Vehicle battery fire prevention system using liquefied carbon dioxide, and electric vehicle battery module and electric vehicle including the same

Abstract

The present invention relates to a vehicle battery fire prevention system using liquefied carbon dioxide, and an electric vehicle battery module and an electric vehicle including the same. The system includes a housing having an accommodation space for accommodating the battery module, a chamber for storing fire extinguishing gas injected into the housing in the form of a fire extinguishing liquid, a fire extinguishing pipe connected to the chamber and extending into the housing along a predetermined path, and a control unit for controlling the injection of the fire extinguishing gas through the fire extinguishing pipe. The control unit controls to execute an injection corresponding to each of a plurality of predetermined conditions injected into the accommodation space. A vehicle battery fire prevention system using liquefied carbon dioxide is provided.

Description

Technical Field

[0001] The present invention relates to a vehicle battery fire prevention system using liquefied carbon dioxide, and an electric vehicle battery module and an electric vehicle including the same.

Background Art

[0002] Currently, there is no control device or system that can extinguish a fire during a fire in an electric vehicle, and problems such as complete combustion or fire spread often occur. As an example, the dedicated frame of the battery of an electric vehicle is installed at the lower part of the vehicle and consists of many cells made of lithium ions. The cells gather to form a module, and this module is packaged in an intensive structure to produce an automotive battery frame. A lithium-ion battery is a chemical energy storage device in which lithium ions are charged and discharged through a positive electrode and a negative electrode. It has a higher charging speed and output density than other types of batteries, can be used for a long time, has a relatively small volume and can be lightweight. When charged in a state where it is not completely discharged, there is no memory effect where the driving time decreases compared to the original driving time, is environmentally friendly, and has a relatively low maintenance cost. However, compared to other types of batteries, it has the disadvantage of being vulnerable to fire. The fire of the battery is mainly caused by the thermal runaway phenomenon of the battery cell. The thermal runaway phenomenon refers to a chemical reaction in which a highly oxidizing positive electrode and a highly reducing negative electrode meet and rapidly self-heat. When the thermal runaway phenomenon occurs, the battery cell releases the stored energy very quickly, and the more energy charged in the battery cell, the more active the thermal runaway reaction occurs. Therefore, there is a need for means to prevent such a fire from occurring in the battery of an electric vehicle and effectively extinguish the fire during a fire.

Summary of the Invention

Problems to be Solved by the Invention

[0003] One embodiment of the present invention aims to suppress a fire that may occur in a battery mounted on an electric vehicle and prevent it from leading to a larger fire.

[0004] One embodiment of the present invention aims to create an optimal environment to improve the efficiency of the electric ratio output from a battery mounted on an electric vehicle.

Means for Solving the Problems

[0005] The present invention relates to a vehicle battery fire prevention system using liquefied carbon dioxide, a battery module for an electric vehicle including the same, and an electric vehicle. The present invention includes a housing having an accommodation space for accommodating the battery module, a chamber for storing fire extinguishing gas injected into the housing in the form of a fire extinguishing liquid, a fire extinguishing pipe connected to the chamber and extending inside the housing along a predetermined path, and a control unit for controlling the injection of the fire extinguishing gas through the fire extinguishing pipe. The control unit provides a vehicle battery fire prevention system using liquefied carbon dioxide that controls to execute injections corresponding to each of a plurality of predetermined conditions injected into the accommodation space.

[0006] And the fire extinguishing pipe may include a first nozzle that opens toward the electrode portion of the battery module inside the housing, and a second nozzle having a smaller opening area and being formed more than the first nozzle.

[0007] Also, the plurality of predetermined conditions of the control unit are different temperature ranges from each other, and the temperature ranges in which the control unit injects the fire extinguishing gas may be a first temperature range including the normal temperature at which the battery module operates, a second temperature range higher than the first temperature range, and a third temperature range higher than the second temperature range and including at least the temperature at which thermal runaway starts, and may be the second temperature range and the third temperature range.

[0008] Also, the control unit can inject the fire extinguishing gas through the first nozzle in the third temperature range and inject the fire extinguishing gas through the second nozzle in the second temperature range.

[0009] In addition, when there is residual fire extinguishing liquid that can fill the accommodation space inside the chamber with fire extinguishing gas, the control unit can restrict the injection of the fire extinguishing gas through the second nozzle.

[0010] In addition, the housing can be provided with an exhaust portion on one side of the housing that maintains airtightness between the accommodation space and the outside, exhausts to the outside when the pressure in the accommodation space exceeds a predetermined value, and opens to exhaust only in one direction formed from the accommodation space to the outside.

