A gas detection device

Abstract

The application discloses a gas detection device, which comprises a shell, a circuit board and a detection module. The shell has a containing cavity, at least part of the circuit board is located in the containing cavity, the detection module is electrically connected with the circuit board, the gas detection device comprises an isolation unit, at least part of the isolation unit is located in the containing cavity, the isolation unit has an isothermal cavity, the isothermal cavity is isolated from the containing cavity, the shell has a gas window, the gas window is communicated with the isothermal cavity, and the detection module is located in the isothermal cavity. The gas detection device of the above technical scheme, at least part of the isolation unit is located in the containing cavity, the detection module is located in the isothermal cavity of the isolation unit, the isothermal cavity is isolated from the containing cavity, so that at least part of the containing cavity serves as a buffer space between the isothermal cavity and the external environment, and then the detection unit is located in a relatively stable space compared with the background technology, so that the influence of the external environment on the detection module is reduced.

Description

Technical Field

[0001] This invention relates to the field of gas detection technology, particularly to the field of air conditioning refrigerant detection technology, and especially to a gas detection device. Background Technology

[0002] The detection device includes a detection component and a housing. The detection component is located inside the housing. Ideally, the detection device emits a signal when the gas to be measured is present. In related technologies, environmental differences at different locations around the detection device can easily affect the detection component, leading to lower detection accuracy. Summary of the Invention

[0003] The purpose of this invention is to at least solve one of the problems in the prior art by providing a gas detection device.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A gas detection device includes a housing, a circuit board, and a detection module. The housing has a receiving cavity, at least a portion of the circuit board is located in the receiving cavity, the detection module is electrically connected to the circuit board, the gas detection device includes an isolation unit located in the receiving cavity, the isolation unit has a temperature equalization cavity isolated from the receiving cavity, the housing has an air window communicating with the temperature equalization cavity, and the detection module is located in the temperature equalization cavity.

[0006] In the gas detection device of the above technical solution, the isolation unit is located in the containment cavity, and the detection module is located in the temperature equalization cavity of the isolation unit. The temperature equalization cavity is isolated from the containment cavity, so that at least a part of the containment cavity serves as a buffer space between the temperature equalization cavity and the external environment, thereby placing the detection unit in a space that is relatively stable compared to the background technology, thus reducing the impact of the external environment on the detection module. Attached Figure Description

[0007] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0008] Figure 1 This is a schematic diagram of the exploded structure of the gas detection device in the first embodiment;

[0009] Figure 2 This is a schematic diagram of the gas detection device according to the first embodiment;

[0010] Figure 3 This is a cross-sectional structural schematic diagram of the gas detection device according to the first embodiment;

[0011] Figure 4 for Figure 3 Enlarged structural diagram at point A;

[0012] Figure 5 This is a schematic diagram illustrating the mounting structure of the detection module and the second housing in the first embodiment;

[0013] Figure 6 for Figure 5 A schematic diagram of the cross-sectional structure;

[0014] Figure 7 This is a schematic diagram of the flow channel structure in the first embodiment;

[0015] Figure 8 This is a schematic cross-sectional view of the gas detection device in the second embodiment;

[0016] Figure 9 This is a schematic cross-sectional view of the gas detection device in the third embodiment;

[0017] Figure 10 This is a schematic diagram illustrating the installation structure of the air vent and the connecting inlet in any embodiment.

[0018] Figure label:

[0019] 1. Outer shell; 11. First shell; 12. Second shell; 100. Receiving cavity; 101. Air vent; 1011. End face; 1012. Snap-fit ​​part; 102. Buckle part; 2. Circuit board; 3. Detection module; 31. Detection unit; 32. Comparison unit; 310. Detection entrance; 4. Isolation unit; 41. First wall; 42. Side wall; 43. Bottom wall; 400. Temperature equalization cavity; 401. Connecting entrance; 5. Flow guide channel; 501. Flared opening; 5010. Collecting cavity; 5011. Protrusion; 502. Extension; 5020. Transmission channel; 6. Electrical connection part; 7. First heat insulation part; 8. Heat insulation layer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Other technical solutions obtained by those skilled in the art without creative effort are all within the protection scope of the present invention. In addition, it should be understood that the following terms such as "upper," "lower," "left," "right," "longitudinal," "lateral," "inner," "outer," "vertical," "horizontal," "top," and "bottom," which indicate orientation or positional relationship, are based only on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device / component referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0021] like Figures 1-9 As shown, a gas detection device includes a housing 1, a circuit board 2, and a detection module 3. The housing 1 has a receiving cavity 100. At least a portion of the circuit board 2 is located in the receiving cavity 100. The detection module 3 is electrically connected to the circuit board 2. The gas detection device includes an isolation unit 4 located in the receiving cavity 100. The isolation unit 4 has a temperature equalization cavity 400, which is isolated from the receiving cavity 100. The housing 1 has an air window 101 that communicates with the temperature equalization cavity 400. The detection module 3 is located in the temperature equalization cavity 400.

