Liquid nitrogen heating vaporization pressurization system and liquid rocket

Abstract

The present invention provides a liquid nitrogen heating, vaporization and pressurization system and a liquid rocket. The liquid nitrogen heating, vaporization and pressurization system includes: an oxygen tank, a fuel tank and a liquid nitrogen tank. The liquid nitrogen tank is arranged inside the oxygen tank. The liquid nitrogen tank is sequentially connected to a liquid nitrogen delivery pipeline, a liquid nitrogen heating and vaporization unit, a fuel tank pressurization main pipeline and a fuel tank energy dissipator. The fuel tank energy dissipator is arranged inside the fuel tank. The liquid nitrogen tank is sequentially connected to the liquid nitrogen delivery pipeline, the liquid nitrogen heating and vaporization unit, the fuel tank pressurization main pipeline, the liquid nitrogen tank pressurization pipeline and the liquid nitrogen tank. The present invention heats and vaporizes liquid nitrogen into nitrogen gas through the liquid nitrogen heating and vaporization unit during rocket flight, and performs liquid nitrogen heating and pressurization on the fuel tank and the liquid nitrogen tank.

Description

Technical Field

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

[0002] The pressurization system is a crucial subsystem of large liquid launch vehicles, and improving its performance plays a crucial role in improving the overall performance of the rocket. Currently, there are three main methods for tank pressurization: autogenous pressurization, room-temperature helium pressurization, and cold helium heating.

[0003] Autogenous supercharging refers to a method in which the propellant stored in a liquid rocket tank enters the engine, whereupon the engine generates pressurized gas that returns to the tank for further pressurization. This system is relatively simple, with the pressurized gas derived from the propellant in the tank. No additional storage for the pressurized medium is required, making system testing and pre-launch operations simple and cost-effective. However, autogenous supercharging is only suitable for media with low boiling points and easy vaporization. Kerosene, a room-temperature medium, cannot achieve vaporization conditions, so autogenous supercharging cannot be used on kerosene tanks.

[0004] Helium heating and pressurization involves pumping a pre-stored pressurizing medium into the rocket's tank at a constant flow rate. This method typically involves a separate storage chamber dedicated to the tank's pressurization. The pressurizing gas is typically a chemically inactive gas, such as nitrogen or helium. The main disadvantage is the requirement for separate pressurizing gas source storage devices, such as high-pressure gas cylinders, along with supporting piping and valves. This system is complex and expensive. Furthermore, for large and heavy-lift launch vehicles, especially for cryogenic rocket tank pressurization, large gas volumes are required, necessitating numerous gas storage units. Furthermore, the cylinders cool and increase in density during deflation, leading to high residual pressure. Consequently, helium utilization rates for helium heating and pressurization are less than 70%. Furthermore, helium is very expensive, making this method costly for large rockets.

[0005] Cold helium heating and pressurization immerses cold helium cylinders in cryogenic propellant tanks, achieving a greater gas mass under equivalent pressure and volume conditions. During use, the cold helium is introduced into a fuel gas or exhaust gas heat exchanger for heating before being fed into the propellant tanks for pressurization. This pressurization method is not only complex but also requires thermal protection for the cold helium cylinders and pressurization piping. Furthermore, placing the cold helium cylinders in an oxygen tank can lead to liquid oxygen compatibility and safety issues. A SpaceX Falcon 9 flight was previously reported to have experienced rocket explosions caused by cold helium cylinders. Therefore, this pressurization solution is unreliable and carries a high risk. Furthermore, the cold helium utilization rate is around 50%, significantly increasing the cost of the helium pressurization medium.

[0006] By explaining and comparing the above-mentioned pressurization methods, it can be seen that the kerosene in the kerosene tanks of large-scale carrier rockets 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 urgent 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, an object of an embodiment of the present invention is to provide a liquid nitrogen heating, vaporization and pressurization system, a liquid nitrogen tank and processing technology and a liquid rocket to solve at least one of the above problems.

[0008] To achieve the above-mentioned object, in a first aspect, a liquid nitrogen heating, vaporization and pressurization system is provided, the system comprising: an oxygen tank, a fuel tank and a liquid nitrogen tank, the liquid nitrogen tank being arranged inside the oxygen tank;

[0009] The liquid nitrogen tank is connected in sequence to a liquid nitrogen delivery pipeline, a liquid nitrogen heating and vaporization unit, a fuel tank pressurization main pipeline, and a fuel tank energy dissipator, and the fuel tank energy dissipator is arranged in the fuel tank;

[0010] The liquid nitrogen tank is connected in sequence to the liquid nitrogen delivery pipeline, the liquid nitrogen heating and vaporization unit, the fuel tank pressurization main pipeline, the liquid nitrogen tank pressurization pipeline and the liquid nitrogen tank.

[0011] In some possible implementations, the liquid nitrogen heating and vaporization unit includes a liquid nitrogen pump with a motor and multiple parallel cavitation tubes and a liquid nitrogen heater;

[0012] One end of the liquid nitrogen pump is connected to the liquid nitrogen delivery pipeline, and the other end is connected to the multi-way parallel cavitation tube and the liquid nitrogen heater;

[0013] A low-temperature stop valve is respectively connected between the liquid nitrogen pump and each cavitation pipe.

