Gas concentration sensor based on Harch type thermal conductivity principle

Abstract

The invention discloses a gas concentration sensor based on a Hough type heat conduction principle. The gas concentration sensor comprises an internal sensor, a temperature balance block, a circuit board, a sensor protection piece and a sensor main body shell, the internal sensor, the temperature balance block and the circuit board are arranged in the sensor main body shell; the circuit board is arranged at the bottom of the sensor main body shell; the temperature balance block is arranged above the circuit board, and the temperature balance block is connected with the circuit board; the internal sensor is installed on the temperature balance block, and the internal sensor penetrates through the temperature balance block and then is connected with the circuit board. The sensor protection piece is of a T-shaped structure and is installed on the outer side of the internal sensor. The arrangement of the sensor protection piece with the T-shaped structure not only can play a role in protecting the internal sensor, but also can play a role in counteracting high-speed airflow, so that the accuracy of gas concentration detection is ensured, and the temperature balance block can balance the temperature among all parts in the gas concentration sensor, so that the overall stability of the gas concentration sensor is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of gas concentration sensors, and particularly relates to a gas concentration sensor based on the Hach thermal conductivity principle. Background Art

[0002] Currently, gas leakage detection and alarm instruments are installed in some places in life. Their function is to monitor combustible or toxic and harmful dangerous gases. When leakage occurs, the concentration value is detected in real time. When the set concentration value is exceeded, an alarm is issued to remind personnel, who will then take relevant safety prevention measures in a timely manner.

[0003] The operation of gas leakage detection and alarm instruments depends on the detection of on-site gases by gas concentration sensors. In existing gas concentration sensors, the space entered from the air inlet blows directly on the surface of the gas sensor. When encountering a high-speed air flow, false alarms are likely to occur. Because when there is a high-speed air flow, within a short period of time, the sensor senses a large number of target detection gas molecules, and the sensor is likely to falsely report an increase in the concentration of the detected target gas. Moreover, the existing gas concentration sensors do not protect the core components. Slight drops, impacts during construction and installation, or vibrations in the working environment after installation will affect the core components inside the sensor, resulting in inaccurate detection concentration or inability to work. In addition, there is a certain temperature gradient in the existing gas concentration sensors, and the sample gas therein generates a thermal convection effect, causing interference and noise to the co-existing information of the instrument, and also causing the problem of low stability of the thermal conductivity gas sensor. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention designs a gas concentration sensor based on the Hach thermal conductivity principle, including: an internal sensor, a temperature balance block, a circuit board, a sensor protection part, and a sensor main body housing; the internal sensor, the temperature balance block, and the circuit board are all arranged inside the sensor main body housing; wherein, the circuit board is arranged at the bottom of the sensor main body housing; the temperature balance block is arranged above the circuit board and is connected to the circuit board; the internal sensor is installed on the temperature balance block, and after passing through the temperature balance block, the internal sensor is connected to the circuit board; the sensor protection part is of a T-shaped structure, wherein the "-" part of the T-shaped structure is arranged on the outside of the sensor main body housing, and the "|" part of the T-shaped structure passes through the sensor main body housing and is connected to the internal sensor.

[0005] Preferably, the sensor protection component includes: a three-way connector, a double ferrule-type clamp and a sample gas inlet component; the three-way connector and the sample gas inlet component are both arranged on the outside of the sensor main body shell; the number of the sample gas inlet components is two, and the two sample gas inlet components are respectively fixedly mounted on the two ends of the three-way connector; one end of the double ferrule-type clamp is fixedly connected to the three-way connector, and the other end of the double ferrule-type clamp passes through the sensor main body shell and is connected to the internal sensor.

[0006] Preferably, the internal sensor includes: a sensor housing and a sensor body; one end of the sensor housing is fixed in the double-ferrule clamp, and the other end of the sensor housing is installed on the temperature balance block; the sensor body is arranged in the sensor housing, and the sensor body is connected to the circuit board after passing through the temperature balance block.

[0007] Preferably, one end of the sensor housing is fixed in the double-ferrule clamp by an interference fit connection, and the other end of the sensor housing is installed on the temperature balance block by an interference fit connection.

[0008] Preferably, a sample gas inlet hole is provided on the sample gas inlet piece, a three-way connector inner sample gas flow cavity is provided on the three-way connector, and an internal sensor inner sample gas flow cavity is provided on the sensor housing; wherein, the sample gas inlet hole is communicated with the three-way connector inner sample gas flow cavity, the three-way connector inner sample gas flow cavity is communicated with the internal sensor inner sample gas flow cavity, and the sensor body is arranged in the internal sensor inner sample gas flow cavity.

