Centrifugal impeller and compressor

Abstract

The utility model discloses a centrifugal impeller and a compressor. The centrifugal impeller comprises a hub, a wheel cover, a plurality of air suction blades and a plurality of air supply blades. The wheel cover is arranged on the outer side of the hub and comprises an air suction wheel cover and an air supply wheel cover which are spaced in the radial direction. The air suction wheel cover is provided with an air suction port for sucking first air. And an air supply channel for sucking second air is formed between the air suction wheel cover and the air supply wheel cover. The multiple air suction blades are arranged between the hub and the air suction wheel cover. The multiple air supply blades are arranged between the hub and the air supply wheel cover, and the multiple air supply blades are arranged on the outer sides of the multiple air suction blades in the radial direction. The front edge of each air supply blade extends into the position between every two adjacent air suction blades in the circumferential direction. The first gas is mixed with the second gas after being subjected to primary compression, and secondary compression is completed through the gas supplementing blade. The single impeller has the two-stage compression function, the high pressure ratio requirement can be met, air supplementing and enthalpy increasing are conducted in the middle of the single impeller, and the aerodynamic efficiency of the impeller is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a centrifugal impeller and a compressor. Background Art

[0002] When used for refrigeration and other purposes, centrifugal compressors have the advantages of large load, stable operation, and high efficiency, and have great application value in industry.

[0003] When centrifugal compressors have high pressure ratios, they usually need to use multi-stage compression and use air replenishment between stages to achieve efficient aerodynamic performance. However, this method usually leads to a complex compressor structure, and the friction loss and mechanical loss accumulate and increase. At the same time, multi-stage compression will cause the operating range of the compressor to become narrower.

[0004] It should be noted that the statements in this background technology section only provide background technology related to this application and do not necessarily constitute prior art. Utility Model Content

[0005] The present application provides a centrifugal impeller and a compressor to effectively improve the aerodynamic efficiency of the centrifugal impeller.

[0006] A first aspect of the present application provides a centrifugal impeller, comprising:

[0007] a hub rotatably disposed about its axis;

[0008] a wheel cover, sleeved on the outer side of the wheel hub, and comprising an air suction wheel cover and an air supply wheel cover spaced apart in the radial direction, the air suction wheel cover having an air suction port for sucking in a first gas, and an annular gap between the air suction wheel cover and the air supply wheel cover forming an air supply channel for sucking in a second gas;

[0009] a plurality of suction blades disposed between the hub and the suction wheel cover, wherein the plurality of suction blades rotate with the hub so as to cause the first gas to flow from the leading edge to the trailing edge of the suction blades to perform a first-stage compression on the first gas, and the suction wheel cover has an exhaust port, which is used to discharge the first gas after the first-stage compression; and

[0010] A plurality of air-supplementing blades are arranged between the wheel hub and the air-supplementing wheel cover, and in the radial direction, the plurality of air-supplementing blades are arranged outside the plurality of air-intake blades;

[0011] In the radial direction, the leading edge of the air-supplementing blade extends between two circumferentially adjacent suction blades so that the first gas is mixed with the second gas after the first-stage compression and passes through the air-supplementing blade to complete the second-stage compression.

[0012] In some embodiments, the second gas is mixed with the first gas compressed at the outlet of the supplementary gas channel, and the flow area of ​​the outlet is related to the ratio of the flow rate of the second gas to the flow rate of the first gas.

[0013] In some embodiments, on a projection of a vertical plane passing through the center of the hub, an endpoint of an outer surface of the suction wheel cover close to a trailing edge of the suction blade is a first point, an inner surface of the supplemental air wheel cover has a second point, a normal to the inner surface of the supplemental air wheel cover at the second point passes through the first point, a straight-line distance between the first point and the second point is a first value, and the first value is related to a size of a gap between the suction wheel cover and the hub.

[0014] In some embodiments, an endpoint of the inner surface of the suction wheel cover close to the trailing edge of the suction blade is a third point, the surface of the hub has a fourth point, a normal line of the surface of the hub at the fourth point passes through the third point, a straight-line distance between the third point and the fourth point is a second value, a size of the gap between the suction wheel cover and the hub includes the second value, and the first value is related to the second value.

[0015] In some embodiments, when the flow rate of the second gas is less than 10% of the flow rate of the first gas, the first value is 5% of the second value, and / or,

[0016] When the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas, the first value is 15% of the second value.

[0017] In some embodiments, the supplementary air blade located between two circumferentially adjacent suction blades is arranged to be closer to the suction blade located downstream in the rotation direction of the two circumferentially adjacent suction blades in the circumferential direction of the hub.

[0018] In some embodiments, the number of blades of the supplemental air blades is greater than or equal to the number of blades of the suction blades.

