Liquid nitrogen heating, vaporizing and pressurizing system and liquid rocket

Abstract

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 and a liquid nitrogen tank, the liquid nitrogen tank is arranged in the oxygen tank, and the liquid nitrogen tank is sequentially connected with a liquid nitrogen conveying pipeline, a liquid nitrogen heating and vaporizing unit, a fuel tank pressurizing main pipeline and a fuel tank energy dissipater; the fuel tank energy dissipater is arranged in the fuel tank; the liquid nitrogen tank is sequentially connected with the liquid nitrogen conveying pipeline, the liquid nitrogen heating and vaporizing unit, the fuel tank pressurizing main pipeline, the liquid nitrogen tank pressurizing pipeline and the liquid nitrogen tank. Liquid nitrogen is heated and vaporized into nitrogen through the liquid nitrogen heating and vaporizing unit when the rocket flies, and liquid nitrogen heating and pressurizing are conducted on the fuel tank and the liquid nitrogen tank.

Description

Technical Field

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

[0002] The pressurization system is one of the important subsystems of liquid large-scale launch vehicles. The improvement and enhancement of its performance plays an important role in improving the overall performance of the rocket. At present, there are three main ways of tank pressurization: autogenous pressurization, normal temperature helium pressurization, and cold helium heating.

[0003] Autogenous supercharging refers to the method in which the propellant stored in the tank of a liquid rocket enters the engine, and the engine generates pressurized gas that returns to the tank for supercharging. The autogenous supercharging system is relatively simple in composition, and the pressurized gas comes from the propellant in the tank. No additional storage device for the supercharging medium is required, and the system testing and pre-launch operation are simple and low in cost. Autogenous supercharging is only suitable for media with low boiling points and easy vaporization. For kerosene at room temperature, the vaporization conditions cannot be reached, so kerosene tanks cannot use autogenous supercharging.

[0004] Normal temperature helium heating and pressurization refers to the method in which the pressurized medium pre-stored in the rocket gas storage device enters the tank for pressurization at a certain flow rate. Generally, it is equipped with an independently stored pressurized medium, which is specially used for tank pressurization. The pressurized gas is generally a chemically inactive gas, such as nitrogen, helium, etc. The main disadvantage is that it is necessary to provide 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 the helium utilization rate of normal temperature helium heating and pressurization being less than 70%. At the same time, helium is very expensive, so for large rockets, the cost of normal temperature helium heating and pressurization is relatively high.

[0005] Cold helium heating and pressurization immerses the cold helium cylinder in a cryogenic propellant tank to obtain a larger gas mass under the same pressure and volume conditions. When in use, the cold helium is introduced into the fuel gas or exhaust gas heat exchanger for heating, and then sent to the propellant tank to pressurize the tank. This pressurization method is not only complex in system, but also requires thermal protection treatment of the cold helium cylinder and the pressurization pipeline. At the same time, placing the cold helium cylinder in the oxygen tank will cause liquid oxygen compatibility safety issues. Spacex Falcon 9 has encountered the problem of rocket explosion caused by cold helium cylinders during flight. Therefore, this pressurization solution has low reliability and high risk. At the same time, the utilization rate of cold helium is about 50%, which greatly increases the cost of 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 launch vehicles has a high boiling point and is not easy to pressurize. The pressurization cost of the kerosene tanks is high and the weight of the pressurization system is high. 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, an object of an embodiment of the present invention is to provide a liquid nitrogen heating, vaporization and pressurization system, a liquid nitrogen box and a processing technology and a liquid rocket to solve at least one of the above problems.