[0011] In addition, the control unit is connected to at least one of a first valve that determines the opening and closing of the first nozzle, a second valve that determines the opening and closing of the second nozzle, and a temperature sensor and a pressure sensor exposed to the accommodation space, and can control the opening and closing of the first valve or the second valve based on the sensing information sensed by at least one of the temperature sensor and the pressure sensor from the accommodation space.

[0012] In addition, the present invention provides a vehicle battery module including a vehicle battery fire prevention system and a battery module using liquefied carbon dioxide.

[0013] In addition, the present invention provides an electric vehicle including a vehicle battery module.

Advantages of the Invention

[0014] According to an embodiment of the present invention, it is possible to provide a vehicle battery fire prevention system that suppresses a fire that may occur in a battery mounted on an electric vehicle and prevents it from leading to a larger fire.

[0015] An embodiment of the present invention can provide a vehicle battery fire prevention system that creates an optimal environment to improve the efficiency of the electric ratio output from a battery mounted on an electric vehicle.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0017] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, this is merely an example, and the present invention is not limited thereto.

[0018] In the description of the present invention, when it is determined that a specific description of a known technique related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. And the terms described below are terms defined in consideration of the functions in the present invention, and these may vary depending on the intention or convention of the user or operator. Therefore, the terms must be defined based on the content throughout this specification.

[0019] The technical idea of the present invention is determined by the claims, and the following embodiments are merely a means for efficiently explaining the technical idea of the present invention to those having ordinary knowledge in the technical field to which the present invention pertains.

[0020] Figure 1 is a diagram showing an example in which a vehicle battery fire prevention system 100 (hereinafter referred to as system 100) using liquefied carbon dioxide CO2 according to an embodiment of the present invention is applied to a vehicle 10.

[0021] Referring to Figure 1, the vehicle battery fire prevention system 100 using liquefied carbon dioxide CO2 of the present invention can be used as a vehicle battery module BM by accommodating a battery module BM therein. Also, in the case of an electric vehicle including such a vehicle battery module BM, in terms of design considering the center of mass and distribution, the batteries can be arranged widely at the bottom to ensure more capacity. Such a battery module BM is used as a high-density energy source, but since a fire may occur due to a defect, preventive measures against this are required. Due to the characteristics of the battery module BM applied to the vehicle 10, once a fire occurs, a thermal runaway phenomenon in which the temperature rapidly increases progresses, so extinguishing the fire is relatively difficult and causes enormous damage. Therefore, the system 100 according to an embodiment of the present invention can effectively create the environment of the battery module BM in situations such as the running of the vehicle 10, improve the electric ratio and the like output from the battery module BM, and immediately extinguish the fire targeting the battery module BM when a fire is expected or detected. Hereinafter, the present invention will be specifically described based on the structure of the system 100.

[0022] Figure 2 is a diagram showing an example in which a fire extinguishing pipe 130 of the system 100 according to an embodiment of the present invention extends.

[0023] Referring to FIG. 2, a system 100 according to an embodiment of the present invention includes a housing 110 having an accommodation space 110a for accommodating a battery module BM, a chamber 120 for storing fire extinguishing gas injected inside the housing 110 in the form of a fire extinguishing liquid, a fire extinguishing pipe 130 connected to the chamber 120 and extending inside the housing 110 along a predetermined path, and a control unit 140 for controlling the injection of the fire extinguishing gas through the fire extinguishing pipe 130. Here, the control unit 140 controls to execute an injection corresponding to each of a plurality of predetermined conditions injected into the accommodation space 110a, and a vehicle battery fire prevention system 100 using liquefied carbon dioxide CO2 is provided. Further, the control unit 140 is a type of electrical equipment, and as long as it is electrically connected, there is no limitation on its shape or arrangement. Therefore, it is shown in FIG. 5 as a schematic diagram, and the illustration for explaining the structure separately is omitted.

[0024] The housing 110 includes a battery module BM in an internal accommodation space 110a and can maintain airtightness with respect to the outside. One end of the fire extinguishing pipe 130 passing through the housing 110 can be connected to a chamber 120 provided outside. By providing a sealing portion 111 at the point where the housing 110 is penetrated, the inside and outside of the housing 110 can be separated. Carbon dioxide CO2 is stored in the chamber 120 in a liquefied state and can be injected in a gas phase by undergoing a phase change when injected into the inside of the housing 110 through the fire extinguishing pipe 130. Therefore, it can contain a large-capacity cooling carbon dioxide CO2 compared to the volume. The fire extinguishing pipe 130 connected to the chamber 120 can extend along a predetermined extension section inside the housing 110 to inject the carbon dioxide CO2 transmitted from the chamber 120. This can extend close to a location where the possibility of a fire occurring is high.

