Gas detector based on TDLAS technology and CAT1 network communication

Abstract

The utility model discloses a gas detector based on TDLAS (tunable diode laser absorption spectroscopy) technology and CAT1 network communication, which belongs to the technical field of gas monitoring and comprises a power supply module, a gas detection module, an MCU (microprogrammed control unit) control module, an alarm output module, an output control module and a data transmission module. According to the gas detector, combustible gas or combustible steam in the environment is monitored, a detection signal is transmitted to the MCU control module, after the MCU control module receives the detection signal, the concentration of the combustible gas is calculated and compared with a preset threshold value, and when the comparison result exceeds the threshold value, related personnel are notified in a telephone, short message reminding mode and the like; meanwhile, an alarm instruction is sent to the alarm output unit to send out an alarm signal, and the control output unit is indicated to cut off the gas valve and open the exhaust fan, so that early prevention of excessive combustible gas concentration is realized, and safety accidents such as fire and explosion are reduced; the system has the advantages of good stability, fast data transmission, small size, low power consumption, low calorific value, low maintenance cost and convenience in popularization.

Description

TECHNICAL FIELD

[0001] The utility model belongs to gas monitoring technical field, specifically a kind of gas detector based on TDLAS technique and CAT1 network communication. BACKGROUND

[0002] The existing combustible gas detector mainly has catalytic combustion type, laser type, infrared absorption type and semiconductor type, wherein the failure rate of catalytic combustion type combustible gas detector is higher, catalytic combustion type and infrared absorption type have advantages and disadvantages respectively, and semiconductor type is relatively general;The environmental adaptability of laser type combustible gas detector is overall superior, and the wavelength stability of laser can always ensure the uniqueness of being absorbed by specific gas molecules, to achieve one-to-one correspondence of fingerprinting. At present, laser type sensor combustible gas detector is gradually realizing domestic self-controlling, and cost is further reduced, which will accelerate the pace of application into thousands of households, solve the problems of field application and maintenance in essence, and improve the urban gas safety guarantee capability. The existing laser type gas detector can only issue local audible and visual alarm signals when detecting overproof combustible gas, to remind people to take corresponding measures, and if no one is at home, corresponding measures cannot be taken in time, which may lead to safety accidents. SUMMARY

[0003] The utility model solves the technical problems of high failure rate, high heat generation, high maintenance cost, short service life and unstable data transmission of existing catalytic combustion type and semiconductor type detectors, and provides a gas detector based on TDLAS technique and CAT1 network communication, which monitors combustible gas existing in surrounding environment through gas sensor, issues local audible and visual alarm signals when detecting overproof combustible gas concentration, informs relevant personnel through 4G communication module, simultaneously cuts off gas valve and opens exhaust fan, realizes local alarm and remote reminding cooperation, and automatically takes safety measures to reduce the occurrence of fire, explosion and other safety accidents.

[0004] To solve the above technical problems, the utility model provides a gas detector based on TDLAS technique and CAT1 network communication, which is integrated and includes:

[0005] A power module is responsible for voltage conversion, realizes wide voltage input and working voltage output, and is used for providing stable power supply voltage VCC and working voltage VDD for the gas detector;

[0006] A gas detection module is used for real-time monitoring of combustible gas concentration in environment, and transmits detection signal to MCU control module for processing;

[0007] MCU control module, connected with the gas detection module, for collecting detection signals transmitted by the gas detection module, calculating the concentration of combustible gas according to the collected detection signals and comparing the calculated concentration with a preset threshold value of the concentration of combustible gas, transmitting the comparison result to an external device through a data transmission module and sending an alarm signal to an alarm output unit and a control signal to a control output unit when the comparison result exceeds the threshold value;

[0008] The alarm output module is connected with the MCU control module and the alarm device, and is used for controlling the alarm device to send an alarm signal according to the instruction of the MCU control module.

[0009] The output control module is connected with the MCU control module, the gas valve and the exhaust fan, and is used for cutting off the gas valve and opening the exhaust fan according to the instruction of the MCU control module.

[0010] The data transmission module is connected with the MCU control module, and is used for transmitting alarm data to a user through a 4G communication mode according to the instruction of the MCU control module.

