Methane on-line full-supercooling filling system and filling method thereof

Abstract

The invention discloses an on-line full-supercooling methane filling system and a filling method thereof, and relates to the technical field of rocket fuel filling systems, the on-line full-supercooling methane filling system comprises a first methane storage tank, a second methane storage tank, a first gas storage tank, a second gas storage tank, a second gas storage tank and a pre-cooling discharge pipeline, the first gas storage tank is connected with a rocket propellant storage tank and the pre-cooling discharge pipeline through a tube pass of a supercooler; the second methane storage tank is connected with the tube pass of the subcooler through a second pipeline; and the liquid nitrogen storage tank is provided with a third pipeline, and the third pipeline is connected with the shell pass of the subcooler. According to the on-line full-supercooling methane filling system, the technical problem that the risk of failure of a launching task is increased due to the fact that liquid level control is unstable when on-line supercooling filling is conducted on a rocket is solved, and the risk of failure of the launching task is increased when the flow in the methane filling process is adjusted. The flow of methane in the tube pass of the subcooler and the liquid level of liquid nitrogen in the shell pass of the subcooler are controlled to be unchanged, the situation of methane icing caused by unstable liquid level control is avoided, and then the risk of failure of a launching task is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of rocket fuel filling systems, and in particular to an online fully subcooled methane filling system and a filling method thereof. Background Art

[0002] The carrier is the foundation of the development of commercial aerospace, and the propellant is the key factor that determines the performance of the carrier. Considering the physical and chemical properties, combustion characteristics, cost and environmental impact of methane, in the context of the current rapid development of commercial aerospace, more and more commercial companies choose liquid oxygen-methane as the propellant for the carrier. At the same time, in order to achieve rapid and reliable precooling of the rocket engine turbopump and improve the carrying capacity of the carrier, the demand for full supercooling and filling of methane to achieve densification has also been proposed. At present, liquid nitrogen is a commonly used cold source for supercooling at the launch site, and the saturation temperature of liquid nitrogen at normal pressure is lower than the freezing point of liquid methane. In order to fully exchange heat between the two, the heat exchange area is controlled by adjusting the liquid nitrogen level to achieve online supercooling filling.

[0003] However, when the rocket is being supercooled online, under conditions of different filling flow rates, the liquid level control may become unstable, causing methane to freeze, resulting in solid particles entering the rocket propellant tank, increasing the risk of launch mission failure. Therefore, a methane online fully supercooled filling system and a filling method thereof are proposed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a methane online fully supercooled filling system and a filling method thereof, which solves the technical problem that when a rocket is supercooled online, liquid level control instability occurs, resulting in methane freezing, thereby causing solid particles to enter the rocket propellant tank, increasing the risk of launch mission failure.

[0005] To achieve the above object, the present invention provides a methane online fully subcooled filling system, comprising:

[0006] A first methane storage tank is provided with a loop pipeline and a first pipeline, the loop pipeline is connected to a main filling pipeline, the main filling pipeline is connected to a rocket propellant tank and a precooling discharge pipeline, and the first methane storage tank is used to store methane;

[0007] A subcooler, wherein the pipe of the subcooler is connected to the first pipeline and the main filling pipeline;

[0008] A second methane storage tank is provided with a second pipeline, the second pipeline is connected to the pipe side of the subcooler, and the second methane storage tank is used to store methane;

[0009] The liquid nitrogen storage tank is provided with a third pipeline, the third pipeline is connected to the shell side of the subcooler, and the liquid nitrogen storage tank is used to store liquid nitrogen.

[0010] Preferably, a first regulating valve and a first stop valve are arranged in the loop pipeline, a second stop valve is arranged in the first pipeline, a third stop valve is arranged in the second pipeline, and a second regulating valve and a fourth stop valve are arranged in the third pipeline.

[0011] Preferably, the pipe line of the subcooler is connected to an input pipeline, the input pipeline is connected to the first pipeline, and a first filter and a front regulating valve are arranged in the input pipeline.

[0012] Preferably, a post-regulating valve, an eighth shut-off valve and a second filter are provided in the main filling pipeline, and a three-way pipe is provided in the main filling pipeline between the regulating valve and the eighth shut-off valve, and the three-way pipe is connected to the pre-cooling discharge pipeline.

[0013] Preferably, a fourth pipeline is provided on the first methane storage tank, a fifth stop valve is provided in the fourth pipeline, the second methane storage tank is provided with a fifth pipeline, a sixth stop valve is provided in the fifth pipeline, the fourth pipeline and the fifth pipeline are commonly connected to a first discharge pipeline, a first check valve is provided in the first discharge pipeline, and the first discharge pipeline is connected to a first combustion and exhaust tower.

