Electric heating type aero-engine pre-cooling device

Abstract

The invention relates to an electric heating type aero-engine pre-cooling device which comprises a propellant storage tank, a propellant conveying pipeline, a backflow pipeline, an electric heating element and an engine. The bottom end of the propellant storage box is communicated with the backflow pipeline and the propellant conveying pipeline, the backflow pipeline and the propellant conveying pipeline are communicated with the engine, and an electric heating element is arranged in the backflow pipeline. Starting or stopping of the electric heating element can be controlled at any time through the control assembly, the electric heating element makes direct contact with fluid, the fluid is boiled, the mass gas content of the backflow pipe is increased, and therefore the circulation flow is increased, and the pre-cooling effect is better. And meanwhile, pipelines and valves are not added, the risk of gas leakage is avoided, and the weight of the aircraft is not remarkably increased while the pre-cooling function is achieved. The precooling system is kept simple and reliable while it is guaranteed that the circulating flow of a propellant is greatly increased, the transport capacity and safety of a spacecraft are improved in a disguised mode, and the production cost is reduced.

Description

Technical Field

[0001] This application relates to the field of rocket technology, and in particular to an electrically heated precooling device for aero engines. Background Technology

[0002] Before ignition and launch, the engine of a cryogenic liquid rocket must be in a "pre-cooled" and "pressurized" state. This is typically achieved through a ground support system combined with onboard tanks for pre-cooling the liquid rocket engine. The onboard tanks are then pressurized to a certain pressure before launch, ensuring the engine is simultaneously "pre-cooled" and "pressurized." Pre-cooling of the cryogenic liquid rocket engine and its delivery system is essential before ignition. Pre-cooling refers to the process of cooling the engine (primarily the turbopump) and its delivery system using the propellant or other cryogenic medium before ignition to reach the allowable starting temperature and ensure reliable turbopump operation. Figure 1 The image shows a scheme for engine precooling using room-temperature helium ejection technology, as described in patent CN202311869615. This scheme utilizes the kinetic energy of helium ejection to drive propellant recirculation, while simultaneously using direct injection of helium into the propellant tank's gas pillow for pressurization. Its core relies on a gas-driven system comprised of helium cylinders, multi-stage solenoid valves, orifice plates, and complex piping. Essentially, it uses the momentum transfer of an external medium (helium) and increases the density difference between the propellant delivery pipe and the return pipe to drive cryogenic fluid for engine precooling. While this solves the propellant consumption and emission safety issues of traditional precooling systems, it suffers from systemic defects. Specifically, the helium system components (cylinders, piping, regulating valves) significantly increase dead weight, and the multi-stage redundant design further amplifies system complexity. Helium cryogenic dissolution residues can easily lead to pump-end cavitation risks, and the strong coupling between pressurization and circulation causes control lag, especially under long coasting conditions where helium storage is significantly limited. Fundamentally, this technology remains an external medium-dependent scheme, sacrificing transport capacity for functional performance.

[0003] Therefore, how to eliminate an engine precooling device that improves the adjustability of the precooling system, enhances overall safety, and indirectly increases the rocket's carrying capacity is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application provides an electrically heated precooling device for an aero-engine, comprising: a propellant tank, a propellant delivery pipeline, a return pipeline, an electric heating element, and an engine; the bottom end of the propellant tank is connected to the return pipeline and the propellant delivery pipeline, the return pipeline and the propellant delivery pipeline are connected to the engine, and an electric heating element is installed in the return pipeline.

[0005] In the electrically heated precooling device for aero-engines described above, the inlet of the reflux line is connected to the bottom of the propellant tank, and the outlet of the reflux line is connected to the outlet of the engine.

[0006] In the electrically heated precooling device for aero-engines described above, the inlet of the propellant delivery pipeline is connected to the outlet of the engine, and the outlet of the propellant delivery pipeline is connected to the propellant tank.

[0007] The electrically heated precooling device for aero-engines described above has a return line located inside the propellant tank, with the return port a specified distance above the bottom of the tank.

