Automatic cryogenic propellant supply system and method for liquid rocket engine

Abstract

The invention relates to a fluid supply system and method, in particular to a cryogenic propellant automatic supply system and method for a liquid rocket engine. The invention aims to solve the problems of tedious process, low efficiency and low safety of a method for pre-cooling and filling a liquid rocket engine by manual operation. Comprising a main container used for storing a low-temperature propellant, a supply pipeline connected to the output end of the main container and the input end of a low-temperature propellant cavity of the liquid rocket engine and used for supplying the low-temperature propellant, an exhaust pipeline connected with the supply pipeline, and a valve and a monitoring assembly arranged on the supply pipeline. The valve and monitoring assembly comprises a discharge valve, a first exhaust valve, a second exhaust valve, a third exhaust valve, a fourth exhaust valve, a first supply valve, a first bypass valve, a second supply valve, a second bypass valve, a blowdown valve, a flow meter assembly, a filter, a plurality of temperature monitoring sensors and a plurality of pressure monitoring sensors.

Description

Technical Field

[0001] The present invention relates to a fluid supply system and method, and in particular to an automatic cryogenic propellant supply system and method for a liquid rocket engine. Background Art

[0002] Liquid rocket engines are currently the most commonly used engines in various types of rockets. During the development of rocket engines, a large number of tests are required to obtain the engine's operating parameters and key indicators.

[0003] The existing types of liquid rocket engines mainly include liquid oxygen-kerosene engines, hydrogen-oxygen engines, and liquid oxygen-methane engines. The above liquid rocket engines are all green and environmentally friendly rocket engines, and the propellants of the engines all have low-temperature characteristics. During the engine test, the cryogenic propellant supply process is a complex process. Before the test, the cryogenic propellant supply system of the test bench needs to be precooled and filled, and then the engine itself needs to be precooled and filled. When the engine and the cryogenic propellant supply system are fully precooled and the temperature of the cryogenic propellant meets the standard, the test conditions are met.

[0004] When supplying cryogenic propellant to liquid rocket engines, there are complex processes such as exhaust, drainage, and large-flow supply. The existing technology usually manually adjusts the parameters of related valves and other components based on the temperature monitoring values ​​and pressure monitoring values ​​of the cryogenic propellant supply system to achieve pre-cooling and filling, which has problems such as cumbersome processes, low efficiency, and low safety. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of complicated process, low efficiency and low safety in the method of manually precooling and filling liquid rocket engines, and to provide an automated cryogenic propellant supply system and method for liquid rocket engines.

[0006] To achieve the above purpose, the technical solution provided by the present invention is:

[0007] An automated cryogenic propellant supply system for liquid rocket engines, the special features of which are:

[0008] It includes a main container for storing cryogenic propellant, a supply pipeline for supplying cryogenic propellant connected to an output end of the main container and an input end of a cryogenic propellant chamber of a liquid rocket engine, an exhaust pipeline connected to the supply pipeline, and a valve and a monitoring assembly arranged on the supply pipeline;

[0009] The valve and monitoring assembly includes a discharge valve, a first exhaust valve, a second exhaust valve, a third exhaust valve, a fourth exhaust valve, a first supply valve, a first bypass valve, a second supply valve, a second bypass valve, a purge valve for supplying purge gas, a flow meter assembly, and a plurality of temperature monitoring sensors and pressure monitoring sensors;

[0010] On the supply pipeline, the first supply valve, the flow meter assembly, and the second supply valve are arranged in order from near to far from the output end of the main container; the first bypass valve is connected in parallel with the first supply valve, and the second bypass valve is connected in parallel with the second supply valve; the fourth exhaust valve is arranged at an upstream position close to the first supply valve, the third exhaust valve is arranged at a downstream position close to the first supply valve, the second exhaust valve is arranged at an upstream position close to the second supply valve, and the first exhaust valve is arranged at a downstream position close to the second supply valve; the discharge valve is arranged at a position close to the input end of the cryogenic propellant chamber of the liquid rocket engine; the downstream of the first exhaust valve, the second exhaust valve, the third exhaust valve, and the fourth exhaust valve are all connected to the exhaust pipeline, and the tail end of the exhaust pipeline is connected to the atmosphere;

