Wheel cover assembly, expander and air cycle machine

Abstract

The present invention relates to the field of refrigeration, and in particular to a wheel cover assembly, an expander, and an air cycle machine. The wheel cover assembly comprises a housing, the housing being provided with an air inlet and an air outlet; a wheel cover, a gas flow channel surrounding the wheel cover being formed between the outer wall surface of the wheel cover and the inner wall surface of the housing, the gas flow channel being connected to both the air inlet and the air outlet, the air inlet being used to introduce gas; when gas is introduced through the air inlet, the gas flows along the gas flow channel, exchanges heat with the wheel cover, and is discharged through the air outlet; when the temperature of the gas filled in the gas flow channel is higher than the temperature of the impeller, the wheel cover can radiate the heat of the absorbed gas to the impeller to prevent the impeller of the expander from being frozen by the low-temperature gas after the gas expands and performs work.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration, and in particular to a wheel cover assembly, an expander and an air cycle machine. Background Art

[0002] When the air cycle machine is working, the gas enters the compressor and expands to do work externally. The temperature of the expanded gas drops and is discharged. The dropped gas temperature is usually below 0°C. In some usage environments, the temperature of the gas after expansion and work even reaches minus 40°C. The excessively low temperature makes it easy for ice to form between the impeller and the wheel cover of the expander, making it impossible for the impeller to rotate effectively. At this time, the high-pressure gas filled in to do work on the impeller can easily cause damage to the impeller blades and even cause safety accidents.

[0003] To address the above issues, no effective solutions have been proposed so far. Summary of the Invention

[0004] In order to prevent the impeller of an expander from being frozen by low-temperature gas after the gas expands and does work, a wheel cover assembly, an expander and an air cycle machine are proposed.

[0005] In a first aspect, the present invention provides a wheel cover assembly for an expander, comprising:

[0006] a housing, the housing being provided with an air inlet and an air outlet;

[0007] A wheel cover, a gas flow channel surrounding the wheel cover is formed between the outer wall surface of the wheel cover and the inner wall surface of the shell, the gas flow channel is connected with the air inlet and the air outlet, and the air inlet is used to allow gas to enter; when gas is introduced from the air inlet, the gas flows along the gas flow channel to exchange heat with the wheel cover and is discharged from the air outlet.

[0008] Preferably, the wheel cover assembly further comprises:

[0009] a volute, the volute being arranged outside the housing and connected to the housing, the volute being provided with a communicating hole;

[0010] The air inlet end of the wheel cover is communicated with the volute;

[0011] The gas outlet of the shell is communicated with the communicating hole, and the gas discharged from the gas outlet enters the volute through the communicating hole.

[0012] Preferably, a heat conductor is provided on the outer wall surface of the wheel cover, and the heat conductor is located in the gas flow channel.

[0013] Preferably, the heat conductor includes an annular heat conducting plate which is arranged along the circumference of the outer wall of the wheel cover and protrudes from the outer wall of the wheel cover.

[0014] Preferably, a plurality of the annular heat conducting plates are provided, and the plurality of the annular heat conducting plates are distributed at intervals along the axial direction of the wheel cover.

[0015] Preferably, the height of the heat conducting plate is h, the thickness is w, the minimum distance between two adjacent heat conducting plates is d, and the diameter of the cavity at the exhaust end of the wheel cover is D, then: 0.01<h / D<0.2,

[0016] 0.01<w / D<0.06, 0.05<d / D<0.2.

[0017] Preferably, h / D=0.1, w / D=0.03, d / D=0.1.

[0018] Preferably, the wall thickness of the wheel cover is t, 0.01<t / D<0.2.

[0019] Preferably, the wall thickness of the wheel cover is t / D=0.05.

[0020] Preferably, the shell includes a first sealing part A and a first sealing part B, and the first mounting part A and the first sealing part B are distributed axially at intervals in the wheel cover; the outer wall surface of the wheel cover close to the exhaust end is provided with a second sealing part A, and the outer wall surface close to the intake end is provided with a second sealing part B; the first sealing part A is sealed in cooperation with the second sealing part A, and the first sealing part B is sealed in cooperation with the second sealing part B; the gas flow channel is located between the first sealing part A, the second sealing part A, the first sealing part B, the second sealing part B, the inner wall surface of the shell and the outer wall surface of the wheel cover.

