Low-voltage power supply

Abstract

The utility model relates to the technical field of battery module design, in particular to a low-voltage power supply, which comprises a shell and an energy module, the shell is wrapped on the periphery of the energy module, a safety module is arranged between the energy module and the bottom wall of the shell, the safety module is a fire-retardant core, and the energy module is arranged in the shell. A smoke exhaust channel is arranged on the bottom wall of the shell, and a plurality of vertically-arranged straight-through flow channels are arranged on the fire arresting core. Through the arrangement of the fire-retardant core, a medium passes through the narrow channel, so that flame is prevented from spreading in a pipeline, energy exchange is carried out in the collision process of the flame and a device wall, the flame is prevented from passing through, heat of the flame is absorbed by enough flow channel length, the flame is extinguished in the core piece, and gas is prevented from being reburnt at the other end of the core piece. According to the invention, no open fire is provided for the outside after thermal runaway of the whole package, and the smoke of thermal runaway is discharged along the smoke exhaust pipeline, so that the whole package has no open fire and no smoke to the outside, and the strict requirements of manufacturers on thermal runaway at present are met.

Description

Technical Field

[0001] The utility model relates to the technical field of battery design, in particular to a low-voltage power supply. Background Art

[0002] In recent years, with the emergence of a new round of scientific and technological revolution and industrial transformation, the new energy vehicle industry has entered a stage of accelerated development. The whole vehicle has also put forward more stringent requirements on battery cells and their corresponding structures. For example, some manufacturers require that when the battery cell has thermal runaway, there should be no open flames or smoke, and no explosion within 5 minutes after thermal runaway occurs, etc.

[0003] For example, a method for disposing thermal runaway batteries in a battery swap station disclosed in application number 202111515898.2 detects the temperature of the battery through a temperature detection device, and sends the temperature of the battery to a monitoring system. The monitoring system identifies the location of the thermal runaway battery with an excessive temperature based on a preset threshold, and controls the palletizer to directly transport the thermal runaway battery to the outside of the battery swap station through the emergency exit on the side wall of the battery swap station. The above patent only deals with thermal runaway batteries, and there are no specific measures for the requirements of no open flames and no smoke during the disposal process. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is to carry out a new structural design of the low-voltage battery in accordance with the requirements of no open flame and no smoke design. Through actual measurement, it is found that when the battery cell has thermal runaway, the whole package is smokeless and has no open flame to the outside.

[0005] The above technical objectives of the utility model are achieved through the following technical solutions:

[0006] A low-voltage power supply comprises a shell and an energy module, wherein the shell is coated on the periphery of the energy module, a safety module is arranged between the energy module and the bottom wall of the shell, the safety module is a fire-blocking core, a smoke exhaust channel is arranged on the bottom wall of the shell, and a plurality of vertically arranged straight-through flow channels are arranged on the fire-blocking core.

[0007] Preferably, the fire-blocking core includes a core member, which includes two layers of stainless steel strips, one of which is in a spiral line, and the other is pressed into an N shape and filled between the stainless steel strips in the spiral line, and the straight flow channel is formed by the end wall between the N-shaped stainless steel strip and the stainless steel strip in the spiral line.

[0008] Preferably, the middle position of the bottom wall of the shell is recessed downward to form a smoke exhaust groove, the smoke exhaust groove is arranged pointing to one side wall of the shell, and the shell is provided with a smoke exhaust channel interconnected with the smoke exhaust groove.

[0009] Preferably, a plurality of vertical plates are arranged on the inner edge of the smoke exhaust groove and on the side pointing to the smoke exhaust passage, one end of the vertical plates abuts against a side wall of one end of the smoke exhaust groove, and the other end points to the smoke exhaust passage.

[0010] Preferably, a V-shaped guide portion is provided at one end of the smoke exhaust groove pointing to the smoke exhaust channel, and the end of the guide portion with a smaller size is arranged pointing to the smoke exhaust channel.

[0011] Preferably, the energy module comprises a plurality of batteries, the batteries are arranged in series, and the top surfaces of the batteries are arranged coplanar with the top surface of the shell.

[0012] Preferably, a plurality of explosion-proof valves are arranged at the bottom of the energy module, the explosion-proof valves are arranged in an array, and the connecting lines of the explosion-proof valves are arranged perpendicular to the vertical plates.

