Full-supercooling large-flow liquid methane filling system and using method thereof

Abstract

The invention relates to a system for full-supercooling large-flow liquid methane filling and a using method of the system. The full-supercooling large-flow liquid methane filling system is stable, reliable, high in automation degree, capable of dynamically adjusting the supercooling temperature and flow of liquid methane and high in accuracy, and comprises a storage box, a pressurization module, a recovery module, a methane filling module, a control module and a nitrogen filling module, and the pressurization module comprises a methane pressurization tank; the methane filling module comprises a methane filling tank, the nitrogen filling module comprises a nitrogen filling tank and a subcooler, the recovery module comprises a methane recovery tank, and the control module pressurizes the methane recovery tank and the methane filling tank by controlling the pressurization module and adjusts the filling flow and temperature of methane to prevent condensation by controlling the methane filling module and the nitrogen filling module. Flow stabilization and backflow are carried out by controlling the methane filling module and the recovery module.

Description

Technical Field

[0001] This invention relates to a liquid methane refueling system, and more particularly to a system for refueling fully subcooled, high-flow-rate liquid methane and its method of use. Background Technology

[0002] Liquid methane / liquid oxygen propellants are widely used in new launch vehicles, especially reusable rockets, both domestically and internationally, due to their high specific impulse and pollution-free characteristics. Examples include Blue Origin's New Glenn rocket, SpaceX's Starship spacecraft, and domestically, the CZ-12R, Zhuque-2, and Hyperbola-2 rockets, all of which use liquid methane-liquid oxygen as propellant.

[0003] Compared to other propellants, liquid methane-liquid oxygen combination has a higher specific impulse, second only to liquid hydrogen-liquid oxygen, and slightly higher than aerospace kerosene-liquid oxygen and unsymmetrical dimethylhydrazine-nitrogen tetroxide. Except for its theoretical density specific impulse being lower than kerosene, methane has a higher specific heat and coking temperature limit than kerosene, and virtually no coking or carbon buildup, making engine maintenance convenient and highly suitable for reusable spacecraft. Meanwhile, to improve spacecraft carrying capacity, supercooling technology is widely used both domestically and internationally to lower the methane temperature below its standard boiling point to improve methane quality. Compared to standard boiling point liquid methane, supercooled liquid methane has advantages such as higher density, lower vaporization pressure, and greater sensible cooling capacity. Currently, SpaceX's Starship spacecraft uses fully supercooled methane (92K) with high-flow-rate refueling (45m³ for the first stage). 3 / min, Level 2 is 13m 3 In China, supercooled methane (100K) is added at a low flow rate (800L / min) to improve the overall performance of the launch vehicle and enhance the quality of refueling. The supercooled methane refueling flow rate is relatively small. In liquid methane supercooling, liquid nitrogen is the most commonly used, economical, and safest cold source. However, because the saturation temperature of liquid nitrogen at atmospheric pressure is lower than the condensation temperature of liquid methane, liquid methane is prone to condensation during supercooling, making it difficult to dynamically adjust and precisely control the supercooling temperature and flow rate. If solid particles formed by methane condensation enter the rocket or block the supercooler channels, it will affect the successful completion of the launch mission. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a stable, reliable, highly automated, and highly accurate liquid methane subcooling temperature and flow rate filling system and its usage method.

[0005] This invention discloses a fully subcooled, high-flow-rate liquid methane refueling system, comprising a storage tank, a pressurization module including a methane pressurization tank, a first pressurization pipe equipped with a pressurization outlet valve and a pressurizer, a second pressurization pipe equipped with a first pressurization inlet valve, and a third pressurization pipe equipped with a second pressurization inlet valve; a recovery module including a methane recovery tank and a reflux pipe equipped with inlet and outlet valves; and a methane refueling module including a methane refueling tank and a system for refueling methane... The system includes a conventional methane filling pipe and a subcooled methane filling pipe with a liquid outlet valve; a nitrogen filling module, comprising a nitrogen filling tank, a subcooler, a nitrogen filling pipe equipped with a nitrogen liquid outlet valve, and a nitrogen discharge pipe equipped with a nitrogen discharge valve; one end of the first, second, and third pressurization pipes are respectively connected to a methane pressurization tank, a methane recovery tank, and a methane filling tank, and the other end of the second and third pressurization pipes are each connected to the other end of the first pressurization pipe; one end of the conventional methane filling pipe is connected to the methane filling tank. The methane filling tank is connected, and the other end of the conventional methane filling pipe is connected to the storage tank. The subcooled methane filling pipe is connected in parallel to the conventional methane filling pipe, and the subcooler is connected in series to the subcooled methane filling pipe to subcool the methane in the pipe. A subcooled methane outlet valve is installed on the subcooled methane filling pipe located between the subcooler and the conventional methane filling pipe. One end of the reflux pipe is connected to the methane recovery tank, and the other end is connected to the subcooled methane filling pipe, with the connection point located between the subcooler and the subcooled methane outlet valve. The nitrogen filling pipe is connected at one end to the nitrogen filling tank and at the other end to the nitrogen inlet of the subcooler. The nitrogen outlet of the subcooler is connected to the nitrogen discharge pipe. The control module pressurizes the methane recovery tank and the methane filling tank by controlling the pressurizing liquid outlet valve, the pressurizer, the first pressurizing inlet valve and the second pressurizing inlet valve. It regulates the methane filling flow rate and temperature to prevent condensation by controlling the nitrogen outlet valve, the methane outlet valve and the subcooled methane outlet valve. It stabilizes the flow and refluxes by controlling the inlet and outlet valves.

[0006] This invention discloses a fully subcooled high-flow-rate liquid methane refueling system, wherein both the methane booster tank and the nitrogen refueling tank are equipped with a self-pressurization mechanism. The self-pressurization mechanism includes a self-pressurization pipe and a self-pressurization outlet valve, a self-pressurization regulating valve, and a self-pressurization vaporizer installed on the self-pressurization pipe. The two ends of the self-pressurization pipes in the two sets of self-pressurization pipe mechanisms are respectively connected to the top and bottom of the methane booster tank and the top and bottom of the nitrogen refueling tank.

[0007] The present invention discloses a fully subcooled high-flow-rate liquid methane injection system, wherein the first booster pipe is further provided with a first filter, a booster flow meter and an external booster shut-off valve, and the first filter, the booster flow meter and the external booster shut-off valve are all located between the booster outlet valve and the booster; the second booster pipe and the third booster pipe are both provided with external booster regulating valves.

[0008] The present invention discloses a fully subcooled high-flow-rate liquid methane filling system, wherein the reflux pipe is further provided with a second filter, a reflux flow meter, a reflux regulating valve, and a reflux valve, and the second filter, the reflux flow meter, the reflux regulating valve, and the reflux valve are all located between the inlet / outlet valve and the connection between the subcooled methane filling pipe and the reflux pipe.

[0009] This invention discloses a fully subcooled high-flow-rate liquid methane filling system, wherein the recovery module further includes a transfer pipe connected to a first pressurization pipe, a reflux pipe, and a conventional methane filling pipe, respectively. The transfer pipe is equipped with a first isolation valve and a second isolation valve. The first isolation valve is located between the connection between the first pressurization pipe and the transfer pipe and the connection between the reflux pipe and the transfer pipe, and the second isolation valve is located between the connection between the reflux pipe and the transfer pipe and the connection between the conventional methane filling pipe and the transfer pipe. Methane filling and transfer are achieved through the transfer pipe.

[0010] This invention discloses a fully subcooled high-flow-rate liquid methane refueling system. The conventional methane refueling pipe is sequentially equipped with a third filter, a conventional pipeline valve, a conventional pipeline regulating valve, a refueling flow meter, a methane inlet valve, and a fourth filter. The methane outlet valve is located between the third filter and the methane refueling tank. The refueling flow meter, methane inlet valve, and fourth filter are positioned close to the storage tank. The connection between the subcooled methane refueling pipe and the conventional methane refueling pipe is located between the third filter and the refueling flow meter. The conventional pipeline valve and the conventional pipeline regulating valve are located between the connection between the subcooled methane refueling pipe and the conventional methane refueling pipe. The subcooled methane refueling pipe is equipped with a subcooled methane flow meter and a subcooled methane inlet valve.

[0011] The present invention discloses a fully subcooled high-flow-rate liquid methane injection system, wherein the nitrogen injection pipe is equipped with a fifth filter, a nitrogen flow meter and a nitrogen regulating valve.

