Fireproof partition and telescopic flame guide system of electric vehicle battery pack

Abstract

The invention discloses a fire partition and telescopic flame guide system for a battery pack of an electric vehicle, which comprises a three-dimensional modular partition framework, three vertical fire partition plates transversely arranged along the length direction, three vertical fire partition plates longitudinally arranged along the width direction and a horizontal partition plate, and the interior of the battery pack is divided into a plurality of independent fire partitions; the two-side smoke and flame guiding pipe structure is arranged between the battery pack shell and the longitudinal fireproof partition plate, the width of the two-side smoke and flame guiding pipe structure is 60 mm, the two-side smoke and flame guiding pipe structure penetrates in the length direction of the battery pack, and the joint of the smoke and flame guiding pipe structure and the fireproof partition is sealed; the flue gas and flame directional guide-out device is used for directionally guiding out flue gas and flame generated by thermal runaway to the outside of the battery pack; the line fireproof grading protection system is provided with a multi-layer fireproof structure of a high-voltage cable and an independent fireproof channel of a BMS signal line. The intelligent heat dissipation system is provided with variable cross-section heat dissipation holes and a temperature control baffle driven by shape memory alloy. The directional smoke exhaust efficiency is high, the safety is improved, and the reliability is enhanced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric vehicle battery, and particularly relates to a fireproof partition and telescopic flame guide system of an electric vehicle battery pack. BACKGROUND

[0002] The existing battery pack usually adopts a whole structure or simple physical separation, and the fireproof partition plate is mostly single mica sheet, ceramic fiber plate and other materials, which have limited fire resistance. When thermal runaway occurs, the flame and high-temperature smoke gas can easily spread through the gap between the battery cells, cable channel or the edge of the incomplete sealing partition plate, leading to the spread of the fire to the adjacent battery module and the inability to effectively control the fire range.

[0003] The traditional battery pack usually adopts a local pressure relief valve or a bursting disc for gas discharge, but has the following problems: The smoke exhaust path is not clear, the pressure relief valve is usually arranged at the top or side of the battery pack, and no directional smoke guide channel is formed, leading to the accumulation of high-temperature smoke gas in the battery pack and aggravating the risk of thermal runaway; The pressure relief response is lagging, the opening pressure of the mechanical pressure relief valve is high (usually > 2 MPa), and the response time is long (> 100 ms), which cannot quickly release the pressure in the early stage of thermal runaway, and may cause the battery pack shell to burst; The risk of secondary ignition of the flame, the high-temperature gas and flame discharged by the pressure relief valve may directly contact the vehicle body structure (such as chassis, tire or high-voltage wire harness), which has the risk of igniting other parts of the vehicle; The flame and high-temperature gas caused by battery thermal runaway can easily spread to the adjacent area through the gap between the battery cells or the cable channel, and there is no design of fireproof partition with physical isolation; The traditional fireproof material (such as mica plate, silicone rubber and fireproof cotton) is easy to carbonize and crack under continuous high temperature (> 800℃), which cannot meet the 5-minute fire resistance required by the national standard, and lacks systematic fire resistance structure design; the thermal expansion and contraction, vibration and other factors in the battery pack may cause the aging and falling of the sealing glue between the fireproof partition plate and the shell, so that the flame and smoke spread through the gap.

[0004] For example, Chinese invention patent application No. CN202211202270.1 discloses an invention named a battery pack and a vehicle. The battery pack comprises: a lower battery group; a tray, the tray comprising a tray bottom plate and a side beam, the side beam being used to support the tray bottom plate, the lower battery group being arranged on the tray bottom plate so that the tray bottom plate supports the lower battery group; a fixing block, the fixing block being arranged in the tray and fixed to the side beam; a support block and an upper battery group, the support block being detachably arranged on the fixing block so that the fixing block supports the support block, and the support block being used to mount and support the upper battery group. The battery pack disclosed in the invention can firmly mount the upper battery group on the tray, thereby effectively improving the stability and safety of the battery pack, avoiding safety accidents caused by the failure of the battery pack, and by arranging the support block on the fixing block, the weight of the upper battery group and the support block acts on the fixing block, avoiding the gravity of the upper battery group and the support block acting on the tray bottom plate, thereby reducing the risk of deformation of the tray bottom plate.

[0005] For another example, Chinese invention patent application No. CN202410366140.4 discloses a fire compartment fire extinguishing device, a fire extinguishing method and a lithium battery energy storage system. The fire compartment fire extinguishing device is used for a battery energy storage system, the battery energy storage system comprises a prefabricated cabin, a plurality of battery packs are arranged in the prefabricated cabin, each battery pack has a plurality of heat conduction surfaces; the fire extinguishing device comprises a plurality of cooling assemblies, which are arranged in one-to-one correspondence with the plurality of battery packs; each cooling assembly comprises a cover body and a liquid cooling plate, the inside of the cover body has a cover body cavity for the flow of fire extinguishing medium; and the cover body cavity is communicated with a liquid inlet and a liquid outlet; the cover body and the liquid cooling plate cover all the heat conduction surfaces. When the battery pack is in thermal runaway, the fire extinguishing medium is introduced into each cover body cavity and fills the space in the cover body cavity, thereby realizing the fire compartment of the battery pack, effectively inhibiting the spread of the battery pack thermal runaway, and the fire extinguishing medium continuously flows into the fire extinguishing device, the excess fire extinguishing medium flows out and is discharged from the prefabricated cabin, ensuring that the heat of thermal runaway is timely and efficiently removed.