[0011] The liquid rocket engine is provided with an engine drain valve; the upper part of the main container is provided with a main container venting main valve communicated with the atmosphere and a main container venting bypass valve connected in parallel with the main container venting main valve;

[0012] Temperature monitoring sensors are provided at downstream positions of the discharge valve, the first exhaust valve, the second exhaust valve, the third exhaust valve and the fourth exhaust valve; a seventh temperature sensor and a first pressure sensor are provided at an upstream position of the second supply valve on the supply pipeline, and an eighth temperature sensor and a second pressure sensor are provided at a position close to the liquid rocket engine.

[0013] Further, the flow meter assembly includes a first flow meter and a second flow meter connected in series, and the first flow meter and the second flow meter are both turbine flow meters;

[0014] The engine drain valve, discharge valve, first exhaust valve, second exhaust valve, third exhaust valve, fourth exhaust valve, first supply valve, first bypass valve, second supply valve, second bypass valve, purge valve, main container venting main valve and main container venting bypass valve are all pneumatic valves, and their opening or closing is controlled by a computer.

[0015] Further, the temperature monitoring sensors corresponding to the discharge valve, the first exhaust valve, the second exhaust valve, the third exhaust valve and the fourth exhaust valve are respectively the second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor.

[0016] Further, a filter is arranged at a downstream position close to the second supply valve, and the first exhaust valve is arranged on the filter.

[0017] Furthermore, the output end of the main container is connected to the supply pipeline through a bellows; and the purge gas is nitrogen.

[0018] Furthermore, the second exhaust valve, the third exhaust valve and the fourth exhaust valve are of the same model.

[0019] Furthermore, the design pressures of the main container, the supply pipeline, the exhaust pipeline, the first flow meter and the second flow meter are all 1.6 MPa; and the outsides of the supply pipeline, the exhaust pipeline and the main container are all coated with an insulation layer.

[0020] At the same time, the present invention also provides a method for automatically supplying cryogenic propellant for a liquid rocket engine, which is special in that it includes the following steps:

[0021] Step 1, assemble the above-mentioned cryogenic propellant automatic supply system for liquid rocket engines, define time 0, t1, t2, t3, t4 in sequence, where time 0 is the initial time, and define durations t5 and t6;

[0022] Step 2: Open the main valve for venting the main container and the bypass valve for venting the main container at time 0;

[0023] Step 3: At time t1, close the main container venting main valve and the main container venting bypass valve, and open the engine drain valve at the same time;

[0024] Step 4: At time t2, close the engine drain valve and open the engine purge valve to introduce purge gas into the supply pipeline to stabilize the pressure in the supply pipeline;

[0025] Step 5: At time t3, the second exhaust valve, the third exhaust valve and the fourth exhaust valve are opened simultaneously;

[0026] Step 6: At time t4, the first bypass valve is opened to start precooling the supply pipeline, and the indication of the flow meter assembly is recorded at the same time, and the valve post temperatures of the discharge valve, the first exhaust valve, the second exhaust valve, the third exhaust valve and the fourth exhaust valve are monitored. The seventh temperature sensor and the first pressure sensor are opened at the same time until the indication of the flow meter assembly becomes 0 and the absolute value of the difference between the temperature value measured by the seventh temperature sensor and the temperature value T0 of the cryogenic propellant in the main container meets the preset requirement, and the pressure value measured by the first pressure sensor is stable, then the first supply valve is opened; the initial value n1 of the first filling and precooling times is defined as 1;

[0027] Step 7, monitoring the valve rear temperatures of the second exhaust valve, the third exhaust valve, and the fourth exhaust valve, until the absolute values ​​of the differences between the valve rear temperatures of the second exhaust valve, the third exhaust valve, and the fourth exhaust valve and the temperature value T0 of the cryogenic propellant in the main container are all less than or equal to 30° C., then closing the second exhaust valve, the third exhaust valve, and the fourth exhaust valve;

