A high-pressure hydrogen leak monitoring and protection system and method

Abstract

This invention discloses a high-pressure hydrogen leak monitoring and protection system and method, including a high-pressure hydrogen storage chamber and a base plate located inside it. A high-pressure hydrogen cylinder group is placed on the base plate. The key feature is that a high-pressure nitrogen source is provided on one side of the high-pressure hydrogen storage chamber, and the high-pressure nitrogen source is connected to a first branch and a second branch via high-pressure nitrogen pipelines. This invention utilizes the principle of throttling and heating during high-pressure hydrogen leak detection. A temperature sensor array is set around the high-pressure hydrogen cylinder group, combined with a hydrogen concentration sensor at the top, to achieve dual detection of high-pressure hydrogen leaks, improving detection accuracy and response time. By using a bottom ejector combined with a top nitrogen injection pressurization system, leaked hydrogen inside the high-pressure hydrogen storage chamber can be rapidly discharged, with a discharge flow rate far exceeding that of traditional methods such as fans, making it suitable for high-pressure hydrogen cylinder group storage scenarios. The overall monitoring and safety protection system also has advantages such as simple structure, few control components, and high safety due to high-pressure nitrogen drive.

Description

Technical Field

[0001] This invention relates to the field of hydrogen safety technology, and in particular to a high-pressure hydrogen leak monitoring and protection system and method. Background Technology

[0002] Hydrogen energy, as one of the most promising clean energy sources to replace traditional fossil fuels in the 21st century, has been commercially promoted and applied in many fields such as hydrogen fuel cells and hydrogen refueling stations. Safety is one of the key bottlenecks throughout the entire lifecycle of the hydrogen energy industry, and high pressure is its core risk factor, affecting all aspects of hydrogen production, storage, transportation, and use. It can easily lead to major safety accidents such as hydrogen leakage, diffusion, and even combustion and explosion. Over the years, hydrogen accidents have occurred frequently both domestically and internationally, sometimes causing significant casualties and property damage. Safety has become a major bottleneck in the promotion of hydrogen energy and has drawn global attention and emphasis to hydrogen safety.

[0003] Hydrogen gas has characteristics such as low density, high diffusion coefficient (3.8 times that of air), low ignition temperature, wide explosion limits (4%~75% by volume), and fast combustion flame speed. If high-pressure hydrogen leaks, it can easily form a large-scale flammable cloud, which, once ignited, can cause a violent explosion, posing a serious threat to life and property. High-pressure hydrogen storage cylinders have long storage times, large storage capacities, and high storage pressures; damage to cylinder assembly instruments and pipelines is the most common cause of leaks. However, current technologies and devices related to hydrogen leaks are not very mature, necessitating the design of new safety protection devices for high-pressure hydrogen storage scenarios. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-pressure hydrogen leak monitoring and protection system and method. This system utilizes an array of temperature sensors and a hydrogen concentration sensor to achieve rapid detection of high-pressure hydrogen leaks. It uses high-pressure nitrogen gas to eject leaking hydrogen at a high flow rate and utilizes the cooling effect generated by the ejection to cool the top of the high-pressure hydrogen cylinder storage space, preventing hydrogen accumulation and achieving monitoring and safety protection against high-pressure hydrogen leaks.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-pressure hydrogen leak monitoring and protection system includes a high-pressure hydrogen storage chamber and a base plate located inside it. A high-pressure hydrogen cylinder assembly is placed on the base plate. The system is characterized in that a high-pressure nitrogen source is provided on one side of the high-pressure hydrogen storage chamber. The high-pressure nitrogen source is connected to a first branch and a second branch via high-pressure nitrogen pipelines. A solenoid valve is installed on the high-pressure nitrogen pipelines. The first branch is connected to a gas collection structure located at the bottom of the high-pressure hydrogen storage chamber, and the second branch is connected to a pressurization structure located at the top of the high-pressure hydrogen storage chamber. A cooling mechanism is provided at the top of the high-pressure hydrogen storage chamber, and a hydrogen leak detection mechanism is installed inside the high-pressure hydrogen storage chamber.

[0007] Preferably, the pressurization structure includes a plurality of high-pressure nozzles located in the upper space of the high-pressure hydrogen storage room. The high-pressure nozzles are equidistantly arranged on the second branch, and the high-pressure nozzles are arranged with their spray direction facing downward. A second nitrogen valve is provided on the second branch.

