Small-flow ground-level liquid nitrous oxide supply system

Abstract

The invention discloses a small-flow ground-level liquid nitrous oxide supply system which is characterized in that a nitrous oxide cylinder group is connected with a nitrous oxide storage tank through a supply valve and then is respectively connected with a gas path matching pipeline and a liquid path pipeline, the gas path matching pipeline is connected with a nitrous oxide storage tank, the nitrous oxide storage tank is connected with a high-low temperature all-in-one machine, and the high-low temperature all-in-one machine is connected with a liquid path pipeline. The blow-off pipeline is connected with the liquid path pipeline, the blow-off pipeline is connected with a blow-off nitrogen cylinder, the liquid path pipeline sequentially comprises a safety hand valve, a main control valve, a filter, a flow meter, a sight glass, a starting connection tested engine, a pressure sensor and a temperature sensor, and a pre-cooling deflation hand valve is connected between the sight glass and the tested engine. The system is an extrusion type supply system, compared with a pressure drop type supply system, the pressure change is more stable, the pressure and temperature of nitrous oxide are more controllable and simpler in a short time, the output nitrous oxide is ensured to be in a liquid state, the requirements of a tested engine are met, and the utilization of the tested engine is facilitated.

Description

Technical Field

[0001] The invention relates to the field of spacecraft propulsion ground test supply systems, and in particular to a small-flow ground-level liquid nitrous oxide supply system. Background Art

[0002] With the rapid development of the aerospace field and the increasing international attention to environmental issues, aerospace products have been given a new core, and non-toxic, environmentally friendly, and high-performance propellant combinations have become an important direction for the development of aerospace products. Nitrous oxide has been favored in the field of non-toxic and environmentally friendly propellants and has become one of the research directions of non-toxic and environmentally friendly propellants at this stage. According to the current situation, it is predicted that aerospace power products using non-toxic and high-energy nitrous oxide as propellants will emerge in an endless stream in the future. The unique physical properties of nitrous oxide make its supply system different from conventional propellant supply forms such as conventional nitrogen tetroxide. The current mainstream supply form is gaseous, but with the continuous in-depth research on nitrous oxide propellants, new requirements have been put forward for the supply form of nitrous oxide. According to the requirements of liquid nitrous oxide supply proposed by the reference engine in the factory, a liquid nitrous oxide supply system is developed, which is of great significance to the research of nitrous oxide propellants.

[0003] Prior art 1: CN114658567B discloses a ground test system and test method for a small-thrust nitrous oxide kerosene rocket engine. The supply system adopted is that the supply state of nitrous oxide can realize gaseous supply. Prior art 2: CN111734554B discloses a regenerative heat compensation system and method for realizing stable self-pressurization supply of nitrous oxide, which is mainly used in aerospace systems. By obtaining heat from different methods, the one-way vaporization and pressurization conversion is completed. The whole is a drop pressure type, with strict requirements on temperature control, and its output state is still gas. Summary of the invention

[0004] The present invention provides a small-flow ground-level liquid nitrous oxide supply system, which can realize the output of liquid nitrous oxide under ground conditions and solve the problem of the state requirements of ground test engines for propellants.

[0005] The technical solution adopted by the present invention is a small-flow ground-level liquid nitrous oxide supply system. The nitrous oxide cylinder group is connected to the nitrous oxide storage tank through a supply valve and then connected to the gas circuit supporting pipeline and the liquid circuit pipeline respectively. The gas circuit supporting pipeline is connected to the nitrous oxide storage tank, the nitrous oxide storage tank is connected to a high and low temperature integrated machine, the blow-off pipeline is connected to the liquid circuit pipeline, the blow-off pipeline is connected to the blow-off nitrogen cylinder, the liquid circuit pipeline sequentially includes a safety manual valve, a main control valve, a filter, a flow meter, a sight glass, and a start valve connected to a test engine, and a pressure sensor, a temperature sensor, and a pre-cooling venting manual valve are connected between the sight glass and the test engine.