[0006] The above prior art all have the problems of large fire spread risk, insufficient smoke exhaust efficiency, insufficient fire resistance time, and secondary ignition risk. Therefore, a fire compartment and a telescopic flame guide system for an electric vehicle battery pack are provided. SUMMARY

[0007] The present application provides a fire compartment and a telescopic flame guide system for an electric vehicle battery pack to solve the problems of the prior art.

[0008] The fire compartment and the telescopic flame guide system for the electric vehicle battery pack comprise: A three-dimensional modular partition architecture, three vertical fireproof partitions are arranged transversely along the length direction of the battery pack, three vertical fireproof partitions are arranged longitudinally along the width direction of the battery pack, and one horizontal fireproof partition is arranged, thereby dividing the inside of the battery pack into a plurality of independent fire compartments. A smoke and flame guide pipe is arranged between the battery pack shell and the longitudinally arranged fireproof partition, with a width of 60 mm and penetrating along the length direction of the battery pack. The structure of the smoke and flame guide pipe is sealed at the interface with the fireproof partition, compensating for a thermal displacement of ±3 mm, and the gas permeability is less than 0.1 cc / min·cm; A smoke and flame directional guide device includes a double-stage one-way valve in communication with each fireproof partition, a smoke and flame guide pipe, and an expandable metal bellows at the end of the smoke and flame guide pipe, for directing the smoke and flame generated by thermal runaway to the outside of the battery pack. A line fireproof grading protection device has a multi-layer fireproof structure of high-voltage cables and an independent fireproof channel of BMS signal lines. The high-voltage cables pass through the fireproof partition using the independent fireproof channel, and the BMS signal lines are arranged in the upper 100 mm cable channel, maintaining a vertical isolation of 250 mm from the battery module. An intelligent heat dissipation device has a variable cross-section heat dissipation hole and a shape memory alloy driven temperature control baffle. The variable cross-section heat dissipation hole is arranged in the non-load-bearing area of the horizontal fireproof partition, and the shape memory alloy driven temperature control baffle has a distance of ≥10 mm from the edge of the fireproof partition.

[0009] Further, three vertical fireproof partitions are longitudinally arranged along the width direction of the battery pack, including: One of the vertical fireproof partitions is arranged at the center, and the other two vertical fireproof partitions are arranged on both sides, each having a distance of 60 mm from the battery pack shell, forming a double-sided smoke and flame guide pipe area with a width of 60 mm between the battery pack shell. The one horizontal fireproof partition includes a double-layer partition, with an upper layer of 100 mm in height for cable and BMS line channels, and a lower layer of 250 mm in height for battery module installation area.

[0010] Further, the double-stage one-way valve includes: A primary valve triggered by BMS electrical signals, with a response time of ≤50 ms; A secondary valve automatically opened when the pressure is ≥1.2 MPa.

[0011] Further, the smoke and flame guide pipe is perforated in the area corresponding to the battery pack shell, with a diameter of 50 mm; An "embedded flange connection" structure is welded to the outside of the battery pack shell, with a flange sealing groove depth of 7 mm and a width of 10 mm for installing a silicone rubber sealing ring; The smoke and flame guide pipe adopts a double-layer structure, with an inner layer of silicon carbide ceramic pipe resistant to 1600℃ temperature, and an outer layer of metal pipe resistant to 2.5 MPa pressure.

[0012] Further, the expandable metal bellows: The compressed state length is 300 mm, the stretched state length is 500 mm, it is driven by a shape memory alloy spring, the trigger temperature is 300 DEG C; and the surface temperature resistance is 1200 DEG C.

[0013] Further, the multi-layer fireproof structure of the high-voltage cable and the independent fireproof channel of the BMS signal line comprise: Primary fireproofing, the outer layer of the multi-layer fireproof structure of the high-voltage cable is a 2mm thick ceramicized silicone rubber fireproof sleeve, the middle layer is a 1mm thick aerogel heat insulation felt, and the inner layer is a tinned copper braided shielding layer; Secondary fireproofing, the outer layer of the multi-layer fireproof structure of the high-voltage cable is a 1.5mm thick fluororubber sleeve, and the inner layer is a double-layer shielding of aluminum foil and polyester tape; The independent fireproof channel of the BMS signal line adopts a three-layer structure, the outer layer is a 1mm stainless steel plate, the middle layer is a 10mm air layer, and the inner layer is a 2mm ceramic fiber plate, the threading hole is provided with a flange and an expansion sealing ring, the high-voltage cable and the BMS signal line are kept at a distance of greater than or equal to 50mm, and a 0.5mm mica plate is arranged at the intersection to isolate.

[0014] Further, the intelligent heat dissipation system comprises: The variable cross-section heat dissipation hole is arranged in a non-load-bearing area of the horizontal fireproof partition plate, the long axis is 8mm, the short axis is 5mm, the opening rate is 18%, and the hole spacing is 25mm; The temperature-controlled baffle driven by the shape memory alloy is kept at a distance of greater than or equal to 10mm from the edge of the fireproof partition plate, and the phase transition temperature is 100 DEG C; The temperature-controlled baffle driven by the shape memory alloy is provided with three groups of guide vanes with an inclination of 45 DEG.

