Multi‑scenario fixed fire extinguishing system for power stations and use method therefor

Abstract

A multi‑scenario fixed fire extinguishing system for power stations and a use method therefor. The multi‑scenario fixed fire extinguishing system for power stations comprises a water supply system, a foam supply system, an inert gas supply system, a fire extinguishing medium mixing and discharge system, and a fire detection and control system. The fire extinguishing medium mixing and discharge system comprises a single-phase binary mixer (18), a multi-component multiphase flow mixer (22) connected in series with the single-phase binary mixer, a ring transformer porous foam liquid discharge pipe (16), a foam gun (30), and a cable trench foam discharge pipe. The fire detection and control system comprises a fire control main unit, a temperature-sensitive fire detector, and an image-type fire detector (27). By combining gas fire extinguishing and foam fire extinguishing, the fire extinguishing capability is improved, fire extinguishing application scenarios are expanded, and main fire hazard sources in substations can be covered; and by coupling the image-type fire detector with the temperature-sensitive fire detector for fire identification, the accuracy of fire identification is improved.

Description

A multi-scenario fixed fire extinguishing system for power stations and its application method

[0001] This invention belongs to the field of fire protection technology, specifically a multi-scenario fixed fire extinguishing system for power stations and its usage method. Background Technology

[0002] Currently, fixed fire suppression systems in substations mainly consist of water spray and synthetic foam spray systems. Water spray systems primarily rely on the cooling effect of water mist for extinguishing fires, but their effectiveness in extinguishing large oil fires is severely insufficient. Synthetic foam spray systems use high-pressure gas to drive the release of the extinguishing medium, resulting in a short foaming time and limited extinguishing capacity. Furthermore, the premixed foam extinguishing medium used in these systems has a short shelf life and poor insulation; if mis-spraying occurs, it cannot be stopped midway, easily leading to transformer tripping. In recent years, compressed air foam fire suppression systems have seen initial application in UHVDC substations. Compressed air foam systems offer a significant improvement in extinguishing capacity compared to water spray and foam spray systems, but these systems are complex, consume a lot of power, and have high costs and maintenance expenses. Moreover, the foaming process introduces a large amount of air, which is detrimental to the oxygen-isolating effect of the foam fire suppression system. The aforementioned fixed fire suppression systems are designed for oil-immersed transformers and cannot be used for other fire suppression scenarios such as cable trenches and reactors.

[0003] Besides oil-immersed transformers, major fire hazard points in substations include cable trenches, oil-filled high-voltage reactors, and current transformers. Currently, each oil-immersed transformer and oil-filled high-voltage reactor is equipped with one fire suppression system, while most substation cable trenches lack fire suppression systems, although some substations have dry powder fire suppression systems installed. These fire suppression systems are configured independently, resulting in high initial investment costs and significant ongoing maintenance workload. Furthermore, fires involving current transformers also occur frequently in substations, but due to their large number, they are not currently equipped with fire suppression systems, and conventional fire extinguishers in substations are ineffective in extinguishing current transformer fires.

[0004] Existing fixed fire suppression systems in substations, whether water mist, foam mist, or compressed air foam systems, primarily rely on heat detectors (mainly heat-sensing cables) and flame detectors for fire detection. The fire signal is configured with three detection signals (two from the heat-sensing cable and one from the flame detector), and receiving two of these signals is sufficient to confirm a fire. However, due to limitations in material strength, heat-sensing cables are prone to damage during long-term operation and maintenance, rendering them ineffective. Furthermore, during a fire, these cables are often damaged and unable to trigger an alarm. To improve the accuracy of fire detection, flame detectors are typically added; however, flame detectors are susceptible to environmental interference, leading to a high false alarm rate.

[0005] Furthermore, the aforementioned fixed fire extinguishing systems primarily utilize water spray and foam spray systems. Both share a similar extinguishing agent delivery system: a main pipe-branch pipe configuration. The main pipe supplies the extinguishing agent, while the branch pipes are fixed to it via fittings. Atomizing nozzles are attached to the ends of the branch pipes to atomize the extinguishing agent before delivery. Because the spray range and penetration of the atomized extinguishing agent are limited, to improve extinguishing effectiveness, the branch pipes typically protrude forward, approaching the protected object as close as possible within a safe range. If the protected object catches fire and explodes, the nearby branch pipes can easily be destroyed, causing localized depressurization of the extinguishing agent delivery system and affecting the extinguishing effect. Summary of the Invention

[0006] To address the shortcomings of existing fire suppression systems in power plants such as substations, including insufficient explosion-proof and fire-resistant capabilities, low fire suppression efficiency, limited application to high-value oil-filled equipment such as large oil-immersed transformers, and significant system losses due to false alarms and missed alarms, this invention provides a multi-scenario fixed fire suppression system for power plants. This system combines gas and foam fire suppression to enhance fire suppression capabilities and expand application scenarios, covering major fire hazard sources in substations. Furthermore, it improves the accuracy of fire identification by coupling image-type fire detectors with heat-sensing fire detectors.

