Centrifugal impeller, compressor and air conditioner

Abstract

The present invention provides a centrifugal impeller, a compressor and an air conditioner. The centrifugal impeller includes: a hub, a wheel cover and blades. An airflow cavity is formed between the hub and the wheel cover. The blades are accommodated in the airflow cavity. A connecting channel is provided on the wheel cover and / or the hub. The connecting channel can connect the airflow cavity with the outside of the centrifugal impeller so as to introduce the airflow outside the centrifugal impeller into the airflow cavity and accelerate the airflow in the airflow cavity. According to the present invention, a high momentum fluid can be sprayed into a low-speed group area in the flow channel through a nozzle to weaken the separation of the boundary layer, improve the operating efficiency of the machine, and ensure the efficiency of the impeller when operating at a high Mach number.

Description

Technical Field

[0001] The invention relates to the technical field of compressors, and in particular to a centrifugal impeller, a compressor and an air conditioner. Background Art

[0002] Centrifugal compressors are widely used in refrigeration, aerospace, metallurgy and power. The impeller, as the heart of the compressor, mainly uses centrifugal force to do work and convert mechanical energy into pressure energy and kinetic energy of the gas. When the speed increases, the Mach number of the airflow inside the impeller will also increase, producing subsonic or even transonic flow, forming shock waves. Shock waves will not only produce large shock wave losses, but also aggravate the separation of the boundary layer and increase the separation loss, which will seriously affect the efficiency of the compressor. Therefore, controlling shock waves and their related losses is of great significance to improving the operating efficiency of the machine.

[0003] The separation loss problem is currently mainly optimized through methods such as boundary layer suction, blade optimization, and blade tip injection. Boundary layer suction can improve the flow state of low-energy group fluid and forcefully weaken separation, but it requires the introduction of additional devices, which poses a challenge to the design difficulty; optimizing blade shape is often only effective under certain working conditions and cannot completely improve separation; blade tip injection is a more appropriate method, but it is necessary to consider how to introduce air.

[0004] As the rotation speed of the centrifugal compressor in the prior art increases, the Mach number of the airflow inside the impeller will also increase, resulting in subsonic or even transonic flow, forming shock waves. The shock waves will not only produce large shock wave losses, but will also intensify the separation of the boundary layer and increase the separation losses, which will seriously affect the efficiency of the compressor and other technical problems. Therefore, the present invention studies and designs a centrifugal impeller, a compressor and an air conditioner. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the centrifugal compressor in the prior art that the separation loss is increased due to the separation of the boundary layer, which seriously affects the efficiency of the compressor, thereby providing a centrifugal impeller, a compressor and an air conditioner.

[0006] In order to solve the above problems, the present invention provides a centrifugal impeller, comprising:

[0007] It includes a wheel hub, a wheel cover and blades, an airflow cavity is formed between the wheel hub and the wheel cover, the blades are accommodated in the airflow cavity, and a connecting channel is opened on the wheel cover and / or the wheel hub, and the connecting channel can connect the airflow cavity with the outside of the centrifugal impeller, so as to guide the airflow outside the centrifugal impeller into the airflow cavity, thereby accelerating the airflow in the airflow cavity.

[0008] In some embodiments, the communication channel is disposed on the wheel cover, the wheel cover includes a first portion and a second portion opposite to each other, a first gap is formed between the first portion and the second portion, and the communication channel includes the first gap.

[0009] In some embodiments, a first protrusion is disposed on a side of the first portion opposite to the second portion, the first protrusion extends toward the second portion and forms a second gap with the second portion.

[0010] A second protruding portion is further provided on the first portion on a side opposite to the second portion, the second protruding portion extends toward the second portion and forms a third gap with the second portion.

[0011] The first protrusion is located outside the wheel cover, and the second protrusion is located inside the wheel cover and in the airflow cavity.

[0012] In some embodiments, the connecting channel includes the second gap and the third gap, one end of the first gap is connected to the second gap, and the other end of the first gap is connected to the third gap, and the airflow passes through the second gap, the first gap and the third gap in sequence during the process of flowing from the outside of the centrifugal impeller through the connecting channel to the airflow flow chamber.

