Non-pressure-stored liquid nitrogen self-sustaining fire extinguishing device and method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA UNIV OF MINING & TECH
- Filing Date
- 2024-03-06
- Publication Date
- 2026-07-21
AI Technical Summary
Existing liquid nitrogen fire extinguishing devices suffer from problems such as high liquid nitrogen dissipation rate, inability to achieve automated rapid response spraying, and the need for periodic refilling, which limit their application in thermal runaway fires in lithium-ion energy storage power plants.
A non-pressurized liquid nitrogen self-sustaining fire extinguishing device was designed. It adopts a double-layered insulated storage tank and a self-sustaining pre-action vaporization chamber. Combined with a linkage triggering mechanism, it achieves efficient pressurization of liquid nitrogen through the pre-action pressurization pipeline and vaporization chamber, preventing liquid nitrogen dissipation and realizing rapid spraying.
It effectively prevents liquid nitrogen dissipation, achieves efficient utilization and rapid response of liquid nitrogen, improves fire extinguishing performance and system adaptability, reduces liquid nitrogen waste, and is suitable for flexible application in various scenarios.
Smart Images
Figure CN118370948B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fire-fighting equipment technology, and in particular to a non-pressurized liquid nitrogen self-sustaining fire extinguishing device and method. Background Technology
[0002] With the explosive growth of the new energy vehicle industry, lithium-ion energy storage power stations are also developing rapidly, and their potential fire risks should not be underestimated. Currently, most fire extinguishing agents or devices for lithium-ion battery thermal runaway fires use environmentally unfriendly extinguishing agents such as perfluorohexanone and heptafluoropropane. Liquid nitrogen, as a fire extinguishing agent with high extinguishing efficiency and low cost, has the potential to be used as the mainstream fire extinguishing agent for thermal runaway fires in lithium-ion energy storage power stations.
[0003] However, there are currently no liquid nitrogen fire extinguishing devices on the market specifically designed for thermal runaway fires in lithium-ion energy storage power plants. Most existing liquid nitrogen fire extinguishing devices use self-pressurized liquid nitrogen tanks to spray liquid nitrogen into the required area, which cannot achieve automation or rapid response to the need for liquid nitrogen fire extinguishing. In addition, liquid nitrogen itself has the disadvantage of a high daily dissipation rate. Without special insulation design or structural considerations, complex additional filling or depressurization operations are required for the liquid nitrogen storage device periodically, which limits the application prospects of liquid nitrogen fire extinguishing devices in fire fighting. Summary of the Invention
[0004] The technical problem solved by this invention: Addressing the issues existing in the storage or use of liquid nitrogen fire extinguishers in the prior art, this invention provides a non-pressurized liquid nitrogen self-sustaining fire extinguishing device and method. It innovatively designs the tank structure and liquid nitrogen injection system of the fire extinguishing device, employing an innovative linkage triggering mechanism to effectively prevent daily dissipation of liquid nitrogen during storage and achieve the collection and reuse of dissipated liquid nitrogen. By introducing a self-sustaining pre-action vaporization chamber and a pre-action pressurization pipeline, a portion of the liquid nitrogen vapor is cleverly combined with the vaporization chamber pressurization system, enabling rapid pressurization of the liquid nitrogen storage cavity and ensuring smooth and efficient fire extinguishing.
