Multi-parameter adjustable low-temperature gas injection type accumulator test device

Abstract

The application discloses a kind of low-temperature injection type accumulator test devices of multiple parameter adjustable, comprising: delivery pipe, accumulator, gas supply assembly, accumulator inflation and exhaust assembly, delivery pipe pressurization and pressure relief assembly, liquid nitrogen heat exchanger, constant temperature water bath, gas component measurement airtight container, vacuum pump, measurement control system.The application can be applicable to the performance parameter influence study of large-volume low-temperature injection type accumulator, can be realized but not limited to the delivery pipe pressure intensity change rate is adjusted in the range of 0~30kPa / s, effectively assesses the working performance of injection type accumulator under different inflation flow, inflation temperature, exhaust aperture, environmental back pressure and other parameters under variable back pressure condition, simultaneously obtains the loss flow, loss total amount of low-temperature liquid in injection type accumulator and the liquid level fluctuation in injection type accumulator during working process.

Description

Technical Field

[0001] This invention relates to the field of testing systems, and more specifically to a multi-parameter adjustable cryogenic gas-injection accumulator testing device. Background Technology

[0002] POGO vibration is a significant low-frequency vibration problem encountered during the flight of large liquid-fueled launch vehicles. It is an unstable, closed-loop, self-excited vibration generated by the interaction between the longitudinal vibration of the structure and the propellant piping system. POGO vibration deteriorates the rocket's vibration environment. For the structural system, it can damage sensitive components and instruments or cause structural overruns. For the propulsion system, the accompanying pressure and flow fluctuations can produce various harmful effects, reducing propulsion system performance and even causing accidents. For manned spaceflight, it can subject astronauts to vibrations exceeding human tolerance. Therefore, suppressing POGO vibration has become one of the important design conditions for modern space launch vehicles and a prerequisite for human spaceflight.

[0003] Currently, my country's operational launch vehicles generally use diaphragm-type accumulators for POGO suppression. However, as launch vehicles become increasingly larger, the limitations of traditional diaphragm-type accumulators are becoming more apparent, including large structural space requirements, difficulties in diaphragm manufacturing, numerous and difficult-to-inspect welds, long manufacturing cycles, and high costs. Larger foreign launch vehicles mostly use gas-injection accumulators for POGO suppression, which can adjust the accumulator's flexibility in real time by charging and decharging its gas chamber according to a predetermined pattern. Compared to traditional diaphragm-type accumulators, they are better suited to cryogenic environments, have a larger volume, longer service life, and better manufacturability and maintainability. However, due to the presence of free liquid surfaces and the charging and decharging actions involved, the design and operation of gas-injection accumulators are relatively more complex.

[0004] Research on gas-injected accumulators in China is still in its early stages, and there is no mature experience of successful use in existing models. Therefore, it is urgent to conduct in-depth research on gas-injected accumulators to obtain the influence of various parameters on their performance, providing a theoretical basis and data support for the formulation of design criteria. Since my country's large launch vehicles generally use liquid oxygen and kerosene as propellants, based on the overall POGO suppression research results, gas-injected accumulators generally need to be installed in liquid oxygen delivery pipelines. Considering the safety of liquid oxygen and the similarity of its physical properties to liquid nitrogen, liquid nitrogen can generally be used as a substitute in ground tests to study the relevant performance of gas-injected accumulators. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-parameter adjustable cryogenic gas-injection accumulator test device, which is applicable to the study of the influence of performance parameters of large-volume cryogenic gas-injection accumulators. The variable parameters include, but are not limited to, accumulator charging flow rate, charging temperature, exhaust orifice diameter, delivery pipe pressure and its rate of change, and ambient back pressure. The measurable parameters include, but are not limited to, accumulator liquid level, cryogenic liquid loss, and temperature and pressure of various parts. It can be used to simulate and obtain the working characteristics of gas-injection accumulators under various working conditions and different operating parameters.

