A supercooled liquid filling system for a large rocket

Abstract

The embodiment of the application provides a supercooled liquid filling system of a large rocket, and relates to the field of large rockets.The supercooled liquid filling system comprises a supercooled liquid supply source (1), a ground supercooled liquid tank (44) and a rocket supercooled liquid tank (65), the ground supercooled liquid tank (44) is connected to the supercooled liquid supply source (1) through a first supercooled liquid filling main pipeline (400), the rocket supercooled liquid tank (65) is connected to the ground supercooled liquid tank (44) through a rocket supercooled liquid filling pipeline (500), and the supercooled liquid filling system further comprises a supercooled liquid vacuumizing and supercooling pipeline (100) connected to the ground supercooled liquid tank (44), wherein the supercooled liquid vacuumizing and supercooling pipeline (100) comprises a supercooled gas vacuum pump (48) and a supercooled gas treatment device (49) downstream of the supercooled gas vacuum pump (48). The pressure of the supercooled liquid is reduced through vacuumizing, so that the supercooled liquid reaches a boiling point temperature below the pressure, and one-time filling is completed, and additional filling is not needed.

Description

Technical Field

[0001] This invention relates to the field of spacecraft, and more specifically to a supercooled liquid filling system for a large rocket. Background Technology

[0002] Compared to ambient temperature propellants, cryogenic propellants have been widely used in next-generation launch vehicles due to their advantages such as high specific impulse and non-toxicity. Among them, liquid oxygen / liquid methane combinations have attracted significant attention in the commercial aerospace sector due to their substantial cost advantages. However, cryogenic propellants have very low boiling points and are highly susceptible to evaporation when near saturation, posing numerous challenges to engine operation and propulsion system thermal management. Using supercooled cryogenic propellants can not only effectively improve the evaporation problem but also reduce system mass, improve engine performance, and extend on-orbit storage time. Therefore, cryogenic propellant supercooling technology has significant application value.

[0003] Currently, apart from the Buran space shuttle and the US Falcon rocket which use fully supercooled propellant loading technology, most cryogenic rockets at home and abroad only use partial supercooled loading technology. For example, my country's CZ-5, the US Saturn V, Russia's Angara and Europe's Ariane rockets all use liquid oxygen supercooling to improve the precooling effect of the rocket engine before launch.

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

[0005] Currently, high-flow-rate supercooled liquid refueling is still in the research and development stage and has not been used in actual rocket refueling systems, either domestically or internationally. This is because liquid methane has only recently been adopted as a new type of rocket fuel due to its high specific impulse, non-toxicity, and pollution-free characteristics. Furthermore, high-flow-rate supercooled liquid refueling is currently a large-scale project with high research and development difficulty and production costs. Although supercooled cryogenic propellants have many performance advantages, achieving supercooling of propellants in practical engineering is not feasible. Summary of the Invention

[0006] This invention provides a supercooled liquid filling system for large rockets, which can solve the technical problem that existing technologies cannot achieve propellant supercooling at low temperatures.

[0007] To achieve the above objectives, in a first aspect, embodiments of the present invention provide a method for injecting supercoolant into a large rocket, comprising:

[0008] After adding subcooling liquid to the ground subcooling liquid storage tank to reach the specified liquid level, the subcooling liquid vacuum subcooling line is turned on, and the subcooling gas vacuum pump installed on the subcooling liquid vacuum subcooling line is started to extract the subcooling gas evaporated in the ground subcooling liquid storage tank.

[0009] When the temperature of the subcooled liquid in the ground subcooled liquid storage tank drops to the first preset temperature, the extraction of the subcooled gas evaporated in the ground subcooled liquid storage tank is stopped, and the vacuum subcooling of the subcooled liquid in the ground subcooled liquid storage tank is completed.

[0010] Shut down the subcooling liquid vacuum subcooling circuit and the subcooling gas vacuum pump.

[0011] Secondly, embodiments of the present invention provide a supercooling fluid refueling system for a large rocket, comprising:

[0012] The system includes a subcooling fluid supply source, a ground subcooling fluid storage tank, and an onboard subcooling fluid tank. The ground subcooling fluid storage tank is connected to the subcooling fluid supply source via a first subcooling fluid filling main pipeline, and the onboard subcooling fluid tank is connected to the ground subcooling fluid storage tank via an onboard subcooling fluid filling pipeline.

[0013] The supercooling system for large rockets also includes: a supercooling vacuum subcooling line connected to a ground-based supercooling tank, which includes a supercooling gas vacuum pump and a supercooling gas treatment device downstream of the supercooling gas vacuum pump.

[0014] Thirdly, embodiments of the present invention provide a computer-readable storage medium storing one or more programs, which, when executed by a computer device, cause the computer device to perform the aforementioned method for adding supercooled liquid to a large rocket.

[0015] Fourthly, embodiments of the present invention provide a computer device, comprising:

[0016] A processor; and a memory arranged to store computer-executable instructions, which, when executed, cause the processor to perform the aforementioned method for adding supercoolant to a large rocket.

[0017] The above technical solution has the following beneficial effects: Vacuuming reduces the pressure of the subcooled liquid, thereby lowering its boiling point (i.e., boiling temperature). The boiling point is reduced from 112K to a first preset temperature. During the vacuuming process, subcooled liquids with a boiling point above 95K (e.g., 112K) will boil under low pressure. Boiling intensifies the evaporation of the subcooled liquid, which carries away a large amount of heat. Only when the subcooled liquid temperature drops below the first preset temperature will it stop boiling. In other words, by lowering the boiling point of the subcooled liquid through vacuuming, the boiling intensifies the evaporation and vaporization, carrying away a large amount of heat until the subcooled liquid reaches below its boiling point at that pressure. Furthermore, the filling is completed in one go, eliminating the need for further replenishment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1A This is a two-dimensional diagram of a supercooled liquid refueling system for a large rocket according to an embodiment of the present invention;

[0020] Figure 1B This is the upper left portion of a two-dimensional diagram of a supercooled liquid refueling system for a large rocket according to an embodiment of the present invention;

[0021] Figure 1C This is the upper right part of a two-dimensional diagram of a supercooled liquid refueling system for a large rocket according to an embodiment of the present invention;

[0022] Figure 1D This is the lower left portion of a two-dimensional diagram of a supercooled liquid refueling system for a large rocket according to an embodiment of the present invention;

[0023] Figure 1E This is the lower right part of a two-dimensional diagram of a supercooled liquid refueling system for a large rocket according to an embodiment of the present invention;

[0024] Figure 2 This is the control logic of the supercooled gas vacuum pump motor in an embodiment of the present invention;

[0025] Figure 3 This is a diagram showing the pressure control bands and other pressure distributions of the second pressure boosting solenoid valve 72 and the third pressure boosting solenoid valve 73 in an embodiment of the present invention.

[0026] Figure 4 This is the control logic for the first booster solenoid valve 71, the second booster solenoid valve 72, and the third booster solenoid valve 73 in this embodiment of the invention.

[0027] Figure 5 This is a schematic flowchart of a method for injecting supercoolant into a large rocket according to an embodiment of the present invention.

[0028] Figure 6 This is a three-dimensional structural (1 / 4 section) schematic diagram of the ground subcooled liquid storage tank 44 according to an embodiment of the present invention;

[0029] Figure 7 This is a three-dimensional (1 / 4 section) schematic diagram of the aluminum-lithium alloy tank shell 443 according to an embodiment of the present invention;

[0030] Figure 8 This is a three-dimensional structural schematic diagram of the negative pressure support plate 444 according to an embodiment of the present invention;

[0031] Figure 9 This is a two-dimensional view of the ground subcooling liquid storage tank 44 according to an embodiment of the present invention;

[0032] Figure 10 This is a two-dimensional view of the aluminum-lithium alloy storage tank shell 443 according to an embodiment of the present invention.

[0033] The reference numerals in the attached figures are as follows:

[0034] 100. Subcoolant vacuum subcooling line; 200. Ground subcoolant filling line; 300. Purge gas delivery line; 400. First subcoolant filling main line; 500. Onboard subcoolant filling line; 600. Nitrogen pressurization line; 700. Gas seal line; 61. Subcoolant drain line; 1. Subcoolant supply source; 2. Ground nitrogen source; 3. First gas filter; 4. First gas tee; 5. First pressure reducer; 6. Second gas filter; 71. First pressurization solenoid valve; 81. First orifice plate; 72. Second pressurization solenoid valve; 82. Second orifice plate; 73. Third pressurization solenoid valve; 83. Third orifice plate; 91. First nitrogen sub-line; 92. Second nitrogen sub-line; 93. Third nitrogen sub-line; 9. 10. Second gas tee; 11. First gas manual switch; 12. Third gas tee; 13. Second gas manual switch; 14. Fourth gas tee; 15. Fifth gas tee; 16. Sixth gas tee; 17. Seventh gas tee; 18. Eighth gas tee; 19. First filling line purging port; 22. Second filling line purging port; 26. Third filling line purging port; 29. ​​Fourth filling line purging port; 33. Fifth filling line purging port; 36. Sixth filling line purging port; 20. First ground subcoolant filling ball valve; 23. Second ground subcoolant filling ball valve; 27. Third ground subcoolant filling ball valve; 30. Fourth ground subcoolant filling ball valve; 34. Fifth ground subcoolant filling ball valve. Valves; 37. Sixth subcooled liquid filling ball valve; 21. First subcooled liquid filter; 24. Second subcooled liquid filter; 28. Third subcooled liquid filter; 31. Fourth subcooled liquid filter; 35. Fifth subcooled liquid filter; 38. Sixth subcooled liquid filter; 25. First subcooled liquid tee; 32. Second subcooled liquid tee; 39. Third subcooled liquid tee; 40. Subcooled liquid four-way valve; 41. Seventh subcooled liquid filling ball valve; 43. Eighth subcooled liquid filling ball valve; 55. Ninth subcooled liquid filling ball valve; 62. Tenth subcooled liquid filling ball valve; 42. Fourth subcooled liquid tee; 44. Subcooled liquid tank; 45. Subcooled liquid tank level sensor; 46. Third gas manual switch; 47. Subcooled gas vacuum valve 48. Air pump motor; 49. Subcooled gas vacuum pump; 50. Subcooled gas treatment device; 51. Ground subcooled liquid storage tank safety valve; 52. First liquid level temperature sensor; 53. Second liquid level temperature sensor; 54. Third liquid level temperature sensor; 55. Fourth liquid level temperature sensor; 56. Subcooled liquid pump; 57. Subcooled liquid pump motor; 58. Subcooled liquid flow sensor; 59. Fifth subcooled liquid tee; 60. Subcooled liquid drain valve; 63. Subcooled liquid filling connector; 64. On-rocket subcooled liquid tank filling valve; 65. On-rocket subcooled liquid tank; 66. On-rocket subcooled liquid tank level sensor; 67. On-rocket subcooled liquid tank exhaust valve; 68. On-rocket subcooled liquid tank safety valve; 69. Ground subcooled liquid filling controller; 70. Subcooled liquid pump inlet pressure sensor;441. Thermal insulation coating; 442. Polyurethane insulation layer; 443. Aluminum-lithium alloy tank shell; 444. Negative pressure support plate; 445. Ground subcooled liquid tank pressurization port; 4432. Subcooled liquid delivery pipe connecting flange; 4433. Subcooled liquid tank safety valve connecting flange; 4434. Subcooled liquid tank pressurization connecting flange; 4435. Subcooled liquid tank vacuum connecting flange. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 5 As shown, in conjunction with embodiments of the present invention, a method for injecting supercoolant into a large rocket is provided, comprising:

[0037] S101: After adding subcooling liquid to the ground subcooling liquid storage tank 44 to the specified liquid level, turn on the subcooling liquid vacuum subcooling line 100 and start the subcooling gas vacuum pump 48 installed on the subcooling liquid vacuum subcooling line 100 to extract the subcooling gas evaporated in the ground subcooling liquid storage tank 44.

[0038] S102: When the temperature of the subcooled liquid in the ground subcooled liquid storage tank 44 drops to the first preset temperature, the extraction of subcooled gas from the ground subcooled liquid storage tank 44 is stopped, completing the vacuum subcooling of the subcooled liquid in the ground subcooled liquid storage tank 44; wherein, during the extraction of subcooled gas from the ground subcooled liquid storage tank 44, the subcooled liquid evaporates, accompanied by a decrease in the pressure and temperature of the subcooled liquid, until the boiling point of the subcooled liquid drops to the first preset temperature. The subcooled liquid is subcooled methane.

[0039] S103: Turn off the subcooled liquid vacuum subcooling line 100 and the subcooled gas vacuum pump 48.

[0040] The purpose of vacuuming is to reduce the pressure of the subcooled fluid, thereby lowering its boiling point (boiling temperature). The boiling point is lowered from 112K to a first preset temperature, such as 95K. During vacuuming, subcooled fluid with a boiling point above 95K (e.g., 112K) will boil under low pressure. This boiling intensifies the evaporation of the subcooled fluid, carrying away a significant amount of heat. Only when the subcooled fluid temperature drops below the first preset temperature of 95K will it cease boiling. In summary, by lowering the boiling point of the subcooled fluid through vacuuming, the boiling intensifies, causing the subcooled fluid to evaporate and carry away a large amount of heat until the subcooled fluid reaches a pressure below its boiling point. Furthermore, the entire process is completed in one go, eliminating the need for further replenishment.

