Drop pressure double-component propelling system

Abstract

The invention provides a pressure drop two-component propulsion system. The pressure drop two-component propulsion system comprises a fuel storage module, an oxidant storage module, a fuel supply module, an oxidant supply module, a main engine module and a backup engine module. The fuel supply module is communicated with the fuel storage module, the main engine module and the backup engine module; and the oxidant supply module is communicated with the oxidant storage module, the main engine module and the backup engine module. On the premise that the light weight of the double-component pressure drop propulsion system is guaranteed and few whole-satellite driving resources are needed, control over the propellant amount and the pressurized gas amount in the storage boxes in the filling process of the double-component pressure drop propulsion system is guaranteed, and then the propellant consumption self-adaptive balance capacity during in-orbit double-storage-box parallel work is guaranteed; meanwhile, switching of multiple in-orbit working modes can be achieved, and satellite centroid adjustment and fault isolation are facilitated.

Description

Technical Field

[0001] The present invention belongs to the field of spacecraft propulsion technology, and in particular relates to a drop-pressure bipropellant propulsion system. Background Art

[0002] The bipropellant drop pressure propulsion system is mainly used in long-life low-orbit and high-orbit satellites because of its simple and reliable system, light weight and small size, strong replenishment capacity, and the ability to self-correct balanced emission deviations in orbit.

[0003] To achieve a more reasonable aspect ratio and reduce the impact of propellant discharge on the center of mass of the entire satellite, the current satellite bipropellant pressure-reduction propulsion system adopts a four-tank flat layout, that is, two tanks of the same component are arranged symmetrically along the satellite axis. The liquid circuits of the two tanks of the same component are connected by pipelines, forming a U-shaped tube device. During filling, propellant is added to both tanks simultaneously through the liquid-end add-discharge valve. After filling is completed, pressurization is carried out through the gas-end add-discharge valve of each tank. When in orbit, the propulsion system expands as the propellant is discharged, and then pressure reduction is carried out. However, this solution has the problem of uneven liquid mass in the tanks of the same component during propellant filling, and the liquid movement in the tanks during filling and pressurization leads to further imbalance. This problem can lead to a large deviation in the gas filling volume of the two tanks during pressurization, exacerbating the uneven discharge volume and unusable propellant during in-orbit use. In order to achieve balanced filling of the two tanks with the same component, the entire filling process relies on expensive satellite center of mass detection equipment and cumbersome two-tank liquid balance adjustment strategies, which limits the use of the two-propellant drop pressure propulsion system.

[0004] At present, the existing relevant technical achievements mainly include:

[0005] The Earth-Moon shuttle propulsion system (patent document CN11491300A) provides a propulsion system for an Earth-Moon shuttle, but uses a constant-pressure system. Because the constant-pressure tanks are well-equipped, each tank has a filling port and a parallel self-locking valve downstream, allowing for the filling of a single tank. Since the filling is not done in parallel, there will be no large deviation in the air volume between the two tanks during pressurization. However, the technical solution in this patent document has a large number of self-locking valves and a complex system structure.

[0006] In response to the technical problems existing in the prior art, the present invention proposes a drop-pressure bipropellant propulsion system, which can ensure balanced filling and balanced pressurization while ensuring the lightweight, small size and less driving resources of the drop-pressure bipropellant propulsion system. Summary of the Invention

[0007] In view of the defects in the prior art, the purpose of the present invention is to provide a drop-pressure bipropellant propulsion system.

[0008] According to the present invention, a drop-pressure bipropellant propulsion system is provided, comprising: a fuel storage module, an oxidant storage module, a fuel supply module, an oxidant supply module, a main engine module, and a backup engine module;

[0009] The fuel supply module is in communication with the fuel storage module, the primary engine module and the backup engine module;

[0010] The oxidant supply module is communicated with the oxidant storage module, the main engine module, and the backup engine module.

[0011] Preferably, the material storage module includes: a first gas circuit adding and discharging valve, a third gas circuit adding and discharging valve, a main fuel tank, a backup fuel tank, a fifth liquid circuit adding and discharging valve, a seventh liquid circuit adding and discharging valve, and a first pressure sensor;

[0012] The fuel storage module is used to store the combustion agent and the pressurized gas;

[0013] The first gas circuit add-discharge valve, the main fuel tank, and the fifth liquid circuit add-discharge valve are connected in sequence;

[0014] The third gas circuit plus and drain valve, the backup fuel tank, and the seventh liquid circuit plus and drain valve are connected in sequence;

[0015] The first pressure sensor is located at one end of the primary fuel tank or the backup fuel tank.

