Gas detection probe
By designing multiple through holes on the housing of the gas detection probe to increase gas convection, the problem of long response time in the prior art is solved, and faster gas detection and higher detection accuracy are achieved.
Patent Information
- Application Number
- CN202310940478.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-28
- Publication Date
- 2025-02-14
AI Technical Summary
The existing gas detection probes have a small gas flow rate and a long response time, so they cannot quickly feel the gas changes.
A gas detection probe is designed, and its housing has multiple through holes in communication with the inner cavity, which increases the convection between the gas and the outside world and shortens the response time. Specifically, at least two through holes are located on the top wall of the housing, or at least one through hole is located on the side wall, and at least one through hole is located on the top wall.
By increasing the number and position of the through holes, the response speed of the gas detection probe is significantly improved, the impact of external thermal radiation on the thermistor is reduced, and the detection accuracy is improved.
Smart Images
Figure CN119438331A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of measurement technology, and in particular to a gas detection probe. Background Art
[0002] The gas detection probe includes a detection element and a shell. The shell includes a first shell with an opening, the detection element includes a first thermistor, and the first shell has a first inner cavity. When the detected gas enters the first inner cavity from the opening of the first shell, the resistance value of the first thermistor will change with the change of the gas. When the flow rate between the gas in the first inner cavity and the external gas is small, the first thermistor senses the gas change slowly, and the resistance value changes slowly, resulting in a longer response time of the gas detection probe. Summary of the invention
[0003] In order to solve the above technical problems, the present application provides a gas detection probe with a short response time.
[0004] A first aspect of the present application provides a gas detection probe, including a housing and a detection element, wherein the housing includes a first housing, the first housing having a first inner cavity and two or more first through holes, the first through holes being connected to the first inner cavity, and the first through holes being connected to the outside of the gas detection probe;
[0005] The detection element includes a first thermistor, and the first thermistor is located in the first inner cavity;
[0006] The first shell includes a top wall and a side wall, and the top wall and the side wall are both located at the periphery of the first inner cavity; the gas detection probe has a first direction, and along the first direction, the side wall is at least partially close to the detection element relative to the top wall;
[0007] The at least two first through holes are both located on the top wall; or, at least one of the first through holes is located on the side wall, and at least one of the first through holes is located on the top wall.
[0008] The gas detection probe in the first aspect of the present application has two or more first through holes on the top wall of the first shell, or both the top wall and the side wall have first through holes, which increases the convection between the first inner cavity gas and the external gas, thereby increasing the flow rate between the first inner cavity gas and the external gas. The first thermistor can quickly sense the temperature changes caused by the gas, thereby shortening the response time of the gas detection probe.
[0009] A second aspect of the present application provides a gas detection probe, comprising a housing and a detection element, wherein the housing comprises a first housing, the first housing has a first inner cavity, the detection element comprises a first thermistor, and the first thermistor is located in the first inner cavity;
[0010] The first shell includes a top wall and a side wall, and the top wall and the side wall are both located at the periphery of the first inner cavity; the gas detection probe has a first direction, and along the first direction, the side wall is at least partially close to the detection element relative to the top wall;
[0011] The first shell has a first through hole, the first through hole is connected to the first inner cavity, and the first through hole is connected to the outside of the gas detection probe;
[0012] The first through hole is arranged on the top wall, and the flow area of the first through hole accounts for 20% to 70% of the area of the top wall; or the first through hole is arranged on the side wall, and the flow area of the first through hole accounts for 20% to 70% of the area of the side wall.
