Aircraft fuel pipeline pressure pulsation system and working method thereof

Abstract

The present invention discloses an aircraft fuel pipeline pressure pulsation system and a working method thereof. The aircraft fuel pipeline pressure pulsation system adopts an open cycle mode, a measurement and control device collects fuel pipeline pressure and temperature, automatically controls the motor speed to adjust the flow, controls the opening size and speed of the proportional pressure reducing valves at the front and rear ends of the fuel pipeline test section, and tests the fuel pipeline pressure pulsation; the fuel pipeline system is provided with a relief valve, an accumulator and a radiator to ensure the reliability and stability of the system operation. Through the present invention, the aircraft fuel pipeline pressure pulsation system has a fast startup speed, high test accuracy, good safety, and can automatically collect and control system operation. It is suitable for studying the failure mechanism of components or systems that cause pressure increase or fluctuation in the fuel system, considering the failure of components or systems that may cause its maximum possible pressure and possible pressure pulsation, and providing support for determining the maximum possible pressure of the fuel system pipeline of a typical static pressure-bearing part.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel pipeline protection, and in particular to an aircraft fuel pipeline pressure pulsation system and a working method thereof. Background Art

[0002] The fuel system is one of the important systems of aerospace and other products. When the fuel system is working, at the moment when the solenoid valve is opened or closed, a strong pressure impact, namely pressure pulse, will occur in the pressure supply pipeline and the return oil pipeline. On the high-pressure pipeline, the peak value of the pressure pulse may reach more than 1.5 times the rated pressure of the system, and on the return oil pipeline, it may reach more than 10 times the normal return oil pressure value. If it is not properly matched with the system, the oil pump outlet pressure will produce high-frequency equal-amplitude oscillations. The pressure pulse may cause the breakage of system pipelines, connectors, actuators, etc., and the failure of system accessories. In severe cases, it may cause major aircraft accidents. For example, in a certain model developed in my country in the 1970s, the pipeline accessories connection from the oil pump outlet to the accumulator was constantly broken, affecting the design finalization. In the early 1980s, during the ground test of a certain model developed in my country, a fire caused by a rupture of the hydraulic pipeline caused the entire aircraft to be destroyed, which not only caused huge economic losses, but also delayed the progress of model development.

[0003] At present, with the widespread application of pipeline automation control and inverse problem analysis based on transient flow, pipeline leakage detection and pipeline evaluation in pipeline systems, traditional water hammer control methods have encountered many challenges for the following reasons:

[0004] 1) Pipeline automation control technology not only requires the maximum and minimum pressure values ​​of water hammer under the most unfavorable conditions of the pipeline system, but also requires the parameter changes of the pressure fluctuations of transient flows caused by the joint action of different valves and water pumps. In this case, the maximum and minimum values ​​of the pressure fluctuations are not equal to the accumulation of the maximum and minimum values ​​of the water hammer pressure waves generated by the individual actions of each component, but depend on the mutual superposition of the attenuation results of different pressure waves at different times. This requires an accurate transient flow model to calculate the attenuation results of transient flow pressure fluctuations generated by the actions of different components.

[0005] 2) With the continuous development of technologies such as inverse problem analysis, pipeline leakage detection and pipeline evaluation based on transient flow, the scope of application is expanding, and the factors to be considered are becoming more and more complex. An accurate transient flow model is needed to truly reflect the transient flow pressure fluctuations in actual pipelines. If the transient flow model can only accurately calculate the peak and trough values ​​in the first cycle of pressure fluctuations but cannot accurately reflect the attenuation of pressure fluctuations other than the first cycle, it will severely limit the accurate and efficient application of these technologies in practice. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an aircraft fuel pipeline pressure pulsation system and a working method thereof in view of the defects involved in the background technology.

