An integrated thermal management system for hypersonic vehicles based on Brayton cycle

Abstract

The present invention discloses a hypersonic aircraft integrated thermal management system based on Brayton cycle, which relates to the field of aircraft thermal management technology. The system comprises: equipment heat load, regenerator, heat exchanger, cooling channel and engine; the cooling channel is arranged on the outer wall of the combustion chamber of the engine; the output end of the equipment heat load is connected to the first input end of the regenerator, and the first output end of the regenerator is connected to the first input end of the heat exchanger; the output end of the cooling channel is connected to the second input end of the regenerator, and the second output end of the regenerator is connected to the second input end of the heat exchanger, and the second output end of the heat exchanger is connected to the input end of the cooling channel. The present invention adopts fuel and carbon dioxide as coolants, and the fuel absorbs the equipment heat load and exchanges heat with high-temperature carbon dioxide, and the heated fuel exchanges heat with low-temperature carbon dioxide. Compared with direct heat exchange with carbon dioxide, the fuel is used as an intermediate medium, which reduces the temperature difference between the cold and hot fluids of the regenerator and avoids the pinch point problem of the regenerator.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft thermal management, and in particular to an integrated thermal management system for a hypersonic aircraft based on a Brayton cycle. Background Art

[0002] With the development of power technology in the field of aerospace, hypersonic aircraft present the characteristics of wide envelope, long flight time and reusability. Aircraft thermal protection and power supply are facing new technical challenges. It is imperative to develop a system that converts waste heat generated during flight into electrical energy. The thermal protection of hypersonic aircraft includes its surface thermal protection, internal equipment thermal load and engine thermal protection. At present, the commonly used cooling method for engines is regenerative cooling. The fuel first flows through the cooling channel composed of the inner and outer walls of the combustion chamber, absorbs heat through convection heat transfer and cracking reaction, and then is injected into the combustion chamber to generate thrust. Its advantage is that it can realize the recycling of heat energy and avoid the mass penalty brought by carrying additional coolant. However, with the increase of Mach number, the high-temperature coking problem of fuel is a major bottleneck restricting the improvement of the life of high Mach number engines. If the waste heat generated is utilized, on the one hand, the thermal protection problem can be solved, and on the other hand, it can be converted into usable energy, thereby improving the energy efficiency ratio of the aircraft.

[0003] In order to solve the problems of insufficient heat sink for engine regenerative cooling fuel, high-temperature coking blocking cooling channels, and increased power demand for aircraft after the Mach number of hypersonic aircraft increases, a solution is proposed to generate electricity through the power cycle system using the heat absorbed in the thermal protection of the aircraft. The invention patent named "A Regenerative Closed Brighton Cooling Cycle System" uses supercritical helium to cool the engine. The high-temperature and high-pressure helium after absorbing heat expands through the turbine to generate electricity while driving other parts of the system to operate. However, when helium is used as the circulating working fluid, the power consumption of the compressor accounts for a large proportion of the turbine output power, reaching about 45%. In addition, in the traditional regenerator, high and low temperature carbon dioxide is used for direct heat exchange, and the temperature difference between the cold and hot fluids in the regenerator is large, and there is a pinch point problem in the regenerator. Summary of the invention

[0004] The purpose of the present invention is to provide a comprehensive thermal management system for hypersonic aircraft based on the Brayton cycle, which reduces the proportion of compressor power consumption in turbine output power and avoids the pinch point problem in the regenerator.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A hypersonic vehicle integrated thermal management system based on a Brayton cycle, comprising: a device thermal load, a regenerator, a heat exchanger, a cooling channel and an engine; the cooling channel is arranged on the outer wall of a combustion chamber in the engine;

[0007] The output end of the equipment heat load is connected to the first input end of the regenerator, and the first output end of the regenerator is connected to the first input end of the heat exchanger; the output end of the cooling channel is connected to the second input end of the regenerator, and the second output end of the regenerator is connected to the second input end of the heat exchanger, and the second output end of the heat exchanger is connected to the input end of the cooling channel;

[0008] The equipment heat load is used to output the initially heated fuel to the regenerator; the initially heated fuel is the fuel after the target fuel entering the equipment heat load absorbs heat;