[0014] Preferably, the liquid nitrogen storage tank is provided with a sixth pipeline, a seventh stop valve is provided in the sixth pipeline, the shell side of the subcooler is connected to the seventh pipeline, a discharge butterfly valve is provided in the seventh pipeline, the sixth pipeline and the seventh pipeline are commonly connected to a second discharge pipeline, a second check valve is provided in the second discharge pipeline, and the second discharge pipeline is connected to a liquid nitrogen discharge tower.

[0015] Preferably, the rocket propellant tank is connected to a third discharge pipeline, the third discharge pipeline is connected to a second combustion and exhaust tower, a third check valve is arranged in the third discharge pipeline, and the third discharge pipeline is connected to the precooling discharge pipeline.

[0016] Preferably, the first methane storage tank is connected to a first self-pressurizing vaporizer, which is used to provide positive pressure to the interior of the first methane storage tank; the second methane storage tank is connected to a second self-pressurizing vaporizer, which is used to provide positive pressure to the interior of the second methane storage tank; the liquid nitrogen storage tank is connected to a third self-pressurizing vaporizer, which is used to provide positive pressure to the interior of the liquid nitrogen storage tank.

[0017] Correspondingly, the technical solution of the present invention further provides a methane online fully subcooled filling system method, which is applied to any of the above-mentioned methane online fully subcooled filling systems, comprising:

[0018] Controlling the liquid nitrogen storage tank to transport liquid nitrogen to the third pipeline in a self-pressurizing manner, and the liquid nitrogen is transported to the shell side of the subcooler through the third pipeline to precool the shell side of the subcooler;

[0019] The first methane storage tank is controlled to maintain a slight positive pressure, and the second methane storage tank transports methane to the pipe side of the subcooler through the second pipeline by means of self-pressurization. The methane after passing through the pipe side of the subcooler enters the main filling pipeline, and the end of the main filling pipeline close to the rocket propellant tank is controlled to be closed, and the precooling discharge pipeline is opened, and methane is discharged through the precooling discharge pipeline until the supercooling temperature of the methane in the main filling pipeline meets the arrow feed index;

[0020] The pressure of the second methane storage tank is controlled to remain unchanged, the precooling discharge pipeline is controlled to be closed, and one end of the main filling pipeline close to the rocket propellant tank and the loop pipeline are controlled to be opened, so that a part of the methane is transported to the rocket propellant tank through the main filling pipeline, and another part of the methane is transported to the first methane storage tank through the loop pipeline, and the methane flow in the pipe side of the subcooler is controlled to remain unchanged, and the flow of methane in the main filling pipeline and the flow of methane in the loop pipeline are adjusted until the methane in the rocket propellant tank reaches a first preset liquid level;

[0021] Controlling the loop pipeline to be gradually closed, while increasing the pressure of the first methane storage tank, and after the pressure of the first methane storage tank is equal to the pressure of the second methane storage tank, controlling the first pipeline to be opened and the second pipeline to be closed, the first methane storage tank transports methane to the pipe side of the subcooler through the first pipeline, and transports all of it to the rocket propellant tank through the main filling pipeline, until the methane in the rocket propellant tank reaches a second preset liquid level;

[0022] The first pipeline is controlled to be closed, and the first methane storage tank is depressurized. After the pressure relief of the first methane storage tank is completed, the loop pipeline is controlled to be opened, and the flow rate of methane in the main filling pipeline and the flow rate of methane in the loop pipeline are adjusted until the methane in the rocket propellant tank reaches the final liquid level, thereby completing the methane supercooling filling.

[0023] Preferably, after the step of transporting methane from the second methane storage tank to the tube side of the subcooler through the second pipeline by self-pressurization, the method further includes: controlling the liquid nitrogen in the shell side of the subcooler to reach a standard liquid level, and keeping the liquid nitrogen level in the shell side of the subcooler matched and stable with the methane flow in the tube side of the subcooler.

[0024] Compared with the above background technology, the methane online full supercooling filling system provided by the present invention has the following beneficial effects: during the online supercooling filling process of methane, the methane flow in the tube side of the supercooler and the liquid nitrogen level in the shell side of the supercooler are always maintained unchanged, and the flow rate of methane in the main filling pipeline, the flow rate of methane in the loop pipeline, and the distribution of methane flow between the first methane storage tank and the second methane storage tank are controlled to achieve the flow size adjustment during the methane filling process, and there is no need to adjust the liquid nitrogen level to control the heat exchange area to achieve online supercooling filling of methane, avoiding the situation where the liquid level control is unstable and causes methane to freeze, thereby reducing the risk of launch mission failure. On the other hand, before methane enters the rocket propellant tank, the methane that cannot meet the arrow entry index is discharged through the precooling discharge pipeline, further avoiding the frozen methane from entering the rocket propellant tank, which plays a role in reducing the risk of launch mission failure. The methane online full supercooling filling method adopted in the present invention also has the above beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the working principle of the methane online fully subcooled filling system provided in an embodiment of the present invention.

