Electrochemical energy storage power station liquid nitrogen and water mist linkage cooling and fire extinguishing method

Abstract

The present disclosure relates to the field of firefighting, and particularly to a method for cooling and extinguishing fire by using electrochemical energy storage power station liquid nitrogen and water mist linkage. The extinguishing system used comprises a nitrogen supply device, a nitrogen recovery device, a water supply device and a gas-liquid two-phase flow nozzle; the nitrogen supply device comprises a liquid nitrogen pump, a liquid nitrogen storage tank, a vaporization device, a gas mixing chamber and a pressure boosting device; the nitrogen recovery device comprises a pressure sensor, a nitrogen valve, an air induction device, a rotary separation device, a nitrogen purification device and a cooler; the water supply device comprises a nitrogen branch pipe, a water tank, a water outlet pipe and a water valve; the nitrogen branch pipe is in communication with the top of the water tank; the nozzle is formed with a water channel, a gas phase channel branch pipe and a gas phase channel; the cross-sectional area of the water channel has a trend of first being constant, then decreasing and finally expanding in the water flow direction; the gas phase channel branch pipe is provided with a gas outlet hole; a turbulence protruding part is arranged in the water channel near the gas phase channel branch pipe. The system is green, has high extinguishing efficiency and strong anti-reignition capacity.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of firefighting, and in particular to a method for cooling and extinguishing fire by using electrochemical energy storage power station liquid nitrogen and water mist linkage. BACKGROUND

[0002] The electrochemical energy storage power station is a power supply facility that uses large battery packs to store the excess power of the power grid during the valley period and sends the power back to the power grid during the peak period to alleviate the power supply tension. The electrochemical energy storage power station usually includes an energy storage cabin. The battery packs (such as lithium battery packs) are stored on a support frame with a multi-layer structure. During the storage of the battery packs, a large amount of heat is generated due to mechanical abuse, electrical abuse, or thermal abuse, and if the released heat is not dissipated in time, it will accumulate inside the energy storage cabin, and even cause fire and explosion.

[0003] The conventional fire extinguishing device usually produces toxic and harmful substances during the process of extinguishing fire, or has low extinguishing efficiency for the fire of the electrochemical energy storage power station. SUMMARY

[0004] Technical problem:

[0005] To provide a fire extinguishing system and method suitable for the electrochemical energy storage power station, which has high extinguishing efficiency, strong anti-rekindling ability, and is green, environmentally friendly, and low in cost.

[0006] Technical solution:

[0007] In one aspect, an electrochemical energy storage power station liquid nitrogen and water mist linkage cooling and fire extinguishing system is provided. It comprises: a nitrogen supply device, a nitrogen recovery device, a water supply device, and at least one gas-liquid two-phase flow nozzle; the nitrogen supply device comprises a liquid nitrogen pump, a liquid nitrogen storage tank, a vaporization device, a gas mixing chamber, and a booster device connected in sequence; the gas mixing chamber and the booster device are connected by a first pipeline; the nitrogen recovery device comprises a pressure sensor, a nitrogen valve, an air induction device, a rotary separation device, a nitrogen purification device, and a cooler connected in sequence; the outlet of the cooler is connected with the inlet of the gas mixing chamber; the water supply device comprises a nitrogen branch pipe, a water tank, a water outlet pipe, and a water valve; the inlet of the nitrogen branch pipe is connected with the first pipeline, and the outlet of the nitrogen branch pipe is connected with the top of the water tank; the water outlet pipe is connected with a position close to the bottom of the water tank; the water valve is installed on the water outlet pipe to transport water in the water tank along the water outlet pipe by using the air pressure provided by the nitrogen branch pipe; the gas-liquid two-phase flow nozzle comprises a nozzle body and a nozzle head; a water channel, a gas phase channel branch pipe, and a plurality of gas phase channels are formed in the nozzle body; the inlet end of the water channel is connected with the water outlet pipe; the inlet ends of the gas phase channel branch pipe and the plurality of gas phase channels are respectively connected with the booster device; the outlet ends of the water channel and the plurality of gas phase channels are respectively connected with the nozzle head; the plurality of gas phase channels are uniformly arranged around the water channel; the cross-sectional area of the water channel has a trend of first being constant, then decreasing, and finally expanding in the water flow direction; the gas phase channel branch pipe extends along the central axis of the water channel, the end opposite to the inlet end of the gas phase channel branch pipe is closed, and a plurality of gas outlet holes are formed on the gas phase channel branch pipe in different directions; the plurality of gas outlet holes are located upstream of the neck of the water channel; a plurality of turbulence protrusions are further arranged on the inner wall of the water channel close to the gas phase channel branch pipe.

[0008] In some embodiments, the number of gas phase channels is four; the four gas phase channels are uniformly arranged on the circumference of the water channel.

[0009] In some embodiments, the angle between the tangent direction of the outlet end of the gas phase channel and the central axis direction of the water channel is 60°.

[0010] In some embodiments, the shape of the gas outlet hole is square.

[0011] In some embodiments, the electrochemical energy storage power station liquid nitrogen and water mist linkage cooling and fire extinguishing system further comprises a humidity sensor, a controller and a ventilation device; the electrochemical energy storage power station comprises an energy storage cabin; the humidity sensor is configured to monitor the humidity in the energy storage cabin; the ventilation device is configured to enable or disable the gas exchange between the energy storage cabin and the outdoor environment; the controller is electrically connected with the humidity sensor, the water valve and the ventilation device respectively; the controller is configured to: when it is determined that the data of the humidity sensor is outside the preset range, control the water valve to close, while keeping the gas phase channel branch and a plurality of the gas phase channels open; the water tank contains pure water.