[0025] For example, in the case of the battery module BM stacked in the vertical direction with reference to FIG. 2, when the electrode portion is located on the side surface, the electrode portion is arranged on the side surface, and the fire extinguishing pipe 130 extends along the edge and approaches the electrode portion. It goes without saying that the extended form of such a fire extinguishing pipe 130 is not limited to that shown in FIG. 2, and the form of the battery constituting the battery module BM can be similarly applied to various forms of batteries such as rectangular, cylindrical, and pouch-shaped batteries.

[0026] FIG. 3 is a diagram showing an extension example of the fire extinguishing pipe 130 according to an embodiment of the present invention. FIG. 3(a) is a diagram showing an embodiment extending along the edge of the battery module BM, and FIG. 3(b) is a diagram showing an embodiment extending corresponding to the upper surface of the battery module BM.

[0027] Referring to FIG. 3, the fire extinguishing pipe 130 can include a nozzle 130a (the nozzle 130a shown in FIG. 3 indicates an arbitrary position and does not specify the shape or position). The nozzle 130a injects carbon dioxide CO2 provided from the chamber 120 into the housing 110, and the area affected by the injection can be changed depending on the formed position. Preferably, the position where the nozzle 130a is formed can include at least the position where the electrode portion is provided, and can be formed more than that. In the case of FIG. 3, the fire extinguishing pipe 130 extends along the inner peripheral surface of the housing 110, and carbon dioxide CO2 can be injected from the edge of the battery module BM toward the battery module BM side. As described above, the injection direction SD can include at least the electrode portion. This means directly injecting carbon dioxide CO2, which is a fire extinguishing gas, at a location where the possibility of a fire occurring is high.

[0028] In the case of Fig. 3(b), the fire extinguishing pipe 130 is provided on the upper surface of the battery module BM, and can be in a form in which the electrode portion faces upward, such as a cylindrical battery. Corresponding to this, the fire extinguishing pipe 130 is provided in contact with the inner bottom of the upper surface of the housing 110, so that the fire extinguishing gas can be jetted toward the electrode portion. Such a fire extinguishing pipe 130 can be provided as a separate member, or a flow path can be formed on one or more wall surfaces of the housing 110, and the fire extinguishing gas can be jetted along the flow path.

[0029] On the other hand, the battery module BM and the fire extinguishing pipe 130 can be located in the accommodation space 110a formed inside the housing 110, and the remaining space can be filled with air. Here, the air can be composed of atmospheric components such as oxygen, but since the air inside the housing 110 is discharged to the outside by at least one injection of carbon dioxide CO2, the gas filling the accommodation space 110a can be carbon dioxide CO2. Of course, as a preferred example, it can be initially set so that at least 90% or more is composed of carbon dioxide CO2.

[0030] Here, in order to be able to exhaust the air existing in the accommodation space 110a to the outside of the housing 110 by the injection of carbon dioxide CO2, the housing 110 can be provided with an exhaust portion 110b. Specifically, the housing 110 can be provided with an exhaust portion 110b on one side of the housing 110 that maintains airtightness between the accommodation space 110a and the outside, and when the pressure in the accommodation space 110a exceeds a predetermined value, exhausts to the outside and opens to exhaust only in one direction from the accommodation space 110a to the outside. That is, when the internal pressure of the housing 110 exceeds a predetermined pressure, a one-way flow can be allowed so that it can be exhausted to the outside.

[0031] On one hand, inside the housing 110, it can be equipped with a sensor that senses one or more of the pressure and temperature of the accommodation space 110a. For example, the temperature sensor 151 is connected to the control unit 140, and the control unit 140 that has received the internal temperature can determine whether to inject carbon dioxide CO2. Also, when the internal pressure of the housing 110 increases, the control unit 140 that has received the increased pressure information can also open the exhaust part 110b through the pressure sensor 152. Of course, the exhaust part 110b can be configured to be electronically controlled by the sensed pressure or to operate mechanically to open when exceeding a predetermined pressure.

[0032] FIG. 4 is a cross-sectional view of the fire extinguishing pipe 130 according to an embodiment of the present invention. FIG. 4(a) is a cross-sectional view of the point where the first nozzle 131a is formed, and FIG. 4(b) is a cross-sectional view of the point where the second nozzle 132a is formed.

