. When h0 decreases to 0.1h1, the volumetric flow rate begins to decrease, and this value is generally sufficient to meet the impeller assembly's airflow requirements. When h0 continues to decrease to 0.05h1, the volumetric flow rate continues to decrease, and the impeller assembly's airflow decreases, failing to meet the requirements. When h0 increases to 0.5h1, the volumetric flow rate also begins to decrease, and this value is generally sufficient to meet the impeller assembly's airflow requirements. When h0 continues to increase to 0.75h1, the volumetric flow rate continues to decrease. When h0 increases to the same value as h1, the volumetric flow rate decreases further, and the impeller assembly's airflow decreases, failing to meet the requirements. Only when h0 is within the range of 0.1h1 to 0.5h1 can the volumetric flow rate reach its maximum value and meet the impeller's airflow requirements.

[0037] Preferably, one end of the airflow channel 4 is located at the first end face 21 and the other end is located at the second end face 22. That is, an airflow channel 4 with the same length and similar shape as the blade 2 is formed on the surface of the blade 2, which increases the influence of the airflow channel 4 on the airflow on the surface of the blade 2, while ensuring the overall strength of the blade 2.

[0038] Specifically, the separation plate 3 is arc-shaped. The shape of the separation plate 3 is similar to that of the blade 2.

[0039] The blade 2 has a fourth end face 25 away from the hub 1, and at least one weight-reducing groove 5 is provided on the fourth end face 25. The weight-reducing groove 5 can reduce the weight of the blade 2 while ensuring the strength of the blade 2, thereby increasing the critical speed of the impeller, reducing energy consumption, and improving the performance of the blade 2. The fourth end face 25 is the end face of the blade 2 facing the hub cover.

[0040] Preferably, weight-reducing grooves 5 are provided on the blade 2 to form a mesh-like structure, such as the steel structure of the Bird's Nest Stadium or the honeycomb structure. While ensuring lightweight design, this can effectively protect the structural strength and reduce impeller wear.

[0041] Optionally, the depth of the weight reduction groove 5 is equal to the height of the blade 2 at the location of the blade 2, so as to reduce the weight of the blade 2 as much as possible.

[0042] The cross-section of the weight-reducing groove 5 is one or more of the following: oblong, circular, rectangular, elliptical, or polygonal. The specific shape is set according to actual needs, and the size and shape of the weight-reducing groove 5 can also be determined based on the simulation results of simulation software.

[0043] like Figure 4 As shown, the relationship between the width a0 of the weight-reducing groove 5 and the thickness a1 of the blade 2 is 0.1a1≤a0≤0.3a1. This ensures the strength of the blade 2 while reducing its weight, thus meeting the requirements for the blade 2 when water vapor is used as the refrigerant. The width a0 of the weight-reducing groove 5 refers to the maximum dimension in the thickness direction of the blade 2.

[0044] Taking the impeller assembly of this application as an example, simulation was conducted by adjusting the ratio of a0 to a1, and the simulation results are as follows:

[0045] a0 Blade strength (MPa) 0.05a1 1.8532 0.1a1 1.8421 0.2a1 1.8210 0.3a1 1.7895 0.5a1 1.6582

[0046] Simulation results show that when a0 is 0.2a1, although the blade strength does not reach its maximum value, it does not change significantly compared to the maximum value. When a0 decreases to 0.1a1, the blade strength begins to increase, but the volume of the weight-reducing groove 5 begins to decrease, thus reducing the weight-reduction effect on the blade. When a0 continues to decrease to 0.05a1, the blade strength continues to increase, while the weight-reduction effect further decreases. When a0 increases to 0.3a1, the blade strength begins to decrease, but it remains within 2% of the maximum value, which is acceptable. When a0 continues to increase to 0.5a1, the blade strength continues to decrease, and at this point, the blade strength can no longer meet the requirements of the impeller assembly. In other words, only when a0 is within the range of 0.1a1 to 0.3a1 can the blade strength meet the requirements of the impeller assembly, and the blade can achieve the optimal weight-reduction effect.