[0013] In some embodiments, the second protrusion and the second portion form a nozzle, and along the flow direction of the airflow, the flow area of ​​the third gap gradually decreases, and the outlet end of the third gap forms a spray hole of the nozzle.

[0014] In some embodiments, the blade has a pressure surface area and a suction surface area, the total energy of the airflow at the pressure surface area is greater than the total energy of the airflow at the suction surface area, the total energy of the airflow includes the pressure energy and velocity energy of the airflow, and the nozzle is located directly opposite to the suction surface area on the blade.

[0015] In some embodiments, on the surface of the blade, the minimum curved surface distance between the position where the nozzle sprays on the blade and the trailing edge of the blade is L1, the minimum curved surface length between the head of the blade and the trailing edge is L2, and L1 / L2=10%~15%, wherein the trailing edge of the blade is the end located at the most downstream end of the airflow flow of the blade, and the head of the blade is the end located at the most upstream end of the airflow flow of the blade.

[0016] In some embodiments, the diameter of the spray hole is 2 mm, and the spray hole is disposed close to the wheel hub relative to the wheel cover.

[0017] In some embodiments, the first protrusion is formed as a baffle structure: the thickness of the baffle in the axial direction of the centrifugal impeller is not less than 3 mm; and / or the baffle is a concave structure or a straight plate structure.

[0018] In some embodiments, the second protrusion is welded and fixed to the wheel cover; and / or, a rounded transition is formed between the second protrusion and the inner surface of the wheel cover; and / or,

[0019] In a cross section passing through both the axial direction and the radial direction, the second protrusion is a square structure, and a width of the square structure is 7 to 9 mm.

[0020] In some embodiments, the first gap is a through hole, there are multiple first gaps, and the multiple first gaps are spaced apart in the circumferential direction of the wheel cover; and / or the centrifugal impeller includes an impeller outlet, and the first gap is arranged close to the impeller outlet relative to the central axis of the centrifugal impeller.

[0021] In some embodiments, when the first gap is a through hole, the diameter of the through hole is 3-5 mm, and there is a rounded transition between the through hole and the surface of the wheel cover.

[0022] The present invention also provides a compressor, comprising the centrifugal impeller as described in any of the preceding items.

[0023] In some embodiments, when the centrifugal impeller includes an impeller outlet,

[0024] The compressor also includes a stationary part, which blocks at least a portion of the impeller outlet, and a circulation channel is formed between the stationary part and the wheel cover at a preset distance. The airflow at the impeller outlet enters the circulation channel after being blocked by the stationary part, and the circulation channel is connected with the connecting channel to guide the airflow in the circulation channel into the airflow flow chamber through the connecting channel.

[0025] In some embodiments, the stationary member is a sealing member, a sealing cavity is formed between the sealing member and the wheel cover, and the sealing cavity is the flow channel; and / or,

[0026] In the radial direction of the centrifugal impeller, the radial distance between the impeller outlet and the stationary member is 2.5-3.5 mm.

[0027] The present invention also provides an air conditioner, comprising the compressor as described in any of the preceding items.

[0028] In some embodiments, a gas supplement port is further included, and the gas supplement port can be communicated with the communication channel to guide the airflow in the gas supplement port into the airflow flow cavity through the communication channel.