[0016] Preferably, the oxidant storage module comprises: a second gas circuit and a drain valve, a fourth gas circuit and a drain valve, a primary oxidant storage tank, a backup oxidant storage tank, a second pressure sensor, a sixth liquid circuit and a drain valve, and an eighth liquid circuit and a drain valve;

[0017] The oxidant storage module is used to store oxidant and pressurized gas; the second gas line with a discharge valve, the main oxidant storage tank, and the sixth liquid line with a discharge valve are connected in sequence;

[0018] The fourth gas line with a drain valve, a backup oxidant storage tank, and the eighth liquid line with a drain valve are connected in sequence;

[0019] The second pressure sensor is located at one end of the main oxidant tank or the backup oxidant tank.

[0020] Preferably, the fuel supply module comprises: a first self-latching valve, a third self-latching valve, a fifth self-latching valve, a third pressure sensor, and a fifth pressure sensor;

[0021] The third self-locking valve is connected to the fifth liquid circuit adding and discharging valve and then connected to the main fuel tank;

[0022] The fifth self-locking valve is connected to the seventh liquid line adding and discharging valve and then connected to the backup fuel tank;

[0023] The two ends of the first self-latching valve are respectively connected to the inlet of the third self-latching valve and the fifth self-latching valve;

[0024] The third pressure sensor and the fifth pressure sensor are respectively arranged at the outlets of the third self-locking valve and the fifth self-locking valve.

[0025] Preferably, the oxidant supply module comprises: a second latching valve, a fourth latching valve, a sixth latching valve, a fourth pressure sensor, and a sixth pressure sensor;

[0026] The fourth self-locking valve is connected to the sixth liquid line and then connected to the main oxidant storage tank;

[0027] The sixth self-locking valve is connected to the eighth liquid line drain valve and then connected to the backup oxidant storage tank;

[0028] The two ends of the second self-latching valve are connected to the inlet of the fourth self-latching valve and the sixth self-latching valve respectively;

[0029] The fourth pressure sensor and the sixth pressure sensor are respectively arranged at the outlets of the fourth self-locking valve and the sixth self-locking valve.

[0030] Preferably, the main engine module comprises a plurality of main bipropellant engines, the fuel path of the main bipropellant engine is connected to the downstream of the third self-locking valve, and the oxidant path of the main bipropellant engine is connected to the downstream of the fourth self-locking valve;

[0031] The backup engine module includes a plurality of backup bipropellant engines, wherein the fuel path of the backup bipropellant engine is connected to the downstream of the fifth self-latching valve, and the oxidant path of the backup bipropellant engine is connected to the downstream of the sixth self-latching valve;

[0032] All components of the drop-pressure bipropellant propulsion system are connected by conduits, and all non-metallic seals in contact with the propellant in the drop-pressure bipropellant propulsion system are first-level compatible.

[0033] According to a method for filling a drop-pressure bipropellant propulsion system provided by the present invention, the drop-pressure bipropellant propulsion system provided by the present invention is used, comprising:

[0034] Step SF1: The fuel enters the primary fuel tank through the fifth fluid line adding and discharging valve, and enters the backup fuel tank through the seventh fluid line adding and discharging valve;

[0035] Step SF2: the pressurized gas enters the primary fuel tank through the first gas path addition and discharge valve, and enters the backup fuel tank through the third gas path addition and discharge valve;

[0036] Step SF3: The oxidant enters the primary oxidant storage tank through the sixth liquid line adding and discharging valve, and enters the backup oxidant storage tank through the eighth liquid line adding and discharging valve;

[0037] Step SF4: the pressurized gas enters the primary oxidant tank through the second gas path addition and discharge valve, and enters the backup oxidant tank through the fourth gas path addition and discharge valve;

[0038] During the filling process, all self-locking valves are in the closed state.

[0039] According to a working method of a drop-pressure bipropellant propulsion system provided by the present invention, the drop-pressure bipropellant propulsion system provided by the present invention is used, comprising:

[0040] Step SW1: The fuel stored in the primary fuel tank and the backup fuel tank is delivered to the primary engine module or the backup engine module through the fuel supply module (3);

[0041] Step SW2: The oxidant stored in the primary oxidant tank and the backup oxidant tank is delivered to the primary engine module or the backup engine module through the oxidant supply module;

[0042] Step SW3: The fuel and oxidizer are mixed and burned in the engine and ejected through the nozzle to generate thrust;

[0043] When the system is working, there is a thermal control component to control the temperature of the tank to achieve pressure regulation of different tanks.

