CN114039113A

CN114039113A - Optical detection device and optical detection method

Info

Publication number: CN114039113A
Application number: CN202111233875.2A
Authority: CN
Inventors: 刘秀华; 李飞
Original assignee: Zephyr Intelligent System Shanghai Co Ltd
Current assignee: Zephyr Intelligent System Shanghai Co Ltd
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2022-02-11

Abstract

The invention discloses an optical detection device, which is characterized in that the optical detection device is placed in a battery box, a transmitting piece transmits detection light to a corresponding receiving piece along a first direction, when a battery generates a large amount of gas and smoke due to thermal runaway, the pressure in the battery box is increased, an elastic membrane is extruded towards a first detection cavity, the elastic membrane is protruded into the first detection cavity to block at least one detection light from directly entering the receiving piece, and therefore the conditions that the light energy received by different receiving pieces is different occur. The smoke can enter the second detection cavity through the second opening, the energy value of the detection light passing through the smoke is reduced, and therefore the light energy received by each receiving piece is reduced. Therefore, whether pressure increase exists in the battery box or not and whether smoke exists can be judged according to the change of the light energy received by the receiving piece, and whether thermal runaway occurs in the battery box or not is judged. The invention also relates to an optical detection method.

Description

Optical detection device and optical detection method

Technical Field

The invention relates to the technical field of detection equipment, in particular to an optical detection device and an optical detection method.

Background

With the rapid development of new energy electric vehicles and battery energy storage industries, the application of lithium batteries is more extensive, and battery firing events also occur frequently while bringing convenience to people. The safety accidents of the lithium battery are directly related to the internal constituent materials of the battery and the use mode of the battery. During the use of the battery, especially the abuse of the battery, such as overcharge, overdischarge, external short circuit, extrusion, collision, high temperature and the like of the battery, may cause the reaction of chemical substances inside the battery, so that a large amount of heat is generated inside the battery, thereby causing thermal runaway of the battery, and if the reaction is not effectively prevented, the battery finally catches fire or explodes, thereby causing serious safety accidents.

When the battery takes place thermal runaway, can release a large amount of gas and smog, a large amount of gas make the pressure increase in the battery package, in order to guarantee the accurate thermal runaway who detects the battery, so can set up pressure sensor and smoke transducer and detect pressure and smog respectively to make the structure more, the cost is higher.

Disclosure of Invention

The invention aims to provide an optical detection device and an optical detection method which are simple in structure and low in cost.

An optical detection device comprising:

the shell is provided with an inner cavity, a first opening and a second opening which are communicated with the inner cavity;

the n emitting pieces are arranged at one end of the inner cavity along a first direction and are arranged at intervals along a second direction perpendicular to the first direction, and each emitting piece is used for emitting detection light towards the other end of the inner cavity along the first direction;

the n receiving pieces are arranged at the other end of the inner cavity along the first direction, the n receiving pieces correspond to the n emitting pieces in the first direction one by one, and each receiving piece can receive the detection light;

the transparent plate is arranged in the inner cavity to divide the inner cavity into a first detection cavity and a second detection cavity which are sequentially arranged along a first direction and are not communicated with each other, the first opening is communicated with the first detection cavity, and the second opening is communicated with the second detection cavity; and

an elastic membrane hermetically connected to the first opening, the elastic membrane being configured to deform under pressure outside the housing and protrude into the first detection cavity to block the detection light emitted by the m emitters;

the plane where the first opening is located is vertical to the second direction, n and m are integers, n is larger than or equal to 2, and m is larger than or equal to 1 and smaller than n.

Placing foretell optical detection device in the battery box, every transmitter is followed first direction transmission and is detected light to a receiver that corresponds, when the battery takes place a large amount of gas of thermal runaway production and smog, the pressure increase in the battery box, the outside pressure increase of casing promptly, form high-pressure environment, the high pressure extrudees elastic diaphragm towards first detection intracavity for elastic diaphragm is protruding to first detection intracavity, with stopping that at least one detects the direct piece that jets into of light, thereby the different condition of receiving the light energy that receives of piece appears. And smoke can enter the second detection cavity through the second opening, the energy value of the detection light passing through the smoke is reduced, and the light energy received by each receiving piece is reduced. Therefore, whether pressure increase exists in the battery box or not and whether smoke exists can be judged according to the change of the light energy received by the receiving piece, and whether thermal runaway occurs in the battery box or not is judged.

In one embodiment, n emitting elements are disposed in the first detection cavity, and n receiving elements are disposed in the second detection cavity.

In one embodiment, n emitting elements are disposed in the second detection cavity, and n receiving elements are disposed in the first detection cavity.

In one embodiment, the first opening and the second opening are spaced apart along the first direction, and the first opening and the second opening are located on the same side of the housing.

