Air cycle machine

Abstract

The invention provides an air cycle machine which comprises a turbine, the turbine comprises a turbine cover, a spiral pipeline surrounds the outer wall face of the turbine cover, an inner hole of the spiral pipeline is used for being filled with fluid for heating the turbine cover, and therefore the technical problem that in the prior art, a turbine cover of a turbine is heated unevenly can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of air cycle machines, and in particular relates to an air cycle machine. Background Art

[0002] In the air cycle machine, the air cooled by primary heat exchange enters the compressor from C1 (compressor inlet), and is pressurized and heated by the impeller; the high-temperature and high-pressure gas is discharged from C2 (compressor outlet) and after intermediate heat exchange cooling, it enters the turbine through T1 (turbine inlet) to complete expansion cooling and output mechanical work, and the cooling gas is discharged from T2 (turbine outlet), realizing the air cycle refrigeration function. The air cycle machine system is as follows: Figure 1 As shown. The air flow temperature at the turbine outlet T2 can be as low as -40°C, and it is necessary to consider the possible icing at the turbine outlet and the drainage problem after deicing. In the past, the anti-icing measures for the turbine outlet were mainly to form an anti-icing cavity on the outer wall of the turbine wheel cover, introduce high-temperature gas into the cavity for heat exchange, and achieve the anti-icing effect. However, the high-temperature gas does not flow evenly after entering the cavity, and low-temperature areas may appear locally on the turbine wheel cover, resulting in ice in some areas of the turbine wheel cover. Due to the uneven temperature of the turbine wheel cover, the pressure of the gas flowing in the turbine wheel cover is also uneven, resulting in vibration.

[0003] How to heat the turbine wheel cover more evenly is a technical problem that urgently needs to be solved. Summary of the invention

[0004] Therefore, the present invention provides an air cycle machine, which can solve the technical problem of uneven heating of the turbine wheel cover in the prior art.

[0005] The present invention provides an air cycle machine, comprising a turbine, wherein the turbine comprises a turbine cover, the outer wall surface of the turbine cover is surrounded by a spiral pipe, and the inner hole of the spiral pipe is used to be filled with a fluid for heating the turbine cover.

[0006] In some embodiments, the spiral pipe includes a first section of pipe and a second section of pipe, the end of the first section of pipe is connected to the head end of the second section of pipe and is located at the first end of the turbine cover, and the head end of the first section of pipe and the end of the second section of pipe are both located at the second end of the turbine cover; the flow direction of the fluid in the first section of pipe is opposite to the flow direction in the second section of pipe.

[0007] In some embodiments, the spiral duct is in surface contact with an outer wall of the turbine cover.

[0008] In some embodiments, each circle of tubes formed by the first section of tube surrounding the turbine cover is spaced apart from each circle of tubes formed by the second section of tube surrounding the turbine cover.

[0009] In some embodiments, the air cycle machine further includes a compressor volute, and the inlet of the spiral duct is connected to the outlet of the compressor volute via an inlet pipe.

[0010] In some embodiments, the air cycle machine further includes a turbine volute, and the outlet of the spiral duct is connected to the inner cavity of the turbine volute via an outlet pipe.

[0011] In some embodiments, the turbine cover includes a turbine hood and an air guide section connected to the outlet end of the turbine hood, one end of the air guide section connected to the turbine hood is an air inlet end, and the other end is an air outlet end; from the air inlet end to the air outlet end, the wall thickness of the air guide section gradually becomes thinner.

[0012] In some embodiments, the spiral duct is interference fit around the air guide section.

[0013] In some embodiments, the flow area of ​​the spiral duct gradually increases from the air inlet end to the air outlet end.

[0014] In some embodiments, the inner diameter of the spiral duct is d1, the inner diameter of the air guide section is d2, and 0.1≤d1 / d2≤0.2.

[0015] By surrounding the outer wall of the turbine cover with a spiral pipe, and filling the spiral pipe with high-temperature fluid, the high-temperature fluid heats the turbine cover after passing through the spiral pipe for heat conduction, and the heating fluid flows along the spiral pipe, which is arranged around the outer wall of the turbine cover. In this way, the high-temperature fluid can flow through most of the surface of the turbine cover, achieving more uniform heating of the turbine cover, avoiding low temperatures in some areas of the turbine cover, resulting in local icing inside the turbine cover; at the same time, it also avoids uneven pressure when the gas flows inside the turbine cover due to uneven temperature, resulting in poor gas flow and vibration. The anti-icing performance of the turbine cover is effectively improved, the ice blockage problem of the air cycle machine is solved, and the operating temperature and reliability of the air cycle machine are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0017] Figure 1 is a schematic structural diagram of an air cycle machine according to an embodiment of the present invention;