[0006] Preferably, the blow-off pipeline includes an air circuit supporting pipeline, a first blow-off valve, and a second blow-off valve. The first blow-off valve is connected between the safety manual valve and the main control valve, and the second blow-off valve is connected between the starting valve and the test engine.

[0007] Preferably, the nitrous oxide storage tank is built into a constant temperature box.

[0008] Preferably, the nitrous oxide storage tank, the high and low temperature integrated machine, the liquid pipeline, the first blow-off valve, and the second blow-off valve are integrated on an integrated frame.

[0009] Preferably, the supply system also includes a driving gas pipeline connected to a driving gas nitrogen cylinder.

[0010] The beneficial effects of the present invention are as follows: This system is an extrusion supply system. Compared with the pressure drop supply system, the pressure change is more stable, the pressure and temperature of nitrous oxide in a short time are more controllable and simple, and the output nitrous oxide is guaranteed to be liquid, meeting the requirements of the test engine, facilitating the use of the test engine, and the control is simpler. The control valves designed in this system are all connected to the integrated system, and the test safety problem can be greatly reduced through remote control means. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the system schematic diagram.

[0012] Figure 2 This is the schematic diagram of the gas pipeline.

[0013] Figure 3 This is the schematic diagram of the blow-off pipeline.

[0014] Figure 4 This is the schematic diagram of the liquid pipeline.

[0015] Markings in the figure: 1-nitrous oxide cylinder group, 2-supply valve, 3-nitrous oxide storage tank, 4-high and low temperature integrated machine, 5-nitrous oxide storage tank, 6-constant temperature box, 7-gas pipeline, 8-gas supply valve, 9-liquid pipeline, 10-purge nitrogen cylinder, 11-purge pipeline, 12-driving gas nitrogen cylinder, 13-driving gas pipeline, 14-integrated frame, 701-pressure reducer, 702-pressure gauge, 703-filter, 704-air release valve, 901-safety hand valve, 902-main control valve, 903-filter, 904-flow meter, 905-sight glass, 906-pressure sensor, 907-temperature sensor, 908-precooling air release hand valve, 909-start valve, 1101-first purge valve, 1102-second purge valve. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0017] The schematic diagram of the system of the present invention is shown in Figure 1 , Main principle: Nitrous oxide gas cylinder group 1 (gas supply source) is connected to nitrous oxide storage tank 3 through supply valve 2, and then connected to gas line supporting pipeline 7 and liquid line pipeline 9 respectively, the gas line supporting pipeline 7 is connected to nitrous oxide storage tank 5, the nitrous oxide storage tank 3 is connected to high and low temperature integrated machine 4, the purge pipeline 11 is connected to the liquid line pipeline 9, the purge pipeline 11 is connected to the purge nitrogen gas cylinder 10, first, by controlling the pressure of high-pressure nitrous oxide storage tank 5 and the temperature of nitrous oxide storage tank 3, the test medium state is guaranteed. Second, considering that there is a certain amount of heat interaction between nitrous oxide and the pipeline during the process, a sight glass 905 is arranged at the end of the system to observe the medium state at the output end. The system utilizes the physical properties of nitrous oxide, controls the temperature in the nitrous oxide storage tank 3 and the temperature in the thermostat 6, and extrude with high-pressure nitrous oxide. When it is determined that the cross-section of the storage tank is small, the effect of the extrusion of nitrous oxide gas and the self-balance in the storage tank after pressurization on the temperature of the liquid nitrous oxide at the bottom of the storage tank can be ignored in a short period of time, so as to ensure that the nitrous oxide is far away from the phase change point, thereby ensuring the supply of liquid nitrous oxide. The final output state of the product can be determined by the sight glass 905, the temperature sensor 907, and the pressure sensor 906. The liquid pipeline 9 is heat-insulated to reduce the influence of external heat. Considering that nitrous oxide has weak oxidizing properties, the sealing structure in the system of the present invention adopts metal hard seals, and the non-metallic sealing auxiliary materials are selected from polytetrafluoroethylene and acid-resistant rubber.