[0008] To achieve the above-mentioned purpose, 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 to the liquid nitrogen delivery pipeline, the liquid nitrogen heating and vaporization unit, the fuel tank pressurization main pipeline, and the fuel tank energy dissipator in sequence, 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 a multi-channel parallel cavitation tube 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-channel parallel cavitation tube and the liquid nitrogen heater;

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

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

[0015] In some possible embodiments, the system further includes a plurality of parallel-connected engines, each of the engines being provided with an oxygen evaporator, the oxygen evaporator being connected in sequence to an oxygen box boost main line and an oxygen box energy dissipator, and the oxygen box energy dissipator being provided in the oxygen box.

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

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

[0018] In some possible embodiments, a fuel tank pressure sensor for measuring the air pressure of the fuel tank is provided on the fuel tank, and the fuel tank pressure sensor is electrically connected to a fuel tank boost controller, and 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 a first branch for pressurizing the fuel tank before firing, a second branch for pressurizing the liquid nitrogen tank before firing, and a third branch for pressurizing the oxygen tank before firing.

[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 pipe, and a fuel tank energy dissipator connected in sequence;

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

[0022] And / or, the third branch includes a branch road of the pre-fire boost main line, the fifth three-way valve, and the seventh three-way valve connected in sequence, passing through the oxygen box pre-fire boost solenoid valve, the fifth one-way valve, the fourth three-way valve and the oxygen box 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 oxygen tank energy dissipators in a plurality of oxygen tanks;

[0025] and / or, a second cross-pressurization pipeline 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 liquid nitrogen delivery pipelines.

[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 disposed 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 precooling unit, and the liquid nitrogen pump discharge precooling 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] The embodiment of the present invention uses a liquid nitrogen pump to pressurize the fuel tank after being heated by multiple liquid nitrogen heaters. A branch is formed between the main fuel pressurization circuit and the liquid nitrogen tank. The liquid nitrogen pump is driven by a motor, thereby ensuring the reliable operation of the liquid nitrogen pump, reducing the effective mass of the pressurization system, and completing the closed control of the fuel tank pressure through the motor.

[0032] The embodiment of the present invention uses oxygen evaporators of multiple parallel engines to vaporize liquid oxygen into oxygen for oxygen tank pressurization. Each engine only needs to develop one set of heater system to meet the system requirements, which reduces the difficulty of developing the engine heater.

[0033] The oxygen box 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 accurate control of the fuel tank pressure.

[0034] The embodiment of the present invention utilizes multiple engine oxygen evaporators to heat liquid oxygen into oxygen gas for oxygen tank pressurization, and multiple liquid nitrogen heaters to heat liquid nitrogen into nitrogen gas for fuel tank pressurization, thereby achieving independent pressurization of the oxygen tank and fuel tank. The motor power and liquid nitrogen pump flow are controlled by the fuel tank pressure, thereby 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 heater of a certain engine, resulting in excessively low pressures in the oxygen tank, the fuel tank, and the 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 the core stage, only one relief valve is used for the three tanks to meet the overpressure protection and propellant filling of the three tanks, thereby reducing the number of valves, and reducing the number and cost of valves. 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 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.

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

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

[0039] Figure 3 It is a structural schematic diagram of a liquid nitrogen filling unit and a liquid nitrogen pump discharge precooling unit according to an embodiment of the present invention;

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

[0041] Figure 5 It is a structural schematic diagram of a ground pressurizing 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. Low temperature stop 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 , fuel tank safety overflow valve; 19, oxygen tank boost main line; 20, fourth three-way valve; 21, oxygen tank energy dissipator; 22, oxygen tank pressure sensor; 23, oxygen tank boost controller; 24, oxygen tank safety overflow valve; 25, second three-way valve; 26, second one-way valve; 27, thirteenth-way valve; 28, third three-way valve; 29, liquid nitrogen tank boost pipeline; 30, liquid nitrogen tank exhaust pipe; 31, liquid nitrogen tank exhaust valve; 32, liquid nitrogen tank safety valve;