[0027] Specifically, 1-first methane storage tank; 2-loop pipeline; 201-first regulating valve; 202-first stop valve; 3-first pipeline; 301-second stop valve; 4-second pipeline; 401-third stop valve; 5-third pipeline; 501-second regulating valve; 502-fourth stop valve; 6-second methane storage tank; 7-liquid nitrogen storage tank; 8-supercooler; 9-input pipeline; 901-first filter; 902-front regulating valve; 10-main filling pipeline; 1001-rear regulating valve; 1002-eighth stop valve; 1003-second filter; 11-rocket propellant tank; 12-precooling discharge pipeline; 1201-ninth stop valve; 13-fourth pipeline; 1301-fifth stop valve; 14-fifth pipeline; 1401-sixth stop valve; 15-first discharge pipeline; 16-first check valve; 17 - second discharge pipeline; 18 - second check valve; 19 - third discharge pipeline; 1901 - tenth stop valve; 20 - third check valve; 21 - sixth pipeline; 2101 - seventh stop valve; 22 - seventh pipeline; 2201 - discharge butterfly valve; 23 - first combustion and exhaust tower; 24 - second combustion and exhaust tower; 25 - liquid nitrogen discharge tower; 26 - first self-pressurizing pipeline; 2601 - first self-pressurizing vaporizer; 2602 - The first self-boosting pipeline stop valve; 2603-the first self-boosting pipeline regulating valve; 27-the second self-boosting pipeline; 2701-the second self-boosting vaporizer; 2702-the second self-boosting pipeline stop valve; 2703-the second self-boosting pipeline regulating valve; 28-the third self-boosting pipeline; 2801-the third self-boosting vaporizer; 2802-the third self-boosting pipeline stop valve; 2803-the third self-boosting pipeline regulating valve. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] like Figure 1 As shown, in order to achieve the above-mentioned purpose, the present invention provides a methane online fully subcooled filling system, comprising: a first methane storage tank 1, a second methane storage tank 6, a liquid nitrogen storage tank 7 and a subcooler 8.

[0031] Among them, the first methane storage tank 1 is provided with a loop pipeline 2 and a first pipeline 3, the loop pipeline 2 is connected to the main filling pipeline 10, the main filling pipeline 10 is connected to the rocket propellant tank 11 and the precooling discharge pipeline 12, and methane is stored in the first methane storage tank 1. The methane in the first methane storage tank 1 can be transported to the rocket propellant tank 11 through the first pipeline 3 and the main filling pipeline 10.

[0032] The pipe side of the subcooler 8 connects the first pipeline 3 and the main filling pipeline 10. The methane in the first methane storage tank 1 is transported to the pipe side of the subcooler 8 through the first pipeline 3. The methane is cooled by the pipe side of the subcooler 8 and then enters the main filling pipeline 10.

[0033] A second pipeline 4 is provided on the second methane storage tank 6, and the second pipeline 4 is connected to the pipe side of the subcooler 8. Methane is stored in the second methane storage tank 6, and the methane in the second methane storage tank 6 is transported to the pipe side of the subcooler 8 through the first pipeline 3. The methane is cooled in the pipe side of the subcooler 8 and then enters the main filling pipeline 10.

[0034] A third pipeline 5 is provided on the liquid nitrogen storage tank 7, and the third pipeline 5 is connected to the shell side of the subcooler 8. Liquid nitrogen is stored in the liquid nitrogen storage tank 7. The liquid nitrogen in the liquid nitrogen storage tank 7 is transported to the shell side of the subcooler 8 through the third pipeline 5. Methane exchanges heat with the tube side of the subcooler 8 through the shell side of the subcooler 8 to achieve cooling of the subcooled gas tube side.