[0009] The regenerator is used for:

[0010] The fuel heated up for the first time absorbs the heat of the high-temperature carbon dioxide, and the fuel heated up for the second time is output to the heat exchanger from the first output end of the regenerator, and the carbon dioxide cooled down is output to the heat exchanger from the second output end of the regenerator; the high-temperature carbon dioxide is input through the second input end of the regenerator;

[0011] The heat exchanger is used for:

[0012] The cooled carbon dioxide absorbs the heat of the secondary heated fuel, and the primary cooled fuel is sprayed into the combustion chamber from the first output end of the heat exchanger, and the heated carbon dioxide is provided to the cooling channel from the second output end of the heat exchanger;

[0013] The cooling channel is used for:

[0014] The heated carbon dioxide absorbs the heat generated by the combustion of the fuel that has been cooled once in the combustion chamber, so as to output the high-temperature carbon dioxide to the regenerator.

[0015] Optionally, the integrated thermal management system for a hypersonic aircraft based on the Brayton cycle further comprises: a compressor; a first input end of the compressor is connected to a second output end of the regenerator, and an output end of the compressor is connected to a second input end of the heat exchanger;

[0016] The compressor is used to compress the cooled carbon dioxide.

[0017] Optionally, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle further comprises: a turbine; an input end of the turbine is connected to an output end of the cooling channel, and a first output end of the turbine is connected to a second input end of the regenerator;

[0018] The turbine is used to expand the high-temperature carbon dioxide to produce work.

[0019] Optionally, the integrated thermal management system for a hypersonic aircraft based on the Brayton cycle further comprises: a fuel tank; the fuel tank is connected to an input end of the thermal load of the equipment;

[0020] The fuel tank is used to provide the target fuel.

[0021] Optionally, the integrated thermal management system for a hypersonic aircraft based on the Brayton cycle further comprises: a fuel pump, one end of the fuel pump being connected to the fuel tank, and the other end of the fuel pump being connected to the input end of the thermal load of the equipment;

[0022] The fuel pump is used to pump the target fuel from the fuel tank into the equipment heat load.

[0023] Optionally, the hypersonic vehicle integrated thermal management system based on the Brayton cycle further includes: a fuel injector, the fuel injector is arranged in the engine, and the input end of the fuel injector is connected to the first output end of the heat exchanger;

[0024] The fuel injector is used to inject the fuel that has been cooled once into the combustion chamber.

[0025] Optionally, the Brayton cycle-based hypersonic vehicle integrated thermal management system further comprises: a carbon dioxide storage tank; the carbon dioxide storage tank is connected to the first input end of the compressor;

[0026] The carbon dioxide storage tank is used to provide carbon dioxide;

[0027] The compressor is further used for compressing the carbon dioxide output from the carbon dioxide storage tank.

[0028] Optionally, the Brayton cycle-based hypersonic vehicle integrated thermal management system further comprises: a generator; the generator is connected to the second output end of the turbine;

[0029] The generator is used to generate electricity by utilizing the work generated by the expansion of the high-temperature carbon dioxide.

[0030] Optionally, the hypersonic vehicle integrated thermal management system based on the Brayton cycle further includes: a central shaft; one end of the central shaft is connected to the second input end of the compressor, and the other end of the central shaft is connected to the third output end of the turbine;

[0031] The central shaft is used to transmit the electricity generated by the generator to the compressor to provide power for the compressor.

[0032] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0033] The present invention discloses a hypersonic vehicle integrated thermal management system based on the Brayton cycle, comprising: equipment heat load, a regenerator, a heat exchanger, a cooling channel and an engine; the cooling channel is arranged on the outer wall of the combustion chamber in the engine; the output end of the equipment heat load is connected to the first input end of the regenerator, the first output end of the regenerator is connected to the first input end of the heat exchanger; the output end of the cooling channel is connected to the second input end of the regenerator, the second output end of the regenerator is connected to the second input end of the heat exchanger, and the second output end of the heat exchanger is connected to the input end of the cooling channel. The present invention adopts fuel and carbon dioxide as coolants, and the fuel absorbs the equipment heat load and exchanges heat with high-temperature carbon dioxide in the regenerator, and the heated fuel exchanges heat with low-temperature carbon dioxide in the heat exchanger. The use of a regenerator helps to improve the thermal efficiency of the cycle. Compared with the direct heat exchange of high and low temperature carbon dioxide in the traditional regenerator, the use of fuel as an intermediate medium reduces the temperature difference between cold and hot fluids in the regenerator and avoids the pinch point problem in the regenerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 A schematic diagram of a hypersonic vehicle integrated thermal management system based on a Brayton cycle provided in an embodiment of the present invention.

