Pressurizing and deflating system for low-temperature storage tank of engine test bed

Abstract

The invention provides a pressurizing and deflating system for a low-temperature storage tank of an engine test bed. The pressurizing and deflating system comprises a nitrogen gas source, a pressure regulating and gas distributing plate, a safe pressurizing module, a gas distributing control module, an air tightness module, a liquid oxygen / liquid methane storage tank and a gas discharging module. Wherein the nitrogen gas source is connected with the pressure-regulating gas distribution plate through the gas supply pipeline of the gas storage tank to carry out gas distribution and pressure regulation, and the pressure-regulating gas distribution plate is sequentially connected with the safety pressurization module, the gas distribution control module and the liquid oxygen / liquid methane storage tank through the nitrogen pressurization pipeline in the gas supply direction to realize pressurization gas distribution. The liquid oxygen / liquid methane storage tank is connected with a gas discharging module which is used for safely discharging gas in the storage tank. According to the system, air tightness detection can be carried out on the pressurization pipeline through the air tightness module before testing, and the control accuracy of the pressurization process is guaranteed. And due to the arrangement of the multiple pressurization pipelines, flexible adjustment can be conducted according to pressurization requirements, and the pressurization accuracy and stability are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of rocket engine test stand testing technology, specifically to a pressurization and venting system for a cryogenic storage tank on an engine test stand. Background Technology

[0002] Before testing a liquid oxygen-methane rocket engine, the cryogenic tanks for liquid oxygen and liquid methane propellants must be pressurized. Only when the tank pressure reaches the set value can the liquid oxygen and liquid methane propellants be stably delivered to the rocket engine via pipeline for ignition testing.

[0003] In rocket engine testing, traditional nitrogen pressurization systems typically employ a relatively simple piping layout and pressure regulation method. For example, the flow and pressure of nitrogen entering the cryogenic tank are controlled via simple valves. However, this approach has limitations in terms of precise control and cannot meet the requirements of modern high-precision rocket engine testing. The compatibility between the nitrogen pressurization system and the tank is not ideal, potentially leading to uneven nitrogen distribution within the tank and affecting stable propellant delivery. Furthermore, traditional nitrogen pressurization systems lack flexibility in handling different operating conditions (such as different propellant requirements and different engine start-up modes), frequently requiring technical modifications.

[0004] The stable control of the cryogenic tank's nitrogen pressurization system plays a crucial role in the stable delivery of propellant during engine testing, and thus can affect the test results. If the nitrogen pressurization system cannot accurately maintain the tank pressure at an appropriate level, the flow rate of liquid oxygen or methane propellant entering the engine will fluctuate unstablely during engine ignition, leading to deviations in the rocket engine's fuel mixture ratio. Deviations in the liquid oxygen and liquid methane flow ratio may cause engine ablation or insufficient propellant power entering the engine, resulting in cavitation in the engine's liquid oxygen or liquid methane pumps, ultimately causing ignition test failure.

[0005] In addition, the venting systems for the cryogenic storage tanks of liquid oxygen and liquid methane are also crucial. They can promptly release excess gas from the tanks after engine testing, reducing the tank pressure to a safer low level. Furthermore, they can promptly activate the venting system if the nitrogen pressurization system malfunctions or is misoperated, causing the tank pressure to exceed a certain limit, thus ensuring the stability and safety of the equipment.

[0006] Therefore, those skilled in the art urgently need a pressurization and venting system for the cryogenic storage tank of an engine test bench that provides precise and stable pressurization and safe and timely exhaust. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a pressurization and venting system for a cryogenic storage tank on an engine test bench, so as to solve the problems of unstable pressurization, inaccurate pressurization control, simple exhaust structure, and unsafe exhaust in the prior art for liquid oxygen and liquid methane storage tanks.

[0008] This invention provides a pressurization and venting system for a cryogenic storage tank on an engine test bench. The system includes: a nitrogen source, a pressure regulating and distribution plate, a safety pressurization module, a gas distribution control module, an airtightness module, a liquid oxygen / liquid methane storage tank, and an exhaust gas module. The nitrogen source is connected to the pressure regulating and distribution plate via a gas delivery pipeline from a storage tank for gas distribution and pressure regulation. The pressure regulating and distribution plate is sequentially connected to the safety pressurization module and the gas distribution control module along the gas delivery direction via a nitrogen pressurization pipeline. Together with the liquid oxygen / liquid methane storage tank, it achieves pressurization and gas distribution; the liquid oxygen / liquid methane storage tank is connected to the exhaust gas module for the safe discharge of gas in the storage tank; the airtightness module, the safety pressurization module, and the gas distribution control module are all set in parallel for on-site airtightness checks of the pressurization system pipeline; the outlet of the nitrogen pressurization pipeline connected to the liquid oxygen / liquid methane storage tank is equipped with a nitrogen diffuser for uniformly diffusing nitrogen into the liquid oxygen / liquid methane storage tank.

[0009] Furthermore, the pressurization and venting system also includes a purging isolation module and a control module, wherein the inlet end of the purging isolation module is connected to the pressure regulating distribution plate, and the outlet end is connected to the exhaust end of the exhaust gas module, for nitrogen purging isolation of ignition sources outside the exhaust gas module; the control module controls and connects the pressure regulating distribution plate, the safety pressurization module, the gas distribution control module, the exhaust gas module and the purging isolation module, for remote control.

