Fluid mixing device for a pre-cooler of an aircraft

Abstract

A fluid mixing device (100) for a precooler of an aircraft is formed as a double-layered pipe, comprising: an inner layer pipe (1) formed with an inlet (11) and an outlet (13); an outer layer pipe (2) sleeved on the outer circumferential surface of the inner layer pipe to form an annular space with the inner layer pipe; a cladding layer (3) sealingly connecting between the inner layer pipe and the outer layer pipe along the radial direction; and a bypass pipe (4) connected in communication with the peripheral wall of the outer layer pipe and extending towards a direction different from the extending direction of the inner layer pipe, a plurality of through holes (121) being formed in the pipe wall of the inner layer pipe and opening towards the annular space.

Description

Technical Field

[0001] This utility model relates to the field of aircraft engine cooling, and more particularly to a fluid mixing device for an aircraft precooler. Background Technology

[0002] In existing technologies, aircraft environmental control systems are equipped with plate-fin precoolers that precool the engine's high-temperature bleed air before it flows into the downstream air conditioning or anti-icing system. However, the gas exiting the precooler often exhibits temperature stratification. This stratification can lead to uncertainty in the bleed air temperature of the downstream anti-icing system, lacking a controlled reference temperature value and affecting the temperature control of the anti-icing system. Furthermore, the temperature of the gas exiting the precooler is still significantly higher than the withstand temperature of the anti-icing system's structural components and the materials of the wing leading edge, thus reducing the material life of the anti-icing system's piping and the wing, and increasing aircraft operating costs. Utility Model Content

[0003] This invention was made in view of the above-mentioned technical problems, and its purpose is to provide a fluid mixing device for an aircraft precooler, which is used to fully mix the temperature-stratified fluids flowing out of the aircraft precooler, thereby maintaining the temperature of the fluids stable.

[0004] To achieve the above objectives, a first aspect of this utility model provides a fluid mixing device for an aircraft precooler, formed as a double-layered tube, comprising: an inner tube having an inlet and an outlet, the inlet being connected to the outlet of the aircraft precooler; an outer tube sleeved on the outer circumferential surface of the inner tube to form an annular space between them; a sandwich layer sealingly connecting the inner tube and the outer tube radially; and a bypass tube communicating with the peripheral wall of the outer tube and extending in a direction different from the extension direction of the inner tube, wherein the inner tube has a plurality of through holes opening toward the annular space in its wall.

[0005] According to the above structure, since an annular space is formed between the inner and outer tubes, and multiple through holes opening towards the annular space are provided on the wall of the inner tube, the fluid flowing into the annular space from the inner tube through the through holes can form annular mixed flow within the annular space, thus becoming more uniform. In this way, the high-temperature bleed air flowing into the inner tube, which is subject to temperature stratification, is sufficiently cooled, and its temperature stabilizes after cooling, thereby ensuring that the temperature of the bleed air is sufficiently reduced before flowing into the anti-icing system.

[0006] The fluid mixing device for an aircraft precooler according to the second aspect of this utility model is based on the fluid mixing device for an aircraft precooler according to the first aspect of this utility model, wherein the cross-sectional area of ​​the inlet of the inner tube is the same as the cross-sectional area of ​​the outlet, and the cross-sectional area of ​​the inlet of the inner tube is the same as the total cross-sectional area of ​​the plurality of through holes.

[0007] According to the above structure, since the cross-sectional area of ​​the inlet of the inner tube is the same as the cross-sectional area of ​​the outlet, and the cross-sectional area of ​​the inlet of the inner tube is the same as the total cross-sectional area of ​​the multiple through holes, the local loss of the high-temperature induced airflow through the inner tube is close to 0, and the flow resistance along the path is also close to 0. This can avoid the low-pressure alarm of the downstream anti-icing system caused by excessive pressure loss of the induced airflow.

[0008] The fluid mixing device for an aircraft precooler according to the third aspect of this invention is based on the fluid mixing device for an aircraft precooler according to the first or second aspect of this invention, wherein a plurality of through holes in the wall of the inner tube are formed at equal intervals along the axial direction.