[0044] According to a working method of a drop-pressure bipropellant propulsion system provided by the present invention, the drop-pressure bipropellant propulsion system provided by the present invention is used, comprising:

[0045] Before filling the system, the first, third, fifth, second, fourth, and sixth self-locking valves are set to the closed state; the corresponding tanks are quantitatively filled through multiple liquid filling and discharge valves connected in series with each tank. After filling is completed, the corresponding tanks are quantitatively pressurized through the gas filling and discharge valves connected in series with each tank.

[0046] When flying in orbit, the first self-locking valve, the third self-locking valve, the fifth self-locking valve, the second self-locking valve, the fourth self-locking valve, and the sixth self-locking valve are set to the open state; at this time, the two boxes with the same component work in parallel, and the main or backup engine is used according to demand.

[0047] According to the present invention, a method for operating a pressure drop bipropellant propulsion system in a fault state is provided, which uses the pressure drop bipropellant propulsion system provided by the present invention, comprising:

[0048] When a single tank of a component fails, the first and second self-locking valves are closed to isolate the faulty tank, and the system switches to single-tank operation mode.

[0049] When the satellite's center of mass deviation needs to be corrected, by closing the first and second self-locking valves, the pre-set main tank main engine module and backup tank backup engine module are used respectively to control the remaining propellant in different tanks and thus adjust the center of mass of the entire satellite;

[0050] When an engine module failure occurs, the fault is isolated by closing the self-locking valve upstream of the faulty engine module, and the operation mode is switched to the dual-tank single engine module mode or the single-tank single engine module mode by opening and closing other self-locking valves;

[0051] When a self-locking valve fails to open, if the first or second self-locking valve fails to open, the single-box working mode is used on-track; if the self-locking valve at the inlet of an engine module fails to open, the other self-locking valves are switched to the dual-box single engine module working mode or the single-box single engine module working mode.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. Compared with the traditional bipropellant drop pressure propulsion system, the present invention can achieve isolated filling of the tank by adjusting the pipeline connection relationship and adding an isolation self-locking valve, while maintaining the original advantages of the traditional bipropellant drop pressure propulsion system in miniaturization and low drive resources. It also improves the redundancy reliability of the system and realizes balanced filling quantity control and balanced pressurization functions. Since the tank drops pressure and the gas mass and propellant mass in the same component tank are the same, the tank discharge rate and discharge amount are further self-regulated during on-orbit use, ensuring balanced discharge, and the system is simple and reliable to use.

[0054] 2. The present invention controls the self-locking valve of the propellant supply module, and can achieve fault isolation and use mode switching of the tank module through on-orbit reconstruction, ensuring any combination and reliable switching of the dual-tank parallel discharge mode, single-tank discharge mode, main thruster operating mode, and backup thruster operating mode; by closing the self-locking valve downstream of the tank for isolated filling during ground filling; opening the self-locking valve downstream of the tank during on-orbit use, and the tanks working in parallel; so that when the self-locking valve downstream of the tank cannot be opened or other faults occur, fault isolation can be achieved and the working state can be maintained; solving the problem of balanced filling of parallel tanks while greatly improving the reliability of the overall equipment.

[0055] 3. Compared with the traditional technology, the present invention reduces the parallel self-locking valves through pipeline improvement, and simplifies the system structure while ensuring the reliability of the equipment.

[0056] 4. The present invention has the function of adjusting the center of mass of the entire satellite by controlling the propellant filling amount and on-orbit usage strategy.

[0057] 5. The present invention can achieve full utilization of propellant and prevent the propellant in another tank from being unusable due to air entrainment discharge in a single tank at the end of the equipment life. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0059] Figure 1 Schematic diagram of a drop-pressure bipropellant propulsion system.

[0060] The figure shows:

[0061] DETAILED DESCRIPTION

[0062] The present invention is described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0063] like Figure 1 As shown, an embodiment of the present invention provides a drop-pressure bipropellant propulsion system, comprising: a fuel storage module 1, an oxidizer storage module 2, a fuel supply module 3, an oxidizer supply module 4, a primary engine module 5, and a backup engine module 6. The fuel supply module 3 is in communication with the fuel storage module 1, the primary engine module 5, and the backup engine module 6; the oxidizer supply module 4 is in communication with the oxidizer storage module 2, the primary engine module 5, and the backup engine module 6.

