Point type combustible gas detector
By employing two printed circuit boards and a sealed insulation layer structure in the sensor, the problem of icing in catalytic combustion sensors at low temperatures was solved, enabling accurate detection by the detector in low-temperature environments.
Patent Information
- Application Number
- CN202520286883.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2035-02-21
AI Technical Summary
Existing catalytic combustion sensors are prone to icing at low temperatures, which leads to inaccurate detector readings and fails to meet the experimental requirements of GB15322.1-2019.
The design employs a dual-printed circuit board structure to increase the heat conduction path, and a support and sealing insulation layer are placed between the sensor and the circuit board to reduce the direct heat conduction effect of low temperature on the sensor.
Maintaining sensor stability and airtightness in low-temperature environments ensures accurate detector readouts and meets detector standards for industrial and commercial applications.
Smart Images
Figure CN223637432U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to industrial and commercial purposes point type combustible gas detector, especially, it is catalytic combustion type sensor to the detection application of carbon hydrogen type combustible gas. BACKGROUND
[0002] The sensor of point type combustible gas detector is catalytic combustion type sensor, is mainly used for detecting combustible gas, and mainly comprises a detection element and a compensation element in the sensor, and the main principle is that the detection element will heat when electrified, the surface of the detection element contains a catalyst, and flameless combustion will occur when contacting the combustible gas, the impedance of the detection element changes due to the flameless combustion, different concentrations of gas correspond to different degrees of flameless combustion, so as to correspond to different impedance changes of the detection element, and the corresponding gas concentration value is detected through the signal conditioning circuit corresponding to the impedance change.
[0003] Catalytic combustion type sensor is widely used in detecting combustible gas, and the low temperature condition of GB15322.1-2019 is-40 DEG C for the environmental tolerance of industrial and commercial purposes point type combustible gas detector, and the test error is ± 7% LEL, it is found that the simple gas chamber structure has the phenomenon of icing in the sensor under the test condition of low temperature-40 DEG C, the icing leads to the change of the impedance of the detection element in the sensor, so that the mainboard cannot correctly collect the gas concentration information, finally leading to the fact that the detector cannot meet the experimental requirements of GB15322.1-2019 on industrial and commercial purposes point type combustible gas detector.
[0004] The following is the experimental record of the detector reading back methane gas under the condition of low temperature-40 DEG C:
[0005]
[0006] From the experimental results, with the increase of the ventilation time under low temperature, the reading of the detector reading back gradually decreases. It is found through the experiment that there is icing phenomenon in the sensor under-40 DEG C, the main reason is that the water vapor produced by the flameless combustion of combustible gas at the detection element meets low temperature and produces icing in the sensor, and the icing between the legs of the sensor detection element is equivalent to connecting a resistance on the detection element, and the resistance value of the connected resistance is related to the icing degree. Since the detection element of the catalytic combustion sensor is a few ohms resistance in principle, the impedance of the detection element changes (the equivalent impedance of the connected resistance decreases) after icing, and finally the experimental phenomenon of the detector is that the reading of the detector reading back is lower and lower with the increase of the ventilation time under low temperature, which causes the inaccurate reading of the detector reading back. CONTENT OF THE UTILITY MODEL
[0007] The utility model wants to solve the technical problem to provide a point type combustible gas detector, the problem of the existing sensor internal icing is solved, has the back reading number of the detector accurate effect.
[0008] In order to solve the above technical problem, the utility model provides a point type combustible gas detector, it includes mutually connected end cover, explosion -proof net, gas chamber and gas chamber and sensor module, the sensor module is contained in the gas chamber, the sensor module includes: sensor, the second printed circuit board and the first printed circuit board are sequentially set up and are spaced apart in the top of sensor, the support part is arranged between the sensor and the second printed circuit board, and the high connector is arranged between the second printed circuit board and the first printed circuit board, the sealing heat preservation layer is arranged between the outside of the sensor module and the gas chamber, the upper end surface of the first printed circuit board and the sealing heat preservation layer is mutually flush, and the flush upper end surface and the gas chamber are glued and connected.
[0009] Further optimization scheme lies in that: the high connector is provided with a plurality, and the height of each high connector is 1.9~2.1mm.
[0010] Further optimization scheme lies in that: the support part is provided with a plurality, and the height of each support part is 0.9~1.1mm.
[0011] Further optimization scheme lies in that: the width of the sensor is less than the second printed circuit board and the first printed circuit board, and the width of the second printed circuit board and the first printed circuit board remains consistent.
[0012] Further optimization scheme lies in that: the sealing heat preservation layer is attached to the inner wall of the gas chamber, and a gap is left between the sealing heat preservation layer.
[0013] Further optimization scheme lies in that: the sealing heat preservation layer has a platform for positioning and clamping the sensor module.
[0014] Further optimization scheme lies in that: the sealing heat preservation layer is a foam sealing heat preservation layer.
[0015] Further optimization scheme lies in that: the width of the sensor module is 18±1mm, and the height is 12±1mm.
[0016] The technical effect of the utility model lies in:
[0017] 1, the combustible gas detector of the utility model adjusts the hardware circuit structure to be the first, second two printed circuit boards from the printed circuit board of prior art, to reduce low temperature experimental environment and the low temperature heat conduction of sensor tube leg.
[0018] 2. The combustible gas detector of the utility model can be connected through 2.0mm high connector between the first and second printed circuit boards, increase the heat conduction path of low temperature to the sensor, and reduce the direct influence of low temperature on the sensor through the higher temperature in the air chamber.
