Active flow control stamping heat dissipation system

Abstract

The invention belongs to the technical field of aircraft heat management, and particularly relates to an active flow control stamping heat dissipation system which comprises an S-shaped air inlet flow channel, a heat exchanger, a heat exchanger outlet injection nozzle, a heat exchanger outlet flow channel and a heat exchanger outlet flow channel grating. An inlet of the S-bent air inlet channel protrudes out of the surface of an airplane, and is responsible for introducing ram air flow into the heat exchanger from an outlet after passing through the S-bent air inlet channel and cooling fluid on the hot side of the heat exchanger as a cold source on the cold side of the heat exchanger. According to heat exchanger outlet flow data obtained through flow calculation, a set of injection spray pipes are arranged on the side, with the low flow speed, of the outlet, and high-pressure gas led out of an engine or an auxiliary power device gas compressor is sprayed out of a nozzle after being conveyed through a connecting pipeline and mixed with cold edge air at the outlet of the heat exchanger; the air is discharged out of the machine through the grid at the outlet of the exhaust runner; due to the injection effect of the high-pressure airflow, the high-pressure airflow sprayed out of the injection spray pipe can accelerate cold-side air at an outlet of the heat exchanger, so that the cold-side flow of the heat exchanger is increased, and the overall heat dissipation performance of the heat exchanger is improved. The invention can effectively solve the problems of non-uniform inlet pressure and insufficient flow of the heat exchanger in the existing stamping heat dissipation system.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft thermal management, and in particular relates to an active flow control ram heat dissipation system. Background Art

[0002] The ram cooling system is responsible for dissipating heat from the aircraft. It introduces ambient air from the ram air bleed ports on the aircraft surface or inside the air inlet. The onboard heat exchanger uses convection heat transfer to dissipate the heat collected by the aircraft thermal management system from other onboard systems into the air, thereby achieving heat sink regeneration and providing continuous thermal management capabilities for the aircraft.

[0003] In order to obtain good air intake efficiency under various flight attitudes, the traditional ram cooling system needs to arrange the air intake and exhaust flow channels between the ram air intake and the heat exchanger inlet. The ram cooling system is generally composed of an air intake grille, an air intake flow channel, a heat exchanger, an exhaust flow channel and an exhaust grille. In actual work, in order to reduce the volume of the system, the S-shaped air intake flow channel between the ram air intake and the heat exchanger adopts a large curvature design. On the one hand, it increases the flow resistance, and at the same flight altitude and speed, the heat exchanger inlet flow rate is reduced. On the other hand, the large curvature of the flow channel interface will cause the flow velocity and pressure of the final heat exchanger inlet section to be uneven. The existing heat exchangers are designed based on a uniform inlet pressure field. In areas where the inlet pressure is too high, the air flow in the heat exchanger is too large, and the air heat sink is wasted. In areas where the inlet pressure is too low, the air flow in the heat exchanger is insufficient, and the heat dissipation capacity of the heat exchanger is insufficient. In summary, due to the lack of active flow control means in the existing ram cooling system, the ram air inside the system lacks active pressurization and flow control means, resulting in a decrease in the heat dissipation efficiency of the cooling system, making it difficult to effectively reduce the volume and weight of the system.

[0004] In order to solve the problem of low heat dissipation efficiency caused by large flow resistance and uneven flow in the ram cooling system, some foreign aircraft have electric fan assemblies in the ram cooling system, which pressurize the air flow in the system through the fan to increase the air flow of the system. However, this method has three problems. First, the electric fan is large in size and weight. Second, it requires the aircraft to provide electricity. Third, it has high reliability requirements for the electric system. Once the motor fails, the flow resistance caused by the fan will cause the performance of the cooling system to drop sharply. Summary of the invention

[0005] Purpose of the present invention: The present invention aims to solve the problems of insufficient cold edge flow and uneven flow distribution inside the system heat exchanger caused by the large curvature flow channel of the current stamping heat dissipation system, such as large intake pressure loss and uneven outlet pressure, and invents an active flow control stamping heat dissipation system. The system adds a high-pressure injection air source to the exhaust flow channel of the existing stamping heat dissipation system, arranges an injection nozzle on the low-pressure side according to the outlet flow field of the S-bend inlet duct, and uses the high-pressure airflow ejected from the nozzle to inject and suck the airflow on the low-pressure side, thereby increasing the pressure and flow on the low-pressure side, and solving the problems of uneven inlet pressure and insufficient flow at the heat exchanger in the existing stamping heat dissipation system.

