A liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines

Abstract

A liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines, comprising a liquid nitrogen supply / recovery subsystem I, a liquid nitrogen supply / recovery subsystem II, a test subsystem, and a measurement and control subsystem; under the control of the measurement and control subsystem, one of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II is used to supply liquid nitrogen for ground cold tests, and the other is used to recover the liquid nitrogen after the test; the measurement and control subsystem is connected to the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II through the test subsystem, controls the liquid nitrogen filling of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II, purges the test device with nitrogen, and controls the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II to achieve liquid nitrogen supply and liquid nitrogen recovery, and perform liquid nitrogen or nitrogen exchange. The present invention provides liquid nitrogen during the test and recovers the liquid nitrogen after the test to achieve the purpose of reuse.

Description

Technical Field

[0001] The present invention belongs to the field of liquid rocket engine design, and particularly relates to a liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines. Background Art

[0002] The components of liquid rocket engines need to undergo ground cold tests and can only be put into formal flight use after passing the tests. For the safety of the tests, liquid nitrogen is currently used as the test medium. The traditional test system has a low secondary utilization rate of liquid nitrogen. After the ground cold test, a large amount of liquid nitrogen is directly discharged into the atmosphere, and there is a lot of noise pollution during the discharge process. At the same time, the cryogenic liquid also causes certain damage to the surrounding buildings. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and provide a liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines, which is used to supply liquid nitrogen during the test and recover the used liquid nitrogen to achieve the purpose of reuse.

[0004] The technical solution of the present invention is as follows:

[0005] A liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines includes a liquid nitrogen supply / recovery subsystem I, a liquid nitrogen supply / recovery subsystem II, a test subsystem, and a measurement and control subsystem;

[0006] Under the control of the measurement and control subsystem, one of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II is used to supply liquid nitrogen for the ground cold test, and the other subsystem is used to recover the liquid nitrogen after the test;

[0007] The measurement and control subsystem is connected to the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II through the test subsystem;

[0008] The measurement and control subsystem controls the liquid nitrogen filling of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II; controls the nitrogen purging of the test device by the liquid nitrogen supply / recovery subsystem I or the liquid nitrogen supply / recovery subsystem II; controls the liquid nitrogen supply and liquid nitrogen recovery of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II; and controls the liquid nitrogen or nitrogen exchange between the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II.

[0009] Preferably, the test subsystem collects the pressure and flow rate of the test device and feeds them back to the measurement and control subsystem;

[0010] The measurement and control sub-system monitors the pressures of the liquid nitrogen supply / recovery sub-system I and the liquid nitrogen supply / recovery sub-system II; monitors the flow rate and pressure of the test device (3) according to the feedback data of the test sub-system.

[0011] Preferably, the liquid nitrogen supply / recovery sub-system I includes a liquid nitrogen container I, a cryogenic safety valve I, a container pressure sensor I, a pneumatic recovery stop valve I, a pneumatic exhaust valve I, a relief valve I, a filter I, a pneumatic supply stop valve I, a heating module I, and a pneumatic filling stop valve I;

[0012] The liquid nitrogen container I has a double-layer structure, and the cavity formed by the inner layer structure is the liquid nitrogen storage cavity I; the liquid nitrogen storage cavity I is evacuated, and a cryogenic safety valve I is installed at the top. The top of the liquid nitrogen container I is connected to the container pressure sensor I, the inlet of the pneumatic recovery stop valve I, the inlet of the pneumatic exhaust valve I, and the inlet of the relief valve I through pipelines respectively; the bottom of the liquid nitrogen storage cavity I is connected to the inlet of the filter I through a pipeline, and the outlet of the filter I is connected to the inlet of the pneumatic supply stop valve I through a pipeline; the heating module I is installed at the bottom of the liquid nitrogen container I and is located between the outer layer structure and the inner layer structure, and is used to provide heat to accelerate the vaporization of liquid nitrogen, and the vaporization rate of liquid nitrogen is adjusted by adjusting the power of the heating module I; the pneumatic filling stop valve I is installed at the bottom of the liquid nitrogen storage cavity I through a pipeline.

[0013] Preferably, the liquid nitrogen supply / recovery sub-system II includes a liquid nitrogen container II, a cryogenic safety valve II, a container pressure sensor II, a pneumatic recovery stop valve II, a pneumatic exhaust valve II, a relief valve II (025), a filter II, a pneumatic supply stop valve II, a heating module II, and a pneumatic filling stop valve II;

[0014] The liquid nitrogen container II has a double-layer structure, and the cavity formed by the inner layer structure is the liquid nitrogen storage cavity II; the liquid nitrogen storage cavity II is evacuated, and a cryogenic safety valve II is installed at the top. The top of the liquid nitrogen container II is connected to the container pressure sensor II, the inlet of the pneumatic recovery stop valve II, the inlet of the pneumatic exhaust valve II, and the inlet of the relief valve I through pipelines respectively; the bottom of the liquid nitrogen storage cavity II is connected to the inlet of the filter II through a pipeline, and the outlet of the filter II is connected to the inlet of the pneumatic supply stop valve II through a pipeline; the heating module II is installed at the bottom of the liquid nitrogen container II and is located between the outer layer structure and the inner layer structure, and is used to provide heat to accelerate the vaporization of liquid nitrogen, and the vaporization rate of liquid nitrogen is adjusted by adjusting the power of the heating module II; the inlet of the pneumatic filling stop valve II is installed at the bottom of the liquid nitrogen storage cavity II through a pipeline.