[0007] Therefore, the present invention adopts the following technical solution.

[0008] In a first aspect, the present invention provides a fixed fire extinguishing system for power stations in multiple scenarios, which includes a water supply system, a foam supply system, an inert gas supply system, a fire extinguishing medium mixing and release system, and a fire detection and control system.

[0009] The water supply system includes a fire water tank, a fire water tank outlet valve, a fire pump inlet valve, a fire pump, and a fire pump outlet valve, which are connected in sequence by pipelines.

[0010] The foam supply system includes a foam liquid storage tank, a foam liquid storage tank outlet valve, a foam liquid pump inlet valve, a foam liquid pump, and a foam liquid pump outlet valve connected in sequence by pipelines. The foam liquid storage tank contains foam extinguishing agent concentrate.

[0011] The inert gas supply system includes an inert gas storage tank, an inert gas storage tank outlet valve, and a gas flow regulator, which are connected in sequence via pipelines.

[0012] The fire extinguishing medium mixing and release system includes a single-phase binary mixer, a multi-phase flow mixer connected in series with the single-phase binary mixer, a porous foam liquid release pipe for a ring transformer, a foam gun, and a foam release pipe for cable trenches. The porous foam liquid release pipe for the ring transformer is arranged in a ring around the transformer. The multi-phase flow mixer is connected to the porous foam liquid release pipe for the ring transformer, the foam gun, and the foam release pipe for cable trenches via pipelines. The outlet of the fire pump outlet valve and the outlet of the foam liquid pump outlet valve are both connected to the single-phase binary mixer, and the outlet of the gas flow regulator is connected to the multi-phase flow mixer.

[0013] The water pumped by the fire pump and the foam liquid pumped by the foam liquid pump are mixed in a single-phase binary mixer to form a foam aqueous solution. The well-mixed foam aqueous solution and the inert gas output by the inert gas supply system are fully mixed and foamed in a multi-phase flow mixer to form a ternary two-phase flow foam extinguishing liquid.

[0014] The fire detection and control system includes a fire control host, a heat-sensing fire detector, and an image-type fire detector. The image-type fire detector is installed above the transformer and sends the detected image signal to the fire control host. The heat-sensing fire detector sends the detected temperature signal to the fire control host, which then determines the authenticity and source of the signal and issues corresponding instructions.

[0015] This invention combines gaseous and foam fire extinguishing methods, improving fire extinguishing capabilities and expanding fire extinguishing application scenarios. Compared with traditional foam solutions, the ternary two-phase flow foam extinguishing liquid of this invention has stable foam, long range, and releases a large amount of inert gas during the fire extinguishing process, rapidly forming a liquid film covering the surface of the burning object. At the same time, the suffocation effect is enhanced, improving fire extinguishing efficiency.

[0016] The fire extinguishing medium mixing and dispensing system of the present invention can adopt the "solid-moving combination" fire extinguishing liquid dispensing method of foam gun, which expands the application range of the fire extinguishing system; the multi-phase flow mixer of the present invention can adopt the "inert gas active foaming" method, which reduces the mass of the fire extinguishing liquid, and the fire hose filled with the fire extinguishing liquid is also lighter. The foam gun using this fire extinguishing liquid is easier to operate than the conventional foam gun.

[0017] Furthermore, the water supply system also includes a fire pump outlet recirculation valve. The inlet of the fire pump outlet recirculation valve is connected to the fire pump outlet valve, and the outlet of the fire pump outlet recirculation valve is connected to the fire water tank. The fire water is circulated through the fire pump outlet recirculation valve.

[0018] Furthermore, the water supply system also includes a desalination device inlet valve, a desalination device, and a desalination device outlet valve connected in sequence via pipelines. The outlet of the desalination device outlet valve is connected to the fire water tank, and the inlet of the desalination device inlet valve is connected to the outlet pipeline of the fire water tank.