[0010] Furthermore, the safety boosting module includes: a boosting shut-off valve, a pressure equalizing valve, and a bypass pressure equalizing pipeline. The boosting shut-off valve is installed on the nitrogen boosting pipeline and is controlled and connected to the control module to control the opening and closing of the pipeline. The two ends of the bypass pressure equalizing pipeline are connected to the nitrogen boosting pipeline upstream and downstream of the boosting shut-off valve, and the pressure equalizing valve is installed on the bypass pressure equalizing pipeline and is controlled and connected to the control module. The valve orifice diameter of the pressure equalizing valve is smaller than that of the boosting shut-off valve.

[0011] Furthermore, the gas distribution control module includes: a pressure boosting control module, a pressure boosting control module, and a pressure boosting control module. The pressure boosting control module includes a pressure boosting solenoid valve and a pressure boosting orifice plate installed on the nitrogen pressure boosting pipeline. The pressure boosting control module includes a pressure boosting pipeline for a bypass branch of the nitrogen pressure boosting pipeline, and a pressure boosting solenoid valve and a pressure boosting orifice plate installed on the pressure boosting pipeline. The pressure boosting control module includes a pressure boosting pipeline connected in parallel with the pressure boosting pipeline, and a pressure boosting solenoid valve and a pressure boosting orifice plate installed on the pressure boosting pipeline.

[0012] Furthermore, the flow rates of the pressure boosting orifice plate, the pressure boosting orifice plate, and the pressure boosting orifice plate are all different, which are used for throttling control and adjustment of nitrogen flow rate.

[0013] In an embodiment of the present invention, the airtightness module includes: a bypass airtight pipe and a booster bypass pipe, wherein the bypass airtight pipe is connected in parallel with the bypass equalization pipe, both ends of the bypass airtight pipe are connected to the nitrogen booster pipe upstream and downstream of the booster shut-off valve, and a manual airtight valve is provided on the bypass airtight pipe for on-site manual control to perform airtightness checks on the booster pipe; the booster bypass pipe is connected in parallel with the booster second pipe and the booster third pipe, and a booster bypass valve is provided on the booster bypass pipe for on-site manual control to perform airtightness checks on the booster pipe.

[0014] In an embodiment of the present invention, the venting module includes: a storage tank safety venting pipe, a bypass storage tank venting pipe on the storage tank safety venting pipe, and a storage tank self-regulating venting pipe and a storage tank anti-pressure pipe connected in parallel with the storage tank venting pipe, wherein a storage tank safety valve is provided on the storage tank safety venting pipe, and the storage tank safety valve is located between the upstream and downstream ports of the storage tank venting pipe;

[0015] The storage tank venting pipeline is equipped with a storage tank venting valve, and the control module controls and connects to the storage tank venting valve; the storage tank self-venting pipeline is equipped with a storage tank self-venting valve for self-venting, and the control module controls and connects to the storage tank self-venting valve; the storage tank anti-pressure-out pipeline is equipped with a storage tank anti-pressure-out manual valve and a storage tank anti-pressure-out check valve.

[0016] Furthermore, the storage tank safety venting pipe is also equipped with a storage tank exhaust outlet manual valve, a flame arrester, and a silencer along the airflow direction. The flame arrester is located at the downstream end of the storage tank safety venting pipe to prevent external fire sources from entering the storage tank from the exhaust pipe. The silencer is located at the outlet of the storage tank safety venting pipe to reduce noise during gas discharge.

[0017] Furthermore, the purging isolation module includes a nitrogen purging pipe connected upstream to the pressure regulating and gas distribution plate, and a nitrogen purging pipe connected downstream to the storage tank safety venting pipe between the flame arrester and the silencer; a nitrogen purging isolation valve is provided on the nitrogen purging pipe, and the control module controls and connects to the nitrogen purging isolation valve.

[0018] In an embodiment of the present invention, a booster filter for filtering impurities in the pipeline and a first pressure detection module are sequentially arranged downstream of the nitrogen booster pipeline near the liquid oxygen / liquid methane storage tank; the pressure detection module includes a first pressure sensor and a first field pressure gauge, wherein the control module is connected to the first pressure sensor; a second pressure monitoring module is arranged at the outlet of the liquid oxygen / liquid methane storage tank, the second pressure detection module includes a second pressure sensor and a second field pressure gauge, wherein the control module is connected to the second pressure sensor.

[0019] As can be seen from the above embodiments, the pressurization and venting system for a cryogenic storage tank on an engine test bench provided by the present invention has at least the following advantages: Before testing, the pressurization and venting system can perform airtightness testing on the pressurization pipeline through an airtightness module, ensuring the accuracy of pressurization process control. The multi-line pressurization pipeline configuration can be flexibly adjusted according to pressurization requirements. When dealing with different test conditions and pressures, by calculating and matching different pressurization orifice plates to control the nitrogen pressurization flow rate, it can ensure that the tank pressure is maintained around the set pressure value without extensive technical modifications, guaranteeing accuracy and stability. The pressure sensor can monitor the pressure inside the tank, feed the signal back to the control module in real time, and make logical judgments based on the preset pressure range, making timely adjustments to ensure the stability of the tank pressure through adjustment and compensation.