[0041] Specifically, in S102, the process of evacuating the subcooled gas from the ground subcooled liquid storage tank 44 to achieve vacuum subcooling of the ground subcooled liquid storage tank 44 is as follows:

[0042] After the ground subcooling fluid tank 44 is filled, the ground subcooling fluid tank 44 is evacuated to subcool the subcooling fluid.

[0043] Before the ground subcoolant tank 44 is evacuated for subcooling, the following ball valves on each branch of the subcoolant supply source 1 are closed: the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37. The seventh ground subcoolant filling ball valve 41 on the first ground subcoolant filling main line 400 is closed, and the eighth ground subcoolant filling ball valve 43 on the ground subcoolant filling line 200 is closed. The ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62 are also closed.

[0044] Open the third gas manual switch 46 on the subcooling liquid vacuum subcooling line 100 to start the subcooling gas vacuum pump motor 47 and subcooling gas vacuum pump 48 to evacuate the ground subcooling liquid storage tank 44. The subcooling gas vacuum pump motor 47 provides power to the subcooling gas vacuum pump 48, which extracts the gas (evaporated subcooled gas) from the ground subcooling liquid storage tank 44. Continuously evacuate the ground subcooling liquid storage tank 44 to reduce the saturated vapor pressure of the subcooling liquid, thereby reducing the temperature of the subcooling liquid, until the boiling point of the subcooling liquid is reduced to the first preset temperature, for example, which may take about 23 hours. After the subcooling of the ground subcooling liquid storage tank 44 is completed, close all ground valves.

[0045] Preferably, the method for adding supercoolant to a large rocket further includes:

[0046] S104: Simultaneously with starting the subcooled gas vacuum pump 48 installed on the subcooled liquid vacuum subcooling line 100, start the subcooled gas processing device 49 installed on the subcooled liquid vacuum subcooling line 100; wherein, the subcooled gas processing device 49 is located downstream of the gas flow path of the subcooled liquid vacuum subcooling line 100, and the subcooled gas vacuum pump 48 is located upstream of the gas flow path of the subcooled liquid vacuum subcooling line 100.

[0047] S105: The evaporated subcooled liquid is treated by the subcooled gas treatment device 49 to prevent the direct discharge of subcooled gas into the atmosphere, which could cause environmental pollution or safety accidents. The subcooled liquid is treated to generate exhaust gas that meets the requirements for emission into the atmosphere, and then the treated exhaust gas is directly discharged into the atmosphere.

[0048] S106: When the vacuum subcooling of the subcooling liquid in the ground subcooling liquid storage tank 44 is completed, shut down the subcooling gas treatment device 49.

[0049] Preferably, the method for adding supercoolant to a large rocket further includes S107: precooling the first supercoolant filling main pipeline 400 and the ground supercoolant filling pipeline 200 before adding supercoolant to the ground supercoolant storage tank 44; S107, the step of precooling the first supercoolant filling main pipeline 400 and the ground supercoolant filling pipeline 200 includes:

[0050] S1071: Open the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200, and open the subcoolant vacuum subcooling line 100.

[0051] S1072: Turn on the subcooling supply source 1, output the subcooling in the subcooling supply source 1 at the first flow rate, and then transport the subcooling to the ground subcooling storage tank 44 through the first subcooling filling main pipeline 400 and the ground subcooling filling pipeline 200 in sequence, and discharge the gas through the subcooling vacuum subcooling line 100; the first flow rate is set according to the requirements.

[0052] S1073: When the temperature of the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200 reaches the second preset temperature, stop supplying subcoolant from the subcoolant supply source 1 to the first subcoolant filling main pipeline 400, and complete the precooling of the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200.

[0053] S1074: Close the first subcoolant filling main line 400 and the ground subcoolant filling line 200, close the subcoolant vacuum subcooling line 100, and close the subcoolant supply source 1.

[0054] The temperature of the subcoolant is usually 112K-161℃. At this temperature, the subcoolant filling pipeline is at room temperature. The purpose of pre-cooling is to reduce the temperature of the solid in the subcoolant filling pipeline to about 112K. This prevents the subcoolant from transferring heat to the subcoolant during filling, causing the temperature of the subcoolant in the pipeline to rise, or prevents the subcoolant from boiling due to excessive temperature in the pipeline.

[0055] Specifically, the precooling process for the ground subcoolant pipeline (including the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200) is as follows:

[0056] After the ground subcoolant filling system has undergone nitrogen purging for a first preset time of 1 hour, the ground subcoolant pipeline precooling process is carried out until the temperature of the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200 reaches the second preset temperature. At this time, the subcoolant no longer evaporates, and the precooling is stopped. The precooling of the ground subcoolant pipeline takes about 1 hour.

[0057] Subcoolant supply source 1 consists of 3 subcoolant tank trucks. First, open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of subcoolant supply source 1. Then, open the seventh ground subcoolant filling ball valve 41 located on the first subcoolant filling main pipeline 400, and open the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling pipeline 200. The ground subcoolant filling pipeline 200 is connected to the subcoolant delivery pipe flange 4432 (e.g., ...). Figure 10 and Figure 7 (As shown) is connected to the ground subcooled liquid storage tank 44;

[0058] Close the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62; finally, close the first gas manual switch 11 and the second gas manual switch 13.

[0059] Turn on the third gas manual switch 46 located on the subcooling liquid vacuum subcooling line 100 to precool the ground subcooling liquid pipeline.

[0060] During the pre-cooling process of the ground subcoolant pipeline, the subcoolant in the first subcoolant tanker is transported through the first branch, passing sequentially through the first filling pipeline purging port 19, the first ground subcoolant filling ball valve 20, and the first subcoolant filter 21; the subcoolant in the first subcoolant tanker is transported through the second branch, passing sequentially through the second filling pipeline purging port 22, the second ground subcoolant filling ball valve 23, and the second subcoolant filter 24; the first branch and the second branch of the first subcoolant tanker merge at the first subcoolant tee 25.

[0061] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0062] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the third subcoolant tanker converge at the third subcoolant tee 39.

[0063] After the first subcooling liquid tee 25 merges, the second subcooling liquid tee 32 merges, and the third subcooling liquid tee 39 merges, the liquid flows through a pipeline to the subcooling liquid four-way 40 and enters the first subcooling liquid filling main pipeline 400. It then passes sequentially through the seventh ground subcooling liquid filling ball valve 41 on the first subcooling liquid filling main pipeline 400, and then through the fourth subcooling liquid tee 42 into the ground subcooling liquid filling pipeline 200. After passing through the eighth ground subcooling liquid filling ball valve 43 on the ground subcooling liquid filling pipeline 200, it enters the ground subcooling liquid storage tank 44 and is discharged through the subcooling liquid vacuum subcooling line 100. On the subcooling liquid vacuum subcooling line 100, it sequentially passes through the third gas manual switch 46, the subcooling gas vacuum pump 48, the subcooling gas treatment device 49, and the third gas tee 12 before being directly discharged into the atmosphere. The ground subcooling liquid pipeline precooling takes approximately 1 hour. The precooling process ends after 1 hour. All ground valves are closed.

[0064] Preferably, the method for adding supercoolant to a large rocket also includes S108: before precooling the first supercoolant filling main pipeline 400 and the ground supercoolant filling pipeline 200, purging the first supercoolant filling main pipeline 400 and the ground supercoolant filling pipeline 200; wherein, the step of purging the first supercoolant filling main pipeline 400 and the ground supercoolant filling pipeline 200 includes:

[0065] S1081: Open the purging gas delivery pipeline 300, open the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200, and open the subcoolant vacuum subcooling line 100; wherein, the purging gas delivery pipeline 300 is connected to the first subcoolant filling main pipeline 400 at one end near the subcoolant supply source 1.

[0066] S1082: Turn on the ground nitrogen source 2, blow the nitrogen in the ground nitrogen source 2 into the first subcooling liquid filling main pipeline 400 and the ground subcooling liquid filling pipeline 200 through the purging gas delivery pipeline 300, blow the foreign objects in the first subcooling liquid filling main pipeline 400 and the ground subcooling liquid filling pipeline 200 into the ground subcooling liquid storage tank 44, and discharge them through the subcooling liquid vacuum subcooling line 100;

[0067] S1083: After the first preset time is reached, the purging of the ground subcoolant injection pipeline 200 is completed;

[0068] S1084: Close the purging gas delivery line 300, close the first subcoolant filling main line 400 and the ground subcoolant filling line 200, close the subcoolant vacuum subcooling line 100, and close the ground nitrogen source 2.

[0069] Air (including water vapor) should be purged from the pipeline to prevent the low-temperature subcoolant (112K, -161℃) from freezing and forming excess material upon contact with water vapor. Therefore, water vapor should be purged before adding subcoolant to ensure that the pipeline is filled with nitrogen. Nitrogen is used to replace water vapor, preventing water vapor from forming excess material at low temperatures that could cause valve jamming and affect valve performance, resulting in uneven subcoolant delivery.

[0070] Specifically, the purging process is as follows:

[0071] Before adding subcoolant to the ground subcoolant storage tank 44, the ground subcoolant filling system needs to be purged with nitrogen for a first preset time, such as 1 hour.

[0072] The ground subcoolant filling system includes a first subcoolant filling main pipeline 400 and a ground subcoolant filling pipeline 200. The first subcoolant filling main pipeline 400 is connected to the subcoolant supply source 1. It is assumed that the subcoolant supply source 1 consists of 3 subcoolant tank trucks, each with two branches connected to the first subcoolant filling main pipeline 400.

[0073] First, open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1. Then, open the seventh ground subcoolant filling ball valve 41 located on the first subcoolant filling main line 400, open the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling line 200, open the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62 located on the rocket subcoolant filling line 500, and open the subcoolant drain valve 60 of the rocket subcoolant tank 65 located on the subcoolant venting line.

[0074] Close the subcoolant filling valve 64 located on the rocket subcoolant filling line 500, which is adjacent to the rocket subcoolant tank.

[0075] Finally, open the first gas manual switch 11 located on the gas seal pipeline 700, the second gas manual switch 13 located on the purging gas delivery pipeline, and the third gas manual switch 46 located on the subcooling liquid vacuum subcooling line 100 to purge nitrogen from the ground subcooling liquid filling system.

[0076] During the purging process of the ground supercoolant filling system, in the direction of the supercoolant tank on the rocket at 65 degrees, the nitrogen in the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the second pressure reducer 9, the second gas tee 10, and the second gas manual switch 13 respectively; and enters the fourth gas tee 14, the sixth gas tee 16, and the eighth gas tee 18 respectively.

[0077] After entering through the fourth gas tee 14, it splits into two paths through the fifth gas tee 15, entering the two branch paths of the first subcooled liquid tanker. In the first branch path of the first subcooled liquid tanker, it passes sequentially through the first filling pipeline purging port 19, the first ground subcooled liquid filling ball valve 20, and the first subcooled liquid filter 21. In the second branch path of the first subcooled liquid tanker, it passes sequentially through the second filling pipeline purging port 22, the second ground subcooled liquid filling ball valve 23, and the second subcooled liquid filter 24. The first and second branch paths of the first subcooled liquid tanker converge at the first subcooled liquid tee 25.

[0078] After entering through the sixth gas tee 16, it splits into two paths through the seventh gas tee 17, entering the two branch paths of the second subcooled liquid tanker. In the first branch path of the second subcooled liquid tanker, it passes sequentially through the third filling pipeline purging port 26, the third ground subcooled liquid filling ball valve 27, and the third subcooled liquid filter 28. In the second branch path of the second subcooled liquid tanker, it passes sequentially through the fourth filling pipeline purging port 29, the fourth ground subcooled liquid filling ball valve 30, and the fourth subcooled liquid filter 31. The first and second branches of the second subcooled liquid tanker converge at the second subcooled liquid tee 32.

[0079] After entering from the eighth gas tee 18, it splits into two paths leading to the two branch paths of the third subcooled liquid tanker. In the first branch path of the third subcooled liquid tanker, it passes sequentially through the fifth filling pipeline purging port 33, the fifth ground subcooled liquid filling ball valve 34, and the fifth subcooled liquid filter 35. In the second branch path of the third subcooled liquid tanker, it passes sequentially through the sixth filling pipeline purging port 36, the sixth ground subcooled liquid filling ball valve 37, and the sixth subcooled liquid filter 38. The first and second branches of the third subcooled liquid tanker converge at the third subcooled liquid tee 39.

[0080] After the subcooling liquid tee 25 merges, then merges at the second subcooling liquid tee 32 and the third subcooling liquid tee 39, it enters the first subcooling liquid filling main pipeline 400 through the subcooling liquid four-way 40; it then passes through the seventh ground subcooling liquid filling ball valve 41 located on the first subcooling liquid filling main pipeline 400, and enters the arrow-mounted subcooling liquid filling pipeline 500 through the fourth subcooling liquid tee 42; the fourth subcooling liquid tee 42 is also connected to the ground subcooling liquid filling pipeline 200.