[0007] The present invention adopts the following technical solutions to solve the above technical problems:

[0008] An aircraft fuel line pressure pulsation system comprises a fuel tank, a liquid level meter, a first filter, a flow meter, a fuel pump, a heater, a check valve, a first pressure sensor, a first temperature sensor, a first pressure reducing valve, a second pressure sensor, a fuel pipeline, a third pressure sensor, a second pressure reducing valve, a normally open relief valve, a radiator, a second temperature sensor, a second filter, a normally closed relief valve, an accumulator, a first electric regulating valve, a nitrogen bottle, a second electric regulating valve, and a controller;

[0009] The oil tank is provided with an outlet, an inlet and an oil return port;

[0010] The outlet of the oil tank is connected to one end of the first filter and one end of the second electric regulating valve through pipelines respectively;

[0011] The other end of the second electric regulating valve is connected to the nitrogen bottle pipeline, and the nitrogen bottle is used to purge and replace the air in the fuel pipeline;

[0012] The other end of the first filter, the flow meter, and the inlet of the fuel pump are connected in sequence through a pipeline, and the first filter is used to filter impurities in the fuel in the pipeline;

[0013] The outlet of the fuel pump is connected to the inlet of the heater and the inlet pipe of the normally closed overflow valve respectively;

[0014] The outlet of the normally closed relief valve is connected to the oil return port pipeline of the fuel tank, and the normally closed relief valve is used to open when the inlet pressure of the normally closed relief valve is greater than a preset first pressure threshold, so that the fuel in the pipeline flows to the oil return port of the fuel tank;

[0015] The outlet of the heater is connected to the inlet pipeline of the one-way valve, and the heater is used to control the fuel temperature;

[0016] The outlet of the one-way valve is respectively connected to one end of the first electric regulating valve and the inlet pipeline of the first pressure reducing valve;

[0017] The other end of the first electric regulating valve is connected to the accumulator pipeline, and the accumulator is used to reduce the pressure pulsation caused by the plunger pump;

[0018] The inlet end of the fuel pipeline is connected to the outlet pipeline of the first pressure reducing valve, and the outlet end of the fuel pipeline is connected to the inlet pipeline of the first pressure reducing valve; the fuel pipeline is used for pressure pulsation;

[0019] The outlet of the second pressure reducing valve is connected to the inlet pipeline of the normally open relief valve, and the outlet of the normally open relief valve, the radiator, and the inlet of the second filter oil tank are connected in sequence through pipelines;

[0020] The overflow port of the normally open overflow valve is connected to the external container pipeline, and the normally open overflow valve is used to close when the inlet pressure is greater than a preset second pressure threshold, so that the fuel in the pipeline flows to the external container;

[0021] The radiator is used to reduce the temperature of the fuel in the pipeline; the second filter is used to filter impurities in the fuel in the pipeline;

[0022] The first pressure sensor and the first temperature sensor are arranged at the inlet of the first pressure reducing valve, and are used to sense the pressure and temperature there, respectively, and transmit them to the controller; the second pressure sensor is arranged at the inlet of the fuel pipeline, and is used to sense the pressure there, and transmit it to the controller; the third pressure sensor is arranged at the outlet of the fuel pipeline, and is used to sense the pressure there, and transmit it to the controller; the second temperature sensor is arranged at the outlet of the radiator, and is used to sense the temperature there, and transmit it to the controller;

[0023] The controller is electrically connected to the liquid level meter, flow meter, fuel pump, heater, first pressure sensor, first temperature sensor, first pressure reducing valve, second pressure sensor, third pressure sensor, second pressure reducing valve, radiator, second temperature sensor, first electric regulating valve, and second electric regulating valve, respectively, and is used to control the fuel pump, heater, first pressure reducing valve, second pressure reducing valve, radiator, first electric regulating valve, and second electric regulating valve to operate according to the sensing data of the liquid level meter, flow meter, first pressure sensor, first temperature sensor, second pressure sensor, third pressure sensor, and second temperature sensor.

[0024] As a further optimization solution of the aircraft fuel pipeline pressure pulsation system of the present invention, the fuel pump adopts a multi-stage plunger pump.