[0014] In some possible implementations, a first one-way valve is connected between each liquid nitrogen heater and the fuel tank pressurization main line.

[0015] In some possible embodiments, the system further includes multiple groups of parallel engines, each of which is provided with an oxygen evaporator, which is sequentially connected to the oxygen box boost main line and the oxygen box energy dissipator, and the oxygen box energy dissipator is provided in the oxygen box.

[0016] In some possible implementations, an oxygen tank safety overflow valve is provided on the oxygen tank, and the safety valve and the exhaust valve of the oxygen tank safety overflow valve are integrated into one design.

[0017] In some possible implementations, a fuel tank overflow valve is provided on the fuel tank, and the safety valve and the exhaust valve of the fuel tank overflow valve are integrated into one design.

[0018] In some possible embodiments, the fuel tank is provided with a fuel tank pressure sensor for measuring the air pressure of the fuel tank. The fuel tank pressure sensor is electrically connected to a fuel tank boost controller. The fuel tank boost controller controls the power of the motor according to the pressure value measured by the fuel tank pressure sensor.

[0019] In some possible embodiments, a ground helium pressurization unit is further included, and the ground helium pressurization unit is connected to at least any one of the first branch for pressurizing the fuel tank before launch, the second branch for pressurizing the liquid nitrogen tank before launch, and the third branch for pressurizing the oxygen tank before launch.

[0020] In some possible implementations, the first branch includes a pre-fire boost main line, a fifth three-way valve, a fuel tank pre-fire boost solenoid valve, a third one-way valve, a fuel tank pre-fire boost branch line, a sixth three-way valve, a fuel tank boost branch line, and a fuel tank energy dissipator connected in sequence;

[0021] And / or, the second branch includes a pre-shot boost main pipeline, a fifth three-way valve, a seventh three-way valve, a liquid nitrogen tank pre-shot boost solenoid valve, a fourth one-way valve, a liquid nitrogen tank pre-shot boost branch pipeline, a third three-way valve and a liquid nitrogen tank boost pipeline connected in sequence;

[0022] And / or, the third branch includes a branch of the pre-shot boost main line, the fifth three-way valve, and the seventh three-way valve connected in sequence, passing through the oxygen tank pre-shot boost solenoid valve, the fifth one-way valve, the fourth three-way valve and the oxygen tank energy dissipator.

[0023] In some possible implementations, the liquid nitrogen heating, vaporization and pressurization system further includes:

[0024] A first cross-pressurization pipeline is used to connect the oxygen tank energy dissipators in the multiple oxygen tanks;

[0025] and / or, a second cross-pressurization line for connecting the fuel tank energy absorbers in the plurality of fuel tanks;

[0026] And / or, a third cross-pressurization pipeline and a fourth cross-pressurization pipeline, the third cross-pressurization pipeline is used to connect multiple liquid nitrogen tanks, and the fourth cross-pressurization pipeline is used to connect the liquid nitrogen delivery pipeline.

[0027] In some possible implementations, the liquid nitrogen heating, vaporization and pressurization system further includes a liquid nitrogen filling unit, which is connected to the first three-way valve, and the first three-way valve is arranged on the liquid nitrogen delivery pipeline between the liquid nitrogen tank and the liquid nitrogen pump.

[0028] In some possible implementations, the liquid nitrogen heating, vaporization and pressurization system further includes a liquid nitrogen pump discharge pre-cooling unit, and the liquid nitrogen pump discharge pre-cooling unit is disposed between the liquid nitrogen pump and the cryogenic shut-off valve.

[0029] In a second aspect, a liquid rocket is provided, comprising the liquid nitrogen heating and vaporization system described in the first aspect.

[0030] The beneficial effects of the embodiments of the present invention are as follows:

[0031] In the embodiment of the present invention, a liquid nitrogen pump is used to pressurize the fuel tank after being heated by multiple liquid nitrogen heaters. A branch line is formed from the main fuel pressurization circuit to pressurize the liquid nitrogen tank. The liquid nitrogen pump is driven by a motor, thereby ensuring reliable operation of the liquid nitrogen pump, reducing the effective mass of the pressurization system, and achieving closed-loop control of the fuel tank pressure through the motor.

[0032] The embodiment of the present invention uses oxygen evaporators of multiple parallel-connected engines to vaporize liquid oxygen into oxygen for pressurizing the oxygen tank. Only one set of heater system needs to be developed for each engine to meet the system requirements, which reduces the difficulty of developing the engine heater.

[0033] The oxygen tank used in the embodiment of the present invention adopts an open pressurization mode, and the fuel tank adopts a closed pressurization mode. The power of the motor is controlled by the fuel tank pressure, thereby achieving precise control of the fuel tank pressure.

[0034] The present invention utilizes multiple engine oxygen evaporators to heat liquid oxygen into oxygen for oxygen tank pressure boosting, and multiple liquid nitrogen heaters to heat liquid nitrogen into nitrogen for fuel tank pressure boosting, enabling independent pressure boosting of the oxygen and fuel tanks. The fuel tank pressure controls the motor power and liquid nitrogen pump flow, achieving precise control of the fuel tank pressure.