[0081] After entering the onboard supercoolant filling line 500, the fluid sequentially passes through the ninth ground supercoolant filling ball valve 55, supercoolant pump 56, and supercoolant flow sensor 58, all located on the onboard supercoolant filling line 500. It then flows through the fifth supercoolant tee 59 into the supercoolant drain line 61, and after passing through the supercoolant drain valve 60, is directly discharged into the atmosphere. The purging process is completed in 1 hour. All ground valves are then closed.

[0082] In addition, during the purging process of the ground subcooling fluid filling system, the nitrogen in the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the second pressure reducer 9, the second gas tee 10, and the second gas manual switch 13 respectively, and enters the fourth gas tee 14, the sixth gas tee 16, and the eighth gas tee 18 respectively, in the direction of the ground subcooling fluid storage tank 44.

[0083] After entering through the fourth gas tee 14, it splits into two paths through the fifth gas tee 15, entering the two branch paths of the first subcooled liquid tanker. In the first branch path of the first subcooled liquid tanker, it passes sequentially through the first filling pipeline purging port 19, the first ground subcooled liquid filling ball valve 20, and the first subcooled liquid filter 21. In the second branch path of the first subcooled liquid tanker, it passes sequentially through the second filling pipeline purging port 22, the second ground subcooled liquid filling ball valve 23, and the second subcooled liquid filter 24. The first and second branch paths of the first subcooled liquid tanker converge at the first subcooled liquid tee 25.

[0084] After entering through the sixth gas tee 16, it splits into two paths through the seventh gas tee 17, entering the two branch paths of the second subcooled liquid tanker. In the first branch path of the second subcooled liquid tanker, it passes sequentially through the third filling pipeline purging port 26, the third ground subcooled liquid filling ball valve 27, and the third subcooled liquid filter 28. In the second branch path of the second subcooled liquid tanker, it passes sequentially through the fourth filling pipeline purging port 29, the fourth ground subcooled liquid filling ball valve 30, and the fourth subcooled liquid filter 31. The first and second branches of the second subcooled liquid tanker converge at the second subcooled liquid tee 32.

[0085] After entering from the eighth gas tee 18, it splits into two paths leading to the two branch paths of the third subcooled liquid tanker. In the first branch path of the third subcooled liquid tanker, it passes sequentially through the fifth filling pipeline purging port 33, the fifth ground subcooled liquid filling ball valve 34, and the fifth subcooled liquid filter 35. In the second branch path of the third subcooled liquid tanker, it passes sequentially through the sixth filling pipeline purging port 36, the sixth ground subcooled liquid filling ball valve 37, and the sixth subcooled liquid filter 38. The first and second branch paths of the third subcooled liquid tanker converge at the third subcooled liquid tee 39.

[0086] After the first subcooling liquid tee 25, the second subcooling liquid tee 32, and the third subcooling liquid tee 39 converge, they merge through pipelines at the subcooling liquid four-way 40 and enter the first subcooling liquid filling main pipeline 400. They then pass sequentially through the seventh ground subcooling liquid filling ball valve 41 on the first subcooling liquid filling main pipeline 400, through the fourth subcooling liquid tee 42, and into the ground subcooling liquid filling pipeline 200. After entering the ground subcooling liquid filling pipeline 200, they pass through the eighth ground subcooling liquid filling ball valve 43 on the ground subcooling liquid filling pipeline 200 and into the ground subcooling liquid storage tank 44. Finally, they are discharged through the subcooling liquid vacuum subcooling line 100, passing sequentially through the third gas manual switch 46, the subcooling gas vacuum pump 48, the subcooling gas treatment device 49, and the third gas tee 12, before being directly discharged into the atmosphere. The first preset purging time ends. All ground valves are closed.

[0087] Among them, the first gas filter 3, the first gas tee 4, the second pressure reducer 9, the second gas tee 10, the second gas manual switch 13, the fourth gas tee 14, the fifth gas tee 15, the sixth gas tee 16, the seventh gas tee 17, the eighth gas tee 18, the first subcoolant tee 25, the second subcoolant tee 32, the third subcoolant tee 39, the fourth subcoolant tee 42, and the third gas tee 12 are all of the same specification and model. The first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, the sixth ground subcoolant filling ball valve 37, the seventh ground subcoolant filling ball valve 41, and the eighth ground subcoolant filling ball valve 43 are all of the same specification and model. All manual switches are of the same model.

[0088] Preferably, the method for adding supercoolant to the large rocket further includes:

[0089] S109: After completing the vacuum subcooling of the subcooling liquid in the ground subcooling liquid storage tank 44, the subcooling liquid in the ground subcooling liquid storage tank 44 is added to the rocket subcooling liquid tank 65.

[0090] S109: The step of filling the supercoolant in the ground supercoolant tank 44 into the rocket supercoolant tank 65 includes:

[0091] S1091: The subcoolant in the subcoolant supply source 1 is injected into the on-rocket subcoolant tank 65 using the second flow rate;

[0092] S1092: Then, the subcoolant in the ground subcoolant tank 44 is added to the rocket subcoolant tank 65 at a third flow rate; wherein, the third flow rate is greater than the second flow rate;

[0093] Preferably, S1081: The subcoolant in the subcoolant supply source 1 is added to the onboard subcoolant tank 65 using a second flow rate, specifically including:

[0094] S1091-1: Open the first subcoolant filling main line 400 and the arrow-mounted subcoolant filling line 500 connected to the first subcoolant filling main line 400, and open the arrow-mounted subcoolant tank exhaust valve 67.

[0095] S1091-2: Turn on the subcoolant supply source 1, output the subcoolant in the subcoolant supply source 1 at the second flow rate, and transport the subcoolant at the second flow rate sequentially through the first subcoolant filling main pipeline 400 and the rocket subcoolant filling pipeline 500 to the rocket subcoolant tank 65.

[0096] S1091-3: After the second preset time is reached, close the first subcoolant filling main pipeline 400 and the rocket subcoolant filling pipeline 500, close the rocket subcoolant tank exhaust valve 67, and close the subcoolant supply source 1 to complete the small-flow filling of the rocket subcoolant tank 65; the second flow rate is a small flow rate, and the small-flow filling can fully cool down the rocket subcoolant filling pipeline 500 to prevent the temperature of the subcoolant in the rocket subcoolant filling pipeline 500 from rising or boiling during the process of filling the ground subcoolant storage tank 44 into the rocket subcoolant tank 65.

[0097] Specifically, the pre-cooling and filling process for the 65°C subcooled liquid tank on the rocket is as follows:

[0098] Before adding supercoolant to the supercoolant tank 65 on the rocket at a high flow rate (third flow rate), the supercoolant tank 65 on the rocket needs to be pre-cooled and added at a low flow rate. The pre-cooling and adding of the supercoolant tank 65 on the rocket at a low flow rate takes about the second preset time, such as 1 hour.

[0099] During the small-flow pre-cooling filling process of the onboard subcoolant tank 65, first open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1; so that the eighth ground subcoolant filling ball valve 43 is closed; then open the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main line 400; and open the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62 on the onboard subcoolant filling line 500; so that the subcoolant drain valve 60 on the subcoolant drain line 61 is closed. Then open the onboard subcoolant tank filling valve 64 of the onboard subcoolant tank 65.

[0100] The subcoolant in the first subcoolant tanker is transported via the first branch line, passing sequentially through the first filling pipeline purging port 19, the first ground subcoolant filling ball valve 20, and the first subcoolant filter 21. The subcoolant in the first subcoolant tanker is transported via the second branch line, passing sequentially through the second filling pipeline purging port 22, the second ground subcoolant filling ball valve 23, and the second subcoolant filter 24. The first and second branches of the first subcoolant tanker converge at the first subcoolant tee 25.

[0101] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0102] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the third subcoolant tanker converge at the third subcoolant tee 39.

[0103] After the first subcooling liquid tee 25 merges, the second subcooling liquid tee 32 merges, and the third subcooling liquid tee 39 merges, they converge through pipelines at the subcooling liquid four-way 40 and enter the first subcooling liquid filling main pipeline 400. They then pass through the seventh ground subcooling liquid filling ball valve 41 on the first subcooling liquid filling main pipeline 400, and then through the fourth subcooling liquid tee 42 to enter the on-board subcooling liquid filling pipeline 500. They then pass through the ninth ground subcooling liquid filling ball valve 55, the subcooling liquid pump 56, the subcooling liquid flow sensor 58, the fifth subcooling liquid tee 59, the tenth ground subcooling liquid filling ball valve 62, the subcooling liquid filling connector 63, and the on-board subcooling liquid tank filling valve 64 on the on-board subcooling liquid filling pipeline 500 to enter the on-board subcooling liquid tank 65, quickly filling the on-board subcooling liquid tank 65.

[0104] During the small-flow pre-cooling and refueling process of the supercooled liquid tank 65 on the rocket, the supercooled liquid tank refueling valve 64 on the rocket is opened.

[0105] After the pre-cooling and filling of the supercooled liquid tank on the rocket at a low flow rate of 65 is completed, all valves on the ground are closed.

[0106] Preferably, S1092: The subcoolant in the ground subcoolant tank 44 is added to the rocket subcoolant tank 65 using a third flow rate, specifically including:

[0107] S1092-1: Open the ground subcoolant filling pipeline 200 and the arrow-mounted subcoolant filling pipeline 500 connected to the ground subcoolant filling pipeline 200, and open the arrow-mounted subcoolant tank vent valve 67; wherein, one end of the ground subcoolant filling pipeline 200 is connected to the ground subcoolant storage tank 44, and the other end of the ground subcoolant filling pipeline 200 is connected to the arrow-mounted subcoolant filling pipeline 500 and the first subcoolant filling main pipeline 400 respectively;

[0108] S1092-2: Open the ground subcoolant tank 44 and output the subcoolant in the ground subcoolant tank 44 at the third flow rate. The subcoolant at the third flow rate is then transported sequentially through the ground subcoolant filling pipeline 200 and the rocket subcoolant filling pipeline 500 to the rocket subcoolant tank 65. The third flow rate is a large flow rate, the purpose of which is to quickly fill the subcoolant in the ground subcoolant tank 44 into the rocket subcoolant tank 65.

[0109] S1092: The supercoolant level sensor 66 installed in the supercoolant tank 65 measures the level of supercoolant added to the supercoolant tank 65. When the supercoolant level in the supercoolant tank 65 reaches the first designated level, which is set according to the flight requirements of the large rocket, the ground supercoolant filling pipeline 200 and the supercoolant filling pipeline 500 are closed, the supercoolant tank exhaust valve 67 is closed, and the ground supercoolant storage tank 44 is closed, thus completing the large-flow filling of the supercoolant tank 65. The supercoolant added to the supercoolant tank 65 can meet the supercoolant supply requirements of the large rocket during the designated flight phase.

[0110] Specifically, the high-flow-rate subcooling filling process for the 65°C subcooling tank on the rocket is as follows:

[0111] After the pre-cooling and filling of the supercooled liquid tank 65 on the rocket with a small flow rate of supercooled liquid is completed, the supercooled liquid tank 65 on the rocket is filled with a large flow rate of supercooled liquid for about 55 minutes.

[0112] Before filling the onboard subcoolant tank 65 with a large flow of subcoolant, the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1 are closed, and the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main pipeline 400 is closed; the eighth ground subcoolant filling ball valve 43, the ninth ground subcoolant filling ball valve 55, and the tenth ground subcoolant filling ball valve 62 are opened, so that the subcoolant drain valve 60 on the subcoolant drain pipeline 61 is closed, and the onboard subcoolant tank filling valve 64 is opened, so that the first gas manual switch 11, the second gas manual switch 13, and the third gas manual switch 46 are closed.

[0113] During the high-flow-rate subcoolant filling process of the onboard subcoolant tank 65, the subcoolant in the ground subcoolant storage tank 44 passes through the eighth ground subcoolant filling ball valve 43 on the ground subcoolant filling pipeline 200, enters the onboard subcoolant filling pipeline 500 through the fourth subcoolant tee 42, and sequentially passes through the ninth ground subcoolant filling ball valve 55, the subcoolant pump 56, the subcoolant flow sensor 58, the fifth subcoolant tee 59, the tenth ground subcoolant filling ball valve 62, the subcoolant filling connector 63, and the onboard subcoolant tank filling valve 64 on the onboard subcoolant filling pipeline 500 before entering the onboard subcoolant tank 65. The subcoolant pump motor 57 provides power to the subcoolant pump 56, which assists in delivering the subcoolant to the onboard subcoolant tank 65. Furthermore, when the pressure inside the supercooled liquid tank 65 on the rocket becomes too high, the safety valve 68 of the supercooled liquid tank on the rocket will be opened to ensure the safety of the ground supercooled liquid storage tank 44.

