Method for improving heat sink of aircraft

Abstract

The invention discloses a method for improving heat sink of an aircraft, which comprises the following steps of: arranging a cooling flow channel and an oil inlet pipe on an upper skin of a wing, inputting hot return oil to be cooled into the cooling flow channel through the oil inlet pipe, cooling the hot return oil by utilizing the heat sink of the upper skin, and arranging an oil conveying pipe at an outlet of the cooling flow channel and at a position close to a lower skin in a wing oil tank, the cooled hot return oil is mixed with original low-temperature fuel oil in the wing oil tank, and the mixed oil is conveyed to the oil collecting tank together and enters each heat dissipation system as a heat sink again to form circulation; high-temperature fuel oil is in large-area full contact with the wing upper skin through a cooling flow channel for heat exchange, high-temperature hot return oil is cooled through a low-temperature air heat sink outside the upper skin so as to improve the heat sink of the high-temperature hot return oil, the cooled return oil and low-temperature fuel oil in a wing oil tank are mixed and enter an oil collecting tank, the fuel oil is cooled again through an air heat sink of the wing lower skin, and the fuel oil is cooled again. The aircraft does not need to introduce ram air to cool the hot return oil, so that the fuel oil cooling efficiency and the aircraft stealth performance are improved, and the flight resistance is reduced.

Description

Technical Field

[0001] The present invention relates to a method for improving heat sink of an aircraft, and in particular to the field of aircraft thermal management and fuel cooling. Background Art

[0002] With the increase in onboard electronic equipment and the improvement in overall performance, the heat load and fuel capacity within aircraft have also increased significantly. To ensure effective cooling of onboard equipment, fuel is drawn from the aircraft's fuel tanks to serve as a heat sink for various cooling systems. This heat is absorbed and heated to become high-temperature fuel. A portion of this high-temperature fuel is cooled and returned to the tanks (called hot return fuel), while the remainder enters the engines for combustion.

[0003] As aircraft performance improves, the heat dissipation pressure on fuel increases. Excessively high fuel temperatures significantly reduce cooling efficiency and engine life, necessitating the use of heat sinks to cool the high-temperature return fuel and improve its heat absorption capacity. Currently, research on aircraft fuel thermal management systems mostly involves the introduction of ram air to cool the return fuel. However, under certain flight conditions, this can lead to insufficient fuel cooling efficiency, increased flight drag, and negative impacts on stealth performance. Therefore, finding new cooling media that can utilize the aircraft itself as a heat sink has become an important area of ​​thermal management research.

[0004] From the perspective of the aircraft's structure, the wing skin is in direct contact with the external environment, making it susceptible to heat exchange. When an aircraft flies for extended periods at high altitude (≥10,000m) and subsonic speed (typically ≤0.8Ma), the external ambient temperature is relatively low, and the wing skin is less susceptible to flight aerodynamic heat. Consequently, the wing skin and the internal environment (fuel and air) of the wing fuel tanks, to which it is in direct contact, also remain relatively low, typically stabilizing below 0°C. This makes it a high-potential heat sink built into the aircraft, useful for cooling hot return fuel.

[0005] However, the wing tanks are usually in a half-fuel state, and the fuel is concentrated in the lower part of the wing tank due to gravity, making it difficult to effectively utilize the upper skin heat sink. Summary of the Invention

[0006] The present invention provides a method for improving heat sink of an aircraft to overcome the defect in the prior art of insufficient cooling medium for the aircraft in a high-altitude, subsonic cruise state.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] The present invention discloses a method for improving heat sink of an aircraft, comprising the following steps:

[0009] S1: Cooling channels and oil inlet pipes are set on the wing skin;

[0010] S2: The hot return oil to be cooled, which has been heated after passing through the aircraft's cooling systems and serves as a heat sink, is introduced into the cooling channel through the oil inlet pipe. The hot return oil is then cooled using the air heat sink outside the wing upper skin.