[0035] The embodiment of the present invention adopts a cross-pressurization scheme for multiple tanks, which can avoid damage to a certain engine heater, resulting in excessively low pressure in the oxygen tank, fuel tank, and liquid nitrogen tank, thereby improving the redundancy of the power system; by adopting a cross-pressurization scheme for the three identical tanks of the booster and core stage, only one relief valve is used for the three tanks to meet the overpressure protection and propellant filling requirements of the three tanks, thereby reducing the number of valves, the number of valves and the supporting costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0037] Figure 1This is a schematic diagram of the overall structure of a liquid nitrogen heating, vaporization and pressurization system according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of the oxygen tank and the fuel tank being independently pressurized according to an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the structure of the liquid nitrogen filling unit and the liquid nitrogen pump discharge pre-cooling unit according to an embodiment of the present invention;

[0040] Figure 4 This is a control logic diagram of a liquid nitrogen pump motor according to an embodiment of the present invention;

[0041] Figure 5 This is a structural schematic diagram of a ground boosting mechanism according to an embodiment of the present invention;

[0042] Figure 6 The figure is a schematic structural diagram of a first-stage tank cross-pressurization according to an embodiment of the present invention.

[0043] Description of Figure Numbers:

[0044] 1. Oxygen tank; 2. Fuel tank; 3. Engine; 4. Liquid nitrogen tank; 5. Liquid nitrogen delivery pipeline; 6. Liquid nitrogen pump; 7. Motor; 8. Cryogenic shut-off valve; 9. Cavitation tube; 10. Liquid nitrogen heater; 11. First check valve; 12. Fuel tank boost main pipeline; 13. Sixth three-way valve; 14. Fuel tank boost branch pipe; 15. Fuel tank energy dissipator; 16. Fuel tank pressure sensor; 17. Fuel tank boost controller; 18 1. Fuel tank safety overflow valve; 2. Oxygen tank boost main line; 3. Fourth three-way valve; 4. Oxygen tank energy dissipator; 5. Oxygen tank pressure sensor; 6. Oxygen tank boost controller; 7. Oxygen tank safety overflow valve; 8. Second three-way valve; 9. Second check valve; 10. Thirteenth-way valve; 11. Third three-way valve; 12. Liquid nitrogen tank boost line; 13. Liquid nitrogen tank exhaust pipe; 14. Liquid nitrogen tank safety valve; 15. Second three-way valve; 16. Second check valve; 17. Thirteenth-way valve; 18. Third three-way valve; 19. Liquid nitrogen tank boost line; 20. Liquid nitrogen tank exhaust pipe; 21. Liquid nitrogen tank exhaust valve; 22. Liquid nitrogen tank safety valve.

[0045] 33. Helium source; 34. Filter; 35. Pressure reducer; 36. First stage tail-end plug-in connector; 37. Main pre-launch boost line; 38. Fifth three-way valve; 39. Fuel tank pre-launch boost solenoid valve; 40. Third one-way valve; 41. Fuel tank pre-launch boost branch line; 42. Seventh three-way valve; 43. Liquid nitrogen tank pre-launch boost solenoid valve; 44. Fourth one-way valve; 45. Liquid nitrogen tank pre-launch boost branch line; 46. Oxygen tank pre-launch boost solenoid valve; 47. Fifth one-way valve; 48. Eleventh three-way valve; 49. Liquid nitrogen discharge shut-off valve.

[0046] 50. Liquid nitrogen direct discharge pipeline; 51. Liquid nitrogen filling system; 52. Liquid nitrogen filling valve; 53. Second and first-stage tail end plug-in connector; 54. Sixth one-way valve; 55. First three-way valve; 56. Oxygen evaporator; 57. First cross-boost pipeline; 58. Eighth three-way valve; 59. Third cross-boost pipeline; 60. Second cross-boost pipeline; 61. Ninth three-way valve; 62. Fourth cross-boost pipeline; 63. Twelfth three-way valve, 64. Thirteenth three-way valve; 65. Four-way valve. DETAILED DESCRIPTION

[0047] The features and exemplary embodiments of various aspects of the present invention are described in detail below. In the detailed description that follows, many specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent 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 intended only to provide a better understanding of the present invention by illustrating examples of the present invention. In the accompanying drawings and the following description, at least some of the well-known structures and techniques are not shown in order to avoid unnecessary ambiguity in the present invention; and, for clarity, the sizes of some structures may be exaggerated. In addition, the features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments.

[0048] Example 1

[0049] like Figure 1 As shown, the system includes: an oxygen tank 1, a fuel tank 2 and a liquid nitrogen tank 4, the liquid nitrogen tank 4 is arranged inside the oxygen tank 1; the liquid nitrogen tank 4 is connected to the liquid nitrogen delivery pipeline 5, the liquid nitrogen heating and vaporization unit, the fuel tank pressurization main pipeline 12, and the fuel tank energy dissipator 15 in sequence, and the fuel tank energy dissipator 15 is arranged in the fuel tank; the liquid nitrogen tank 4 is connected to the liquid nitrogen delivery pipeline 5, the liquid nitrogen heating and vaporization unit, the fuel tank pressurization main pipeline 12, the liquid nitrogen tank pressurization pipeline 29 and the liquid nitrogen tank 4 in sequence.

