Aircraft step thermal management system and thermal management method

Abstract

The present application relates to the technical field of heat management, and particularly provides an aircraft step heat management system and a heat management method, comprising a liquid metal bypass heat sink connected with a high heat flux density heat source; the liquid metal bypass heat sink is used for absorbing heat impact heat of the high heat flux density heat source and is filled with a phase change heat storage working medium; a liquid metal loop comprising a heat sink and a driving pump, and a first heat dissipation working medium which is liquid metal flows through; the heat sink is connected with the high heat flux density heat source, and the heat sink is a device for heat exchange between the high heat flux density 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 present application adopts a combination of liquid metal active fluid cooling and passive phase change heat storage for the high heat flux density heat source, the liquid phase temperature range of the liquid metal working medium is wide, and the boiling point is usually greater than 1000 DEG C, thereby avoiding the problems of heat transfer deterioration and reduction of pipeline sealing reliability caused by working medium vaporization in water cooling technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal management, in particular to an aircraft cascade thermal management system and a thermal management method. BACKGROUND

[0002] High-speed aircrafts face severe aerodynamic heat load when flying in space, especially in a long-time, high-Mach number, high-power demand working environment, the local temperature of the leading edge surface of the aircraft and the surface of the rudder shaft can exceed 1000℃, and the heat flux density can exceed 1MW / m 2 Overly high aerodynamic heat load can reduce the rigidity of the aircraft itself and also have a significant impact on the internal electronic equipment of the aircraft, thereby reducing the reliability and life of the aircraft operation, so effective thermal management of the aircraft is an important problem.

[0003] The aircraft has the characteristics of scattered heat sources and different heat flux densities during operation. The heat flux density of the leading edge surface of the aircraft and the surface of the rudder shaft is high, and the heat power is large. However, the avionics system, hydraulic system, and high-power electrical equipment inside the cabin have relatively small heat flux density, irregular shape of the heat dissipation surface, and are relatively scattered. SUMMARY

[0004] The present application provides an aircraft cascade thermal management system and a thermal management method to solve the problem of difficult thermal management design caused by scattered heat sources and different heat flux densities in the prior art, and to achieve efficient heat dissipation of the aircraft.

[0005] The present application provides an aircraft cascade thermal management system for cooling high heat flux density heat sources, comprising:

[0006] A liquid metal bypass heat sink connected to the high heat flux density heat source; the liquid metal bypass heat sink is used to absorb heat shock heat of the high heat flux density heat source and is filled with a phase change heat storage working medium;

[0007] A liquid metal loop including a heat sink and a driving pump, which circulates a first heat dissipation working medium that is liquid metal; the heat sink is connected to the high heat flux density heat source, and the heat sink is a device for heat exchange between the high heat flux density heat source and the liquid metal loop; the driving pump is used to pump the heat dissipation working medium in the liquid metal loop.

[0008] According to the aircraft cascade thermal management system provided by the present application, a low heat flux density heat source heat dissipation passage is further included, which circulates a second heat dissipation working medium; the liquid metal loop further includes a flow meter; the flow meter is used to measure the flow of the first heat dissipation working medium in real time;

[0009] The low heat flux density heat source heat dissipation passage includes a pressure vessel, a heat exchanger, and a controller;

[0010] The pressure container, the heat exchanger, the controller and the low heat flow density heat source are sequentially connected to form a first branch;

[0011] The pressure container, the controller and the low heat flow density heat source are sequentially connected to form a second branch;

[0012] The pressure container is used for storing the second heat dissipation working medium in the low heat flow density heat source heat dissipation passage; the heat exchanger is a device for heat exchange between the liquid metal loop and the low heat flow density heat source heat dissipation passage; the controller is used for switching on the first branch and the second branch according to the temperature of the second heat dissipation working medium and the temperature of the low heat flow density heat source; and adjusting the flow size of the second heat dissipation working medium.

[0013] The aircraft step-by-step thermal management system provided by the application further comprises a heat pipe array connected between the high heat flow density heat source and the heat sink, and the heat pipe array is used for heat extraction from the high heat flow density heat source.