[0019] In some embodiments, the number of blades of the supplementary gas blade is related to the ratio of the flow rate of the second gas to the flow rate of the first gas.

[0020] In some embodiments, when the flow rate of the second gas is less than 10% of the flow rate of the first gas, the number of blades of the air-supplementing blades is equal to the number of blades of the air-inhaling blades; and / or

[0021] When the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas and less than or equal to 30% of the flow rate of the first gas, the number of blades of the air supply blades is equal to 1.15 times the number of blades of the air intake blades; and / or

[0022] When the flow rate of the second gas is greater than 30% of the flow rate of the first gas, the number of the air-supplementing blades is equal to 1.3 times the number of the air-intake blades.

[0023] A second aspect of the present application provides a compressor comprising the centrifugal impeller as described in the above embodiments.

[0024] Based on the technical solution provided in the present application, a centrifugal impeller includes a hub, a wheel cover, a plurality of suction blades and a plurality of air-supplementing blades. The hub is rotatably arranged around its axis. The wheel cover is sleeved on the outer side of the hub, and the wheel cover includes an suction wheel cover and an air-supplementing wheel cover spaced apart in the radial direction. The suction wheel cover has an air intake for inhaling a first gas. The annular gap between the suction wheel cover and the air-supplementing wheel cover forms an air-supplementing channel for inhaling a second gas. A plurality of suction blades are arranged between the hub and the suction wheel cover. As the hub rotates, the plurality of suction blades cause the first gas to flow from the leading edge to the trailing edge of the suction blades to perform a first-stage compression on the first gas. The suction wheel cover has an exhaust port. The exhaust port is used to discharge the first gas after a first-stage compression. A plurality of air-supplementing blades are arranged between the hub and the air-supplementing wheel cover, and in the radial direction, the plurality of air-supplementing blades are arranged on the outer sides of the plurality of suction blades. Among them, in the radial direction, the leading edge of the air-supplementing blade extends into between two circumferentially adjacent intake blades so that the first gas is mixed with the second gas after the first-stage compression and passes through the air-supplementing blade to complete the second-stage compression. By arranging segmented intake blades and air-supplementing blades on the hub of a single centrifugal impeller, and combining the segmented intake wheel cover and air-supplementing wheel cover to form an air-supplementing channel, a single impeller has the function of two-stage compression, which can meet the high pressure ratio requirements, and air-supplementing enthalpy is increased in the middle of a single impeller, effectively improving the aerodynamic efficiency of the impeller. Secondly, based on the improvement of aerodynamic efficiency, energy loss can also be reduced, so that the centrifugal impeller can process more gas flow under the same operating conditions, so that the overall efficiency of the compressor is improved, and it can work in a more efficient state, thereby improving the overall performance of the compressor, increasing the pressure ratio of the compressor, and effectively reducing the number of stages of the compressor.

[0025] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0027] Figure 1 This is a cross-sectional view of a centrifugal impeller according to some embodiments of the present application.

[0028] Figure 2 This is a top view of a centrifugal impeller according to some embodiments of the present application.

[0029] Figure 3 for Figure 2The top view of the centrifugal impeller after omitting the suction wheel cover and the air supply wheel cover.

[0030] Figure 4 This is a geometric analysis diagram of the "outlet end" position where the first gas and the second gas mix in the centrifugal impeller of some embodiments of the present application.

[0031] In the picture:

[0032] 1. Wheel hub; 2. Intake blades; 3. Air supply blades; 4. Intake wheel cover; 5. Air supply wheel cover; 6. Air supply channel;

[0033] A, outlet end; B, air inlet; P1, first point; P2, second point; P3, third point P4, fourth point. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. Technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, technology, methods and equipment should be considered as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0036] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be subsequently positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device may also be positioned in other different ways, and the spatially relative descriptions used herein are interpreted accordingly.

[0037] The inventors of this application have discovered through research that in related technologies, in order to meet the high pressure ratio requirements, a two-stage compression section is usually set up, and air is replenished between the two-stage compression sections to achieve air replenishment and enthalpy increase to achieve the target pressure ratio, which to a certain extent leads to the complexity of the overall system.