[0009] Preferably, an external cable interface is provided on the temperature balancing block, and the external cable interface is used to fix an external cable connection, and the external cable connection is connected to the circuit board.

[0010] Preferably, the number of internal sensors is at least two, and each of the internal sensors is provided with a corresponding sensor protection component; a temperature balancing pool is provided on the temperature balancing block, and the temperature balancing pool is used to balance the temperature between the components in the gas concentration sensor.

[0011] Preferably, a sensing system isolation cavity is formed between the circuit board and the sensor main body housing, and the sensing system isolation cavity is used for temperature conduction between components in the gas concentration sensor and heat dissipation of the circuit board.

[0012] Preferably, the three-way connector, the double ferrule clamp and the sample gas inlet are all made of polytetrafluoroethylene; the sensor housing is made of tempered glass; the sensor body is made of tempered glass, platinum, rhodium or gold; the temperature balance block is made of aluminum or copper; and the circuit board is made of resin.

[0013] Preferably, a reference sensor is also provided on the temperature balancing block, and the reference sensor passes through the temperature balancing block and is connected to the circuit board. The reference sensor is used to compensate for the signal of the internal sensor.

[0014] Compared with the closest prior art, the beneficial effects of the present invention are:

[0015] 1. The present invention installs a sensor protection component on the outside of the internal sensor, which avoids direct exposure of the internal sensor, can protect the internal sensor, enhance the overall impact resistance of the gas concentration sensor, and can reduce the impact of slight drops and impacts during construction and installation or vibrations in the working environment after installation on the gas concentration sensor, thereby ensuring the accuracy of gas concentration detection.

[0016] 2. The present invention sets the sensor protection part as a T-shaped structure, so that the sample gas can enter from both sides of the sensor protection part and gather at the center of the sensor protection part, thereby offsetting the impact of the gas. In this way, when encountering high-speed airflow, it can avoid the internal sensor from sensing a large number of target detection gas molecules in a short time, thereby reducing the occurrence of sensor false alarms and ensuring the accuracy of gas concentration detection.

[0017] 3. The setting of the temperature balance block of the present invention can balance the temperature between the components in the gas concentration sensor, thereby avoiding the symbiotic information interference and noise caused by the thermal convection effect of the sample gas, and ensuring the overall stability of the gas concentration sensor.

[0018] 4. The provision of the reference sensor of the present invention serves to compensate for the signal of the internal sensor, thereby achieving a more accurate measurement of the thermal conductivity of the gas medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the Hatch thermal conductivity principle gas concentration sensor of the present invention.

[0020] Reference numerals:

[0021] 1 - Three - way connector, 2 - Double - ferrule type tightener, 3 - Internal sensor, 4 - Sample gas inlet part, 5 - Sensor housing, 6 - Sensor body, 7 - Temperature balance block, 8 - Circuit board, 9 - Sample gas inlet hole, 10 - Sensor main body housing, 11 - Sample gas flow inner cavity in the three - way connector, 12 - Sample gas flow inner cavity in the internal sensor, 13 - External cable interface, 14 - Reference sensor, 15 - Temperature balance cell, 16 - Sensing system isolation cavity. Detailed implementation mode

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0023] Embodiment 1

[0024] As Figure 1 shown, the present invention provides a Hatch - type thermal conductivity principle gas concentration sensor, including: an internal sensor 3, a temperature balance block 7, a circuit board 8, a sensor protection part, and a sensor main body housing 10; the internal sensor 3, the temperature balance block 7, and the circuit board 8 are all arranged inside the sensor main body housing 10; wherein, the circuit board 8 is arranged at the bottom of the sensor main body housing 10; the temperature balance block 7 is arranged above the circuit board 8, and the temperature balance block 7 is connected to the circuit board 8; the internal sensor 3 is installed on the temperature balance block 7, and after passing through the temperature balance block 7, the internal sensor 3 is connected to the circuit board 8; the sensor protection part is of a T - shaped structure, wherein, the "-" part of the T - shaped structure is arranged outside the sensor main body housing 10, and the "|" part of the T - shaped structure passes through the sensor main body housing 10 and is connected to the internal sensor 3. Installing and setting a sensor protection part outside the internal sensor avoids the direct exposure of the internal sensor, can play a protective role for the internal sensor, enhances the overall impact resistance of the gas concentration sensor, and can reduce the influence on the gas concentration sensor caused by slight drops, impacts during the construction and installation process, or vibrations in the working environment after installation, thereby ensuring the accuracy of gas concentration detection. Setting the sensor protection part as a T - shaped structure enables the sample gas to enter from both sides of the sensor protection part and converge at the central position of the sensor protection part, so as to offset the impact of the gas on each other. In this way, when encountering a high - speed gas flow, the situation that the internal sensor senses a large number of target detection gas molecules in a short time can be avoided, and thus the occurrence of sensor false alarms is reduced, ensuring the accuracy of gas concentration detection. The setting of the temperature balance block can balance the temperature between the components inside the gas concentration sensor, which can avoid the co - generated information interference and noise caused by the thermal convection effect of the sample gas, and ensure the overall stability of the gas concentration sensor.