[0021] Preferably, a ring plate is protruded from the housing, and a first sealing surface A facing the wheel cover is formed on the inner side surface of the ring plate in the radial direction of the wheel cover. A first sealing surface B is also formed on the inner wall surface of the housing, and the first sealing surface B extends circumferentially along the inner wall surface of the housing to form an annular shape; the first sealing portion A is the first sealing surface A, and the first sealing portion B is the second sealing surface B;

[0022] The outer wall surface of the wheel cover near the exhaust end extends along the circumference of the wheel cover to form an annular first protrusion, and the first protrusion is formed with a first groove, which extends along the length direction of the first protrusion and faces the first sealing surface A; a first sealing member is arranged in the first protrusion; the outer wall surface of the wheel cover near the intake end protrudes to form an annular second protrusion, and the second protrusion is formed with a second groove, which extends along the length direction of the second protrusion and faces the first sealing surface B; a second sealing member is arranged in the second groove; the second sealing part A includes the first groove and the first seal, and the second sealing part B includes the second groove and the second seal; the first protrusion and the first sealing surface A are sealed by the first seal; the second protrusion and the second sealing surface B are sealed by the second seal.

[0023] Preferably, the first sealing member is a first O-ring, and the second sealing member is a second O-ring.

[0024] In a second aspect, the present invention further provides an expander, comprising an impeller, the impeller and the wheel cover assembly, wherein the impeller is disposed in the wheel cover, and a gap is formed between the impeller and the wheel cover.

[0025] In a third aspect, the present invention further provides an air cycle machine, comprising a compressor and the expander; the compressor comprises a compression inlet and a compression outlet, and the compression outlet is connected to the air inlet of the shell.

[0026] Preferably, compression blades are provided in the compression shell;

[0027] The impeller and the compression blades are coaxially arranged. When gas enters the expander and drives the impeller to rotate, the compression blades rotate simultaneously with the impeller and suck the external gas into the compression shell through the compression inlet. The gas sucked into the compression shell is compressed by the compression blades and heated up, and then discharged from the compression outlet. At least a part of the heated airflow discharged from the compression outlet enters the gas flow channel through the air inlet.

[0028] The present invention arranges a wheel cover in the expander and a gas flow channel between the wheel cover and the casing. High-temperature gas is filled into the gas flow channel to heat the wheel cover. The heating of the wheel cover effectively avoids ice formation between the impeller and the wheel cover. The rotation of the impeller drives the movement of the compressor, and part of the high-temperature gas generated by the operation of the compressor enters the gas flow channel, thereby improving energy utilization and reducing power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of a wheel cover of an expander according to an embodiment of the present invention;

[0030] Figure 2Schematic diagram of the housing of the expander according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of an expander according to an embodiment of the present invention;

[0032] Figure 4 For the present invention Figure 1 Enlarged view of point A in the middle;

[0033] Figure 5 Schematic diagram of the relationship between the expander and the compressor in an embodiment of the present invention.

[0034] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0035] In the accompanying drawings: 1-wheel cover; 101-air inlet end; 102-exhaust end; 2-gas flow channel; 3-impeller; 4-heat conducting plate; 401-annular spacer; 501-air inlet hole; 502-exhaust hole; 601-first protrusion; 602-second protrusion; 701-first O-ring; 702-second O-ring; 8-housing; 801-volute; 802-connecting hole; 901-compression inlet; 902-compression outlet. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first," "second," and so on, in the present description, claims, and drawings are used to distinguish similar items and are not necessarily used to describe a specific order or precedence; "front end" and "back end" are relative. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0038] The present invention relates to the field of refrigeration, and in particular to an impeller cover, an expander, and an air cycle machine. When an air cycle machine is operating, gas enters the compressor, expands, and performs external work. The expanded gas cools and is discharged. The cooled gas temperature is typically below 0°C. In some operating environments, the gas temperature after expansion and work can even reach -40°C. Excessively low temperatures can easily cause ice to form between the impeller and the impeller cover, preventing the impeller from rotating effectively. At this time, the high-pressure gas injected into the impeller can easily damage the impeller blades and even cause safety accidents. To address the above-mentioned problems, a impeller cover, an expander, and an air cycle machine are proposed.