[0022] Gas detection devices can be used to detect gaseous fluids such as refrigerants, for example, in air conditioning or refrigerator systems, to detect refrigerant leaks and issue an alarm promptly. Of course, gas detection devices can also be used to detect leaks of other gases. In one embodiment, the detection module 3 includes a detection unit 31 and a control unit 32. The detection unit 31 contains a first thermistor, and the control unit 32 contains a second thermistor. The detection unit 31 has an inlet hole, while the control unit 32 is sealed. The control unit 32 contains a gas with a different thermal conductivity than the gas being detected. For example, if the gas inside the control unit 32 is atmospheric air, when no leak occurs, the gas inside the detection unit 31 is also atmospheric air, and the gas detection device is in a standby state. When a leak occurs in the gas being detected, the gas enters the detection unit 31 through the inlet hole. Due to the different thermal conductivity of the gases... Due to differences in thermal conductivity, those skilled in the art can accurately determine the gas leakage amount by measuring the temperature difference between the detection unit 31 and the control unit 32 based on the different thermal conductivityes of the gases. For example, when a gas leaks, the leaking gas enters the detection unit 31. At this time, the thermal conductivity of the gas in the detection unit 31 is different from that in the control unit 32, resulting in different heat dissipation efficiencies between the detection unit 31 and the control unit 32. Consequently, the temperature and resistance values ​​of the first thermistor and the second thermistor in the detection unit 31 differ. The leakage of the gas to be detected can then be accurately determined using a Wheatstone bridge. The principle of the Wheatstone bridge will not be elaborated further; those skilled in the art can clearly implement it using conventional techniques and the description in the specification.

[0023] The isolation unit 4 is located in the receiving cavity 100, and the detection module 3 is located in the temperature equalization cavity 400 of the isolation unit 4. The temperature equalization cavity 400 is isolated from the receiving cavity 100, so that at least part of the receiving cavity 100 serves as a buffer space between the temperature equalization cavity 400 and the external environment, thereby reducing the direct impact of the external environment on the detection module 3. This makes the temperature equalization cavity 400 a relatively stable space, further allowing the gas to be detected to be as close as possible to the single factor that directly affects the detection module 3, thereby improving the accuracy of the detection module 3 in detecting the gas to be detected.

[0024] Furthermore, the detection module 3 includes a detection unit 31 and a control unit 32. Since the detection unit 31 and the control unit 32 are located in different positions, and the influence of the external environment on different positions is also different, the detection unit 31 and the control unit 32 are both located in the temperature equalization cavity 400. At least part of the temperature equalization cavity 400 is isolated from the external environment by the receiving cavity 100, which reduces the direct influence of the external environment on the temperature equalization cavity 400, improves the temperature uniformity of various places in the temperature equalization cavity 400, and thus improves the detection accuracy of the detection module 3.

[0025] On the other hand, the temperature equalization cavity 400 also effectively reduces the different degrees of influence of the circuit board 2 on the detection unit 31 and the control unit 32. Since the circuit board 2 has a heating chip, the different distances between the detection unit 31 and the control unit 32 and the heating chip will also affect the detection accuracy of the detection module 3. The temperature equalization cavity 400 is isolated from the receiving cavity 100, which reduces the influence of the circuit board 2 located in the receiving cavity 100 on the detection module 3.

[0026] In one embodiment, such as Figure 3 , Figure 4 As shown, at least a portion of the cavity wall corresponding to the temperature equalization cavity 400 has a heat insulation layer 8, which increases the heat insulation performance of the receiving cavity 100 and the temperature equalization cavity 400, reduces the influence of the receiving cavity 100 on the temperature equalization cavity 400, and further improves the stability of the temperature equalization cavity 400.