[0013] The low-voltage power supply described above, through the setting of the fire-blocking core, the medium passes through the triangular narrow channel, thereby preventing the flame from spreading in the pipeline. Through the wall effect, the flame exchanges energy during the collision with the wall, thereby preventing the flame from passing through. In addition, the sufficient flow channel length can absorb the heat of the flame, so that it is extinguished in the core, avoiding the possibility of the gas being reignited at the other end of the core. Through the setting of the fire-blocking core, there is no open flame to the outside after the whole package is thermally runaway, and the smoke from the thermal runaway is also exhausted along the specific smoke exhaust pipe. The overall performance is that there is no open flame and smoke to the outside, which meets the stringent requirements of some manufacturers for thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall structure of a low-voltage power supply in one embodiment of the utility model;

[0015] Figure 2 This is a schematic diagram of a low-voltage power supply split structure in one embodiment of the utility model;

[0016] Figure 3 A top view of a low-voltage power supply housing in one embodiment of the utility model;

[0017] Figure 4 It is a cross-sectional schematic diagram of a low-voltage power supply in one embodiment of the utility model.

[0018] In the figure, 1. shell; 11. connecting foot; 111. threaded hole; 12. smoke exhaust groove; 121. vertical plate; 122. guide part; 13. smoke exhaust channel; 2. energy module; 21. battery; 22. explosion-proof valve; 3. safety module; 31. fire-blocking core. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0020] See also Figure 1 and Figure 2 A low-voltage power supply comprises a shell 1, an energy module 2 and a safety module 3, wherein the shell 1 is used to cover the outer periphery of the energy module 2 and the safety module 3, and the safety module 3 is arranged below the energy module 2 to prevent thermal runaway during the use of the low-voltage power supply, and the whole package is smokeless and flameless to the outside.

[0021] Specifically, in one embodiment, please refer to Figure 2 and Figure 3 The shell 1 is a rectangular shell 1 with an open top, and connecting feet 11 are arranged at the four corners of the bottom of the shell 1. The connecting feet 11 are provided with threaded holes 111 that penetrate the connecting feet 11. The threaded holes 111 are used to penetrate bolts to fix the shell 1. In one embodiment, the middle position of the bottom wall of the shell 1 is recessed downward to form a smoke exhaust groove 12, and the smoke exhaust groove 12 is arranged pointing to one side wall of the shell 1. The shell 1 is provided with a smoke exhaust channel 13 that is interconnected with the smoke exhaust groove 12. A plurality of vertical plates 121 are arranged in the smoke exhaust groove 12 along the side pointing to the smoke exhaust channel 13. One end of the vertical plate 121 abuts against one end side wall of the smoke exhaust groove 12, and the other end points to the smoke exhaust channel 13. The vertical plates 121 are arranged in an array, and a slot is formed between adjacent vertical plates 121 to facilitate the exhaust of smoke. In one embodiment, a V-shaped guide portion 122 is disposed at one end of the smoke exhaust groove 12 pointing to the smoke exhaust passage 13 , and a smaller end of the guide portion 122 is disposed pointing to the smoke exhaust passage 13 .

[0022] See also Figure 4 The energy module 2 includes a battery 21 and a plurality of explosion-proof valves 22 arranged in series. In one embodiment, the explosion-proof valves 22 are arranged in an array along the length direction of the energy module 2. Specifically, the connection line of the explosion-proof valves 22 is perpendicular to the vertical plate 121 and is located below the battery 21. The top surface of the energy module 2 is arranged coplanar with the top surface of the shell 1.

[0023] In one embodiment, please refer to 4, the safety module 3 is a fire-blocking core 31, and the fire-blocking core 31 is arranged between the energy module 2 and the smoke exhaust groove 12. The fire-blocking core 31 is provided with a vertical straight-through flow channel. Specifically, in one embodiment, the fire-blocking core 31 includes a core member, and the core member is composed of two layers of ultra-thin stainless steel strips, one of which is a spiral line, and the other is pressed into an N shape and filled between the stainless steel strips of the spiral line, thereby forming countless end faces, which are small triangular straight-through flow channels, and there is a cross-structured bracket inside the core member (or a Y-shaped bracket is pressed on the surface) to enhance the reliability of the core member and prevent the core member from being dispersed by the explosion pressure generated by the ignited medium. The medium passes through the triangular narrow channel, and the flame arrester also uses it to prevent the flame from spreading in the pipeline. Its principle is the "vessel wall effect", that is, the collision between the flame and the vessel wall converts energy and reduces the temperature. Based on this principle, the height of the triangular hole is designed to prevent the flame from passing through, and the sufficient flow channel length is added to absorb the heat of the flame so that it is extinguished in the core, avoiding the possibility of the gas being reignited at the other end of the core.