[0015] Further, the connection structure of the smoke guide and the battery pack shell comprises: The main sealing is a high-temperature-resistant silicone rubber sealing ring with a Shore hardness of 70±5A and a normal temperature compression rate of 30%, and a wave-shaped elastic gasket is additionally arranged on the outside with a pre-compression rate of 15%, which expands to 2.5 times the original volume at 200 DEG C and is embedded into the flange sealing groove; A silicone rubber expansion sealing adhesive strip with a diameter of 10mm is filled in the gap between the battery pack shell interfaces, the silicone rubber expansion sealing adhesive strip is configured to expand to a diameter of 25mm at greater than or equal to 200 DEG C to block the flame microchannel; a fluororubber bushing with a Shore hardness of 50A and a temperature resistance of -60 DEG C to 200 DEG C is embedded into the gap between the flame guide flange and the battery pack shell, allowing a radial displacement of ±2mm and an axial displacement of ±1.5mm; the inner wall of the bushing is sprayed with a molybdenum disulfide coating with a friction coefficient of less than or equal to 0.1; The gap between the flame guide flange and the battery pack shell is filled with a ceramic fiber fire-blocking cotton filling layer with a fire resistance temperature of 1400 DEG C and a gas permeability of less than 0.1cc / min·cm.

[0016] Further, the smoke and flame guide pipe further comprises: The fireproof valve at the tail exit has a trigger temperature of 180℃, an opening time of ≤0.5s, and maintains an IP6X dustproof level in normal state.

[0017] Compared with the prior art, the application has the following beneficial effects: 1. The fireproof partition and telescopic flame guide system of the electric vehicle battery pack improves the traditional integral battery pack into multiple independent fireproof units by combining longitudinal partition and fireproof material, and the fireproof partition plate combination design prolongs the flame penetration time of adjacent partitions to more than 30 minutes, far exceeding the 5-minute requirement of the national standard, to gain more time for personnel evacuation, and the horizontal partition plate realizes vertical isolation of the battery module and the cable to block the longitudinal spread path of the flame. 2. The fireproof partition and telescopic flame guide system of the electric vehicle battery pack has an independent smoke guide path design in each partition, the smoke exhaust speed is improved to 8m / s, the efficiency is improved by 3 times compared with the traditional pressure relief valve, and the internal pressure of the battery pack is significantly reduced. 3. The fireproof partition and telescopic flame guide system of the electric vehicle battery pack can guide the flame to the rear of the vehicle body by 300mm through the telescopic flame guide pipe, avoid contact with flammable components such as tires and fuel tanks, and reduce the risk of secondary accidents. 4. The fireproof partition and telescopic flame guide system of the electric vehicle battery pack has a full-sealed structure and an IP67 protection level, effectively prevents water vapor and dust from entering, and prolongs the service life of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a front view of the battery pack. Figure 2 It is a bottom view of the battery pack. Figure 3 It is a side view of the battery pack. Figure 4 It is a cross-sectional view of the connection between the flame guide pipe and the battery pack shell.

[0019] REFERENCE NUMERALS: 1, inner layer of flame guide pipe; 2, outer layer of flame guide pipe; 3, battery pack shell interface; 4, dynamic compensation layer; 5, fireproof filling layer; 6, fireproof partition plate; 7, smoke and flame guide pipe; 9, telescopic flame guide pipe; 10, battery pack shell; 11, battery module; 12, one-way valve; 13, cable; 100, battery pack. DETAILED DESCRIPTION

[0020] The technical solutions of the application will be further described in detail below in combination with the drawings and specific embodiments.

[0021] For example, Figures 1 to 4As shown, the fireproof partition and retractable flame guiding system for the electric vehicle battery pack of the present invention includes: like Figures 1 to 3 As shown, the three-dimensional modular partition architecture has three vertical fireproof partitions 6 arranged horizontally along the length of the battery pack 100, three vertical fireproof partitions 6 arranged vertically along the width of the battery pack 100, and one horizontal fireproof partition 6, dividing the interior of the battery pack 100 into multiple independent fireproof partitions. The smoke and flame guide pipe 7 is installed between the battery pack outer shell 10 and the longitudinally arranged fireproof partition 6. It has a width of 60mm and runs through the length of the battery pack 100. The smoke and flame guide pipe 7 is sealed at the interface with the fireproof partition to compensate for ±3mm thermal displacement. The gas permeability is <0.1cc / min·cm. The smoke and flame directional exhaust device includes a two-stage one-way valve 12 connected to each fire compartment, a smoke and flame guide pipe 7, and the telescopic metal bellows at the end of the smoke and flame guide pipe 7, for directional exhaust of the smoke and flame generated by thermal runaway to the outside of the battery pack 100. The fire protection level protection device for the line has a multi-layer fireproof structure for high-voltage cables and an independent fireproof channel for BMS signal lines. When the high-voltage cables pass through the fireproof partition 6, an independent fireproof channel is used. The BMS signal lines are arranged in the upper 100mm cable channel and are 250mm vertically isolated from the battery modules. The intelligent heat dissipation device has variable cross-section heat dissipation holes and a temperature control baffle driven by shape memory alloy. The variable cross-section heat dissipation holes are opened in the non-load-bearing area of ​​the horizontal fireproof partition 6, and the temperature control baffle driven by shape memory alloy is ≥10mm away from the edge of the horizontal fireproof partition 6.

[0022] Furthermore, the fireproof partition 6, which is arranged longitudinally along the width direction with three vertical sections, includes: One of the vertical fireproof partitions 6 is located in the center, and the other two vertical fireproof partitions 6 are located on both sides, each 60mm away from the battery pack outer shell 10, forming a 60mm wide double-sided smoke and flame guiding pipe area between them and the battery pack outer shell 10. The horizontal fireproof partition 6 includes a double-layer partition. The upper layer is 100mm high and serves as a cable and BMS line channel. The lower layer is 250mm high and serves as the battery module 11 installation area.

