Battery thermal runaway flue gas treatment system

Abstract

The invention discloses a battery thermal runaway flue gas treatment system which comprises a flue gas collection end and a flue gas collection hood provided with an air supplement cooling device and used for collecting original flue gas generated by thermal runaway and introducing diluted cold air; the high-corrosion-resistance pipeline is of a sleeve telescopic structure, and a pipeline material is of a multi-layer composite structure and sequentially comprises a polytetrafluoroethylene lining layer with corrosion resistance and a 316L stainless steel main structure layer from inside to outside. And the safety protection module comprises an explosion venting device and an equipotential grounding system which are arranged along the high-corrosion-resistance pipeline. According to the system, the service life of the main structure layer is greatly prolonged through the design of the cooling device and the polytetrafluoroethylene lining layer in the exhaust fume collecting hood, and meanwhile, the static electricity and explosion risks are reduced through the safety protection module.

Description

Technical Field

[0001] This invention belongs to the field of battery safety protection and environmental protection equipment technology, specifically relating to a battery thermal runaway flue gas treatment system. Background Technology

[0002] When a lithium-ion battery experiences thermal runaway, it releases a large amount of energy instantaneously, generating fumes with temperatures exceeding 800°C. These fumes are complex in composition, containing flammable and explosive gases such as hydrogen and carbon monoxide, as well as highly corrosive acidic gases such as hydrogen fluoride.

[0003] Existing flue gas emission ducts have the following technical defects:

[0004] 1. It is difficult to balance corrosion resistance and high temperature resistance: Ordinary stainless steel pipes cannot resist the corrosion of hydrogen fluoride for a long time, while polymer anti-corrosion materials (such as polytetrafluoroethylene) are prone to thermal creep failure at ultra-high temperatures.

[0005] 2. Thermal stress damage: The flue gas flow rate is fast and the temperature rise is drastic. The axial displacement of the pipeline caused by thermal expansion and contraction can easily lead to cracking or sealing failure at the fixed connection.

[0006] 3. Static electricity and explosion risks: The high-speed flow of flue gas and the insulating properties of the PTFE lining make it easy for static electricity to accumulate, posing a serious risk of secondary explosion in pipelines filled with flammable gases.

[0007] This invention aims to solve the technical problem that pipelines cannot simultaneously meet the requirements of long-stroke thermal displacement compensation, extreme chemical corrosion resistance, and electrical explosion-proof safety during the treatment of battery thermal runaway flue gas. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a battery thermal runaway flue gas treatment system. It includes:

[0009] The flue gas collection end is equipped with a smoke collection hood with a make-up air cooling device, which is used to collect the original flue gas generated by thermal runaway and introduce diluted cold air;

[0010] The highly corrosion-resistant pipeline features a sleeve telescopic structure and a multi-layer composite material, consisting of a corrosion-resistant polytetrafluoroethylene inner lining and a 316L stainless steel main structural layer, from the inside out.

[0011] Safety protection module, explosion relief device and equipotential grounding system installed along highly corrosion-resistant pipeline.

[0012] According to the provided battery thermal runaway flue gas treatment system, the safety protection module also includes an insulation layer installed outside the highly corrosion-resistant pipe.

[0013] According to the provided battery thermal runaway flue gas treatment system, a high-temperature buffer pipe is also provided at the front end of the highly corrosion-resistant pipe, and the high-temperature buffer pipe and the highly corrosion-resistant pipe are detachably connected through a flange.

[0014] According to a battery thermal runaway flue gas treatment system, the polytetrafluoroethylene lining at the front end of the highly corrosion-resistant pipe extends to the flange sealing surface and is flanged.

[0015] According to the provided battery thermal runaway flue gas treatment system, the high-temperature buffer section pipe is made of 316L stainless steel, and its length is set according to the initial temperature of the flue gas and the cooling rate, which is used to reduce the temperature of the flue gas entering the highly corrosion-resistant pipe to below 260°.

[0016] According to the provided battery thermal runaway flue gas treatment system, the air supply and cooling device on the fume hood includes an electric regulating valve and a temperature sensor. The system automatically adjusts the amount of cold air supplied by monitoring the flue gas temperature in the pipe in real time, ensuring that the polytetrafluoroethylene lining of the highly corrosion-resistant pipe is at a safe operating temperature.

[0017] According to the provided battery thermal runaway flue gas treatment system, the make-up air cooling device also includes a spray device that can spray water mist to achieve a cooling effect.

