Compressor and air-conditioning unit

Abstract

The present invention provides a compressor and an air-conditioning unit. An implementation manner of the compressor includes an open impeller and a volute casing correspondingly arranged with the open impeller. A gas injection hole is arranged at a position on the volute casing corresponding to the air inlet end of the open impeller. The gas injection hole is used for injecting gas to form a gas sealing barrier at the air inlet end of the open impeller. By applying the technical solution of the present invention, gas is injected through the gas injection hole to form a gas sealing barrier at the air inlet end of the open impeller, thereby avoiding the leakage of air flow from the high-pressure side at the outlet end of the open impeller to the low-pressure side at the inlet end of the open impeller, and ensuring the effective efficiency of the compressor operation.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and more particularly, to a compressor and an air-conditioning unit. Background Art

[0002] Air compressors, as general power air sources, are widely used in industries such as machinery, automobiles, medical treatment, food, electric power, building materials, petroleum, chemical industry, and military industry. According to different compression methods, common ones include centrifugal air compressors, screw air compressors, scroll air compressors, etc.

[0003] In the field of new energy, hydrogen fuel cell vehicles have high power performance, fast hydrogen refueling, and long endurance mileage, making them the most strategically significant breakthrough in new energy vehicles in the 21st century. An air compressor provides a high-pressure air source for the fuel cell system. Compared with screw compressors and scroll compressors, a centrifugal air compressor can provide a higher pressure ratio air source, significantly improving the power density and overall performance of the fuel cell stack. The working principle of a centrifugal air compressor is that after being powered on, a high-speed motor drives an impeller to do work on the inlet air, turning it into high-pressure air. Therefore, the impeller is the "heart" of the air compressor, continuously providing a high-pressure air source for the fuel cell system. The working efficiency of the impeller directly affects the working efficiency of the entire fuel cell system. Impellers can be divided into open impellers and closed impellers according to their structures. The structure of an open impeller is as shown in Figure 1 , generally consisting of a blade 1 and a hub 2; the structure of a closed impeller is as shown in Figure 2 , generally consisting of a blade 1, a hub 2, and a shroud 3. Since the closed impeller has an additional shroud 3, the impeller does work on the air flow in the closed blades, reducing leakage losses. Therefore, the closed impeller has high efficiency.

[0004] The power of a vehicle fuel cell air compressor is relatively small, generally within 25 kw, belonging to a small centrifugal compressor, especially those with a power of within 20 kw. Because of its light weight and small volume, it can be applied to small cars or commercial vehicles. Since the small volume of the compressor results in limited internal space, it is difficult to arrange a closed impeller. In addition, because the shroud of a small closed impeller is difficult to weld and the stress after welding of the small closed impeller in the prior art is large, resulting in great processing difficulty for the small closed impeller, small centrifugal compressors generally use open impellers.

[0005] Thus, in some centrifugal compressors that have to use open impellers, the working efficiency of the impeller restricts the working efficiency of the compressor, affecting the energy efficiency of the centrifugal compressor. Summary of the Invention

[0006] Embodiments of the present invention provide a compressor and an air-conditioning unit to solve the technical problem that the use of an open impeller in a compressor in the prior art reduces the energy efficiency of the compressor.

[0007] An embodiment of the present invention provides a compressor, including an open impeller and a volute corresponding to the open impeller. An air injection hole is provided at a position on the volute corresponding to the air inlet end of the open impeller. The air injection hole is used to inject gas to form a gas sealing barrier at the air inlet end of the open impeller.

[0008] In one embodiment, there are multiple air injection holes, and the multiple air injection holes are distributed on the wall of the volute.

[0009] In one embodiment, the multiple air injection holes are annularly distributed on the wall of the volute around the axis line of the open impeller.

[0010] In one embodiment, the multiple air injection holes are equally spaced.

[0011] In one embodiment, the jet direction of the air injection hole is inclined towards the air inlet direction of the open impeller.

[0012] In one embodiment, the included angle between the jet direction of the air injection hole and the axis line direction of the open impeller is θ1, and 90° < θ1 < 145°.

[0013] In one embodiment, a gas storage cavity communicating with the air injection hole is provided in the volute, and a gas supply port communicating with the gas storage cavity is further provided on the volute. The gas storage cavity is used to receive gas from the gas supply port and supply the gas to the air injection hole.

[0014] In one embodiment, a jet hole is provided at a position on the volute corresponding to the air outlet end of the open impeller. The jet hole is used to jet fluid to form a fluid sealing barrier at the air outlet end of the open impeller.