[0018] Figure 2 is a cross-sectional view of an air cycle machine according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of the spiral pipeline structure of an embodiment of the present invention;

[0020] Figure 4 is a radial cross-sectional view of a spiral pipeline according to an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of the structure of a turbine cover according to an embodiment of the present invention;

[0022] The accompanying drawings are marked as follows:

[0023] 1. Turbine cover; 101. Turbine hood; 102. Air guide section; 1021. First end; 1022. Second end; 2. Spiral duct; 201. First section of the pipe; 202. Second section of the pipe; 3. Compressor volute; 301. Compressor outlet; 4. Turbine volute; 501. Anti-icing air inlet; 502. Anti-icing air inlet; 503. Anti-icing air outlet; 504. Anti-icing air exhaust hole; 505. Anti-icing air duct; 601. Inlet pipe; 602. Outlet pipe. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0026] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0027] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0028] In an air cycle machine, there is still a certain amount of water vapor in the air entering the turbine after high-pressure water removal. During the expansion and cooling process, the temperature drops below zero, even below -40°C, and part of the water vapor will condense into ice particles. As the turbine outlet airflow rotates, the ice particles in the airflow accumulate on the wall surface of the turbine outlet due to inertial impact, blocking the turbine outlet after a period of time. In order to prevent ice particles from blocking the turbine outlet, the present application discloses the following technical solution.

[0029] The present invention provides an air cycle machine, such as Figure 1-5 As shown, the turbine comprises a turbine, wherein the turbine comprises a turbine cover 1 , an outer wall surface of the turbine cover 1 is surrounded by a spiral pipe 2 , and an inner hole of the spiral pipe 2 is used for filling a fluid for heating the turbine cover 1 .

[0030] By surrounding the outer wall of the turbine cover 1 with a spiral pipe 2, the spiral pipe 2 extends from the end of the outlet end of the turbine cover 1 to the turbine cover 1 corresponding to the blades of the turbine, and in the radial direction of the turbine, the spiral pipe 2 covers part of the blades of the turbine; in this way, a high-temperature fluid is filled in the spiral pipe 2, and the high-temperature fluid heats the turbine cover 1 after passing through the spiral pipe for heat conduction, and the heating fluid flows along the spiral pipe 2, and the spiral pipe 2 is arranged around the outer wall of the turbine cover 1, so that the high-temperature fluid can flow through most of the surface of the turbine cover 1, so as to achieve more uniform heating of the turbine cover 1, and avoid the low temperature in some areas of the turbine cover 1, resulting in local icing in the turbine cover 1; at the same time, it also avoids the uneven pressure when the gas in the turbine cover 1 flows due to uneven temperature, resulting in poor gas flow and vibration. The anti-icing performance of the turbine cover 1 is effectively improved, the ice blockage problem of the air cycle machine is solved, and the operating temperature and reliability of the air cycle machine are improved.

[0031] Furthermore, the spiral pipe 2 is detachably arranged on the turbine cover 1 , and the spiral pipe 2 is detachably arranged on the outer wall surface of the turbine cover 1 to facilitate replacement and maintenance of the spiral pipe 2 .

[0032] Preferably, Figure 3 and Figure 4 As shown, the spiral pipe 2 includes a first section pipe 201 and a second section pipe 202, the end of the first section pipe 201 is connected to the head end of the second section pipe 202 and is located at the first end 1021 of the turbine cover 1, and the head end of the first section pipe 201 and the end of the second section pipe 202 are both located at the second end 1022 of the turbine cover 1; the flow direction of the fluid in the first section pipe 201 is opposite to the flow direction in the second section pipe 202.

[0033] When the high-temperature fluid for heating enters the rear spiral pipe 2 from the head end of the first pipe section 201, the temperature of the fluid will gradually increase, and when the fluid flows out from the end of the second pipe section 202, the temperature reaches the highest, which makes the temperature of the entire middle portion of the spiral pipe 2 higher than the head end of the first pipe section 201 and lower than the end of the second pipe section 202. By connecting the end of the first pipe section 201 and the head end of the second pipe section 202 and both being arranged at the first end 1021 of the turbine cover 1, the temperature of the fluid heated at the first end 1021 of the turbine cover 1 is relatively moderate, and the fluid heated at the second end 1022 of the turbine cover 1 includes the lower temperature fluid near the head end of the first pipe section 201 and the higher temperature fluid near the end of the second pipe section 202; in this way, the entire turbine cover 1 is heated more evenly.

