Liquid nitrogen heating, vaporizing and pressurizing system and liquid rocket

Abstract

The embodiment of the invention provides a liquid nitrogen heating, vaporizing and pressurizing system and a liquid rocket. The liquid nitrogen heating, vaporizing and pressurizing system comprises 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 pressurizing pipe. An oxygen tank pressurizing pipe is arranged at the top of the oxygen tank; a fuel tank pressurizing pipe is arranged at the top of the fuel tank; the liquid nitrogen box is arranged in the oxygen box, and the bottom of the liquid nitrogen box is connected with a liquid nitrogen conveying pipe; the liquid nitrogen pump is arranged on the liquid nitrogen conveying pipe; the cavitation pipe is used for stabilizing the liquid nitrogen conveying flow; the liquid nitrogen heater is used for heating liquid nitrogen conveyed by the liquid nitrogen pump into high-temperature nitrogen, the heated nitrogen is used for pressurizing the oxygen tank, the fuel tank and the liquid nitrogen tank at the same time, and the liquid nitrogen heater is connected with the oxygen tank pressurizing pipe and the fuel tank pressurizing pipe. According to the liquid nitrogen heating, vaporizing and pressurizing system, the integrated pressurizing technology is adopted, the pressurizing system is simplified through the technology, meanwhile, the cost and weight of the pressurizing system are reduced through liquid nitrogen heating, vaporizing and pressurizing, and the safety and stability of the pressurizing system are improved.

Description

Technical Field

[0001] The invention relates to the technical field of liquid rockets, and in particular to a liquid nitrogen heating, vaporization and pressurization system and a liquid rocket. Background Art

[0002] Liquid rockets are rockets that use liquid rocket engines as their power plant. They are generally composed of power plants, rocket body structures, and control systems. Liquid rockets are mainly used as the propulsion part of space vehicles and missile nuclear weapons. The power plant system of liquid rockets is mainly composed of two parts: the propellant delivery and pressurization system and the liquid rocket engine. The propellant delivery and pressurization system is an important system to ensure the reliable operation of liquid rocket engines.

[0003] At present, the choice of boosting schemes for launch vehicles at home and abroad mainly considers improving boosting efficiency, system simplicity and reliability, and taking into account technical capabilities and other factors. The mainstream cryogenic engines mainly use a combination of liquid oxygen and kerosene propellants. Commonly used boosting schemes mainly include autogenous boosting, room temperature helium boosting, room temperature helium boosting, and cold helium boosting. The following conclusions were drawn through investigation: For liquid oxygen and kerosene engines, the kerosene tank mainly adopts the room temperature helium boosting scheme.

[0004] In the process of implementing the present invention, the inventors found that there are at least the following problems in the prior art:

[0005] Normal temperature helium heating and pressurization requires independent pressurized gas source storage devices such as high-pressure gas cylinders, as well as supporting pipelines and valves. The system composition is relatively complex and the cost is high. For large and heavy launch vehicles, especially for low-temperature rocket tank pressurization, the required gas volume is large and the number of gas storage devices is large. At the same time, the gas cylinder cools down during the deflation process, the density increases, and the residual pressure of the gas cylinder is high, resulting in a helium utilization rate of less than 70% for normal temperature helium heating and pressurization. At the same time, helium is relatively expensive, so for large rockets, the cost of normal temperature helium heating and pressurization is relatively high.

[0006] By explaining and comparing the above-mentioned pressurization methods, it can be seen that the kerosene in the kerosene tanks of large launch vehicles has a high boiling point and is not easy to pressurize. The pressurization cost of the kerosene tanks is high and the pressurization system is heavy. Therefore, it is urgently needed and of great significance to carry out engineering application research based on low-cost and lightweight pressurization systems for kerosene tanks. Summary of the invention

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

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

[0009] The oxygen box is used to store liquid oxygen, and an oxygen box pressurizing pipe is provided on the top of the oxygen box.

[0010] The fuel tank is arranged on a side of the oxygen tank close to the engine and is used to store fuel. A fuel tank pressurization pipe is arranged on the top of the fuel tank.

[0011] The liquid nitrogen box is arranged in the oxygen box and is used to store liquid nitrogen. The bottom of the liquid nitrogen box is connected to a liquid nitrogen delivery pipe.

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

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

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

[0015] Furthermore, a liquid nitrogen box boosting pipe is provided on the top of the liquid nitrogen box, and one end of the liquid nitrogen box boosting pipe away from the liquid nitrogen box is connected to the oxygen box boosting pipe, or to the fuel tank boosting 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 boosting 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 boosting pipe; the inlet end of the liquid nitrogen tank boosting pipe is connected to the fuel tank boosting pipe.

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

[0018] Furthermore, the liquid nitrogen heating, vaporizing and pressurizing system further comprises an oxygen box air pillow pressure sensor and an oxygen box pressurizing controller arranged on the outer wall of the oxygen box;

[0019] The oxygen box air pillow pressure sensor is used to detect the pressure of the oxygen box air pillow and send the pressure detection result to the oxygen box boost controller;

[0020] The oxygen box pressure boost controller is used to adjust the opening of the first cavitation tube and the second cavitation tube according to the pressure detection result.