[0028] Step 8, after t5, open the second exhaust valve, the third exhaust valve and the fourth exhaust valve at the same time, and judge whether n1 reaches the preset number of times. If not, set n1=n1+1, and then return to step 7; if yes, it is assumed that the filling and precooling of the supply pipeline are sufficient, and then the supply system is self-checked for a duration of t6 by judging the temperature value measured by the seventh temperature sensor. If the self-check is qualified, proceed to step 9; if the self-check is unqualified, close the supply system for maintenance, and then return to step 2;

[0029] Step 9, close the purge valve, and simultaneously open the discharge valve and the first exhaust valve;

[0030] Step 10, open the second bypass valve, start precooling of the liquid rocket engine, and start recording the reading of the flow meter assembly at the same time, until the reading of the flow meter assembly becomes 0 and the absolute value of the difference between the temperature value measured by the eighth temperature sensor and the temperature value T0 of the cryogenic propellant in the main container meets the preset requirements, and the pressure values ​​measured by the first pressure sensor and the second pressure sensor are stable; define the initial value of the second filling and precooling times n2 = 1;

[0031] Step 11, monitoring the valve rear temperature of the discharge valve and the first exhaust valve, until the absolute value of the difference between the valve rear temperature of the discharge valve and the first exhaust valve and the temperature value T0 of the cryogenic propellant in the main container is less than or equal to 30° C., closing the discharge valve and the first exhaust valve;

[0032] Step 12: After t5, open the discharge valve and the first exhaust valve at the same time to determine whether n2 has reached the preset number of times. If not, set n2=n2+1 and then return to step 11. If so, it is assumed that the filling and precooling of the liquid rocket engine are sufficient to complete the supply of cryogenic propellant to the liquid rocket engine.

[0033] Furthermore, in step 6, "start monitoring the post-valve temperature of the discharge valve, the first exhaust valve, the second exhaust valve, the third exhaust valve and the fourth exhaust valve" is specifically: turn on the second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor to monitor the post-valve temperature of the discharge valve, the first exhaust valve, the second exhaust valve, the third exhaust valve and the fourth exhaust valve.

[0034] Furthermore, the preset times in step 8 and step 12 are both 2.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The cryogenic propellant automatic supply system for liquid rocket engines provided by the present invention can realize the full-process automated cryogenic propellant supply through the cooperation of multiple valves and multiple temperature and pressure sensors, meet the precooling and filling requirements of the supply system and liquid rocket engines, quickly reach the engine test conditions, and almost no manual operation is required, thus simplifying the operation steps and saving manpower and material resources;

[0037] 2. The method for automatically supplying cryogenic propellant for liquid rocket engines provided by the present invention adopts program automation control, has high reliability, and ensures the stability of the supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of an embodiment of a cryogenic propellant automatic supply system for a liquid rocket engine according to the present invention;

[0039] Description of reference numerals:

[0040] M-main container; A1-engine drain valve, A2-discharge valve, A2b-purge valve, A3-first exhaust valve, A4-second supply valve, A4a-second bypass valve, A5-second exhaust valve, A6-third exhaust valve, A7-first supply valve, A7a-first bypass valve; A8-fourth exhaust valve, A9-main container vent valve, A9a-main container vent bypass valve; D-supply pipeline, D1-exhaust pipeline; P-first pressure sensor, P10-second pressure sensor; T2-second temperature sensor, T3-third temperature sensor, T5-fourth temperature sensor, T6-fifth temperature sensor, T8-sixth temperature sensor, T1-seventh temperature sensor, T10-eighth temperature sensor, F-filter; N-liquid rocket engine; C-bellows; qmo1-first flowmeter, qmo2-second flowmeter; G-purge gas. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0042] See also Figure 1 , a cryogenic propellant automatic supply system for a liquid rocket engine comprises a main container M for storing cryogenic propellant, a supply pipeline D for supplying cryogenic propellant connected to an output end of the main container M and an input end of a cryogenic propellant chamber of a liquid rocket engine N, an exhaust pipeline D1 connected to the supply pipeline D, and a valve and a monitoring assembly arranged on the supply pipeline D; the output end of the main container M is connected to the supply pipeline D through a bellows C;