[0006] To achieve the above objectives, the present invention provides a multi-parameter adjustable low-temperature gas-injection accumulator test device, comprising: a delivery pipe, an accumulator, a gas supply component, an accumulator charging and decharging component, a delivery pipe pressurization and depressurization component, a liquid nitrogen heat exchanger, a constant temperature water bath, a gas component measurement sealed container, a vacuum pump, and a measurement and control system.

[0007] The liquid in the delivery pipe enters the accumulator through the damping orifice, and forms a free liquid surface and a gas cavity in the accumulator;

[0008] The gas supply assembly provides a high-pressure gas source for filling the accumulator gas chamber and pressurizing the delivery pipe gas chamber;

[0009] The accumulator charging assembly controls the flow rate and temperature of the gas entering the accumulator chamber;

[0010] The accumulator exhaust assembly controls the flow rate of the gas-liquid two-phase flow discharged from the accumulator and collects its flow rate in real time.

[0011] The pressurization component of the delivery pipe controls the flow rate of gas entering the air cushion of the delivery pipe, thereby adjusting the rate of pressure increase in the delivery pipe.

[0012] The pressure relief assembly of the delivery pipe controls the flow rate of gas discharged from the air cushion of the delivery pipe, thereby adjusting the rate of pressure reduction in the delivery pipe.

[0013] The liquid nitrogen heat exchanger can provide cooling to the ambient temperature helium in the accumulator charging pipeline and reduce its temperature to the liquid nitrogen temperature range, which is used to simulate the gas supply temperature of the cold helium cylinder stored in the liquid oxygen tank of an actual rocket.

[0014] The constant temperature water bath can provide heat to the cryogenic liquid nitrogen in the accumulator exhaust pipeline and completely vaporize it into nitrogen gas, thereby facilitating the measurement of its mass flow rate.

[0015] The sealed container for measuring gas components can completely collect the helium and nitrogen gas discharged during the experiment. Combined with a gas concentration tester, pressure sensor, and temperature sensor, the total mass of liquid nitrogen consumed by the accumulator is obtained, which is verified with the mass flow rate calculation results of the liquid nitrogen discharged from the accumulator below.

[0016] The vacuum pump can create a low-pressure environment downstream of the accumulator exhaust assembly, simulating the back pressure of the gas-injection accumulator during actual rocket high-altitude flight.

[0017] The measurement and control system measures and collects information on the system's pressure, temperature, liquid level, and gas flow rate. It controls the charging and discharging of the accumulator's gas chamber and the pressurization and depressurization of the delivery pipe's gas chamber through valves and switches.

[0018] The above-mentioned multi-parameter adjustable low-temperature gas injection accumulator test device, wherein the delivery pipe includes a delivery pipe liquid chamber and a delivery pipe gas chamber, and the accumulator includes an accumulator liquid chamber and an accumulator gas chamber;

[0019] The gas-injected accumulator is connected to the liquid propellant delivery pipeline by welding. A certain amount of cryogenic liquid is injected into the liquid chamber of the delivery pipeline through a liquid nitrogen injection / release valve. The liquid can enter the accumulator liquid chamber through the damping orifice and form a free liquid surface and gas chamber in the accumulator through the overflow pipe. The pressure of the liquid chamber of the delivery pipeline is changed by supplementing the gas chamber of the delivery pipeline with a certain pressure of booster gas. By adjusting the pressure of the gas chamber of the delivery pipeline, the performance of the accumulator under different delivery pipeline pressure conditions and under different rates of change of delivery pipeline pressure can be studied.

[0020] The above-mentioned multi-parameter adjustable cryogenic gas-injection accumulator test device includes a manual shut-off valve, which can be used to supply helium at room temperature or cryogenic helium by controlling its opening and closing.

[0021] The above-mentioned multi-parameter adjustable cryogenic gas-injection accumulator test device includes a gas flow regulating valve, whose opening degree is controlled by a program to regulate the flow rate of helium entering the accumulator, and the actual helium flow rate can be monitored in real time by a gas flow meter Q1.