[0018] The nitrous oxide storage tank 3 integrates a liquid level gauge, a vent valve, a safety valve, a drain valve, etc. The nitrous oxide storage tank 5 is built into a constant temperature box 6. See the schematic diagram of the gas circuit supporting pipeline 7. Figure 2 The gas line 7 includes a pressure reducer 701, a pressure gauge 702, a filter 703, and a vent valve 704. The schematic diagram of the liquid line 9 is shown in FIG. Figure 4 The liquid pipeline 9 includes a safety manual valve 901, a main control valve 902, a filter 903, a flow meter 904, a sight glass 905, a pressure sensor 906, a temperature sensor 907, a pre-cooling and venting manual valve 908, and a start valve 909.

[0019] See the schematic diagram of the blow-off pipeline 11 Figure 3The purge pipeline 11 includes the gas line supporting pipeline 7, the first purge valve 1101, and the second purge valve 1102. The first purge valve 1101 is connected to the liquid line 9 between the safety hand valve 901 and the main control valve 902, and the second purge valve 1102 is connected to the liquid line 9 between the start valve 909 and the test engine. The driving gas pipeline 13 equipment is consistent with the gas line supporting pipeline 7. The purge nitrogen bottle 10, the driving gas nitrogen bottle 12 and the nitrous oxide storage tank 5 are all connected to the gas line supporting pipeline 7. The driving gas nitrogen bottle 12 and the driving gas pipeline 13 are connected to all pneumatic pilot valves. The supply valve 2, the gas supply valve 8, the main control valve 902, the start valve 909, the first purge valve 1101, and the second purge valve 1102 are all pneumatic pilot valves and need to be connected for use. The nitrous oxide storage tank 3 , the high and low temperature integrated machine 4 , the liquid pipeline 9 , the first purge valve 1101 , and the second purge valve 1102 are integrated on the integrated frame 14 .

[0020] A small flow rate ground-level liquid nitrous oxide supply system test steps: (1) Determine the required nitrous oxide state based on the requirements of the test engine; (2) Fill the nitrous oxide storage tank 5 with nitrous oxide in advance, determine the nitrous oxide supply pressure according to calculation, adjust the temperature of the thermostat 6 to above the saturation temperature corresponding to the nitrous oxide supply pressure, and control the temperature of the high-pressure nitrous oxide storage tank 5 in advance to ensure that the pressure in the high-pressure nitrous oxide storage tank 5 meets the test requirements (the temperature selection here should be in accordance with the physical properties of nitrous oxide, and the pressure control cannot exceed the cylinder limit pressure); (3) According to the requirements of the hot test and the matching pneumatic pilot valve, calculate the supply pressure, top blow-off pressure and driving pressure, and adjust the pressure reducer 701 in the gas matching pipeline 7, blow-off pipeline 11 and driving gas pipeline 13 to achieve the calculated supply pressure, blow-off pressure and driving gas pressure; (4) Check the system to ensure that the system is airtight, all equipment functions normally, and all valves are in the closed state.