[0011] S3: Connect the oil pipe between the outlet of the cooling channel and the outlet of the wing oil tank close to the lower wing skin;

[0012] S4: The cooled hot return oil is mixed with the fuel in the wing tanks and transported to the fuel collecting tank on the fuselage through the oil pipeline to reduce the temperature of the fuel entering the tank and improve the heat sink of the fuel;

[0013] S5: The fuel in the oil collecting tank enters each cooling system again as a heat sink, forming a cycle.

[0014] Furthermore, the cooling channel is located inside the wing upper skin.

[0015] Furthermore, the cooling channel has an upper surface and a lower surface, the upper surface is the inner surface of the wing upper skin; the lower surface is parallel to the upper surface and forms an interlayer channel.

[0016] Furthermore, the cooling channel is provided with an inlet and an outlet, the inlet is connected to the oil inlet pipe, and the outlet is connected to the oil delivery pipe.

[0017] Furthermore, the wing oil tank is provided with an outlet located inside the wing oil tank near the oil collecting tank and the lower wing skin.

[0018] Furthermore, the oil pipeline has two inlets and one outlet, and the two inlets of the oil pipeline are respectively connected to the outlet of the cooling channel and the outlet of the wing oil tank; the outlet of the oil pipeline is connected to the oil collecting tank.

[0019] The beneficial effects achieved by the present invention are as follows: high-temperature fuel fully contacts and exchanges heat with the upper wing skin over a large area through the cooling flow channel, effectively utilizing the low-temperature air heat sink outside the upper skin to cool the high-temperature hot return oil, thereby improving its heat sink; the cooled return oil is mixed with the low-temperature fuel in the wing tank and enters the oil collecting tank, thereby utilizing the air heat sink of the lower wing skin to cool the fuel again; the aircraft no longer needs to introduce ram air to cool the hot return oil, thereby improving the fuel cooling efficiency and the aircraft's stealth performance and reducing flight resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1Schematic diagram of the wing cross-sectional structure and external airflow of the present invention;

[0022] Figure 2 Schematic diagram of the fuel tank structure and fuel flow path of the present invention;

[0023] Figure 3 Schematic diagram of the operating principle of the present invention.

[0024] In the figure: 1. Upper wing skin; 2. Cooling channel; 3. Oil inlet pipe; 4. Wing oil tank; 5. Oil delivery pipe; 6. Oil collecting tank; 7. Lower wing skin. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0026] Example 1

[0027] like Figure 1-3 As shown, a method for improving heat sink of an aircraft includes the following steps:

[0028] S1: Cooling channel 2 and oil inlet pipe 3 are provided on the wing upper skin 1;

[0029] S2: The hot return oil to be cooled, which has been heated after absorbing heat and passing through the aircraft's cooling systems, is fed into the cooling channel 2 through the oil inlet pipe 3 and cooled by the air heat sink outside the wing upper skin 1;

[0030] S3: Connect the oil pipe 5 between the outlet of the cooling channel 2 and the outlet of the wing oil tank 4 near the wing lower skin 7;

[0031] S4: The cooled hot return oil is mixed with the fuel in the wing fuel tank 4 and transported to the fuel collecting tank 6 on the fuselage through the fuel pipe 5 to reduce the temperature of the fuel entering the fuel collecting tank and improve the heat sink of the fuel;

[0032] S5: The fuel in the oil collecting tank 6 enters each heat dissipation system again as a heat sink, forming a cycle.

[0033] The cooling channel 2 is located inside the wing upper skin 1 .

[0034] The cooling channel 2 has an upper surface and a lower surface, wherein the upper surface is the inner surface of the wing upper skin 1; and the lower surface is parallel to the upper surface and forms an interlayer channel.

[0035] The cooling channel 2 is provided with an inlet and an outlet. The inlet is connected to the oil inlet pipe 3 ; the outlet is connected to the oil delivery pipe 5 .

[0036] The wing oil tank 4 has an outlet located inside the wing oil tank 4 near the oil collecting tank 6 and the wing lower skin 7 .