[0005] Technical solution: The present invention provides a non-pressurized liquid nitrogen self-sustaining fire extinguishing device, which includes a double-layered insulated storage tank. The inner layer of the double-layered insulated storage tank is a liquid nitrogen storage cavity made of a low-temperature resistant alloy material. The outer metal shell of the double-layered insulated storage tank and the liquid nitrogen storage cavity form a vacuum-sealed insulated interlayer. The double-layered insulated storage tank is provided with a low-temperature resistant liquid nitrogen injection pipeline extending from the bottom of its liquid nitrogen storage cavity to the top outer side. The liquid nitrogen injection pipeline is located on the outside of the double-layered insulated storage tank and is detachably connected to a linkage adjustment device and a nozzle. The top of the double-layer insulated storage tank is divided into a self-sustaining pre-action vaporization chamber by a partition dome plate corresponding to the liquid nitrogen storage cavity. The self-sustaining pre-action vaporization chamber is connected to the liquid nitrogen storage cavity through at least one set of condenser throttle, gas phase check pipe, and liquid phase check pipe. The gas phase check pipe is connected to a second gas phase check valve, and the liquid phase check pipe is connected to a liquid phase check valve. The self-sustaining pre-action vaporization chamber is provided with pre-action pressurization pipelines at the bottom of both sides of the partition dome plate, which are connected to the inner wall of the insulation jacket of the storage tank. The pre-action pressurization pipelines are respectively connected to the two-phase flow pre-action valves that control the one-way screening between the gas and liquid phases. Upon receiving an action trigger signal, the liquid phase check valve in the two-phase flow pre-action valve of the self-sustaining pre-action vaporization chamber opens to connect the pre-action pressurization pipeline with the self-sustaining pre-action vaporization chamber. Liquid nitrogen enters the pre-action pressurization pipeline and vaporizes through heat exchange in contact with the insulation jacket of the storage tank. Then, the gas phase check valve in the two-phase flow pre-action valve opens, and the vaporized nitrogen flows into the self-sustaining pre-action vaporization chamber, pushing and driving the liquid nitrogen from the first gas phase check valve into the liquid nitrogen storage cavity to pressurize and drive the liquid nitrogen to be sprayed out along the liquid nitrogen injection pipeline.
[0006] Preferably, the insulation interlayer of the storage tank is filled with an MLI insulation layer, and the MLI insulation layer forms a tiny gap between the insulation interlayer of the storage tank and the tank wall. The MLI insulation layer consists of a reflective film and a heat insulation layer. The reflective film is made of a lightweight metallized polyester film material with excellent heat reflection performance, and the heat insulation layer is made of a polyester fiber cloth material with low thermal conductivity and good mechanical strength.
[0007] Preferably, the MLI insulation layer is composed of 10 layers of metallized polyester film and 10 layers of polyester fiber laid alternately, the reflective film has a thickness of 12μm, the insulation layer has a thickness of 25μm, and the total thickness of the MLI insulation layer is 0.5~1.0mm.
[0008] Preferably, the upper and lower ends of the condenser are respectively connected between the liquid nitrogen storage cavity and the self-sustaining pre-action vaporization chamber, and the condenser is provided with a Venturi port in the liquid nitrogen storage cavity; The condenser is equipped with a multi-stage throttling device, and the self-sustaining pre-action vaporization chamber is filled with cryogenic liquid nitrogen for pre-action pressurization and vaporization of liquid nitrogen.
[0009] Preferably, the top of the double-layer insulated storage tank is provided with a vaporization pressure relief chamber, and a third gas phase check valve is provided between the vaporization pressure relief chamber and the self-sustaining pre-action vaporization chamber; at least one automatic pressure relief valve is provided outside the vaporization pressure relief chamber, and the automatic pressure relief valve is a self-responsive spring self-starting safety pressure regulating valve.
[0010] Preferably, the linkage adjustment device can be a hand-held trigger linkage adjustment device or an automatic linkage solenoid valve linkage adjustment device. The linkage regulating device is mechanically linked with the liquid phase check valve in the two-phase flow pre-action valve. The linkage regulating device sends an active trigger signal to the two-phase flow pre-action valve to start the pressurization process of the pre-action pressurization pipeline.
[0011] Preferably, the liquid nitrogen injection pipeline is made of a high-strength, lightweight, low-temperature resistant alloy material, and the pipeline at the injection point is provided with various alternative nozzles for different scenarios, such as soft, hard, and multi-nozzle nozzles. The nozzle is mounted at the distal end of the liquid nitrogen injection line, and the nozzle provides adjustable pressure injection or intermittent injection modes.
[0012] Preferably, the liquid phase check line is arranged at the outer edge of the partition dome plate, connecting the self-sustaining pre-action vaporization chamber and the liquid nitrogen storage cavity. The liquid phase check line flows back to the liquid nitrogen storage cavity through a one-way valve group only after receiving secondary cooling and reprocessing of liquid nitrogen from the condenser throttle.