[0019] Furthermore, the outlet pipe of the fire water tank is equipped with a conductivity meter for measuring fire water usage, and the pipe connecting the outlet valve of the fire pump and the single-phase binary mixer is equipped with a fire water flow meter.

[0020] Furthermore, the foam supply system also includes a foam liquid pump outlet recirculation valve. The inlet of the foam liquid pump outlet recirculation valve is connected to the outlet of the foam liquid pump outlet valve, and the outlet of the foam liquid pump outlet recirculation valve is connected to the foam liquid storage tank. The foam liquid is circulated through the foam liquid pump outlet recirculation valve.

[0021] Furthermore, the porous foam liquid dispensing pipe of the ring transformer is equipped with multiple short pipe nozzles and multiple micro-orifice nozzles. By employing "short pipe nozzles and micro-orifice nozzles," there are no protruding branch pipes. Even if a small number of short pipe nozzles or micro-orifice nozzles are damaged due to the explosion of the burning object, it will not cause a loss of pressure in the fire extinguishing medium dispensing system and affect the dispensing effect.

[0022] Secondly, the present invention provides a method for using the above-mentioned multi-scenario fixed fire extinguishing system for power stations, the content of which is as follows: when the fire control host determines that there is a real fire signal, the fire control host controls the start and stop of the water supply system, the foam supply system and the inert gas supply system and the opening degree of the valves, adjusts the gas-liquid ratio of the ternary two-phase flow foam extinguishing liquid according to the source of the fire signal, and releases the ternary two-phase flow foam extinguishing liquid to the transformer, cable trench and other protected objects through the fire extinguishing medium mixing and release system to achieve fire extinguishing.

[0023] Furthermore, the methods for extinguishing transformer fires are as follows: After determining that the fire signal originates from the transformer, the fire control host is switched to transformer fire extinguishing mode. The foam liquid pump and fire water pump are started. The foam liquid is mixed with water, and then mixed with inert gas. The gas-liquid ratio is adjusted to 4:1~7:1, and the flow rate is 3~25L / (m³). 2 (min), through the fire extinguishing medium mixing and release system, the ternary two-phase flow foam fire extinguishing liquid is applied to the transformer to extinguish the fire.

[0024] Furthermore, the method for extinguishing cable trench fires is as follows: After determining that the fire signal originates from the cable trench, adjust the working mode to cable trench fire extinguishing mode, start the foam liquid pump and fire water pump, mix the foam liquid with water, and then mix it with inert gas, adjust the gas-liquid ratio to 8:1~15:1, and the flow rate to be no less than 200L / min. Through the fire extinguishing medium mixing and release system, the three-dimensional two-phase flow foam fire extinguishing liquid is released to the fire location to extinguish the fire.

[0025] Furthermore, the fire extinguishing methods for other protected objects are as follows: After determining that the fire signal originates from other protected objects, adjust the working mode to single foam gun extinguishing mode, start the foam liquid pump and fire water pump, mix the foam liquid with water, and then mix it with inert gas, adjust the gas-liquid ratio to 15:1~22:1, and the flow rate is not less than 100L / min. Through the extinguishing medium mixing and release system, aim the three-dimensional two-phase flow foam extinguishing liquid at the fire location and carry out fire extinguishing.

[0026] The beneficial effects of this invention are as follows: This invention combines the advantages of gas extinguishing and foam extinguishing, improving extinguishing capability and expanding extinguishing application scenarios, covering the main fire hazard sources in substations; the ternary two-phase flow foam extinguishing liquid of this invention has stable foam and long range, and releases a large amount of inert gas during the extinguishing process, rapidly forming a liquid film covering the surface of the burning object, while enhancing the suffocation effect and improving extinguishing efficiency; the accuracy of fire identification is improved by combining image recognition with temperature detection; and the extinguishing foam is modified by desalinating the fire water, reducing the impact on energized standby operation.

[0027] This invention adaptively adjusts the flow rate and gas-liquid ratio according to the type of fire source, improving fire extinguishing efficiency and expanding the application scope and scenarios of the system. This invention can be used in indoor and outdoor substations, pumped storage power stations, machine rooms, converter valve halls, integrated utility tunnels, cable tunnels, underground cable trenches, cable shafts, etc., and can also be used in power plant coal bunkers, cable trenches, cable trays, oil systems, oil storage tanks, coal wharves, etc.; with appropriate modifications, it can also be used in hazardous chemical storage yards, garages, etc. Attached Figure Description

[0028] Figure 1 is a structural schematic diagram of a fixed fire extinguishing system for power stations in multiple scenarios according to the present invention.

