Airplane environment control system heat exchanger and heat exchange method

Abstract

The invention discloses an aircraft environmental control system heat exchanger and a heat exchange method, an injection device is integrated at a cold side outlet of the heat exchanger, in the high altitude, ram air is introduced from an outer duct of an engine to serve as a cold source to flow through a cold side channel to exchange heat with high-temperature and high-pressure air flowing through a hot side channel, and the ram air is used for cooling the high-temperature air; on the ground, a part of high-temperature and high-pressure air forms high-speed jet flow under the action of a nozzle of the injection assembly, and ambient air is injected under the suction action generated by the pressure difference between exhaust pressure and ambient pressure, so that low-temperature air flows through the cold side channel and exchanges heat with the high-temperature and high-pressure air flowing through the hot side channel; and the aircraft can still cool high-temperature air when no ram air exists on the ground. According to the invention, high-temperature air from the engine is cooled to a proper temperature through stamping or injected air, so that the air can be used by a downstream air system. According to the invention, the aircraft environment control system can be normally used at high altitude and on the ground.

Description

Technical Field

[0001] The present invention belongs to the field of the design of the thermal management system of aircraft engines and environmental control systems, and in particular relates to a heat exchanger and a heat exchange method for an aircraft environmental control system. Background Art

[0002] When an aircraft ascends from the ground to high altitude, the external environmental conditions change extremely violently. The external atmospheric pressure can change from one atmosphere to near vacuum, and the temperature will also drop sharply. In order to ensure the normal life of passengers and flight crew and the reliable operation of equipment during flight, the cabins and equipment compartments of modern aircraft need to be environmentally controlled.

[0003] The air cycle system of an aircraft generally uses the air drawn from the main engine as the supply air. However, at this time, the temperature of the air is relatively high and cannot be directly used for the subsequent environmental control system. Therefore, a pre-cooler is required to reduce the temperature of the engine bleed air. The pre-cooler is a type of heat exchanger and is an important component of the aircraft environmental control system. It is generally divided into plate-fin type, tube-in-tube type, shell-and-tube type, etc. Usually, high-altitude ram air is used as the cold source to exchange heat with the engine bleed air in the heat exchanger to reduce the bleed air temperature.

[0004] When the aircraft is on the ground and has not taken off, the environmental control system still needs to work to maintain the life of personnel and the safe operation of equipment. However, at this time, due to the lack of high-altitude ram air as the cold source, other cold sources need to be adopted to pre-cool the engine bleed air. Summary of the Invention

[0005] The present invention aims to provide a heat exchanger and a heat exchange method for an aircraft environmental control system, which are used for the aircraft environmental control system, enabling the environmental control system of the aircraft to be normally used both at high altitude and on the ground, and having a compact, lightweight structure and low energy consumption.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A heat exchanger for an aircraft environmental control system, comprising:

[0008] A core assembly, the core assembly being of a plate-fin heat exchange structure, comprising heat-side channels and cold-side channels that are arranged crosswise, independent of each other, and sealed;

[0009] A heat-side inlet and outlet assembly, the heat-side inlet and outlet assembly comprising a heat-side inlet assembly and a heat-side outlet assembly, wherein the heat-side inlet assembly is communicated with the inlet of the heat-side channel, and the heat-side outlet assembly is communicated with the outlet of the heat-side channel;

[0010] A cold-side inlet and outlet assembly, the cold-side inlet and outlet assembly comprising a cold-side inlet assembly and a cold-side outlet assembly, wherein the cold-side inlet assembly is communicated with the inlet of the cold-side channel, and the cold-side outlet assembly is communicated with the outlet of the cold-side channel;

[0011] An ejector assembly is provided on the cold-side outlet assembly. The intake end of the ejector assembly introduces high-temperature and high-pressure air from an aircraft engine, and the air jet end of the ejector assembly is in communication with the atmospheric environment.

[0012] Furthermore:

[0013] The hot-side inlet assembly includes a hot-side inlet joint and a hot-side inlet end cover. The hot-side inlet end cover is located between the inlet of the hot-side channel and the hot-side inlet joint. The hot-side inlet joint is a concave joint, and the hot-side inlet end cover has an arc transition structure, and its cross-section gradually decreases from the inlet of the hot-side channel towards the hot-side inlet joint.