[0012] In some embodiments, a gas phase channel main pipe is further formed in the gas-liquid two-phase flow nozzle; the inlet end of the gas phase channel main pipe is in communication with the pressure increasing device; the outlet end of the gas phase channel main pipe is in communication with a gas phase channel branch and a plurality of gas phase channels respectively; the main body part of a plurality of the gas phase channels extends in a straight line and is located outside the water channel.

[0013] In some embodiments, at least one air channel is further formed in the nozzle body near the nozzle head; the air channel is configured to communicate external air with the gas phase channel; a one-way air inlet valve is installed on the air channel.

[0014] In some embodiments, a recovery nitrogen gas inlet valve and a first thermometer are further installed on the pipeline between the cooler and the gas mixing chamber.

[0015] In some embodiments, the water tank contains a composite aqueous solution containing 10% potassium chloride and 10% ammonium dihydrogen phosphate.

[0016] In some embodiments, the nozzle port of the nozzle head is hexagonal in shape.

[0017] In some embodiments, the vaporization device is an air temperature type vaporization device.

[0018] In some embodiments, the number of the gas-liquid two-phase flow nozzles is a plurality; a plurality of layers of support frames are arranged in the energy storage cabin; a plurality of battery groups are layered and placed on the plurality of layers of support frames; a plurality of the gas-liquid two-phase flow nozzles are respectively arranged facing the top surface and the side surface of the battery groups, and a preset distance is maintained between the gas-liquid two-phase flow nozzles and the battery groups.

[0019] In some embodiments, a liquid nitrogen inlet valve is installed at the inlet end of the vaporization device, and a nitrogen gas outlet valve, a nitrogen gas flow meter and a second thermometer are installed at the outlet end of the vaporization device.

[0020] In some embodiments, a first pressure gauge is installed on the nitrogen branch pipe; a water flow meter is also installed on the water outlet pipe; a second pressure gauge is also installed on the pipeline between the pressure boosting device and the gas-liquid two-phase flow nozzle; a nitrogen flow control valve is installed on the gas phase channel.

[0021] In another aspect, a method for cooling and extinguishing fire by using liquid nitrogen and water mist in an electrochemical energy storage power station is also provided. The method is based on the aforementioned cooling and extinguishing system, and comprises the following steps: when it is determined to start the nitrogen recovery device, the recovered nitrogen inlet valve is controlled to adjust the flow of recovered nitrogen into the gas mixing chamber according to the data of the first and second thermometers.

[0022] In some embodiments, the method comprises the following steps:

[0023] According to the measured data of the nitrogen flow meter and the second thermometer, the nitrogen outlet valve is controlled to adjust the flow of nitrogen out of the vaporization device and control the temperature of the nitrogen out of the vaporization device, wherein the temperature of the nitrogen out of the vaporization device is above 0 degrees;

[0024] When it is determined that the data of the pressure sensor is within the preset pressure range, the nitrogen valve is opened to start the nitrogen recovery device.

[0025] In some embodiments, the method further comprises the following steps:

[0026] According to the measured data of the first pressure gauge and the water flow meter, the flow of nitrogen in the nitrogen branch pipe and the water valve are controlled to adjust the water flow in the water channel;

[0027] The nitrogen flow control valve is controlled to adjust the nitrogen flow in the gas phase channel by the pressure value of the second pressure gauge reaching 0.5 MPa through the pressure boosting device;

[0028] By adjusting the water flow in the water channel and the nitrogen flow in the gas phase channel, the mixing ratio of nitrogen and water at the nozzle head is adjusted, and the atomization effect of the water mist sprayed by the nozzle head is adjusted.

[0029] Advantages:

[0030] 1. The liquid nitrogen cooling and extinguishing fire and the water mist cooling and extinguishing fire are coupled together by a specially designed liquid nitrogen and water mist cooling and extinguishing system, which is simple in structure, green, high in extinguishing efficiency, strong in anti-reburning ability, does not cause damage to the equipment in the electrochemical energy storage power station, and low in extinguishing cost.

[0031] 2. Unlike existing methods that directly use nitrogen for fire extinguishing, this invention utilizes a liquid nitrogen storage tank in conjunction with a vaporization device to supply low-temperature nitrogen. The nitrogen temperature can be adjusted as needed, resulting in a better cooling and fire extinguishing effect.

[0032] 3. This invention uses a nitrogen branch pipe to enter the top of the water tank and makes reasonable use of nitrogen pressure to transport water in the water tank to the gas-liquid two-phase flow nozzle. It does not require high-energy-consuming power devices such as water pumps. The equipment has a simple structure, low energy consumption and equipment cost, and can ensure the high-pressure fine water mist effect of the gas-liquid two-phase flow nozzle.

[0033] 4. This invention also introduces a nitrogen recovery device, which controls the opening and closing of the nitrogen valve based on data from a pressure sensor, thereby controlling the nitrogen recovery device's operation. When the nitrogen recovery device is activated, a negative pressure is created inside the fire-fighting space of the electrochemical energy storage power station through an induced draft device, drawing the gases generated by the fire and firefighting into the nitrogen recovery pipeline, reducing the gas pressure and combustible gas content inside the fire-fighting space. A rotary separator separates nitrogen from the mixed gas; a nitrogen purification device purifies the separated nitrogen; a cooler cools the purified nitrogen to obtain recovered nitrogen; finally, the recovered nitrogen is mixed with low-temperature nitrogen flowing from the vaporization device in a gas mixing chamber. By recycling nitrogen through the nitrogen recovery device, nitrogen utilization can be improved, costs reduced, fire-fighting efficiency enhanced, and environmental protection strengthened.