[0022] The aforementioned multi-parameter adjustable cryogenic gas-injection accumulator test device includes an accumulator venting assembly comprising a solenoid valve and a throttling orifice plate. The solenoid valve is controlled by feedback from the level gauge H2 to open when the venting capacity of the throttling orifice plate is insufficient under extreme deviation conditions, causing the free liquid level in the accumulator to drop to a dangerous threshold. By increasing the area of ​​the venting channel, the accumulator gas chamber is rapidly depressurized, thereby restoring the liquid level to a safe range. Alternatively, it can be used to open when the solenoid valve fails to open, thus providing the system with fault redundancy capability.

[0023] The above-mentioned multi-parameter adjustable cryogenic gas-injection accumulator test device, wherein the constant temperature water bath can measure the total mass flow rate of the discharged gas in real time through gas flow meter Q2, and the mass flow rate of liquid nitrogen discharged from the accumulator can be calculated by combining the helium mass flow rate measured by gas flow meter Q1.

[0024] The above-mentioned multi-parameter adjustable cryogenic gas injection accumulator test device includes a gas flow regulating valve, whose opening degree is controlled by a program to regulate the flow rate of pressurized helium gas entering the gas pillow of the delivery pipe, thereby changing the rate of increase of liquid pressure in the delivery pipe.

[0025] The above-mentioned multi-parameter adjustable cryogenic gas injection accumulator test device includes a gas flow regulating valve in the delivery pipe. The opening degree of the valve is controlled by a program to regulate the flow rate of helium gas discharged from the gas pillow in the delivery pipe, thereby changing the rate of decrease of liquid pressure in the delivery pipe.

[0026] The aforementioned multi-parameter adjustable cryogenic gas-injection accumulator test device further includes a dual-stage safety valve. The first safety valve is a mechanical safety valve with an opening pressure of 1.0 MPa. It opens to release gas when the pressure in the delivery pipe exceeds 1.0 MPa and closes after the pressure drops to 0.97 MPa, allowing for multiple reliable operations. The second safety valve is a diaphragm safety valve with an opening pressure of 1.2 MPa. It serves as a backup when the pressure release capacity of the first safety valve is insufficient. It rapidly releases gas when the pressure in the delivery pipe exceeds 1.2 MPa to prevent structural damage to the test system. It requires only one reliable operation but can be replaced multiple times.

[0027] In the above-mentioned multi-parameter adjustable cryogenic gas-injection accumulator test device, the outer walls of the delivery pipe, the accumulator shell, and the downstream gas-injection pipeline of the liquid nitrogen heat exchanger need to be wrapped with heat-insulating material.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1) This invention can change the charging flow rate by adjusting the opening of the gas flow regulating valve in the accumulator charging circuit as needed, thereby studying the performance of the gas-injected accumulator under different charging flow rates.

[0030] 2) This invention allows for the selection of whether the gas in the accumulator charging path flows through the liquid nitrogen heat exchanger as needed. The condition where the gas flows through the liquid nitrogen heat exchanger is mainly used to simulate the temperature of the gas in the cold helium cylinder in the liquid oxygen tank under the cold helium pressurization method in actual rocket tanks. The condition where the gas does not flow through the liquid nitrogen heat exchanger corresponds to the temperature of the gas in the helium cylinder under the normal temperature helium pressurization method. Based on this, the performance of the gas-injection accumulator under different charging temperatures can be studied.

[0031] 3) This invention can change the exhaust and liquid discharge flow rate by adjusting the orifice diameter of the throttling orifice plate in the accumulator exhaust path as needed, thereby studying the performance of the gas-injection accumulator under different exhaust orifice diameters;

[0032] 4) In this invention, the accumulator exhaust path is equipped with two parallel solenoid valves and a throttling orifice plate. In actual operation, one solenoid valve remains open, while the other solenoid valve is controlled to open and close based on the accumulator liquid level feedback. It can be used to open when the exhaust capacity of the normally open throttling orifice plate is insufficient under extreme deviation conditions, causing the free liquid level in the accumulator to drop to a dangerous threshold. By increasing the exhaust channel area, the accumulator gas chamber can be quickly depressurized, thereby restoring the liquid level to a safe range. Alternatively, it can be used to open when the normally open solenoid valve fails to open, thereby giving the system fault redundancy capability and avoiding catastrophic consequences.

