Gas detection device

Abstract

The invention provides a gas detection device which comprises a shell and a detection unit, the shell is provided with a first cavity, a second cavity and a channel, the shell comprises a shell body, the shell is provided with corresponding walls for constructing the first cavity, the second cavity and the channel, the first cavity is communicated with the outside of the shell body through the channel, and the second cavity is a closed cavity; the detection unit comprises a first detection part, a second detection part and a third detection part, a first sensing element of the first detection part is located in the first cavity, a second sensing element of the second detection part is located in the second cavity, and a third sensing element of the third detection part is located in the channel. The detection result of the third detection part can be used as a consideration factor in refrigerant leakage calculation, such as algorithm compensation, so as to reduce the influence of the interference variable of the refrigerant on the detection accuracy of the refrigerant leakage. The detection result of the third detection part is relatively close to the real size of the interference variable of the refrigerant influencing the resistance value of the first sensing element, so that the compensation is relatively accurate, and the detection accuracy of the leakage amount of the refrigerant is relatively high.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a gas detection device. Background Technology

[0002] Some air conditioning systems use flammable refrigerants, and leaks can pose safety hazards. Therefore, gas detection devices are needed to monitor refrigerant leaks and address these hazards promptly. The gas detection device has sensing elements installed in both an open and a closed cavity. These elements act as the two arms of a Wheatstone bridge. When refrigerant leaks into the open cavity, it affects the thermal conductivity of the gas there, causing a change in the resistance of the sensing element and disrupting the Wheatstone bridge balance, thus detecting the leak. However, the resistance of the sensing element is affected not only by the amount of refrigerant leak but also by other interfering variables, such as refrigerant temperature. Both the open and closed cavity sensing elements are affected by these interfering variables, with the open cavity element being more significantly affected by refrigerant temperature. The influence of these interfering variables reduces the accuracy of refrigerant leak detection. Summary of the Invention

[0003] This application provides a gas detection device, the gas detection device comprising:

[0004] The housing includes a first cavity, a second cavity, and a channel. The housing comprises a shell body, which has corresponding walls that form the first cavity, the second cavity, and the channel. The channel connects the first cavity to the outside of the shell body, and the second cavity is a closed cavity.

[0005] The detection unit includes a first detection section, a second detection section, and a third detection section. The first detection section includes a first sensing element, the second detection section includes a second sensing element, and the third detection section includes a third sensing element. The first sensing element is located in the first cavity, the second sensing element is located in the second cavity, and the third sensing element is located in the channel.

[0006] The gas detection device provided in this application includes a first detection unit and a second detection unit that detect refrigerant leakage based on the Wheatstone bridge principle. The third detection unit can detect refrigerant interference variables that affect the resistance values ​​of the first and second sensing elements, in addition to the refrigerant leakage amount. The detection results of the third detection unit can be used as a factor to consider when calculating the refrigerant leakage amount, such as through algorithmic compensation to reduce the impact of refrigerant interference variables on the accuracy of refrigerant leakage detection. Since the third sensing element of the third detection unit is located in the channel, and the channel connects the inside and outside of the first cavity where the first sensing element is located, the refrigerant detected by the third sensing element is the portion of refrigerant that will enter the first cavity. Therefore, the detection results of the third detection unit are closer to the true magnitude of the interference variables affecting the resistance value of the first sensing element, so the compensation is more accurate, thereby improving the accuracy of refrigerant leakage detection. Attached Figure Description

[0007] Figure 1 This is a cross-sectional view of the first embodiment of the gas detection device provided in this application;

[0008] Figure 2 for Figure 1 A magnified view of the area inside the center circle;

[0009] Figure 3 for Figure 1 A perspective view of the top cover of the middle shell;

[0010] Figure 4 for Figure 1 A perspective view of the base, first detection section, second detection section, and third detection section of the middle shell;

[0011] Figure 5 for Figure 1 A 3D view of the central support structure;

[0012] Figure 6 This is a cross-sectional view of the second embodiment of the gas detection device provided in this application;

[0013] Figure 7 for Figure 6 A magnified view of the area inside the center circle;

[0014] Figure 8 for Figure 6 A perspective view of the top cover of the middle shell;

[0015] Figure 9 for Figure 6 A perspective view of the top cover of the middle shell from another angle;

[0016] Figure 10 for Figure 6 A perspective view of the base, first detection section, second detection section, and third detection section of the middle shell.