[0015] In one embodiment, the jet hole is a liquid injection hole, and the liquid injection hole is used to inject liquid to form a liquid sealing barrier at the air outlet end of the open impeller.

[0016] In one embodiment, the liquid jet direction of the liquid injection hole is inclined towards the air outlet direction of the air outlet end of the open impeller.

[0017] In one embodiment, the included angle between the liquid jet direction of the liquid injection hole and the radial direction of the open impeller is θ2, and 110° < θ2 < 170°.

[0018] In one embodiment, a liquid storage cavity communicating with the liquid injection hole is provided in the volute, and a liquid supply port communicating with the liquid storage cavity is further provided on the volute. The liquid storage cavity is used to receive liquid from the liquid supply port and supply the liquid to the liquid injection hole.

[0019] The present invention also provides an air conditioning unit, including a compressor, and the compressor is the above-mentioned compressor.

[0020] In the above embodiment, gas is ejected through the gas ejection holes to form a gas sealing barrier at the air inlet end of the open impeller, thereby preventing air flow from leaking from the high-pressure side at the outlet end of the open impeller to the low-pressure side at the inlet end of the open impeller, and ensuring the effective efficiency of the compressor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic structural diagram of an open impeller in the prior art;

[0023] Figure 2 is a schematic structural diagram of a closed impeller in the prior art;

[0024] Figure 3 is a sectional structural schematic diagram of an embodiment of a compressor according to the present invention and a partial enlarged structural schematic diagram thereof;

[0025] Figure 4 is Figure 3 a three-dimensional structural schematic diagram of the volute of the compressor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. Herein, the schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not limit the present invention.

[0027] Based on the research on compressors with open impellers in the prior art, it is found that the main factor restricting the working efficiency of the compressor lies in the gap c formed between the open impeller and the volute. In the production of compressors with open impellers, the open impeller is a high-speed rotating part, while the volute is a stationary part. To avoid collision between the open impeller and the volute and considering the machining deformation of the open impeller, a gap c of a certain size will be formed between the open impeller and the volute. During the operation of the compressor, the open impeller does work on the inlet air flow of the compressor to make it a high-pressure air flow, which is finally delivered to the hydrogen fuel cell reactor to improve the fuel efficiency of hydrogen. During this process, the outlet end of the open impeller is the high-pressure side, while the inlet end of the open impeller is the low-pressure side. The above-mentioned gap c will cause air flow to leak from the high-pressure side at the outlet end of the open impeller to the low-pressure side at the inlet end of the open impeller, greatly reducing the system working efficiency of the compressor.

[0028] To solve the above technical problems, in the technical solution of the present invention, as Figure 3 and Figure 4, The implementation of this compressor includes an open impeller 10 and a volute 20 correspondingly arranged with the open impeller 10. At a position on the volute 20 corresponding to the intake end of the open impeller 10, an air injection hole 21 is provided. The air injection hole 21 is used to eject gas to form a gas sealing barrier at the intake end of the open impeller 10.

[0029] Applying the technical solution of the present invention, gas is ejected through the air injection hole 21 to form a gas sealing barrier at the intake end of the open impeller 10, thereby preventing the air flow from leaking from the high-pressure side at the outlet end of the open impeller to the low-pressure side at the inlet end of the open impeller, and ensuring the effective efficiency of the compressor operation.

[0030] As a preferred implementation, in the technical solution of this embodiment, there are multiple air injection holes 21. The multiple air injection holes 21 are distributed on the wall of the volute 20. Applying multiple air injection holes 21 can better form a gas sealing barrier. Preferably, in the technical solution of this embodiment, the multiple air injection holes 21 are distributed around the axis of the open impeller 10 on the wall of the volute 20, thereby helping to form a circumferentially enclosed gas sealing barrier. More preferably, the multiple air injection holes 21 are annularly distributed on the wall of the volute 20, thereby helping to form a circular gas sealing barrier, which is more adaptable to the shape of the intake end of the open impeller 10.

[0031] Preferably, in the technical solution of this embodiment, the multiple air injection holes 21 are equidistantly distributed, thereby forming a more uniform gas sealing barrier.

[0032] As Figure 3 shown, in the technical solution of this embodiment, the jet direction of the air injection hole 21 is inclined towards the intake direction of the open impeller 10, which can better prevent the air flow along the open impeller 10 from flowing back to the intake end of the open impeller. Preferably, in the technical solution of this embodiment, the included angle between the jet direction of the air injection hole 21 and the axis direction of the open impeller 10 is θ1, and 90° < θ1 < 180°.