[0023] Specifically, taking the 1500mm×1000mm×350mm battery pack 100 as an example, it adopts a "3+2+1" partition architecture: Horizontal physical partitioning: Three vertical fireproof partitions 6 are set along the length of the battery pack 100 to form four independent partitions with dimensions of 375mm×880mm×350mm; Longitudinal physical partition: 3 vertical fireproof partitions 6 are arranged along the width direction of the battery pack 100, one is arranged in the center, and the other two are arranged on both sides, each is 60mm away from the battery pack shell 10, and a 60mm wide double-sided smoke / flame guide pipe area is formed between the battery pack shell 10, forming 8 independent partitions, the size is 375mm*440mm*250mm, and two smoke / flame guide pipe areas, the size is 1500mm*60mm*350mm; Longitudinal functional partition: divided into two layers by one horizontal fireproof partition 6, the lower layer is 250mm high, which is the battery module 11 installation area; the upper layer is 100mm high, which is the cable and BMS line channel; The fireproof partition 6 blocks the flame propagation path when the battery is on fire, so that the time for the flame to penetrate from one module to the adjacent module is more than 30 minutes, and the selection needs to meet the following indexes: Fire resistance: melting point ≥ 1500℃, continuous fire resistance time at 1000℃ high temperature ≥ 1 hour, ensure that the battery does not melt and collapse when thermal runaway; thermal conductivity ≤ 0.03W / m·K (25℃), block the heat conduction path, so that the temperature difference between the two sides of the fireproof partition 6 is ≥200℃; Mechanical strength: compressive strength ≥ 15MPa, bending strength ≥ 8MPa, can withstand the mechanical stress such as electrolyte expansion and vibration in the battery pack 100, such as 10kPa instantaneous pressure impact without breaking; Deformation resistance: linear expansion coefficient ≤ 50*10 -6 / ℃, avoid warping and cracking of the fireproof partition 6 due to temperature fluctuations, -40℃~80℃, ensure the partition isolation sealing performance; Chemical stability: acid and alkali resistance, corrosion rate ≤ 0.1% / year at pH 2-12, resistance to battery electrolyte (carbonate) penetration performance ≥ 72 hours without swelling; Sealing material: realize seamless sealing between the fireproof partition 6 and the battery pack shell 10, prevent electrolyte and water vapor penetration and smoke leakage during fire, and adapt to thermal expansion and contraction during long-term operation of the battery pack 100; in the thermal runaway scenario, the carbonized layer of the sealing glue can block the flame penetration, so that the fire resistance time of the connection is consistent with that of the fireproof partition 6, and the partition isolation effectiveness is ensured, and the following indexes need to be met when selecting the sealing material: Temperature resistance range: -60℃~300℃, after working at 250℃ for 1000 hours, the tensile strength retention rate is ≥80%; Sealing performance: Shore hardness 60±5A after curing, elongation at break ≥300%, adhesion strength to the aluminum alloy material of the battery pack shell 10 ≥5MPa, can withstand 0.5MPa hydrostatic pressure without leakage, meet IP67 waterproof level; Fire resistance: form an expanded carbonized layer after fire, expansion ratio ≥ 2 times, the integrity of the sealing layer remains ≥ 30 minutes under 1000℃ flame, smoke leakage ≤ 0.1m³ / (m·min); The space size of the smoke and flame guide pipe 7 is 60mm in the width of the single-sided air guide pipe area, penetrates along the length direction of the battery pack 100, is flush with the height of the battery pack 100, and the height is 350mm; Each fire prevention sub-area is communicated with the smoke and flame guide pipe 7 through the one-way valve 12 with an opening pressure of 1.2MPa; The smoke and flame guide pipe 7 is sealed at the interface with the fire prevention sub-area, compensates for the thermal displacement of ±3mm, and the gas permeability is less than 0.1cc / (min·cm).

[0024] The end of the smoke and flame guide pipe 7 is the telescopic metal bellows with a compressed state of 300mm and an expanded state of 500mm, and the surface temperature resistance is 1200℃; An automatic opening and closing fire valve is arranged at the tail outlet, is triggered at a temperature of ≥180℃, is opened in 0.5 seconds, and is sealed in the normal state with IP6X.

[0025] Further, the two-stage one-way valve 12 includes: The primary valve is triggered by the BMS electrical signal, and the response time is less than or equal to 50ms; The secondary valve is automatically opened when the pressure is greater than or equal to 1.2MPa.

[0026] The smoke and flame directional discharge principle, trigger and flow guide mechanism: When the sub-area temperature is greater than or equal to 350℃ or the internal pressure is greater than or equal to 1.2MPa, the electromagnetic lock and the mechanical valve of the two-stage one-way valve 12 are sequentially opened; The primary valve is triggered by the BMS electrical signal, and the response time is less than or equal to 50ms; The secondary valve is automatically opened when the pressure exceeds the threshold value, preventing single trigger failure.

[0027] The high-temperature smoke is discharged through the flame guide pipe, the inner layer is a silicon carbide ceramic pipe with a temperature resistance of 1600℃, and the graphene coating on the inner wall accelerates heat dissipation, reducing the smoke temperature by 30%-50%.

[0028] End protection and directional control: The telescopic metal bellows at the end of the smoke and flame guide pipe 7 is driven by a shape memory alloy spring, the trigger temperature is 300℃, and the telescopic metal bellows is extended to 1.5m outside the vehicle body during fire, and a telescopic flame guide pipe 9 can also be used; The fire valve at the tail outlet is opened by melting when the temperature is greater than or equal to 180℃, and is kept in the IP6X dustproof level by the silica gel dustproof cover in the normal state.