In one embodiment, the first opening and the second opening are both circular openings.

An optical detection method comprising the steps of:

a. placing the shell at a detection position;

the shell is provided with an inner cavity, a first opening and a second opening which are communicated with the inner cavity, n emitting pieces, n receiving pieces and a transparent plate are arranged in the inner cavity, the n emitting pieces and the n receiving pieces are respectively positioned at two opposite ends of the inner cavity along a first direction and are arranged at intervals along a second direction which is vertical to the first direction, the n emitting pieces and the n receiving pieces are in one-to-one correspondence to each other in the first direction, the transparent plate is used for dividing the inner cavity into a first detection cavity and a second detection cavity which are sequentially arranged along the first direction and are not communicated with each other, the first opening is communicated with the first detection cavity, the second opening is communicated with the second detection cavity, the first opening is connected with an elastic membrane in a sealing mode, and the elastic membrane is constructed to deform under the external pressure of the shell and protrude into the first detection cavity, so as to block the detection light rays emitted by the m emitting pieces;

the plane where the first opening is located is vertical to the second direction, n and m are integers, n is larger than or equal to 2, and m is larger than or equal to 1 and smaller than n;

b. each emitting piece emits detection light towards the other end of the inner cavity along the first direction, and each receiving piece receives light energy;

c. and calculating the light ray energy received by each receiving piece and the light ray energy difference value between different receiving pieces.

Drawings

Fig. 1 is a schematic structural diagram of an optical detection apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the optical detection device shown in FIG. 1 in a smoke environment;

fig. 3 is a schematic structural diagram of the optical detection device shown in fig. 1 under a high-pressure and smoke environment.

Reference numerals:

10. a housing; 20. a launch member; 30. a receiver; 40. a transparent plate; 50. an elastic diaphragm; 11. a first opening; 12. a second opening; 13. a first detection chamber; 14. a second detection chamber; 21. light is detected.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

As shown in fig. 1 to 3, an optical detection apparatus 100 according to an embodiment of the present invention includes a housing 10, n emitting elements 20, n receiving elements 30, a transparent plate 40, and an elastic membrane 50.

The housing 10 has an inner cavity and first and

second openings

11 and 12 communicating with the inner cavity.

The n emitting pieces 20 are arranged at one end of the inner cavity along the first direction and are arranged at intervals along a second direction perpendicular to the first direction, and each emitting piece 20 is used for emitting detection light 21 towards the other end of the inner cavity along the first direction.

The n receiving pieces 30 are arranged at the other end of the inner cavity along the first direction, the n receiving pieces 30 correspond to the n emitting pieces 20 in the first direction one by one, and each receiving piece 30 can receive the detection light 21.

The transparent plate 40 is disposed in the inner cavity to divide the inner cavity into a first detection cavity 13 and a second detection cavity 14 which are sequentially arranged along a first direction and are not communicated with each other, the first opening 11 is communicated with the first detection cavity 13, and the second opening 12 is communicated with the second detection cavity 14.

The elastic membrane 50 is hermetically connected to the first opening 11, and the elastic membrane 50 is configured to be deformed by a pressure outside the housing 10 and protrude into the first detection chamber 13 to block the detection light 21 emitted by the m emitters 20.

The plane of the first opening 11 is perpendicular to the second direction, n and m are integers, n is greater than or equal to 2, and m is greater than or equal to 1 and less than n.

The first direction is the left-right direction in fig. 1, and the second direction is the up-down direction in fig. 1.

The optical detection device is placed in a battery box, each emitting element 20 emits detection light 21 to a corresponding receiving element 30 along a first direction, when the battery generates a large amount of gas and smoke due to thermal runaway, the pressure in the battery box is increased, namely the pressure outside the shell 10 is increased, a high-pressure environment is formed, the elastic membrane 50 is pressed towards the first detection cavity 13 by the high pressure, so that the elastic membrane 50 protrudes into the first detection cavity 13 to block at least one detection light 21 from directly emitting into the receiving element 30, and therefore the situation that the light energy received by different receiving elements 30 is different occurs. Smoke can enter the second detection chamber 14 through the second opening 12, and the energy of the detection light 21 passing through the smoke is reduced, so that the light energy received by each receiving member 30 is reduced. In this way, whether pressure increase and smoke in the battery box exist can be judged according to the change of the light energy received by the receiving part 30, so that whether thermal runaway occurs in the battery box can be judged.