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

[0022]

[0023] In the formula, A Y It represents the opening of the first cavitation tube, and the unit is dimensionless;

[0024] A Y1 It represents the minimum opening of the first cavitation tube, and the unit is dimensionless;

[0025] P Y Indicates the oxygen box air pillow pressure, in MPa;

[0026] P Y0 Indicates the lower limit of the oxygen box air pillow pressure control band, in MPa;

[0027] P Y1 Indicates the upper limit of the oxygen box air pillow pressure control band, in MPa;

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

[0029]

[0030] In the formula, A R It represents the opening of the second cavitation tube, and the unit is dimensionless;

[0031] A R1 It represents the minimum opening of the second cavitation tube, and the unit is dimensionless;

[0032] P R Indicates the air pillow pressure of the fuel tank, in MPa;

[0033] P R0 Indicates the lower limit of the fuel tank air pillow pressure control band, in MPa;

[0034] P R1 Indicates the upper limit of the fuel tank air pillow pressure control band, in MPa.

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

[0036] Further, the ground helium source assembly includes a ground helium source, a first filter, a pressure reducer and a control assembly connected in series in sequence, and 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 box control assembly includes a first valve assembly, a second filter and an oxygen box ground pressure relief valve; the first valve assembly includes an oxygen box pressure supplement solenoid valve, an oxygen box pre-injection pressure boost solenoid valve and an oxygen box manual switch connected in parallel, 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 box ground pressure relief valve is connected to the pipeline between the second filter and the first valve assembly, and the other end is connected 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 compensation solenoid valve, a fuel tank pre-injection pressure relief 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 connected to the atmosphere;

[0039] The liquid nitrogen box control assembly includes a third valve assembly, a fourth filter and a liquid nitrogen box ground pressurization and release valve; the third valve assembly includes a liquid nitrogen box pressure-compensating solenoid valve, a liquid nitrogen box pre-shooting pressurization solenoid valve and a liquid nitrogen box 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 box ground pressurization and release valve is connected to the pipeline between the fourth filter and the third valve assembly, and the other end is connected to the atmosphere.

[0040] Furthermore, the liquid nitrogen heating, vaporizing and pressurizing system also includes a liquid nitrogen pump driving cylinder, which is connected to the liquid nitrogen pump turbine drive through a driving orifice plate, and the liquid nitrogen pump driving cylinder is used to store the pressurized medium.

[0041] In a second aspect, an embodiment of the present invention provides a liquid rocket, comprising the liquid nitrogen heating, vaporization and pressurization system as described above.

[0042] The above technical scheme has the following beneficial effects: the liquid nitrogen heating, vaporization and pressurization system and liquid rocket provided by the present application place the liquid nitrogen box in the oxygen box so that the nitrogen is stored in a liquid state, and then the nitrogen is heated by the liquid nitrogen heater to form nitrogen. The heated nitrogen is used to pressurize the oxygen box, the fuel tank and the liquid nitrogen box at the same time. The overall structure of the pressurization system is simple and light in weight, which effectively improves the carrying capacity of the liquid rocket. Compared with the helium pressurization, the nitrogen pressurization reduces the use of expensive helium and effectively reduces the cost. At the same time, the utilization rate of the pressurization medium is also significantly improved relative to the helium pressurization method. The liquid nitrogen heating, vaporization and pressurization system of the present application sets the oxygen box pressurization pipe and the fuel tank pressurization pipe separately, which can realize the independent pressurization of the oxygen box and the fuel tank, avoids the safety problems caused by the gas in the oxygen box flowing back to the fuel tank, and makes the liquid nitrogen heating, vaporization and pressurization system safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It 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 Schematic diagram of the partial structure of the liquid nitrogen heating, vaporization and pressurization system.

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

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

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

[0049] Figure 6 Schematic diagram of the structure of the liquid nitrogen pump driving system according to an embodiment of the present invention.

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

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

[0052] Fig. 9 It is a schematic half-section view of the three-dimensional structure of the liquid oxygen delivery system according to an embodiment of the present invention.

[0053] The meanings of the symbols in the accompanying drawings are as follows:

[0054] 10. Oxygen box; 11. Oxygen box booster pipe; 12. Oxygen box energy dissipator; 13. Oxygen box overflow 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 fixture; 15. Oxygen box air pillow pressure sensor; 16. Oxygen box boost controller;

[0055] 20. Fuel tank; 21. Fuel tank boost pipe; 22. Fuel tank energy dissipator; 23. Fuel tank overflow valve; 24. Tunnel pipe; 25. Fuel tank air pillow pressure sensor; 26. Fuel tank boost controller;

[0056] 30. Liquid nitrogen box; 31. Liquid nitrogen delivery pipe; 311. Liquid nitrogen pump; 312. First liquid nitrogen stop valve; 313. First cavitation tube; 314. Second liquid nitrogen stop valve; 315. Second cavitation tube; 32. Liquid nitrogen box booster pipe; 321. Liquid nitrogen box check valve; 33. First heater; 34. Second heater; 35. Liquid nitrogen box exhaust valve; 36. Liquid nitrogen box safety valve;