[0027] Furthermore, in one embodiment, the cavity walls corresponding to the temperature equalization cavity 400 are all equipped with a heat insulation layer 8, so that the temperature equalization cavity 400 is as close as possible to being affected only by the gas to be detected entering through the inlet hole. Furthermore, the detection unit 31 and the control unit 32 are equidistant from the inlet hole, and their actual error value should be less than 10%, so that the convection effects of the gas to be detected on the detection unit 31 and the control unit 32 are also similar, and the heat dissipation of the detection unit 31 and the control unit 32 is as close as possible to being affected only by the thermal conductivity of the relevant gas, thereby improving the detection accuracy of the detection module 3.

[0028] In one embodiment, the heat insulation layer 8 can be located inside the cavity wall corresponding to the temperature equalization cavity 400. The heat insulation layer 8 can be fixed to the cavity wall corresponding to the temperature equalization cavity 400 by coating, attaching, or spraying. In one embodiment, the heat insulation layer 8 includes heat insulation cotton, which is attached to the cavity wall corresponding to the temperature equalization cavity 400.

[0029] In one embodiment, such as Figure 3 , Figure 5As shown, the isolation unit 4 includes a first wall 41, at least a portion of which is part of the cavity wall corresponding to the temperature equalization cavity 400. The circuit board 2 and the detection unit 31 are located on both sides of the first wall 41, respectively. The detection module 3 is electrically connected to the circuit board 2 through the power connection part 6, at least a portion of which penetrates the first wall 41.

[0030] In one embodiment, the power receiving part 6 is a pin, which is soldered to the circuit board 2.

[0031] In one embodiment, such as Figure 5 As shown, the isolation unit 4 includes a side wall portion 42 and a bottom wall portion 43. The temperature equalization chamber 400 includes a space enclosed by the side wall portion 42, the bottom wall portion 43, and the first wall body 41. The first wall body 41 has a gap with the circuit board 2. The side wall portion 42 or the bottom wall portion 43 is fixed to the outer shell 1. The side wall portion 42, the bottom wall portion 43, and the first wall body 41 together enclose to form the temperature equalization chamber 400. The isolation unit 4 can be installed and fixed to the outer shell 1 of the gas detection device as a whole. Specifically, the bottom wall portion 43 extends out of the area enclosed by the side wall portion 42. The inner wall of the outer shell 1 has a corresponding latching portion 102. The latching portion 102 latches the bottom wall portion 43 out of the area enclosed by the side wall portion 42, so that the isolation unit 4 is detachably installed on the outer shell 1.

[0032] The isolation unit 4 has two annular mounting portions for mounting the detection unit 31 and the control unit 32, respectively. In one embodiment, the annular mounting portions are located on the bottom wall portion 43, and the bottom wall portion 43 and the side wall portion 42 are integrally formed. After the detection unit 31 and the control unit 32 are respectively mounted on the two annular mounting portions, the first wall body 41 and the side wall portion 42 are fixed by welding or snap-fitting. During the fixing process of the first wall body 41, the power-connecting portion 6 should penetrate the first wall body 41 so that the detection unit 31 is electrically connected to the circuit board 2.

[0033] Of course, in other embodiments, the annular mounting portion can also be located on the side wall portion 42 or the first wall 41; in a typical embodiment, the annular mounting portion is located on the first wall 41, the detection unit 31 and the reference unit 32 are respectively mounted on the two annular mounting portions, and the power connection portion 6 penetrates through the first wall 41, and then the first wall 41 is fixed to the side wall portion 42. Of course, the first wall 41 can also be integrally formed with the side wall portion 42, and after the detection unit 31 and the reference unit 32 are installed, the bottom wall portion 43 is fixed to the side wall portion 42 by welding or snap-fitting.

[0034] In one embodiment, such as Figure 1 , Figure 3 , Figure 7As shown, the gas detection device includes a flow channel section 5, which connects the air window 101 and the temperature equalization chamber 400. The circuit board 2 is located between the air window 101 and the isolation unit 4, and the flow channel section 5 passes through the circuit board 2.

[0035] Furthermore, the air vent 101 and the isolation unit 4 are located on opposite sides of the circuit board 2. When a leak occurs, the gas to be detected enters the flow channel 5 through the air vent 101, flows through the flow channel 5, and then enters the temperature equalization chamber 400. The leakage amount of the gas to be detected is then detected by the detection module 3. This arrangement also increases the flow path of the gas to be detected into the temperature equalization chamber 400, thereby reducing the influence of factors such as gas convection on the detection error of the detection module 3. This is especially important when the gas detection device is used in an air conditioner outdoor unit to detect leaks of high-temperature and high-pressure gases.