[0114] During the process of adding a large flow of subcoolant to the rocket's subcoolant tank 65, the exhaust valve 67 of the rocket's subcoolant tank is opened.

[0115] After the supercooled liquid tank 65 on the rocket has been filled with a large flow of supercooled liquid, close all valves on the ground and close the exhaust valve 67 of the supercooled liquid tank on the rocket.

[0116] Five minutes before ignition of the large rocket (i.e., 5 minutes before launch), the supercoolant filling connector 63 automatically detaches, and then all ground valves are closed. At 0 seconds, the rocket ignites, and the ground supercoolant filling system completes its operation.

[0117] Preferably, the method for adding supercoolant to a large rocket further includes:

[0118] S110: While the third flow rate of subcoolant is sequentially delivered to the onboard subcoolant tank 65 through the ground subcoolant filling pipeline 200 and the onboard subcoolant filling pipeline 500, the ground subcoolant storage tank 44 is pressurized; wherein, pressurizing the ground subcoolant storage tank 44 specifically includes:

[0119] S1101: Turn on the nitrogen pressurization line 600. One end of the nitrogen pressurization line 600 is connected to the ground nitrogen source 2, and the other end of the nitrogen pressurization line 600 is connected to the ground subcooled liquid storage tank 44.

[0120] S1102: Nitrogen from the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the first pressure reducer 5, and the second gas filter 6 of the nitrogen pressurization line 600, as well as the first nitrogen pressure control circuit, the second nitrogen pressure control circuit, and the third nitrogen pressure control circuit connected in parallel. It then enters the ground subcooled liquid storage tank 44 through the ground subcooled liquid storage tank pressurization port 445 above the ground subcooled liquid storage tank 44, thereby pressurizing the ground subcooled liquid storage tank 44 until the pressure on the rocket is increased. The high-flow-rate filling of the supercooled liquid tank 65 is achieved through a first nitrogen pressure control circuit comprising a first booster solenoid valve 71 (main solenoid valve) and a first orifice plate 81 sequentially mounted on a first nitrogen sub-pipeline 91; a second nitrogen pressure control circuit comprising a second booster solenoid valve 72 (auxiliary solenoid valve) and a second orifice plate 82 sequentially mounted on a second nitrogen sub-pipeline 92; and a third nitrogen pressure control circuit comprising a third booster solenoid valve 73 (backup solenoid valve) and a third orifice plate 83 sequentially mounted on a third nitrogen sub-pipeline 93. During the high-flow-rate filling of the supercooled liquid tank 65, the purpose of pressurizing the ground supercooled liquid storage tank 44 with nitrogen is to prevent insufficient inlet pressure of the supercooled liquid pump 56, which could lead to vaporization of the inlet liquid and cavitation of the supercooled liquid pump 56. Therefore, pressurizing the ground supercooled liquid storage tank 44 ensures a higher inlet pressure for the supercooled liquid pump 56.

[0121] like Figure 3 and Figure 4 As shown, in step S1102, the method for selecting at least one of the first nitrogen pressure control circuit, the second nitrogen pressure control circuit, and the third nitrogen pressure control circuit is as follows:

[0122] S1102-1: Determine whether the large-flow subcoolant injection has ended.

[0123] S1102-2: If the process ends, open the first booster solenoid valve 71, close the second booster solenoid valve 72, and close the third booster solenoid valve 73, where P1 represents the opening threshold of the third booster solenoid valve 73; and execute S1102-8.

[0124] S1102-3: If not finished, then for the inlet pressure P0, make a judgment based on P0≥P1;

[0125] S1102-4: If P0 is not greater than P1, then open the first booster solenoid valve 71, open the second booster solenoid valve 72, and close the third booster solenoid valve 73, where P1 represents the opening threshold of the third booster solenoid valve 73.

[0126] S1102-5: If P0≥P1 and P2≥P0>P1, then the first booster solenoid valve 71 is opened, the second booster solenoid valve 72 is opened, and the third booster solenoid valve 73 remains in the previous state; where P2 represents the opening threshold of the second booster solenoid valve 72.

[0127] S1102-6: If P2≥P0>P1 and P3≥P0>P2 is not true, then the first booster solenoid valve 71 is opened, the second booster solenoid valve 72 remains in the previous state, and the third booster solenoid valve 73 is closed; where P3 represents the opening threshold of the second booster solenoid valve 72 and the closing threshold of the third booster solenoid valve 73.

[0128] S1102-7: If P2 ≥ P0 > P1 and P3 ≥ P0 > P2, then open the first booster solenoid valve 71, close the second booster solenoid valve 72, and close the third booster solenoid valve 73.

[0129] S1102-8: Open the third gas manual switch 46 to vent the ground subcooled liquid storage tank 44.

[0130] Preferably, the method for adding supercoolant to the large rocket further includes:

[0131] S120: During the process of extracting the subcooled gas evaporated in the ground subcooled liquid storage tank 44, the subcooled liquid temperature is obtained by the first liquid level temperature sensor 51, the second liquid level temperature sensor 52, the third liquid level temperature sensor 53 and the fourth liquid level temperature sensor 54, which are arranged from bottom to top in the ground subcooled liquid storage tank 44.

[0132] S130: When the maximum value of the acquired subcooled liquid temperature is lower than the first preset temperature, stop pumping the subcooled liquid from the ground subcooled liquid storage tank 44. During the process of pumping the evaporated subcooled gas from the ground subcooled liquid storage tank 44, multiple liquid level temperature sensors are spaced apart to collect the temperature of the subcooled liquid at different heights. If the maximum value of the multiple temperatures is lower than the first preset temperature, it indicates that the temperature of the subcooled liquid has reached the requirement, avoiding the defect of inaccurate temperature acquisition by a single local liquid level temperature sensor. The control logic diagram of the subcooled gas vacuum pump motor is shown below. Figure 2 As shown.

[0133] S1301: The ground subcoolant filling controller 69 takes the maximum value among the subcoolant temperatures T1, T2, T3, and T4 as T0, where T0 = max{T1, T2, T3, T4};

[0134] S1302: Is the subcoolant temperature T0 lower than the first preset temperature?

[0135] S1303: If the temperature is not lower than the first preset temperature, start the subcooled gas vacuum pump motor 47, and use the subcooled gas vacuum pump 48 to evacuate the ground subcooled liquid storage tank 44 to subcool the subcooled liquid.

[0136] S1304: If yes, then determine whether the vacuum cooling process has ended;

[0137] S1305: Is the vacuum cooling process complete?

[0138] S1306: If the vacuuming and subcooling process is completed, the subcooled gas vacuum pump motor 47 will be turned off and the subcooled gas vacuum pump 48 will stop working.

[0139] S1307: If the vacuuming and subcooling process has not ended, shut down the subcooled gas vacuum pump motor 47 and stop the subcooled gas vacuum pump 48; and execute S120.

[0140] Preferably, the method for adding supercoolant to a large rocket further includes:

[0141] S140: Before adding the subcoolant from subcoolant supply source 1 to the on-board subcoolant tank 65 using the second flow rate, the subcoolant from subcoolant supply source 1 is added to the on-board subcoolant tank 65 to pre-cool the on-board subcoolant filling pipeline 500; wherein, the pre-cooling of the on-board subcoolant filling pipeline 500 specifically includes:

[0142] S1401: Open the first subcoolant filling main line 400, open the subcoolant drain line 61, and connect the subcoolant drain line 61 to the subcoolant filling line 500 on the side adjacent to the subcoolant tank 65 on the rocket.

[0143] S1402: Open the supercooled liquid filling line 500 between the supercooled liquid drain line 61 and the first supercooled liquid filling main line 400;

[0144] S1403: Turn on the subcooling liquid supply source 1, output the subcooling liquid in the subcooling liquid supply source 1 at the fourth flow rate, and let the subcooling liquid at the fourth flow rate pass through the first subcooling liquid filling main pipe 400 and the arrow subcooling liquid filling pipe 500 in sequence, and discharge the subcooled gas through the subcooling liquid discharge pipe 61; the fourth flow rate is set according to the specific situation.

[0145] S1404: When no subcooled gas is discharged from the subcooled liquid discharge pipe 61, close the first subcooled liquid filling main pipe 400, close the subcooled liquid discharge pipe 61, close the on-rocket subcooled liquid filling pipe 500 between the subcooled liquid discharge pipe 61 and the first subcooled liquid filling main pipe 400, close and open the subcooled liquid supply source 1, and complete the precooling of the on-rocket subcooled liquid filling pipe 500.

[0146] The temperature of the supercoolant is usually 112K-161℃. At this temperature, the supercoolant filling pipeline on the ground is at room temperature. The purpose of precooling is to reduce the temperature of the solid in the supercoolant filling pipeline 500 on the rocket to about 112K. This is to prevent the supercoolant from transferring heat to the supercoolant during filling, which would cause the temperature of the supercoolant in the supercoolant filling pipeline 500 to rise, or to prevent the supercoolant from boiling due to excessive temperature in the supercoolant filling pipeline 500 on the rocket.

[0147] Specifically, the pre-cooling process of the pipeline before filling the supercooled liquid tank 65 on the rocket is as follows:

[0148] Before adding supercooling fluid to the supercooling fluid tank 65 on the rocket, the supercooling fluid filling pipeline 500 on the rocket needs to be precooled until no supercooling gas is discharged from the supercooling fluid discharge pipeline 61. For example, the precooling process of the supercooling fluid filling pipeline 500 on the rocket takes about 1 hour.

[0149] Before precooling the onboard subcoolant filling pipeline 500, first open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1; so that the eighth ground subcoolant filling ball valve 43 is closed; so that the tenth ground subcoolant filling ball valve 62 on the onboard subcoolant filling pipeline 500 (the tenth ground subcoolant filling ball valve 62 is located in front of the onboard subcoolant tank 65) is closed; open the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main pipeline 400; open the ninth ground subcoolant filling ball valve 55 on the onboard subcoolant filling pipeline 500; and open the subcoolant drain valve 60 on the subcoolant drain pipeline 61.

[0150] During the precooling process of the supercoolant filling pipeline 500 on the rocket, the supercoolant in the first supercoolant tanker is transported through the first branch, passing sequentially through the first filling pipeline purging port 19, the first ground supercoolant filling ball valve 20, and the first supercoolant filter 21; the supercoolant in the first supercoolant tanker is transported through the second branch, passing sequentially through the second filling pipeline purging port 22, the second ground supercoolant filling ball valve 23, and the second supercoolant filter 24; the first main line and the second branch line in the first supercoolant tanker converge at the first supercoolant tee 25.

[0151] The subcoolant in the second subcoolant tanker passes through the first branch line, and then sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker passes through the second branch line, and then sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first main line and the second branch line in the second subcoolant tanker converge at the second subcoolant tee 32.

[0152] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first main road and the second branch in the third subcoolant tanker converge at the third subcoolant tee 39.

[0153] After the first subcooling fluid tee 25 merges, the second subcooling fluid tee 32 merges, and the third subcooling fluid tee 39 merges, the fluids converge through a pipeline at the subcooling fluid four-way valve 40 and enter the first subcooling fluid filling main pipeline 400. The fluids then pass sequentially through the seventh ground subcooling fluid filling ball valve 41 on the first subcooling fluid filling main pipeline 400, and then through the fourth subcooling fluid tee 42 into the onboard subcooling fluid filling pipeline 500. From there, the fluids pass sequentially through the ninth ground subcooling fluid filling ball valve 55, the subcooling fluid pump 56, the subcooling fluid flow sensor 58, and the fifth subcooling fluid tee 59 on the onboard subcooling fluid filling pipeline 500 into the subcooling fluid discharge pipeline 61. Finally, the fluids are discharged directly into the atmosphere through the subcooling fluid discharge valve 60 on the subcooling fluid discharge pipeline 61. Pre-cooling of the onboard subcooling fluid filling pipeline 500 for 1 hour is completed, after which all ground valves are closed.

[0154] Preferably, the method for adding supercoolant to a large rocket further includes S150: adding supercoolant to the ground supercoolant tank 44. The step of adding supercoolant to the ground supercoolant tank 44 includes:

[0155] S1501: Open the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200, and open the subcoolant vacuum subcooling line 100;

[0156] S1502: Turn on the subcooling liquid supply source 1 and output the subcooling liquid in the subcooling liquid supply source 1 at the fifth flow rate. The subcooling liquid at the fifth flow rate enters the ground subcooling liquid storage tank 44 through the first subcooling liquid filling main pipeline 400 and the ground subcooling liquid filling pipeline 200 in sequence. The gas in the ground subcooling liquid storage tank 44 is discharged through the subcooling liquid vacuum subcooling line 100.

