Device and method for medium consumption and heat reutilization of a liquid nitrogen fire extinguishing device

Abstract

The application discloses a device and method for medium loss and heat recycling of a liquid nitrogen fire extinguishing device, and aims to solve the problem of resource waste in the use of the existing liquid nitrogen fire extinguishing device. The device comprises a liquid nitrogen fire extinguishing device and an energy storage cabin. Three nitrogen cylinders and a self-pressurized liquid nitrogen tank are installed in the liquid nitrogen fire extinguishing device. A liquid supplementing port, an electromagnetic valve, an electromagnetic liquid level meter and a pressure gauge are arranged on the self-pressurized liquid nitrogen tank. The cold head of a refrigerator is connected to the top of the self-pressurized liquid nitrogen tank through a flange. A pressure relief valve is connected to the side of the top of the self-pressurized liquid nitrogen tank. The output end of the nitrogen pressure relief valve is connected to a pipeline. A battery management system is installed in the energy storage cabin. A liquid cooling system is installed in the energy storage cabin and located at the bottom of each pack-level battery box. The application is used for the recycling of the medium of the liquid nitrogen fire extinguishing device and the reduction of the control space environment temperature, can reduce energy consumption, save energy, improve the efficiency and economy of the system, and meet the control requirements of the environment temperature in specific application fields.

Description

Technical Field

[0001] This invention belongs to the field of fire safety and energy storage system protection technology, specifically relating to a device and method for recovering media loss and heat generated during the use of a liquid nitrogen fire extinguishing device. Background Technology

[0002] Liquid nitrogen fire suppression systems are a common fire fighting device. Their basic principle is to extinguish fires using the high-pressure release and low-temperature properties of liquid nitrogen. Typically, liquid nitrogen is stored in a container under high pressure. When a fire occurs, the system automatically releases the liquid nitrogen, rapidly evaporating it to reduce the oxygen concentration in the space to a level that cannot support combustion, thus extinguishing the fire. As an advanced fire suppression technology, liquid nitrogen fire suppression provides an efficient and reliable fire protection solution for lithium battery energy storage stations and is one of the important choices for future industrial and energy storage safety management. However, traditional liquid nitrogen fire suppression systems face several technical challenges in their use:

[0003] 1. In liquid nitrogen fire extinguishing devices, liquid nitrogen is in a state of continuous evaporation without the action of a refrigeration unit. The pressure in the tank gradually increases, and the continuous increase may cause the tank to explode. Therefore, a safety valve is installed to reduce the pressure inside the tank. Excess gas is discharged through the valve body, resulting in waste.

[0004] 2. In order to better store liquid nitrogen, a refrigeration unit is needed to liquefy the nitrogen gas in liquid nitrogen fire extinguishing equipment. Liquid nitrogen itself has a low temperature of -196°C. When it vaporizes without refrigeration, it absorbs heat and takes away some heat. If this part of the heat exchange is not utilized, it will easily lead to resource waste. Summary of the Invention

[0005] To address the aforementioned technical shortcomings, the purpose of this invention is to provide an apparatus and method for reusing the medium loss and heat generated by a liquid nitrogen fire extinguishing device. This method is used for the reuse of the liquid nitrogen fire extinguishing device medium and to reduce the ambient temperature of the controlled space, thereby reducing energy consumption, saving energy, improving system efficiency and economy, and meeting the ambient temperature control requirements of specific application areas.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A device for recovering the medium loss and heat generated by a liquid nitrogen fire extinguishing system, including the liquid nitrogen fire extinguishing system and the energy storage compartment;

[0008] The liquid nitrogen fire extinguishing device is equipped with three nitrogen cylinders and a self-pressurizing liquid nitrogen tank. The self-pressurizing liquid nitrogen tank is equipped with a liquid replenishment port, a solenoid valve, an electromagnetic level gauge, and a pressure gauge. The cold head of the refrigeration unit is connected to the top of the self-pressurizing liquid nitrogen tank via a flange. A pressure relief valve is connected to the top side of the self-pressurizing liquid nitrogen tank, and the output end of the nitrogen pressure relief valve is connected to a pipeline.