[0012] This invention discloses a fully subcooled, high-flow-rate liquid methane filling system, which further includes a methane emission module. The methane emission module comprises a booster emission pipe equipped with a first emission valve and a check valve, a storage pipe, a methane station emission pipe equipped with a second emission valve and a check valve, a flare pipe equipped with a check valve and a third emission valve, a methane buffer tank, and a methane flare system. One end of the booster emission pipe is connected to the first booster pipe, and the other end is connected to the methane buffer tank. The storage pipe includes a first storage pipe equipped with a fourth emission valve, a second storage pipe equipped with a fifth emission valve, and a third storage pipe equipped with a sixth emission valve. One end of the first storage pipe is connected to the top of the methane booster tank, and the other end is connected to the booster emission pipe, with the connection point located at the first flare pipe. Between the discharge valve and the check valve, one end of the second storage pipe is connected to the top of the methane recovery tank, and the other end of the second storage pipe is connected to the first storage pipe; one end of the third storage pipe is connected to the top of the methane filling tank, and the other end of the third storage pipe is connected to the first storage pipe; one end of the methane station discharge pipe is connected to the booster discharge pipe, and the connection point is located between the first discharge valve and the methane buffer tank; the other end of the methane station discharge pipe is connected to the conventional methane filling pipe, and the connection point is located between the filling flow meter and the methane inlet valve; one end of the arrow pipe is connected to the storage tank, and the other end of the arrow pipe is connected to the methane buffer tank; the methane flare system includes a flare tower and a flare pipe, one end of the flare pipe is connected to the methane buffer tank, and the other end of the flare pipe is connected to the flare tower.

[0013] This invention discloses a fully subcooled, high-flow-rate liquid methane filling system, which further includes a nitrogen emission module. The nitrogen emission module includes a first nitrogen emission pipe equipped with a first nitrogen emission valve and a check valve, a second nitrogen emission pipe equipped with a second nitrogen emission valve and a check valve, a third nitrogen emission pipe equipped with a check valve, a liquid nitrogen reheater, and a nitrogen emission tower. One end of the first nitrogen emission pipe is connected to the top of the nitrogen filling tank, and the other end is connected to the nitrogen emission tower. One end of the second nitrogen emission pipe is connected to the top of the subcooler, and the other end is connected to the first nitrogen emission pipe. The inlet of the liquid nitrogen reheater is connected to a nitrogen discharge pipe, and the outlet is connected to one end of the third nitrogen emission pipe, and the other end of the third nitrogen emission pipe is connected to the nitrogen emission tower.

[0014] A method for using a fully subcooled, high-flow-rate liquid methane refueling system includes the following steps:

[0015] (1) System self-test

[0016] The control module performs a comprehensive check on the fully subcooled high-flow liquid methane filling system to confirm that the valves are operating and the signals are normal, and that all tanks are in normal condition.

[0017] Otherwise, an alarm will be triggered.

[0018] (2) Methane pressurization tank pressurization and subcooler precooling

[0019] The control module activates the self-pressurization mechanism of the methane booster tank and nitrogen filling tank, opens the self-pressurization outlet valve and the self-pressurization regulating valve, and enables the self-pressurization vaporizer to work, thereby self-pressurizing the methane booster tank and nitrogen filling tank.

[0020] The control module opens the pressurized liquid outlet valve, the external pressurization shut-off valve, and the pressurizer, and pressurizes the methane in the methane pressurization tank through the pressurizer;

[0021] The control module opens the nitrogen outlet valve and the nitrogen regulating valve to add nitrogen at a low level to the subcooler for precooling.

[0022] (3) Pre-cooling of the methane filling pipe

[0023] The control module opens the second booster inlet valve, the external booster regulating valve on the third booster pipe, the methane outlet valve, the subcooled methane inlet valve, the inlet and outlet valves, the reflux regulating valve, and the reflux valve. The methane in the methane filling tank flows through the conventional methane filling pipe and the cold methane filling pipe into the reflux pipe and then into the methane recovery tank, pre-cooling the conventional methane filling pipe and the subcooled methane filling pipe.

[0024] (4) Methane stabilization in the subcooler

[0025] When the control module detects that the flow rate of the subcooled methane flow meter has reached the target flow range, it replenishes the nitrogen in the subcooler to the target liquid level, and the control module closes the inlet and outlet valves, the reflux regulating valve and the reflux valve.

[0026] Otherwise, continue with a steady flow;

[0027] (5) Methane injection

[0028] The control module opens the subcooled methane outlet valve, the conventional pipeline valve, the conventional pipeline regulating valve, and the methane inlet valve to add methane to the storage tank;

[0029] When the control module detects that the flow rate of the filling flow meter exceeds the target range, it opens the inlet and outlet valves, the reflux regulating valve and the reflux valve to return part of the methane to the methane recovery tank.

[0030] When methane is added to the target level, the control module shuts down the pressurization module, the recovery module, and the methane injection module, stopping the injection.

[0031] The difference between this invention and the prior art lies in the fact that the refueling system of this invention completes the refueling of subcooled high-flow liquid methane through the cooperation of seven modules. During the entire refueling process, various sensors monitor each module in real time and transmit the monitoring signals to the control module in real time. The control module flexibly adjusts according to the status of the refueling system to ensure the efficient and stable operation of the refueling system.

[0032] The fully subcooled high-flow-rate liquid methane refueling system of the present invention has at least the following beneficial effects:

[0033] (1) The dynamic adjustment of the methane subcooling temperature from 92K to 112K was achieved by mixing subcooled methane with conventional methane;

[0034] (2) By designing the methane reflux pipeline, the subcooler is kept running under design conditions, and dynamic adjustment of the methane injection inlet flow rate is achieved.

[0035] (3) Through the design of methane recovery tanks, transfer pipelines, etc., methane recovery and utilization have been realized;

[0036] (4) Through the design of the methane buffer tank and methane flare system, the safe combustion and emission of methane gas during the operation of the methane refueling system were achieved;

[0037] The invention will now be further described with reference to the accompanying drawings. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a fully subcooled high-flow-rate liquid methane refueling system according to the present invention;

[0039] Figure 2 This is a flowchart illustrating the usage method of a fully subcooled high-flow-rate liquid methane refueling system according to the present invention.

[0040] Figure 3 This is a control flow diagram of a fully subcooled high-flow-rate liquid methane refueling system according to the present invention.

[0041] Figure label:

[0042] 01-Storage tank; 02-Pressure boosting module; 21-Methane pressure boosting tank; 211-Self-pressurizing mechanism; 2111-Self-pressurizing pipe; 2112-Self-pressurizing outlet valve; 2113-Self-pressurizing regulating valve; 2114-Self-pressurizing vaporizer; 22-First pressure boosting pipe; 221-Pressure boosting outlet valve; 222-Pressure booster; 223-First filter; 224-Pressure boosting flow meter; 225-External pressure boosting shut-off valve; 23-Second pressure boosting pipe; 231-First pressure boosting inlet valve; 232-External pressure boosting regulating valve; 24-Third pressure boosting pipe; 241-Second pressure boosting inlet valve; 03-Recovery module; 31-Methane recovery tank; 32-Return pipe; 32 1-Inlet / outlet valve; 322-Second filter; 323-Reflux flow meter; 324-Reflux regulating valve; 325-Reflux valve; 33-Transfer pipe; 331-Transfer port; 332-First isolation valve; 333-Second isolation valve; 04-Methane filling module; 41-Methane filling tank; 42-Conventional methane filling pipe; 421-Methane outlet valve; 422-Third filter; 423-Conventional pipeline valve; 424-Conventional pipeline regulating valve; 425-Filling flow meter; 426-Methane inlet valve; 427-Fourth filter; 43-Subcooled methane filling pipe; 431-Subcooled methane outlet valve; 432-Subcooled methane flow meter ; 433-Subcooled methane inlet valve; 05-Nitrogen filling module; 51-Nitrogen filling tank; 52-Subcooler; 53-Nitrogen filling pipe; 531-Nitrogen outlet valve; 532-Fifth filter; 533-Nitrogen flow meter; 534-Nitrogen regulating valve; 535-Nitrogen vent pipe; 536-Nitrogen vent valve; 06-Control module; 07-Methane emission module; 71-Pressure booster emission pipe; 711-First emission valve; 712-Check valve; 72-Storage discharge pipe; 721-First storage discharge pipe; 7211-Fourth emission valve; 722-Second storage discharge pipe; 7221-Fifth emission valve; 723-Third storage discharge pipe; 7231-Sixth emission valve; 73 - Methane emission pipe at workstation; 731- Second emission valve; 732- Workstation emission regulating valve; 74- Arrow vent pipe; 741- Third emission valve; 742- Arrow vent flow meter; 75- Methane buffer tank; 76- Methane flare system; 761- Flare emission tower; 762- Flare emission pipe; 763- Flame arrester; 764- Butterfly valve; 08- Nitrogen emission module; 81- First nitrogen vent pipe; 811- First nitrogen vent valve; 812- Check valve; 82- Second nitrogen vent pipe; 821- Second nitrogen vent valve; 822- Check valve; 83- Third nitrogen vent pipe; 831- Check valve; 84- Liquid nitrogen reheater; 85- Regulating butterfly valve; 86- Nitrogen emission tower. Detailed Implementation