[0036] In one embodiment, the flow channel portion 5 includes a flared portion 501 and an extension portion 502. The flared portion 501 has a flow collecting cavity 5010, and the extension portion 502 has a transmission flow channel 5020. The flow collecting cavity 5010 is connected to the transmission flow channel 5020. The flow collecting cavity 5010 is connected to the air window 101, and the transmission flow channel 5020 is connected to the temperature equalization cavity 400.

[0037] In one embodiment, such as Figure 10 As shown, the flared portion 501 is trumpet-shaped and faces the vent 101. The vent 101 includes an end face 1011 and a snap-fit ​​portion 1012 located at the edge of the end face 1011. The end face has an air hole, and the flared portion 501 has a protrusion 5011 that can be snapped and fixed with the snap-fit ​​portion 1012. In another embodiment, the vent 101 may also include an end face with a protrusion, and the flared portion 501 has a snap-fit ​​portion that cooperates with the protrusion. In other embodiments, the flared portion 501 may also be fixed to the outer shell 1. The two can be fixed by snap-fit ​​or welding, etc. After the flared portion 501 is fixed to the outer shell 1, its trumpet-shaped opening faces the vent 101 and the two are sealed.

[0038] The flared part 501 is sealed with the air window 101. When gas leakage occurs, it reduces the probability of the gas to be tested entering the receiving cavity 100 and reduces its impact on the circuit board 2 inside the receiving cavity 100. Especially when the gas to be tested is under high temperature and high pressure or contains water vapor, it is easy to damage the circuit board 2.

[0039] In one embodiment, the outer casing 1 includes a first casing 11 and a second casing 12. An air vent 101 is located in the first casing 11. A circuit board 2 is located between the bottom end of the first casing 11 and the detection module 3. The circuit board 2 has a clearance hole, and a portion of the extension 502 is located within the clearance hole. The gas detection device includes a first heat insulation part 7, at least a portion of which is located between the extension 502 and the sidewall corresponding to the clearance hole. The first heat insulation part 7 can be made of materials such as heat-insulating cotton. The first casing 11 and the second casing 12 can be detachably fixed by snap-fitting or welding.

[0040] The clearance hole can be located in the middle of circuit board 2 or at the edge of circuit board 2. Chip components on circuit board 2 should avoid or stay as far away from the clearance hole as possible. In one embodiment, such as... Figure 9 As shown, the clearance hole is located at the edge of the circuit board 2, which facilitates processing and manufacturing.

[0041] The first heat insulation part 7 further reduces the impact of the gas to be tested on the circuit board 2, such as reducing the temperature transfer of the high-temperature gas to the circuit board 2 and preventing damage to the chips on the circuit board 2.

[0042] In another embodiment, such as Figure 8 As shown, the detection module 3 can also be located between the bottom end of the first housing 11 and the circuit board 2. In this case, the extension 502 does not need to penetrate the circuit board 2, further reducing the impact of the gas to be detected on the circuit board 2. Furthermore, the isolation unit 4 and the air window 101 are located at different horizontal positions, and the flow guiding channel 5 has a vertical extension 502 and a horizontal extension 502, which reduces the impact of airflow on the detection module 3.

[0043] In one embodiment, the detection unit 31 of the detection module 3 is further away from the communication inlet 401 of the isolation unit 4 than the control unit 32. Therefore, when the gas to be detected enters the equalization chamber, it first covers the control unit 32, then covers the detection unit 31 and enters the interior of the detection unit 31, so that the two are further in the same external environment. This further avoids the deviation in detection accuracy caused by the difference in the environment between the two when the gas to be detected enters the detection unit 31 without covering the control unit 32.

[0044] In one embodiment, the isolation unit 4 has a connecting inlet 401 located on the first wall 41 and connected to the air window 101. The plane of the first wall 41 is a projection plane, and the projection of the connecting inlet 401 and the projection of the detection module 3 are located in two non-overlapping areas. This avoids the connecting inlet 401 directly facing the detection module 3, thereby reducing the probability that the gas to be detected will blow directly onto the detection module 3, reducing the impact of airflow on detection accuracy, and allowing the detection module 3 to detect only the single factor of gas thermal conductivity as closely as possible, thus improving its detection accuracy. For example, the connecting inlet 401 is located on one side of the isolation unit 4 away from its center, while the detection module 3 is located on the other side.