[0018] According to the provided battery thermal runaway flue gas treatment system, the thickness of the polytetrafluoroethylene inner lining of the highly corrosion-resistant pipe is between 1.5 mm and 3.0 mm; the thickness of the 316L stainless steel main structural layer is between 1.5 mm and 3.0 mm.

[0019] According to the provided battery thermal runaway flue gas treatment system, the explosion relief device is an explosion-proof disc installed at pipe bends or airflow turning points. The static opening pressure of the explosion-proof disc is set to 80% to 90% of the pipe design pressure, and the explosion relief port points to a safe and open area.

[0020] According to the provided battery thermal runaway flue gas treatment system, the equipotential grounding system includes copper braided wire bridging devices at each flange connection of the pipeline, and the entire pipeline system is connected to the building lightning protection grounding network through a grounding wire, with a grounding resistance value ≤ 4 ohms.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. Highly efficient and proactive cooling to ensure pipeline safety. The fume hood integrates a supplementary air cooling device, which monitors the temperature in real time and is linked with an electric regulating valve to automatically introduce ambient cool air to dilute the high-temperature flue gas. When the temperature exceeds the set threshold, the spray device is activated to spray water mist, achieving two-stage forced cooling. This ensures that the temperature of the flue gas entering the highly corrosion-resistant pipeline is below the safe operating limit of the PTFE lining, preventing heat damage from the source.

[0023] 2. Multiple anti-corrosion structures extend service life. The highly corrosion-resistant pipeline adopts a multi-layer composite design of "PTFE inner lining + 316L stainless steel main structural layer". The PTFE inner lining (1.5-3.0mm thick) fully resists the chemical corrosion of highly corrosive gases such as hydrogen fluoride; the 316L stainless steel layer (1.5-3.0mm thick) provides sufficient mechanical strength and resistance to external impacts. The PTFE inner lining flange design at flange connections achieves a non-metallic seal throughout the flue gas flow path, eliminating corrosion at leakage points and significantly extending system life.

[0024] 3. Thermal displacement self-adaptation, eliminating stress damage. The piping system adopts a sleeve expansion structure, which can effectively absorb the axial displacement caused by the violent thermal expansion during battery thermal runaway, avoiding pipe deformation, joint cracking or sealing failure caused by thermal expansion and contraction, and ensuring the structural integrity of the system.

[0025] 4. Active explosion venting and electrostatic protection to prevent secondary disasters. Explosion venting devices (explosion-proof discs) are installed along pipe bends and airflow turning points. Their static opening pressure is set at 80%–90% of the pipe design pressure. In the event of a gas deflagration, they can promptly release pressure in a directional manner to prevent the entire pipe from rupturing. Simultaneously, the equipotential grounding system, through flange-connected copper braided wire and reliable connection to the building's lightning protection network (grounding resistance ≤4Ω), promptly dissipates static electricity buildup caused by high-speed airflow friction, eliminating the risk of explosion in flammable environments.

[0026] 5. Thermal Insulation and Anti-condensation with Modular Maintenance. An outer insulation layer is installed on the pipeline to reduce heat loss and prevent tar and water vapor in the flue gas from condensing on the inner wall of the pipe, thus avoiding corrosion from the condensate; it also protects the safety of operators. High-temperature buffer pipelines and highly corrosion-resistant pipelines are connected by detachable flanges, allowing for easy adjustment of the buffer section length according to actual operating conditions, reducing maintenance costs and improving system adaptability. Attached Figure Description

[0027] Figure 1 This is a structural diagram of a battery thermal runaway flue gas treatment system. Figure 2 This is a cross-sectional view of a multi-layer composite structure for a battery thermal runaway flue gas treatment system. Figure 3 This is a detailed drawing of the PTFE flange and bridging device at the flange connection.

[0028] Figure reference numerals: 11-Fume hood; 12-Make-up air cooling device; 13-Spraying device; 21-Highly corrosion-resistant pipe; 22-High-temperature buffer pipe; 23-316L stainless steel flange; 3-PTFE inner lining; 4-316L stainless steel main structural layer; 51-Explosion relief device; 52-Equipotential grounding system. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. The technical solutions of this invention will be further described below with reference to the accompanying drawings.

[0030] See Figure 1 This embodiment provides a battery thermal runaway flue gas treatment system. Some details are omitted in the part below the dotted line. The system mainly includes three parts: flue gas collection end, highly corrosion-resistant pipe 21, and safety protection module.