[0034] 5. This invention also optimizes the structure of the gas-liquid two-phase flow nozzle, achieving efficient linkage between low-temperature nitrogen and fine water mist. This effectively improves the atomization degree and spray intensity of the fine water mist, resulting in a low failure rate. It can efficiently absorb the heat generated by a fire, providing rapid cooling; simultaneously, it isolates oxygen and other oxidizers from contact with combustibles, inhibiting the occurrence and spread of fire; and it possesses excellent rapid fire extinguishing capabilities and resistance to reignition.

[0035] Low-temperature nitrogen-assisted atomization is used. The gas-liquid two-phase flow nozzle can fully mix low-temperature nitrogen and water, so that water and nitrogen form a uniform two-phase mixture of nitrogen and fine water mist under mutual impact. The fine water mist and nitrogen are sprayed out from the same nozzle head to cool and extinguish the fire, which improves the atomization level of fine water mist.

[0036] By using multiple air outlets on the gas phase channel branch pipe, some nitrogen gas is introduced into the water channel, causing the liquid to break into large droplets, liquid filaments, and liquid films, and then break into small droplets, thereby improving the atomization effect at the nozzle head.

[0037] The turbulence protruding part is arranged in the water channel, which increases the turbulence degree of water in the water channel, so that the water is broken into small droplets, and the atomization degree is improved; on the other hand, the turbulence protruding part is close to the gas phase channel branch pipe, and can guide part of the water flow out of the air hole, so that the water flow and the nitrogen gas flowing out of the gas phase channel branch pipe interact more easily, so as to reduce the water mist particle size of the fine water mist and improve the atomization effect.

[0038] By designing the structure of the water channel in the direction of water flow, the cross-sectional area of the water channel is first constant, then reduced, and finally expanded, so that the water flow rate can be improved, a negative pressure is formed at the nozzle head, and the atomization degree of the fine water mist is improved. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present disclosure, the drawings needed in some embodiments of the present disclosure will be briefly introduced below, however, the drawings in the following description are only the drawings of some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art according to these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limited to the actual size of the products involved in the embodiments of the present disclosure.

[0040] Figure 1 Structure schematic diagram of the liquid nitrogen and fine water mist linkage cooling and fire extinguishing system of the electrochemical energy storage power station of some embodiments;

[0041] Figure 2 For Figure 1 Layout sectional structure schematic diagram of the gas-liquid two-phase flow nozzle;

[0042] Figure 3 Layout schematic diagram of the liquid nitrogen and fine water mist linkage cooling and fire extinguishing system of the electrochemical energy storage power station of some embodiments in the energy storage cabin;

[0043] Figure 4 The relative position of the gas-liquid two-phase flow nozzle and the battery pack of some embodiments is shown. DETAILED DESCRIPTION

[0044] The technical solutions in some embodiments of the present disclosure will be described clearly and completely below in combination with the drawings, obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments provided in the present disclosure, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present disclosure.

[0045] Unless otherwise required by context, as used herein, the term "comprises" or "comprising" is to be interpreted as an open term meaning "including but not limited to," and the like. In describing the embodiments, specific terminology is employed for the sake of clarity. However, the disclosure should not be construed as limited to the specific terminology so selected. A person skilled in the art will recognize that the embodiments described can be practiced with modifications and changes, which are not specified in detail. Any and all such modifications and changes are intended to be included within the meaning and range of equivalents of the particular embodiments described.

[0046] Hereinafter, the terms "first", "second", etc. are used only for the purpose of description and should not be construed as indicating or implying relative importance or indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise stated.

[0047] In describing some embodiments, "coupled" and "connected", and variations thereof, can be used. The term "connected" is to be interpreted broadly, for example, "connected" can be fixedly connected, or detachably connected, or integrated; can be directly connected, or connected through an intermediate medium. The term "coupled" indicates that two or more components have direct physical contact or electrical contact. The term "coupled" or "communicatively coupled" can also mean that two or more components do not have direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content herein.

[0048] "A, B, and C at least one of" has the same meaning as "at least one of A, B, or C", and includes the following combinations of A, B, and C: only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B, and C.

[0049] "A and / or B" includes the following three combinations: only A, only B, and a combination of A and B.

[0050] As used herein, the term "if' is optionally interpreted as meaning "when" or "upon" or "in response to a determination" or "in response to a detection" depending on the context. Similarly, the phrase "if determined" or "if detected [a stated condition or event]" is optionally interpreted as meaning "upon a determination" or "in response to a determination" or "upon a detection" or "in response to a detection" depending on the context.

[0051] The use of "adapted to" or "configured to" herein means open and inclusive language that does not exclude additional devices or steps not explicitly described.

[0052] Additionally, the use of "based on" means open and inclusive language that does not exclude additional conditions or values from being used in the process, step, calculation, or other action.

[0053] As used herein, "about," "approximately," or "around" includes the recited value and the average value within an acceptable range of deviation from the particular value, as determined by one of ordinary skill in the art considering the measurement being discussed and the error in measurement associated with the particular quantity being measured (i.e., the limitations of the measurement system).