[0014] The liquid metal adopts a gallium-based or bismuth-based alloy with a melting point less than 300 DEG C.

[0015] The heat dissipation working medium of the low heat flow density heat source heat dissipation passage comprises one of carbon dioxide, nitrogen, ammonia and methane.

[0016] The phase change heat storage material in the liquid metal bypass heat sink adopts an aluminum-based or tin-based alloy with a melting point less than 800 DEG C.

[0017] The heat exchanger comprises a double-pipe heat exchanger or a partition wall heat exchanger.

[0018] The application further provides an aircraft step-by-step thermal management method, which utilizes the aircraft step-by-step thermal management system as described above, and comprises the following steps.

[0019] The high heat flow density heat source is passively phase change heat stored by the liquid metal bypass heat sink;

[0020] The high heat flow density heat source is actively cooled by the liquid metal loop.

[0021] The aircraft step-by-step thermal management method further comprises heat dissipation of the low heat flow density heat source, which comprises the following steps.

[0022] The upper limit of the normal temperature range is set as T H ;

[0023] The temperature of the low heat flux density heat source is T1, and the temperature of the second heat dissipation working medium in the heat dissipation passage of the low heat flux density heat source is T2;

[0024] When T2<T H <T1, the first branch is started, and the first branch is used for heat dissipation of the low heat flux density heat source through the heat dissipation passage and the liquid metal loop heat exchange and then heat dissipation of the low heat flux density heat source;

[0025] When T H <T2<T1, the second branch is started; the second branch is used for direct heat dissipation of the low heat flux density heat source through the heat dissipation passage of the low heat flux density heat source.

[0026] According to the aircraft step-by-step thermal management method provided by the application, the heat dissipation of the low heat flux density heat source further comprises:

[0027] The temperature T0 of the liquid metal loop is obtained;

[0028] When T0>T H , the second branch is started.

[0029] The aircraft step-by-step thermal management system and the thermal management method provided by the application adopt the combination of the liquid metal active fluid cooling and the passive phase change heat storage for the high heat flux density heat source, the liquid phase temperature range of the liquid metal working medium is wide, and the boiling point is usually greater than 1000 DEG C, so that the problems such as heat transfer deterioration and reduced pipeline sealing reliability caused by working medium gasification in the traditional water cooling technology are avoided; the phase change heat storage material adopts a metal with a lower melting point, compared with the traditional phase change material such as paraffin, the thermal conductivity is higher, the response time is shorter, the temperature uniformity is better, and there is no phase separation, phase stratification, evaporation and other phenomena.

[0030] In addition, different heat dissipation methods are used for different characteristics of the high heat flux density heat source and the low heat flux density heat source, for the high heat flux density heat source, the liquid metal circulating cooling and the metal phase change heat storage method are adopted, and for the low heat flux density heat source, the gas cooling method is adopted, the two heat dissipation methods are coupled with each other, and high-efficiency heat dissipation is realized. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0032] Figure 1 It is a structural schematic diagram of the aircraft step-by-step thermal management system provided by the application.

[0033] Figure 2 is a control strategy diagram of the aircraft step thermal management method provided by the application.

[0034] Reference signs:

[0035] 1, high heat flux heat source; 2, liquid metal bypass heat sink; 3, heat sink; 4, driving pump; 5, flow meter; 6, low heat flux heat source; 7, pressure container; 8, heat exchanger; 9, controller; 10, heat pipe array; 11, external environment. DETAILED DESCRIPTION

[0036] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below in combination with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0037] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms “center”, “longitudinal”, “transverse”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms “first”, “second”, “third” are only for description purposes, and cannot be understood as indicating or implying relative importance.

[0038] The following will be described in combination with Figure 1 The aircraft step thermal management system of the present application is used for cooling the high heat flux heat source 1, and comprises a liquid metal bypass heat sink 2, a heat sink 3 and a driving pump 4. The liquid metal bypass heat sink 2 is connected with the high heat flux heat source 1. The liquid metal bypass heat sink 2 is used for absorbing heat shock heat of the high heat flux heat source 1, and is filled with a phase change heat storage working medium.