[0020] Furthermore, by setting up multiple discharge pipelines and different venting valve structures, various operating conditions can be covered. Through interlocking with the control module, automatic venting is achieved upon completion of the test or when the storage tank is overpressurized. Additionally, introducing nitrogen gas before the discharge pipeline outlet as a gas seal reduces the concentration of methane gas emitted from the outlet, preventing ignition by open flame.

[0021] It should be understood that the above general description and the following specific embodiments are merely exemplary and illustrative, and do not limit the scope of the invention. Attached Figure Description

[0022] The accompanying drawings, which are part of the specification of this invention, illustrate exemplary embodiments of the invention. The drawings, together with the description in the specification, serve to illustrate the principles of the invention.

[0023] Figure 1This is a schematic diagram of a pressurization and venting system for a cryogenic storage tank on an engine test bench, provided by the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] V1 - High-pressure nitrogen storage tank, V2 - Liquid oxygen / liquid methane storage tank, P - Pressure regulating and gas distribution plate, X - Nitrogen diffuser, H - Control module;

[0026] A1-Gas tank supply valve, A2-Pressure boosting shut-off valve, A3-Pressure equalization valve, A4-Manual airtight valve, A5-Pressure boosting solenoid valve (path 1), A6-Pressure boosting solenoid valve (path 2), A7-Pressure boosting solenoid valve (path 3), A8-Pressure boosting bypass valve, A9-Pressure gauge root valve, A10-Storage tank pressure boosting inlet manual valve, A11-Storage tank exhaust outlet manual valve, A12-Storage tank safety valve, A13-Storage tank exhaust valve, A14-Storage tank self-operated exhaust valve, A15-Storage tank anti-pressure stagnation manual valve, A16-Storage tank anti-pressure stagnation check valve, A17-Flame arrester, A18-Silencer, A19-Nitrogen purging isolation valve, A20-Storage tank liquid outlet valve;

[0027] G1 - Booster filter, K1 - Booster orifice plate, K2 - Booster orifice plate, K3 - Booster orifice plate, P1 - First pressure sensor, P2 - First field pressure gauge, P3 - Second pressure sensor, P4 - Second field pressure gauge;

[0028] a1-Gas supply pipeline to the storage tank, a2-Nitrogen pressurization pipeline, a3-Bypass pressure equalization pipeline, a4-Bypass airtight pipeline, a5-Second pressurization pipeline, a6-Third pressurization pipeline, a7-Pressure bypass pipeline, b1-Safe venting pipeline for the storage tank, b2-Venting pipeline for the storage tank, b3-Self-operated venting pipeline for the storage tank, b4-Pressure-resistant pipeline for the storage tank, c1-Nitrogen purging pipeline. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0030] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0031] This invention provides a pressurization and venting system for a cryogenic storage tank on an engine test bench, such as... Figure 1The diagram shows the structural connections of the system. In a specific embodiment, the pressurization and venting system includes: a nitrogen source, a pressure regulating and distribution plate P, a safety pressurization module, a gas distribution control module, an airtightness module, a liquid oxygen / liquid methane storage tank V2, a venting module, a purging and isolation module, and a control module H. The nitrogen source is connected to the pressure regulating and distribution plate P via a gas delivery pipe a1 from the storage tank for gas distribution and pressure regulation. The pressure regulating and distribution plate P is connected sequentially to the safety pressurization module, the gas distribution control module, and the liquid oxygen / liquid methane storage tank V2 along the gas delivery direction via a nitrogen pressurization pipe a2, achieving pressurization and gas distribution. In this embodiment, the nitrogen source is a high-pressure nitrogen storage tank V1, and a storage tank delivery valve A1 is installed upstream of the storage tank delivery pipe a1 near the high-pressure nitrogen storage tank V1. The control module H controls and connects to the storage tank delivery valve A1 for remote control.

[0032] An exhaust gas module is connected to the liquid oxygen / liquid methane storage tank V2 for the safe discharge of gas from the tank.

[0033] The airtightness module, the safety booster module, and the gas distribution control module are all connected in parallel. They are used to conduct an airtightness check on the booster system pipelines on-site before the test run to ensure the pipeline is airtight and to ensure the accuracy of the test.

[0034] The outlet of the nitrogen pressurization pipeline a2, which connects to the liquid oxygen / liquid methane storage tank V2, is equipped with a nitrogen diffuser X for uniformly diffusing nitrogen into the liquid oxygen / liquid methane storage tank V2, so that the pressure in the liquid oxygen / liquid methane storage tank V2 is more uniform and the liquid oxygen or liquid methane is transported more smoothly.

[0035] The inlet end of the purging isolation module is connected to the pressure regulating and distribution plate P, and the outlet end is connected to the exhaust end of the exhaust module. It is used to purge and isolate the fire source outside the exhaust module with nitrogen to prevent the fire source from entering the pipeline.

[0036] The control module H controls the pressure regulating and gas distribution plate P, the safety booster module, the gas distribution control module, the exhaust gas module, and the purging isolation module for remote control.

