Liquid nitrogen heating vaporization pressurization system and liquid rocket

Abstract

This invention provides a liquid nitrogen heating and vaporization pressurization system and a liquid rocket. The liquid nitrogen heating and vaporization pressurization system includes an oxygen tank, a fuel tank, a liquid nitrogen tank, a liquid nitrogen pump, a cavitation pipe, a liquid nitrogen heater, and a liquid nitrogen tank pressurization pipe. An oxygen tank pressurization pipe is located at the top of the oxygen tank, and a fuel tank pressurization pipe is located at the top of the fuel tank. The liquid nitrogen tank is located inside the oxygen tank, and a liquid nitrogen delivery pipe is connected to the bottom of the liquid nitrogen tank. The liquid nitrogen pump is located on the liquid nitrogen delivery pipe. The cavitation pipe is used to stabilize the liquid nitrogen delivery flow rate. The liquid nitrogen heater is used to heat the liquid nitrogen delivered by the liquid nitrogen pump into high-temperature nitrogen gas. The heated nitrogen gas is used to simultaneously pressurize the oxygen tank, fuel tank, and liquid nitrogen tank. The liquid nitrogen heater is connected to both the oxygen tank pressurization pipe and the fuel tank pressurization pipe. The liquid nitrogen heating and vaporization pressurization system provided in this application adopts integrated pressurization technology. This technology simplifies the pressurization system, and the liquid nitrogen heating and vaporization pressurization reduces the cost and weight of the pressurization system while improving its safety and stability.

Description

Technical Field

[0001] This invention relates to the field of liquid rocket technology, and in particular to a liquid nitrogen heating and vaporization pressurization system and a liquid rocket. Background Technology

[0002] A liquid-fuel rocket is a rocket powered by a liquid-fuel rocket engine. It generally consists of a propulsion system, rocket body structure, and control system. Liquid-fuel rockets are primarily used as propulsion systems for space launch vehicles and missiles / nuclear weapons. The propulsion system of a liquid-fuel rocket mainly consists of two parts: the propellant delivery and pressurization system and the liquid-fuel rocket engine. The propellant delivery and pressurization system is a crucial system for ensuring the reliable operation of the liquid-fuel rocket engine.

[0003] Currently, the selection of pressurization schemes for launch vehicles, both domestically and internationally, mainly considers factors such as improving pressurization efficiency, system simplicity and reliability, and technical capabilities. Mainstream cryogenic engines primarily use a combination of liquid oxygen and kerosene propellants. Commonly used pressurization schemes mainly include self-generated pressurization, ambient temperature helium pressurization, ambient temperature helium heated pressurization, and cold helium heated pressurization. The investigation has led to the following conclusion: For liquid oxygen and kerosene engines, the kerosene tank mainly adopts the ambient temperature helium pressurization scheme.

[0004] In the process of realizing this invention, the inventors discovered at least the following problems in the prior art:

[0005] Room temperature helium pressurization requires independent pressurization gas source storage devices such as high-pressure cylinders, as well as supporting pipelines and valves. The system composition is relatively complex and costly. For large and heavy launch vehicles, especially for pressurizing the propellant tanks of cryogenic rockets, the required gas volume is large, and the number of gas storage devices is numerous. At the same time, the cylinders cool down during the venting process, increasing their density, and the remaining pressure in the cylinders is relatively high. This results in the helium utilization rate of room temperature helium pressurization being less than 70%. In addition, helium is relatively expensive. Therefore, room temperature helium pressurization is costly for large rockets.

[0006] By explaining and comparing the above pressurization methods, it is clear that kerosene in the kerosene tanks of large launch vehicles is difficult to pressurize due to its high boiling point, resulting in high pressurization costs and heavy pressurization systems. Therefore, conducting research on the engineering application of low-cost, lightweight pressurization systems based on kerosene tanks is of urgent need and great significance. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a liquid nitrogen heating and vaporization pressurization system and a liquid rocket, so as to improve at least one of the problems existing in the prior art, such as high pressurization cost, complex structure and large weight of pressurization system.

[0008] In a first aspect, embodiments of the present invention provide a liquid nitrogen heating and vaporization pressurization system for a liquid rocket, comprising an oxygen tank, a fuel tank, a liquid nitrogen tank, a cavitation pipe, a liquid nitrogen pump, and a liquid nitrogen heater;

[0009] The oxygen tank is used to store liquid oxygen, and an oxygen tank pressurization pipe is installed on the top of the oxygen tank.

[0010] The fuel tank is located on the side of the oxygen tank near the engine and is used to store fuel. A fuel tank pressurization pipe is provided on the top of the fuel tank.

[0011] The liquid nitrogen tank is located inside the oxygen tank and is used to store liquid nitrogen. The bottom of the liquid nitrogen tank is connected to a liquid nitrogen delivery pipe.

[0012] The liquid nitrogen pump is installed on the liquid nitrogen delivery pipe to increase the output pressure of the liquid nitrogen;

[0013] The cavitation tube is used to regulate and stabilize the liquid nitrogen delivery flow rate;

[0014] The liquid nitrogen heater is used to vaporize and heat the liquid nitrogen delivered by the liquid nitrogen pump into high-temperature nitrogen gas. The heated and vaporized nitrogen gas is used to simultaneously pressurize the oxygen tank, the fuel tank, and the liquid nitrogen tank. The liquid nitrogen heater is connected to the oxygen tank pressurization pipe and the fuel tank pressurization pipe, respectively.

[0015] Furthermore, the top of the liquid nitrogen tank is provided with a liquid nitrogen tank pressurization pipe, and the end of the liquid nitrogen tank pressurization pipe away from the liquid nitrogen tank is connected to the oxygen tank pressurization pipe, or to the fuel tank pressurization pipe, or directly connected to the outlet of the liquid nitrogen heater.

[0016] Furthermore, the liquid nitrogen heater includes a first heater and a second heater connected in parallel; the inlet of the first heater is connected to the liquid nitrogen pump, and the outlet of the first heater is connected to the oxygen tank pressurization pipe; the inlet of the second heater is connected to the liquid nitrogen pump, and the outlet of the second heater is connected to the fuel tank pressurization pipe; the inlet end of the liquid nitrogen tank pressurization pipe is connected to the fuel tank pressurization pipe.

[0017] Furthermore, the cavitation tube includes a first cavitation tube and a second cavitation tube; a first liquid nitrogen shut-off valve and the first cavitation tube are connected in series between the liquid nitrogen pump and the first heater, and a second liquid nitrogen shut-off valve and the second cavitation tube are connected in series between the liquid nitrogen pump and the second heater.

[0018] Furthermore, the liquid nitrogen heating and vaporization pressurization system also includes an oxygen tank pressure sensor and an oxygen tank pressurization controller installed on the outer wall of the oxygen tank;

[0019] The oxygen chamber air pillow pressure sensor is used to detect the pressure of the oxygen chamber air pillow and send the pressure detection result to the oxygen chamber pressurization controller.

[0020] The oxygen tank pressurization controller is used to adjust the opening degree of the first cavitation pipe and the second cavitation pipe according to the pressure detection result.

[0021] Furthermore, the opening degree of the first cavitation tube is adjusted according to the following formula:

[0022]

[0023] In the formula, A Y This indicates the opening degree of the first cavitation tube, in dimensionless units;

[0024] A Y1 This indicates the minimum opening of the first cavitation tube, in dimensionless units;

[0025] P Y This indicates the pressure of the oxygen chamber's air cushion, in MPa.