[0057] 40. Pre-launch boost pressure assembly; 41. Oxygen tank boost pressure pipe; 411. Oxygen tank boost pressure check valve; 42. Fuel tank boost pressure pipe; 421. Fuel tank boost pressure check valve; 43. Liquid nitrogen tank boost pressure pipe; 431. Liquid nitrogen tank boost pressure check valve; 44. Secondary tail section plug connector; 45. Ground helium source; 451. First filter; 452. Pressure reducer; 46. Oxygen tank control assembly; 461. Oxygen tank boost pressure solenoid valve; 462. Oxygen tank pre-launch boost solenoid valve; 463. Oxygen tank manual switch; 46 4. Second filter; 465. Ground pressure relief valve of oxygen tank; 47. Fuel tank control assembly; 471. Fuel tank pressure-replenishing solenoid valve; 472. Fuel tank pre-fire pressure-replenishing solenoid valve; 473. Fuel tank manual switch; 474. Third filter; 475. Ground pressure relief valve of fuel tank; 48. Liquid nitrogen tank control assembly; 481. Liquid nitrogen tank pressure-replenishing solenoid valve; 482. Liquid nitrogen tank pre-fire pressure-replenishing solenoid valve; 483. Liquid nitrogen tank manual switch; 484. Fourth filter; 485. Ground pressure relief valve of liquid nitrogen tank;

[0058] 50. Liquid nitrogen filling and precooling components; 51. Liquid nitrogen filling and precooling pipeline; 52. Liquid nitrogen filling and precooling one-way valve; 53. Tail end plug connector; 54. Liquid nitrogen filling valve; 55. Liquid nitrogen filling system; 56. Liquid nitrogen discharge stop valve;

[0059] 60. Engine;

[0060] 70. Liquid nitrogen pump drives the gas cylinder; 71. Drives the orifice plate. DETAILED DESCRIPTION

[0061] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed in order to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. In the drawings and the following description, at least part of the known structures and technologies are not shown in order to avoid unnecessary ambiguity of the present invention; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.

[0062] See also Figure 1 and Figure 2 An embodiment of the present application provides a liquid rocket. Specifically, this embodiment takes a two-stage rocket system of a liquid rocket as an example for explanation. The two-stage rocket system includes a liquid nitrogen heating, vaporization and pressurization system and also includes an engine 60.

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

[0064] The oxygen box 10 is used to store liquid oxygen. An oxygen box pressurizing pipe 11 is provided on the top of the oxygen box 10. One end of the oxygen box pressurizing pipe 11 is connected to the oxygen box energy dissipator 12 inside the oxygen box 10, and the other end is connected to the liquid nitrogen heater for pressurizing the oxygen box air pillow.

[0065] The fuel tank 20 is arranged on one side of the oxygen tank 10 close to the engine 60 for storing fuel, and a fuel tank boosting pipe 21 is arranged on the top of the fuel tank 20. One end of the fuel tank boosting pipe 21 is connected to the fuel tank energy dissipator 22 in the fuel tank 20, and the other end is connected to the liquid nitrogen heater for pressurizing the fuel tank air pillow.

[0066] The liquid nitrogen tank 30 is arranged in the oxygen tank 10 for storing liquid nitrogen, and a liquid nitrogen delivery pipe 31 is connected to the bottom of the liquid nitrogen tank 30, and a liquid nitrogen tank boosting pipe 32 is arranged on the top for pressurizing the liquid nitrogen tank 30. One end of the liquid nitrogen tank boosting pipe 32 away from the liquid nitrogen tank 30 is connected to the oxygen tank boosting pipe 11, or to the fuel tank boosting pipe 21, or directly to the outlet of the liquid nitrogen heater.

[0067] The liquid nitrogen pump 311 is arranged on the liquid nitrogen delivery pipe 31 to increase the output pressure of the liquid nitrogen. The cavitation tube is used to adjust and stabilize the liquid nitrogen delivery flow rate.

[0068] The liquid nitrogen heater is used to vaporize the liquid nitrogen delivered by the liquid nitrogen pump 311 and heat it 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, and 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, the oxygen tank 10 of this embodiment is a two-stage oxygen tank, the fuel tank 20 is a two-stage fuel tank, and the engine 60 is a two-stage engine. A liquid oxygen delivery system is provided at the bottom of the oxygen tank 10, and the liquid oxygen delivery system includes an oxygen delivery pipe 14 provided 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. The end of the oxygen delivery pipe 14 close to the oxygen tank 10 is connected with a bellows 142 and a delivery pipe inlet flange 141 in sequence, and is connected to the bottom of the oxygen tank 10 through the delivery pipe inlet flange 141. The end of the oxygen delivery pipe 14 close to the engine 60 is connected with a liquid oxygen filter 143, a liquid oxygen compensator 144 and an oxygen pump inlet flange 145 in sequence, and is connected to the oxygen pump inlet of the engine 60 through the oxygen pump inlet flange 145. The three-dimensional structure of the liquid oxygen delivery system of this embodiment is shown in FIG. Figure 8 and Fig. 9 As shown, an oxygen delivery pipe fixing device 146 is also provided between the oxygen delivery pipe 14 and the liquid oxygen compensator 144. In this embodiment, the delivery pipe inlet flange 141 is integrated with the rear bottom outlet flow profile of the secondary oxygen tank, and the rear bottom outlet flow profile of the secondary oxygen tank is set on the oxygen delivery pipe 14, which simplifies the structure of the liquid oxygen delivery system. Two compensation structures (bellows 142 and liquid oxygen compensator 144) are provided 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 provided in the oxygen delivery pipe 14, and the oxygen delivery pipe 14 and the liquid oxygen filter 143 are integrated. An oxygen delivery pipe fixing device 146 is provided in the liquid oxygen delivery pipe 14, which can achieve the fixing and installation of the oxygen delivery pipe 14. The fixing of the pipeline of the liquid oxygen delivery system is achieved through the bottom of the fuel tank.