[0025] The present invention also discloses a working method of the aircraft fuel pipeline pressure pulsation system, comprising the following steps:

[0026] Step 1), the controller controls the fuel pump to drive the fuel to suck the fuel from the lower part of the fuel tank, and the system working pressure is ensured to be stable through the normally closed relief valve, the one-way valve and the accumulator. When the pressure at the inlet of the normally closed relief valve is greater than the preset first pressure threshold, the normally closed relief valve opens, and the fuel flows back to the return port of the fuel tank from the normally closed relief valve;

[0027] Step 2), the fuel flowing out of the fuel pump flows into the fuel pipeline after passing through the first pressure reducing valve, and the flow rate, pressure and fuel temperature of the fuel system are monitored by the flow meter, the first pressure sensor, the first temperature sensor and the second temperature sensor, and the signal is transmitted to the controller, and the controller controls the second pressure reducing valve, the heater and the radiator to work according to the received signal to adjust the flow rate, pressure and fuel temperature in the fuel pipeline; the controller sends different displacement instructions to control the movement of the first pressure reducing valve to change the valve closing time, and monitors the pressure pulsation at the inlet and outlet of the fuel pipeline during the valve closing process through the second pressure sensor and the third pressure sensor;

[0028] Step 3), the liquid level gauge monitors the liquid level of the fuel tank and transmits the signal to the controller. When the liquid level is lower than the set value, the controller outputs a signal to control the fuel pump to stop working;

[0029] Step 4), in order to prevent the pressure fluctuation from causing the fuel pressure in the pipeline after the second pressure reducing valve to be higher than the safety pressure that the radiator can withstand, when the pressure at the inlet of the normally open relief valve is greater than the preset second pressure threshold, the normally open relief valve is closed, so that the fuel is directly bypassed to the external container to avoid the radiator from bursting; when not conducting the test, all valves on the fuel tank that are connected to the outside are closed, and the air on the top of the fuel tank is replaced by the nitrogen bottle (22) to put the fuel tank in an inert state.

[0030] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0031] The present invention discloses an aircraft fuel pipeline pressure pulsation system and a working method thereof. The aircraft fuel pipeline pressure pulsation system adopts an open cycle mode, a measurement and control device collects fuel pipeline pressure and temperature, automatically controls the motor speed to adjust the flow, controls the opening size and speed of the proportional pressure reducing valves at the front and rear ends of the fuel pipeline test section, and tests the fuel pipeline pressure pulsation; the fuel pipeline system is provided with a relief valve, an accumulator and a radiator to ensure the reliability and stability of the system operation. Through the present invention, the aircraft fuel pipeline pressure pulsation system has a fast startup speed, high test accuracy, good safety, and can automatically collect and control system operation. It is suitable for studying the failure mechanism of components or systems that cause pressure increase or fluctuation in the fuel system, considering the failure of components or systems that may cause its maximum possible pressure and possible pressure pulsation, and providing support for determining the maximum possible pressure of the fuel system pipeline of a typical static pressure-bearing part. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of an aircraft fuel line pressure pulsation system.

[0033] Among them, 1-fuel tank, 2-liquid level meter, 3-first filter, 4-flow meter, 5-fuel pump, 6-heater, 7-check valve, 8-first pressure sensor, 9-first temperature sensor, 10-first pressure reducing valve, 11-second pressure sensor, 12-fuel pipeline, 13-third pressure sensor, 14-second pressure reducing valve, 15-normally open overflow valve, 16-radiator, 17-second temperature sensor, 18-second filter, 19-normally closed overflow valve, 20-accumulator, 21-first electric regulating valve, 22-nitrogen bottle, 23-second electric regulating valve, 24-controller. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0035] The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete, and will fully express the scope of the present invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0036] like Figure 1 As shown, the present invention discloses an aircraft fuel pipeline pressure pulsation system, comprising a fuel tank 1, a liquid level meter 2, a first filter 3, a flow meter 4, a fuel pump 5, a heater 6, a one-way valve 7, a first pressure sensor 8, a first temperature sensor 9, a first pressure reducing valve 10, a second pressure sensor 11, a fuel pipeline 12, a third pressure sensor 13, a second pressure reducing valve 14, a normally open relief valve 15, a radiator 16, a second temperature sensor 17, a second filter 18, a normally closed relief valve 19, an accumulator 20, a first electric regulating valve 21, a nitrogen bottle 22, a second electric regulating valve 23, and a controller 24;

[0037] The oil tank 1 is provided with an outlet, an inlet and an oil return port;

[0038] The outlet of the oil tank 1 is connected to one end of the first filter 3 and one end of the second electric regulating valve 23 through pipelines respectively;

[0039] The other end of the second electric regulating valve 23 is connected to the nitrogen bottle 22 pipeline, and the nitrogen bottle 22 is used to purge and replace the air in the fuel pipeline;