[0013] In the gas detection probe in the second aspect of the present application, the first through hole is arranged on the top wall, and the flow area of the first through hole accounts for 20% to 70% of the top wall area; or, the first through hole is arranged on the side wall, and the flow area of the first through hole accounts for 20% to 70% of the side wall area. In the present application, the flow area of the first through hole accounts for more than 20%, so that the flow volume between the first inner cavity gas and the external gas increases, and the first thermistor can quickly sense the temperature change caused by the gas, shortening the response time of the gas detection probe. At the same time, the flow area of the first through hole accounts for less than 70%, which can reduce the influence of external thermal radiation on the first thermistor. In other words, the present application limits the flow area of the first through hole to the range of 20% to 70%, which can reduce the influence of external thermal radiation on the first thermistor while shortening the response time of the gas detection probe. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 A schematic diagram of a gas detection probe provided in one embodiment of the present application;
[0015] Figure 2 A schematic diagram of an explosion of a gas detection probe provided in one embodiment of the present application;
[0016] Figure 3 A schematic diagram of an explosion of a gas detection probe provided in one embodiment of the present application from another perspective;
[0017] Figure 4 A cross-sectional view of a gas detection probe provided in one embodiment of the present application;
[0018] Figure 5 A schematic diagram of a gas detection probe provided in another embodiment of the present application;
[0019] Figure 6 for Figure 5 A cross-sectional view of the provided gas detection probe;
[0020] Figure 7 A projection diagram of a gas detection probe provided in one embodiment of the present application. DETAILED DESCRIPTION
[0021] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0022] It should be clear that the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0023] At present, the relevant gas detection probe includes a shell 2 and a detection element 3. Among them, the shell 2 includes a first shell 21, and the first shell 21 has a first inner cavity 211, and the first inner cavity 211 is an open cavity. When the detected gas enters the open cavity, it will cause the resistance value of the first thermistor 31 in the first inner cavity 211 to change. When the resistance value changes to a set value, it will trigger the propagation of an electrical signal and issue an alarm prompt, thereby achieving the effect of detecting the gas. The flow rate of the gas to be detected when entering the first inner cavity 211 will affect the response speed of the gas detection probe 1.
[0024] In order to improve the response speed of the gas detection probe 1, the present application provides a gas detection probe 1, referring to Figure 1 and Figure 3As shown, the first shell 21 has a first inner cavity 211 and more than two first through holes 212, wherein the first through hole 212 is connected to the first inner cavity 211, and the first through hole 212 is connected to the outside of the gas detection probe 1. The detection element 3 includes a first thermistor 31, and the first thermistor 31 is located in the first inner cavity 211. The first shell 21 includes a top wall 213 and a side wall 214, and the top wall 213 and the side wall 214 are both located at the periphery of the first inner cavity 211. The gas detection probe 1 has a first direction H, wherein the first direction H is parallel to the height direction of the gas detection probe 1, and along the first direction H, the side wall 214 is at least partially close to the detection element 3 relative to the top wall 213. At least two first through holes 212 are located in the top wall 213; or, at least one first through hole 212 is located in the side wall 214, and at least one first through hole 212 is located in the top wall 213. When the top wall 213 has two or more first through holes 212, the convection between the external gas and the gas inside the first inner cavity 211 can be increased, and the flow rate of the gas in the first inner cavity 211 and the external gas can be further increased. The first thermistor 31 can quickly sense the temperature change caused by the gas, and reduce the response time of the gas detection probe 1. Similarly, when the side wall 214 and the top wall 213 each have one or more first through holes 212, the convection between the external gas and the gas inside the first inner cavity 211 will also be increased, so that the flow rate of the gas in the first inner cavity 211 and the external gas will be increased, and the gas detection probe 1 will be improved.
[0025] In order to further improve the convection between the external gas and the gas inside the first inner cavity 211, in one embodiment, as Figure 2 As shown, when the first through holes 212 are all located on the top wall 213, the first through holes 212 should be arranged symmetrically on the top wall 213. Furthermore, the symmetrical arrangement can be arranged in a central symmetric or axisymmetric manner. For example, the number of the first through holes 212 is four. When the first top wall 213 is circular, the axis of symmetry can be any diameter of the circle, and the first through holes 212 are evenly distributed on both sides of the axis of symmetry; at the same time, the axis of symmetry can also be multiple diameters of the circle, and the first through holes 212 are evenly distributed near or on the axis of symmetry. When the first top wall 213 is square, the axis of symmetry can be a diagonal line, and the first through holes 212 are evenly distributed on both sides of the axis of symmetry; at the same time, the axis of symmetry can also be multiple diagonals, and the first through holes 212 are evenly distributed around or on the axis of symmetry.
[0026] When there are five first through holes 212, one of the first through holes 212 may be disposed on the first top wall 213, and the other four first through holes 212 may be disposed on the side wall 214. The first through holes 212 are preferably at least one of polygonal, circular or polygonal.
[0027] In order to make the first thermistor 31 sense the gas change more quickly and make a quick detection, in one embodiment, as Figure 7As shown, a plane perpendicular to the first direction H is defined as a projection plane S. Along the first direction H, the orthographic projection of the hole wall corresponding to the first through hole 212 on the projection plane S is a first projection S1, and the orthographic projection of the first thermistor 31 on the projection plane S is a second projection S2. The second projection S2 is at least partially located within the outline of the first projection S1. In other words, the first thermistor 31 is at least partially aligned with the first through hole 212.