[0009] The energy storage compartment is equipped with a battery management system; the energy storage compartment is also equipped with a liquid cooling system located at the bottom of each pack-level battery box. The output of the liquid cooling system in the energy storage compartment is connected to two electromagnetic selection valves. One electromagnetic selection valve is connected to a conventional pipeline, and the other electromagnetic selection valve is connected to a transmission pipeline that covers a self-pressurized liquid nitrogen tank. A heat exchanger is provided when it comes into contact with the self-pressurized liquid nitrogen tank. The opening of the electromagnetic selection valve is controlled by the control system.

[0010] This invention also relates to a method for recovering the medium loss and heat generated by a liquid nitrogen fire extinguishing device, comprising the following specific steps:

[0011] Step 1: When the internal pressure of the self-pressurized liquid nitrogen tank in the liquid nitrogen fire extinguishing device exceeds the safety threshold, open the pressure relief valve;

[0012] Step 2: Detect the ambient temperature of the pipeline, battery compartment, and electrical control room using temperature sensors to determine if adjustments are needed and thus identify adjustment requirements.

[0013] Step 3: The low-temperature nitrogen gas discharged from the liquid nitrogen fire extinguishing device through the pressure relief valve is transported to the pipeline, battery compartment, and electrical control room through a dedicated transmission pipeline for cooling and energy consumption reduction.

[0014] Step 4: Determine the heat exchange status using the detection equipment in the liquid nitrogen fire extinguishing device to determine whether it can be used in a liquid cooling system;

[0015] Step 5: Trigger the control system settings, the traditional pipeline valve body is closed, and the self-pressurized liquid nitrogen tank-encased pipeline valve body is opened;

[0016] Step 6: The liquid in the liquid cooling system exchanges heat with the self-pressurized liquid nitrogen tank through a heat exchanger, transferring the cooling effect of the liquid nitrogen to the liquid cooling system, thereby helping to maintain the suitable temperature range of the energy storage device.

[0017] Preferably, the pipeline for transmitting cryogenic nitrogen in step 3 should be made of materials such as stainless steel, carbon steel, or special cryogenic alloys.

[0018] Preferably, in step 6, a heat exchanger suitable for the heat transfer generated by the liquid nitrogen fire extinguishing device is selected, which may be a shell-and-tube heat exchanger or other high-efficiency heat exchange equipment.

[0019] The beneficial effects of this invention are as follows: First, it enables the reuse of liquid nitrogen medium, while also reducing energy consumption, which is in line with the principle of sustainable development, reduces the consumption of liquid nitrogen, improves resource utilization efficiency, reduces costs, and reduces the impact on the environment.

[0020] Second, utilizing the heat exchange during liquid nitrogen storage and vaporization can reduce the need for additional cooling or energy-consuming equipment, improve energy efficiency, and lower system costs, especially in environments requiring long-term, stable temperature control. This method helps reduce environmental impact and aligns with sustainable development principles. This is particularly important for industries and organizations concerned with energy consumption and environmental impact, and deserves attention and promotion. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating the process of media loss and heat reuse during the use of the liquid nitrogen fire extinguishing device provided in Embodiment 1 of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the liquid nitrogen fire extinguishing device provided in Embodiment 1 of the present invention, which is used to recover the medium loss and heat generated by the device.

