Low-power-consumption methane detection device
By combining low-power semiconductor and catalytic combustion methane sensors, the shortcomings in existing methane sensors in terms of sensitivity, measurement accuracy and power consumption are solved, and efficient and reliable methane detection is achieved.
Patent Information
- Application Number
- CN202422032204.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-08-21
AI Technical Summary
Existing methane sensors have shortcomings in sensitivity, measurement accuracy and power consumption, especially semiconductor sensors have weak anti-interference capabilities, high power consumption of catalytic combustion sensors, and infrared absorption sensors are susceptible to dust and humidity.
A low-power semiconductor methane sensor is used as a normal detection "switch", combined with a catalytic combustion methane sensor, semiconductor sensor monitoring at low concentrations, and catalytic combustion sensor starting at high concentrations, achieving accurate measurement and reducing the power consumption of catalytic combustion sensor.
It realizes low-power methane detection with high sensitivity, accurate measurement and wide application range, improves the reliability and detection efficiency of the sensor, and reduces the power consumption of the catalytic combustion sensor.
Smart Images
Figure CN223078231U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of natural gas leakage, especially to the field of methane detection, and specifically refers to a low-power methane detection device. Background Art
[0002] With the continuous popularization of natural gas in residential life, accidents such as explosion, asphyxiation and poisoning caused by natural gas leakage or improper use have attracted people's high attention. In addition, gas explosion is also an important hidden danger in energy production safety problems such as gas drilling and coal mining. In public and industrial environments, timely detection of flammable gases below the lower explosion limit is crucial for the safety of national and residents' lives and property. Methane is the main component of natural gas and gas. Monitoring the content of methane in the air through a methane sensor has become the main monitoring method for natural gas leakage and gas explosion. Methane sensors include semiconductor type, optical interference, catalytic combustion and infrared absorption type. The semiconductor type methane sensor has advantages such as high sensitivity, fast response speed and low power consumption, but its anti-interference ability is weak; the catalytic combustion type methane sensor can accurately measure low-concentration methane, usually with a measurable range of 0-4% vol, and has a fast response speed, but relatively high power consumption; the optical interference type methane sensor has a long service life and small measurement error, but is also easily affected by the interference of other gases; the infrared absorption type methane sensor also has the characteristics of high sensitivity and accurate measurement, but is easily affected by dust and humidity, resulting in large errors, and the cost is relatively high compared with semiconductor and catalytic combustion type sensors. Summary of the Utility Model
[0003] The purpose of the utility model is to overcome the above-mentioned disadvantages of the prior art, and provide a low-power methane detection device that meets the requirements of high sensitivity, accurate measurement and relatively wide application range.
[0004] In order to achieve the above purpose, the low-power methane detection device of the utility model is as follows:
[0005] The low-power methane detection device, its main feature is that the device includes a first sensor, and the first sensor includes a heating resistor RH, a sensitive resistor RS, and a load resistor RL. The sensitive resistor RS is connected to the load resistor RL. The other end of the load resistor RS is connected to the collector of a triode. The other end of the heating resistor RH is connected to the collector of another triode. The triodes are respectively connected to the heating resistor RH and the sensitive resistor RS, and the load resistor RL outputs a voltage.
[0006] Preferably, the device further includes a second sensor, which is connected to the first sensor. The second sensor includes a first fixed resistor R1, a second fixed resistor R2, a catalytic combustion type sensor detection element D, and a compensation element C. The first fixed resistor R1 and the compensation element C are respectively connected to the supply voltage. The first fixed resistor R1 is connected in series with the second fixed resistor R2. The detection element D is connected in series with the compensation element C. The second fixed resistor R2 and the catalytic combustion type sensor detection element D are both grounded, and the voltage is output between the center nodes of the series resistors.
[0007] Preferably, the first sensor has a built-in heating end, and the heating resistor RH is heated at a certain heating period, and a pulse voltage is applied across the sensitive resistor RS and the load resistor RL.
[0008] Preferably, the first sensor is a low-power semiconductor type methane sensor.
[0009] Preferably, the second sensor is a catalytic combustion type methane sensor.
