CN113464486A

CN113464486A - Impeller with vortex-eliminating, restraining and separating functions, compressor, air conditioner and automobile

Info

Publication number: CN113464486A
Application number: CN202110926314.4A
Authority: CN
Inventors: 叶文腾; 钟瑞兴; 刘华; 张治平; 陈玉辉; 梁湖
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-08-12
Filing date: 2021-08-12
Publication date: 2021-10-01

Abstract

The invention discloses an impeller with a vortex-eliminating, inhibiting and separating function, a compressor, an air conditioner and an automobile. Wherein the impeller comprises a hub, blades and a shroud. The edge of a main runner outlet between every two adjacent blades is provided with at least one airfoil blade, the two ends of each airfoil blade are sheet-shaped bodies formed by streamline curved surfaces, and the setting direction of each airfoil blade is the same as the direction of each blade. The wing section blade that has set up in the sprue for inside wing section drainage runner that constitutes of impeller, in order to eliminate the formation of whirlpool and restrain the air separation, reduce the loss, promote compressor aerodynamic efficiency. By improving the flow guide effect inside the impeller and homogenizing the airflow angle, the problem of direction matching of the airflow at the outlet of the impeller and the inlet of the diffuser is optimized, the exhaust noise of the compressor is effectively reduced, and the efficiency and the comfort of the fuel cell system are comprehensively improved.

Description

Impeller with vortex-eliminating, restraining and separating functions, compressor, air conditioner and automobile

Technical Field

The invention relates to fluid conveying equipment, in particular to an impeller with a vortex-eliminating, inhibiting and separating function, a compressor with the impeller, an air conditioner with the compressor and an automobile with the compressor.

Background

The air compressor is used as a general power air source and is widely applied to the industries of machinery, automobiles, medical treatment, food, electric power, building materials, petroleum, chemical industry, military industry and the like. Different compressor modes are common, such as a centrifugal air compressor, a screw air compressor, a scroll air compressor, and the like. In the aspect of new energy, the hydrogen fuel cell automobile has high power performance, quick hydrogenation and long endurance, and is the most strategic breakthrough of the new energy automobile in the 21 st century. The compressor provides high-pressure air source for the fuel cell system, and centrifugal compressor compares with helical-lobe compressor, scroll compressor, and centrifugal compressor can provide the air supply of higher pressure ratio, can show the power density and the wholeness ability that promote the pile. The working principle of the centrifugal compressor is as follows: after the power is switched on, the high-speed motor drives the impeller to compress the entering air to do work, so that the air becomes high-pressure air. The impeller is thus the "heart" of the air compressor, which constantly supplies the fuel cell system with a high-pressure air source, and therefore the operating efficiency of the impeller directly affects the operating efficiency of the entire fuel cell system. The loss of the airflow after passing through the impeller is roughly divided into four parts, namely friction loss, separation loss, secondary flow loss and wake loss. The friction loss is generated by the friction between the gas and the wall surface and is inevitable; separation loss is mainly caused by vortex generated by separation of a boundary layer, so that energy loss is caused by reverse flow of air flow; the secondary flow loss is mainly due to the fact that pressure difference exists on the wall surface, gas flows from the working surface to the non-working surface, the direction of the gas is perpendicular to the fluid of the main flow area, and energy loss is caused; the wake loss is mainly due to the fact that the tail edge of the impeller has a certain thickness, when gas flows out of an impeller flow channel, the flow area is suddenly expanded, and energy loss caused by vortexes is generated.

In the case of a fuel cell compressor for a vehicle, which is mainly used in a small-sized automobile or a commercial vehicle, the compressor has a small size and a light weight, resulting in relatively few impellers. The impeller losses will greatly reduce the operating efficiency of the compressor. There is therefore a need to further limit flow losses inside the impeller to improve the efficiency of the compressor. As can be seen from the foregoing, the friction loss and the wake loss are unavoidable, and further reduction is difficult. Separation losses and secondary flow losses account for a major part of the energy losses, and therefore how to further optimize the impeller internal flow path limits boundary layer separation and vortex formation.