[0047] like Figure 4As shown, the number of weight-reducing grooves 5 is at least two. Along the length direction of the blade 2, the minimum distance b0 between the edges of two adjacent weight-reducing grooves 5 is related to the dimension b1 of the weight-reducing groove 5 along the length direction of the blade 2 as follows: 1.5b1≤b0≤3b1. Taking a circular cross-section of the weight-reducing groove 5 as an example, b1 is the diameter of the circle, and b0 is the minimum distance between the edges of two adjacent weight-reducing grooves 5. Taking an oblong cross-section of the weight-reducing groove 5 as an example, where the length direction of the oblong is parallel to the length direction of the blade 2, b1 is the length of the oblong, and b0 is the minimum distance between the edges of two adjacent weight-reducing grooves 5. This approach ensures the strength of the blade 2 while reducing its weight, thus meeting the requirements for the blade 2 when water vapor is used as the refrigerant.

[0048] Taking the impeller assembly of this application as an example, simulation was conducted by adjusting the ratio of b0 to b1, and the simulation results are as follows:

[0049] b0 Blade strength (MPa) 1b1 1.8541 1.5b1 1.9203 2b1 1.9238 2.5b1 1.9325 3b1 1.9451 5b1 1.9432

[0050] Simulation results show that when b0 is 2.5b1, although the blade strength does not reach its maximum value, it does not change significantly compared to the maximum value. When b0 decreases to 2b1, the blade strength begins to decrease, and the number of weight-reducing grooves 5 increases, thus increasing the weight-reducing effect on the blade. However, the blade strength still meets the requirements of the impeller assembly. When b0 continues to decrease to 1.5b1, the blade strength continues to decrease, and the weight-reducing effect on the blade increases further, but the change in blade strength is less than 3% of the maximum value, which is within the permissible range. When b0 continues to decrease to 1b1, the blade strength continues to decrease, and the weight-reducing grooves 5 connect to form a long strip shape. At this point, although the weight-reducing effect on the blade increases further, the blade strength can no longer meet the requirements of the impeller assembly. When b0 increases to 3b1, the blade strength begins to increase, but the number of weight-reducing grooves 5 decreases, meaning the weight-reducing effect on the blade begins to decrease. When b0 continues to increase to 5b1, the blade strength actually begins to decrease, and the number of weight-reducing grooves 5 also decreases further, further reducing the weight-reducing effect on the blade. That is, only when b0 is in the range of 1.5b1 to 3b1 can the blade strength meet the requirements of the impeller assembly for blade strength, and the blade can also achieve the best weight reduction effect.

[0051] Another aspect of the present invention provides a centrifugal impeller, including the impeller assembly described above.

[0052] Another aspect of the present invention provides a steam compressor, including the impeller assembly described above or the centrifugal impeller described above.

[0053] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An impeller assembly for use in a compressor, comprising a hub (1) and a plurality of blades (2) disposed on the hub (1), characterized in that: The blade (2) has multiple separation plates (3) on its side, and an airflow channel (4) is formed between two adjacent separation plates (3). The airflow channel extends from the center of the hub (1) to the edge of the hub (1). The side of the blade (2) includes a windward side (23) and a leeward side (24). The separation plates (3) are provided on both the windward side (23) and the leeward side (24), and the number of separation plates (3) on the windward side (23) is greater than the number of separation plates (3) on the leeward side (24). The thickness d of the separation plate (3) is ≤0.5mm. And / or, the width h0 of the airflow channel (4) is greater than the thickness d of the separation plate (3). The height h1 of the blade (2) is 0.1h1≤h0≤0.5h1; the blade (2) has a fourth end face (25) away from the hub (1), and at least one weight-reducing groove (5) is provided on the fourth end face (25); the width a0 of the weight-reducing groove (5) is related to the thickness a1 of the blade (2) as 0.1a1≤a0≤0.3a1; the number of weight-reducing grooves (5) is at least two, and the minimum distance b0 between the edges of two adjacent weight-reducing grooves (5) along the length direction of the blade (2) is related to the dimension b1 of the weight-reducing groove (5) in the length direction of the blade (2) as 1.5b1≤b0≤3b1.

2. The impeller assembly according to claim 1, characterized in that: The blade (2) has a first end face (21) located at the edge of the hub (1) and a second end face (22) located at the center of the hub (1), and one end of the airflow channel (4) is located at the first end face (21) and the other end is located at the second end face (22).

3. The impeller assembly according to claim 1, characterized in that: The width of the airflow channel (4) gradually increases along the edge of the hub (1) toward the center of the hub (1).

4. A centrifugal impeller, characterized in that: The impeller assembly includes any one of claims 1 to 3.

5. A steam compressor, characterized in that: It includes the impeller assembly according to any one of claims 1 to 3 or the centrifugal impeller according to claim 4.

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