Fire extinguishing device and method for an immersion liquid-cooled cabinet

Abstract

The application relates to the technical field of fire extinguishing, in particular to a submerged liquid cooling cabinet fire extinguishing device and method, which comprises a submerged liquid cooling cabinet, a pre-stored pressure fire extinguishing bottle, a tree-shaped fractal distribution pipeline, a jet port and a trigger valve opening device, the pre-stored pressure fire extinguishing bottle is arranged on the top or outside of the submerged liquid cooling cabinet; the tree-shaped fractal distribution pipeline is arranged on the inner top of the submerged liquid cooling cabinet, the tree-shaped fractal distribution pipeline comprises a main pipeline and a plurality of levels of branch pipelines which are communicated with the main pipeline, the input end of the main pipeline is connected with the output end of the pre-stored pressure fire extinguishing bottle; a plurality of jet ports are arranged at the ends of the last level of branch pipelines in the tree-shaped fractal distribution pipeline, the trigger valve opening device is connected with a bottle head valve on the pre-stored pressure fire extinguishing bottle and is used for opening the bottle head valve when a fire is detected, the submerged liquid cooling cabinet fire extinguishing device and method provided by the application have the advantages of simple structure, high reliability, fast response, uniform coverage, easy installation and maintenance and the like.

Description

Technical Field

[0001] This invention relates to the field of fire extinguishing technology, and in particular to a fire extinguishing device and method for an immersion liquid-cooled cabinet. Background Technology

[0002] In recent years, with the continuous increase in power density per rack in data centers, immersion liquid cooling technology is being adopted by more and more data centers due to its advantages such as high heat dissipation efficiency and low operating noise. Among them, single-phase immersion liquid cooling systems are the most widely used in practical engineering because of their relatively low coolant price, simple system design, and convenient maintenance.

[0003] Single-phase immersion liquid cooling systems typically use mineral oil, hydrofluoric acid compounds, or perfluorinated compounds as coolants. While these coolants possess good insulation and thermal conductivity, most are flammable or easily decompose at high temperatures. As system loads increase, the coolant operates at high temperatures for extended periods. Leaks, electrical faults, or localized overheating can easily ignite fires, resulting in high-temperature oil fires or even flowing fires. Due to the confined space and densely packed equipment within the server rack, and the fact that the coolant itself is flammable, extinguishing a fire is extremely difficult.

[0004] Several fire extinguishing technologies exist for immersion liquid cooling systems. For example, Chinese patent CN120771488A proposes a fire extinguishing mechanism that uses a circulating pump to pressurize the extinguishing mixture before spraying it through a sprinkler pipe, while simultaneously embedding extinguishing microcapsules in the extinguishing lining to achieve dual fire extinguishing. However, this solution has several significant shortcomings: First, the system structure is relatively complex. This solution requires a storage tank, circulating pump, inlet and outlet water pipes, spray pipes, and auxiliary components such as multiple solenoid valves, vortex flow meters, and level sensors. This not only increases equipment costs but also introduces numerous potential points of failure, thus limiting long-term operational reliability. In particular, precision components such as vortex flow meters and solenoid valves may become stuck or fail during prolonged periods of inactivity.

[0005] Secondly, the method of embedding fire-extinguishing microcapsules inside the fire-extinguishing liner presents a response delay problem. The fire-extinguishing liner itself is a protective structure; after a fire occurs, the liner must first be burned through or damaged before the microcapsules can be exposed to participate in fire extinguishing. In other words, there is a time lag between the ignition of the fire and the microcapsules actually starting to function. For locations like data centers with extremely high security requirements, this delay may lead to the fire spreading.

[0006] Third, the sprinkler system in this scheme uses liquid extinguishing agent injection. The penetration ability and coverage uniformity of the liquid jet are limited by the layout and number of nozzles. When the internal space of the cabinet is large or the equipment layout is complex, blind spots that cannot be covered by the extinguishing agent may easily appear. Summary of the Invention

[0007] The purpose of this invention is to provide a fire extinguishing device and method for immersion liquid-cooled cabinets that is simple in structure, highly reliable, fast in response, uniform in coverage, and easy to install and maintain, so as to solve the technical problems of existing immersion liquid-cooled cabinet fire extinguishing schemes in the background art, such as complex structure, slow response speed, and insufficient coverage uniformity.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: A fire extinguishing device for an immersion liquid-cooled cabinet includes: an immersion liquid-cooled cabinet, a pre-pressurized fire extinguishing bottle, a tree-shaped fractal distribution pipe, nozzles, and a trigger-activated valve opening device. The pre-pressurized fire extinguishing bottle stores a mixture of high-pressure extinguishing gas and extinguishing microcapsules and is located on the top or outside of the immersion liquid-cooled cabinet. The tree-shaped fractal distribution pipe is located on the inner top of the immersion liquid-cooled cabinet and includes a main pipe and several branch pipes connected to the main pipe. The input end of the main pipe is connected to the output end of the pre-pressurized fire extinguishing bottle. Several nozzles are provided, each located at the end of the last branch pipe in the tree-shaped fractal distribution pipe. The nozzles face downwards and are used to spray the mixture of high-pressure extinguishing gas and extinguishing microcapsules into the interior of the immersion liquid-cooled cabinet in the form of a gas-solid two-phase flow. The trigger-activated valve opening device is connected to the cylinder head valve on the pre-pressurized fire extinguishing bottle and is used to open the cylinder head valve when a fire is detected.

