Water mist and heating inert gas combined fire extinguishing system for hydrogen leakage scene

Abstract

The invention relates to the technical field of fire fighting, in particular to a water mist and heating inert gas combined fire fighting system for a hydrogen leakage scene, which comprises a water mist spray head, the water mist spray head is arranged above a hydrogen refueling station, and the water mist spray head sprays water downwards; the gas spray head is arranged in the hydrogen refueling station, the gas spray head is located below the water mist spray head, and a nozzle of the gas spray head faces the water mist spray head; the gas storage tank is used for storing inert gas, and the gas storage tank is connected with the gas nozzle through a gas conveying pipe; and the supply system is used for supplying cold water to the water mist spraying head and heating the gas in the gas conveying pipe. On one hand, the hot inert gas is used for pressing hydrogen upwards to the water mist spray head to compress the space occupied by the hydrogen, on the other hand, the inert gas is used for reducing the oxygen content in the space, and the water mist is used for humidifying air to reduce the possibility of static electricity, so that the risk of fire blast caused by hydrogen leakage is reduced.

Description

Technical Field

[0001] The present application relates to the field of fire protection technology, and particularly to a combined fire protection system of fine water mist and heated inert gas for hydrogen leakage scenarios. Background Art

[0002] As a clean and efficient energy source, hydrogen energy has the advantages of high calorific value per unit mass, fast combustion speed, non-toxic and pollution-free, and diverse sources, and is widely used in industries, energy, transportation and other fields. At present, the development of hydrogen energy has attracted much attention at home and abroad. Against the background of the continuous expansion of the scale of hydrogen energy utilization, the safety of hydrogen refueling stations is of crucial importance, and the development of hydrogen leakage prevention and control technology is based on multiple backgrounds.

[0003] From the perspective of the properties of hydrogen, hydrogen is the lightest gas, with small molecules and fast diffusion speed. Once leaked, it will quickly diffuse in the air. Moreover, hydrogen has a wide flammable range (4.0%-75.6%) and low ignition energy. The use conditions in its production-storage-transportation-utilization and other links are harsh, and leakage is likely to occur, causing serious combustion and explosion accidents.

[0004] In terms of the facilities of the hydrogen refueling station itself, it includes complex equipment combinations such as hydrogen storage systems (such as high-pressure hydrogen storage tanks, etc.), hydrogen filling systems (hydrogen dispensers, etc.), and pipelines. Due to the long-term high pressure, these devices are at risk of seal aging, pipeline wear, valve failure, etc., which are likely to cause hydrogen leakage. In addition, the increasing operation frequency of hydrogen refueling stations also raises the leakage risk. With more and more hydrogen fuel cell vehicles put into use, the hydrogen refueling stations are used more frequently, the equipment wears out faster, and the probability of hydrogen leakage also increases.

[0005] At present, the commonly used traditional dry powder fire extinguishing agent has limited effect on suppressing gas fires, and there is a problem of re-ignition of gas leakage fires; the water-based fire extinguishing agent has the problem of being unable to effectively dilute the hydrogen concentration and reduce the influence range of hydrogen leakage; existing technologies mostly focus on extinguishing the fire, but ignore the problem of the continuous diffusion risk of the leakage source. Summary of the Invention

[0006] The present invention aims to solve one of the problems existing in the background art.

[0007] To this end, the present invention provides a combined fire protection system of fine water mist and heated inert gas for hydrogen leakage scenarios.

[0008] The technical solution adopted by the present invention to solve its technical problems is:

[0009] A combined fire protection system of fine water mist and heated inert gas for hydrogen leakage scenarios, comprising

[0010] Fine water mist spray heads, which are arranged above the hydrogen refueling station and spray water downward.

[0011] A gas nozzle, which is arranged in a hydrogen refueling station, below a fine water mist sprinkler head, and the nozzle direction of the gas nozzle is set towards the fine water mist sprinkler head;

[0012] A gas storage tank for storing inert gas, and the gas storage tank is connected to the gas nozzle through a gas pipeline;

[0013] A supply system for supplying cold water to the fine water mist sprinkler head and heating the gas in the gas pipeline.