[0043] The valve and monitoring assembly includes a discharge valve A2, a first exhaust valve A3, a second exhaust valve A5, a third exhaust valve A6, a fourth exhaust valve A8, a first supply valve A7, a first bypass valve A7a, a second supply valve A4, a second bypass valve A4a, a purge valve A2b for supplying nitrogen G, a first flow meter qmo1, a second flow meter qmo2, a filter F, and a plurality of temperature monitoring sensors and pressure monitoring sensors;

[0044] On the supply pipeline D, from near to far away from the output end of the main container M are the first supply valve A7, the first flow meter qmo1, the second flow meter qmo2, the second supply valve A4 and the filter F; the first bypass valve A7a is connected in parallel with the first supply valve A7, and the second bypass valve A4a is connected in parallel with the second supply valve A4; the fourth exhaust valve A8 is arranged at an upstream position close to the first supply valve A7, the third exhaust valve A6 is arranged at a downstream position close to the first supply valve A7, the second exhaust valve A5 is arranged at an upstream position close to the second supply valve A4, and the first exhaust valve A3 is arranged on the filter F close to the downstream position of the second supply valve A4; the discharge valve A2 is arranged at a position close to the input end of the cryogenic propellant chamber of the liquid rocket engine N; the downstream of the first exhaust valve A3, the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8 are all connected to the exhaust pipeline D1, and the tail end of the exhaust pipeline D1 is connected to the atmosphere; the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8 are of the same model.

[0045] The liquid rocket engine N is provided with an engine drain valve A1; the upper part of the main container M is provided with a main container venting main valve A9 communicating with the atmosphere and a main container venting bypass valve A9a connected in parallel with the main container venting main valve A9;

[0046] The above-mentioned engine drain valve A1, discharge valve A2, first exhaust valve A3, second exhaust valve A5, third exhaust valve A6, fourth exhaust valve A8, first supply valve A7, first bypass valve A7a, second supply valve A4, second bypass valve A4a, purge valve A2b, main container venting main valve A9 and main container venting bypass valve A9a are all pneumatic valves, and their opening or closing is controlled by computer.

[0047] Temperature monitoring sensors are provided at the downstream positions of the discharge valve A2, the first exhaust valve A3, the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8, which are the second temperature sensor T2, the third temperature sensor T3, the fourth temperature sensor T5, the fifth temperature sensor T6 and the sixth temperature sensor T8 respectively; the seventh temperature sensor T1 and the first pressure sensor P are provided between the first flow meter qmo1 and the second flow meter qmo2 on the supply pipeline D, and the eighth temperature sensor T10 and the second pressure sensor P10 are provided near the liquid rocket engine N.

[0048] The first flowmeter qmo1 and the second flowmeter qmo2 are both turbine flowmeters. The first flowmeter qmo1 and the second flowmeter qmo2 serve as backup for each other to improve the measurement accuracy.

[0049] In order to ensure the consistency of the components of the supply system, the design pressure of the main container M, the supply pipeline D, the exhaust pipeline D1, the first flow meter qmo1 and the second flow meter qmo2 are all 1.6MPa. In order to reduce the interference of the external environment, the supply pipeline D, the exhaust pipeline D1 and the main container M are all covered with an insulation layer.

[0050] The engine drain valve A1 is used for the discharge of cryogenic propellant and the control of overflow during the precooling process of the liquid rocket engine N; the discharge valve A2 is used for discharging cryogenic propellant to ensure that the temperature of the cryogenic propellant when entering the liquid rocket engine N meets the test requirements; the purge valve A2b is used to supply nitrogen G to prevent the water vapor in the cryogenic propellant chamber from entering the interior of the liquid rocket engine N; the fourth exhaust valve A8 is used for high-point exhaust of the main container M; the third exhaust valve A6 is used for high-point exhaust of the supply pipeline D; the first supply valve A7 and the first bypass valve A7a, the second supply valve A4 and the second bypass valve A4a are all used to cut off the cryogenic propellant in the main container M; the main container venting main valve A9 and the main container venting bypass valve A9a are used together for the venting of the main container M. The main container venting main valve A9 and the main container venting bypass valve A9a are used together to achieve the normal pressure state of the main container M.