[0037] In a specific embodiment of the present invention, the safety pressurization module includes: a pressurization shut-off valve A2, a pressure equalization valve A3, and a bypass pressure equalization pipeline a3. The pressurization shut-off valve A2 is installed on the nitrogen pressurization pipeline a2 and is connected to the control module H for remote control of the pipeline's opening and closing, and can perform an emergency shut-off in case of nitrogen pressurization issues during the test.

[0038] The two ends of the bypass pressure equalization pipe a3 are connected to the nitrogen pressurization pipe a2 upstream and downstream of the pressurization shut-off valve A2, and the pressure equalization valve A3 is installed on the bypass pressure equalization pipe a3 and is controlled and connected to the control module H. In this embodiment, the valve orifice diameter of the pressure equalization valve A3 is smaller than that of the pressurization shut-off valve A2. Because the nitrogen pipeline is under high pressure, before opening the pressurization shut-off valve A2, the pressure equalization valve A3 on the smaller diameter pipe needs to be opened first to balance the pipeline pressure before and after the pressurization shut-off valve A2. This prevents the high-pressure nitrogen from impacting the pipeline when the pressurization shut-off valve A2 is opened directly, protecting the pipeline and extending its service life.

[0039] In a specific embodiment of the present invention, the gas distribution control module includes: a pressure boosting control module for one channel, a pressure boosting control module for two channels, and a pressure boosting control module for three channels. The pressure boosting control module for one channel includes a pressure boosting solenoid valve A5 and a pressure boosting orifice plate K1 installed on the nitrogen boosting pipeline a2.

[0040] The booster control module includes a booster secondary pipeline a5, a bypass branch of the nitrogen booster pipeline a2, and a booster secondary solenoid valve A6 and a booster secondary orifice plate K2 installed on the booster secondary pipeline a5. The two ends of the booster secondary pipeline a5 are connected to the nitrogen booster pipeline a2 upstream of the booster primary solenoid valve A5 and downstream of the booster primary orifice plate K1, respectively.

[0041] The three-way pressurization control module includes a three-way pressurization pipeline a6 connected in parallel with the two-way pressurization pipeline a5, a three-way pressurization solenoid valve A7, and a three-way pressurization orifice plate K3 installed on the three-way pressurization pipeline a6. The two ends of the three-way pressurization pipeline a6 are respectively connected to the nitrogen pressurization pipeline a2 upstream of the one-way pressurization solenoid valve A5 and downstream of the one-way pressurization orifice plate K1.

[0042] In this embodiment, the pressure boosting solenoid valve A5, the pressure boosting solenoid valve A6, and the pressure boosting solenoid valve A7 are connected to the control module H, and the valves are opened and closed remotely.

[0043] Furthermore, the flow rates of the three orifice plates, namely, the first pressure booster orifice plate K1, the second pressure booster orifice plate K2, and the third pressure booster orifice plate K3, are all different, and are used for throttling control and adjustment of nitrogen flow.

[0044] In this embodiment, preferably, the flow rate adjusted by the first pressure boosting orifice plate K1 is 80% of the total flow rate; the flow rate adjusted by the second pressure boosting orifice plate K2 is 40% of the total flow rate; and the flow rate adjusted by the third pressure boosting orifice plate K3 is 20% of the total flow rate. By opening the valves of different pressure boosting paths and through the cooperation of one or two orifice plates, different nitrogen flow rates can be supplied, thereby adapting to different nitrogen pressure requirements.

[0045] In a specific embodiment of the present invention, the airtightness module includes: a bypass airtight pipe a4 and a pressurized bypass pipe a7. Wherein,

[0046] The bypass airtight pipe a4 is connected in parallel with the bypass pressure equalization pipe a3. Both ends of the bypass airtight pipe a4 are connected to the nitrogen pressurization pipe a2 upstream and downstream of the pressurization shut-off valve A2. The bypass airtight pipe a4 is equipped with a manual airtight valve A4 for on-site manual control to check the airtightness of the pressurization pipe.

[0047] The booster bypass pipeline a7, booster secondary pipeline a5, and booster tertiary pipeline a6 are all connected in parallel. The booster bypass pipeline a7 is equipped with a booster bypass valve A8, which is used for manual on-site control to check the airtightness of the booster pipeline, ensuring the airtightness of the pipeline and the accuracy of the test data.

[0048] In a specific embodiment of the present invention, the venting module includes: a storage tank safety venting pipe b1, a bypass storage tank venting pipe b2 on the storage tank safety venting pipe b1, a storage tank self-regulating venting pipe b3 connected in parallel with the storage tank venting pipe b2, and a storage tank anti-pressure-locking pipe b4. Wherein,

[0049] A safety valve A12 is installed on the safety venting pipeline b1 of the storage tank. The safety valve A12 is located between the upstream and downstream ports of the venting pipeline b2 of the storage tank and is used for the safe discharge of liquid oxygen / liquid methane from the storage tank V2. In addition, a manual valve A11, a flame arrester A17, and a silencer A18 are also installed on the safety venting pipeline b1 along the airflow direction.

[0050] The manual valve A11 at the tank vent outlet is located upstream of the tank safety venting pipe b1, near the liquid oxygen / liquid methane tank V2, and is used to manually open or close the venting pipe.

[0051] Flame arrester A17 is installed at the downstream end of the safety venting pipe b1 of the storage tank to prevent external ignition sources from entering the liquid oxygen / liquid methane storage tank V2 from the venting pipe, thus ensuring the safety of the system.