[0029] Figure 2 is a schematic diagram of the porous foam liquid dispensing pipe for the ring transformer of the present invention;

[0030] Figure 3 is a control logic diagram of the usage method of the multi-scenario fixed fire extinguishing system for power stations according to the present invention.

[0031] In the diagram, 1. Fire water tank, 2. Conductivity meter, 3. Fire water tank outlet valve, 4. Desalination device inlet valve, 5. Desalination device, 6. Desalination device outlet valve, 7. Fire pump inlet valve, 8. Fire pump, 9. Fire pump outlet valve, 10. Fire pump outlet recirculation valve, 11. Fire water flow meter, 12. Foam liquid storage tank, 13. Foam liquid storage tank outlet valve, 14. Foam liquid pump inlet valve, 15. Foam liquid pump, 16. Foam liquid pump outlet valve, 17. Foam liquid pump outlet recirculation valve, 18. Single-phase binary mixer. 19. Inert gas storage tank; 20. Inert gas storage tank outlet valve; 21. Gas flow regulator; 22. Multi-phase flow mixer; 23. Multi-phase flow mixer outlet manual valve; 24. First ring transformer porous foam liquid discharge pipe inlet valve; 25. Second ring transformer porous foam liquid discharge pipe inlet valve; 26. Ring transformer porous foam liquid discharge pipe; 27. Image-type fire detector; 28. Cable trench foam discharge pipe inlet valve; 29. ​​Foam gun delivery pipe inlet valve; 30. Foam gun; 31. Short pipe nozzle; 32. Micro-orifice nozzle. Embodiments of the present invention

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0033] Example 1

[0034] This embodiment provides a fixed fire extinguishing system for power stations in multiple scenarios, as shown in Figure 1. It consists of a water supply system, a foam supply system, an inert gas supply system, a fire extinguishing medium mixing and release system, and a fire detection and control system.

[0035] The water supply system includes a fire water tank 1, a conductivity meter 2, a fire water tank outlet valve 3, a desalination device inlet valve 4, a desalination device 5, a desalination device outlet valve 6, a fire pump inlet valve 7, a fire pump 8, a fire pump outlet valve 9, and a fire pump outlet recirculation valve 10. There are two fire pump inlet valves 7, 8, and 9, forming a set consisting of one fire pump inlet valve 7, one fire pump 8, and one fire pump outlet valve 9. These two sets are connected in parallel and then in series in the water supply system's outlet pipeline. Even if one fire pump fails, one fire pump can still operate, effectively ensuring the normal operation of the water supply system. The fire pump outlet recirculation valve 10 can also be two, connected in series in the water supply system's outlet pipeline; its inlet is connected to the outlet of the fire pump outlet valve 9, and the outlet of the fire pump outlet recirculation valve 10 is connected to the inlet of the fire water tank 1. The fire water tank 1, conductivity meter 2, fire water tank outlet valve 3, fire pump inlet valve 7, fire pump 8, fire pump outlet valve 9, and fire pump outlet recirculation valve 10 form a water recirculation loop. The inlet of the desalination device inlet valve 4 is connected to the outlet pipe located between the conductivity meter 2 and the fire water tank outlet valve 3. The fire water tank 1, conductivity meter 2, desalination device inlet valve 4, desalination device 5, and desalination device outlet valve 6 form a desalination circulation loop. This loop continuously desalinates the water in the fire water tank 1, removing most of the impurity ions and ensuring that the water supply system outputs finely desalinated water. The resistivity of this finely desalinated water is maintained at 5-10 megohms (MΩ), improving its insulation properties. The conductivity meter 2 is used to detect the conductivity of the finely desalinated water.

[0036] When the water supply system is running, the fire pump inlet valve 7 and the fire pump outlet valve 9 are both open. The fire pump 8 delivers fire water to the single-phase binary mixer 18 according to a fixed quantity. A fire water flow meter 11 is installed on the pipeline connecting the outlet of the fire pump outlet valve 9 and the single-phase binary mixer 18 to measure the flow rate of the desalination water.

