Aircraft cascade thermal management system and thermal management method

Abstract

The invention relates to the technical field of thermal management, and particularly provides an aircraft cascade thermal management system and a thermal management method.The aircraft cascade thermal management system comprises a liquid metal bypass heat sink connected with a high-heat-flux heat source; the liquid metal bypass heat sink is used for absorbing thermal shock heat of a high-heat-flux heat source and is filled with a phase change heat storage working medium; the liquid metal loop comprises a heat sink and a driving pump, and a first heat dissipation working medium which is liquid metal flows in the liquid metal loop; the heat sink is connected with the high-heat-flux heat source and is a device for exchanging heat between the high-heat-flux heat source and the liquid metal loop; and the driving pump is used for pumping the heat dissipation working medium in the liquid metal loop. The mode of combining liquid metal active fluid cooling and passive phase change heat storage is adopted for a high-heat-flux heat source, the adopted liquid metal working medium is wide in liquid phase temperature zone, the boiling point is generally larger than 1000 DEG C, and the problems that in the water cooling technology, due to working medium gasification, heat transfer deteriorates, and the pipeline sealing reliability is reduced are solved.

Description

Technical Field

[0001] The present invention relates to the field of thermal management technology, and in particular to an aircraft step thermal management system and a thermal management method. Background Art

[0002] High-speed aircraft face severe aerodynamic heat loads when flying in space. Especially in long-term, high Mach number, and high power demand working environments, the local temperature of the leading edge surface and the rudder shaft surface of the aircraft can exceed 1000°C, and the heat flux density can exceed 1MW / m 2 Excessive aerodynamic heat load will reduce the stiffness of the aircraft itself and will also have a significant impact on the electronic equipment inside the aircraft, thereby reducing the reliability and life of the aircraft operation. Therefore, effective thermal management of the aircraft is an important issue facing the aircraft.

[0003] When the aircraft is operating, the heat source is relatively dispersed and the heat flux density varies. The heat flux density on the leading edge surface and the rudder shaft surface of the aircraft is high and the heating power is large, while the avionics system, hydraulic system and high-power electrical equipment inside the cabin have relatively small heat flux density, irregular and dispersed heat dissipation surface shape. Summary of the invention

[0004] The present invention provides an aircraft cascade thermal management system and a thermal management method, which are used to solve the defects of difficult thermal management design caused by the dispersion of aircraft heat sources and the uneven heat flux density in the prior art, and realize efficient heat dissipation of the aircraft.

[0005] The present invention provides an aircraft step thermal management system for cooling a high heat flux density heat source, comprising: A liquid metal bypass heat sink is connected to the high heat flux density heat source; the liquid metal bypass heat sink is used to absorb the heat of thermal shock of the high heat flux density heat source and is loaded with a phase change heat storage medium; The liquid metal circuit includes a heat sink and a driving pump, and a first heat dissipation medium for liquid metal flows through the heat sink; the heat sink is connected to the high heat flux density heat source, and the heat sink is a device for exchanging heat between the high heat flux density heat source and the liquid metal circuit; the driving pump is used to pump the heat dissipation medium in the liquid metal circuit.

[0006] According to the present invention, an aircraft step thermal management system further comprises a low heat flux density heat source heat dissipation path, in which a second heat dissipation medium flows; the liquid metal circuit further comprises a flow meter; the flow meter is used to measure the flow rate of the first heat dissipation medium in real time; The low heat flux density heat source heat dissipation path comprises: a pressure vessel, a heat exchanger and a controller; The pressure vessel, the heat exchanger, the controller and the low heat flux density heat source are connected in sequence to form a first branch; The pressure vessel, the controller and the low heat flux density heat source are connected in sequence to form a second branch; Among them, the pressure vessel is used to store the second heat dissipation medium in the low heat flux density heat source heat dissipation path; the heat exchanger is a device for exchanging heat between the liquid metal loop and the low heat flux density heat source heat dissipation path; the controller is used to switch the first branch and the second branch according to the temperature of the second heat dissipation medium and the temperature of the low heat flux density heat source; and to adjust the flow rate of the second heat dissipation medium.

[0007] An aircraft step thermal management system provided according to the present invention also includes a heat pipe array connected between the high heat flux density heat source and the heat sink, and the heat pipe array is used to extract heat from the high heat flux density heat source.