[0008] Preferably, the gas collection structure includes an ejector connected to the first branch, the ejector being connected to a manifold via a hydrogen pipeline, the manifold being installed on the top of the base plate, the ejector being connected to the first heat exchange channel of the cooler via a discharge pipeline, a first nitrogen valve being provided on the first branch, and a hydrogen valve being provided on the hydrogen pipeline.

[0009] Preferably, the ejector includes an ejector contraction section, an ejector mixing section, and an ejector diffusion section, and the ejector contraction section is connected to the first branch and the hydrogen pipeline, respectively.

[0010] Preferably, the cooling mechanism includes a cooler and an evaporator installed on top of the high-pressure hydrogen storage chamber, and the second heat exchange channel of the cooler is connected to the evaporator through a thermosiphon pipe.

[0011] Preferably, the hydrogen leak detection mechanism includes a hydrogen concentration sensor and a temperature sensor array installed inside the high-pressure hydrogen storage room. The temperature sensor array is arranged around the high-pressure hydrogen cylinder group, and the hydrogen concentration sensor is located on top of the high-pressure hydrogen cylinder group. The hydrogen concentration sensor, the temperature sensor array, and the solenoid valve are connected to the controller via signal lines.

[0012] Preferably, a flame arrester is provided at the end of the discharge pipeline.

[0013] Compared with existing technologies, the advantages of this invention are as follows: This invention utilizes the principle of throttling and heating during high-pressure hydrogen leakage. A temperature sensor array is installed around the high-pressure hydrogen cylinder group, combined with a hydrogen concentration sensor at the top, to achieve dual detection of high-pressure hydrogen leakage, improving detection accuracy and response time. By using a bottom ejector combined with a top nitrogen injection pressurization system, leaked hydrogen inside the high-pressure hydrogen storage chamber can be rapidly discharged, with a discharge flow rate far exceeding that of traditional methods such as fans, making it suitable for high-pressure hydrogen cylinder group storage scenarios. The high-pressure nozzles and evaporators at the top of the high-pressure hydrogen storage chamber implement a gradient cooling layout, which can cool some of the leaked hydrogen that has not been discharged in time, promoting the formation of downward-flowing local natural convection, which is then discharged under the action of the ejector, preventing hydrogen accumulation. The overall monitoring and safety protection system also has advantages such as simple structure, few control components, and high safety due to high-pressure nitrogen drive. Attached Figure Description

[0014] To illustrate the technical solutions in the embodiments of the present invention or the prior art more specifically and intuitively, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0015] Figure 1 This invention presents a structural schematic diagram of a high-pressure hydrogen leak monitoring and protection system.

[0016] In the diagram: 1. High-pressure nitrogen pipeline; 2. High-pressure nitrogen source; 3. Solenoid valve; 4. First nitrogen valve; 5. Ejector; 6. Ejector contraction section; 7. Ejector mixing section; 8. Ejector diffusion section; 9. Second nitrogen valve; 10. High-pressure nozzle; 11. Hydrogen pipeline; 12. Manifold; 13. Hydrogen valve; 14. Discharge pipeline; 15. Cooler; 16. Flame arrester; 17. Thermosiphon pipeline; 18. Evaporator; 19. Signal line; 20. Hydrogen concentration sensor; 21. Temperature sensor array; 22. Controller; 23. High-pressure hydrogen storage room; 24. Base plate; 25. High-pressure hydrogen cylinder group. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] Reference Figure 1A high-pressure hydrogen leak monitoring and protection system includes a high-pressure hydrogen storage chamber 23 and a base plate 24 located inside it. A high-pressure hydrogen cylinder group 25 is placed on the base plate 24. The system is characterized in that a high-pressure nitrogen source 2 is provided on one side of the high-pressure hydrogen storage chamber 23. The high-pressure nitrogen source 2 is connected to a first branch and a second branch through a high-pressure nitrogen pipeline 1. A solenoid valve 3 is provided on the high-pressure nitrogen pipeline 1. The first branch is connected to a gas collection structure located at the bottom of the high-pressure hydrogen storage chamber 23, and the second branch is connected to a pressurization structure located at the top of the high-pressure hydrogen storage chamber 23. A cooling mechanism is provided on the top of the high-pressure hydrogen storage chamber 23, and a hydrogen leak detection mechanism is provided inside the high-pressure hydrogen storage chamber 23.

[0019] In this embodiment, the pressurization structure includes several high-pressure nozzles 10 located in the upper space of the high-pressure hydrogen storage room 23. The high-pressure nozzles 10 are equidistantly arranged on the second branch, and the high-pressure nozzles 10 are arranged with the spray direction facing downward. A second nitrogen valve 9 is provided on the second branch.