[0029] The centrifugal impeller, compressor and air conditioner provided by the present invention have the following beneficial effects:

[0030] The present invention provides a connecting channel on the wheel cover and / or the wheel hub, and introduces the high-energy airflow outside the centrifugal impeller into the airflow flow chamber inside the centrifugal impeller through the connecting channel to accelerate the airflow in the airflow flow chamber, so that a nozzle is formed on the impeller, and the high-momentum fluid can be sprayed to the low-speed group area in the flow channel through the nozzle to weaken the separation of the boundary layer, improve the operating efficiency of the machine, and ensure the efficiency of the impeller when running at a high Mach number. Preferably, the leaked gas in the comb seal on the wheel cover side or the high-energy gas in the air supply port can be introduced. The present invention does not need to add an external jet device, and the structure is simple and easy to implement. Especially when the leaked gas in the comb seal on the wheel cover side is introduced, since the jet airflow is introduced by the leakage gas diversion, the leakage loss can be reduced, and the energy efficiency can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the flow structure of the meridian plane of the centrifugal impeller of the present invention;

[0032] Figure 2 for Figure 1 A partial enlarged view of the nozzle portion;

[0033] Figure 3 for Figure 1 Schematic diagram of the airflow structure on the blades;

[0034] Figure 4 for Figure 1 Front view of the impeller outlet.

[0035] The reference numerals are:

[0036] 1. Wheel cover; 11. First part; 12. Second part; 2. Stationary part; 3. Impeller outlet; 4. Blades; 41. Pressure surface area; 42. Suction surface area; 43. Trailing edge; 44. Head; 5. Nozzle; 6. Hub; 7. First protrusion; 8. Second protrusion; 100. Airflow cavity; 101. First gap; 102. Second gap; 103. Third gap; 10. Connecting channel; 200. Circulation channel; 300. Low-speed group area. DETAILED DESCRIPTION

[0037] like Figure 1-4 As shown, the present invention provides a centrifugal impeller, which includes:

[0038] The centrifugal impeller comprises a hub 6, a wheel cover 1 and blades 4, wherein an airflow cavity 100 is formed between the hub 6 and the wheel cover 1, and the blades 4 are accommodated in the airflow cavity 100. A connecting channel 10 is provided on the wheel cover 1 and / or the hub 6, and the connecting channel 10 can connect the airflow cavity 100 with the outside of the centrifugal impeller, so as to guide the airflow outside the centrifugal impeller into the airflow cavity 100, and accelerate the airflow in the airflow cavity 100.

[0039] The present invention provides a connecting channel on the wheel cover and / or the wheel hub, and introduces the high-energy airflow outside the centrifugal impeller into the airflow flow chamber inside the centrifugal impeller through the connecting channel to accelerate the airflow in the airflow flow chamber, so that a nozzle is formed on the impeller, and the high-momentum fluid can be sprayed to the low-speed group area in the flow channel through the nozzle to weaken the separation of the boundary layer (i.e., reduce the separation of the boundary layer), reduce the airflow flow loss, improve the operating efficiency of the machine, and ensure the efficiency of the impeller when operating at a high Mach number. Preferably, the leaked gas in the comb seal on the wheel cover side or the high-energy gas in the air supply port can be introduced. The present invention does not need to add an external jet device, and the structure is simple and easy to implement. In particular, when the leaked gas in the comb seal on the wheel cover side is introduced, since the jet airflow is introduced by the leaked gas diversion, the leakage loss can be reduced, and the energy efficiency can be further improved.

[0040] The present invention proposes an impeller with a nozzle inside, which introduces the leaked gas in the comb seal on the wheel cover side, and then uses the nozzle to spray the high momentum fluid to the low-speed group area 300 in the flow channel to weaken the separation of the boundary layer and improve the operating efficiency of the machine. This invention does not require the addition of an external jet device, has a simple structure and is easy to implement, and the jet airflow is introduced by the leaked gas diversion, which can also reduce leakage losses and further improve energy efficiency.

[0041] The low-speed cluster region refers to a macroscopic region formed by many fluid microclusters with low kinetic energy.

[0042] The boundary layer is mainly due to the viscosity of the wall on the fluid, which reduces the kinetic energy of the fluid to almost 0. This area is the boundary layer. When the impeller runs at a high Mach number, the boundary layer is more likely to separate, resulting in an increase in the low-speed area of ​​the entire flow channel, greatly reducing the flow capacity. This is also one of the reasons that limit the development of the impeller in the direction of high Mach numbers. The high-speed fluid can drive the low-speed group movement by exchanging momentum with the boundary layer, thereby weakening the separation of the boundary layer and improving the flow capacity of the flow channel.