[0033] Referring to FIG. 4, the aforementioned nozzle 130a can be divided into a first nozzle 131a and a second nozzle 132a. Specifically, the fire extinguishing pipe 130 can include a first nozzle 131a that opens inside the housing 110 toward the electrode part of the battery module BM, and a second nozzle 132a that has a smaller opening area than the first nozzle 131a and is formed more. The opening times of the first nozzle 131a and the second nozzle 132a can be different from each other by the control unit 140. The opening conditions can be determined based on the sensed information transmitted from one or more of the temperature sensor 151 and the pressure sensor 152 by the control unit 140. This will be specifically described later based on FIGS. 5 and 6.

[0034] A point determined to have a high fire risk, for example, the first nozzle 131a that opens towards the electrode part, can be opened and closed under the control of the first valve 131. When it opens, carbon dioxide CO2 inside the high-pressure fire extinguishing pipe 130 can be injected into the relatively low-pressure accommodation space 110a. The amount of gaseous carbon dioxide CO2 injected through the first nozzle 131a by the opening of the first valve 131 can be at least an amount sufficient to fill the accommodation space 110a.

[0035] And the amount of carbon dioxide CO2 injected through the second nozzle 132a by the opening of the second valve can also be an amount sufficient to fill the accommodation space 110a. As an example, injection can be repeatedly executed in an amount sufficient to fill the accommodation space 110a once by opening. This is to be repeatedly executed to reach the target temperature.

[0036] Here, the target temperature can be different when injected through the first nozzle 131a and when injected through the second nozzle 132a. For example, injecting carbon dioxide CO2 through the first nozzle 131a is for extinguishing a fire at the fire location, and injecting carbon dioxide CO2 through the second nozzle 132a is to suppress the temperature rise of the battery and maintain the temperature of the battery module BM below a predetermined temperature.

[0037] Therefore, in order to form a wider injection area rather than the injection amount, the second nozzle 132a can be formed in a plurality of directions to inject carbon dioxide CO2. Thus, the accommodation space 110a can be filled with carbon dioxide CO2 and cooled. The temperature at which the liquefied carbon dioxide CO2 is injected while undergoing a phase change to a gas is at least a sub-zero temperature, and since the accommodation space 110a is at a temperature above zero, heat exchange can occur during injection to lower the internal temperature of the housing 110.

[0038] Furthermore, since the normal battery module BM can be maintained within an ideal temperature range for a long time during operation, cooling the battery module BM by the system 100 can improve the power ratio of the electric vehicle including the same.

[0039] FIG. 5 is a schematic diagram for showing that the control unit 140 determines the opening and closing of the valve according to an embodiment of the present invention, and FIG. 6 is a graph showing the temperature that continuously increases over time in the system 100 according to an embodiment of the present invention.

[0040] Referring to FIGS. 5 and 6, the control unit 140 can open the first valve 131 and the second valve 132 in different temperature ranges, respectively. Specifically, the temperature range in which the control unit 140 injects the fire extinguishing gas may be the second temperature range S2 and the third temperature range S3 among the first temperature range S1, which is a temperature range including the normal temperature at which the battery module BM is operated, the second temperature range S2, which is a temperature range higher than the first temperature range S1, and the third temperature range S3, which is a temperature range higher than the second temperature range S2 and includes at least the temperature at which thermal runaway starts.

[0041] Here, when the first temperature range S1 is the ideal operating temperature range of the battery module BM, when the temperature sensor 151 senses that the temperature of the accommodation space 110a increases to a temperature higher than this and transmits it to the control unit 140, the control unit 140 can open the second valve 132 and inject carbon dioxide CO2 through the second nozzle 132a. The injected carbon dioxide CO2 at a sub-zero temperature can exchange heat with the temperature above zero in the accommodation space 110a, so that the temperature of the accommodation space 110a can be reduced. Here, the pressure in the accommodation space 110a inside the housing 110 exceeds the atmospheric pressure due to the injected carbon dioxide CO2, and a part of it can be exhausted through the exhaust part 110b.

[0042] On the other hand, when the temperature of the accommodation space 110a enters the third temperature range S3 through the second temperature range S2, the temperature can rise rapidly beyond the thermal runaway point and combustion can occur. When the temperature of the accommodation space 110a corresponds to the third temperature range S3 and the temperature sensor 151 senses it, and transmits the sensing information to the control unit 140, the control unit 140 opens the first valve 131 to inject carbon dioxide CO2 through the first nozzle 131a. Since the third temperature range S3 includes the thermal runaway point but starts from a temperature lower than the thermal runaway point, by immediately executing the injection of carbon dioxide CO2 when entering the third temperature range S3, the temperature is prevented from reaching the thermal runaway point.