[0013] This invention also discloses a non-pressurized liquid nitrogen self-sustaining fire extinguishing method, comprising the following steps: When the linkage control device is a handheld trigger linkage control device, after the linkage action command is actively triggered, the liquid phase check valve in the two-phase flow pre-action valve is activated. After the pre-action pressurization pipeline is triggered, the pressurization pipeline is connected. A small amount of liquid nitrogen stored in the self-sustaining pre-action vaporization chamber enters the pre-action pressurization pipeline to realize the vaporization of liquid nitrogen inside the self-sustaining pre-action vaporization chamber. The self-sustaining pre-action vaporization chamber is rapidly pressurized to realize the pressurization of liquid nitrogen in the non-pressurized liquid nitrogen storage chamber by vaporizing liquid nitrogen. The pressurized liquid nitrogen is then injected through the liquid nitrogen injection pipeline and nozzle to achieve low-delay response liquid nitrogen fire extinguishing. Alternatively, when the linkage control device is an automatic linkage control device with solenoid valves, after a multi-functional sensor in the solenoid valve linkage valve group detects an action signal, it sends a control signal to the two-phase flow pre-action valve in the control circuit and starts it. After the pre-action pressurization pipeline is triggered, the pressurization pipeline is connected. A small amount of liquid nitrogen stored in the self-sustaining pre-action vaporization chamber enters the pre-action pressurization pipeline to realize the vaporization of liquid nitrogen inside the self-sustaining pre-action vaporization chamber. The self-sustaining pre-action vaporization chamber is rapidly pressurized to achieve the pressurization of liquid nitrogen in the non-pressurized liquid nitrogen storage chamber by vaporizing liquid nitrogen. The pressurized liquid nitrogen is then sprayed through the liquid nitrogen injection pipeline and nozzle in a continuous or intermittent point injection manner to achieve low-delay response liquid nitrogen spray fire extinguishing.
[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The fire extinguishing device of the present invention features an innovative design for the tank structure and liquid nitrogen injection system. It adopts an innovative linkage triggering mechanism to effectively prevent the daily dissipation and waste of liquid nitrogen during storage, and realizes the collection and reuse of dissipated liquid nitrogen. This not only improves the fire extinguishing performance, but also minimizes the waste of liquid nitrogen while maintaining a stable injection pressure. As a result, it achieves efficient liquid nitrogen utilization in actual use, and realizes extremely low daily loss rate and long-term high-quality storage. 2. This fire extinguishing device adopts a unique linkage triggering mechanism, introducing a self-sustaining pre-action vaporization chamber and a pre-action pressurization pipeline. It cleverly combines a portion of the liquid nitrogen vapor with the vaporization chamber pressurization system, which can quickly pressurize the liquid nitrogen in the liquid nitrogen storage chamber, ensuring that the liquid nitrogen can be sprayed smoothly and efficiently for fire extinguishing. This not only improves the system's adaptability, but also maximizes the utilization of the energy dissipated by the liquid nitrogen in daily use, further realizing rapid triggering response to spray liquid nitrogen and achieving high-efficiency liquid nitrogen fire extinguishing. 3. This fire extinguishing device optimizes the liquid nitrogen injection pipeline and nozzle structure, providing a detachable modular design. A variety of selectable detachable linkage adjustment devices and detachable nozzles can be assembled and adjusted according to the user's specific application scenario, ensuring that the liquid nitrogen injection pipeline maintains flexibility in ultra-low temperature environments. The special material of MLI insulation layer is introduced to adapt to the extremely low temperature of liquid nitrogen, which not only ensures the reliability of the injection pipeline in extreme environments, but also improves the efficiency and stability of the injection system. 4. This fire extinguishing device ensures rapid response and efficient operation of the liquid nitrogen injection system through a linkage triggering mechanism and intelligent pressure regulation. It can achieve continuous liquid nitrogen injection or intermittent point injection, and is more stable, safe and reliable, and flexible in operation during use. 5. This fire extinguishing device adopts a modular design, which can be flexibly adjusted and expanded according to the configuration of liquid nitrogen tanks of different capacities and uses. It is suitable for various scenarios and meets the needs of everything from small equipment to large industrial systems, achieving a highly efficient liquid nitrogen fire extinguishing effect. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the non-pressurized liquid nitrogen self-sustaining fire extinguishing device of the present invention; Figure 2 for Figure 1 Schematic diagram of the structure of the central condenser throttling device; Figure 3 for Figure 1 Schematic diagram of the liquid phase check valve and gas phase check valve in a two-phase flow pre-action valve; Figure 4 for Figure 1 Schematic diagram of the second gas phase check valve.