[0036] Description of the drawings: 1-equipment thermal load, 2-regenerator, 3-heat exchanger, 4-cooling channel, 5-engine, 6-compressor, 7-turbine, 8-fuel tank, 9-fuel pump, 10-fuel injector, 11-carbon dioxide storage tank, 12-generator, 13-central shaft. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The purpose of the present invention is to provide a hypersonic aircraft integrated thermal management system based on the Brayton cycle, which aims to reduce the proportion of compressor power consumption in turbine output power and avoid the pinch point problem in the regenerator, and can be applied to the field of aircraft thermal management technology.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Figure 1 Schematic diagram of an integrated thermal management system for a hypersonic aircraft based on a Brayton cycle provided in an embodiment of the present invention. Figure 1 As shown, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle in this embodiment includes: an equipment thermal load 1, a regenerator 2, a heat exchanger 3, a cooling channel 4 and an engine 5; the cooling channel 4 is arranged on the outer wall of the combustion chamber in the engine 5.

[0041] The output end of the equipment heat load 1 is connected to the first input end of the regenerator 2, and the first output end of the regenerator 2 is connected to the first input end of the heat exchanger 3; the output end of the cooling channel 4 is connected to the second input end of the regenerator 2, the second output end of the regenerator 2 is connected to the second input end of the heat exchanger 3, and the second output end of the heat exchanger 3 is connected to the input end of the cooling channel 4.

[0042] The equipment heat load 1 is used to output the initially heated fuel to the regenerator 2; the initially heated fuel is the fuel after the target fuel entering the equipment heat load 1 absorbs heat.

[0043] Regenerator 2, for:

[0044] The fuel heated for the first time absorbs the heat of the high-temperature carbon dioxide, and the fuel heated for the second time is output from the first output end of the regenerator 2 to the heat exchanger 3, and the carbon dioxide cooled is output from the second output end of the regenerator 2 to the heat exchanger 3; the high-temperature carbon dioxide is input through the second input end of the regenerator 2.

[0045] Heat exchanger 3, for:

[0046] The cooled carbon dioxide absorbs the heat of the secondary heated fuel, and the primary cooled fuel is sprayed into the combustion chamber from the first output end of the heat exchanger 3 , and the heated carbon dioxide is provided to the cooling channel 4 from the second output end of the heat exchanger 3 .

[0047] Cooling channel 4, for:

[0048] The heated carbon dioxide absorbs the heat generated by the combustion of the fuel that has been cooled once in the combustion chamber, so as to output the high-temperature carbon dioxide to the regenerator 2.

[0049] As an optional embodiment, the integrated thermal management system for a hypersonic aircraft based on the Brayton cycle also includes: a compressor 6; a first input end of the compressor 6 is connected to the second output end of the regenerator 2, and an output end of the compressor 6 is connected to the second input end of the heat exchanger 3.

[0050] The compressor 6 is used to compress the cooled carbon dioxide.

[0051] As an optional embodiment, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle also includes: a turbine 7; the input end of the turbine 7 is connected to the output end of the cooling channel 4, and the first output end of the turbine 7 is connected to the second input end of the regenerator 2.

[0052] The turbine 7 is used to expand the high-temperature carbon dioxide to produce work.

[0053] As an optional implementation, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle further includes: a fuel tank 8; the fuel tank 8 is connected to the input end of the equipment heat load 1.

[0054] The fuel tank 8 is used to supply target fuel.

[0055] As an optional embodiment, the integrated thermal management system for a hypersonic aircraft based on the Brayton cycle also includes: a fuel pump 9, one end of the fuel pump 9 is connected to the fuel tank 8, and the other end of the fuel pump 9 is connected to the input end of the equipment heat load 1.

