Heterogeneous heat pipe and thermo-acoustic based thermal management system

Abstract

Provided are a special-shaped heat pipe for recovering exhaust gas waste heat, comprising an evaporator, a condenser pipe and a connecting pipe, the evaporator is located at the tail end of a turbine casing and is used for absorbing the heat of exhaust gas emitted by a tail nozzle to vaporize an internal working medium; the condenser pipe is sleeved on the outer periphery of an acoustic pipe; the connecting pipe is used for connecting the evaporator and the condenser pipe; wherein the acoustic pipe is used as a cold source to liquefy the internal working medium. A thermo-acoustic based thermal management system is also provided. The special-shaped heat pipe can efficiently recover exhaust gas waste heat.

Description

Technical Field

[0001] This invention relates to the field of aero-engines, and more specifically to the field of thermal management technology. Background Technology

[0002] With the development of aviation technology and the continuous improvement of aircraft performance, the power of aircraft components such as avionics, electromechanical control actuators, engine accessories, weapons and mission systems is increasing day by day. How to achieve efficient thermal management has become one of the key issues in aircraft design. Summary of the Invention

[0003] One object of the present invention is to provide a shaped heat pipe for waste heat recovery from exhaust gas, which can efficiently recover waste heat from exhaust gas.

[0004] The irregularly shaped heat pipe for achieving the above purpose includes an evaporator, a condenser, and connecting pipes. The evaporator is located at the tail end of the turbine casing and is used to absorb the heat of the exhaust gas ejected from the tailpipe to vaporize the internal working fluid. The condenser is sleeved on the outer periphery of the acoustic tube. The connecting pipes are used to connect the evaporator and the condenser. The acoustic tube serves as a cold source to liquefy the internal working fluid.

[0005] In one or more embodiments, the condenser tube includes a flow guide ring and capillary condenser tubes, the capillary condenser tubes extending axially and arranged circumferentially around the acoustic tube, and the flow guide ring connecting the circumferentially distributed capillary condenser tubes.

[0006] In one or more embodiments, the inner wall surfaces of the flow-guiding ring and the capillary condenser are provided with grooves.

[0007] In one or more embodiments, the difference between the outer diameter and the inner diameter of the drainage ring is greater than the inner diameter of the capillary condenser.

[0008] In one or more embodiments, the diameter of the capillary condenser ranges from 0.5 to 1.5 mm.

[0009] In one or more embodiments, a plurality of drainage rings are distributed axially, with the axial spacing between the drainage rings ranging from 50 to 70 mm.

[0010] In one or more embodiments, the evaporator is disposed on the inner surface of the turbine casing and integrated with the casing support plate.

[0011] In one or more embodiments, the irregularly shaped heat pipe further includes an insulating sleeve located on the outer surface of the condenser tube.

[0012] Another object of the present invention is to provide a thermoacoustic-based thermal management system, including a acoustic tube and a shaped heat pipe, wherein the first end of the acoustic tube is located at the front end of the combustion chamber casing and the second end is located at the front end of the tail nozzle; the shaped heat pipe is disposed at the front end of the tail nozzle and the tail end of the turbine casing; wherein the acoustic tube serves as a cold source to liquefy the internal working fluid and to transfer heat from the second end to the first end.

[0013] In one or more embodiments, a plurality of the acoustic tubes are circumferentially distributed around the outer periphery of the combustion chamber casing or the turbine casing.

[0014] The condenser end of the aforementioned irregularly shaped heat pipe is integrated with the acoustic tube, and the heat exchange area is increased through a ring arrangement to enhance heat exchange and improve system efficiency.

[0015] The aforementioned thermal management system uses acoustic tubes to effectively transfer heat, enabling better long-distance point-to-point energy transmission and avoiding flow losses caused by air propagation, thus effectively improving system efficiency. Attached Figure Description

[0016] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0017] Figure 1 This is a schematic diagram of the thermal management system.

[0018] Figure 2 This is a schematic diagram showing the installation positions of the heat pipes, acoustic pipes, and casing support plates;

[0019] Figure 3 This is a schematic diagram of one embodiment of a condenser;

[0020] Figure 4 This is a cross-sectional view of one embodiment of a capillary condenser.

[0021] Figure 5 This is a cross-sectional view of one embodiment of the drainage ring.