[0009] Based on the above structure, since multiple through holes are formed at equal intervals along the axial direction on the inner tube wall, the manufacturing process is simple.

[0010] The fourth aspect of this utility model, a fluid mixing device for an aircraft precooler, is based on the first or second aspect of this utility model, wherein a plurality of the through holes in the wall of the inner tube are formed at non-equidistant intervals along the axial direction.

[0011] According to the above structure, since multiple through holes in the inner tube wall are formed at non-equal intervals along the axial direction, high-temperature air that can correspond to more complex temperature stratification can be mixed in the annular space to form annular mixed flow.

[0012] The fifth aspect of this invention, a fluid mixing device for an aircraft precooler, is based on the third aspect of this invention, wherein the bypass pipe extends in a direction forming an angle of not less than 30° with the outer pipe.

[0013] According to the above structure, since the bypass pipe extends in a direction forming an angle of not less than 30° with the outer pipe, a pressure difference can be formed between it and the inlet of the inner pipe to guide the circumferential mixing of the fluid flowing in from that inlet. This facilitates the formation of annular mixed flow of the fluid flowing into the annular space from the inlet of the inner pipe.

[0014] The sixth aspect of this invention, a fluid mixing device for an aircraft precooler, is based on the fourth aspect of this invention, wherein the bypass pipe extends in a direction forming an angle of not less than 30° with the outer pipe.

[0015] According to the above structure, since the bypass pipe extends in a direction forming an angle of not less than 30° with the outer pipe, a pressure difference can be formed between it and the inlet of the inner pipe to guide the circumferential mixing of the fluid flowing in from that inlet. This facilitates the formation of annular mixed flow of the fluid flowing into the annular space from the inlet of the inner pipe.

[0016] The fluid mixing device for an aircraft precooler according to the seventh aspect of this invention is based on the fluid mixing device of the fifth or sixth aspect of this invention, wherein the included angle between the bypass pipe and the outer pipe is 90°.

[0017] Based on the above structure, since the angle between the bypass pipe and the outer pipe is 90°, it is easy to change the direction of fluid flow and easy to manufacture.

[0018] The fluid mixing device for an aircraft precooler according to the eighth aspect of this invention is based on the fluid mixing device of the seventh aspect of this invention, wherein the inner tube, the outer tube, and the interlayer are all made of alloy materials.

[0019] Based on the above structure, since the inner tube, outer tube, and interlayer are all made of alloy materials, they can withstand high temperatures and corrosion well, thereby extending the overall service life of the device. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the various embodiments of this utility model, the drawings used in the embodiments are briefly described below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1 This is a schematic diagram showing the outline structure of a fluid mixing device for an aircraft precooler according to a first embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram showing the outline structure of a fluid mixing device for an aircraft precooler, a variation of the first embodiment of the present invention.

[0023] (Symbol Explanation)

[0024] 100 Fluid mixing device for aircraft precoolers;

[0025] 1. Inner tube;

[0026] 11. Inner tube inlet;

[0027] 12. Inner tube body;

[0028] 121 Through hole;

[0029] 13. Inner tube outlet;

[0030] 2. Outer tube;

[0031] 3. Interlayer;

[0032] 4. Bypass pipe. Detailed Implementation

[0033] The following is for reference Figures 1 to 2 Various embodiments and variations of the fluid mixing device for an aircraft precooler according to this invention will be described.

[0034] Although the fluid mixing device for the precooler of an aircraft is used for precooling the high-temperature bleed air of the engine in the first embodiment and its variations described below, the present invention is not limited to this and can also be used for rectifying and cooling non-uniform high-temperature gases in other areas of the aircraft.

[0035] In the following embodiments and their variations, in order to facilitate the explanation of the structure of the fluid mixing device for the precooler of an aircraft, the axial direction of the inner tube and the outer tube is defined as the first direction, i.e. the X direction, the extension direction of the bypass tube perpendicular to the axial direction of the inner tube and the outer tube is defined as the second direction, i.e. the Y direction, and the direction perpendicular to both the X and Y directions is defined as the third direction, i.e. the Z direction.