[0054] As used herein, "parallel," "perpendicular," and "equal" include the recited condition and conditions that approximate the recited condition, the approximation being within an acceptable range of deviation, as determined by one of ordinary skill in the art considering the measurement being discussed and the error in measurement associated with the particular quantity being measured (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and near parallel, where near parallel can be within an acceptable range of deviation of, for example, 5°; "perpendicular" includes absolute perpendicular and near perpendicular, where near perpendicular can also be within an acceptable range of deviation of, for example, 5°. "Equal" includes absolute equality and near equality, where near equality can be within an acceptable range of deviation of, for example, less than or equal to 5% of either of the two quantities being compared.

[0055] In some embodiments, an electrochemical energy storage power plant liquid nitrogen and water mist combined cooling and fire extinguishing system 1000 is provided. As shown in Figures 1 to 4 The system includes a nitrogen supply device 100, a nitrogen recovery device 200, a water supply device 300, and at least one gas-liquid two-phase flow nozzle 400.

[0056] The nitrogen supply device 100 comprises a liquid nitrogen pump 12, a liquid nitrogen storage tank 11, a vaporization device 13 (for example, an air temperature vaporizer), a gas mixing chamber 14 and a pressurizing device 15 which are sequentially communicated. The gas mixing chamber 14 and the pressurizing device 15 are communicated through a first pipeline. Specifically, the liquid nitrogen pump 12 is communicated with the liquid nitrogen storage tank 11 through a pipeline, so that the liquid nitrogen pump 12 can pressurize the liquid nitrogen storage tank 11 to output the liquid nitrogen in the liquid nitrogen storage tank 11 to the vaporization device 13. When cooling and extinguishing fire is needed, the working principle of the nitrogen supply device is as follows: the liquid nitrogen storage tank 11 is pressurized by the liquid nitrogen pump 12 to output the liquid nitrogen in the liquid nitrogen storage tank 11 to the vaporization device 13. The liquid nitrogen is vaporized into nitrogen gas above 0 degrees by the vaporization device 13 (for example, an air temperature vaporizer). The nitrogen gas is pressurized to 0.5 MPa by the pressurizing device 15 and is delivered to the gas-liquid two-phase flow nozzle 400 at low pressure.

[0057] The nitrogen recovery device 200 comprises a pressure sensor 21, a nitrogen valve 22, an air induction device 23, a rotary separation device 24, a nitrogen purification device 25 and a cooler 26 which are sequentially communicated through a nitrogen recovery pipeline 211; the gas outlet of the cooler 26 is communicated with the gas inlet of the gas mixing chamber 14. The opening and closing of the nitrogen valve 22 is controlled according to the data of the pressure sensor 21. Specifically, the nitrogen valve 22 is installed on the space to be extinguished (for example, the energy storage cabin 2000) of the electrochemical energy storage power station. When it is determined that the pressure in the space to be extinguished (for example, the energy storage cabin 2000) of the electrochemical energy storage power station is within a preset pressure range, that is, the pressure data of the pressure sensor 21 is within the preset pressure range, the nitrogen valve 22 is opened to start recovering nitrogen. When it is needed to open the nitrogen recovery device 200, the nitrogen valve 22 is opened, the air induction device 23 is used to generate negative pressure inside the space to be extinguished (for example, the energy storage cabin 2000) of the electrochemical energy storage power station, the gas generated by fire and extinguishing is sucked into the nitrogen recovery pipeline 211 to reduce the internal pressure and the content of combustible gas in the space to be extinguished; the rotary separation device 24 is used to separate nitrogen from the mixed gas; the nitrogen purification device 25 is used to purify the separated nitrogen; the cooler 26 is used to cool the purified nitrogen to obtain recovered nitrogen; finally, the recovered nitrogen is mixed with the low-temperature nitrogen flowing out of the vaporization device 13 in the gas mixing chamber 14. Thus, the nitrogen supply device 100 and the nitrogen recovery device 200 in the embodiment are communicated to form a loop, and the mixing of the nitrogen provided by the nitrogen supply device 100 and the recovered nitrogen provided by the nitrogen recovery device 200 is realized. The nitrogen is recovered and recycled by the nitrogen recovery device 200, which can improve the utilization rate of nitrogen, reduce the cost, help to improve the efficiency of extinguishing fire and strengthen the protection of the environment.

[0058] The water supply device 300 comprises a nitrogen branch pipe 31, a water tank 32, a water outlet pipe 33 and a water valve 34. The gas inlet of the nitrogen branch pipe 31 is communicated with the first pipeline, and the gas outlet of the nitrogen branch pipe 31 is communicated with the top of the water tank 32. The water outlet pipe 33 is communicated with the water tank 32 near the bottom. The water valve 34 is installed on the water outlet pipe 33. The water valve 34 is configured to adjust the water flow rate of the water outlet pipe 33. Thus, part of the nitrogen in the first pipeline can enter the top of the water tank 32 through the nitrogen branch pipe 31, so as to use the nitrogen pressure to deliver the water in the water tank 32 to the gas-liquid two-phase flow nozzle 400. The water supply device 300 of the embodiment does not need high-energy-consumption power devices such as water pumps, and the equipment structure is simple, the energy consumption and equipment cost are low, the delivery of water from the water tank 32 to the gas-liquid two-phase flow nozzle 400 can be realized, and the high-pressure fine water mist effect of the gas-liquid two-phase flow nozzle 400 can be ensured.