[0022] Symbol marking explanation

[0023] 6 Combustion chamber casing

[0024] 7. Casing support plate

[0025] 8. Tail nozzle

[0026] 9. Turbine casing

[0027] 10 Irregularly Shaped Heat Pipes

[0028] 11 Evaporator

[0029] 12 condenser tubes

[0030] 13 Connecting fittings

[0031] 14 Insulation sleeve

[0032] 20 sound tubes

[0033] 21 First End

[0034] 22 Second End

[0035] 125 Drainage Ring

[0036] 126 Capillary condenser

[0037] 127 Groove

[0038] 128 Space Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0040] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0041] An aircraft engine consists of a fan, compressor, combustion chamber, turbine, and nozzle. The fan, with its large-diameter blades at the front, is used to draw in air. The compressor, with its multi-stage blades, compresses the intake air. In the combustion chamber, fuel mixes and burns with the compressed, high-pressure air. The high-temperature combustion gases drive the turbine to rotate, which in turn drives the compressor and fan. The nozzle exhausts the combustion gases, generating thrust.

[0042] Aero engines require thermal management, which involves using a series of technical means to control and optimize the heat distribution inside the engine, ensuring that all components operate stably under high temperature and high pressure, recovering some waste heat to improve efficiency and ensure reliability.

[0043] Thermoacoustic heat engines are a promising solution for waste heat recovery and efficient thermal management. They operate on the principle of the thermoacoustic effect, converting thermal energy into acoustic energy. The thermoacoustic effect refers to the phenomenon where the interaction between a solid medium and an oscillating fluid in a sound field generates a time-averaged heat flow along or against the direction of sound propagation within a certain range from the solid wall, and generates or absorbs acoustic work within this region, such as through temperature gradients or acoustic oscillations inducing sound wave oscillations.

[0044] Thermoacoustic heat engines are based on two components: a heat pipe and an acoustic pipe.

[0045] A heat pipe is a heat-conducting element based on the principle of phase change, which generally includes an evaporation end, a condensation end, and an adiabatic section.

[0046] Sound tubes are conduit components used in thermoacoustic engines and thermoacoustic heat pumps to transmit sound energy.

[0047] Thermoacoustic heat engines have outstanding advantages: First, they have no moving parts, which fundamentally eliminates the wear and tear present in conventional mechanical refrigeration machines; second, because they use inert gas as the working medium, they fully comply with the current ban requirements in refrigeration technology and are in line with the general trend of environmental protection; and third, they are driven by thermal energy and can use waste heat as a heat source.

[0048] Based on the thermoacoustic effect, this disclosure provides a non-circular heat pipe 10 that can effectively recover waste heat from exhaust gas and has a simple structure.

[0049] like Figures 1 to 3 As shown, the irregularly shaped heat pipe 10 includes an evaporator 11, a condenser 12, and a connecting pipe 13.

[0050] Evaporator 11 is located at the tail end of turbine casing 9 and is used to absorb the heat of the exhaust gas ejected from tailpipe 8 to vaporize the internal working fluid. Condenser 12 is sleeved on the outer periphery of acoustic tube 20, with the condensing end integrated with acoustic tube 20, effectively increasing the heat exchange area. Connecting pipe 13 is used to connect evaporator 11 and condenser 12, and to transport the working fluid between them.

[0051] Furthermore, the condenser tube 12 includes a guide ring 125 and capillary condenser tubes 126. The capillary condenser tubes 126 extend axially and are arranged circumferentially around the acoustic tube 20. The guide ring 125 connects each circumferentially distributed capillary condenser tube 126, such as... Figure 3 As shown.

[0052] The capillary condenser tubes 126 extend axially at both ends, with a preferred diameter of 0.5-1.5 mm, and the number includes, but is not limited to, 6 tubes. They release heat to the acoustic tube 20 through a phase change process of the gaseous working fluid. The axial arrangement of the capillary condenser tubes 126 in the condenser tube 12 reduces the flow resistance of the acoustic tube and improves the thermoacoustic conversion efficiency. The space 128 circumferentially enclosed by the multiple capillary condenser tubes 126 is used to accommodate the acoustic tube 20.