[0017] The annotations in the attached figures are explained as follows:

[0018] 1. Housing, 11. Top cover, 111. Top wall, 112. Side wall, 112a. Baffle, 12. Base, 121. Base body, 122. First boss, 123. Second boss, 12a. First through hole, 12b. Second through hole, 12c. Third through hole, 13. First cavity, 14. Second cavity, 15. Channel, 151. First channel, 152. Second channel, 152a. Connecting hole, 152b. Gap, 153. First inlet / outlet hole, 154. Second inlet / outlet hole, A. Notch;

[0019] 2 Detection unit, 21 First detection section, 211 First sensing element, 212 First lead electrode, 213 First conductive terminal, 22 Second detection section, 221 Second sensing element, 222 Second lead electrode, 223 Second conductive terminal, 23 Third detection section, 231 Third sensing element, 232 Third conductive terminal, 24 Circuit board.

[0020] 31 First insulating component, 32 Second insulating component, 33 Third insulating component;

[0021] 4. Support, 41. Flow channel, 411. Main flow channel, 412. Side flow channel, 42. Annular wall, 421. Annular body, 421a. Limiting step, 422. Protrusion. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] refer to Figure 1 or Figure 6 The gas detection device provided in this application includes a housing 1 and a detection unit 2.

[0024] The housing 1 has a first cavity 13, a second cavity 14, and a channel 15. The housing 1 includes a shell body, which has corresponding walls that form the first cavity 13, the second cavity 14, and the channel 15. The channel 15 connects the first cavity 13 to the outside of the shell body. The second cavity 14 is a closed cavity.

[0025] The detection unit 2 includes a first detection unit 21, a second detection unit 22, and a third detection unit 23. The first detection unit 21 includes a first sensing element 211. The second detection unit 22 includes a second sensing element 221. The third detection unit 23 includes a third sensing element 231. The first sensing element 211 is located in the first cavity 13, the second sensing element 221 is located in the second cavity 14, and the third sensing element 231 is located in the channel 15.

[0026] The first detection unit 21 and the second detection unit 22 can detect the refrigerant leakage of the air conditioning system based on the Wheatstone bridge principle. Specifically, when there is no refrigerant leakage in the air conditioning system, the first detection unit 21 and the second detection unit 22 form a Wheatstone bridge balance. When the refrigerant leaks in the air conditioning system, the refrigerant enters the first cavity 13 through the channel 15, causing a change in the amount of refrigerant in the first cavity 13, which in turn causes a change in the thermal conductivity of the first cavity 13, and consequently a change in the resistance of the first sensing element 211 located in the first cavity 13. This breaks the Wheatstone bridge balance between the first detection unit 21 and the second detection unit 22, thereby allowing the refrigerant leakage to be calculated.

[0027] The third detection unit 23 can detect interference variables of the gas to be measured, other than the amount of gas to be measured, that interfere with the resistance values ​​of the first sensing element 211 and the second sensing element 221. These interference variables include, but are not limited to, the temperature, pressure, and humidity of the gas to be measured. These interference variables can cause changes in the resistance values ​​of the first sensing element 211 and / or the second sensing element 221, resulting in inaccurate detection of the amount of gas to be measured (refrigerant leakage).