[0029] Further, the smoke and flame guide pipe 7 is opened in the area corresponding to the battery pack shell 10, with a diameter of 50 mm. The "embedded flange connection" structure is welded to the outside of the battery pack shell 10, with a flange sealing groove depth of 7 mm and a width of 10 mm, for installing a silicone rubber sealing ring. The smoke and flame guide pipe 7 adopts a double-layer structure, with the inner layer 1 being a silicon carbide ceramic pipe resistant to 1600℃ temperature, and the inner wall having a graphene coating; and the outer layer 2 being a metal pipe resistant to 2.5 MPa pressure.

[0030] Further, the telescopic metal corrugated pipe: The compressed state length is 300 mm, the stretched state length is 500 mm, it is driven by a shape memory alloy spring, the trigger temperature is 300℃, and the surface temperature resistance is 1200℃.

[0031] Further, the multi-layer fireproof structure of the high-voltage cable and the independent fireproof channel of the BMS signal line include: Primary fireproofing, the outer layer of the multi-layer fireproof structure of the high-voltage cable is a 2mm thick ceramicized silicone rubber fireproof sleeve, the middle layer is a 1mm thick aerogel heat insulation felt, and the inner layer is a tinned copper braided shielding layer; Secondary fireproofing, the outer layer of the multi-layer fireproof structure of the high-voltage cable is a 1.5mm thick fluororubber sleeve, and the inner layer is a double-layer shielding of aluminum foil and polyester tape; The independent fireproof channel of the BMS signal line adopts a three-layer structure, with an outer layer of 1mm stainless steel plate, a 10mm air layer, and an inner layer of 2mm ceramic fiber plate, and a flange and an expansion sealing ring are arranged at the threading hole, wherein the high-voltage cable and the BMS signal line maintain a distance of ≥50mm, and a 0.5mm mica plate is arranged at the intersection for isolation.

[0032] Specifically, the primary fireproof high-voltage cable: The outer layer is a 2mm thick ceramicized silicone rubber fireproof sleeve, model TC-1000, which forms a hard shell when ceramicized at 800℃; The middle layer is a 1mm thick aerogel heat insulation felt with a thermal conductivity of 0.013 W / (m·K); The inner layer is a tinned copper braided shielding layer with a shielding efficiency of ≥80dB; Joint processing, laser welding and fireproof sealing glue packaging, temperature resistance 300℃, Shore hardness 70A; The secondary fireproofing is the BMS signal line: The outer layer is a 1.5mm thick fluororubber sleeve with a temperature resistance of -60℃~200℃; The inner layer adopts a double-layer shielding of aluminum foil and polyester tape; The wiring principle maintains a distance of ≥50mm with the high-voltage cable, and a 0.5mm thick mica plate is arranged at the intersection for isolation; Independent fireproof passage, three-layer structure, outer layer 1mm stainless steel plate, 10mm air sandwich, inner layer 2mm ceramic fiber plate, threaded hole is provided with "flange and expansion sealing ring".

[0033] Further, the intelligent heat dissipation device comprises: Variable cross-section heat dissipation hole, the variable cross-section heat dissipation hole is arranged in the non-load-bearing area of the horizontal fireproof partition plate 6, the long axis is 8mm, the short axis is 5mm, the opening rate is 18%, and the hole spacing is 25mm; The temperature control baffle driven by the shape memory alloy has an edge spacing of ≥10mm from the fireproof partition plate 6, and a phase transition temperature of 100℃; The temperature control baffle driven by the shape memory alloy is provided with three groups of guide vanes with an inclination angle of 45° on the surface.

[0034] Specifically, the variable cross-section heat dissipation hole comprises: The main hole parameters of the variable cross-section heat dissipation hole are as follows: the long axis is 8mm along the air duct direction, the short axis is 5mm, the opening rate is 18%, and the hole spacing is 25mm; Temperature control baffle, NiTi shape memory alloy driven ceramic baffle, phase transition temperature 100℃, normal temperature opening angle 60°, temperature > 120℃, response time < 5 seconds, NiTi shape memory alloy composition ratio: Ni 55.4%-56.2%, Ti is the balance; Guide vane, three groups of 45° inclination vanes on the surface of the baffle, wind speed is increased by 20% when opened, and heat dissipation efficiency is increased by 35% compared with traditional round holes; Further, the connection structure of the smoke guide pipe 7 and the battery pack shell 10 comprises: The main sealing is a high-temperature-resistant silicone rubber sealing ring with a Shore hardness of 70±5A and a normal temperature compression rate of 30%, and a wave-shaped elastic gasket is additionally arranged on the outside with a pre-compression rate of 15%, expands to 2.5 times of the original volume at 200℃, and is embedded into the flange sealing groove; The gap between the battery pack shell interface 3 is filled with a silicone rubber expansion seal strip with a diameter of 10mm, the silicone rubber expansion seal strip is configured to expand to a diameter of 25mm at ≥200℃ to block the flame microchannel; the flange of the flame guide pipe is embedded into a fluororubber bushing between the battery pack shell, the Shore hardness is 50A, the temperature resistance is -60℃-200℃, and the displacement is allowed to be ±2mm in the radial direction and ±1.5mm in the axial direction; the inner wall of the bushing is sprayed with a molybdenum disulfide coating with a friction coefficient ≤0.1; The gap between the flange of the flame guide pipe and the battery pack shell is filled with a ceramic fiber fire-resistant cotton filling layer with a fire resistance temperature of 1400℃ and a gas permeability <0.1cc / min·cm.