[0043] like Figure 1 , 2As shown in Figure 3, the present invention provides a fully subcooled high-flow-rate liquid methane refueling system, comprising a storage tank 01, a pressurization module 02, the pressurization module 02 comprising a methane pressurization tank 21, a first pressurization pipe 22 equipped with a pressurization outlet valve 221 and a pressurizer 222, a second pressurization pipe 23 equipped with a first pressurization inlet valve 231, and a third pressurization pipe 24 equipped with a second pressurization inlet valve 241; a recovery module 03, the recovery module 03 comprising a methane recovery tank 31 and a return pipe 32 equipped with inlet and outlet valves 321; and a methane refueling module 04, the methane refueling module 04 comprising a methane refueling tank. 41. A conventional methane filling pipe 42 and a subcooled methane filling pipe 43 equipped with a methane outlet valve 421; a nitrogen filling module 05, comprising a nitrogen filling tank 51, a subcooler 52, a nitrogen filling pipe 53 equipped with a nitrogen outlet valve 531, and a nitrogen venting pipe 535 equipped with a nitrogen venting valve 536; one end of the first pressurization pipe 22, the second pressurization pipe 23, and the third pressurization pipe 24 are respectively connected to the methane pressurization tank 21, the methane recovery tank 31, and the methane filling tank 41, and the other end of the second pressurization pipe 23 and the third pressurization pipe 24 are both connected to the other end of the first pressurization pipe 22; conventional methane One end of the filling pipe 42 is connected to the methane filling tank 41, and the other end of the conventional methane filling pipe 42 is connected to the storage tank 01; the subcooled methane filling pipe 43 is connected in parallel to the conventional methane filling pipe 42, and the subcooler 52 is connected in series to the subcooled methane filling pipe 43 to subcool the methane in the pipe. A subcooled methane outlet valve 431 is installed on the subcooled methane filling pipe 43 located between the subcooler 52 and the conventional methane filling pipe 42; one end of the return pipe 32 is connected to the methane recovery tank 31, and the other end is connected to the subcooled methane filling pipe 43, with the connection point located between the subcooler 52 and the subcooled methane outlet valve 431; One end of the nitrogen filling pipe 53 is connected to the nitrogen filling tank 51, and the other end of the nitrogen filling pipe 53 is connected to the nitrogen inlet of the subcooler 52. The nitrogen outlet of the subcooler 52 is connected to the nitrogen discharge pipe 535. The control module 06 pressurizes the methane recovery tank 31 and the methane filling tank 41 by controlling the pressurizing liquid outlet valve 221, the pressurizer 222, the first pressurizing inlet valve 231 and the second pressurizing inlet valve 241. It regulates the methane filling flow rate and temperature to prevent condensation by controlling the nitrogen outlet valve 531, the methane outlet valve 421 and the subcooled methane outlet valve 431. It stabilizes the flow and refluxes the flow by controlling the inlet and outlet valves 321.

[0044] Tank 01 is a key container used by the rocket to store the propellant methane. Its function is to ensure that there is sufficient propellant during the rocket launch process in order to successfully complete the launch mission.

[0045] The fully subcooled high-flow-rate liquid methane refueling system of this invention includes the following modules:

[0046] Boosting module 02: Used to boost the pressure of the recovery module 03 and the methane filling module 04.

[0047] Nitrogen filling module 05: Used to fill the subcooler 52 with liquid nitrogen to subcool methane. The subcooler 52 can be a horizontal subcooler 52 or a vertical subcooler 52.

[0048] Methane filling module 04: works in conjunction with subcooler 52 to fill storage tank 01 with methane at a certain temperature at a certain flow rate.

[0049] Recovery module 03: It is connected to the pressurization module 02 and the methane filling module 04 through pipelines to form a circulation, realizing the recovery and transfer of methane.

[0050] In the pressurization module 02, the left end of the first pressurization pipe 22 is connected to the methane pressurization tank 21 for exporting methane from the tank. The pressurizer 222 is a vaporizer used to pressurize the methane flowing from the methane pressurization tank 21 through the first pressurization pipe 22 to the pressurizer 222. After being pressurized by the pressurizer 222, the liquid methane vaporizes into gas, which then flows into the second pressurization pipe 23 and the third pressurization pipe 24, which are connected to the right end of the first pressurization pipe 22. The right end of the second pressurization pipe 23 is connected to the right end of the first pressurization pipe 22, and the left end of the second pressurization pipe 23 is connected to the top of the methane recovery tank 31 for conveying the pressurized gas to the methane recovery tank 31. The right end of the third pressurization pipe 24 is connected to the right end of the first pressurization pipe 22, and the left end of the third pressurization pipe 24 is connected to the top of the methane filling tank 41 for pressurizing the methane filling tank 41.

[0051] In the nitrogen filling module 05, the left end of the nitrogen filling pipe 53 is connected to the nitrogen filling tank 51, and the right end is connected to the nitrogen filling port of the subcooler 52 for filling with liquid nitrogen. The left end of the nitrogen discharge pipe 535 is connected to the nitrogen discharge port of the subcooler 52 for discharging liquid nitrogen, thus forming a nitrogen channel. By controlling the liquid nitrogen level in the subcooler 52, the subcooling temperature of methane can be regulated.

[0052] In the methane refueling module 04, the conventional methane refueling pipe 42 is connected to the methane refueling tank 41 and the storage tank 01 at its left and right ends, respectively. The supercooled methane refueling pipe 43 is connected in parallel to the conventional methane refueling pipe 42. The supercooler 52 is connected to the supercooled methane refueling pipe 43 to supercool the methane in the pipe and control the temperature of the methane in the supercooled methane refueling pipe 43. By mixing the conventional methane and the supercooled methane, the temperature of the methane refueled into the storage tank 01 is precisely controlled to prevent the methane from condensing during the refueling process. This avoids solid particles formed by the condensation of methane from entering the rocket or blocking the refueling channel, which would affect the normal launch of the rocket.

[0053] In the recovery module 03, the left end of the return pipe 32 is connected to the methane recovery tank 31, and the right end is connected to the subcooled methane filling pipe 43 above the subcooler 52, which is used to return the methane in the subcooled methane filling pipe 43 to the methane recovery tank 31.

[0054] Before methane refueling, control module 06 first performs a comprehensive check on the refueling system to confirm that the opening / closing actions of each valve are normal and that the valve opening / closing return signals are normal. If the valve action is stuck or the opening / closing signal is abnormal, control module 06 will promptly sound an alarm and perform valve maintenance. It will also confirm whether each tank is in normal condition, such as whether the various sensors inside the tank are damaged. If a fault occurs, control module 06 will promptly sound an alarm, and refueling will begin after maintenance is completed.

[0055] Before methane refueling, a pressurization operation is first performed. Control module 06 opens the pressurization outlet valve 221 and starts the pressurizer 222 to pressurize the methane pressurization tank 21. After pressurization, the methane vaporizes in the first pressurization pipe 22 and is transported to the second pressurization pipe 23 and the third pressurization pipe 24. At this time, according to the system process or actual needs, control module 06 opens the first pressurization inlet valve 231 on the second pressurization pipe 23 and / or the second pressurization inlet valve 241 on the third pressurization pipe 24 to pressurize the methane recovery tank 31 and / or the methane refueling tank 41.

[0056] When the subcooler 52 is precooled, the control module 06 opens the nitrogen outlet valve 531 to add nitrogen at a low level to the subcooler 52 for precooling.

[0057] During the pre-cooling of the methane filling pipe, the control module 06 opens the second pressurization inlet valve 241 to pressurize the methane filling tank 41. At the same time, it opens the methane outlet valve 421, the subcooled methane inlet valve 433, the inlet / outlet valve 321, and the reflux valve 325. The methane in the methane filling tank 41 flows under pressure into the conventional methane filling pipe 42, then into the left half of the subcooled methane filling pipe 43, then into the subcooler 52, and then out of the subcooler 52 to the right half of the subcooled methane filling pipe 43. Finally, it flows into the methane recovery tank 31 through the reflux pipe 32, thus completing the pre-cooling of the conventional methane filling pipe 42 and the subcooled methane filling pipe 43.