[0008] In the electrically heated precooling device for aero-engines described above, the electric heating element is fixed in the return pipeline by means of a bracket.

[0009] In the electrically heated precooling device for aero-engines described above, the electric heating element is fixed in the return pipeline by means of wall welding.

[0010] The electrically heated aircraft engine precooling device described above includes an electrically heated element connected to a control component that controls the starting and stopping of the electrically heated element and controls the heating power of the electrically heated element.

[0011] The electrically heated aircraft engine precooling device described above, wherein the electrically heated element is also connected to a power supply component that supplies power to the electrically heated component.

[0012] The electrically heated precooling device for aircraft engines described above, wherein the electrically heated element is a heating plate or a heating wire.

[0013] As described above, in the electrically heated precooling device for aircraft engines, the electrically heated element is located in the lower middle part of the return pipe, near the engine.

[0014] Compared to the aforementioned background technology, this application can control the start or stop of the electric heating element at any time through the control component. The electric heating element directly contacts the fluid, causing the fluid to boil, increasing the gas content in the return pipe, thereby increasing the circulation flow rate and improving the precooling effect.

[0015] This application avoids the addition of pipelines and valves, thus eliminating the risk of gas leakage. While achieving pre-cooling functionality, the weight of the aircraft is not significantly increased. By ensuring a substantial increase in propellant circulation flow rate while maintaining the simplicity and reliability of the pre-cooling system, the spacecraft's carrying capacity and safety are indirectly improved, while production costs are reduced. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1 This is a schematic diagram of an existing engine precooling scheme.

[0018] Figure 2 This is a schematic diagram of the structure of the electrically heated aero-engine precooling device provided in the embodiments of this application. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. Furthermore, spatial relation terms such as "upper," "lower," "left," "right," "front," and "rear" are used for ease of description to explain the positional relationship between two components. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] This application provides an electrically heated precooling system for cryogenic liquid rockets, employing a phase change-driven density difference technology. A distributed microstructure heater is directly implanted into the propellant return pipe, precisely inducing a controlled phase change in cryogenic propellants such as liquid oxygen / methane (boiling bubble rate >30%). The system autonomously drives the cryogenic propellant circulation using the two-phase flow density difference, simultaneously achieving engine precooling and tank pressurization. This breakthrough eliminates reliance on external components such as helium cylinders and complex valve groups. While achieving engine precooling, it avoids adding cylinders, pipes, and valves, improving the precooling system's adjustability, overall safety, and indirectly increasing the rocket's payload capacity.

[0021] like Figure 2 As shown, this application provides an electrically heated precooling device for an aircraft engine, comprising: a propellant tank 210, a propellant delivery pipeline 220, a return pipeline 230, an electric heating element 240, and an engine 250.

[0022] The bottom end of the propellant tank 210 is connected to the return pipe 230. The inlet of the return pipe 230 is connected to the bottom end of the propellant tank 210, and the outlet of the return pipe 230 is connected to the outlet of the engine 250.

[0023] The return pipeline 230 is located inside the propellant tank 210, and the return port is a certain distance above the bottom of the tank.

[0024] The bottom of the propellant tank 210 is also connected to the propellant delivery pipeline 220. The inlet of the propellant delivery pipeline 220 is connected to the outlet of the engine 250, and the outlet of the propellant delivery pipeline 220 is connected to the propellant tank 210.

[0025] The propellant delivery line 220 and the return line 230 connect the propellant tank 210 to the engine 250, so that the propellant can flow from the propellant tank 210 into the engine 250 and be pre-cooled before returning to the propellant tank 210 through the return line 230.

[0026] Still refer to Figure 2 An electric heating element 240 is installed in the return pipe 230. The electric heating element 240 is fixed in the return pipe 230 by means of bracket fixing or wall welding fixing, which improves its structural vibration resistance.

[0027] The electric heating element 240 is connected to a corresponding control component (not shown in the figure) to ensure that the start-up and shutdown of the electric heating element 240 and the heating power can be controlled. The electric heating element 240 is also connected to a power supply component (not shown in the figure), which supplies power to the electric heating element. By changing the supply current / voltage, the heat flux density of the electric heating element 240 or the wall superheat can be adjusted.