[0035] When in use, the liquid nitrogen storage tank 7 is controlled to transport liquid nitrogen to the third pipeline 5 by self-pressurization, and the liquid nitrogen is transported to the shell side of the subcooler 8 through the third pipeline 5 to pre-cool the shell side of the subcooler 8; the first methane storage tank 1 is controlled to maintain a slightly positive pressure, and the second methane storage tank 6 transports methane to the pipe side of the subcooler 8 through the second pipeline 4 by self-pressurization. The methane after passing through the pipe side of the subcooler 8 enters the main filling pipeline 10, and the end of the main filling pipeline 10 close to the rocket propellant tank 11 is controlled to be closed, and the precooling discharge pipeline 12 is opened, and the methane is discharged through the precooling discharge pipeline 12. The methane that cannot meet the arrow feed index is discharged through the precooling discharge pipeline 12 to prevent the methane after freezing from entering the rocket propellant tank 11, thereby reducing the risk of launch mission failure. After the supercooling temperature of the methane in the main filling pipeline 10 meets the arrow feeding index, the pressure of the second methane storage tank 6 is controlled to remain unchanged, the precooling discharge pipeline 12 is controlled to be closed, and the end of the main filling pipeline 10 close to the rocket propellant tank 11 and the loop pipeline 2 are opened. A part of the methane is transported to the rocket propellant tank 11 through the main filling pipeline 10, and the other part of the methane is transported to the first methane storage tank 1 through the loop pipeline 2. The methane flow in the pipe process of the subcooler 8 is controlled to remain unchanged, and the flow of methane in the main filling pipeline 10 and the flow of methane in the loop pipeline 2 are adjusted to achieve small flow filling of methane; after the methane in the rocket propellant tank 11 reaches the first preset liquid level, the loop pipeline 2 is controlled to be gradually closed, and the pressure of the first methane storage tank 1 is increased at the same time. After the pressure of the first methane storage tank 1 is the same as the pressure of the second methane storage tank 6, the first pipeline 3 is controlled to be opened and the second pipeline 4 is closed. The first methane storage tank 1 transports methane to the pipe process of the subcooler 8 through the first pipeline 3, and transports it to the rocket propellant tank 11 through the main filling pipeline 10, so as to realize large-flow filling of methane; after the methane in the rocket propellant tank 11 reaches the second preset liquid level, the first pipeline 3 is controlled to be closed, and the first methane storage tank 1 is depressurized. After the pressure relief of the first methane storage tank 1 is completed, the loop pipeline 2 is opened, and the flow rate of methane in the main filling pipeline 10 and the flow rate of methane in the loop pipeline 2 are adjusted. At this time, methane is filled at a small flow rate until the methane in the rocket propellant tank 11 reaches the final value liquid level, and the methane supercooling filling is completed. During the online supercooling filling process of methane, the flow rate of methane in the main filling pipeline 10, the flow rate of methane in the loop pipeline 2 and the methane flow distribution between the first methane storage tank 1 and the second methane storage tank 6 are controlled to adjust the flow rate during the methane filling process. The methane flow in the tube side of the subcooler 8 and the liquid nitrogen level in the shell side of the subcooler 8 are always maintained unchanged, effectively avoiding the situation where methane freezes due to instability of the liquid level control.

[0036] It should be noted that the adjustment of the flow rate during the methane filling process can adapt to the continuous online supercooled filling under different filling flow conditions. On the one hand, it can reduce the temperature inside the rocket propellant tank 11 and reduce the evaporation of methane; on the other hand, since the rocket propellant tank 11 can be in a filling state all the time, the discharge process of methane that cannot meet the arrow feeding index during the filling process is omitted, which effectively saves fuel costs and simplifies the supercooled filling process of methane.

[0037] It should be further explained that, in the initial state, the first methane storage tank 1, the second methane storage tank 6 and the liquid nitrogen storage tank 7 all maintain a slightly positive pressure state to prevent the first methane storage tank 1, the second methane storage tank 6 and the liquid nitrogen storage tank 7 from inhaling air from the atmosphere.

[0038] In one embodiment of the present invention, a first regulating valve 201 and a first stop valve 202 are provided in the loop pipeline 2, and the methane flow in the loop pipeline 2 can be adjusted by adjusting the opening of the first regulating valve 201, and the first stop valve 202 can control the on-off of the loop pipeline 2. In addition, a second stop valve 301 is provided in the first pipeline 3, and the second stop valve 301 can control the on-off of the first pipeline 3, and a third stop valve 401 is provided in the second pipeline 4, and the third stop valve 401 can control the on-off of the second pipeline 4. A second regulating valve 501 and a fourth stop valve 502 are provided in the third pipeline 5, and the methane flow in the third pipeline 5 can be adjusted by adjusting the opening of the second regulating valve 501, and the fourth stop valve 502 can control the on-off of the second pipeline 4.

[0039] In one embodiment of the present invention, the pipeline of the subcooler 8 is connected to the input pipeline 9, and the input pipeline 9 is connected to the first pipeline 3. A first filter 901 is provided in the input pipeline 9. The first filter 901 is used to filter impurities in the methane in the input pipeline 9 to ensure that the purity of the methane entering the subcooling pipeline is maintained within a safe range. In addition, a front regulating valve 902 is provided in the input pipeline 9. By adjusting the opening of the front regulating valve 902, the methane flow in the pipeline of the subcooler 8 can be accurately controlled, thereby providing a basic condition for maintaining the methane flow in the pipeline of the subcooler 8 unchanged.