[0051] At the same time, this embodiment also provides a method for automatically supplying cryogenic propellant for a liquid rocket engine, comprising the following steps:

[0052] Step 1, assemble the cryogenic propellant automated supply system for liquid rocket engines as described in any one of claims 1-7, define time 0, t1, t2, t3, t4 in sequence, where time 0 is the initial time, and define durations t5 and t6;

[0053] Step 2: At time 0, open the main container venting main valve A9 and the main container venting bypass valve A9a;

[0054] Step 3: At time t1, close the main container venting main valve A9 and the main container venting bypass valve A9a, and open the engine drain valve A1 at the same time;

[0055] Step 4: At time t2, close the engine drain valve A1 and open the engine purge valve A2b to introduce purge gas G into the supply pipe D to stabilize the pressure in the supply pipe D;

[0056] Step 5: At time t3, the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8 are opened simultaneously;

[0057] Step 6: At time t4, the first bypass valve A7a is opened to start precooling the supply pipe D, and the indication of the flow meter assembly is recorded. The second temperature sensor T2, the third temperature sensor T3, the fourth temperature sensor T5, the fifth temperature sensor T6, the sixth temperature sensor T8, the seventh temperature sensor T1 and the first pressure sensor P are opened until the indication of the flow meter assembly becomes 0 and the absolute value of the difference between the temperature value measured by the seventh temperature sensor T1 and the temperature value T0 of the cryogenic propellant in the main container M is less than or equal to 2°C, and the pressure value measured by the first pressure sensor P is stable, then the first supply valve A7 is opened; the initial value n1 of the first filling and precooling times is defined as 1;

[0058] Step 7, monitoring the valve post temperatures of the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8, until the absolute value of the difference between the valve post temperatures of the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8 and the temperature value T0 of the cryogenic propellant in the main container M is less than or equal to 30° C., then closing the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8;

[0059] Step 8: After t5, open the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8 at the same time, and determine whether n1 reaches 2 times. If not, set n1=n1+1, and then return to step 7; if yes, it is assumed that the filling and precooling of the supply pipeline D are sufficient, and then the supply system is self-checked for a duration of t6 by judging the temperature value measured by the seventh temperature sensor T1. If the self-check is qualified, proceed to step 9; if the self-check is unqualified, close the supply system for maintenance, and then return to step 2;

[0060] Step 9, close the purge valve A2b, and simultaneously open the discharge valve A2 and the first exhaust valve A3;

[0061] Step 10, open the second bypass valve A4a, start precooling of the liquid rocket engine N, and start recording the reading of the flow meter assembly at the same time, until the reading of the flow meter assembly becomes 0 and the absolute value of the difference between the temperature value measured by the eighth temperature sensor T10 and the temperature value T0 of the cryogenic propellant in the main container M is less than or equal to 2°C, and the pressure values ​​measured by the first pressure sensor P and the second pressure sensor P10 are both stable; define the initial value of the second filling and precooling times n2 = 1;

[0062] Step 11, monitoring the valve post temperatures of the discharge valve A2 and the first exhaust valve A3, until the absolute value of the difference between the valve post temperatures of the discharge valve A2 and the first exhaust valve A3 and the temperature value T0 of the cryogenic propellant in the main container M is less than or equal to 30° C., closing the discharge valve A2 and the first exhaust valve A3;

[0063] Step 12: After t5, open the discharge valve A2 and the first exhaust valve A3 at the same time to determine whether n2 has reached 2 times. If not, set n2=n2+1 and then return to step 11. If so, it is assumed that the filling and precooling of the liquid rocket engine N are sufficient, and the supply of cryogenic propellant to the liquid rocket engine N is completed.

[0064] It should be noted that the values ​​of t1, t2, t3, t4, t5, and t6 can be adjusted according to actual needs and working conditions.