[0010] The low-power methane detection device of the present utility model combines the advantages of semiconductor type and catalytic combustion type methane sensors. The low-power semiconductor type methane sensor is used as the "switch" for normal methane detection. When the methane concentration is <1% vol, the semiconductor type methane sensor is in a continuous "monitoring" state. When the methane concentration exceeds 1% vol, the catalytic combustion type methane sensor is activated to accurately measure the excess concentration of methane, while reducing the power consumption of the catalytic combustion type methane sensor, ensuring the long-term stable operation of the catalytic combustion type sensor, as well as the accuracy of high-concentration methane detection, and improving the reliability of methane sensor detection. Description of the Drawings
[0011] Figure 1 It is the working flowchart of the low-power methane detection device of the present utility model.
[0012] Figure 2 It is the circuit schematic diagram of the low-power methane detection device of the present utility model.
[0013] Figure 3 It is the structural schematic diagram of the low-power methane detection device of the present utility model. Detailed Embodiments
[0014] In order to be able to more clearly describe the technical content of the present utility model, the following will be further described in conjunction with specific embodiments.
[0015] The low-power methane detection device of the present utility model, wherein the device includes a first sensor, and the first sensor includes a heating resistor RH, a sensitive resistor RS, and a load resistor RL. The sensitive resistor RS is connected to the load resistor RL. The other end of the load resistor RS is connected to the collector of a triode. The other end of the heating resistor RH is connected to the collector of another triode. The triodes are respectively connected to the heating resistor RH and the sensitive resistor RS. The load resistor RL outputs a voltage.
[0016] As a preferred embodiment of the present utility model, the device further includes a second sensor. The second sensor is connected to the first sensor. The second sensor includes a first fixed resistor R1, a second fixed resistor R2, a catalytic combustion type sensor detection element D, and a compensation element C. The first fixed resistor R1 and the compensation element C are respectively connected to the supply voltage. The first fixed resistor R1 is connected in series with the second fixed resistor R2. The detection element D is connected in series with the compensation element C. The second fixed resistor R2 and the catalytic combustion type sensor detection element D are both grounded. A voltage is output between the central nodes of the series resistors.
[0017] As a preferred embodiment of the present utility model, the first sensor has a built-in heating end, and the heating resistor RH is heated at a certain heating period. A pulsed voltage is applied across the sensitive resistor RS and the load resistor RL.
[0018] As a preferred embodiment of the present utility model, the first sensor is a low-power semiconductor type methane sensor.
[0019] As a preferred embodiment of the present utility model, the second sensor is a catalytic combustion type methane sensor.
[0020] As Figure 1 shown, as a preferred embodiment of the present utility model, the device includes a first sensor and a second sensor. The first sensor is a semiconductor type methane sensor, and the second sensor is a catalytic combustion type methane sensor. When the device first performs methane concentration detection in the initial state, the first sensor realizes low-power methane concentration detection in a manner of pulsed periodic voltage modulation. When VSEN_1 does not exceed the set concentration of the first methane sensor, the first sensor maintains a low-power working mode and continuously monitors, and displays a normal state; otherwise, the second sensor is activated. When VSEN_2 does not exceed the set concentration of the second methane sensor, the first sensor remains activated and the second sensor stops working. When the methane concentration exceeds the set concentration of the second sensor, the second sensor remains activated and the first sensor stops working. At the same time, the alarm device is activated and the abnormal methane concentration value is displayed.
[0021] As Figure 2As shown, the circuit schematic diagram of the low-power methane detection device of the present utility model includes a first sensor. The first sensor is a low-power semiconductor methane sensor, which includes a heating resistor RH, a sensitive resistor RS, and a load resistor RL. The sensitive resistor RS is connected to the load resistor RL, and the other end of the load resistor R S is connected to the collector of a triode, and the other end of the heating resistor R H is connected to the collector of another triode. The triodes are respectively connected to RH and RS, which can control the voltage to turn on and off, performing a pulsed periodic voltage modulation function. The load resistor RL outputs a voltage. Resistors R101, R102, R103, and R104 form a voltage divider to reduce the high voltage to a level acceptable to the MCU.
[0022] The device further includes a second sensor, which is connected to the first sensor. The second sensor includes a first fixed resistor R1, a second fixed resistor R2, a catalytic combustion sensor detection element D, and a compensation element C. The first fixed resistor R1 and the compensation element C are respectively connected to the power supply voltage. The first fixed resistor R1 is connected in series with the second fixed resistor R2. The catalytic combustion sensor detection element D is connected in series with the compensation element C. The second fixed resistor R2 and the catalytic combustion sensor detection element D are both grounded, and a voltage is output between the center nodes of the series resistors. The second sensor is a bridge circuit, and the bridge has four arms: a fixed resistor R1, a fixed resistor R2, a detection element D, and a compensation element C. The catalytic combustion sensor includes two arms: a detection element D and a compensation element C.