[0021] (5) Set the temperature of the high and low temperature integrated machine 4 (the temperature should be below the saturation temperature corresponding to the pressure measured by the pressure sensor 906 during the test process), open the supply valve 2, and add nitrous oxide to the nitrous oxide storage tank 3. According to the feedback from the liquid level gauge, after reaching a certain range, close the supply valve 2 and wait for stabilization. If the liquid level decreases after stabilization, it does not meet the test requirements, and repeat (5); (6) Open the safety hand valve 901, the main control valve 902, and the precooling and air release hand valve 908 to precool the liquid pipeline. After the precooling of the pipeline is confirmed through the feedback of the sight glass 905, the pressure sensor 906, and the temperature sensor 907, close the precooling and air release hand valve 908; (7) Start the hot test, open the air supply valve 8 and the start valve 909 to supply the propellant; (8) After the single test is completed, close the air supply valve 8 and the start valve 909, open the second purge valve 1102, and purge the pipeline behind the start valve 909. After the purge sequence is completed, close the second purge valve 1102; (9) If a single test task is not completed, adjust the temperature in the nitrous oxide tank 3 to a stable state through the vent valve 704 in the nitrous oxide tank 3 and the high and low temperature integrated machine 4, monitor the liquid level in the nitrous oxide tank 3, and re-execute (7) and (8) after the temperature and liquid level meet the test requirements; (10) After the test, close the safety hand valve 901, open the first purge valve 1101, purge the liquid pipeline, and close the first purge valve 1101 after the purge sequence is completed; (11) Open the drain valve in the nitrous oxide storage tank 3 to discharge the nitrous oxide in the nitrous oxide storage tank 3, and close the high and low temperature integrated machine 4; (12) Arrange the test bench.

[0022] The present invention provides liquid nitrous oxide in a required state by controlling the temperature in the storage tank and the temperature in the thermostat 6, thereby meeting the requirements of the test engine and facilitating the use of the test engine. It has a precooling function, which can effectively reduce the impact of heat exchange between the pipeline and the propellant. All valves used in the ignition test process are remotely controlled, which greatly reduces the safety of the operator. A sight glass 905 is arranged at the end of the present invention, which can effectively observe and clarify the state of the propellant. Considering that nitrous oxide has weak oxidizing properties, the sealing structure adopts metal hard seals, and the non-metallic sealing auxiliary materials are selected from polytetrafluoroethylene and acid-resistant rubber. A small-flow ground-level liquid nitrous oxide supply system of the present invention has the functions of filling, precooling, liquid supply, and blowing, and the present invention has a certain degree of portability.

[0023] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A small flow rate ground-level liquid nitrous oxide supply system, characterized by: The nitrous oxide cylinder group (1) is connected to the nitrous oxide storage tank (3) through a supply valve (2), and then connected to a gas line supporting pipeline (7) and a liquid line pipeline (9), respectively; the gas line supporting pipeline (7) is connected to the nitrous oxide storage tank (5), the nitrous oxide storage tank (3) is connected to the high and low temperature integrated machine (4), the blow-off pipeline (11) is connected to the liquid line pipeline (9), the blow-off pipeline (11) is connected to the blow-off nitrogen cylinder (10), the liquid line pipeline (9) sequentially includes a safety manual valve (901), a main control valve (902), a filter (903), a flow meter (904), a sight glass (905), and a start valve (909) connected to a test engine, and a pressure sensor (906), a temperature sensor (907), and a pre-cooling venting manual valve (908) are connected between the sight glass (905) and the test engine.

2. A low-flow surface-level liquid nitrous oxide supply system according to claim 1, characterized in that: The blow-off pipeline (11) comprises an air circuit supporting pipeline (7), a first blow-off valve (1101), and a second blow-off valve (1102); the first blow-off valve (1101) is connected between the safety manual valve (901) and the main control valve (902); and the second blow-off valve (1102) is connected between the starting valve (909) and the test engine.

3. A low-flow surface-level liquid nitrous oxide supply system according to claim 1, characterized in that: The nitrous oxide storage tank (5) is built into a constant temperature box (6).

4. A low-flow surface-level liquid nitrous oxide supply system according to claim 2, characterized in that: The nitrous oxide storage tank (3), the high and low temperature integrated machine (4), the liquid pipeline (9), the first purge valve (1101), and the second purge valve (1102) are integrated on an integrated frame (14).

5. A low-flow surface-level liquid nitrous oxide supply system according to claim 1, characterized in that: The supply system also includes a driving gas pipeline (13) connected to the driving gas nitrogen cylinder (12).

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