[0038] Based on the above technical issues and technical ideas, please refer to Figures 1 to 3 Some embodiments of the present application provide a centrifugal impeller, comprising a hub 1, a wheel cover, a plurality of suction blades 2, and a plurality of air-supplementing blades 3. The hub 1 is rotatably arranged around its axis. The wheel cover is sleeved on the outer side of the hub 1, and the wheel cover includes an suction wheel cover 4 and an air-supplementing wheel cover 5 spaced apart in the radial direction. The suction wheel cover 4 has an air intake port B for inhaling a first gas. The annular gap between the suction wheel cover 4 and the air-supplementing wheel cover 5 forms an air-supplementing channel 6 for inhaling a second gas. The plurality of suction blades 2 are arranged between the hub 1 and the suction wheel cover 4. As the hub 1 rotates, the plurality of suction blades 2 cause the first gas to flow from the leading edge to the trailing edge of the suction blades 2 to perform a first-stage compression on the first gas. The suction wheel cover 4 has an exhaust port. The exhaust port is used to discharge the first gas after the first-stage compression. The plurality of air-supplementing blades 3 are arranged between the hub 1 and the air-supplementing wheel cover 5, and in the radial direction, the plurality of air-supplementing blades 3 are arranged on the outer side of the plurality of suction blades 2. In the radial direction, the leading edge of the air-supplementing blade 3 extends between two circumferentially adjacent suction blades 2 so that the first gas is mixed with the second gas after the first-stage compression and passes through the air-supplementing blade 3 to complete the second-stage compression.

[0039] For ease of description, the structures of the hub 1 and the blades (ie, the suction blades 2 and the air supply blades 3 ) are first defined.

[0040] The hub 1 is shaped like a truncated cone, with multiple suction blades 2 arranged on the circumferential side of the cone. Multiple air supply blades 3 are also arranged on the circumferential side of the cone. The hub 1 has parallel upper and lower end surfaces, both of which are perpendicular to the axis of the hub 1. The leading edge of the blade is closer to the upper end surface of the hub 1 than the trailing edge, while the trailing edge of the blade is closer to the lower end surface of the hub 1 than the leading edge.

[0041] The lower edge of the blade connecting to the circumferential side of the hub 1 is defined as the blade root. The upper edge of the blade, away from the circumferential side of the hub 1, is defined as the blade tip. The inner edge of the blade, closer to the center of the hub 1, is defined as the leading edge, and the outer edge of the blade, away from the center of the hub 1, is defined as the trailing edge. Each blade is configured so that its leading edge is closer to the rear side of the hub 1 in the direction of rotation than its trailing edge, and the blade curl is configured so that the blade has a pressure side facing downstream in the direction of rotation and a suction side facing upstream in the direction of rotation.

[0042] The blade roots of the suction blades 2 can be fixedly connected to the circumferential side surfaces of the hub 1 by welding, gluing, clamping, riveting, or other means. The blade tips of the suction blades 2 can be fixedly connected to the suction wheel cover 4 by welding, gluing, clamping, riveting, or other means. The blade roots of the supplemental air blades 3 can be fixedly connected to the circumferential side surfaces of the hub 1 by welding, gluing, clamping, riveting, or other means. The blade tips of the supplemental air blades 3 can be fixedly connected to the supplemental air wheel cover 5 by welding, gluing, clamping, riveting, or other means.

[0043] Multiple suction blades 2 are evenly distributed circumferentially around the circumferential side of the cone, forming multiple, evenly distributed, primary compression channels. Similarly, multiple air supply blades 3 are evenly distributed circumferentially around the circumferential side of the cone, forming multiple, evenly distributed, secondary compression channels. The end of the primary compression channel near the upper end of the hub 1 is defined as the channel inlet, and the end of the primary compression channel near the lower end of the hub 1 is defined as the channel outlet.

[0044] Each primary compression flow channel has at least one corresponding secondary compression flow channel, so that the flow channel outlet of the primary compression flow channel leads to the flow channel outlet of the corresponding secondary compression flow channel, so that the first gas can complete two-stage compression in the primary compression flow channel and the secondary compression flow channel successively.

[0045] More specifically, during the rotation of the hub 1, the first gas is directed toward the upper end surface of the hub 1 and enters each primary compression channel through the intake port B, undergoing primary compression and achieving the first stage of compression work. Subsequently, after undergoing primary compression, the first gas flows into each secondary compression channel. Simultaneously, the second gas also enters each secondary compression channel through the annular gap. Within the secondary compression channel, the first and second gases mix, lowering the overall temperature of the mixed gas. They then undergo secondary compression together and are discharged from the impeller, achieving the designed pressure ratio upon discharge.

[0046] The direction from the lower end surface to the upper end surface of the hub 1 is defined as the centrifugal impeller's height direction. The leading edge of the suction blade 2 is higher than the leading edge of the supplemental blade 3, while the trailing edge of the suction blade 2 is lower than the leading edge of the supplemental blade 3 and higher than the trailing edge of the supplemental blade 3. Within the plane of the upper end of the supplemental impeller cover 5 in the height direction, a gap exists between the supplemental impeller cover 5 and the suction impeller cover 4 along the entire circumference of the hub 1. This gap serves as the entrance to the supplemental impeller passage 6. The inner wall of the supplemental impeller passage 6 is formed from the outer surface of the suction impeller cover 4, where it is flush with the upper end, to the end of the suction impeller cover 4 near the trailing edge of the suction blade 2 (hereinafter referred to as the rear end).