[0008] According to an aircraft step thermal management system provided by the present invention, the liquid metal is a gallium-based or bismuth-based alloy having a melting point less than 300°C.

[0009] According to an aircraft step thermal management system provided by the present invention, the heat dissipation medium of the low heat flux density heat source heat dissipation path includes one of carbon dioxide, nitrogen, ammonia and methane.

[0010] According to an aircraft step thermal management system provided by the present invention, the phase change thermal storage material in the liquid metal bypass heat sink is an aluminum-based or tin-based alloy with a melting point less than 800°C.

[0011] According to an aircraft step thermal management system provided by the present invention, the heat exchanger includes a shell-and-tube heat exchanger or a partition-type heat exchanger.

[0012] The present invention also provides an aircraft step thermal management method, using the aircraft step thermal management system as described above, comprising: Passive phase change heat storage of high heat flux density heat sources through liquid metal bypass heat sink; The high heat flux density heat source is actively cooled by a liquid metal loop.

[0013] According to an aircraft step thermal management method provided by the present invention, the method further includes dissipating heat from a low heat flux density heat source, including: Set the upper limit of the normal temperature range to T H ; The temperature of the low heat flux heat source is T 1 And the temperature of the second heat sink in the heat source heat dissipation path with low heat flux density is T 2; when T 2< T H <T 1, the first branch is opened, and the first branch is used for the heat dissipation path of the low heat flux density heat source and the liquid metal circuit to heat the low heat flux density heat source; when T H < T 2< T 1 or T H < T 1< T 2, the second branch is opened; the second branch is used as the heat dissipation path of the low heat flux density heat source to directly dissipate the heat of the low heat flux density heat source.

[0014] According to an aircraft step thermal management method provided by the present invention, the heat dissipation of a low heat flux density heat source further comprises: Get the temperature of the liquid metal circuit T 0; when T 0> T H When the second branch is opened.

[0015] The aircraft step thermal management system and thermal management method provided by the present invention adopt a combination of liquid metal active fluid cooling and passive phase change heat storage for high heat flux density heat sources. The liquid metal working fluid used has a wide liquid phase temperature range and a boiling point generally greater than 1000°C, thereby avoiding the problems of heat transfer deterioration and reduced pipeline sealing reliability caused by working fluid gasification in traditional water cooling technology. The phase change heat storage material adopts a metal with a lower melting point. Compared with traditional phase change materials such as paraffin, it has a higher thermal conductivity, a shorter response time, better temperature uniformity, and no phase separation, phase stratification, evaporation, etc.

[0016] In addition, different heat dissipation methods are used according to the different characteristics of high heat flux density and low heat flux density heat sources. For high heat flux density heat sources, liquid metal circulation cooling and metal phase change heat storage methods are adopted. For low heat flux density heat sources, gas cooling method is adopted. The two heat dissipation methods are coupled with each other to achieve efficient heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the structure of the aircraft step thermal management system provided by the present invention.

[0019] Figure 2 It is a control strategy diagram of the aircraft step thermal management method provided by the present invention.

[0020] Reference numerals: 1. High heat flux density heat source; 2. Liquid metal bypass heat sink; 3. Heat sink; 4. Drive pump; 5. Flow meter; 6. Low heat flux density heat source; 7. Pressure vessel; 8. Heat exchanger; 9. Controller; 10. Heat pipe array; 11. External environment. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] Combine the following Figure 1 The aircraft step thermal management system of the present invention is described, which is used for cooling a high heat flux density heat source 1. The aircraft step thermal management system includes a liquid metal bypass heat sink 2, a heat sink 3 and a drive pump 4. The liquid metal bypass heat sink 2 is connected to the high heat flux density heat source 1; the liquid metal bypass heat sink 2 is used to absorb the thermal shock heat of the high heat flux density heat source 1 and is loaded with phase change heat storage medium.

[0024] The liquid metal circuit includes a heat sink 3 and a driving pump 4, through which flows a first heat dissipation medium for liquid metal; the heat sink 3 is connected to a high heat flux density heat source 1, and the heat sink 3 is a device for exchanging heat between the high heat flux density heat source 1 and the liquid metal circuit; the driving pump 4 is used to pump the heat dissipation medium in the liquid metal circuit.