[0040] The other end of the first filter 3, the flow meter 4, and the inlet of the fuel pump 5 are connected in sequence through a pipeline. The first filter 3 is used to filter impurities in the fuel in the pipeline;

[0041] The outlet of the fuel pump 5 is connected to the inlet of the heater 6 and the inlet pipe of the normally closed relief valve 19 respectively;

[0042] The outlet of the normally closed relief valve 19 is connected to the oil return port pipeline of the fuel tank 1. The normally closed relief valve 19 is used to open when the inlet pressure is greater than a preset first pressure threshold, so that the fuel in the pipeline flows to the oil return port of the fuel tank;

[0043] The outlet of the heater 6 is connected to the inlet pipe of the one-way valve 7, and the heater 6 is used to control the fuel temperature;

[0044] The outlet of the one-way valve 7 is connected to one end of the first electric regulating valve 21 and the inlet pipeline of the first pressure reducing valve 10 respectively;

[0045] The other end of the first electric regulating valve 21 is connected to the pipeline of the accumulator 20, and the accumulator 20 is used to reduce the pressure pulsation caused by the plunger pump;

[0046] The inlet end of the fuel pipeline 12 is connected to the outlet pipeline of the first pressure reducing valve 10, and the outlet end of the fuel pipeline 12 is connected to the inlet pipeline of the first pressure reducing valve 10; the fuel pipeline 12 is used for pressure pulsation;

[0047] The outlet of the second pressure reducing valve 14 is connected to the inlet pipeline of the normally open relief valve 15, and the outlet of the normally open relief valve 15, the radiator 16, and the inlet of the second filter 18 oil tank 1 are connected in sequence through pipelines;

[0048] The overflow port of the normally open overflow valve 15 is connected to the external container pipeline. The normally open overflow valve 15 is used to close when its inlet pressure is greater than a preset second pressure threshold, so that the fuel in the pipeline flows to the external container;

[0049] The radiator 16 is used to reduce the temperature of the fuel in the pipeline; the second filter 18 is used to filter impurities in the fuel in the pipeline;

[0050] The first pressure sensor 8 and the first temperature sensor 9 are arranged at the inlet of the first pressure reducing valve 10, and are used to sense the pressure and temperature there, respectively, and transmit them to the controller 24; the second pressure sensor 11 is arranged at the inlet of the fuel pipeline 12, and is used to sense the pressure there, and transmit it to the controller 24; the third pressure sensor 11 is arranged at the outlet of the fuel pipeline 12, and is used to sense the pressure there, and transmit it to the controller 24; the second temperature sensor 17 is arranged at the outlet of the radiator 16, and is used to sense the temperature there, and transmit it to the controller 24;

[0051] The controller 24 is electrically connected to the liquid level meter 2, the flow meter 4, the fuel pump 5, the heater 6, the first pressure sensor 8, the first temperature sensor 9, the first pressure reducing valve 10, the second pressure sensor 11, the third pressure sensor 13, the second pressure reducing valve 14, the radiator 16, the second temperature sensor 17, the first electric regulating valve 21, and the second electric regulating valve 23, respectively, and is used to control the fuel pump 5, the heater 6, the first pressure reducing valve 10, the second pressure reducing valve 14, the radiator 16, the first electric regulating valve 21, and the second electric regulating valve 23 to work according to the sensing data of the liquid level meter 2, the flow meter 4, the first pressure sensor 8, the first temperature sensor 9, the second pressure sensor 11, the third pressure sensor 13, and the second temperature sensor 17.

[0052] The fuel pump 5 is a multi-stage plunger pump.