[0052] The silencer A18 is installed at the outlet of the safety venting pipe b1 of the storage tank and is used to reduce noise during gas discharge.

[0053] A tank venting valve A13 is installed on the tank venting pipeline b2. The control module H is connected to the tank venting valve A13 for remote control of the opening and closing of the tank venting pipeline b2.

[0054] The storage tank self-venting pipeline b3 is equipped with a storage tank self-venting valve A14 for self-venting, and the control module H controls and connects to the storage tank self-venting valve A14.

[0055] The anti-backpressure pipeline b4 of the storage tank is equipped with a storage tank anti-backpressure manual valve A15 and a storage tank anti-backpressure check valve A16. In this embodiment, the storage tank anti-backpressure manual valve A15 has a smaller diameter and its function is to slowly release the pressure inside the storage tank. It is opened when the backpressure in the liquid oxygen / liquid methane storage tank V2 does not reach the opening pressure of the storage tank self-operated vent valve A14. Usually, after the test run is completed, the storage tank anti-backpressure manual valve A15 is manually opened to prevent the pressure inside the liquid oxygen / liquid methane storage tank V2 from becoming too high. When the pressure inside the liquid oxygen / liquid methane storage tank V2 reaches the discharge pressure of the storage tank self-operated vent valve A14, the storage tank self-operated vent valve A14 automatically opens to release pressure.

[0056] In a specific embodiment of the present invention, the purging isolation module includes a nitrogen purging pipe c1 connected upstream to a pressure regulating and gas distribution plate P. Downstream of the nitrogen purging pipe c1 is a storage tank safety venting pipe b1 connected between a flame arrester A17 and a silencer A18. This pipe guides the purged nitrogen to before the flame arrester A17, acting as a gas seal. The nitrogen reduces the methane gas concentration at the outlet of the storage tank safety venting pipe b1, preventing ignition by an open flame. Additionally, a nitrogen purging isolation valve A19 is installed on the nitrogen purging pipe c1, and a control module H controls and connects to the nitrogen purging isolation valve A19.

[0057] In a specific embodiment of the present invention, a pressurization filter G1 for filtering impurities in the pipeline and a first pressure detection module are sequentially installed downstream of the nitrogen pressurization pipeline a2 near the liquid oxygen / liquid methane storage tank V2. The pressure detection module includes a first pressure sensor P1 and a first field pressure gauge P2. The control module H is connected to the first pressure sensor P1 to provide feedback on the pressure value in the pressurization pipeline at the top of the liquid oxygen / liquid methane storage tank V2, and adjusts the opening and closing of the system valves in real time based on this pressure value to control the nitrogen pressurization effect. A pressure gauge root valve A9 is installed on the pipeline connecting the first pressure sensor P1 and the first field pressure gauge P2 to the nitrogen pressurization pipeline a2.

[0058] A second pressure monitoring module is installed at the outlet of the liquid oxygen / liquid methane storage tank V2. This module includes a second pressure sensor P3 and a second field pressure gauge P4. The control module H is connected to the second pressure sensor P3. The pressure value of the second pressure sensor P3 needs to be adjusted by adding the static pressure of the medium in the storage tank. The first pressure sensor P1 and the second pressure sensor P3 are remotely interlocked with the control module H, various pressurization solenoid valves, and various exhaust valves. The use of dual pressure sensors for pressure monitoring serves as a comparative verification method, improving pressurization accuracy. A pressure gauge root valve A9 is installed on the pipeline connecting the second pressure sensor P3 and the second field pressure gauge P4 to the outlet of the liquid oxygen / liquid methane storage tank V2.

[0059] In addition, a positive pressure inlet manual valve A10 is installed on the nitrogen pressurization pipeline a2 near the liquid oxygen / liquid methane storage tank V2.

[0060] The liquid oxygen / liquid methane storage tank V2 is equipped with a tank outlet valve A20 on the outlet pipe at the bottom, and the control module H controls and connects to the tank outlet valve A20.

[0061] Operating procedures and methods for the pressurization and venting system of the cryogenic storage tank on the engine test bench:

[0062] 1. Conduct an on-site airtightness inspection of the pressurization pipeline of the pressurization and venting system of the cryogenic storage tank.

[0063] (1) By remotely starting the gas supply valve A1 of the gas storage tank through the control module H, the high-pressure nitrogen gas of 23-35MPa in the high-pressure nitrogen storage tank V1 is transported to the pressure regulating and gas distribution plate P through the gas supply pipeline a1 of the storage tank.

[0064] (2) Pressure is regulated and distributed by the pressure reducing valve on the pressure regulating and distribution plate P to reduce the nitrogen booster gas pressure and the nitrogen gas seal purging pressure to the required set pressure. The nitrogen booster gas pressure is set to 5-7 MPa and the nitrogen gas seal purging pressure is set to 1-1.6 MPa in this invention.