[0006] Technical solution of the present invention: In order to achieve the above-mentioned invention object, the present invention designs an active flow control ram heat dissipation system, which mainly comprises an S-bend inlet airflow channel, a heat exchanger, an ejector nozzle at the outlet of the heat exchanger, a heat exchanger outlet airflow channel, and a grille at the outlet of the heat exchanger; wherein the inlet of the S-bend inlet airflow channel protrudes from the aircraft surface, and is responsible for introducing the ram air flow through the S-bend airflow channel and then entering the heat exchanger from the outlet, and serving as a cold source of the cold side of the heat exchanger to cool the fluid at the hot side of the heat exchanger; according to the heat exchanger outlet flow data obtained by flow calculation, a group of ejector nozzles are arranged on the side with lower outlet flow rate, and the high-pressure gas drawn from the engine or the auxiliary power unit compressor is transmitted through the connecting pipeline and ejected from the nozzle, and after mixing with the cold side air at the outlet of the heat exchanger, it is discharged outside the aircraft through the grille at the outlet of the exhaust airflow channel; due to the ejection effect of the high-pressure airflow, the high-pressure airflow ejected from the ejector nozzle will increase the speed of the cold side air at the outlet of the heat exchanger, thereby increasing the cold side flow of the heat exchanger and improving the overall heat dissipation performance of the heat exchanger.

[0007] Furthermore, a low pressure zone is generated at the inlet of the heat exchanger at the rear end of the inlet flow channel, and the ejector nozzle is arranged at the end of the hot side flow channel of the heat exchanger in the low pressure zone.

[0008] Furthermore, the inlet of the S-bend inlet airflow duct protrudes from the aircraft surface along the heading of the aircraft to capture the ram air in the flight direction, and the outlet is connected to the inlet of the heat exchanger to introduce the ram air into the heat exchanger as its heat exchange cold source.

[0009] Furthermore, the inlet of the S-bend inlet airflow passage adopts a V-shaped opening structure to accommodate as much external ram air as possible.

[0010] Furthermore, the S-bend inlet airflow passage is integrally formed by two curved sections with relatively large curvatures.

[0011] Furthermore, the S-bend inlet airflow passage is composed of two pipes with a curvature of not less than 60°.

[0012] Furthermore, the ejection nozzle is arranged at a side of a cold side flow channel outlet of the heat exchanger where the pressure is relatively low, and the ejected high-pressure gas thereof pressurizes the cold side ram air intake at the heat exchanger outlet.

[0013] Furthermore, the fluid at the hot side of the heat exchanger is a fluid medium from an aircraft thermal management system that needs to dissipate heat, including but not limited to a liquid medium or a gas medium.

[0014] Furthermore, the exhaust flow channel is arranged between the heat exchanger outlet and the grille, and the high-pressure and high-speed airflow ejected from the injector nozzle at the heat exchanger outlet is fully mixed inside the exhaust flow channel with the low-speed airflow at the heat exchanger outlet.

[0015] Furthermore, the exhaust grille is installed on the machine surface to prevent foreign matter from entering the exhaust flow channel and causing blockage.

[0016] Beneficial effects of the present invention: The present invention proposes an active flow control ram heat dissipation system, which adds a high-pressure ejection air source to the exhaust flow channel of the existing ram heat dissipation system, arranges an ejection nozzle on the low-pressure side according to the S-bend inlet outlet flow field, and uses the high-pressure airflow ejected from the nozzle to eject and suck the low-pressure side airflow, thereby increasing the pressure and flow on the low-pressure side and solving the problems of uneven inlet pressure and insufficient flow at the heat exchanger inlet of the existing ram heat dissipation system. After being equipped with an ejection nozzle, the uneven inlet pressure problem of the heat exchanger of the ram heat dissipation system will be improved, and the air flow on the cold side of the system will be increased, thereby improving the heat dissipation capacity of the system during the flight of the aircraft. At the same time, the system can also be used without a ram air source, providing the aircraft with a heat dissipation function in ground maintenance scenarios.

[0017] Compared with the fan boosting scheme currently used abroad, the high-pressure ejection boosting scheme has no rotating parts, small additional resistance, and does not require the use of power. It has low weight cost and good reliability, and is more in line with the current domestic mainstream aircraft energy system and the current capabilities of the electromechanical industry.

[0018] The present invention has at least the following outstanding design features:

[0019] 1) An S-curved inlet airflow passage with two large curvature sections is adopted. The large curvature section can also effectively shorten the length of the inlet passage and reduce the space occupied by the fuselage;

[0020] 2) The high-pressure injection nozzle is integrated into the outlet side of the heat exchanger, which takes up little space and has little additional resistance;

[0021] 3) After the ram air passes through the S-bend inlet flow channel, it enters the heat exchanger. Due to the influence of the curved shape of the flow channel, a low-pressure area will be formed on one side of the heat exchanger. The high-pressure airflow ejected from the ejector nozzle pressurizes and speeds up the ram air at the heat exchanger outlet through the ejector principle, alleviating the problem of low air velocity on one side of the heat exchanger caused by the low-pressure area at the entrance of the S-bend inlet duct;