[0028] When the first housing 21 is a square body, the four first through holes 212 may be disposed on the four side walls 214 of the square body. Furthermore, at least a portion of the first thermistor 31 may be disposed in alignment with the four first through holes 212 , respectively.
[0029] In order to improve the accuracy of the gas detection probe 1, in one embodiment, Figure 4 As shown, the housing 2 includes a second housing 22, the second housing has a second inner cavity 221, and the second inner cavity 221 is a closed cavity; the detection element 3 includes a second thermistor 32, the second thermistor 32 is located in the second inner cavity 221, and the second thermistor 32 is used as a reference resistor in the second inner cavity 221. When the first thermistor 31 and the second thermistor 32 reach a certain resistance difference, the gas detection probe 1 will sound an alarm. Further, in one embodiment, the first thermistor 31 and the second thermistor 32 are both NTC thermistor chips, so as to facilitate the selection of components.
[0030] In order to reduce the influence of the external gas temperature on the second thermistor 32, thereby affecting the detection accuracy of the gas detection probe 1, in one embodiment, as Figure 5 As shown, there is a gap between the first shell 21 and the second shell 22. Alternatively, in one embodiment, as shown in FIG. Figure 5 As shown, the first shell 21 and the second shell 22 are an integral part, and the shell 2 includes a connecting wall 23, and the first shell 21 and the second shell 22 are both connected to the connecting wall 23. In some embodiments, the first shell 21 and the second shell 22 are cylindrical or square or other shapes. Further, there is a spacing groove 20 between the first shell 21 and the second shell 22; along the first direction H, the connecting wall 23 is away from the top wall 213 relative to the spacing groove 20, and the size of the spacing groove 20 in the first direction H is greater than the size of the connecting wall 23 in the first direction H, so that the spacing groove 20 isolates the heat conduction between the shared partition wall of the first shell 21 and the second shell 22, thereby further improving the detection accuracy of the gas detection probe 1.
[0031] In one embodiment, if Figure 6As shown, the size of the spacing groove 20 in the first direction H of the gas detection probe 1 is h1, and the size of the connecting wall 23 in the first direction H of the gas detection probe 1 is h2, where h1 and h2 satisfy the following relationship: 2≤h1 / h2≤4. When the size of the spacing groove 20 in the first direction H is more than twice and less than four times the size of the connecting wall 23 in the first direction H, the heat transfer between the first inner cavity 211 and the second inner cavity 221 is further reduced, thereby further improving the detection accuracy of the gas detection probe 1, while taking into account the connection strength of the spacing groove 20. Preferably, h1 / h2=3, which can reduce the heat transfer between the first inner cavity 211 and the second inner cavity 221, and the connection strength between the first shell 21 and the second shell 22 is strong enough.
[0032] The second aspect of the present application provides a gas detection probe, wherein the first through hole 212 is arranged on the top wall 213, and the flow area of the first through hole 212 accounts for 20% to 70% of the area of the top wall 213, or the first through hole 212 is arranged on the side wall 214, and the flow area of the first through hole 212 accounts for 20% to 70% of the area of the side wall 214. The area of the top wall 213 is the area of the entire top wall 213, including the area of the first through hole 212; the area of the side wall 214 is the area of the entire unfolded surface of the side wall 214, including the area of the first through hole 212. For example, when the first shell 21 is a cylindrical shell, the top wall 213 is a circle with a radius of R, the height of the first shell 21 is l, and the area of the top wall 213 is πR 2 , the area of the side wall 214 is 2πr·l; the aperture corresponding to the first through hole 212 is d, and the flow area of the first through hole 212 is πd 2 / 4. In this application, d 2 / 4R 2 The range is 20% to 70%. Figure 3 As shown, when the top wall 213 has a first through hole 212 and the flow area of the first through hole 212 accounts for 20% to 70% of the area of the top wall 213, when the flow area of the first through hole 212 is large, the flow volume of the gas in the first inner cavity 211 and the external gas increases, and the first thermistor 31 can quickly sense the temperature change caused by the gas, shortening the response time of the gas detection probe 1. At the same time, the flow area of the first through hole 212 is limited, reducing the influence of external heat radiation on the first thermistor 31 caused by the excessive flow area of the first through hole 212, causing the gas detection probe 1 to have a false alarm. Further, the flow area of the first through hole 212 accounts for 30% to 60% of the area of the top wall 213. Similarly, when the side wall 214 has a first through hole 212 and the flow area of the first through hole 212 accounts for 20% to 70% of the area of the side wall 214, the gas detection probe 1 can also respond quickly when encountering the detection gas and issue an alarm; further, the flow area of the first through hole 212 accounts for 30% to 60% of the area of the side wall 214.