[0028] The gas detection device provided in this application allows the detection results of the third detection unit 23 to be used as a factor to consider when calculating the refrigerant leakage amount. For example, compensation can be performed through an algorithm to reduce the impact of refrigerant interference variables on the accuracy of refrigerant leakage detection. Furthermore, since the third sensing element 231 of the third detection unit 23 is located in the channel 15, and the channel 15 connects the inside and outside of the first cavity 13 where the first sensing element 211 is located, the refrigerant detected by the third sensing element 231 is the portion of refrigerant that will enter the first cavity 13. Therefore, the detection results of the third detection unit 23 are closer to the true magnitude of the interference variables affecting the resistance value of the first sensing element 211, so the compensation is more accurate, and thus the accuracy of refrigerant leakage detection can be greatly improved.

[0029] In some embodiments, the first sensing element 211 and the second sensing element 221 include a thermistor.

[0030] In some embodiments, the third sensing element 231 is a temperature and humidity sensor.

[0031] In some embodiments, the detection unit 2 includes a circuit board 24, which includes a first detection circuit and a second detection circuit. A first detection unit 21 and a second detection unit 22 are electrically connected to the first detection circuit. The first detection circuit includes a Wheatstone bridge, and the first detection unit 21 and the second detection unit form two arms of the Wheatstone bridge. A third detection unit 23 is electrically connected to the second detection circuit.

[0032] In some embodiments, reference is made to Figure 2The channel 15 includes a first channel 151, and the shell body includes a baffle portion 112a. The baffle portion 112a is at least partially located between the first cavity 13 and the second cavity 14, separating the first cavity 13 and the second cavity 14. The first channel 151 is disposed in the baffle portion 112a. The third sensing element 231 is located in the first channel 151. With this design, the third sensing element 231 is located between the first cavity 13 and the second cavity 14. The third sensing element 231 is close to the first cavity 13 and the second cavity 14, so the refrigerant quickly enters the first cavity 13 after flowing through the third sensing element 231. Therefore, the detection result of the third detection unit 23 is closer to the true magnitude of the interference variable affecting the resistance value of the first sensing element 211. At the same time, the true magnitude of the interference variable affecting the resistance value of the second sensing element 221 can be calculated more accurately based on the detection result of the third detection unit 23. The refrigerant temperature sensed by the third sensing element 231 needs to be measured in the first cavity 13. The algorithm compensates for the refrigerant temperature sensed by the third sensing element 231 between the first cavity 13 and the second cavity 14. Therefore, the difference in the influence of the refrigerant temperature sensed by the third sensing element 231 on the first sensing element 211 in the first cavity 13 and the second sensing element 221 in the second cavity 14 is small, making the first cavity 13 and the second cavity 14 more uniform in temperature. This reduces the possibility of inaccurate compensation due to the large difference in the influence of the refrigerant temperature sensed by the third sensing element 231 on the first sensing element 211 in the first cavity 13 and the second sensing element 221 in the second cavity 14.

[0033] Specifically, in the illustrated embodiments, such as Figures 1-4 or Figures 6-10 As shown, the housing 1 includes a top cover 11 and a base 12. The base 12 is at least partially located at the bottom of the top cover 11. The top cover 11 includes a side wall portion 112 and a top wall portion 111. The side wall portion 112 includes the aforementioned baffle portion 112a. The top wall portion 111 is at least partially located at the top of the side wall portion 112. The top cover 11 has a first groove with an open bottom end and a second groove with an open bottom end. The side wall portion 112 and the top wall portion 111 have corresponding walls that form the first groove and the second groove. The first cavity 13 includes the first groove, and the second cavity 14 includes the second groove. The base 12 includes a first seat portion with an open bottom end facing the first groove, a second seat portion with an open bottom end facing the second groove, and a third seat portion located between the first seat portion and the second seat portion. The base 12 and the top cover 11 together enclose the first cavity 13 and the second cavity 14. More specifically, in the figure, the first cavity 13 and the second cavity 14 are two roughly parallel cylindrical cavities. In actual implementation, the shapes of the first cavity 13 and the second cavity 14 can be flexibly designed according to the actual space requirements.