[0014] The hot-side outlet assembly includes a hot-side outlet joint and a hot-side outlet end cover. The hot-side outlet end cover is located between the outlet of the hot-side channel and the hot-side outlet joint. The hot-side outlet joint is a convex joint, and the hot-side outlet end cover has an arc transition structure, and its cross-section gradually decreases from the outlet of the hot-side channel towards the hot-side outlet joint.

[0015] Furthermore:

[0016] One end of the hot-side inlet end cover connected to the hot-side inlet joint includes a straight edge, and one end connected to the inlet of the hot-side channel also includes a straight edge;

[0017] One end of the hot-side outlet end cover connected to the hot-side outlet structure includes a straight edge, and one end connected to the outlet of the hot-side channel also includes a straight edge.

[0018] Furthermore:

[0019] The cold-side inlet assembly includes a cold-side inlet end cover and a cold-side inlet flange. The cold-side inlet end cover is located between the cold-side inlet flange and the inlet of the cold-side channel. The flange surface of the cold-side inlet flange forms an acute angle with the windward surface, and the cold-side inlet end cover has an arc transition structure, and its cross-section gradually decreases from the inlet of the cold-side channel towards the cold-side inlet flange;

[0020] The cold-side outlet assembly includes a cold-side outlet end cover and a cold-side outlet flange. The cold-side outlet end cover is located between the cold-side outlet flange and the outlet of the cold-side channel. The flange surface of the cold-side outlet flange is perpendicular to the windward surface, and the cold-side outlet end cover has an arc transition structure, and its cross-section gradually decreases from the outlet of the cold-side channel towards the cold-side outlet flange.

[0021] As a solution, an ejector assembly is provided between the cold-side outlet end cover and the cold-side outlet flange, and the ejector assembly includes:

[0022] A ring pipe, which is a circumferentially closed annular pipe. The inner cavity of the annular pipe forms a gas flow channel. The first axial end of the annular pipe is connected to the cold-side outlet flange, and the second axial end is connected to the cold-side outlet end cover;

[0023] Nozzles, which are circumferentially and equally distributed at the same central angle along the inner circumferential surface of the annular pipe. The nozzles are of the Laval nozzle structure. The air inlet end of the nozzle is communicated with the inner cavity of the annular pipe, and the air exhaust end of the nozzle is communicated with the atmospheric environment.

[0024] Ejector inlet flange, which is arranged on the outer circumferential surface of the annular pipe. The inlet of the ejector inlet flange introduces high-temperature and high-pressure air from the aircraft engine, and the outlet of the ejector inlet flange is communicated with the inner cavity of the annular pipe.

[0025] Furthermore, the air flow jet direction at the air exhaust end of the nozzle is parallel to the axial direction of the annular pipe.

[0026] Furthermore, a mounting seat is also arranged on one end face of the core assembly.

[0027] As a solution:

[0028] The core assembly is mainly formed by vacuum brazing fins, seals, partitions and side plates. The fins corresponding to the hot-side channels and the cold-side channels are all wavy fins, and the hot-side channels and the cold-side channels are arranged in a cross-flow form;

[0029] The hot-side inlet and outlet assembly and the cold-side inlet and outlet assembly are welded to different end faces of the core assembly by argon arc welding.

[0030] An aircraft environmental control system precooler, adopting the heat exchanger of any of the above solutions.

[0031] An aircraft environmental control system heat exchange method, adopting the above precooler, and including:

[0032] At high altitude, low-temperature air is led out from the engine outer bypass duct and enters the precooler to exchange heat with the high-temperature and high-pressure air, reducing the temperature of the high-temperature and high-pressure air from the engine;

[0033] On the ground, low-temperature air is obtained by means of an ejector. A part of the high-temperature and high-pressure air flow is formed into a high-speed jet through the ejector, and the entrainment of the ambient air is realized by the suction effect generated by the pressure difference between the exhaust pressure and the ambient pressure, so that the relatively low-temperature ambient air flows into the precooler and then exchanges heat with another part of the high-temperature and high-pressure air flowing into the precooler.

