Inclined test bed and test method for multi-engine parallel liquid rocket engine

Abstract

The invention relates to a rocket engine and a propellant supply method thereof, in particular to a multi-machine parallel liquid rocket engine for an inclined test bed and a low-temperature propellant supply method of the multi-machine parallel liquid rocket engine, and aims at solving the problems that an existing propellant supply method of the liquid rocket engine is low in efficiency, errors exist, and the personnel safety is poor. The parallel liquid-propellant rocket engine unit comprises a thrust frame obliquely arranged on the ground, an adapter ring with one end arranged on the oblique side face of the thrust frame, a propellant supply system and a propellant flow dividing device, wherein a shell of the parallel liquid-propellant rocket engine unit is connected with the other end of the adapter ring; the propellant shunting device comprises an input pipeline and X output pipelines with the same length and inner diameter, and the propellant cavity input end of each liquid rocket engine is connected with one output pipeline of the propellant shunting device; and a ninth temperature sensor is arranged in a propellant cavity of each liquid rocket engine, and a propellant discharge valve is mounted in the propellant cavity of each liquid rocket engine.

Description

Technical Field

[0001] The invention relates to a test bench and a test method, in particular to an inclined test bench and a test method for multi-machine parallel liquid rocket engines. Background Art

[0002] Liquid rocket engines are currently used 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. In actual application scenarios, liquid rocket engines are usually used in parallel in multiple machines. How to supply propellant to liquid rocket engines in parallel is an issue that needs to be considered.

[0004] The existing method of supplying propellant during the test run of multiple parallel liquid rocket engines usually adopts the form of manual observation and manual control of each propellant discharge valve based on experience. When a liquid rocket engine is fully precooled, the propellant discharge valve on that liquid rocket engine is manually closed. However, this method has the following defects: low efficiency, error and poor personnel safety. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of low efficiency, error and poor personnel safety in the existing method of supplying propellant during the test of liquid rocket engines, and to provide a tilting test bench and test method for multiple parallel liquid rocket engines.

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

[0007] A tilt test bench for multiple parallel liquid rocket engines is used for testing a parallel liquid rocket engine group consisting of X liquid rocket engines, where X is an integer greater than or equal to 2, and its special features are:

[0008] It comprises a thrust frame arranged on the ground, an adapter ring arranged on the thrust frame, and a propellant supply system and a propellant diversion device matched with the thrust frame; one side of the thrust frame is an inclined side, one end of the adapter ring is connected to the inclined side of the thrust frame, and the other end is connected to the shell of the parallel liquid rocket engine group;

[0009] The propellant supply system comprises a main container and a supply pipeline connected in sequence; the main container is used to store cryogenic propellant;

[0010] The propellant flow splitter device comprises an input pipeline and X output pipelines of the same length and inner diameter, each output pipeline being connected to the input end of the propellant chamber of the corresponding liquid rocket engine; the input pipeline of the propellant flow splitter device is connected to the output end of the supply pipeline; a temperature sensor is provided in the propellant chamber of each liquid rocket engine, and a propellant discharge valve is provided;

[0011] Define the intersection edge of the inclined side surface α on which the adapter ring is installed on the thrust frame and the ground β as L, then the plane angle θ of the dihedral angle α-L-β is an acute angle.

[0012] Furthermore, the angle θ has a value range of 45°≤θ≤80°.

[0013] Furthermore, the propellant supply system further comprises an exhaust pipe connected to the supply pipe and a valve and a monitoring assembly arranged on the supply pipe;

[0014] 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;

[0015] 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;

[0016] The upper part of the main container is provided with a main container deflation main valve communicated with the atmosphere and a main container deflation bypass valve connected in parallel with the main container deflation main valve;

[0017] 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, which are the second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor and the sixth temperature sensor respectively; 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.

[0018] 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;

[0019] The discharge valve, the first exhaust valve, the second exhaust valve, the third exhaust valve, the fourth exhaust valve, the first supply valve, the first bypass valve, the second supply valve, the second bypass valve, the purge valve, the main container venting main valve and the main container venting bypass valve are all pneumatic valves, and their opening or closing is controlled by a computer.

[0020] Furthermore, a filter is arranged near the downstream position of the second supply valve, the first exhaust valve is arranged on the filter, and the output end of the main container is connected to the supply pipeline through a bellows; the second exhaust valve, the third exhaust valve and the fourth exhaust valve are of the same model.

[0021] Furthermore, X=4.