[0011] Further, the MCU control module comprises an MCU chip U2, and the MCU chip U2 further has a pin CH4_RX, a pin CH4_TX, a pin CH4_RST, a pin 4G_ON, a pin MCU_4G_RST, a pin MCU_TX, a pin MUC_RX, a pin MCU_4G_EN, a pin BOOT0 and a pin VCAP, wherein the pin BOOT0 is connected with one end of a resistor R9 and one end of a resistor R10 respectively, the other end of the resistor R9 is connected with a working voltage VDD, and the other end of the resistor R10 is grounded; the pin VCAP is connected with one end of a capacitor C61 and one end of a capacitor C62 respectively, and the other ends of the capacitor C61 and the capacitor C62 are connected and then grounded.

[0012] Further, the gas detection module comprises a gas sensor J6, a power supply pin V of the gas sensor J6 is connected with one end of a resistor R27, one end of a capacitor C37 and one end of a capacitor C38 respectively, the other end of the resistor R27 is connected with a power supply voltage VCC, and the other ends of the capacitor C37 and the capacitor C38 are connected and then grounded; a transmission pin T of the gas sensor J6 is connected with an S_RX port of a serial port, the S_RX port of the serial port is connected with one end of a resistor R28, the other end of the resistor R28 is connected with a terminal S-R and a pin CH4_RX of an MCU chip U2 respectively; a transmission pin R of the gas sensor J6 is connected with an S_TX port of the serial port, the S_TX port of the serial port is connected with a terminal S-T, one end of a resistor R29 and one end of a capacitor C40 respectively, the other end of the resistor R29 is connected with a pin CH4_TX of the MCU chip U2, and the other end of the capacitor C40 is connected with the other ends of the capacitor C37 and the capacitor C38 and then grounded; the pin CH4_RX of the MCU chip U2 is further connected with one end of a capacitor C39, and the other end of the capacitor C39 is grounded.

[0013] Furthermore, the data transmission module includes:

[0014] Energy storage unit: used for decoupling filtering and energy storage of the data transmission module;

[0015] Power supply unit: used to turn off or on the power supply of the data transmission module and provide a regulated power supply;

[0016] Data transmission unit: used to export the alarm data transmitted by the MCU controller through the USB interface or convert it into a radio frequency signal and transmit it through the radio frequency antenna.

[0017] Furthermore, the energy storage unit has a terminal VBAT, which is respectively connected to the resistor R50, the capacitor C51, the capacitor C52, the capacitor C53, one end of the diode D10 and the positive electrode of the polarity capacitor C47, the other end of the resistor R50 is connected to the operating voltage VCC, and the other ends of the capacitors C51, C52, C53 and the diode D10 are connected together with the negative electrode of the polarity capacitor C47 and grounded.

[0018] Furthermore, the power supply unit includes a power management chip U3A, and the pin VBAT_1 and pin VBAT_2 of the power management chip U3A are connected to the drain of the field effect transistor Q11, and the gate of the field effect transistor Q11 is respectively connected to the pin 4G_ON of the MCU chip U2 and one end of the resistor R51. The other end of the resistor R51 is connected to the source of the field effect transistor Q11 and connected to the operating voltage VCC; the power management chip U3A outputs a 1.8V regulated power supply through the pin VDD_EXT, and the pin VDD_EXT is also connected to one end of the capacitor C46 and the capacitor C48 respectively, and the other ends of the capacitor C46 and the capacitor C48 are grounded.

[0019] Furthermore, the data transmission unit includes a communication chip U3B, which has a SIM socket, a 4G communication unit and a radio frequency antenna interface CON1; the SIM socket is used to insert a SIM card U8 to realize network user access authentication; the 4G communication unit is used to realize 4G communication; and the radio frequency antenna interface CON1 is used to install a radio frequency antenna.