[0050] Specifically, the liquid nitrogen in the liquid nitrogen tank 4 is sequentially transported to the liquid nitrogen heating and vaporization unit through the liquid nitrogen delivery pipeline 5 and the first three-way valve 55. After the liquid nitrogen is heated and vaporized, it is sequentially passed through the fuel tank pressurization main line 12, the second three-way valve 25, the fuel tank pressurization branch pipe 14, and the fuel tank energy dissipator 15 to heat and pressurize the fuel tank; the liquid nitrogen in the liquid nitrogen tank 4 is transported to the liquid nitrogen heating and vaporization unit through the liquid nitrogen delivery pipeline 5 and the first three-way valve 55. After the liquid nitrogen is heated and vaporized, it is sequentially passed through the fuel tank pressurization main line 12, the second three-way valve 25, the second one-way valve 26, the third three-way valve 28, and the liquid nitrogen tank pressurization pipeline 29 to heat and pressurize the liquid nitrogen tank 4. In addition, the liquid nitrogen tank 4 is also provided with a liquid nitrogen tank exhaust pipe 30 connected to the third three-way valve 28, a liquid nitrogen tank exhaust valve 31, and a liquid nitrogen tank safety valve 32.

[0051] In this embodiment, both the fuel tank 2 and the liquid nitrogen tank 4 are heated and pressurized with liquid nitrogen. The liquid nitrogen pressure is increased by a liquid nitrogen pump, and the flow rate is controlled by a liquid nitrogen heating and vaporization unit to pressurize the fuel tank. A second three-way valve 25 is provided on the fuel tank pressurization main line 12 to separate a line for pressurizing the liquid nitrogen tank 4. In this embodiment, the nitrogen pump motor drive mechanism simultaneously pressurizes the fuel tank 2 and the liquid nitrogen tank 4.

[0052] like Figure 2 As shown, in some embodiments, the liquid nitrogen heating and vaporization unit includes a liquid nitrogen pump 6 with a motor 7 and multiple parallel cavitation tubes 9 and a liquid nitrogen heater 10; one end of the liquid nitrogen pump 6 is connected to the liquid nitrogen delivery pipeline 5, and the other end is connected to the multiple parallel cavitation tubes 9 and the liquid nitrogen heater 10; a low-temperature stop valve 8 is respectively connected between the liquid nitrogen pump 6 and each cavitation tube 9.

[0053] In some embodiments, a first one-way valve 11 may be further connected between each liquid nitrogen heater 10 and the fuel tank pressurization main line 12 .

[0054] Specifically, one end of the liquid nitrogen pump 6 is connected to the liquid nitrogen delivery pipeline 5 through the first three-way valve 55, and the other end is connected to multiple parallel cavitation tubes 9 and liquid nitrogen heaters 10; a low-temperature stop valve 8 is connected between the liquid nitrogen pump 6 and each cavitation tube 9; and a first one-way valve 11 is connected between each liquid nitrogen heater 10 and the fuel tank boost main line 12.

[0055] In this embodiment, the liquid nitrogen tank 4 and the fuel tank 2 are pressurized using a liquid nitrogen heating and pressurization method. The liquid nitrogen is heated and vaporized into nitrogen gas by a liquid nitrogen heater 10. The high-temperature nitrogen gas is pressurized in the fuel tank through the fuel tank pressurization main line 12, and a small stream is separated from the fuel tank 2. The high-temperature nitrogen passes through a second one-way valve 26 and a liquid nitrogen tank pressurization line 29 to the liquid nitrogen tank 4 for liquid nitrogen heating and pressurization. In this embodiment, a liquid nitrogen pump 6 and a motor 7 are used to pressurize the liquid nitrogen. After the liquid nitrogen is diverted through the liquid nitrogen cavitation tube 9 and heated by multiple liquid nitrogen heaters 10, it is pressurized in the fuel tank 2. At the same time, a small stream is separated to pressurize the liquid nitrogen tank 4. At the same time, the motor 7 drives the liquid nitrogen pump 6. By controlling the motor power, the head of the liquid nitrogen pump 6 can be controlled, ensuring the reliable operation of the liquid nitrogen pump 6 while reducing the effective mass of the pressurization system. In addition, the liquid nitrogen box 4 is stored in the oxygen box 1. By utilizing the characteristic that the temperature difference between liquid oxygen and liquid nitrogen is similar, the liquid oxygen in the oxygen box 1 can keep the liquid nitrogen box 4 warm, thereby avoiding the need for thermal insulation coating of the liquid nitrogen box 4 and reducing the workload of thermal insulation coating of the liquid nitrogen box.

[0056] like Figure 2As shown, in some embodiments, the system further includes multiple groups of engines 3 connected in parallel, each engine 3 being provided with an oxygen evaporator 56. The oxygen evaporator 56 is sequentially connected to the oxygen tank pressurization main line 19 and the oxygen tank energy dissipator 21, which is disposed within the oxygen tank 1. The high-temperature oxygen generated by the oxygen evaporator 56 is supplied to the oxygen tank 1 via the oxygen tank pressurization main line 19, the fourth three-way valve 20, and the oxygen tank energy dissipator 21 for self-generated oxygen pressurization.