[0039] The liquid metal circuit comprises the heat sink 3 and the driving pump 4, and circulates a first heat dissipation working medium which is liquid metal. The heat sink 3 is connected with the high heat flux heat source 1, and is a device for heat exchange between the high heat flux heat source 1 and the liquid metal circuit. The driving pump 4 is used for pumping the heat dissipation working medium in the liquid metal circuit.

[0040] The aircraft step thermal management system provided by the application adopts a liquid metal active fluid cooling and passive phase change heat storage combined mode for a high heat flux density heat source 1, the liquid metal has a wide liquid phase temperature zone, and the boiling point is usually greater than 1000 DEG C, thereby avoiding problems such as heat transfer deterioration and reduced pipeline sealing reliability caused by gasification of a working medium in traditional water cooling technology; the phase change heat storage material adopts a metal with a relatively low melting point, compared with a traditional phase change material such as paraffin, the thermal conductivity is relatively high, the response time is relatively short, and the temperature uniformity is better, and there are no phenomena such as phase separation, phase stratification and evaporation.

[0041] In a feasible embodiment of the application, the low heat flux density heat source heat dissipation channel is further included, and a second heat dissipation working medium flows in the low heat flux density heat source heat dissipation channel; the liquid metal circuit further includes a flow meter 5; the flow meter 5 is used for measuring the flow of the first heat dissipation working medium in real time. The low heat flux density heat source 6 heat dissipation channel includes a pressure container 7, a heat exchanger 8 and a controller 9. The pressure container 7, the heat exchanger 8, the controller 9 and the low heat flux density heat source 6 are sequentially connected to form a first branch; the pressure container 7, the controller 9 and the low heat flux density heat source 6 are sequentially connected to form a second branch; wherein the pressure container 7 is used for storing the second heat dissipation working medium in the low heat flux density heat source heat dissipation channel; the heat exchanger 8 is a device for heat exchange between the liquid metal circuit and the low heat flux density heat source heat dissipation channel; the controller 9 is used for switching on the first branch and the second branch according to the temperature of the second heat dissipation working medium and the temperature of the low heat flux density heat source 6; and adjusting the flow size of the second heat dissipation working medium.

[0042] The aircraft step thermal management system provided by the embodiment realizes efficient heat dissipation by adopting a gas cooling method for the low heat flux density heat source.

[0043] In a feasible embodiment of the application, a heat pipe array 10 is further included, and the heat pipe array 10 is connected between the high heat flux density heat source 1 and the heat sink 3, and the heat pipe array 10 is used for taking heat from the high heat flux density heat source.

[0044] The liquid metal adopts a gallium-based or bismuth-based alloy with a melting point less than 300 DEG C.

[0045] The heat dissipation working medium of the low heat flux density heat source heat dissipation channel includes one of carbon dioxide, nitrogen, ammonia and methane.

[0046] The phase change heat storage material in the liquid metal bypass heat sink adopts an aluminum-based or tin-based alloy with a melting point less than 800 DEG C, and other phase change heat storage materials can also be used.

[0047] The heat exchanger 8 includes a double-pipe heat exchanger or a partition wall heat exchanger, and other types of heat exchangers can also be used.

[0048] It should be noted that the controller 9 can also be in communication with an external environment 11 for discharge of the cooling gas. In addition, the external environment 11 can also be connected with the low heat flux density heat source 6.

[0049] As Figure 1 shown, the embodiment of the present application provides a kind of aircraft ladder heat management system, including heat pipe array 10, heat sink 3, liquid metal bypass heat sink 2, heat exchanger 8, flowmeter 5, driven pump 4, pressure vessel 7 and controller 9.Heat sink 3, heat exchanger 8, flowmeter 5 and driven pump 4 constitute liquid metal circuit, and heat dissipation working medium is liquid metal gallium indium tin alloy, and melting point is 11 ℃.Pressure vessel 7, controller 9 and heat exchanger 8 constitute low heat flow density heat source heat dissipation passage, and low heat flow density heat source 6 includes cabin interior avionics system, hydraulic system, high-power electrical equipment, and heat dissipation working medium is nitrogen.