[0022] 4) The heat exchanger outlet is connected to the exhaust flow channel with a straight section, and the high-speed jet flow can fully mix and increase the cold edge flow of the low-speed heat exchanger, thereby improving the jet effect;

[0023] 5) In scenarios where there is no ram flow, such as ground maintenance, the system can still generate a certain amount of air flow on the cold side of the heat exchanger through the ejection effect, providing the aircraft with heat dissipation capabilities in ground maintenance scenarios;

[0024] 6) The system uses compressed air as the energy source for injection and boosting, which can be directly extracted from the engine or auxiliary power unit without using the aircraft's secondary energy source;

[0025] 7) The system does not contain rotating parts such as motors and fans, has high reliability, small additional resistance, and low technical difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of an active flow control stamping heat dissipation system;

[0027] Figure 2 A schematic diagram of active ejection of a ram heat dissipation system;

[0028] Among them, the ram air inlet 1, the first S-bend air inlet channel 2, the second S-bend air inlet channel 3, the low pressure area 4, DETAILED DESCRIPTION

[0029] 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, not all of the embodiments. 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.

[0030] Figure 1 The present invention is a schematic diagram of an active flow control ram heat dissipation system. A ram air inlet 1 protrudes from an aircraft surface 11. During flight, ram air 7 enters the system from the ram air inlet 1, passes through a first S-bend inlet air channel 2 and a second S-bend inlet air channel 3, two pipes with a curvature of not less than 60°, and then enters an air heat exchanger 5. After absorbing the heat of the engine's high-temperature and high-pressure bleed air 10 as a cold source, the ram air is discharged from the heat exchanger outlet to the exhaust flow channel 12, and then is discharged into the air through an exhaust grille 13 arranged on the aircraft surface, thereby achieving the purpose of cooling the engine bleed air.

[0031] After the ram air 7 passes through the two large curvature pipes of the first S-bend inlet airflow channel 2 and the second S-bend inlet airflow channel 3, the flow will separate due to the changes in the curvature and cross-section of the flow channels, and a low-pressure area 4 will be generated at the inlet of the heat exchanger at the rear end of the inlet airflow channel. The pressure and flow rate in this area are significantly lower than those in other areas, resulting in uneven flow in the heat exchanger 5, affecting the heat dissipation effect.

[0032] During flight, in order to solve the problem of reduced flow velocity in the low-pressure area 4, an ejector nozzle 6 is arranged at the outlet of the heat exchanger, and a portion of the engine high-pressure bleed air 10 with a temperature of not less than 200°C and a pressure of not less than 0.4Mpa is ejected from the nozzle 6. By actively ejecting the flow, the flow velocity in this area is increased, the low-pressure area 4 is eliminated, and the pressure at the heat exchanger inlet is made more balanced. At the same time, the flow rate of the ram air 7 entering the entire system is increased, thereby achieving the effect of improving the heat dissipation capacity of the system.

[0033] At the same time, in the ground maintenance environment, an ejector nozzle 6 is arranged at the outlet of the heat exchanger, and a portion of the engine's high-pressure air 10 is ejected from the nozzle 6 to form a high-speed airflow. This high-speed airflow will generate air flow in the exhaust flow channel 12 through the ejector boost principle, thereby driving the surface air to enter the system from the ram air inlet 1, and then enter the heat exchanger 5, providing a certain heat dissipation capacity for the heat exchanger.

[0034] Figure 2 It is the active ejection control realization principle of the air heat exchanger 5. After the high-temperature and high-pressure bleed air 10 of the engine enters the heat exchanger, it is distributed into multiple high-temperature and high-pressure airflows 21 and enters the hot side flow channel of the heat exchanger. The heat dissipation fins 27 are connected between the hot side flow channels to increase the heat exchange area of ​​the heat exchanger. 23 is the opening distributed at the end of the hot side flow channel of the heat exchanger. The high-temperature and high-pressure airflow 21 is discharged into the cold side flow channel through the opening. The ejection principle is used to increase the flow rate of the ram air 26 in the cold side flow channel, so as to achieve the purpose of ejection pressurization of the ram air on one side of the heat exchanger. When there is no ram air available for the aircraft during the ground maintenance stage, there is a high-temperature and high-pressure airflow 21 in the main heat exchanger. The ejection principle can be used to generate the flow rate of the ram air 26 in the cold side flow channel to produce a heat dissipation effect.

[0035] The main design features of the present invention are:

[0036] 1) The system mainly consists of an S-bend inlet flow channel, a heat exchanger, an ejector nozzle, an exhaust flow channel and an exhaust grille;

[0037] 2) The ram air of the machine surface enters the system from the S-bend inlet flow channel and protrudes from the inlet of the machine surface. After passing through the S-bend flow channel, it enters the heat exchanger. After absorbing the heat of the hot side of the heat exchanger as a cold source, it is discharged outside the machine through the exhaust flow channel and the grille.