[0025] The aircraft step thermal management system provided by the present invention adopts a combination of liquid metal active fluid cooling and passive phase change heat storage for the high heat flux density heat source 1. The liquid metal used has a wide liquid phase temperature range and a boiling point generally greater than 1000°C, thereby avoiding the problems of heat transfer deterioration and reduced pipeline sealing reliability caused by working fluid gasification in traditional water cooling technology. The phase change heat storage material adopts a metal with a lower melting point. Compared with traditional phase change materials such as paraffin, it has a higher thermal conductivity, a shorter response time, better temperature uniformity, and no phase separation, phase stratification, evaporation, and the like.

[0026] In a feasible embodiment of the present invention, it also includes a low heat flux density heat source heat dissipation path, in which a second heat dissipation medium flows; the liquid metal loop also includes a flow meter 5; the flow meter 5 is used to measure the flow of the first heat dissipation medium in real time. The heat dissipation path of the low heat flux density heat source 6 includes: a pressure vessel 7, a heat exchanger 8 and a controller 9. The pressure vessel 7, the heat exchanger 8, the controller 9 and the low heat flux density heat source 6 are connected in sequence to form a first branch; the pressure vessel 7, the controller 9 and the low heat flux density heat source 6 are connected in sequence to form a second branch; wherein the pressure vessel 7 is used to store the second heat dissipation medium in the low heat flux density heat source heat dissipation path; the heat exchanger 8 is a device for heat exchange between the liquid metal loop and the low heat flux density heat source heat dissipation path; the controller 9 is used to switch the first branch and the second branch according to the temperature of the second heat dissipation medium and the temperature of the low heat flux density heat source 6; and adjust the flow of the second heat dissipation medium.

[0027] The aircraft step thermal management system provided in this embodiment adopts a gas cooling method for low heat flux density heat sources to achieve efficient heat dissipation.

[0028] In a feasible embodiment of the present invention, a heat pipe array 10 is further included, which is connected between the high heat flux density heat source 1 and the heat sink 3. The heat pipe array 10 is used to extract heat from the high heat flux density heat source.

[0029] Among them, the liquid metal uses gallium-based and bismuth-based alloys with a melting point less than 300°C.

[0030] The heat dissipation medium of the low heat flux density heat source heat dissipation path includes one of carbon dioxide, nitrogen, ammonia and methane.

[0031] The phase change heat storage material in the liquid metal bypass heat sink uses an aluminum-based or tin-based alloy with a melting point less than 800° C., and other phase change heat storage materials may also be used.

[0032] The heat exchanger 8 includes a shell-and-tube heat exchanger or a partitioning heat exchanger, and other types of heat exchangers may also be used.

[0033] It should be noted that the controller 9 can also be connected to the external environment 11 for discharging cooling gas. In addition, the external environment 11 can also be connected to the low heat flux density heat source 6.

[0034] like Figure 1 As shown, an embodiment of the present invention provides an aircraft step thermal management system, including a heat pipe array 10, a heat sink 3, a liquid metal bypass heat sink 2, a heat exchanger 8, a flow meter 5, a drive pump 4, a pressure vessel 7 and a controller 9. The heat sink 3, the heat exchanger 8, the flow meter 5 and the drive pump 4 form a liquid metal circuit, and the heat dissipation medium is a liquid metal gallium indium tin alloy with a melting point of 11°C. The pressure vessel 7, the controller 9 and the heat exchanger 8 form a low heat flux density heat source heat dissipation path, and the low heat flux density heat source 6 includes an avionics system, a hydraulic system, and high-power electrical equipment inside the cabin, and the heat dissipation medium is nitrogen.

[0035] The heat pipe array 10 is used to extract heat from the leading edge of the aircraft with a high heat flux density heat source 1, and is a metal heat pipe; the heat sink 3 is a device for heat exchange between the high heat flux density heat source 1 / heat pipe array 10 and the liquid metal loop; the heat exchanger 8 is a device for heat exchange between the liquid metal loop and the liquid metal and nitrogen in the heat dissipation path of the low heat flux density heat source, and is a shell-and-tube heat exchanger; the liquid metal bypass heat sink 2 is used to absorb the heat of the thermal shock of the high heat flux density heat source 1, and is filled with a phase change heat storage medium bismuth-tin alloy with a melting point of 138°C; the flow meter 5 is used to measure the flow of liquid metal in real time, and is an ultrasonic flow meter; the drive pump 4 is used to pump the heat dissipation medium liquid metal in the liquid metal loop, and is a DC conduction electromagnetic pump; the pressure vessel 7 is used to store the heat dissipation medium carbon dioxide; the controller 9 is used to switch the conduction branch according to the nitrogen temperature in the heat exchanger branch and the temperature of the low heat flux density heat source 6, and adjust the nitrogen flow rate in the first branch L1 and the second branch L2.