[0034] Specifically, in the illustrated embodiment, the base 12 includes a base body 121, a first boss 122, and a second boss 123. The top surface of the base body 121 abuts against the bottom surface of at least a portion of the sidewall portion 112. The first boss 122 protrudes upward from the top surface of the base body 121, and the second boss 123 protrudes upward from the top surface of the base body 121. The first boss 122 at least partially extends into the first groove, and the second boss 123 at least partially extends into the second groove. By providing the first boss 122 and the second boss 123, the base 12 and the top cover 11 are easier to align and assemble.

[0035] Specifically, in the illustrated embodiment, the top cover 11 and the base 12 are both integral structures. This reduces the number of parts in the gas detection device, making assembly easier. In other embodiments, the top cover 11 may be an integral structure and the base 12 may be a separate structure, or both the top cover 11 and the base 12 may be separate structures.

[0036] Specifically, in the illustrated embodiment, the circuit board 24 is at least partially located at the bottom of the base 12. The first detection unit 21 includes a first conductive structure, the second detection unit 22 includes a second conductive structure, and the third detection unit 23 includes a third conductive structure. The first sensing element 211 is electrically connected to the first detection circuit of the circuit board 24 via the first conductive structure, the second sensing element 221 is electrically connected to the first detection circuit of the circuit board 24 via the second conductive structure, and the third sensing element 231 is electrically connected to the second detection circuit of the circuit board 24 via the third conductive structure. More specifically, in the figure, the first conductive structure includes two first conductive terminals 213 and two first lead-out electrodes 212. The two first lead-out electrodes 212 are electrically connected to the first sensing element 211, the top ends of the two first conductive terminals 213 are electrically connected to the two first lead-out electrodes 212, and the bottom ends of the two first conductive terminals 213 are electrically connected to the first detection circuit of the circuit board 24. The second conductive structure includes two second conductive terminals 223 and two second lead-out electrodes 222. The two second lead-out electrodes 222 are electrically connected to the second sensing element 221. The top ends of the two second conductive terminals 223 are electrically connected to the two second lead-out electrodes 222, and the bottom ends of the two second conductive terminals 223 are electrically connected to the first detection circuit of the circuit board 24. The third conductive structure includes a third conductive terminal 232. The top end of the third conductive terminal 232 is electrically connected to the third sensing element 231, and the bottom end of the third conductive terminal 232 is electrically connected to the second detection circuit of the circuit board 24. The electrical connection method is not limited and can be soldering, plugging, lapping, etc.

[0037] Specifically, in the illustrated embodiment, the first seat portion of the base 12 is provided with a first through hole 12a, the second seat portion of the base 12 is provided with a second through hole 12b, and the third seat portion of the base 12 is provided with a third through hole 12c. A first conductive terminal 213 is inserted through the first through hole 12a, with its top end located within the first cavity 13 and its bottom end extending through the first through hole 12a to the outside of the first cavity 13. A second conductive terminal 223 is inserted through the second through hole 12b, with its top end located within the second cavity 14 and its bottom end extending through the second through hole 12b to the outside of the second cavity 14. A third conductive terminal 232 is inserted through the third through hole 12c, with its top end located within the first channel 151 and its bottom end extending through the third through hole 12c to the outside of the first channel 151.

[0038] Specifically, in the illustrated embodiment, the gas detection device includes a first insulating member 31, a second insulating member 32, and a third insulating member 33. The first insulating member 31 passes through a first through-hole 12a and is fitted over a first conductive terminal 213, insulating the first conductive terminal 213 from the base 12 to prevent the base 12 from becoming energized. The second insulating member 32 passes through a second through-hole 12b and is fitted over a second conductive terminal 223, insulating the second conductive terminal 223 from the base 12 to prevent the base 12 from becoming energized. The third insulating member 33 passes through a third through-hole 12c and is fitted over a third conductive terminal 232, insulating the third conductive terminal 232 from the base 12 to prevent the base 12 from becoming energized. More specifically, the base 12 can be made of metal, and the first insulating member 31, the second insulating member 32, and the third insulating member 33 can be made of sealant, such as silicone sealant, providing both insulation and sealing.