[0015] Preferably, the liquid nitrogen container I and the liquid nitrogen container II have the same structure, and both include a vacuum insulation layer, a check valve I, a check valve II, a nitrogen pipeline, and a pressurization cavity;

[0016] The vacuum insulation layer is arranged at the bottom of the liquid nitrogen container and covers the heating area of the heating module to form a pressurization chamber with an annular structure; the bottom of the pressurization chamber is connected to the inside of the liquid nitrogen container through a check valve I. When the liquid nitrogen container is being filled, the liquid nitrogen in the liquid nitrogen container enters the pressurization chamber unidirectionally through the check valve I. One end of the check valve II is connected to the top of the pressurization chamber, and the other end is connected to the nitrogen gas pipeline. The vaporized nitrogen gas enters the nitrogen gas pipeline unidirectionally through the check valve II. The nitrogen gas pipeline reaches the top along the cavity between the outer structure and the inner structure of the liquid nitrogen container and enters the inside of the liquid nitrogen storage chamber, reducing the heat exchange with the liquid nitrogen in the liquid nitrogen container.

[0017] Preferably, the test sub-system includes a pneumatic shut-off valve I, a filter III, a test device, a flow meter, a filter IV, a pressure sensor, a filter V, a pneumatic shut-off valve II, and a pneumatic shut-off valve III; one end of the pneumatic shut-off valve I is connected to the liquid nitrogen filling pipeline, and the other end is connected to the inlet of the filter III through a pipeline. The outlet of the filter III is jointly connected to the inlet of the pneumatic filling shut-off valve I and the outlet of the pneumatic filling shut-off valve II through a pipeline to form a tee structure; one end of the flow meter is connected to the inlet of the filter IV through a pipeline, and the other end is jointly connected to the inlet of the pneumatic shut-off valve III, the outlet of the pneumatic supply shut-off valve II, and the outlet of the pneumatic supply shut-off valve I through a pipeline to form a four-way structure; the outlet of the filter IV is connected to the medium inlet of the test device through a pipeline; the pressure sensor is installed on the test device to monitor the pressure inside the test device; the inlet of the filter V is connected to the medium outlet of the test device through a pipeline, and the outlet is connected to the inlet of the pneumatic shut-off valve II; the outlet of the pneumatic shut-off valve II is jointly connected to the outlet of the pneumatic shut-off valve III, the outlet of the pneumatic recovery shut-off valve I, and the outlet of the pneumatic recovery shut-off valve II through a pipeline to form a four-way structure.

[0018] Preferably, the measurement and control sub-system controls the liquid nitrogen filling of the liquid nitrogen supply / recovery sub-system I and the liquid nitrogen supply / recovery sub-system II, and the implementation method is as follows:

[0019] The measurement and control sub-system controls the pneumatic shut-off valve I and the pneumatic filling shut-off valve I to open simultaneously to achieve the individual filling of the liquid nitrogen container I;

[0020] The measurement and control sub-system controls the pneumatic shut-off valve I and the pneumatic filling shut-off valve II to open simultaneously to achieve the individual filling of the liquid nitrogen container II;

[0021] The measurement and control sub-system controls the pneumatic shut-off valve I, the pneumatic filling shut-off valve II, and the pneumatic filling shut-off valve I to open simultaneously to achieve the simultaneous filling of the liquid nitrogen container I and the liquid nitrogen container II.

[0022] Preferably, the measurement and control sub-system controls the liquid nitrogen supply / recovery sub-system I to perform nitrogen purging on the test device, and the implementation method is as follows:

[0023] The measurement and control sub-system controls the heating module I to heat the liquid nitrogen container I, vaporizing the liquid nitrogen. At the same time, the pressure of the liquid nitrogen container I is monitored through the container pressure sensor I. After the required pressure is reached, the measurement and control sub-system controls the pneumatic recovery stop valve I and the pneumatic stop valve III to open, and the nitrogen in the liquid nitrogen container I enters the test device to purge the test device.

[0024] Preferably, the measurement and control sub-system controls the liquid nitrogen supply / recovery sub-system I and the liquid nitrogen supply / recovery sub-system II to achieve liquid nitrogen supply and liquid nitrogen recovery. When the liquid nitrogen supply / recovery sub-system I is used for liquid nitrogen supply and the liquid nitrogen supply / recovery sub-system II is used for liquid nitrogen recovery, the specific implementation method is as follows:

[0025] The measurement and control sub-system controls the heating module I to heat the liquid nitrogen container I, vaporizing the liquid nitrogen. At the same time, the pressure of the liquid nitrogen container I is monitored through the container pressure sensor I. After the appropriate pressure is reached, the measurement and control sub-system controls the pneumatic supply stop valve I to open, and the liquid nitrogen flows out from the bottom of the liquid nitrogen container I into the test device. During the test, the flowmeter and the pressure sensor collect the flow rate and pressure of the test device and send them to the measurement and control sub-system. The measurement and control sub-system adjusts the pressure in the liquid nitrogen container I by controlling the heating module I and the pneumatic exhaust valve I, thereby affecting the outflowing liquid nitrogen, so that the parameters of the test device meet the requirements.