[0043] Such a mechanism has a strong purpose of cooling for managing the temperature of the battery based on the sensing information sensed by the temperature sensor 151 by the control unit 140 (injection through the second nozzle 132a), and is for executing internal cooling and oxygen removal (injection through the first nozzle 131a) of the accommodation space 110a to prevent thermal runaway during a fire.

[0044] On the other hand, the control unit 140 is connected to one or more of the first valve 131 that determines the opening and closing of the first nozzle 131a, the second valve 132 that determines the opening and closing of the second nozzle 132a, the temperature sensor 151 and the pressure sensor 152 exposed to the accommodation space 110a, and can control the opening and closing of the first valve 131 or the second valve 132 based on the sensing information sensed by one or more of the temperature sensor 151 and the pressure sensor 152 from the accommodation space 110a. That is, the control unit 140 can be electrically connected to the first valve 131, the second valve 132, the pressure sensor 152, and the temperature sensor 151, and execute control based on the transmitted sensing information.

[0045] Furthermore, when the control unit 140 can fill the accommodation space 110a with fire extinguishing gas less than twice and only the fire extinguishing liquid remains inside the chamber 120, the injection of the fire extinguishing gas through the second nozzle 132a can be restricted. In this case, the control unit 140 can maintain the second valve 132 in a closed state and sense the opening and closing of the first valve 131 based on the sensed information transmitted from the temperature sensor 151. To perform such an operation, the control unit 140 can receive the sensed information from the sensor unit 120a connected to the chamber 120. The sensor unit 120a can transmit the internal pressure of the chamber 120 and the remaining amount of liquefied carbon dioxide CO2.

[0046] The representative embodiments of the present invention have been described in detail above. However, those having ordinary knowledge in the technical field to which the present invention pertains will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention. Therefore, the scope of the rights of the present invention should not be limited to the above-described embodiments, and should be determined not only by the following claims but also by those equivalent to the following claims.

Claims

1. A housing having an accommodation space for accommodating a battery module, A chamber for storing fire extinguishing gas injected inside the housing in the form of a fire extinguishing liquid, A fire extinguishing pipe connected to the chamber and extending inside the housing, and extending along a predetermined path, A control unit for controlling the injection of the fire extinguishing gas through the fire extinguishing pipe, The control unit controls to execute injections corresponding to each of a plurality of predetermined conditions injected into the accommodation space, a vehicle battery fire prevention system using liquefied carbon dioxide.

2. The fire extinguishing pipe includes a first nozzle that opens inside the housing toward the electrode portion of the battery module, and a second nozzle that has a smaller opening area and is formed in a larger number than the first nozzle. The vehicle battery fire prevention system using liquefied carbon dioxide according to claim 1.

3. The control unit, The plurality of predetermined conditions are different temperature ranges from each other, The temperature ranges in which the control unit injects the fire extinguishing gas are a first temperature range including the normal temperature at which the battery module is operated, a second temperature range higher than the first temperature range, and a third temperature range higher than the second temperature range and including at least the temperature at which thermal runaway starts. The vehicle battery fire prevention system using liquefied carbon dioxide according to claim 2, which are the second temperature range and the third temperature range.

4. The control unit injects the fire extinguishing gas through the first nozzle in the third temperature range and injects the fire extinguishing gas through the second nozzle in the second temperature range. The vehicle battery fire prevention system using liquefied carbon dioxide according to claim 3.

5. The control unit restricts the injection of the fire extinguishing gas through the second nozzle when there is remaining fire extinguishing liquid that can fill the accommodation space inside the chamber with fire extinguishing gas. The vehicle battery fire prevention system using liquefied carbon dioxide according to claim 4.

6. The housing includes an exhaust part on one side of the housing that maintains airtightness between the accommodation space and the outside, exhausts to the outside when the pressure in the accommodation space exceeds a predetermined value, and opens to exhaust only in one direction formed from the accommodation space to the outside. The vehicle battery fire prevention system using liquefied carbon dioxide according to claim 5.

7. The control unit is connected to a first valve that determines the opening and closing of the first nozzle, a second valve that determines the opening and closing of the second nozzle, and one or more of a temperature sensor and a pressure sensor exposed to the accommodation space. Based on the sensing information sensed by one or more of the temperature sensor and the pressure sensor from the accommodation space, the control unit controls the opening and closing of the first valve or the second valve. The vehicle battery fire prevention system using liquefied carbon dioxide according to claim 4.

8. A vehicle battery module including the vehicle battery fire prevention system using liquefied carbon dioxide according to claim 1 and a battery module.

9. An electric vehicle including the vehicle battery module according to claim 8.

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