[0043] The boundary layer refers to the boundary layer. It does not mean that increasing the Mach number will definitely improve efficiency, because the flow separation produced at a high Mach number will greatly affect the efficiency. If the separation problem is solved, its efficiency can be improved.

[0044] In some embodiments, the communication channel 10 is provided on the wheel cover 1, the wheel cover 1 comprises a first portion 11 and a second portion 12 opposite to each other, a first gap 101 is formed between the first portion 11 and the second portion 12, and the communication channel 10 comprises the first gap 101. This is a preferred structural form of the communication channel and the preferred structural form of the wheel cover of the present invention, by cutting off the wheel cover part to form the first portion and the second portion, at least a part of the communication channel can be formed at the first gap between the two, so as to introduce the high-energy airflow outside the centrifugal impeller into the inside of the centrifugal impeller through the first gap, accelerate the low-speed airflow inside the centrifugal impeller, reduce the separation of the boundary layer, reduce the airflow loss, and improve the airflow flow efficiency of the impeller.

[0045] In some embodiments, a first protrusion 7 is disposed on the first portion 11 on a side opposite to the second portion 12. The first protrusion 7 extends toward the second portion 12 and forms a second gap 102 with the second portion 12.

[0046] A second protruding portion 8 is further provided on the first portion 11 on a side opposite to the second portion 12. The second protruding portion 8 extends toward the second portion 12 and forms a third gap 103 with the second portion 12.

[0047] The first protruding portion 7 is located outside the wheel cover 1 , and the second protruding portion 8 is located inside the wheel cover 1 and in the airflow cavity 100 .

[0048] That is, the first protrusion 7 is farther away from the airflow cavity 100 than the second protrusion 8 , and the second protrusion is closer to the airflow cavity than the first protrusion.

[0049] The present invention has a first protrusion arranged on the first part, the first protrusion extends toward the second protrusion and forms a second gap with the second protrusion. Since the first protrusion is located outside the centrifugal impeller, the airflow outside the centrifugal impeller can be effectively introduced into the first gap through the second gap; and the second protrusion arranged on the first part protrudes toward the second part, and a third gap is formed between the second protrusion and the second part, and the third gap is connected with the first gap, so that the airflow in the first gap can be introduced into the airflow flow cavity inside the impeller, so as to complete the low-speed group area inside the impeller, so as to weaken the separation of the boundary layer in this area, reduce flow loss, and improve the operation efficiency of the impeller.

[0050] In some embodiments, the communication channel 10 includes the second gap 102 and the third gap 103, one end of the first gap 101 is connected to the second gap 102, and the other end of the first gap 101 is connected to the third gap 103, and the airflow passes through the second gap 102, the first gap 101 and the third gap 103 in sequence during the process of flowing from the outside of the centrifugal impeller through the communication channel 10 to the airflow flow chamber 100. The second gap of the present disclosure is used to introduce high-speed or high-pressure airflow from the outside, the first gap is used for drainage, and the third gap is used to introduce the introduced high-speed and / or high-pressure airflow into the airflow flow chamber, effectively reducing the separation of the boundary layer in the low-speed area.