[0036] The aircraft step thermal management method provided by the present invention is described below. The aircraft step thermal management method described below and the aircraft step thermal management system described above can be referenced to each other.

[0037] An aircraft step thermal management method, using an aircraft step thermal management system, comprises: S1. Passive phase change heat storage of high heat flux density heat source 1 through liquid metal bypass heat sink 2.

[0038] S2. Actively cool the high heat flux density heat source 1 through a liquid metal loop.

[0039] A flight vehicle cascade thermal management method provided by the present invention combines active liquid metal cooling and passive phase change heat storage for a high heat flux density heat source 1. The liquid metal working fluid used has a wide liquid phase temperature range, and its boiling point is usually greater than 1000 °C, avoiding problems such as deterioration of heat transfer caused by vaporization of the working fluid and reduced reliability of pipeline sealing in traditional water cooling technologies. The phase change heat storage material uses a metal with a relatively low melting point. Compared with traditional phase change materials such as paraffin, it has a higher thermal conductivity, a shorter response time, better temperature uniformity, and no phenomena such as phase separation, phase stratification, and evaporation.

[0040] As Figure 2 shown, in a feasible embodiment of the present invention, the flight vehicle cascade thermal management method further includes S3: dissipating heat from a low heat flux density heat source 6, including: Setting the upper limit of the normal temperature range to T H ; Obtaining the temperature of the low heat flux density heat source 6 as T1 and the temperature of the second heat dissipation working fluid in the heat dissipation path of the low heat flux density heat source as T2; When T2 < T H < T1, turn on the first branch. The first branch is used for the heat dissipation path of the low heat flux density heat source to exchange heat with the liquid metal loop and then dissipate heat to the low heat flux density heat source 6; When T H < T2 < T1 or T H < T1 < T2, turn on the second branch. The second branch is used for the heat dissipation path of the low heat flux density heat source to directly dissipate heat to the low heat flux density heat source 6.

[0041] Through the above thermal management method, the present invention can use different heat dissipation methods according to the different characteristics of high heat flux density and low heat flux density heat sources. For high heat flux density heat sources, liquid metal circulation cooling and metal phase change heat storage methods are used; for low heat flux density heat sources, gas cooling methods are used. The two heat dissipation methods are coupled with each other to achieve efficient heat dissipation.

[0042] In a feasible embodiment of the present invention, dissipating heat from the low heat flux density heat source further includes: Obtaining the temperature T0 of the liquid metal loop; When T0 > T H , turn on the second branch.

[0043] In the above embodiments, the heat dissipation working fluid of the liquid metal loop in the flight vehicle cascade thermal management system is a liquid metal bismuth-indium-tin alloy with a melting point of 60 °C, and the heat dissipation working fluid of the heat dissipation path of the low heat flux density heat source is carbon dioxide.

[0044] The heat pipe array is a molten salt heat pipe, the heat exchanger is a shell-and-tube heat exchanger, the phase change heat storage working medium of the liquid metal bypass heat sink is lead-bismuth alloy with a melting point of 271°C, the flowmeter 5 is an electromagnetic flowmeter, and the driving pump 4 is a variable-speed diaphragm pump. To ensure the normal operation of the liquid metal loop, a heating and insulation device needs to be added outside the pipeline of this loop, and the insulation temperature is T0, where T0 > 271°C. The control strategy of the controller is as follows: The temperature of the low heat flux density heat source is T1, and the upper limit of the normal temperature range is T H , the first branch of the carbon dioxide heat exchanger is L1, the pressure vessel branch is L2, the temperature of carbon dioxide in the first branch L1 is T2, and the control strategy flowchart of the controller is as Figure 2 shown. If T2 < T H < T1, the first branch L1 is opened, and if T0 > T H , T H < T2 < T1 or T H < T1 < T2, the second branch L2 is opened.