[0009] Furthermore, the trigger-type valve opening device includes: an electric starting unit, a controller, a fire detector, a mechanical starting unit, and a temperature-sensing glass bulb. The electric starting unit, controller, and fire detector are electrically connected in sequence. When the fire detector detects a fire, the controller controls the electric starting unit to open the bottle head valve. The mechanical starting unit is installed on the immersion liquid cooling cabinet. The temperature-sensing glass bulb is installed inside the immersion liquid cooling cabinet and connected to the trigger end of the mechanical starting unit. When the ambient temperature reaches a set value, the temperature-sensing glass bulb breaks and triggers the mechanical starting unit to open the bottle head valve. The bottle head valve is a handle-type ball valve.

[0010] Furthermore, the fire detector includes a temperature sensor and a smoke sensor, which are electrically connected to the controller.

[0011] Furthermore, the electric start unit includes a servo motor, a lever, and a motor mounting bracket. The servo motor is fixedly mounted on the pre-pressurized fire extinguishing bottle via the motor mounting bracket. The lever is fixedly connected to the output shaft of the servo motor. The lever cooperates with the handle on the bottle head valve. When the fire detector detects a fire, the servo motor drives the lever to rotate, thereby opening the bottle head valve by moving the handle on the bottle head valve via the lever.

[0012] Furthermore, the mechanical actuation unit includes: a vertical plate, a push rod, a lever, a hinge fulcrum, a pull wire, a fixed pulley, a spring, and a fixing frame. One end of the push rod is hinged to the handle on the bottle head valve, and the other end of the push rod is hinged to one end of the lever. The middle of the lever is connected to the hinge fulcrum, which is fixedly mounted on the vertical plate. The other end of the lever is connected to one end of the pull wire. The fixed pulley is rotatably mounted on the vertical plate, and the pull wire is connected to the fixed pulley. The other end of the pull wire slides through the top of the immersion liquid-cooled cabinet and... The lower end of a fixed connection spring is attached inside the cabinet. The spring is sleeved on a pull line and its upper end is pressed against the inner top wall of the immersion liquid cooling cabinet. The temperature-sensing glass ball is suspended and fixed on the inner top wall of the immersion liquid cooling cabinet by a fixing bracket and is pressed against the lower end of the spring. When the ambient temperature inside the immersion liquid cooling cabinet reaches the set value, the temperature-sensing glass ball breaks and is crushed by the pressure of the spring. At this time, the spring pulls the lever through the pull line, causing the lever to rotate along the hinge fulcrum and push the handle on the bottle head valve through the push rod to open the bottle head valve.

[0013] Furthermore, the high-pressure extinguishing gas is one or a mixture of any combination of nitrogen, argon, and carbon dioxide; the extinguishing microcapsule comprises: a temperature-sensitive capsule shell and a extinguishing substance core material encapsulated inside the capsule shell, the capsule shell remains intact at room temperature, and ruptures and releases the extinguishing substance core material within a temperature range of 80°C to 150°C; the extinguishing substance core material is perfluorohexanone and / or perfluorotriethylamine; the capsule shell is a temperature-sensitive polymer material that can be vaporized and decomposed at high temperatures, specifically a copolymer of polymethyl methacrylate and N,N-dimethylacrylamide.

[0014] Furthermore, the bottom of the immersion liquid cooling cabinet is provided with a slag discharge port, and the slag discharge port is provided with an openable sealing cover.

[0015] A fire extinguishing method for an immersion liquid-cooled cabinet, using the fire extinguishing device described above, includes the following steps: Step 1: Store the gas-solid mixture of fire extinguishing microcapsules and high-pressure fire extinguishing gas in a pre-pressurized fire extinguishing bottle; Step 2: When the fire detector installed inside the immersion liquid-cooled cabinet detects a fire, the trigger-type valve opening device opens the valve of the pre-pressurized fire extinguishing bottle. Step 3: The high-pressure extinguishing gas carrying the extinguishing microcapsules is ejected in the form of a gas-solid two-phase flow and enters the tree-shaped fractal distribution pipe located at the top of the inner side of the cabinet. Step 4: After the gas-solid two-phase flow is gradually divided through several branch pipes of the tree-shaped fractal distribution pipe, it is sprayed into the interior of the immersion liquid-cooled cabinet from each injection port. Under the dual action of injection power and gravity, the gas-solid two-phase flow covers the interior space of the immersion liquid-cooled cabinet from top to bottom. Step 5: After the fire extinguishing microcapsules reach the high-temperature area, they rupture and release the fire extinguishing substance, which works in conjunction with the high-pressure fire extinguishing gas to extinguish the fire.