[0020] Furthermore, the 4G communication unit has pins 4G_RX, 4G_TX, 4G_STATUS, 4G_POWER and 4G_RST for realizing 4G communication, wherein pin 4G_RX is respectively connected to resistor R36, one end of capacitor C59 and the collector of transistor Q7, the other end of resistor R36 and capacitor C59 is connected to a regulated power supply, the emitter of transistor Q7 is connected to pin MCU_TX of MCU chip U2, the base of transistor Q7 is respectively connected to one end of resistor R39 and capacitor R60, and the other end of resistor R39 and capacitor C60 is connected to a regulated power supply; pin 4G_TX of communication chip U3B is connected to the emitter of transistor Q6, the collector of transistor Q6 is respectively connected to one end of resistor R42 and pin MCU_RX of MCU chip U2, the other end of resistor R42 is connected to operating voltage VDD, the base of transistor Q6 is respectively connected to the emitter of transistor Q6, the collector of transistor Q6 is respectively connected to one end of resistor R42 and pin MCU_RX of MCU chip U2, the other end of resistor R42 is connected to operating voltage VDD, and the base of transistor Q6 is respectively connected to the working voltage VDD. It is connected to one end of the resistor R44 and the capacitor C42, and the other ends of the resistor R44 and the capacitor C42 are connected to a regulated power supply; the pin 4G_POWER of the communication chip U3B is respectively connected to one end of the capacitor C41 and the collector of the transistor Q10, the emitter of the capacitor C41 and the transistor Q10 is grounded, the base of the transistor Q10 is respectively connected to one end of the resistor R34 and the resistor R41, the other end of the resistor R34 is connected to the pin MCU_4G_EN of the MCU chip U2, and the other end of the resistor R41 is grounded; the pin 4G_RST of the communication chip U3B is respectively connected to one end of the capacitor C43 and the collector of the transistor Q5, the emitter of the capacitor C43 and the transistor Q5 is grounded, the base of the transistor Q5 is respectively connected to one end of the resistor R48 and the resistor R45, the other end of the resistor R48 is connected to the pin MCU_4G_RST of the MCU chip U2, and the other end of the resistor R45 is grounded.

[0021] Furthermore, the SIM socket has a pin SIM_VDD, a pin SIM_DATA, a pin SIM_CLK and a pin SIM_RST, and the SIM card U8 has a pin S_RST, a pin S_CLK, a pin S_DATA and a pin VDD, wherein the pin S_RST is respectively connected to the resistor R54 and the capacitor C58, the resistor R54 is connected to the pin SIM_RST of the SIM socket, and the capacitor C58 is grounded; the pin S_CLK is respectively connected to the resistor R52 and the capacitor C57, the resistor R52 is connected to the pin SIM_CLK of the SIM socket, and the capacitor C57 is grounded; the pin S_DATA is respectively connected to the resistor R53, the resistor R55 and the capacitor C56, the resistor R53 is connected to the pin SIM_DATA of the SIM socket, the capacitor C56 is grounded, the resistor R55 is respectively connected to the pin SIM_VDD of the SIM socket, the capacitor C55 and the pin VDD of the SIM card U8, and the capacitor C55 is grounded.

[0022] Furthermore, the communication chip U3B also has a USB port for connecting to a USB data cable for data transmission.

[0023] The gas detector of the present invention monitors the combustible gas or combustible vapor in the surrounding environment through the gas detection module and transmits the detection signal to the MCU control module. After receiving the detection signal transmitted by the gas detection module, the MCU control module calculates the combustible gas concentration and compares it with the preset combustible gas concentration threshold. If the comparison result exceeds the threshold, the comparison result is notified to relevant personnel through the 4G communication module of the data transmission module by telephone, SMS reminder, etc., and at the same time, an alarm signal is sent to the alarm output unit to emit a vibration or sound and light alarm, prompting on-site personnel to take corresponding measures and send a control signal to the control output unit to cut off the gas valve and turn on the exhaust fan, so as to achieve early prevention of excessive combustible gas concentration and reduce the occurrence of safety accidents such as fire and explosion. It only detects methane gas and is not interfered by other gases, so it has good stability. It adopts 4G communication, so data transmission is faster and more stable. Multiple modules are integrated into one, with a small size, suitable for a variety of installation places. It has low power consumption, low heat generation, long service life, low maintenance cost, and is easy to popularize. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a system block diagram of a gas detector based on TDLAS technology and CAT1 network communication in this utility model;

[0025] Figure 2 This is the circuit schematic diagram of the MCU control module;

[0026] Figure 3 This is the circuit schematic diagram of the gas detection monitoring module;

[0027] Figure 4 This is the circuit schematic diagram of the energy storage unit in the data transmission module;

[0028] Figure 5 This is the circuit schematic diagram of the power supply unit in the data transmission module;

[0029] Figure 6 It is a circuit schematic diagram of the data transmission unit in the data transmission module;

[0030] Figure 7 This is the circuit schematic diagram of the connection between the SIM card and the SIM socket. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the “connection” described in this embodiment refers to an electrical connection or a communication connection.