[0040] Of course, an output pipeline (not shown in the figure) can also be connected to the pipe side of the subcooler 8, and the output pipeline is connected to the loop pipeline 2 and the main filling pipeline 10 at the same time. The purpose is to ensure that when a small flow rate of methane is filled, the methane flow in the pipe side of the subcooler 8 remains unchanged, which can effectively ensure that a part of the methane is transported to the rocket propellant tank 11 through the main filling pipeline 10, and the other part of the methane is transported to the first methane storage tank 1 through the loop pipeline 2.

[0041] The main filling pipeline 10 is provided with a rear regulating valve 1001, an eighth stop valve 1002 and a second filter 1003, wherein the methane flow in the main filling pipeline 10 can be accurately controlled by adjusting the opening of the rear regulating valve 1001, the eighth stop valve 1002 can control the on-off of the main filling pipeline 10, and the second filter 1003 further filters the methane to further prevent the methane after freezing from entering the rocket propellant tank 11, so as to reduce the risk of launch mission failure.

[0042] Preferably, a three-way pipe is provided between the regulating valve and the eighth stop valve 1002 in the main filling pipeline 10, and the three-way pipe is connected to the precooling discharge pipeline 12. A ninth stop valve 1201 is provided in the precooling discharge pipeline 12, and the ninth stop valve 1201 can control the on-off of the precooling discharge pipeline 12. Specifically, before methane enters the rocket propellant tank 11, the eighth stop valve 1002 is controlled to be closed, and the ninth stop valve 1201 is opened, and the methane that cannot meet the arrow entry index is discharged through the precooling discharge pipeline 12, so as to prevent the frozen methane from entering the rocket propellant tank 11, thereby reducing the risk of launch mission failure.

[0043] In one embodiment of the present invention, a fourth pipeline 13 is provided on the first methane storage tank 1, and the fourth pipeline 13 and the fifth pipeline 14 are commonly connected to the first discharge pipeline 15, and the first discharge pipeline 15 is connected to the first combustion tower 23. When the first methane storage tank 1 and the second methane storage tank 6 need to be depressurized, the mixed gas containing methane in the first methane storage tank 1 and the second methane storage tank 6 can be discharged to the first combustion tower 23 through the first discharge pipeline 15. After the mixed gas containing methane is processed by the first combustion tower 23, it is discharged into the atmosphere, which effectively prevents pollution to the atmosphere.

[0044] In addition, a fifth stop valve 1301 is provided in the fourth pipeline 13, and the fifth stop valve 1301 can control the on-off of the fourth pipeline 13. A sixth stop valve 1401 is provided in the fifth pipeline 14, and the sixth stop valve 1401 can control the on-off of the fourth pipeline 13. A first check valve 16 is provided in the first discharge pipeline 15. The setting of the first check valve 16 can ensure that the mixed gas containing methane in the first discharge pipeline 15 is discharged to the first combustion tower 23, while preventing the gas in the atmosphere from entering the first methane storage tank 1 and the second methane storage tank 6.

[0045] The liquid nitrogen storage tank 7 is provided with a sixth pipeline 21, the shell side of the subcooler 8 is connected to the seventh pipeline 22, the sixth pipeline 21 and the seventh pipeline 22 are connected to the second discharge pipeline 17, the second discharge pipeline 17 is connected to the liquid nitrogen discharge tower 25, the liquid nitrogen in the liquid nitrogen storage tank 7 enters the seventh pipeline 22 after passing through the shell side of the subcooler 8, and enters the second discharge pipeline 17 after passing through the seventh pipeline 22. At the same time, the liquid nitrogen in the liquid nitrogen storage tank 7 can also directly enter the second discharge pipeline 17 through the sixth pipeline 21, and the liquid nitrogen in the second discharge pipeline 17 is input to the liquid nitrogen discharge tower 25, and the liquid nitrogen is processed by the liquid nitrogen discharge tower 25 and then discharged into the atmosphere to prevent the liquid nitrogen from polluting the atmosphere.

[0046] In addition, a seventh stop valve 2101 is provided in the sixth pipeline 21, and the seventh stop valve 2101 can control the on-off of the sixth pipeline 21. A discharge butterfly valve 2201 is provided in the seventh pipeline 22, and the discharge butterfly valve 2201 can control the on-off of the seventh pipeline 22. When the seventh stop valve 2101 is closed and the discharge butterfly valve 2201 is opened, the liquid nitrogen in the liquid nitrogen storage tank 7 enters the seventh pipeline 22 after passing through the shell side of the subcooler 8, and enters the second discharge pipeline 17 after passing through the seventh pipeline 22. When the seventh stop valve 2101 is opened and the discharge butterfly valve 2201 is closed, the liquid nitrogen in the liquid nitrogen storage tank 7 can also directly enter the second discharge pipeline 17 through the sixth pipeline 21. A second check valve 18 is provided in the second discharge pipeline 17, and the setting of the second check valve 18 can ensure that the liquid nitrogen in the second discharge pipeline 17 is input to the second combustion and exhaust tower 24, while preventing the gas in the atmosphere from entering the interior of the liquid nitrogen storage tank 7.