[0016] Furthermore, in step three, the pre-pressurized fire extinguishing bottle releases the gas-solid two-phase flow in a pulse manner, with a time interval between two adjacent pulses.

[0017] Furthermore, step six is ​​included: after the fire is extinguished, open the slag discharge port located at the bottom of the submersible liquid cooling cabinet, and use inert gas to purge from the top to discharge the residue from the slag discharge port.

[0018] Compared with the prior art, the beneficial effects of the present invention are: First, the system structure of this invention is simple, omitting the circulating pump, liquid storage tank, complex spray pipe and nozzle structure, as well as a series of auxiliary monitoring components such as solenoid valve, vortex flow meter, and liquid level sensor. The number of potential system failure points is greatly reduced, and the manufacturing and maintenance costs are significantly reduced.

[0019] Second, the pre-pressurized fire extinguishing bottle in this invention is always in a standby state and releases immediately upon triggering. The fire extinguishing microcapsules are directly sprayed into the fire scene with the airflow, and rupture instantly at high temperatures to release the fire extinguishing substance, eliminating the time delay of first damaging the inner lining and then releasing it. This can prevent the fire from spreading due to time delays, thus avoiding significant economic and data security losses.

[0020] Third, this invention achieves uniform distribution of gas-solid two-phase flow on the top plane of the immersion liquid-cooled cabinet through the tree-like fractal distribution pipe configuration. The multiple distribution of injection nozzles, combined with the vertical settling effect of gravity, effectively covers all areas inside the cabinet, reducing blind spots and improving fire suppression coverage. The gas-solid two-phase flow possesses both gas-phase asphyxiation and solid-phase chemical extinguishing mechanisms; their synergistic effect is more effective than a single extinguishing method, thus improving fire suppression efficiency.

[0021] Fourth, the trigger-type valve opening device in this invention has a dual triggering mechanism with mutual backups, resulting in high control redundancy and high operational reliability. Furthermore, the pre-pressurized fire extinguishing bottle does not require continuous power consumption and will not fail due to power outages during long-term standby. There are no solid residues after fire extinguishing, and the equipment can be quickly restored to operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the fire extinguishing device for the immersion liquid-cooled cabinet provided by the present invention; Figure 2 This is a schematic diagram of the tree-like fractal distribution pipeline in this invention; Figure 3 This is a schematic diagram of the structure of the pressurized fire extinguishing bottle in this invention; Figure 4 This is a schematic diagram of the structure of the fire extinguishing microcapsule in this invention; Figure 5 This is a schematic diagram of the mechanical starting unit in this invention; Figure 6 This is a flowchart of the fire extinguishing method for the immersion liquid-cooled cabinet provided by the present invention.

[0023] The labels in the attached diagram are as follows: 1-Immersion liquid-cooled cabinet, 2-Pre-pressurized fire extinguishing bottle, 21-Bottle body, 22-Bottle head valve, 23-Pressure gauge, 24-Rupture disc, 3-Tree-shaped fractal distribution pipe, 31-Main pipe, 32-Primary branch pipe, 33-Secondary branch pipe, 4-Spray nozzle, 5-Trigger valve opening device, 51-Electric start unit, 52-Controller, 53-Temperature sensor, 54-Smoke sensor, 55-Mechanical start unit, 551-Push rod, 552-Lever, 553-Hinged fulcrum, 554-Pull wire, 555-Fixed pulley, 556-Spring, 557-Fixed frame, 56-Temperature-sensing glass bulb, 6-Fire extinguishing microcapsule, 61-Capsule shell, 62-Fire extinguishing material core material, 7-Slag discharge port. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1 like Figure 1 As shown, the fire extinguishing device for an immersion liquid-cooled cabinet provided in this embodiment includes: an immersion liquid-cooled cabinet 1, a pre-pressurized fire extinguishing bottle 2, a tree-shaped fractal distribution pipe 3, a spray nozzle 4, and a trigger-type valve opening device 5.

[0026] The immersion liquid-cooled cabinet 1 is a vertical cuboid structure filled with a certain level of coolant (mineral oil is used in this embodiment). During operation, server blades and other electronic equipment are immersed in the coolant. The top of the immersion liquid-cooled cabinet 1 is equipped with an openable cover for routine maintenance.

[0027] The pre-pressurized fire extinguishing bottle 2 contains a mixture of high-pressure extinguishing gas and extinguishing microcapsules 6 and is located on the top or outside of the immersion liquid-cooled cabinet 1, connected to the interior of the immersion liquid-cooled cabinet 1 via a pipe. Figure 3 As shown, the pre-pressurized fire extinguishing bottle 2 includes a bottle body 21, a bottle head valve 22, a pressure gauge 23, and a rupture disc 24. The bottle body 21 is filled with a mixture of high-pressure gas (nitrogen in this embodiment, with a working pressure of 4 MPa to 8 MPa) and fire extinguishing microcapsules 9. The bottle head valve 22 is normally kept closed and sealed, but will quickly open upon receiving a trigger signal. The rupture disc 24 serves as a safety device; it will automatically rupture and release pressure when the pressure inside the bottle abnormally rises above a design threshold. The pressure gauge 23 is used to observe the pressure status inside the bottle during routine inspections, and to remind maintenance personnel to refill when the pressure falls below the set value.