[0025] Preferably, the sensor protection component includes: a three-way connector 1, a double ferrule-type clamp 2 and a sample gas inlet component 4; the three-way connector 1 and the sample gas inlet component 4 are both arranged on the outside of the sensor main body housing 10; the number of the sample gas inlet components 4 is two, and the two sample gas inlet components 4 are respectively fixedly installed at both ends of the three-way connector 1; one end of the double ferrule-type clamp 2 is fixedly connected to the three-way connector 1, and the other end of the double ferrule-type clamp 2 passes through the sensor main body housing 10 and is connected to the internal sensor 3.

[0026] Preferably, the internal sensor 3 includes: a sensor housing 5 and a sensor body 6; one end of the sensor housing 5 is fixed in the double-ferrule clamp 2, and the other end of the sensor housing 5 is installed on the temperature balance block 7; the sensor body 6 is arranged in the sensor housing 5, and the sensor body 6 is connected to the circuit board 8 after passing through the temperature balance block 7.

[0027] Preferably, one end of the sensor housing 5 is fixed in the double-ferrule clamp 2 by an interference fit connection, and the other end of the sensor housing 5 is installed on the temperature balance block 7 by an interference fit connection.

[0028] Preferably, a sample gas inlet hole 9 is provided on the sample gas inlet piece 4, a three-way connector internal sample gas flow cavity 11 is provided on the three-way connector 1, and an internal sensor internal sample gas flow cavity 12 is provided on the sensor housing 5; wherein, the sample gas inlet hole 9 is connected with the three-way connector internal sample gas flow cavity 11, the three-way connector internal sample gas flow cavity 11 is connected with the internal sensor internal sample gas flow cavity 12, and the sensor body 6 is arranged in the internal sensor internal sample gas flow cavity 12.

[0029] Preferably, an external cable interface 13 is provided on the temperature balancing block 7 , and the external cable interface 13 is used to fix an external cable connection, and the external cable connection is connected to the circuit board 8 .

[0030] Preferably, the number of internal sensors 3 is at least two, and each internal sensor 3 is provided with a corresponding sensor protection member; a temperature balancing pool 15 is provided on the temperature balancing block 7, and the temperature balancing pool 15 is used to balance the temperature between the components in the gas concentration sensor. The provision of multiple internal sensors 3 can further ensure the accuracy of gas concentration detection.

[0031] Preferably, a sensing system isolation cavity 16 is formed between the circuit board 8 and the sensor main body housing 10, and the sensing system isolation cavity 16 is used for temperature conduction between the components in the gas concentration sensor and heat dissipation of the circuit board 8. The setting of the sensing system isolation cavity 16 is similar to the function of the temperature balance block 7, and both can balance the temperature between the components in the gas concentration sensor, thereby avoiding the symbiotic information interference and noise caused by the thermal convection effect of the sample gas, and ensuring the overall stability of the gas concentration sensor.

[0032] Preferably, the three-way connector 1, the double-ferrule clamp 2 and the sample gas inlet 4 are all made of polytetrafluoroethylene; the sensor housing 5 is made of tempered glass; the sensor body 6 is made of tempered glass, platinum, rhodium or gold; the temperature balance block 7 is made of aluminum or copper; and the circuit board 8 is made of resin.

[0033] Preferably, a reference sensor 14 is also provided on the temperature balance block 7, and the reference sensor 14 passes through the temperature balance block 7 and is connected to the circuit board 8. The reference sensor 14 is used to compensate the signal of the internal sensor 3, thereby achieving a more accurate measurement of the thermal conductivity of the gas medium.