[0016] Reference numerals: 100, Fire extinguishing device; 1, Double-layered insulated storage tank; 2, Insulation jacket of the storage tank; 3, Liquid nitrogen storage cavity; 4, Liquid nitrogen; 5, Liquid nitrogen injection pipeline; 6, Pre-action pressurization pipeline; 7, Two-phase flow pre-action valve; 71, Liquid phase check valve; 72, First gas phase check valve; 8, Condensation throttle; 81, Venturi port; 9, Self-sustaining pre-action vaporization chamber; 10, Second gas phase check valve; 11, Vaporization pressure relief chamber; 12, Automatic pressure relief valve; 13, Linkage adjustment device; 14, Nozzle; 15, Third gas phase check valve; 16, Gas phase check pipeline; 17, Liquid phase check pipeline; 18, Separating dome plate; 19, Cryogenic liquid nitrogen. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be combined with Figures 1-4 The technical solutions of the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.
[0018] Example 1: As Figure 1In the illustrated embodiment, the present invention discloses a non-pressurized liquid nitrogen self-sustaining fire extinguishing device. The fire extinguishing device 100 includes a double-layered insulated storage tank 1, a liquid nitrogen injection pipeline 5, a pre-action pressurization pipeline 6, a two-phase flow pre-action valve 7, a condensation throttling device 8, a self-sustaining pre-action vaporization chamber 9, a vaporization pressure relief chamber 11, an automatic pressure relief valve 12, a linkage adjustment device 13, a nozzle 14, a gas phase check valve pipeline 16, and a liquid phase check valve pipeline 17. The inner layer of the double-layered insulated storage tank 1 is a liquid nitrogen storage cavity 3 made of a low-temperature alloy material. The outer metal shell of the double-layered insulated storage tank 1 and the liquid nitrogen storage cavity 3 form a vacuum-sealed storage tank insulation interlayer 2. The storage tank insulation interlayer 2 is filled with an MLI insulation layer, which consists of a reflective film and a heat insulation layer. The reflective film is made of a lightweight metallized polyester film material with excellent heat reflectivity, and the heat insulation layer is made of a polyester fiber cloth material with low thermal conductivity and good mechanical strength. The MLI insulation layer consists of 10 layers of metallized polyester film and 10 layers of polyester fiber, laid alternately. The reflective film is 12μm thick, and the insulation layer is 25μm thick. The total thickness of the MLI insulation layer is controlled between 0.5 and 1.0 mm to maintain good insulation performance while reducing its weight. During pretreatment, the MLI material is pretreated in a vacuum environment before assembly to remove air and moisture, optimize insulation performance, and then the MLI material is layered, with the reflective film and insulation layer alternately placed, and fixed with special tape or a lightweight frame to avoid direct contact between layers. A small gap is formed between the MLI insulation layer and the tank wall within the insulation jacket 2 of the storage tank to reduce thermal bridging. Sufficient safety space is also provided for pipelines and valve assemblies to ensure that the MLI insulation layer does not obstruct functions while meeting maximum insulation performance requirements.
[0019] like Figure 1 In the illustrated embodiment, a cryogenic liquid nitrogen injection pipeline 5 is installed on the outer side of the double-walled insulated storage tank 1, extending from the bottom to the top of its liquid nitrogen storage cavity 3. The liquid nitrogen injection pipeline 5 is made of a high-strength, lightweight, cryogenic alloy material, and various optional nozzles, such as soft, hard, and multi-nozzle nozzles, are provided at the injection point. A linkage adjustment device 13 and a nozzle 14 are detachably connected sequentially to the outer side of the double-walled insulated storage tank 1. The linkage adjustment device 13 can be a handheld trigger linkage adjustment device or an automatic linkage solenoid valve linkage adjustment device. The linkage adjustment device 13 is mechanically linked to the liquid phase check valve 71 in the two-phase flow pre-action valve. The linkage adjustment device 13 sends an active trigger signal to the two-phase flow pre-action valve 7 to initiate the pressurization process of the pre-action pressurization pipeline 6. The nozzle 14 is mounted at the distal end of the liquid nitrogen injection pipeline 5 and provides adjustable pressure injection or intermittent injection modes.
