High-pressure hydrogen leakage monitoring and protecting system and method

Abstract

The high-pressure hydrogen leakage monitoring and protecting system comprises a high-pressure hydrogen storage room and a bottom plate located in the high-pressure hydrogen storage room, a high-pressure hydrogen cylinder set is placed on the bottom plate, and the high-pressure hydrogen leakage monitoring and protecting system is characterized in that a high-pressure nitrogen source is arranged on one side of the high-pressure hydrogen storage room; the high-pressure nitrogen source is connected with a first branch and a second branch through a high-pressure nitrogen pipeline. According to the high-pressure hydrogen leakage throttling and heating principle, the temperature sensor array is arranged around the high-pressure hydrogen cylinder set, the hydrogen concentration sensor on the top is combined, double detection of high-pressure hydrogen leakage is achieved, the detection accuracy is improved, and the response time is prolonged. The ejector at the bottom is combined with the nitrogen injection pressurizing device at the top, leaked hydrogen in the high-pressure hydrogen storage room is rapidly discharged, the discharging flow is far larger than that of a traditional mode such as a fan, and the high-pressure hydrogen storage room is suitable for high-pressure hydrogen cylinder set storage scenes. The overall monitoring and safety protection system also has the advantages of simple structure, few control parts, high-pressure nitrogen driving safety and the like.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen safety technology, and in particular to a high-pressure hydrogen leakage monitoring and protection system and method. Background Art

[0002] As a clean energy with the most promising alternative to traditional fossil fuels in the 21st century, hydrogen energy has been commercially promoted and applied in many fields such as hydrogen fuel cells and hydrogen refueling stations. Safety is one of the key bottleneck issues in the entire life cycle of the hydrogen energy industry, and high pressure is its core risk factor, involving various links such as hydrogen production, storage, transportation and use, which can easily cause hydrogen leakage, diffusion, and even major safety accidents such as combustion and explosion. Over the years, hydrogen accidents have been common at home and abroad, and have even caused significant casualties and property losses. Safety issues have become one of the important bottlenecks in the promotion of hydrogen energy, and have attracted the attention and attention of countries around the world to hydrogen energy safety.

[0003] Hydrogen has the characteristics of low density, large diffusion coefficient (3.8 times the diffusion rate of air), low ignition temperature, wide explosion limit (volume fraction of 4%~75%), and fast combustion flame speed. If high-pressure hydrogen leaks, it is very easy to form a large-scale flammable gas cloud, which will cause a violent explosion accident once ignited, posing a serious threat to life and property safety. High-pressure hydrogen storage cylinders have a long storage time, large hydrogen storage capacity, and high hydrogen storage pressure. The most common damage is the instrument pipeline of the cylinder group, which is easy to cause leakage accidents. However, the current maturity of hydrogen leakage-related technologies and devices is relatively low, and new safety protection devices need to be designed for high-pressure hydrogen storage scenarios. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and propose a high-pressure hydrogen leakage monitoring and protection system and method, which uses an array temperature sensor and a hydrogen concentration sensor to quickly detect high-pressure hydrogen leakage, uses a large flow of high-pressure nitrogen to inject the leaked hydrogen, and uses the cold energy generated by the injection to cool the top of the storage space of the high-pressure hydrogen cylinder group to prevent hydrogen accumulation, thereby realizing the monitoring and safety protection of high-pressure hydrogen leakage.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A high-pressure hydrogen leakage monitoring and protection system comprises a high-pressure hydrogen storage room and a bottom plate located inside the high-pressure hydrogen storage room, a high-pressure hydrogen cylinder group is placed on the bottom plate, and is characterized in that a high-pressure nitrogen source is arranged on one side of the high-pressure hydrogen storage room, the high-pressure nitrogen source is respectively connected to a first branch and a second branch through a high-pressure nitrogen pipeline, an electromagnetic valve is arranged on the high-pressure nitrogen pipeline, the first branch is connected to a gas collecting structure arranged at the lower part of the high-pressure hydrogen storage room, the second branch is connected to a pressurizing structure arranged at the upper part of the high-pressure hydrogen storage room, a cooling mechanism is arranged on the top of the high-pressure hydrogen storage room, and a hydrogen leakage detection mechanism is arranged inside the high-pressure hydrogen storage room.