[0032] This embodiment provides a gas detector based on TDLAS technology and CAT1 network communication, such as Figure 1 As shown, it includes integrated:

[0033] The power supply module is responsible for voltage conversion, realizing wide voltage input and operating voltage output, and is used to provide a stable power supply voltage VCC and operating voltage VDD for the gas detector;

[0034] Gas detection module; used for real-time monitoring of combustible gas concentration in the environment and transmits the detection signal to the MCU control module for processing;

[0035] The MCU control module is connected to the gas detection module and is used to collect the detection signal transmitted by the gas detection module, calculate the combustible gas concentration based on the collected detection signal, and compare it with a preset combustible gas concentration threshold. If the comparison result exceeds the threshold, the comparison result is transmitted to the external device through the data transmission module, and an alarm signal is sent to the alarm output unit and a control signal is sent to the control output unit.

[0036] The alarm output module is connected to the MCU control module and the alarm device, and is used to control the alarm device to send an alarm signal according to the instructions of the MCU control module;

[0037] Output control module: connected to the MCU control module, gas valve and exhaust fan, used to cut off the gas valve and open the exhaust fan according to the instructions of the MCU control module;

[0038] Data transmission module: connected to the MCU control module, used to transmit alarm data to the user through 4G communication according to the instructions of the MCU control module.

[0039] like Figure 2As shown, the MCU control module includes an MCU chip U2, and the MCU chip U2 has pins 4G_ON, LED_R, LED_Y, LED_G, CH4_RST, U_TX, U_RX, SV, RELAY, BEEP, KEY, MCU_4G_RST, MCU_TX, MUC_RX, MUC_4G_STATUS, AD1, CH4_TX, CH4_RX, SWDIO, SWCLK, MCU_4G_EN, OSC_IN, and O SC_OUT, pin BOOT0, pin NRST and pin VCAP; pin BOOT0 is connected to one end of resistor R9 and one end of resistor R10 respectively, the other end of resistor R9 is connected to the operating voltage VDD, and the other end of resistor R10 is grounded. Resistors R9 and R10 are used to configure the startup mode of MCU chip U2; pin VCAP is connected to one end of capacitor C61 and one end of capacitor C62 respectively, the other ends of capacitor C61 and capacitor C62 are connected and then grounded, capacitor C61 and capacitor C62 are connected in parallel to decouple pin VACP; pins LED_R, LED_Y and LED_G are connected to the onboard LED fault indicator.

[0040] like Figure 3 As shown, the gas detection module includes a gas sensor J6, the power pin V of the gas sensor J6 is respectively connected to one end of the resistor R27, the capacitor C37 and the capacitor C38, the other end of the resistor R27 is connected to the power supply voltage VCC, the other ends of the capacitors C37 and C38 are connected and grounded, and the resistor R27, the capacitor C37 and the capacitor C38 are used to decouple and filter the gas sensor J6; the sending pin T of the gas sensor J6 is connected to the S_RX port of the serial port, the S_RX port of the serial port is connected to one end of the resistor R28, and the other end of the resistor R28 is respectively connected to the terminal SR and the MCU chip U2. Pin CH4_RX; the sending pin R of the gas sensor J6 is connected to the S_TX port of the serial port, and the S_TX port of the serial port is respectively connected to the terminal ST, one end of the resistor R29 and one end of the capacitor C40. The other end of the resistor R29 is connected to the pin CH4_TX of the MCU chip U2, and the other end of the capacitor C40 is connected to the other end of the capacitor C37 and the capacitor C38 and then grounded. The resistors R28, R29 and the capacitors C39 and C40 are used for serial communication decoupling filtering and protection; the pin CH4_RX of the MCU chip U2 is also connected to one end of the capacitor C39, and the other end of the capacitor C39 is grounded.