[0070] The cavitation tube includes a first cavitation tube 313 and a second cavitation tube 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 box boosting 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 boosting pipe 21. The inlet end of the liquid nitrogen box boosting pipe 32 of this embodiment is connected to the fuel tank boosting pipe 21, and a liquid nitrogen box check valve 321 is provided on the liquid nitrogen box boosting pipe 32. In this embodiment, the first liquid nitrogen stop valve 312 and the first cavitation tube 313 are connected in series between the liquid nitrogen pump 311 and the first heater 33, and the second liquid nitrogen stop valve 314 and the second cavitation tube 315 are connected in series between the liquid nitrogen pump 311 and the second heater 34. That is, the liquid nitrogen delivery pipe 31 is divided into two paths through the liquid nitrogen pump 311 through a three-way connection. One path is connected to the first heater 33 through the first liquid nitrogen stop valve 312 and the first cavitation tube 313, and the other path is connected to the second heater 34 through the second liquid nitrogen stop valve 314 and the second cavitation tube 315.

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

[0072] In the secondary flight stage, the liquid nitrogen in the liquid nitrogen tank 30 is used to pressurize the oxygen tank 10 via the liquid nitrogen delivery pipe 31, the liquid nitrogen pump 311, the first low-temperature stop valve, the first cavitation pipe 313, the first liquid nitrogen heater, the oxygen tank booster 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 low temperature stop 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 is separated from the fuel tank boosting pipe 21 through a three-way connection and is fed to the liquid nitrogen tank 30 for boosting the pressure via the liquid nitrogen tank check valve 321 and the liquid nitrogen tank boosting pipe 32 .

[0075] This patent realizes the control of the liquid nitrogen heating and pressurizing flow rate of the oxygen box 10 by controlling the opening of the adjustable first cavitation tube 313, and realizes the control of the liquid nitrogen heating and pressurizing flow rate of the fuel tank 20 by controlling the opening of the adjustable second cavitation tube 315.

[0076] In this embodiment, the liquid nitrogen tank 30 is stored in the oxygen tank 10, and the liquid nitrogen pressure is increased by a liquid nitrogen pump 311, and the liquid nitrogen flow rate is controlled to increase the pressure of the oxygen tank 10 by an adjustable first cavitation tube 313. The liquid nitrogen pressure is increased by a liquid nitrogen pump 311, and the liquid nitrogen flow rate is controlled to increase the pressure of the fuel tank 20 by an adjustable second cavitation tube 315. A three-way is set on the fuel tank pressurization pipe 21, and a route is separated to increase the pressure of the liquid nitrogen tank 30. In this embodiment, the three tanks are pressurized by heating the liquid nitrogen.

[0077] The oxygen tank 10 adopts a liquid nitrogen heating and pressurizing solution. The liquid nitrogen is heated by a liquid nitrogen heater and then vaporized into nitrogen. The high-temperature nitrogen is pressurized to the oxygen tank 10 through the oxygen tank pressurizing pipe 11 and to the fuel tank 20 through the fuel tank pressurizing pipe 21. A small amount of high-temperature nitrogen is separated from the fuel tank 20 and is heated and pressurized to the liquid nitrogen tank through the liquid nitrogen tank one-way valve 321 and the liquid nitrogen tank pressurizing pipe 32.

[0078] In this embodiment, the first heater 33 is used to heat the liquid nitrogen into nitrogen gas to pressurize the oxygen tank 10, and the second heater 34 is used to heat the liquid nitrogen into nitrogen gas to pressurize the fuel tank 20, so that the oxygen tank 10 and the fuel tank 20 can be independently pressurized. The oxygen tank pressurization system and the fuel tank 20 pressurization system are separated to achieve independent pressurization of the two tanks, thereby avoiding the gas in the oxygen tank 10 from flowing back to the fuel tank 20 and causing safety problems.

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

[0080] The first cavitation tube 313 can be controlled to open at a controlled degree, and the liquid nitrogen heating and pressurizing flow rate can be precisely controlled by controlling the opening of the first cavitation tube 313. The air pillow pressure of the oxygen box 10 is measured by the oxygen box air pillow pressure sensor 15, and the air pillow pressure value is transmitted to the oxygen box boost controller 16. The oxygen box boost controller 16 calculates and makes decisions to control the opening of the adjustable first cavitation tube 313, and the flow rate of the pressurized liquid nitrogen of the oxygen box 10 is controlled, thereby stabilizing the air pillow pressure of the oxygen box 10 and achieving closed-loop control of the air pillow pressure of the oxygen box. The opening adjustment logic of the first cavitation tube 313 is as follows: Figure 3 As shown, P Y0 Indicates the lower limit of the fuel tank pressure control band, P Y1 represents the upper limit of the fuel tank pressure control band, 1 represents the maximum opening of the first cavitation tube 313, A Y1 Indicates the minimum opening of the first cavitation tube 313.