[0056] The fuel pump 9 is used to pump the target fuel from the fuel tank 8 into the equipment heat load 1 .

[0057] As an optional embodiment, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle also includes: a fuel injector 10, which is arranged in the engine 5, and the input end of the fuel injector 10 is connected to the first output end of the heat exchanger 3.

[0058] The fuel injector 10 is used to inject the fuel, which has been cooled once, into the combustion chamber.

[0059] As an optional implementation, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle further includes: a carbon dioxide tank 11 ; the carbon dioxide tank 11 is connected to the first input end of the compressor 6 .

[0060] The carbon dioxide storage tank 11 is used to provide carbon dioxide.

[0061] The compressor 6 is also used to compress the carbon dioxide output from the carbon dioxide storage tank.

[0062] As an optional implementation, the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle further includes: a generator 12; the generator 12 is connected to the second output end of the turbine 7.

[0063] The generator 12 is used to generate electricity by utilizing the work generated by the expansion of high-temperature carbon dioxide.

[0064] As an optional embodiment, the integrated thermal management system for a hypersonic aircraft based on the Brayton cycle also includes: a central shaft 13; one end of the central shaft 13 is connected to the second input end of the compressor 6, and the other end of the central shaft 13 is connected to the third output end of the turbine 7.

[0065] The central shaft 13 is used to transmit the electricity generated by the generator 12 to the compressor 6 to provide power for the compressor 6.

[0066] The working process of the integrated thermal management system for a hypersonic vehicle based on the Brayton cycle provided by an embodiment of the present invention is as follows:

[0067] By utilizing the function of the fuel pump 9, the fuel in the fuel tank 8 first passes through the equipment heat load 1 (the equipment heat load 1 carries the heat required to be dissipated generated by the equipment in the aircraft during operation), absorbs the heat required to be dissipated by the aircraft, and then enters the regenerator 2 through the first input end of the regenerator 2 to absorb the heat of the carbon dioxide input from the second input end of the regenerator 2, and then enters the heat exchanger 3 to transfer the heat to the carbon dioxide provided by the carbon dioxide storage tank 11 and the carbon dioxide output from the second output end of the regenerator 2, and finally enters the fuel injector 10 of the engine 5, and the fuel injector 10 injects the fuel into the combustion chamber for combustion, thereby providing power for the engine 5;

[0068] The carbon dioxide provided by the carbon dioxide storage tank 11 first passes through the compressor 6, is compressed and pressurized by the compressor 6, and then is provided to the second input end of the heat exchanger 3 to enter the heat exchanger 3, absorbs the heat of the fuel input from the first input end of the heat exchanger 3, and then enters the cooling channel 4 on the outer wall of the engine 5, absorbs the heat generated by the combustion of the fuel in the combustion chamber, and then enters the turbine 7, expands and does work in the turbine 7, and the work done is provided to the generator 12 to generate electricity, and then enters the regenerator 2 through the second input end of the regenerator 2, transfers the heat to the fuel input through the first input end of the regenerator 2, and enters the compressor 6 again for the next cycle.

[0069] Technical effects:

[0070] (1) The system of the present invention is divided into two cooling circuits, primary and secondary. The cooling inside the engine is completed by the primary cooling circuit, and a supercritical carbon dioxide closed Brayton cycle system is adopted. Compared with other cycles, the Brayton cycle system occupies a small space and has a light equipment load. The cycle efficiency can reach 45% in the medium temperature range (500-650°C), and the cycle efficiency can reach 50% when the heat source temperature reaches 700°C. Under the same power generation, the volume ratio of the turbine unit required for supercritical carbon dioxide and water vapor is about 1:20, and the weight ratio is about 1:30. In addition, supercritical carbon dioxide has low viscosity, high density, and low circulation system loss. Compared with helium, the power consumption of the carbon dioxide compressor only accounts for about 30% of the turbine output power, which can further optimize the power generation capacity of the Brayton cycle system.