[0157] S1503: The supercooled liquid level in the ground supercooled liquid storage tank is monitored by the level sensor 45. When the supercooled liquid level in the ground supercooled liquid storage tank 44 reaches the second specified level, the first supercooled liquid filling main pipeline 400 and the ground supercooled liquid filling pipeline 200 are closed, the supercooled liquid vacuum supercooling line 100 is closed, and the supercooled liquid supply source 1 is shut off, stopping the output of supercooled liquid from the supercooled liquid supply source 1 to the ground supercooled liquid storage tank 44, thus completing the filling of the ground supercooled liquid storage tank 44. The second specified level is set according to the flight requirements of the large rocket. Furthermore, when the pressure in the ground supercooled liquid storage tank 44 is too high, the ground supercooled liquid storage tank safety valve 50, connected to the ground supercooled liquid storage tank 44 via the supercooled liquid storage tank safety valve docking flange 4433, is opened to ensure the safety of the ground supercooled liquid storage tank 44.

[0158] Specifically, the filling procedure for the ground subcoolant storage tank 44 is as follows:

[0159] After the ground subcooling fluid filling system is purged with nitrogen for 1 hour and the ground subcooling fluid pipeline is pre-cooled for about 2 hours, the ground subcooling fluid storage tank 44 is filled with subcooling fluid.

[0160] Before adding subcoolant to the ground subcoolant storage tank 44, first open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1. Then open the seventh ground subcoolant filling ball valve 41 located on the first subcoolant filling main pipeline 400 and the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling pipeline 200.

[0161] Close the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62; finally, close the first gas manual switch 11 and the second gas manual switch 13.

[0162] Turn on the third gas manual switch 46 located on the subcooling liquid vacuum subcooling line 100 to fill the ground subcooling liquid storage tank.

[0163] During the filling process of the ground subcoolant tank 44, the subcoolant in the first subcoolant tanker is transported through the first branch, passing sequentially through the first filling pipeline purging port 19, the first ground subcoolant filling ball valve 20, and the first subcoolant filter 21; the subcoolant in the first subcoolant tanker is transported through the second branch, passing sequentially through the second filling pipeline purging port 22, the second ground subcoolant filling ball valve 23, and the second subcoolant filter 24; the first branch and the second branch of the first subcoolant tanker converge at the first subcoolant tee 25.

[0164] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0165] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the second subcoolant tanker converge at the third subcoolant tee 39.

[0166] After the first subcooling liquid tee 25 merges, the second subcooling liquid tee 32 merges, and the third subcooling liquid tee 39 merges, they converge through the pipeline at the subcooling liquid four-way 40 and enter the first subcooling liquid filling main pipeline 400; they then pass through the seventh ground subcooling liquid filling ball valve 41 located on the first subcooling liquid filling main pipeline 400, and then through the fourth subcooling liquid tee 42 into the ground subcooling liquid filling pipeline 200, and finally through the eighth ground subcooling liquid filling ball valve 43 located on the ground subcooling liquid filling pipeline 200 into the ground subcooling liquid storage tank 44.

[0167] It is discharged through the subcooling liquid vacuum subcooling line 100, and then passes through the third gas manual switch 46, the subcooled gas vacuum pump 48, the subcooled gas treatment device 49, and the third gas tee 12 in sequence before being directly discharged into the atmosphere.

[0168] The filling of the ground subcoolant tank 44 takes about 2 hours. After 2 hours of filling, the process is completed, and all ground valves are closed.

[0169] Preferably, the method for adding supercoolant to a large rocket is characterized by further comprising:

[0170] S160: At the same time as opening the subcooling liquid vacuum subcooling line 100, open the gas seal line 700. One end of the gas seal line 700 is connected to the ground nitrogen source 2, and the other end of the gas seal line 700 is connected to one end of the subcooling liquid vacuum subcooling line 100, and is the end of the subcooling liquid vacuum subcooling line 100 that is far away from the ground subcooling liquid storage tank 44.

[0171] S170: Turn on the ground nitrogen source 2, and transport the nitrogen from the ground nitrogen source 2 to the subcooling liquid vacuum subcooling line 100 through the gas seal pipeline 700. This gas seals the subcooling liquid vacuum subcooling line 100. Specifically, it gas seals the subcooled gas treatment device 49. The gas seal refers to continuously filling the cryogenic device, i.e., the subcooled gas treatment device 49, with gas to form a positive pressure, preventing water vapor in the air from being drawn back into the cryogenic device and freezing into excess material that would affect the operation of the cryogenic device.

[0172] In conjunction with embodiments of the present invention, a computer-readable storage medium is also provided, which stores one or more programs that, when executed by a computer device, cause the computer device to perform the supercoolant filling method for any of the aforementioned large rockets.

[0173] The present invention provides a computer device comprising:

[0174] A processor; and a memory arranged to store computer-executable instructions, which, when executed, cause the processor to perform the supercooling method of any of the aforementioned large rockets.

[0175] like Figure 1B , Figure 1C , Figure 1D , Figure 1E and Figure 1A As shown, in conjunction with an embodiment of the present invention, a supercoolant filling system for a large rocket is provided, comprising:

[0176] Subcoolant supply source 1, ground subcoolant storage tank 44 and on-rocket subcoolant tank 65. Ground subcoolant storage tank 44 is connected to subcoolant supply source 1 through first subcoolant filling main pipeline 400. On-rocket subcoolant tank 65 is connected to ground subcoolant storage tank 44 through on-rocket subcoolant filling pipeline 500.

[0177] The supercooling system for a large rocket also includes a supercooling vacuum subcooling line 100 connected to a ground supercooling tank 44. The supercooling vacuum subcooling line 100 includes a supercooling gas vacuum pump 48 and a supercooling gas treatment device 49 located downstream of the supercooling gas vacuum pump 48.

[0178] Subcooling liquid supply source 1 supplies subcooling liquid to ground subcooling liquid storage tank 44. After the subcooling liquid is added to the ground subcooling liquid storage tank 44 to reach the specified liquid level, the subcooling liquid vacuum subcooling line 100 is turned on and the subcooling gas vacuum pump 48 installed on the subcooling liquid vacuum subcooling line 100 is started. The subcooling gas vacuum pump 48 extracts the subcooling gas evaporated in the ground subcooling liquid storage tank 44.

[0179] During the extraction of subcooled gas evaporated from the ground subcooling liquid storage tank 44, the subcooling liquid evaporates, accompanied by a decrease in pressure and temperature until the boiling point of the subcooling liquid is lowered to a first preset temperature. At this point, extraction of the subcooling liquid from the ground subcooling liquid storage tank 44 is stopped, completing the vacuum subcooling of the subcooling liquid in the tank 44. The evaporated subcooling liquid is then treated by the subcooled gas treatment device 49 to prevent direct discharge of the subcooled gas into the atmosphere, which could cause environmental pollution or safety accidents. The treated subcooling liquid generates exhaust gas suitable for atmospheric discharge, which is then directly released into the atmosphere. The purpose of vacuuming is to reduce the pressure of the subcooled liquid, thereby lowering its boiling point (boiling temperature). The boiling point is lowered from 112K to a first preset temperature, such as 95K. During vacuuming, subcooled liquids with a boiling point above 95K (e.g., 112K) will boil under low pressure. Boiling intensifies the evaporation of the subcooled liquid, carrying away a large amount of heat. Only when the subcooled liquid temperature drops below 95K will it stop boiling. In summary, by lowering the boiling point of the subcooled liquid through vacuuming, the boiling intensifies, causing the subcooled liquid to evaporate and carry away a large amount of heat until the subcooled liquid reaches a boiling point below that pressure.

[0180] Preferably, such as Figure 1B and Figure 1A As shown, the supercooled liquid refueling system of the large rocket also includes a ground nitrogen source 2, and the pipeline of the ground nitrogen source 2 is connected to the first supercooled liquid refueling main pipeline 400.

[0181] Ground-based nitrogen source 2 enters the first subcoolant filling main line 400, ground-based subcoolant filling line 200, and rocket-mounted subcoolant filling line 500 through purging gas delivery line 300. This purging process removes water vapor from the air in the lines, preventing the low-temperature subcoolant (112K, -161℃) from freezing and forming excess material. Therefore, water vapor should be removed before subcoolant filling to ensure the lines are entirely filled with nitrogen. Nitrogen replaces the water vapor, preventing it from forming excess material at low temperatures that could cause valve jamming and affect valve performance, thus hindering the smooth flow of subcoolant.

[0182] Preferably, such as Figure 1B and Figure 1AThe supercoolant refueling system for a large rocket also includes a purging gas delivery pipeline 300. One end of the purging gas delivery pipeline 300 is connected to the first supercoolant refueling main pipeline 400, and the other end is connected to a ground nitrogen source 2. The purging steps for the first supercoolant refueling main pipeline 400 and the ground supercoolant refueling pipeline 200 include: opening the purging gas delivery pipeline 300; opening the first supercoolant refueling main pipeline 400 and the ground supercoolant refueling pipeline 200; opening the supercoolant vacuum supercooling line 100; and opening the ground nitrogen source 2, blowing nitrogen from the ground nitrogen source 2 into the first supercoolant refueling main pipeline 400 and the ground supercoolant refueling pipeline 200 through the purging gas delivery pipeline 300. Foreign objects in the first subcoolant filling main line 400 and the ground subcoolant filling line 200 are blown into the ground subcoolant storage tank 44 and discharged through the subcoolant vacuum subcooling line 100. After the first preset time is reached, the purging of the ground subcoolant filling line 200 is completed. The purging gas delivery line 300 is closed, the first subcoolant filling main line 400 and the ground subcoolant filling line 200 are closed, the subcoolant vacuum subcooling line 100 is closed, and the ground nitrogen source 2 is shut off. The air (including water vapor) in the pipeline is purged to prevent the low-temperature subcoolant (112K, -161℃) from freezing upon contact with water vapor and forming excess material. Therefore, water vapor should be purged before subcoolant filling to ensure that the pipeline is entirely filled with nitrogen. Nitrogen is used to replace the water vapor, preventing water vapor from forming excess material at low temperatures that could cause valve jamming and affect valve performance, resulting in uneven subcoolant delivery.

[0183] Preferably, such as Figure 1B and Figure 1A The supercooling fluid refueling system for a large rocket also includes: a gas-sealing pipe 700, one end of which is connected to a ground nitrogen source 2, and the other end of which is connected to one end of a supercooling fluid vacuum subcooling line 100, located away from the ground supercooling fluid storage tank 44. Simultaneously with opening the supercooling fluid vacuum subcooling line 100, the gas-sealing pipe 700 is opened, and the ground nitrogen source 2 is activated. Nitrogen from the ground nitrogen source 2 is then transported through the gas-sealing pipe 700 to the supercooling fluid vacuum subcooling line 100, thus providing a gas seal for the supercooling fluid vacuum subcooling line 100. Specifically, this gas seal applies to the supercooled gas treatment device 49. The gas seal refers to continuously filling the cryogenic device, i.e., the supercooled gas treatment device 49, with positive pressure to prevent water vapor in the air from being drawn back into the cryogenic device and icing into excess material that could affect the operation of the cryogenic device.

[0184] Preferably, such as Figure 1B and Figure 1AThe supercoolant refueling system of a large rocket also includes a nitrogen pressurization line 600. One end of the nitrogen pressurization line 600 is connected to the ground supercoolant storage tank 44 via a supercoolant tank pressurization flange 4434, and the other end is connected to the ground nitrogen source 2. During the high-flow-rate supercoolant refueling process of the rocket's supercoolant tank 65, the ground supercoolant storage tank 44 needs to be pressurized with nitrogen. This is to prevent insufficient inlet pressure of the supercoolant pump 56, which could lead to vaporization of the inlet liquid and cavitation of the supercoolant pump 56. Therefore, pressurizing the ground supercoolant storage tank 44 ensures a higher inlet pressure for the supercoolant pump 56. Specifically, during the process of injecting supercoolant into the rocket's supercoolant tank 65 at a high flow rate, the ground supercoolant injection controller 69 receives the inlet pressure P0 of the supercoolant pump 56 detected by the supercoolant pump inlet pressure sensor 70 located on the rocket's supercoolant injection pipeline 500, and sets the nitrogen pressure in the nitrogen pressurization line 600 according to the inlet pressure P0.

[0185] Preferably, such as Figure 1C and Figure 1A As shown, the supercooled liquid filling system of the large rocket also includes:

[0186] A first liquid level temperature sensor 51, a second liquid level temperature sensor 52, a third liquid level temperature sensor 53, and a fourth liquid level temperature sensor 54 are arranged at intervals from bottom to top inside the ground supercooled liquid storage tank 44. The supercooled liquid filling system of the large rocket also includes a ground supercooled liquid filling controller 69, which is electrically connected to the first liquid level temperature sensor 51, the second liquid level temperature sensor 52, the third liquid level temperature sensor 53, and the fourth liquid level temperature sensor 54; the ground supercooled liquid filling controller 69 is also electrically connected to a nitrogen pressurization line 600. During the process of extracting the supercooled gas evaporated in the ground supercooled liquid storage tank 44, the temperature of the supercooled liquid at different altitudes is collected by multiple liquid level temperature sensors arranged at intervals. If the maximum temperature among the multiple temperatures is lower than a first preset temperature, it indicates that the temperature of the supercooled liquid has reached the requirement, avoiding the defect of inaccurate temperature acquisition by a single liquid level temperature sensor in a localized area.