Therefore, how to overcome the defect that the boundary layer of the impeller flow channel of the existing compressor is easy to separate and form vortices is an urgent problem to be solved in the industry.

Disclosure of Invention

The invention provides an impeller which can eliminate the vortex in the flow passage and inhibit the air separation, namely a centrifugal compressor with the impeller, an air conditioner with the compressor and an automobile with the compressor, so as to solve the problems that the boundary layer of the flow passage of the impeller of the existing compressor is easy to separate and form the vortex, thereby eliminating the formation of the vortex, reducing the separation loss and improving the pneumatic efficiency of the air compressor.

The invention provides an impeller with a vortex-eliminating, inhibiting and separating function. The edge of a main runner outlet between every two adjacent blades is provided with at least one airfoil blade, the two ends of each airfoil blade are sheet-shaped bodies formed by streamline curved surfaces, and the setting direction of each airfoil blade is the same as the direction of each blade.

Preferably, the airfoil blade is disposed on an inner surface of the shroud and/or on an inner surface of the hub.

Preferably, the ratio of the height H of the airfoil blade to the height B of the impeller outlet is H/B = 0.025-0.4.

Preferably, in the main flow passage, the position of the inlet of the airfoil vane is such that the ratio of the inlet mounting diameter D3 to the diameter D2 of the impeller is D3/D2= 0.6-0.7.

Preferably, the outlet position of the airfoil blade is that the ratio of the outlet installation diameter D4 to the impeller diameter D2 is D4/D2= 0.8-0.9.

Preferably, the airfoil vane is in a shape that one end of the gas inlet is thick and one end of the gas outlet is thin.

Preferably, the two sides of the airfoil blade are parallel side surfaces, and the two parallel side surfaces are correspondingly connected with the streamline curved surfaces at the two ends to form the airfoil blade.

Preferably, the two sides of the airfoil blade are convex curved side surfaces, and the convex curved side surfaces are correspondingly and smoothly connected with the streamline curved surfaces at the two ends.

Preferably, a pair of airfoil blades is arranged on the inner surface of the wheel cover or the wheel hub in parallel; or, the inner surfaces of the wheel cover and the hub are respectively provided with a wing-shaped blade which is in a double-row parallel state.

The invention provides a compressor, which comprises the impeller with the vortex-eliminating, inhibiting and separating functions.

The invention provides an air conditioner, which comprises the compressor.

The invention provides an automobile which comprises the compressor.

According to the invention, at least one wing-shaped blade is arranged in each main flow channel of the impeller, so that a wing-shaped flow guide channel is formed in the impeller, the formation of a vortex is eliminated, the air flow separation is inhibited, the loss is reduced, and the pneumatic efficiency of the compressor is improved. By improving the flow guide effect inside the impeller and homogenizing the airflow angle, the problem of direction matching of the airflow at the outlet of the impeller and the inlet of the diffuser is optimized, the exhaust noise of the compressor is effectively reduced, and the efficiency and the comfort of the fuel cell system are comprehensively improved.

Drawings

FIG. 1 is a schematic perspective view of an impeller embodiment of the present invention;

FIG. 2 is a front view of an embodiment of the impeller of the present invention with the shroud removed;

FIG. 3 is a perspective view of an airfoil blade embodiment of the present invention;

FIG. 4 is a schematic view of a single airfoil blade mounting location of the present invention

FIG. 5 is a series airfoil blade mounting structure of the present invention

Fig. 6 is a schematic structural view of a compressor having the impeller according to the present invention.