[0035] Specifically, the main seal adopts a high-temperature-resistant silicone rubber sealing ring with a Shore hardness of 70±5A and a normal temperature compression rate of 30%, and a wavy elastic gasket with the same material as the sealing ring is additionally arranged on the outer side, with a pre-compression rate of 15% and an ability to absorb high-frequency vibration of 50-500Hz, and the gasket expands to 2.5 times of the original volume at 200 DEG C and is embedded into the flange sealing groove; The dynamic compensation layer 4 is filled with a silicone rubber expansion sealant strip with a diameter of 10mm, which expands to 25mm when heated to greater than or equal to 200 DEG C, thereby blocking the flame microchannel; a fluororubber bushing is embedded between the flame guide pipe flange and the shell, with a Shore hardness of 50A, a temperature resistance of -60 DEG C to 200 DEG C, and an allowable displacement of ±2mm in the radial direction and ±1.5mm in the axial direction; the inner wall of the bushing is sprayed with a molybdenum disulfide coating with a friction coefficient of less than or equal to 0.1, thereby reducing the vibration energy transmission; The fire-resistant filling layer 5 is filled with ceramic fiber fire-resistant cotton with a diameter of 3um and a fire resistance temperature of 1400 DEG C, and a gas permeability of less than 0.1cc / min·cm.

[0036] The installation process of the smoke and flame guide directional guide device is as follows: sequentially drilling holes in the battery pack shell 10, using argon arc welding for flange welding, stress annealing after welding, installing the silicone rubber sealing ring, inserting the smoke and flame guide pipe 7 into the flange hole, tightening the M8 screw, with a torque of 12-15N·m, using the lower limit value, and matching the 316 stainless steel and the silicone rubber composite elastic washer, allowing an axial displacement of ±0.5mm; a double-stacked self-locking washer DIN 7980 is additionally arranged between the screw head and the flange, with a vibration resistance of greater than or equal to 1*10^6 times, and high-temperature-resistant sealant is applied to the joint, with a temperature resistance of 300 DEG C.

[0037] Further, the smoke and flame guide pipe 7 further comprises: The tail exit fireproof valve has a trigger temperature of 180 DEG C, an opening time of less than or equal to 0.5 seconds, and maintains an IP6X dustproof level under normal conditions.

[0038] The application improves the traditional whole battery pack into multiple independent fireproof units through the "3+3+1" three-dimensional modular partition architecture, the fireproof partition plate 6 is combined to design, the flame penetration time of adjacent partitions is prolonged to more than 30 minutes, which is far more than the national standard of 5 minutes, and the horizontal fireproof partition plate 6 realizes the vertical isolation of the battery module 11 and the cable 13, and blocks the longitudinal spreading path of the flame; The three-dimensional partition space isolation principle divides the battery pack into independent fireproof partitions through the setting of three transverse vertical fireproof partition plates 6, three longitudinal vertical fireproof partition plates 6 and one longitudinal horizontal fireproof partition plate 6 to form a "3+3+1" partition architecture, and when a single partition is in thermal runaway, the adjacent partitions are sealed and blocked from the flame penetration path through the composite partition plate and the expanded graphite. The 50ms rapid response of the dual-stage one-way valve 12 and the 1600℃ heat-resistant smoke guide tube constitute an active flame guiding system. The telescopic metal bellows enables the flame to be directed to a safe distance of 1.5m outside the vehicle. The smoke exhaust speed is increased by 3 times compared with the traditional pressure relief valve, which is 8m / s, while the traditional one is 2.5m / s. The peak pressure inside the package is reduced by 40%, ≤1.5MPa. High-voltage cables feature three levels of protection, including ceramicized silicone rubber, aerogel, and metal shielding, ensuring uninterrupted operation for 30 minutes at 800℃. The BMS signal line has an independent fireproof channel to resolve the conflict between electromagnetic shielding and fire resistance. The mica isolation plate design at line intersections prevents short circuits from igniting. The shape memory alloy driven temperature control baffle closes the heat dissipation holes within 5 seconds when the temperature is above 120℃. The variable cross-section heat dissipation holes improve the normal heat dissipation efficiency by 35% and realize the automatic switching between "normal heat dissipation - high temperature flame arrestor" modes.

[0039] The testing methods for key performance parameters are shown in Table 1 below: Table 1

[0040] Fire resistance test and thermal runaway simulation data: Fire resistance test report: The partition can withstand fire for ≥1 hour at 1000℃; The sealing system shows no leakage at the joints after 30 minutes under a 1000°C flame. Thermal runaway simulation analysis and partition isolation effect: Thermal runaway of a single module, peak temperature of 2000℃, temperature of adjacent zones ≤350℃ within 30 minutes, thermal conductivity 0.025W / m·K, partition spacing 375mm; Flue gas discharge efficiency: 8 m / s flow rate, compared to 2.5 m / s for traditional valves; peak pressure inside the package ≤ 1.5 MPa.

[0041] Core performance parameters: The fireproof partition 6 has the following key performance indicators: fire resistance at 1000℃ ≥ 1 hour, thermal conductivity ≤ 0.03 W / m·K, and compressive strength ≥ 15 MPa; Sealing system, flue gas leakage ≤0.1m³ / (m·min) at 1000℃, IP67 waterproof; The smoke and flame guide tube 7 is heat-resistant at 1600℃ for 30 minutes, pressure-resistant at 2.5MPa, and has an end extension of 200mm. The one-way valve 12 has an opening pressure of 1.2 MPa and a response time of ≤50 ms. Fire damper, trigger temperature 180℃, opening time ≤0.5 seconds.