[0047] A two-stage compression channel is divided into two parts in the direction of gas flow. The first part (i.e., the air supply channel 6) is located upstream of the second part in the flow direction. In this part, the second gas has not yet mixed with the first gas and only flows from the first part toward the second part. The second part is the part where the second gas and the first gas are mixed and then undergo two-stage compression together. Specifically, after the second gas enters the air supply channel 6 from the inlet, the part of the second gas flowing along the inner wall of the air supply channel 6 begins to converge with the part of the first gas flowing along the inner surface of the air supply channel 4 at the rear end of the air intake cover 5. As the gas flows further toward the outlet of the two-stage compression channel, the first gas and the second gas gradually mix, and finally complete uniform mixing and two-stage compression at the outlet and are discharged from the centrifugal impeller.

[0048] By arranging segmented suction blades and air supply blades on the hub of a single centrifugal impeller, and combining segmented suction wheel cover and air supply wheel cover to form an air supply channel, a single impeller has the function of two-stage compression, which can meet the high pressure ratio requirements, and air supply is performed in the middle of the single impeller to increase enthalpy, effectively improving the aerodynamic efficiency of the impeller.

[0049] Secondly, based on the improvement of aerodynamic efficiency, energy loss can also be reduced. The centrifugal impeller can do more useful work under the same operating conditions, so that the overall efficiency of the compressor is improved and it can work in a more efficient state, thereby improving the overall performance of the compressor and increasing the compression ratio of the compressor, which can effectively reduce the number of stages of the compressor.

[0050] In order to improve the aerodynamic efficiency and compression performance of the centrifugal impeller, in some embodiments, the circumferential gap between two circumferentially adjacent suction blades 2 gradually decreases from the radial outer side to the radial inner side of the hub 1, that is, the first-stage compression flow channel gradually narrows in the direction approaching the center of the hub 1.

[0051] In order to improve the aerodynamic efficiency and compression performance of the centrifugal impeller, in some embodiments, the circumferential gap between two circumferentially adjacent air-supplementing blades 3 gradually decreases from the radial outer side to the radial inner side of the hub 1, that is, the secondary compression flow channel gradually narrows in the direction approaching the center of the hub 1.

[0052] To balance the flow rate relationship between the first and second gases and optimize the compression performance of the centrifugal impeller, in some embodiments, the second gas is mixed with the first compressed gas at outlet A of the supplemental gas channel 6. The flow area of ​​outlet A is related to the ratio of the flow rate of the second gas to the flow rate of the first gas.

[0053] In other words, the greater the flow rate of the second gas, the larger the flow area of ​​the outlet end A of the gas supply channel 6. If the flow area is not controlled according to the flow rate of the second gas, then under the condition of the same flow channel area, the greater the flow rate of the second gas, the greater the flow rate of the second gas, which will affect the effect of mixing the second gas with the first gas, resulting in incomplete and uneven mixing of the first gas and affecting the compression performance.

[0054] In some embodiments, reference Figure 1 and Figure 4 On a projection of a vertical plane passing through the center of the hub 1, the endpoint of the outer surface of the suction impeller cover 4, closest to the trailing edge of the suction blade 2, is a first point P1. The inner surface of the supplemental impeller cover 5 has a second point P2. The normal to the inner surface of the supplemental impeller cover 5 at second point P2 passes through first point P1. The straight-line distance between first point P1 and second point P2 is a first value L1. First value L1 is related to the size of the gap between the suction impeller cover 4 and the hub 1.

[0055] Figure 1 The projection of the vertical plane through the center of the hub 1 is shown. Figure 4 yes Figure 1A partial enlarged view in FIG. As described above, the outlet end A (which can also be understood as the width of the air supply port) is defined as the position of the end face where the second gas begins to mix with the first gas in the air supply channel 6. The line connecting the first point P1 and the second point P2, that is, the first value L1, can be regarded as the width of the air supply port on this projection surface. The size of the gap between the air intake wheel cover 4 and the hub 1 reflects the size of the gap between the circumferential side surfaces of the air intake wheel cover 4 and the hub 1 at the intersection of the primary compression flow channel and the secondary compression flow channel. By setting the size of the gap to be associated with the width of the air supply port, the air supply port structure design of the centrifugal impeller can be optimized, so that the flow distribution of the primary compression flow channel and the secondary compression flow channel is more in line with the design requirements, thereby improving the aerodynamic efficiency of the centrifugal impeller, optimizing the compression performance, and improving the compression ratio.