[0058] After the methane filling pipe is precooled, the methane flow stabilization operation of the subcooler 52 begins. Before the flow stabilization, the subcooled methane outlet valve 431 and the conventional pipeline valve 423 are both closed. The methane in the methane filling tank 41 continuously flows back to the methane recovery tank 31 through the return pipe 32. A subcooled methane flow meter 432 is installed on the subcooled methane filling pipe 43. When the control module 06 detects that the flow rate of the subcooled methane flow meter 432 has reached the target flow range, the nitrogen outlet valve 531 is opened to replenish the liquid nitrogen in the subcooler 52 to the target level. If the liquid nitrogen level is lower than the target level during operation, it will be automatically replenished. Then the inlet and outlet valves 321 and the return valve 325 are closed to stop the return flow.

[0059] After the methane flow in the subcooler 52 is stabilized, methane filling begins. The control module 06 opens the subcooled methane outlet valve 431 and the conventional pipeline valve 423. The methane in the methane filling tank 41 flows into the conventional methane filling pipe 42, and a portion is diverted to the subcooled methane filling pipe 43. The methane in the subcooled methane filling pipe 43 is subcooled by the subcooler 52 to obtain subcooled methane with a temperature lower than that of conventional methane. Then, it flows back to the conventional methane filling pipe 42 through the subcooled methane outlet valve 431, thus achieving the merging of subcooled methane and conventional methane in the conventional methane filling pipe 42. A temperature and pressure sensor is installed on the conventional methane filling pipe 42 downstream of the merging point. The temperature and pressure sensor transmits the real-time monitored temperature and pressure signals to the control module 06. The control module 06 adjusts the subcooling temperature of the subcooler 52 in real time according to the received signals to ensure that the temperature and pressure values ​​of the methane added to the storage tank 01 are within the target range, thus preventing methane condensation during the filling process. When methane is added to the target level, control module 06 shuts down pressurization module 02, recovery module 03 and methane injection module 04, stopping the injection operation.

[0060] It should be noted that this filling system is equipped with multiple pressure and temperature sensors on different pipelines and tanks. A level sensor is installed inside the tank to monitor the liquid level. These sensors transmit the detected signals to the control module 06 in real time. The control module 06 flexibly adjusts the filling system based on the received signals to ensure its safe and stable operation.

[0061] like Figure 1 As shown, both the methane booster tank 21 and the nitrogen filling tank 51 are equipped with a self-pressurizing mechanism 211. The self-pressurizing mechanism 211 includes a self-pressurizing pipe 2111 and a self-pressurizing liquid outlet valve 2112, a self-pressurizing regulating valve 2113, and a self-pressurizing vaporizer 2114 installed on the self-pressurizing pipe 2111. The two ends of the self-pressurizing pipe 2111 in the two sets of self-pressurizing mechanisms are respectively connected to the top and bottom of the methane booster tank 21 and the top and bottom of the nitrogen filling tank 51.

[0062] The self-pressurizing mechanism 211 is used to self-pressurize the methane pressurizing tank 21 and the nitrogen filling tank 51 to ensure that the liquid medium (i.e., liquid methane and liquid nitrogen) in the tank can flow out quickly, thereby improving the filling efficiency.

[0063] The self-pressurization mechanism 211 on the methane pressurization tank 21 and the nitrogen filling tank 51 has the same structure and connection method. Both ends of the self-pressurization pipe 2111 are connected to the top and bottom of the tank body, respectively. That is, the two ends of one self-pressurization pipe 2111 are connected to the top and bottom of the methane pressurization tank 21, respectively, and the two ends of the other self-pressurization pipe 2111 are connected to the top and bottom of the nitrogen filling pipe 53, respectively.

[0064] During the self-pressurization process, the control module 06 first opens the self-pressurization outlet valve 2112 and the self-pressurization regulating valve 2113, and simultaneously starts the self-pressurization vaporizer 2114. The liquid medium in the tank flows into the self-pressurization pipe 2111, and the flow rate is adjusted by controlling the opening of the self-pressurization regulating valve 2113. The liquid medium is pressurized and vaporized by the self-pressurization vaporizer 2114 and transformed into gas. This gas flows back into the tank through the self-pressurization pipe 2111, thereby pressurizing the tank. Under pressure, the liquid medium in the tank flows out from the tank.

[0065] like Figure 1 As shown, the first booster pipe 22 is also equipped with a first filter 223, a booster flow meter 224 and an external booster shut-off valve 225, and the first filter 223, the booster flow meter 224 and the external booster shut-off valve 225 are all located between the booster outlet valve 221 and the booster 222; the second booster pipe 23 and the third booster pipe 24 are both equipped with external booster regulating valves 232.

[0066] The first filter 223 is used to filter the methane in the methane booster tank 21 to prevent impurities from entering the booster 222 and other pipelines, thus preventing blockage or damage.

[0067] The external pressure regulating valve 232 is mainly used to control the pressure of the second pressure boosting pipe 23 and the third pressure boosting pipe 24. According to the pressure boosting requirements, the control module controls the pressure boosting of the second pressure boosting pipe 23 and the third pressure boosting pipe 24 by adjusting the opening of the external pressure regulating valve 232, so as to realize the dynamic adjustment of the pressure boosting of the methane recovery tank 31 and the methane filling tank 41.

[0068] To precisely control the flow rate of methane, a booster flow meter 224 is installed. The booster flow meter 224 is used to monitor the flow rate of the first booster pipe 22 in real time and transmit the flow signal to the control module 06 in real time. Based on the received flow signal and the pressure requirements of the methane filling tank 41 and the methane recovery tank 31, the control module 06 adjusts the self-pressurization mechanism 211 of the methane booster tank 21, thereby precisely controlling the output flow rate of the methane booster tank 21 and improving the dynamic adjustment efficiency of the filling system.

[0069] In addition, to achieve flexible control of the pressurization process, the external pressurization shut-off valve 225 is located near the pressurizer 222. On the one hand, it is used to close the pressurization channel of the filling system and stop pressurizing the methane recovery tank 31 and the methane filling tank 41. On the other hand, other pipelines, such as the transfer pipe 33, are also connected to the first pressurization pipe 22. The connection between the two is located to the left of the external pressurization shut-off valve 225. When the pressurization stops and the control module 06 closes the external pressurization shut-off valve 225, the transfer pipe 33 can still be used normally. At this time, liquid methane can be injected into the methane pressurization tank 21 and the methane filling tank 41 through the transfer pipe 33, or the liquid methane in the methane recovery tank 31 can be transferred to another tank.

[0070] like Figure 1 As shown, the return pipe 32 is also equipped with a second filter 322, a return flow meter 323, a return regulating valve 324, and a return valve 325, and the second filter 322, the return flow meter 323, the return regulating valve 324, and the return valve 325 are all located between the inlet / outlet valve 321 and the connection between the subcooled methane filling pipe 43 and the return pipe 32.

[0071] The second filter 322 is used to filter the methane flowing out of and returning to the methane recovery tank 31 during the transfer process, so as to prevent impurities from entering other tanks and pipelines and prevent them from causing blockages.

[0072] During the methane stabilization process in the subcooler 52, the methane in the methane filling tank 41 continuously flows back to the methane recovery tank 31 through two filling pipelines and the return pipe 32. In order to accurately control the methane return flow rate, a return flow meter 323 is set up. The control module 06 determines whether the methane recovery tank 31 is saturated and whether to start the tank transfer operation based on the flow signal sent by the return flow meter 323 and the pressure and liquid level signals of the methane recovery tank 31. The return flow rate can also be adjusted by the return regulating valve 324.

[0073] To enhance the flexibility of system control, a reflux valve 325 is installed at the right end of the reflux pipe 32. This design serves two purposes: firstly, the reflux valve 325 can prevent methane reflux; secondly, the connection between the transfer pipe 33 and the reflux pipe 32 is located between the inlet / outlet valve 321 and the reflux valve 325. When the reflux valve 325 is closed and reflux stops, the inlet / outlet valve 321 is opened. Through the cooperation of the transfer pipe 33 and the reflux pipe 32, methane can be added to or transferred from the methane recovery tank 31.

[0074] like Figure 1 As shown, the recovery module 03 also includes a transfer pipe 33 connected to the first pressurization pipe 22, the return pipe 32, and the conventional methane filling pipe 42 respectively. The transfer pipe 33 is equipped with a first isolation valve 332 and a second isolation valve 333. The first isolation valve 332 is located between the connection between the first pressurization pipe 22 and the transfer pipe 33 and the connection between the return pipe 32 and the transfer pipe 33. The second isolation valve 333 is located between the connection between the return pipe 32 and the transfer pipe 33 and the connection between the conventional methane filling pipe 42 and the transfer pipe 33. The methane filling and transfer are realized through the transfer pipe 33.