[0006] Preferably, the pressurizing structure comprises 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 spraying direction of the high-pressure nozzles is arranged downward, and a second nitrogen valve is arranged on the second branch.

[0007] Preferably, the gas collection structure includes an ejector connected to the first branch, the ejector is connected to a combiner through a hydrogen pipeline, the combiner is installed on the top of the base plate, the ejector is connected to the first heat exchange channel of the cooler through a discharge pipeline, a first nitrogen valve is provided on the first branch, and a hydrogen valve is provided on the hydrogen pipeline.

[0008] Preferably, the ejector comprises an ejector contraction section, an ejector mixing section and an ejector diffusion section, and the ejector contraction section is respectively connected to the first branch and the hydrogen pipeline.

[0009] Preferably, the cooling mechanism comprises a cooler and an evaporator installed on the top of the high-pressure hydrogen storage room, and the second heat exchange channel of the cooler is connected to the evaporator through a thermosiphon pipeline.

[0010] Preferably, the hydrogen leakage 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 arranged on the 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 a signal line.

[0011] Preferably, a flame arrester is provided at the tail end of the discharge pipeline.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention utilizes the principle of throttling and heating of high-pressure hydrogen leakage, sets a temperature sensor array around the high-pressure hydrogen cylinder group, and combines with the hydrogen concentration sensor on the top to realize dual detection of high-pressure hydrogen leakage, thereby improving detection accuracy and response time. The bottom ejector is combined with the nitrogen injection pressurization setting on the top to realize the rapid discharge of leaked hydrogen inside the high-pressure hydrogen storage room, and the discharge flow rate is much larger than traditional methods such as fans, which is suitable for the storage scenario of high-pressure hydrogen cylinder groups. The high-pressure nozzle and evaporator on the top of the high-pressure hydrogen storage room realize a gradient cooling layout, which can cool some of the leaked hydrogen that has not been discharged in time, prompting it to form a local natural convection that flows downward, and then discharged under the action of the ejector to prevent the accumulation of hydrogen. The overall monitoring and safety protection system also has the advantages of simple structure, few control components, and high safety of high-pressure nitrogen drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more specifically and intuitively illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0014] Figure 1 The present invention provides a structural schematic diagram of a high-pressure hydrogen leakage monitoring and protection system.

[0015] In the figure: high-pressure nitrogen pipeline 1, high-pressure nitrogen source 2, solenoid valve 3, first nitrogen valve 4, ejector 5, ejector contraction section 6, ejector mixing section 7, ejector diffusion section 8, second nitrogen valve 9, high-pressure nozzle 10, hydrogen pipeline 11, merger 12, hydrogen valve 13, discharge pipeline 14, cooler 15, flame arrester 16, thermal siphon pipeline 17, evaporator 18, signal line 19, hydrogen concentration sensor 20, temperature sensor array 21, controller 22, high-pressure hydrogen storage room 23, bottom plate 24, high-pressure hydrogen cylinder group 25. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0017] Reference Figure 1A high-pressure hydrogen leakage monitoring and protection system comprises a high-pressure hydrogen storage room 23 and a bottom plate 24 located inside the high-pressure hydrogen storage room 23, a high-pressure hydrogen cylinder group 25 is placed on the bottom plate 24, and is characterized in that a high-pressure nitrogen source 2 is arranged on one side of the high-pressure hydrogen storage room 23, the high-pressure nitrogen source 2 is respectively connected to a first branch and a second branch through a high-pressure nitrogen pipeline 1, a solenoid valve 3 is arranged on the high-pressure nitrogen pipeline 1, the first branch is connected to a gas collection structure arranged at the lower part of the high-pressure hydrogen storage room 23, the second branch is connected to a pressurizing structure arranged at the upper part of the high-pressure hydrogen storage room 23, a cooling mechanism is arranged on the top of the high-pressure hydrogen storage room 23, and a hydrogen leakage detection mechanism is arranged inside the high-pressure hydrogen storage room 23.