[0022] At the same time, the present invention also provides a test method for multiple parallel liquid rocket engines, which is special in that it includes the following steps:

[0023] Step 1: Assemble the above-mentioned tilt test bench for multiple parallel liquid rocket engines, then install the parallel liquid rocket engine group to the preset position, set the cut-off temperature T 01 ;

[0024] Step 2: Open the ninth temperature sensor in each liquid rocket engine propellant chamber to monitor the temperature in each propellant chamber in real time; start the propellant supply system to start preliminary precooling of each liquid rocket engine in the parallel liquid rocket engine group; open the propellant discharge valve of each liquid rocket engine;

[0025] Step 3: When the temperature value monitored by the ninth temperature sensor drops to the cut-off temperature T 01 When the propellant discharge valve of the corresponding liquid rocket engine is closed;

[0026] Step 4: When the propellant discharge valves of all liquid rocket engines are closed, it is assumed that the parallel liquid rocket engine group is fully filled and precooled;

[0027] Step 5: Ignite and test the parallel liquid rocket engine group.

[0028] Furthermore, step 2 is specifically as follows:

[0029] Step 2.1, define time 0, t1, t2, t3, t4 in sequence, where time 0 is the initial time, and define durations t5 and t6;

[0030] Step 2.2, open the main valve for venting the main container and the bypass valve for venting the main container at time 0;

[0031] Step 2.3: At time t1, close the main container venting main valve and the main container venting bypass valve, and open all the propellant discharge valves at the same time;

[0032] Step 2.4: At time t2, close all propellant discharge valves and open the engine purge valve to introduce purge gas into the supply pipeline to stabilize the pressure in the supply pipeline;

[0033] Step 2.5: at time t3, the second exhaust valve, the third exhaust valve and the fourth exhaust valve are opened simultaneously;

[0034] Step 2.6, 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 second temperature sensor, the third temperature sensor, the fourth temperature sensor, the fifth temperature sensor, the sixth temperature sensor, the seventh temperature sensor and the first pressure sensor are turned on until the indication of the flow meter assembly becomes and the absolute value of the difference between the temperature value measured by the seventh temperature sensor and the temperature value 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; define the initial value n1 of the first filling and precooling times = 1;

[0035] Step 2.7, monitoring the valve rear temperatures of the second exhaust valve, the third exhaust valve, and the fourth exhaust valve, until the absolute value of the difference 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 is less than or equal to 30° C., then closing the second exhaust valve, the third exhaust valve, and the fourth exhaust valve;

[0036] Step 2.8, after t5, open the second exhaust valve, the third exhaust valve and the fourth exhaust valve at the same time, and determine whether n1 reaches 2 times. If not, set n1=n1+1, and then return to step 2.7; 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 2.9; if the self-check is unqualified, close the supply system for maintenance, and then return to step 2.2;

[0037] Step 2.9, close the purge valve and open the discharge valve and the first exhaust valve at the same time;

[0038] Step 2.10: Turn on the temperature sensor in each liquid rocket engine propellant chamber to monitor the temperature in each propellant chamber in real time; open the second bypass valve and all propellant discharge valves to start precooling of the parallel liquid rocket engine group.

[0039] Furthermore, step 4 is specifically as follows:

[0040] Step 4.1, when all the propellant discharge valves of the liquid rocket engines are closed, start recording the reading of the flow meter assembly 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 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;

[0041] Step 4.2, 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;

[0042] Step 4.3: After t5, open the discharge valve and the first exhaust valve at the same time to determine whether n2 has reached 2 times. If not, set n2=n2+1 and then return to step 4.2. If so, it is assumed that the parallel liquid rocket engine group is fully filled and precooled.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The tilting test bench for multiple parallel liquid rocket engines provided by the present invention is provided with a propellant flow splitter, which can ensure that the propellant enters each parallel liquid rocket engine at almost the same flow rate, thereby achieving uniform and efficient precooling of the parallel liquid rocket engines;

[0045] 2. The tilting test bench for multiple parallel liquid rocket engines provided by the present invention has a thrust frame that is tilted to ensure rapid inflow of propellant when the propellant is supplied, thereby achieving sufficient precooling of each liquid rocket engine;

[0046] 3. The test method for multiple parallel liquid rocket engines provided by the present invention can realize the fully automated propellant supply through the cooperation of multiple valves and multiple temperature and pressure sensors, meet the pre-cooling and filling requirements of the supply system and liquid rocket engines, quickly reach the test conditions of the engine, and almost no manual operation is required, thereby simplifying the operating steps and saving manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the assembly structure of a parallel liquid rocket engine group and an embodiment of the tilting test bench for multiple parallel liquid rocket engines of the present invention (the propellant supply system and the propellant diverter are not shown);