[0059] The gas-liquid two-phase flow nozzle 400 comprises a nozzle body 41 and a nozzle head 42; the nozzle body 41 is internally formed with a water channel 411, a gas phase channel branch pipe 412 and a plurality of gas phase channels 413; the inlet end of the water channel 411 is in communication with the water outlet pipe; the gas phase channel branch pipe 413 and the inlet end of the plurality of gas phase channels 413 are respectively in communication with the pressurizing device 15; the outlet end of the water channel 411 and the plurality of gas phase channels 413 are respectively in communication with the nozzle head 42; the plurality of gas phase channels 413 are uniformly arranged around the water channel 411; the cross-sectional area of the water channel 411 presents a trend of first being constant, then being reduced and finally being enlarged in the water flow direction; the gas phase channel branch pipe 412 extends along the central axis of the water channel 411, the end of the gas phase channel branch pipe 412 opposite to the inlet end is closed, a plurality of gas outlet holes 4121 are formed on the gas phase channel branch pipe 412 in different directions; the plurality of gas outlet holes 4121 are all located upstream of the necked portion 4111 of the water channel 411; a plurality of turbulence protrusions 4112 are further arranged on the inner wall of the water channel 411 near the position of the gas phase channel branch pipe 412. The gas-liquid two-phase flow nozzle 400 is configured to link the nitrogen supply device 100 and the water supply device 300. The nitrogen supply device 100 is used to provide liquid nitrogen. The liquid nitrogen has the characteristics of low temperature and non-combustibility, and can be used as fire extinguishing, can quickly reduce temperature and isolate oxygen, and will not cause damage to the equipment in the electrochemical energy storage power station, and is green and environmentally friendly. The water supply device 300 and the gas-liquid two-phase flow nozzle 400 are used together to generate fine water mist. The fine water mist has small water mist particle size, can increase the contact area with air, improve the heat absorption capacity of fire extinguishing, can effectively reduce the temperature generated by fire explosion, thereby being beneficial to fire extinguishing. The nitrogen supply device 100 and the water supply device 300 of the embodiment have simple structure. Through the optimization design of the gas-liquid two-phase flow nozzle 400: low-temperature nitrogen gas is used for auxiliary atomization, the gas-liquid two-phase flow nozzle 400 can fully mix the low-temperature nitrogen gas and water, so that the water and the nitrogen gas form a uniform two-phase mixture of nitrogen gas and fine water mist under mutual impact, the fine water mist and the nitrogen gas are sprayed out from the same nozzle head 42 to cool and extinguish the fire, and the atomization level of the fine water mist is improved; the plurality of gas outlet holes 4121 on the gas phase channel branch pipe 412 are used to introduce part of the nitrogen gas into the water channel 411, so that the liquid is broken into large droplets, liquid filaments and liquid membranes, and then broken into small droplets, thereby being beneficial to improving the atomization effect at the nozzle head 42; the turbulence protrusions 4112 are arranged on one hand to increase the turbulence degree of the water in the water channel 411, so that the water is broken into small droplets and the atomization degree is improved; on the other hand, since the turbulence protrusions 4112 are close to the gas phase channel branch pipe 412, part of the water flow can be guided to the gas outlet holes 4121, thereby being more beneficial to the interaction between the water flow and the nitrogen gas flowing out of the gas phase channel branch pipe 412, so as to reduce the water mist particle size of the fine water mist and improve the atomization effect; through the trend of the cross-sectional area of the water channel 411 being first constant, then being reduced and finally being enlarged in the water flow direction, the water flow rate can be improved, a negative pressure is formed at the nozzle head 42, and thereby the atomization degree of the fine water mist is improved.In summary, the gas-liquid two-phase flow nozzle 400 effectively improves the atomization degree and spray intensity of fine water mist, achieves efficient linkage between nitrogen and fine water mist, has strong spray capability, low failure rate, can efficiently absorb the heat generated by fire, and plays a role in rapid cooling; at the same time, it isolates oxygen and other oxidizers from contact with combustibles, inhibiting the occurrence and spread of fire; it has good rapid fire extinguishing capability and anti-reignition capability.

[0060] This embodiment achieves a high-pressure fine water mist effect while reducing the fine water mist delivery pressure based on the aforementioned structure. It has strong spray pressure, simple structure, is green and environmentally friendly, will not damage the equipment in the electrochemical energy storage power station, and has low fire extinguishing cost.

[0061] In some embodiments, a third pressure gauge 111 is connected to the pipeline between the liquid nitrogen pump 12 and the liquid nitrogen storage tank 11, thereby enabling real-time monitoring of the pressure data of the pipeline. A liquid nitrogen flow meter 1301 is connected to the nitrogen pipeline 130 between the liquid nitrogen pump 12 and the vaporization device 13, thereby enabling real-time monitoring of the liquid nitrogen flow data of the nitrogen pipeline 130.

[0062] In some embodiments, such as Figure 2 As shown, there are four gas phase channels 413; the four gas phase channels 413 are evenly arranged around the water channel 411. For example, the four gas phase channels 413 are arranged above, below, left, and right of the water channel 411.

[0063] In some embodiments, the angle between the tangential direction of the outlet end of the gas phase channel 413 and the central axis direction of the water channel 411 is 60°.

[0064] In some embodiments, the air vent 4121 is square in shape.