[0028] The fire extinguishing microcapsule 6 adopts a temperature-sensitive structure, consisting of a capsule shell 61 and a fire extinguishing material core material 62 encapsulated inside. The capsule shell 61 is made of a copolymer of polymethyl methacrylate and N,N-dimethylacrylamide, which is structurally stable at room temperature, but softens and cracks when the temperature reaches the range of 100°C to 150°C. In this embodiment, the fire extinguishing material core material 62 is perfluorohexanone.

[0029] The tree-like fractal distribution pipe 3 mimics the fractal pattern of tree trunks and branches in nature. It is located on the inner top of the immersion liquid-cooled cabinet 1 and fixed to the lower surface of the top cover by a mounting bracket. Rubber shock-absorbing pads are installed between the mounting bracket and the immersion liquid-cooled cabinet 1 to absorb vibrations generated during equipment operation. Figure 2 As shown, the tree-like fractal distribution pipeline 3 includes a main pipeline 31, primary branch pipelines 32, and secondary branch pipelines 33. The main pipeline 31 is arranged along the centerline of the top of the immersion liquid-cooled cabinet 1, and its input end is connected to the output end of the pre-pressurized fire extinguishing bottle 2 via a pipeline. The primary branch pipelines 32 branch off from both ends of the main pipeline 31 to both sides, in a symmetrical distribution. Each primary branch pipeline 32 further branches off to secondary branch pipelines 33, extending to various areas on the top of the immersion liquid-cooled cabinet 1. The connections between the branch pipelines use quick couplings for easy on-site assembly and disassembly.

[0030] In this embodiment, the angle between the primary branch pipe 32 and the main pipe 31 is set to 45°, and the angle between the secondary branch pipe 33 and the primary branch pipe 32 is also set to 45°. The diameter of the main pipe 31 is set to 25 mm, the diameter of the primary branch pipe 32 is set to 16 mm, and the diameter of the secondary branch pipe 33 is set to 10 mm. The design of the pipes gradually narrowing from the main pipe to the final stage helps to maintain sufficient flow velocity during the staged splitting of the gas-solid two-phase flow, thus preventing premature settling of solid particles.

[0031] Each injection port 4 is located at the end of each secondary branch pipe 33, with its opening facing downwards and directly into the internal space of the immersion liquid-cooled cabinet 1. The inner diameter of the injection port 4 is the same as the inner diameter of the secondary branch pipe 33, both being 10 mm, without any narrowing treatment to reduce the flow resistance of the gas-solid two-phase flow. Injection ports 4 are provided throughout the entire top, evenly distributed in a matrix on the top plane of the cabinet, ensuring that the gas-solid two-phase flow can evenly cover the entire horizontal cross-section of the cabinet after injection; this mixed motion mode of horizontal distribution and vertical settling helps the gas-solid two-phase flow to better bypass the obstruction of the internal equipment of the cabinet and evenly reach all corners.

[0032] The trigger-type valve opening device 5 is connected to the cylinder head valve 22 on the pre-pressurized fire extinguishing bottle 2, and is used to open the cylinder head valve 22 when a fire is detected. The trigger-type valve opening device 5 includes: an electric start unit 51, a controller 52, a fire detector (temperature sensor 53 and smoke sensor 54), a mechanical start unit 55, and a temperature-sensing glass bulb 56. The electric start unit 51, the controller 52, and the fire detector are electrically connected in sequence. When the fire detector detects a fire, the controller 52 controls the electric start unit 51 to open the cylinder head valve 22. The mechanical start unit 52 is installed on the immersion liquid cooling cabinet 1. The temperature-sensing glass bulb 56 is installed inside the immersion liquid cooling cabinet 1 and connected to the trigger end of the mechanical start unit 52. When the ambient temperature reaches a set value, the temperature-sensing glass bulb 56 breaks and triggers the mechanical start unit 55 to open the cylinder head valve 22. The cylinder head valve 22 is a handle-type ball valve.

[0033] The electric start unit 51 includes a servo motor, a lever, and a motor mounting bracket. The servo motor is fixedly mounted on the pre-pressurized fire extinguishing bottle 2 via the motor mounting bracket. The lever is fixedly connected to the output shaft of the servo motor. The lever cooperates with the handle on the bottle head valve 22. When the fire detector detects a fire (i.e., when the temperature sensor 53 and the smoke sensor 54 detect that the temperature or smoke concentration inside the immersion liquid-cooled cabinet 1 exceeds the set threshold), the controller 52 controls the servo motor to drive the lever to rotate, thereby opening the bottle head valve 22 by moving the handle on the bottle head valve 22 via the lever.