[0038] 3) The inlet of the S-bend inlet airflow channel protrudes from the surface of the aircraft to capture the ram air in the flight direction, and the outlet is connected to the inlet of the heat exchanger to introduce the ram air into the heat exchanger as its heat exchange cold source

[0039] 4) The S-bend inlet airflow passage consists of two curved sections with larger curvatures;

[0040] 5) The heat exchanger includes two flow channels, the cold side and the hot side. The cold side flow channel carries the ram air introduced from the S-bend inlet flow channel, and the hot side flow channel carries the fluid medium that needs to be cooled by the aircraft thermal management system.

[0041] 6) The ejector nozzle is arranged on the side with lower pressure at the outlet of the cold side flow channel of the heat exchanger, and the high-pressure gas ejected from it boosts the cold side ram air intake at the outlet of the heat exchanger.

[0042] 7) The exhaust flow channel is arranged between the heat exchanger outlet and the grille, and the high-pressure and high-speed airflow ejected from the nozzle at the heat exchanger outlet is fully mixed with the low-speed airflow inside the exhaust flow channel and at the heat exchanger outlet.

[0043] 8) The exhaust grille is installed on the machine surface to prevent foreign matter from entering the exhaust flow channel and causing blockage.

[0044] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An active flow control stamping heat dissipation system, characterized in that: The heat dissipation system comprises an S-bend inlet airflow passage, a heat exchanger, an ejector nozzle at the outlet of the heat exchanger, an outlet airflow passage of the heat exchanger, and a grille at the outlet of the heat exchanger; wherein the inlet of the S-bend inlet airflow passage protrudes from the aircraft surface, is responsible for introducing the ram air flow through the S-bend airflow passage and then entering the heat exchanger from the outlet, and serves as a cold source at the cold side of the heat exchanger to cool the fluid at the hot side of the heat exchanger; according to the heat exchanger outlet flow data obtained by flow calculation, a group of ejector nozzles are arranged on the side with a lower outlet flow rate, and the high-pressure gas drawn out from the compressor of the engine or auxiliary power unit is transmitted through the connecting pipeline and ejected from the nozzle, and after being mixed with the cold side air at the outlet of the heat exchanger, it is discharged outside the aircraft through the grille at the outlet of the exhaust airflow passage; due to the ejection effect of the high-pressure airflow, the high-pressure airflow ejected from the ejector nozzle will increase the speed of the cold side air at the outlet of the heat exchanger, thereby increasing the cold side flow rate of the heat exchanger and improving the overall heat dissipation performance of the heat exchanger.

2. An active flow control stamping heat dissipation system as claimed in claim 1, characterized in that: A low pressure area is generated at the heat exchanger inlet at the rear end of the inlet flow channel, and the ejector nozzle is arranged at the end of the hot side flow channel of the heat exchanger in the low pressure area.

3. The active flow control stamping heat dissipation system according to claim 1, characterized in that: The inlet of the S-bend inlet airflow duct protrudes from the aircraft surface along the aircraft heading to capture the ram air in the flight direction, and the outlet is connected to the inlet of the heat exchanger to introduce the ram air into the heat exchanger as its heat exchange cold source.

4. An active flow control stamping heat dissipation system as claimed in claim 3, characterized in that: The entrance of the S-bend inlet air duct adopts a V-shaped opening structure to accommodate as much external ram air as possible.

5. An active flow control stamping heat dissipation system as claimed in claim 4, characterized in that: The S-bend inlet airflow passage is integrally formed by two curved sections with larger curvatures.

6. An active flow control stamping heat dissipation system as claimed in claim 1 or 5, characterized in that: The S-bend inlet airflow duct is composed of two pipes with a curvature of not less than 60°.

7. The active flow control stamping heat dissipation system according to claim 1, characterized in that: The ejection nozzle is arranged at the side with lower pressure at the outlet of the cold side flow channel of the heat exchanger, and the ejected high-pressure gas pressurizes the cold side ram air intake at the outlet of the heat exchanger.

8. The active flow control stamping heat dissipation system according to claim 1, characterized in that: The fluid at the hot side of the heat exchanger is a fluid medium from the aircraft thermal management system that needs to dissipate heat, including but not limited to liquid medium or gas medium.

9. The active flow control stamping heat dissipation system according to claim 1, characterized in that: The exhaust flow channel is arranged between the heat exchanger outlet and the grille, and the high-pressure and high-speed airflow ejected from the injector nozzle at the heat exchanger outlet is fully mixed inside the exhaust flow channel with the low-speed airflow at the heat exchanger outlet.

10. The active flow control stamping heat dissipation system according to claim 1, characterized in that: The heat exchanger outlet flow channel grille is installed on the machine surface.

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