[0020] The high-pressure nitrogen pipeline 1 is connected in sequence to the high-pressure nitrogen source 2 and the solenoid valve 3 at the front end, and splits into two branches at the rear end. The first branch is connected in sequence to the first nitrogen valve 4 and the ejector 5, which delivers the high-pressure nitrogen from the high-pressure nitrogen source 2 to the ejector 5 for ejection. The second branch is connected in sequence to the second nitrogen valve 9 and the high-pressure nozzle 10, which sprays the high-pressure nitrogen from the high-pressure nitrogen source 2 to increase the pressure at the top of the high-pressure hydrogen storage room 23 and reduce the temperature of the corresponding space by using throttling cooling capacity.

[0021] In this embodiment, the gas collection structure includes an ejector 5 connected to the first branch, the ejector 5 is connected to a manifold 12 via a hydrogen pipeline 11, the manifold 12 is installed on the top of the base plate 24, the ejector 5 is connected to the first heat exchange channel of the cooler 15 via a discharge pipeline 14, a first nitrogen valve 4 is provided on the first branch, and a hydrogen valve 13 is provided on the hydrogen pipeline 11.

[0022] The hydrogen pipeline 11 is connected in sequence to the manifold 12, the hydrogen valve 13, and the ejector 5. The suction force generated by the ejector 5 is used to quickly discharge the hydrogen leaking from the high-pressure hydrogen storage room 23.

[0023] In this embodiment, the ejector 5 includes an ejector contraction section 6, an ejector mixing section 7, and an ejector diffusion section 8, and the ejector contraction section 6 is connected to the first branch and the hydrogen pipeline 11, respectively.

[0024] The ejector 5 includes an ejector contraction section 6, an ejector mixing section 7, an ejector diffusion section 8, etc. The front end of the ejector contraction section 6 also includes a nozzle connected to the first branch of the high-pressure nitrogen pipeline 1 and an air inlet connected to the hydrogen pipeline 11.

[0025] In this embodiment, the cooling mechanism includes a cooler 15 and an evaporator 18 installed on top of the high-pressure hydrogen storage chamber 23. The second heat exchange channel of the cooler 15 is connected to the evaporator 18 through a thermosiphon pipe 17.

[0026] The thermosiphon pipe 17 is sequentially connected to the second heat exchange channel of the cooler 15 and the evaporator 18. The thermosiphon pipe 17 is filled with circulating working fluid. Under the action of heat, it transports the cold energy absorbed by the cooler 15 to the evaporator 18 to cool the hydrogen at the top of the high-pressure hydrogen storage chamber 23, so that it flows downward under the action of natural convection and is then discharged through the hydrogen pipe 11 to prevent the accumulation of hydrogen.

[0027] In this embodiment, the hydrogen leak detection mechanism includes a hydrogen concentration sensor 20 and a temperature sensor array 21 installed inside the high-pressure hydrogen storage chamber 23. The temperature sensor array 21 is arranged around the high-pressure hydrogen cylinder group 25, and the hydrogen concentration sensor 20 is located on top of the high-pressure hydrogen cylinder group 25. The hydrogen concentration sensor 20, the temperature sensor array 21, and the solenoid valve 3 are connected to the controller 22 via a signal line 19.

[0028] Temperature sensor array 21 is installed around high-pressure hydrogen cylinder group 25. According to the principle of throttling and heating of room temperature hydrogen, when high-pressure hydrogen leaks, the temperature around high-pressure hydrogen cylinder group 25 will rise, which will cause the test data of temperature sensor array 21 to change, thus realizing the first type of high-pressure hydrogen leak detection.

[0029] The hydrogen concentration sensor 20 is installed on the top of the high-pressure hydrogen cylinder group 25. Leaking hydrogen at normal pressure will flow to the top of the high-pressure hydrogen storage room 23, thereby realizing the second high-pressure hydrogen leakage detection.

[0030] The hydrogen concentration sensor 20 and the temperature sensor array 21 are connected via signal line 19 and sequentially connected to the controller 22 and the solenoid valve 3. When either the hydrogen concentration sensor 20 or the temperature sensor array 21 detects a high-pressure hydrogen leak, or when both detect a leak simultaneously, the solenoid valve 3 is opened to rapidly discharge hydrogen from the high-pressure hydrogen storage chamber 23.

[0031] In this embodiment, a flame arrester 16 is provided at the end of the discharge pipeline 14. The discharge pipeline 14 is connected in sequence to the ejector diffuser section 8 of the ejector 5, the first heat exchange channel of the cooler 15, and the flame arrester 16. The hydrogen-nitrogen mixture discharged from the ejector 5 is input into the cooler 15 to provide cooling, and then discharged at high altitude through the flame arrester 16.

