Airborne electronic component efficient closed type phase change cooling system adopting ammonia working medium

Abstract

The invention belongs to the technical field of thermal management of airborne equipment, and particularly relates to an efficient closed phase change cooling system for airborne electronic components adopting ammonia working media, which comprises a cold plate heat exchanger, a compressor, an air heat exchanger, a control valve and an electronic expansion valve, the cold plate heat exchangers are distributed on the heating electronic components in a parallel connection state; an outlet of the compressor is connected with an inlet of the compressor, and the compressor provides power for conveying of the ammonia coolant in the whole cooling system pipeline and compresses the ammonia vapor after heat absorption into high-temperature and high-pressure ammonia vapor; an outlet of the compressor is connected with an inlet of the air heat exchanger, and the air heat exchanger cools high-temperature ammonia steam through engine outer culvert air or ram air. An outlet of the air heat exchanger is connected with an inlet of the control valve, the control valve is installed on a branch of each cold plate heat exchanger, and the cooling flow is adjusted according to the cooling requirement. An inlet of the control valve is connected with an inlet of the electronic expansion valve, and the electronic expansion valve is used for throttling an ammonia coolant so as to improve the cooling capacity of the ammonia coolant; and an outlet of the electronic expansion valve is connected with an inlet of the cold plate heat exchanger. According to the air heat exchanger, engine outer culvert air or ram air is used for cooling high-temperature ammonia steam, and the air heat exchanger is not limited by the temperature of fuel oil at an engine inlet.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal management of airborne equipment, and in particular relates to a high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium. Background Art

[0002] Airborne electronic equipment is mostly placed in the aircraft's airtight cabin. When the temperature of the electronic equipment exceeds 80°C, the reliability of the electronic components decreases by 5% for every 1°C increase. These airborne electronic equipment will generate a lot of heat during operation. If the heat is not discharged in time, the reliability and safety of the equipment will decrease rapidly. With the development of technology, the heat dissipation of high-power electronic equipment mainly presents the following characteristics: (1) concentrated heat generation and limited heat dissipation area; (2) varied application scenarios and complex and changeable environments. (3) Involving multi-physical field coupling research. Higher requirements are placed on the cooling capacity of aircraft electronic equipment.

[0003] Aircraft generally use natural convection and forced air cooling to cool onboard equipment, but for long-duration flight missions, high heat flux density onboard electronic equipment cannot be effectively and quickly cooled by traditional cooling methods. Liquid cooling technology is widely used in the heat dissipation system of high heat flux density components, and requires a large amount of cooling fluid. Although its heat exchange capacity is high, it is difficult to achieve synchronous regulation of heat flux and flow rate, especially in aircraft. Under stable flow rate, instantaneous heat flow is still a huge threat to electronic components. Using the highest heat flux density as the design point will cause the liquid cooling system to be large in size and weight, which is not conducive to the long-term, lightweight and high-reliability operation of advanced combat aircraft.

[0004] Compared with single-phase flow, phase change cooling has obvious advantages. The phase change process of the medium absorbs more latent heat than the single phase, maintains the boiling point temperature, and has higher heat exchange efficiency. It has the advantages of simplicity, high reliability, and strong overload capacity. Summary of the invention

[0005] The purpose of the present invention is to propose an efficient closed phase change cooling system for airborne electronic components using ammonia as a working medium, so as to achieve rapid and efficient cooling of airborne electronic equipment with high heat flux density.

[0006] Technical solution of the present invention: In order to achieve the above-mentioned invention object, the present invention proposes an efficient closed phase change cooling system for airborne electronic components using ammonia as a working medium, wherein the cooling system comprises a cold plate heat exchanger, a compressor, an air heat exchanger, a control valve, and an electronic expansion valve; the cold plate heat exchanger is distributed in parallel on each heat-generating electronic component; its outlet is connected to the inlet of the compressor, and the compressor provides power for the transportation of ammonia coolant in the entire cooling system pipeline, and compresses the ammonia vapor after heat absorption into high-temperature and high-pressure ammonia vapor; the compressor outlet is connected to the inlet of the air heat exchanger, and the air heat exchanger uses engine external air or ram air to cool the high-temperature ammonia vapor; the air heat exchanger outlet is connected to the inlet of the control valve, and the control valve is installed on the branch of each cold plate heat exchanger to adjust the cooling flow according to the cooling demand; the control valve inlet is connected to the inlet of the electronic expansion valve, and the electronic expansion valve is used for throttling the ammonia coolant to improve the cooling capacity of the ammonia coolant; the electronic expansion valve outlet is connected to the inlet of the cold plate heat exchanger.