[0033] 5) The present invention can activate the vacuum pump downstream of the accumulator exhaust path as needed to create a low-pressure environment downstream of the accumulator exhaust assembly, simulate the back pressure of the environment of the gas-injection accumulator during actual rocket high-altitude flight, and thus study the influence of environmental back pressure on the performance of the gas-injection accumulator.

[0034] 6) This invention can change the boosting flow rate by adjusting the opening of the gas flow regulating valve in the gas chamber boosting circuit of the delivery pipe as needed, thereby changing the rate of increase of liquid pressure in the delivery pipe, so as to simulate the process of pressure increase at the pump inlet during actual rocket flight, and thus study the influence of the rate of increase of pressure in the delivery pipe on the performance of the gas injection accumulator.

[0035] 7) This invention can change the pressure relief flow rate by adjusting the opening of the gas flow regulating valve in the gas chamber of the delivery pipe as needed, thereby changing the rate of pressure reduction of the liquid in the delivery pipe, so as to simulate the process of pressure reduction at the pump inlet during actual rocket flight, and thus study the influence of the rate of pressure reduction in the delivery pipe on the performance of the gas injection accumulator.

[0036] 8) This invention can heat the low-temperature liquid discharged from the accumulator in a constant temperature water bath to make it completely vaporized, thereby facilitating its flow measurement;

[0037] 9) The present invention can measure and obtain the flow rate and total amount of cryogenic liquid consumed by the accumulator through a gas flow meter in the accumulator exhaust path and a gas concentration tester on a gas component measuring sealed container, and verify each other. Attached Figure Description

[0038] The following embodiments and figures illustrate a multi-parameter adjustable cryogenic gas injection accumulator test device of the present invention.

[0039] Figure 1This is a schematic diagram of a multi-parameter adjustable cryogenic gas-injection accumulator test device. In the diagram, 1 is the liquid chamber of the delivery pipe; 2 is the gas chamber of the delivery pipe; 3 is the liquid chamber of the accumulator; 4 is the gas chamber of the accumulator; 5 is the damping orifice; 6, 12, 15, 17, 19, and 24 are solenoid valves; 7 and 20 are pressure reducers; 8, 21, and 25 are gas flow regulating valves; 9, 10, 13, 26, 27, and 36 are manual shut-off valves; 11 and 22 are check valves; 14 is the overflow pipe; 16 and 18 are throttling orifice plates; 23 is a double-channel safety valve; and 28 and 29 are liquid... Nitrogen filling and releasing valve; 30 is the gas distribution platform; 31 is the helium cylinder group; 32 is the measurement and control system; 33 is the liquid nitrogen heat exchanger; 34 is the constant temperature water bath; 35 is the sealed container; 37 is the vacuum pump; P1-P7 are pressure sensors; T1-T5 are temperature sensors; H1 and H2 are level gauges; Q1 and Q2 are gas flow meters; C1 is the gas concentration tester; A is the gas supply assembly; B is the gas filling assembly; C is the gas exhaust assembly; D is the pressurization assembly; E is the pressure relief assembly. Detailed Implementation

[0040] The following is a further detailed description of a multi-parameter adjustable cryogenic gas injection accumulator test device of the present invention.