[0047] In one embodiment of the present invention, the rocket propellant tank 11 is connected to the third discharge pipeline 19, and the third discharge pipeline 19 is connected to the second combustion tower 24. The methane in the rocket propellant tank 11 can be directly discharged to the second combustion tower 24 through the third discharge pipeline 19, wherein the third discharge pipeline 19 is provided with a tenth stop valve 1901, and the tenth stop valve 1901 is used to control the on-off of the third discharge pipeline 19. In addition, a third check valve 20 is provided in the third discharge pipeline 19, and the third discharge pipeline 19 is connected to the precooling discharge pipeline 12. The provision of the third check valve 20 can ensure that the mixed gas containing methane in the third discharge pipeline 19 is discharged to the first combustion tower 23, while preventing the gas in the atmosphere from entering the interior of the rocket propellant tank 11.

[0048] The first methane storage tank 1 is connected to the first self-pressurizing vaporizer 2601, and the first self-pressurizing vaporizer 2601 is used to provide positive pressure to the interior of the first methane storage tank 1. Specifically, the first self-pressurizing vaporizer 2601 is connected to the first methane storage tank 1 through the first self-pressurizing pipeline 26, and the first self-pressurizing pipeline stop valve 2602 and the first self-pressurizing pipeline regulating valve 2603 are provided in the first self-pressurizing pipeline 26. The first self-pressurizing pipeline stop valve 2602 can control the on-off of the first self-pressurizing pipeline 26. By controlling the opening of the first self-pressurizing pipeline regulating valve 2603, the pressure of the first methane storage tank 1 can be accurately controlled.

[0049] Similarly, the second methane storage tank 6 is connected to the second self-pressurizing vaporizer 2701, and the second self-pressurizing vaporizer 2701 is used to provide positive pressure to the interior of the second methane storage tank 6. Specifically, the second self-pressurizing vaporizer 2701 is connected to the second methane storage tank 6 via the second self-pressurizing pipeline 27, and the second self-pressurizing pipeline stop valve 2702 and the second self-pressurizing pipeline regulating valve 2703 are provided in the second self-pressurizing pipeline 27. The second self-pressurizing pipeline stop valve 2702 can control the on-off of the second self-pressurizing pipeline 27, and the pressure of the second methane storage tank 6 can be accurately controlled by controlling the opening of the second self-pressurizing pipeline regulating valve 2703.

[0050] The liquid nitrogen storage tank 7 is connected to the third self-pressurizing vaporizer 2801, and the third self-pressurizing vaporizer 2801 is used to provide positive pressure to the interior of the liquid nitrogen storage tank 7. Specifically, the third self-pressurizing vaporizer 2801 is connected to the liquid nitrogen storage tank 7 through the third self-pressurizing pipeline 28. A third self-pressurizing pipeline stop valve 2802 and a third self-pressurizing pipeline regulating valve 2803 are provided in the third self-pressurizing pipeline 28. The third self-pressurizing pipeline stop valve 2802 can control the on-off of the third self-pressurizing pipeline 28. By controlling the opening of the third self-pressurizing pipeline regulating valve 2803, the pressure of the liquid nitrogen storage tank 7 can be accurately controlled.