[0019] 3. The sensor of the combustible gas detector of the utility model is not directly in contact with the circuit board when being welded on the second two printed circuit boards, and is welded by being lifted by 1mm, so that the heat conduction distance is increased, and the direct heat conduction of low temperature to the sensor through the wire is reduced.
[0020] 4. The utility model discloses a combustible gas detector sensor and external structure spare between adding sealed heat preservation layer as sealing element, sealing element uses heat preservation material to make the air chamber in low temperature experiment keep relatively stable temperature and also can satisfy the air tightness requirement. BRIEF DESCRIPTION OF DRAWINGS
[0021] Fig. 1 is the exploded structure schematic view of the point type combustible gas detector of the utility model;
[0022] Fig. 2 is the longitudinal section schematic view of the point type combustible gas detector of the utility model;
[0023] Fig. 3 is the sensor module structure schematic view of the point type combustible gas detector of the utility model. DETAILED DESCRIPTION
[0024] The utility model will be further described below in combination with the drawings and specific embodiments, so that the person skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation of the utility model.
[0025] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings of the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.
[0026] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element 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 this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0028] like Figs. 1-2 As shown, this utility model is a combustible gas detector, which includes an end cap 4 and an explosion-proof mesh 3, a gas chamber 2 and a sensor module 1 disposed inside it. The explosion-proof mesh 3 is located at the bottom of the end cap 4. A sealing and heat-insulating layer 16 is isolated on the outside of the sensor module 1. The space formed by the top of the sealing and heat-insulating layer 16 and the end cap 4 is provided with an adhesive seal 13. The space formed by the adhesive seal 13, the heat-insulating layer 16 and the explosion-proof mesh 3 is the gas chamber 2, and the sensor module 1 is housed in the gas chamber 2.
[0029] like Figs. 2-3 As shown, the sensor module 1 includes a sensor 17, with a second printed circuit board 15 and a first printed circuit board 14 sequentially spaced upwards from the top of the sensor 17. The width of the sensor 17 is smaller than that of the second printed circuit board 15 and the first printed circuit board 14, while the widths of the second printed circuit board 15 and the first printed circuit board 14 are the same. The top of the first printed circuit board 14 does not exceed the top of the sealing insulation layer 16. The overall width of the sensor module 1 is 18±1mm, and the height is 12±1mm.
[0030] In this embodiment, the two second printed circuit boards 15 and the first printed circuit board 14 are connected by 2.0mm high connectors 11. Multiple high connectors 11 are provided, each with a height of 1.9~2.1mm, with an optimal height of 2mm. This increases the heat conduction path from low temperature to the sensor, and reduces the direct impact of low temperature on the sensor 17 by maintaining a higher temperature within the air chamber.
[0031] Supporting parts 12 are arranged between the sensor 17 and the second printed circuit board 15, the sensor 17 is not in direct contact with the second printed circuit board 15 when welded on the second printed circuit board 15, the sensor 12 is lifted by 1mm to form the supporting part 12 between the two, which plays the role of gap, increases the heat conduction distance, reduces the direct heat conduction of low temperature through the wire and the sensor 17, the supporting part 12 is provided with a plurality of supporting parts, the height of each supporting part is 0.9-1.1mm, and the best height of the embodiment is 1mm.
[0032] The sealing and heat preservation layer 16 is attached to the inner wall of the end cover 4, and the best material of the sealing and heat preservation layer 16 is foam. The foam sealing and heat preservation layer can keep the temperature in the air chamber 2 relatively stable during low-temperature experiments and also meet the air tightness requirement.
[0033] The above-described embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present application are all within the protection scope of the present application. The protection scope of the present application is subject to the claims.
Claims
1. A point-type combustible gas detector comprising an end cap, an explosion-proof net, a gas chamber and a sensor module arranged in the end cap, characterized in that, A sealing and heat preservation layer is arranged outside the sensor module, a space formed by the top of the sealing and heat preservation layer and the end cover is provided with a rubber seal, and a containing space formed by the rubber seal, the heat preservation layer and the explosion-proof net is an air chamber, and the sensor module is contained in the air chamber; the sensor module comprises a sensor, a second printed circuit board and a first printed circuit board are sequentially and spaced apart upwards on the top of the sensor, a support portion is arranged between the sensor and the second printed circuit board, a high connector is arranged between the second printed circuit board and the first printed circuit board, and the top of the first printed circuit board is not higher than the top of the sealing and heat preservation layer.
2. The point type combustible gas detector according to claim 1, characterized by, The high connector is provided in a plurality of forms, and the height of each high connector is 1.9-2.1 mm.
3. The point type combustible gas detector according to claim 1, characterized by, The support portion is provided in a plurality of forms, and the height of each support portion is 0.9-1.1 mm.
4. The point type combustible gas detector according to claim 1, characterized by, The width of the sensor is smaller than that of the second printed circuit board and the first printed circuit board, and the widths of the second printed circuit board and the first printed circuit board are consistent.
5. The point type combustible gas detector according to claim 1, wherein The outer side surface of the sealing and heat preservation layer is attached to the inner wall of the end cover.
6. The point type combustible gas detector according to claim 1, wherein The sealing and heat preservation layer is provided with a platform for positioning and clamping the sensor module.
7. The point type combustible gas detector according to claim 1, wherein The material of the sealing and heat preservation layer is foam.
8. The point type combustible gas detector according to claim 1, wherein The width of the sensor module is 18±1 mm, and the height is 12±1 mm.