[0026] P Y0 This indicates the lower limit of the oxygen chamber's pressure control zone, expressed in MPa.

[0027] P Y1 This indicates the upper limit of the pressure control zone for the oxygen chamber's air pillow, in MPa.

[0028] The opening of the second cavitation tube is adjusted according to the following formula.

[0029]

[0030] In the formula, A R This indicates the opening degree of the second cavitation tube, in dimensionless units;

[0031] A R1 This indicates the minimum opening of the second cavitation tube, in dimensionless units;

[0032] P R This indicates the pressure of the fuel tank cushion, in MPa.

[0033] P R0 This indicates the lower limit of the fuel tank air cushion pressure control zone, in MPa.

[0034] P R1 This indicates the upper limit of the fuel tank air cushion pressure control band, in MPa.

[0035] Furthermore, the liquid nitrogen heating and vaporization pressurization system also includes a pre-launch pressurization assembly, which includes a ground helium source assembly, an oxygen tank pressurization pipe, a fuel tank pressurization pipe, and a liquid nitrogen tank pressurization pipe. One end of the oxygen tank pressurization pipe is connected to the oxygen tank pressurization pipe, and the other end is detachably connected to the ground helium source assembly. One end of the fuel tank pressurization pipe is connected to the fuel tank pressurization pipe, and the other end is detachably connected to the ground helium source assembly. One end of the liquid nitrogen tank pressurization pipe is connected to the liquid nitrogen tank pressurization pipe, and the other end is detachably connected to the ground helium source assembly.

[0036] Furthermore, the ground helium source assembly includes a ground helium source, a first filter, a pressure reducer, and a control assembly connected in series. The control assembly includes an oxygen tank control assembly, a fuel tank control assembly, and a liquid nitrogen tank control assembly connected in parallel.

[0037] The oxygen tank control assembly includes a first valve assembly, a second filter, and an oxygen tank ground pressurization and release valve; the first valve assembly includes a parallel oxygen tank pressure replenishment solenoid valve, an oxygen tank pre-injection pressurization solenoid valve, and an oxygen tank manual switch, one end of the first valve assembly is connected to the pressure reducer, and the other end is connected to the second filter; one end of the oxygen tank ground pressurization and release valve is connected to the pipeline between the second filter and the first valve assembly, and the other end is open to the atmosphere;

[0038] The fuel tank control assembly includes a second valve assembly, a third filter, and a fuel tank ground pressure relief valve; the second valve assembly includes a fuel tank pressure replenishment solenoid valve, a fuel tank pre-injection pressure boosting solenoid valve, and a fuel tank manual switch connected in parallel; one end of the second valve assembly is connected to the pressure reducer, and the other end is connected to the third filter; one end of the fuel tank ground pressure relief valve is connected to the pipeline between the third filter and the second valve assembly, and the other end is open to the atmosphere;

[0039] The liquid nitrogen tank control assembly includes a third valve assembly, a fourth filter, and a liquid nitrogen tank ground pressurization and release valve. The third valve assembly includes a liquid nitrogen tank pressure replenishment solenoid valve, a liquid nitrogen tank pre-injection pressurization solenoid valve, and a liquid nitrogen tank manual switch connected in parallel. One end of the third valve assembly is connected to the pressure reducer, and the other end is connected to the fourth filter. One end of the liquid nitrogen tank ground pressurization and release valve is connected to the pipeline between the fourth filter and the third valve assembly, and the other end is open to the atmosphere.

[0040] Furthermore, the liquid nitrogen heating and vaporization pressurization system also includes a liquid nitrogen pump drive cylinder, which is connected to the liquid nitrogen pump turbine drive via a drive orifice plate, and is used to store the pressurization medium.

[0041] Secondly, embodiments of the present invention provide a liquid rocket, including the liquid nitrogen heating and vaporization pressurization system described above.

[0042] The above technical solution has the following beneficial effects: The liquid nitrogen heating and vaporization pressurization system and liquid rocket provided in this application place the liquid nitrogen tank in the oxygen tank, storing the nitrogen in a liquid state. The nitrogen is then heated by a liquid nitrogen heater to form nitrogen gas. The heated nitrogen gas is used to simultaneously pressurize the oxygen tank, fuel tank, and liquid nitrogen tank. The overall structure of the pressurization system is simple and lightweight, effectively improving the carrying capacity of the liquid rocket. Furthermore, nitrogen pressurization reduces the use of expensive helium compared to helium pressurization, effectively lowering costs. Simultaneously, the utilization rate of the pressurization medium is significantly improved compared to helium pressurization. The liquid nitrogen heating and vaporization pressurization system of this application sets up separate pressurization pipes for the oxygen tank and fuel tank, enabling independent pressurization of the oxygen tank and fuel tank. This avoids safety issues caused by gas backflow from the oxygen tank to the fuel tank, making the liquid nitrogen heating and vaporization pressurization system safer and more reliable. Attached Figure Description

[0043] 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 of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the overall structure of the liquid nitrogen heating, vaporization, and pressurization system according to an embodiment of the present invention.

[0045] Figure 2 yes Figure 1 A partial structural diagram of a liquid nitrogen heating and vaporization pressurization system.

[0046] Figure 3 This is a schematic diagram of the opening adjustment logic of the first cavitation tube in an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram of the opening adjustment logic of the second cavitation tube in an embodiment of the present invention.

[0048] Figure 5 This is a schematic diagram of the pre-injection supplementary pressure assembly according to an embodiment of the present invention.

[0049] Figure 6 This is a schematic diagram of the liquid nitrogen pump drive system according to an embodiment of the present invention.

[0050] Figure 7 This is a schematic diagram of the liquid nitrogen filling and precooling assembly according to an embodiment of the present invention.

[0051] Figure 8 This is a three-dimensional structural schematic diagram of the liquid oxygen delivery system according to an embodiment of the present invention.

[0052] Figure 9 This is a three-dimensional structural half-sectional view of the liquid oxygen delivery system according to an embodiment of the present invention.

[0053] The meanings of the labels in the attached diagram are as follows:

[0054] 10. Oxygen tank; 11. Oxygen tank pressurization pipe; 12. Oxygen tank energy dissipator; 13. Oxygen tank safety relief valve; 14. Oxygen delivery pipe; 141. Delivery pipe inlet flange; 142. Bellows; 143. Liquid oxygen filter; 144. Liquid oxygen compensator; 145. Oxygen pump inlet flange; 146. Oxygen delivery pipeline fixing device; 15. Oxygen tank air pillow pressure sensor; 16. Oxygen tank pressurization controller;

[0055] 20. Fuel tank; 21. Fuel tank booster pipe; 22. Fuel tank energy dissipator; 23. Fuel tank safety relief valve; 24. Tunnel pipe; 25. Fuel tank air cushion pressure sensor; 26. Fuel tank booster controller;

[0056] 30. Liquid nitrogen tank; 31. Liquid nitrogen delivery pipe; 311. Liquid nitrogen pump; 312. First liquid nitrogen shut-off valve; 313. First cavitation pipe; 314. Second liquid nitrogen shut-off valve; 315. Second cavitation pipe; 32. Liquid nitrogen tank pressurization pipe; 321. Liquid nitrogen tank check valve; 33. First heater; 34. Second heater; 35. Liquid nitrogen tank vent valve; 36. Liquid nitrogen tank safety valve;