[0051] The methane online full subcooling filling method adopted by the present invention specifically comprises the following steps: controlling the liquid nitrogen storage tank 7 to transport the liquid nitrogen to the third pipeline 5 by self-pressurization, the liquid nitrogen is transported to the shell side of the subcooler 8 through the third pipeline 5 to pre-cool the shell side of the subcooler 8, the liquid nitrogen in the liquid nitrogen storage tank 7 enters the seventh pipeline 22 after passing through the shell side of the subcooler 8, and enters the second discharge pipeline 17 after passing through the seventh pipeline 22, the liquid nitrogen in the second discharge pipeline 17 is input to the liquid nitrogen discharge tower 25, and the liquid nitrogen is discharged into the atmosphere after being processed by the liquid nitrogen discharge tower 25; controlling the first methane storage tank 1 to maintain a slight positive pressure, and the second methane storage tank 6 to transport the methane through the third pipeline 5 by self-pressurization. The methane is transported to the pipe side of the subcooler 8 through the second pipeline 4. After passing through the pipe side of the subcooler 8, the methane enters the main filling pipeline 10, the eighth stop valve 1002 is controlled to be closed, the ninth stop valve 1201 is opened, and the methane is discharged through the pre-cooling discharge pipeline 12; after the supercooling temperature of the methane in the main filling pipeline 10 meets the arrow feed index, the pressure of the second methane storage tank 6 is controlled to remain unchanged, the ninth stop valve 1201 is controlled to be closed, the eighth stop valve 1002 and the loop pipeline 2 are opened, a part of the methane is transported to the rocket propellant tank 11 through the main filling pipeline 10, and the other part of the methane is transported to the first methane storage tank 1 through the loop pipeline 2, and the methane in the pipe side of the subcooler 8 is controlled to be The methane flow rate remains unchanged, and the methane flow rates in the main filling pipeline 10 and the methane flow rates in the loop pipeline 2 are adjusted to achieve small-flow filling of methane; after the methane in the rocket propellant tank 11 reaches the first preset liquid level, the first stop valve 202 is controlled to be gradually closed, and at the same time, the first self-pressurizing vaporizer 2601 and the first self-pressurizing pipeline stop valve 2602 are opened and the opening of the first self-pressurizing pipeline regulating valve 2603 is adjusted to increase the pressure of the first methane storage tank 1. After the pressure of the first methane storage tank 1 is the same as the pressure of the second methane storage tank 6, the second stop valve 301 is controlled to be opened, and the third stop valve 401 is closed. The first methane storage tank 1 transfers methane through the first pipeline 3. The methane is transported to the pipe line of the supercooler 8, and is all transported to the rocket propellant tank 11 through the main filling pipeline 10, so as to realize the large-flow filling of methane; after the methane in the rocket propellant tank 11 reaches the second preset liquid level, the second stop valve 301 is controlled to be closed, and the first methane storage tank 1 is depressurized through the first discharge pipeline 15. After the pressure relief of the first methane storage tank 1 is completed, the second stop valve 301 is controlled to be opened, and the opening of the rear regulating valve 1001 and the opening of the first regulating valve 201 are adjusted, and the flow rate of methane in the main filling pipeline 10 and the flow rate of methane in the loop pipeline 2 are adjusted until the methane in the rocket propellant tank 11 reaches the final value liquid level, and the methane supercooling filling is completed.

[0052] It should be noted that after the step of transporting methane from the second methane storage tank 6 to the tube side of the subcooler 8 through the second pipeline 4 by self-pressurization, it also includes: controlling the liquid nitrogen to reach a standard liquid level in the shell side of the subcooler 8, keeping the liquid nitrogen level in the shell side of the subcooler 8 matched and stable with the methane flow in the tube side, so as to ensure that the methane can enter the main filling pipeline 10 at a set temperature after coming out of the tube side of the subcooler 8, thereby ensuring that the temperature of the methane entering the rocket propellant tank 11 always remains constant.

[0053] In summary, by controlling the methane flow in the tube side of the subcooler 8 and the liquid nitrogen level in the shell side of the subcooler 8 to remain unchanged, adjusting the methane flow in the main filling pipeline 10, the methane flow in the loop pipeline 2, and controlling the methane flow distribution between the first methane storage tank 1 and the second methane storage tank 6, the flow rate during methane filling can be adjusted to avoid methane freezing due to instability in liquid level control, thereby reducing the risk of launch mission failure.

[0054] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0055] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A methane online fully subcooled filling system, characterized in that: include: A first methane storage tank is provided with a loop pipeline and a first pipeline, the loop pipeline is connected to a main filling pipeline, the main filling pipeline is connected to a rocket propellant tank and a precooling discharge pipeline, and the first methane storage tank is used to store methane; A subcooler, wherein the pipe of the subcooler is connected to the first pipeline and the main filling pipeline; A second methane storage tank is provided with a second pipeline, the second pipeline is connected to the pipe side of the subcooler, and the second methane storage tank is used to store methane; The liquid nitrogen storage tank is provided with a third pipeline, the third pipeline is connected to the shell side of the subcooler, and the liquid nitrogen storage tank is used to store liquid nitrogen.

2. A methane online fully subcooled filling system according to claim 1, characterized in that: A first regulating valve and a first stop valve are arranged in the loop pipeline, a second stop valve is arranged in the first pipeline, a third stop valve is arranged in the second pipeline, and a second regulating valve and a fourth stop valve are arranged in the third pipeline.

3. A methane online fully subcooled filling system according to claim 2, characterized in that: The pipe line of the subcooler is connected to the input pipeline, the input pipeline is connected to the first pipeline, and a first filter and a front regulating valve are arranged in the input pipeline.