[0041] Example 1

[0042] like Figure 1 The diagram shows a schematic of the multi-parameter adjustable test device for a cryogenic gas-injection accumulator according to the present invention. As shown in the diagram, the multi-parameter adjustable test device for a cryogenic gas-injection accumulator includes a liquid chamber 1 (delivery pipe), a gas chamber 2 (delivery pipe), a liquid chamber 3 (accumulator), a gas chamber 4 (accumulator), a damping orifice 5, solenoid valves (6, 12, 15, 17, 19, 24), a pressure reducer (7, 20), a gas flow regulating valve (8, 21, 25), and a manual shut-off valve (9, 10, 13, 26, 27, 3). 6) Check valves (11, 22), overflow pipe 14, orifice plate (16, 18), double safety valve 23, liquid nitrogen filling and drain valves (28, 29), gas distribution platform 30, helium cylinder group 31, measurement and control system 32, liquid nitrogen heat exchanger 33, constant temperature water bath 34, sealed container 35, vacuum pump 37, pressure sensors P1~P7, temperature sensors T1~T5, level gauges H1~H2, gas flow meters Q1~Q2, gas concentration tester C1.

[0043] The gas-injected accumulator is connected to the liquid propellant delivery pipeline by welding. A certain amount of cryogenic liquid is injected into the liquid chamber 1 of the delivery pipeline through the liquid nitrogen injection / release valve 29. The liquid can enter the accumulator liquid chamber 3 through the damping orifice 5 and form a free liquid surface and gas chamber 4 in the accumulator through the overflow pipe 14. The pressure of the liquid chamber 1 of the delivery pipeline is changed by supplementing the gas chamber 2 of the delivery pipeline with a certain pressure of pressurized gas. By adjusting the pressure of the gas chamber 2 of the delivery pipeline, the performance of the accumulator under different delivery pipeline pressure conditions and under different rates of change of delivery pipeline pressure can be studied.

[0044] In the accumulator filling assembly, the liquid nitrogen heat exchanger 33 can provide cooling to the ambient temperature helium in the accumulator filling pipeline and reduce its temperature to the liquid nitrogen temperature range, which is used to simulate the temperature of the gas in the cold helium cylinder in the liquid oxygen tank when the actual rocket propellant tank adopts the cold helium pressurization method; the ambient temperature helium supply or the cryogenic helium supply can be controlled by selecting to open the manual shut-off valve 9 or the manual shut-off valve 10; when it is necessary to change the accumulator filling flow rate, the opening of the gas flow regulating valve 8 can be controlled and adjusted by the program, and the actual helium flow rate can be monitored in real time by the gas flow meter Q1;

[0045] In the accumulator venting assembly, the venting path is equipped with two parallel solenoid valves and a throttling orifice plate. During actual operation, solenoid valve 15 remains normally open, while solenoid valve 17 is controlled to open and close based on feedback from the accumulator level gauge H2. This can be used to open when the normally open throttling orifice plate 16's venting capacity is insufficient under extreme deviation conditions, causing the free liquid level in the accumulator to drop to a dangerous threshold. By increasing the venting channel area, rapid pressure relief is achieved in the accumulator's gas chamber, thereby restoring the liquid level to a safe range. Alternatively, it can be used to open when the normally open solenoid valve 15 fails to open, thus providing the system with fault redundancy and preventing catastrophic consequences. When it is necessary to change the accumulator venting and discharge flow rate, the throttling orifice plate 16 and... The orifice size of the throttling orifice plate 18 is determined; the constant temperature water bath 34 provides heat to the cryogenic liquid nitrogen in the accumulator exhaust pipe, allowing it to completely vaporize into nitrogen gas. The total mass flow rate of the discharged gas can be measured in real time by the gas flow meter Q2. Combined with the helium mass flow rate measured by the gas flow meter Q1, the mass flow rate of the liquid nitrogen discharged from the accumulator can be calculated. The gas component measurement sealed container 35 can be used to completely collect the helium and nitrogen gas discharged during the experiment. Combined with the pressure sensor P7, temperature sensor T5, and gas concentration tester C1, the total mass of liquid nitrogen consumed by the accumulator in each experiment can be obtained, which can be mutually verified with the calculated mass flow rate of the discharged liquid nitrogen. The vacuum pump 37 can be turned on to create a low-pressure environment downstream of the accumulator exhaust assembly, thereby simulating the back pressure environment of the gas injection accumulator during actual rocket high-altitude flight.