[0039] In some embodiments, channel 15 may further include a second channel 152, which connects the first cavity 13 and the first channel 151. The third sensing element 231 and the second channel 152 are located in at least one plane perpendicular to the arrangement direction of the first cavity 13 and the second cavity 14 (e.g., Figure 2 or Figure 7 The orthographic projections on the plane (pointed to by B) at least partially overlap, so that the refrigerant quickly enters the first cavity 13 after flowing through the third sensing element 231, making the detection result of the third detection unit 23 closer to the true magnitude of the interference variable affecting the resistance value of the first sensing element 211.

[0040] Specifically, the second channel 152 may include a gap 152b and / or a connecting hole 152a. For example... Figures 1-3As shown, the second channel 152 includes a gap 152b, the housing 1 includes a top cover 11 and a base 12, the base 12 is located at the bottom of the top cover 11, the top cover 11 includes a side wall portion 112, the side wall portion 112 includes the baffle portion 112a, and the gap 152b is provided between at least a portion of the base 12 and the baffle portion 112a. In this case, the third conductive structure that electrically connects the third sensing element 231 and the circuit board 24 is set relatively short so that the third sensing element 231 can be close to the second channel 152. More specifically, Figure 3 In the design, the bottom end of the baffle portion 112a, near the first cavity 13, has a notch A. The gap 152b is formed between the notch A and the base 12. The bottom end of the baffle portion 112a, near the second cavity 14, abuts against the base 12. The housing 1 has three first channels 151, all of which are connected to the first cavity 13 through the gap 152b. Figure 7 and Figure 9 As shown, the second channel 152 includes a connecting hole 152a, which is located on the side of the baffle portion 112a near the first cavity 13. More specifically, Figure 9 In the middle, the baffle part 112a is provided with three connecting holes 152a and three first channels 151, and each of the three first channels 151 is connected to the first cavity 13 through a connecting hole 152a.

[0041] In some embodiments, channel 15 may include a first inlet / outlet 153 and a second inlet / outlet 154. The first inlet / outlet 153 is located on the top cover 11, and the second inlet / outlet 154 is located on the base 12. The first inlet / outlet 153 connects the first channel 151 to the outside of the shell body, and the second inlet / outlet 154 connects the first cavity 13 to the outside of the shell body. This design allows the refrigerant to enter and exit the first cavity 13 through both the first inlet / outlet 153 and the second inlet / outlet 154, giving the refrigerant strong fluidity within the first cavity 13, which improves the accuracy of refrigerant leakage detection. More specifically, in the figure, there are three first inlet / outlet 153s and three first channels 151, with each first inlet / outlet 153 connecting one first channel 151 to the outside of the shell body. Alternatively, only the first inlet / outlet 153 or only the second inlet / outlet 154 may be provided.

[0042] Specifically, the location of the first inlet / outlet hole 153 on the top cover 11 can be flexibly chosen, as long as the first inlet / outlet hole 153 ensures that the outer side of the shell body is connected to the first channel 151. Preferably, such as... Figure 3As shown, the first inlet / outlet hole 153 is located in the top wall portion 111, between the top and bottom surfaces of the top wall portion 111. One end of the first inlet / outlet hole 153 extends to the side of the top wall portion 111 (the side of the top wall portion 111 in the figure that is away from the baffle portion 112a in a direction parallel to the circuit board 24), and the other end of the first inlet / outlet hole 153 connects to the first channel 151. This design results in a relatively long length between the two ends of the first inlet / outlet hole 153, which serves as a guide, reducing the impact of airflow on the third sensing element 231 within the first channel 151 and extending the service life of the third sensing element 231. More specifically, as... Figure 3 As shown, the first inlet / outlet hole 153 can penetrate the corresponding wall portion of the top wall 111 that forms the first cavity 13, or, as... Figure 8 As shown, the first inlet / outlet hole 153 can also penetrate the corresponding wall portion of the top wall portion 111 to construct the second cavity 14.