[0064] Furthermore, the fuel storage module 1 includes: a first air circuit add-drain valve 11, a third air circuit add-drain valve 12, a main fuel tank 13, a backup fuel tank 14, a fifth liquid circuit add-drain valve 15, a seventh liquid circuit add-drain valve 16, and a first pressure sensor 17; the fuel storage module 1 is used to store fuel and pressurized gas; the first air circuit add-drain valve 11, the main fuel tank 13, and the fifth liquid circuit add-drain valve 15 are connected in sequence; the third air circuit add-drain valve 12, the backup fuel tank 14, and the seventh liquid circuit add-drain valve 16 are connected in sequence; the first pressure sensor 17 is located at one end of the main fuel tank 13 or the backup fuel tank 14.

[0065] Furthermore, the oxidant storage module 2 includes: a second gas circuit add-discharge valve 21, a fourth gas circuit add-discharge valve 22, a main oxidant tank 23, a backup oxidant tank 24, a second pressure sensor 27, a sixth liquid circuit add-discharge valve 25, and an eighth liquid circuit add-discharge valve 26; the oxidant storage module 2 is used to store oxidant and pressurized gas; the second gas circuit add-discharge valve 21, the main oxidant tank 23, and the sixth liquid circuit add-discharge valve 25 are connected in sequence; the fourth gas circuit add-discharge valve 22, the backup oxidant tank 24, and the eighth liquid circuit add-discharge valve 26 are connected in sequence; the second pressure sensor 27 is located at one end of the main oxidant tank 23 or the backup oxidant tank 24.

[0066] Furthermore, the fuel supply module 3 includes: a first self-locking valve 31, a third self-locking valve 32, a fifth self-locking valve 33, a third pressure sensor 34, and a fifth pressure sensor 35; the third self-locking valve 32 is connected to the fifth liquid circuit and drain valve 15 and then connected to the main fuel tank 13; the fifth self-locking valve 33 is connected to the seventh liquid circuit and drain valve 16 and then connected to the backup fuel tank 14; the two ends of the first self-locking valve 31 are respectively connected to the inlets of the third self-locking valve 32 and the fifth self-locking valve 33; the third pressure sensor 34 and the fifth pressure sensor 35 are respectively arranged at the outlets of the third self-locking valve 32 and the fifth self-locking valve 33.

[0067] Furthermore, the oxidant supply module 4 includes: a second self-locking valve 41, a fourth self-locking valve 42, a sixth self-locking valve 43, a fourth pressure sensor 44, and a sixth pressure sensor 45; the fourth self-locking valve 42 is connected to the sixth liquid circuit and drain valve 25 and then connected to the main oxidant storage tank 23; the sixth self-locking valve 43 is connected to the eighth liquid circuit and drain valve 26 and then connected to the backup oxidant storage tank 24, and the two ends of the second self-locking valve 41 are respectively connected to the inlets of the fourth self-locking valve 42 and the sixth self-locking valve 43; the fourth pressure sensor 44 and the sixth pressure sensor 45 are respectively arranged at the outlets of the fourth self-locking valve 42 and the sixth self-locking valve 43.

[0068] Furthermore, the main engine module 5 includes multiple main bipropellant engines, the fuel circuit of the main bipropellant engine is connected to the downstream of the third self-locking valve 32, and the oxidant circuit of the main bipropellant engine is connected to the downstream of the fourth self-locking valve 42; the backup engine module 6 includes multiple backup bipropellant engines, the fuel circuit of the backup bipropellant engine is connected to the downstream of the fifth self-locking valve 33, and the oxidant circuit of the backup bipropellant engine is connected to the downstream of the sixth self-locking valve 43.

[0069] Furthermore, all components of the drop-pressure bipropellant propulsion system are connected by conduits, and all non-metallic seals in contact with the propellant in the drop-pressure bipropellant propulsion system are first-level compatible.