[0053] The present invention also discloses a working method of the aircraft fuel pipeline pressure pulsation system, comprising the following steps:

[0054] Step 1, the controller 24 controls the fuel pump 5 to drive the fuel to suck the fuel from the lower part of the fuel tank 1, and the normally closed relief valve 19, the one-way valve 7 and the accumulator 20 ensure that the system working pressure is stable. When the pressure at the inlet of the normally closed relief valve 19 is greater than the preset first pressure threshold, the normally closed relief valve 19 opens, and the fuel flows back to the return port of the fuel tank 1 from the normally closed relief valve 19;

[0055] Step 2, the fuel flowing out of the fuel pump 5 flows into the fuel pipeline 12 after passing through the first pressure reducing valve 10, and the flow rate, pressure and fuel temperature of the fuel system are monitored by the flow meter 4, the first pressure sensor 8, the first temperature sensor 9, and the second temperature sensor 17, and the signal is transmitted to the controller 24. The controller 24 controls the second pressure reducing valve 14, the heater 6, and the radiator 16 to work according to the received signal to adjust the flow rate, pressure and fuel temperature in the fuel pipeline 12; the controller 24 sends different displacement instructions to control the movement of the first pressure reducing valve 10 to change the valve closing time, and monitors the pressure pulsation at the inlet and outlet of the fuel pipeline 12 during the valve closing process through the second pressure sensor 11 and the third pressure sensor 13;

[0056] Step 3, the liquid level meter 2 monitors the liquid level of the fuel tank 1 and transmits a signal to the controller 24. When the liquid level is lower than a set value, the controller 24 outputs a signal to control the fuel pump 5 to stop working;

[0057] Step 4: In order to prevent the pressure fluctuation from causing the fuel pressure in the pipeline after the second pressure reducing valve 14 to be higher than the safety pressure that the radiator 16 can withstand, when the pressure at the inlet of the normally open relief valve 15 is greater than the preset second pressure threshold, the normally open relief valve 15 is closed, so that the fuel is directly bypassed to the external container to prevent the radiator 16 from bursting; when not conducting the test, all valves on the fuel tank 1 that are connected to the outside are closed, and the air in the upper part of the fuel tank is replaced by the nitrogen bottle (22) to put the fuel tank 1 in an inert state.

[0058] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0059] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An aircraft fuel line pressure pulsation system, characterized in that: It comprises a fuel tank (1), a liquid level meter (2), a first filter (3), a flow meter (4), a fuel pump (5), a heater (6), a one-way valve (7), a first pressure sensor (8), a first temperature sensor (9), a first pressure reducing valve (10), a second pressure sensor (11), a fuel pipeline (12), a third pressure sensor (13), a second pressure reducing valve (14), a normally open relief valve (15), a radiator (16), a second temperature sensor (17), a second filter (18), a normally closed relief valve (19), an accumulator (20), a first electric regulating valve (21), a nitrogen bottle (22), a second electric regulating valve (23), and a controller (24); The oil tank (1) is provided with an outlet, an inlet and an oil return port; The outlet of the oil tank (1) is respectively connected to one end of the first filter (3) and one end of the second electric regulating valve (23) through pipelines; The other end of the second electric regulating valve (23) is connected to a pipeline of the nitrogen bottle (22), and the nitrogen bottle (22) is used to purge and displace the air in the fuel pipeline; The other end of the first filter (3), the flow meter (4), and the inlet of the fuel pump (5) are connected in sequence through a pipeline, and the first filter (3) is used to filter impurities in the fuel in the pipeline; The outlet of the fuel pump (5) is respectively connected to the inlet of the heater (6) and the inlet pipe of the normally closed overflow valve (19); The outlet of the normally closed relief valve (19) is connected to the oil return port pipeline of the oil tank (1), and the normally closed relief valve (19) is used to open when the inlet pressure of the normally closed relief valve (19) is greater than a preset first pressure threshold, so that the fuel in the pipeline flows to the oil return port of the oil tank; The outlet of the heater (6) is connected to the inlet pipeline of the one-way valve (7), and the heater (6) is used to control the fuel temperature; The outlet of the one-way valve (7) is respectively connected to one end of the first electric regulating valve (21) and the inlet pipeline of the first pressure reducing valve (10); The other end of the first electric regulating valve (21) is connected to a pipeline of the accumulator (20), and the accumulator (20) is used to reduce pressure pulsation caused by the plunger pump; The inlet end of the fuel pipeline (12) is connected to the outlet pipeline of the first pressure reducing valve (10), and the outlet end of the fuel pipeline (12) is connected to the inlet pipeline of the first pressure reducing valve (10); the fuel pipeline (12) is used for pressure pulsation; The outlet of the second pressure reducing valve (14) is connected to the inlet pipeline of the normally open relief valve (15), and the outlet of the normally open relief valve (15), the radiator (16), and the inlet of the oil tank (1) of the second filter (18) are connected in sequence through pipelines; The overflow port of the normally open overflow valve (15) is connected to an external container pipeline, and the normally open overflow valve (15) is used to close when the inlet pressure is greater than a preset second pressure threshold, so that the fuel in the pipeline flows to the external container; The radiator (16) is used to reduce the temperature of the fuel in the pipeline; the second filter (18) is used to filter impurities in the fuel in the pipeline; The first pressure sensor (8) and the first temperature sensor (9) are arranged at the inlet of the first pressure reducing valve (10), and are used to sense the pressure and temperature there, respectively, and transmit the same to the controller (24); the second pressure sensor (11) is arranged at the inlet of the fuel pipeline (12), and is used to sense the pressure there, and transmit the same to the controller (24); the third pressure sensor (11) is arranged at the outlet of the fuel pipeline (12), and is used to sense the pressure there, and transmit the same to the controller (24); the second temperature sensor (17) is arranged at the outlet of the radiator (16), and is used to sense the temperature there, and transmit the same to the controller (24); The controller (24) is electrically connected to the liquid level meter (2), the flow meter (4), the fuel pump (5), the heater (6), the first pressure sensor (8), the first temperature sensor (9), the first pressure reducing valve (10), the second pressure sensor (11), the third pressure sensor (13), the second pressure reducing valve (14), the radiator (16), the second temperature sensor (17), the first electric regulating valve (21), and the second electric regulating valve (23), respectively, and is used to control the fuel pump (5), the heater (6), the first pressure reducing valve (10), the second pressure reducing valve (14), the radiator (16), the first electric regulating valve (21), and the second electric regulating valve (23) to operate according to sensing data of the liquid level meter (2), the flow meter (4), the first pressure sensor (8), the first temperature sensor (9), the second pressure sensor (11), the third pressure sensor (13), and the second temperature sensor (17).