[0051] The impeller has n small holes (first gaps) uniformly opened on the circumference of the wheel cover side, and the number of small holes n is the same as the number of flow channels and the number of blades. The small hole is slightly biased towards the impeller outlet in the middle of the wheel cover, and the aperture is 3 to 5 mm. And the small hole and the wheel cover surface need to be transitioned with fillets. A circle of baffles is added to the outer surface of the wheel cover, and the cavity formed with the wheel cover is used for drainage. The baffle is welded to the outer surface of the wheel cover and transitioned with fillets. The minimum thickness of the baffle is not less than 3 mm, and the distance between its highest point and the stationary part is not less than 2 mm. The baffle can be concave or straight. The nozzle assembly is mainly composed of a base and a spray hole with a gradually shrinking inner diameter, which corresponds to the small hole on the wheel cover and is welded to the inner surface of the wheel cover. The nozzle assembly should be smooth enough and transition with the inner surface of the wheel cover with a large fillet (to reduce flow loss). In order to facilitate processing, the nozzle assembly can be made square in the width direction; the nozzle assembly can also be shaped according to the blade, so that the nozzle assembly plays a role similar to the splitter blade and reduces the disturbance of the airflow inside the impeller. The width of the nozzle assembly is 7-9 mm (not too wide to avoid reducing the flow area and affecting the flow channel, and not too narrow to avoid ineffective nozzle arrangement). The diameter of the spray hole is 2 mm (not too small to avoid airflow blockage, and not too large to avoid poor spraying effect), facing 10%-15% of the trailing edge of the blade suction surface outlet, and the spray hole is slightly inclined toward the hub side.

[0052] In some embodiments, the second protrusion 8 and the second part 12 form a nozzle 5, and the flow area of ​​the third gap 103 gradually decreases along the flow direction of the airflow, and the outlet end of the third gap 103 forms a spray hole of the nozzle 5. The present invention also forms a nozzle by the second protrusion and the second part together, and the flow area of ​​the third gap gradually decreases, so that the airflow can be continuously accelerated when flowing through the third gap, and then the flow velocity of the airflow is relatively large when it is injected into the airflow flow cavity, so as to effectively accelerate the airflow in the low-speed area inside the impeller, reduce the separation of the boundary layer, and reduce the flow loss.

[0053] In some embodiments, the blade 4 has a pressure surface area 41 and a suction surface area 42, the total energy of the airflow at the pressure surface area 41 is greater than the total energy of the airflow at the suction surface area 42, the total energy of the airflow includes the pressure energy and velocity energy of the airflow, and the nozzle hole is located opposite to the suction surface area on the blade 4. This is the preferred position of the injection position inside the impeller disclosed in the present invention, that is, the nozzle hole is located opposite to the suction surface area, and since the sum of the pressure energy and velocity energy at the suction surface is less than the total energy at the pressure surface area, the injection process can effectively increase the flow velocity of the airflow in the suction surface area, effectively reduce the boundary layer separation in the area, reduce flow losses, and improve the operating efficiency of the impeller.

[0054] The present invention mainly utilizes the high momentum fluid ejected from the nozzle to weaken the separation loss of the low energy fluid zone. Figure 1 and Figure 3 As shown, the refrigerant enters the impeller through the suction port, and the mainstream fluid flows out radially and enters the diffuser. At the same time, due to the gap between the impeller and the stationary part 2 (comb seal), part of the air flow will leak into the comb seal cavity. The baffle is used to guide part of the leaked gas into the nozzle assembly, and then it is accelerated to flow out through the nozzle, mixed with the low-energy fluid area generated at the trailing edge of the suction surface to inhibit separation.

[0055] In some embodiments, on the surface of the blade 4, the minimum curved surface distance between the position where the nozzle hole sprays on the blade 4 and the trailing edge 43 of the blade 4 is L1, the minimum curved surface length between the head 44 of the blade 4 and the trailing edge 43 is L2, and L1 / L2=10%-15%, wherein the trailing edge 43 of the blade is the end located at the most downstream end of the airflow of the blade, and the head 44 of the blade is the end located at the most upstream end of the airflow of the blade. The present invention sets the injection position close to the trailing edge of the blade by setting this numerical range. Since the position close to the trailing edge and the suction surface is a position where the boundary layer is easily separated, the flow loss is large at this position, so aligning the nozzle hole at this position can enhance the degree of reducing the flow loss.

[0056] In some embodiments, the diameter of the spray hole is 1 to 3 mm, preferably 2 mm; relative to the wheel cover 1, the spray hole is arranged close to the wheel hub 6. The spray hole of the present invention is also preferably arranged close to the wheel hub, because the airflow near the wheel hub is prone to boundary layer separation, so the above arrangement can increase the length of the boundary layer weakening. The diameter of the spray hole cannot be too small to prevent airflow blockage, and cannot be too large to prevent a poor spraying effect.