[0070] The following is a more specific description of the embodiments of the present invention:

[0071] More specifically, when the propellant is added, it is divided into the following steps:

[0072] Step SF1: The fuel enters the primary fuel tank 13 through the fifth liquid line adding and discharging valve 15 and enters the backup fuel tank 14 through the seventh liquid line adding and discharging valve 16;

[0073] Step SF2: The pressurized gas enters the primary fuel tank 13 through the first gas path adding and discharging valve 11 and enters the backup fuel tank 14 through the third gas path adding and discharging valve 12;

[0074] Step SF3: The oxidant enters the primary oxidant storage tank 23 through the sixth liquid line addition and discharge valve 25 and enters the backup oxidant storage tank 24 through the eighth liquid line addition and discharge valve 26;

[0075] Step SF4: The pressurized gas enters the primary oxidant tank 23 through the second gas path addition and discharge valve 21 and enters the backup oxidant tank 24 through the fourth gas path addition and discharge valve 22;

[0076] In all the above steps, all self-locking valves are in the closed state during the filling process.

[0077] More specifically, when the system works, it is divided into the following steps:

[0078] Step SW1: The fuel stored in the primary fuel tank 13 and the backup fuel tank 14 passes through the fuel supply module 3 and reaches the primary engine module 5 or the backup engine module 6;

[0079] Step SW2: The oxidant stored in the primary oxidant tank 23 and the backup oxidant tank 24 passes through the oxidant supply module 4 and reaches the primary engine module 5 or the backup engine module 6;

[0080] Step SW3: The fuel and oxidizer are mixed and burned in the engine and ejected through the nozzle to generate thrust;

[0081] When the system is working, there is a thermal control component to control the temperature of the tank to achieve pressure regulation of different tanks, thereby adjusting the discharge rate of different tanks and the center of mass of the entire satellite.

[0082] Specifically, the present invention also provides a working method of a drop-pressure bipropellant propulsion system:

[0083] When filling the system:

[0084] Before filling the system, the first self-locking valve 31, the third self-locking valve 32, the fifth self-locking valve 33, the second self-locking valve 41, the fourth self-locking valve 42, and the sixth self-locking valve 43 are set to the closed state; the corresponding tanks are quantitatively filled through multiple liquid filling and discharge valves connected in series with each tank. After filling is completed, the corresponding tanks are quantitatively pressurized through the gas filling and discharge valves connected in series with each tank.

[0085] While in orbit:

[0086] During on-orbit flight, the first, third, fifth, and sixth self-latching valves 31, 32, 33, 41, 42, and 43 are set to the open state. Dual tanks with the same component operate in parallel, with either the primary or backup engine operating as needed. Because the dual tanks operate in parallel with reduced pressure and the gas and propellant masses within the tanks are maintained equal during refueling, the tank discharge rate and volume can be adaptively adjusted during on-orbit operation, ensuring balanced discharge.

[0087] Flying under fault conditions:

[0088] When a single tank of a component fails, the first self-locking valve 31 and the second self-locking valve 41 are closed to isolate the failed tank and the system switches to a single tank operation mode.

[0089] When satellite center of mass deviation needs to be corrected, the first self-locking valve 31 and the second self-locking valve 41 are closed, and the pre-set main tank main engine module and backup tank backup engine module are used respectively to control the remaining propellant in different tanks and thus adjust the center of mass of the entire satellite.

[0090] When an engine module failure occurs, the fault is isolated by closing the self-locking valve upstream of the faulty engine module, and the system is switched to a dual-box single engine module operating mode or a single-box single engine module operating mode by opening and closing other self-locking valves.

[0091] When a self-locking valve fails to open, if the first self-locking valve 31 or the second self-locking valve 41 fails to open, the single-box working mode is used on track; if the self-locking valve at the inlet of a certain engine module fails to open, the other self-locking valves are switched to the dual-box single engine module working mode or the single-box single engine module working mode.

[0092] Furthermore, the embodiment of the present invention can ensure that each tank is individually filled with propellant by only using a single self-locking valve and optimizing the direction of the pipeline connection. The system availability is reliable in a fault mode without the need for parallel self-locking valves.

[0093] In summary, the present invention discloses a drop pressure bipropellant propulsion system, comprising: a fuel storage module 1, an oxidizer storage module 2, a fuel supply module 3, an oxidizer supply module 4, a main engine module 5, and a backup engine module 6. The fuel supply module 3 is connected to the fuel storage module 1, the main engine module 5, and the backup engine module 6; the oxidizer supply module 4 is connected to the oxidizer storage module 2, the main engine module 5, and the backup engine module 6. The present invention ensures the control of the amount of propellant and the amount of pressurized gas in the tank during the filling process of the bipropellant drop pressure propulsion system while ensuring the lightweight of the bipropellant drop pressure propulsion system and requiring less driving resources for the entire satellite, thereby ensuring the adaptive balancing capability of the propellant consumption when the two tanks work in parallel on orbit; at the same time, it can realize the switching of multiple working modes on orbit, which is helpful for satellite center of mass adjustment and fault isolation.