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

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

[0083]

[0084] In the formula, A Y It represents the opening of the first cavitation tube, and the unit is dimensionless;

[0085] A Y1 It represents the minimum opening of the first cavitation tube, and the unit is dimensionless;

[0086] P Y Indicates the oxygen box air pillow pressure, in MPa;

[0087] P Y0 Indicates the lower limit of the oxygen box air pillow pressure control band, in MPa;

[0088] P Y1 Indicates the upper limit of the oxygen box air pillow pressure control band, 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 It represents the opening of the second cavitation tube, and the unit is dimensionless;

[0092] A R1 It represents the minimum opening of the second cavitation tube, and the unit is dimensionless;

[0093] P R Indicates the air pillow pressure of the fuel tank, in MPa;

[0094] P R0 Indicates the lower limit of the fuel tank air pillow pressure control band, in MPa;

[0095] PR1 Indicates the upper limit of the fuel tank air pillow pressure control band, in MPa.

[0096] like Figure 1 and Figure 5 As shown, in some embodiments, the liquid nitrogen heating vaporization and pressurization system also includes a pre-fire booster pressure assembly 40, which includes a ground helium source assembly, an oxygen tank booster pressure pipe 41, a fuel tank booster pressure pipe 42 and a liquid nitrogen tank booster pressure pipe 43; one end of the oxygen tank booster pressure pipe 41 is connected to the oxygen tank booster pipe 11, and the other end is detachably connected to the ground helium source assembly; one end of the fuel tank booster pressure pipe 42 is connected to the fuel tank booster pipe 21, and the other end is detachably connected to the ground helium source assembly; one end of the liquid nitrogen tank booster pressure pipe 43 is connected to the liquid nitrogen tank booster pressure 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 in sequence, and 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 box control assembly 46 includes a first valve assembly, a second filter 464 and an oxygen box ground boost and release valve 465; the first valve assembly includes an oxygen box pressure replenishment solenoid valve 461, an oxygen box pre-injection boost solenoid valve 462 and an oxygen box 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 box ground boost and release 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.

[0099] The fuel tank control assembly 47 includes a second valve assembly, a third filter 474 and a fuel tank ground boost and relief valve 475; the second valve assembly includes a fuel tank pressure replenishing solenoid valve 471, a fuel tank pre-injection boost 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 boost and 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.

[0100] The liquid nitrogen box control assembly 48 includes a third valve assembly, a fourth filter 484 and a liquid nitrogen box ground boost and release valve 485; the third valve assembly includes a liquid nitrogen box pressure-making solenoid valve 481, a liquid nitrogen box pre-shooting boost solenoid valve 482 and a liquid nitrogen box 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 box ground boost 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.

[0101] Specifically, in this embodiment, an oxygen tank boost pressure check valve 411 is provided on the oxygen tank boost pressure pipe 41, one end of the oxygen tank boost pressure pipe 41 is connected to the oxygen tank boost pressure pipe 11 through a tee, and the other end is connected to the second filter 464 of the helium source assembly through a secondary tail section plug connector 44. A fuel tank boost pressure check valve 421 is provided on the fuel tank boost pressure pipe 42, one end of the fuel tank boost pressure pipe 42 is connected to the fuel tank boost pressure pipe 21 through a tee, and the other end is connected to the third filter 474 of the helium source assembly through a secondary tail section plug connector 44. A liquid nitrogen tank boost pressure check valve 431 is provided on the liquid nitrogen tank boost pressure pipe 43, one end of the liquid nitrogen tank boost pressure pipe 43 is connected to the liquid nitrogen tank boost pressure pipe 32 through a tee, and the other end is connected to the fourth filter 484 of the helium source assembly through a secondary tail section plug connector 44.

[0102] When the electrical system is not powered on, it is necessary to inflate the fuel tank 20 through a ground tank for a gas inspection. The helium provided by the ground helium source 45 is pressurized in the fuel tank 20 through the first filter 451, the pressure reducer 452, the fuel tank manual switch 473, the orifice plate, the third filter 474, the secondary tail section plug-in connector 44, the fuel tank supplementary pressure check valve 421, the fuel tank boost pipe 21 and the fuel tank energy dissipator 22. The fuel tank 20 is inflated on the ground without power to conduct a tank gas inspection.

[0103] When pressurizing the fuel tank 20 before the rocket is launched, the helium provided by the ground helium source 45 passes through the first filter 451, the pressure reducer 452, the fuel tank pre-launch pressurization solenoid valve 472, the orifice plate, the third filter 474, the second-stage tail section plug-in connector 44, the fuel tank supplementary pressure check valve 421, the fuel tank boosting pipe 21 and the fuel tank energy dissipator 22 to pressurize the fuel tank 20 before the rocket is ignited.

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

[0105] When the electrical system is not powered on, the liquid nitrogen tank 30 needs to be inflated and inspected through the ground tank. The helium provided by the ground helium source 45 is pressurized to the liquid nitrogen tank 30 through the first filter 451, the pressure reducer 452, the liquid nitrogen tank manual switch 483, the orifice plate, the fourth filter 484, the secondary tail section plug connector 44, the liquid nitrogen tank supplementary pressure check valve 431 and the liquid nitrogen tank booster pipe 32, and the liquid nitrogen tank 30 is inflated and inspected for ground unpowered tanks.

[0106] When pressurizing the rocket before launch, the liquid nitrogen tank 30 needs to be pressurized before launch. The helium provided by the ground helium source 45 is passed through the first filter 451, the pressure reducer 452, the liquid nitrogen tank pre-launch pressurization solenoid valve 482, the orifice plate, the fourth filter 484, the secondary tail section plug-in connector 44, the liquid nitrogen tank supplementary pressure check valve 431 and the liquid nitrogen tank boosting pipe 32 to pressurize the liquid nitrogen tank 30 before the rocket is ignited.