[0045] 33. Helium source; 34. Filter; 35. Pressure reducer; 36. First and second stage tail end plug-in connector; 37. Pre-fire boost main pipeline; 38. Fifth three-way valve; 39. Pre-fire boost solenoid valve for fuel tank; 40. Third one-way valve; 41. Pre-fire boost branch pipeline for fuel tank; 42. Seventh three-way valve; 43. Pre-fire boost solenoid valve for liquid nitrogen tank; 44. Fourth one-way valve; 45. Pre-fire boost branch pipeline for liquid nitrogen tank; 46. Pre-fire boost solenoid valve for oxygen tank; 47. Fifth one-way valve; 48. Eleventh three-way valve; 49. Liquid nitrogen discharge stop 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-boosting pipeline; 58. Eighth three-way valve; 59. Third cross-boosting pipeline; 60. Second cross-boosting pipeline; 61. Ninth three-way valve; 62. Fourth cross-boosting 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 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.

[0048] Embodiment 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, and the liquid nitrogen is heated and vaporized, and then sequentially passes through the fuel tank pressurization main pipeline 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 with liquid nitrogen; 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, and the liquid nitrogen is heated and vaporized, and then sequentially passes through the fuel tank pressurization main pipeline 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 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 fuel tank 2 and the liquid nitrogen tank 4 are pressurized at the same time by the nitrogen pump motor drive mechanism.

[0052] like Figure 2 As shown, in some embodiments, the liquid nitrogen heating 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 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; 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 by liquid nitrogen heating and pressurization. The liquid nitrogen is heated and vaporized into nitrogen by the liquid nitrogen heater 10. The high-temperature nitrogen is pressurized to the fuel tank through the fuel tank pressurization main line 12. A small stream is separated from the fuel tank 2. The high-temperature nitrogen is heated and pressurized to the liquid nitrogen tank 4 through the second one-way valve 26 and the liquid nitrogen tank pressurization line 29. In this embodiment, the liquid nitrogen pump 6 and the motor 7 are used. After the liquid nitrogen is pressurized, the liquid nitrogen is diverted by the liquid nitrogen cavitation tube 9 and heated by multiple liquid nitrogen heaters 10 to pressurize 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 is used to drive the liquid nitrogen pump 6. The head of the liquid nitrogen pump 6 can be controlled by controlling the motor power, which ensures 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 a plurality of parallel-connected engines 3, each engine 3 is provided with an oxygen evaporator 56, and the oxygen evaporator 56 is connected to the oxygen box pressurization main line 19 and the oxygen box energy dissipator 21 in sequence, and the oxygen box energy dissipator 21 is arranged in the oxygen box 1. The high-temperature oxygen generated by the oxygen evaporator 56 is supplied to the oxygen box 1 through the oxygen box pressurization main line 19, the fourth three-way valve 20, and the oxygen box energy dissipator 21 for self-generated oxygen pressurization.

[0057] Specifically, oxygen evaporators 56 are provided at the five engines 3, and 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, and 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 separately pressurized, so that the two tanks can be independently pressurized, and the gas in the oxygen tank 1 is prevented from being reversed 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 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 overflow valve 18 is provided on the fuel tank, and the safety valve and the exhaust valve of the fuel tank safety overflow valve 18 are of integrated design; during the fuel tank refueling process on the ground, the fuel tank safety overflow valve 18 is opened; in the first-stage flight stage, when the pressure of the fuel tank 2 is higher than the opening pressure of the fuel tank safety overflow valve 18, the fuel tank safety overflow valve 18 is opened, and when the pressure of the fuel tank 2 is lower than the closing pressure of the fuel tank safety overflow valve 18, the fuel tank safety overflow 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 a fuel tank pressure sensor 16 , and the value of the fuel tank pressure is transmitted to a fuel tank boost controller 17 , and the power of the motor 7 is controlled by the fuel tank boost controller 17 . Figure 4 : 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 also included, and the ground helium pressurization unit is connected to at least any one of the first branch for pressurizing the fuel tank before firing, the second branch for pressurizing the liquid nitrogen tank before firing, and the third branch for pressurizing the oxygen tank before firing.