[0057] In some embodiments, the first protrusion 7 is formed into a baffle structure: the thickness of the baffle in the axial direction of the centrifugal impeller is not less than 3 mm; and / or the baffle is a concave structure or a straight plate structure. This is the preferred structural form of the first protrusion of the present invention. The baffle structure can face the flow channel and be opposite to the direction of the airflow, so as to obtain a greater flow rate of the high-energy airflow entering the flow channel. The thickness of the baffle is greater than or equal to 3 mm, which can enhance its structural strength and improve the drainage effect. The baffle is preferably a concave structure or a straight plate structure, which can effectively play the role and effect of drainage.

[0058] In some embodiments, the second protrusion 8 is welded and fixed to the wheel cover 1; and / or, a rounded transition is formed between the second protrusion 8 and the inner surface of the wheel cover 1; and / or,

[0059] In a cross section passing through both the axial direction and the radial direction, the second protrusion 8 is a square structure, and the width of the square structure is 7-9 mm.

[0060] The second protrusion of the present invention is preferably welded and fixed to the wheel cover to achieve fixation of the second protrusion, and the rounded transition between it and the inner surface of the wheel cover can reduce flow losses; the second protrusion 8 is a square structure, and the second protrusion cannot be too wide to avoid reducing the flow area and affecting the flow channel, and cannot be too narrow to avoid ineffective arrangement of the nozzles. Therefore, the width of the square structure is 7 to 9 mm, which can avoid the ineffective arrangement of the nozzles without reducing the flow area.

[0061] In some embodiments, the first gap 101 is a through hole, there are multiple first gaps 101, and multiple first gaps 101 are spaced apart in the circumferential direction of the wheel cover 1; and / or, the centrifugal impeller includes an impeller outlet 3, and the first gap 101 is arranged close to the impeller outlet 3 relative to the central axis of the centrifugal impeller. This is the preferred structural form of the first gap of the damper. The through hole and multiple first gaps are spaced apart in the circumferential direction to increase the injection area and improve the degree of reduction of the flow loss of the impeller. The present invention also can inject high-energy airflow to a position close to the impeller outlet by arranging the first gap close to the impeller outlet instead of the central axis. Since the airflow of the centrifugal impeller enters from the central axis, it is easy to cause boundary layer separation when it flows to a position close to the impeller outlet and close to the suction surface. Therefore, the above-mentioned arrangement of the first gap can further spray at a position where the boundary layer is easy to separate, so as to improve the effect of reducing boundary layer separation and improve the degree of reduction of flow loss.

[0062] In some embodiments, when the first gap 101 is a through hole, the aperture of the through hole is 3-5 mm, and a rounded transition is formed between the through hole and the surface of the wheel cover 1. The aperture of the through hole is 3-5 mm, which can achieve the introduction of sufficient flow of airflow without reducing the flow speed, and the rounded transition can reduce flow loss.

[0063] The present invention also provides a compressor (preferably a centrifugal compressor), which comprises the centrifugal impeller described in any of the preceding items.

[0064] The present invention designs an impeller with a nozzle inside, which introduces the leaked gas in the comb seal on the wheel cover side, and then uses the nozzle to spray high momentum fluid to the low-speed group area in the flow channel to weaken the separation of the boundary layer and improve the operating efficiency of the machine. This invention does not require the addition of an external jet device, has a simple structure and is easy to implement, and the jet airflow is introduced by the leaked gas diversion, which can also reduce leakage losses and further improve energy efficiency.

[0065] In some embodiments, when the centrifugal impeller comprises an impeller outlet 3,

[0066] The compressor further includes a stationary part 2, the stationary part 2 shields at least part of the impeller outlet 3, and the stationary part 2 and the wheel cover 1 are spaced at a preset distance to form a circulation channel 200, the airflow at the impeller outlet 3 enters the circulation channel 200 after being blocked by the stationary part 2, and the circulation channel 200 is communicated with the communication channel 10 to guide the airflow in the circulation channel 200 into the airflow flow chamber 100 through the communication channel 10. This is a preferred structural form of the main embodiment of the present invention, and the centrifugal impeller introduces high-energy airflow from the external stationary part into the impeller interior for injection, thereby reducing airflow flow losses.