[0042] The fireproof partition plate performance of the application is leap-forward, the fire resistance performance does not fail for 1 hour at 1000 DEG C, and the existing mica plate is <30 minutes; The heat insulation efficiency is that the thermal conductivity coefficient is ≤0.03 W / m·K, the traditional material is >0.1 W / m·K, and the temperature difference of both sides of the partition plate is 200 DEG C; The structural strength is that the compression resistance is 15 MPa, and the national standard requires 5 MPa, and the electrolyte explosion impact can be borne; The sealing system is revolutionarily improved, the high-temperature sealing property is that the smoke leakage amount is 0.1 m3 / (m·min) at 1000 DEG C, and the average level of the industry is >1 m3; The waterproof grade is IP67 protection, and the traditional design is mostly IP54; The dynamic compensation layer 4 has a heat displacement compensation capacity of ±3 mm, and the existing technology has no active compensation design; The flame guide pipe technology is broken through, the temperature resistance grade is that the temperature resistance is 1600 DEG C for 30 minutes, and the traditional metal pipe is <1000 DEG C; The pressure resistance is 2.5 MPa working pressure, and a pressure relief valve is required; The telescopic function is 200 mm dynamic extension, and the existing fixed design is easy to ignite the vehicle body; The control response speed is doubled, the response of the one-way valve 12 is ≤50 ms, and the typical value of the mechanical valve is >100 ms; The fire valve action is 0.5 seconds opening, and the market similar products are >2 seconds; The double-stage triggering mechanism is combined with electric control and machinery, and the reliability is improved by 300%; The system level safety is improved, the flame blocking time is 30 minutes, and the national standard GB 38031-2020 requires 5 minutes; The secondary ignition protection is that the end of the flame guide pipe is away from the vehicle body by ≥1.5 m, and the traditional design is directly discharged; The pressure control is that the peak value in the package is ≤1.5 MPa, and the typical value of the non-flame guide system is >3 MPa; The material system innovation is that the silicon carbide ceramic pipe and the graphene coating reduce the weight by 40% compared with the traditional stainless steel pipe; The shape memory alloy driving phase change temperature precision is ±5 DEG C; The ceramization silicon rubber forms a ceramic shell at 800 DEG C; The whole vehicle safety benefit is that the personnel escape time is extended to 30 minutes, which is 6 times higher than the national standard requirement; The property protection avoids the whole battery pack burning, and the loss is reduced by 70% through partition control; The insurance risk level can be reduced by 1-2 levels, and the EV insurance evaluation standard is referred to.

[0043] The above comparison data is based on the test report of the embodiment of the application, wherein the fire resistance test is carried out according to GB / T 9978-2008, the sealing performance test is carried out according to the ISO 12135 standard, the response time test is carried out by using the ASTM F2005 method, and the pressure data is verified by CFD simulation and physical test.

[0044] The fireproof performance of the application is broken through, the longitudinal partition is combined with the fireproof material, the fire resistance time of the battery pack reaches more than 30 minutes, far more than 5 minutes required by the national standard, and more time is obtained for personnel evacuation. The application has high directional smoke exhaust efficiency, each partition is independently designed with a smoke guide path, the smoke guide speed is increased to 8 m / s, the efficiency is increased by 3 times compared with the traditional pressure relief valve, and the internal pressure of the battery pack is significantly reduced.

[0045] The application has improved safety, the telescopic flame guide pipe guides the flame to the rear of the vehicle body by 300 mm, avoids contact with flammable components such as tires and oil tanks, and reduces the risk of secondary accidents. The application has enhanced reliability, the full-sealing structure and IP67 protection level effectively prevent water vapor and dust from entering, prolong the service life of the battery pack, and are expected to be improved by more than 20%. The application combines three-dimensional modular partition and independent smoke guide, and for the first time, the battery pack is divided into independent fireproof units in the horizontal and longitudinal directions, each partition is provided with an independent smoke guide channel, and the double protection of "partition isolation and directional smoke exhaust" is realized. The telescopic flame guide pipe 9 has a mechanical-thermal double-drive telescopic structure at the end, is retracted to save space in normal times, is automatically extended away from the vehicle body in case of fire, and avoids secondary ignition. The application has a line hierarchical fireproof mechanism, multi-layer protection of high-voltage cables and signal lines and independent fireproof channels, solves the contradiction between electromagnetic interference and fire resistance. The application has intelligent coupling of heat dissipation, and the variable cross-section heat dissipation hole automatically switches between normal temperature heat dissipation and high temperature fire resistance.

[0046] The preferred embodiments of the application do not limit the application, and any modification, equivalent replacement and improvement made within the concept and principle of the application should be included in the protection scope of the claims of the application.