[0023] The device further includes a first sensor heating power supply VH, a detection power supply VC, a second sensor power supply VSEN2, and a resistor R110 for overvoltage protection.
[0024] According to the feedback of the concentration detection mechanism, in the initial state, the first sensor is activated to detect whether the concentration exceeds the set threshold of the first sensor. If the set concentration is not exceeded, the first sensor continues to monitor, the second sensor does not work, and the normal state is displayed; if the set concentration is exceeded, the second sensor is activated. According to the concentration detection feedback mechanism, if the set concentration is not exceeded, the first sensor is activated and the second sensor stops working; if the set concentration is exceeded, the second sensor continues to monitor and the alarm device and concentration display are activated.
[0025] The first sensor has a built-in heating end, and a heating resistor RH is powered and heated with a certain pulsed voltage VH. A pulsed voltage VC is applied across both ends of the sensitive resistor RS and the load resistor RL. When methane gas is encountered, the sensitive resistor RS decreases and the load resistor RL increases. The output voltage VSEN_1 of the load resistor is proportional to the methane concentration.
[0026] When the second sensor encounters methane gas, its resistance increases and the output voltage of the bridge changes. The output voltage is connected to an operational amplifier. Resistors R105, R106, R107, R108, and R109 form the feedback and gain of the operational amplifier, and the amplified output voltage signal VSEN_2 is proportional to the methane concentration.
[0027] In the initial state, when methane concentration detection is first performed, the output voltage VSEN_1 of the first sensor is an analog signal, which is converted into a concentration ADC by the single-chip microcomputer MCU unit. It is judged whether the ADC value exceeds the first threshold ADC. If it is less than the first threshold ADC, the working state of the first sensor is maintained, and SEN OUT is output to display the concentration. If it is greater than or equal to the first threshold ADC, VH SWICH and VC SWICH of the first sensor are controlled to be in the off state, and VSEN2 SWICH is turned on.
[0028] The output voltage VSEN_2 of the second sensor is an analog signal, which is converted into a concentration ADC by the single-chip microcomputer MCU unit. It is judged whether the ADC value exceeds the second threshold ADC. If it is less than the second threshold ADC, VH SWICH and VC SWICH of the first sensor are controlled to be in the on state, and VSEN2 SWICH is turned off. If it is greater than or equal to the second threshold ADC, VSEN2 SWICH remains in the on state, the alarm device is started, and SEN OUT is output to display the concentration.
[0029] In the specific implementation manner of the present utility model, a low-power methane detection device is provided, which can realize the detection of a low-power methane sensor and improve the reliability of sensor detection at the same time. The methane detection device of the present utility model combines the characteristics of a semiconductor-type and a catalytic combustion-type methane sensor. A low-power semiconductor-type methane sensor is used as the "switch" for normal methane gas detection. When the methane concentration is <1% vol, the semiconductor-type methane sensor is in the "monitoring" state. When the methane concentration exceeds 1% vol, the catalytic combustion-type methane sensor is started, and the excessive concentration of methane can be measured quickly and accurately, greatly reducing the power consumption of the catalytic combustion-type methane sensor. The low-power methane detection device of the present utility model has a low manufacturing cost, can accurately and efficiently detect the methane concentration, and provides an effective and safe detection means for natural gas pipelines and coal mine surveys.
[0030] As Figure 3As shown, the first sensor is a low-power semiconductor methane sensor. The built-in heating end of the first sensor is powered by a 2V pulse to heat the heating resistor R H at a certain heating cycle. Usually, one heating cycle can be 5 seconds (or 10 seconds), with 0.1 second of heating and the remaining 4.9 seconds (or 9.9 seconds) without heating. While applying Pulse Signal 1, a pulse voltage of 2V is also applied across the sensor's sensitive resistor R S and the load resistor R L . When Pulse Signal 1 heats for 0.1 second, the application time of Pulse Signal 2 needs to be < 0.1 second. At this time, the voltage V RL output to the load resistor is measured, and then it remains at 0V until the next pulse cycle arrives. The voltage V RL output across the load resistor is proportional to the methane concentration. The ADC output value reflects the change in the voltage output of the load resistor. The higher the methane concentration, the larger the ADC value.