[0065] (3) With the tank pressurization inlet manual valve A10 and tank exhaust outlet manual valve A11 open, remotely activate the gas supply valve on the pressure regulating and distribution plate P. The pressurized nitrogen gas, after pressure regulation, is delivered through nitrogen pressurization pipeline a2 to the pressurization shut-off valve A2, pressure equalization valve A3, and manual airtight valve A4. Manually open the manual airtight valve A4, and the nitrogen gas is delivered through the bypass airtight pipeline a4 to the pressurization first solenoid valve A5, pressurization second solenoid valve A6, pressurization third solenoid valve A7, and pressurization bypass valve A8. Then manually open the pressurization bypass valve A8, and the nitrogen gas is delivered through the pressurization bypass pipeline a7 and nitrogen pressurization pipeline a2 to the liquid oxygen / liquid methane tank V2. Continuously observe the pressure value of the first field pressure gauge P2. When the pressure value reaches the airtightness check requirement (≤1.6MPa, tank design pressure), remotely close the gas supply valve on the pressure regulating and distribution plate P. Then, the airtightness of the connections between the pressure-boosting shut-off valve A2, the pressure-balancing valve A3, the manual airtight valve A4, the pressure-boosting solenoid valve A5 (first line), the pressure-boosting solenoid valve A6 (second line), the pressure-boosting solenoid valve A7 (third line), the pressure-boosting bypass valve A8, the tank pressure-boosting inlet manual valve A10, the tank exhaust outlet manual valve A11, and the pressure-boosting filter G1, both before and after the valves, and the pipelines, was checked. The airtightness of the connections between the tank safety valve A12, the tank exhaust valve A13, the tank self-operated exhaust valve A14, and the tank anti-pressure-locking manual valve A15, both before and after the valves, and the pipelines, was also checked. Finally, the airtightness of the connections between the pressure-boosting orifice plate K1 (first line), pressure-boosting orifice plate K2 (second line), and pressure-boosting orifice plate K3 (third line) and the pipelines was checked.

[0066] (4) After the airtightness check is completed, manually open the anti-pressure venting valve A15 of the storage tank or remotely open the storage tank exhaust valve A13 to vent the gas. The vented gas is discharged into the atmosphere through the storage tank safety venting pipe b1, flame arrester A17, and silencer A18. When the pressure value of the first field pressure gauge P2 is normal pressure, the gas is discharged. Then close the manual airtightness valve A4, the booster bypass valve A8, the storage tank anti-pressure venting valve A15, or the storage tank exhaust valve A13 in sequence.

[0067] 2. Before nitrogen pressurization of the liquid oxygen / liquid methane storage tank using a remote automatic control program.

[0068] (1) By remotely starting the gas supply valve A1 of the gas storage tank through the control module H, the high-pressure nitrogen gas of 23-35MPa in the high-pressure nitrogen storage tank V1 is transported to the pressure regulating and gas distribution plate P through the gas supply pipeline a1 of the storage tank.

[0069] (2) Pressure is regulated and distributed by the pressure reducing valve on the pressure regulating and distribution plate P to reduce the nitrogen booster gas pressure and the nitrogen gas seal purging pressure to the required set pressure. The nitrogen booster gas pressure is set to 5-7 MPa and the nitrogen gas seal purging pressure is set to 1-1.6 MPa in this invention.

[0070] (3) The manual valve A10 at the pressurization inlet of the storage tank and the manual valve A11 at the exhaust outlet of the storage tank are in the open state. The gas supply valve on the pressure regulating and gas distribution plate P is remotely activated. The pressurized nitrogen gas after pressure regulation is delivered to the pressurization shut-off valve A2 through the nitrogen pressurization pipeline a2. The pressure equalization valve A3 is remotely opened to equalize the pressure in the nitrogen pressurization pipeline a2. After equalization, the pressurization shut-off valve A2 is remotely opened, and then the pressure equalization valve A3 is closed. The pressurized nitrogen gas is delivered from the nitrogen pressurization pipeline a2 to the pressurization first solenoid valve A5, the pressurization second solenoid valve A6, the pressurization third solenoid valve A7, and the pressurization bypass valve A8.

[0071] (4) Set up a remote automatic control program based on the nitrogen boost value of the tank required during engine test run.

[0072] 3. When using a remote automatic control program to pressurize the liquid oxygen / liquid methane cryogenic storage tank with nitrogen.

[0073] (1) After step 2 is completed, when the engine is tested under rated operating conditions at 100% thrust: the remote automatic control program is started by the control module H. The signal is first fed back to the booster solenoid valve A5 to open the valve. The booster orifice plate K1 is used to adjust the flow rate to 80% for boosting. The boosted nitrogen is delivered from the nitrogen booster pipe a2 through the booster solenoid valve A5, the booster orifice plate K1, the booster filter G1, the tank booster inlet hand valve A10, and the nitrogen diffuser X to the liquid oxygen / liquid methane tank V2. When the first pressure sensor P1 or the second pressure sensor P3 reaches the pressure value set by the automatic boosting, the automatic control program opens the tank outlet valve A20 to deliver the propellant in the tank to the engine for ignition test by extrusion. During the boosting delivery process, the boosted nitrogen continuously replenishes and boosts the tank pressure through the booster solenoid valve A5 and the booster orifice plate K1 to maintain the stability of the tank pressure.