[0034] The working principle of the heat exchanger of the present invention is as follows: The high-temperature and high-pressure hot air led out from the engine enters the hot-side flow channel of the core assembly evenly after being rectified through the hot-side inlet, and exchanges convective heat with the low-temperature air. The heat of the high-temperature air is transferred to the low-temperature air through the fins and partitions. The fins can increase the heat transfer area and increase the flow disturbance at the same time, improving the heat transfer efficiency. Moreover, the plate-fin heat exchanger adopted by the present invention has a high compactness, and the structure is lightweight and efficient.

[0035] Compared with the prior art, the present invention provides a heat exchanger integrated with an ejector device, which combines the heat exchanger with the ejector. When the aircraft is operating on the ground, the ejector device can be relied on to suck in normal-temperature atmosphere through the cold-side channel of the heat exchanger, and perform heat exchange on the high-temperature and high-pressure air from the engine flowing through the hot-side channel. Moreover, the air flow at the ejector inlet is also the high-temperature and high-pressure air from the engine. This high-temperature and high-pressure air mixes and exchanges heat with the air at the cold-side outlet of the heat exchanger at the outlet of the ejector nozzle, thereby achieving the purpose of reducing the temperature of the engine bleed air. The structure is compact and lightweight, and can enable the normal operation of the aircraft environmental control system on the ground.

[0036] When the present invention is at high altitude, low-temperature air is led out from the engine bypass duct, enters the cold-side flow channel of the core component after being rectified at the cold-side inlet, and exchanges heat with the high-temperature and high-pressure air flowing through the hot-side channel, thereby reducing the temperature of the high-temperature and high-pressure air from the engine. When on the ground, the low-temperature air is obtained by relying on the ejector device. A part of the high-temperature and high-pressure air flow enters the annular circular tube through the ejector inlet flange, forms a high-speed jet through the expansion effect of the nozzle, and uses the suction effect generated by the pressure difference between the exhaust pressure and the ambient pressure to achieve the ejection of ambient air, so that the relatively low-temperature ambient air flows into the cold-side flow channel of the core component and then exchanges heat with another part of the high-temperature and high-pressure air flowing through the hot-side channel. The present invention realizes the reduction of the temperature of the high-temperature and high-pressure air from the engine without additional energy consumption at both high altitude and on the ground. Brief Description of the Drawings

[0037] Figure 1 is a schematic structural diagram of the present invention;

[0038] Figure 2 is a schematic structural diagram of the core component of the present invention;

[0039] Figure 3 is a schematic structural diagram of the hot-side inlet and outlet component of the present invention;

[0040] Figure 4 is a schematic diagram of the cold-side inlet and outlet component and the ejector component of the present invention;

[0041] Figure 5 is a schematic structural diagram of the ejector component of the present invention;

[0042] Figure 6 is a schematic structural diagram of the nozzle of the present invention;

[0043] Figure 7 is a schematic diagram of the installation of the mounting seat of the present invention;

[0044] In the figure: 1. Core component; 2. Hot-side inlet and outlet component; 3. Cold-side inlet and outlet component; 4. Ejector component; 5. Mounting seat. Detailed Embodiments

[0045] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter of the present invention is limited to the following embodiments. Without departing from the above technical idea of the present invention, all modifications, substitutions, and changes made according to ordinary technical knowledge and customary means in the art are included in the scope of the present invention.

[0046] As Figures 1 to 7 shown, an integrated heat exchanger structure with an ejector device designed by the present invention is applicable to the precooler of the environmental control system and mainly consists of component parts such as a core component 1, a hot-side inlet and outlet component 2, a cold-side inlet and outlet component 3, an ejector component 4, and a mounting seat 5.

[0047] The core component 1 is of a plate-fin structure, divided into a cold side and a hot side, and consists of component parts such as fins, seals, partitions, brazing materials, and side plates. Both the cold and hot sides are wavy fins. The core component 1 is a sealed channel for cold and hot media, and its cold and hot channels are arranged in a cross-independent manner, enabling the high-temperature air from the engine to fully exchange heat with the low-temperature ram air or ejector air through heat transfer surfaces such as partitions and fins, reducing the temperature of the high-temperature air to supply the aircraft environmental control system.