[0014] Further, a plurality of the gas nozzles are provided, and the plurality of gas nozzles are arranged in a matrix and are staggeredly arranged with the fine water mist sprinkler head located above the hydrogen refueling station.

[0015] Further, the gas nozzle and the fine water mist sprinkler head are arranged in a parallel cross arrangement.

[0016] Further, the gas nozzle and the fine water mist sprinkler head are arranged in an arc cross arrangement.

[0017] Further, the supply system includes

[0018] A hot water tank, an outlet pipe is connected to the hot water tank, and the outlet pipe is used for heating the gas in the gas pipeline;

[0019] A solar water heater, and the solar water heater is connected to the hot water tank.

[0020] Further, a return pipe is also connected to the hot water tank, a heat exchanger is connected between the outlet pipe and the return pipe, and the heat exchanger is connected to the gas pipeline.

[0021] Further, a monitoring system is also included, and the monitoring system includes

[0022] An alarm, and

[0023] A hydrogen sensor, which is arranged on the body of the hydrogen refueling station;

[0024] A control cabinet, which is connected to both the hydrogen sensor and the alarm, and the control cabinet can control the fine water mist sprinkler head to spray water, the gas nozzle to spray gas, and the water circulation in the heat exchanger.

[0025] Further, a gas flow controller is arranged on the gas pipeline, and the gas flow controller is connected to the control cabinet.

[0026] Further, the gas flow controller adjusts the output amount of the inert gas in real time according to the hydrogen concentration monitored by the hydrogen sensor, and the calculation formula for the output amount of the inert gas is as follows: In the formula, Qfuel is the hydrogen leakage rate (m 3 / s); C target is the target safety concentration of hydrogen (volume fraction); C measured is the hydrogen concentration (volume fraction) detected in real time by the hydrogen sensor; k air is the natural dilution factor of air, with a value range of 0 to 1. The closer its value is to 1, the better the air dilution effect on hydrogen is characterized; η is the mixing efficiency of inert gas and hydrogen, with a value range of 0 to 1; S is the safety factor; Constant is a constant.

[0027] The beneficial effects of the present invention are as follows. In this application, the fine water mist humidifies the ambient air in the hydrogen leakage scenario, making it difficult for static electricity to appear in the environment and reducing the ignition sources caused by static electricity ignition. In addition, when combustion occurs after hydrogen leakage, the fine water mist can absorb the heat generated by combustion and reduce the flame temperature. This is because water absorbs a large amount of heat during the vaporization process, making it difficult for the combustion reaction to continue due to insufficient heat, achieving the effect of suppressing the fire.

[0028] The hot inert gas can displace the air in the leakage area and reduce the oxygen content. Since hydrogen combustion requires oxygen, reducing the oxygen concentration can effectively prevent hydrogen combustion. On the one hand, the gas with a higher temperature can press the hydrogen upwards towards the fine water mist sprinkler head, improving the sprinkling effect. On the other hand, in a closed or semi-closed hydrogen refueling station space, after filling with hot inert gas, the oxygen concentration in the environment is reduced to a certain extent, and even if hydrogen leaks, it is difficult to have a combustion reaction. The hot inert gas can form a relatively stable inert atmosphere around the key equipment and storage areas in the hydrogen refueling station, preventing hydrogen from coming into contact with air. This is like putting a "protective coat" on the equipment, greatly reducing the possibility of danger after hydrogen leakage. Compared with some other gases, inert gases also have relatively stable properties and are not prone to generating static electricity during the injection process.

[0029] The purging of the hot inert gas helps the rapid dispersion of the leaked hydrogen, preventing its local accumulation and reducing the risk of combustion and explosion caused by hydrogen leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the drawings and embodiments.

[0031] Figure 1 is the overall schematic diagram of the combined fire-fighting system of fine water mist and inert gas.