[0020] like Figures 1-4In the illustrated embodiment, the top of the double-layered insulated storage tank 1 is divided into a self-sustaining pre-acting vaporization chamber 9 by a partition dome plate 18 corresponding to the liquid nitrogen storage cavity 3. The partition dome plate 18 has an upward convex structure in the middle, forming a dome structure. The self-sustaining pre-acting vaporization chamber 9 is connected to the liquid nitrogen storage cavity 3 through at least one set of condenser throttles 8, a gas phase check valve 16, and a liquid phase check valve 17. The gas phase check valve 16 is connected to a second gas phase check valve 10, and the liquid phase check valve 17 is connected to a liquid phase check valve (not shown in the figure). Specifically, the condenser throttles 8, the gas phase check valve 16, and the liquid phase check valve 17 each include two sets symmetrically arranged along the liquid nitrogen injection pipeline 5. The liquid phase check valve 17 is arranged in the partition... The outer edge of the dome plate 18 connects the self-sustaining pre-acting vaporization chamber 9 and the liquid nitrogen storage cavity 3. The liquid phase check pipe 17 returns to the liquid nitrogen storage cavity 3 through the one-way valve group only after receiving secondary cooling and reprocessing of liquid nitrogen from the condenser throttle 8. The gas phase check pipe 16 is located near the center of the partition dome plate 18 and connects the self-sustaining pre-acting vaporization chamber 9 and the liquid nitrogen storage cavity 3. When the self-sustaining pre-acting vaporization chamber 9 is triggered to pressurize, a large amount of nitrogen in the self-sustaining pre-acting vaporization chamber flows in from the second gas phase check valve 10 and is continuously driven, so that the vaporized nitrogen quickly enters the liquid nitrogen storage cavity 3 to further pressurize the liquid nitrogen, so that the liquid nitrogen enters the liquid nitrogen injection pipe 5 to achieve vaporization and pressurization injection.
[0021] The self-sustaining pre-acting vaporization chamber 9 has pre-acting pressurization pipelines 6 connected to the inner wall of the insulation jacket 2 of the storage tank at the bottom ends of both sides of the partition dome plate 18. The pre-acting pressurization pipelines 6 are respectively connected to two-phase flow pre-acting valves 7 that control the one-way screening between the gas and liquid phases. A small amount of liquid nitrogen is stored at the bottom ends of both sides of the partition dome plate 18 corresponding to the two-phase flow pre-acting valves 7. After receiving the action trigger signal, the liquid phase check valve 71 in the two-phase flow pre-acting valve 7 opens to connect the pre-acting pressurization pipeline 6 and the self-sustaining pre-acting vaporization chamber 9. Liquid nitrogen 4 enters the pre-acting pressurization pipeline 6 and contacts the insulation jacket 2 of the storage tank for heat exchange and vaporization. Then, the gas phase check valve in the two-phase flow pre-acting valve 7 opens. After vaporization, nitrogen flows into the self-sustaining pre-acting vaporization chamber 9 and pushes the liquid nitrogen from the first gas phase check valve 72 into the liquid nitrogen storage cavity 3 for pressurization and drive the liquid nitrogen to be sprayed out along the liquid nitrogen injection pipeline 5.
[0022] like Figures 1-2In the illustrated embodiment, the upper and lower ends of the condenser throttle 8 are respectively connected between the liquid nitrogen storage cavity 3 and the self-sustaining pre-action vaporization chamber 9. The condenser throttle 8 is provided with a Venturi port 81 in the liquid nitrogen storage cavity 3. The Venturi port 81 has adsorption characteristics based on the Venturi effect, and the liquid nitrogen vapor that may be dissipated daily in the liquid nitrogen storage cavity can be adsorbed by the condenser throttle 8 and enter its interior. The condenser throttle 8 is provided with a multi-stage throttling device to further achieve secondary cooling and reprocessing of the captured liquid nitrogen vapor and vaporized liquid nitrogen back into liquid nitrogen. The self-sustaining pre-acting vaporization chamber 9 is filled with cryogenic liquid nitrogen 19 for pre-acting pressurization and reprocessing of vaporized liquid nitrogen in the partition dome plate 18. The secondary cooling mechanism of the condenser throttle is based on the cryogenic environment provided by the cryogenic liquid nitrogen for pre-acting pressurization pre-placed at the bottom left and right sides of the self-sustaining pre-acting vaporization chamber 9, plus the multi-stage throttling cooling device provided by the condenser throttle 8, so as to achieve secondary cooling and reprocessing of daily dissipated liquid nitrogen vapor and vaporized liquid nitrogen, so as to achieve an acceptable ultra-low daily liquid nitrogen loss. The reprocessed liquid nitrogen flows into the liquid nitrogen storage cavity 3 for storage through the liquid phase check pipe 17.