[0048] The hot-side inlet component 2 includes a hot-side inlet joint, a hot-side outlet joint, a hot-side inlet end cover, and a hot-side outlet end cover. The hot-side inlet joint is in the form of a concave joint, and the hot-side outlet joint is a convex joint; the hot-side inlet end cover and the hot-side outlet end cover are transition parts between the core component 1 and the pipeline, mainly serving the functions of collecting air and guiding the flow, and also playing the role of sealing and bearing pressure. Therefore, both the hot-side inlet end cover and the hot-side outlet end cover are designed with an arc transition structure, which not only improves the pressure-bearing performance of the structure but also allows the air flow to be fully mixed; at the same time, in order to improve the welding quality, straight-edge sections are designed at the inlets and outlets of the hot-side inlet end cover and the hot-side outlet end cover.

[0049] The cold-side inlet and outlet component 3 includes a cold-side inlet end cover, a cold-side outlet end cover, a cold-side inlet flange, and a cold-side outlet flange. The cold-side inlet end cover and the cold-side outlet end cover are also designed with an arc transition structure; flange connections are adopted at the cold-side inlets and outlets. The flange surface of the cold-side inlet flange forms a 60° angle with the windward surface, and the flange surface of the cold-side outlet flange is perpendicular to the windward surface; at the same time, the cold-side outlet flange is connected to the ejector component 4. When the aircraft is on the ground, the ejector air is used to exchange heat with the high-temperature and high-pressure air to ensure the normal operation of the environmental control system when the aircraft is on the ground.

[0050] The ejector assembly 4 includes an annular pipe, a nozzle, and an ejector inlet flange. The ejector assembly 4 is connected between the cold-side outlet end cover and the cold-side outlet flange. The nozzle is of a Laval nozzle structure, that is, the inner diameter of the first half of the nozzle decreases from large to small and contracts to a narrow throat in the middle, and then expands from small to large outward after the narrow throat, which can continuously accelerate the gas to form a pressure difference between the cold-side inlet and outlet, thereby generating ejector air. The inlet of the ejector assembly 4 is connected by a flange.

[0051] The material of the mounting seat 5 is a superalloy, and it is installed and welded on the core assembly 1.

[0052] The heat exchanger mainly adopts processes such as welding and machining. The core assembly 1 uses vacuum brazing to weld components such as fins, seals, partitions, brazing filler metals, and side plates into a whole, and the remaining components are welded by argon arc welding process. The cold-side inlet and outlet end covers, the hot-side inlet and outlet end covers, and the mounting seat 5 are welded on the core assembly.

[0053] At high altitude, the high-temperature and high-pressure gas led out from the engine enters the hot-side channel of the core assembly 1 through the hot-side inlet joint and is rectified by the hot-side inlet end cover. After transferring the heat to the cold-side fluid through the fins and partitions, it flows out of the heat exchanger through the hot-side outlet end cover. At high altitude, ram air is led from the engine bypass duct as a cold source, and after being rectified by the cold-side inlet end cover through the cold-side inlet flange, it flows into the cold-side channel of the core assembly 1 to exchange heat with the high-temperature and high-pressure air flowing through the hot-side channel. On the ground, a part of the high-temperature and high-pressure gas enters the hot-side channel of the core assembly 1 through the hot-side inlet joint and is rectified by the hot-side inlet end cover. After transferring the heat to the cold-side fluid through the fins and partitions, it flows out of the heat exchanger through the hot-side outlet end cover. A part of the high-temperature and high-pressure gas flows into the annular pipe through the ejector inlet flange, and after expanding and accelerating through the nozzle, it forms a high-speed jet, and uses the suction effect generated by the pressure difference between the exhaust pressure and the ambient pressure to realize the ejection of ambient air, so that the low-temperature air flows through the cold-side channel of the core assembly 1 to exchange heat with the high-temperature and high-pressure air flowing through the hot-side channel.

[0054] As Figure 2 shown, it is a schematic structural diagram of the core assembly 1. The core assembly is a plate-fin heat exchanger, which is vacuum brazed by fins, seals, partitions, brazing filler metals, and side plates. Both the cold side and the hot side are wavy fins, and the flow pattern is cross flow. Its cold and hot channels are arranged independently and crosswise, so that the high-temperature air from the engine and the low-temperature ram air or ejector air can fully exchange heat through heat transfer surfaces such as partitions and fins.

