Metal fuel ramjet engines, aircraft and metal fuel engine operation methods

Abstract

This invention provides a metal-fueled ramjet engine, an aircraft, and a method for operating the metal-fueled engine, relating to the field of aerospace technology. It employs a heat-conducting device connected to a molten metal injection device, which is thermally connected to the engine flow channel and / or the aircraft fuselage. Molten metal fuel is injected into the engine flow channel via the molten metal injection device. High-enthalpy airflow mixes and combusts with the molten metal fuel within the engine flow channel, generating propulsion. Furthermore, utilizing the heat from the engine flow channel and the aircraft fuselage to heat the metal fuel ensures it remains in a molten state and allows for cooling and heat absorption of the high-temperature walls of the engine fuselage and flow channel. This not only improves the equivalent fuel energy and energy utilization rate but also meets the requirements of high-flight Mach number conditions. Moreover, the molten metal fuel supply structure is easier to arrange than that of powdered fuel supply, making it easier to reduce the engine's structural size.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, and in particular to a metal fuel ramjet engine, an aircraft, and a method for operating a metal fuel engine. Background Technology

[0002] Because hydrocarbon-fueled ramjet engines suffer from insufficient fuel heat release at high Mach numbers, it is difficult for aircraft to exceed Mach 10. While hydrogen-fueled ramjet engines can reach Mach 10, their applications are still limited by fuel storage issues. Although powdered fuel can be used to improve fuel calorific value, the powder supply system is large and requires carrier gas for fluidization or dispersion, and the powder loading ratio is difficult to exceed 0.8, which still limits the equivalent fuel energy.

[0003] Furthermore, hypersonic aircraft airframes and engines generate a significant amount of heat, and the heat sinks of liquid hydrocarbon fuels cannot meet their cooling requirements, which in turn shortens the service life of the airframes and engines. Summary of the Invention

[0004] The purpose of this invention is to provide a metal fuel ramjet engine, an aircraft, and a method for operating the metal fuel engine, so as to alleviate the technical problem that ramjet engines cannot meet the energy requirements of high flight Mach numbers.

[0005] In a first aspect, the metal fuel ramjet engine provided by the present invention includes:

[0006] An engine flow passage is used to intake and mix molten metal fuel, and to generate propulsion through the combustion of the molten metal fuel.

[0007] A molten metal injection device, wherein the molten metal injection device is used to inject molten metal fuel into the engine flow channel;

[0008] A heat-conducting device is connected to the molten metal injection device and is thermally connected to the engine flow channel and / or the aircraft body.

[0009] In conjunction with the first aspect, the present invention provides a first possible implementation of the first aspect, wherein the molten metal injection device comprises: a nitrogen high-pressure tank, a metal fuel storage chamber, and a molten metal nozzle;

[0010] The heat-conducting device is connected to the metal fuel storage chamber, and the nitrogen high-pressure tank, the metal fuel storage chamber, and the molten metal nozzle are connected in sequence.

[0011] In conjunction with the first possible implementation of the first aspect, the present invention provides a second possible implementation of the first aspect, wherein the heat-conducting device includes a fuel line connecting the metal fuel storage tank and the molten metal nozzle;

[0012] The fuel line extends through the sidewall of the engine flow channel and the aircraft fuselage.

[0013] In conjunction with the second possible implementation of the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the fuel line extends to the tail of the aircraft body to vaporize the molten metal in the fuel line and eject it from the tail of the aircraft body.

[0014] In conjunction with the first aspect, the present invention provides a fourth possible implementation of the first aspect, wherein the metal fuel ramjet engine further includes: a heat exchanger, heat exchange pipelines, a steam feedstock storage tank, a steam nozzle, and a steam release valve;

[0015] The heat-conducting device is connected to the heat exchanger, and the heat exchanger and the steam raw material storage tank are respectively connected to the heat exchange pipeline;

[0016] The steam nozzle is in fluid communication with the steam raw material storage tank, the open end of the steam nozzle is located at the tail of the aircraft body, and the steam release valve is installed on the steam nozzle.

[0017] Secondly, the aircraft provided by the present invention is equipped with the metal fuel ramjet engine described in the first aspect.

[0018] Thirdly, the metal fuel engine operation method provided by the present invention includes the following steps:

[0019] The heat from the engine flow channels and / or the aircraft body is used to heat the metallic fuel to bring it to a molten state.

[0020] Molten metal fuel is injected into the engine flow channel;

[0021] Air and molten metallic fuel are mixed and ignited in the engine's flow path to generate propulsion.

[0022] In conjunction with the third aspect, the present invention provides a first possible implementation of the third aspect, wherein the metal fuel engine operation method further includes:

[0023] Molten metallic fuel is directed along fuel lines to the sidewalls of the engine flow channels and the aircraft fuselage to dissipate heat from these surfaces.