[0023] like Figure 1 In the illustrated embodiment, a vaporization pressure relief chamber 11 is provided at the top of the double-layer insulated storage tank 1. A third gas phase check valve 15 is provided between the vaporization pressure relief chamber 11 and the self-sustaining pre-action vaporization chamber 9. At least one automatic pressure relief valve 12 is provided on the outside of the vaporization pressure relief chamber 11. The automatic pressure relief valve 12 is a self-responsive spring self-starting safety pressure regulating valve. The vaporization pressure relief chamber 11 is activated only when vaporizing and depressurizing liquid nitrogen vapor or vaporized liquid nitrogen that has failed to be successfully re-cooled and regenerated by the condenser throttle 8. It works in cooperation with the automatic pressure relief valve 12 to automatically remove abnormal pressure and ensure safe storage in non-triggered states.
[0024] In Example 1, as Figures 3-4 As shown, the two-phase flow pre-acting valve 7 includes a liquid phase check valve 71 and a first gas phase check valve 72. The valve assembly of this two-phase flow pre-acting valve 7 can control the flow or blockage of corresponding fluids according to working requirements. For example, the liquid phase check valve 71 only allows liquid fluids such as liquid nitrogen to pass through and achieve pressurization, while gaseous fluids are screened out and will not pass through it. The valve assembly material of the liquid phase check valve 71 is made of temperature-sensitive memory material. Due to the low temperature characteristics of liquid nitrogen, the temperature-sensitive material will expand and open, causing liquid nitrogen to enter the liquid phase check valve 71 and then enter the pre-acting pressurization pipeline 6. The first gas phase check valve 72, on the other hand, allows gaseous gases such as nitrogen to pass through and is a pressure-responsive check valve. Due to the expansion characteristics of nitrogen, the pressurized vaporized liquid nitrogen or nitrogen gas will continuously flow into the first gas phase check valve 72, allowing liquid nitrogen vapor or nitrogen gas to smoothly enter the self-sustaining pre-acting vaporization chamber 9 to complete the entire pressurization process. The second gas phase check valve 10 and the third gas phase check valve 15 adopt the same structure as the first gas phase check valve 72 to realize the gaseous fluid control function.
[0025] Example 2: Based on Example 1, the present invention also discloses a non-pressurized liquid nitrogen self-sustaining fire extinguishing method. When the linkage adjustment device 13 is a handheld trigger linkage adjustment device, after actively triggering the linkage action command, the liquid phase check valve 71 in the two-phase flow pre-action valve 7 is activated. After the pre-action pressurization pipeline 6 is triggered, the pressurization pipeline is connected. A small amount of liquid nitrogen stored in the self-sustaining pre-action vaporization chamber 9 enters the pre-action pressurization pipeline 6 to realize the vaporization of liquid nitrogen inside the self-sustaining pre-action vaporization chamber 9. The self-sustaining pre-action vaporization chamber 9 is rapidly pressurized to realize the pressurization of liquid nitrogen in the non-pressurized liquid nitrogen storage cavity 3 by vaporizing liquid nitrogen. The pressurized liquid nitrogen is injected through the liquid nitrogen injection pipeline 5 and the nozzle 14 to realize the low-delay response injection fire extinguishing of liquid nitrogen.
[0026] Example 3: Based on Example 1, the present invention also discloses a non-pressurized liquid nitrogen self-sustaining fire extinguishing method. When the linkage adjustment device is an automatic linkage adjustment device of solenoid valve, after a certain multi-in-one detection sensor in the solenoid valve linkage valve group detects the action signal, it sends a control signal to the two-phase flow pre-action valve 7 in the control circuit and starts it. After the pre-action pressurization pipeline 6 is triggered, the pressurization pipeline is connected. A small amount of liquid nitrogen stored in the self-sustaining pre-action vaporization chamber 9 enters the pre-action pressurization pipeline 6 to realize the vaporization of liquid nitrogen inside the self-sustaining pre-action vaporization chamber 9. The self-sustaining pre-action vaporization chamber 9 is rapidly pressurized to realize the pressurization of liquid nitrogen in the non-pressurized liquid nitrogen storage cavity 3 by vaporizing liquid nitrogen. The pressurized liquid nitrogen is injected through the liquid nitrogen injection pipeline 5 and the nozzle 14 to realize the low-delay response injection fire extinguishing of liquid nitrogen through continuous injection or intermittent point injection.