In the figure: 1-locking screw; 2-an impeller; 3, a volute; 4-a diffuser; 5, a cylinder body; 6-front axial bearing; 7-a thrust disc; 8-rear axial bearing; 9-front bearing seat; 10-front radial bearing; 11-water cooling jacket; 12-spiral cooling flow channel; 13-a motor stator; 14-motor shaft; 15-rear radial bearing; 16-rear bearing seat;

20-hub, 21-blade, 22-shroud, 23-impeller outlet, 24-impeller inlet, 26-airfoil blade, 27-pressure surface,

28-suction surface, 29-outer end of airfoil blade.

Detailed Description

The invention is further illustrated with reference to the following figures and examples:

as shown in fig. 1 and 2, an embodiment of the impeller with a vortex-reducing separation-suppressing function according to the present invention includes a hub 20, a shroud 22, and blades 21 disposed between the hub and the shroud. The main flow path of the impeller 2 is formed by two adjacent blades, a hub, a shroud, an impeller outlet 23 and an impeller inlet 24. The invention is provided with at least one airfoil vane 26 at the edge of the main runner outlet of the impeller. Referring to fig. 3, the airfoil vane 26 is a sheet-shaped body with left and right ends formed by streamline curved surfaces, the front and rear of the sheet-shaped body are parallel side surfaces, the distance between the parallel side surfaces is the height H of the airfoil vane, and the direction of the airfoil vane 26 is the same as the direction of the vane 21. If necessary, the airfoil blades may be provided on the inner surface of the shroud 22 or on the inner surface of the hub 20, or the airfoil blades may be provided on the inner surfaces of the shroud 22 and the hub 20 in a staggered manner. In this embodiment, one airfoil blade 26 is disposed on the inner surface of the wheel cover, that is, the top surface of the airfoil blade is fixedly connected to the inner surface of the wheel cover, and the rounded and smooth ends of the airfoil blade are disposed in the same direction as the blade 21 (see the schematic position of the airfoil blade in fig. 2). In order to maintain a good airflow field, the height H of the airfoil blades 26 is related to the impeller outlet height B, defined as the ratio of H/B = 0.025-0.4, the impeller outlet height B being the axial distance between the hub and the shroud. The partition wall formed between the airfoil blades and the blades can effectively block the formation of a vortex, accelerate the flow velocity at the relative position and limit the separation of the outlet position of the impeller and the airflow. Depending on where the actual vortex is formed, the height H of the airfoil blades 26 may also extend from the shroud 22 toward the hub 20. The aerofoil blades 26 are arranged in the main flow passage with a gap to the adjacent blades 21 and also at a distance from the outer circumference of the impeller 2. So install and form wing section drainage flow passage in making the sprue of impeller. As shown in fig. 4, the gas inlet position (inner end) of the airfoil vane 26 is generally the position of the end of the airfoil vane near the center of the impeller 2. The ratio of the inlet installation diameter D3 to the impeller diameter D2 is controlled to be D3/D2= 0.6-0.7. D3 is the diameter of the circle in which one end (inner end) of each airfoil vane gas inlet lies. Since the gas is deflected and the separation occurs first near the wheel cover, the separation can be suppressed. As the wing-shaped blades are added, wake vortexes can be formed at the outlet positions, and therefore the outlets of the wing-shaped blades are separated from the outlets of the impellers by a certain distance, tail airflow can be sufficiently and uniformly distributed, airflow angles at airflow outlets are optimized, airflow pulsation is reduced, and noise is reduced. The gas outlet position (outer end) of the airfoil vane 26, namely the position of one end of the airfoil vane close to the outer circle of the impeller, controls the ratio of the outlet installation diameter D4 to the impeller diameter D2 to be D4/D2= 0.8-0.9. D4 is the diameter of the circle on which one end (outer end) of each airfoil vane gas outlet is located. Therefore, the gas can be mixed to a certain degree at the tail edge, and the gas entering the inlet of the diffuser is ensured to be uniform. In order to reduce the loss of the trailing edge of the airfoil vane, the trailing edge, i.e., the outer end 29 of the airfoil vane 26, needs to be thinned (as shown in fig. 3), and the airfoil vane can also be configured to have a thick head part of the gas inlet and a thin tail part of the gas outlet. According to the requirement, two sides of the airfoil blade can be designed into parallel straight surfaces and then are correspondingly connected with streamline curved surfaces at two ends to form the airfoil blade; as shown in fig. 3, two sides of the airfoil blade may also be designed as convex curved sides, and then are correspondingly connected with the streamline curved surfaces at the two ends. As shown in fig. 5, the airfoil blades 26 may be arranged in a double-row parallel state according to the size of the blade flow passage separation, that is, one airfoil blade may be arranged on each of the inner surfaces of the shroud 22 and the hub 20; a pair of airfoil blades may also be arranged in parallel on the shroud or hub.