[0057] Specifically, oxygen evaporators 56 are provided at the five engines 3. The oxygen evaporators 56 of the five engines 3 are used to heat the liquid oxygen into high-temperature oxygen to pressurize the oxygen tank 1. A plurality of parallel liquid nitrogen heaters 10 are provided at the outlet of the liquid nitrogen pump 6. The liquid nitrogen is heated and vaporized into high-temperature nitrogen gas by the plurality of liquid nitrogen heaters 10 to pressurize the fuel tank 2. The pressure in the oxygen tank is adjusted by the oxygen tank pressure sensor 22 and the oxygen tank pressurization controller 23, so that the oxygen tank and the fuel tank can be independently pressurized. The oxygen tank adopts a self-generated pressurization method. In this embodiment, the oxygen tank 1 adopts self-generated oxygen pressurization, and the fuel tank 2 adopts closed liquid nitrogen heating and pressurization. The oxygen tank 1 and the fuel tank 2 are pressurized separately, so that the two tanks can be independently pressurized, and the gas in the oxygen tank 1 is prevented from flowing back to the fuel tank 2, thereby avoiding safety problems. Optionally, the oxygen tank pressure sensor 22 can be an oxygen tank air pillow pressure sensor.

[0058] like Figure 1 As shown, in some embodiments, an oxygen tank safety valve 24 is provided on the oxygen tank, and the safety valve and the exhaust valve of the oxygen tank safety valve 24 are of an integrated design; during the process of filling the oxygen tank with liquid oxygen on the ground, the oxygen tank safety valve 24 is opened; during the first-level flight, when the pressure of the oxygen tank 1 is higher than the opening pressure of the oxygen tank safety valve 24, the oxygen tank safety valve 24 is opened, and when the pressure of the oxygen tank 1 is lower than the closing pressure of the oxygen tank safety valve 24, the oxygen tank safety valve 24 is closed.

[0059] like Figure 1 As shown, in some embodiments, a fuel tank safety valve 18 is provided on the fuel tank, and the safety valve and the exhaust valve of the fuel tank safety valve 18 are of an integrated design; during the fuel tank refueling process on the ground, the fuel tank safety valve 18 is opened; in the first-stage flight phase, when the pressure of the fuel tank 2 is higher than the opening pressure of the fuel tank safety valve 18, the fuel tank safety valve 18 is opened, and when the pressure of the fuel tank 2 is lower than the closing pressure of the fuel tank safety valve 18, the fuel tank safety valve 18 is closed.

[0060] like Figure 1 As shown, in some embodiments, a fuel tank pressure sensor 16 for measuring the air pressure of the fuel tank 2 is provided on the fuel tank 2. The fuel tank pressure sensor 16 is electrically connected to a fuel tank boost controller 17. The fuel tank boost controller 17 controls the power of the motor 7 according to the pressure value measured by the fuel tank pressure sensor 16.

[0061] In this embodiment, the fuel tank pressure is measured by the fuel tank pressure sensor 16 , and the value of the fuel tank pressure is transmitted to the fuel tank boost controller 17 , and the power of the motor 7 is controlled by the fuel tank boost controller 17 . Figure 4 This is a control logic diagram of a liquid nitrogen pump motor according to an embodiment of the present invention, such as Figure 4 As shown, WR1 is the lower power limit of the motor 7, WR2 is the upper power limit of the motor 7, PR1 is the lower pressure control limit of the fuel tank 2, and PR2 is the upper pressure control limit of the fuel tank 2.

[0062] Specifically, the pressure of the fuel tank 2 is measured by the fuel tank pressure sensor 16, and the pressure value is transmitted to the fuel tank boost controller 17. The fuel tank boost controller 17 calculates and makes decisions to control the output power of the motor 7, thereby stabilizing the pressure of the fuel tank 2 and achieving closed-loop control of the pressure of the fuel tank 2.

[0063] like Figure 1 and Figure 5 As shown, in some embodiments, a ground helium pressurization unit is further included, and the ground helium pressurization unit is connected to at least any one of the first branch for pressurizing the fuel tank before launch, the second branch for pressurizing the liquid nitrogen tank before launch, and the third branch for pressurizing the oxygen tank before launch.