[0007] Furthermore, the cold plate heat exchanger is a rectangular cold plate; optionally, the cooling channel arranged on the rectangular cold plate is formed by two headers and a plurality of branch pipes connected in parallel.

[0008] Furthermore, both the header and the branch pipes are rectangular flow channels, the header has a width of about 10-15 mm and a height of 2-4 mm; in addition, the branch pipes can optionally have a width of 2-5 mm and a height the same as that of the header; and the spacing between the branch pipes is 10-15 mm.

[0009] Furthermore, ammonia refrigerant only exists in the pipeline, without any additional storage tank.

[0010] Furthermore, the ammonia coolant undergoes isenthalpic throttling in the electronic expansion valve, the pressure is reduced to near atmospheric pressure, and the temperature is reduced to near the saturation temperature corresponding to the atmospheric pressure, and the ammonia refrigerant becomes a two-phase state with a strong heat absorption capacity.

[0011] Furthermore, the incoming air can be taken from the engine's external air, ram air, etc., to achieve rapid cooling of the high-temperature and high-pressure ammonia steam.

[0012] Beneficial effects of the present invention: In the closed phase-change cooling system proposed by the present invention, the ammonia coolant only circulates in the pipeline, and no additional storage tank is required. At the same time, the extremely high phase-change latent heat of the ammonia coolant is utilized to achieve efficient and rapid cooling of airborne electronic components. The ammonia coolant after absorbing heat is cooled by the engine bypass air or ram air, thereby achieving the purpose of reusing the ammonia coolant, which can effectively cope with long-duration flight missions.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. Compared with the traditional cooling method of airborne electronic components, the extremely high phase change latent heat of ammonia coolant can achieve efficient and rapid cooling of airborne electronic components.

[0015] 2. No additional cooling medium is required, making it suitable for long-duration flight missions.

[0016] 3. The traditional environmental control system transfers heat to the fuel and further transmits it to the engine for combustion; since the fuel temperature at the engine inlet is limited, a thermal management system is required to discharge the excess fuel heat out of the engine through an air radiator. The air heat exchanger of the present invention uses the engine external air or ram air to cool the high-temperature ammonia vapor, which is not limited by the fuel temperature at the engine inlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The ammonia fuel chemical endothermic cooling structure and thermal protection system described in the present invention,

[0018] Among them, 1-cold plate heat exchanger; 2-compressor; 3-air heat exchanger; 4-control valve; 5-electronic expansion valve;

[0019] Figure 2 This is a schematic diagram of the specific structure of the cold plate heat exchanger. DETAILED DESCRIPTION

[0020] 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.

[0021] See attached Figure 1 , 2 As shown, in the specific implementation process of the present invention, a high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium is designed, characterized in that: the system includes a cold plate heat exchanger 1, a compressor 2, an air heat exchanger 3, a control valve 4, and an electronic expansion valve 5;

[0022] The cold plate heat exchanger 1 is distributed in parallel on each heat-generating electronic component; its outlet is connected to the inlet of the compressor 2, the compressor 2 provides power for the transportation of ammonia coolant in the entire cooling system pipeline, and compresses the ammonia vapor after heat absorption into high-temperature and high-pressure ammonia vapor; the compressor 2 outlet is connected to the inlet of the air heat exchanger 3, the air heat exchanger 3 uses the engine external air or ram air to cool the high-temperature ammonia vapor; the air heat exchanger (3) outlet is connected to the inlet of the control valve 4, the control valve 4 is installed on the branch of each cold plate heat exchanger 1, and adjusts the cooling flow according to the cooling demand; the control valve 4 inlet is connected to the inlet of the electronic expansion valve 5, the electronic expansion valve is used for throttling the ammonia coolant to improve the cooling capacity of the ammonia coolant; the electronic expansion valve 5 outlet is connected to the inlet of the cold plate heat exchanger 1.