[0039] First, as Figure 1-4 As shown, the present invention proposes a wheel cover assembly for an expander, comprising a shell, the shell being provided with an air inlet and an exhaust port; a wheel cover, a gas flow channel 2 surrounding the wheel cover is formed between the outer wall surface of the wheel cover and the inner wall surface of the shell, the gas flow channel 2 is connected to the air inlet and the air outlet, and the air inlet is used to introduce gas; when gas is introduced from the air inlet, the gas flows along the gas flow channel 2 to exchange heat with the wheel cover and is discharged from the air outlet.

[0040] A wheel cover is provided in the expander, and a gas flow channel is provided between the wheel cover and the casing. High-temperature gas is filled into the gas flow channel to heat the wheel cover. The heating of the wheel cover effectively prevents ice from forming between the impeller 3 inside the wheel cover and the wheel cover. The rotation of the impeller 3 drives the compressor to move, and part of the high-temperature gas generated by the operation of the compressor enters the gas flow channel, thereby improving energy utilization and reducing power consumption.

[0041] Preferably, Figure 3 As shown, the wheel cover assembly also includes: a volute, which is arranged outside the shell and connected to the shell, and the volute is provided with a connecting hole; the air inlet end 101 of the wheel cover is connected to the volute; the air outlet of the shell is connected to the connecting hole, and the gas discharged from the air outlet enters the volute through the connecting hole.

[0042] The high-pressure gas discharged from the gas flow channel 2 enters the volute and then enters the air inlet end 101 of the wheel cover. When an impeller 3 is provided in the wheel cover, it is used to drive the impeller 3 to rotate, thereby improving the utilization rate of the high-pressure gas and saving energy.

[0043] Preferably, Figure 1 As shown, the outer wall of the wheel cover is provided with a heat conductor, which is located in the gas flow channel 2. The heat conductor accelerates the high-temperature airflow in the gas flow channel to transfer heat to the wheel cover, thereby accelerating the heating of the wheel cover.

[0044] Preferably, the heat conductor includes an annular heat conducting sheet 4 extending circumferentially along the outer wall of the wheel cover. A plurality of heat conducting sheets 4 conduct heat to the wheel cover, and the heating is more uniform.

[0045] Preferably, the heat conductor includes an annular heat conducting sheet 4 protruding from the outer wall of the wheel cover and arranged circumferentially along the outer wall of the wheel cover. An annular spacer 401 extending circumferentially along the wheel cover is formed between two adjacent heat conducting sheets 4. The high-temperature airflow flows within the gas flow channel 2 and enters the spacer. The multiple spacers in the axial direction provide a more uniform distribution of the airflow and a more uniform heating of the wheel cover. Furthermore, the heat conducting sheet 4 can be vertically connected to the outer wall of the wheel cover so that the axial spacing between each annular spacer 401 is substantially uniform, which facilitates the flow and heating of the high-temperature airflow within different annular spacers 401.

[0046] Preferably, Figure 1 and Figure 4 As shown, the height of the heat conducting plate 4 is h, the thickness is w, the minimum distance between two adjacent heat conducting plates 4 is d, and the cavity diameter of the exhaust end 102 of the wheel cover is D. Then: 0.01<h / D<0.2, 0.01<w / D<0.06, 0.05<d / D<0.2.

[0047] Preferably, h / D=0.1, w / D=0.03, d / D=0.1.