It is understood that when there is only a pressure increase, the elastic membrane 50 blocks m emitting elements 20 from emitting the detecting light 21, m is smaller than n, in other words, the elastic membrane 50 cannot block the detecting light 21 emitted by at least one emitting element 20, so that the receiving elements 30 receive different light energies, and at least one receiving element 30 can receive all the detecting light 21 emitted by the corresponding emitting element 20. When only smoke is present, the light energy received by all of the receiving members 30 is reduced and the energy values are substantially the same. When there is both the case where the pressure is increased and the case where the smoke is present, there may be both the case where the light energy received by the different receiving members 30 is different and the case where the light energy received by all the receiving members 30 is reduced. The increase in pressure and the presence of smoke can be detected according to the condition of the receiving member 30. And sensors for detecting pressure and smoke are not required to be arranged respectively, so that the structure is simplified, and the cost is reduced.

It can be understood that the plane of the first opening 11 is perpendicular to the second direction, so that when the elastic membrane 50 hermetically connected to the first opening 11 is deformed, the elastic membrane 50 can protrude toward the inside of the first detection cavity 13 along the second direction, thereby blocking the detection light 21 emitted by the m emitters 20.

In addition, the minimum value of the pressure increase when thermal runaway occurs in the battery box can be calculated according to a plurality of experiments, and then the material and the size of the elastic membrane 50 are selected according to the minimum value, so that the elastic membrane 50 can directly reach the deformation limit and block the detection light 21 emitted by the m emitting members 20 under the minimum pressure. Of course, the elastic diaphragm 50 also needs to be ensured to be able to withstand greater pressures.

It should be noted that, for a total of n emitting elements 20, the elastic membrane 50 can block m detecting light 21 emitted from the emitting elements 20, m is smaller than n, and the corresponding elastic membrane 50 can block m receiving elements 30 from receiving the detecting light 21, so that there is at least one detecting light 21 emitted from the emitting element 20, which cannot be blocked by the elastic membrane 50, so as to retain at least one control group.

It should also be explained that when the detection light 21 passes through the smoke, part of the detection light 21 is not blocked, and part of the detection light 21 is scattered to form scattered light. When the pressure is increased and smoke is also present, scattered light can be incident on all the receiving pieces 30, but since the receiving pieces 30 of the comparison group can receive both the scattered light and the detection light 21, the receiving pieces 30 of the comparison group receive more light energy, and the other receiving pieces 30 can receive only the scattered light, so that less light energy is received.

In embodiment 1, n emitting elements 20 are disposed in the first detecting chamber 13, and n receiving elements 30 are disposed in the second detecting chamber 14. In the embodiment shown in fig. 1, the number of the transmitting element 20 and the receiving element 30 is two, and the transmitting element and the receiving element are arranged at intervals in the vertical direction.

The description is made with reference to fig. 1 to 3:

in fig. 1, neither pressure increase nor smoke is present, and therefore the two emitting elements 20 at the left end in the first detection chamber 13 can be controlled to emit detection light rays 21, and all detection light rays 21 can pass through the transparent plate 40 and enter the second detection chamber 14 for the corresponding reception of the two receiving elements 30 at the right end of the second detection chamber 14, and the light energy received by each receiving element 30 is calculated, and ideally, the light energy received by the two receiving elements 30 is the same.

In fig. 2, only smoke exists, so that the detection light 21 emitted by the two emitting elements 20 at the left end of the first detection cavity 13 can pass through the transparent plate 40 and enter the second detection cavity 14, and due to the blocking of smoke after the detection light 21 enters the second detection cavity 14, the light energy received by the two receiving elements 30 at the right end of the second detection cavity 14 is reduced, and the light energy received by the two receiving elements 30 is smaller than the preset threshold.

In fig. 3, both pressure increase and smoke are present, the detecting light 21 emitted from the upper emitting element 20 in the first detecting chamber 13 is blocked by the pressure membrane, so that only the detecting light 21 emitted from the lower emitting element 20 can pass through the transparent plate 40 and enter the second detecting chamber 14, and only the lower receiving element 30 in the second detecting chamber 14 can directly receive the detecting light 21, and both receiving elements 30 can receive scattered light, but the energy of the light received by the upper receiving element 30 is different from that of the lower receiving element 30 and is larger than the preset threshold value.

It should be noted that, in fig. 2, both the detecting light 21 and the scattered light are incident into the two receiving members 30, but the variations of the blocked detecting light 21 and the scattered light are large, so that there may be a case where the light energy received by different receiving members 30 is different, and smoke can be input into the second detecting cavity 14, and then a plurality of experiments are performed. The light energy received by the two receiving pieces 30 can be calculated in each experiment, and then the preset threshold value is determined according to the difference value of the light energy received by the two receiving pieces 30 in a plurality of experiments, namely, when the light energy received by the two receiving pieces 30 is smaller than the preset threshold value, the optical detection device is only influenced by smoke.