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

[0108] When the electrical system is not powered on, it is necessary to perform an air-inflating inspection on the oxygen tank 10 through the ground tank. The helium provided by the ground helium source 45 is pressurized in the oxygen tank 10 through the first filter 451, the pressure reducer 452, the oxygen tank manual switch 463, the orifice plate, the second filter 464, the secondary tail section plug-in connector 44, the oxygen tank supplementary pressure check valve 411, the oxygen tank boosting pipe 11 and the oxygen tank energy dissipator 12, and the oxygen tank 10 is inflated and inspected on the ground without power supply.

[0109] When pressurizing the rocket before launch, the oxygen tank 10 needs to be pressurized before launch. The helium provided by the ground helium source 45 passes through the first filter 451, the pressure reducer 452, the oxygen tank pre-launch pressurization solenoid valve 462, the orifice plate, the second filter 464, the secondary tail section plug-in connector 44, the second one-way valve, the oxygen tank boosting pipe 11 and the oxygen tank energy dissipator 12 to pressurize the oxygen tank 10, and the oxygen tank 10 is pressurized before the rocket is ignited.

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

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

[0112] The ground control component is equipped with three-way boost control valves, namely a manual switch, a pre-launch boost solenoid valve and a supplementary pressure solenoid valve. The manual switch is used to perform an air inspection of the unpowered tank inflation on the ground, the pre-launch boost solenoid valve is used to perform pre-launch boosting of the tank before rocket ignition, and the supplementary pressure solenoid valve is used to supplement the tank pressure during the rocket propulsion system test.

[0113] The pre-launch pressure-boosting assembly 40 of this embodiment can meet the requirements of tank inflation and gas inspection when there is no power on the ground, pre-launch pressure-boosting of the rocket pre-launch pressure-boosting system, and tank pressure replenishment after the power system test ignition. The pre-launch pressure-boosting assembly 40 integrates the pre-launch pressure-boosting system, the ground inflation tank gas inspection system, and the power system test pressure-boosting system, thereby improving the compactness of the system structure and reducing the number of components used. At the same time, the pre-launch pressure-boosting assembly 40 is relatively simple in device, with a single type and a small number of valves and pipelines, low difficulty in development, and a short processing and production cycle.

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

[0115] The driving gas source of the liquid nitrogen pump 311 of this embodiment 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, and 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, and 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 may be provided on the secondary oxygen tank 10, and the oxygen tank overflow valve 13 integrates the safety valve and the exhaust valve. When the ground oxygen tank fills the secondary oxygen tank 10 with liquid oxygen, the oxygen tank overflow valve 13 opens. A fuel tank overflow valve 23 may also be provided on the secondary fuel tank 20, and the fuel tank overflow valve 23 integrates the safety valve and the exhaust valve. When the ground fuel tank fills the secondary fuel tank 20 with fuel, the fuel tank overflow valve 23 opens.

[0117] During the secondary flight, when the oxygen tank air pillow pressure is higher than the opening pressure of the oxygen tank safety overflow valve 13, the oxygen tank safety overflow valve 13 is opened, and when the oxygen tank air pillow pressure is lower than the closing pressure of the oxygen tank safety overflow valve 13, the oxygen tank safety overflow valve 13 is closed. During the secondary flight, when the fuel tank air pillow pressure is higher than the opening pressure of the fuel tank safety overflow valve 23, the fuel tank safety overflow valve 23 is opened, and when the fuel tank air pillow pressure is lower than the closing pressure of the fuel tank safety overflow valve 23, the fuel tank safety overflow valve 23 is closed.

[0118] In some embodiments, the liquid nitrogen box 30 is also connected in series with a liquid nitrogen box exhaust valve 35 and a liquid nitrogen box safety valve 36, and the liquid nitrogen box exhaust valve 35 and the liquid nitrogen box safety valve 36 are connected to the liquid nitrogen box booster pipe 32 through pipelines and tees.

[0119] like Figure 1 and Figure 7 As shown, in some embodiments, a liquid nitrogen filling and precooling component 50 is also included. The liquid nitrogen filling and precooling component 50 includes a liquid nitrogen filling and precooling pipeline 51, a liquid nitrogen discharge stop valve 56 and a liquid nitrogen filling and precooling one-way valve 52. The liquid nitrogen filling and precooling one-way valve 52 is arranged 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 filling and precooling pipeline 51 is connected to the liquid nitrogen delivery pipe 31 at the outlet of the liquid nitrogen pump 311 through a tee, and the other end is detachably connected to the liquid nitrogen filling system 55 through a tail plug connector 53, and 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 stop valve 56 is connected to the liquid nitrogen filling and precooling pipeline 51 at the inlet of the liquid nitrogen filling and precooling check valve 52 through a pipeline, and the outlet is connected to the atmosphere.

[0121] The liquid nitrogen filling system 55 delivers the liquid nitrogen to the liquid nitrogen tank 30 through the liquid nitrogen filling valve 54 , the tail end plug connector 53 , the liquid nitrogen filling pre-cooling one-way valve 52 and the liquid nitrogen delivery pipe 31 , so as to fill the liquid nitrogen tank 30 with liquid nitrogen.