[0048] Figure 2 It is a structural schematic diagram of a parallel liquid rocket engine group and a propellant flow splitter device in an embodiment of a tilting test bench for multiple parallel liquid rocket engines of the present invention;

[0049] Figure 3 It is a structural schematic diagram of a propellant supply system in an embodiment of a tilt test bench for multiple parallel liquid rocket engines of the present invention;

[0050] Description of reference numerals:

[0051] 1-thrust frame, 2-adapter ring, 3-propellant discharge valve, 4-propellant diverter, M-main container, 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-parallel liquid rocket engine group, C-bellows, qmo1-first flow meter, qmo2-second flow meter. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0053] A tilt test bench for multiple parallel liquid rocket engines, see Figure 1 , used for parallel liquid rocket engine group N consisting of four liquid rocket engines arranged in four quadrants (see Figure 3 ) for test run; it comprises a thrust frame 1 arranged on the ground, an adapter ring 2 arranged on the thrust frame 1, and a propellant supply system and a propellant diversion device 4 matched with the thrust frame 1; one side of the thrust frame 1 is an inclined side, one end of the adapter ring 2 is connected to the inclined side of the thrust frame 1, and the other end is connected to the shell of the parallel liquid rocket engine group N;

[0054] The propellant supply system comprises a main container M and a supply pipeline D which are connected in sequence; the main container M is used to store cryogenic propellant;

[0055] The propellant flow dividing device 4 includes an input pipeline and four output pipelines of the same length and inner diameter, each output pipeline is connected to the input end of the propellant chamber of the corresponding liquid rocket engine; the input pipeline of the propellant flow dividing device 4 is connected to the output end of the supply pipeline D; a temperature sensor is provided in the propellant chamber of each liquid rocket engine, and a propellant discharge valve 3 is provided;

[0056] Define the intersection edge between the inclined side surface α on which the adapter ring 2 is installed on the thrust frame 1 and the ground β as L, then the plane angle θ of the dihedral angle α-L-β is 30°.

[0057] Propellant supply system see Figure 3 , comprising a main container M for storing cryogenic propellant, a supply pipeline D for supplying cryogenic propellant connected to the output end of the main container M and the input end of the cryogenic propellant chamber of the parallel liquid rocket engine group N, an exhaust pipeline D1 connected to the supply pipeline D, and a valve and 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;

[0058] 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, a first flow meter qmo1, a second flow meter qmo2, a filter F, and a plurality of temperature monitoring sensors and pressure monitoring sensors;

[0059] On the supply pipeline D, the first supply valve A7, the first flow meter qmo1, the second flow meter qmo2, the second supply valve A4 and the filter F are arranged 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 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 parallel liquid rocket engine group 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.

[0060] Each liquid rocket engine of the parallel liquid rocket engine group N is provided with a propellant discharge valve 3; 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;

[0061] The above-mentioned propellant discharge valve 3, 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.

[0062] 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 parallel liquid rocket engine group N.

[0063] 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.

[0064] 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.

[0065] The propellant discharge valve 3 is used for the discharge of cryogenic propellant and the control of overflow during the precooling process of the parallel liquid rocket engine group N; the discharge valve A2 is used for discharging cryogenic propellant to ensure that the temperature of the cryogenic propellant when entering the parallel liquid rocket engine group N meets the test requirements; the purge valve A2b is used to supply nitrogen G to prevent the water vapor in the cryogenic propellant cavity from entering the interior of the parallel liquid rocket engine group 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 deflation main valve A9 and the main container deflation bypass valve A9a are used together for deflation of the main container M. The main container deflation main valve A9 and the main container deflation bypass valve A9a are used together to achieve the normal pressure state of the main container M.