[0071] (2) The secondary cooling circuit of the present invention uses fuel as a coolant. After absorbing the heat load of the equipment, it exchanges heat with the high-temperature carbon dioxide at the turbine outlet in the regenerator. The heated fuel exchanges heat with the low-temperature carbon dioxide at the compressor outlet in the heat exchanger. The use of a regenerator helps to improve the thermal efficiency of the cycle. Compared with the direct heat exchange of high and low temperature carbon dioxide in a traditional regenerator, the use of fuel as an intermediate medium reduces the temperature difference between the cold and hot fluids in the regenerator and avoids the pinch point problem in the regenerator.

[0072] (3) The turbine of the system of the present invention drives the generator to establish a power generation system, which not only solves the thermal protection problem in the engine, but also effectively utilizes the waste heat while absorbing heat, converting thermal energy into mechanical energy, and ultimately solves the problem of increased power demand in the aircraft.

[0073] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0074] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the device and its core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A hypersonic vehicle integrated thermal management system based on Brayton cycle, characterized in that: include: Equipment heat loads, regenerators, heat exchangers, cooling channels and engines; The cooling channel is arranged on the outer wall of the combustion chamber in the engine; The output end of the equipment heat load is connected to the first input end of the regenerator, and the first output end of the regenerator is connected to the first input end of the heat exchanger; The output end of the cooling channel is connected to the second input end of the regenerator, the second output end of the regenerator is connected to the second input end of the heat exchanger, and the second output end of the heat exchanger is connected to the input end of the cooling channel; The equipment heat load is used to output the initially heated fuel to the regenerator; the initially heated fuel is the fuel after the target fuel entering the equipment heat load absorbs heat; The regenerator is used for: The fuel heated up for the first time absorbs the heat of the high-temperature carbon dioxide, and the fuel heated up for the second time is output to the heat exchanger from the first output end of the regenerator, and the carbon dioxide cooled down is output to the heat exchanger from the second output end of the regenerator; the high-temperature carbon dioxide is input through the second input end of the regenerator; The heat exchanger is used for: The cooled carbon dioxide absorbs the heat of the secondary heated fuel, and the primary cooled fuel is sprayed into the combustion chamber from the first output end of the heat exchanger, and the heated carbon dioxide is provided to the cooling channel from the second output end of the heat exchanger; The cooling channel is used for: The heated carbon dioxide absorbs the heat generated by the combustion of the fuel that has been cooled once in the combustion chamber, so as to output the high-temperature carbon dioxide to the regenerator.

2. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 1, characterized in that: Also includes: compressor; The first input end of the compressor is connected to the second output end of the regenerator, and the output end of the compressor is connected to the second input end of the heat exchanger; The compressor is used to compress the cooled carbon dioxide.

3. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 2, characterized in that: Also includes: turbine; The input end of the turbine is connected to the output end of the cooling channel, and the first output end of the turbine is connected to the second input end of the regenerator; The turbine is used to expand the high-temperature carbon dioxide to produce work.

4. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 1, characterized in that: Also includes: A fuel tank; the fuel tank is connected to the input end of the heat load of the equipment; The fuel tank is used to provide the target fuel.

5. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 4, characterized in that: Also includes: A fuel pump, one end of which is connected to the fuel tank, and the other end of which is connected to an input end of the thermal load of the equipment; The fuel pump is used to pump the target fuel from the fuel tank into the equipment heat load.

6. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 1, characterized in that: Also includes: A fuel injector, wherein the fuel injector is disposed in the engine, and an input end of the fuel injector is connected to a first output end of the heat exchanger; The fuel injector is used to inject the fuel that has been cooled once into the combustion chamber.

7. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 2, characterized in that: Also includes: A carbon dioxide storage tank; the carbon dioxide storage tank is connected to the first input end of the compressor; The carbon dioxide storage tank is used to provide carbon dioxide; The compressor is further used for compressing the carbon dioxide outputted from the carbon dioxide storage tank.

8. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 3, characterized in that: Also includes: dynamo; The generator is connected to the second output end of the turbine; The generator is used to generate electricity by utilizing the work generated by the expansion of the high-temperature carbon dioxide.

9. The Brayton cycle-based hypersonic vehicle integrated thermal management system according to claim 8, characterized in that: Also includes: Central axis; One end of the central shaft is connected to the second input end of the compressor, and the other end of the central shaft is connected to the third output end of the turbine; The central shaft is used to transmit the electricity generated by the generator to the compressor to provide power for the compressor.

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