[0027] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A non-pressurized liquid nitrogen self-sustaining fire extinguishing device, characterized in that, The fire extinguishing device (100) includes a double-layer insulated storage tank (1), the inner layer of which is a liquid nitrogen storage cavity (3) made of alloy low temperature resistant material, and the outer metal shell of the double-layer insulated storage tank (1) and the liquid nitrogen storage cavity (3) form a vacuum-sealed storage tank insulation interlayer (2). The double-layer insulated storage tank (1) is provided with a low-temperature resistant liquid nitrogen injection pipeline (5) extending from the bottom of its liquid nitrogen storage cavity (3) to the top outside. The liquid nitrogen injection pipeline (5) is located on the outside of the double-layer insulated storage tank (1) and is detachably connected to a linkage adjustment device (13) and a nozzle (14). The top of the double-layer insulated storage tank (1) is separated from the liquid nitrogen storage cavity (3) by a partition dome plate (18) to form a self-sustaining pre-action vaporization chamber (9). The self-sustaining pre-action vaporization chamber (9) is connected to the liquid nitrogen storage cavity (3) through at least one set of condenser throttles (8), a gas phase check valve (16), and a liquid phase check valve (17). The gas phase check valve (16) is connected to a second gas phase check valve (10), and the liquid phase check valve (17) is connected to a liquid nitrogen storage cavity (3). A check valve; wherein, the upper and lower ends of the condenser (8) are respectively connected between the liquid nitrogen storage cavity (3) and the self-sustaining pre-action vaporization chamber (9), and the condenser (8) is provided with a Venturi port (81) in the liquid nitrogen storage cavity (3); the condenser (8) is provided with a multi-stage throttling device inside, and the self-sustaining pre-action vaporization chamber (9) is filled with cryogenic liquid nitrogen for pre-action pressurization and vaporization liquid nitrogen reprocessing in the partition dome plate (18); The self-sustaining pre-action gasification chamber (9) is provided with pre-action pressurization pipelines (6) that are connected to the inner wall of the insulation jacket (2) of the storage tank at the bottom of both sides of the partition dome plate (18). The pre-action pressurization pipelines (6) are respectively connected to the two-phase flow pre-action valves (7) that control the one-way screening between the gas and liquid phases. When the self-sustaining pre-acting vaporization chamber (9) receives the action trigger signal, the liquid phase check valve (71) in the two-phase flow pre-acting valve (7) opens to connect the pre-acting pressurization pipeline (6) and the self-sustaining pre-acting vaporization chamber (9). Liquid nitrogen (4) enters the pre-acting pressurization pipeline (6) and contacts the insulation jacket (2) of the storage tank for heat exchange and vaporization. Then, the gas phase check valve in the two-phase flow pre-acting valve (7) is opened. After vaporization, nitrogen flows into the self-sustaining pre-acting vaporization chamber (9) and pushes the liquid nitrogen from the first gas phase check valve (72) into the liquid nitrogen storage cavity (3) to pressurize and drive the liquid nitrogen to be sprayed out along the liquid nitrogen injection pipeline (5).
2. The non-pressurized liquid nitrogen self-sustaining fire extinguishing device according to claim 1, characterized in that, The storage tank insulation interlayer (2) is filled with an MLI insulation layer, and the MLI insulation layer forms a tiny gap between the storage tank insulation interlayer (2) and the tank wall. The MLI insulation layer consists of a reflective film and a heat insulation layer. The reflective film is made of a lightweight metallized polyester film material with excellent heat reflection performance, and the heat insulation layer is made of a polyester fiber cloth material with low thermal conductivity and good mechanical strength.
3. The non-pressurized liquid nitrogen self-sustaining fire extinguishing device according to claim 2, characterized in that, The MLI insulation layer is composed of 10 layers of metallized polyester film and 10 layers of polyester fiber laid alternately. The thickness of the reflective film is 12μm, the thickness of the insulation layer is 25μm, and the total thickness of the MLI insulation layer is 0.5~1.0mm.