[0024] In conjunction with the first possible implementation of the third aspect, the present invention provides a second possible implementation of the third aspect, wherein the metal fuel engine operation method further includes:

[0025] The molten metal fuel is directed to the tail of the aircraft body, where it is vaporized and ejected.

[0026] In conjunction with the third aspect, the present invention provides a third possible implementation of the third aspect, wherein the metal fuel engine operation method further includes:

[0027] The heat from the engine flow channel and / or the aircraft body is used to heat the steam feedstock, and the steam generated by the heated steam feedstock is ejected from the tail of the aircraft body.

[0028] The embodiments of the present invention bring the following beneficial effects: a heat-conducting device is used to connect the molten metal injection device, and the heat-conducting device is thermally connected to the engine flow channel and / or the aircraft body. Molten metal fuel is injected into the engine flow channel through the molten metal injection device. The engine flow channel intakes and mixes with the molten metal fuel. Propulsion is generated by the combustion of the molten metal fuel. The heat of the engine flow channel and the aircraft body can be used to heat the metal fuel. On the one hand, it can ensure that the metal fuel is kept in a molten state. On the other hand, the waste heat of the engine flow channel and the aircraft body can be utilized. This not only improves the equivalent fuel energy and energy utilization rate, but is also more suitable for the energy requirements of high flight Mach numbers. Moreover, the molten metal fuel supply structure is easier to arrange than the powder fuel supply structure, and it is easier to reduce the structural size of the engine.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a metal fuel ramjet engine provided in an embodiment of the present invention.

[0032] Icons: 100 - Engine flow path; 110 - Air intake; 120 - Isolation section; 130 - Main combustion chamber; 131 - Cavity; 140 - Tail nozzle; 200 - Molten metal injection device; 201 - Injection port; 210 - Nitrogen high-pressure tank; 220 - Metal fuel storage tank; 230 - Molten metal nozzle; 300 - Heat conduction device; 310 - Fuel pipeline; 400 - Aircraft fuselage; 500 - Heat exchanger; 600 - Heat exchange pipeline; 700 - Steam feedstock storage tank; 800 - Steam nozzle; 900 - Steam release valve. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used only to describe differences in name and should not be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise specified, should be understood as basic quantities in the International System of Units (SI), or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] like Figure 1 As shown, the metal fuel ramjet engine provided in this embodiment of the invention includes:

[0037] Engine flow passage 100 is used to intake air and mix molten metal fuel, and to generate propulsion by burning the molten metal fuel.

[0038] Molten metal injection device 200 is used to inject molten metal fuel into the engine flow channel 100. The injection method can be direct injection, plate injection, or vertical wall injection, etc.

[0039] The heat-conducting device 300 is connected to at least one of the following: the molten metal injection device 200, the engine flow channel 100, and the aircraft body 400.

[0040] In this embodiment, the waste heat from the engine flow channel 100 and the aircraft body 400 is used to heat the metallic fuel via heat transfer through the heat-conducting device 300. This maintains the metallic fuel in a molten state, and the molten metallic fuel supply structure is easier to arrange and allows for smaller engine dimensions compared to powdered fuel supply. Furthermore, molten metallic fuel has a higher energy density, resulting in higher energy utilization efficiency when utilizing the waste heat from the engine flow channel 100 and the aircraft body 400, making it more suitable for the energy demands of high flight Mach numbers.

[0041] In this embodiment of the invention, the engine flow channel 100 includes an intake channel 110, an isolation section 120, a main combustion chamber 130 and an exhaust nozzle 140 connected in sequence, and the injection port 201 of the molten metal injection device 200 is disposed in the main combustion chamber 130.

[0042] Specifically, the isolator section 120 has a shield or guide bend at one end connected to the intake duct 110 to ensure that airflow can flow from the intake duct 110 into the isolator section 120 and to prevent gas from flowing back from the isolator section 120 into the intake duct 110. In a cross-section perpendicular to the propulsion direction, the cross-sectional area of ​​the main combustion chamber 130 is larger than that of the isolator section 120, allowing the molten metal fuel and air to mix thoroughly within the main combustion chamber 130 for complete combustion. Furthermore, the cross-sectional area of ​​the pipe from the main combustion chamber 130 to the tailpipe 140 increases perpendicular to the propulsion direction, thereby reducing the resistance encountered during gas ejection and fully utilizing the propulsion force of the metal fuel ramjet engine.