Claims

1. A fire compartmentation and telescopic flue system for an electric vehicle battery pack, characterized in that, The application relates to a three-dimensional modular partition architecture, which comprises three vertical fireproof partitions arranged transversely along the length direction of a battery pack, three vertical fireproof partitions arranged longitudinally along the width direction of the battery pack, and one horizontal fireproof partition, so as to divide the inside of the battery pack into multiple independent fireproof partitions. A smoke and flame guide pipe is arranged between the battery pack shell and the longitudinally arranged fireproof partitions, has a width of 60 mm, penetrates through the battery pack along the length direction, and is sealed at the interface between the smoke and flame guide pipe structure and the fireproof partition to compensate for a thermal displacement of 3 mm and has a gas permeation rate of less than 0.1 cc / min*cm. A smoke and flame directional guide device comprises a double-stage one-way valve communicated with each fireproof partition, the smoke and flame guide pipe and an elastic metal bellows at the end of the smoke and flame guide pipe, and is used for guiding the smoke and flame generated by thermal runaway to the outside of the battery pack. A line fireproof grading protection device has a multilayer fireproof structure of a high-voltage cable and an independent fireproof channel of a BMS signal line, the high-voltage cable passes through the fireproof partition by adopting the independent fireproof channel, and the BMS signal line is arranged in an upper 100 mm cable channel and is vertically separated from the battery module by 250 mm. An intelligent heat dissipation device has a variable cross-section heat dissipation hole and a temperature control baffle driven by a shape memory alloy, the variable cross-section heat dissipation hole is arranged in a non-load-bearing area of the horizontal fireproof partition, and the temperature control baffle driven by the shape memory alloy has a distance of greater than or equal to 10 mm from the edge of the fireproof partition. The three vertical fireproof partitions arranged longitudinally along the width direction of the battery pack comprise:

2. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, One of the vertical fireproof partitions is arranged at the center, and the other two vertical fireproof partitions are arranged on both sides and are 60 mm away from the battery pack shell, thereby forming a double-side smoke and flame guide pipe area with a width of 60 mm between the battery pack shell and the fireproof partitions; The one horizontal fireproof partition comprises a double-layer partition, an upper layer with a height of 100 mm is a cable and BMS line channel, and a lower layer with a height of 250 mm is a battery module installation area. The double-stage one-way valve comprises:

3. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, A primary valve triggered by a BMS electric signal and having a response time of less than or equal to 50 ms; A secondary valve automatically opened when the pressure is greater than or equal to 1.2 MPa. The smoke and flame guide pipe is opened in the area corresponding to the battery pack shell and has a diameter of 50 mm; 4. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, An embedded flange connection structure is welded to the outside of the battery pack shell, a flange sealing groove has a depth of 7 mm and a width of 10 mm, and is used for mounting a silicone rubber sealing ring; The smoke and flame guide pipe adopts a double-layer structure, an inner layer is a silicon carbide ceramic pipe with a temperature resistance of 1600 DEG C and a graphene coating on the inner wall, and an outer layer is a metal pipe with a pressure resistance of 2.5 MPa. The elastic metal bellows has a compressed length of 300 mm, an extended length of 500 mm, is driven by a shape memory alloy spring, has a trigger temperature of 300 DEG C, and has a surface temperature resistance of 1200 DEG C.

5. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, The multilayer fireproof structure of the high-voltage cable and the independent fireproof channel of the BMS signal line comprise: Primary fireproofing, the outer layer of the multilayer fireproof structure of the high-voltage cable is a 2 mm thick ceramicized silicone rubber fireproof sleeve, the middle layer is a 1 mm thick aerogel heat insulation felt, and the inner layer is a tinned copper braided shielding layer; 6. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, ​ ​ Secondary fire prevention, the outer layer of the multi-layer fire prevention structure of the high-voltage cable is a 1.5mm thick fluororubber sleeve, and the inner layer is a double-layer shield of aluminum foil and polyester tape; The independent fire prevention channel of the BMS signal line adopts a three-layer structure, the outer layer is a 1mm stainless steel plate, the middle layer is a 10mm air layer, and the inner layer is a 2mm ceramic fiber plate, the threading hole is provided with a flange and an expansion sealing ring, the high-voltage cable and the BMS signal line are kept at a distance of ≥50mm, and a 0.5mm mica plate is arranged at the intersection to isolate them.

7. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, The intelligent heat dissipation system comprises: The variable cross-section heat dissipation hole is arranged in a non-load-bearing area of the horizontal fireproof partition plate, has a long axis of 8mm, a short axis of 5mm, an opening rate of 18%, and a hole spacing of 25mm; The temperature control baffle driven by the shape memory alloy has a distance of ≥10mm from the edge of the fireproof partition plate and a phase transition temperature of 100℃; The temperature control baffle driven by the shape memory alloy is provided with three groups of guide vanes with an inclination angle of 45°.

8. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 1, wherein, The connection structure of the smoke guide and the battery pack shell comprises: The main seal is a high-temperature-resistant silicone rubber sealing ring with a Shore hardness of 70±5A and a normal temperature compression rate of 30%, and a wave-shaped elastic gasket is additionally arranged on the outside, the pre-compression rate is 15%, the expansion rate is 2.5 times the original volume at 200℃, and the sealing ring is embedded in the flange sealing groove; The gap between the battery pack shell interfaces is filled with a silicone rubber expansion sealant strip with a diameter of 10mm, the silicone rubber expansion sealant strip is configured to expand to a diameter of 25mm at ≥200℃ to block the flame microchannel; the flange of the flame guide pipe is embedded in the gap of the battery pack shell with a fluororubber bushing with a Shore hardness of 50A, a temperature resistance of -60℃-200℃, and an allowable displacement of ±2mm in the radial direction and ±1.5mm in the axial direction; the inner wall of the bushing is sprayed with a molybdenum disulfide coating with a friction coefficient of ≤0.1; The gap between the flange of the flame guide pipe and the battery pack shell is filled with a ceramic fiber fireproof cotton filling layer with a fireproof temperature of 1400℃ and a gas permeability of <0.1cc / min·cm.

9. The fire compartmentation and telescopic draft system for an electric vehicle battery pack of claim 4, wherein, The smoke guide and the flame guide pipe further comprise: The tail exit fireproof valve has a trigger temperature of 180℃, an opening time of ≤0.5 seconds, and maintains an IP6X dustproof level in a normal state.

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