[0057] 40. Pre-launch pressurization assembly; 41. Oxygen tank pressurization hose; 411. Oxygen tank pressurization check valve; 42. Fuel tank pressurization hose; 421. Fuel tank pressurization check valve; 43. Liquid nitrogen tank pressurization hose; 431. Liquid nitrogen tank pressurization check valve; 44. Secondary tail section plug-in connector; 45. Ground helium source; 451. First filter; 452. Pressure regulator; 46. Oxygen tank control assembly; 461. Oxygen tank pressurization solenoid valve; 462. Oxygen tank pre-launch pressurization solenoid valve; 463. Oxygen tank manual switch; 46 4. Second filter; 465. Oxygen tank ground pressurization and release valve; 47. Fuel tank control assembly; 471. Fuel tank pressure replenishment solenoid valve; 472. Fuel tank pre-injection pressurization solenoid valve; 473. Fuel tank manual switch; 474. Third filter; 475. Fuel tank ground pressurization and release valve; 48. Liquid nitrogen tank control assembly; 481. Liquid nitrogen tank pressure replenishment solenoid valve; 482. Liquid nitrogen tank pre-injection pressurization solenoid valve; 483. Liquid nitrogen tank manual switch; 484. Fourth filter; 485. Liquid nitrogen tank ground pressurization and release valve;

[0058] 50. Liquid nitrogen filling and precooling assembly; 51. Liquid nitrogen filling and precooling pipeline; 52. Liquid nitrogen filling and precooling check valve; 53. Tail-end plug-in connector; 54. Liquid nitrogen filling valve; 55. Liquid nitrogen filling system; 56. Liquid nitrogen discharge shut-off valve;

[0059] 60. Engine;

[0060] 70. Liquid nitrogen pump drives gas cylinder; 71. Drive orifice plate. Detailed Implementation

[0061] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. In the accompanying drawings and the following description, at least some well-known structures and techniques have not been shown in order to avoid unnecessarily obscuring the invention; and, for clarity, the dimensions of some structures may be exaggerated. Furthermore, the features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments.

[0062] See also Figure 1 and Figure 2 This application provides a liquid rocket, specifically using a two-stage rocket system as an example. The two-stage rocket system includes a liquid nitrogen heating and vaporization pressurization system and an engine 60.

[0063] The liquid nitrogen heating and vaporization pressurization system includes an oxygen tank 10, a fuel tank 20, a cavitation pipe, a liquid nitrogen tank 30, a liquid nitrogen pump 311, and a liquid nitrogen heater.

[0064] The oxygen tank 10 is used to store liquid oxygen. The top of the oxygen tank 10 is equipped with an oxygen tank pressurization pipe 11. One end of the oxygen tank pressurization pipe 11 is connected to the oxygen tank energy dissipator 12 inside the oxygen tank 10, and the other end is connected to the liquid nitrogen heater, which is used to pressurize the oxygen tank air pillow.

[0065] The fuel tank 20 is located on the side of the oxygen tank 10 near the engine 60 and is used to store fuel. The top of the fuel tank 20 is equipped with a fuel tank pressurization pipe 21. One end of the fuel tank pressurization pipe 21 is connected to the fuel tank energy dissipator 22 inside the fuel tank 20, and the other end is connected to the liquid nitrogen heater to pressurize the fuel tank air cushion.

[0066] The liquid nitrogen tank 30 is located inside the oxygen tank 10 and is used to store liquid nitrogen. The bottom of the liquid nitrogen tank 30 is connected to a liquid nitrogen delivery pipe 31, and the top is equipped with a liquid nitrogen tank pressurization pipe 32 for pressurizing the liquid nitrogen tank 30. The end of the liquid nitrogen tank pressurization pipe 32 away from the liquid nitrogen tank 30 is connected to the oxygen tank pressurization pipe 11, or to the fuel tank pressurization pipe 21, or directly to the outlet of the liquid nitrogen heater.

[0067] A liquid nitrogen pump 311 is installed on the liquid nitrogen delivery pipe 31 to increase the output pressure of liquid nitrogen. A cavitation pipe is used to regulate and stabilize the liquid nitrogen delivery flow rate.

[0068] The liquid nitrogen heater is used to vaporize and heat the liquid nitrogen delivered by the liquid nitrogen pump 311 into high-temperature nitrogen gas. The heated and vaporized nitrogen gas is used to pressurize the oxygen tank 10, the fuel tank 20 and the liquid nitrogen tank 30 at the same time. The liquid nitrogen heater is connected to the oxygen tank pressurization pipe 11 and the fuel tank pressurization pipe 21 respectively.

[0069] like Figure 2 As shown, in this embodiment, the oxygen tank 10 is a secondary oxygen tank, the fuel tank 20 is a secondary fuel tank, and the engine 60 is a secondary engine. A liquid oxygen delivery system is provided at the bottom of the oxygen tank 10. The liquid oxygen delivery system includes an oxygen delivery pipe 14 located at the bottom of the oxygen tank 10. The oxygen tank 10 is connected to the inlet of the engine 60 through the oxygen delivery pipe 14. The oxygen delivery pipe 14 passes through the tunnel pipe 24 of the fuel tank 20 below. A corrugated pipe 142 and a delivery pipe inlet flange 141 are sequentially connected to the end of the oxygen delivery pipe 14 near the oxygen tank 10, and the pipe inlet flange 141 connects to the bottom of the oxygen tank 10. A liquid oxygen filter 143, a liquid oxygen compensator 144, and an oxygen pump inlet flange 145 are sequentially connected to the end of the oxygen delivery pipe 14 near the engine 60, and the pipe inlet flange 145 connects to the oxygen pump inlet of the engine 60. The three-dimensional structure of the liquid oxygen delivery system in this embodiment is shown below. Figure 8 and Figure 9 As shown, an oxygen delivery pipeline fixing device 146 is also provided between the oxygen delivery pipe 14 and the liquid oxygen compensator 144. In this embodiment, the inlet flange 141 of the delivery pipe and the bottom outlet profile of the secondary oxygen tank are integrated into a single design, and the bottom outlet profile of the secondary oxygen tank is set on the oxygen delivery pipe 14, simplifying the structure of the liquid oxygen delivery system. Two compensation structures (bellows 142 and liquid oxygen compensator 144) are set in the liquid oxygen delivery system to achieve axial compensation of the oxygen delivery pipe 14 of the secondary oxygen tank. A liquid oxygen filter 143 is installed in the oxygen delivery pipe 14, and the oxygen delivery pipe 14 and the liquid oxygen filter 143 are integrated into a single design. An oxygen delivery pipeline fixing device 146 is set in the liquid oxygen delivery pipe 14 to achieve the fixing and installation of the oxygen delivery pipe 14. The pipeline of the liquid oxygen delivery system is fixed through the bottom of the fuel tank.