[0037] The foam supply system includes a foam liquid storage tank 12, a foam liquid storage tank outlet valve 13, a foam liquid pump inlet valve 14, a foam liquid pump 15, a foam liquid pump outlet valve 16, and a foam liquid pump outlet recirculation valve 17. There are two of each of the foam liquid pump inlet valve 14, foam liquid pump 15, and foam liquid pump outlet valve 16. Each set consists of one set of these three valves, connected in parallel and then in series in the foam supply system's outlet pipeline. This ensures that if one foam liquid pump fails, another will still operate, effectively guaranteeing the normal operation of the foam supply system. The foam liquid pump outlet recirculation valve 17 can also be two, connected in series in the outlet pipeline of the foam supply system; its inlet is connected to the outlet of the foam liquid pump outlet valve 16, and the outlet of the foam liquid pump outlet recirculation valve 17 is connected to the inlet of the foam liquid storage tank 12. The foam liquid storage tank 12, the foam liquid storage tank outlet valve 13, the foam liquid pump inlet valve 14, the foam liquid pump 15, the foam liquid pump outlet valve 16, and the foam liquid pump outlet recirculation valve 17 form a foam liquid recirculation loop. The foam liquid storage tank 12 contains foam extinguishing agent concentrate (referred to as foam liquid). In this embodiment, the foam liquid is a low conductivity thickening nonionic gel foam liquid.

[0038] The outlets of the fire pump outlet valve 9 and the foam liquid pump outlet valve 16 are both connected to the single-phase binary mixer 18. During operation of the foam supply system, the foam liquid pump inlet valve 14 and the foam liquid pump outlet valve 16 are open. The foam liquid pump 15 delivers a metered amount of foam liquid to the single-phase binary mixer 18, where it mixes with the desalinated water from the fire pump 8 to form a foam-water solution. This solution, composed of low-conductivity, thickened non-ionic gel foam liquid and desalinated water, forms a highly efficient, high-resistance extinguishing liquid, improving fire safety and reducing losses caused by accidental discharge from the fire extinguishing system.

[0039] In this embodiment, the outlet flow rate of the foam liquid pump 15 and the outlet flow rate of the fire pump 8 are in a fixed ratio of 3:97, which can also be adjusted according to the concentration of the foam extinguishing agent concentrate.

[0040] The inert gas supply system includes an inert gas storage tank 19, an inert gas storage tank outlet valve 20, and a gas flow regulator 21 connected sequentially via pipelines. The gas flow regulator 21 is used to regulate the gas flow rate in the inert gas supply system, and its outlet is connected to a multi-phase flow mixer 22. The inert gas used is nitrogen, carbon dioxide, heptafluoropropane, or a mixture of one or more of their haloalkanes. The foam-water solution mixed in the single-phase binary mixer 18 is fully mixed and foamed with the inert gas output from the inert gas supply system in the multi-phase flow mixer 22 to form a stable ternary two-phase flow foam extinguishing liquid with fire extinguishing effect. This invention adopts an "active foaming of inert gas" method, which reduces the mass of the extinguishing liquid, allows the extinguishing liquid to be delivered over a distance covering the entire substation, and can adjust the gas-liquid ratio according to the type of fire source, thereby realizing a protection system covering all major hazardous points of the substation.

[0041] This embodiment employs an inert gas active foaming process combined with a low-conductivity, thickening non-ionic gel foam liquid to form a stable ternary two-phase flow foam extinguishing liquid consisting of inert gas, gel foam, and water. Compared to traditional foam solutions, this ternary two-phase flow foam extinguishing liquid exhibits more stable foam, a longer range, and releases a large amount of inert gas during the extinguishing process, rapidly forming a liquid film covering the surface of the burning object. Simultaneously, the suffocation effect is enhanced, improving extinguishing efficiency. This embodiment modifies all gaseous and liquid media used in the fire extinguishing system, improving overall extinguishing efficiency while also enhancing electrical insulation, viscosity, environmental friendliness, and other indicators.