[0018] In this embodiment, the pressurizing structure includes a plurality of 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 spraying direction of the high-pressure nozzles 10 is arranged downward. A second nitrogen valve 9 is arranged on the second branch.

[0019] The front end of the high-pressure nitrogen pipeline 1 is connected to the high-pressure nitrogen source 2 and the solenoid valve 3 in sequence, and the rear end is divided into two branches. The first branch is connected to the first nitrogen valve 4 and the ejector 5 in sequence, and the high-pressure nitrogen of the high-pressure nitrogen source 2 is transported to the ejector 5 for injection. The second branch is connected to the second nitrogen valve 9 and the high-pressure nozzle 10 in sequence, and the high-pressure nitrogen of the high-pressure nitrogen source 2 is injected, thereby increasing the pressure at the top of the high-pressure hydrogen storage room 23 and reducing the temperature of the corresponding space by throttling cooling capacity.

[0020] In this embodiment, the gas collection structure includes an ejector 5 connected to the first branch, the ejector 5 is connected to the combiner 12 through the hydrogen pipeline 11, the combiner 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 the discharge pipeline 14, the first nitrogen valve 4 is arranged on the first branch, and the hydrogen valve 13 is arranged on the hydrogen pipeline 11.

[0021] The hydrogen pipeline 11 is connected to the combiner 12, the hydrogen valve 13, and the ejector 5 in sequence, and the suction force generated by the ejector 5 is used to quickly discharge the hydrogen leaked in the high-pressure hydrogen storage room 23.

[0022] 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.

[0023] The ejector 5 includes an ejector contraction section 6, an ejector mixing section 7, an ejector diffusion section 8 and other parts, wherein 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.

[0024] In this embodiment, the cooling mechanism includes a cooler 15 and an evaporator 18 installed on the top of the high-pressure hydrogen storage room 23 , and the second heat exchange channel of the cooler 15 is connected to the evaporator 18 through a thermosiphon pipeline 17 .

[0025] The thermosiphon pipeline 17 is connected to the second heat exchange channel of the cooler 15 and the evaporator 18 in sequence. The thermosiphon pipeline 17 is filled with circulating working fluid. Under the action of thermal drive, the cold absorbed by the cooler 15 is transported to the evaporator 18, cooling the hydrogen at the top of the high-pressure hydrogen storage room 23, allowing it to flow downward under the action of natural convection, and then discharged through the hydrogen pipeline 11 to prevent hydrogen accumulation.

[0026] In this embodiment, the hydrogen leakage 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 the 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.

[0027] The temperature sensor array 21 is installed around the high-pressure hydrogen cylinder group 25. According to the principle of throttling and heating of hydrogen at room temperature, when high-pressure hydrogen leaks, the temperature around the high-pressure hydrogen cylinder group 25 will rise, thereby causing the test data of the temperature sensor array 21 to change, thereby realizing the first type of high-pressure hydrogen leakage detection.

[0028] The hydrogen concentration sensor 20 is installed on the top of the high-pressure hydrogen cylinder group 25. The leaked hydrogen under normal pressure will flow to the top of the high-pressure hydrogen storage room 23, thereby realizing the second high-pressure hydrogen leakage detection.

[0029] The hydrogen concentration sensor 20 and the temperature sensor array 21 are connected via a signal line 19, and are connected in turn to a controller 22 and a solenoid valve 3. When either or both of the hydrogen concentration sensor 20 and the temperature sensor array 21 detect a high-pressure hydrogen leak, the solenoid valve 3 is opened to quickly discharge hydrogen from the high-pressure hydrogen storage room 23.