[0036] (First Implementation)

[0037] (Outline structure of the fluid mixing device used in an aircraft precooler)

[0038] like Figure 1 As shown, the inlet of the fluid mixing device 100 for the precooler of the aircraft in this embodiment is into the high-temperature bleed air of the engine (not shown), which flows in through the inlet of the mixing device and is cooled by the mixing device before flowing into the anti-icing system of the wing through the bypass pipe 4.

[0039] The fluid mixing device 100 for an aircraft precooler includes: an inner tube 1, which is generally cylindrical, with an inlet 11 for receiving high-temperature bleed air from the engine and an outlet 13 for receiving cooled gas to an air conditioning system, a wastewater system, etc., and five through holes 121 are formed at equal intervals along the X direction on the body 12 of the inner tube 1; an outer tube 2, which is nested on the outer circumferential surface of the inner tube 1 and has an axial length less than that of the inner tube 1; a sandwich 3, which extends radially inward from both ends of the outer tube 2 in the X direction to the outer circumferential surface of the inner tube 1; and a bypass tube 4, which opens from the peripheral wall of the outer tube 2 and extends in the Y2 direction, which is perpendicular to the axial direction (i.e., the X direction) of the inner tube 1.

[0040] In the fluid mixing device 100 for an aircraft precooler configured as described above, a sealed annular space is formed by the outer tube 2, the jacket 3, and the inner tube 1. High-temperature induced gas in the inner tube 1 flows into the annular space through a through hole 121 formed in the tube wall.

[0041] Because high-temperature induced draft gas exhibits temperature stratification, for example, assuming... Figure 1 The temperature of the induced gas flowing into the through-hole 121 (shaded on the Z1 side) is T1, and the temperature of the induced gas flowing into the through-hole 121 (blackened on the Z2 side) is T2, and T1 > T2. According to the ideal gas law, P = ρ * Rg * T (where Rg is a constant, T is the temperature of the ideal gas, and ρ is the density of the ideal gas), as the temperature T increases, the density decreases. In the annular space, the density ρ1 caused by the induced gas flowing into the through-hole 121 on the Z1 side is less than the density ρ2 of the induced gas flowing into the through-hole 121 on the Z2 side, i.e., ρ1 < ρ2. Therefore, under the action of this density difference, the high-temperature induced gas flows from the low-density through-hole 121 to the high-density through-hole 121, thereby forming an annular mixed flow in the circumferential direction of the inner tube 1.

[0042] In this way, the high-temperature bleed air flowing in with stratified temperature is thoroughly mixed and cooled, thereby stabilizing its temperature and facilitating temperature control by the downstream anti-icing system. Furthermore, because the bleed air flowing into the downstream anti-icing system from bypass pipe 4 is sufficiently cooled, the service life of materials is extended, improving the aircraft's operational economy.

[0043] Furthermore, in fluid mechanics, when a fluid flows through two cross-sections of the same horizontal plane, it satisfies the following Bernoulli equation:

[0044] Z1+P1 / ρg+V1 2 / 2g=Z2+P2 / ρg+V2 2 / 2g+h j ,

[0045] Where "Z1" and "Z2" represent the gravitational potential energy per unit volume of fluid, "P1" and "P2" represent the fluid pressure, "ρ" represents the fluid density, "V1" and "V2" represent the fluid velocity, "P1 / ρg" and "P2 / ρg" represent the static pressure energy per unit volume of fluid, and "V1 2 / 2g”, V2 2 " / 2g" represents the kinetic energy per unit volume of fluid, "h" j "" indicates the local loss in the friction resistance of a unit volume of fluid.

[0046] Furthermore, the high-temperature induced gas in the inner tube 1 also satisfies the momentum equation:

[0047] (Z1+P1 / ρg)-(Z2+P2 / ρg)=V2(V2-V1) / g.