[0031] The second sensor consists of four arms of a bridge formed by the first fixed resistor R1, the second fixed resistor R2, the catalytic combustion sensor detection element D, and the compensation element C. The compensation element C plays a role in reference and temperature compensation. It is powered by 3V. When the detection element D encounters methane gas, its resistance increases, and the output voltage between the series center node of the first fixed resistor R1 and the second fixed resistor R2 and the series center node of the detection element D and the compensation element C changes. The output voltage is proportional to the methane concentration. The ADC output value reflects the change in the bridge output voltage. The higher the methane concentration, the faster the rising rate of the ADC and the larger the value it reaches.
[0032] The working principle of the low-power methane detection device is as follows:
[0033] In the initial state, for the first methane concentration detection, the first sensor is activated:
[0034] For the first methane detection, the first sensor is activated and the second sensor stops working:
[0035] ① The detection signal of the first sensor passes through the ADC analog-to-digital converter. The ADC output value reflects the change in the load voltage of the sensitive resistor. The higher the methane concentration, the larger the ADC value.
[0036] ② When the ADC does not reach the set threshold, the first sensor continuously monitors the low-concentration methane content, and the second sensor remains in the stopped working state. Usually, the set threshold methane concentration can be 1% vol.
[0037] ③ When it is detected that the ADC value reaches the set threshold, indicating a relatively high methane concentration, the first sensor stops working, and at the same time, the second sensor is activated.
[0038] ④ The detection signal of the second sensor passes through the ADC analog-to-digital converter, and it is judged again whether the ADC output value reaches the threshold. When the set threshold is reached, the methane concentration value detected by the second sensor is finally displayed and the alarm device is started simultaneously. When the set threshold is not reached, the first sensor is started to continuously monitor low-concentration methane, and the second sensor stops working.
[0039] For the specific implementation solution of this embodiment, reference can be made to the relevant descriptions in the above embodiments, which will not be elaborated here.
[0040] It can be understood that the same or similar parts in the above embodiments can be referred to each other, and the content not described in detail in some embodiments can be referred to the same or similar content in other embodiments.
[0041] It should be noted that in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" refers to at least two.
[0042] In the description of this specification, the description with reference to the terms "an embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0043] The low-power methane detection device of the present invention combines the advantages of semiconductor and catalytic combustion methane sensors. The low-power semiconductor methane sensor is used as the "switch" for normal methane detection. When the methane concentration is <1% vol, the semiconductor methane sensor is in a continuous "monitoring" state. When the methane concentration exceeds 1% vol, the catalytic combustion methane sensor is started to accurately measure the excess concentration of methane, while reducing the power consumption of the catalytic combustion methane sensor to ensure the long-term stable operation of the catalytic combustion sensor and improve the reliability of methane sensor detection.
[0044] In this specification, the present invention has been described with reference to its specific embodiments. However, it is obvious that various modifications and transformations can still be made without departing from the spirit and scope of the present invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive.
Claims
1. A low-power methane detection device, characterized in that, The device described includes a first sensor. The first sensor includes a heating resistor RH, a sensitive resistor RS, and a load resistor RL. The sensitive resistor RS is connected to the load resistor RL. The other end of the load resistor RS is connected to the collector of a triode. The other end of the heating resistor RH is connected to the collector of another triode. The triodes are respectively connected to the heating resistor RH and the sensitive resistor RS. The load resistor RL outputs a voltage.
2. The low-power methane detection device according to claim 1, wherein The device further includes a second sensor. The second sensor is connected to the first sensor. The second sensor includes a first fixed resistor R1, a second fixed resistor R2, a catalytic combustion type sensor detection element D, and a compensation element C. The first fixed resistor R1 and the compensation element C are respectively connected to the supply voltage. The first fixed resistor R1 is in series with the second fixed resistor R2. The detection element D is in series with the compensation element C. The second fixed resistor R2 and the catalytic combustion type sensor detection element D are both grounded. A voltage is output between the center nodes of the series resistors.
3. The low-power methane detection device according to claim 1, characterized in that, The first sensor has a built-in heating end, and the heating resistor RH is heated with a certain heating cycle. Pulse voltages are applied across both ends of the sensitive resistor RS and the load resistor RL.
4. The low-power methane detection device according to claim 1, characterized in that, The first sensor is a low-power semiconductor type methane sensor.
5. The low-power methane detection device according to claim 2, characterized in that, The second sensor is a catalytic combustion type methane sensor.