[0030] In this embodiment, a flame arrester 16 is provided at the tail end of the discharge pipeline 14, and the discharge pipeline 14 is connected in sequence to the ejector diffusion section 8 of the ejector 5, the first heat exchange channel of the cooler 15, and the flame arrester 16, so that the hydrogen-nitrogen mixed gas discharged from the ejector 5 is input into the cooler 15 to provide cooling capacity, and then discharged into the air through the flame arrester 16.

[0031] The first nitrogen valve 4, the second nitrogen valve 9 and the hydrogen valve 13 in the system are all in a normally open state, and the solenoid valve 3 is in a normally closed state.

[0032] a. High-pressure hydrogen leakage detection: When hydrogen leakage occurs in the high-pressure hydrogen cylinder group 25, the temperature of the temperature sensor array 21 around the high-pressure hydrogen cylinder group 25 will increase due to the increase in temperature of the room-temperature high-pressure hydrogen after throttling. At the same time, the leaked hydrogen will flow upward, and the hydrogen concentration sensor 20 will detect the hydrogen. When either of the two detects hydrogen leakage, a signal is sent to the controller 22 through the signal line 19, and the controller 22 opens the solenoid valve 3 through the signal line 19 for safe discharge.

[0033] b. Nitrogen ejection discharge: High-pressure nitrogen from high-pressure nitrogen source 2 enters high-pressure nitrogen pipeline 1 through solenoid valve 3, and a part of 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 room 23 through high-pressure nozzle 10, increasing the pressure at the top of high-pressure hydrogen storage room 23 and preventing hydrogen diffusion; another part of 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. Under the dual effects of suction of ejector 5 and pressurization at the top of high-pressure hydrogen storage room 23, the leaked hydrogen around high-pressure hydrogen cylinder group 25 quickly enters discharge pipeline 14 through merger 12, and then forms hydrogen-nitrogen mixed gas in ejector 5 and is discharged. The hydrogen-nitrogen mixed gas discharged from ejector 5 enters the first heat exchange channel of cooler 15 to provide cooling capacity, and then passes through flame arrester 16 for high-altitude discharge.

[0034] c. Prevent hydrogen accumulation: Under the action of thermal drive, the circulating medium inside the thermosiphon pipeline 17 enters the second heat exchange channel of the cooler 15 to absorb cold energy, then enters the evaporator 18 to release cold energy and enters the second heat exchange channel of the cooler 15 again to absorb cold energy, and the cycle repeats. If part of the hydrogen generated by the leakage of the high-pressure hydrogen cylinder group 25 is not discharged in time, it will flow downward, and will pass through the first cooling and cooling of the high-pressure nozzle, generating a local natural convection flowing downward, and will 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 cool under the action of the evaporator 18 with a lower temperature, continue to form a local natural convection flowing downward, and will be discharged again under the action of the ejector 5, which can effectively prevent the accumulation of hydrogen at the top of the high-pressure hydrogen storage room 23.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-pressure hydrogen leakage monitoring and protection system, comprising a high-pressure hydrogen storage room (23) and a bottom plate (24) located inside the room, a high-pressure hydrogen cylinder group (25) being placed on the bottom plate (24), characterized in that: A high-pressure nitrogen source (2) is provided on one side of the high-pressure hydrogen storage room (23); the high-pressure nitrogen source (2) is connected to a first branch and a second branch respectively 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 collecting structure provided at the bottom of the high-pressure hydrogen storage room (23); the second branch is connected to a pressurizing structure provided at the top of the high-pressure hydrogen storage room (23); a cooling mechanism is provided at the top of the high-pressure hydrogen storage room (23); and a hydrogen leakage detection mechanism is provided inside the high-pressure hydrogen storage room (23).

2. A high-pressure hydrogen leakage monitoring and protection system according to claim 1, characterized in that: The pressurizing structure comprises a plurality of high-pressure nozzles (10) located in the upper space of the high-pressure hydrogen storage room (23), the high-pressure nozzles (10) being arranged equidistantly on the second branch, and the high-pressure nozzles (10) being arranged with their spraying direction facing downward, and a second nitrogen valve (9) being arranged on the second branch.