[0033] It should be noted that in the technical solution of the present invention, the meaning that the jet direction of the air injection hole 21 is inclined towards the intake direction of the open impeller 10 means that, as Figure 3 shown, the horizontal component of the jet direction of the air injection hole 21 and the intake direction are the same. In Figure 3 , the intake direction is horizontally to the right.

[0034] As Figure 3As shown, in the technical solution of this embodiment, an air storage cavity 22 communicating with the air injection holes 21 is provided in the volute 20. The volute 20 is further provided with an air supply port 23 communicating with the air storage cavity 22. The air storage cavity 22 is used to receive gas from the air supply port 23 and supply the gas to the air injection holes 21. During use, the air storage cavity 22 is supplied with gas through the air supply port 23, and then the air storage cavity 22 receives gas from the air supply port 23 and supplies the gas to the air injection holes 21. During this process, a certain air pressure can be stored through the air storage cavity 22, which is conducive to continuously generating stable high-pressure gas in the air injection holes 21, so that the gas sealing barrier is formed more stably.

[0035] Optionally, in the technical solution of this embodiment, as Figure 3 and Figure 4 shown, in the technical solution of this embodiment, the air storage cavity 22 is jointly formed by the air storage housing 27 and the volute 20, and the air supply port 23 is provided on the air storage housing 27. More preferably, a sealing ring 271 is installed between the air storage housing 27 and the volute 20 to prevent gas from leaking through the gap between the air storage housing 27 and the volute 20. As another optional implementation manner, the air storage cavity 22 may also be only provided on the air storage housing 27; or the air storage cavity 22 may be provided on the volute 20 and then a closed structure is used for closing, which is also feasible.

[0036] In order to achieve the sealing effect and not cause an impact on the inlet air field of the open impeller 10 due to the high-pressure gas in the air injection holes 21, the air injection holes 21 generally adopt small holes with a hole diameter < 1 mm. The air storage cavity 22 provided in the present invention mainly stores gas, which can continuously and stably supply gas to the air injection holes 21, avoiding interruption and fluctuation of the sealing air flow. The high-pressure gas at the air supply port 23 can be manufactured by a high-pressure pump or introduced from the exhaust port of the volute, and it is only necessary to ensure that the gas pressure ≥ the pressure at the outlet of the open impeller 10.

[0037] Preferably, in the technical solution of this embodiment, in order to match the gas flow field at the inlet of the open impeller 10, the above θ1 should be an obtuse angle, and 90° < θ1 < 145° can be preferably selected, so as to better avoid the reverse flow of the gas flow along the open impeller 10 back to the intake end of the open impeller 10.

[0038] More preferably, in the technical solution of this embodiment, a jet hole is provided at a position corresponding to the outlet end of the open impeller 10 on the volute 20. The jet hole is used to eject fluid to form a fluid sealing barrier at the outlet end of the open impeller 10. During use, by forming a fluid sealing barrier at the outlet end of the open impeller 10, the air flow can be prevented from leaking from the high-pressure side at the outlet end of the open impeller 10 to the above gap c. Through the above settings, double sealing can be achieved.

[0039] As an alternative embodiment, in the technical solution of this embodiment, as Figure 3 shown, the jet hole is the liquid injection hole 24, and the liquid injection hole 24 is used to eject liquid to form a liquid sealing barrier at the gas outlet end of the open impeller 10. As other alternative embodiments, the above jet hole can also be set to eject gas.

[0040] Preferably, in the technical solution of this embodiment, the liquid injection direction of the liquid injection hole 24 is inclined on the volute 20 toward the gas outlet direction of the open impeller 10. Preferably, in the technical solution of this embodiment, the liquid injection hole 24 uses high-pressure liquid. This is mainly because the air compressor in the hydrogen fuel cell system has a high rotational speed, some are above 100,000 revolutions per minute, and the temperature of the impeller exhaust is often above 100 °C. Therefore, the gas at the outlet of the open impeller 10 is high-temperature, high-speed, and high-pressure gas. Among them, the high temperature increases the heat resistance requirements of the system, and the high speed brings greater noise. In order to reduce the high temperature and high speed, the liquid injection hole 24 uses high-pressure liquid, and the liquid can be a refrigerant or water, or a gas-liquid two-phase mixture. On the one hand, the liquid can cool the airflow at the impeller outlet. On the other hand, since the original pure gas outlet airflow is mixed with the liquid sealing fluid, the molecular mass of the mixed fluid increases, which can reduce the flow rate and thus reduce the noise. Preferably, in the technical solution of this embodiment, θ2 should be an obtuse angle.