[0094] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0095] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A drop-pressure bipropellant propulsion system, characterized in that: include: A fuel storage module (1), an oxidant storage module (2), a fuel supply module (3), an oxidant supply module (4), a main engine module (5), and a backup engine module (6); The fuel supply module (3) is in communication with the fuel storage module (1), the main engine module (5) and the backup engine module (6); The oxidant supply module (4) is in communication with the oxidant storage module (2), the main engine module (5), and the backup engine module (6).

2. The drop-pressure bipropellant propulsion system according to claim 1, characterized in that: The material storage module (1) comprises: a first gas circuit adding and discharging valve (11), a third gas circuit adding and discharging valve (12), a main fuel storage tank (13), a backup fuel storage tank (14), a fifth liquid circuit adding and discharging valve (15), a seventh liquid circuit adding and discharging valve (16), and a first pressure sensor (17); The fuel storage module (1) is used to store combustion agent and pressurized gas; The first gas circuit adding and discharging valve (11), the main fuel storage tank (13), and the fifth liquid circuit adding and discharging valve (15) are connected in sequence; The third gas circuit adding and discharging valve (12), the backup fuel storage tank (14), and the seventh liquid circuit adding and discharging valve (16) are connected in sequence; The first pressure sensor (17) is located at one end of the main fuel tank (13) or the backup fuel tank (14).

3. The drop-pressure bipropellant propulsion system according to claim 1, characterized in that: The oxidant storage module (2) comprises: a second gas circuit addition and discharge valve (21), a fourth gas circuit addition and discharge valve (22), a primary oxidant storage tank (23), a backup oxidant storage tank (24), a second pressure sensor (27), a sixth liquid circuit addition and discharge valve (25), and an eighth liquid circuit addition and discharge valve (26); The oxidant storage module (2) is used to store oxidant and pressurized gas; the second gas circuit adding and discharging valve (21), the main oxidant storage tank (23), and the sixth liquid circuit adding and discharging valve (25) are connected in sequence; The fourth gas circuit with a discharge valve (22), a backup oxidant storage tank (24), and the eighth liquid circuit with a discharge valve (26) are connected in sequence; The second pressure sensor (27) is located at one end of the main oxidant tank (23) or the backup oxidant tank (24).

4. The drop-pressure bipropellant propulsion system according to claim 2, characterized in that: The fuel supply module (3) comprises: a first self-locking valve (31), a third self-locking valve (32), a fifth self-locking valve (33), a third pressure sensor (34), and a fifth pressure sensor (35); The third self-locking valve (32) is connected to the fifth liquid line adding and discharging valve (15) and then connected to the main fuel tank (13); The fifth self-locking valve (33) is connected to the seventh liquid line adding and discharging valve (16) and then connected to the backup fuel tank (14); The two ends of the first self-locking valve (31) are connected to the inlets of the third self-locking valve (32) and the fifth self-locking valve (33) respectively; The third pressure sensor (34) and the fifth pressure sensor (35) are respectively arranged at the outlets of the third self-locking valve (32) and the fifth self-locking valve (33).

5. The drop-pressure bipropellant propulsion system according to claim 3, characterized in that: The oxidant supply module (4) comprises: a second self-locking valve (41), a fourth self-locking valve (42), a sixth self-locking valve (43), a fourth pressure sensor (44), and a sixth pressure sensor (45); The fourth self-locking valve (42) is connected to the sixth liquid line discharge valve (25) and then connected to the main oxidant storage tank (23); The sixth self-locking valve (43) is connected to the eighth liquid line adding and discharging valve (26) and then connected to the backup oxidant storage tank (24); The two ends of the second self-locking valve (41) are connected to the inlets of the fourth self-locking valve (42) and the sixth self-locking valve (43) respectively; The fourth pressure sensor (44) and the sixth pressure sensor (45) are respectively arranged at the outlets of the fourth self-locking valve (42) and the sixth self-locking valve (43).