[0034] like Figure 5 As shown, the mechanical starting unit 55 includes: a vertical plate, a push rod 551, a lever 552, a hinge fulcrum 553, a pull wire 554, a fixed pulley 555, a spring 556, and a fixing frame 557. One end of the push rod 551 is hinged to the handle on the bottle head valve 22, and the other end of the push rod 551 is hinged to one end of the lever 552. The middle part of the lever 552 is connected to the hinge fulcrum 553, which is fixedly installed on the vertical plate. The other end of the lever 552 is connected to one end of the pull wire 554. The fixed pulley 555 is rotatably installed on the vertical plate, and the pull wire 554 is connected to the fixed pulley 555. The other end of the pull wire 554 slides through the top of the immersion liquid cooling cabinet 1 and is fixedly connected inside it. The lower end of the spring 556 is sleeved on the pull wire 554, and its upper end is pressed against the inner top wall of the immersion liquid cooling cabinet 1. The temperature-sensing glass ball 56 is suspended and fixed on the inner top wall of the immersion liquid cooling cabinet 1 by the fixing bracket 557 and is pressed against the lower end of the spring 556. When the ambient temperature inside the immersion liquid cooling cabinet 1 reaches the set value, the temperature-sensing glass ball (a temperature-sensing glass ball with a temperature of 93°C is selected in this embodiment) breaks and is crushed by the pressure of the spring 556. At this time, the spring 556 pulls the lever 552 through the pull wire 554, so that the lever 552 rotates along the hinge fulcrum 553 and pushes the handle on the bottle head valve 22 through the push rod 551 to open the bottle head valve 22.

[0035] To improve control redundancy and enhance operational reliability, the two triggering systems in the trigger-type valve opening device 5 are independent of each other, and the bottle head valve 22 can be opened by activating either system.

[0036] The working process of the fire extinguishing device in this embodiment is as follows: The pre-pressurized fire extinguishing cylinder 2 is normally in standby mode, with the cylinder valve 22 kept closed, and the high-pressure nitrogen and fire extinguishing microcapsules 6 inside the cylinder maintained at a stable level. The fire detector continuously monitors the environmental conditions inside the immersion liquid-cooled cabinet 1.

[0037] When a fire occurs inside the immersion liquid-cooled cabinet 1, the temperature will rise rapidly. The fire detector will detect the abnormal signal and send it to the controller 52. After verification, the controller 52 will immediately send a start signal to the electric start unit 51, quickly opening the cylinder valve 22. If the electric start unit 51 fails to respond due to a malfunction, as the temperature continues to rise, when the temperature at the location of the heat-sensing glass bulb 56 reaches 93°C, the heat-sensing glass bulb 56 will break, opening the cylinder valve 22 via the mechanical start unit 55. At least one of the two triggering links must be operational.

[0038] After the cylinder valve 22 is opened, the high-pressure nitrogen gas in the pre-pressurized fire extinguishing cylinder 2, carrying the fire extinguishing microcapsules 6, is ejected in the form of a gas-solid two-phase flow. It then enters the main pipe 31 of the tree-like fractal distribution pipe 3 via the connecting pipe. The gas-solid two-phase flow flows in the main pipe 31, and after reaching the first-level branch node, it is evenly distributed into the first-level branch pipe 32, and then further distributed into the second-level branch pipe 33. After this step-by-step distribution, the gas-solid two-phase flow is ejected from each nozzle 4. The nozzles 4 are downward-facing, and the gas-solid two-phase flow moves from top to bottom under the propulsion of the jetting force and its own gravity, covering the entire internal space of the immersion liquid-cooled cabinet 1.

[0039] Upon reaching the high-temperature area, the fire-extinguishing microcapsule 6 ruptures its outer shell 61, releasing the perfluorohexanone core material 62. Perfluorohexanone extinguishes the fire by capturing free radicals in the combustion reaction, thus interrupting the chain reaction. Simultaneously, the high-pressure nitrogen gas dilutes the oxygen concentration and lowers the fire temperature. The two extinguishing mechanisms work synergistically to achieve rapid fire suppression.

[0040] In this embodiment, the pre-pressurized fire extinguishing bottle 2 is released using pulse-type spray. The controller 52 controls the bottle head valve 22 to open and close in the form of intermittent pulses. Each pulse lasts for 1 second, and the interval between two pulses is 3 seconds. After a total of 4 pulses, the valve closes. The purpose of pulse-type spray is that the high-speed airflow creates a scouring effect on the inner wall of the pipe during each pulse, re-entraining and carrying away microcapsule particles that may have deposited at pipe bends or branch connections after the previous spray, preventing particles from gradually accumulating in the pipe and causing blockage.

[0041] After the fire is extinguished, perfluorohexanone evaporates and dissipates under ventilation conditions, and the capsule shell 61 gradually decomposes and vaporizes under the influence of residual heat inside the cabinet. Manual cleaning of internal solid residues is usually unnecessary before the system is restored to operation.

[0042] Example 2 The difference between this embodiment and Embodiment 1 lies in the different structure of the tree-like fractal distribution pipe 3.

[0043] In Example 1, the tree-like fractal distribution pipe 3 adopts a three-level structure of "trunk - primary branch - secondary branch", which is suitable for standard-sized cabinets. This example is for larger cabinets and adopts a four-level structure of "trunk - primary branch - secondary branch - tertiary branch". The number of terminal branch pipes is increased accordingly, the distribution density of each nozzle 4 is higher, and the coverage is more uniform.