4. The methane online fully subcooled filling system according to claim 1 is characterized in that: The main filling pipeline is provided with a rear regulating valve, an eighth stop valve and a second filter. The main filling pipeline is provided with a three-way pipe between the regulating valve and the eighth stop valve, and the three-way pipe is connected to the precooling discharge pipeline.

5. A methane online fully subcooled filling system according to claim 4, characterized in that: The first methane storage tank is provided with a fourth pipeline, in which a fifth stop valve is provided, the second methane storage tank is provided with a fifth pipeline, in which a sixth stop valve is provided, the fourth pipeline and the fifth pipeline are commonly connected to a first discharge pipeline, in which a first check valve is provided, and the first discharge pipeline is connected to a first combustion and exhaust tower.

6. A methane online fully subcooled filling system according to claim 5, characterized in that: The liquid nitrogen storage tank is provided with a sixth pipeline, a seventh stop valve is provided in the sixth pipeline, the shell side of the subcooler is connected to the seventh pipeline, a discharge butterfly valve is provided in the seventh pipeline, the sixth pipeline and the seventh pipeline are commonly connected to a second discharge pipeline, a second check valve is provided in the second discharge pipeline, and the second discharge pipeline is connected to a liquid nitrogen discharge tower.

7. The methane online fully subcooled filling system according to claim 4, characterized in that: The rocket propellant tank is connected to a third discharge pipeline, the third discharge pipeline is connected to a second combustion and discharge tower, a third check valve is arranged in the third discharge pipeline, and the third discharge pipeline is connected to the precooling discharge pipeline.

8. The methane online fully subcooled filling system according to claim 1, characterized in that: The first methane storage tank is connected to a first self-pressurizing vaporizer, which is used to provide positive pressure to the interior of the first methane storage tank; the second methane storage tank is connected to a second self-pressurizing vaporizer, which is used to provide positive pressure to the interior of the second methane storage tank; the liquid nitrogen storage tank is connected to a third self-pressurizing vaporizer, which is used to provide positive pressure to the interior of the liquid nitrogen storage tank.

9. A methane online fully subcooled filling method, applied to the methane online fully subcooled filling system according to any one of claims 1 to 8, characterized in that: The filling method comprises: Controlling the liquid nitrogen storage tank to transport liquid nitrogen to the third pipeline in a self-pressurizing manner, and the liquid nitrogen is transported to the shell side of the subcooler through the third pipeline to precool the shell side of the subcooler; The first methane storage tank is controlled to maintain a slight positive pressure, and the second methane storage tank transports methane to the pipe side of the subcooler through the second pipeline by means of self-pressurization. The methane after passing through the pipe side of the subcooler enters the main filling pipeline, and the end of the main filling pipeline close to the rocket propellant tank is controlled to be closed, and the precooling discharge pipeline is opened, and methane is discharged through the precooling discharge pipeline until the supercooling temperature of the methane in the main filling pipeline meets the arrow feed index; The pressure of the second methane storage tank is controlled to remain unchanged, the precooling discharge pipeline is controlled to be closed, and one end of the main filling pipeline close to the rocket propellant tank and the loop pipeline are controlled to be opened, so that a part of the methane is transported to the rocket propellant tank through the main filling pipeline, and another part of the methane is transported to the first methane storage tank through the loop pipeline, and the methane flow in the pipe side of the subcooler is controlled to remain unchanged, and the flow of methane in the main filling pipeline and the flow of methane in the loop pipeline are adjusted until the methane in the rocket propellant tank reaches a first preset liquid level; Controlling the loop pipeline to be gradually closed, while increasing the pressure of the first methane storage tank, and after the pressure of the first methane storage tank is equal to the pressure of the second methane storage tank, controlling the first pipeline to be opened and the second pipeline to be closed, the first methane storage tank transports methane to the pipe side of the subcooler through the first pipeline, and transports all of it to the rocket propellant tank through the main filling pipeline, until the methane in the rocket propellant tank reaches a second preset liquid level; The first pipeline is controlled to be closed, and the first methane storage tank is depressurized. After the pressure relief of the first methane storage tank is completed, the loop pipeline is controlled to be opened, and the flow rate of methane in the main filling pipeline and the flow rate of methane in the loop pipeline are adjusted until the methane in the rocket propellant tank reaches the final liquid level, thereby completing the methane supercooling filling.

10. A methane online fully subcooled filling method according to claim 9, characterized in that: After the step of transporting methane from the second methane storage tank to the tube side of the subcooler through the second pipeline by self-pressurization, the method further includes: controlling the liquid nitrogen in the shell side of the subcooler to reach a standard liquid level, and keeping the liquid nitrogen level in the shell side of the subcooler matched and stable with the methane flow in the tube side of the subcooler.

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