[0024] Explanation of reference numerals in the attached figures

[0025] 1—Energy storage compartment; 2—Nitrogen cylinder; 3—Liquid replenishment port; 4—Solenoid valve; 5—Self-pressurized liquid nitrogen tank; 6—Heat exchanger; 7—Flange; 8—Pressure relief valve; 9—Electromagnetic level gauge; 10—Pressure gauge; 11—Output end; 12—Liquid cooling unit; 13—Solenoid selector valve on conventional pipeline; 14—Control system; 15—Temperature sensor; 16—Ring distribution pipeline; 17—Battery cabinet; 18—Solenoid valve on pipeline covering self-pressurized liquid nitrogen tank. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] like Figure 1 As shown, the device for recovering the medium loss and heat generated by the liquid nitrogen fire extinguishing device includes the liquid nitrogen fire extinguishing device and the energy storage compartment 1.

[0029] The liquid nitrogen extinguishing device contains three nitrogen cylinders (drive cylinders) 2. The self-pressurizing liquid nitrogen tank 5 is equipped with a liquid replenishment port 3, a solenoid valve 4, an electromagnetic level gauge 9, and a pressure gauge 10. The cold head of the refrigeration unit is connected to the top of the self-pressurizing liquid nitrogen tank via a flange 7. A pressure relief valve 8 is connected to the top side of the self-pressurizing liquid nitrogen tank, and the output end 11 of the nitrogen pressure relief valve is connected to a pipeline. A liquid cooling system is installed inside the energy storage compartment, located at the bottom of each pack-level battery box. The output end of the liquid cooling system in the energy storage compartment is connected to two electromagnetic selector valves. One selector valve 13 is connected to a conventional pipeline, and the other selector valve 18 is connected to a transmission pipeline that covers the self-pressurizing liquid nitrogen tank. A heat exchanger 6 is provided when in contact with the self-pressurizing liquid nitrogen tank. The opening of the electromagnetic selector valve is controlled by the control system 14.

[0030] Example 2:

[0031] like Figure 2 As shown, the methods for recovering the medium loss and heat generated by the liquid nitrogen fire extinguishing device include:

[0032] Dielectric loss reuse:

[0033] In liquid nitrogen fire extinguishing systems, liquid nitrogen continuously evaporates without a refrigeration unit, causing the tank pressure to gradually increase. This continuous increase could lead to a tank explosion. Therefore, a safety valve is installed to reduce the internal pressure of the tank, allowing excess gas to be discharged through the valve. When the internal pressure of the self-pressurizing liquid nitrogen tank exceeds a safety threshold, the pressure relief valve 8 opens. Temperature sensor 15 continuously monitors the ambient temperature of the pipelines, battery compartment, and electrical control room to determine if adjustment is necessary. Once adjustment is confirmed, the low-temperature nitrogen discharged from the liquid nitrogen fire extinguishing system via the pressure relief valve is transported through a dedicated pipeline to the pipelines, battery compartment, and electrical control room for cooling, reducing energy consumption. Temperature sensor 15 monitors the ambient temperature in real time, working in conjunction with the internal pressure of the self-pressurizing liquid nitrogen tank to coordinate the opening and closing of the pressure relief valve 8, ensuring the reuse of the consumed medium and the stability of the ambient temperature.

[0034] Temperature reuse:

[0035] In liquid nitrogen fire extinguishing systems, a refrigeration unit is used to liquefy nitrogen gas for better storage. When vaporization occurs without refrigeration, heat absorption occurs, and some heat is also carried away. This heat exchange can be detected by monitoring equipment installed in the liquid nitrogen fire extinguishing system to determine if it can be used for a liquid cooling system. When it can, the control system is triggered, the conventional pipeline selection valve 13 closes, and the self-pressurizing liquid nitrogen tank-covered pipeline selection valve 18 opens. The liquid in the liquid cooling system flows through the pipeline covering the self-pressurizing liquid nitrogen tank and reaches the heat exchanger 6 outside the self-pressurizing liquid nitrogen tank, where heat exchange occurs. The liquid transfers heat to the self-pressurizing liquid nitrogen tank 5, thereby reducing the temperature of the liquid cooling plate and helping to maintain the suitable temperature range of the energy storage device. When it cannot, the self-pressurizing liquid nitrogen tank-covered pipeline selection valve 18 closes, and the conventional pipeline selection valve 13 opens. The liquid cooling system operates normally without any impact, achieving portable switching and ensuring a reduction in the ambient temperature of the control space.