[0042] The fire extinguishing medium mixing and release system includes a single-phase binary mixer 18, a multi-phase flow mixer 22 connected in series with the single-phase binary mixer, a manual valve 23 at the outlet of the multi-phase flow mixer, a porous foam liquid release pipe 26 for a ring transformer, a foam gun 30, and a foam release pipe for cable trenches. The porous foam liquid release pipe 26 for the ring transformer is arranged in a ring around the transformer, and its surface is coated with a thin fire-retardant coating. The multi-phase flow mixer 22, after passing through the manual valve 23 at the outlet of the multi-phase flow mixer, connects to the porous foam liquid release pipe of the ring transformer via pipelines. The foam liquid discharge pipe 26, foam gun 30, and cable trench foam discharge pipe are connected; the multi-phase flow mixer 22 is connected to the porous foam liquid discharge pipe 26 of the ring transformer through two pipes, and the corresponding pipes are respectively equipped with a first ring transformer porous foam liquid discharge pipe front valve 24 and a second ring transformer porous foam liquid discharge pipe front valve 25; the multi-phase flow mixer 22 is equipped with a cable trench foam liquid discharge pipe front valve 28 on the pipe connecting it to the cable trench foam discharge pipe; the multi-phase flow mixer 22 is equipped with a foam gun delivery pipe front valve 29 on the pipe connecting it to the foam gun 30, which is used to control the operation of the foam gun 30.

[0043] The fire detection and control system includes a fire control host, a heat-sensing fire detector, and an image-type fire detector 27. The image-type fire detector 27 is arranged above the transformer and sends the detected image signal to the fire control host. The heat-sensing fire detector sends the detected temperature signal to the fire control host, which then uses the fire control host to determine the authenticity and source of the signal and issues corresponding instructions.

[0044] As shown in Figure 2, the porous foam liquid dispensing pipe 26 of the ring transformer is equipped with multiple short pipe nozzles 31 and multiple micro-orifice nozzles 32, without protruding branch pipes. Even if a small number of short pipe nozzles or micro-orifice nozzles are damaged due to the explosion of the burning object, the porous foam liquid dispensing pipe of the ring transformer will not lose pressure and affect the dispensing effect. The main body of the porous foam liquid dispensing pipe of the ring transformer is made of high-strength thickened stainless steel, and a thin fireproof coating is applied to the outer layer of stainless steel, allowing it to withstand 1000℃ for 1 hour in an environment, preventing the pipe from deforming due to high temperature. Through these structural settings, the explosion-proof and high-temperature resistance of the fire extinguishing system is improved.

[0045] The multi-scenario fire extinguishing system for power plants in this embodiment is an inert gas foam fire extinguishing system that can adapt to multiple fire scenarios in substations. It uses inert gas for foaming and driving, which shortens the start-up time of the fire extinguishing system, eliminates the introduction of accelerants during the fire extinguishing process, and enhances the suffocation fire extinguishing effect.

[0046] Example 2

[0047] This embodiment provides a method for using the multi-scenario fixed fire extinguishing system for power stations described in Embodiment 1. The content is as follows: When the fire control host determines that there is a real fire signal, the fire control host controls the start and stop of the water supply system, the foam supply system, and the inert gas supply system, as well as the valve opening. According to the source of the fire signal, the gas-liquid ratio of the ternary two-phase flow foam extinguishing liquid is adjusted. The ternary two-phase flow foam extinguishing liquid is released to the transformer, cable trench, and other protected objects through the fire extinguishing medium mixing and release system to achieve fire extinguishing.

[0048] As shown in Figure 3, the method for extinguishing a transformer fire is as follows: After determining that the fire signal originates from oil-filled equipment such as a transformer, the fire control host is switched to transformer fire extinguishing mode. The foam liquid pump and fire water pump are started. The foam liquid is mixed with water, and then mixed with inert gas. The gas-liquid ratio is adjusted to 4:1~7:1, and the flow rate is 3~25L / (m³). 2 (min), through the fire extinguishing medium mixing and release system, the ternary two-phase flow foam fire extinguishing liquid is applied to the transformer to extinguish the fire.

[0049] As shown in Figure 3, the method for extinguishing cable trench fires is as follows: After determining that the fire signal originates from the cable trench, adjust the working mode to cable trench fire extinguishing mode, start the foam liquid pump and fire water pump, mix the foam liquid with water, and then mix it with inert gas, adjust the gas-liquid ratio to 8:1~15:1, and the flow rate to be no less than 200L / min. The three-dimensional two-phase flow foam extinguishing liquid is then delivered to the fire location through the fire extinguishing medium mixing and release system to extinguish the fire.