[0067] In some embodiments, the stationary member 2 is a sealing member, and a sealing cavity is formed between the sealing member and the wheel cover 1, and the sealing cavity is the flow channel 200; and / or,

[0068] In the radial direction of the centrifugal impeller, the radial distance between the impeller outlet 3 and the stationary member 2 is 2.5-3.5 mm.

[0069] This is the preferred structural form of the stationary part of the present disclosure, i.e., the sealing part, and a flow channel is formed between the sealing part and the wheel cover to introduce the high-energy fluid into the interior of the impeller through the flow channel;

[0070] In the present invention, the gas that originally leaked into the comb teeth seal can be effectively utilized, so the radial clearance between the impeller outlet and the stationary part and the comb teeth cavity can be increased to increase the amount of gas to be drained. The radial clearance between the impeller outlet and the stationary part is 2.5 to 3.5 mm. Because part of the airflow is drained to the nozzle, the amount of gas leaking to the comb teeth is reduced accordingly, and the comb teeth clearance can be appropriately increased. This can reduce the wear of the comb teeth and improve operational reliability. As shown in the attached Figure 1 As shown. Most of the airflow passing through the impeller flows from the impeller outlet to the next part, and the sealing gap formed by the impeller and the comb teeth (stationary part 2) will inevitably cause leakage, and this part of the leaked gas will be guided to the nozzle. The flow direction is shown by the arrow.

[0071] The present invention also provides an air conditioner, comprising the compressor as described in any of the preceding items.

[0072] In some embodiments, a gas replenishment port is further included, and the gas replenishment port can be connected to the communication channel 10 to guide the airflow in the gas replenishment port through the communication channel 10 and into the airflow flow chamber 100. The above-mentioned jet structure can also lead a path of airflow from the gas replenishment port to the nozzle to spray the low-energy fluid area. The advantage of this method is that it can increase the air volume and is more effective in weakening the boundary layer separation.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A centrifugal impeller, characterized in that: include: The centrifugal impeller comprises a wheel hub (6), a wheel cover (1) and blades (4), wherein an airflow cavity (100) is formed between the wheel hub (6) and the wheel cover (1), and the blades (4) are accommodated in the airflow cavity (100). A connecting channel (10) is provided on the wheel cover (1) and / or the wheel hub (6), and the connecting channel (10) is capable of connecting the airflow cavity (100) with the outside of the centrifugal impeller, so as to guide the airflow outside the centrifugal impeller into the airflow cavity (100), thereby accelerating the airflow in the airflow cavity (100); The communication channel (10) is arranged on the wheel cover (1), the wheel cover (1) comprises a first portion (11) and a second portion (12) which are opposite to each other, a first gap (101) is formed between the first portion (11) and the second portion (12), and the communication channel (10) comprises the first gap (101); A first protruding portion (7) is provided on a side of the first portion (11) opposite to the second portion (12); the first protruding portion (7) extends in the direction of the second portion (12) and forms a second gap (102) with the second portion (12). A second protruding portion (8) is also provided on the first portion (11) on a side opposite to the second portion (12); the second protruding portion (8) extends in the direction of the second portion (12) and forms a third gap (103) with the second portion (12). The first protruding portion (7) is located outside the wheel cover (1), and the second protruding portion (8) is located inside the wheel cover (1) and in the airflow cavity (100).

2. The centrifugal impeller according to claim 1, characterized in that: The communication channel (10) comprises the second gap (102) and the third gap (103); one end of the first gap (101) is connected to the second gap (102), and the other end of the first gap (101) is connected to the third gap (103); in the process of airflow flowing from the outside of the centrifugal impeller through the communication channel (10) to the airflow flow chamber (100), the airflow passes through the second gap (102), the first gap (101) and the third gap (103) in sequence.