[0034] The first end 1021 of the turbine cover 1 may be an end away from the turbine, and the other end thereof may be a second end 1022 .

[0035] Preferably, the spiral pipe 2 is in surface contact with the outer wall of the turbine cover 1 .

[0036] The first section of the tube 201 and the second section of the tube 202 are close to the outer wall of the turbine cover 1, which is beneficial to improving the heat exchange efficiency between the spiral tube and the worm wheel cover.

[0037] Preferably, Figure 4 As shown, each circle of tubes formed by the first section of tube 201 surrounding the turbine cover 1 is spaced apart from each circle of tubes formed by the second section of tube 202 surrounding the turbine cover 1 .

[0038] Each circle of tubes formed by the first section of tubes 201 surrounding the turbine cover 1 is spaced apart from each circle of tubes formed by the second section of tubes 202 surrounding the turbine cover 1, so that fluids of different temperatures in the two sections of tubes can alternately heat the turbine cover 1, further improving the uniformity of heating of the turbine cover 1.

[0039] Preferably, Figure 2 As shown, the air cycle machine further includes a compressor volute 3 , and the inlet of the spiral duct 2 is connected to the outlet of the compressor volute 3 via an inlet pipe 601 .

[0040] A portion of the high-temperature gas flowing out of the outlet of the compressor volute 3 enters the spiral pipe 2 through the inlet pipe 601 to heat the turbine. No external heat source is required, and only a portion of the high-temperature gas needs to be introduced from the existing compressor volute 3, which is conducive to simplifying the overall size of the air cycle machine, does not require an additional heat source, and can reduce energy consumption.

[0041] Preferably, Figure 2 As shown, the air cycle machine further includes a turbine volute 4 , and the outlet of the spiral duct 2 is connected to the inner cavity of the turbine volute 4 through an outlet pipe 602 .

[0042] The gas heated by the turbine cover 1 enters the turbine volute 4 to participate in expansion and work, thereby realizing the recovery and reuse of the heated airflow, which is beneficial to reducing energy loss.

[0043] Preferably, Figure 2 and Figure 5 As shown, the turbine cover 1 includes a turbine cover 101 and an air guide section 102 connected to the outlet end of the turbine cover 101, one end of the air guide section 102 connected to the turbine cover 101 is an air inlet end, and the other end is an air outlet end; from the air inlet end to the air outlet end, the wall thickness of the air guide section 102 gradually becomes thinner.

[0044] When there is no device for heating the turbine cover 1, the thickness of ice in the air guide section 102 gradually increases from the air inlet end to the air outlet end. By gradually thinning the wall thickness of the air guide section 102 from the air inlet end to the air outlet end, it is beneficial to improve the heating efficiency near the air outlet end, and further to improve the temperature uniformity of the air guide section 102 in the axial direction.

[0045] Preferably, the spiral duct 2 is interference fit around the air guide section 102 .

[0046] The spiral pipe 2 is interference fit around the air guide section 102. The spiral pipe has a binding effect on the air guide section 102, improving the ability of the air guide section 102 to resist internal pressure. On the one hand, the wall thickness of the air guide section 102 can be made thinner, thereby improving the heat exchange efficiency; on the other hand, the heat exchange efficiency between the spiral pipe 2 and the air guide section 102 is higher.

[0047] Furthermore, the spiral duct 2 is made of copper or aluminum. Copper and aluminum have high thermal conductivity and certain ductility, and can be more tightly wrapped around the air guide section 102 to absorb the vibration of the gas flow in the air guide section 102 and improve the stability of the air cycle machine.

[0048] Preferably, the flow area of ​​the spiral duct 2 gradually increases from the air inlet end to the air outlet end.

[0049] From the air inlet end to the air outlet end, the flow area of ​​the spiral pipe 2 gradually increases; this makes the flow rate of the heating fluid gradually slow down from the air inlet end to the air outlet end, and the fluid can exchange heat with the turbine cover 1 more fully; considering the heat loss of the fluid (the heat that does not heat the turbine cover 1), the larger the flow area, the larger the volume of the fluid in the pipe per unit length, the larger the volume of the fluid, the more heat, and the heat after removing the heat loss is still relatively large, which can fully heat the turbine cover 1. In this way, the temperature uniformity in the axial direction of the air guide section 102 is further improved.