[0026] The measurement and control sub-system controls the pneumatic stop valve II and the pneumatic recovery stop valve II to open, so that the liquid nitrogen flowing out of the test device flows into the liquid nitrogen container II. At the same time, the measurement and control sub-system controls the pneumatic exhaust valve II to open to prevent the pressure in the liquid nitrogen container II from being too high.

[0027] Preferably, the measurement and control sub-system controls the liquid nitrogen supply / recovery sub-system I and the liquid nitrogen supply / recovery sub-system II to perform liquid nitrogen or nitrogen exchange. When the liquid nitrogen and nitrogen in the liquid nitrogen supply / recovery sub-system I are given to the liquid nitrogen supply / recovery sub-system II, the specific implementation method is as follows:

[0028] The liquid nitrogen in the liquid nitrogen container I is given to the liquid nitrogen container II: The measurement and control sub-system controls the heating module I to heat the liquid nitrogen container I to vaporize the liquid nitrogen and increase the pressure of the liquid nitrogen container I. At the same time, the pressure of the liquid nitrogen container I is monitored through the container pressure sensor I. After the appropriate pressure is reached, the measurement and control sub-system controls the pneumatic filling stop valve I and the pneumatic filling stop valve II to open, and the liquid nitrogen flows out from the bottom of the liquid nitrogen container I into the liquid nitrogen container II.

[0029] The nitrogen gas in the liquid nitrogen container I is supplied to the liquid nitrogen container II: The measurement and control sub-system controls the heating module I to heat the liquid nitrogen container I, vaporizing the liquid nitrogen to increase the pressure of the liquid nitrogen container I; at the same time, the pressure of the liquid nitrogen container I is monitored through the container pressure sensor I. After reaching the appropriate pressure, the measurement and control sub-system controls the pneumatic recovery stop valve I and the pneumatic recovery stop valve II to open, and the nitrogen gas flows out from the top of the liquid nitrogen container I and enters the liquid nitrogen container II.

[0030] The beneficial effects of the present invention are as follows:

[0031] (1) The present invention is used for ground cold tests, can realize liquid nitrogen supply and liquid nitrogen recovery, and thus realize the reuse of liquid nitrogen, saving test costs.

[0032] (2) The present invention can monitor the flow rate and pressure of the test device, and automatically adjust the liquid nitrogen pressure and flow rate according to the test needs, improving the automation degree of the test, and thus improving the test efficiency.

[0033] (3) The system of the present invention has a nitrogen purging function, can purge the test device and the pipeline system, avoiding the use of other gases for purging, simplifying the test system, improving the purging and replacement quality, and at the same time ensuring the liquid nitrogen purity, reducing the risk of introducing other gases to form redundant substances and causing test failures.

[0034] (4) The two sub-systems can be interchanged, and nitrogen gas and liquid nitrogen can also be exchanged, maximizing the flexibility of the use of the liquid nitrogen container.

[0035] (5) The present invention is not limited to conducting liquid nitrogen tests, but can also conduct other cryogenic liquid tests, thus greatly reducing the construction cost of the test system. Description of the Drawings

[0036] Figure 1 It is the overall structure block diagram of a liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines provided by the present invention;

[0037] Figure 2 It is the overall system schematic diagram of a liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines provided by the present invention;

[0038] Figure 3 It is the internal structure schematic diagram of the liquid nitrogen container in a liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines provided by the present invention;

[0039] Figure 4 It is the connection relationship schematic diagram of the measurement and control sub-system with the main functions and system structure components in a liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines provided by the present invention. Detailed Embodiment

[0040] The present invention will be further described below in conjunction with embodiments.

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer and more understandable, the spirit of the content disclosed by the present invention will be clearly described below with reference to the drawings and detailed descriptions. After any person skilled in the relevant technical field understands the embodiments of the content of the present invention, they can make changes and modifications based on the technology taught by the content of the present invention, which do not depart from the spirit and scope of the content of the present invention.

[0042] The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not limit the present invention. In addition, elements / components with the same or similar reference numerals used in the drawings and embodiments are used to represent the same or similar parts.

[0043] Regarding the directional terms used in the present invention, such as: up, down, left, right, front or back, etc., they are only references to the directions in the drawings. Therefore, the directional terms used are for illustration and not for limiting this creation.

[0044] Regarding the "comprising", "including", "having", "containing", etc. used in the present invention, they are all open-ended terms, that is, they mean including but not limited to.

[0045] Regarding the "and / or" used in the present invention, it includes any one or all combinations of the described things.

[0046] As Figure 1 shown, a liquid nitrogen supply and recovery system for ground cold-state tests of liquid rocket engines includes a liquid nitrogen supply / recovery subsystem I, a liquid nitrogen supply / recovery subsystem II, a test subsystem, and a measurement and control subsystem; the liquid nitrogen supply / recovery subsystem I, the liquid nitrogen supply / recovery subsystem II, and the test subsystem can realize functions such as liquid nitrogen container filling, liquid nitrogen / nitrogen exchange, nitrogen purging, liquid nitrogen supply, and liquid nitrogen recovery under the control of the measurement and control subsystem.