[0031] The core component of the flue gas collection end is the smoke collection hood 11, on which a make-up air cooling device 12 is installed. In this embodiment, the make-up air cooling device 12 includes an electrically adjustable air valve, a temperature sensor, and a spray device 13. When the battery experiences thermal runaway and generates high-temperature raw flue gas, the temperature sensor monitors the flue gas temperature in real time. The system controls the opening of the electrically adjustable air valve according to preset logic to introduce ambient cold air to mix with the flue gas for primary dilution and cooling. If the temperature exceeds a set threshold (e.g., 300°C), the spray device 13 is activated to spray water mist for secondary forced cooling.

[0032] The flue gas, after initial cooling, enters the pipeline system. To prevent the extremely high initial temperature from directly damaging the corrosion-resistant pipeline, a high-temperature buffer pipe 22 is installed at the very beginning of the pipeline. This high-temperature buffer pipe 22 is made of 316L stainless steel and has excellent high-temperature resistance. Its length is set according to simulation calculations to ensure that after the flue gas flows through this section, the temperature drops below 260°C due to heat dissipation from the pipe wall.

[0033] See Figure 2 The flue gas then enters the highly corrosion-resistant pipe 21. Combined with... Figure 2 As shown, the highly corrosion-resistant pipe 21 has a multi-layer composite structure. From the inside out, it consists of a polytetrafluoroethylene (PTFE) inner lining layer 3 and a 316L stainless steel main structural layer 4. The PTFE inner lining layer 3 has a thickness of 2.0 mm (adjustable between 1.5-3.0 mm) and is responsible for resisting chemical corrosion from acidic gases such as HF; the 316L stainless steel main structural layer 4 has a thickness of 2.5 mm (adjustable between 1.5-3.0 mm) and provides structural strength for pressure resistance and resistance to external impacts. Furthermore, the highly corrosion-resistant pipe 21 adopts a sleeve telescopic structure, allowing the pipe to slide axially within a certain range.

[0034] See Figure 3The high-temperature buffer pipe 22 and the highly corrosion-resistant pipe 21 are connected by a 316L stainless steel flange 23. To ensure the sealing and corrosion resistance of the connection, the PTFE liner 3 of the highly corrosion-resistant pipe 21 extends outward to the sealing surface of the 316L stainless steel flange 23 and is flanged to form a flanged structure that wraps around the flange face. Between the flanges, a spiral wound gasket filled with PTFE is used for sealing to prevent flue gas from leaking from the flange gaps.

[0035] Safety protection modules are installed along the pipeline system. These modules include:

[0036] Insulation layer: An insulation layer (such as rock wool or aerogel felt) is wrapped around the outside of the highly corrosion-resistant pipe 21. On the one hand, it reduces heat loss and prevents tar and moisture in the flue gas from condensing on the inner wall of the pipe. On the other hand, it protects the operators and the surrounding environment.

[0037] Explosion relief device 51: Typically installed at bends or airflow deflections in pipelines. Explosion relief device 51 is an explosion-proof disc, with its static start-up pressure set at 80%-90% of the pipeline design pressure (e.g., if the design pressure is 10 kPa, the start-up pressure is 8-9 kPa). In the event of a gas explosion within the pipeline, the pressure rises instantaneously, and the explosion-proof disc ruptures first, guiding the high-pressure, high-temperature airflow to a safe, open area, preventing the entire pipeline from bursting.

[0038] Equipotential grounding system 52: Includes copper braided wire jumper devices installed at each flange connection of the pipeline to ensure conductivity on both sides of the flange. The entire pipeline system (including fume hood, pipes, and supports) is reliably connected to the building's lightning protection grounding network at at least two points. The system grounding resistance has been rigorously tested to ensure ≤4 ohms, and static electricity generated by high-speed airflow friction is promptly dissipated.

[0039] In summary, this system, through a combination of "fume hood for air supply and cooling + high-temperature buffering + PTFE lining for corrosion protection + explosion-proof grounding," constitutes a complete and safe solution for handling battery thermal runaway flue gas. The beneficial effects of this invention are as follows:

[0040] 1. Highly efficient and proactive cooling to ensure pipeline safety. The fume hood integrates a supplementary air cooling device, which monitors the temperature in real time and is linked with an electric regulating valve to automatically introduce ambient cool air to dilute the high-temperature flue gas. When the temperature exceeds the set threshold, the spray device is activated to spray water mist, achieving two-stage forced cooling. This ensures that the temperature of the flue gas entering the highly corrosion-resistant pipeline is below the safe operating limit of the PTFE lining, preventing heat damage from the source.