3. The centrifugal impeller according to claim 2, characterized in that: The second protruding portion (8) and the second portion (12) form a nozzle (5), and along the flow direction of the airflow, the flow area of ​​the third gap (103) gradually decreases, and the outlet end of the third gap (103) forms a spray hole of the nozzle (5).

4. The centrifugal impeller according to claim 3, characterized in that: The blade (4) has a pressure surface area (41) and a suction surface area (42); the total energy of the airflow at the pressure surface area (41) is greater than the total energy of the airflow at the suction surface area (42); the total energy of the airflow includes pressure energy and velocity energy of the airflow; and the nozzle hole is located directly opposite to the suction surface area on the blade (4).

5. The centrifugal impeller according to claim 4, characterized in that: On the surface of the blade (4), the minimum curved surface distance between the position where the spray hole sprays on the blade (4) and the trailing edge (43) of the blade (4) is L1, the minimum curved surface length between the head (44) of the blade (4) and the trailing edge (43) is L2, and L1 / L2=10%~15%, wherein the trailing edge (43) of the blade is located at the most downstream end of the airflow of the blade, and the head (44) of the blade is located at the most upstream end of the airflow of the blade.

6. The centrifugal impeller according to claim 3, characterized in that: The diameter of the spray hole is 1-3 mm, and relative to the wheel cover (1), the spray hole is arranged close to the wheel hub (6).

7. The centrifugal impeller according to claim 1, characterized in that: The first protrusion (7) is formed into a baffle structure: the thickness of the baffle in the axial direction of the centrifugal impeller is not less than 3 mm; and / or the baffle is a concave structure or a straight plate structure.

8. The centrifugal impeller according to any one of claims 1 to 7, characterized in that: The second protruding portion (8) is welded and fixed to the wheel cover (1); and / or, a rounded transition is formed between the second protruding portion (8) and the inner surface of the wheel cover (1); and / or, In a cross section passing through both the axial direction and the radial direction of the centrifugal impeller, the second protrusion (8) is a square structure, and the width of the square structure is 7 to 9 mm.

9. The centrifugal impeller according to any one of claims 1 to 7, characterized in that: The first gap (101) is a through hole, there are a plurality of the first gaps (101), and the plurality of the first gaps (101) are spaced apart in the circumferential direction of the wheel cover (1); and / or the centrifugal impeller comprises an impeller outlet (3), and the first gap (101) is arranged close to the impeller outlet (3) relative to the central axis of the centrifugal impeller.

10. The centrifugal impeller according to claim 9, characterized in that: When the first gap (101) is a through hole, the diameter of the through hole is 3-5 mm, and there is a rounded transition between the through hole and the surface of the wheel cover (1).

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

12. The compressor according to claim 11, characterized in that: When the centrifugal impeller comprises an impeller outlet (3), The compressor further comprises a stationary part (2), the stationary part (2) shielding at least a portion of the impeller outlet (3), and a preset distance between the stationary part (2) and the wheel cover (1) to form a circulation channel (200), the airflow at the impeller outlet (3) entering the circulation channel (200) after being blocked by the stationary part (2), and the circulation channel (200) being communicated with the connecting channel (10) so as to guide the airflow in the circulation channel (200) through the connecting channel (10) into the airflow flow chamber (100).

13. The compressor according to claim 12, characterized in that: The stationary member (2) is a sealing member, a sealing cavity is formed between the sealing member and the wheel cover (1), and the sealing cavity is the circulation channel (200); and / or, In the radial direction of the centrifugal impeller, the radial distance between the impeller outlet (3) and the stationary part (2) is 2.5-3.5 mm.

14. An air conditioner, characterized in that: A compressor comprising the compressor described in any one of claims 11-13.

15. The air conditioner according to claim 14, characterized in that: It also comprises an air supply port, which can be in communication with the communication channel (10) so as to guide the air flow in the air supply port through the communication channel (10) into the air flow cavity (100).

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