Device and method for recycling medium loss and heat generated by liquid nitrogen fire extinguishing device

Abstract

The invention discloses a device and method for medium loss and heat recycling generated by a liquid nitrogen fire extinguishing device, and aims to solve the problem of resource waste generated in the using process of an 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-pressurization liquid nitrogen tank are installed in the liquid nitrogen fire extinguishing device, a liquid supplementing opening, an electromagnetic valve, an electromagnetic liquid level meter and a pressure gauge are arranged on the self-pressurization liquid nitrogen tank, a cold head of a refrigerating machine is connected with the top of the self-pressurization liquid nitrogen tank through a flange, and the side of the top of the self-pressurization liquid nitrogen tank is connected with a pressure release valve. The output end of the nitrogen pressure release valve is connected with a pipeline; a battery management system is mounted in the energy storage cabin; and a liquid cooling system is arranged in the energy storage cabin and is positioned at the bottom of each pack-level battery box body. The system is used for reusing a medium of a liquid nitrogen fire extinguishing device and reducing the environment temperature of a control space, energy consumption can be reduced, energy is saved, the efficiency and economical efficiency of the system are improved, and meanwhile the control requirement of a specific application field for the environment temperature is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire safety and energy storage system protection, and in particular relates to a device and method for recycling medium loss and heat generated during the use of a liquid nitrogen fire extinguishing device. Background Art

[0002] Liquid nitrogen fire extinguishing system is a common fire fighting device. Its basic principle is to use the high-pressure release and low-temperature characteristics of liquid nitrogen to extinguish fires. Generally, liquid nitrogen is stored in containers in high pressure. When a fire occurs, the system will automatically release liquid nitrogen, and through rapid evaporation, the oxygen concentration in the space will be reduced to a level that cannot support combustion, thereby achieving the effect of extinguishing the fire. As an advanced fire extinguishing technology, liquid nitrogen fire extinguishing 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 extinguishing systems face several technical problems during use: 1. In the liquid nitrogen fire extinguishing device, liquid nitrogen is in a state of continuous volatilization without the action of a refrigerator. The pressure in the tank gradually increases, and continued increase may cause the tank to explode. Therefore, a safety valve is set to reduce the pressure inside the tank, and excess gas is discharged through the valve body, causing waste.

[0003] 2. In order to better store liquid nitrogen in the liquid nitrogen fire extinguishing device, a refrigerator is needed to liquefy nitrogen. The temperature of liquid nitrogen itself is relatively low, at -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 is easy to cause a waste of resources. Summary of the invention

[0004] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a device and method for recycling the medium loss and heat generated by a liquid nitrogen fire extinguishing device. The method is used to reuse the medium of the liquid nitrogen fire extinguishing device and reduce the ambient temperature of the control space, which can reduce energy consumption, save energy, improve the efficiency and economy of the system, and at the same time meet the control requirements of the ambient temperature in specific application fields. In order to solve the above technical problems, the present invention adopts the following technical solutions: Device for recycling medium loss and heat generated by liquid nitrogen fire extinguishing device, including liquid nitrogen fire extinguishing device and energy storage cabin; Three nitrogen cylinders and a self-pressurized liquid nitrogen tank are installed in the liquid nitrogen fire extinguishing device. The self-pressurized liquid nitrogen tank is provided with a liquid replenishing port, a solenoid valve, an electromagnetic liquid level gauge, and a pressure gauge. The cold head of the refrigerator is connected to the top of the self-pressurized liquid nitrogen tank through a flange. The top side of the self-pressurized liquid nitrogen tank is connected to a pressure relief valve, and the output end of the nitrogen pressure relief valve is connected to a pipeline.

[0005] A battery management system is installed inside the energy storage cabin; a liquid cooling system is installed inside the energy storage cabin and is 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 setting. On this basis, another electromagnetic selection valve is connected to a transmission pipeline that covers a self-pressurized liquid nitrogen tank. A heat exchanger is provided when in contact with the self-pressurized liquid nitrogen tank. The opening of the electromagnetic selection valve is controlled by a control system.