[0056] Furthermore, in this embodiment, the geometric relationship between the first point P1 and the second point P2 on a projection plane is illustrated. For multiple suction blades 2, the high end of the trailing edge of each suction blade 2 can be found at a corresponding point P1 on the outer surface of the suction wheel cover 4. For each of the multiple points P1, a point P2 that satisfies the aforementioned geometric relationship can be found on the inner surface of the air supply wheel cover 5. The line connecting the multiple points P1 constitutes the inner boundary of the outlet port A, and the line connecting the multiple points P2 constitutes the outer boundary of the outlet port A. The area of ​​the annular region (which can be understood as the air supply port) defined by the inner and outer boundaries is the flow area of ​​the outlet port A.

[0057] For further details, the "size of the gap between the intake wheel cover 4 and the wheel hub 1" will be explained below.

[0058] Continue to refer Figure 1 and Figure 4 In some embodiments, the inner surface of the suction wheel cover 4 has an endpoint near the trailing edge of the suction blade 2 as a third point P3. The surface of the hub 1 has a fourth point P4. The normal to the surface of the hub 1 at the fourth point P4 passes through the third point P3. The straight-line distance between the third point P3 and the fourth point P4 is a second value L2. The dimension of the gap between the suction wheel cover 4 and the hub 1 includes the second value L2. The first value L1 is related to the second value L2.

[0059] Specifically, the size of the L2 value reflects, to a certain extent, the cross-sectional area at the intersection of the primary compression flow channel and the secondary compression flow channel. The larger L2 is, the larger the flow area of ​​the first gas at the point where it enters the secondary compression flow channel. The smaller L2 is, the smaller the flow area of ​​the first gas at the point where it enters the secondary compression flow channel. Associating the first value L1 with the second value L2 is beneficial to coordinating the internal gas flow distribution design of the centrifugal impeller, thereby improving the aerodynamic efficiency of the centrifugal impeller, optimizing the compression performance, and improving the compression ratio.

[0060] In order to optimize the compression performance of the centrifugal impeller and effectively improve the aerodynamic efficiency of the centrifugal impeller, the relationship between the first value L1 and the second value L2 changes with the change of the proportional relationship between the flow rates of the first gas and the second gas.

[0061] In order to optimize the compression performance of the centrifugal impeller and effectively improve the aerodynamic efficiency of the centrifugal impeller, in some embodiments, when the flow rate of the second gas is less than 10% of the flow rate of the first gas, the first value L1 is 5% of the second value L2.

[0062] In order to optimize the compression performance of the centrifugal impeller and effectively improve the aerodynamic efficiency of the centrifugal impeller, in some embodiments, when the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas, the first value L1 is 15% of the second value L2.

[0063] Based on the ratio of gas flow and the numerical relationship between L1 and L2 in the above embodiments, the aerodynamic efficiency of the centrifugal impeller can be effectively improved, and the number of compressor stages can be effectively reduced, thereby achieving the purpose of improving the overall performance of the compressor.

[0064] Furthermore, by further refining the numerical relationship between the first value L1 and the second value L2, the centrifugal impeller can be accurately controlled to operate in the optimal working state, effectively solving the mechanical losses, processing costs, structural costs, aerodynamic losses and other aspects of human and material resources consumed by two-stage or multi-stage compression, extending the service life of the compressor and thereby reducing production and operating costs, and improving the stability and reliability of the overall system.

[0065] It is worth noting that the maximum value of the first value L1 is 15% of L2. As the flow rate of the second gas further increases, the first value L1 no longer increases. This is because the continued increase in the first value L1 means that the width of the air supply port is further expanded, which results in a reduction in the flow area of ​​the first gas from the primary compression flow channel to the secondary compression flow channel, making it difficult for the first gas and the second gas to mix well, thereby negatively affecting the aerodynamic efficiency of the centrifugal impeller. Moreover, if the overall size of the centrifugal impeller remains unchanged, the larger the first value L1, the larger the gap between the air supply impeller cover 5 and the intake impeller cover 4, and the smaller the gap between the intake impeller cover 4 and the hub 1, which to a certain extent affects the structural stability of the centrifugal impeller.

[0066] refer to Figure 3 In some embodiments, the supplementary air blade 3 located between two circumferentially adjacent suction blades 2 is configured to be closer to the suction blade 2 located downstream in the rotation direction of the two circumferentially adjacent suction blades 2 in the circumferential direction of the hub 1.

[0067] Specifically, the two circumferentially adjacent suction blades are respectively called the first suction blade and the second suction blade. The suction surface of the first suction blade faces the pressure surface of the second suction blade. The air supply blade located between the first suction blade and the second suction blade is circumferentially closer to the first suction blade.