[0050] Heat pipe array 10 is used to heat from high heat flow density heat source 1 aircraft leading edge, and type is metal heat pipe;Heat sink 3 is the device for heat exchange between high heat flow density heat source 1 / heat pipe array 10 and liquid metal circuit;Heat exchanger 8 is the device for heat exchange between liquid metal and nitrogen in liquid metal circuit and low heat flow density heat source heat dissipation passage, and type is double-pipe heat exchanger;Liquid metal bypass heat sink 2 is used to absorb high heat flow density heat source 1 heat shock heat, and is filled with phase change heat storage working medium bismuth tin alloy, and melting point is 138 ℃;Flowmeter 5 is used to measure the flow of liquid metal in real time, and type is ultrasonic flowmeter;Driven pump 4 is used to pump heat dissipation working medium liquid metal in liquid metal circuit, and type is direct current conduction type electromagnetic pump;Pressure vessel 7 is used to store heat dissipation working medium carbon dioxide;Controller 9 is used to switch on according to the temperature of nitrogen in heat exchanger branch and the temperature of low heat flow density heat source 6 and adjust the flow size of nitrogen in the first branch L1 and the second branch L2 of on.

[0051] The aircraft ladder heat management method provided by the present application will be described below, and the aircraft heat management method described below can be correspondingly referred to the aircraft ladder heat management system described above.

[0052] A kind of aircraft ladder heat management method, utilizes aircraft ladder heat management system, including:

[0053] S1, through liquid metal bypass heat sink 2 passive phase change heat storage to high heat flow density heat source 1.

[0054] S2, through liquid metal circuit to high heat flow density heat source 1 active cooling.

[0055] The aircraft step heat management method provided by the application adopts a combination of liquid metal active fluid cooling and passive phase change heat storage for a high heat flux density heat source 1, the liquid metal working medium has a wide liquid phase temperature range, and the boiling point is usually greater than 1000 DEG C, thereby avoiding problems such as heat transfer deterioration and reduced pipeline sealing reliability caused by working medium vaporization in traditional water cooling technology; the phase change heat storage material adopts a metal with a relatively low melting point, and compared with traditional phase change materials such as paraffin, the thermal conductivity is higher, the response time is shorter, and the temperature uniformity is better, and there are no phenomena such as phase separation, phase stratification and evaporation.

[0056] As shown in Figure 2 , in one possible embodiment of the application, the aircraft step heat management method further comprises S3, heat dissipation for a low heat flux density heat source 6, comprising:

[0057] The upper limit of the normal temperature range is set to T H ;

[0058] The temperature of the low heat flux density heat source 6 is obtained as T1, and the temperature of the second heat dissipation working medium in the low heat flux density heat source heat dissipation channel is obtained as T2;

[0059] When T2<T H <T1, the first branch is opened, and the first branch is used for heat dissipation of the low heat flux density heat source after heat exchange between the low heat flux density heat source heat dissipation channel and the liquid metal loop, and then heat dissipation of the low heat flux density heat source 6;

[0060] When T H <T2<T1, the second branch is opened; the second branch is used for direct heat dissipation of the low heat flux density heat source 6 in the low heat flux density heat source heat dissipation channel.

[0061] Through the above heat management method, different heat dissipation methods can be used for different characteristics of the high heat flux density heat source and the low heat flux density heat source, liquid metal circulation cooling and metal phase change heat storage methods are used for the high heat flux density heat source, and a gas cooling method is used for the low heat flux density heat source, the two heat dissipation methods are coupled with each other, and high-efficiency heat dissipation is achieved.

[0062] In one possible embodiment of the application, heat dissipation for the low heat flux density heat source further comprises:

[0063] The temperature T0 of the liquid metal loop is obtained;

[0064] When T0>T H , the second branch is opened.

[0065] In the above embodiment, the aircraft step heat management system adopts a liquid metal bismuth-indium-tin alloy as the heat dissipation working medium of the liquid metal loop, and the melting point is 60 DEG C; and carbon dioxide is used as the heat dissipation working medium of the low heat flux density heat source heat dissipation channel.