[0006] The present invention also relates to a method for recycling medium loss and heat generated by a liquid nitrogen fire extinguishing device, comprising 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 the safety threshold, open the pressure relief valve; Step 2: Use temperature sensors to detect the ambient temperature of pipelines, battery compartments, and electric control rooms to determine whether adjustments are needed and the adjustment requirements; Step 3: Use a dedicated transmission pipeline to transport the low-temperature nitrogen discharged from the liquid nitrogen fire extinguishing device through the pressure relief valve to the pipeline, battery compartment, and electric control room to cool down and reduce energy consumption; Step 4: Determine the heat exchange condition by using the detection equipment in the liquid nitrogen fire extinguishing device to determine whether it can be used in the liquid cooling system; Step 5: trigger the control system setting, the traditional pipeline valve body is closed, and the self-pressurized liquid nitrogen tank sheathed pipeline valve body is opened; 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 appropriate temperature range of the energy storage device.

[0007] Preferably, the pipeline for transmitting the cryogenic nitrogen in step 3 needs to be made of materials such as stainless steel, carbon steel and special low-temperature alloys.

[0008] Preferably, in step 6, a heat exchanger suitable for transferring the heat generated by the liquid nitrogen fire extinguishing device is selected, and a shell and tube heat exchanger or other high-efficiency heat exchange equipment can be used. The beneficial effects of the present invention are: 1. It realizes the reuse of liquid nitrogen medium, and at the same time reduces energy consumption, complies 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.

[0009] Second, utilizing heat exchange during liquid nitrogen storage and gasification can reduce the need for additional cooling equipment or energy-consuming equipment, improve energy efficiency, and reduce system costs, especially in environments that require long-term, stable temperature control. This method helps reduce the impact on the environment and is in line with the principles of sustainable development. This is particularly important for industries and organizations that are concerned about energy consumption and environmental impact, and is worthy of attention and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0011] Figure 1 A flowchart of a method for recycling medium loss and heat generated during use of a liquid nitrogen fire extinguishing device provided in Example 1 of the present invention.

[0012] Figure 2 A schematic diagram of the structure of a device for medium loss and heat recycling generated by a liquid nitrogen fire extinguishing device provided in Example 1 of the present invention.

[0013] Description of Reference Numerals 1—Energy storage cabin; 2—Nitrogen cylinder; 3—Liquid filling port; 4—Solenoid valve; 5—Self-pressurized liquid nitrogen tank; 6—Heat exchanger; 7—Flange; 8—Pressure relief valve; 9—Electromagnetic liquid level gauge; 10—Pressure gauge; 11—Output end; 12—Liquid cooling host; 13—Solenoid selection valve on traditional pipeline; 14—Control system; 15—Temperature sensor; 16—Annular distribution pipeline; 17—Battery cabinet; 18—Solenoid valve on the pipeline covering the self-pressurized liquid nitrogen tank. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] Example 1 like Figure 1 As shown, a device for recycling medium loss and heat generated by a liquid nitrogen fire extinguishing device comprises a liquid nitrogen fire extinguishing device and an energy storage cabin 1; Three nitrogen bottles (driving bottles) 2 are installed in the liquid nitrogen fire extinguishing device. The self-pressurized liquid nitrogen tank 5 is provided with a liquid replenishing port 3, a solenoid valve 4, an electromagnetic liquid level gauge 9, and a pressure gauge 10. The cold head of the refrigerator is connected to the top of the self-pressurized liquid nitrogen tank through a flange 7. The top of the self-pressurized liquid nitrogen tank is connected to a pressure relief valve 8 on the side, and the output end 11 of the nitrogen pressure relief valve is connected to the pipeline. A liquid cooling system is installed inside the energy storage cabin, 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 selection valve 13 is connected to the traditional pipeline setting. On this basis, another selection valve 18 is connected to a transmission pipeline covering the self-pressurized liquid nitrogen tank. When in contact with the self-pressurized liquid nitrogen tank, a heat exchanger 6 is provided. The opening of the electromagnetic selection valve is controlled by a control system 14.