[0074] (2) When the engine is running under rated conditions with 100% thrust, there is a condition with 110% variable thrust: the liquid flow rate of liquid oxygen / liquid methane tank V2 increases. When it is difficult to meet the pressure replenishment of the tank through the first pressure orifice plate K1, the pressure replenishment system automatically opens the second pressure solenoid valve A6 or the third pressure solenoid valve A7 to replenish the pressure of liquid oxygen / liquid methane tank V2 through the second pressure orifice plate K2 or the third pressure orifice plate K3 and the first pressure orifice plate K1 to maintain the stability of the tank pressure of liquid oxygen / liquid methane tank V2, thereby ensuring the stability of liquid supply.

[0075] (3) During the engine's rated operation at 100% thrust, when there is a variable thrust condition of 60-80%, the liquid oxygen / liquid methane tank V2's outlet flow rate decreases. When the booster flow rate through the booster orifice plate K1 is too large, it becomes difficult to quickly reduce the tank pressure to maintain stability. The booster system then automatically closes the booster solenoid valve A5 and opens the booster solenoid valve A6 or the booster solenoid valve A7 to boost the tank pressure through the booster orifice plate K2 or the booster orifice plate K3 to maintain stable tank pressure.

[0076] (4) During engine testing, a remote automatic control program is used to pressurize nitrogen in the liquid oxygen / liquid methane tank V2. If the pressure of the liquid oxygen / liquid methane tank V2 is too high momentarily due to improper selection of the orifice diameter, the remote control program will automatically open the tank exhaust valve A13 to exhaust gas when the set exhaust gas pressure value is reached. The tank exhaust valve A13 will automatically close when the pressure drops to the set value.

[0077] 4. After the liquid oxygen / liquid methane storage tank has completed nitrogen pressurization using a remote automatic control program.

[0078] (1) The remote control module H first closes the pressure cut-off valve A2 to quickly cut off the nitrogen pressurization, and then opens the tank exhaust valve A13 to exhaust the tank. After the tank pressure drops to the required value, the first pressure boosting solenoid valve A5, the second pressure boosting solenoid valve A6, and the third pressure boosting solenoid valve A7 are closed, and the tank exhaust valve A13 completes the tank exhaust. During the exhaust process, if an open flame source appears within the specified range of the atmospheric environment outside the tank exhaust port, the control module H closes the tank exhaust valve A13 and simultaneously opens the nitrogen purging isolation valve A19. The nitrogen purging gas is provided by the pressure regulating and distribution plate P, and is delivered to the tank exhaust port through the nitrogen purging pipeline c1 and the nitrogen purging isolation valve A19 to perform nitrogen purging and seal to prevent the entry of external flames and ensure the safety of the liquid oxygen / liquid methane tank.

[0079] (2) After the storage tank is vented, remotely close the gas supply valve A1 of the storage tank. After the venting pressure is satisfied by the venting valve on the pressure regulating and distribution plate P, close the gas supply valve and venting valve on the pressure regulating and distribution plate P.

[0080] (3) The storage tank exhaust outlet manual valve A11 remains normally open. The storage tank anti-backpressure manual valve A15 is manually opened, and the volatile gas in the storage tank is exhausted through the storage tank anti-backpressure manual valve A15, the storage tank anti-backpressure check valve A16, the storage tank anti-backpressure pipeline b4, and the storage tank safety venting pipeline b1 to prevent backpressure in the liquid oxygen / liquid methane storage tank V2. When the pressure of the volatile gas in the liquid oxygen / liquid methane storage tank V2 becomes too high and reaches the discharge pressure value of the storage tank self-operated exhaust valve A14, the storage tank self-operated exhaust valve A14 automatically vents the storage tank to prevent the storage tank safety valve A12 from opening and discharging, thus extending the service life of the storage tank safety valve A12.

[0081] The above description is merely an illustrative embodiment of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A pressurization and venting system for a cryogenic storage tank on an engine test bench, characterized in that, The pressurization and venting system includes: a nitrogen source, a pressure regulating and distribution plate (P), a safety pressurization module, a gas distribution control module, an airtightness module, a liquid oxygen / liquid methane storage tank (V2), and an exhaust gas module. The nitrogen gas source is connected to the pressure regulating and gas distribution plate (P) through the gas storage tank gas delivery pipe (a1) for gas distribution and pressure regulation. The pressure regulating and gas distribution plate (P) is connected to the safety boosting module, the gas distribution control module and the liquid oxygen / liquid methane storage tank (V2) in sequence along the gas delivery direction through the nitrogen boosting pipe (a2) to realize boosting and gas distribution. The liquid oxygen / liquid methane storage tank (V2) is connected to the exhaust gas module for the safe discharge of gas from the storage tank. The airtightness module, the safety booster module, and the gas distribution control module are all connected in parallel for on-site airtightness checks of the booster system pipelines. The outlet of the nitrogen pressurization pipeline (a2) connected to the liquid oxygen / liquid methane storage tank (V2) is provided with a nitrogen diffuser (X) for uniformly diffusing nitrogen into the liquid oxygen / liquid methane storage tank (V2).

2. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 1, characterized in that, The pressurization and venting system also includes: a purging isolation module and a control module (H), wherein, The air inlet of the purge isolation module is connected to the pressure regulating and air distribution plate (P), and the air outlet is connected to the exhaust end of the exhaust module, which is used to purge and isolate the fire source outside the exhaust module with nitrogen. The control module (H) is connected to the pressure regulating and gas distribution plate (P), the safety booster module, the gas distribution control module, the exhaust gas module, and the purging isolation module for remote control.