[0041] The data transmission module includes:

[0042] Energy storage unit: used for decoupling filtering and energy storage of the data transmission module;

[0043] Power supply unit: used to turn off or on the power supply of the data transmission module and provide a regulated power supply;

[0044] Data transmission unit: used to export the alarm data received from the MCU controller through the USB interface or convert it into a radio frequency signal and transmit it through the radio frequency antenna.

[0045] like Figure 4 As shown, the energy storage unit has a terminal VBAT, which is respectively connected to the resistor R50, the capacitor C51, the capacitor C52, the capacitor C53, one end of the diode D10 and the positive electrode of the polarity capacitor C47. The other end of the resistor R50 is connected to the operating voltage VCC, and the other ends of the capacitors C51, C52, C53 and the diode D10 are connected together with the negative electrode of the polarity capacitor C47 and grounded. The resistor R50 and the capacitors C47, C51, C52 and C53 are used for decoupling filtering and energy storage of the data transmission module. The diode D10 is a reserved device for electrostatic protection.

[0046] like Figure 5 As shown, the power supply unit includes a power management chip U3A, and the pin VBAT_1 and the pin VBAT_2 of the power management chip U3A are connected to the drain of the field effect transistor Q11, and the gate of the field effect transistor Q11 is respectively connected to the pin 4G_ON of the MCU chip U2 and one end of the resistor R51. The other end of the resistor R51 is connected to the source of the field effect transistor Q11 and connected to the operating voltage VCC; the power management chip U3A outputs a 1.8V regulated power supply through the pin VDD_EXT, and the pin VDD_EXT is also connected to one end of the capacitor C46 and the capacitor C48 respectively. The other ends of the capacitor C46 and the capacitor C48 are grounded. The field effect transistor Q11 is used to turn off or turn on the power supply of the 4G communication module, and the capacitor C46 and the capacitor C48 are used to decouple and filter the output power of the data transmission module.

[0047] like Figure 6 As shown, the data transmission unit includes a communication chip U3B, which has a USB interface, a SIM socket, a 4G communication unit and a radio frequency antenna interface CON1. ​​The USB socket is used to connect to a USB data cable for data transmission; the SIM socket is used to insert a SIM card U8 to realize network user access authentication; the 4G communication unit is used to realize 4G communication; and the radio frequency antenna interface CON1 is used to install a radio frequency antenna to realize radio frequency signal transmission.

[0048] The 4G communication unit has a pin 4G_RX, a pin 4G_TX, a pin 4G_STATUS, a pin 4G_POWER and a pin 4G_RST, wherein the pin 4G_RX is connected with the resistance R36, one end of the capacitor C59 and the collector of the transistor Q7 respectively, the other end of the resistance R36 and the capacitor C59 is connected with the stabilized power supply, the emitter of the transistor Q7 is connected with the pin MCU_TX of the MCU chip U2, the base of the transistor Q7 is connected with the resistance R39 and one end of the capacitor R60 respectively, the other end of the resistance R39 and the capacitor C60 is connected with the stabilized power supply, the resistance R36, R39, the capacitor C59, C60 and the transistor Q7 are used for the level conversion when the 4G communication unit RX communicates with the MCU control module TX; the pin 4G_TX is connected with the emitter of the transistor Q6, the collector of the transistor Q6 is connected with one end of the resistance R42 and the pin MCU_RX of the MCU chip U2 respectively, the other end of the resistance R42 is connected with the working voltage VDD, the base of the transistor Q6 is connected with the resistance R44 and one end of the capacitor C42 respectively, the other end of the resistance R44 and the capacitor C42 is connected with the stabilized power supply, the resistance R42, R44, the capacitor C42 and the transistor Q6 are used for the level conversion when the 4G communication unit TX communicates with the MCU control module RX; the pin 4G_POWER is connected with one end of the capacitor C41 and the collector of the transistor Q10 respectively, the capacitor C41 and the emitter of the transistor Q10 are connected with the ground, the base of the transistor Q10 is connected with the resistance R34 and one end of the resistance R41 respectively, the other end of the resistance R34 is connected with the pin MCU_4G_EN of the MCU chip U2, the other end of the resistance R41 is connected with the ground, the resistance R34, R41, the capacitor C41 and the transistor Q10 are used for the switch-on and switch-off of the data transmission module; the pin 4G_RST is connected with one end of the capacitor C43 and the collector of the transistor Q5 respectively, the capacitor C43 and the emitter of the transistor Q5 are connected with the ground, the base of the transistor Q5 is connected with the resistance R48 and one end of the resistance R45 respectively, the other end of the resistance R48 is connected with the pin MCU_4G_RST of the MCU chip U2, the other end of the resistance R45 is connected with the ground, the resistance R45, R48, the capacitor C43 and the transistor Q5 are used for controlling the reset of the data transmission module.