[0032] Figure 2 is the schematic diagram of the control cabinet line connection of the combined fire-fighting system of fine water mist and inert gas.

[0033] Figure 3 is the schematic diagram of the parallel cross-arrangement of gas nozzles and fine water mist sprinkler heads.

[0034] Figure 4 It is a schematic diagram showing that the gas nozzle and the fine water mist sprinkler head are arranged in an arc-shaped staggered pattern.

[0035] In the figure: 1. Solar water heater; 2. Connecting pipe; 3. Cold water tank; 4. Hot water tank; 5. Water delivery pipe; 6. Installation panel; 7. Fine water mist sprinkler head; 8. Water outlet pipe; 9. Return pipe; 10. Heat exchanger; 11. Gas storage tank; 12. Gas flow controller; 13. Control valve; 14. Gas delivery pipe; 15. Gas nozzle; 16. First water pump; 17. First water valve; 18. Second water pump; 19. Second water valve; 20. Valve; 21. Hydrogen sensor; 22. Alarm; 23. Control cabinet; 24. Hydrogen refueling machine. Specific embodiments

[0036] Now, the present invention will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only showing the basic structure of the present invention in a schematic way, so they only show the components related to the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation to the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] A combined fire protection system of fine water mist and heated inert gas for hydrogen leakage scenarios, comprising a monitoring system, a fine water mist sprinkler system, a hot inert gas ejection system, and a supply system.

[0040] The fine water mist spraying system includes fine water mist spray heads 7. A plurality of fine water mist spray heads 7 are arranged in a rectangular array through a mounting panel 6 and are located above the hydrogen filling station.

[0041] The hot gas ejection system includes a gas storage tank 11 and a number of gas nozzles 15. The gas nozzles 15 are arranged in the floor of the hydrogen filling station. Preferably, the gas nozzles 15 are embedded in the floor of the hydrogen filling station and the gas nozzles 15 are exposed; a plurality of gas nozzles 15 are arranged in a matrix and are staggered with the fine water mist spray heads 7 located above the hydrogen filling station. The gas storage tank 11 is used to store inert gas. In this embodiment, the inert gas in the gas storage tank 11 can be one of nitrogen, carbon dioxide, argon or a combined gas thereof. A gas transmission pipe 14 is connected to the gas storage tank 11, and a branch pipe is connected between the gas transmission pipe 14 and each gas nozzle 15. A control valve 13 is connected to the gas transmission pipe 14, and a gas flow controller 12 is further arranged between the control valve 13 and the gas storage tank 11. The gas flow controller 12 is connected to the gas transmission pipe 14.

[0042] The supply system is used to supply cold water to the fine water mist spraying system and supply heat to the hot inert gas ejection system. The supply system includes a solar water heater 1, a hot water tank 4, a cold water tank 3 and a heat exchanger 10. Among them, the hot water tank 4 and the cold water tank 3 can be set as two independent cavities of the same water supply tank. Further, a heat insulation layer can be arranged between the hot water tank 4 and the cold water tank 3.

[0043] A water transmission pipe 5 is connected between the cold water tank 3 and the fine water mist spray heads 7. One end of the water transmission pipe 5 away from the cold water tank 3 is provided with a plurality of branches for connecting with a plurality of fine water mist spray heads 7. A first water pump 16 and a first water valve 17 are connected to the water transmission pipe 5.

[0044] The solar water heater 1 is connected to the hot water tank 4 through a connecting pipe 2, and a valve 20 is arranged on the connecting pipe 2; an outlet pipe 8 and a return pipe 9 are connected between the hot water tank 4 and the heat exchanger 10. A second water pump 18 and a second water valve 19 are connected to the return pipe 9. The heat exchanger 10 is connected to the gas transmission pipe 14 and is located on the side of the control valve 13 away from the gas storage tank 11. The water in the hot water tank 4 is heated by solar energy. The water in the hot water tank 4 is input into the heat exchanger 10 through the outlet pipe 8. The hot water entering the heat exchanger 10 heats the inert gas in the gas transmission pipe 14 and flows back into the hot water tank 4 through the return pipe 9 after participating in the heat exchange.