[0028] The electric heating element 240 is a heating plate or a heating wire. Preferably, the heating element can be cylindrical or straight heating wire and is installed along the flow direction to minimize local flow resistance.

[0029] Furthermore, the electric heating element 240 is positioned slightly below the middle of the return pipe 230. Since the return pipe 230 is located inside the propellant tank 210 and the return port is a certain distance above the bottom of the tank, positioning the electric heating element 240 slightly below the middle of the return pipe 230 can create a greater height difference, thereby increasing the circulation flow rate.

[0030] The hydraulic characteristics of the electric heating element 240 are: 1. The heating surface is in full contact with liquid oxygen; 2. The shape and installation direction are in line with the fluid flow direction to minimize local flow resistance.

[0031] The electric heating element 240 has the following thermophysical characteristics: low heat transfer area and high superheat. The low heat transfer area ensures that the heating process will not affect the overall average temperature of the liquid propellant in the rocket tank. The high superheat ensures that after liquid oxygen comes into contact with the heating element, it will directly undergo nucleation boiling, transition boiling, film boiling, or supercooled boiling to generate bubbles. The boiling mode that generates more bubbles at the same heat flux density is preferred.

[0032] Through the above structure, the cryogenic fluid enters the engine 250 from the propellant delivery pipeline 220, precools the engine 250, and then returns to the propellant tank 210 after contacting the heating element 240 through the return pipeline 230.

[0033] After the electric heating element 240 is activated by the control unit, it heats the locally cryogenic propellant to boiling, thus performing boiling heat exchange. The bubbles generated during boiling, along with the returning propellant, return to the propellant tank 210 through the return pipe 230. Due to the presence of bubbles, the average density of the fluid in the return pipe 230 decreases, while the density of the propellant in the propellant delivery pipe 220 remains essentially unchanged. Consequently, the density difference between the propellant delivery pipe 220 and the return pipe 230 increases, the driving force of the circulation loop increases, and the circulation flow rate increases accordingly, ultimately completing the pre-cooling of the engine.

[0034] The beneficial effects of this application are:

[0035] (1) This application can control the start or stop of the electric heating element at any time through the control component. The electric heating element directly contacts the fluid, causing the fluid to boil, increasing the gas content of the return pipe, thereby increasing the circulation flow rate and making the precooling effect better.

[0036] (2) This application does not involve adding pipelines and valves, thus avoiding the risk of gas leakage. While achieving the pre-cooling function, the weight of the aircraft is not significantly increased. By ensuring a significant increase in propellant circulation flow rate while maintaining the simplicity and reliability of the pre-cooling system, the spacecraft's carrying capacity and safety are indirectly improved, while production costs are reduced.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electrically heated precooling device for an aircraft engine, characterized in that, include: Propellant tanks, propellant delivery pipelines, return pipelines, electric heating elements, and engines; The bottom of the propellant tank is connected to the return pipeline and the propellant delivery pipeline, which are connected to the engine. An electric heating element is installed in the return pipeline.

2. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The inlet of the reflux line is connected to the bottom of the propellant tank, and the outlet of the reflux line is connected to the engine outlet.

3. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The inlet of the propellant delivery pipeline is connected to the outlet of the engine, and the outlet of the propellant delivery pipeline is connected to the propellant tank.

4. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The return line is located inside the propellant tank, and the return port is a specified distance above the bottom of the tank.

5. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The electric heating element is fixed in the return pipe by means of a bracket.

6. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The electric heating element is fixed in the return pipeline by wall welding.

7. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The electric heating element is connected to a control component that controls the start and stop of the electric heating element and controls the heating power of the electric heating element.

8. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The electric heating element is also connected to a power supply component that supplies power to the electric heating component.

9. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The electric heating element is a heating plate or a heating wire.

10. The electrically heated aero-engine precooling device as described in claim 1, characterized in that, The electric heating element is located in the lower middle part of the return pipeline, near the transmitter.

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