[0075] The transfer pipe 33 connects the methane pressurization tank 21, the methane recovery tank 31, and the methane filling tank 41 to form a circulation system that can both add methane to the methane pressurization tank 21 and the methane filling tank 41 and transfer methane from the methane recovery tank 31 to the methane pressurization tank 21 and the methane filling tank 41.

[0076] The upper end of the transfer pipe 33 is equipped with a transfer port 331 for adding methane. The connection between the transfer pipe 33 and the first pressurization pipe 22 is located between the external pressurization shut-off valve 225 and the pressurization outlet valve 221; the connection between the transfer pipe 33 and the return pipe 32 is located between the inlet / outlet valve 321 and the return valve 325; the connection between the transfer pipe 33 and the conventional methane filling pipe 42 is located to the left of the connection between the subcooled methane filling pipe 43 and the conventional methane filling pipe 42. This arrangement facilitates methane circulation and enables efficient recovery and utilization of methane.

[0077] (1) When the pressurization stops, the external pressurization shut-off valve 225 is closed, and the transfer pipe 33 can cooperate with the first pressurization pipe 22 to inject liquid methane into the methane pressurization tank 21.

[0078] The specific filling process is as follows: Control module 06 closes the first isolation valve 332 and the external pressure shut-off valve 225, and at the same time opens the pressure outlet valve 221. Then, liquid methane is added to the transfer pipe 33 through the transfer port 331. The liquid methane flows into the first pressure pipe 22 along the transfer pipe 33, and finally flows into the methane pressure tank 21 to complete the filling. After the filling is completed, control module 06 can close the relevant valves.

[0079] Similarly, when only methane is added to the methane filling tank 41, the control module 06 can open only the first isolation valve 332, the second isolation valve 333 and the methane outlet valve 421 to add methane to the methane filling tank 41.

[0080] (2) When the reflux stops, the reflux valve 325 is closed, and the transfer pipe 33 can cooperate with the reflux pipe 32 to transfer the liquid methane in the methane recovery tank 31 according to the system requirements.

[0081] When the control module 06 detects that the methane level in the methane recovery tank 31 exceeds a certain level, it initiates the methane transfer procedure. During the transfer, the methane recovery tank 31 is first externally pressurized by the pressurization module 02. That is, the control module 06 opens the inlet / outlet valve 321, the pressurization outlet valve 221, the external pressurization shut-off valve 225, and the first pressurization inlet valve 231. At the same time, the self-pressurization mechanism 211 and the pressurizer 222 on the methane pressurization tank 21 are activated to pressurize the methane recovery tank 31. The methane in the methane recovery tank 31 flows out from the return pipe 32 under pressure. Subsequently, according to system requirements, if methane needs to be poured into the methane pressurization tank 21, the first isolation valve 332 can be opened while the self-pressurization mechanism 211, the external pressurization shut-off valve 225, and the pressurizer 222 are closed to avoid the inability to transfer due to excessive pressurization pressure. If it needs to be poured into the methane filling tank 41, only the second isolation valve 333 and the methane outlet valve 421 need to be opened. Of course, the methane booster tank 21 and the methane filling tank 41 can be switched at the same time. After the switching is completed, the control module 06 can close the relevant valves.

[0082] like Figure 1As shown, the conventional methane filling pipe 42 is sequentially equipped with a third filter 422, a conventional pipeline valve 423, a conventional pipeline regulating valve 424, a filling flow meter 425, a methane inlet valve 426, and a fourth filter 427. The methane outlet valve 421 is located between the third filter 422 and the methane filling tank 41. The filling flow meter 425, the methane inlet valve 426, and the fourth filter 427 are located near the storage tank 01. The connection between the subcooled methane filling pipe 43 and the conventional methane filling pipe 42 is located between the third filter 422 and the filling flow meter 425. The conventional pipeline valve 423 and the conventional pipeline regulating valve 424 are located between the connection between the subcooled methane filling pipe 43 and the conventional methane filling pipe 42. The subcooled methane filling pipe 43 is equipped with a subcooled methane flow meter 432 and a subcooled methane inlet valve 433.

[0083] The third filter 422 is located near the outlet of the methane refueling tank 41 and is mainly used to perform preliminary filtration of the methane in the methane refueling tank 41, that is, to perform preliminary filtration of the methane that has not been subcooled by the cooler 52. The fourth filter 427 is located near the storage tank 01 and is used to further filter the methane after the mixture of subcooled methane and conventional methane to prevent impurities from entering the storage tank 01 and affecting the rocket launch.

[0084] The flow meter 425 is used to monitor the flow rate of the mixture of conventional methane and subcooled methane in real time. Based on this flow rate value, the filling flow rate of the filling system is controlled. When the filling flow rate exceeds the target range, the control module 06 immediately opens the reflux valve 325, reflux regulating valve 324, and inlet / outlet valve 321 on the reflux pipe 32, returning part of the methane to the methane recovery tank 31 through the reflux pipe 32. The reflux flow rate is adjusted by controlling the opening of the reflux regulating valve 324. At this time, methane filling and reflux proceed simultaneously. When the filling flow rate stabilizes within the target range, the control module 06 closes the reflux valve 325 and the inlet / outlet valve 321 to stop the methane reflux, thereby achieving dynamic adjustment of the methane filling flow rate and ensuring the safe and stable operation of the filling system.

[0085] The subcooled methane flow meter 432 is used to monitor the flow rate of the subcooled methane filling pipe 43 in real time, while the subcooled methane inlet valve 433 is used to control the opening and closing of the subcooled methane filling pipe 43. When the subcooled methane inlet valve 433 is closed, it ensures that liquid methane will not flow into the subcooler 52, avoiding methane condensation and damage, and also facilitates the coordination of the conventional methane filling pipe 42 with other pipelines, improving the flexibility and adaptability of the filling system.

[0086] The subcooled methane filling pipe 43 is connected in parallel to the conventional methane filling pipe 42 to form two connection points. The left side is the first connection point and the right side is the second connection point. The conventional methane filling pipe 42 is divided into three pipe sections from left to right. The first pipe section is from the methane filling tank 41 to the first connection point between the subcooled methane filling pipe 43 and the conventional methane filling pipe 42. The methane temperature in this pipe section is approximately the same as that in the methane filling tank 41.

[0087] The second pipeline section extends from the first connection point to the second connection point of the subcooled methane filling pipe 43 and the conventional methane filling pipe 42. The methane flow rate in this section is lower than that in the first section, while the temperature is approximately the same. A conventional pipeline valve 423 and a conventional pipeline regulating valve 424 are installed in this section. The conventional pipeline valve 423 is mainly used to stop the methane delivery in this section, facilitating the first section to cooperate with other pipelines to complete other operations, such as tank transfer and flow stabilization. The conventional pipeline regulating valve 424 is used to control the methane flow rate in this section, enabling dynamic adjustment of the methane filling flow rate.

[0088] The third pipe section is the second connection point between the supercooled methane refueling pipe 43 and the conventional methane refueling pipe 42 to the storage tank 01. The refueling flow meter 425, the methane inlet valve 426, and the fourth filter 427 are installed in this pipe section to facilitate the detection and control of the liquid methane mixed by the two methane refueling pipes, ensuring that the liquid methane refueled into the storage tank 01 is qualified (i.e., the temperature and flow rate are qualified), thereby ensuring the smooth launch of the rocket.

[0089] like Figure 1 As shown, the nitrogen filling pipe 53 is equipped with a fifth filter 532, a nitrogen flow meter 533, and a nitrogen regulating valve 534.

[0090] The fifth filter 532 is mainly used to filter the liquid nitrogen in the nitrogen filling tank 51 to prevent impurities from entering the subcooler 52 and other pipelines, and to prevent them from being blocked.

[0091] The nitrogen flow meter 533 is used to monitor the nitrogen flow rate in real time, and the nitrogen regulating valve 534 is used to control the nitrogen injection flow rate. Together with the level, temperature and pressure sensors in the subcooler 52, the liquid nitrogen level is dynamically adjusted to prevent methane from condensing in the subcooler 52, thereby ensuring the stable operation of the injection system.