[0068] When the centrifugal impeller rotates and performs work, since the suction surface of the blade is more likely to separate, this setting can effectively reduce the deterioration and extension of the airflow separation of the suction blade 2, thereby effectively improving the aerodynamic efficiency of the centrifugal impeller, improving the compression performance and compression ratio, and improving the overall performance of the compressor.

[0069] In order to allow the second gas and the first gas to be fully mixed and to ensure that the second gas can effectively cool the first gas, thereby completing secondary compression and optimizing the aerodynamic efficiency of the centrifugal impeller, in some embodiments, the number of blades of the air supply blades 3 is greater than or equal to the number of blades of the intake blades 2.

[0070] If the number of air-supplementing blades 3 is designed to be small, the number of secondary compression flow channels will be small, resulting in a decrease in secondary compression performance. At the same time, it is also impossible to ensure that the second gas and the first gas are fully mixed, so the first gas cannot be effectively cooled. This affects the aerodynamic efficiency of the centrifugal impeller to a certain extent, and therefore the ideal compression effect cannot be achieved.

[0071] To further improve compression performance and effectively enhance the aerodynamic efficiency of the centrifugal impeller, it is necessary to control the relationship between the number of supply blades and the number of suction blades according to changes in the supply air flow rate. The basic control rule is that the number of supply blades must be greater than or equal to the number of suction blades.

[0072] In some embodiments, the number of blades of the gas supplementary blades 3 is related to the ratio of the flow rate of the second gas to the flow rate of the first gas.

[0073] In order to optimize the compression performance of the centrifugal impeller and effectively improve the aerodynamic efficiency of the centrifugal impeller, in some embodiments, when the flow rate of the second gas is less than 10% of the flow rate of the first gas, the number of blades of the air supply blade 3 is equal to the number of blades of the suction blade 2.

[0074] In order to optimize the compression performance of the centrifugal impeller and effectively improve the aerodynamic efficiency of the centrifugal impeller, in some embodiments, when the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas and less than or equal to 30% of the flow rate of the first gas, the number of blades of the air supply blade 3 is equal to 1.15 times the number of blades of the suction blade 2.

[0075] In order to optimize the compression performance of the centrifugal impeller and effectively improve the aerodynamic efficiency of the centrifugal impeller, in some embodiments, when the flow rate of the second gas is greater than 30% of the flow rate of the first gas, the number of blades of the air supply blade 3 is equal to 1.3 times the number of blades of the suction blade.

[0076] Based on the above-mentioned relationship between the number of suction blades 2 and air supply blades 3, the aerodynamic efficiency of the centrifugal impeller can be effectively improved, and the number of stages of the compressor can be effectively reduced, thereby achieving the purpose of improving the overall performance of the compressor.

[0077] In some embodiments, reference Figure 2 The inlet of the gas supply channel 6 is in a circular shape, and a pipeline can be installed at this position to connect to an external gas source so that the gas source directly delivers the second gas to the gas supply channel 6.

[0078] In some embodiments, each component of the centrifugal impeller is made of an alloy material, such as an aluminum alloy or a titanium alloy.

[0079] This can ensure the structural strength and stability of the centrifugal impeller and improve the service life of the centrifugal impeller.

[0080] Some embodiments of the present application further provide a compressor, comprising the centrifugal impeller as described in the above embodiments.

[0081] The centrifugal impeller significantly improves compressor performance, and its high aerodynamic efficiency reduces energy loss, meaning the compressor requires less energy to achieve the same compression effect under the same operating conditions, thereby improving energy efficiency. Furthermore, improving the aerodynamic efficiency of the centrifugal impeller optimizes compressor performance, reduces operating costs, and improves overall system stability.

[0082] The following is combined with Figures 1 to 4 , a detailed introduction to the structure of a centrifugal impeller of a specific embodiment of the present application.

[0083] The centrifugal impeller includes a hub 1, a plurality of suction blades 2, a plurality of air supply blades 3, an suction wheel cover 4, and an air supply wheel cover 5. The various components of the centrifugal impeller are made of alloy materials, such as aluminum alloy or titanium alloy. The hub 1 is in the shape of a truncated cone. The plurality of suction blades 2 are evenly spaced around the circumferential side of the hub 1, and the plurality of air supply blades 3 are evenly spaced around the circumferential side of the hub 1. The roots of the plurality of suction blades 2 are fixedly connected to the circumferential side of the hub 1, and the tips of the plurality of air supply blades 3 are fixedly connected to the circumferential side of the hub 1. The tips of the plurality of suction blades 2 are fixedly connected to the inner surface of the suction wheel cover 4. The tips of the plurality of air supply blades 3 are fixedly connected to the inner surface of the air supply wheel cover 5.