[0032] The first nitrogen valve 4, the second nitrogen valve 9, and the hydrogen valve 13 in the system are all normally open, while the solenoid valve 3 is normally closed.

[0033] a. High-pressure hydrogen leak detection: When hydrogen leaks from the high-pressure hydrogen cylinder group 25, the temperature of the high-pressure hydrogen increases after throttling at room temperature. Therefore, the temperature sensor array 21 around the high-pressure hydrogen cylinder group 25 will experience a temperature increase. At the same time, the leaked hydrogen will flow upward, and the hydrogen concentration sensor 20 will detect the hydrogen. When either of them detects a hydrogen leak, a signal is sent to the controller 22 through the signal line 19. The controller 22 then opens the solenoid valve 3 through the signal line 19 for safe discharge.

[0034] b. Nitrogen Ejector Discharge: High-pressure nitrogen from high-pressure nitrogen source 2 enters high-pressure nitrogen pipeline 1 through solenoid valve 3. A portion of the high-pressure nitrogen enters the second branch of high-pressure nitrogen pipeline 1 through second nitrogen valve 9, and then enters high-pressure hydrogen storage chamber 23 through high-pressure nozzle 10, increasing the pressure at the top of high-pressure hydrogen storage chamber 23 and preventing hydrogen diffusion. Another portion of the high-pressure nitrogen enters the first branch of high-pressure nitrogen pipeline 1 through first nitrogen valve 4, and then enters ejector 5 to generate suction. Leaking hydrogen around high-pressure hydrogen cylinder group 25, under the combined effect of suction from ejector 5 and pressurization at the top of high-pressure hydrogen storage chamber 23, rapidly enters discharge pipeline 14 through confluencer 12, and then forms a hydrogen-nitrogen mixture within ejector 5 before being discharged. The hydrogen-nitrogen mixture discharged from ejector 5 enters the first heat exchange channel of cooler 15 to provide cooling, and then passes through flame arrester 16 for high-altitude discharge.

[0035] c. Preventing Hydrogen Accumulation: Driven by heat, the circulating working fluid inside the thermosiphon pipe 17 enters the second heat exchange channel of the cooler 15 to absorb cooling, then enters the evaporator 18 to release cooling and re-enters the second heat exchange channel of the cooler 15 to absorb cooling, repeating the cycle. If some of the hydrogen generated by the leakage of the high-pressure hydrogen cylinder group 25 is not discharged in time, it will flow downwards, passing through the first cooling of the high-pressure nozzle, generating local natural convection flowing downwards, and then being discharged again under the action of the ejector 5; if the first cooling does not completely discharge the rising leaked hydrogen, the remaining hydrogen will continue to move upwards, continue to be cooled under the action of the lower-temperature evaporator 18, continue to form local natural convection flowing downwards, and then be discharged again under the action of the ejector 5, ultimately effectively preventing hydrogen accumulation at the top of the high-pressure hydrogen storage room 23.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-pressure hydrogen leak monitoring and protection system, comprising a high-pressure hydrogen storage chamber (23) and a base plate (24) located therein, wherein a high-pressure hydrogen cylinder assembly (25) is placed on the base plate (24), characterized in that, A high-pressure nitrogen source (2) is provided on one side of the high-pressure hydrogen storage chamber (23). The high-pressure nitrogen source (2) is connected to a first branch and a second branch through a high-pressure nitrogen pipeline (1). A solenoid valve (3) is provided on the high-pressure nitrogen pipeline (1). The first branch is connected to a gas collection structure located at the bottom of the high-pressure hydrogen storage chamber (23). The second branch is connected to a pressurization structure located at the top of the high-pressure hydrogen storage chamber (23). A cooling mechanism is provided at the top of the high-pressure hydrogen storage chamber (23). A hydrogen leakage detection mechanism is provided inside the high-pressure hydrogen storage chamber (23). The pressurization structure includes several high-pressure nozzles (10) located in the upper space of the high-pressure hydrogen storage room (23). The high-pressure nozzles (10) are equidistantly arranged on the second branch, and the high-pressure nozzles (10) are arranged with the spray direction facing downward. A second nitrogen valve (9) is provided on the second branch. The gas collection structure includes an ejector (5) connected to the first branch. The ejector (5) is connected to a manifold (12) through a hydrogen pipeline (11). The manifold (12) is installed on the top of the base plate (24). The ejector (5) is connected to the first heat exchange channel of the cooler (15) through a discharge pipeline (14). A first nitrogen valve (4) is provided on the first branch. A hydrogen valve (13) is provided on the hydrogen pipeline (11). The cooling mechanism includes a cooler (15) and an evaporator (18) installed on top of the high-pressure hydrogen storage chamber (23). The second heat exchange channel of the cooler (15) is connected to the evaporator (18) through a thermosiphon pipe (17).