[0066] At the same time, the embodiment of the present invention also provides a test method for multiple parallel liquid rocket engines, comprising the following steps:

[0067] Step 1: Assemble the above-mentioned tilt test bench for multiple parallel liquid rocket engines, then install the parallel liquid rocket engine group N to the preset position, set the cut-off temperature T 01 =-165℃;

[0068] Step 2.1, define time 0, t1, t2, t3, t4 in sequence, where time 0 is the initial time, and define durations t5 and t6;

[0069] Step 2.2, at time 0, open the main container venting main valve A9 and the main container venting bypass valve A9a;

[0070] Step 2.3, at time t1, close the main container venting main valve A9 and the main container venting bypass valve A9a, and open all the propellant discharge valves 3 at the same time;

[0071] Step 2.4: At time t2, all propellant discharge valves 3 are closed, and at the same time, the engine purge valve A2b is opened to introduce purge gas into the supply pipe D to stabilize the pressure in the supply pipe D;

[0072] Step 2.5: At time t3, the second exhaust valve A5, the third exhaust valve A6 and the fourth exhaust valve A8 are opened simultaneously;

[0073] Step 2.6, 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 at the same time, and 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;

[0074] Step 2.7, 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;

[0075] Step 2.8, 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 2.7; 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 2.9. If the self-check is unqualified, shut down the supply system for maintenance, and then return to step 2.2;

[0076] Step 2.9, close the purge valve A2b, and simultaneously open the discharge valve A2 and the first exhaust valve A3;

[0077] Step 2.10, turn on the temperature sensor in each liquid rocket engine propellant chamber to monitor the temperature in each propellant chamber in real time; open the second bypass valve A4a and all propellant discharge valves 3 to start precooling of the parallel liquid rocket engine group N;

[0078] Step 3: When the temperature value monitored by the ninth temperature sensor drops to the cut-off temperature T 01 When , close the propellant discharge valve 3 of the corresponding liquid rocket engine;

[0079] Step 4.1, when the propellant discharge valves 3 of all liquid rocket engines are closed, start recording the reading of the flow meter assembly 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 n2 of the second filling and precooling times = 1;

[0080] Step 4.2, monitoring the valve post temperature of the discharge valve A2 and the first exhaust valve A3, until the absolute value of the difference between the valve post temperature 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;

[0081] Step 4.3, after t5, open the discharge valve A2 and the first exhaust valve A3 at the same time, and determine whether n2 has reached 2 times. If not, set n2=n2+1, and then return to step 4.2; if so, it is assumed that the parallel liquid rocket engine group N is fully filled and precooled;

[0082] Step 5: Ignite and test the parallel liquid rocket engine group N.

[0083] During the precooling process of the parallel liquid rocket engine group N, the propellant is supplied to the inside of each liquid rocket engine at the same time. The low-temperature propellant will vaporize into gas. Due to the effect of gravity, the propellant in liquid state first gathers in the two liquid rocket engines located at the bottom, and the vaporized gas propellant gathers in the two liquid rocket engines located at the top. There is uneven temperature inside each liquid rocket engine. Therefore, in step 2.10, all the propellant discharge valves 3 need to be opened at the same time to discharge the vaporized low-temperature gas propellant in time. As the propellant further cools each liquid rocket engine, the vaporized gas of each liquid rocket engine decreases. When the propellant discharge valves 3 of the two liquid rocket engines located at the top begin to discharge liquid propellant, it indicates that the parallel liquid rocket engine group N has been sufficiently cooled and the next test run can be carried out.

Claims

1. A tilt test bench for multiple parallel liquid rocket engines, used for testing a parallel liquid rocket engine group (N) consisting of X liquid rocket engines, where X is an integer greater than or equal to 2, characterized in that: The invention comprises a thrust frame (1) arranged on the ground, an adapter ring (2) arranged on the thrust frame (1), and a propellant supply system and a propellant diversion device (4) matched with the thrust frame (1); one side of the thrust frame (1) is an inclined side, one end of the adapter ring (2) is connected to the inclined side of the thrust frame (1), and the other end is connected to the shell of a parallel liquid rocket engine group (N); The propellant supply system comprises a main container (M) and a supply pipeline (D) connected in sequence; the main container (M) is used to store cryogenic propellant; The propellant flow dividing device (4) comprises an input pipeline and X output pipelines of the same length and inner diameter, each output pipeline being connected to the input end of the propellant chamber of the corresponding liquid rocket engine; the input pipeline of the propellant flow dividing device (4) is connected to the output end of the supply pipeline (D); a ninth temperature sensor is provided in the propellant chamber of each liquid rocket engine, and a propellant discharge valve (3) is provided; Define the intersection edge between the inclined side surface α on which the adapter ring (2) is installed on the thrust frame (1) and the ground β as L, then the plane angle θ of the dihedral angle α-L-β is an acute angle.

2. The tilt test bench for multiple parallel liquid rocket engines according to claim 1, characterized in that: The angle θ has a value range of 45°≤θ≤80°.