[0065] In the process of using water mist to extinguish the fire of the electrochemical energy storage power station, part of the water mist droplets will quickly vaporize, part of the water mist droplets can be suspended in the air for a long time, and only a small part of the water mist will fall on the surface of the battery and enter the internal circuit of the battery. The water mist that enters the internal circuit of the battery is also very small in diameter, and a very large number of droplets and a very long time are needed to complete the condensation and coagulation, so it is difficult to form a continuous water flow or surface water area that can conduct electricity. Therefore, water mist can be used for extinguishing the fire of the electrochemical energy storage power station, but long-term water mist injection may form a conductive water flow in the internal circuit of the battery, causing the battery to short circuit. In order to solve the above technical problems, in some embodiments, the electrochemical energy storage power station liquid nitrogen and water mist linkage cooling and fire extinguishing system 1000 further comprises a humidity sensor, a controller and a ventilation device; the electrochemical energy storage power station comprises an energy storage cabin 2000; the humidity sensor is configured to monitor the humidity (and water mist concentration) in the energy storage cabin 2000; the ventilation device is configured to enable the energy storage cabin 2000 to exchange gas with the outdoor environment; the controller is electrically connected with the humidity sensor, the water valve 34 and the ventilation device; the controller is configured to: when the data of the humidity sensor is determined to be outside the preset range, control the water valve 34 to be closed, and at the same time keep the gas phase passage branch pipe 412 and the plurality of gas phase passages 413 open; the water tank 32 contains pure water.

[0066] Based on the electrochemical energy storage power station liquid nitrogen and water mist linkage cooling and fire extinguishing system 1000 of the embodiment, the following measures can be taken to reduce the accumulation of water mist and reduce the possibility of battery short circuit:

[0067] (1) Use pure water with lower conductivity as the extinguishing medium;

[0068] (2) Monitor the humidity by the humidity sensor to confirm whether the water mist concentration is within the safe range, and automatically close the water valve 34 or manually close the water valve 34 by the controller to close the water passage 411, stop the water mist supply, and continue to keep the gas phase passage branch pipe 412 and the plurality of gas phase passages 413 open to cool and extinguish the fire by low-temperature nitrogen gas;

[0069] (3) After the fire is controlled, the ventilation device is opened in time to ventilate the energy storage cabin 2000, which can timely exhaust the water mist suspended in the air, reduce the accumulation of water mist and reduce the possibility of battery short circuit.

[0070] In some embodiments, a ventilation device is installed on the top of the energy storage chamber 2000, and a pressure relief valve is provided inside it. The opening and closing of the pressure relief valve is controlled according to the data of the pressure sensor 21. Specifically, when it is determined that the pressure inside the energy storage chamber 2000 is higher than a preset pressure value, that is, the pressure data of the pressure sensor 21 is higher than the preset pressure value (the preset pressure value is greater than the upper limit of the aforementioned preset pressure range), the pressure relief valve opens, and ventilation and pressure relief begin through the ventilation device; when it is determined that the pressure inside the energy storage chamber 2000 is lower than the preset pressure value, that is, the pressure data of the pressure sensor 21 is lower than the preset pressure value but within the preset pressure range, the pressure relief valve closes, the nitrogen valve 22 opens, and nitrogen is recovered to relieve pressure in the energy storage chamber 2000.

[0071] In some embodiments, such as Figure 2 As shown, a gas phase channel main pipe 414 is also formed inside the gas-liquid two-phase flow nozzle 400; the inlet end of the gas phase channel main pipe 414 is connected to the pressurization device 15; the outlet end of the gas phase channel main pipe 414 is connected to the gas phase channel branch pipe 412 and multiple gas phase channels 413 respectively; the main body of the multiple gas phase channels 413 extends in a straight line and is located outside the water channel 411. Thus, nitrogen injection into the gas phase channel branch pipe 412 and multiple gas phase channels 413 can be achieved through a single port at the inlet end of the gas phase channel main pipe 414, which helps to reduce the size of the gas-liquid two-phase flow nozzle 400.

[0072] In some embodiments, such as Figure 2 As shown, at least one air passage 415 is formed inside the nozzle body 41 near the nozzle head 42; the air passage 415 is configured to connect external air with the gas phase passage 413; a one-way air intake valve 4151 is installed on the air passage 415. Upstream of the nozzle head 42, water is accelerated in the water passage 411 (the cross-sectional area of ​​the water passage 411 first shrinks), and the water flow velocity is high, forming a negative pressure at the atomization chamber of the nozzle head 42. A pressure difference is formed between the external atmospheric pressure and the liquid pressure inside the jet section. When the one-way air intake valve 4151 is opened, air enters the atomization chamber of the nozzle head 42 through the one-way air intake valve 4151, and interacts with the water to form a fine water mist. Therefore, the one-way air intake valve 4151 can be opened as needed to allow air to enter, utilizing the interaction of air and water to form a fine water mist, reducing or stopping the supply of nitrogen, thus saving liquid nitrogen resources and reducing fire extinguishing costs.

[0073] In some embodiments, such as Figure 2 As shown, a nitrogen recovery inlet valve 261 and a first thermometer 262 are also installed on the pipeline between the cooler 26 and the gas mixing chamber 14. The nitrogen recovery inlet valve 261 is used to control the flow rate of recovered nitrogen into the gas mixing chamber 14.

[0074] In some embodiments, the water tank 32 contains a composite aqueous solution containing potassium chloride at a concentration of 10% and ammonium dihydrogen phosphate at a concentration of 10%. In this way, the heat absorption capacity of the fine water mist and its atomization capacity are effectively improved, the cooling capacity of the fine water mist is improved, and the fire extinguishing speed is improved.