[0070] The cavitation pipe includes a first cavitation pipe 313 and a second cavitation pipe 315. The liquid nitrogen heater includes a first heater 33 and a second heater 34 connected in parallel; the inlet of the first heater 33 is connected to the liquid nitrogen pump 311, and the outlet of the first heater 33 is connected to the oxygen tank pressurization pipe 11; the inlet of the second heater 34 is connected to the liquid nitrogen pump 311, and the outlet of the second heater 34 is connected to the fuel tank pressurization pipe 21. In this embodiment, the inlet end of the liquid nitrogen tank pressurization pipe 32 is connected to the fuel tank pressurization pipe 21, and a liquid nitrogen tank check valve 321 is provided on the liquid nitrogen tank pressurization pipe 32. In this embodiment, a first liquid nitrogen shut-off valve 312 and a first cavitation pipe 313 are connected in series between the liquid nitrogen pump 311 and the first heater 33, and a second liquid nitrogen shut-off valve 314 and a second cavitation pipe 315 are connected in series between the liquid nitrogen pump 311 and the second heater 34. That is, after passing through the liquid nitrogen pump 311, the liquid nitrogen delivery pipe 31 is divided into two paths by a three-way valve. One path is connected to the first liquid nitrogen shut-off valve 312, the first cavitation pipe 313, and the first heater 33. The other path is connected to the second heater 34 via the second liquid nitrogen shut-off valve 314 and the second cavitation pipe 315.

[0071] In this embodiment, both the secondary oxygen tank and the secondary fuel tank are heated and pressurized with liquid nitrogen, and the liquid nitrogen flow rate is controlled by an adjustable cavitation pipe.

[0072] During the second stage of flight, the liquid nitrogen in the liquid nitrogen tank 30 is pressurized to the oxygen tank 10 via the liquid nitrogen delivery pipe 31, the liquid nitrogen pump 311, the first cryogenic shut-off valve, the first cavitation pipe 313, the first liquid nitrogen heater, the oxygen tank pressurization pipe 11, and the oxygen tank energy dissipator 12.

[0073] The liquid nitrogen in the liquid nitrogen tank 30 is pressurized to the fuel tank 20 via the liquid nitrogen delivery pipe 31, the liquid nitrogen pump 311, the second cryogenic shut-off valve, the second cavitation pipe 315, the second liquid nitrogen heater, the fuel tank pressurization pipe 21, and the fuel tank energy dissipator 22.

[0074] A stream of high-temperature nitrogen gas is distributed from the fuel tank pressurization pipe 21 through a three-way valve and then supplied to the liquid nitrogen tank 30 via the liquid nitrogen tank check valve 321 and the liquid nitrogen tank pressurization pipe 32.

[0075] This patent controls the flow rate of liquid nitrogen heating and pressurization in the oxygen tank 10 by controlling the opening of the adjustable first cavitation pipe 313, and controls the flow rate of liquid nitrogen heating and pressurization in the fuel tank 20 by controlling the opening of the adjustable second cavitation pipe 315.

[0076] In this embodiment, liquid nitrogen tank 30 is stored in oxygen tank 10. Liquid nitrogen pressure is increased via a liquid nitrogen pump 311, and the liquid nitrogen flow rate is controlled via an adjustable first cavitation pipe 313 to pressurize oxygen tank 10. Similarly, liquid nitrogen pressure is increased via another liquid nitrogen pump 311, and the liquid nitrogen flow rate is controlled via an adjustable second cavitation pipe 315 to pressurize fuel tank 20. A T-junction is installed on the fuel tank pressurization pipe 21, branching off one line to pressurize liquid nitrogen tank 30. This embodiment achieves pressurization of all three tanks through liquid nitrogen heating.

[0077] The oxygen tank 10 adopts a liquid nitrogen heating and pressurization scheme. After being heated by the liquid nitrogen heater, the liquid nitrogen is vaporized into nitrogen gas. The high-temperature nitrogen gas pressurizes the oxygen tank 10 through the oxygen tank pressurization pipe 11 and pressurizes the fuel tank 20 through the fuel tank pressurization pipe 21. A small stream of high-temperature nitrogen gas is separated from the fuel tank 20 and fed into the liquid nitrogen tank for liquid nitrogen heating and pressurization through the liquid nitrogen tank check valve 321 and the liquid nitrogen tank pressurization pipe 32.

[0078] In this embodiment, the first heater 33 heats liquid nitrogen into nitrogen gas to pressurize the oxygen tank 10, and the second heater 34 heats liquid nitrogen into nitrogen gas to pressurize the fuel tank 20, thus achieving independent pressurization of the oxygen tank 10 and the fuel tank 20. Separating the oxygen tank pressurization system and the fuel tank 20 pressurization system enables independent pressurization of the two tanks, preventing gas from the oxygen tank 10 from flowing back into the fuel tank 20 and causing safety issues.

[0079] In some embodiments, an oxygen chamber pressure sensor 15 and an oxygen chamber pressurization controller 16 may also be provided on the outer wall of the oxygen chamber 10, with the oxygen chamber pressure sensor 15 connected to the oxygen chamber. The oxygen chamber pressure sensor 15 is used to detect the pressure of the oxygen chamber and send the pressure detection result to the oxygen chamber pressurization controller 16; the oxygen chamber pressurization controller 16 is used to adjust the opening of the first cavitation pipe 313 and the second cavitation pipe 315 according to the pressure detection result.

[0080] The opening degree of the first cavitation pipe 313 can be controlled, thereby achieving precise control of the liquid nitrogen heating and pressurization flow rate. The oxygen tank 10's pressure is measured by the oxygen tank cushion pressure sensor 15, and the pressure value is transmitted to the oxygen tank pressurization controller 16. The controller 16 calculates and makes decisions to control the opening degree of the adjustable first cavitation pipe 313, thus controlling the pressurization liquid nitrogen flow rate of the oxygen tank 10 and stabilizing the oxygen tank cushion pressure, achieving closed-loop control of the oxygen tank cushion pressure. The opening degree adjustment logic of the first cavitation pipe 313 is as follows: Figure 3 As shown, P Y0 P indicates the lower limit of the fuel tank pressure control band. Y1 Indicates the upper limit of the fuel tank pressure control band, 1 indicates the maximum opening of the first cavitation pipe 313, A Y1 This indicates the minimum opening of the first cavitation tube 313.

[0081] The fuel tank cushion pressure is measured by the fuel tank cushion pressure sensor 25 and transmitted to the fuel tank booster controller 26. The booster controller 26 calculates and makes decisions to control the opening of the adjustable second cavitation pipe 315, thereby controlling the flow rate of pressurized liquid nitrogen in the fuel tank 20 and stabilizing the fuel tank cushion pressure, achieving closed-loop control of the fuel tank cushion pressure. The opening adjustment logic of the second cavitation pipe 315 is as follows: Figure 4 As shown, P R0 P indicates the lower limit of the fuel tank pressure control band. R1 Indicates the upper limit of the fuel tank pressure control band, 1 indicates the maximum opening of the second cavitation pipe 315, A R1 This indicates the minimum opening of the second cavitation tube 315.

[0082] Specifically, the opening degree of the first cavitation tube 313 is adjusted according to the following formula.

[0083]

[0084] In the formula, A Y This indicates the opening degree of the first cavitation tube, in dimensionless units;

[0085] A Y1 This indicates the minimum opening of the first cavitation tube, in dimensionless units;

[0086] P Y This indicates the pressure of the oxygen chamber's air cushion, in MPa.