2. The high-pressure hydrogen leak monitoring and protection system according to claim 1, characterized in that, The ejector (5) includes an ejector contraction section (6), an ejector mixing section (7), and an ejector diffusion section (8), and the ejector contraction section (6) is connected to the first branch and the hydrogen pipeline (11) respectively.

3. The high-pressure hydrogen leak monitoring and protection system according to claim 2, characterized in that, The hydrogen leak detection mechanism includes a hydrogen concentration sensor (20) and a temperature sensor array (21) installed inside the high-pressure hydrogen storage room (23). The temperature sensor array (21) is arranged around the high-pressure hydrogen cylinder group (25), and the hydrogen concentration sensor (20) is arranged on top of the high-pressure hydrogen cylinder group (25). The hydrogen concentration sensor (20), the temperature sensor array (21) and the solenoid valve (3) are connected to the controller (22) through the signal line (19).

4. The high-pressure hydrogen leak monitoring and protection system according to claim 3, characterized in that, A flame arrester (16) is installed at the end of the discharge pipeline (14).

5. The method of using the high-pressure hydrogen leak monitoring and protection system as described in claim 4, characterized in that, The method is as follows: The first nitrogen valve (4), the second nitrogen valve (9), and the hydrogen valve (13) in the system are all normally open, and the solenoid valve (3) is normally closed. a. High-pressure hydrogen leak detection: When hydrogen leaks from the high-pressure hydrogen cylinder group (25), the temperature rises after the high-pressure hydrogen is throttled at room temperature, so the temperature sensor array (21) around the high-pressure hydrogen cylinder group (25) will rise. At the same time, the leaked hydrogen will flow upward, and the hydrogen concentration sensor (20) will detect the hydrogen. When either of them detects hydrogen leak, a signal is sent to the controller (22) through the signal line (19). The controller (22) then opens the solenoid valve (3) through the signal line (19) to safely discharge the hydrogen. b. Nitrogen ejection discharge: High-pressure nitrogen from the high-pressure nitrogen source (2) enters the high-pressure nitrogen pipeline (1) through the solenoid valve (3). A portion of the high-pressure nitrogen enters the second branch of the high-pressure nitrogen pipeline (1) through the second nitrogen valve (9), and then enters the high-pressure hydrogen storage chamber (23) through the high-pressure nozzle (10), increasing the pressure at the top of the high-pressure hydrogen storage chamber (23) and preventing hydrogen diffusion; another portion of the high-pressure nitrogen enters the first branch of the high-pressure nitrogen pipeline (1) through the first nitrogen valve (4). The branch line then enters the ejector (5) to generate suction. Under the combined effect of the suction of the ejector (5) and the pressurization at the top of the high-pressure hydrogen storage room (23), the leaked hydrogen around the high-pressure hydrogen cylinder group (25) quickly enters the discharge pipeline (14) through the confluencer (12), and then forms a hydrogen-nitrogen mixture in the ejector (5) for discharge. The hydrogen-nitrogen mixture discharged from the ejector (5) enters the first heat exchange channel of the cooler (15) to provide cooling, and then passes through the flame arrester (16) for high-altitude discharge. c. Preventing hydrogen accumulation: Under the action of heat, the circulating working fluid inside the thermosiphon pipe (17) enters the second heat exchange channel of the cooler (15) to absorb the cold energy, and then enters the evaporator (18) to release the cold energy and enters the second heat exchange channel of the cooler (15) again to absorb the cold energy, and repeats the cycle; if some of the hydrogen generated by the leakage of the high-pressure hydrogen cylinder group (25) is not discharged in time, it will flow downward, cool down after the first cooling of the high-pressure nozzle, generate local natural convection flowing downward, and be discharged again under the action of the ejector (5); if the first cooling does not completely discharge the rising leaked hydrogen, the remaining hydrogen will continue to move upward, continue to be cooled under the action of the lower temperature evaporator (18), continue to form local natural convection flowing downward, and be discharged again under the action of the ejector (5), which can effectively prevent hydrogen accumulation at the top of the high-pressure hydrogen storage room (23).

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