[0023] In some feasible cases, the cold plate heat exchanger 1 is a rectangular cold plate, wherein the cooling channel is formed by two headers and a plurality of branch pipes connected in parallel.

[0024] In some feasible cases, both the header and the branch pipes are rectangular flow channels. The width of the header is approximately 10-15 mm and the height is 2-4 mm. The width of the branch pipe is 2-5 mm and the height is the same as the header. The spacing between the branch pipes is 10-15 mm.

[0025] In some feasible cases, ammonia refrigerant only exists in the pipeline without additional storage tank.

[0026] In some feasible cases, the ammonia coolant undergoes isenthalpic throttling in the electronic expansion valve 5, the pressure is reduced to near atmospheric pressure, and the temperature is reduced to near the saturation temperature corresponding to the atmospheric pressure, and the ammonia refrigerant becomes a two-phase state with a strong heat absorption capacity.

[0027] In some feasible cases, the incoming air can be taken from the engine's external air, ram air, etc., to achieve rapid cooling of high-temperature and high-pressure ammonia steam.

[0028] The traditional environmental control system transfers heat to the fuel, which is then further transported to the engine for combustion. Since the fuel temperature at the engine inlet is limited, a thermal management system is required to discharge the excess fuel heat out of the engine through an air radiator. The air heat exchanger of the present invention uses the engine external air or ram air to cool the high-temperature ammonia vapor, which is not limited by the fuel temperature at the engine inlet.

[0029] 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. A high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working fluid, characterized in that: The cooling system comprises a cold plate heat exchanger (1), a compressor (2), an air heat exchanger (3), a control valve (4), and an electronic expansion valve (5); the cold plate heat exchanger (1) is distributed in parallel on each heat-generating electronic component; its outlet is connected to the inlet of the compressor (2), the compressor (2) provides power for the transportation of ammonia coolant in the pipeline of the entire cooling system, and compresses the ammonia vapor after absorbing heat into high-temperature and high-pressure ammonia vapor; the compressor (2) outlet is connected to the inlet of the air heat exchanger (3), and the air heat exchanger (3) uses engine external air or ram air to cool the high-temperature ammonia vapor; the air heat exchanger (3) outlet is connected to the inlet of the control valve (4), and the control valve (4) is installed on the branch of each cold plate heat exchanger (1) to adjust the cooling flow according to the cooling demand; the control valve (4) inlet is connected to the inlet of the electronic expansion valve (5), and the electronic expansion valve is used for throttling the ammonia coolant to improve the cooling capacity of the ammonia coolant; the electronic expansion valve (5) outlet is connected to the inlet of the cold plate heat exchanger (1).

2. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium according to claim 1, characterized in that: The cold plate heat exchanger (1) is a rectangular cold plate.

3. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium according to claim 2, characterized in that: A cooling channel is arranged on the rectangular cold plate, and the cooling channel is formed by two headers and a plurality of branch pipes connected in parallel.

4. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium as claimed in claim 3, characterized in that: The manifold and the branch pipes are both rectangular flow channels, and the width of the manifold is 10-15 mm and the height is 2-4 mm.

5. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium as claimed in claim 3, characterized in that: The width of the branch pipe is 2 to 5 mm, and the height is the same as the collecting pipe; the spacing between the branch pipes is 10 to 15 mm.

6. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium according to claim 1, characterized in that: Ammonia refrigerant only exists in the pipeline, without any additional storage tank.

7. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium according to claim 6, characterized in that: The ammonia coolant undergoes isenthalpic throttling in the electronic expansion valve (5), the pressure is reduced to near atmospheric pressure, and the temperature is reduced to near the saturation temperature corresponding to the atmospheric pressure, and the ammonia refrigerant becomes a two-phase state with a strong heat absorption capacity.

8. The high-efficiency closed phase-change cooling system for airborne electronic components using ammonia as a working medium according to claim 1, characterized in that: The incoming air can be taken from the engine's external air, ram air, etc., to achieve rapid cooling of high-temperature and high-pressure ammonia steam.

Images