[0087] P Y0 This indicates the lower limit of the oxygen chamber's pressure control zone, expressed in MPa.

[0088] P Y1 This indicates the upper limit of the pressure control zone for the oxygen chamber's air pillow, in MPa.

[0089] The opening of the second cavitation tube 315 is adjusted according to the following formula.

[0090]

[0091] In the formula, A R This indicates the opening degree of the second cavitation tube, in dimensionless units;

[0092] A R1 This indicates the minimum opening of the second cavitation tube, in dimensionless units;

[0093] P R This indicates the pressure of the fuel tank cushion, in MPa.

[0094] P R0 This indicates the lower limit of the fuel tank air cushion pressure control zone, in MPa.

[0095] PR1 This indicates the upper limit of the fuel tank air cushion pressure control band, in MPa.

[0096] like Figure 1 and Figure 5 As shown, in some embodiments, the liquid nitrogen heating and vaporization pressurization system further includes a pre-launch pressurization assembly 40, which includes a ground helium source assembly, an oxygen tank pressurization pipe 41, a fuel tank pressurization pipe 42, and a liquid nitrogen tank pressurization pipe 43. One end of the oxygen tank pressurization pipe 41 is connected to the oxygen tank pressurization pipe 11, and the other end is detachably connected to the ground helium source assembly. One end of the fuel tank pressurization pipe 42 is connected to the fuel tank pressurization pipe 21, and the other end is detachably connected to the ground helium source assembly. One end of the liquid nitrogen tank pressurization pipe 43 is connected to the liquid nitrogen tank pressurization pipe 32, and the other end is detachably connected to the ground helium source assembly.

[0097] The ground helium source assembly includes a ground helium source 45, a first filter 451, a pressure reducer 452 and a control assembly connected in series. The control assembly includes an oxygen tank control assembly 46, a fuel tank control assembly 47 and a liquid nitrogen tank control assembly 48 connected in parallel.

[0098] The oxygen tank control assembly 46 includes a first valve assembly, a second filter 464, and an oxygen tank ground pressure boosting and release valve 465. The first valve assembly includes an oxygen tank pressure replenishing solenoid valve 461, an oxygen tank pre-injection pressure boosting solenoid valve 462, and an oxygen tank manual switch 463 connected in parallel. One end of the first valve assembly is connected to the pressure reducer 452, and the other end is connected to the second filter 464. One end of the oxygen tank ground pressure boosting and release valve 465 is connected to the pipeline between the second filter 464 and the first valve assembly, and the other end is open to the atmosphere.

[0099] The fuel tank control assembly 47 includes a second valve assembly, a third filter 474, and a fuel tank ground pressure relief valve 475. The second valve assembly includes a fuel tank pressure replenishment solenoid valve 471, a fuel tank pre-injection pressure boosting solenoid valve 472, and a fuel tank manual switch 473 connected in parallel. One end of the second valve assembly is connected to the pressure reducer 452, and the other end is connected to the third filter 474. One end of the fuel tank ground pressure relief valve 475 is connected to the pipeline between the third filter 474 and the second valve assembly, and the other end is open to the atmosphere.

[0100] The liquid nitrogen tank control assembly 48 includes a third valve assembly, a fourth filter 484, and a liquid nitrogen tank ground pressurization and release valve 485. The third valve assembly includes a liquid nitrogen tank pressure replenishment solenoid valve 481, a liquid nitrogen tank pre-injection pressurization solenoid valve 482, and a liquid nitrogen tank manual switch 483 connected in parallel. One end of the third valve assembly is connected to the pressure reducer 452, and the other end is connected to the fourth filter 484. One end of the liquid nitrogen tank ground pressurization and release valve 485 is connected to the pipeline between the fourth filter 484 and the third valve assembly, and the other end is open to the atmosphere.

[0101] Specifically, in this embodiment, the oxygen tank replenishment pipe 41 is equipped with an oxygen tank replenishment check valve 411. One end of the oxygen tank replenishment pipe 41 is connected to the oxygen tank pressurization pipe 11 via a tee, and the other end is connected to the second filter 464 of the helium source assembly via a two-stage tail plug connector 44. The fuel tank replenishment pipe 42 is equipped with a fuel tank replenishment check valve 421. One end of the fuel tank replenishment pipe 42 is connected to the fuel tank pressurization pipe 21 via a tee, and the other end is connected to the third filter 474 of the helium source assembly via a two-stage tail plug connector 44. The liquid nitrogen tank replenishment pipe 43 is equipped with a liquid nitrogen tank replenishment check valve 431. One end of the liquid nitrogen tank replenishment pipe 43 is connected to the liquid nitrogen tank pressurization pipe 32 via a tee, and the other end is connected to the fourth filter 484 of the helium source assembly via a two-stage tail plug connector 44.

[0102] When no power is applied, the fuel tank 20 needs to be filled with gas through the ground storage tank for a gas test. The helium provided by the ground helium source 45 is pressurized to the fuel tank 20 through the first filter 451, pressure reducer 452, fuel tank manual switch 473, orifice plate, third filter 474, secondary tail section plug-in connector 44, fuel tank pressure replenishment check valve 421, fuel tank pressure boosting pipe 21 and fuel tank energy dissipator 22, so that the fuel tank 20 can be filled with gas without power on the ground for a gas test.

[0103] During rocket pre-launch pressurization, the fuel tank 20 needs to be pressurized. Helium supplied by the ground helium source 45 is pressurized to the fuel tank 20 through the first filter 451, pressure reducer 452, fuel tank pre-launch pressurization solenoid valve 472, orifice plate, third filter 474, secondary tail section plug-in connector 44, fuel tank supplemental pressure check valve 421, fuel tank pressurization pipe 21 and fuel tank energy dissipator 22, thus performing pre-launch pressurization of the fuel tank 20 before rocket ignition.

[0104] During the power system test, the pre-launch pressurization assembly 40 of the secondary fuel tank 20 is used to pressurize the fuel tank 20. During the second stage power system test, helium supplied by the ground helium source 45 passes through the first filter 451, pressure reducer 452, fuel tank pressurization solenoid valve 471, orifice plate, third filter 474, secondary tail section plug-in connector 44, fuel tank pressurization check valve 421, fuel tank pressurization pipe 21 and fuel tank energy dissipator 22 to pressurize the fuel tank 20 during the power system test.

[0105] When the electrical system is not powered, the liquid nitrogen tank 30 needs to be filled with gas through the ground storage tank. The helium provided by the ground helium source 45 is pressurized to the liquid nitrogen tank 30 through the first filter 451, pressure reducer 452, liquid nitrogen tank manual switch 483, orifice plate, fourth filter 484, secondary tail plug-in connector 44, liquid nitrogen tank pressure replenishment check valve 431 and liquid nitrogen tank pressure boosting pipe 32, so that the liquid nitrogen tank 30 can be filled with gas without power on the ground.

[0106] During the pre-launch pressurization of the rocket, the liquid nitrogen tank 30 needs to be pressurized. The helium provided by the ground helium source 45 is pressurized to the liquid nitrogen tank 30 through the first filter 451, pressure reducer 452, liquid nitrogen tank pre-launch pressurization solenoid valve 482, orifice plate, fourth filter 484, secondary tail section plug-in connector 44, liquid nitrogen tank replenishment check valve 431 and liquid nitrogen tank pressurization pipe 32, so as to perform pre-launch pressurization of the liquid nitrogen tank 30 before rocket ignition.