[0050] The air cycle machine also includes a temperature control shell, which surrounds the outer peripheral side of the turbine cover 1, and forms an annular space between the temperature control shell and the turbine cover 1; after the ice in the turbine cover 1 thaws, water flows out from the air guide section 102 along with the air flow into the annular space and flows out from the annular space.

[0051] Preferably, the inner diameter of the spiral duct 2 is d1, the inner diameter of the air guide section 102 is d2, and 0.1≤d1 / d2≤0.2.

[0052] The anti-icing pipe diameter d1 (mm) needs to be controlled within a certain range. If the pipe diameter d1 is too large, although the air intake is large and the anti-icing effect can be guaranteed, the energy loss will also increase; if the pipe diameter is too small, the flow resistance is large, the air intake is small, the heat exchange is insufficient, and the anti-icing effect cannot be achieved. The turbine wheel cover outlet pipe diameter is d2, and the anti-icing effect is good within the range of 0.1≤d1 / d2≤0.2, and the preferred d1 / d2=0.15.

[0053] Under the action of pressure, the high-temperature and high-pressure gas discharged from the compressor outlet 301 can enter the inlet pipe 601 along the anti-icing air intake hole 501 on the compressor volute 3 and the anti-icing air bleed pipe 505. The high-temperature and high-pressure bleed air will pass through the anti-icing air intake port 502 on the temperature control shell along the inlet pipe 601, and then enter the spiral pipe 2 through the inlet pipe 601. The high-temperature airflow will flow in a ring along the spiral pipe 2, transfer heat to the turbine cover 1, and under the guidance of the spiral pipe 2, the heat will be evenly exchanged with the turbine cover 1 to avoid the low-temperature area of ​​the turbine cover 1, resulting in anti-icing failure. The gas that has fully exchanged heat with the turbine cover 1 will flow to the anti-icing air outlet 503 on the temperature control shell through the outlet pipe 602. Finally, the gas is discharged into the turbine volute 4 through the anti-icing air exhaust hole 504, participates in expansion work, realizes the recycling and reuse of the anti-icing airflow, and reduces energy loss.

[0054] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0055] 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. An air cycle machine, comprising a turbine, the turbine comprising a turbine cover (1), characterized in that: The outer wall surface of the turbine cover (1) is surrounded by a spiral pipe (2), and the inner hole of the spiral pipe (2) is used to fill with a fluid for heating the turbine cover (1).

2. The air cycle machine according to claim 1, characterized in that: The spiral pipe (2) comprises a first pipe section (201) and a second pipe section (202); the end of the first pipe section (201) is connected to the beginning of the second pipe section (202) and is located at the first end (1021) of the turbine cover (1); the beginning of the first pipe section (201) and the end of the second pipe section (202) are both located at the second end (1022) of the turbine cover (1); and the flow direction of the fluid in the first pipe section (201) is opposite to the flow direction in the second pipe section (202).

3. The air cycle machine according to claim 1, characterized in that: The spiral pipe (2) is in surface contact with the outer wall of the turbine cover (1).

4. The air cycle machine according to claim 2, characterized in that: Each circle of tubes formed by the first section of tube (201) surrounding the turbine cover (1) is arranged at intervals from each circle of tubes formed by the second section of tube (202) surrounding the turbine cover (1).

5. The air cycle machine according to claim 1, characterized in that: The air cycle machine further comprises a compressor volute (3), and the inlet of the spiral duct (2) is connected to the outlet of the compressor volute (3) via an inlet pipe (601).

6. The air cycle machine according to claim 1, characterized in that: The air cycle machine further comprises a turbine volute (4), and the outlet of the spiral duct (2) is connected to the inner cavity of the turbine volute (4) via an outlet pipe (602).

7. The air cycle machine according to any one of claims 1 to 6, characterized in that: The turbine cover (1) comprises a turbine cover (101) and an air guide section (102) connected to the outlet end of the turbine cover (101); one end of the air guide section (102) connected to the turbine cover (101) is an air inlet end, and the other end is an air outlet end; and the wall thickness of the air guide section (102) gradually becomes thinner from the air inlet end to the air outlet end.

8. The air cycle machine according to claim 7, characterized in that: The spiral duct (2) is interference fit around the air guide section (102).

9. The air cycle machine according to claim 7, characterized in that: From the air inlet end to the air outlet end, the flow area of ​​the spiral duct (2) gradually increases.

10. The air cycle machine according to claim 7, characterized in that: The inner diameter of the spiral duct (2) is d1, the inner diameter of the air guide section (102) is d2, and 0.1≤d1 / d2≤0.2.

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