[0047] One of the liquid nitrogen containers in the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II can be used to supply liquid nitrogen for cold-state tests, and the other container can recover the liquid nitrogen after the test. The two subsystems can be interchanged according to actual usage; the two containers can vaporize the liquid nitrogen through a heating module to increase the pressure of the containers and provide the power for liquid nitrogen / nitrogen transportation;

[0048] As Figure 2 shown, the liquid nitrogen supply / recovery subsystem I includes a liquid nitrogen container I 01, a container pressure sensor I011, a cryogenic safety valve I 012, a pneumatic recovery stop valve I 013, a pneumatic exhaust valve I 014, an overflow valve I 015, a filter I016, a pneumatic supply stop valve I 017, a heating module I 018, and a pneumatic filling stop valve I 019.

[0049] The liquid nitrogen supply / recovery subsystem II includes a liquid nitrogen container II 02, a container pressure sensor II 021, a cryogenic safety valve II 022, a pneumatic recovery stop valve II 023, a pneumatic exhaust valve II 024, a relief valve II 025, a filter II 026, a pneumatic supply stop valve II 027, a heating module II 028, and a pneumatic filling stop valve II 029.

[0050] The interior of the liquid nitrogen container I 01 or the liquid nitrogen container II 02 has a special structural design. Part of the liquid nitrogen is heated by the heating module I 018 or the heating module II 028, and the one-way flow of liquid nitrogen and nitrogen is realized through a one-way valve; that is, the pressurization of the container is achieved, and the stability of the liquid nitrogen supply can be ensured.

[0051] The special structural design inside the liquid nitrogen container I 01 or the liquid nitrogen container II 02 includes a vacuum insulation layer 031, a one-way valve I 032, a one-way valve II 033, a nitrogen gas pipeline 034, and a pressurization chamber 035. There is a vacuum insulation layer 031 inside the liquid nitrogen container I 01 or the liquid nitrogen container II 02. The liquid nitrogen enters the pressurization chamber 035 through the one-way valve I 032. The internal liquid nitrogen is heated by the heating module I 018 or the heating module II 028 and turns into nitrogen gas. The nitrogen gas reaches the top of the liquid nitrogen container I 01 or the liquid nitrogen container II 02 through the one-way valve II 033 and the nitrogen gas pipeline 034 to pressurize the liquid nitrogen container I 01 or the liquid nitrogen container II 02.

[0052] The test subsystem includes a test device 3, a pneumatic stop valve I 1, a filter III 2, a flow meter 4, a filter IV 5, a pressure sensor 6, a filter V 7, a pneumatic stop valve II 8, and a pneumatic stop valve III 9; the pressure sensor 6 and the flow meter 4 can respectively detect the pressure and flow rate in the test device and feedback them to the measurement and control subsystem. The measurement and control subsystem adjusts the parameters according to the test requirements.

[0053] The liquid nitrogen container I 01 has a double-layer structure, with the inside evacuated. A cryogenic safety valve I 012 is installed at the top to prevent the pressure inside the liquid nitrogen container I 01 from being too high, playing a protective role. The top of the liquid nitrogen container I 01 is connected by a pipeline to install a container pressure sensor I 011 for monitoring the pressure inside the liquid nitrogen container I 01; the top of the liquid nitrogen container I 01 is connected by a pipeline to install a pneumatic recovery stop valve I 013, and a pneumatic exhaust valve I 014 discharges the excess nitrogen inside the liquid nitrogen container I 01. The overflow valve I 015 causes liquid nitrogen to overflow when the liquid nitrogen container I 01 is filled with liquid nitrogen; the bottom of the liquid nitrogen container I 01 is connected by a pipeline to a filter I 016, and the filter I 016 is connected to a pneumatic supply stop valve I 017 through a pipeline; a heating module I 018 is installed at the bottom of the liquid nitrogen container I 01, in the middle of the double-layer structure, and can provide heat to accelerate the vaporization of liquid nitrogen; a pneumatic filling stop valve I 019 is installed at the bottom of the liquid nitrogen container I 01 through a pipeline.

[0054] The liquid nitrogen container II 02 has a double-layer structure, with the inside evacuated. A cryogenic safety valve II 022 is installed at the top to prevent the pressure inside the liquid nitrogen container II 02 from being too high, playing a protective role. The top of the liquid nitrogen container II 02 is connected by a pipeline to install a container pressure sensor II 021 for monitoring the pressure inside the liquid nitrogen container II 02; the top of the liquid nitrogen container II 02 is connected by a pipeline to install a pneumatic recovery stop valve II 023, and a pneumatic exhaust valve II 024 discharges the excess nitrogen inside the liquid nitrogen container II 02. The overflow valve II 025 causes liquid nitrogen to overflow when the liquid nitrogen container II 02 is filled with liquid nitrogen; the bottom of the liquid nitrogen container II 02 is connected by a pipeline to a filter II 026, and the filter II 026 is connected to a pneumatic supply stop valve II 027 through a pipeline; a heating module II 028 is installed at the bottom of the liquid nitrogen container II 02, in the middle of the double-layer structure, and can provide heat to accelerate the vaporization of liquid nitrogen; a pneumatic filling stop valve II 029 is installed at the bottom of the liquid nitrogen container II 02 through a pipeline.