Claims

1. An automated cryogenic propellant supply system for liquid rocket engines, Features: It comprises a main container (M) for storing cryogenic propellant, a supply pipeline (D) connected to the output end of the main container (M) and the input end of the cryogenic propellant chamber of the liquid rocket engine (N) for supplying cryogenic propellant, an exhaust pipeline (D1) connected to the supply pipeline (D), and a valve and monitoring assembly arranged on the supply pipeline (D); The valve and monitoring assembly includes a discharge valve (A2), a first exhaust valve (A3), a second exhaust valve (A5), a third exhaust valve (A6), a fourth exhaust valve (A8), a first supply valve (A7), a first bypass valve (A7a), a second supply valve (A4), a second bypass valve (A4a), a purge valve (A2b) for supplying purge gas (G), a flow meter assembly, and a plurality of temperature monitoring sensors and pressure monitoring sensors; On the supply pipeline (D), the first supply valve (A7), the flow meter assembly and the second supply valve (A4) are arranged in order from near to far from the output end of the main container (M); the first bypass valve (A7a) is connected in parallel with the first supply valve (A7), and the second bypass valve (A4a) is connected in parallel with the second supply valve (A4); the fourth exhaust valve (A8) is arranged at an upstream position close to the first supply valve (A7), the third exhaust valve (A6) is arranged at a downstream position close to the first supply valve (A7), the second exhaust valve (A5) is arranged at an upstream position close to the second supply valve (A4), and the first exhaust valve (A3) is arranged at a downstream position close to the second supply valve (A4); the discharge valve (A2) is arranged at a position close to the input end of the cryogenic propellant chamber of the liquid rocket engine (N); the downstream of the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are all connected to the exhaust pipeline (D1), and the tail end of the exhaust pipeline (D1) is connected to the atmosphere; The liquid rocket engine (N) is provided with an engine drain valve (A1); the upper part of the main container (M) is provided with a main container venting main valve (A9) communicated with the atmosphere and a main container venting bypass valve (A9a) connected in parallel with the main container venting main valve (A9); Temperature monitoring sensors are provided at downstream positions of the discharge valve (A2), the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8); a seventh temperature sensor (T1) and a first pressure sensor (P) are provided at an upstream position of the second supply valve (A4) on the supply pipeline (D), and an eighth temperature sensor (T10) and a second pressure sensor (P10) are provided at a position close to the liquid rocket engine (N).

2. The automatic cryogenic propellant supply system for a liquid rocket engine according to claim 1, Features: The flow meter assembly comprises a first flow meter (qmo1) and a second flow meter (qmo2) connected in series, and both the first flow meter (qmo1) and the second flow meter (qmo2) are turbine flow meters; The engine drain valve (A1), the discharge valve (A2), the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6), the fourth exhaust valve (A8), the first supply valve (A7), the first bypass valve (A7a), the second supply valve (A4), the second bypass valve (A4a), the purge valve (A2b), the main container venting main valve (A9) and the main container venting bypass valve (A9a) are all pneumatic valves, and their opening or closing is controlled by a computer.

3. The automatic cryogenic propellant supply system for a liquid rocket engine according to claim 2, Features: The temperature monitoring sensors corresponding to the discharge valve (A2), the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are respectively the second temperature sensor (T2), the third temperature sensor (T3), the fourth temperature sensor (T5), the fifth temperature sensor (T6) and the sixth temperature sensor (T8).

4. The automatic cryogenic propellant supply system for a liquid rocket engine according to claim 3, Features: A filter (F) is provided at a downstream position close to the second supply valve (A4), and the first exhaust valve (A3) is provided on the filter (F).

5. The automatic cryogenic propellant supply system for a liquid rocket engine according to claim 1, Features: The output end of the main container (M) is connected to the supply pipe (D) through a bellows (C); The purge gas (G) is nitrogen.

6. The automatic cryogenic propellant supply system for a liquid rocket engine according to claim 1, Features: The second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are of the same model.

7. The automatic cryogenic propellant supply system for a liquid rocket engine according to claim 4, Features: The design pressures of the main container (M), the supply pipeline (D), the exhaust pipeline (D1), the first flow meter (qmo1) and the second flow meter (qmo2) are all 1.6 MPa; the outside of the supply pipeline (D), the exhaust pipeline (D1) and the main container (M) are all covered with an insulation layer.