[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 comprises a helium source 33, and a filter 34, a pressure reducer 35 and a first-stage tail-end plug-in connector 36 connected in sequence to the helium source 33; the first branch comprises 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 connected in sequence, 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 pre-fire pressurization on the ground, only one pre-fire pressurization main line 37 can be 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 also includes: a first cross-boosting line 57, used to connect the oxygen box energy absorbers 21 in multiple oxygen boxes 1; and / or, a second cross-boosting line 60, used to connect the fuel tank energy absorbers 15 in multiple fuel tanks 2; and / or, a third cross-boosting line 59 and a fourth cross-boosting line 62, used to connect multiple liquid nitrogen tanks 4 and the liquid nitrogen delivery pipeline 5.

[0067] Specifically, the first cross-pressurization pipeline 57 connects the oxygen tank 1 among the multiple tanks through the eighth three-way valve 58; the second cross-pressurization pipeline 60 connects the fuel tank among the multiple tanks through the ninth three-way valve 61; the third cross-pressurization pipeline 59 connects the multiple liquid nitrogen tanks through the thirteenth way valve 27, and connects the multiple liquid nitrogen delivery pipelines 5 through the fourth cross-pressurization pipeline 62, 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 3 or 5.

[0068] This embodiment uses cross-boosting 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, in the first stage of flight, the three oxygen tanks 1 of two boosters and one core stage are connected through the first cross-pressurization pipeline 57 and the eighth three-way valve 58 to achieve the connection of the three oxygen tanks 1, ensure the same pressure of the three tanks, and achieve cross-pressurization of the two boosters and one core stage oxygen tanks. The three fuel tanks 2 of two boosters and one core stage are connected through the second cross-pressurization pipeline 60 and the ninth three-way valve 61 to achieve the connection of the three fuel tanks 2, ensure the same pressure of the three tanks, and achieve cross-pressurization of the two boosters and one core stage fuel tanks. The three liquid nitrogen tanks 4 of two boosters and one core stage are connected through the third cross-pressurization pipeline 59 and the thirteenth-way valve 27, and then the multiple liquid nitrogen delivery pipelines 5 are connected through the fourth cross-pressurization pipeline 62, the four-way valve 65, the twelfth three-way valve 63 and the thirteenth three-way valve 64 to achieve the connection of the three liquid nitrogen tanks 4, ensure the same pressure of the three tanks, and achieve cross-pressurization of 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. The liquid nitrogen of the three liquid nitrogen delivery systems can be consumed cleanly, and the situation in which a certain liquid nitrogen delivery system has a lot of residual propellant due to the difference in the flow rate of the liquid nitrogen pumps can be prevented.

[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 through the liquid nitrogen filling valve 52 connected to the liquid nitrogen filling system 51, the second first-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] The three tanks in this embodiment adopt a cross-pressurization scheme, which can avoid damage to a certain engine heater, resulting in too low pressure in the oxygen tank, fuel tank, and liquid nitrogen tank. For example, if two engines of the core stage engine are shut down, the high-temperature oxygen and nitrogen generated by the booster heater will pressurize the core stage oxygen tank 1, fuel tank 2, and liquid nitrogen tank 4, respectively, thereby improving the redundancy of the power system.

[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, thereby 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, and the liquid nitrogen heating, vaporization and pressurization system also includes a liquid nitrogen filling unit, which is connected to the first three-way valve 55, and 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 first-stage tail end plug connector 53 and a sixth one-way valve 54 which are sequentially connected to the liquid nitrogen filling system 51.