[0044] The included angles between the branch pipes also differ in this embodiment: the included angle between the main pipe 31 and the first-level branch pipe 32 is set to 60°, the included angle between the first-level branch pipe 32 and the second-level branch pipe 33 is set to 50°, and the included angle between the second-level branch pipe 33 and the third-level branch pipe is set to 40°. The design of the branch pipes narrowing step by step and the included angle decreasing step by step helps to maintain the flow velocity and transport stability of the gas-solid two-phase flow during the process of pipe branching.

[0045] The various piping modules are connected via quick-connect couplings. Due to the modular design, the piping modules have standardized specifications, allowing for flexible adjustments to the number and levels of branches based on the cabinet size. Small cabinets use a two-level branch structure, standard cabinets use a three-level branch structure, and large cabinets use a four-level branch structure. The structure and operation of other parts in this embodiment are the same as in Embodiment 1, and therefore will not be repeated here.

[0046] Example 3 The difference between this embodiment and Embodiment 1 is that the high-pressure extinguishing gas filled in the pre-pressurized fire extinguishing bottle 2 is different.

[0047] High-pressure nitrogen was used in Example 1. In this example, a mixture of nitrogen and carbon dioxide in a 1:1 volume ratio was used, with the filling pressure set to 5 MPa to 10 MPa. Carbon dioxide has a better fire extinguishing effect than nitrogen. It not only dilutes the oxygen concentration but also absorbs a large amount of heat, lowering the temperature of the fire. Furthermore, carbon dioxide is denser than air, allowing it to better cover and protect the equipment underneath the cabinet. However, a drawback of carbon dioxide is that it requires a longer ventilation period after extinguishing the fire to remove any remaining carbon dioxide. Therefore, this example is more suitable for unattended data center cabinets. The structure and connections of other parts in this example are the same as in Example 1, and will not be repeated here.

[0048] Example 4 The difference between this embodiment and Embodiment 1 is that it includes measures for handling the residue left after fire extinguishing.

[0049] The perfluorohexanone core material used in Example 1 has good volatility and naturally dissipates after fire extinguishing. The capsule shell 61 vaporizes and decomposes on its own at high temperatures, and no additional cleaning is required under normal circumstances. However, in some applications with particularly high cleanliness requirements, users may wish to more thoroughly remove any possible trace residues.

[0050] Therefore, in this embodiment, a slag discharge port 7 is added to the bottom of the immersion liquid-cooled cabinet 1. The structure of the slag discharge port 7 is a pipe interface opened on the side wall of the bottom of the cabinet. It is normally sealed with a threaded sealing cap, and can be unscrewed when slag discharge is needed. The inner diameter of the slag discharge port 7 is set to 25mm, and its position is at the lowest point of the bottom of the cabinet, so that the residue can be discharged in a concentrated manner under the action of gravity.

[0051] The specific operating procedure is as follows: After the fire is extinguished and the internal temperature of the cabinet drops to a safe range, open the sealing cover of the slag discharge port 7, and introduce low-pressure nitrogen gas from the top cover of the cabinet, gently blowing the internal space from top to bottom for about 1 to 2 minutes. Any trace solid residues that may exist will be blown to the bottom by the airflow and gravity, and discharged from the slag discharge port 7. After the purging is completed, close the sealing cover of the slag discharge port 7, and the cabinet can resume operation. The structure and connection relationship of other parts in this embodiment are the same as in Embodiment 1, so they will not be described again here.

[0052] Example 5 like Figure 6 As shown, this embodiment provides a fire extinguishing method for an immersion liquid-cooled cabinet, specifically including the following steps: Step S1: The fire extinguishing microcapsules 6 are mixed with high-pressure fire extinguishing gas in a certain proportion and then filled into the pre-pressurized fire extinguishing bottle 2. The filling ratio of the fire extinguishing microcapsules 6 is generally controlled between 5% and 20% of the mass of the fire extinguishing gas. The pre-pressurized fire extinguishing bottle 2 is connected to the tree-shaped fractal distribution pipe 3 installed on the top of the inner side of the immersion liquid-cooled cabinet 1 through a pipeline.

[0053] Step S2: Temperature sensor 53 and smoke sensor 54, installed inside the immersion liquid-cooled cabinet 1, continuously monitor the environmental conditions inside the cabinet. Controller 52 receives sensor signals in real time and makes judgments. When the temperature exceeds a set threshold or the smoke concentration exceeds a set threshold and the duration exceeds a certain time (e.g., 3 seconds), controller 52 determines that a fire has occurred.