[0187] Preferably, such as Figure 1B , Figure 1C and Figure 1A As shown, the supercooled liquid refueling system of a large rocket also includes:

[0188] A first nitrogen pressure control circuit, a second nitrogen pressure control circuit, and a third nitrogen pressure control circuit are connected in parallel on the nitrogen pressurization line 600. The first nitrogen pressure control circuit includes a first pressurization solenoid valve 71 and a first orifice plate 81 sequentially arranged on the first nitrogen sub-pipeline 91. The second nitrogen pressure control circuit includes a second pressurization solenoid valve 72 and a second orifice plate 82 sequentially arranged on the second nitrogen sub-pipeline 92. The third nitrogen pressure control circuit includes a third pressurization solenoid valve 73 and a third orifice plate 83 sequentially arranged on the third nitrogen sub-pipeline 93. The ground subcooling fluid injection controller 69 is electrically connected to the first pressurization solenoid valve 71, the second pressurization solenoid valve 72, and the third pressurization solenoid valve 73.

[0189] When pressurizing the ground subcooled liquid storage tank 44, nitrogen from the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the first pressure reducer 5, the second gas filter 6 of the nitrogen pressurization line 600, and the first nitrogen pressure control circuit, the second nitrogen pressure control circuit, and the third nitrogen pressure control circuit connected in parallel. It enters the ground subcooled liquid storage tank 44 from the ground subcooled liquid storage tank pressurization port 445 above the ground subcooled liquid storage tank 44, thereby pressurizing the ground subcooled liquid storage tank 44 until the large-flow filling of the rocket-mounted subcooled liquid tank 65 is completed. During the large-flow filling of the rocket-mounted subcooled liquid tank 65, the purpose of pressurizing the ground subcooled liquid storage tank 44 with nitrogen is to avoid insufficient inlet pressure of the subcooled liquid pump 56, which would cause the inlet liquid of the subcooled liquid pump 56 to vaporize and cause cavitation of the subcooled liquid pump 56. Therefore, pressurizing the ground subcooled liquid storage tank 44 ensures that the inlet pressure of the subcooled liquid pump 56 is high. Specifically, during the process of injecting supercoolant into the rocket's supercoolant tank 65 at a high flow rate, the ground supercoolant injection controller 69 receives the inlet pressure P0 of the supercoolant pump 56 detected by the supercoolant pump inlet pressure sensor 70 located on the rocket's supercoolant injection pipeline 500, and sets the nitrogen pressure in the nitrogen booster line 600 according to the inlet pressure P0. Furthermore, the ground supercoolant injection controller 69 controls the first booster solenoid valve 71 on the first nitrogen pressure control circuit, the second booster solenoid valve 72 on the second nitrogen pressure control circuit, and the third booster solenoid valve 73 on the third nitrogen pressure control circuit to continuously inject nitrogen from the ground nitrogen source 2 into the ground supercoolant storage tank 44.

[0190] Preferably, such as Figure 1D and Figure 1A As shown, the supercooling fluid filling system of a large rocket also includes a supercooling fluid drain pipe 61, which is connected to the supercooling fluid filling pipe 500 on the side adjacent to the supercooling fluid tank 65. When purging the supercooling fluid filling pipe 500, the gas in the pipe is discharged through the supercooling fluid drain pipe 61; and when precooling the supercooling fluid filling pipe 500, the precooling gas is discharged.

[0191] Preferably, such as Figure 6 and Figure 8 As shown, in the supercoolant refueling system of a large rocket, the ground supercoolant tank 44 includes an aluminum-lithium alloy tank shell 443 and a negative pressure support plate 444 disposed on the inner wall of the aluminum-lithium alloy tank shell 443. The negative pressure support plate 444 can improve the structural stability and load-bearing capacity of the aluminum-lithium alloy tank shell 443. The ground supercoolant tank 44 needs to be evacuated. Without the negative pressure support plate 444, the aluminum-lithium alloy tank shell 443 would collapse during the evacuation process. The negative pressure support plate 444 disposed on the inner wall of the aluminum-lithium alloy tank shell 443 can resist the pressure of the external atmospheric pressure during the evacuation process and prevent the aluminum-lithium alloy tank shell 443 from collapsing. In addition, during the process of supercoolant being refueled into the ground supercoolant tank 44, thermal expansion and contraction of the ground supercoolant tank 444 are avoided.

[0192] Preferably, such as Figure 9 and Figure 6 As shown, in the supercoolant refueling system of a large rocket, the ground supercoolant tank 44 further includes: a polyurethane insulation layer 442 and a heat-insulating coating 441. The polyurethane insulation layer 442 is disposed on the outer wall of the aluminum-lithium alloy tank shell 443; the polyurethane insulation layer 442 increases the thermal resistance between the tank and the outside environment, reduces heat leakage from the tank, and provides insulation for the tank. The heat-insulating coating 441 is disposed on the outer wall of the polyurethane insulation layer 442. The heat-insulating coating 441 can reduce the heat transfer effect, reduce heat leakage from the tank, and at the same time make the tank more aesthetically pleasing and improve its strength.

[0193] The following are the sequential steps of the supercooling method using a supercooling system for a large rocket in an embodiment of the present invention.

[0194] I. Blowout Procedure

[0195] Before adding liquid methane to the ground subcooling fluid storage tank 44, the ground subcooling fluid filling system needs to be purged with nitrogen for a first preset time, such as 1 hour, to remove air (including water vapor) from the pipeline. This prevents the low-temperature subcooling fluid (112K, -161℃) from freezing upon contact with water vapor and forming excess material. Therefore, water vapor should be purged before adding subcooling fluid to ensure that the pipeline is entirely filled with nitrogen. Nitrogen replaces the water vapor, preventing water vapor from forming excess material at low temperatures that could cause valve jamming and affect valve performance, resulting in uneven subcooling fluid delivery.

[0196] The ground subcoolant filling system includes a first subcoolant filling main pipeline 400 and a ground subcoolant filling pipeline 200. The first subcoolant filling main pipeline 400 is connected to the subcoolant supply source 1. It is assumed that there are 3 subcoolant supply sources 1, each with two branches connected to the first subcoolant filling main pipeline 400.

[0197] First, open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1. Then, open the seventh ground subcoolant filling ball valve 41 located on the first subcoolant filling main line 400, open the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling line 200, open the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62 located on the rocket subcoolant filling line 500, and open the subcoolant drain valve 60 of the rocket subcoolant tank 65 located on the subcoolant venting line.

[0198] Close the subcoolant filling valve 64 located on the rocket subcoolant filling line 500, which is adjacent to the rocket subcoolant tank.

[0199] Finally, open the first gas manual switch 11 located on the gas seal pipeline 700, the second gas manual switch 13 located on the purging gas delivery pipeline, and the third gas manual switch 46 located on the subcooling liquid vacuum subcooling line 100 to purge nitrogen from the ground subcooling liquid filling system.

[0200] During the purging process of the ground supercoolant filling system, in the direction of the supercoolant tank on the rocket at 65 degrees, the nitrogen in the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the second pressure reducer 9, the second gas tee 10, and the second gas manual switch 13 respectively; and enters the fourth gas tee 14, the sixth gas tee 16, and the eighth gas tee 18 respectively.

[0201] After entering through the fourth gas tee 14, it splits into two paths through the fifth gas tee 15, entering the two branch paths of the first subcooled liquid tanker. In the first branch path of the first subcooled liquid tanker, it passes sequentially through the first filling pipeline purging port 19, the first ground subcooled liquid filling ball valve 20, and the first subcooled liquid filter 21. In the second branch path of the first subcooled liquid tanker, it passes sequentially through the second filling pipeline purging port 22, the second ground subcooled liquid filling ball valve 23, and the second subcooled liquid filter 24. The first and second branch paths of the first subcooled liquid tanker converge at the first subcooled liquid tee 25.

[0202] After entering through the sixth gas tee 16, it splits into two paths through the seventh gas tee 17, entering the two branch paths of the second subcooled liquid tanker. In the first branch path of the second subcooled liquid tanker, it passes sequentially through the third filling pipeline purging port 26, the third ground subcooled liquid filling ball valve 27, and the third subcooled liquid filter 28. In the second branch path of the second subcooled liquid tanker, it passes sequentially through the fourth filling pipeline purging port 29, the fourth ground subcooled liquid filling ball valve 30, and the fourth subcooled liquid filter 31. The first and second branches of the second subcooled liquid tanker converge at the second subcooled liquid tee 32.

[0203] After entering from the eighth gas tee 18, it splits into two paths leading to the two branch paths of the third subcooled liquid tanker. In the first branch path of the third subcooled liquid tanker, it passes sequentially through the fifth filling pipeline purging port 33, the fifth ground subcooled liquid filling ball valve 34, and the fifth subcooled liquid filter 35. In the second branch path of the third subcooled liquid tanker, it passes sequentially through the sixth filling pipeline purging port 36, the sixth ground subcooled liquid filling ball valve 37, and the sixth subcooled liquid filter 38. The first and second branches of the third subcooled liquid tanker converge at the third subcooled liquid tee 39.

[0204] After the two main routes of the first subcooled liquid tanker truck merge, the two main routes of the second subcooled liquid tanker truck merge, and the two main routes of the third subcooled liquid tanker truck merge, they all enter the first subcooled liquid filling main pipeline 400 through the subcooled liquid four-way valve 40. They then pass sequentially through the seventh ground subcooled liquid filling ball valve 41 located on the first subcooled liquid filling main pipeline 400, and through the fourth subcooled liquid tee 42 into the arrow-mounted subcooled liquid filling pipeline 500; the fourth subcooled liquid tee 42 is also connected to the ground subcooled liquid filling pipeline 200.

[0205] After entering the onboard supercoolant filling line 500, the fluid sequentially passes through the ninth ground supercoolant filling ball valve 55, supercoolant pump 56, and supercoolant flow sensor 58, all located on the onboard supercoolant filling line 500. It then flows through the fifth supercoolant tee 59 into the supercoolant drain line 61, and after passing through the supercoolant drain valve 60, is directly discharged into the atmosphere. The purging process is completed in 1 hour. All ground valves are then closed.

[0206] During the purging process of the ground subcoolant filling system, in the direction of the ground subcoolant storage tank 44, the nitrogen in the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the second pressure reducer 9, the second gas tee 10, and the second gas manual switch 13, and enters the fourth gas tee 14, the sixth gas tee 16, and the eighth gas tee 18 respectively.

[0207] After entering through the fourth gas tee 14, it splits into two paths through the fifth gas tee 15, entering the two branch paths of the first subcooled liquid tanker. In the first branch path of the first subcooled liquid tanker, it passes sequentially through the first filling pipeline purging port 19, the first ground subcooled liquid filling ball valve 20, and the first subcooled liquid filter 21. In the second branch path of the first subcooled liquid tanker, it passes sequentially through the second filling pipeline purging port 22, the second ground subcooled liquid filling ball valve 23, and the second subcooled liquid filter 24. The first and second branch paths of the first subcooled liquid tanker converge at the first subcooled liquid tee 25.

[0208] After entering through the sixth gas tee 16, it splits into two paths through the seventh gas tee 17, entering the two branch paths of the second subcooled liquid tanker. In the first branch path of the second subcooled liquid tanker, it passes sequentially through the third filling pipeline purging port 26, the third ground subcooled liquid filling ball valve 27, and the third subcooled liquid filter 28. In the second branch path of the second subcooled liquid tanker, it passes sequentially through the fourth filling pipeline purging port 29, the fourth ground subcooled liquid filling ball valve 30, and the fourth subcooled liquid filter 31. The first and second branches of the second subcooled liquid tanker converge at the second subcooled liquid tee 32.

[0209] After entering from the eighth gas tee 18, it splits into two paths leading to the two branch paths of the third subcooled liquid tanker. In the first branch path of the third subcooled liquid tanker, it passes sequentially through the fifth filling pipeline purging port 33, the fifth ground subcooled liquid filling ball valve 34, and the fifth subcooled liquid filter 35. In the second branch path of the third subcooled liquid tanker, it passes sequentially through the sixth filling pipeline purging port 36, the sixth ground subcooled liquid filling ball valve 37, and the sixth subcooled liquid filter 38. The first and second branches of the third subcooled liquid tanker converge at the third subcooled liquid tee 39.

[0210] After the first subcooling fluid tee 25 merges, the second subcooling fluid tee 32 merges, and the third subcooling fluid tee 39 merges, the fluids converge through pipelines at the subcooling fluid cross 40 and enter the first subcooling fluid filling main pipeline 400. The fluids then pass sequentially through the seventh ground subcooling fluid filling ball valve 41 located on the first subcooling fluid filling main pipeline 400, and finally through the fourth subcooling fluid tee 42 into the rocket-mounted subcooling fluid filling pipeline 500.