[0092] like Figure 1As shown, this invention discloses a fully subcooled high-flow-rate liquid methane filling system, which further includes a methane emission module 07. The methane emission module 07 includes a booster emission pipe 71 equipped with a first emission valve 711 and a check valve 712, a storage pipe 72, a methane station emission pipe 73 equipped with a second emission valve 731 and a check valve 712, an arrow-shaped emission pipe 74 equipped with a check valve 712 and a third emission valve 741, a methane buffer tank 75, and a methane flare system 76. The booster emission pipe 71... One end of the pressurized discharge pipe 71 is connected to the first pressurized pipe 22, and the other end of the pressurized discharge pipe 71 is connected to the methane buffer tank 75. The storage discharge pipe 72 includes a first storage discharge pipe 721 equipped with a fourth discharge valve 7211, a second storage discharge pipe 722 equipped with a fifth discharge valve 7221, and a third storage discharge pipe 723 equipped with a sixth discharge valve 7231. One end of the first storage discharge pipe 721 is connected to the top of the methane pressurized tank 21, and the other end of the first storage discharge pipe 721 is connected to the pressurized discharge pipe 71, and the connection point is located at... Between the first discharge valve 711 and the check valve 712, one end of the second discharge pipe 722 is connected to the top of the methane recovery tank 31, and the other end of the second discharge pipe 722 is connected to the first discharge pipe 721. One end of the third discharge pipe 723 is connected to the top of the methane filling tank 41, and the other end of the third discharge pipe 723 is connected to the first discharge pipe 721. One end of the methane station discharge pipe 73 is connected to the booster discharge pipe 71, and the connection point is located between the first discharge valve 711 and the methane buffer tank 75. The other end of the methane station discharge pipe 73 is connected to the conventional methane filling pipe 42, and the connection is located between the filling flow meter 425 and the methane inlet valve 426; one end of the arrow pipe 74 is connected to the storage tank 01, and the other end of the arrow pipe 74 is connected to the methane buffer tank 75; the methane flare system 76 includes a flare tower 761 and a flare pipe 762, one end of the flare pipe 762 is connected to the methane buffer tank 75, and the other end of the flare pipe 762 is connected to the flare tower 761.

[0093] The methane emission module 07 plays a crucial role in ensuring the safe and stable operation of the system. Its main function is to properly handle the gaseous methane in various pipelines, tanks and storage tanks 01, avoid safety accidents caused by methane accumulation, and ensure that the gaseous methane can be discharged efficiently and safely. Since methane is a flammable gas, if it is not handled in time, the accumulated methane gas may cause safety accidents such as combustion and explosion.

[0094] The methane buffer tank 75 is mainly used for gas-liquid separation of methane to prevent liquid methane from entering the flare, which could lead to unstable combustion or extinguishing, thus affecting the flare's combustion efficiency for gaseous methane. The methane buffer tank 75 is also equipped with a self-pressurizing pipe 2111, which is fitted with a pressurizing valve and a vaporizer. The vaporizer vaporizes the liquid methane carried by the gaseous methane in the methane buffer tank 75 and the liquefied liquid methane from the gaseous methane into gas, thus pressurizing the methane buffer tank 75 before discharging it to the flare tower 761 for combustion and emission, preventing liquid accumulation in the tank.

[0095] The flare pipe 762 connects the methane buffer tank 75 and the flare tower 761, and its function is to transport the gaseous methane collected in the methane buffer tank 75 to the flare tower 761 for combustion and emission. A flame arrester 763 and a check valve 712 are installed in series on the flare pipe 762. The flame arrester 763 prevents flame propagation, and the check valve 712 prevents backflow of air. In addition, a butterfly valve 764 is installed on the flare pipe 762 in parallel with the flame arrester 763, providing redundancy. If the flame arrester 763 fails, methane gas can be discharged to the flare tower 761 through the butterfly valve 764. These components work together to enhance the stability and safety of the methane flare system 76's exhaust.

[0096] The booster discharge pipe 71 is used to discharge gaseous methane in the booster pipeline. The left and right ends of the booster discharge pipe 71 are connected to the first booster pipe 22 and the methane buffer tank 75, respectively. When the boosting ends or an overpressure occurs, the control module 06 will open the first discharge valve 711 to discharge the residual gaseous methane in the booster pipe into the methane buffer tank 75.

[0097] The discharge pipe 72 is used to discharge gaseous methane from the three tanks. The left ends of the first discharge pipe 721, the second discharge pipe 722, and the third discharge pipe 723 are connected to the tops of the methane pressurization tank 21, the methane recovery tank 31, and the methane filling tank 41, respectively, facilitating the discharge of gaseous methane from the tanks. The other end of the first discharge pipe 721 is connected to the pressurization discharge pipe 71, with the connection point located to the right of the first discharge valve 711 and to the left of the check valve 712, allowing the pressurization discharge pipe 71 and the discharge pipe 72 to discharge gaseous methane simultaneously or individually. The right ends of the second discharge pipe 722 and the third discharge pipe 723 are both connected to the first discharge pipe 721, with the connection points located to the right of the fourth discharge valve 7211, similarly facilitating simultaneous or individual discharge from the three discharge pipes 72. During discharge, the control module 06 opens the fourth discharge valve, the fifth discharge valve 7221, and the sixth discharge valve 7231 as needed by the system, discharging the gaseous methane into the methane buffer tank 75.

[0098] The lower end of the methane discharge pipe 73 is connected to the third section of the conventional methane filling pipe 42, and the upper end is connected to the booster discharge pipe 71. The connection point is also located to the right of the first discharge valve 711 and to the left of the methane buffer tank 75. It is used to discharge the gas generated after mixing with methane. The methane discharge pipe 73 is also equipped with a discharge regulating valve 732. During discharge, the control module 06 opens the second discharge valve 731 and controls the methane discharge rate by adjusting the opening of the discharge regulating valve 732, ultimately discharging the methane gas into the methane buffer tank 75. The check valves 712 on the pipeline are all for preventing gas backflow and avoiding impact on the filling system.

[0099] The rocket exhaust pipe 74 is used to discharge gases (methane and air) from the rocket propellant tank 01. The lower end of the exhaust pipe 74 is connected to the propellant tank 01, and the upper end is connected to the methane buffer tank 75. An exhaust flow meter 742 is also installed on the exhaust pipe 74. Together with pressure, temperature, and liquid level sensors inside the propellant tank 01, these sensors regulate the pressure, temperature, and liquid level of the propellant tank 01. During discharge, the control module 06 opens the third exhaust valve 741, discharging the gas into the methane buffer tank 75.

[0100] The working principle of the methane emission module 07 is as follows: the pressurized emission pipe 71, the storage pipe 72, the methane station emission pipe 73, and the arrow pipe 74 respectively discharge their corresponding gases, liquids, or gas-liquid mixtures to the methane buffer tank 75. The methane buffer tank 75 performs gas-liquid separation on these gases, liquids, or gas-liquid mixtures. The separated gaseous methane is transported to the flare emission tower 761 through the flare emission pipe 762 for high-altitude combustion and emission, thereby achieving safe and effective treatment of gaseous methane by the entire system.

[0101] like Figure 1 As shown, the present invention discloses a fully subcooled high-flow-rate liquid methane filling system, which further includes a nitrogen emission module 08. The nitrogen emission module 08 includes a first nitrogen emission pipe 81 equipped with a first nitrogen emission valve 811 and a check valve 712, a second nitrogen emission pipe 82 equipped with a second nitrogen emission valve 821 and a check valve 712, a third nitrogen emission pipe 83 equipped with a check valve 712, a liquid nitrogen reheater 84, and a nitrogen emission tower 86. One end of the first nitrogen emission pipe 81 is connected to the top of the nitrogen filling tank 51, and the other end of the first nitrogen emission pipe 81 is connected to the nitrogen emission tower 86. One end of the second nitrogen emission pipe 82 is connected to the top of the subcooler 52, and the other end of the second nitrogen emission pipe 82 is connected to the first nitrogen emission pipe 81. The inlet of the liquid nitrogen reheater 84 is connected to the nitrogen discharge pipe 535, and the outlet is connected to one end of the third nitrogen emission pipe 83. The other end of the third nitrogen emission pipe 83 is connected to the nitrogen emission tower 86.

[0102] The working principle of the nitrogen emission module 08 is similar to that of the methane emission module 07. It is mainly used to discharge nitrogen gas from the subcooler 52 and the nitrogen filling tank 51, as well as to handle the liquid nitrogen leaked from the subcooler 52. The nitrogen emission tower 86 is an important component of this module and is mainly used to safely discharge nitrogen gas at high altitude to meet the technical requirements of the "Integrated Emission Standard for Air Pollutants".

[0103] The left end of the first nitrogen venting pipe 81 is connected to the top of the nitrogen filling pipe 53 to facilitate nitrogen venting, and the right end is connected to the nitrogen venting tower 86. When venting, the control module 06 opens the first nitrogen venting valve 811 to vent the nitrogen in the nitrogen filling tank 51 to the high altitude through the nitrogen venting tower 86.