[0048] The thickness, height, and spacing between adjacent heat conducting sheets 4 are related to the inner diameter of the wheel cover exhaust end 102. Within the above numerical range, the heat conducting sheet 4 has a good heat conduction effect, while also ensuring the structural strength of the heat conducting sheet 4 itself, avoiding excessive consumables and waste. The spacing between the heat conducting sheets 4 can ensure uniform heat conduction and also play a relatively good guiding role, preventing airflow from gathering at one end in the axial direction, resulting in uneven heating. The specifications and spacing of the heat conducting sheets 4 are related to the caliber of the exhaust end 102. The larger the caliber of the exhaust end 102, the larger the specifications and dimensions of the corresponding heat conducting sheets 4.

[0049] Preferably, the wall thickness of the wheel cover is t, 0.01<t / D<0.2.

[0050] Preferably, the wall thickness of the wheel cover is t / D=0.05.

[0051] The wheel cover wall thickness being within the above range can not only ensure the strength of the wheel cover, but also facilitate heat conduction.

[0052] Preferably, the shell includes a first sealing part A and a first sealing part B, and the first mounting part A and the first sealing part B are axially spaced apart on the wheel cover; a second sealing part A is provided on the outer wall surface of the wheel cover close to the exhaust end 102, and a second sealing part B is provided on the outer wall surface close to the intake end 101; the first sealing part A is sealed in cooperation with the second sealing part A, and the first sealing part B is sealed in cooperation with the second sealing part B; the gas flow channel 2 is located between the first sealing part A, the second sealing part A, the first sealing part B, the second sealing part B, the inner wall surface of the shell and the outer wall surface of the wheel cover.

[0053] The air flow is sealed in the annular space, effectively allowing the high-temperature gas to flow in the gas flow channel 2, avoiding the flow of the high-temperature gas and improving the utilization rate of the high-temperature gas.

[0054] Preferably, a ring plate is formed protruding from the housing, and a first sealing surface A facing the wheel cover is formed on the inner side surface of the ring plate in the radial direction of the wheel cover. A first sealing surface B is also formed on the inner wall surface of the housing, and the first sealing surface B extends circumferentially along the inner wall surface of the housing to form an annular shape; the first sealing portion A is the first sealing surface A, and the first sealing portion B is the second sealing surface B;

[0055] The outer wall surface of the wheel cover near the exhaust end 102 extends along the circumference of the wheel cover to form an annular first protrusion 601, and the first protrusion 601 is formed with a first groove, which extends along the length direction of the first protrusion 601 and faces the first sealing surface A; a first sealing member is arranged in the first protrusion 601; the outer wall surface of the wheel cover near the intake end 101 protrudes to form an annular second protrusion 602, and the second protrusion 602 is formed with a second groove, which extends along the length direction of the second protrusion 602 and faces the first sealing surface B; a second sealing member is arranged in the second groove; the second sealing part A includes the first groove and the first sealing member, and the second sealing part B includes the second groove and the second sealing member; the first protrusion 601 and the first sealing surface A are sealed by the first sealing member; the second protrusion 602 and the second sealing surface B are sealed by the second sealing member; the first sealing member is a first O-ring 701, and the second sealing member is a second O-ring 702.

[0056] Second, as Figure 1-4 As shown, the present invention also provides an expander including an impeller 3 and a wheel cover assembly for the impeller 3. The impeller 3 is disposed within the wheel cover, with a gap formed between the impeller 3 and the wheel cover. The expander operates stably and effectively prevents freezing between the impeller 3 and the wheel cover.

[0057] Thirdly, as Figure 5 As shown, the present invention also provides an air cycle machine, including a compressor and an expander; the compressor includes a compression inlet 901 and a compression outlet 902, and the compression outlet 902 is connected to the air inlet of the shell. The compressor includes a compression shell, which is formed with a compression inlet 901 and a compression outlet 902, and the compression shell is provided with compression blades 8; the compression outlet 902 on the compression shell is connected to the air inlet 501 on the expander; the impeller 3 is coaxially arranged with the compression blades 8. When gas enters the expander and drives the impeller 3 to rotate, the compression blades 8 rotate simultaneously with the impeller 3 and draw other external gas from the compression inlet 901 into the compression shell. The gas drawn into the compression shell is compressed and heated by the compression blades 8 and then discharged from the compression outlet 902. At least part of the heated air discharged from the compression outlet 902 enters the gas flow channel through the air inlet 501.