As shown in fig. 2, the impeller 2 rotates counterclockwise, the working surface of the blade 21 facing the counterclockwise direction of rotation of the impeller 2 is a pressure surface 27, i.e., the "back surface" of the blade 21, and the surface facing the pressure surface 27 of the blade is a suction surface 28. The gas is sucked from the impeller inlet 24 and discharged from the impeller outlet 23, the speed of the gas is gradually reduced due to friction when the gas passes through the surfaces of the parts such as the blades 21, and the fluid of a boundary layer (a thin gas attachment layer formed on the surfaces of the blades, the wheel cover and the hub) flows in reverse direction due to the diffusion effect of the impeller, so that the co-flow area of a main flow channel is reduced, and the diffusion effect cannot be achieved. Meanwhile, because of the speed difference between the working surface 27 and the suction surface 28 of the blade, the flow is generated on the surface of the hub in the direction vertical to the axis of the impeller, and a vortex is easily formed to disturb the flow field of the main flow area. In order to solve the separation loss and the formation of the vortex, an airfoil vane 26 with a proper flow passage is added in each main flow passage of the impeller 2, the direction of the airfoil vane is the same as that of the main flow passage vane, and after the airflow turns along the wheel cover, the airflow enters the position of the inlet of the diffuser, so that the flow guiding is inhibited or the vortex formation is prevented. The aerofoil blades 26 are spaced from the adjacent blades 21 by a distance from the outer circumference of the impeller. The cross-sectional shape of the impeller inlet is similar to an ellipse, being narrow near the hub 20 and wide near the shroud 22. So the installation forms wing section drainage runner in making the sprue of impeller to eliminate the formation of whirlpool and restrain the air separation, reduce the loss, promote compressor aerodynamic efficiency. By improving the flow guide effect inside the impeller and homogenizing the airflow angle, the problem of direction matching of the airflow at the outlet of the impeller and the inlet of the diffuser is optimized, the exhaust noise of the compressor is effectively reduced, and the efficiency and the comfort of the fuel cell system are comprehensively improved.

The invention also provides a centrifugal compressor which comprises the impeller with the vortex-eliminating and separation-inhibiting function. As shown in fig. 6, the compressor includes: the vortex-eliminating impeller-based cooling device comprises a locking screw 1, an impeller 2 with a vortex-eliminating, inhibiting and separating function, a volute 3, a diffuser 4, a barrel 5, a front axial bearing 6, a thrust disc 7, a rear axial bearing 8, a front bearing seat 9, a front radial bearing 10, a water cooling sleeve 11, a spiral cooling flow channel 12, a motor stator 13, a motor shaft 14, a rear radial bearing 15 and a rear bearing seat 16. The impeller 2 is a core part of the air compressor, and when the air compressor works, the impeller 2 compresses air flow at the inlet of the compressor to do work so as to enable the air flow to become high-pressure air flow which is finally conveyed to a hydrogen fuel cell reactor, and the fuel efficiency of hydrogen is improved.