[0211] Simultaneously, the coolant enters the onboard subcoolant filling line 500, then passes through the fourth subcoolant tee 42 into the ground subcoolant filling line 200. After entering the ground subcoolant filling line 200, it passes through the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling line 200 into the ground subcoolant storage tank 44. The subcoolant vacuum subcooling line 100 is connected to the ground subcoolant storage tank 44 via the subcoolant storage tank vacuum connection flange 4435. The coolant is discharged through the subcoolant vacuum subcooling line 100, passing sequentially through the third gas manual switch 46, the subcooled gas vacuum pump 48, the subcooled gas treatment device 49, and the third gas tee 12, before being directly discharged into the atmosphere. The purging process is completed after the first preset time, for example, 1 hour. All ground valves are then closed.

[0212] Among them, the first gas filter 3, the first gas tee 4, the second pressure reducer 9, the second gas tee 10, the second gas manual switch 13, the fourth gas tee 14, the fifth gas tee 15, the sixth gas tee 16, the seventh gas tee 17, the eighth gas tee 18, the first subcoolant tee 25, the second subcoolant tee 32, the third subcoolant tee 39, the fourth subcoolant tee 42, and the third gas tee 12 are all of the same specification and model. The first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, the sixth ground subcoolant filling ball valve 37, the seventh ground subcoolant filling ball valve 41, and the eighth ground subcoolant filling ball valve 43 are all of the same specification and model. All manual switches are of the same model.

[0213] II. Precooling Process of Ground Subcooling Liquid Piping

[0214] After the ground subcoolant filling system is purged with nitrogen for 1 hour, the ground subcoolant pipeline precooling process is carried out until the temperature of the first subcoolant filling main pipeline 400 and the ground subcoolant filling pipeline 200 reaches the second preset temperature. At this time, the subcoolant no longer evaporates, and the precooling is stopped. The precooling of the ground subcoolant pipeline takes about 1 hour.

[0215] The temperature of the subcoolant is usually 112K-161℃. At this temperature, the subcoolant filling pipeline (including the subcoolant filling pipeline 200) is at room temperature. The purpose of pre-cooling is to reduce the temperature of the solid in the subcoolant filling pipeline to about 112K, so as to prevent the subcoolant from transferring heat to the subcoolant during filling, causing the temperature of the subcoolant in the pipeline to rise, or to prevent the subcoolant from boiling due to excessive temperature in the pipeline.

[0216] First, open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1. Then, open the seventh ground subcoolant filling ball valve 41 located on the first subcoolant filling main pipeline 400, and open the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling pipeline 200.

[0217] Close the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62; finally, close the first gas manual switch 11 and the second gas manual switch 13.

[0218] Turn on the third gas manual switch 46 located on the subcooling liquid vacuum subcooling line 100 to precool the ground subcooling liquid pipeline.

[0219] During the pre-cooling process of the ground subcoolant pipeline, the subcoolant in the first subcoolant tanker is transported through the first branch, passing sequentially through the first filling pipeline purging port 19, the first ground subcoolant filling ball valve 20, and the first subcoolant filter 21; the subcoolant in the first subcoolant tanker is transported through the second branch, passing sequentially through the second filling pipeline purging port 22, the second ground subcoolant filling ball valve 23, and the second subcoolant filter 24; the first branch and the second branch of the first subcoolant tanker merge at the first subcoolant tee 25;

[0220] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0221] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the third subcoolant tanker converge at the third subcoolant tee 39.

[0222] After the first subcooling liquid tee 25 merges, the second subcooling liquid tee 32 merges, and the third subcooling liquid tee 39 merges, the liquid flows through a pipeline to the subcooling liquid four-way 40 and enters the first subcooling liquid filling main pipeline 400. It then passes sequentially through the seventh ground subcooling liquid filling ball valve 41 on the first subcooling liquid filling main pipeline 400, and then through the fourth subcooling liquid tee 42 into the ground subcooling liquid filling pipeline 200. After passing through the eighth ground subcooling liquid filling ball valve 43 on the ground subcooling liquid filling pipeline 200, it enters the ground subcooling liquid storage tank 44 and is discharged through the subcooling liquid vacuum subcooling line 100. On the subcooling liquid vacuum subcooling line 100, it sequentially passes through the third gas manual switch 46, the subcooling gas vacuum pump 48, the subcooling gas treatment device 49, and the third gas tee 12 before being directly discharged into the atmosphere. The ground subcooling liquid pipeline precooling takes approximately 1 hour. The precooling process ends after 1 hour. All ground valves are closed.

[0223] III. Filling Procedure for Ground Subcoolant Storage Tank 44

[0224] After the ground subcooling fluid filling system is purged with nitrogen for 1 hour and the ground subcooling fluid pipeline is pre-cooled for about 2 hours, the ground subcooling fluid storage tank 44 is filled with subcooling fluid.

[0225] Before adding subcoolant to the ground subcoolant storage tank 44, first open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1. Then open the seventh ground subcoolant filling ball valve 41 located on the first subcoolant filling main pipeline 400 and the eighth ground subcoolant filling ball valve 43 located on the ground subcoolant filling pipeline 200.

[0226] Close the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62; finally, close the first gas manual switch 11 and the second gas manual switch 13.

[0227] Turn on the third gas manual switch 46 located on the subcooling liquid vacuum subcooling line 100 to fill the ground subcooling liquid storage tank.

[0228] During the filling process of the ground subcoolant tank 44, the subcoolant in the first subcoolant tanker is transported through the first branch, passing sequentially through the first filling pipeline purging port 19, the first ground subcoolant filling ball valve 20, and the first subcoolant filter 21; the subcoolant in the first subcoolant tanker is transported through the second branch, passing sequentially through the second filling pipeline purging port 22, the second ground subcoolant filling ball valve 23, and the second subcoolant filter 24; the first branch and the second branch of the first subcoolant tanker merge at the first subcoolant tee 25.

[0229] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0230] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the third subcoolant tanker converge at the third subcoolant tee 39.

[0231] After the first subcooling liquid tee 25 merges, the second subcooling liquid tee 32 merges, and the third subcooling liquid tee 39 merges, they converge through the pipeline at the subcooling liquid four-way 40 and enter the first subcooling liquid filling main pipeline 400; they then pass through the seventh ground subcooling liquid filling ball valve 41 located on the first subcooling liquid filling main pipeline 400, and then through the fourth subcooling liquid tee 42 into the ground subcooling liquid filling pipeline 200, and finally through the eighth ground subcooling liquid filling ball valve 43 located on the ground subcooling liquid filling pipeline 200 into the ground subcooling liquid storage tank 44.

[0232] It is discharged through the subcooling liquid vacuum subcooling line 100, and then passes through the third gas manual switch 46, the subcooled gas vacuum pump 48, the subcooled gas treatment device 49, and the third gas tee 12 in sequence before being directly discharged into the atmosphere.

[0233] The filling of the ground subcoolant tank 44 takes about 2 hours. After 2 hours of filling, the process is completed, and all ground valves are closed.

[0234] IV. Vacuuming and Subcooling Process of Ground Subcoolant Storage Tank 44

[0235] After the ground subcooling fluid storage tank 44 is filled, it is evacuated to subcool the subcooling fluid. Vacuum subcooling takes approximately 23 hours. The purpose of evacuation is to reduce the pressure of the subcooling fluid, thereby lowering its boiling point (boiling temperature), from 112K to a first preset temperature, such as 95K. During the evacuation process, subcooling fluid with a boiling point above 95K (e.g., 112K) will boil under low pressure. Boiling intensifies the evaporation of the subcooling fluid, which carries away a large amount of heat. Only when the subcooling fluid temperature drops below 95K will it stop boiling. In summary, by lowering the boiling point of the subcooling fluid through evacuation, the boiling intensifies the evaporation and vaporization, carrying away a large amount of heat until the subcooling fluid reaches a boiling point below the specified pressure.

[0236] Before the ground subcoolant tank 44 is evacuated and subcooled, the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1 are in the closed state, the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main line 400 is in the closed state, and the eighth ground subcoolant filling ball valve 43 on the ground subcoolant filling line 200 is in the closed state.

[0237] The ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62 are in the closed state.

[0238] Open the third gas manual switch 46 on the subcooling liquid vacuum subcooling line 100 to start the subcooling gas vacuum pump motor 47 and subcooling gas vacuum pump 48 to evacuate the ground subcooling liquid storage tank. The subcooling gas vacuum pump motor 47 provides power to the subcooling gas vacuum pump 48, which extracts the gas (evaporated subcooling gas) from the ground subcooling liquid storage tank 44. Continuously evacuate the ground subcooling liquid storage tank 44 to reduce the saturated vapor pressure of the subcooling liquid, thereby reducing the temperature of the subcooling liquid until the boiling point of the subcooling liquid is reduced to the first preset temperature, for example, which may take about 23 hours. After the subcooling of the ground subcooling liquid storage tank 44 is completed, close all ground valves.

[0239] V. Pre-cooling process of pipelines before filling the supercooled liquid tank 65 on the rocket

[0240] Before adding supercoolant to the supercoolant tank 65 on the rocket, the supercoolant filling pipeline 500 needs to be pre-cooled. The pre-cooling process for the supercoolant filling pipeline 500 takes approximately 1 hour. The supercoolant temperature is typically 112K -161℃. At this temperature, the supercoolant filling pipeline on the ground is at room temperature. The purpose of pre-cooling is to lower the solid temperature of the supercoolant filling pipeline 500 to around 112K. This prevents the supercoolant from transferring heat to the supercoolant during filling, which could cause the temperature of the supercoolant to rise within the pipeline 500, or it could prevent the supercoolant from boiling due to excessive temperature within the pipeline 500.

[0241] Before precooling the onboard subcoolant filling pipeline 500, first open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1; so that the eighth ground subcoolant filling ball valve 43 is closed; so that the tenth ground subcoolant filling ball valve 62 on the onboard subcoolant filling pipeline 500 (the tenth ground subcoolant filling ball valve 62 is located in front of the onboard subcoolant tank 65) is closed; open the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main pipeline 400; open the ninth ground subcoolant filling ball valve 55 on the onboard subcoolant filling pipeline 500; and open the subcoolant drain valve 60 on the subcoolant drain pipeline 61.

[0242] During the precooling process of the supercoolant filling pipeline 500 on the rocket, the supercoolant in the first supercoolant tanker is transported through the first branch, passing sequentially through the first filling pipeline purging port 19, the first ground supercoolant filling ball valve 20, and the first supercoolant filter 21; the supercoolant in the first supercoolant tanker is transported through the second branch, passing sequentially through the second filling pipeline purging port 22, the second ground supercoolant filling ball valve 23, and the second supercoolant filter 24; the first branch and the second branch of the first supercoolant tanker merge at the first supercoolant tee 25.

[0243] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0244] The subcoolant in the third subcoolant tanker truck flows through the first branch, passing sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker truck flows through the second branch, passing sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the third subcoolant tanker truck converge at the third subcoolant tee 39.

[0245] After the first subcooling fluid tee 25 merges, the second subcooling fluid tee 32 merges, and the third subcooling fluid tee 39 merges, the fluids converge through a pipeline at the subcooling fluid four-way valve 40 and enter the first subcooling fluid filling main pipeline 400. The fluids then pass sequentially through the seventh ground subcooling fluid filling ball valve 41 on the first subcooling fluid filling main pipeline 400, and then through the fourth subcooling fluid tee 42 into the onboard subcooling fluid filling pipeline 500. From there, the fluids pass sequentially through the ninth ground subcooling fluid filling ball valve 55, the subcooling fluid pump 56, the subcooling fluid flow sensor 58, and the fifth subcooling fluid tee 59 on the onboard subcooling fluid filling pipeline 500 into the subcooling fluid discharge pipeline 61. Finally, the fluids are discharged directly into the atmosphere through the subcooling fluid discharge valve 60 on the subcooling fluid discharge pipeline 61. Pre-cooling of the onboard subcooling fluid filling pipeline 500 for 1 hour is completed, after which all ground valves are closed.

[0246] VI. Low-flow pre-cooling and refueling process for the supercooled liquid tank on the rocket (65).

[0247] Before adding supercoolant to the onboard supercoolant tank 65 at a high flow rate, it is necessary to pre-cool the tank at a low flow rate (second flow rate). The second preset time for this low-flow pre-cooling process is, for example, approximately 1 hour. This low-flow pre-cooling process ensures that the supercoolant filling pipeline 500 is sufficiently cooled, preventing the supercoolant from overheating or boiling within the pipeline 500 during the process of transferring it from the ground supercoolant storage tank 44 to the onboard supercoolant tank 65.

[0248] During the small-flow pre-cooling filling process of the onboard subcoolant tank 65, first open the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1; so that the eighth ground subcoolant filling ball valve 43 is closed; then open the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main line 400; and open the ninth ground subcoolant filling ball valve 55 and the tenth ground subcoolant filling ball valve 62 on the onboard subcoolant filling line 500; so that the subcoolant drain valve 60 on the subcoolant drain line 61 is closed. Then open the onboard subcoolant tank filling valve 64 of the onboard subcoolant tank 65.

[0249] The subcoolant in the first subcoolant tanker is transported via the first branch line, passing sequentially through the first filling pipeline purging port 19, the first ground subcoolant filling ball valve 20, and the first subcoolant filter 21. The subcoolant in the first subcoolant tanker is transported via the second branch line, passing sequentially through the second filling pipeline purging port 22, the second ground subcoolant filling ball valve 23, and the second subcoolant filter 24. The first and second branches of the first subcoolant tanker converge at the first subcoolant tee 25.