[0055] The test subsystem includes a pneumatic stop valve I1, a filter III 2, a test device 3, a flow meter 4, a filter IV5, a pressure sensor 6, a filter V 7, a pneumatic stop valve II 8, and a pneumatic stop valve III 9. One end of the pneumatic stop valve I1 is connected to the liquid nitrogen filling pipeline, and the other end is connected to the filter III 2 through a pipeline. The filter III 2 is connected to the pneumatic filling stop valve I 019 and the pneumatic filling stop valve II 029 through a pipeline to form a three-way structure. One end of the flow meter 4 is connected to the filter IV 5 through a pipeline, and the other end is connected to the pneumatic stop valve III 9, the pneumatic supply stop valve II 027, and the pneumatic supply stop valve I 017 to form a four-way structure. The filter IV 5 is connected to the medium inlet of the test device 3 through a pipeline. The pressure sensor 6 is installed on the test device 3 for monitoring the pressure inside the test device 3. One end of the filter V 7 is connected to the medium outlet of the test device 3 through a pipeline, and the other end is connected to the pneumatic stop valve II the other end of the pneumatic stop valve II 8 is connected to the pneumatic stop valve III9, the pneumatic recovery stop valve I 013, and the pneumatic recovery stop valve II 023 to form a four-way structure.

[0056] There is a vacuum insulation layer 031 inside the liquid nitrogen container I 01 or liquid nitrogen container II 02, which covers the heating area of the heating module I 018 or heating module II 028; the one-way valve I 032 is connected to the bottom of the boosting chamber 035, one end of the one-way valve II 033 is connected to the top of the boosting chamber 035, and the other end is connected to the nitrogen pipeline 034. The nitrogen pipeline 034 reaches the top along the double-layer structure of the liquid nitrogen container I 01 or liquid nitrogen container II 02 and enters the interior of the liquid nitrogen container I 01 or liquid nitrogen container II 02.

[0057] Filter I 016 and filter II 026 are used to filter out liquid nitrogen from liquid nitrogen container I 01 and liquid nitrogen container II 02, respectively;

[0058] Filter III 2 is used to filter the liquid nitrogen filled in liquid nitrogen container I 01 and liquid nitrogen container II 02;

[0059] Filter IV 5 is used to filter the liquid nitrogen before entering the test device 03;

[0060] Filter V 7 is used to filter the recovered liquid nitrogen;

[0061] It should be noted that the low temperature mentioned in the embodiment of the present invention may be around -196°C, but the application of the test system of the present invention is not limited to this temperature range.

[0062] Figure 3 Schematic diagram of the internal structure of the liquid nitrogen container.

[0063] Figure 4 It is a schematic diagram showing the connection relationship between the measurement and control sub-system and the main functions and the system structure composition in a liquid nitrogen supply and recovery system for ground cold test of a liquid rocket engine provided by an embodiment of the present invention.

[0064] Function 1, Parameter Measurement:

[0065] The measurement and control sub-system monitors the parameters of the test device 3 through the signal feedback of the flowmeter 4 and the pressure sensor 6, and monitors the pressures inside the liquid nitrogen containers I 01 and II 02 through the signal feedback of the container pressure sensor 011 and the container pressure sensor 021.

[0066] Function 2, Filling of Liquid Nitrogen Containers:

[0067] The measurement and control sub-system can achieve the filling of the liquid nitrogen containers I 01 and II 02 by controlling the pneumatic shut-off valve I1, the pneumatic filling shut-off valve II 029, and the pneumatic filling shut-off valve I019; if the pneumatic shut-off valve I 1 and the pneumatic filling shut-off valve I 019 are opened simultaneously, the liquid nitrogen container I 01 can be filled separately; if the pneumatic shut-off valve I1 and the pneumatic filling shut-off valve II 029 are opened simultaneously, the liquid nitrogen container II 02 can be filled separately; if the pneumatic shut-off valve I 1, the pneumatic filling shut-off valve I019, and the pneumatic filling shut-off valve II 029 are opened simultaneously, the liquid nitrogen containers I 01 and II 02 can be filled simultaneously.

[0068] When filling the liquid nitrogen container I 01 or the liquid nitrogen container II 02, the measurement and control sub-system will control the pneumatic exhaust valve I014 or the pneumatic exhaust valve II 024 to open to avoid excessive pressure inside the liquid nitrogen container I 01 or the liquid nitrogen container II 02; open the overflow valve I 015 and the overflow valve II 025, and if liquid nitrogen flows out, it means that the liquid nitrogen container I 01 or the liquid nitrogen container II 02 is filled up.

[0069] Function 3, Nitrogen Purging:

[0070] The test device 3 can be purged with nitrogen using the liquid nitrogen container I 01 or the liquid nitrogen container II 02. Before nitrogen purging, the pipeline between the test device 3 and the filter V 7 needs to be disconnected first. The following takes the liquid nitrogen container I 01 as an example for introduction.

[0071] The measurement and control sub-system controls the heating module I 018 to heat the liquid nitrogen container I 01 to vaporize the liquid nitrogen; at the same time, the pressure of the liquid nitrogen container I 01 is monitored through the container pressure sensor I 011. After the required pressure is reached, the measurement and control sub-system controls the pneumatic recovery shut-off valve I 013 and the pneumatic shut-off valve III9 to open, and the nitrogen in the liquid nitrogen container I 01 purges the test device 3.

[0072] Function 4, Liquid Nitrogen Supply and Liquid Nitrogen Recovery:

[0073] During the ground cold test, any one of the liquid nitrogen containers I 01 or II 02 can be used as the liquid nitrogen supply, and the other as the liquid nitrogen recovery. Here, liquid nitrogen container I 01 is used as the liquid nitrogen supply and liquid nitrogen container II 02 as the liquid nitrogen recovery.