[0058] When the expander is working, it drives the compressor to work. A part of the high-temperature airflow compressed by the compressor enters the gas flow channel 2 to heat the wheel cover, thereby improving the working effect of the compressor and avoiding ice formation between the expander impeller 3 and the wheel cover.

[0059] The working process and principle of the present invention are described below by taking an air cycle machine as an example; high-pressure gas is filled in from the air inlet end 101, and the high-pressure gas expands and does work and drives the impeller 3 to rotate and then is discharged from the exhaust end 102; on the one hand, when the high-pressure gas expands and does work, the high-pressure gas becomes low-pressure gas (normal pressure) and the temperature drops to below zero degrees. The gas below zero freezes the impeller 3, and ice forms on the surface of the impeller 3, which affects the force relationship between the impeller 3 and the airflow; on the other hand, when the impeller 3 rotates, the compressor blades coaxial with the impeller 3 rotate, and the compressor blades suck air into the compressor from the compression inlet 901, and the air is compressed by the compressor As the pressurized temperature rises, some of the elevated high-temperature gas is discharged from the compression outlet 902, while a portion enters the gas flow channel 2 through the air inlet 501. The high-temperature gas flows within the gas flow channel 2 and within the spaces between the heat conducting fins 4. The high-temperature gas heats the heat conducting fins 4 and the impeller cover, improving the thermal conductivity between the high-temperature gas and the impeller cover. The heat conducting fins 4 then conduct the heat to the impeller cover. The impeller cover then radiates the heat to the impeller 3 within the impeller cover, raising the temperature of the impeller 3 and preventing ice from forming on the impeller 3 surface and between the impeller 3 and the inner portion of the impeller cover. After flowing within the gas flow channel 2, the high-temperature gas is discharged through the exhaust vent 502. The gas flow channel 2 is enclosed by the first protrusion 601, the first O-ring 701, the second protrusion 602, the second O-ring 702, the first sealing surface, and the second sealing surface. The high-temperature gas flows within the enclosed gas flow channel 2, preventing leakage and improving the efficiency of heating the impeller cover.

[0060] The present invention arranges a wheel cover in the expander and a gas flow channel between the wheel cover and the casing. High-temperature gas is filled into the gas flow channel to heat the wheel cover. The heating of the wheel cover effectively avoids ice formation between the impeller and the wheel cover. The rotation of the impeller drives the movement of the compressor, and part of the high-temperature gas generated by the operation of the compressor enters the gas flow channel, thereby improving energy utilization and reducing power consumption. The high-pressure gas discharged from the gas flow channel enters the volute, and enters the intake end of the wheel cover again from the volute to collide and perform work, thereby improving the utilization rate of the high-pressure airflow.

[0061] The exemplary embodiments of the present disclosure are specifically shown and described above. It should be understood that the present disclosure is not limited to the detailed structures, configurations or implementations described herein; on the contrary, the present disclosure is intended to cover various modifications and equivalent configurations included within the spirit and scope of the appended claims.

Claims

1. A wheel cover assembly for an expander, characterized in that: include: a housing, wherein the housing is provided with an air inlet and an air outlet; A wheel cover, wherein a gas flow channel surrounding the wheel cover is formed between an outer wall surface of the wheel cover and an inner wall surface of the housing, the gas flow channel being in communication with both the air inlet and the air outlet, the air inlet being used to admit gas; when gas is introduced through the air inlet, the gas flows along the gas flow channel to perform heat exchange with the wheel cover and is discharged through the air outlet; An impeller is also provided in the wheel cover; The wheel cover assembly further comprises: A volute is provided outside the housing and connected to the housing, and the volute is provided with a communication hole; the air inlet end of the wheel cover is connected to the volute; The air outlet of the shell is connected to the communicating hole. The gas discharged from the air outlet enters the volute through the communicating hole, and then enters the air inlet end of the wheel cover from the volute to drive the impeller to rotate.