[0048] Substituting this momentum equation into the Bernoulli equation above yields the following equation:

[0049] h j = (V2 - V1) 2 / 2g.

[0050] According to the law of conservation of fluid flow, V1·A1=V2·A2 (where A1 and A2 represent the cross-sectional area of ​​the flow path), from which we can conclude:

[0051] h j =(1-A1 / A2) 2 / 2g.

[0052] Therefore, the greater the change in cross-sectional area through which the fluid flows, the greater h j The larger the value, the greater the local loss, and therefore the greater the flow resistance along the flow path, including the local loss.

[0053] In this embodiment, the cross-sectional area A1 at the inlet 11 of the inner tube 1 is the same as the cross-sectional area A2 at the outlet 13, and this cross-sectional area A1 is the same as the total cross-sectional area of ​​all through holes 121 formed on the body 12 of the inner tube 1, that is, A1 / A2 is close to 1. Therefore, the local loss h j With a pressure close to zero, the flow resistance along the path is also very small, meaning that the pressure loss (or energy loss) of the airflow through the inner tube 1 is minimal. This avoids the risk of low-pressure alarms caused by excessively low air pressure in downstream anti-icing systems, etc.

[0054] It should be noted that the above-mentioned "same" is not limited to the case where the cross-sectional area at the inlet of the inner tube 1 is exactly the same as the cross-sectional area at the outlet, but also includes the case where the cross-sectional area at the inlet of the inner tube 1 is basically the same as the cross-sectional area at the outlet.

[0055] Furthermore, to allow the inflow of high-temperature bleed air from the engine (typically around 650°C), the inner tube 1, outer tube 2, and interlayer 3 in this embodiment are all made of 321 stainless steel. As is well known, 321 stainless steel can be used for extended periods at 870°C, exhibits excellent corrosion resistance to oxidizing acids, and is suitable for welded components and high-temperature pipes. Moreover, due to the addition of chromium, it effectively reduces the oxidation rate and provides excellent oxidation resistance.

[0056] (Technical effects of the fluid mixing device for an aircraft precooler according to this embodiment)

[0057] According to the fluid mixing device 100 for an aircraft precooler of this embodiment, the high-temperature bleed air flowing into the annular space from the inner tube 1 can be fully mixed and form an annular mixed flow, thereby enabling the high-temperature bleed air to be fully cooled and the temperature after cooling to become stable, so as to facilitate temperature control of the downstream anti-icing system.

[0058] Furthermore, since the inlet and outlet cross-sectional areas of the inner tube 1 are the same, the flow resistance along the pipe can be made zero. This prevents the downstream anti-icing system from triggering a low-pressure alarm due to a significant decrease in the bleed air pressure.

[0059] (A fluid mixing device for an aircraft precooler, a variation of this embodiment)

[0060] like Figure 1 As shown, in the fluid mixing apparatus 100 for an aircraft precooler according to the first embodiment, through holes 121 formed in the wall of the inner tube 1 are formed at equal intervals in the X direction. In the fluid mixing apparatus 100A for an aircraft precooler of this modified example, except that the formation of the through holes 121A is different from that of the first embodiment, all other components are the same as those in the first embodiment. Hereinafter, detailed descriptions of the components that are the same as those in the first embodiment are omitted.

[0061] In this modified example, the fluid mixing device 100A for the aircraft precooler is the same as in the first embodiment described above, mainly consisting of an outer tube 2 fitted onto an inner tube 1 via a jacket 3. Four through holes 121A are formed in the wall of the inner tube 1, and these through holes 121A are arranged non-equidistantly in the X direction according to the temperature stratification of the incoming high-temperature bleed air. Since temperature differences can cause velocity differences in the high-temperature bleed air, the high-temperature bleed air flowing into the annular space through the through holes 121A can be mixed more appropriately, resulting in more uniform cooling of the high-temperature bleed air and a more stable temperature after cooling. This allows the temperature of the high-temperature bleed air to be sufficiently reduced before entering the anti-icing system.