[0053] The drainage ring 125 serves to connect and guide the flow, according to... Figure 3As shown, the capillary condenser 126 is fluidly connected to each of the flow guide rings 125. Because the capillary condenser 126 is connected to the annular region of the flow guide rings 125, the difference between the outer diameter and the inner diameter of the flow guide rings 125 must be greater than the inner diameter of the capillary condenser 126 to ensure the spatial continuity of the internal flow channels. The flow guide rings 125 are distributed axially, as shown... Figure 3 The rings shown are preferably evenly spaced along the axial direction in the left-right direction, with a spacing range of 50-70mm, and the number includes, but is not limited to, 3. Using the drainage ring 126 to collect and guide condensate can prevent localized heat transfer degradation and improve reliability.

[0054] exist Figure 4 and Figure 5 In the illustrated embodiment, grooves 127 are machined into the inner wall surfaces of the capillary condenser 125 and the guide ring 126 to fill the liquid-absorbing core material and enhance the adsorption force of the wall surface on the liquid.

[0055] Among them, the sound tube 20 serves as a cold source, using a liquefied working fluid that has become vaporized inside to absorb the heat released by the condenser tube 12.

[0056] In this way, the evaporator 11 absorbs the waste heat from the engine exhaust gas, and the working fluid in the shaped heat pipe 10 absorbs the heat of the exhaust gas and vaporizes in the evaporator 11. It then flows through the connecting pipe 13 to the capillary condenser tube 126 and the flow guide ring 125 of the condenser 12. The capillary condenser tube 126 is arranged around the sound tube 20. The sound tube 20 acts as a cold source, causing the working fluid to release heat and liquefy. It then flows back to the evaporator 11, and so on, transferring heat energy in a continuous cycle.

[0057] The irregularly shaped heat pipe also includes an insulating sleeve 14 located on the outer surface of the condenser tube 12, such as Figure 2 As shown, the insulation sleeve 14 covers the outer periphery of the drainage ring 125 and the capillary condenser tube 126. In some embodiments, the insulation sleeve 14 has a vacuum layer, for example, the thickness of the vacuum layer is 2 mm, to prevent heat from dissipating from the acoustic tube 20 into the environment. The connecting pipe 13 passes through the insulation sleeve 14 and communicates with the condenser tube 12. The vacuum insulation sleeve has better thermal insulation performance, which can reduce heat dissipation to the environment and improve the overall system performance.

[0058] To reduce engine flow resistance, the evaporator 11 is disposed on the inner surface of the turbine casing 9 and integrated with the casing support plate 7, such as... Figure 2 As shown, this structure avoids increasing engine flow resistance while providing cooling for the turbine rear casing support plate.

[0059] Therefore, the aforementioned irregular heat pipe 10 can effectively recover exhaust gas heat, and the irregular heat pipe is integrated with the sound pipe and the turbine rear casing support plate, which has a simple structure and light weight, and can also effectively reduce the flow resistance of the engine.

[0060] Based on current thermoacoustic technology, thermal management systems generally have the following problems:

[0061] (1) The heat generated by thermoacoustic engines and thermoacoustic heat pumps is generally transferred through heat exchangers installed at both ends of the plate stack. However, traditional shell-and-tube heat exchangers cannot meet the requirements of long-distance point-to-point energy transfer, resulting in unsatisfactory heat exchange effect and failure to dissipate heat in a timely manner.

[0062] (2) Sound energy propagates through the air in a traditional shell-and-tube heat exchanger, resulting in significant flow losses and low system efficiency.

[0063] (3) Traditional shell-and-tube heat exchangers are heavy and bulky, which is not conducive to reducing the weight of aero engines and can easily increase the main flow resistance and reduce engine efficiency.

[0064] Based on the above problems, this disclosure also proposes a thermal management system based on thermoacoustics, such as... Figure 1 As shown, the thermal management system includes a sound tube 20 and the aforementioned irregularly shaped heat pipe 10.

[0065] The first end 21 of the acoustic tube 20 is located at the front end of the combustion chamber casing 6, and the second end 22 is located at the front end of the tail nozzle 8. The condenser tube 12 of the irregular heat pipe 10 is sleeved on the outer periphery of the second end 22 of the acoustic tube 20.