3. A high-pressure hydrogen leakage monitoring and protection system according to claim 2, characterized in that: The gas collection structure comprises an ejector (5) connected to a first branch, the ejector (5) being connected to a merger (12) via a hydrogen pipeline (11), the merger (12) being mounted on the top of a base plate (24), the ejector (5) being connected to a first heat exchange channel of a cooler (15) via a discharge pipeline (14), a first nitrogen valve (4) being provided on the first branch, and a hydrogen valve (13) being provided on the hydrogen pipeline (11).

4. A high-pressure hydrogen leakage monitoring and protection system according to claim 3, characterized in that: The ejector (5) comprises 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.

5. A high-pressure hydrogen leakage monitoring and protection system according to claim 4, characterized in that: The cooling mechanism comprises a cooler (15) and an evaporator (18) installed on the top of the high-pressure hydrogen storage room (23); the second heat exchange channel of the cooler (15) is connected to the evaporator (18) via a thermosiphon pipeline (17).

6. A high-pressure hydrogen leakage monitoring and protection system according to claim 5, characterized in that: The hydrogen leakage detection mechanism comprises a hydrogen concentration sensor (20) and a temperature sensor array (21) installed inside a high-pressure hydrogen storage room (23); the temperature sensor array (21) is arranged around the high-pressure hydrogen cylinder group (25); the hydrogen concentration sensor (20) is arranged on the 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 a controller (22) via a signal line (19).

7. A high-pressure hydrogen leakage monitoring and protection system according to claim 6, characterized in that: A flame arrester (16) is provided at the tail end of the discharge pipeline (14).

8. The method for using a high-pressure hydrogen leakage monitoring and protection system according to claim 7, 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 in a normally open state, and the solenoid valve (3) is in a normally closed state; a. High-pressure hydrogen leakage detection: When hydrogen leakage occurs in the high-pressure hydrogen cylinder group (25), the temperature of the temperature sensor array (21) around the high-pressure hydrogen cylinder group (25) will increase due to the increase in temperature of the room-temperature high-pressure hydrogen after throttling. At the same time, the leaked hydrogen will flow upward, and the hydrogen concentration sensor (20) will detect the hydrogen. When either of the two detects hydrogen leakage, a signal is sent to the controller (22) through the signal line (19), and the controller (22) opens the solenoid valve (3) through the signal line (19) for safe discharge; 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 room (23) through the high-pressure nozzle (10), thereby increasing the pressure at the top of the high-pressure hydrogen storage room (23) and preventing hydrogen from diffusing; another portion of the high-pressure nitrogen enters the first branch of the high-pressure nitrogen pipeline (1) through the first nitrogen valve (4), and then enters the ejector (5) to generate suction. The leaked hydrogen around the high-pressure hydrogen cylinder group (25) is rapidly discharged into the discharge pipeline (14) through the merger (12) under the dual effects of the suction force of the ejector (5) and the pressurization at the top of the high-pressure hydrogen storage room (23), and then forms a hydrogen-nitrogen mixed gas in the ejector (5) and is discharged; the hydrogen-nitrogen mixed gas discharged from the ejector (5) enters the first heat exchange channel of the cooler (15) to provide cooling capacity, and then passes through the flame arrester (16) for high-altitude discharge; c. Preventing hydrogen accumulation: Under the action of heat drive, the circulating medium inside the thermosiphon pipeline (17) enters the second heat exchange channel of the cooler (15) to absorb cold energy, then enters the evaporator (18) to release cold energy and enters the second heat exchange channel of the cooler (15) again to absorb cold energy, and repeats the cycle; if part of the hydrogen generated by the leakage of the high-pressure hydrogen cylinder group (25) is not discharged in time, it will flow downward, pass through 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 fails to completely discharge the rising leaked hydrogen, the remaining hydrogen continues to move upward, continues to cool under the action of the evaporator (18) with a lower temperature, continues to form local natural convection flowing downward, and is 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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