[0054] Step S3: The controller 52 sends a start signal to the electric start unit 51 to open the cylinder head valve 22 of the pre-pressurized fire extinguishing bottle 2. If the electric start path fails to respond due to a fault, when the internal temperature of the cabinet further rises to 93 ℃, the temperature-sensing glass bulb 56 breaks, opening the cylinder head valve 22 through the mechanical start unit 55. The two triggering links are independent of each other; the next step can proceed if either one is successfully triggered. Step S4: After the cylinder valve 22 is opened, the high-pressure extinguishing gas carrying the extinguishing microcapsules 6 is ejected in the form of a gas-solid two-phase flow and enters the main pipe 31 of the tree-shaped fractal distribution pipe 3. The cylinder valve 22 is opened and closed in a pulse manner, with each pulse lasting 1 second and an interval of 3 seconds, for a total of 4 pulses.

[0055] Step S5: The gas-solid two-phase flow passes through the first-level branch pipe 32 and the second-level branch pipe 33 in the tree-shaped fractal distribution pipe 3 in sequence, and after multi-stage diversion, it reaches the injection port 4 at the end of each final branch pipe.

[0056] Step S6: The gas-solid two-phase flow is ejected from each injection port 4. Each injection port 4 is set downwards, and the gas-solid two-phase flow moves from top to bottom under the combined action of injection power and its own gravity, covering the entire internal space of the immersion liquid-cooled cabinet 1.

[0057] Step S7: After the fire extinguishing microcapsule 6 reaches the high-temperature area, the capsule shell 61 ruptures within a temperature range of 100 ℃ to 150 ℃, releasing the perfluorohexanone core material inside. Perfluorohexanone interrupts the combustion reaction through chemical inhibition. At the same time, the high-pressure fire extinguishing gas exerts a physical fire extinguishing effect by diluting the oxygen concentration and absorbing heat. The synergistic effect of chemical inhibition and physical asphyxiation achieves rapid fire extinguishing.

[0058] Step S8: After the fire is extinguished, perfluorohexanone naturally evaporates and dissipates. The capsule shell 61 vaporizes and decomposes under the action of residual heat, and operation can usually be resumed without manual cleaning. For scenarios with particularly high cleanliness requirements, the slag discharge port 7 at the bottom of the immersion liquid-cooled cabinet 1 can be opened, and low-pressure inert gas can be used to purge from the top for about 1 to 2 minutes to remove any trace residues that may exist from the slag discharge port 7. After that, the slag discharge port 7 can be closed, and operation can be resumed.

[0059] The controller 52 records the system's operating status and fire extinguishing process data throughout the entire process for subsequent analysis and maintenance reference.

[0060] In the description of this invention, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", "top / bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the technical solution of the present invention, based on the technical essence of the present invention, shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A fire extinguishing device for an immersion liquid-cooled cabinet, characterized in that, include: The submersible liquid-cooled cabinet (1), pre-pressurized fire extinguishing bottle (2), tree-shaped fractal distribution pipe (3), nozzle (4), and trigger-type valve opening device (5) are provided. The pre-pressurized fire extinguishing bottle (2) stores a mixture of high-pressure fire extinguishing gas and fire extinguishing microcapsules (6) and is located on the top or outside of the submersible liquid-cooled cabinet (1). The tree-shaped fractal distribution pipe (3) is located on the inner top of the submersible liquid-cooled cabinet (1). The tree-shaped fractal distribution pipe (3) includes a main pipe (31) and several branch pipes connected to the main pipe (31). The input end of (31) is connected to the output end of the pre-pressurized fire extinguishing bottle (2); the spray port (4) is provided with several, and the several spray ports (4) are respectively set at the end of the last branch pipe in the tree-like fractal distribution pipe (3). The spray port (4) is set downward and is used to spray the mixture of high-pressure fire extinguishing gas and fire extinguishing microcapsule (6) into the immersion liquid-cooled cabinet (1) in the form of gas-solid two-phase flow; the trigger-type valve opening device (5) is connected to the bottle head valve (22) on the pre-pressurized fire extinguishing bottle (2) and is used to open the bottle head valve (22) when a fire is detected.

2. The fire extinguishing device for an immersion liquid-cooled cabinet according to claim 1, characterized in that: The trigger-type valve opening device (5) includes: an electric start unit (51), a controller (52), a fire detector, a mechanical start unit (55), and a temperature-sensing glass ball (56). The electric start unit (51), the controller (52), and the fire detector are electrically connected in sequence. When the fire detector detects a fire, the controller (52) controls the electric start unit (51) to open the bottle head valve (22). The mechanical start unit (52) is installed on the immersion liquid cooling cabinet (1). The temperature-sensing glass ball (56) is installed inside the immersion liquid cooling cabinet (1) and connected to the trigger end of the mechanical start unit (52). When the ambient temperature reaches a set value, the temperature-sensing glass ball (56) breaks and triggers the mechanical start unit (55) to open the bottle head valve (22). The bottle head valve (22) is a handle-type ball valve.

3. The fire extinguishing device for an immersion liquid-cooled cabinet according to claim 2, characterized in that: The fire detector includes a temperature sensor (53) and a smoke sensor (54), which are electrically connected to the controller (52).