As shown in fig. 6, the locking screw 1 is a solid, revolving type component, which is externally threaded and is connected to the motor shaft 14 by a screw thread, thereby fastening the impeller 2. The diffuser 4 is a rotary part and is a common structure in the turbine machinery, and the left end face of the diffuser and the corresponding right end face of the volute 3 form a diffusion flow channel, so that the outlet airflow of the impeller 2 obtains a diffusion effect, and the pressure is improved. The cylinder 5 is a cylindrical part, generally cast, and plays a role in supporting and protecting. The water cooling jacket 11 is embedded in the cylinder body, and forms a spiral cooling flow passage 12 together with the water cooling jacket 11. The front axial bearing 6 and the rear axial bearing 8, the front radial bearing 10 and the rear radial bearing 15 are air type gas bearings, the working medium of the air type gas bearings is air, and an air film suspension thrust disc 7 is formed during working and rotates along with a motor shaft 14. The front bearing seat 9 and the rear bearing seat 16 are hollow and rotary parts and provide support for the gas bearing. The motor stator 13 is a rotary part and mainly comprises a stator core and a stator winding. The motor shaft 14 is a shaft-like, solid part. The locking screw 1, the impeller 2, the thrust disc 7 and the motor shaft 14 form a rotor, and when the rotor works, the motor stator 13 generates a magnetic field, and the rotor rotates at a high speed under the action of the electromagnetic field.

The invention provides an automobile, which is provided with the compressor provided by the invention. The invention also provides an air conditioner which is provided with the compressor provided by the invention.

The above description is only exemplary of the present invention and should not be taken as limiting the invention, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The impeller with the vortex-eliminating, inhibiting and separating functions comprises a hub, blades and a wheel cover, and is characterized in that at least one airfoil-shaped blade is arranged at the edge of an outlet of a main runner between every two adjacent blades, two ends of each airfoil-shaped blade are flaky bodies formed by streamline curved surfaces, and the direction of each airfoil-shaped blade is the same as the direction of each blade.

2. The impeller with vortex-eliminating separation suppressing function as claimed in claim 1, wherein said airfoil blades are provided on an inner surface of said shroud and/or an inner surface of said hub.

3. The impeller with the vortex-eliminating and inhibiting separation function as claimed in claim 1, wherein the ratio of the height H of the airfoil blades to the impeller outlet height B is H/B =0.025 to 0.4.

4. The impeller with vortex-eliminating and separation-suppressing function according to claim 1, wherein the inlet position of said airfoil vane is set to the ratio of the inlet mounting diameter D3 to the impeller diameter D2: D3/D2=0.6~ 0.7.

5. The impeller with vortex-eliminating and separation-inhibiting function according to claim 1, wherein the outlet position of said airfoil vane is set to the ratio of the outlet mounting diameter D4 to the impeller diameter D2: D4/D2=0.8~ 0.9.

6. The impeller with a vortex-eliminating and separation-suppressing function according to claim 1, wherein said airfoil vane has a shape in which one end of the gas inlet is thick and one end of the gas outlet is thin.

7. The impeller with the function of vortex elimination and separation suppression as claimed in claim 1, wherein said airfoil blade is formed by connecting parallel side surfaces on both sides of the airfoil blade with curved surfaces on both sides.

8. The impeller with vortex-eliminating separation-inhibiting function according to claim 1, wherein both sides of said airfoil vane are convexly curved side surfaces, and the convexly curved side surfaces of both sides are smoothly connected with curved surfaces of both ends.

9. The impeller with the function of vortex elimination and separation suppression as claimed in claim 1, wherein a pair of airfoil blades are arranged in parallel on the inner surface of the shroud or the hub; or, the inner surfaces of the wheel cover and the hub are respectively provided with an airfoil blade in a double-row parallel state.

10. A compressor comprising an impeller having a vortex-eliminating and vortex-suppressing separation function as claimed in any one of claims 1 to 9.

11. An air conditioner characterized by comprising the compressor of claim 10.

12. An automobile, characterized by comprising the compressor of claim 10.