[0107] During the power system test, the pre-launch pressurization assembly 40 of the liquid nitrogen tank 30 is used to pressurize the liquid nitrogen tank 30. During the second stage power system test, helium supplied by the ground helium source 45 passes through the first filter 451, pressure reducer 452, liquid nitrogen tank pressurization solenoid valve 481, orifice plate, fourth filter 484, second stage tail section plug-in connector 44, liquid nitrogen tank pressurization check valve 431 and liquid nitrogen tank pressurization pipe 32 to pressurize the liquid nitrogen tank 30 during the power system test.

[0108] When the electrical system is not powered, the oxygen tank 10 needs to be filled with gas through the ground storage tank. The helium provided by the ground helium source 45 is pressurized to the oxygen tank 10 through the first filter 451, pressure reducer 452, oxygen tank manual switch 463, orifice plate, second filter 464, secondary tail plug connector 44, oxygen tank pressure replenishment check valve 411, oxygen tank pressure boosting pipe 11 and oxygen tank energy dissipator 12, so that the oxygen tank 10 can be filled with gas without the ground power supply.

[0109] During rocket pre-launch pressurization, oxygen tank 10 needs to be pressurized. Helium supplied by ground helium source 45 is pressurized to oxygen tank 10 through first filter 451, pressure reducer 452, oxygen tank pre-launch pressurization solenoid valve 462, orifice plate, second filter 464, second stage tail section plug-in connector 44, second check valve, oxygen tank pressurization pipe 11 and oxygen tank energy dissipator 12, so as to perform pre-launch pressurization of oxygen tank 10 before rocket ignition.

[0110] During the power system test run, the pre-launch pressurization assembly 40 of the secondary oxygen tank is used to pressurize the oxygen tank 10. During the second stage power system test run, helium supplied by the ground helium source 45 is pressurized to the oxygen tank 10 through the first filter 451, pressure reducer 452, oxygen tank pressurization solenoid valve 461, orifice plate, second filter 464, secondary tail section plug-in connector 44, oxygen tank pressurization check valve 411, oxygen tank pressurization pipe 11 and oxygen tank energy dissipator 12 to perform pressurization for the power system test run.

[0111] During the power test, oxygen tank 10, fuel tank 20 and liquid nitrogen tank 30 were all heated and pressurized with liquid nitrogen, while oxygen tank 10, fuel tank 20 and liquid nitrogen tank 30 were pressurized with room temperature helium.

[0112] The ground control unit is equipped with three pressurization control valves: a manual switch, a pre-launch pressurization solenoid valve, and a pressure replenishment solenoid valve. The manual switch is used for ground-based unpowered tank inflation and testing. The pre-launch pressurization solenoid valve is used for pre-launch pressurization of the tank before rocket ignition. The pressure replenishment solenoid valve is used for pressurization of the tank during rocket propulsion system testing.

[0113] The pre-launch pressurization assembly 40 of this embodiment can meet the requirements of tank filling and testing when no power is applied on the ground, pre-launch pressurization of the rocket's pre-launch pressurization system, and pressurization of the tank after the test ignition of the propulsion system. This pre-launch pressurization assembly 40 integrates the pre-launch pressurization system, the ground-based tank filling and testing system, and the propulsion system test pressurization system into a single design, improving the system's compactness and reducing the number of components used. Furthermore, the pre-launch pressurization assembly 40 is relatively simple, with a limited variety and number of valves and pipelines, resulting in low development difficulty and a short manufacturing cycle.

[0114] like Figure 6 As shown, in some embodiments, the liquid nitrogen heating and vaporization pressurization system further includes a liquid nitrogen pump drive cylinder 70. The liquid nitrogen pump drive cylinder 70 is connected to the liquid nitrogen pump 311 turbine drive via a drive orifice plate 71. The liquid nitrogen pump drive cylinder 70 is used to store the pressurizing medium. The pressurizing medium in the liquid nitrogen pump drive cylinder 70 can be, for example, oxygen, nitrogen, compressed air, or helium. The drive orifice plate 71 can be a constant orifice plate to output the drive gas at a constant flow rate, or it can be a variable orifice plate to control the head of the liquid nitrogen pump 311 by changing the flow rate of the drive gas, thereby controlling the liquid nitrogen flow rate.

[0115] In this embodiment, the driving gas source of the liquid nitrogen pump 311 is the driving gas in the driving gas cylinder of the liquid nitrogen pump 311. For example, when the driving gas is helium, the helium in the driving gas cylinder of the liquid nitrogen pump 311 is output to the turbine of the liquid nitrogen pump 311 through the driving orifice plate. The helium drives the turbine of the liquid nitrogen pump 311 to rotate, and the turbine of the liquid nitrogen pump 311 drives the liquid nitrogen pump 311, thereby realizing the driving of the liquid nitrogen pump 311. Then, the driving gas is directly discharged into the atmosphere through the exhaust pipe on the liquid nitrogen pump 311.

[0116] like Figure 1 As shown, in some embodiments, an oxygen tank overflow valve 13 can also be installed on the secondary oxygen tank 10. The oxygen tank overflow valve 13 integrates the safety valve and the vent valve. When the ground oxygen tank adds liquid oxygen to the secondary oxygen tank 10, the oxygen tank overflow valve 13 opens. A fuel tank overflow valve 23 can also be installed on the secondary fuel tank 20. The fuel tank overflow valve 23 integrates the safety valve and the vent valve. When the ground fuel tank adds fuel to the secondary fuel tank 20, the fuel tank overflow valve 23 opens.

[0117] During secondary flight, when the oxygen tank cushion pressure is higher than the opening pressure of the oxygen tank overflow valve 13, the oxygen tank overflow valve 13 opens; when the oxygen tank cushion pressure is lower than the closing pressure of the oxygen tank overflow valve 13, the oxygen tank overflow valve 13 closes. During secondary flight, when the fuel tank cushion pressure is higher than the opening pressure of the fuel tank overflow valve 23, the fuel tank overflow valve 23 opens; when the fuel tank cushion pressure is lower than the closing pressure of the fuel tank overflow valve 23, the fuel tank overflow valve 23 closes.

[0118] In some embodiments, a liquid nitrogen tank exhaust valve 35 and a liquid nitrogen tank safety valve 36 are also connected in series on the liquid nitrogen tank 30. The liquid nitrogen tank exhaust valve 35 and the liquid nitrogen tank safety valve 36 are connected to the liquid nitrogen tank pressurization pipe 32 through pipelines and tees.

[0119] like Figure 1 and Figure 7 As shown, in some embodiments, a liquid nitrogen filling and precooling assembly 50 is also included. The liquid nitrogen filling and precooling assembly 50 includes a liquid nitrogen filling and precooling pipeline 51, a liquid nitrogen discharge shut-off valve 56, and a liquid nitrogen filling and precooling one-way valve 52. The liquid nitrogen filling and precooling one-way valve 52 is provided on the liquid nitrogen filling and precooling pipeline 51. One end of the liquid nitrogen filling and precooling pipeline 51 is connected to the pipeline at the outlet of the liquid nitrogen pump 311, and the other end is detachably connected to the liquid nitrogen filling system 55 on the ground.