[0045] The monitoring system includes a hydrogen sensor 21, an alarm 22 and a control cabinet 23 arranged on the hydrogen filling machine 24 of the hydrogen filling station. The hydrogen sensor 21 is respectively connected to the first water pump 16, the first valve 20, the second water pump 18, the second valve 20, the control valve 13 and the alarm 22 through the output line of the control cabinet 23.

[0046] The implementation principle of this application is:

[0047] When hydrogen leaks at the leakage position P, the hydrogen sensor 21 responds. At the same time, the alarm 22, the control valve 13, the second water pump 18 and the second water valve 19 are opened through the output line of the control cabinet 23. The inert gas flowing out of the gas storage tank 11 absorbs the heat of the circulating hot water in the hot water tank 4 through the heat exchanger 10 and is ejected upward by the gas spray head 15. The hot inert gas reduces the hydrogen concentration while increasing the hydrogen temperature, accelerating the upward floating rate of hydrogen. It should be noted that the ejection amount of nitrogen is controlled by the gas flow controller 12, and its flow rate is automatically adjusted according to the hydrogen concentration monitored by the hydrogen sensor 21.

[0048] The ejection flow rate of the inert gas controlled by the gas flow controller 12 is adjusted in real time according to the hydrogen concentration monitored by the hydrogen sensor 21. The adjustment of its ejection amount adopts PID control. The calculation formula of the ejection flow rate of the inert gas (m 3 / s) is as follows:

[0049]

[0050] In the formula, Q fuel is the hydrogen leakage rate (m 3 / s); C target is the target safety concentration of hydrogen (volume fraction), and its value is lower than 4% of the lower explosion limit of hydrogen, and is set to be below 80% of its lower explosion limit; C measured is the hydrogen concentration (volume fraction) detected by the hydrogen sensor 21 in real time; k air is the natural dilution factor of air (the value range is 0-1. The greater the wind speed, the opposite the wind direction and the leakage direction, and the more open the terrain of the leakage position, the closer its value is to 1, indicating that the air has a better dilution effect on hydrogen); η is the mixing efficiency of the inert gas and hydrogen (the value range is 0-1: the wind accelerates the diffusion of the inert gas and reduces the local mixing efficiency of the inert gas. Therefore, the greater the wind speed, the closer η is to 0; the higher the coverage efficiency of the inert gas injection direction on the leakage path, the closer its value is to 1; the high-speed injection and turbulent injection of the inert gas reduce gas stratification, and its value is closer to 1); S is the safety factor used to compensate for environmental uncertainty, and its value is greater than 1. Constant is a fixed constant, which is used to continuously eject a small amount of inert gas when the hydrogen concentration monitored by the hydrogen sensor 21 is lower than the target safety concentration of hydrogen, so as to maintain a certain inert gas action time and ensure safety.

[0051] When using the above formula for inert gas ejection, the inert gas ejection logic is that if the detected hydrogen concentration is higher than the target concentration, the flow rate of the inert gas is increased; conversely, if the concentration is already lower than the target, the flow rate can be appropriately reduced.

[0052] While the hydrogen sensor 21 responds, the first water pump 16 and the first water valve 17 are opened through the control cabinet 23, and the water in the cold water tank 3 is sprayed downward through the fine water mist sprinkler head 7 to perform pre-fire extinguishing operations, while increasing the air humidity and reducing the possibility of static ignition caused by high-speed airflows.

[0053] Figure 3 Shows a spatial relationship between the gas sprinkler head 15 and the fine water mist sprinkler head 7. As shown in the figure, the gas sprinkler head 15 and the fine water mist sprinkler head 7 are arranged in a parallel staggered manner. This arrangement can isolate the leaked hydrogen in a local unit through the fine water mist curtain, and dilute the hydrogen concentration through the convection of the hot inert gas flow to reduce the hydrogen concentration.