3. The tilt test bench for multiple parallel liquid rocket engines according to claim 2, characterized in that: The propellant supply system further comprises an exhaust pipe (D1) connected to the supply pipe (D) and a valve and a monitoring assembly arranged on the supply pipe (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, 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 upper part of the main container (M) is provided with a main container deflation main valve (A9) communicated with the atmosphere and a main container deflation bypass valve (A9a) connected in parallel with the main container deflation main valve (A9); 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) in sequence; a seventh temperature sensor (T1) and a first pressure sensor (P) are provided at the 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).

4. The tilt test bench for multiple parallel liquid rocket engines according to claim 3, characterized in that: 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 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.

5. The tilt test bench for multiple parallel liquid rocket engines according to claim 4, characterized in that: A filter (F) is arranged at a downstream position close to the second supply valve (A4), the first exhaust valve (A3) is arranged on the filter (F), and the output end of the main container (M) is connected to the supply pipe (D) through a bellows (C); the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are of the same model.

6. The tilt test bench for multiple parallel liquid rocket engines according to claim 1, characterized in that: Said X=4.

7. A test method for multiple parallel liquid rocket engines, characterized in that: The following steps are involved: Step 1: Assemble the tilt test bench for multiple parallel liquid rocket engines according to any one of claims 1 to 6, then install the parallel liquid rocket engine group (N) to a preset position, set the cut-off temperature T 01 ; Step 2, turning on the ninth temperature sensor in each liquid rocket engine propellant cavity to monitor the temperature in each propellant cavity in real time; activating the propellant supply system to begin initial precooling of each liquid rocket engine in the parallel liquid rocket engine group (N); opening the propellant discharge valve (3) of each liquid rocket engine; Step 3: When the temperature value monitored by the ninth temperature sensor drops to the cut-off temperature T 01 When the propellant discharge valve (3) of the corresponding liquid rocket engine is closed; Step 4, when the propellant discharge valves (3) of all liquid rocket engines are closed, it is assumed that the parallel liquid rocket engine group (N) is fully filled and precooled; Step 5: Ignite and test the parallel liquid rocket engine group (N).

8. A test run method for multiple parallel liquid rocket engines according to claim 7, characterized in that: Step 2 is as follows: Step 2.1, define time 0, t1, t2, t3, t4 in sequence, where time 0 is the initial time, and define durations t5 and t6; Step 2.2, at time 0, open the main container venting main valve (A9) and the main container venting bypass valve (A9a); Step 2.3, at time t1, close the main container venting main valve (A9) and the main container venting bypass valve (A9a), and open all the propellant discharge valves (3); Step 2.4, at time t2, all the propellant discharge valves (3) are closed, and at the same time, the engine purge valve (A2b) is opened to introduce purge gas into the supply pipeline (D) to stabilize the pressure in the supply pipeline (D); Step 2.5: at time t3, the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8) are opened simultaneously; Step 2.6, at time t4, the first bypass valve (A7a) is opened to start precooling the supply pipe (D), and the reading of the flow meter assembly is recorded at the same time, and 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 reading 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) meets the preset requirements, and the pressure value measured by the first pressure sensor (P) is stable, then the first supply valve (A7) is opened; define the initial value n1 of the first filling and precooling times = 1; Step 2.7, 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., closing the second exhaust valve (A5), the third exhaust valve (A6) and the fourth exhaust valve (A8); Step 2.8, 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 2.7; if so, 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 2.9; if the self-check is unqualified, shut down the supply system for maintenance, and then return to step 2.2; Step 2.9, close the purge valve (A2b), and simultaneously open the discharge valve (A2) and the first exhaust valve (A3); Step 2.10, turn on the temperature sensor in each liquid rocket engine propellant chamber to monitor the temperature in each propellant chamber in real time; open the second bypass valve (A4a) and all propellant discharge valves (3) to start precooling of the parallel liquid rocket engine group (N).

9. A test run method for multiple parallel liquid rocket engines according to claim 8, characterized in that: Step 4 is as follows: Step 4.1, when all the propellant discharge valves (3) of the liquid rocket engines are closed, start recording the reading of the flow meter assembly 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) meets the preset requirements, and the pressure values ​​measured by the first pressure sensor (P) and the second pressure sensor (P10) are stable; define the initial value n2 of the second filling and precooling times = 1; Step 4.2, monitoring the valve post temperature of the discharge valve (A2) and the first exhaust valve (A3), until the absolute value of the difference between the valve post temperature 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); Step 4.3: 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 4.

2. If so, it is assumed that the parallel liquid rocket engine group (N) is fully filled and precooled.

Images