[0041] 2. Multiple anti-corrosion structures extend service life. The highly corrosion-resistant pipeline adopts a multi-layer composite design of "PTFE inner lining + 316L stainless steel main structural layer". The PTFE inner lining (1.5-3.0mm thick) fully resists the chemical corrosion of highly corrosive gases such as hydrogen fluoride; the 316L stainless steel layer (1.5-3.0mm thick) provides sufficient mechanical strength and resistance to external impacts. The PTFE inner lining flange design at flange connections achieves a non-metallic seal throughout the flue gas flow path, eliminating corrosion at leakage points and significantly extending system life.

[0042] 3. Thermal displacement self-adaptation, eliminating stress damage. The piping system adopts a sleeve expansion structure, which can effectively absorb the axial displacement caused by the violent thermal expansion during battery thermal runaway, avoiding pipe deformation, joint cracking or sealing failure caused by thermal expansion and contraction, and ensuring the structural integrity of the system.

[0043] 4. Active explosion venting and electrostatic protection to prevent secondary disasters. Explosion venting devices (explosion-proof discs) are installed along pipe bends and airflow turning points. Their static opening pressure is set at 80%–90% of the pipe design pressure. In the event of a gas deflagration, they can promptly release pressure in a directional manner to prevent the entire pipe from rupturing. Simultaneously, the equipotential grounding system, through flange-connected copper braided wire and reliable connection to the building's lightning protection network (grounding resistance ≤4Ω), promptly dissipates static electricity buildup caused by high-speed airflow friction, eliminating the risk of explosion in flammable environments.

[0044] 5. Thermal Insulation and Anti-condensation with Modular Maintenance. An outer insulation layer is installed on the pipeline to reduce heat loss and prevent tar and water vapor in the flue gas from condensing on the inner wall of the pipe, thus avoiding corrosion from the condensate; it also protects the safety of operators. High-temperature buffer pipelines and highly corrosion-resistant pipelines are connected by detachable flanges, allowing for easy adjustment of the buffer section length according to actual operating conditions, reducing maintenance costs and improving system adaptability.

Claims

1. A battery thermal runaway flue gas treatment system, characterized in that, include: The flue gas collection end is equipped with a smoke collection hood with a make-up air cooling device, which is used to collect the original flue gas generated by thermal runaway and introduce diluted cold air; The highly corrosion-resistant pipeline features a sleeve telescopic structure and a multi-layer composite material, consisting of a corrosion-resistant polytetrafluoroethylene inner lining and a 316L stainless steel main structural layer, from the inside out. The safety protection module includes an explosion venting device and an equipotential grounding system installed along the highly corrosion-resistant pipeline.

2. The system according to claim 1, characterized in that, The safety protection module also includes an insulation layer installed outside the highly corrosion-resistant pipeline.

3. The system according to claim 1, characterized in that, The highly corrosion-resistant pipe is also equipped with a high-temperature buffer pipe at its front end, and the high-temperature buffer pipe is detachably connected to the highly corrosion-resistant pipe via a flange.

4. The system according to claim 3, characterized in that, The polytetrafluoroethylene lining at the front end of the highly corrosion-resistant pipe extends to the flange sealing surface and is flanged.

5. The system according to claim 3, characterized in that, The high-temperature buffer pipe is made of 316L stainless steel, and its length is set according to the initial temperature of the flue gas and the cooling rate. It is used to reduce the temperature of the flue gas entering the highly corrosion-resistant pipe to below 260°.

6. The system according to claim 1, characterized in that, The air supply and cooling device on the smoke hood includes an electric regulating valve and a temperature sensor. The system monitors the temperature of the flue gas in the pipe in real time and automatically adjusts the amount of cold air supplied to ensure that the polytetrafluoroethylene lining of the highly corrosion-resistant pipe is at a safe working temperature.

7. The system according to claim 1, characterized in that, The air supply and cooling device also includes a spraying device, which can spray water mist to achieve a cooling effect.

8. The system according to claim 1, characterized in that, The thickness of the polytetrafluoroethylene inner lining of the highly corrosion-resistant pipe is 1.5mm to 3.0mm; the thickness of the 316L stainless steel main structural layer is 1.5mm to 3.0mm.

9. The system according to claim 1, characterized in that, The explosion relief device is an explosion-proof disc installed at pipe bends or airflow turning points. The static opening pressure of the explosion-proof disc is set to 80% to 90% of the pipe design pressure, and the explosion relief port points to a safe and open area.

10. The system according to claim 1, characterized in that, The equipotential grounding system includes copper braided wire jumper devices at each flange connection of the pipeline, and the entire pipeline system is connected to the building lightning protection grounding network through a grounding wire, with a grounding resistance value ≤ 4 ohms.

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