[0250] The subcoolant in the second subcoolant tanker flows through the first branch, passing sequentially through the third filling pipeline purging port 26, the third ground subcoolant filling ball valve 27, and the third subcoolant filter 28. The subcoolant in the second subcoolant tanker flows through the second branch, passing sequentially through the fourth filling pipeline purging port 29, the fourth ground subcoolant filling ball valve 30, and the fourth subcoolant filter 31. The first and second branches of the second subcoolant tanker converge at the second subcoolant tee 32.

[0251] The subcoolant in the third subcoolant tanker passes through the first branch, and then sequentially through the fifth filling pipeline purging port 33, the fifth ground subcoolant filling ball valve 34, and the fifth subcoolant filter 35. The subcoolant in the third subcoolant tanker passes through the second branch, and then sequentially through the sixth filling pipeline purging port 36, the sixth ground subcoolant filling ball valve 37, and the sixth subcoolant filter 38. The first and second branches of the third subcoolant tanker converge at the third subcoolant tee 39.

[0252] After the first subcooling liquid tee 25 merges, the second subcooling liquid tee 32 merges, and the third subcooling liquid tee 39 merges, they converge through pipelines at the subcooling liquid four-way 40 and enter the first subcooling liquid filling main pipeline 400. They then pass through the seventh ground subcooling liquid filling ball valve 41 on the first subcooling liquid filling main pipeline 400, and then through the fourth subcooling liquid tee 42 to enter the on-board subcooling liquid filling pipeline 500. They then pass through the ninth ground subcooling liquid filling ball valve 55, the subcooling liquid pump 56, the subcooling liquid flow sensor 58, the fifth subcooling liquid tee 59, the tenth ground subcooling liquid filling ball valve 62, the subcooling liquid filling connector 63, and the on-board subcooling liquid tank filling valve 64 on the on-board subcooling liquid filling pipeline 500 to enter the on-board subcooling liquid tank 65, quickly filling the on-board subcooling liquid tank 65.

[0253] During the small-flow pre-cooling and refueling process of the supercooled liquid tank 65 on the rocket, the exhaust valve 67 of the supercooled liquid tank on the rocket is opened.

[0254] After the pre-cooling and filling of the supercooled liquid tank on the rocket at a low flow rate of 65 is completed, all valves on the ground are closed.

[0255] VII. High-flow-rate subcooling filling process for the 65°C subcooling tank on the rocket

[0256] After the pre-cooling and filling of the supercooled liquid tank 65 on the rocket with a small flow rate of supercooled liquid is completed, the supercooled liquid tank 65 on the rocket is then filled with supercooled liquid with a large flow rate (third flow rate). The supercooled liquid filling of the supercooled liquid tank 65 on the rocket takes about 55 minutes.

[0257] Before filling the onboard subcoolant tank 65 with a large flow of subcoolant, the first ground subcoolant filling ball valve 20, the second ground subcoolant filling ball valve 23, the third ground subcoolant filling ball valve 27, the fourth ground subcoolant filling ball valve 30, the fifth ground subcoolant filling ball valve 34, and the sixth ground subcoolant filling ball valve 37 on each branch of the subcoolant supply source 1 are closed, and the seventh ground subcoolant filling ball valve 41 on the first subcoolant filling main pipeline 400 is closed; the eighth ground subcoolant filling ball valve 43, the ninth ground subcoolant filling ball valve 55, and the tenth ground subcoolant filling ball valve 62 are opened, so that the subcoolant drain valve 60 on the subcoolant drain pipeline 61 is closed, and the onboard subcoolant tank filling valve 64 is opened, so that the first gas manual switch 11, the second gas manual switch 13, and the third gas manual switch 46 are closed.

[0258] During the process of adding high-flow-rate subcoolant to the onboard subcoolant tank 65, the subcoolant in the ground subcoolant storage tank 44 passes through the eighth ground subcoolant filling ball valve 43 on the ground subcoolant filling pipeline 200, enters the onboard subcoolant filling pipeline 500 through the fourth subcoolant tee 42, and then passes sequentially through the ninth ground subcoolant filling ball valve 55, the subcoolant pump 56, the subcoolant flow sensor 58, the fifth subcoolant tee 59, the tenth ground subcoolant filling ball valve 62, the subcoolant filling connector 63, and the onboard subcoolant tank filling valve 64 on the onboard subcoolant filling pipeline 500 before entering the onboard subcoolant tank 65.

[0259] During the process of adding a large flow of subcoolant to the rocket's subcoolant tank 65, the exhaust valve 67 of the rocket's subcoolant tank is opened.

[0260] During the high-flow-rate subcoolant filling process of the onboard subcoolant tank 65, nitrogen pressurization is required in the ground subcoolant storage tank 44. This is to prevent insufficient inlet pressure of the subcoolant pump 56, which could lead to liquid vaporization at the pump's inlet and cavitation. Therefore, pressurizing the ground subcoolant storage tank 44 ensures a higher inlet pressure for the subcoolant pump 56. Specifically, the nitrogen pressurization line 600 is opened, with one end connected to the ground nitrogen source 2 and the other end connected to the ground subcoolant storage tank 44. Nitrogen from the ground nitrogen source 2 passes through the first gas filter 3, the first gas tee 4, the first pressure reducer 5, and the second gas filter 6 of the nitrogen pressurization line 600, as well as the parallel-connected first, second, and third nitrogen pressure control circuits, and is released from the ground subcoolant storage tank 44 above the ground subcoolant storage tank. The liquid storage tank pressurization port 445 enters the ground subcooled liquid storage tank 44 until the large-flow injection of the rocket's subcooled liquid tank 65 is completed; wherein, the first nitrogen pressure control circuit includes a first pressurization solenoid valve 71 and a first orifice plate 81 sequentially arranged on the first nitrogen sub-pipeline 91, the second nitrogen pressure control circuit includes a second pressurization solenoid valve 72 and a second orifice plate 82 sequentially arranged on the second nitrogen sub-pipeline 92, and the third nitrogen pressure control circuit includes a third pressurization solenoid valve 73 and a third orifice plate 83 sequentially arranged on the third nitrogen sub-pipeline 93.

[0261] After the supercooled liquid tank 65 on the rocket has been filled with a large flow of supercooled liquid, close all valves on the ground and close the exhaust valve 67 of the supercooled liquid tank on the rocket.

[0262] Five minutes before ignition of the large rocket (i.e., 5 minutes before launch), the supercoolant filling connector 63 automatically detaches, and then all ground valves are closed. At 0 seconds, the rocket ignites, and the ground supercoolant filling system completes its operation.

[0263] The beneficial technical effects achieved by the embodiments of the present invention are as follows:

[0264] 1. Using a vacuum pump in a ground-based subcooling tank to subcool the subcooling fluid is a more efficient method than using a liquid nitrogen subcooler. This method not only reduces the need for large ground-based equipment such as subcoolers and liquid nitrogen tanks, as well as associated piping and valves, but also lowers the cost of the subcooling fluid filling system.

[0265] 2. Compared to using a liquid nitrogen subcooler to subcool the subcooled liquid, the vacuum subcooling method also avoids the problem of subcooled liquid freezing that often occurs with liquid nitrogen subcoolers.

[0266] 3. The purging air source and the booster air source have been unified, reducing the types of air sources. This simplifies the system's air supply and reduces system complexity.

[0267] 4. Use four temperature sensors at different liquid levels to measure the temperature of the subcooled liquid to determine whether the subcooled liquid has been subcooled to the design temperature during the vacuuming process.

[0268] 5. The method of using subcooled liquid vacuuming to reduce the temperature of the subcooled liquid achieves the effect of subcooling, which reduces the difficulty of research and development, reduces production costs, and is relatively easy to implement.

[0269] 6. During the high-flow subcooling injection process of the on-board subcooled liquid tank, the ground nitrogen source 2 is used to pressurize the ground subcooled liquid storage tank 44 to avoid insufficient inlet pressure of the subcooled liquid pump 56, which would cause the liquid at the inlet of the subcooled liquid pump 56 to vaporize and cause cavitation of the subcooled liquid pump 56. Therefore, pressurizing the ground subcooled liquid storage tank (44) is used to ensure that the inlet pressure of the subcooled liquid pump 56 is high.

[0270] 7. The subcoolant filling system has fewer component types, improving its parts versatility. Furthermore, the large number of valves and pipes can be produced in small batches, reducing processing costs.

[0271] 8. The ground subcooling fluid storage tank can withstand negative pressure and meet the requirements for ground subcooling fluid vacuuming, ground subcooling fluid storage tank pressurization, and large-flow subcooling fluid filling.

[0272] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0273] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0274] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0275] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0276] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A supercooled liquid fueling system for a large rocket, characterized in that, include: The system includes a subcooling fluid supply source (1), a ground subcooling fluid storage tank (44), and an onboard subcooling fluid tank (65). The ground subcooling fluid storage tank (44) is connected to the subcooling fluid supply source (1) via a first subcooling fluid filling main pipeline (400), and the onboard subcooling fluid tank (65) is connected to the ground subcooling fluid storage tank (44) via an onboard subcooling fluid filling pipeline (500). The supercooling liquid filling system of the large rocket also includes: a supercooling liquid vacuum supercooling line (100) connected to the ground supercooling liquid storage tank (44), the supercooling liquid vacuum supercooling line (100) includes a supercooling gas vacuum pump (48) and a supercooling gas processing device (49) located downstream of the supercooling gas vacuum pump (48). The supercooling liquid refueling system of the large rocket also includes a ground nitrogen source (2), the pipeline of which is connected to the first supercooling liquid refueling main pipeline (400); The supercooling fluid filling system of the large rocket also includes a gas-sealed pipeline (700), one end of which is connected to the ground nitrogen source (2), and the other end of which is connected to one end of the supercooling fluid vacuum subcooling line (100) and is located away from the ground supercooling fluid storage tank (44).

2. A supercooled liquid fuel filling system for large rockets according to claim 1, characterized in that, It also includes a purge gas delivery pipeline (300), one end of which is connected to the first subcooling liquid injection main pipeline (400), and the other end of which is connected to the ground nitrogen source (2).

3. A supercooled liquid fuel filling system for large rockets as defined in claim 1, characterized in that It also includes a nitrogen booster line (600), one end of which is connected to the ground subcooled liquid storage tank (44), and the other end of which is connected to the ground nitrogen source (2).

4. The supercoolant filling system for a large rocket according to claim 3, characterized in that, Also includes: A first liquid level temperature sensor (51), a second liquid level temperature sensor (52), a third liquid level temperature sensor (53), and a fourth liquid level temperature sensor (54) are arranged at intervals from bottom to top in the ground subcooled liquid storage tank (44); The supercooled liquid filling system for the large rocket also includes: The ground subcooling fluid filling controller (69) is electrically connected to the first liquid level temperature sensor (51), the second liquid level temperature sensor (52), the third liquid level temperature sensor (53) and the fourth liquid level temperature sensor (54); the ground subcooling fluid filling controller (69) is also electrically connected to the nitrogen pressurization line (600).

5. The supercoolant filling system for a large rocket according to claim 4, characterized in that, Also includes: A first nitrogen pressure control circuit, a second nitrogen pressure control circuit, and a third nitrogen pressure control circuit are connected in parallel on the nitrogen boosting line (600); wherein, the first nitrogen pressure control circuit includes a first boosting solenoid valve (71) and a first orifice plate (81) sequentially disposed on the first nitrogen sub-pipeline (91), the second nitrogen pressure control circuit includes a second boosting solenoid valve (72) and a second orifice plate (82) sequentially disposed on the second nitrogen sub-pipeline (92), and the third nitrogen pressure control circuit includes a third boosting solenoid valve (73) and a third orifice plate (83) sequentially disposed on the third nitrogen sub-pipeline (93); The ground subcooling fluid injection controller (69) is electrically connected to the first booster solenoid valve (71), the second booster solenoid valve (72), and the third booster solenoid valve (73).

6. The supercoolant filling system for a large rocket according to claim 1, characterized in that, It also includes a subcoolant drain line (61), which is connected to the on-rocket subcoolant filling line (500) on the side adjacent to the on-rocket subcoolant tank (65).

7. The supercoolant filling system for a large rocket according to claim 1, characterized in that, The ground subcooled liquid storage tank (44) includes an aluminum-lithium alloy storage tank shell (443) and a negative pressure support plate (444) disposed on the inner wall of the aluminum-lithium alloy storage tank shell (443).

8. The supercoolant filling system for a large rocket according to claim 7, characterized in that, The ground subcooled liquid storage tank (44) further includes a polyurethane insulation layer (442) and a heat insulation coating (441). The polyurethane insulation layer (442) is disposed on the outer wall of the aluminum-lithium alloy storage tank shell (443); the heat insulation coating (441) is disposed on the outer wall of the polyurethane insulation layer (442).

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