[0064] During the ground pre-launch pressurization, the ground helium pressurization unit respectively performs pre-launch pressurization on the fuel tank through the first branch, pre-launch pressurization on the liquid nitrogen tank through the second branch, and pre-launch pressurization on the oxygen tank through the third branch; wherein the ground helium pressurization unit includes a helium source 33, and a filter 34, a pressure reducer 35 and a first-stage tail end plug connector 36 connected in sequence to the helium source 33; the first branch includes a pre-launch pressurization main line 37, a fifth three-way valve 38, a fuel tank pre-launch pressurization solenoid valve 39 (K1), a third one-way valve 40, a fuel tank pre-launch pressurization branch line 41, a sixth three-way valve 38 and a fuel tank pre-launch pressurization solenoid valve 39 (K2), a third one-way valve 40, a fuel tank pre-launch pressurization branch line 41, a sixth three-way valve 38 and a fuel tank pre-launch pressurization solenoid valve 39 (K3), a third one-way valve 40 and a fuel tank pre-launch pressurization branch line 41, a sixth three-way valve 38 and a fuel tank pre-launch pressurization solenoid valve 39 (K1), a third one-way valve 40 and a fuel tank pre-launch pressurization branch line 41, a sixth three-way valve 38 and a fuel tank pre-launch pressurization solenoid valve 39 (K2), a third one-way valve 40 and a fuel tank pre-launch pressurization branch line 41, a sixth three-way valve 38 and a fuel tank pre-launch pressurization solenoid valve 39 (K3), a third one-way valve 40 and a fuel tank pre-launch pressurization branch line 41, a sixth three-way valve 38 and a fuel tank pre-launch pressurization Valve 13, fuel tank boost branch pipe 14 and fuel tank energy dissipator 15; the second branch includes the pre-fire boost main line 37, the fifth three-way valve 38, the seventh three-way valve 42, the liquid nitrogen tank pre-fire boost solenoid valve 43 (K2), the fourth one-way valve 44, the liquid nitrogen tank pre-fire boost branch line 45, the third three-way valve 28 and the liquid nitrogen tank boost line 29 connected in sequence; the third branch includes the pre-fire boost main line 37, the fifth three-way valve 38, the branch line of the seventh three-way valve 42 connected in sequence, through the oxygen tank pre-fire boost solenoid valve 46 (K3), the fifth one-way valve 47, the fourth three-way valve 20 and the oxygen tank energy dissipator 21.

[0065] In this embodiment, during the ground pre-shot pressurization period, only one pre-shot pressurization main line 37 is used to complete the pressurization function of the three storage tanks: the oxygen tank 1, the fuel tank 2, and the liquid nitrogen tank 4.

[0066] like Figure 6 As shown, in some embodiments, the liquid nitrogen heating, vaporization and pressurization system further includes: a first cross-pressurization line 57 for connecting the oxygen tank energy absorbers 21 in multiple oxygen tanks 1; and / or, a second cross-pressurization line 60 for connecting the fuel tank energy absorbers 15 in multiple fuel tanks 2; and / or, a third cross-pressurization line 59 and a fourth cross-pressurization line 62 for connecting the multiple liquid nitrogen tanks 4 and the liquid nitrogen delivery pipeline 5.

[0067] Specifically, the first cross-pressurization line 57 connects the oxygen tank 1 among the multiple tanks via the eighth three-way valve 58; the second cross-pressurization line 60 connects the fuel tank among the multiple tanks via the ninth three-way valve 61; the third cross-pressurization line 59 connects the multiple liquid nitrogen tanks via the thirteenth three-way valve 27; and the fourth cross-pressurization line 62 connects the multiple liquid nitrogen delivery lines 5 via the twelfth three-way valve 63, the thirteenth three-way valve 64, and the four-way valve 65. Preferably, the number of tanks is an odd number, preferably three or five.

[0068] This embodiment uses a cross-boosting method to merge the above-mentioned identical sub-stages to form a booster + core stage + booster form. The booster and core stage are the same, which reduces the types and complexity of the sub-stage.

[0069] Specifically, during the first stage flight phase, the three oxygen tanks 1 of the two boosters and one core stage are connected via the first cross-pressurization line 57 and the eighth three-way valve 58 to achieve connectivity among the three oxygen tanks 1, ensuring equal pressures across the three tanks and achieving cross-pressurization across the two boosters and one core stage oxygen tanks. The three fuel tanks 2 of the two boosters and one core stage are connected via the second cross-pressurization line 60 and the ninth three-way valve 61 to achieve connectivity among the three fuel tanks 2 and ensure equal pressures across the three tanks and achieving cross-pressurization across the two boosters and one core stage fuel tanks. The three liquid nitrogen tanks 4 of the two boosters and one core stage are connected via the third cross-pressurization line 59 and the thirteenth-way valve 27. Multiple liquid nitrogen delivery lines 5 are then connected via the fourth cross-pressurization line 62, the four-way valve 65, the twelfth three-way valve 63, and the thirteenth three-way valve 64 to achieve connectivity among the three liquid nitrogen tanks 4 and ensure equal pressures across the three tanks and achieving cross-pressurization across the two boosters and one core stage liquid nitrogen tanks.

[0070] In this embodiment, the flow rates of the three liquid nitrogen pumps 6 are different. By connecting the liquid nitrogen pressurization and delivery systems, the pressures of the three liquid nitrogen tanks 4 can be kept consistent, and the liquid nitrogen levels of the three liquid nitrogen delivery systems can also be kept consistent. This can ensure that the liquid nitrogen of the three liquid nitrogen delivery systems is completely consumed, preventing a situation in which a certain liquid nitrogen delivery system has a large amount of residual propellant due to the difference in the flow rates of the liquid nitrogen pumps.

[0071] The delivery system in front of the liquid nitrogen pump 6 is connected, and liquid nitrogen only needs to be added to the central liquid nitrogen tank 4, which reduces the number of interfaces of the liquid nitrogen filling port and simplifies the rocket-ground interface; the liquid nitrogen filling system 51 is divided by the liquid nitrogen filling valve 52 connected to the liquid nitrogen filling system 51, the second-stage tail end plug-in connector 53 and the sixth one-way valve 54, the first three-way valve 55, and the four-way valve 65. One stream is used to fill the liquid nitrogen of the left liquid nitrogen tank through the twelfth three-way valve 63, one stream is used to fill the liquid nitrogen of the middle liquid nitrogen tank 4 through the main delivery pipe, and the other stream is used to fill the liquid nitrogen of the right liquid nitrogen tank 4 through the thirteenth three-way valve 64; this embodiment only uses one set of liquid nitrogen filling system to realize the filling of three liquid nitrogen storage tanks.