[0033] Furthermore, under the condition of controlling the flow area of the first through hole 212, more than two first through holes 212 can be provided. When the first through holes 212 are provided on the top wall 213, the total area of each first through hole 212 accounts for 20% to 70% of the area of the top wall 213; or when the first through holes 212 are provided on the side wall 214, the total area of each first through hole 212 accounts for 20% to 70% of the area of the side wall 214. The convection and flow rate of the gas to be measured are increased at the same time, thereby greatly improving the detection accuracy of the gas detection probe 1 and shortening the response time of the gas detection probe 1.
[0034] In order to further enable the first thermistor 31 to sense gas changes more quickly and make rapid detection, in one embodiment, as Figure 3 As shown, the first thermistor 31 is at least partially disposed in alignment with the first through hole 212 .
[0035] In one embodiment, if Figure 3 As shown, the gas detection probe includes a base 4, the base 4 has a third through hole 41 and a second through hole 42, the detection element 3 includes a second mounting portion 391 and a first mounting portion 392, the second mounting portion 391 includes a second step 3912 and a second protrusion 3911, the first mounting portion 392 includes a first step 3922 and a first protrusion 3921, the second protrusion 3911 protrudes from the second mounting portion 391 in a direction away from the second mounting portion 391, and the first protrusion 3921 protrudes from the first mounting portion 392 in a direction away from the first mounting portion 392.
[0036] The second mounting portion 391 is at least partially located in the third through hole 41, and the first mounting portion 392 is at least partially located in the second through hole 42. To facilitate installation, the second step 3912 is at least partially connected to the hole wall of the third through hole 41, and the first step 3922 is at least partially connected to the hole wall of the second through hole 42, wherein the second protrusion 3911 and the first protrusion 3921 have a positioning function.
[0037] In one embodiment, if Figure 3As shown, the first housing 21 includes a first flange portion 215, which is close to the first mounting portion 392 relative to the first through hole 212, and the second housing includes a top portion 222, a side portion 223 and a second flange portion 224. The top portion 222 and the side portion are located at the periphery of the second inner cavity 221. Along the first direction H, the side portion 223 is at least partially close to the detection element 3 relative to the top portion 222, and the second flange portion 224 is close to the second mounting portion 391 relative to the top portion 222. The first mounting portion 392 is provided with a first end surface 3923, which is connected to the first step 3922 and is away from the top wall 213 relative to the first step 3922; the second mounting portion 391 is provided with a second end surface 3913, which is connected to the second step 3912 and is away from the top 222 relative to the second step 3912. In order to achieve better sealing installation, the first flange portion 215 is sealed to the first end face 3923, and the second flange portion 224 is sealed to the second end face 3913, wherein the sealing connection method includes welding or sealing adhesive connection or connection through a sealing ring.
[0038] like Figure 3 As shown, the detection element 3 includes first leads 34a, 34b, first conductive terminals 36a, 36b, the first leads 34a, 34b, the first conductive terminals 36a, 36b and the first thermistor 31 are located on the same side of the first mounting portion 392, the first thermistor 31 is electrically connected to the first leads 34a, 34b, the first leads 34a, 34b are electrically connected to the first conductive terminals 36a, 36b; the detection element 3 includes second leads 33a, 33b, second conductive terminals 35a, 35b, the second leads 33a, 33b, the second conductive terminals 35a, 35b and the second thermistor 32 are located on the same side of the second mounting portion 391, the second thermistor 32 is electrically connected to the second leads 33a, 33b, the second leads 33a, 33b are electrically connected to the second conductive terminals 35a, 35b.
[0039] In order to make the first lead wires 34a, 34b and the first conductive terminals 36a, 36b more firmly connected, as shown in FIG. Figure 3As shown, the first leads 34a, 34b include a first connecting portion 3a, and the first leads 34a, 34b are connected to the first conductive terminals 36a, 36b through the first connecting portion 3a. When the first connecting portion 3a is linear, the connection between the first leads 34a, 34b and the first conductive terminals 36a, 36b is a linear connection. When the first connecting portion 3a is planar, the connection between the first leads 34a, 34b and the first conductive terminals 36a, 36b is a planar connection. Similarly, the second leads 33a, 33b include a second connecting portion 3b, and the second leads 33a, 33b are connected to the second conductive terminals 35a, 35b through the second connecting portion 3b. When the second connecting portion 3b is linear, the connection between the second leads 33a, 33b and the second conductive terminals 35a, 35b is a linear connection. When the second connecting portion 3b is planar, the connection between the second leads 33a, 33b and the second conductive terminals 35a, 35b is a planar connection. In one embodiment, planar connection is preferred.