[0016] Example 2: like Figure 2 As shown, the method for recycling the medium loss and heat generated by the liquid nitrogen fire extinguishing device includes: Dielectric loss reuse: In the liquid nitrogen fire extinguishing device, liquid nitrogen is in a state of continuous volatilization without the action of a refrigerator, and the tank pressure gradually increases. Continuous increase may cause the tank to explode, so a safety valve is set to reduce the pressure inside the tank, and excess gas is discharged through the valve body. When the internal pressure of the self-pressurized liquid nitrogen tank exceeds the safety threshold, the pressure relief valve 8 opens; the temperature sensor 15 continuously detects the ambient temperature of the pipeline, battery compartment, and electric control room scene to confirm whether adjustment is required. After confirmation, the low-temperature nitrogen discharged from the liquid nitrogen fire extinguishing device through the pressure relief valve is transported to the pipeline, battery compartment, and electric control room scene through a dedicated transmission pipeline for cooling and reducing energy consumption. The temperature sensor 15 detects the ambient temperature in real time, and cooperates with the internal pressure of the self-pressurized liquid nitrogen tank to open and close the pressure relief valve 8, ensuring the reuse of medium consumption and the stability of the ambient temperature.

[0017] Temperature Reuse: In order to better store liquid nitrogen in the liquid nitrogen fire extinguishing device, a refrigerator is needed to liquefy nitrogen. When gasification occurs without refrigeration, heat absorption will take away part of the heat. This part of the heat exchange can be determined by the detection equipment arranged in the liquid nitrogen fire extinguishing device to determine whether it can be used for the liquid cooling system. When it is possible, the control system is triggered to set, the traditional pipeline selection valve 13 is closed, and the self-pressurized liquid nitrogen tank sheathed pipeline selection valve 18 is opened. The liquid in the liquid cooling system flows through the pipeline sheathed with the self-pressurized liquid nitrogen tank, and heat exchange occurs when it reaches the heat exchanger 6 outside the self-pressurized liquid nitrogen tank. The liquid transfers heat to the self-pressurized liquid nitrogen tank 5, thereby reducing the temperature of the liquid cooling plate and helping to maintain the appropriate temperature range of the energy storage device. When it is not possible, the sheathed self-pressurized liquid nitrogen tank pipeline selection valve 18 is closed, the traditional pipeline selection valve 13 is opened, and the liquid cooling system operates normally without any impact, realizing portable switching and ensuring the reduction of the control space environment temperature. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A device for recycling the medium loss and heat generated by a liquid nitrogen fire extinguishing device, characterized in that: Includes liquid nitrogen fire extinguishing equipment and energy storage cabin; Three nitrogen cylinders and a self-pressurized liquid nitrogen tank are installed in the liquid nitrogen fire extinguishing device. The self-pressurized liquid nitrogen tank is provided with a liquid replenishing port, a solenoid valve, an electromagnetic liquid level gauge, and a pressure gauge. The cold head of the refrigerator is connected to the top of the self-pressurized liquid nitrogen tank through a flange. The top side of the self-pressurized liquid nitrogen tank is connected to a pressure relief valve, and the output end of the nitrogen pressure relief valve is connected to a pipeline.

2. A battery management system is installed inside the energy storage cabin; a liquid cooling system is installed inside the energy storage cabin, which is 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 setting, and on this basis, another electromagnetic selection valve is connected to a transmission pipeline wrapped with a self-pressurized liquid nitrogen tank. A heat exchanger is equipped when in contact with the self-pressurized liquid nitrogen tank, and the opening of the electromagnetic selection valve is controlled by the control system.

3. A method for recycling the medium loss and heat generated by a liquid nitrogen fire extinguishing device, characterized in that: The specific steps include: 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; Step 2: Use temperature sensors to detect the ambient temperature of pipelines, battery compartments, and electric control rooms to determine whether adjustments are needed and the adjustment requirements; 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 electric control room through a dedicated transmission pipeline for cooling to reduce energy consumption; Step 4: Determine the heat exchange condition by using the detection equipment in the liquid nitrogen fire extinguishing device to determine whether it can be used in the liquid cooling system; Step 5: trigger the control system setting, the traditional pipeline valve body is closed, and the self-pressurized liquid nitrogen tank sheathed pipeline valve body is opened; 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 appropriate temperature range of the energy storage device.

4. The method for recycling medium loss and heat generated by a liquid nitrogen fire extinguishing device according to claim 2, characterized in that: The pipeline for transmitting the cryogenic nitrogen in step 3 needs to be made of stainless steel, carbon steel or special cryogenic alloy material.

5. The method for recycling medium loss and heat generated by a liquid nitrogen fire extinguishing device according to claim 2 or 3, characterized in that: The heat exchanger in step 6 is a shell and tube heat exchanger.

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