[0024] The fire-blocking core 31 used in this application works by the following principles:

[0025] (1) Heat transfer: The filter element of the flame arrester is composed of many small channels or pores. When the flame enters these small channels, many small flame flows are formed. Due to the large heat transfer area of ​​the channel, the flame exchanges heat through the channel wall, and the temperature drops. When it reaches a certain level, the flame can be extinguished. According to the test conducted by M. Roper of the United Kingdom on the corrugated flame arrester, when the thermal conductivity of the flame arrester material is increased by 460 times, its extinguishing diameter only changes by 216%. This shows that the material problem is secondary. In other words, heat transfer is a reason for extinguishing the flame, but not the main reason.

[0026] (2) Wall effect: According to the chain reaction theory of combustion and explosion, it is believed that the combustion and explosion phenomenon is not the result of direct interaction between molecules, but the molecular bonds are destroyed under the stimulation of external energy (heat energy, radiation energy, electrical energy, chemical energy, etc.), resulting in molecules with reaction ability (called active molecules). When these active molecules undergo chemical reactions, they first split into very active and short-lived free radicals. Chemical reactions are carried out by these free radicals. In addition to the product, the result of the interaction between free radicals and another molecule can also produce new free radicals. These new free radicals react repeatedly, are consumed and generated again, and the process continues. It can be seen from this that the condition for the spontaneous combustion of flammable mixed gas (after the combustion begins, there is no external energy) is that the number of newly generated free radicals is equal to or greater than the number of disappeared free radicals. As the size of the flame arrester channel decreases, the probability of collision between free radicals and reactive molecules decreases, while the probability of collision between free radicals and the channel wall increases, which reduces the free radical reaction. When the channel size is reduced to a certain value, the wall effect creates a condition where the flame cannot continue to propagate, and the flame is blocked. Therefore, the wall effect is the main mechanism for blocking the flame. It can also be seen that the flame arrester cannot prevent the open flame combustion of flammable gases and liquids.

[0027] A low-voltage power supply provided in the present application, through the setting of the fire-blocking core 31, the medium passes through the triangular narrow channel, thereby preventing the flame from spreading in the pipeline, and through the wall effect, the flame exchanges energy during the collision with the wall, thereby preventing the flame from passing through, and the sufficient flow channel length is used to absorb the heat of the flame, so that it is extinguished in the core, avoiding the possibility of the gas being reignited at the other end of the core. Through the setting of the fire-blocking core 31, there is no open flame to the outside after the whole package is thermally runaway, and the smoke of thermal runaway is also discharged along a specific smoke exhaust pipe. The overall performance is that there is no open flame and smoke to the outside, which meets the stringent requirements of some manufacturers for thermal runaway.

Claims

1. A low-voltage power supply, comprising a housing and an energy module, wherein the housing is wrapped around the outer periphery of the energy module, characterized in that: A safety module is arranged between the energy module and the bottom wall of the shell. The safety module is a fire-blocking core. A smoke exhaust channel is arranged on the bottom wall of the shell. A plurality of vertically arranged straight-through flow channels are arranged on the fire-blocking core.

2. The low voltage power supply according to claim 1, characterized in that: The fire-blocking core includes a core component, which includes two layers of stainless steel strips, one of which is in a spiral line, and the other is pressed into an N shape and filled between the stainless steel strips in the spiral line. The straight flow channel is formed by the end wall between the N-shaped stainless steel strip and the stainless steel strip in the spiral line.

3. The low voltage power supply according to claim 2, characterized in that: The middle position of the bottom wall of the shell is recessed downward to form a smoke exhaust groove, the smoke exhaust groove is arranged toward one side wall of the shell, and the shell is provided with a smoke exhaust channel interconnected with the smoke exhaust groove.

4. The low voltage power supply according to claim 3, characterized in that: A plurality of vertical plates are arranged on the inner edge of the smoke exhaust groove and on the side facing the smoke exhaust passage. One end of the vertical plates abuts against a side wall of one end of the smoke exhaust groove, and the other end faces the smoke exhaust passage.

5. The low voltage power supply according to claim 4, characterized in that: A V-shaped guide portion is arranged at one end of the smoke exhaust groove pointing to the smoke exhaust channel, and the smaller end of the guide portion is arranged pointing to the smoke exhaust channel.

6. The low voltage power supply according to claim 5, characterized in that: The energy module includes a plurality of batteries, the batteries are arranged in series, and the top surfaces of the batteries are arranged coplanar with the top surface of the shell.

7. The low voltage power supply according to claim 6, characterized in that: A plurality of explosion-proof valves are arranged at the bottom of the energy module. The explosion-proof valves are arranged in an array, and the connection lines of the explosion-proof valves are arranged perpendicular to the vertical plates.

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