[0049] As Figure 7As shown, the SIM socket has pins SIM_VDD, SIM_DATA, SIM_CLK and SIM_RST, and the SIM card U8 has pins S_RST, S_CLK, S_DATA and VDD, wherein the pin S_RST is connected with the resistor R54 and the capacitor C58 respectively, the resistor R54 is connected with the pin SIM_RST of the SIM socket, and the capacitor C58 is grounded; the pin S_CLK is connected with the resistor R52 and the capacitor C57 respectively, the resistor R52 is connected with the pin SIM_CLK of the SIM socket, and the capacitor C57 is grounded; the pin S_DATA is connected with the resistor R53, the resistor R55 and the capacitor C56 respectively, the resistor R53 is connected with the pin SIM_DATA of the SIM socket, the capacitor C56 is grounded, the resistor R55 is connected with the pin SIM_VDD of the SIM socket, the capacitor C55 and the pin VDD of the SIM card U8 respectively, and the capacitor C55 is grounded; the capacitor C55 is used for decoupling filtering of the power supply of the SIM card U8, the resistors R52, R53 and R54 are used for debugging, the capacitors C56, C57 and C58 are used for decoupling filtering of the communication line between the SIM card U8 and the data transmission module, and the resistor R55 is used for pulling up the data pin of the SIM card U8.

[0050] The gas detector provided by the embodiment has three states: a normal monitoring state, an alarm state and a fault state, and the working principles are as follows.

[0051] Normal monitoring state: the gas detection module converts the concentration of the monitored gas into an electrical signal recognizable by the MCU chip, the MCU chip converts the collected electrical signal into the concentration of the gas, compares the concentration with a preset threshold value, and determines that the MCU control module does not issue an alarm, data transmission and action instruction if the preset threshold value is not reached.

[0052] Alarm state: the gas detection module converts the concentration of the monitored gas into an electrical signal recognizable by the MCU chip, the MCU chip converts the collected electrical signal into the concentration of the gas, compares the concentration with a preset threshold value, and determines that the MCU control module issues an alarm instruction if the preset threshold value is reached, starts the local vibration and / or sound-light alarm to issue an alarm prompt, simultaneously issues an instruction to the data transmission module, the data transmission module converts the alarm data into a radio frequency signal for emission and notifies relevant personnel through a telephone, a short message or other modes, and the MCU control module issues an action instruction to the output control module to control the gas valve to be cut off and the exhaust fan to be opened.

[0053] Fault state: when the MCU control module monitors that the service life of the gas sensor J6 expires or the gas sensor J6 is detached or other abnormalities occur, the MCU control module controls the on-board LED fault indicator lamp to be lighted.

[0054] The gas detector based on TDLAS technology and CAT1 network communication can monitor the combustible gas existing in the surrounding environment through the gas sensor, can send a local audible and light alarm signal when detecting that the combustible gas concentration exceeds the standard, can inform the relevant personnel through the 4G communication module, can cut off the gas valve and open the exhaust fan at the same time, can realize the cooperation of local alarm and remote reminding, and can automatically take safety measures to reduce the occurrence of fire, explosion and other safety accidents.

[0055] The above examples are only used to illustrate the technical solutions of the present application, but not to limit them; those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced equivalently; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the protection scope of the present application.