3. The pressurization and venting system for the cryogenic storage tank of the engine test bench according to claim 2, characterized in that, The safety booster module includes: a booster shut-off valve (A2), a pressure equalization valve (A3), and a bypass pressure equalization pipeline (A3), wherein, The pressure-boosting shut-off valve (A2) is installed on the nitrogen pressure-boosting pipeline (a2) and is connected to the control module (H) for controlling the opening and closing of the pipeline; The two ends of the bypass pressure equalization pipe (a3) ​​are connected to the nitrogen pressure equalization pipe (a2) upstream and downstream of the pressure equalization shut-off valve (A2), and the pressure equalization valve (A3) is installed on the bypass pressure equalization pipe (a3) ​​and is controlled and connected to the control module (H). The orifice diameter of the equalizing valve (A3) is smaller than that of the booster shut-off valve (A2).

4. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 3, characterized in that, The gas distribution control module includes: a booster control module (channel 1), a booster control module (channel 2), and a booster control module (channel 3), wherein... The booster control module includes a booster solenoid valve (A5) and a booster orifice plate (K1) installed on the nitrogen booster pipe (a2); The booster control module includes a booster pipe (a5) of the bypass branch of the nitrogen booster pipe (a2), a booster solenoid valve (A6) and a booster orifice plate (K2) installed on the booster pipe (a5); The booster three-way control module includes a booster three-way pipeline (a6) connected in parallel with the booster two-way pipeline (a5), a booster three-way solenoid valve (A7) and a booster three-way orifice plate (K3) installed on the booster three-way pipeline (a6).

5. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 4, characterized in that, The flow rates of the three orifice plates (K1, K2, and K3) are different and are used for throttling control and regulation of nitrogen flow.

6. The pressurization and venting system for the cryogenic storage tank of the engine test bench according to claim 4, characterized in that, The airtight module includes: a bypass airtight pipe (a4) and a pressurized bypass pipe (a7), wherein, The bypass airtight pipe (a4) is connected in parallel with the bypass pressure equalization pipe (a3). Both ends of the bypass airtight pipe (a4) are connected to the nitrogen pressurization pipe (a2) upstream and downstream of the pressurization shut-off valve (A2). A manual airtight valve (A4) is installed on the bypass airtight pipe (a4) for on-site manual control to check the airtightness of the pressurization pipe. The booster bypass pipeline (a7), the booster second pipeline (a5), and the booster third pipeline (a6) are all connected in parallel. The booster bypass pipeline (a7) is equipped with a booster bypass valve (A8) for manual on-site control to check the airtightness of the booster pipeline.

7. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 2, characterized in that, The exhaust gas module includes: a storage tank safety venting pipe (b1), a bypass storage tank venting pipe (b2) on the storage tank safety venting pipe (b1), a storage tank self-regulating venting pipe (b3) connected in parallel with the storage tank venting pipe (b2), and a storage tank anti-pressure pipe (b4), wherein, A storage tank safety valve (A12) is installed on the storage tank safety venting pipe (b1), and the storage tank safety valve (A12) is located between the upstream and downstream ports of the storage tank venting pipe (b2); The storage tank venting pipeline (b2) is equipped with a storage tank venting valve (A13), and the control module (H) controls and connects to the storage tank venting valve (A13); The storage tank self-venting pipeline (b3) is equipped with a storage tank self-venting valve (A14) for self-venting, and the control module (H) controls and connects to the storage tank self-venting valve (A14). The anti-pressure-out pipe (b4) of the storage tank is equipped with an anti-pressure-out manual valve (A15) and an anti-pressure-out check valve (A16).

8. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 7, characterized in that, The storage tank safety venting pipe (b1) is also equipped with a storage tank exhaust outlet hand valve (A11), a flame arrester (A17), and a silencer (A18) along the airflow direction. The flame arrester (A17) is located at the downstream end of the safety venting pipe (b1) of the storage tank to prevent external fire sources from entering the storage tank from the venting pipe; The silencer (A18) is installed at the outlet of the safety venting pipe (b1) of the storage tank and is used to reduce noise during gas discharge.

9. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 8, characterized in that, The purge isolation module includes a nitrogen purge pipe (c1) connected upstream to the pressure regulating and gas distribution plate (P), and the nitrogen purge pipe (c1) is connected downstream to the tank safety vent pipe (b1) between the flame arrester (A17) and the silencer (A18). The nitrogen purging pipeline (c1) is equipped with a nitrogen purging isolation valve (A19), and the control module (H) is connected to the nitrogen purging isolation valve (A19).

10. The pressurization and venting system of the cryogenic storage tank of the engine test bench according to claim 2, characterized in that, Downstream of the nitrogen booster pipeline (a2) near the liquid oxygen / liquid methane storage tank (V2), a booster filter (G1) for filtering debris in the pipeline and a first pressure detection module are sequentially installed. The pressure detection module includes a first pressure sensor (P1) and a first field pressure gauge (P2), wherein the control module (H) controls and connects to the first pressure sensor (P1); The liquid oxygen / liquid methane storage tank (V2) is equipped with a second pressure monitoring module at its outlet. The second pressure monitoring module includes a second pressure sensor (P3) and a second field pressure gauge (P4). The control module (H) is connected to the second pressure sensor (P3).

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