[0034] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In addition, the terms "above" and "below" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "above" and "below" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A Hatch type thermal conductivity principle gas concentration sensor, characterized in that: Comprising: Internal sensor (3), temperature balance block (7), circuit board (8), sensor protection member and sensor main body housing (10); The internal sensor (3), the temperature balance block (7) and the circuit board (8) are all arranged inside the sensor main body housing (10); Wherein, the circuit board (8) is arranged at the bottom of the sensor main body housing (10); The temperature balance block (7) is arranged above the circuit board (8), and the temperature balance block (7) is connected to the circuit board (8); The internal sensor (3) is installed on the temperature balance block (7), and the internal sensor (3) is connected to the circuit board (8) after passing through the temperature balance block (7); The sensor protection member is of a T-shaped structure. Among them, the "one" part of the T-shaped structure is arranged outside the sensor main body housing (10), and the "vertical" part of the T-shaped structure passes through the sensor main body housing (10) and is connected to the internal sensor (3).

2. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 1, characterized in that: The sensor protection member includes: a tee joint (1), a double ferrule type tightening band (2) and a sample gas inlet member (4); The tee joint (1) and the sample gas inlet member (4) are both arranged outside the sensor main body housing (10); The number of the sample gas inlet members (4) is two, and the two sample gas inlet members (4) are respectively fixedly installed at both ends of the tee joint (1); One end of the double ferrule type tightening band (2) is fixedly connected to the tee joint (1), and the other end of the double ferrule type tightening band (2) passes through the sensor main body housing (10) and is connected to the internal sensor (3).

3. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 2, characterized in that: The internal sensor (3) includes: a sensor housing (5) and a sensor body (6); One end of the sensor housing (5) is fixed inside the double ferrule type tightening band (2), and the other end of the sensor housing (5) is installed on the temperature balance block (7); The sensor body (6) is arranged inside the sensor housing (5), and the sensor body (6) is connected to the circuit board (8) after passing through the temperature balance block (7); 4. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 3, characterized in that: One end of the sensor housing (5) is fixed inside the double ferrule type tightening band (2) by an interference fit connection method, and the other end of the sensor housing (5) is installed on the temperature balance block (7) by an interference fit connection method.

5. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 3, characterized in that: The sample gas inlet member (4) is provided with a sample gas inlet hole (9), the tee joint (1) is provided with a sample gas flow through inner cavity (11) of the tee joint, and the sensor housing (5) is provided with an inner sample gas flow through cavity (12) of the internal sensor; Wherein, the sample gas inlet hole (9) is communicated with the sample gas flow through inner cavity (11) of the tee joint, the sample gas flow through inner cavity (11) of the tee joint is communicated with the inner sample gas flow through cavity (12) of the internal sensor, and the sensor body (6) is arranged inside the inner sample gas flow through cavity (12) of the internal sensor.

6. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 1, characterized in that: The temperature balancing block (7) is provided with an external cable interface (13), the external cable interface (13) being used to fix an external cable connection, and the external cable connection is connected to the circuit board (8).

7. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 1, characterized in that: The number of the internal sensors (3) is at least two, and each of the internal sensors (3) is provided with a corresponding sensor protection element; The temperature balancing block (7) is provided with a temperature balancing pool (15), and the temperature balancing pool (15) is used to balance the temperatures among various components in the gas concentration sensor.

8. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 1, characterized in that: A sensing system isolation cavity (16) is formed between the circuit board (8) and the sensor main body housing (10), and the sensing system isolation cavity (16) is used for temperature conduction between components in the gas concentration sensor and heat dissipation of the circuit board (8).

9. The Hatch thermal conductivity principle gas concentration sensor as claimed in claim 3, characterized in that: The three-way connector (1), the double-ferrule clamp (2) and the sample gas inlet (4) are all made of polytetrafluoroethylene; The sensor housing (5) is made of tempered glass; The sensor body (6) is made of tempered glass, platinum, rhodium or gold; The temperature balance block (7) is made of aluminum or copper; The circuit board (8) is made of resin.

10. The Hatch thermal conductivity principle gas concentration sensor according to any one of claims 1 to 9, characterized in that: A reference sensor (14) is also provided on the temperature balancing block (7). The reference sensor (14) passes through the temperature balancing block (7) and is connected to the circuit board (8). The reference sensor (14) is used to compensate for the signal of the internal sensor (3).

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