[0120] Specifically, in this embodiment, one end of the liquid nitrogen pre-cooling pipeline 51 is connected to the liquid nitrogen delivery pipe 31 at the outlet of the liquid nitrogen pump 311 via a tee, and the other end is detachably connected to the liquid nitrogen filling system 55 via a tail plug connector 53. A liquid nitrogen filling valve 54 is also provided on the pipeline between the tail plug connector 53 and the liquid nitrogen filling system 55. The inlet of the liquid nitrogen discharge shut-off valve 56 is connected to the liquid nitrogen pre-cooling pipeline 51 at the inlet of the liquid nitrogen pre-cooling check valve 52 via a pipeline, and the outlet is open to the atmosphere.

[0121] The liquid nitrogen filling system 55 delivers liquid nitrogen to the liquid nitrogen tank 30 via the liquid nitrogen filling valve 54, the tail plug-in connector 53, the liquid nitrogen filling pre-cooling check valve 52, and the liquid nitrogen delivery pipe 31, thereby filling the liquid nitrogen tank 30 with liquid nitrogen.

[0122] During rocket flight, the tail connector 53 disengages, and the liquid nitrogen in the liquid nitrogen tank 30 is prevented from leaking through the liquid nitrogen filling and pre-cooling check valve 52. Positioning the liquid nitrogen filling port downstream of the liquid nitrogen pump 311 allows for pre-cooling of the pump during liquid nitrogen filling, improving the reliability of the pre-cooling process.

[0123] When the liquid nitrogen pump 311 is started, it needs to be pre-cooled. The cryogenic coolant flows through the liquid nitrogen delivery pipe 31 and the turbine pump chamber of the liquid nitrogen pump 311, and after cooling the liquid nitrogen delivery pipe 31 and the turbine pump body, it is pre-cooled and discharged from the liquid nitrogen pump 311 to the outside of the rocket. This pre-cooling method is called discharge pre-cooling.

[0124] Due to the low-temperature characteristics of liquid nitrogen, the engine 60, liquid nitrogen delivery pipe 31, and the external environment form a high-temperature heat source relative to the liquid nitrogen. When liquid nitrogen enters the liquid nitrogen pump 311, it boils and vaporizes due to the heat, which affects the blades of the liquid nitrogen pump 311, leading to cavitation. To ensure the normal operation of the liquid nitrogen pump 311, it needs to be pre-cooled to the same temperature as the liquid nitrogen to prevent the liquid nitrogen from vaporizing into gas when passing through the pump during normal operation.

[0125] During the pre-cooling process of the ground liquid nitrogen pump 311, the liquid nitrogen in the liquid nitrogen tank 30 is directly discharged into the atmosphere after passing through the liquid nitrogen delivery pipe 31, the liquid nitrogen pump 311 and the liquid nitrogen discharge shut-off valve 56, ensuring the reliable operation of the liquid nitrogen pump 311 during ignition and preventing cavitation caused by the vaporization of liquid nitrogen during ignition.

[0126] During rocket ignition and flight, the liquid nitrogen pre-cooling check valve 52 remains closed, and the liquid nitrogen after the liquid nitrogen pump 311 is heated into high-temperature nitrogen gas by the liquid nitrogen heater to pressurize the oxygen tank 10 and the fuel tank 20.

[0127] The pre-cooling of liquid nitrogen pump 311 is only performed before liquid nitrogen pump 311 starts working. After liquid nitrogen pump 311 starts working, the pre-cooling of liquid nitrogen pump 311 is not performed. Therefore, the one-way valve 52 for liquid nitrogen filling and pre-cooling is closed.

[0128] In this embodiment, the liquid nitrogen filling system 55 and the liquid nitrogen pump 311 precooling system are integrated into a single design. The liquid nitrogen filling and precooling component 50 is located downstream of the liquid nitrogen pump 311, so that the liquid nitrogen pump 311 can be precooled during liquid nitrogen filling. The liquid nitrogen filling and precooling check valve 52 is installed on the liquid nitrogen filling pipeline, so that the liquid nitrogen filling and precooling component 50 can perform both the function of liquid nitrogen filling and the function of liquid nitrogen discharge precooling.

[0129] The liquid nitrogen heating and vaporization pressurization system provided in this application embodiment uses liquid nitrogen for oxygen tank pressurization. After the liquid nitrogen is pressurized by a liquid nitrogen pump, the flow rate is regulated by a first cavitation pipe, and then heated by a first liquid nitrogen heater, causing the liquid nitrogen to vaporize into high-temperature nitrogen gas to pressurize the oxygen tank. Similarly, after the liquid nitrogen is pressurized by a liquid nitrogen pump, the flow rate is regulated by a second cavitation pipe, and then heated by a second liquid nitrogen heater, causing the liquid nitrogen to vaporize into high-temperature nitrogen gas to pressurize the fuel tank. This achieves independent pressurization of the oxygen tank and fuel tank, improving the safety and reliability of the liquid nitrogen heating and vaporization pressurization system. After entering the fuel tank pressurization pipe, a branch line is used to pressurize the liquid nitrogen tank. Both the oxygen tank and fuel tank adopt a closed-loop pressurization method. The opening of the first cavitation pipe is controlled by the oxygen tank cushion pressure to control the liquid nitrogen flow rate, thereby achieving precise control of the oxygen tank cushion pressure. The opening of the second cavitation pipe is controlled by the fuel tank cushion pressure to control the liquid nitrogen flow rate, thereby achieving precise control of the fuel tank cushion pressure.

[0130] The liquid nitrogen heating and vaporization pressurization system of this application embodiment uses the first heater of the engine 60 to heat liquid nitrogen into high-temperature nitrogen gas to pressurize the oxygen tank, and uses the second heater of the engine 60 to heat liquid nitrogen into high-temperature nitrogen gas to pressurize the fuel tank, thus achieving independent pressurization of the oxygen tank and the fuel tank. A powerful driving force is provided to the liquid nitrogen pump by driving the liquid nitrogen pump with helium or other pressurizing media.

[0131] In this embodiment, the liquid nitrogen heating and vaporization pressurization system incorporates supplementary pressurization pipes on both the oxygen tank pressurization pipe and the fuel tank pressurization pipe. This effectively shortens the length of the pre-launch pressurization pipeline, allowing for an integrated design of the pre-launch pressurization pipelines (oxygen tank supplementary pressurization pipe, fuel tank supplementary pressurization pipe, and liquid nitrogen tank supplementary pressurization pipe) and the main pressurization pipelines (oxygen tank pressurization pipe, fuel tank pressurization pipe, and liquid nitrogen tank pressurization pipe), thus improving the integration of the main pressurization pipeline. This embodiment integrates the pre-launch pressurization system, the ground-based gas filling and testing system for the gas tanks, and the propulsion system test pressurization system. This pre-launch pressurization system simultaneously enables the ground-based gas tanks to fill and test each tank when no power is applied, the pre-launch pressurization of the rocket's pre-launch pressurization system, and the pressurization of the tanks after the propulsion system test ignition.