[0043] Furthermore, the inner wall of the main combustion chamber 130 is recessed to form a cavity 131, with the injection port 201 facing the cavity 131. The cavity 131 is located at one end of the main combustion chamber 130 near the isolation section 120, thus making the cross-sectional area of ​​the end of the main combustion chamber 130 near the isolation section 120 larger than the cross-sectional area of ​​the isolation section 120 in the direction of propulsion. The cavity 131 has a combustion-stabilizing effect and can improve the mixing degree of molten metal and high-enthalpy air. The cross-sectional area of ​​the pipe from the cavity 131 to the tail nozzle 140 in the main combustion chamber 130 increases in the direction of propulsion.

[0044] Furthermore, the molten metal injection device 200 includes: a nitrogen high-pressure tank 210, a metal fuel storage chamber 220, and a molten metal nozzle 230; the heat-conducting device 300 is connected to the metal fuel storage chamber 220, and the nitrogen high-pressure tank 210, the metal fuel storage chamber 220, and the molten metal nozzle 230 are connected in sequence.

[0045] In an optional embodiment, the heat-conducting device 300 may be made of a heat-conducting material or a pipeline for circulating a heat-conducting medium, in order to transfer heat from at least one of the engine flow channel 100 and the aircraft body 400 to the metal fuel storage tank 220, thereby heating the metal fuel, and using high-pressure nitrogen in the nitrogen high-pressure tank 210 to drive the molten metal in the metal fuel storage tank 220 to be sprayed into the main combustion chamber 130 of the engine flow channel 100 through the molten metal nozzle 230.

[0046] In this embodiment, the heat-conducting device 300 includes a fuel line 310 connecting the metal fuel storage tank 220 and the molten metal nozzle 230; the fuel line 310 extends through the side wall of the engine flow channel 100 and the aircraft body 400. On the one hand, the molten metal in the metal fuel storage tank 220 can flow to the molten metal nozzle 230 through the fuel line 310; on the other hand, the fuel line 310 extending through the side wall of the engine flow channel 100 and the aircraft body 400 allows the molten metal to directly absorb heat from the engine flow channel 100 and the aircraft body 400, thereby achieving heat dissipation for the engine and the aircraft body 400 and improving energy utilization.

[0047] It should be noted that the metal fuel storage compartment 220 can store metal blocks to improve the equivalent fuel energy. The metal fuel can be made of high-energy solid materials such as magnesium, lithium, magnesium-aluminum alloy, and magnesium-boron alloy.

[0048] In an optional embodiment, the fuel line 310 extends to the tail of the aircraft fuselage 400 to vaporize the molten metal within the fuel line 310 and eject it from the tail of the aircraft fuselage 400. The longer heating path of the fuel line 310 extending to the tail of the aircraft fuselage 400 allows for greater heating of the molten metal within it, enabling it to be further heated to its boiling point. The resulting gas can then be ejected from the tail of the aircraft fuselage 400, thereby increasing thrust.

[0049] In this embodiment, the metal-fueled ramjet engine further includes: a heat exchanger 500, a heat exchange pipeline 600, a steam feedstock tank 700, a steam nozzle 800, and a steam release valve 900; a heat-conducting device 300 is connected to the heat exchanger 500, and the heat exchanger 500 and the steam feedstock tank 700 are respectively connected to the heat exchange pipeline 600; the steam nozzle 800 is in fluid communication with the steam feedstock tank 700, and the open end of the steam nozzle 800 is located at the tail of the aircraft fuselage 400; the steam release valve 900 is installed on the steam nozzle 800. The steam feedstock is selected from low-boiling-point metals or solids, such as sodium blocks, lithium blocks, etc., which can be vaporized after heating and ejected through the steam nozzle 800.

[0050] The heat from the molten metal in the fuel line 310 can be absorbed by the heat exchanger 500, thereby further improving the thermal energy utilization rate of the engine flow channel 100 and the aircraft body 400. The heat energy absorbed by the heat exchanger 500 is transferred to the steam fuel storage tank 700 through the heat exchange line 600, which can heat and vaporize the steam fuel in the steam fuel storage tank 700. The generated steam can be ejected when the steam release valve 900 is open, thereby providing additional jet thrust and improving the thrust performance of the engine.

[0051] The aircraft provided in this embodiment of the invention is equipped with the metal fuel ramjet engine described in the above embodiments, and the aircraft has the technical effects of the metal fuel ramjet engine, which will not be repeated here.

[0052] The metal fuel engine operation method provided in this embodiment of the invention includes the following steps:

[0053] The heat from the engine flow channel 100 and / or the aircraft body 400 is used to heat the metallic fuel so that the metallic fuel reaches a molten state;

[0054] Molten metal fuel is injected into the engine flow channel 100;

[0055] Air and molten metallic fuel are mixed and ignited in the engine flow channel 100 to generate propulsion.