4. The fire extinguishing device for an immersion liquid-cooled cabinet according to claim 2, characterized in that: The electric start unit (51) includes a servo motor, a lever, and a motor mounting bracket. The servo motor is fixedly mounted on the pre-pressurized fire extinguishing bottle (2) via the motor mounting bracket. The lever is fixedly connected to the output shaft of the servo motor. The lever cooperates with the handle on the bottle head valve (22). When the fire detector detects a fire, the servo motor drives the lever to rotate, thereby opening the bottle head valve (22) by moving the handle on the bottle head valve (22) via the lever.

5. The fire extinguishing device for an immersion liquid-cooled cabinet according to claim 2, characterized in that: The mechanical actuation unit (55) includes: a vertical plate, a push rod (551), a lever (552), a hinge fulcrum (553), a pull wire (554), a fixed pulley (555), a spring (556), and a fixing frame (557). One end of the push rod (551) is hinged to the handle on the bottle head valve (22), and the other end of the push rod (551) is hinged to one end of the lever (552). The middle part of the lever (552) is connected to the hinge fulcrum (553), and the hinge fulcrum (553) is fixedly installed on the vertical plate. The other end of the lever (552) is connected to one end of the pull wire (554). The fixed pulley (555) is rotatably installed on the vertical plate, and the pull wire (554) is connected to the fixed pulley (555). The other end of the pull wire (554) slides through the immersion liquid. The top of the refrigeration cabinet (1) is fixedly connected to the lower end of a spring (556) inside it. The spring (556) is sleeved on a pull wire (554) and its upper end is pressed against the inner top wall of the immersion liquid refrigeration cabinet (1). The temperature-sensing glass ball (56) is suspended and fixed on the inner top wall of the immersion liquid refrigeration cabinet (1) by a fixing bracket (557) and pressed against the lower end of the spring (556). When the ambient temperature inside the immersion liquid refrigeration cabinet (1) reaches the set value, the temperature-sensing glass ball breaks and is crushed by the pressure of the spring (556). At this time, the spring (556) pulls the lever (552) through the pull wire (554), so that the lever (552) rotates along the hinge fulcrum (553) and pushes the handle on the bottle head valve (22) through the push rod (551) to open the bottle head valve (22).

6. The fire extinguishing device for an immersion liquid-cooled cabinet according to claim 1, characterized in that: The high-pressure extinguishing gas is one or a mixture of any combination of nitrogen, argon and carbon dioxide; the extinguishing microcapsule (6) includes: a temperature-sensitive capsule shell (61) and an extinguishing substance core material (62) encapsulated inside the capsule shell (61). The capsule shell (61) remains intact at room temperature and ruptures and releases the extinguishing substance core material (62) within a temperature range of 80°C to 150°C; the extinguishing substance core material (62) is perfluorohexanone and / or perfluorotriethylamine; the capsule shell (61) is a temperature-sensitive polymer material that can be vaporized and decomposed at high temperature, specifically a copolymer of polymethyl methacrylate and N,N-dimethylacrylamide.

7. The fire extinguishing device for an immersion liquid-cooled cabinet according to claim 1, characterized in that: The immersion liquid cooling cabinet (1) is provided with a slag discharge port (7) at the bottom, and the slag discharge port (7) is provided with an openable sealing cover.

8. A fire extinguishing method for an immersion liquid-cooled cabinet, using the fire extinguishing device according to any one of claims 1 to 7, characterized in that: Includes the following steps: Step 1: Store the gas-solid mixture of fire extinguishing microcapsules (6) and high-pressure fire extinguishing gas in a pre-pressurized fire extinguishing bottle (2); Step 2: When the fire detector installed inside the immersion liquid cooling cabinet (1) detects a fire, the trigger valve opening device (5) opens the bottle head valve (22) of the pre-pressurized fire extinguishing bottle (2). Step 3: The high-pressure extinguishing gas carrying the extinguishing microcapsules (6) is sprayed out in the form of a gas-solid two-phase flow and enters the tree-shaped fractal distribution pipe (3) located on the top of the inner side of the cabinet (1). Step 4: After the gas-solid two-phase flow is divided into several levels of branch pipes through the tree-shaped fractal distribution pipe (3), it is sprayed into the interior of the immersion liquid cooling cabinet (1) from each injection port (4). Under the dual action of injection power and gravity, the gas-solid two-phase flow covers the interior space of the immersion liquid cooling cabinet (1) from top to bottom. Step 5: After the fire extinguishing microcapsule (6) reaches the high temperature area, it ruptures and releases the fire extinguishing substance, which works in conjunction with the high-pressure fire extinguishing gas to extinguish the fire.

9. A fire extinguishing method for an immersion liquid-cooled cabinet according to claim 8, characterized in that: In step three, the pre-pressurized fire extinguishing bottle (2) releases the gas-solid two-phase flow in a pulse manner, with a time interval between two adjacent pulses.

10. A fire extinguishing method for an immersion liquid-cooled cabinet according to claim 8, characterized in that: It also includes step six: After the fire is extinguished, open the slag discharge port (7) located at the bottom of the immersion liquid cooling cabinet (1), and blow the residue from the top with inert gas to discharge the residue from the slag discharge port (7).

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