[0084] In the radial direction of the hub 1, multiple supplemental air blades 3 are arranged radially outwardly of the multiple intake blades 2, with the leading edges of the supplemental air blades 3 extending between circumferentially adjacent intake blades 2. In the axial direction of the hub 1, the leading edges of the intake blades 2 are higher than the leading edges of the supplemental air blades 3, while the trailing edges of the intake blades 2 are lower than and higher than the leading edges of the supplemental air blades 3. The outer surface of the intake impeller cover 4, near the trailing edges of the intake blades 2, nests radially inwardly of the outer surface of the supplemental air impeller cover 5, near the leading edges of the supplemental air blades 3. An annular gap is defined between the outer surface of the intake impeller cover 4 and the inner surface of the supplemental air impeller cover 5 along the entire circumference of the hub 1, forming a supplemental air passage 6 for drawing in the secondary gas.

[0085] In the rotation direction of the hub 1, the leading edge of the suction blade 2 is located downstream of the trailing edge, the leading edge of the supplementary air blade 3 is located downstream of the trailing edge, and the supplementary air blade 3 located between two circumferentially adjacent suction blades 2 is configured to be closer to the suction blade 2 located downstream in the rotation direction of the two circumferentially adjacent suction blades 2 in the circumferential direction of the hub 1.

[0086] Multiple suction blades 2 rotate with the hub 1, causing the first gas to flow from the leading edge to the trailing edge of the suction blades 2, thereby performing a primary compression of the first gas. The suction wheel cover 4 has an exhaust port. This exhaust port is used to discharge the first gas after the primary compression. At this point, the primary compressed first gas mixes with the second gas input through the air supply channel 6. The second gas cools the compressed first gas, and the two gas, after mixing, are combined to complete the secondary compression under the action of the air supply blades 3.

[0087] On the projection of a vertical plane passing through the center of the hub 1, the endpoint of the outer surface of the intake impeller cover 4 near the trailing edge of the intake blade 2 is a first point P1. The inner surface of the supplemental impeller cover 5 has a second point P2. The normal to the inner surface of the supplemental impeller cover 5 at second point P2 passes through first point P1. The straight-line distance between first point P1 and second point P2 is a first value L1. The endpoint of the inner surface of the intake impeller cover 4 near the trailing edge of the intake blade 2 is a third point P3. The surface of the hub 1 has a fourth point P4. The normal to the surface of the hub 1 at fourth point P4 passes through third point P3. The straight-line distance between the third and fourth points is a second value L2. When the flow rate of the second gas is less than 10% of the flow rate of the first gas, the first value L1 is 5% of the second value L2. When the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas, the first value L1 is 15% of the second value L2. When the flow rate of the second gas is less than 10% of the flow rate of the first gas, the number of blades of the air-supplementing blades 3 is equal to the number of blades of the air-intake blades 2. When the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas and less than or equal to 30% of the flow rate of the first gas, the number of blades of the air-supplementing blades 3 is equal to 1.15 times the number of blades of the air-intake blades 2. When the flow rate of the second gas is greater than 30% of the flow rate of the first gas, the number of blades of the air-supplementing blades 3 is equal to 1.3 times the number of blades of the air-intake blades.

[0088] Typically, in the centrifugal impeller provided in this application, if Figure 3 As shown, the number of the suction blades 2 is the same as the number of the air supply blades 3. The following briefly describes the flow process of the gas in the primary compression flow channel and the secondary compression flow channel in this embodiment.

[0089] It should be understood that when the number of intake blades 2 and the number of air supply blades 3 are the same, the multiple intake blades 2 correspond one-to-one with the multiple air supply blades 3, and the intake blades 2 and the air supply blades 3 are arranged alternately in the circumferential direction of the hub 1. In other words, the number of primary compression flow channels formed by the multiple intake blades 2 on the circumferential side surface of the hub 1 is the same as the number of secondary compression flow channels formed by the multiple air supply blades 3 on the circumferential side surface of the hub 1, and they correspond one-to-one. The end of the primary compression flow channel close to the upper end surface of the hub 1 is defined as the inlet end, and the end of the primary compression flow channel close to the lower end surface of the hub 1 is defined as the outlet end.

[0090] After the first gas enters the primary compression flow channel through the intake port B, it flows along the primary compression flow channel to the outlet end. Since the leading edge of the air-supplementing blade 3 extends between two circumferentially adjacent intake blades 2, the outlet end of each primary compression flow channel leads to two circumferentially adjacent secondary compression flow channels. That is, the first gas will be extended and separated by the air-supplementing blades 3 of the primary compression flow channel in the process of flowing to the outlet end of the primary compression flow channel, thereby forming two air flows. The two air flows flow into the two circumferentially adjacent secondary compression flow channels respectively, and further mix with the second gas in the two secondary compression flow channels. Finally, the two air flows complete the two-stage compression and reach the target pressure ratio.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present application. They should all be included in the scope of the technical solution for protection requested in this application.