[0037] The oil pipeline 5 has two inlets and one outlet. The two inlets of the oil pipeline 5 are respectively connected to the outlet of the cooling channel 2 and the outlet of the wing oil tank 4 ; the outlet of the oil pipeline 5 is connected to the oil collecting tank 6 .

[0038] Working principle:

[0039] When an aircraft flies for a long time at high altitude (≥10,000m) and subsonic speed (≤0.8Ma) cruising conditions, the external ambient temperature of the aircraft is relatively low, and the flight aerodynamic heat borne by the wing upper skin 1 and the wing lower skin 7 is relatively low. Therefore, the temperature of the internal environment (fuel and air) of the wing tank 4 with which they are in direct contact is also relatively low, usually stable at below 0°C, and is a heat sink with great potential that comes with the aircraft.

[0040] Since the fuel in the wing tank 4 is usually concentrated in the lower part due to gravity, and the fuel is at a low temperature due to direct contact and heat exchange with the lower wing skin 7, the air heat sink of the lower wing skin 7 has been utilized. The present invention arranges the cooling flow channel 2 inside the wing upper skin 1 and determines a suitable upper and lower surface distance so that the hot return oil fills the cooling flow channel 2 and performs forced convection heat exchange with the inner surface of the wing upper skin 1, thereby reducing the fuel temperature.

[0041] The high-temperature hot return oil enters the wing cooling channel 2 through the oil inlet pipe 3, and is then cooled by the wing upper skin 1. It is then mixed with the low-temperature fuel in the oil pipeline 5 and the wing oil tank 4, and enters the oil collecting tank 6 to be cooled again, completing two cooling operations in total, thereby further improving the heat sink of the aircraft.

[0042] It should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will appreciate that they may modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, improvements, and the like that fall within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention. The terms used in the description of this application are intended only to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to scale. Technologies, methods, and devices known to persons skilled in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely illustrative and not limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0043] It should be noted that the terms "first," "second," etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0044] It should be noted that, in the description of this application, the directions or positional relationships indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional terms do not indicate or imply that the device or element 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 this application; the directional terms "inside and outside" refer to the inside and outside relative to the outline of each component itself.

Claims

1. A method for improving heat sink of an aircraft, characterized in that: The steps include: S1: Cooling channels and oil inlet pipes are set on the wing skin; S2: The hot return oil to be cooled, which has been heated after passing through the aircraft's cooling systems and serves as a heat sink, is introduced into the cooling channel through the oil inlet pipe. The hot return oil is then cooled using the air heat sink outside the wing upper skin. S3: Connect the oil pipe between the outlet of the cooling channel and the outlet of the wing oil tank close to the lower wing skin; S4: The cooled hot return oil is mixed with the fuel in the wing tanks and transported to the fuel collecting tank on the fuselage through the oil pipeline to reduce the temperature of the fuel entering the tank and improve the heat sink of the fuel; S5: The fuel in the oil collecting tank enters each cooling system again as a heat sink, forming a cycle.

2. The method for improving heat sink of an aircraft according to claim 1, characterized in that: The cooling channel is located inside the wing upper skin.

3. The method for improving heat sink of an aircraft according to claim 1, characterized in that: The cooling channel has an upper surface and a lower surface, wherein the upper surface is the inner surface of the wing upper skin; the lower surface is parallel to the upper surface and forms an interlayer channel.

4. The method for improving heat sink of an aircraft according to claim 1, characterized in that: The cooling channel is provided with an inlet and an outlet, wherein the inlet is connected to the oil inlet pipe, and the outlet is connected to the oil delivery pipe.

5. The method for improving heat sink of an aircraft according to claim 4, characterized in that: The wing oil tank is provided with an outlet located inside the wing oil tank near the oil collecting tank and the lower wing skin.

6. The method for improving heat sink of an aircraft according to claim 5, characterized in that: The oil pipeline has two inlets and one outlet. The two inlets of the oil pipeline are respectively connected to the outlet of the cooling channel and the outlet of the wing oil tank; the outlet of the oil pipeline is connected to the oil collecting tank.

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