[0062] (Technical effect of the fluid mixing device for an aircraft precooler in this variation)

[0063] According to the fluid mixing device for an aircraft precooler in this modified example, the high-temperature bleed air from the engine has different temperatures, resulting in different flow velocities. These different flow velocities lead to different flow rates as the air flows into the annular space through the through-holes, resulting in different air pressures and thus different pressure differentials. Therefore, the axial spacing of the through-holes formed in the inner tube wall is flexibly configured according to the temperature stratification, so that the high-temperature bleed air is mixed more thoroughly and uniformly in the annular space, its temperature is more stable, and its temperature drops more sufficiently before flowing into the downstream anti-icing system.

[0064] In order to make the objectives, technical solutions and advantages of the various embodiments and their modifications of this utility model clearer, in conjunction with... Figures 1 to 2 The technical solutions of various embodiments and their modifications of this utility model have been clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0065] In the above embodiments and their variations, the number of through holes formed in the inner tube wall is 5 or 4, but the present invention is not limited to this. As long as the total cross-sectional area of ​​the through holes in the inner tube wall is the same as the cross-sectional area at the entrance of the inner tube, it can be appropriately adjusted to other numbers.

[0066] In the above embodiments and their variations, the axial length of the outer tube is less than the axial length of the inner tube. However, this invention is not limited to this, and the axial length of the outer tube can also be equal to the axial length of the inner tube.

[0067] In the above embodiments and their variations, only one bypass pipe extends from the outer tube, but the present invention is not limited to this, and multiple bypass pipes can be extended as needed.

[0068] In the above embodiments and their variations, the bypass pipe extends in a direction perpendicular to the outer pipe, but the present invention is not limited to this and may also extend in a direction at other angles to the outer pipe.

[0069] In the above embodiments and their variations, the inner tube, outer tube and bypass tube are made of the same material, but the present invention is not limited to this. The inner tube, outer tube and bypass tube can also be made of different kinds of materials as long as they can withstand the high temperature of the engine's bleed air.

[0070] In the above embodiments and their variations, the inner tube, outer tube and bypass tube are all made of 321 stainless steel, but the present invention is not limited to this and may also be made of other alloy materials.

Claims

1. A fluid mixing device for an aircraft precooler, formed as a double-layered sleeve, characterized in that, include: An inner tube having an inlet and an outlet; An outer tube is fitted onto the outer circumferential surface of the inner tube to form an annular space between them. A sandwich layer that provides a radially sealed connection between the inner tube and the outer tube; as well as A bypass pipe is connected to the peripheral wall of the outer pipe and extends in a direction different from the extending direction of the inner pipe. The inner tube has multiple through holes on its wall that open toward the annular space.

2. The fluid mixing device for an aircraft precooler as described in claim 1, characterized in that, The inlet cross-sectional area of ​​the inner tube is the same as the outlet cross-sectional area. The cross-sectional area of ​​the inlet of the inner tube is the same as the total cross-sectional area of ​​the plurality of through holes.

3. The fluid mixing device for an aircraft precooler as described in claim 1 or 2, characterized in that, The inner tube has a plurality of through holes formed at equal intervals along the axial direction in its tube wall.

4. The fluid mixing device for an aircraft precooler as described in claim 1 or 2, characterized in that, The inner tube has a plurality of through holes formed along the axial direction at non-equidistant intervals in its tube wall.

5. The fluid mixing device for an aircraft precooler as described in claim 3, characterized in that, The bypass pipe extends in a direction that forms an angle of not less than 30° with the outer pipe.

6. The fluid mixing device for an aircraft precooler as described in claim 4, characterized in that, The bypass pipe extends in a direction that forms an angle of not less than 30° with the outer pipe.

7. The fluid mixing device for an aircraft precooler as described in claim 5 or 6, characterized in that, The angle between the bypass pipe and the outer pipe is 90°.

8. The fluid mixing device for an aircraft precooler as described in claim 7, characterized in that, The inner tube, the outer tube, and the interlayer are all made of alloy materials.

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