Claims

1. A centrifugal impeller, characterized in that: include: A wheel hub (1) is rotatably arranged around its axis; A wheel cover is sleeved on the outer side of the wheel hub (1), and the wheel cover includes an air suction wheel cover (4) and an air supply wheel cover (5) spaced apart in a radial direction, the air suction wheel cover (4) has an air suction port (B) for sucking in a first gas, and an annular gap between the air suction wheel cover (4) and the air supply wheel cover (5) forms an air supply channel (6) for sucking in a second gas; A plurality of suction blades (2) are arranged between the hub (1) and the suction wheel cover (4); the plurality of suction blades (2) cause a first gas to flow from a leading edge to a trailing edge of the suction blades (2) as the hub (1) rotates, thereby performing a first-stage compression on the first gas; the suction wheel cover (4) has an exhaust port, and the exhaust port is used to discharge the first gas after the first-stage compression; as well as A plurality of air-supplementing blades (3) are arranged between the wheel hub (1) and the air-supplementing wheel cover (5), and in the radial direction, the plurality of air-supplementing blades (3) are arranged outside the plurality of air-intake blades (2); Wherein, in the radial direction, the leading edge of the air-supplementing blade (3) extends between two circumferentially adjacent air-intake blades (2) so that the first gas is mixed with the second gas after the first-stage compression and passes through the air-supplementing blade (3) to complete the second-stage compression.

2. The centrifugal impeller according to claim 1, characterized in that: The second gas is mixed with the first gas that has undergone a first stage of compression at the outlet end (A) of the gas supplement channel (6), and the flow area of ​​the outlet end (A) is related to the ratio of the flow rate of the second gas to the flow rate of the first gas.

3. The centrifugal impeller according to claim 1, characterized in that: On a projection of a vertical plane passing through the center of the hub (1), an endpoint of the outer surface of the suction wheel cover (4) close to the trailing edge of the suction blade (2) is a first point (P1), an inner surface of the supplementary air wheel cover (5) has a second point (P2), a normal of the inner surface of the supplementary air wheel cover (5) at the second point (P2) passes through the first point (P1), a straight-line distance between the first point (P1) and the second point (P2) is a first value (L1), and the first value (L1) is related to the size of a gap between the suction wheel cover (4) and the hub (1).

4. The centrifugal impeller according to claim 3, characterized in that: The endpoint of the inner surface of the suction wheel cover (4) close to the trailing edge of the suction blade (2) is a third point (P3), the surface of the hub (1) has a fourth point (P4), the normal of the surface of the hub (1) at the fourth point (P4) passes through the third point (P3), the straight-line distance between the third point and the fourth point is a second value (L2), the size of the gap between the suction wheel cover (4) and the hub (1) is the second value (L2), and the first value (L1) is related to the second value (L2).

5. The centrifugal impeller according to claim 4, characterized in that: When the flow rate of the second gas is less than 10% of the flow rate of the first gas, the first value (L1) is 5% of the second value (L2), and / or When the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas, the first value (L1) is 15% of the second value (L2).

6. The centrifugal impeller according to any one of claims 1 to 5, characterized in that: The supplementary air blade (3) located between two circumferentially adjacent suction blades (2) is configured to be closer to the suction blade (2) located downstream in the rotation direction of the two circumferentially adjacent suction blades (2) in the circumferential direction of the hub (1).

7. The centrifugal impeller according to any one of claims 1 to 5, characterized in that: The number of blades of the air-supplementing blades (3) is greater than or equal to the number of blades of the air-intake blades (2).

8. The centrifugal impeller according to claim 7, characterized in that: The number of blades of the air-supplementing blades (3) is related to the ratio of the flow rate of the second gas to the flow rate of the first gas.

9. The centrifugal impeller according to claim 8, characterized in that: When the flow rate of the second gas is less than 10% of the flow rate of the first gas, the number of blades of the air supply blades (3) is equal to the number of blades of the air suction blades (2); and / or When the flow rate of the second gas is greater than or equal to 10% of the flow rate of the first gas and less than or equal to 30% of the flow rate of the first gas, the number of blades of the air supply blades (3) is equal to 1.15 times the number of blades of the air intake blades (2); and / or When the flow rate of the second gas is greater than 30% of the flow rate of the first gas, the number of blades of the air-supplementing blades (3) is equal to 1.3 times the number of blades of the air-intake blades.

10. A compressor, characterized in that: The centrifugal impeller comprises the centrifugal impeller according to any one of claims 1 to 9.

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