[0046] In the pressurization and depressurization assembly of the delivery pipe, when it is necessary to change the rate of pressure increase or decrease in the delivery pipe, the opening size of the gas flow regulating valve 21 or the gas flow regulating valve 25 can be controlled and adjusted by the program to simulate the process of pump inlet pressure change during actual rocket flight, thereby studying the influence of the rate of pressure increase or decrease in the delivery pipe on the performance of the gas injection accumulator.

[0047] Insulating material is wrapped around the outer walls of the delivery pipe, the accumulator shell, and the downstream section of the gas filling pipeline of the liquid nitrogen heat exchanger 33 to reduce the heat input from the environment to the cryogenic system and slow down the temperature rise and evaporation loss of the cryogenic liquid nitrogen in the accumulator and delivery pipe.

[0048] In summary, the multi-parameter adjustable cryogenic gas-injection accumulator test device of the present invention can realize, but is not limited to, changes in parameters such as accumulator charging flow rate, charging temperature, exhaust orifice diameter, delivery pipe pressure and its rate of change, and ambient back pressure. Measurable parameters include, but are not limited to, accumulator liquid level, cryogenic liquid loss, and temperature and pressure of various parts. Therefore, the present invention can be used to simulate and obtain the working characteristics of gas-injection accumulators under various working conditions and different working parameters.

[0049] Contents not described in detail in this specification are common knowledge to those skilled in the art. The above descriptions are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this invention should be included within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A multi-parameter adjustable cryogenic gas-injection accumulator test device, characterized in that, include: Delivery pipes, accumulators, gas supply components, accumulator charging and decharging components, delivery pipe pressurization and depressurization components, liquid nitrogen heat exchangers, constant temperature water baths, sealed containers for gas component measurement, vacuum pumps, and measurement and control systems; The liquid in the delivery pipe enters the accumulator through the damping orifice, and forms a free liquid surface and a gas cavity in the accumulator; The gas supply assembly provides a high-pressure gas source for filling the accumulator gas chamber and pressurizing the delivery pipe gas chamber; The accumulator charging assembly controls the flow rate and temperature of the gas entering the accumulator chamber; The accumulator exhaust assembly controls the flow rate of the gas-liquid two-phase flow discharged from the accumulator and collects its flow rate in real time. The pressurization component of the delivery pipe controls the flow rate of gas entering the air cushion of the delivery pipe, thereby adjusting the rate of pressure increase in the delivery pipe. The pressure relief assembly of the delivery pipe controls the flow rate of gas discharged from the air cushion of the delivery pipe, thereby adjusting the rate of pressure reduction in the delivery pipe. The liquid nitrogen heat exchanger can provide cooling to the ambient temperature helium in the accumulator charging pipeline and reduce its temperature to the liquid nitrogen temperature range, which is used to simulate the gas supply temperature of the cold helium cylinder stored in the liquid oxygen tank of an actual rocket. The constant temperature water bath can provide heat to the cryogenic liquid nitrogen in the accumulator exhaust pipeline and completely vaporize it into nitrogen gas, thereby facilitating the measurement of its mass flow rate. The sealed container for measuring gas components can completely collect the helium and nitrogen gas discharged during the test. Combined with a gas concentration tester, pressure sensor, and temperature sensor, the total mass of liquid nitrogen consumed by the accumulator can be obtained. The vacuum pump can create a low-pressure environment downstream of the accumulator exhaust assembly, simulating the back pressure of the gas-injection accumulator during actual rocket high-altitude flight. The measurement and control system measures and collects information on the system's pressure, temperature, liquid level, and gas flow rate. It controls the charging and discharging of the accumulator's gas chamber and the pressurization and depressurization of the delivery pipe's gas chamber through valves and switches.