4. The non-pressurized liquid nitrogen self-sustaining fire extinguishing device according to claim 1, characterized in that, The top of the double-layer insulated storage tank (1) is provided with a vaporization pressure relief chamber (11), and a third gas phase check valve (15) is provided between the vaporization pressure relief chamber (11) and the self-sustaining pre-action vaporization chamber (9); at least one automatic pressure relief valve (12) with automatic safety pressure relief is provided outside the vaporization pressure relief chamber (11), and the automatic pressure relief valve (12) is a self-responsive spring self-starting safety pressure regulating valve.
5. The non-pressurized liquid nitrogen self-sustaining fire extinguishing device according to claim 1, characterized in that, The linkage adjustment device (13) can be a hand-held trigger linkage adjustment device or an automatic linkage solenoid valve linkage adjustment device. The linkage regulating device (13) is mechanically linked with the liquid phase check valve (71) in the two-phase flow pre-acting valve. The linkage regulating device (13) sends an active trigger signal to the two-phase flow pre-acting valve (7) to start the pressurization process of the pre-acting pressurization pipeline (6).
6. The non-pressurized liquid nitrogen self-sustaining fire extinguishing device according to claim 5, characterized in that, The liquid nitrogen injection pipeline (5) is made of high-strength, lightweight alloy low-temperature resistant material, and the pipeline at the injection point is provided with a variety of alternatives such as soft, hard, and multi-nozzle nozzles. The nozzle (14) is mounted at the far end of the liquid nitrogen injection line (5), and the nozzle (14) provides adjustable pressure injection or intermittent injection modes.
7. The non-pressurized liquid nitrogen self-sustaining fire extinguishing device according to claim 1, characterized in that, The liquid phase check line (17) is arranged on the outer edge of the partition dome plate (18) and connects the self-sustaining pre-action vaporization chamber (9) and the liquid nitrogen storage cavity (3). The liquid phase check line (17) flows back to the liquid nitrogen storage cavity (3) through a one-way valve group only after receiving secondary cooling and reprocessing of liquid nitrogen from the condenser throttle (8).
8. A non-pressurized liquid nitrogen self-sustaining fire extinguishing method, characterized in that, The non-pressurized liquid nitrogen self-sustaining fire extinguishing device as described in any one of claims 1 to 7 includes the following steps: When the linkage adjustment device (13) is a hand-held trigger linkage adjustment device, after the linkage action command is actively triggered, the liquid phase check valve (71) in the two-phase flow pre-action valve (7) is activated. After the pre-action pressurization pipeline (6) is triggered, the pressurization pipeline is connected. A small amount of liquid nitrogen stored in the self-sustaining pre-action vaporization chamber (9) enters the pre-action pressurization pipeline (6) to realize the vaporization of liquid nitrogen inside the self-sustaining pre-action vaporization chamber (9). The self-sustaining pre-action vaporization chamber (9) is rapidly pressurized to realize the pressurization of liquid nitrogen in the non-pressurized liquid nitrogen storage cavity (3) by vaporizing liquid nitrogen. The pressurized liquid nitrogen is then injected through the liquid nitrogen injection pipeline (5) and the nozzle (14) to achieve low-delay response liquid nitrogen injection fire extinguishing. Or when the linkage adjustment device is an automatic linkage adjustment device of solenoid valve, after a certain multi-in-one detection sensor in the solenoid valve linkage valve group detects the action signal, it sends a control signal to the two-phase flow pre-action valve (7) in the control circuit and starts it. After the pre-action pressurization pipeline (6) is triggered, the pressurization pipeline is connected. A small amount of liquid nitrogen stored in the self-sustaining pre-action vaporization chamber (9) enters the pre-action pressurization pipeline (6) to realize the vaporization of liquid nitrogen inside the self-sustaining pre-action vaporization chamber (9). The self-sustaining pre-action vaporization chamber (9) is rapidly pressurized to realize the pressurization of liquid nitrogen in the non-pressurized liquid nitrogen storage cavity (3) by vaporizing liquid nitrogen. After pressurization, the liquid nitrogen is injected through the liquid nitrogen injection pipeline (5) and the nozzle (14) to realize the liquid nitrogen low-delay response injection fire extinguishing in the form of continuous injection or intermittent point injection.