[0076] In some embodiments, the liquid nitrogen heating, vaporization and pressurization system also includes a liquid nitrogen pump discharge precooling unit, and the liquid nitrogen pump discharge precooling unit 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 arranged 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] Embodiment 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] The embodiment of the present invention uses a liquid nitrogen pump to pressurize the fuel tank after being heated by multiple liquid nitrogen heaters. A branch is formed between the main fuel pressurization circuit and the liquid nitrogen tank. The liquid nitrogen pump is driven by a motor, thereby ensuring the reliable operation of the liquid nitrogen pump, reducing the effective mass of the pressurization system, and completing the closed control of the fuel tank pressure through the motor.

[0081] The embodiment of the present invention uses oxygen evaporators of multiple parallel engines to vaporize liquid oxygen into oxygen for oxygen tank pressurization. Each engine only needs to develop one set of heater system 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 mode, and the fuel tank adopts a closed pressurization mode, and the power of the motor is controlled by the fuel tank pressure to achieve accurate control of the fuel tank pressure;

[0083] The embodiment of the present invention utilizes multiple engine oxygen evaporators to heat liquid oxygen into oxygen gas for oxygen tank pressurization, and multiple liquid nitrogen heaters to heat liquid nitrogen into nitrogen gas for fuel tank pressurization, thereby achieving independent pressurization of the oxygen tank and fuel tank. The motor power and liquid nitrogen pump flow are controlled by the fuel tank pressure, thereby 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 heater of a certain engine, resulting in excessively low pressures in the oxygen tank, the fuel tank, and the 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 the core stage, only one relief valve is used for the three tanks to meet the overpressure protection and propellant filling of the three tanks, thereby reducing the number of valves, and reducing the number and cost of valves.

[0085] In the description of the embodiments of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the orientations 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 orientation, be constructed and operated in a specific orientation, 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.

[0086] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed, connected, connected" 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.

[0087] 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, characterized in that: The system comprises: an oxygen box (1), a fuel tank (2) and a liquid nitrogen box (4), wherein the liquid nitrogen box (4) is arranged inside the oxygen box (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 sequentially 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).

2. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 1, characterized in that: The liquid nitrogen heating and vaporizing unit comprises a liquid nitrogen pump (6) with a motor (7) and 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 pipes (9).

3. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 2, 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).

4. 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).

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

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

7. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 1 or 2, characterized in that: The fuel tank (2) is provided with a fuel tank pressure sensor (16) for measuring the air pressure of the fuel tank (2); the fuel tank pressure sensor (16) is electrically connected to a fuel tank boost controller (17); and 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) received.

8. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 1 or 2, characterized in that: It also comprises a ground helium pressurizing unit, which is connected to at least 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.

9. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 8, characterized in that: The first branch comprises a pre-fire boost main pipeline (37), a fifth three-way valve (38), a fuel tank pre-fire boost solenoid valve (39), a third one-way valve (40), a fuel tank pre-fire boost branch pipeline (41), a sixth three-way valve (13), a fuel tank boost branch pipe (14) and the fuel tank energy dissipator (15) which are connected in sequence; And / or, the second branch comprises a pre-shooting pressurization main pipeline (37), a fifth three-way valve (38), a seventh three-way valve (42), a liquid nitrogen tank pre-shooting pressurization solenoid valve (43), a fourth one-way valve (44), a liquid nitrogen tank pre-shooting pressurization branch pipeline (45), a third three-way valve (28) and the liquid nitrogen tank pressurization 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).

10. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 1 or 2, characterized in that: The liquid nitrogen heating, vaporizing and pressurizing system also includes: 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).

11. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 1 or 2, characterized in that: The liquid nitrogen heating, vaporizing and pressurizing system further comprises a liquid nitrogen filling unit, wherein the liquid nitrogen filling unit is connected to a first three-way valve (55), and the first three-way valve (55) is arranged on a liquid nitrogen delivery pipeline (5) between the liquid nitrogen tank (4) and the liquid nitrogen pump (6).

12. A liquid nitrogen heating, vaporizing and pressurizing system according to claim 1 or 2, 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).

13. 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 1-12.

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