[0066] The irregularly shaped heat pipe 10 is located at the front end of the tail nozzle 8 and the rear end of the turbine casing 9. More specifically, the axial position of the irregularly shaped heat pipe 10 is generally located between the tail nozzle 8 and the turbine rear casing support plate 7. The turbine casing 9 and the combustion chamber casing 6 have the same axis.

[0067] The irregularly shaped heat pipe 10 absorbs waste heat from the engine exhaust, causing the working fluid flowing inside to vaporize. The sound pipe 20 acts as a cold source, liquefying the working fluid inside the irregularly shaped heat pipe 10 and absorbing heat released from the condenser.

[0068] The acoustic tube 20 also transfers heat from the second end 22 to the first end 21, and then to the combustion chamber casing 2, to preheat the inlet air. Based on the acoustic tube principle, the oscillation of sound waves causes gas molecules to undergo periodic compression and expansion at a microscale, allowing heat energy to transfer along the direction of sound wave propagation. Thus, heat can be transferred from the axial rear side to the axial front side of the combustion chamber casing 2 through the acoustic tube 3, thereby increasing the combustion chamber intake temperature and preheating the inlet air.

[0069] Multiple acoustic tubes 20 are circumferentially distributed around the outer periphery of the combustion chamber casing 6 or the turbine casing 9. For example, 40 units are evenly distributed circumferentially, each unit including an acoustic tube 20 and a shaped heat pipe 10.

[0070] The above-mentioned thermal management system has the following advantages:

[0071] (1) The use of the sound tube 20 can effectively achieve heat transfer, can better achieve long-distance point-to-point energy transmission, and can also avoid flow loss caused by propagation in the air, effectively improving system efficiency.

[0072] (2) The thermal management system is small in size and lightweight, and does not easily increase the main flow resistance, thus having better thermal management efficiency.

[0073] It should be noted that the use of terms such as "first" and "second" to define components in the above description is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning, do not represent primary or secondary, and therefore should not be construed as limiting the scope of protection of this application.

[0074] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0075] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0076] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A shaped heat pipe for waste heat recovery from exhaust gas, characterized in that, include: The evaporator, located at the rear end of the turbine casing, is used to absorb the heat of the exhaust gas ejected from the tailpipe in order to vaporize the internal working fluid. The condenser tube is fitted around the outer circumference of the sound tube; as well as Connecting pipe fittings for connecting the evaporator pipe and the condenser pipe; The acoustic tube serves as a cold source to liquefy the internal working fluid.

2. The irregularly shaped heat pipe as described in claim 1, characterized in that, The condenser tube includes a flow guide ring and a capillary condenser tube. The capillary condenser tube extends axially and is arranged circumferentially around the acoustic tube. The flow guide ring connects each capillary condenser tube distributed circumferentially.

3. The irregularly shaped heat pipe as described in claim 2, characterized in that, The inner wall surfaces of the flow guide ring and the capillary condenser are provided with grooves.

4. The irregularly shaped heat pipe as described in claim 3, characterized in that, The difference between the outer diameter and the inner diameter of the flow-guiding ring is greater than the inner diameter of the capillary condenser.

5. The irregularly shaped heat pipe as described in claim 2, characterized in that, The diameter of the capillary condenser is in the range of 0.5-1.5 mm.

6. The irregularly shaped heat pipe as described in claim 2, characterized in that, Multiple drainage rings are distributed along the axial direction, with an axial spacing of 50-70 mm between the drainage rings.

7. The irregularly shaped heat pipe as described in claim 1, characterized in that, The evaporator is disposed on the inner surface of the turbine casing and integrated with the casing support plate.

8. The irregularly shaped heat pipe as described in claim 1, characterized in that, The irregularly shaped heat pipe also includes an insulating sleeve located on the outer surface of the condenser tube.

9. A thermal management system based on thermoacoustics, characterized in that, include: The sound tube has its first end located at the front end of the combustion chamber casing and its second end located at the front end of the tail nozzle. The irregularly shaped heat pipe as described in any one of claims 1 to 8 is disposed at the front end of the tail nozzle and the rear end of the turbine casing; The acoustic tube serves as a cold source to liquefy the internal working fluid and to transfer heat from the second end to the first end.

10. The thermal management system as described in claim 9, characterized in that, Multiple acoustic tubes are circumferentially distributed around the outer periphery of the combustion chamber casing or the turbine casing.

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