Claims

1. A gas detector based on TDLAS technology and CAT1 network communication, characterized in that: Includes integrated: The power supply module is responsible for voltage conversion, realizing wide-range voltage input and operating voltage output, and is used to provide a stable power supply voltage VCC and operating voltage VDD for the gas detector; Gas detection module; used for real-time monitoring of combustible gas concentration in the environment and transmits the detection signal to the MCU control module for processing; The MCU control module is connected to the gas detection module and is used to collect the detection signal transmitted by the gas detection module, calculate the combustible gas concentration based on the collected detection signal, and compare it with a preset combustible gas concentration threshold. If the comparison result exceeds the threshold, the comparison result is transmitted to the external device through the data transmission module, and an alarm signal is sent to the alarm output unit and a control signal is sent to the control output unit. The alarm output module is connected to the MCU control module and the alarm device, and is used to control the alarm device to send an alarm signal according to the instructions of the MCU control module; Output control module: connected to the MCU control module, gas valve and exhaust fan, used to cut off the gas valve and open the exhaust fan according to the instructions of the MCU control module; Data transmission module: connected to the MCU control module, used to transmit alarm data to the user through 4G communication according to the instructions of the MCU control module.

2. The gas detector based on TDLAS technology and CAT1 network communication according to claim 1, characterized in that: The MCU control module includes an MCU chip U2, which also has pins CH4_RX, CH4_TX, CH4_RST, 4G_ON, MCU_4G_RST, MCU_TX, MUC_RX, MCU_4G_EN, BOOT0 and VCAP, wherein pin BOOT0 is connected to one end of resistor R9 and resistor R10 respectively, the other end of resistor R9 is connected to the operating voltage VDD, and the other end of resistor R10 is grounded; pin VCAP is connected to one end of capacitor C61 and capacitor C62 respectively, and the other ends of capacitor C61 and capacitor C62 are connected and grounded.

3. The gas detector based on TDLAS technology and CAT1 network communication according to claim 2, characterized in that: The gas detection module includes a gas sensor J6, the power pin V of the gas sensor J6 is respectively connected to one end of the resistor R27, the capacitor C37 and the capacitor C38, the other end of the resistor R27 is connected to the power supply voltage VCC, and the other ends of the capacitors C37 and C38 are connected and then grounded; the sending pin T of the gas sensor J6 is connected to the S_RX port of the serial port, the S_RX port of the serial port is connected to one end of the resistor R28, and the other end of the resistor R28 is respectively connected to the terminal SR and the pin CH4_RX of the MCU chip U2; the sending pin R of the gas sensor J6 is connected to the S_TX port of the serial port, the S_TX port of the serial port is respectively connected to the terminal ST, one end of the resistor R29 and one end of the capacitor C40, the other end of the resistor R29 is connected to the pin CH4_TX of the MCU chip U2, and the other end of the capacitor C40 is connected to the other end of the capacitor C37 and the capacitor C38 and then grounded; the pin CH4_RX of the MCU chip U2 is also connected to one end of the capacitor C39, and the other end of the capacitor C39 is grounded.

4. The gas detector based on TDLAS technology and CAT1 network communication according to claim 2, characterized in that: The data transmission module includes: Energy storage unit: used for decoupling filtering and energy storage of the data transmission module; Power supply unit: used to turn off or on the power supply of the data transmission module and provide a regulated power supply; Data transmission unit: used to export or convert the alarm data received from the MCU controller into radio frequency signals and transmit them through the radio frequency antenna.

5. The gas detector based on TDLAS technology and CAT1 network communication according to claim 4, characterized in that: The energy storage unit has a terminal VBAT, which is respectively connected to the resistor R50, the capacitor C51, the capacitor C52, the capacitor C53, one end of the diode D10 and the positive electrode of the polarity capacitor C47. The other end of the resistor R50 is connected to the operating voltage VCC, and the other ends of the capacitors C51, C52, C53 and the diode D10 are connected together with the negative electrode of the polarity capacitor C47 and grounded.