[0043] Specifically, the second inlet / outlet hole 154 can be located in the first seat, or it can be located in both the first and third seats. For example... Figure 4 As shown, the second inlet / outlet 154 is located in both the first and third seats. That is, the second inlet / outlet 154 is partially located in the first seat and partially in the third seat. In this case, the second inlet / outlet 154 connects the first cavity 13 to the outside of the shell body, and also connects the first channel 151 to the outside of the shell body. Figure 10 As shown, the second inlet / outlet hole 154 is provided in the first seat, more specifically, in the central region of the first seat, or alternatively, in the edge region of the first seat.

[0044] In some embodiments, the gas detection device includes a bracket 4, with a circuit board 24 at least partially located at the bottom of a base 12. The bracket 4 includes a bracket body, which is at least partially located between the circuit board 24 and the base 12 and supports the base 12. Furthermore, as... Figure 5 As shown, the support 4 has a flow channel 41, and the support body has a corresponding wall for constructing the flow channel 41. Figure 1 or Figure 6 As shown, the flow channel 41 connects the second inlet / outlet hole 154 to the outside of the bracket body. In this way, the bracket 4 creates a certain distance between the base 12 and the circuit board 24, preventing the circuit board 24 from blocking the second inlet / outlet hole 154 on the base 12. At the same time, the flow channel 41 of the bracket 4 connects the second inlet / outlet hole 154 to the outside of the bracket body, allowing the gas to be tested to smoothly enter and exit the first chamber 13 through the second inlet / outlet hole 154, which is more conducive to improving the flow of the gas to be tested in the first chamber 13.

[0045] In some embodiments, reference is made to Figure 5The support body includes an annular wall portion 42, and the flow channel 41 includes a main flow channel 411 and a side flow channel 412. The main flow channel 411 includes an inner hole of the annular wall portion 42. The side flow channel 412 is disposed in the annular wall portion 42 and extends from the inner circumferential surface of the annular wall portion 42 to the outer circumferential surface of the annular wall portion 42. The main flow channel 411 connects the second inlet / outlet hole 154 and the side flow channel 412. The side flow channel 412 connects the main flow channel 411 and the outside of the support body.

[0046] Specifically, in the illustrated embodiments, such as Figure 5 As shown, the annular wall portion 42 includes an annular body 421 and a plurality of protrusions 422. The plurality of protrusions 422 are located at the bottom end of the annular body 421 and are arranged sequentially at intervals along the circumference of the annular body 421, forming the aforementioned side flow channel 412 between adjacent protrusions 422. With this design, when the gas to be tested passes through the side flow channel 412, it will come into contact with the surface of the circuit board 24, thus having a cooling effect on the circuit board 24. Alternatively, the side flow channel 412 can also be formed by opening holes in the annular wall portion 42. More specifically, Figure 5 In the middle, the top of the annular body 421 is provided with a limiting step 421a, and the bottom end of the base 12 is inserted into the inner hole of the annular body 421 and abuts against the limiting step 421a.

[0047] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A gas detection device, characterized in that, The gas detection device includes: The shell (1) is provided with a first cavity (13), a second cavity (14) and a channel (15). The shell (1) includes a shell body, which has corresponding walls that form the first cavity (13), the second cavity (14) and the channel (15). The channel (15) connects the first cavity (13) and the outside of the shell body. The second cavity (14) is a closed cavity. The detection unit (2) includes a first detection section (21), a second detection section (22), and a third detection section (23). The first detection section (21) includes a first sensing element (211), the second detection section (22) includes a second sensing element (221), and the third detection section (23) includes a third sensing element (231). The first sensing element (211) is located in the first cavity (13), the second sensing element (221) is located in the second cavity (14), and the third sensing element (231) is located in the channel (15).

2. The gas detection device according to claim 1, characterized in that, The channel (15) includes a first channel (151), the shell body includes a baffle portion (112a), at least a portion of the baffle portion (112a) is located between the first cavity (13) and the second cavity (14), separating the first cavity (13) and the second cavity (14), the first channel (151) is disposed in the baffle portion (112a), and the third sensing element (231) is located in the first channel (151).