[0036] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for reusing the medium loss and heat generated by a liquid nitrogen fire extinguishing device, characterized in that, It comprises a liquid nitrogen fire extinguishing device and an energy storage cabin. Three nitrogen cylinders and a self-pressurized liquid nitrogen tank are installed in the liquid nitrogen fire extinguishing device, and a liquid supplementing port, an electromagnetic valve, an electromagnetic liquid level meter and a pressure gauge are arranged on the self-pressurized liquid nitrogen tank. The cold head of the refrigeration machine is connected to the top of the self-pressurized liquid nitrogen tank through a flange, and a pressure relief valve is connected to the top side of the self-pressurized liquid nitrogen tank. The output end of the nitrogen pressure relief valve is connected to a pipeline. A battery management system is installed in the energy storage cabin, and a liquid cooling system is installed in the energy storage cabin and located at the bottom of each pack-level battery box. Two electromagnetic selection valves are connected to the output end of the liquid cooling system in the energy storage cabin. One electromagnetic selection valve is connected to a traditional pipeline, and the other electromagnetic selection valve is connected to a pipeline surrounding the self-pressurized liquid nitrogen tank. When the self-pressurized liquid nitrogen tank is contacted, a heat exchanger is arranged. The opening of the electromagnetic selection valve is controlled by a control system. When the internal pressure of the self-pressurized liquid nitrogen tank exceeds a safety threshold, the pressure relief valve is opened. The temperature sensor continuously detects the ambient temperature of the pipeline, the battery compartment and the electric control room scene to determine whether adjustment is needed. After adjustment is confirmed, the low-temperature nitrogen gas discharged from the liquid nitrogen fire extinguishing device through the pressure relief valve is transported to the pipeline, the battery compartment and the electric control room scene through a dedicated transmission pipeline for cooling, thereby reducing energy consumption.

2. Method for the reuse of the medium depletion and heat produced by a liquid nitrogen fire extinguishing device, characterized in that, The method comprises the following specific steps: Step 1: When the internal pressure of the self-pressurized liquid nitrogen tank in the liquid nitrogen fire extinguishing device exceeds a safety threshold, the pressure relief valve is opened. Step 2: The temperature sensor detects the ambient temperature of the pipeline, the battery compartment and the electric control room scene to determine whether adjustment is needed. Step 3: The low-temperature nitrogen gas discharged from the liquid nitrogen fire extinguishing device through the pressure relief valve is transported to the pipeline, the battery compartment and the electric control room through a dedicated transmission pipeline for cooling, thereby reducing energy consumption. Step 4: The heat exchange condition is determined by a detection device in the liquid nitrogen fire extinguishing device to determine whether it can be used for the liquid cooling system. Step 5: The control system is triggered to set the traditional pipeline valve body to be closed and the self-pressurized liquid nitrogen tank surrounding pipeline valve body to be opened. Step 6: The liquid in the liquid cooling system exchanges heat with the self-pressurized liquid nitrogen tank through the heat exchanger, so as to transfer the cooling effect of the liquid nitrogen to the liquid cooling system, thereby helping to maintain the appropriate temperature range of the energy storage device.

3. The method of medium depletion and heat re-use from a liquid nitrogen fire suppression device of claim 2, wherein, The pipeline for transporting low-temperature nitrogen gas in step 3 needs to be made of stainless steel, carbon steel or special low-temperature alloy material.

4. The method of medium depletion and heat reutilization produced by the liquid nitrogen fire extinguishing device according to claim 2 or 3, characterized in that, The heat exchanger in step 6 is a tube-shell heat exchanger.

Images