[0045] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0046] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or mode are included in at least one embodiment or mode of the embodiments of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or modes. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or modes described in this specification and the features of different embodiments or modes.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An aircraft step thermal management system, characterized in that: For cooling a high heat flux density heat source (1), comprising: A liquid metal bypass heat sink (2) is connected to the high heat flux density heat source (1); the liquid metal bypass heat sink (2) is used to absorb the heat of thermal shock of the high heat flux density heat source (1) and is loaded with a phase change heat storage medium; A liquid metal circuit comprises a heat sink (3) and a driving pump (4), wherein a first heat dissipation medium for liquid metal flows; the heat sink (3) is connected to a high heat flux density heat source (1), and the heat sink (3) is a device for exchanging heat between the high heat flux density heat source (1) and the liquid metal circuit; the driving pump (4) is used to pump the heat dissipation medium in the liquid metal circuit.

2. The aircraft step thermal management system according to claim 1, characterized in that: It also includes a low heat flux density heat source heat dissipation passage, in which a second heat dissipation medium flows; the liquid metal circuit also includes a flow meter (5); the flow meter (5) is used to measure the flow rate of the first heat dissipation medium in real time; The low heat flux density heat source heat dissipation path comprises: a pressure vessel (7), a heat exchanger (8) and a controller (9); The pressure vessel (7), the heat exchanger (8), the controller (9) and the low heat flux density heat source (6) are connected in sequence to form a first branch; The pressure container (7), the controller (9) and the low heat flux density heat source (6) are connected in sequence to form a second branch; The pressure vessel (7) is used to store a second heat dissipation medium in a low heat flux density heat source heat dissipation path; the heat exchanger (8) is a device for exchanging heat between the liquid metal circuit and the low heat flux density heat source heat dissipation path; the controller (9) is used to switch between the first branch and the second branch according to the temperature of the second heat dissipation medium and the temperature of the low heat flux density heat source (6); and to adjust the flow rate of the second heat dissipation medium.

3. The aircraft step thermal management system according to claim 1, characterized in that: It also comprises a heat pipe array (10) connected between the high heat flux density heat source (1) and the heat sink (3), the heat pipe array (10) being used to extract heat from the high heat flux density heat source.

4. The aircraft step thermal management system according to claim 1, characterized in that: The liquid metal is a gallium-based or bismuth-based alloy with a melting point less than 300°C.

5. The aircraft step thermal management system according to claim 2, characterized in that: The heat dissipation medium of the low heat flux density heat source heat dissipation path includes one of carbon dioxide, nitrogen, ammonia and methane.

6. The aircraft step thermal management system according to claim 1, characterized in that: The phase change heat storage material in the liquid metal bypass heat sink is an aluminum-based or tin-based alloy with a melting point less than 800°C.

7. The aircraft step thermal management system according to claim 2, characterized in that: The heat exchanger (8) comprises a shell-and-tube heat exchanger or a partition-type heat exchanger.

8. An aircraft step thermal management method, using the aircraft step thermal management system according to any one of claims 1 to 7, characterized in that: include: Passive phase change heat storage of a high heat flux density heat source (1) through a liquid metal bypass heat sink (2); The high heat flux density heat source (1) is actively cooled by a liquid metal loop.

9. The aircraft step thermal management method according to claim 8, characterized in that: It also includes heat dissipation for a low heat flux density heat source (6), including: Set the upper limit of the normal temperature range to T H ; The temperature of the low heat flux heat source (6) is obtained as T 1 And the temperature of the second heat sink in the heat source heat dissipation path with low heat flux density is T 2; when T 2< T H < T 1, opening the first branch, the first branch being used for heat dissipation of the low heat flux density heat source (6) after heat exchange between the heat dissipation path of the low heat flux density heat source and the liquid metal circuit; when T H < T 2< T 1 or T H < T 1< T 2, the second branch is opened; the second branch is used for the low heat flux density heat source heat dissipation passage to directly dissipate heat from the low heat flux density heat source (6).

10. The aircraft step thermal management method according to claim 8, characterized in that: The heat dissipation of the low heat flux density heat source also includes: Get the temperature of the liquid metal circuit T 0; when T 0> T H When the second branch is opened.

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