It is understood that if the light energy received by the two receiving members 30 is not reduced but the difference between the light energy received by the two receiving members is greater than the preset threshold, it can be judged that there is only an increase in pressure; if the light energy received by the two receiving pieces 30 is reduced and the difference value of the light energy received by the two receiving pieces is smaller than a preset threshold value, it can be judged that only the influence of smoke exists; if the two receiving members 30 receive less light energy and the difference between the light energy received by the two receiving members is greater than the preset threshold, it is determined that there is a pressure increase and smoke.

In embodiment 2, n emitting elements 20 are disposed in the second detection cavity 14, and n receiving elements 30 are disposed in the first detection cavity 13, i.e., the positions of the emitting elements 20 and the receiving elements 30 are interchanged in fig. 1.

It should be noted that the difference between the embodiment 1 and the embodiment 2 is that the positions of the emitting element 20 and the receiving element 30 are exchanged, but in the embodiment 2, since the elastic membrane 50 is close to the receiving element 30, the elastic membrane 50 can be made to reduce the light energy received by the receiving element 30 located above as much as possible.

Specifically, when smoke exists in the second detection chamber 14, the light entering the first detection chamber 13 through the smoke and the transparent plate 40 includes the detection light 21 and the scattered light, and the elastic membrane 50 deformed by the pressure is close to the receiving member 30 located above, so that the detection light 21 and part or all of the scattered light can be directly blocked from entering the receiving member 30 located above, and the difference between the light energies received by the two receiving members 30 is larger, i.e., whether there is a pressure increase is easier to distinguish.

In some embodiments, the first opening 11 and the second opening 12 are spaced along the first direction, and the first opening 11 and the second opening 12 are located on the same side of the housing 10, so as to facilitate manufacturing.

It is understood that, since the elastic membrane 50 needs to block the detection light 21 when being deformed, the first opening 11 needs to be disposed with its plane perpendicular to the second direction.

Further, the first opening 11 and the second opening 12 are both circular openings to facilitate manufacturing and to facilitate installation of the elastic membrane 50.

In some embodiments, the housing 10 is a rectangular parallelepiped, and the first opening 11 and the second opening 12 are located on one side surface of the housing 10 in the second direction.

An optical detection method comprising the steps of:

s110, the housing 10 is placed at a detection position, i.e., a preset position installed in the battery box.

It can be understood that, the structure and internal components of the housing 10 are as described above, the housing 10 has an inner cavity, and the first opening 11 and the second opening 12 which are communicated with the inner cavity, and the inner cavity is provided with n emitting elements 20, n receiving elements 30 and a transparent plate 40, the transparent plate 40 is used for dividing the inner cavity into the first detection cavity 13 and the second detection cavity 14 which are sequentially arranged along the first direction and are not communicated with each other, the first opening 11 is communicated with the first detection cavity 13, the second opening 12 is communicated with the second detection cavity 14, and the elastic membrane 50 is hermetically connected at the first opening 11.

S120, each emitting element 20 emits the detecting light 21 toward the other end of the inner cavity along the first direction, and each receiving element 30 receives light energy.

S130, the light energy received by each receiving element 30 and the light energy difference between different receiving elements 30 are calculated.

When the light energy received by each receiving member 30 is not reduced, it can be judged that no pressure increase or no smoke occurs in the battery box; when the light energy received between each receiving piece 30 is not reduced and the difference value of the light energy received by the two receiving pieces 30 is larger than the preset threshold value, it can be judged that only the pressure in the battery box is increased; when the light energy received by each receiving piece 30 is reduced and the difference value of the light energy received by any two receiving pieces 30 is smaller than a preset threshold value, it can be judged that only smoke exists in the battery box; when the light energy received by each receiving member 30 is reduced and the difference value of the light energy received by two receiving members 30 is larger than the preset threshold value, it can be judged that both the pressure increase and the smoke exist in the battery box.

By adopting the optical detection method, the pressure and smoke can be detected simultaneously through the set of emitting elements 20 and the set of receiving elements 30 in the shell 10, and compared with the existing method of arranging two sensors, the structure is simpler and the cost is lower.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An optical detection device, comprising:

2. The optical detection device according to claim 1, wherein n emitting elements are disposed in the first detection cavity and n receiving elements are disposed in the second detection cavity.

3. The optical detection device according to claim 1, wherein n emitting elements are disposed in the second detection cavity and n receiving elements are disposed in the first detection cavity.

4. The optical detection device of claim 1, wherein the first opening and the second opening are spaced apart along the first direction, and the first opening and the second opening are located on a same side of the housing.

5. The optical detection device of claim 1, wherein the first opening and the second opening are both circular openings.

6. An optical detection method, comprising the steps of:

a. placing the shell at a detection position;