[0041] It should be noted that in the technical solution of the present invention, the meaning that the liquid injection direction of the liquid injection hole 24 is inclined on the volute 20 toward the gas outlet direction of the open impeller 10 is that, as Figure 3 shown, the component of the liquid injection direction of the liquid injection hole 24 in the vertical direction is the same as the gas outlet direction, and in Figure 3 the gas outlet direction is the outward radial direction of the impeller 10.

[0042] Preferably, in the technical solution of this embodiment, the angle between the liquid injection direction of the liquid injection hole 24 and the radial direction of the open impeller 10 is θ2, 110° < θ2 < 170°, which can improve the entrainment effect of the high-pressure liquid on the airflow at the gas outlet end of the open impeller 10 and avoid impact loss.

[0043] As Figure 3As shown, a liquid storage cavity 25 communicating with the liquid spraying holes 24 is formed in the volute 20. A liquid supply port 26 communicating with the liquid storage cavity 25 is further formed on the volute 20. The liquid storage cavity 25 is used to receive liquid from the liquid supply port 26 and supply the liquid to the liquid spraying holes 24. During use, the liquid storage cavity 25 is supplied with liquid through the liquid supply port 26, and then the liquid storage cavity 25 receives the liquid from the liquid supply port 26 and supplies the liquid to the liquid spraying holes 24. During this process, a certain hydraulic pressure can be stored through the liquid storage cavity 25, which is conducive to continuously generating stable high-pressure liquid from the liquid spraying holes 24, thereby making the formed liquid sealing barrier more stable. During operation, the high-pressure liquid fluid enters the liquid storage cavity 25 from the liquid supply port 26, and the liquid storage cavity 25 continuously supplies liquid to the liquid spraying holes 24, achieving high-pressure liquid sealing at the outlet of the split impeller 10 and preventing the air flow from flowing from the outlet of the split impeller 10 along the gap c to the impeller inlet. The liquid spraying holes 24 are uniformly arranged in a circle at the volute 20, and the structural schematic diagram is as shown in Figure 4 the liquid spraying holes 24 shown. Similarly, in order to achieve the sealing effect and not cause an impact on the flow field at the outlet of the split impeller 10 due to the high-pressure liquid in the liquid spraying holes 24, the liquid spraying holes 24 generally adopt small holes with a hole diameter < 1 mm. The liquid storage cavity 25 provided in this patent is mainly used to store liquid, which can continuously and stably supply liquid to the liquid spraying holes 24 and prevent the sealing liquid flow from being interrupted and fluctuating. The high-pressure liquid of the liquid supply port 26 can be manufactured by a high-pressure pump, and it is only necessary to ensure that the liquid pressure ≥ the pressure at the outlet of the split impeller 10.

[0044] Optionally, in the technical solution of this embodiment, as shown in Figure 3 and Figure 4 shown, in the technical solution of this embodiment, the liquid storage cavity 25 is jointly formed by the liquid storage housing 28 and the volute 20, and the liquid supply port 23 is formed on the liquid storage housing 28. More preferably, a sealing ring 281 is installed between the liquid storage housing 28 and the volute 20 to prevent liquid from leaking from the gap between the liquid storage housing 28 and the volute 20. As another optional implementation method, the liquid storage cavity 25 can also be only formed in the liquid storage housing 28; or the liquid storage cavity 25 can be formed in the volute 20 and then a closed structure can be used for closing, which is also feasible.

[0045] As can be seen from the above, in the technical solution of the present invention, through double sealing, the loss caused by easy leakage of the split impeller is reduced. Through the liquid spraying effect, the exhaust temperature and flow rate are effectively reduced. The reduction of the flow rate can reduce the compressor exhaust noise, greatly improve the compressor aerodynamic efficiency, and comprehensively improve the high-temperature resistance performance and comfort of the fuel cell system.

[0046] In addition to the compressor structure involved in the above invention points, the structure of the compressor is as shown in Figure 3As shown in the figure, it also includes other components: lock nut 44, diffuser 43, cylinder 42, front axial bearing 41, thrust disk 40, rear axial bearing 39, front bearing housing 38, front radial bearing 37, water-cooled jacket 36, spiral cooling channel 35, motor stator 32, motor shaft 31, rear radial bearing 33, and rear bearing housing 34.

[0047] The above-mentioned lock nut 44 is a solid, rotary part with external threads on it, which is connected to the motor shaft 31 through the threads to fasten the open impeller 10.