6. The gas detector based on TDLAS technology and CAT1 network communication according to claim 5, characterized in that: The power supply unit includes a power management chip U3A, and the pins VBAT_1 and VBAT_2 of the power management chip U3A are connected to the drain of the field-effect transistor Q11. The gate of the field-effect transistor Q11 is respectively connected to the pin 4G_ON of the MCU chip U2 and one end of the resistor R51. The other end of the resistor R51 is connected to the source of the field-effect transistor Q11 and connected to the operating voltage VCC; the power management chip U3A outputs a 1.8V regulated power supply through the pin VDD_EXT, and the pin VDD_EXT is also connected to one end of the capacitor C46 and the capacitor C48 respectively, and the other ends of the capacitor C46 and the capacitor C48 are grounded.

7. The gas detector based on TDLAS technology and CAT1 network communication according to claim 6, characterized in that: The data transmission unit includes a communication chip U3B, which has a SIM socket, a 4G communication unit and a radio frequency antenna interface CON1; the SIM socket is used to insert a SIM card U8 to realize network user access authentication; the 4G communication unit is used to realize 4G communication; and the radio frequency antenna interface CON1 is used to install a radio frequency antenna.

8. The gas detector based on TDLAS technology and CAT1 network communication according to claim 7, characterized in that: The 4G communication unit has pins 4G_RX, 4G_TX, 4G_STATUS, 4G_POWER and 4G_RST, which are used to realize 4G communication, wherein pin 4G_RX is respectively connected to resistor R36, one end of capacitor C59 and the collector of transistor Q7, the other end of resistor R36 and capacitor C59 is connected to a regulated power supply, the emitter of transistor Q7 is connected to pin MCU_TX of MCU chip U2, the base of transistor Q7 is respectively connected to one end of resistor R39 and capacitor R60, and the other end of resistor R39 and capacitor C60 is connected to a regulated power supply; pin 4G_TX of communication chip U3B is connected to the emitter of transistor Q6, the collector of transistor Q6 is respectively connected to one end of resistor R42 and pin MCU_RX of MCU chip U2, the other end of resistor R42 is connected to operating voltage VDD, the base of transistor Q6 is respectively connected to voltage regulator. Resistor R44 is connected to one end of capacitor C42, and the other ends of resistor R44 and capacitor C42 are connected to a regulated power supply; pin 4G_POWER of communication chip U3B is connected to one end of capacitor C41 and the collector of transistor Q10 respectively, the emitter of capacitor C41 and transistor Q10 is grounded, the base of transistor Q10 is connected to one end of resistor R34 and one end of resistor R41 respectively, the other end of resistor R34 is connected to pin MCU_4G_EN of MCU chip U2, and the other end of resistor R41 is grounded; pin 4G_RST of communication chip U3B is connected to one end of capacitor C43 and the collector of transistor Q5 respectively, the emitter of capacitor C43 and transistor Q5 is grounded, the base of transistor Q5 is connected to one end of resistor R48 and one end of resistor R45 respectively, the other end of resistor R48 is connected to pin MCU_4G_RST of MCU chip U2, and the other end of resistor R45 is grounded.

9. The gas detector based on TDLAS technology and CAT1 network communication according to claim 8, characterized in that: The SIM socket has a pin SIM_VDD, a pin SIM_DATA, a pin SIM_CLK and a pin SIM_RST, and the SIM card U8 has a pin S_RST, a pin S_CLK, a pin S_DATA and a pin VDD, wherein the pin S_RST is respectively connected to the resistor R54 and the capacitor C58, the resistor R54 is connected to the pin SIM_RST of the SIM socket, and the capacitor C58 is grounded; the pin S_CLK is respectively connected to the resistor R52 and the capacitor C57, the resistor R52 is connected to the pin SIM_CLK of the SIM socket, and the capacitor C57 is grounded; the pin S_DATA is respectively connected to the resistor R53, the resistor R55 and the capacitor C56, the resistor R53 is connected to the pin SIM_DATA of the SIM socket, the capacitor C56 is grounded, the resistor R55 is respectively connected to the pin SIM_VDD of the SIM socket, the capacitor C55 and the pin VDD of the SIM card U8, and the capacitor C55 is grounded.

10. The gas detector based on TDLAS technology and CAT1 network communication according to claim 7, characterized in that: The communication chip U3B also has a USB socket for connecting to a USB data cable for data transmission.

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