[0122] When the rocket is flying, the tail end plug connector 53 is disconnected, and the liquid nitrogen in the liquid nitrogen tank 30 can be prevented from leaking through the liquid nitrogen filling precooling check valve 52. The liquid nitrogen filling port is arranged downstream of the liquid nitrogen pump 311, and the liquid nitrogen pump 311 can be precooled when the liquid nitrogen is filled, thereby improving the reliability of the precooling of the liquid nitrogen pump 311.

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

[0124] Due to the low temperature characteristics of liquid nitrogen, the engine 60, the liquid nitrogen delivery pipe 31 and the external environment form a high temperature heat source relative to the liquid nitrogen. After the liquid nitrogen enters the liquid nitrogen pump 311, it is heated to boil and vaporize, which will affect the blades of the liquid nitrogen pump 311 and cause cavitation of the liquid nitrogen pump 311. In order to ensure the normal operation of the liquid nitrogen pump 311, the liquid nitrogen pump 311 needs to be precooled to the same temperature as the liquid nitrogen to ensure that the liquid nitrogen will not vaporize into gas when passing through the liquid nitrogen pump 311 during normal operation.

[0125] During the discharge precooling process of the ground liquid nitrogen pump 311, the liquid nitrogen in the liquid nitrogen tank 30 is directly discharged into the atmosphere through the liquid nitrogen delivery pipe 31, the liquid nitrogen pump 311 and the liquid nitrogen discharge stop valve 56, so as to ensure the reliable operation of the ignition of the liquid nitrogen pump 311 and prevent the cavitation caused by the vaporization of liquid nitrogen when the liquid nitrogen pump 311 is ignited.

[0126] When the rocket is ignited and flying, the liquid nitrogen filling pre-cooling one-way valve 52 remains closed, and the liquid nitrogen after the liquid nitrogen pump 311 is heated by the liquid nitrogen heater to become high-temperature nitrogen gas to pressurize the oxygen tank 10 and the fuel tank 20.

[0127] The discharge precooling of the liquid nitrogen pump 311 is only performed before the liquid nitrogen pump 311 works. The discharge precooling of the liquid nitrogen pump 311 is not performed after the liquid nitrogen pump 311 works, so the liquid nitrogen filling precooling one-way valve 52 is closed.

[0128] In this embodiment, the liquid nitrogen filling system 55 and the liquid nitrogen pump 311 precooling system are integrated into a design, and the liquid nitrogen filling and precooling component 50 is arranged downstream of the liquid nitrogen pump 311, so that the liquid nitrogen pump 311 can be precooled during the liquid nitrogen filling period. The liquid nitrogen filling and precooling one-way valve 52 is arranged on the liquid nitrogen filling pipeline, so that the liquid nitrogen filling and precooling component 50 can realize both the function of liquid nitrogen filling and the function of liquid nitrogen discharge precooling.

[0129] The liquid nitrogen heating, vaporization and pressurization system provided in the embodiment of the present application adopts liquid nitrogen heating and pressurization in its oxygen box. After the liquid nitrogen pump pressurizes the liquid nitrogen, after the flow rate is adjusted by the first cavitation tube, the first liquid nitrogen heater heats the liquid nitrogen to vaporize the liquid nitrogen into high-temperature nitrogen to pressurize the oxygen box. After the liquid nitrogen pump pressurizes the liquid nitrogen, after the flow rate is adjusted by the second cavitation tube, the second liquid nitrogen heater heats the liquid nitrogen to vaporize the liquid nitrogen into high-temperature nitrogen to pressurize the fuel tank, realizing the independent pressurization of the oxygen box and the fuel tank, and improving the safety and reliability of the liquid nitrogen heating, vaporization and pressurization system. After the nitrogen enters the fuel tank pressurization pipe, a branch is separated to pressurize the liquid nitrogen tank. Both the oxygen box and the fuel tank adopt a closed pressurization method, and the opening of the first cavitation tube is controlled by the oxygen box air pillow pressure to realize the control of the liquid nitrogen flow rate, thereby realizing the precise control of the oxygen box air pillow pressure. The opening of the second cavitation tube is controlled by the fuel tank air pillow pressure to realize the control of the liquid nitrogen flow rate, thereby realizing the precise control of the fuel tank air pillow pressure.

[0130] The liquid nitrogen heating, vaporization and pressurization system of the embodiment of the present application utilizes the first heater of the engine 60 to heat the liquid nitrogen into high-temperature nitrogen gas to pressurize the oxygen tank, and utilizes the second heater of the engine 60 to heat the liquid nitrogen into high-temperature nitrogen gas to pressurize the fuel tank, thereby realizing independent pressurization of the oxygen tank and the fuel tank. The liquid nitrogen pump is driven by helium or other pressurization media, providing a strong driving force for the liquid nitrogen pump.

[0131] The liquid nitrogen heating, vaporizing and pressurizing system of this embodiment is provided with supplementary pressure pipes on the oxygen tank boosting pipe and the fuel tank boosting pipe, respectively, which can effectively shorten the length of the pre-launch boosting pipeline, so that the pre-launch boosting pipeline (oxygen tank supplementary pressure pipe, fuel tank supplementary pressure pipe and liquid nitrogen tank supplementary pressure pipe) and the main boosting pipeline (oxygen tank boosting pipe, fuel tank boosting pipe and liquid nitrogen tank boosting pipe) are integrated, thereby improving the integration of the main boosting pipeline. The embodiment of the present application integrates the pre-launch boosting system, the ground inflation tank gas inspection system and the power system test pressurization system. The pre-launch boosting system simultaneously realizes the inflation gas inspection of each tank by the ground tank when the ground is not powered on, the pre-launch pressurization of the tank of the rocket pre-launch boosting system, and the tank pressurization after the power system test ignition.