[0066] The heat pipe array is a molten salt heat pipe, the heat exchanger is a partition heat exchanger, the phase change heat storage working medium of the liquid metal bypass heat sink is lead bismuth alloy, the melting point is 271 DEG C, the flowmeter 5 is an electromagnetic flowmeter, and the driving pump 4 is a variable speed diaphragm pump. In order to ensure the normal operation of the liquid metal loop, a heating and heat preservation device needs to be added outside the pipeline of the loop, the heat preservation temperature is T0, T0>271 DEG C, and the control strategy of the controller is as follows:

[0067] The low heat flow density heat source temperature is T1, the upper limit of the normal temperature range is T H , the heat exchanger first branch of carbon dioxide is L1, the pressure container branch is L2, the carbon dioxide temperature in the first branch L1 is T2, and the control strategy flow chart of the controller is as shown in Figure 2 If T2 H <T1, the first branch L1 is started, and if T0>T H , T H <T2<T1, the second branch L2 is started.

[0068] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0069] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "way", "specific way" or "some ways" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or way are included in at least one embodiment or way of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or way. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or ways in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or features of the embodiments described in the present application without contradiction.

[0070] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part 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 application.

Claims

1. A cascaded thermal management system for an aircraft, characterized in that, For cooling a high heat flux density heat source (1), including: 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 thermal shock heat from the high heat flux density heat source (1) and is filled with a phase change heat storage medium. The liquid metal circuit includes a heat sink (3) and a drive pump (4), through which a first heat dissipation medium of liquid metal flows; and the heat sink (3) is connected to the high heat flux density heat source (1), and the heat sink (3) is a device for heat exchange between the high heat flux density heat source (1) and the liquid metal circuit; the drive pump (4) is used to pump the heat dissipation medium in the liquid metal circuit; It also includes a low heat flux density heat source heat dissipation path, through which a second heat dissipation working fluid 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 working fluid in real time; The heat dissipation path of the low heat flux density heat source 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 the 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; The pressure vessel (7) is used to store the second heat dissipation medium in the heat dissipation path of the low heat flux density heat source; the heat exchanger (8) is a device for heat exchange between the liquid metal circuit and the heat dissipation path of the low heat flux density heat source; 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 to adjust the flow rate of the second heat dissipation medium.

2. The aircraft cascade thermal management system according to claim 1, characterized in that, It also includes 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.

3. The aircraft cascade 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 of less than 300°C.

4. The aircraft cascade thermal management system according to claim 1, 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.

5. The aircraft cascade 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 of less than 800°C.

6. The aircraft cascade thermal management system according to claim 1, characterized in that, The heat exchanger (8) includes a shell-and-tube heat exchanger or a wall-and-wall heat exchanger.

7. A method for cascade thermal management of an aircraft, utilizing the cascade thermal management system for an aircraft as described in any one of claims 1-6, characterized in that, include: Passive phase change heat storage of high heat flux density heat source (1) through liquid metal bypass heat sink (2); The high heat flux density heat source (1) is actively cooled by a liquid metal circuit.

8. The aircraft cascade thermal management method according to claim 7, characterized in that, It also includes heat dissipation from low heat flux density heat sources (6), including: Set the upper limit of the normal temperature range to T H ; The temperature at which the low heat flux density heat source (6) is obtained is T 1 The temperature of the second heat dissipation medium in the heat dissipation path of the low heat flux density heat source is T 2; when T 2< T H < T At time 1, the first branch is opened. The first branch is used as a heat dissipation path for the low heat flux density heat source and the liquid metal circuit to exchange heat and then dissipate heat to the low heat flux density heat source (6). when T H < T 2< T At time 1, the second branch is opened; the second branch is used to directly dissipate heat from the low heat flux density heat source (6) through the heat dissipation path of the low heat flux density heat source.

9. The aircraft cascade thermal management method according to claim 8, characterized in that, The heat dissipation from the low heat flux density heat source also includes: Temperature of liquid metal circuit T 0; when T 0> T H At that time, the second branch is activated.

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