[0054] Figure 4 Shows another spatial relationship between the gas sprinkler head 15 and the fine water mist sprinkler head 7. The gas sprinkler head 15 and the fine water mist sprinkler head 7 are arranged in an arc-shaped staggered manner. This arrangement can reduce the number of fine water mist sprinkler heads 7 and gas sprinkler heads 15 used on the premise of realizing hydrogen leakage fire protection according to the hydrogen leakage speed type.

[0055] Through the combined action of the fine water mist and the hot inert gas, the fine water mist and heated inert gas combined hydrogen leakage fire protection system proposed by the present invention can reduce the hydrogen concentration in the hydrogen leakage area, increase the hydrogen evacuation speed, reduce the risk of static ignition caused by high-speed airflow injection, and reduce the safety hazards of the hydrogen filling station.

[0056] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A combined fire-fighting system of fine water mist and heated inert gas for hydrogen leakage scenarios, characterized in that: include A fine water mist spray head (7), wherein the fine water mist spray head (7) is arranged above the hydrogenation station, and the fine water mist spray head (7) sprays water downward; A gas spray head (15), the gas spray head (15) is arranged in the hydrogen filling station, the gas spray head (15) is located below the fine water mist spray head (7), and the nozzle direction of the gas spray head (15) is arranged toward the fine water mist spray head (7); A gas storage tank (11), the gas storage tank (11) is used to store inert gas, and the gas storage tank (11) is connected to the gas nozzle (15) via a gas delivery pipe (14); A supply system is provided, wherein the supply system is used to supply cold water to the fine water mist spray head (7) for heating the gas in the gas transmission pipe (14).

2. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 1 is characterized in that: A plurality of the gas spray heads (15) are provided, and the plurality of the gas spray heads (15) are arranged in a matrix and are staggered with the fine water mist spray heads (7) located above the hydrogen filling station.

3. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 2 is characterized in that: The air spray head (15) and the water mist spray head (7) are arranged in parallel and in a staggered row.

4. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 2, characterized in that: The air spray head (15) and the water mist spray head (7) are arranged in an arc-shaped cross row.

5. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 1, characterized in that: The supply system includes A hot water tank (4), the hot water tank (4) being connected to a water outlet pipe (8), the water outlet pipe (8) being used to heat the gas in the gas transmission pipe (14); A solar water heater (1), wherein the solar water heater (1) is connected to a hot water tank (4).

6. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 5, characterized in that: The hot water tank (4) is also connected to a return pipe (9), a heat exchanger (10) is connected between the water outlet pipe (8) and the return pipe (9), and the heat exchanger (10) is connected to a gas transmission pipe (14).

7. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 6, characterized in that: Also includes a monitoring system, the monitoring system includes an alarm (22), and A hydrogen sensor (21), wherein the hydrogen sensor (21) is arranged on a body of the hydrogen filling station; A control cabinet (23) is connected to the hydrogen sensor (21) and the alarm (22), and the control cabinet (23) is capable of controlling the water spraying of the water mist spray head (7), the air jetting of the air spray head (15), and the water circulation in the heat exchanger (10).

8. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 7, characterized in that: A gas flow controller (12) is provided on the gas delivery pipe (14), and the gas flow controller (12) is connected to a control cabinet (23).

9. The water mist and heated inert gas combined fire fighting system for hydrogen leakage scenarios according to claim 8, characterized in that: The gas flow controller (12) adjusts the inert gas output in real time according to the hydrogen concentration monitored by the hydrogen sensor (21). The calculation formula of the inert gas output is as follows: In the formula, Q fuel is the hydrogen leakage rate (m 3 / s); C target is the target safe concentration of hydrogen (volume fraction); C measured k is the hydrogen concentration (volume fraction) detected in real time by the hydrogen sensor (21); air is the natural dilution factor of air, ranging from 0 to 1. The closer the value is to 1, the better the dilution effect of air on hydrogen. η is the mixing efficiency of inert gas and hydrogen, ranging from 0 to 1; S is the safety factor; Constant is a constant.

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