[0040] The first lead wires 34a and 34b include first electrodes 34a1 and 34b1, and the second lead wires 33a and 33b include second electrodes 33a1 and 33b1. The first electrodes 34a1 and 34b1 and the second electrodes 33a1 and 33b1 can be made of a material with low thermal conductivity, such as Constantan alloy, which is a copper-nickel alloy composed of 55% copper and 45% nickel (Cu 55 Ni 45 ) and its characteristics are that it is not easy to change its properties with temperature changes and has high resistivity. It has a low temperature coefficient of resistivity and medium resistivity (resistivity is 0.48μΩ·m).
[0041] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.
Claims
1. A gas detection probe, comprising a housing and a detection element, characterized in that: The housing comprises a first housing, the first housing having a first inner cavity and two or more first through holes, the first through holes being in communication with the first inner cavity, and the first through holes being in communication with the outside of the gas detection probe; The detection element includes a first thermistor, and the first thermistor is located in the first inner cavity; The first shell includes a top wall and a side wall, and the top wall and the side wall are both located at the periphery of the first inner cavity; The gas detection probe has a first direction, along which the side wall is at least partially close to the detection element relative to the top wall; The at least two first through holes are both located on the top wall; or, at least one of the first through holes is located on the side wall, and at least one of the first through holes is located on the top wall.
2. The gas detection probe according to claim 1, characterized in that: The first through holes are all located on the top wall, and the first through holes are symmetrically arranged on the top wall.
3. The gas detection probe according to claim 1, characterized in that: A plane perpendicular to the first direction is defined as a projection plane. Along the first direction, the orthographic projection of the hole wall corresponding to the first through hole on the projection plane is a first projection. The orthographic projection of the first thermistor on the projection plane is a second projection. The second projection is at least partially located within the outline of the first projection.
4. The gas detection probe according to claim 1, characterized in that: The housing comprises a second housing, the second housing has a second inner cavity, and the second inner cavity is a closed cavity; The detection element includes a second thermistor, and the second thermistor is located in the second inner cavity; There is a distance between the first shell and the second shell; or, the first shell and the second shell are an integral piece, the shell comprises a connecting wall, and the first shell and the second shell are both connected to the connecting wall.
5. The gas detection probe according to claim 4, characterized in that: A spacing groove is provided between the first shell and the second shell; Along the first direction, the connecting wall is away from the top wall relative to the spacing groove, and a size of the spacing groove in the first direction is greater than a size of the connecting wall in the first direction.
6. The gas detection probe according to claim 5, characterized in that: The dimension of the spacing groove in the first direction is h1, and the dimension of the connecting wall in the first direction is h2, wherein h1 and h2 satisfy the following relationship: 2≤h1 / h2≤4.
7. A gas detection probe, comprising a housing and a detection element, characterized in that: The housing comprises a first housing, the first housing has a first inner cavity, the detection element comprises a first thermistor, and the first thermistor is located in the first inner cavity; The first shell includes a top wall and a side wall, and the top wall and the side wall are both located at the periphery of the first inner cavity; The gas detection probe has a first direction, along which the side wall is at least partially close to the detection element relative to the top wall; The first shell has a first through hole, the first through hole is connected to the first inner cavity, and the first through hole is connected to the outside of the gas detection probe; The first through hole is arranged on the top wall, and the flow area of the first through hole accounts for 20% to 70% of the area of the top wall; or the first through hole is arranged on the side wall, and the flow area of the first through hole accounts for 20% to 70% of the area of the side wall.
8. The gas detection probe according to claim 7, characterized in that: The first thermistor is at least partially aligned with the first through hole.
9. The gas detection probe according to claim 7, characterized in that: The housing comprises a second housing, the second housing has a second inner cavity, and the second inner cavity is a closed cavity; The detection element includes a second thermistor, and the second thermistor is located in the second inner cavity; There is a distance between the first shell and the second shell; or, the first shell and the second shell are an integral piece, the shell comprises a connecting wall, and the first shell and the second shell are both connected to the connecting wall.
10. The gas detection probe according to claim 9, characterized in that: A spacing groove is provided between the first shell and the second shell; Along the first direction, the connecting wall is away from the top wall relative to the spacing groove, and a size of the spacing groove in the first direction is greater than a size of the connecting wall in the first direction.