8. A method for automatically supplying cryogenic propellant to a liquid rocket engine, It is characterized in that The following steps are involved: Step 1: Assemble the cryogenic propellant automatic supply system for liquid rocket engines according to any one of claims 1 to 7, and define time 0, t 1 ,t 2 ,t 3 ,t 4 , where time 0 is the initial time and the duration t is defined 5 ,t 6 ; Step 2: At time 0, open the main container venting main valve (A9) and the main container venting bypass valve (A9a); Step 3: 1 Always close the main container venting main valve (A9) and the main container venting bypass valve (A9a), and open the engine drain valve (A1); Step 4: 2 Keep the engine drain valve (A1) closed at all times, and at the same time open the engine purge valve (A2b), and introduce purge gas (G) into the supply pipe (D) to stabilize the pressure in the supply pipe (D); Step 5: 3 The second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are opened simultaneously at all times; Step 6: 4 The first bypass valve (A7a) is opened at all times to start precooling the supply pipe (D), and the reading of the flow meter assembly is recorded at the same time. The valve post temperatures of the discharge valve (A2), the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are monitored, and the seventh temperature sensor (T1) and the first pressure sensor (P) are opened at the same time until the reading of the flow meter assembly becomes 0 and the temperature value measured by the seventh temperature sensor (T1) is equal to the temperature value T of the cryogenic propellant in the main container (M). 0 When the absolute value of the difference between the pressure and the pressure value meets the preset requirement and the pressure value measured by the first pressure sensor (P) is stable, the first supply valve (A7) is opened; the initial value n1 of the first filling and precooling times is defined as 1; Step 7: Monitor the valve post temperatures of the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) until the valve post temperatures of the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are equal to the temperature T of the cryogenic propellant in the main container (M). 0 When the absolute value of the difference between the two is less than or equal to 30°C, the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are closed; Step 8: After t 5 After the time period, the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are opened at the same time to determine whether n1 reaches the preset number of times. If not, n1=n1+1 is set, and then the process returns to step 7. If so, it is assumed that the filling and precooling of the supply pipeline (D) are sufficient, and then the supply system is conditioned for a time period of t by determining the temperature value measured by the seventh temperature sensor (T1). 6 If the self-test is qualified, proceed to step 9. If the self-test is unqualified, shut down the supply system for maintenance and then return to step 2. Step 9, close the purge valve (A2b), and simultaneously open the discharge valve (A2) and the first exhaust valve (A3); Step 10: Open the second bypass valve (A4a), start precooling the liquid rocket engine (N), and start recording the reading of the flow meter assembly until the reading of the flow meter assembly becomes 0 and the temperature value measured by the eighth temperature sensor (T10) is equal to the temperature value T of the cryogenic propellant in the main container (M). 0 When the absolute value of the difference between the first pressure sensor (P) and the second pressure sensor (P10) meets the preset requirement and the pressure values ​​measured by the first pressure sensor (P) and the second pressure sensor (P10) are both stable; the initial value of the second filling and precooling times n2 is defined as 1; Step 11: Monitor the valve post temperature of the discharge valve (A2) and the first exhaust valve (A3) until the valve post temperature of the discharge valve (A2) and the first exhaust valve (A3) is equal to the temperature value T of the cryogenic propellant in the main container (M). 0 When the absolute value of the difference between the temperature and the pressure is less than or equal to 30°C, close the discharge valve (A2) and the first exhaust valve (A3); Step 12: After t 5 After the time period, the discharge valve (A2) and the first exhaust valve (A3) are opened simultaneously to determine whether n2 has reached the preset number of times. If not, n2=n2+1 is set, and then the process returns to step 11. If so, it is assumed that the filling and precooling of the liquid rocket engine (N) are sufficient, and the supply of cryogenic propellant to the liquid rocket engine (N) is completed.

9. A method for automatically supplying cryogenic propellant for a liquid rocket engine according to claim 8, Features: In step 6, "start monitoring the post-valve temperatures of the discharge valve (A2), the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8)" specifically includes: turning on the second temperature sensor (T2), the third temperature sensor (T3), the fourth temperature sensor (T5), the fifth temperature sensor (T6) and the sixth temperature sensor (T8) to monitor the post-valve temperatures of the discharge valve (A2), the first exhaust valve (A3), the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8).

10. A method for automatically supplying cryogenic propellant for a liquid rocket engine according to claim 8, Features: The preset times described in step 8 and step 12 are both 2.

Images