[0074] The measurement and control sub-system controls the heating module I 018 to heat the liquid nitrogen container I 01 to vaporize the liquid nitrogen. At the same time, the pressure of the liquid nitrogen container I 01 is monitored through the container pressure sensor I 011. After reaching the appropriate pressure, the measurement and control sub-system controls the pneumatic supply cut-off valve I 017 to open, and the liquid nitrogen flows out from the bottom of the liquid nitrogen container I 01 into the test device 3. During the test, through the parameter monitoring of the flowmeter 4 and the pressure sensor 6, the measurement and control sub-system adjusts the pressure in the liquid nitrogen container I 01 by controlling the heating module I 018 and the pneumatic exhaust valve I 014, thereby affecting the outflowing liquid nitrogen to meet the test parameters of the test device 3.

[0075] The measurement and control sub-system controls the pneumatic cut-off valve II 8 and the pneumatic recovery cut-off valve II 023 to open, so that the liquid nitrogen flowing out of the test device 3 flows into the liquid nitrogen container II 02. At the same time, the measurement and control sub-system controls the pneumatic exhaust valve II 024 to open to prevent the pressure in the liquid nitrogen container II 02 from being too high.

[0076] Function 5, Liquid Nitrogen / Nitrogen Exchange:

[0077] The liquid nitrogen container I 01 or the liquid nitrogen container II 02 can exchange their respective liquid nitrogen or nitrogen with each other according to actual needs. Here, the case of giving the liquid nitrogen and nitrogen in the liquid nitrogen container I 01 to the liquid nitrogen container II 02 is taken as an example for illustration.

[0078] Giving the liquid nitrogen in the liquid nitrogen container I 01 to the liquid nitrogen container II 02: The measurement and control sub-system controls the heating module I 018 to heat the liquid nitrogen container I 01 to vaporize the liquid nitrogen and increase the pressure in the liquid nitrogen container I 01. At the same time, the pressure of the liquid nitrogen container I 01 is monitored through the container pressure sensor I 011. After reaching the appropriate pressure, the measurement and control sub-system controls the pneumatic filling cut-off valve I019 and the pneumatic filling cut-off valve II 029 to open, and the liquid nitrogen flows out from the bottom of the liquid nitrogen container I 01 into the liquid nitrogen container II 02. At the same time, the pneumatic exhaust valve II 024 can be controlled by the measurement and control sub-system according to actual needs to reduce the pressure in the liquid nitrogen container II 02.

[0079] The nitrogen gas in the liquid nitrogen container I 01 is supplied to the liquid nitrogen container II 02: The measurement and control sub-system controls the heating module I 018 to heat the liquid nitrogen container I 01, vaporize the liquid nitrogen to increase the pressure of the liquid nitrogen container I 01; at the same time, the pressure of the liquid nitrogen container I 01 is monitored through the container pressure sensor I 011. After reaching the appropriate pressure, the measurement and control sub-system controls the pneumatic recovery cut-off valve I 013 and the pneumatic recovery cut-off valve II 023 to open, and the nitrogen gas flows out from the top of the liquid nitrogen container I 01 and enters the liquid nitrogen container II 02; at the same time, the pneumatic exhaust valve II 024 can be controlled by the measurement and control sub-system according to actual needs to reduce the pressure in the liquid nitrogen container II 02.

[0080] It should be particularly noted that the pneumatic cut-off valve, pneumatic exhaust valve, etc. described in the present invention can be replaced by electric or manual ones, and their functions remain unchanged, and the judgment logic can also be changed from automatic to manual judgment.

[0081] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A liquid nitrogen supply and recovery system for ground cold tests of liquid rocket engines, characterized in that: It includes a liquid nitrogen supply / recovery subsystem I, a liquid nitrogen supply / recovery subsystem II, a test subsystem, and a measurement and control subsystem; Under the control of the measurement and control subsystem, one of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II is used to supply liquid nitrogen for the ground cold test, and the other subsystem is used to recover the liquid nitrogen after the test; The measurement and control subsystem is connected to the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II through the test subsystem; The measurement and control subsystem controls the liquid nitrogen filling of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II; controls the liquid nitrogen supply / recovery subsystem I or the liquid nitrogen supply / recovery subsystem II to perform nitrogen purging on the test device; controls the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II to achieve liquid nitrogen supply and liquid nitrogen recovery; controls the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II to perform liquid nitrogen or nitrogen exchange.

2. The liquid nitrogen supply and recovery system for ground cold test of liquid rocket engine according to claim 1, characterized in that: The test subsystem collects the pressure and flow rate of the test device and feeds them back to the measurement and control subsystem; The measurement and control subsystem monitors the pressure of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II; monitors the flow rate and pressure of the test device (3) according to the feedback data of the test subsystem.