[0055] As Figure 3As shown in the figure, it is the hot side inlet and outlet assembly 2, including a hot side inlet joint, a hot side outlet joint, a hot side inlet end cover, and a hot side outlet end cover. The hot side inlet joint is in the form of a concave joint, and the hot side outlet joint is a convex joint; the hot side inlet end cover and the hot side outlet end cover are transition parts between the core assembly 1 and the pipeline, which play the role of collecting air and guiding the flow, and also play the role of sealing and bearing pressure. The hot side inlet end cover and the hot side outlet end cover are designed with an arc transition structure, which not only improves the pressure-bearing performance of the structure but also allows the air flow to be fully mixed; at the same time, in order to improve the welding quality, 8-mm straight-edge sections are designed at the inlets and outlets of the hot side inlet end cover and the hot side outlet end cover.

[0056] As Figure 4 shown in the figure, it is the cold side inlet and outlet assembly 3 and the ejector assembly 4. The cold side inlet end cover and the cold side outlet end cover are both designed with an arc transition structure; flange connections are adopted at the cold side inlet and outlet. The flange surface of the cold side inlet flange forms a 60° angle with the windward surface, and the flange surface of the cold side outlet flange is perpendicular to the windward surface; at the same time, an ejector assembly 4 is connected between the cold side outlet flange and the cold side outlet end cover.

[0057] As Figure 5 、 Figure 6 shown in the figure, it is a schematic structural diagram of the ejector assembly 4 and the ejector nozzle, including an annular pipe, a nozzle, and an ejector inlet flange. The nozzle is a Laval nozzle structure. The first half of the Laval nozzle contracts from large to small towards the middle to a throat, and then expands from small to large outward after the throat. High-pressure gas flows into the first half of the nozzle and is ejected from the second half after passing through the throat. When the gas enters the contraction section of the nozzle, the movement of the gas follows the principle that "when a fluid moves in a pipe, the flow velocity is high at a small cross-section and low at a large cross-section", so the air flow is continuously accelerated, and the flow velocity increases from subsonic to sonic. When reaching the narrow throat, the flow velocity exceeds the sonic speed. At this time, the movement of the gas follows the principle that "the larger the cross-section, the faster the flow velocity", so in the flare section of the nozzle, the velocity of the gas is further accelerated until it is accelerated to supersonic speed. The high-speed fluid is ejected to generate thrust, and the entrainment of ambient air is achieved by the suction effect generated by the pressure difference between the exhaust pressure and the ambient pressure.

[0058] As Figure 7 shown in the figure, it is an installation schematic diagram of the mounting seat 5. The mounting seat 5 is welded to the core assembly 1 by the TIG welding process.

[0059] The above embodiments do not limit the protection scope of the present invention. Any deformation, modification, or equivalent replacement made on the basis of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. Aircraft environmental control system heat exchanger, characterized in that, Comprising: A core component (1), the core component (1) being a plate-fin heat exchange structure, including heat-side channels and cold-side channels that are arranged crosswise, independent of each other, and sealed. A heat-side inlet and outlet component (2), the heat-side inlet and outlet component (2) including a heat-side inlet component and a heat-side outlet component, where the heat-side inlet component is in communication with the inlet of the heat-side channel, and the heat-side outlet component is in communication with the outlet of the heat-side channel. A cold-side inlet and outlet component (3), the cold-side inlet and outlet component (3) including a cold-side inlet component and a cold-side outlet component, where the cold-side inlet component is in communication with the inlet of the cold-side channel, and the cold-side outlet component is in communication with the outlet of the cold-side channel. An ejector component (4), the ejector component (4) being arranged on the cold-side outlet component, the air inlet end of the ejector component (4) introducing high-temperature and high-pressure air from an aircraft engine, and the air jet end of the ejector component (4) being in communication with the atmospheric environment.

2. The aircraft environmental control system heat exchanger according to claim 1, wherein: The heat-side inlet component includes a heat-side inlet joint and a heat-side inlet end cover, the heat-side inlet end cover being between the inlet of the heat-side channel and the heat-side inlet joint, where the heat-side inlet joint is a concave joint, and the heat-side inlet end cover is an arc transition structure, and its cross-section gradually decreases from the inlet of the heat-side channel towards the heat-side inlet joint. The heat-side outlet component includes a heat-side outlet joint and a heat-side outlet end cover, the heat-side outlet end cover being between the outlet of the heat-side channel and the heat-side outlet joint, where the heat-side outlet joint is a convex joint, and the heat-side outlet end cover is an arc transition structure, and its cross-section gradually decreases from the outlet of the heat-side channel towards the heat-side outlet joint.