[0050] As shown in Figure 3, the fire extinguishing method for other protected objects is as follows: After determining that the fire signal originates from other protected objects (such as current transformers, capacitor rooms, etc.), adjust the working mode to single foam gun extinguishing mode, start the foam liquid pump and fire water pump, mix the foam liquid with water, and then mix it with inert gas, adjust the gas-liquid ratio to 15:1~22:1, and the flow rate is not less than 100L / min. Through the extinguishing medium mixing and release system, aim the three-dimensional two-phase flow foam extinguishing liquid at the fire position and carry out fire extinguishing.

[0051] In transformer fire extinguishing or cable trench fire extinguishing mode, fire extinguishing can generally be carried out through the corresponding ring transformer porous foam liquid release pipe or cable trench foam release pipe; if necessary, the foam extinguishing liquid can be sent to the foam gun through the foam gun delivery pipe, and the foam gun can be moved to achieve mobile fire extinguishing, that is, the "fixed and moved combination" fire extinguishing liquid release method of fixed type + foam gun is adopted.

[0052] The technical effects of the above two embodiments are as follows:

[0053] 1) The ring transformer porous foam liquid dispensing pipe adopts the "short pipe nozzle + micro-hole nozzle" and the surface of the ring transformer porous foam liquid dispensing pipe is coated with fireproof coating, which improves the explosion resistance and high temperature resistance of the fire extinguishing system.

[0054] 2) The use of "inert gas active foaming + low conductivity thickening non-ionic gel foam liquid" improves the fire extinguishing efficiency of the fire extinguishing system.

[0055] 3) The flow rate and gas-liquid ratio can be adaptively adjusted according to the source of the fire, which improves the fire extinguishing efficiency and expands the application scope and application scenarios of the fire extinguishing system.

[0056] 4) Use low-conductivity thickening non-ionic gel foam liquid and refined water to form a high-resistance extinguishing liquid, which improves fire extinguishing safety and reduces losses caused by accidental system spraying.

[0057] 5) By adopting the "inert gas active foaming" method, the mass of the foam extinguishing liquid is reduced, and the delivery distance of the foam extinguishing liquid can cover the entire substation, thereby realizing a complete protection system for the main hazardous points of the substation.

[0058] 6) The fire extinguishing liquid is delivered using a fixed delivery pipe and a foam gun in a "fixed-moving combination" manner, which expands the application range of the fire extinguishing system. Due to the adoption of "inert gas active foaming", the mass of the foam extinguishing liquid is reduced, and the fire hose filled with the foam extinguishing liquid is also lighter. The foam gun using this foam extinguishing liquid is easier to operate than the conventional foam gun.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A multi-scenario fixed fire extinguishing system for power stations, characterized in that, This includes water supply systems, foam supply systems, inert gas supply systems, extinguishing medium mixing and release systems, and fire detection and control systems; The water supply system includes a fire water tank (1), a fire water tank outlet valve (3), a fire pump inlet valve (7), a fire pump (8), and a fire pump outlet valve (9) connected in sequence by pipelines; The foam supply system includes a foam liquid storage tank (12), a foam liquid storage tank outlet valve (13), a foam liquid pump inlet valve (14), a foam liquid pump (15), and a foam liquid pump outlet valve (16) connected in sequence by pipelines. The foam liquid storage tank (12) contains foam extinguishing agent concentrate. The inert gas supply system includes an inert gas storage tank (19), an inert gas storage tank outlet valve (20), and a gas flow regulator (21) connected in sequence by pipelines; The fire extinguishing medium mixing and release system includes a single-phase binary mixer (18), a multi-phase flow mixer (22) connected in series with the single-phase binary mixer, a ring transformer porous foam liquid release pipe (26), a foam gun (30), and a cable trench foam release pipe. The ring transformer porous foam liquid release pipe (26) is arranged in a ring around the transformer. The multi-phase flow mixer (22) is connected to the ring transformer porous foam liquid release pipe (26), the foam gun (30), and the cable trench foam release pipe through pipelines. The outlet of the fire pump outlet valve (9) and the outlet of the foam liquid pump outlet valve (16) are both connected to the single-phase binary mixer (18), and the outlet of the gas flow regulator (21) is connected to the multi-phase flow mixer (22). The water pumped by the fire pump (8) and the foam liquid pumped by the foam liquid pump (15) are mixed in the single-phase binary mixer (18) to form a foam aqueous solution. The well-mixed foam aqueous solution and the inert gas output by the inert gas supply system are fully mixed and foamed in the multi-phase flow mixer (22) to form a ternary two-phase flow foam extinguishing liquid. The fire detection and control system includes a fire control host, a heat-sensing fire detector, and an image-type fire detector (27); the image-type fire detector (27) is arranged above the transformer and sends the detected image signal to the fire control host; the heat-sensing fire detector is used to send the detected temperature signal to the fire control host, and the fire control host judges the authenticity and source of the above signal and issues corresponding instructions.