3. The liquid nitrogen supply and recovery system for ground cold test of liquid rocket engine according to claim 1, characterized in that: The liquid nitrogen supply / recovery subsystem I includes a liquid nitrogen container I (01), a low-temperature safety valve I (012), a container pressure sensor I (011), a pneumatic recovery shut-off valve I (013), a pneumatic exhaust valve I (014), a relief valve I (015), a filter I (016), a pneumatic supply shut-off valve I (017), a heating module I (018), and a pneumatic filling shut-off valve I (019); The liquid nitrogen container I (01) is a double-layer structure, and the cavity formed by the inner layer structure is the liquid nitrogen storage cavity I; the liquid nitrogen storage cavity I is evacuated, and a low-temperature safety valve I (012) is installed at the top. The top of the liquid nitrogen container I (01) is connected to the container pressure sensor I (011), the inlet of the pneumatic recovery shut-off valve I (013), the inlet of the pneumatic exhaust valve I (014), and the inlet of the relief valve I (015) through pipelines respectively; the bottom of the liquid nitrogen storage cavity I is connected to the inlet of the filter I (016) through a pipeline, and the outlet of the filter I (016) is connected to the inlet of the pneumatic supply shut-off valve I (017) through a pipeline; the heating module I (018) is installed at the bottom of the liquid nitrogen container I (01) and is located between the outer layer structure and the inner layer structure, and is used to provide heat to accelerate the vaporization of liquid nitrogen, and the vaporization rate of liquid nitrogen is adjusted by adjusting the power of the heating module I (018); the pneumatic filling shut-off valve I (019) is installed at the bottom of the liquid nitrogen storage cavity I through a pipeline.

4. The liquid nitrogen supply and recovery system for ground cold test of liquid rocket engine according to claim 3, wherein: The liquid nitrogen supply / recovery subsystem II includes a liquid nitrogen container II (02), a low-temperature safety valve II (022), a container pressure sensor II (021), a pneumatic recovery shut-off valve II (023), a pneumatic exhaust valve II (024), a relief valve II (025), a filter II (026), a pneumatic supply shut-off valve II (027), a heating module II (028), and a pneumatic filling shut-off valve II (029); The liquid nitrogen container II (02) has a double-layer structure. The cavity formed by the inner-layer structure is the liquid nitrogen storage cavity II. The liquid nitrogen storage cavity II is evacuated, and a cryogenic safety valve II (022) is installed at the top. The top of the liquid nitrogen container II (02) is respectively connected to the container pressure sensor II (021), the inlet of the pneumatic recovery shut-off valve II (023), the inlet of the pneumatic exhaust valve II (024), and the inlet of the overflow valve II (025) through pipelines. The bottom of the liquid nitrogen storage cavity II is connected to the inlet of the filter II (026) through a pipeline, and the outlet of the filter II (026) is connected to the inlet of the pneumatic supply shut-off valve II (027) through a pipeline. The heating module II (028) is installed at the bottom of the liquid nitrogen container II (02) and is located between the outer-layer structure and the inner-layer structure, and is used to provide heat to accelerate the vaporization of liquid nitrogen. The vaporization rate of liquid nitrogen is adjusted by adjusting the power of the heating module II (028). The inlet of the pneumatic filling shut-off valve II (029) is installed at the bottom of the liquid nitrogen storage cavity II through a pipeline.

5. A liquid nitrogen supply and recovery system for ground cold-state tests of liquid rocket engines according to claim 4, characterized in that: The liquid nitrogen container I (01) and the liquid nitrogen container II (02) have the same structure, and both include a vacuum insulation layer (031), a check valve I (032), a check valve II (033), a nitrogen pipeline (034), and a pressurizing cavity (035). The vacuum insulation layer (031) is arranged at the bottom of the liquid nitrogen container and covers the heating area of the heating module, forming a ring-shaped pressurizing cavity (035). The bottom of the pressurizing cavity (035) is connected to the inside of the liquid nitrogen container through the check valve I (032). When the liquid nitrogen container is being filled, the liquid nitrogen in the liquid nitrogen container enters the pressurizing cavity (035) unidirectionally through the check valve I (032). One end of the check valve II (033) is connected to the top of the pressurizing cavity (035), and the other end is connected to the nitrogen pipeline (034). The vaporized nitrogen enters the nitrogen pipeline (034) unidirectionally through the check valve II (from 033). The nitrogen pipeline (034) reaches the top along the cavity between the outer-layer structure and the inner-layer structure of the liquid nitrogen container and enters the inside of the liquid nitrogen storage cavity, reducing the heat exchange with the liquid nitrogen in the liquid nitrogen container.

6. The liquid nitrogen supply and recovery system for ground cold test of liquid rocket engine according to claim 4, characterized in that: The test subsystem includes a pneumatic shut-off valve I (1), a filter III (2), a test device (3), a flowmeter (4), a filter IV (5), a pressure sensor (6), a filter V (7), a pneumatic shut-off valve II (8), and a pneumatic shut-off valve III (9); one end of the pneumatic shut-off valve I (1) is connected to the liquid nitrogen filling pipeline, and the other end is connected to the inlet of the filter III (2) through a pipeline. The outlet of the filter III (2) is connected to the inlet of the pneumatic filling shut-off valve I (019) and the outlet of the pneumatic filling shut-off valve II (029) through a pipeline, forming a tee structure; one end of the flowmeter (4) is connected to the inlet of the filter IV (5) through a pipeline, and the other end is connected to the inlet of the pneumatic shut-off valve III (9), the outlet of the pneumatic supply shut-off valve II (027), and the outlet of the pneumatic supply shut-off valve I (017) through a pipeline, forming a four-way structure; the outlet of the filter IV (5) is connected to the medium inlet of the test device (3) through a pipeline; the pressure sensor (6) is installed on the test device (3) to monitor the pressure inside the test device (3); the inlet of the filter V (7) is connected to the medium outlet of the test device (3) through a pipeline, and the outlet is connected to the inlet of the pneumatic shut-off valve II (8); the outlet of the pneumatic shut-off valve II (8) is connected to the outlet of the pneumatic shut-off valve III (9), the outlet of the pneumatic recovery shut-off valve I (013), and the outlet of the pneumatic recovery shut-off valve II (023) through a pipeline, forming a four-way structure.