[0104] The second nitrogen venting pipe 82 is mainly used for venting nitrogen from the subcooler 52. Its left end is connected to the nitrogen venting outlet at the top of the subcooler 52, and its right end is connected to the first nitrogen venting pipe 81 and located to the right of the first nitrogen venting valve 811. This arrangement facilitates the simultaneous or separate venting of nitrogen from the two nitrogen venting pipes. In addition, a regulating butterfly valve 85 is installed on the first nitrogen venting pipe 81 near the nitrogen venting tower 86 to regulate the nitrogen venting rate. The venting flow rate of the first nitrogen venting pipe 81 and the second nitrogen venting pipe 82 is controlled by regulating the butterfly valve 85.

[0105] The third nitrogen drain pipe 83 is used to handle liquid nitrogen in the subcooler 52. The right end of the nitrogen drain pipe 535 is connected to the inlet of the liquid nitrogen regenerator 84, and the outlet of the liquid nitrogen regenerator 84 is connected to the left end of the third nitrogen drain pipe 83. The right end of the third nitrogen drain pipe 83 is connected to the nitrogen discharge tower 86. When the control module 06 adjusts the subcooling temperature of the subcooler 52 or when subcooling is complete and liquid nitrogen needs to be discharged, the liquid nitrogen in the subcooler 52 is discharged from the nitrogen drain pipe 535. The discharged liquid nitrogen is reheated and vaporized into nitrogen gas through the liquid nitrogen regenerator 84. The nitrogen gas then flows into the third nitrogen drain pipe 83 and is finally discharged from the nitrogen discharge tower 86 at high altitude. When it is necessary to discharge nitrogen gas from the subcooler 52, the control module 06 opens the second nitrogen discharge valve 821, and nitrogen gas flows from the second nitrogen drain pipe 82 to the first nitrogen drain pipe 81, finally flowing into the nitrogen discharge tower 86 and being discharged at high altitude.

[0106] This refueling system uses seven modules that work together to refuel subcooled, high-flow-rate liquid methane. Throughout the refueling process, various sensors monitor each module in real time and transmit the monitoring signals to the control module 06. The control module 06 flexibly adjusts the system according to its status to ensure efficient and stable operation.

[0107] The illustration shown in this invention is for refueling only one methane storage tank 01. When the rocket has multiple methane storage tanks 01, corresponding refueling tanks, methane supercoolers 52, refueling pipelines and discharge pipelines can be added according to the principle shown in this invention.

[0108] A method for using a fully subcooled, high-flow-rate liquid methane refueling system includes the following steps:

[0109] (1) System self-test

[0110] Control module 06 performs a comprehensive check on the fully subcooled high-flow liquid methane filling system to confirm that the valves are operating normally and the signals are normal, and that all tanks are in normal condition.

[0111] Otherwise, an alarm will be triggered.

[0112] After the inspection is completed, liquid methane is added to the methane pressurization tank 21 and the methane filling tank 41 through the transfer pipe 33. During the filling, the control module 06 opens the pressurization outlet valve 221, the first isolation valve 332, the second isolation valve 333 and the methane outlet valve 421 to add the target liquid level of methane to the methane pressurization tank 21 and the methane filling tank 41. At the same time, the methane emission module 07 is activated to release the gas in the methane pressurization tank 21 and the methane filling tank 41. After the filling is completed, the control module 06 closes the relevant valves.

[0113] (2) Methane pressurization tank 21 pressurization and subcooler 52 precooling

[0114] The control module 06 starts the self-pressurization mechanism 211 of the methane pressurization tank 21 and the nitrogen filling tank 51, opens the self-pressurization outlet valve 2112 and the self-pressurization regulating valve 2113, and makes the self-pressurization vaporizer 2114 work to self-pressurize the methane pressurization tank 21 and the nitrogen filling tank 51.

[0115] The control module 06 opens the pressurized liquid outlet valve 221, the external pressurization shut-off valve 225 and the pressurizer 222, and pressurizes the methane in the methane pressurization tank 21 through the pressurizer 222;

[0116] The control module 06 opens the nitrogen outlet valve 531 and the nitrogen regulating valve 534 to add nitrogen at a low level to the subcooler 52 for precooling.

[0117] (3) Pre-cooling of the methane filling pipe

[0118] The control module 06 opens the second booster inlet valve 241, the external booster regulating valve 232 on the third booster pipe 24, the methane outlet valve 421, the subcooled methane inlet valve 433, the inlet and outlet valves 321, the reflux regulating valve 324, and the reflux valve 325. The methane in the methane filling tank 41 flows into the reflux pipe 32 and then into the methane recovery tank 31 through the conventional methane filling pipe 42 and the liquid-cooled methane filling pipe 43, pre-cooling the conventional methane filling pipe 42 and the subcooled methane filling pipe 43.

[0119] (4) Subcooler 52 Methane stabilization

[0120] When the control module 06 detects that the flow rate of the subcooled methane flow meter 432 has reached the target flow range, the nitrogen in the subcooler 52 is replenished to the target liquid level, and the control module 06 closes the inlet / outlet valve 321, the reflux regulating valve 324 and the reflux valve 325.

[0121] Otherwise, continue with a steady flow;

[0122] (5) Methane injection

[0123] Control module 06 opens subcooled methane outlet valve 431, conventional pipeline valve 423, conventional pipeline regulating valve 424 and methane inlet valve 426 to add methane to storage tank 01;

[0124] When the control module 06 detects that the flow rate of the filling flow meter 425 exceeds the target range, it opens the inlet / outlet valve 321, the reflux regulating valve 324 and the reflux valve 325 to return part of the methane to the methane recovery tank 31.

[0125] When methane is added to the target level, control module 06 shuts down pressurization module 02, recovery module 03 and methane injection module 04, stopping the injection.

[0126] During the process of adding methane to storage tank 01,

[0127] If the control module 06 detects that the liquid methane level in the methane recovery tank 31 has reached the transfer level, it immediately opens the inlet / outlet valve 321, the booster outlet valve 221, the external booster shut-off valve 225, and the first booster inlet valve 231. At this time, if the self-boosting mechanism 211 and the booster 222 are not open, the self-boosting mechanism 211 and the booster 222 on the methane booster tank 21 are simultaneously activated to boost the pressure in the methane recovery tank 31. Based on the methane level in the methane booster tank 21 and the methane filling tank 41, the methane in the methane recovery tank 31 is poured into the methane booster tank 21 or the methane filling tank 41. After the transfer is completed, the control module 06 closes the relevant valves.

[0128] If the control module 06 detects that the pressure in the storage tank 01, methane booster tank 21, methane recovery tank 31, or methane filling tank 41 exceeds the preset pressure range, it immediately starts the methane emission module 07, opens the emission valves on the corresponding gas emission pipelines of the storage tank 01 and the three tanks (i.e., the corresponding emission valves on the arrow discharge pipe 74, the first storage discharge pipe 721, the second storage discharge pipe 722, or the third storage discharge pipe 723) to release gas until the pressure in the storage tank 01 and the three tanks returns to normal, the control module 06 closes the relevant valves.

[0129] Similarly, if the control module 06 detects that the pressure in the nitrogen filling tank 51 exceeds the preset pressure range, it will immediately start the nitrogen discharge module 08, open the first nitrogen discharge valve 811 and the regulating butterfly valve 85, and discharge the gas through the first nitrogen discharge pipe 81.

[0130] If the control module 06 detects that the pressure inside the subcooler 52 exceeds the preset pressure range, it will immediately open the second nitrogen venting valve 821 and the regulating butterfly valve 85 to vent the nitrogen.

[0131] It should be noted that the terms "center", "upper", "lower", "front", "rear", "left", "right", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0132] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0133] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A full subcooling high flow liquid methane refueling system comprising a tank, characterized in that: The booster module comprises a methane booster tank, a first booster pipe provided with a booster outlet valve and a booster, a second booster pipe provided with a first booster inlet valve, and a third booster pipe provided with a second booster inlet valve; The recovery module comprises a methane recovery tank and a return pipe provided with an inlet and outlet valve; The methane filling module comprises a methane filling tank, a conventional methane filling pipe provided with a methane outlet valve, and a subcooled methane filling pipe; The nitrogen filling module comprises a nitrogen filling tank, a subcooler, a nitrogen filling pipe provided with a nitrogen outlet valve, and a nitrogen discharge pipe provided with a nitrogen discharge valve; One end of each of the first booster pipe, the second booster pipe, and the third booster pipe is connected to the methane booster tank, the methane recovery tank, and the methane filling tank, respectively, and the other end of each of the second booster pipe and the third booster pipe is connected to the other end of the first booster pipe. One end of the conventional methane filling pipe is connected to the methane filling tank, and the other end of the conventional methane filling pipe is connected to a storage tank; the subcooled methane filling pipe is connected in parallel to the conventional methane filling pipe, and the subcooler is connected in series to the subcooled methane filling pipe to subcool the methane in the pipe; a subcooled methane outlet valve is arranged on the subcooled methane filling pipe between the subcooler and the conventional methane filling pipe. One end of the return pipe is connected to the methane recovery tank, and the other end of the return pipe is connected to the subcooled methane filling pipe, and the connection is located between the subcooler and the subcooled methane outlet valve. One end of the nitrogen filling pipe is connected to the nitrogen filling tank, and the other end of the nitrogen filling pipe is connected to a nitrogen inlet of the subcooler; a nitrogen outlet of the subcooler is connected to the nitrogen discharge pipe. The control module controls the methane recovery tank and the methane filling tank to be boosted by controlling the booster outlet valve, the booster, the first booster inlet valve, and the second booster inlet valve, controls the filling flow rate and temperature of the methane to prevent condensation by controlling the nitrogen outlet valve, the methane outlet valve, and the subcooled methane outlet valve, and controls the flow stabilization and return by controlling the inlet and outlet valve.