2. The multi-parameter adjustable cryogenic gas-injection accumulator test device as described in claim 1, characterized in that, The delivery pipe includes a delivery pipe liquid chamber and a delivery pipe gas chamber, and the accumulator includes an accumulator liquid chamber and an accumulator gas chamber; The accumulator is connected to the delivery pipe by welding. A certain amount of cryogenic liquid is added to the liquid chamber of the delivery pipe through a liquid nitrogen injection / release valve. The liquid can enter the liquid chamber of the accumulator through the damping orifice and form a free liquid surface and gas chamber in the accumulator through the overflow pipe. The pressure of the liquid chamber of the delivery pipe is changed by adding pressurized gas of a certain pressure to the gas chamber of the delivery pipe. By adjusting the pressure of the gas chamber of the delivery pipe, the performance of the accumulator under different delivery pipe pressure conditions and under different rates of change of delivery pipe pressure can be studied.

3. The multi-parameter adjustable low-temperature gas injection accumulator test device as described in claim 1, characterized in that, The accumulator charging assembly includes a manual shut-off valve, which controls the opening and closing of the valve to supply helium at room temperature or at low temperature.

4. The multi-parameter adjustable cryogenic gas injection accumulator test device as described in claim 1, characterized in that, The accumulator charging assembly includes a gas flow regulating valve, whose opening degree is controlled by a program to regulate the flow of helium gas entering the accumulator, and the actual helium flow rate can be monitored in real time by a gas flow meter Q1.

5. The multi-parameter adjustable cryogenic gas injection accumulator test device as described in claim 1, characterized in that, The accumulator venting assembly includes a solenoid valve and a throttling orifice plate. The solenoid valve is controlled to open and close via feedback from the level gauge H2. It is used to open when the venting capacity of the throttling orifice plate is insufficient under extreme deviation conditions, causing the free liquid level in the accumulator to drop to a dangerous threshold. By increasing the area of ​​the venting channel, the accumulator gas chamber is quickly depressurized, thereby restoring the liquid level to a safe range. Alternatively, it can be used to open when the solenoid valve fails to open, thus providing the system with fault redundancy.

6. The multi-parameter adjustable cryogenic gas injection accumulator test device as described in claim 1, characterized in that, The constant temperature water bath can measure the total mass flow rate of the discharged gas in real time through gas flow meter Q2, and then calculate the mass flow rate of liquid nitrogen discharged from the accumulator by combining the helium mass flow rate measured by gas flow meter Q1.

7. The multi-parameter adjustable cryogenic gas-injection accumulator test device as described in claim 1, characterized in that, The delivery pipe pressurization assembly includes a gas flow regulating valve, whose opening degree is controlled by a program to regulate the flow rate of pressurized helium gas entering the delivery pipe air cushion, thereby changing the rate of increase in liquid pressure inside the delivery pipe.

8. The multi-parameter adjustable cryogenic gas-injection accumulator test device as described in claim 1, characterized in that, The pressure relief assembly of the delivery pipe includes a gas flow regulating valve, whose opening degree is controlled by a program to regulate the flow rate of helium gas discharged from the gas pillow in the delivery pipe, thereby changing the rate of decrease in liquid pressure inside the delivery pipe.

9. The multi-parameter adjustable cryogenic gas-injection accumulator test device as described in claim 1, characterized in that, It also includes a dual-stage safety valve. The first safety valve is a mechanical safety valve with an opening pressure of 1.0 MPa. It opens to release air when the pressure in the delivery pipe exceeds 1.0 MPa and closes after the pressure drops to 0.97 MPa. It can operate reliably multiple times. The second safety valve is a diaphragm safety valve with an opening pressure of 1.2 MPa. It is used as a backup when the pressure release capacity of the first safety valve is insufficient. It releases air quickly when the pressure in the delivery pipe exceeds 1.2 MPa to prevent structural damage to the test system. It can operate reliably only once but can be replaced multiple times.

10. The multi-parameter adjustable cryogenic gas injection accumulator test device as described in claim 1, characterized in that, The outer walls of the delivery pipe, accumulator shell, and downstream gas filling pipeline of the liquid nitrogen heat exchanger need to be wrapped with heat insulation material.

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