[0072] This embodiment employs a cross-pressurization scheme for the three tanks, preventing damage to a particular engine heater from causing low pressures in the oxygen, fuel, and liquid nitrogen tanks. For example, if two core stage engines shut down, the high-temperature oxygen and nitrogen generated by the booster heaters can boost the pressures of core stage oxygen tank 1, fuel tank 2, and liquid nitrogen tank 4, respectively, thereby increasing power system redundancy.

[0073] In addition, by adopting a cross-pressurization scheme for the three tanks, the pressure of the three tanks is the same, and only one overflow valve is used for the three tanks to meet the overpressure protection and propellant filling of the three tanks, reducing the number of valves and the number and cost of valves.

[0074] like Figure 3 As shown, in some embodiments, the liquid nitrogen heating, vaporization and pressurization system also includes a liquid nitrogen filling unit. The liquid nitrogen heating, vaporization and pressurization system also includes a liquid nitrogen filling unit. The liquid nitrogen filling unit is connected to the first three-way valve 55. The first three-way valve 55 is arranged on the liquid nitrogen delivery pipeline 5 between the liquid nitrogen tank 4 and the liquid nitrogen pump 6.

[0075] In this embodiment, the liquid nitrogen filling unit includes: a liquid nitrogen filling system 51, and a liquid nitrogen filling valve 52, a second-stage tail end plug connector 53 and a sixth one-way valve 54 connected to the liquid nitrogen filling system 51 in sequence.

[0076] In some embodiments, the liquid nitrogen heating, vaporization and pressurization system further includes a liquid nitrogen pump discharge precooling unit, which is arranged between the liquid nitrogen pump 6 and the low-temperature stop valve 8.

[0077] In this embodiment, the liquid nitrogen pump discharge precooling unit includes: a liquid nitrogen discharge stop valve 49 and a liquid nitrogen direct discharge to atmosphere pipeline 50. An eleventh three-way valve 48 is provided on the pipeline between the liquid nitrogen pump 6 and the low-temperature stop valve 8. The liquid nitrogen discharge stop valve 49 is connected to the eleventh three-way valve 48. When the liquid nitrogen pump 6 is precooled and discharged, the liquid nitrogen discharge stop valve 49 is opened to precool the liquid nitrogen pump through the liquid nitrogen direct discharge to atmosphere pipeline 50.

[0078] Example 2

[0079] An embodiment of the present invention further provides a liquid rocket, which includes the liquid nitrogen heating, vaporization and pressurization system of embodiment one.

[0080] In the embodiment of the present invention, a liquid nitrogen pump is used to pressurize the fuel tank after being heated by multiple liquid nitrogen heaters. A branch line is formed from the main fuel pressurization circuit to pressurize the liquid nitrogen tank. The liquid nitrogen pump is driven by a motor, thereby ensuring reliable operation of the liquid nitrogen pump, reducing the effective mass of the pressurization system, and achieving closed-loop control of the fuel tank pressure through the motor.

[0081] The embodiment of the present invention uses oxygen evaporators of multiple parallel-connected engines to vaporize liquid oxygen into oxygen for pressurizing the oxygen tank. Only one set of heater system needs to be developed for each engine to meet the system requirements, which reduces the difficulty of developing the engine heater.

[0082] The oxygen tank used in the embodiment of the present invention adopts an open pressurization method, and the fuel tank adopts a closed pressurization method. The power of the motor is controlled by the fuel tank pressure to achieve precise control of the fuel tank pressure;

[0083] The present invention utilizes multiple engine oxygen evaporators to heat liquid oxygen into oxygen for oxygen tank pressure boosting, and multiple liquid nitrogen heaters to heat liquid nitrogen into nitrogen for fuel tank pressure boosting, enabling independent pressure boosting of the oxygen and fuel tanks. The fuel tank pressure controls the motor power and liquid nitrogen pump flow, achieving precise control of the fuel tank pressure.

[0084] The embodiment of the present invention adopts a cross-pressurization scheme for multiple tanks, which can avoid damage to a certain engine heater, resulting in excessively low pressure in the oxygen tank, fuel tank, and liquid nitrogen tank, thereby improving the redundancy of the power system; by adopting a cross-pressurization scheme for the three identical tanks of the booster and core stage, only one relief valve is used for the three tanks to meet the overpressure protection and propellant filling requirements of the three tanks, thereby reducing the number of valves, the number of valves and the supporting costs.

[0085] In describing the embodiments of the present invention, it should be noted that the terms "upper, lower, inner, and outer" and other references to orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present 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.