2. The wheel cover assembly according to claim 1, wherein: A heat conductor is provided on the outer wall surface of the wheel cover, and the heat conductor is located in the gas flow channel.

3. The wheel cover assembly according to claim 2, wherein: The heat conductor includes an annular heat conducting sheet which is arranged along the circumference of the outer wall of the wheel cover and protrudes from the outer wall of the wheel cover.

4. The wheel cover assembly according to claim 3, characterized in that: There are multiple annular heat conducting plates, and the multiple annular heat conducting plates are distributed at intervals along the axial direction of the wheel cover.

5. The wheel cover assembly according to claim 4, characterized in that: The height of the heat conducting plate is h, the thickness is w, the minimum distance between two adjacent heat conducting plates is d, and the diameter of the cavity at the exhaust end of the wheel cover is D. Then: 0.01<h / D<0.2, 0.01<w / D<0.06, 0.05<d / D<0.

2.

6. The wheel cover assembly according to claim 5, characterized in that: The h / D=0.1, w / D=0.03, and d / D=0.

1.

7. The wheel cover assembly according to claim 5, characterized in that: The wall thickness of the wheel cover is t, 0.01<t / D<0.

2.

8. The wheel cover assembly according to claim 7, wherein: The wall thickness of the wheel cover is t / D=0.

05.

9. The wheel cover assembly according to claim 1, wherein: The housing includes a first sealing portion A and a first sealing portion B, which are spaced apart in the axial direction of the wheel cover; a second sealing portion A is provided on the outer wall surface of the wheel cover near the exhaust end, and a second sealing portion B is provided on the outer wall surface near the intake end; the first sealing portion A and the second sealing portion A are in sealing engagement, and the first sealing portion B and the second sealing portion B are in sealing engagement; The gas flow channel is located between the first sealing part A, the second sealing part A, the first sealing part B, the second sealing part B, the inner wall surface of the shell and the outer wall surface of the wheel cover.

10. The wheel cover assembly according to claim 9, wherein: An annular plate is protruded from the housing, and a first sealing surface A is formed on the inner side of the annular plate in the radial direction of the wheel cover, facing the wheel cover. A first sealing surface B is also formed on the inner wall of the housing, and the first sealing surface B extends circumferentially along the inner wall of the housing to form an annular shape. The first sealing portion A is the first sealing surface A, and the first sealing portion B is the second sealing surface B. The outer wall surface of the wheel cover near the exhaust end extends along the circumference of the wheel cover to form an annular first protrusion, the first protrusion is formed with a first groove, the first groove extends along the length direction of the first protrusion and faces the first sealing surface A; a first sealing member is provided in the first protrusion; the outer wall surface of the wheel cover near the intake end protrudes to form an annular second protrusion, the second protrusion is formed with a second groove, the second groove extends along the length direction of the second protrusion and faces the first sealing surface B; a second sealing member is provided in the second groove; the second sealing portion A includes the first groove and the first seal, the second sealing portion B includes the second groove and the second seal; the first protrusion and the first sealing surface A are sealed by the first seal; the second protrusion and the second sealing surface B are sealed by the The second seal seals.

11. The wheel cover assembly according to claim 10, wherein: The first sealing member is a first O-ring, and the second sealing member is a second O-ring.

12. An expander, characterized in that: It comprises an impeller, the impeller and the wheel cover assembly according to any one of claims 1 to 11, wherein the impeller is arranged in the wheel cover, and a gap is formed between the impeller and the wheel cover.

13. An air cycle machine, characterized in that: The expander comprises a compressor and the expander according to claim 12; the compressor comprises a compression inlet and a compression outlet, and the compression outlet is communicated with the air inlet of the shell.

14. The air cycle machine according to claim 13, wherein: Compression blades are provided in the compression shell; The impeller is coaxially arranged with the compression blades. When gas enters the expander and drives the impeller to rotate, the compression blades rotate simultaneously with the impeller and draw air into the compression shell from the compression inlet. The gas drawn into the compression shell is compressed and heated by the compression blades and then discharged from the compression outlet. At least a portion of the heated airflow discharged from the compression outlet enters the gas flow channel through the air inlet.

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