[0075] In some embodiments, the nozzle port of the nozzle head 42 is hexagonal in shape. In this way, the degree of last atomization of the fine water mist before being sprayed by the nozzle head 42 can be effectively improved.

[0076] In some embodiments, the vaporization device 13 is an adiabatic vaporizer.

[0077] In some embodiments, as shown in Figure 3 and Figure 4 The number of gas-liquid two-phase flow nozzles 400 is multiple; the electrochemical energy storage power station includes an energy storage cabin 2000; the energy storage cabin 2000 is provided with a plurality of multi-layer support frames 500; the multi-layer support frames 500 are layered and contain a plurality of battery packs 600; the plurality of gas-liquid two-phase flow nozzles 400 are respectively arranged to face the top surface and the side surface of the battery packs 600, and a predetermined distance is maintained between the gas-liquid two-phase flow nozzles 400 and the battery packs 600. In this way, the gas-liquid two-phase flow nozzles 400 are arranged in two dimensions of vertical and horizontal within the energy storage cabin 2000, and a predetermined distance is maintained between the gas-liquid two-phase flow nozzles 400 and the battery packs 600, which effectively cools and isolates oxygen while reducing the probability of fine water mist falling on the surface of the battery and entering the internal circuit of the battery.

[0078] For example, three gas-liquid two-phase flow nozzles 400 are arranged in each battery pack, two of which are arranged horizontally and one of which is arranged vertically, to extinguish and cool the thermal runaway battery from two directions of horizontal and vertical.

[0079] In some embodiments, as shown in Figure 1 The inlet end of the vaporization device 13 is provided with a liquid nitrogen inlet valve 131, and the outlet end of the vaporization device 13 is provided with a nitrogen outlet valve 132, a nitrogen flow meter 133, and a second thermometer 134. In this way, the flow of liquid nitrogen into the vaporization device 13 can be adjusted by adjusting the liquid nitrogen inlet valve 131. The flow rate of nitrogen gas flowing out of the vaporization device 13 is adjusted by the nitrogen outlet valve 132, thereby adjusting the temperature of the nitrogen gas flowing out of the vaporization device 13. The faster the flow rate of nitrogen gas flowing out of the vaporization device 13, the lower the temperature of the nitrogen gas flowing out; the slower the flow rate of nitrogen gas flowing out of the vaporization device 13, the higher the temperature of the nitrogen gas flowing out.

[0080] In some embodiments, as shown in Figure 1The first pressure gauge 311 is installed on the nitrogen branch pipe 31. The water flow meter 331 is installed on the water outlet pipe 33. The second pressure gauge 151 is installed on the pipeline between the pressure boosting device 15 and the gas-liquid two-phase flow nozzle 400. The nitrogen flow control valve 4131 is installed on the gas phase channel 413.

[0081] In some embodiments, a method for cooling and extinguishing fire by using liquid nitrogen and water mist in an electrochemical energy storage power station is provided. The method is based on the aforementioned cooling and extinguishing system 1000, and comprises the following steps:

[0082] When it is determined to start the nitrogen recovery device 200, the recovery nitrogen inlet valve 261 is controlled according to the data of the first thermometer 262 and the second thermometer 134 to adjust the flow rate of the recovery nitrogen into the gas mixing chamber 14.

[0083] In some embodiments, the method comprises the following steps:

[0084] According to the measured data of the nitrogen flow meter 133 and the second thermometer 134, the liquid nitrogen inlet valve 131 is controlled to adjust the flow rate of the liquid nitrogen into the vaporization device 13. The nitrogen outlet valve 134 is controlled to adjust the flow rate of the nitrogen flowing out of the vaporization device 13 to control the temperature of the nitrogen flowing out of the vaporization device 13, wherein the temperature of the nitrogen flowing out of the vaporization device is above 0 degrees.

[0085] When it is determined that the data of the pressure sensor 21 is within the preset pressure range, the nitrogen valve 22 is opened to start the nitrogen recovery device 200.

[0086] In some embodiments, the method further comprises the following steps:

[0087] According to the measured data of the first pressure gauge 311 and the water flow meter 331, the flow rate of the nitrogen in the nitrogen branch pipe 31 and the water valve 34 are controlled to adjust the flow rate of the water in the water channel 411.

[0088] The nitrogen flow control valve 4131 is controlled to adjust the flow rate of the nitrogen in the gas phase channel 413 by the pressure boosting device 15 to make the pressure value of the second pressure gauge 151 reach 0.5 MPa.

[0089] The mixing ratio of the nitrogen and the water at the nozzle head 42 is adjusted by adjusting the flow rate of the water in the water channel 411 and the flow rate of the nitrogen in the gas phase channel 413 to adjust the spraying area, the atomization degree, and the spraying intensity of the water mist sprayed by the nozzle head 42.