[0086] In the embodiments of the present invention, unless otherwise specified or limited, the terms "mounted, connected, and connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections. They can also refer to mechanical connections, electrical connections, direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0087] While the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner, provided no structural conflicts exist. The present invention is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A liquid nitrogen heating, vaporization and pressurization system, characterized in that: The system comprises: an oxygen tank (1), a fuel tank (2) and a liquid nitrogen tank (4), wherein the liquid nitrogen tank (4) is arranged inside the oxygen tank (1); The liquid nitrogen tank (4) is connected in sequence to a liquid nitrogen delivery pipeline (5), a liquid nitrogen heating and vaporization unit, a fuel tank pressurization main pipeline (12), and a fuel tank energy dissipator (15), and the fuel tank energy dissipator (15) is arranged in the fuel tank; The liquid nitrogen tank (4) is connected in sequence to the liquid nitrogen delivery pipeline (5), the liquid nitrogen heating and vaporization unit, the fuel tank pressurization main pipeline (12), the liquid nitrogen tank pressurization pipeline (29), and the liquid nitrogen tank (4); The liquid nitrogen heating and vaporization unit comprises a liquid nitrogen pump (6), a multi-channel parallel cavitation tube (9), and a liquid nitrogen heater (10); One end of the liquid nitrogen pump (6) is connected to the liquid nitrogen delivery pipeline (5), and the other end is connected to the multi-channel parallel cavitation tube (9) and the liquid nitrogen heater (10); A low-temperature stop valve (8) is respectively connected between the liquid nitrogen pump (6) and each of the cavitation tubes (9).

2. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: A first one-way valve (11) is connected between each of the liquid nitrogen heaters (10) and the fuel tank pressurization main line (12).

3. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: The system further comprises a plurality of parallel-connected engines (3), each of the engines (3) being provided with an oxygen evaporator (56), the oxygen evaporator (56) being connected in sequence to an oxygen box pressurization main line (19) and an oxygen box energy dissipator (21), and the oxygen box energy dissipator (21) being provided in the oxygen box (1).

4. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: An oxygen box overflow valve (24) is provided on the oxygen box (1), and the safety valve and exhaust valve of the oxygen box overflow valve (24) are integrated.

5. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: A fuel tank overflow valve (18) is provided on the fuel tank (2), and the safety valve and exhaust valve of the fuel tank overflow valve (18) are of integrated design.

6. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: The fuel tank (2) is provided with a fuel tank pressure sensor (16) for measuring the gas pressure of the fuel tank (2). The fuel tank pressure sensor (16) is electrically connected to a fuel tank boost controller (17). The fuel tank boost controller (17) controls the power of the motor (7) on the liquid nitrogen pump (6) according to the pressure value measured by the fuel tank pressure sensor (16).

7. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: It also includes a ground helium pressurizing unit, which is connected to at least any one of a first branch for pressurizing the fuel tank (2) before firing, a second branch for pressurizing the liquid nitrogen tank (4) before firing, and a third branch for pressurizing the oxygen tank (1) before firing.

8. The liquid nitrogen heating, vaporization and pressurization system according to claim 7, characterized in that: The first branch comprises a pre-injection boost main line (37), a fifth three-way valve (38), a fuel tank pre-injection boost solenoid valve (39), a third one-way valve (40), a fuel tank pre-injection boost branch line (41), a sixth three-way valve (13), a fuel tank boost branch line (14), and the fuel tank energy dissipator (15), which are connected in sequence; And / or, the second branch includes a pre-shooting boost main pipeline (37), a fifth three-way valve (38), a seventh three-way valve (42), a liquid nitrogen tank pre-shooting boost solenoid valve (43), a fourth one-way valve (44), a liquid nitrogen tank pre-shooting boost branch pipeline (45), a third three-way valve (28), and the liquid nitrogen tank boost pipeline (29) connected in sequence; And / or, the third branch includes a branch of the pre-injection boost main line (37), the fifth three-way valve (38), and the seventh three-way valve (42) connected in sequence, passing through the oxygen box pre-injection boost solenoid valve (46), the fifth one-way valve (47), the fourth three-way valve (20) and the oxygen box energy dissipator (21).

9. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: The liquid nitrogen heating, vaporization and pressurization system further comprises: A first cross-pressurization pipeline (57) is used to connect the oxygen box energy dissipators (21) in the plurality of oxygen boxes (1); and / or, a second cross-pressurization pipeline (60) for connecting the fuel tank energy absorbers (15) in the plurality of fuel tanks (2); and / or, a third cross-pressurization pipeline (59) and a fourth cross-pressurization pipeline (62), wherein the third cross-pressurization pipeline (59) is used to connect multiple liquid nitrogen tanks (4), and the fourth cross-pressurization pipeline (62) is used to connect the liquid nitrogen delivery pipeline (5).

10. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: The liquid nitrogen heating, vaporizing and pressurizing system further comprises a liquid nitrogen filling unit, which is connected to a first three-way valve (55). The first three-way valve (55) is arranged on the liquid nitrogen delivery pipeline (5) between the liquid nitrogen tank (4) and the liquid nitrogen pump (6).

11. The liquid nitrogen heating, vaporization and pressurization system according to claim 1, characterized in that: The liquid nitrogen heating, vaporizing and pressurizing system further comprises a liquid nitrogen pump discharge precooling unit, wherein the liquid nitrogen pump discharge precooling unit is arranged between the liquid nitrogen pump (6) and the low-temperature stop valve (8).

12. A liquid rocket, characterized in that: The liquid rocket includes a liquid nitrogen heating, vaporization and pressurization system as described in any one of claims 1-11.

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