2. The aircraft fuel line pressure pulsation system according to claim 1, characterized in that: The fuel pump (5) is a multi-stage plunger pump.

3. The operating method of the aircraft fuel line pressure pulsation system according to claim 1, characterized in that: The following steps are involved: Step 1), the controller (24) controls the fuel pump (5) to drive the fuel to draw fuel from the lower part of the fuel tank (1), and ensures that the system working pressure is stable through the normally closed relief valve (19), the one-way valve (7) and the accumulator (20). When the pressure at the inlet of the normally closed relief valve (19) is greater than a preset first pressure threshold, the normally closed relief valve (19) opens, and the fuel flows back from the normally closed relief valve (19) to the return port of the fuel tank (1); Step 2), the fuel flowing out of the fuel pump (5) passes through the first pressure reducing valve (10) and flows into the fuel pipeline (12), and the flow rate, pressure and fuel temperature of the fuel system are monitored by the flow meter (4), the first pressure sensor (8), the first temperature sensor (9) and the second temperature sensor (17), and the signal is transmitted to the controller (24). The controller (24) controls the operation of the second pressure reducing valve (14), the heater (6) and the radiator (16) according to the received signal to adjust the flow rate, pressure and fuel temperature in the fuel pipeline (12); the controller (24) sends different displacement instructions to control the movement of the first pressure reducing valve (10) to change the valve closing time, and monitors the pressure pulsation at the inlet and outlet of the fuel pipeline (12) during the valve closing process through the second pressure sensor (11) and the third pressure sensor (13); Step 3), the liquid level meter (2) monitors the liquid level of the fuel tank (1) and transmits a signal to the controller (24). When the liquid level is lower than a set value, the controller (24) outputs a signal to control the fuel pump (5) to stop working; Step 4), in order to prevent the pressure fluctuation from causing the fuel pressure in the pipeline after the second pressure reducing valve (14) to be higher than the safety pressure that the radiator (16) can withstand, when the pressure at the inlet of the normally open relief valve (15) is greater than the preset second pressure threshold, the normally open relief valve (15) is closed, so that the fuel is directly bypassed to the external container to prevent the radiator (16) from bursting; when not conducting the test, all valves on the fuel tank (1) that are connected to the outside are closed, and the air on the top of the fuel tank is replaced by the nitrogen bottle (22) to put the fuel tank (1) in an inert state.

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