[0132] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0133] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0134] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present 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, vaporization and pressurization system for liquid rockets, characterized in that: It comprises an oxygen box (10), a fuel tank (20), a liquid nitrogen box (30), a cavitation tube, a liquid nitrogen pump (311) and a liquid nitrogen heater; The oxygen box (10) is used to store liquid oxygen. The top of the oxygen box (10) is provided with an oxygen box pressurizing pipe (11). The fuel tank (20) is arranged on a side of the oxygen tank (10) close to the engine and is used to store fuel. A fuel tank pressurizing pipe (21) is arranged on the top of the fuel tank (20); The liquid nitrogen box (30) is arranged in the oxygen box (10) and is used to store liquid nitrogen. The bottom of the liquid nitrogen box (30) is connected to a liquid nitrogen delivery pipe (31); The liquid nitrogen pump (311) is arranged on the liquid nitrogen delivery pipe (31) and is used to increase the output pressure of the liquid nitrogen; The cavitation tube is used to adjust 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, and the heated nitrogen gas is used to simultaneously pressurize the oxygen tank (10), the fuel tank (20) and the liquid nitrogen tank (30), and the liquid nitrogen heater is respectively connected to the oxygen tank pressurization pipe (11) and the fuel tank pressurization pipe (21).

2. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 1, characterized in that: A liquid nitrogen box pressurizing pipe (32) is provided on the top of the liquid nitrogen box (30); one end of the liquid nitrogen box pressurizing pipe (32) away from the liquid nitrogen box (30) is connected to the oxygen box pressurizing pipe (11), or to the fuel tank pressurizing pipe (21), or directly to the outlet of the liquid nitrogen heater.

3. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 2, characterized in that: The liquid nitrogen heater comprises 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 boosting 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 boosting pipe (21); the inlet end of the liquid nitrogen tank boosting pipe (32) is connected to the fuel tank boosting pipe (21).

4. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 3, characterized in that: The cavitation tube comprises a first cavitation tube (313) and a second cavitation tube (315); a first liquid nitrogen stop valve (312) and the first cavitation tube (313) are sequentially connected in series between the liquid nitrogen pump (311) and the first heater (33); and a second liquid nitrogen stop valve (314) and the second cavitation tube (315) are sequentially connected in series between the liquid nitrogen pump (311) and the second heater (34).

5. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 4, characterized in that: It also includes an oxygen box air pillow pressure sensor (15) and an oxygen box pressure boost controller (16) arranged on the outer wall of the oxygen box (10); The oxygen box air pillow pressure sensor (15) is used to detect the pressure of the oxygen box air pillow and send the pressure detection result to the oxygen box boost controller (16); The oxygen box pressure boost controller (16) is used to adjust the opening of the first cavitation tube (313) and the second cavitation tube (315) according to the pressure detection result.

6. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 5, characterized in that: The opening of the first cavitation tube (313) is adjusted according to the following formula: In the formula, A Y It represents the opening of the first cavitation tube, and the unit is dimensionless; A Y1 It represents the minimum opening of the first cavitation tube, and the unit is dimensionless; P Y Indicates the oxygen box air pillow pressure, in MPa; P Y0 Indicates the lower limit of the oxygen box air pillow pressure control band, in MPa; P Y1 Indicates the upper limit of the oxygen box air pillow pressure control band, in MPa; The opening of the second cavitation tube (315) is adjusted according to the following formula: In the formula, A R It represents the opening of the second cavitation tube, and the unit is dimensionless; A R1 It represents the minimum opening of the second cavitation tube, and the unit is dimensionless; P R Indicates the air pillow pressure of the fuel tank, in MPa; P R0 Indicates the lower limit of the fuel tank air pillow pressure control band, in MPa; P R1 Indicates the upper limit of the fuel tank air pillow pressure control band, in MPa.

7. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 2, characterized in that: The invention also comprises a pre-launch pressure-boosting assembly (40), wherein the pre-launch pressure-boosting assembly (40) comprises a ground helium source assembly, an oxygen tank pressure-boosting pipe (41), a fuel tank pressure-boosting pipe (42) and a liquid nitrogen tank pressure-boosting pipe (43); one end of the oxygen tank pressure-boosting pipe (41) is connected to the oxygen tank pressure-boosting pipe (11), and the other end is detachably connected to the ground helium source assembly; one end of the fuel tank pressure-boosting pipe (42) is connected to the fuel tank pressure-boosting pipe (21), and the other end is detachably connected to the ground helium source assembly; one end of the liquid nitrogen tank pressure-boosting pipe (43) is connected to the liquid nitrogen tank pressure-boosting pipe (32), and the other end is detachably connected to the ground helium source assembly.

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

9. The liquid nitrogen heating, vaporizing and pressurizing system according to claim 1, characterized in that: It also includes a liquid nitrogen pump (311) driving gas cylinder, the liquid nitrogen pump (311) driving gas cylinder is connected to the liquid nitrogen pump (311) turbine drive through a driving orifice plate, and the liquid nitrogen pump (311) driving gas cylinder is used to store pressurized medium.

10. A liquid rocket, characterized in that: It comprises the liquid nitrogen heating, vaporizing and pressurizing system as claimed in any one of claims 1 to 9.

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