7. A liquid nitrogen supply and recovery system for ground cold test of liquid rocket engines according to claim 6, characterized in that: The measurement and control subsystem controls the liquid nitrogen filling of the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II, and the implementation method is as follows: The measurement and control subsystem controls the pneumatic shut-off valve I (1) and the pneumatic filling shut-off valve I (019) to open simultaneously to achieve the separate filling of the liquid nitrogen container I (01); The measurement and control subsystem controls the pneumatic shut-off valve I (1) and the pneumatic filling shut-off valve II (029) to open simultaneously to achieve the separate filling of the liquid nitrogen container II (02); The measurement and control subsystem controls the pneumatic shut-off valve I (1), the pneumatic filling shut-off valve II (029), and the pneumatic filling shut-off valve I (019) to open simultaneously to achieve the simultaneous filling of the liquid nitrogen container I (01) and the liquid nitrogen container II (02).

8. A liquid nitrogen supply and recovery system for ground cold test of liquid rocket engines according to claim 6, characterized in that: The measurement and control subsystem controls the liquid nitrogen supply / recovery subsystem I to perform nitrogen purging on the test device (3), and the implementation method is as follows: The measurement and control subsystem controls the heating module I (018) to heat the liquid nitrogen container I (01) to vaporize the liquid nitrogen; at the same time, the container pressure sensor I (011) monitors the pressure of the liquid nitrogen container I (01). After the required pressure is reached, the measurement and control subsystem controls the pneumatic recovery shut-off valve I (013) and the pneumatic shut-off valve III (9) to open, and the nitrogen in the liquid nitrogen container I (01) enters the test device to purge the test device (3).

9. A liquid nitrogen supply and recovery system for ground cold-state tests of liquid rocket engines according to claim 6, characterized in that: The measurement and control subsystem controls the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II to achieve liquid nitrogen supply and liquid nitrogen recovery. When the liquid nitrogen supply / recovery subsystem I is used as the liquid nitrogen supply and the liquid nitrogen supply / recovery subsystem II is used as the liquid nitrogen recovery, the specific implementation method is as follows: The measurement and control subsystem controls the heating module I (018) to heat the liquid nitrogen container I (01) to vaporize the liquid nitrogen. At the same time, the pressure of the liquid nitrogen container I (01) is monitored by the container pressure sensor I (011). After reaching the appropriate pressure, the measurement and control subsystem controls the pneumatic supply shut-off valve I (017) to open, and the liquid nitrogen flows out from the bottom of the liquid nitrogen container I (01) into the test device (3). During the test, the flowmeter (4) and the pressure sensor (6) collect the flow rate and pressure of the test device and send them to the measurement and control subsystem. The measurement and control subsystem adjusts the pressure in the liquid nitrogen container I (01) by controlling the heating module I (018) and the pneumatic exhaust valve I (014), thereby affecting the outflowing liquid nitrogen, so that the parameters of the test device (3) meet the requirements. The measurement and control subsystem controls the pneumatic shut-off valve II (8) and the pneumatic recovery shut-off valve II (023) to open, so that the liquid nitrogen flowing out of the test device (3) flows into the liquid nitrogen container II (02). At the same time, the measurement and control subsystem controls the pneumatic exhaust valve II (024) to open to prevent the pressure in the liquid nitrogen container II (02) from being too high.

10. A liquid nitrogen supply and recovery system for ground cold test of liquid rocket engines according to claim 6, characterized in that: The measurement and control subsystem controls the liquid nitrogen supply / recovery subsystem I and the liquid nitrogen supply / recovery subsystem II to perform liquid nitrogen or nitrogen exchange. When the liquid nitrogen and nitrogen of the liquid nitrogen supply / recovery subsystem I are given to the liquid nitrogen supply / recovery subsystem II, the specific implementation method is as follows: The liquid nitrogen in the liquid nitrogen container I (01) is given to the liquid nitrogen container II (02): The measurement and control subsystem controls the heating module I (018) to heat the liquid nitrogen container I (01) to vaporize the liquid nitrogen and increase the pressure of the liquid nitrogen container I (01). At the same time, the pressure of the liquid nitrogen container I (01) is monitored by the container pressure sensor I (011). After reaching the appropriate pressure, the measurement and control subsystem controls the pneumatic filling shut-off valve I (019) and the pneumatic filling shut-off valve II (029) to open, and the liquid nitrogen flows out from the bottom of the liquid nitrogen container I (01) into the liquid nitrogen container II (02). The nitrogen in the liquid nitrogen container I (01) is given to the liquid nitrogen container II (02): The measurement and control subsystem controls the heating module I (018) to heat the liquid nitrogen container I (01) to vaporize the liquid nitrogen and increase the pressure of the liquid nitrogen container I (01). At the same time, the pressure of the liquid nitrogen container I (01) is monitored by the container pressure sensor I (011). After reaching the appropriate pressure, the measurement and control subsystem controls the pneumatic recovery shut-off valve I (013) and the pneumatic recovery shut-off valve II (023) to open, and the nitrogen flows out from the top of the liquid nitrogen container I (01) into the liquid nitrogen container II (02).

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