[0090] In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0091] The above merely provides the specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, any person skilled in the art can think of the changes or replacements within the technical range disclosed by the present disclosure, which should be covered in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A liquid nitrogen and fine water mist combined cooling and fire extinguishing system for an electrochemical energy storage power station, characterized in that, include: A nitrogen supply device, a nitrogen recovery device, a water supply device, and at least one gas-liquid two-phase flow nozzle; The nitrogen supply device includes a liquid nitrogen pump, a liquid nitrogen storage tank, a vaporization device, a gas mixing chamber, and a pressurization device connected in sequence; the gas mixing chamber and the pressurization device are connected by a first pipeline; The nitrogen recovery device includes a pressure sensor, a nitrogen valve, an exhaust fan, a rotary separator, a nitrogen purification device, and a cooler connected in sequence; the outlet of the cooler is connected to the inlet of the gas mixing chamber. The water supply device includes a nitrogen branch pipe, a water tank, a water outlet pipe, and a water valve; the inlet of the nitrogen branch pipe is connected to the first pipeline, and the outlet of the nitrogen branch pipe is connected to the top of the water tank; the water outlet pipe is connected to a position near the bottom of the water tank; the water valve is installed on the water outlet pipe to use the gas pressure provided by the nitrogen branch pipe to transport water from the water tank to the outside along the water outlet pipe; The gas-liquid two-phase flow nozzle includes a nozzle body and a nozzle head. The nozzle body contains a water channel, a gas phase channel branch pipe, and multiple gas phase channels. The inlet end of the water channel is connected to the outlet pipe. The inlet ends of the gas phase channel branch pipe and the multiple gas phase channels are respectively connected to the pressurization device. The outlet ends of the water channel and the multiple gas phase channels are respectively connected to the nozzle head. The multiple gas phase channels are evenly arranged around the water channel. The cross-sectional area of ​​the water channel initially remains constant, then decreases, and finally increases in the direction of water flow. The gas phase channel branch pipe extends along the central axis of the water channel, and its end opposite to its inlet end is sealed. Multiple air outlets are provided on the gas phase channel branch pipe in different directions. All air outlets are located upstream of the constriction point of the water channel. Multiple turbulence protrusions are also provided on the inner wall of the water channel near the gas phase channel branch pipe. At least one air passage is formed in the nozzle body near the nozzle head; the air passage is configured to connect external air with the gas phase passage; a one-way air intake valve is installed on the air passage.

2. The electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 1, characterized in that, The angle between the tangent direction at the outlet end of the gas phase channel and the central axis direction of the water channel is 60°; the shape of the gas outlet is square.

3. The electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 1, characterized in that, It also includes humidity sensors, controllers, and ventilation devices; The electrochemical energy storage power station includes an energy storage chamber; the humidity sensor is configured to monitor the humidity inside the energy storage chamber; and the ventilation device is configured to open and close to allow gas exchange between the energy storage chamber and the outdoor environment. The controller is electrically connected to the humidity sensor, the water valve, and the ventilation device, respectively. The controller is configured to: when it is determined that the data of the humidity sensor exceeds a preset range, control the water valve to close, while keeping the gas phase channel branch pipe and the multiple gas phase channels open; The water tank contains purified water.

4. The electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 1, characterized in that, A gas phase channel main pipe is also formed inside the gas-liquid two-phase flow nozzle; the inlet end of the gas phase channel main pipe is connected to the pressurization device; the outlet end of the gas phase channel main pipe is connected to gas phase channel branch pipes and multiple gas phase channels respectively. The main body of each of the gas phase channels extends in a straight line and is located outside the water channel.

5. The electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 1, characterized in that, The number of gas-liquid two-phase flow nozzles is multiple; the electrochemical energy storage power station includes an energy storage compartment; the energy storage compartment is equipped with a multi-layer support frame; multiple battery packs are placed on the multi-layer support frame in layers. Multiple gas-liquid two-phase flow nozzles are respectively arranged facing the top and side surfaces of the battery pack, and the gas-liquid two-phase flow nozzles maintain a preset distance from the battery pack.

6. The electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to any one of claims 1 to 5, characterized in that, The vaporization device is equipped with a liquid nitrogen inlet valve at its inlet end and a nitrogen outlet valve, a nitrogen flow meter, and a second thermometer at its outlet end.

7. The electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 6, characterized in that, A first pressure gauge is installed on the nitrogen branch pipe; a water flow meter is also installed on the water outlet pipe; a second pressure gauge is also installed on the pipeline between the pressurization device and the gas-liquid two-phase flow nozzle. A nitrogen flow control valve is installed on the gas phase channel.

8. A method for combined cooling and fire suppression using liquid nitrogen and fine water mist in an electrochemical energy storage power station, characterized in that... Based on the electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 6 or 7, the method includes the following steps: Based on the measured data of the nitrogen flow meter and the second thermometer, the nitrogen outlet valve is controlled to adjust the flow rate of nitrogen flowing out of the vaporization device, so as to control the temperature of nitrogen flowing out of the vaporization device, wherein the temperature of nitrogen flowing out of the vaporization device is above 0 degrees. When the pressure sensor data is determined to be within the preset pressure range, the nitrogen valve is opened to start the nitrogen recovery device.

9. The fire extinguishing method according to claim 8, characterized in that, Based on the electrochemical energy storage power station liquid nitrogen and fine water mist linkage cooling and fire extinguishing system according to claim 8, the method further includes the following steps: Based on the measured data from the first pressure gauge and the water flow meter, the flow rate of nitrogen in the nitrogen branch pipe and the water valve are controlled to regulate the water flow rate in the water channel. The pressurization device is used to make the pressure value of the second pressure gauge reach 0.5 MPa, and the nitrogen flow control valve is controlled to adjust the nitrogen flow rate in the gas phase channel. By adjusting the water flow rate in the water channel and the nitrogen flow rate in the gas channel, the mixing ratio of nitrogen and water at the nozzle head is adjusted, thereby adjusting the atomization effect of the fine water mist sprayed from the nozzle head.

Images