[0045] In one embodiment, the detection unit 31 has a detection inlet 310 located on the side of the detection unit 31. When a gas leak occurs, the gas to be detected enters the isolation chamber from the air window 101 through the guide channel 5. The guide channel 5 extends along the height direction of the gas detection device, so that the gas to be detected flows along the height direction of the gas detection device. The detection inlet 310 being located on the side of the detection unit 31 can alleviate the flow rate of the gas to be detected to a certain extent, so that the flow direction of the gas to be detected changes to a certain extent when it enters the detection unit 31, thereby reducing the impact of airflow on detection accuracy. Of course, the guide channel 5 can also be inclined, in which case there is still a certain angle with the detection inlet 310.

[0046] In another embodiment, the connecting inlet 401 can be located on the side wall 42 of the isolation unit 4, while the detection inlet 310 is located at the top of the detection unit 31, thus still avoiding direct gas convection between the two.

[0047] The above are merely typical specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions, concepts, and designs obtained by those skilled in the art by making equivalent substitutions or changes to the technical solutions and inventive concepts of the present invention within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A gas detection device, comprising a housing (1), a circuit board (2), and a detection module (3), wherein the housing (1) has a receiving cavity (100), at least a portion of the circuit board (2) is located in the receiving cavity (100), and the detection module (3) is electrically connected to the circuit board (2), characterized in that, The gas detection device includes an isolation unit (4) located in the receiving cavity (100). The isolation unit (4) has a temperature equalization cavity (400) which is isolated from the receiving cavity (100). The outer shell (1) has an air window (101) which is connected to the temperature equalization cavity (400). The detection module (3) is located in the temperature equalization cavity (400).

2. The gas detection device according to claim 1, characterized in that, At least a portion of the cavity wall corresponding to the uniform temperature cavity (400) has a heat insulation layer (8).

3. The gas detection device according to claim 1 or 2, characterized in that, The isolation unit (4) includes a first wall (41), at least a portion of which is the cavity wall corresponding to the temperature equalization cavity (400). The circuit board (2) and the detection unit (31) are located on opposite sides of the first wall (41). The first wall (41) and the circuit board (2) are spaced apart. The detection module (3) and the circuit board (2) are electrically connected through a power connection part (6), at least a portion of which penetrates the first wall (41).

4. The gas detection device according to claim 3, characterized in that, The isolation unit (4) includes a side wall portion (42) and a bottom wall portion (43). The temperature equalization cavity (400) includes the space enclosed by the side wall portion (42), the bottom wall portion (43) and the first wall body (41). The side wall portion (42) or the bottom wall portion (43) is fixed to the outer shell (1).

5. The gas detection device according to claim 1, 2, or 4, characterized in that, The gas detection device includes a flow channel (5) that connects the air window (101) and the temperature equalization chamber (400). The circuit board (2) is located between the air window (101) and the isolation unit (4), and the flow channel (5) passes through the circuit board (2).

6. The gas detection device according to claim 5, characterized in that, The flow channel (5) includes a flared section (501) and an extension section (502). The flared section (501) has a flow collecting cavity (5010), and the extension section (502) has a transmission channel (5020). The flow collecting cavity (5010) is connected to the transmission channel (5020), the flow collecting cavity (5010) is connected to the air window (101), and the transmission channel (5020) is connected to the temperature equalization cavity (400).

7. The gas detection device according to claim 5, characterized in that, The outer casing (1) includes a first housing (11) and a second housing (12). The air vent (101) is located in the first housing (11). The circuit board (2) is located between the bottom end of the first housing (11) and the detection module (3). The circuit board (2) has a clearance hole. A portion of the extension (502) is located in the clearance hole. The gas detection device includes a first heat insulation part (7). At least a portion of the first heat insulation part (7) is located between the extension (502) and the sidewall of the opening corresponding to the clearance hole.

8. The gas detection device according to claim 1, characterized in that, The outer casing (1) includes a first casing (11) and a second casing (12), the air vent (101) is located at the bottom end of the first casing (11), and the detection module (3) is located between the bottom end of the first casing (11) and the circuit board (2).

9. The gas detection device according to claim 1, 2, 4, 6, 7, or 8, characterized in that, The isolation unit (4) has a communication inlet (401) which is connected to the air window (101). The detection module (3) includes a detection unit (31) and a control unit (32). Both the detection unit (31) and the control unit (32) are located in the temperature equalization chamber (400). The detection unit (31) has a detection inlet (310) which is connected to the communication inlet (401).

10. The gas detection device according to claim 9, characterized in that, The distance between the detection unit (31) and the communication entrance (401) is greater than the distance between the control unit (32) and the communication entrance (401).

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