[0048] The above-mentioned diffuser 43 is a hollow, rotary part, which is a common structure in turbomachinery. Its left end face and the corresponding right end face of the volute 20 form a diffuser channel, enabling the outlet air flow of the open impeller 10 to obtain a diffusing effect and increase the pressure.

[0049] The above-mentioned cylinder 42 is an irregular part, generally cast, which plays a supporting and protecting role. The water-cooled jacket 36 is embedded inside it, and together with the water-cooled jacket 36, it forms the spiral cooling channel 35.

[0050] The above-mentioned front axial bearing 41 and rear axial bearing 39, front radial bearing 37 and rear radial bearing 33 are air-type gas bearings. Their working medium is air, and a gas film is formed during operation to suspend the thrust disk 40 and the motor shaft 31.

[0051] The above-mentioned front bearing housing 38 and rear bearing housing 34 are hollow, rotary parts, which provide support for the gas bearings.

[0052] The above-mentioned motor stator 32 is a rotary part, mainly composed of a stator core and a stator winding. The above-mentioned motor shaft 31 is a shaft-type, solid part. The lock nut 44, open impeller 10, thrust disk 40, and motor shaft 31 form a rotor. During operation, the motor stator 32 generates a magnetic field, and the rotor makes a high-speed rotational motion under the action of the electromagnetic field.

[0053] The above-mentioned liquid storage housing 28 and gas storage housing 27 are both hollow, rotary parts. They are interference-fitted with the volute 20 through cold installation and sealed with a sealing ring 281 and a sealing ring 271. Preferably, the above-mentioned sealing ring is an O-ring.

[0054] The present invention also provides an air-conditioning unit, which includes the above-mentioned compressor. By using the above-mentioned compressor, since the leakage of air flow from the high-pressure side at the outlet end of the open impeller to the low-pressure side at the inlet end of the open impeller can be avoided, the effective efficiency of the compressor operation is ensured, thereby improving the energy efficiency of the air-conditioning unit.

[0055] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A compressor, comprising an open impeller (10) and a volute (20) correspondingly arranged with the open impeller (10). It is characterized in that at a position on the volute (20) corresponding to the air inlet end of the open impeller (10), an air injection hole (21) is provided, and the air injection hole (21) is used for injecting gas to form a gas sealing barrier at the air inlet end of the open impeller (10); the air injection direction of the air injection hole (21) is inclined towards the air inlet direction of the open impeller (10); the included angle between the air injection direction of the air injection hole (21) and the axis direction of the open impeller (10) is θ1, and 90° < θ1 < 145°; at a position on the volute (20) corresponding to the air outlet end of the open impeller (10), a jet hole is provided, and the jet hole is used for injecting fluid to form a fluid sealing barrier at the air outlet end of the open impeller (10); the jet hole is a liquid injection hole (24), and the liquid injection hole (24) is used for injecting liquid to form a liquid sealing barrier at the air outlet end of the open impeller (10).

2. The compressor according to claim 1, It is characterized in that the air injection holes (21) are multiple.

3. The compressor according to claim 2, It is characterized in that the multiple air injection holes (21) are annularly distributed around the axis of the open impeller (10) on the wall of the volute (20).

4. The compressor according to claim 3, It is characterized in that the multiple air injection holes (21) are equidistantly distributed.

5. The compressor according to claim 1, It is characterized in that a gas storage cavity (22) communicating with the air injection hole (21) is formed in the volute (20), and an air supply port (23) communicating with the gas storage cavity (22) is further formed on the volute (20), and the gas storage cavity (22) is used for receiving gas from the air supply port (23) and supplying the gas to the air injection hole (21).

6. The compressor according to claim 1, It is characterized in that the liquid injection direction of the liquid injection hole (24) is inclined towards the air outlet direction of the air outlet end of the open impeller (10).

7. The compressor according to claim 6, It is characterized in that the included angle between the liquid injection direction of the liquid injection hole (24) and the radial direction of the open impeller (10) is θ2, and 110° < θ2 < 170°.

8. The compressor according to claim 1, It is characterized in that a liquid storage cavity (25) communicating with the liquid injection hole (24) is formed in the volute (20), and a liquid supply port (26) communicating with the liquid storage cavity (25) is further formed on the volute (20), and the liquid storage cavity (25) is used for receiving liquid from the liquid supply port (26) and supplying the liquid to the liquid injection hole (24).

9. An air conditioning unit, comprising a compressor, It is characterized in that the compressor is the compressor according to any one of claims 1 to 8.

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