3. The aircraft environmental control system heat exchanger according to claim 1, wherein: One end of the heat-side inlet end cover connected to the heat-side inlet joint includes a straight edge, and one end connected to the inlet of the heat-side channel also includes a straight edge. One end of the heat-side outlet end cover connected to the heat-side outlet structure includes a straight edge, and one end connected to the outlet of the heat-side channel also includes a straight edge.

4. The aircraft environmental control system heat exchanger according to claim 1, wherein: The cold-side inlet component includes a cold-side inlet end cover and a cold-side inlet flange, the cold-side inlet end cover being between the cold-side inlet flange and the inlet of the cold-side channel, where the flange surface of the cold-side inlet flange forms an acute angle with the windward surface, and the cold-side inlet end cover is an arc transition structure, and its cross-section gradually decreases from the inlet of the cold-side channel towards the cold-side inlet flange. The cold-side outlet component includes a cold-side outlet end cover and a cold-side outlet flange, the cold-side outlet end cover being between the cold-side outlet flange and the outlet of the cold-side channel, where the flange surface of the cold-side outlet flange is perpendicular to the windward surface, and the cold-side outlet end cover is an arc transition structure, and its cross-section gradually decreases from the outlet of the cold-side channel towards the cold-side outlet flange.

5. The heat exchanger of the aircraft environmental control system according to claim 4, characterized in that: An ejector component (4) is arranged between the cold-side outlet end cover and the cold-side outlet flange, and the ejector component (4) includes: A ring pipe, the ring pipe being a circumferentially closed annular pipe, the inner cavity of the annular pipe forming a gas flow channel, the first axial end of the annular pipe being connected to the cold-side outlet flange, and the second axial end being connected to the cold-side outlet end cover. Nozzles, which are circumferentially and equiangularly distributed at the center along the inner ring surface of the annular pipe. The nozzles are of Laval nozzle structure. The air inlet end of the nozzle is communicated with the inner cavity of the annular pipe, and the air outlet end of the nozzle is communicated with the atmospheric environment. Ejector inlet flange, which is arranged on the outer ring surface of the annular pipe. The inlet of the ejector inlet flange introduces high-temperature and high-pressure air from the aircraft engine, and the outlet of the ejector inlet flange is communicated with the inner cavity of the annular pipe.

6. The heat exchanger of the aircraft environmental control system according to claim 5, wherein: The air flow ejection direction at the air outlet end of the nozzle is parallel to the axial direction of the annular pipe.

7. The heat exchanger of the aircraft environmental control system according to claim 1, wherein: A mounting seat (5) is also arranged on one end face of the core assembly (1).

8. The aircraft environmental control system heat exchanger according to claim 1, wherein: The core assembly (1) is mainly formed by vacuum brazing fins, seals, partitions and side plates. The fins corresponding to the hot side channels and the cold side channels are all wavy fins, and the hot side channels and the cold side channels are arranged in a cross-flow form. The hot side inlet and outlet assembly (2) and the cold side inlet and outlet assembly (3) are welded to different end faces of the core assembly (1) by argon arc welding.

9. An aircraft environmental control system pre-cooler, characterized in that: Use the heat exchanger according to any one of claims 1 to 8.

10. Aircraft environmental control system heat exchange method, characterized in that, Use the pre-cooler according to claim 9, and it includes: At high altitude, low-temperature air is led out from the engine bypass duct and enters the pre-cooler to exchange heat with the high-temperature and high-pressure air, reducing the temperature of the high-temperature and high-pressure air from the engine. On the ground, low-temperature air is obtained by means of an ejector. A part of the high-temperature and high-pressure air flow forms a high-speed jet through the ejector. The suction effect generated by the pressure difference between the exhaust pressure and the ambient pressure is used to eject the ambient air, so that the relatively low-temperature ambient air flows into the pre-cooler and then exchanges heat with another part of the high-temperature and high-pressure air flowing into the pre-cooler.

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