3. The gas detection device according to claim 2, characterized in that, The channel (15) includes a second channel (152) that connects the first channel (151) and the first cavity (13). The orthographic projections of the third sensing element (231) and the second channel (152) in at least one plane perpendicular to the arrangement direction of the first cavity (13) and the second cavity (14) at least partially overlap.

4. The gas detection device according to claim 3, characterized in that, The baffle portion (112a) is provided with a connecting hole (152a), and the second channel (152) includes the connecting hole (152a); and / or, The shell body includes a top cover (11) and a base (12). The top cover (11) includes the baffle portion (112a). The base (12) is at least partially located at the bottom of the top cover (11). There is a gap (152b) between at least a portion of the base (12) and the baffle portion (112a). The second channel (152) includes the gap (152b).

5. The gas detection device according to any one of claims 2-4, characterized in that, The shell body includes a top cover (11) and a base (12). The base (12) is at least partially located at the bottom of the top cover (11). The channel (15) includes a first inlet / outlet (153) and a second inlet / outlet (154). The first inlet / outlet (153) is located on the top cover (11), and the second inlet / outlet (154) is located on the base (12). The first inlet / outlet (153) connects the first channel (151) and the outside of the shell body, and the second inlet / outlet (154) connects the first cavity (13) and the outside of the shell body.

6. The gas detection device according to claim 5, characterized in that, The top cover (11) includes a side wall portion (112) and a top wall portion (111). The side wall portion (112) includes the baffle portion (112a). The top wall portion (111) is at least partially located on the top of the side wall portion (112). The top cover (11) has a first groove with an open bottom end and a second groove with an open bottom end. The side wall portion (112) and the top wall portion (111) have corresponding walls that form the first groove and the second groove. The first cavity (13) includes the first groove. The second cavity (14) includes the second groove. The base (12) includes a first seat portion with an open bottom end facing the first groove, a second seat portion with an open bottom end facing the second groove, and a third seat portion located between the first seat portion and the second seat portion. The second inlet / outlet hole (154) is provided in the first seat portion; or, The second inlet / outlet hole (154) is provided on the first seat and the third seat.

7. The gas detection device according to claim 6, characterized in that, The first inlet / outlet hole (153) is provided on the top wall portion (111) and located between the top end face and the bottom end face of the top wall portion (111). One end of the first inlet / outlet hole (153) extends to the side of the top wall portion (111), and the other end of the first inlet / outlet hole (153) is connected to the first channel (151).

8. The gas detection device according to any one of claims 1-4, characterized in that, The third sensing element (231) is a temperature and humidity sensor; the shell body includes a top cover (11) and a base (12), the top cover (11) is an integral structure, and the base (12) is an integral structure.

9. The gas detection device according to any one of claims 1-4, characterized in that, The shell body includes a top cover (11) and a base (12). The channel (15) includes a second inlet / outlet hole (154). The gas detection device includes a bracket (4). The detection unit (2) includes a circuit board (24). The circuit board (24) is at least partially located at the bottom of the base (12). The bracket (4) includes a bracket body. The bracket body is at least partially located between the circuit board (24) and the base (12) and supports the base (12). The bracket (4) is provided with a flow channel (41). The bracket body has a corresponding wall that forms the flow channel (41). The flow channel (41) connects the second inlet / outlet hole (154) and the outside of the bracket body.

10. The gas detection device according to claim 9, characterized in that, The support body includes an annular wall portion (42), and the flow channel (41) includes a main flow channel (411) and a side flow channel (412). The main flow channel (411) includes an inner hole of the annular wall portion (42), and the side flow channel (412) is disposed on the annular wall portion (42) and extends from the inner circumferential surface of the annular wall portion (42) to the outer circumferential surface of the annular wall portion (42). The main flow channel (411) connects the second inlet / outlet hole (154) and the side flow channel (412).

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