[0056] In this embodiment, aluminum blocks are preferably used as the metallic fuel. At least one pair of aluminum blocks in the engine flow channel 100 and the aircraft body 400 are heated to form a molten state. The molten metal injected into the engine flow channel 100 is dispersed and atomized by supersonic air intake to achieve thorough mixing. The mixture is then ignited by an igniter or the flame of the previous stroke to generate propulsion.

[0057] In this embodiment of the invention, the metal fuel engine operation method further includes: guiding molten metal fuel along the fuel pipeline 310 to the sidewall of the engine flow channel 100 and the aircraft body 400 to dissipate heat from the sidewall of the engine flow channel 100 and the aircraft body 400. On one hand, the heat from the engine flow channel 100 and the aircraft body 400 is used to heat the metal fuel; on the other hand, the molten metal fuel has a heat dissipation effect on the sidewall of the engine flow channel 100 and the aircraft body 400, thus preventing the sidewall of the engine flow channel 100 and the aircraft body 400 from continuously heating up beyond the temperature limit that the structure can withstand.

[0058] In addition, the molten metal fuel can be directed to the tail of the aircraft body 400, thereby increasing the heating distance and duration of the molten metal, which in turn allows the molten metal to reach its boiling point and vaporize and be ejected at the tail of the aircraft body 400 to generate additional thrust.

[0059] Furthermore, the metal fuel engine operation method also includes: using the heat of at least one of the engine flow channel 100 and the aircraft body 400 to heat the steam feedstock, and causing the steam generated by the heating of the steam feedstock to be ejected at the tail of the aircraft body 400, thereby improving the thermal energy utilization rate of the engine flow channel 100 and the aircraft body 400, and being able to generate additional thrust by steam injection.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A metal-fueled ramjet engine, characterized in that, include: Engine flow passage (100), said engine flow passage (100) is used to intake and mix molten metal fuel, and to generate propulsion by burning the molten metal fuel; A molten metal injection device (200) is used to inject molten metal fuel into the engine flow channel (100); A heat-conducting device (300) is connected to the molten metal injection device (200), and the heat-conducting device (300) is thermally connected to the engine flow channel (100) and / or the aircraft body (400); The metal fuel ramjet engine further includes: a heat exchanger (500), a heat exchange pipeline (600), a steam fuel storage tank (700), a steam nozzle (800), and a steam release valve (900); the heat-conducting device (300) is connected to the heat exchanger (500), and the heat exchanger (500) and the steam fuel storage tank (700) are respectively connected to the heat exchange pipeline (600); the steam nozzle (800) is in fluid communication with the steam fuel storage tank (700), the open end of the steam nozzle (800) is located at the tail of the aircraft body (400), and the steam release valve (900) is installed on the steam nozzle (800).

2. The metal-fueled ramjet engine according to claim 1, characterized in that, The molten metal injection device (200) includes: a nitrogen high-pressure tank (210), a metal fuel storage chamber (220), and a molten metal nozzle (230). The heat-conducting device (300) is connected to the metal fuel storage chamber (220), and the nitrogen high-pressure tank (210), the metal fuel storage chamber (220) and the molten metal nozzle (230) are connected in sequence.

3. The metal-fueled ramjet engine according to claim 2, characterized in that, The heat-conducting device (300) includes a fuel line (310) connecting the metal fuel storage tank (220) and the molten metal nozzle (230). The fuel line (310) extends through the sidewall of the engine flow channel (100) and the aircraft body (400).

4. The metal-fueled ramjet engine according to claim 3, characterized in that, The fuel line (310) extends to the tail of the aircraft body (400) to vaporize the molten metal in the fuel line (310) and eject it from the tail of the aircraft body (400).

5. An aircraft, characterized in that, The aircraft is equipped with a metal fuel ramjet engine as described in any one of claims 1-4.

6. A method for operating a metallic fuel engine, characterized in that, Includes the following steps: The heat from the engine flow channel (100) and / or the aircraft body (400) is used to heat the metallic fuel to bring it to a molten state; Molten metal fuel is injected into the engine flow channel (100); Air and molten metallic fuel are mixed and ignited in the engine flow channel (100) to generate propulsion; The metal fuel engine operation method further includes: Molten metal fuel is directed along fuel line (310) to the side wall of engine flow channel (100) and aircraft body (400) to dissipate heat from the side wall of engine flow channel (100) and aircraft body (400); The steam feedstock is heated by the heat from the engine flow channel (100) and / or the aircraft body (400), and the steam generated by the heated steam feedstock is ejected from the tail of the aircraft body (400).

7. The method for operating a metal fuel engine according to claim 6, characterized in that, The metal fuel engine operation method further includes: The molten metal fuel is directed to the tail of the aircraft body (400) and vaporized and ejected at the tail of the aircraft body (400).

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