6. The drop-pressure bipropellant propulsion system according to claim 4 or 5, characterized in that: The main engine module (5) includes a plurality of main bipropellant engines, wherein the fuel path of the main bipropellant engine is connected to the downstream of the third self-locking valve (32), and the oxidant path of the main bipropellant engine is connected to the downstream of the fourth self-locking valve (42); The backup engine module (6) includes a plurality of backup bipropellant engines, wherein the fuel path of the backup bipropellant engine is connected to the downstream of the fifth self-locking valve (33), and the oxidant path of the backup bipropellant engine is connected to the downstream of the sixth self-locking valve (43); All components of the drop-pressure bipropellant propulsion system are connected by conduits, and all non-metallic seals in contact with the propellant in the drop-pressure bipropellant propulsion system are first-level compatible.

7. A method for filling a drop pressure bipropellant propulsion system, characterized in that: The drop-pressure bipropellant propulsion system according to any one of claims 1 to 6 comprises: Step SF1: The fuel enters the main fuel tank (13) through the fifth liquid line adding and discharging valve (15), and enters the backup fuel tank (14) through the seventh liquid line adding and discharging valve (16); Step SF2: the pressurized gas enters the main fuel tank (13) through the first gas path adding and discharging valve (11), and enters the backup fuel tank (14) through the third gas path adding and discharging valve (12); Step SF3: The oxidant enters the main oxidant storage tank (23) through the sixth liquid line addition and discharge valve (25), and enters the backup oxidant storage tank (24) through the eighth liquid line addition and discharge valve (26); Step SF4: the pressurized gas enters the main oxidant storage tank (23) through the second gas path addition and discharge valve (21), and enters the backup oxidant storage tank (24) through the fourth gas path addition and discharge valve (22); During the filling process, all self-locking valves are in the closed state.

8. A method for operating a drop-pressure bipropellant propulsion system, characterized in that: The drop-pressure bipropellant propulsion system according to any one of claims 1 to 6 comprises: Step SW1: The fuel stored in the main fuel tank (13) and the backup fuel tank (14) passes through the fuel supply module (3) and reaches the main engine module (5) or the backup engine module (6); Step SW2: The oxidant stored in the primary oxidant tank (23) and the backup oxidant tank (24) passes through the oxidant supply module (4) and reaches the primary engine module (5) or the backup engine module (6); Step SW3: The fuel and oxidizer are mixed and burned in the engine and ejected through the nozzle to generate thrust; When the system is working, there is a thermal control component to control the temperature of the tank to achieve pressure regulation of different tanks.

9. A method for operating a drop-pressure bipropellant propulsion system, characterized in that: The drop-pressure bipropellant propulsion system according to any one of claims 1 to 6 comprises: Before filling the system, the first self-locking valve (31), the third self-locking valve (32), the fifth self-locking valve (33), the second self-locking valve (41), the fourth self-locking valve (42), and the sixth self-locking valve (43) are set to a closed state; the corresponding storage tanks are quantitatively filled through a plurality of liquid adding and discharging valves connected in series with each storage tank; after the filling is completed, the corresponding storage tanks are quantitatively pressurized through the gas adding and discharging valves connected in series with each storage tank; When flying on orbit, the first self-locking valve (31), the third self-locking valve (32), the fifth self-locking valve (33), the second self-locking valve (41), the fourth self-locking valve (42), and the sixth self-locking valve (43) are set to the open state; at this time, the two boxes of the same component work in parallel, and the main or backup engine is used according to demand.

10. A method for operating a bipropellant propulsion system in a fault state, characterized in that: The drop-pressure bipropellant propulsion system according to any one of claims 1 to 6 comprises: When a single tank of a component fails, the first self-locking valve (31) and the second self-locking valve (41) are closed to isolate the failed tank, and the system switches to a single tank operation mode; When the satellite mass center deviation needs to be corrected, by closing the first self-locking valve (31) and the second self-locking valve (41), the pre-set main tank main engine module and the backup tank backup engine module are used respectively to control the remaining amount of propellant in different tanks and thus adjust the mass center of the entire satellite; When an engine module failure occurs, the fault is isolated by closing the self-locking valve upstream of the faulty engine module, and the operation mode is switched to the dual-tank single engine module mode or the single-tank single engine module mode by opening and closing other self-locking valves; When a self-locking valve fails to open, if the first self-locking valve (31) or the second self-locking valve (41) fails to open, the single-box working mode is used on track; if the self-locking valve at the inlet of a certain engine module fails to open, the other self-locking valves are switched to the dual-box single engine module working mode or the single-box single engine module working mode.

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