[0132] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms 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," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0133] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0134] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A liquid nitrogen heating and vaporization pressurization system for use in liquid rockets, characterized in that, Includes an oxygen tank (10), a fuel tank (20), a liquid nitrogen tank (30), a cavitation pipe, a liquid nitrogen pump (311), and a liquid nitrogen heater; The oxygen tank (10) is used to store liquid oxygen, and the top of the oxygen tank (10) is equipped with an oxygen tank pressurization pipe (11). The fuel tank (20) is located on the side of the oxygen tank (10) near the engine and is used to store fuel. The top of the fuel tank (20) is provided with a fuel tank pressurization pipe (21). The liquid nitrogen tank (30) is located inside the oxygen tank (10) and is used to store liquid nitrogen. The bottom of the liquid nitrogen tank (30) is connected to a liquid nitrogen delivery pipe (31). The liquid nitrogen pump (311) is installed on the liquid nitrogen delivery pipe (31) to increase the output pressure of liquid nitrogen; The cavitation tube is used to regulate and stabilize the liquid nitrogen delivery flow rate; The liquid nitrogen heater is used to heat the liquid nitrogen delivered by the liquid nitrogen pump (311) into high-temperature nitrogen gas. The heated nitrogen gas is used to pressurize the oxygen tank (10), the fuel tank (20) and the liquid nitrogen tank (30) at the same time. The liquid nitrogen heater is connected to the oxygen tank pressurization pipe (11) and the fuel tank pressurization pipe (21) respectively.

2. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 1, characterized in that, The top of the liquid nitrogen tank (30) is provided with a liquid nitrogen tank pressurization pipe (32). The end of the liquid nitrogen tank pressurization pipe (32) away from the liquid nitrogen tank (30) is connected to the oxygen tank pressurization pipe (11), or to the fuel tank pressurization pipe (21), or directly connected to the outlet of the liquid nitrogen heater.

3. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 2, characterized in that, The liquid nitrogen heater includes a first heater (33) and a second heater (34) connected in parallel; the inlet of the first heater (33) is connected to the liquid nitrogen pump (311), and the outlet of the first heater (33) is connected to the oxygen tank pressurization pipe (11); the inlet of the second heater (34) is connected to the liquid nitrogen pump (311), and the outlet of the second heater (34) is connected to the fuel tank pressurization pipe (21); the inlet end of the liquid nitrogen tank pressurization pipe (32) is connected to the fuel tank pressurization pipe (21).

4. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 3, characterized in that, The cavitation tube includes a first cavitation tube (313) and a second cavitation tube (315); a first liquid nitrogen shut-off valve (312) and the first cavitation tube (313) are connected in series between the liquid nitrogen pump (311) and the first heater (33), and a second liquid nitrogen shut-off valve (314) and the second cavitation tube (315) are connected in series between the liquid nitrogen pump (311) and the second heater (34).

5. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 4, characterized in that, It also includes an oxygen tank air cushion pressure sensor (15) and an oxygen tank pressurization controller (16) installed on the outer wall of the oxygen tank (10); The oxygen chamber air pillow pressure sensor (15) is used to detect the pressure of the oxygen chamber air pillow and send the pressure detection result to the oxygen chamber pressurization controller (16); The oxygen tank pressurization controller (16) is used to adjust the opening degree of the first cavitation pipe (313) and the second cavitation pipe (315) according to the pressure detection result.

6. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 5, characterized in that, The opening degree of the first cavitation pipe (313) is adjusted according to the following formula. In the formula, A Y This indicates the opening degree of the first cavitation tube, in dimensionless units; A Y1 This indicates the minimum opening of the first cavitation tube, in dimensionless units; P Y This indicates the pressure of the oxygen chamber's air cushion, in MPa. P Y0 This indicates the lower limit of the oxygen chamber's pressure control zone, expressed in MPa. P Y1 This indicates the upper limit of the pressure control zone for the oxygen chamber's air pillow, in MPa. The opening degree of the second cavitation tube (315) is adjusted according to the following formula. In the formula, A R This indicates the opening degree of the second cavitation tube, in dimensionless units; A R1 This indicates the minimum opening of the second cavitation tube, in dimensionless units; P R This indicates the pressure of the fuel tank cushion, in MPa. P R0 This indicates the lower limit of the fuel tank air cushion pressure control zone, in MPa. P R1 This indicates the upper limit of the fuel tank air cushion pressure control band, in MPa.

7. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 2, characterized in that, It also includes a pre-launch pressurization assembly (40), which includes a ground helium source assembly, an oxygen tank pressurization pipe (41), a fuel tank pressurization pipe (42), and a liquid nitrogen tank pressurization pipe (43). One end of the oxygen tank pressurization pipe (41) is connected to the oxygen tank pressurization pipe (11), and the other end is detachably connected to the ground helium source assembly. One end of the fuel tank pressurization pipe (42) is connected to the fuel tank pressurization pipe (21), and the other end is detachably connected to the ground helium source assembly. One end of the liquid nitrogen tank pressurization pipe (43) is connected to the liquid nitrogen tank pressurization pipe (32), and the other end is detachably connected to the ground helium source assembly.

8. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 7, characterized in that, The ground helium source assembly includes a ground helium source (45), a first filter (451), a pressure reducer (452), and a control assembly connected in series. The control assembly includes an oxygen tank control assembly (46), a fuel tank control assembly (47), and a liquid nitrogen tank control assembly (48) connected in parallel. The oxygen tank control assembly (46) includes a first valve assembly, a second filter (464), and an oxygen tank ground pressure relief valve (465). The first valve assembly includes a parallel oxygen tank pressure replenishment solenoid valve (461), an oxygen tank pre-injection pressure solenoid valve (462), and an oxygen tank manual switch (463). One end of the first valve assembly is connected to the pressure reducer (452), and the other end is connected to the second filter (464). One end of the oxygen tank ground pressure relief valve (465) is connected to the pipeline between the second filter (464) and the first valve assembly, and the other end is connected to the atmosphere. The fuel tank control assembly (47) includes a second valve assembly, a third filter (474), and a fuel tank ground pressure relief valve (475); the second valve assembly includes a fuel tank pressure replenishment solenoid valve (471), a fuel tank pre-injection pressure boosting solenoid valve (472), and a fuel tank manual switch (473) connected in parallel; one end of the second valve assembly is connected to the pressure reducer (452), and the other end is connected to the third filter (474); one end of the fuel tank ground pressure relief valve (475) is connected to the pipeline between the third filter (474) and the second valve assembly, and the other end is connected to the atmosphere; The liquid nitrogen tank control assembly (48) includes a third valve assembly, a fourth filter (484), and a liquid nitrogen tank ground pressurization and release valve (485). The third valve assembly includes a liquid nitrogen tank pressure replenishment solenoid valve (481), a liquid nitrogen tank pre-injection pressurization solenoid valve (482), and a liquid nitrogen tank manual switch (483) connected in parallel. One end of the third valve assembly is connected to the pressure reducer (452), and the other end is connected to the fourth filter (484). One end of the liquid nitrogen tank ground pressurization and release valve (485) is connected to the pipeline between the fourth filter (484) and the third valve assembly, and the other end is connected to the atmosphere.

9. The liquid nitrogen heating, vaporization, and pressurization system as described in claim 1, characterized in that, It also includes a liquid nitrogen pump (311) drive cylinder, which is connected to the liquid nitrogen pump (311) turbine drive via a drive orifice plate, and is used to store the pressurizing medium.

10. A liquid rocket, characterized in that, Includes the liquid nitrogen heating vaporization pressurization system as described in any one of claims 1 to 9.

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