2. The fixed fire extinguishing system for power stations in multiple scenarios according to claim 1, characterized in that, The water supply system also includes a fire pump outlet recirculation valve (10), the inlet of which is connected to the fire pump outlet valve (9), and the outlet of which is connected to the fire water tank (1).

3. A fixed fire extinguishing system for power stations in multiple scenarios according to claim 1, characterized in that, The water supply system also includes a desalination device inlet valve (4), a desalination device (5) and a desalination device outlet valve (6) connected in sequence by pipelines. The outlet of the desalination device outlet valve (6) is connected to the fire water tank (1), and the inlet of the desalination device inlet valve (4) is connected to the outlet pipeline of the fire water tank (1).

4. A fixed fire extinguishing system for power stations in multiple scenarios according to claim 3, characterized in that, The outlet pipe of the fire water tank (1) is equipped with a conductivity meter (2), and the pipe used to connect the outlet valve (9) of the fire pump and the single-phase binary mixer (18) is equipped with a fire water flow meter (11).

5. A multi-scenario fixed fire extinguishing system for power stations according to claim 1, characterized in that, The foam supply system also includes a foam liquid pump outlet recirculation valve (17), the inlet of which is connected to the outlet of the foam liquid pump outlet valve (16), and the outlet of which is connected to the foam liquid storage tank (12).

6. A fixed fire extinguishing system for power stations in multiple scenarios according to claim 1, characterized in that, The porous foam liquid dispensing pipe (26) of the ring transformer is equipped with multiple short pipe nozzles (31) and multiple micro-hole nozzles (32).

7. The method of using the multi-scenario fixed fire extinguishing system for power stations according to any one of claims 1-6, characterized in that, When the fire control host determines that a real fire signal is detected, the fire control host controls the start and stop of the water supply system, the foam supply system, and the inert gas supply system, as well as the valve opening. It adjusts the gas-liquid ratio of the ternary two-phase flow foam extinguishing liquid according to the source of the fire signal, and releases the ternary two-phase flow foam extinguishing liquid to the transformer, cable trench, and other protected objects through the extinguishing medium mixing and release system to achieve fire suppression.

8. The method of using the multi-scenario fixed fire extinguishing system for power stations according to claim 7, characterized in that, The following are the methods for extinguishing transformer fires: After determining that the fire signal originates from the transformer, the fire control host should be switched to transformer fire extinguishing mode. The foam liquid pump and fire water pump should be started. The foam liquid should be mixed with water, and then mixed with inert gas. The gas-liquid ratio should be adjusted to 4:1 to 7:1, and the flow rate should be 3 to 25 L / (m³). 2 (min), through the fire extinguishing medium mixing and release system, the ternary two-phase flow foam fire extinguishing liquid is applied to the transformer to extinguish the fire.

9. The method of using the multi-scenario fixed fire extinguishing system for power stations according to claim 7, characterized in that, The method for extinguishing cable trench fires is as follows: After determining that the fire signal originates from the cable trench, adjust the working mode to cable trench fire extinguishing mode, start the foam liquid pump and fire water pump, mix the foam liquid with water, and then mix it with inert gas, adjust the gas-liquid ratio to 8:1~15:1, and the flow rate to be no less than 200L / min. Through the fire extinguishing medium mixing and release system, the three-dimensional two-phase flow foam fire extinguishing liquid is released to the fire location to extinguish the fire.

10. The method of using the multi-scenario fixed fire extinguishing system for power stations according to claim 7, characterized in that, The fire extinguishing methods for other protected objects are as follows: After determining that the fire signal originates from other protected objects, adjust the working mode to single foam gun extinguishing mode, start the foam liquid pump and fire water pump, mix the foam liquid with water, and then mix it with inert gas, adjust the gas-liquid ratio to 15:1~22:1, and the flow rate is not less than 100L / min. Through the extinguishing medium mixing and release system, aim the three-dimensional two-phase flow foam extinguishing liquid at the fire position and carry out fire extinguishing.

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