2. A full subcooling high flow rate liquid methane refueling system as in claim 1, wherein: The methane booster tank and the nitrogen filling tank are each provided with a self-boosting mechanism comprising a self-boosting pipe and a self-boosting outlet valve, a self-boosting regulating valve, and a self-boosting vaporizer arranged on the self-boosting pipe; the two ends of the self-boosting pipe in the self-boosting mechanism are connected to the top and bottom of the methane booster tank and the top and bottom of the nitrogen filling tank, respectively.

3. A full subcooling high flow rate liquid methane refueling system as in claim 1, wherein: The first booster pipe is further provided with a first filter, a booster flow meter, and an external booster stop valve, and the first filter, the booster flow meter, and the external booster stop valve are located between the booster outlet valve and the booster; the second booster pipe and the third booster pipe are each provided with an external booster regulating valve.

4. A full subcooling high flow rate liquid methane refueling system as in claim 3, wherein: The return pipe is further provided with a second filter, a return flow meter, a return regulating valve, and a return valve, and the second filter, the return flow meter, the return regulating valve, and the return valve are located between the inlet and outlet valve and the connection between the subcooled methane filling pipe and the return pipe.

5. A full subcooling high flow rate liquid methane refueling system according to claim 4, wherein: The recovery module further comprises a transfer pipe connected with the first booster pipe, the return pipe and the conventional methane filling pipe, respectively, and provided with a first isolation valve and a second isolation valve, the first isolation valve being located between the connection of the first booster pipe and the transfer pipe and the connection of the return pipe and the transfer pipe, and the second isolation valve being located between the connection of the return pipe and the transfer pipe and the connection of the conventional methane filling pipe and the transfer pipe, so as to realize methane filling and tank emptying through the transfer pipe.

6. A full subcooling high flow rate liquid methane refueling system as in claim 5, wherein: The conventional methane filling pipe is sequentially provided with a third filter, a conventional pipeline valve, a conventional pipeline regulating valve, a filling flow meter, a methane liquid inlet valve and a fourth filter, the methane liquid outlet valve being located between the third filter and the methane filling tank, the filling flow meter, the methane liquid inlet valve and the fourth filter being arranged close to the storage tank, the connection of the subcooled methane filling pipe and the conventional methane filling pipe being located between the third filter and the filling flow meter, and the conventional pipeline valve and the conventional pipeline regulating valve being located between the connection of the subcooled methane filling pipe and the conventional methane filling pipe; the subcooled methane filling pipe is provided with a subcooled methane flow meter and a subcooled methane liquid inlet valve.

7. A full subcooling high flow rate liquid methane refueling system as in claim 3, wherein: The nitrogen filling pipe is provided with a fifth filter, a nitrogen flow meter and a nitrogen regulating valve.

8. A full subcooling high flow rate liquid methane refueling system as in claim 3, wherein: The methane discharge module comprises a booster discharge pipe provided with a first discharge valve and a check valve, a library discharge pipe, a methane station discharge pipe provided with a second discharge valve and a check valve, an arrow discharge pipe provided with a check valve and a third discharge valve, a methane buffer tank and a methane flare system, one end of the booster discharge pipe being connected with the first booster pipe, and the other end of the booster discharge pipe being connected with the methane buffer tank; the library discharge pipe comprises a first library discharge pipe provided with a fourth discharge valve, a second library discharge pipe provided with a fifth discharge valve and a third library discharge pipe provided with a sixth discharge valve, one end of the first library discharge pipe being connected at the top of the methane booster tank, the other end of the first library discharge pipe being connected with the booster discharge pipe, and the connection being located between the first discharge valve and the check valve, one end of the second library discharge pipe being connected at the top of the methane recovery tank, the other end of the second library discharge pipe being connected with the first library discharge pipe, and one end of the third library discharge pipe being connected at the top of the methane filling tank, the other end of the third library discharge pipe being connected with the first library discharge pipe; one end of the methane station discharge pipe is connected with the booster discharge pipe, and the connection is located between the first discharge valve and the methane buffer tank, and the other end of the methane station discharge pipe is connected with the conventional methane filling pipe, and the connection is located between the filling flow meter and the methane liquid inlet valve; one end of the arrow discharge pipe is connected with the storage tank, and the other end of the arrow discharge pipe is connected with the methane buffer tank; the methane flare system comprises a flare discharge tower and a flare discharge pipe, one end of the flare discharge pipe being connected with the methane buffer tank, and the other end of the flare discharge pipe being connected with the flare discharge tower.

9. A full subcooling high flow rate liquid methane refueling system as in claim 3, wherein: Also include nitrogen emission module, the nitrogen emission module includes the first nitrogen emission pipe installed with the first nitrogen emission valve and check valve, the second nitrogen emission pipe installed with the second nitrogen emission valve and check valve, the third nitrogen emission pipe installed with check valve, liquid nitrogen back temperature regulator and nitrogen emission tower, one end of the first nitrogen emission pipe is connected at the top of nitrogen filling tank, the other end of the first nitrogen emission pipe is connected with nitrogen emission tower;The second nitrogen emission pipe one end is connected at the top of supercooler, the other end of the second nitrogen emission pipe is connected with the first nitrogen emission pipe;The liquid nitrogen back temperature regulator inlet is connected with nitrogen discharge pipe, the outlet is connected with one end of the third nitrogen emission pipe, the other end of the third nitrogen emission pipe is connected with nitrogen emission tower.

10. A method of using a full subcooling high flow rate liquid methane refueling system as claimed in any one of claims 1-9, characterized by Including the following steps: (1) System self-checking The control module checks the full supercooling large flow liquid methane filling system comprehensively, confirms that each valve switch action and signal is normal, and each tank body is in normal state; Otherwise, start alarm; (2) Methane booster tank pressurization and supercooler precooling The control module starts the self-pressurization mechanism of the methane booster tank and the nitrogen filling tank, opens the self-pressurization outlet valve and the self-pressurization regulating valve, so that the self-pressurization vaporizer works, and the methane booster tank and the nitrogen filling tank are self-pressurized; The control module opens the pressurization outlet valve, the external pressurization stop valve and the pressurizer, and pressurizes the methane in the methane booster tank through the pressurizer; The control module opens the nitrogen outlet valve and the nitrogen regulating valve, and adds low liquid level nitrogen to the supercooler to precool the supercooler; (3) Methane filling pipe precooling The control module opens the second pressurization inlet valve, the external pressurization regulating valve on the third pressurization pipe, the methane outlet valve, the supercooled methane inlet valve, the inlet and outlet valve, the backflow regulating valve and the backflow valve, the methane in the methane filling tank flows into the backflow pipe and then into the methane recovery tank through the conventional methane filling pipe and the cold methane filling pipe, and the conventional methane filling pipe and the supercooled methane filling pipe are pre-cooled; (4) Supercooler methane flow stabilization When the control module detects that the flow of the supercooled methane flowmeter reaches the target flow range, the nitrogen in the supercooler is added to the target liquid level, and the control module closes the inlet and outlet valve, the backflow regulating valve and the backflow valve; Otherwise, continue to stabilize the flow; (5) Methane filling The control module opens the supercooled methane outlet valve, the conventional pipe valve, the conventional pipe regulating valve and the methane inlet valve to fill the tank with methane; When the control module detects that the flow of the filling flowmeter exceeds the target range, open the inlet and outlet valve, the backflow regulating valve and the backflow valve, and return part of the methane to the methane recovery tank; When the methane is filled to the target liquid level, the control module closes the pressurization module, the recovery module and the methane filling module, and stops filling.

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