CN114038166A - Natural gas alarm device and control method thereof - Google Patents

Natural gas alarm device and control method thereof Download PDF

Info

Publication number
CN114038166A
CN114038166A CN202111396636.9A CN202111396636A CN114038166A CN 114038166 A CN114038166 A CN 114038166A CN 202111396636 A CN202111396636 A CN 202111396636A CN 114038166 A CN114038166 A CN 114038166A
Authority
CN
China
Prior art keywords
alarm
module
gas concentration
infrared
methane gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202111396636.9A
Other languages
Chinese (zh)
Inventor
武斌
申涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Meisi Xianrui Electronic Co ltd
Original Assignee
Shenzhen Meisi Xianrui Electronic Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Meisi Xianrui Electronic Co ltd filed Critical Shenzhen Meisi Xianrui Electronic Co ltd
Publication of CN114038166A publication Critical patent/CN114038166A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/02—Alarms for ensuring the safety of persons
    • G08B21/12—Alarms for ensuring the safety of persons responsive to undesired emission of substances, e.g. pollution alarms
    • G08B21/16—Combustible gas alarms
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D21/00—Measuring or testing not otherwise provided for
    • G01D21/02—Measuring two or more variables by means not covered by a single other subclass
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/18—Status alarms
    • G08B21/182—Level alarms, e.g. alarms responsive to variables exceeding a threshold
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B25/00—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
    • G08B25/01—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium
    • G08B25/10—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems characterised by the transmission medium using wireless transmission systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00—Network arrangements or protocols for supporting network services or applications
    • H04L67/01—Protocols
    • H04L67/10—Protocols in which an application is distributed across nodes in the network
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00—Network arrangements or protocols for supporting network services or applications
    • H04L67/01—Protocols
    • H04L67/12—Protocols specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
    • H04L67/125—Protocols specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks involving control of end-device applications over a network

Landscapes

  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Physics & Mathematics (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Signal Processing (AREA)
  • Computing Systems (AREA)
  • Medical Informatics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Environmental & Geological Engineering (AREA)
  • Toxicology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

The invention discloses a natural gas alarm device and a control method thereof, wherein the natural gas alarm device is arranged in a kitchen and comprises a box body, a methane gas concentration detection module, a control module, a gas concentration alarm module and a display module, wherein the box body is internally provided with a ventilation port; the control module is used for receiving the methane concentration signal detected by the methane gas concentration detection module. According to the invention, the methane gas concentration detection module and the control module are arranged in the box body, so that the purposes of measuring the indoor methane gas concentration by using an NDIR detection technology and simultaneously realizing indoor alarm and remote alarm are realized.

Description

Natural gas alarm device and control method thereof
Technical Field
The invention belongs to the technical field of natural gas leakage alarm, and particularly relates to a natural gas alarm device and a control method thereof.
Background
With the improvement of the living standard of people, natural gas gradually becomes a main energy source in daily life of people, and gas is also gradually paid high attention to as flammable and explosive gas, and various gas alarms are also gradually appeared in the life of people. However, the gas alarm adopting the electrochemical, semiconductor and catalytic combustion principles in the market has the defects of short service life, poor safety and the like, influences the use experience of users and causes hidden dangers to human and property; the existing infrared gas alarm has the defects of nonstandard size, non-uniform installation mode, no screen display and the like, so that a user does not know the gas concentration condition in the current environment in a kitchen, and the user experience is poor.
At present, a semiconductor methane gas sensor is taken as a core element, an oxidation-reduction reaction is carried out between an oxide semiconductor gas-sensitive material (tin dioxide) and methane gas to cause the conductivity change of the gas-sensitive material, and the concentration change of the methane gas can be known by detecting the resistance change of the sensor through a circuit. And comparing the detected methane gas concentration with a preset concentration threshold, and activating an acousto-optic alarm function in the device to remind a user that the current indoor methane gas concentration is too high when the current methane gas concentration is greater than or equal to the preset threshold.
However, the size of the device is not in an industrial standard, the device is various in installation mode and single in function, only the sound and light alarm function is realized, and no interface is used for connecting external equipment to block or evacuate methane gas to diffuse; in addition, in order to increase the reaction speed of the tin dioxide gas sensor, the working temperature must be maintained at a higher level, and the power consumption is higher.
Disclosure of Invention
In view of this, the main object of the present invention is to provide a natural gas alarm device, which solves the problem in the prior art that the air intake of an air conditioning device cannot be automatically adjusted according to the concentration of carbon dioxide gas.
The invention also aims to provide a control method of the natural gas alarm device.
In order to achieve the purpose, the technical scheme of the invention is realized as follows: which is arranged in a kitchen and comprises a box body which is internally provided with a ventilation port, a methane gas concentration detection module, a control module, a gas concentration alarm module and a display module,
the methane gas concentration detection module is used for detecting the concentration of methane in the air and transmitting the detected signal to the control module;
the control module is used for receiving a methane concentration signal detected by the methane gas concentration detection module;
when methane gas enters the box body through the ventilation port and contacts the methane gas concentration detection module, the methane gas concentration detection module detects the content of the methane gas concentration, the control module judges whether the content of the methane gas concentration exceeds a preset value according to a content electric signal of the methane gas concentration fed back by the methane gas concentration detection module, and when the content of the methane gas concentration exceeds the preset value, the control module sends an alarm signal to the gas concentration alarm module to alarm and transmits the gas concentration signal to the display module to be displayed.
Preferably, the gas concentration alarm module comprises an alarm and a remote alarm assembly, and the control module sends an alarm signal to the alarm to give an alarm and sends the alarm signal to external electronic equipment to give an alarm through the remote alarm assembly.
Preferably, the methane gas concentration detection module comprises an upper cover body, a bottom plate, an infrared light source, an infrared thermopile gas sensor and a waterproof breathable film, the upper cover body and the bottom plate are connected in a matched manner to form an air chamber for detecting the methane gas concentration, the infrared light source and the infrared thermopile gas sensor are arranged in the air chamber and fixedly connected with the bottom plate, and the waterproof breathable film is arranged above the upper cover body and used for preventing external atmospheric water vapor components from entering the air chamber to influence the detection gas concentration.
Preferably, the infrared thermopile gas sensor comprises a filtering module, an infrared thermopile module, an NTC chip and a pin column, wherein the input end of the NTC chip is connected with the infrared thermopile module, and the output end of the NTC chip is connected with the pin column;
methane gas contacts behind the light filtering module, by the content of methane gas concentration is detected out to infrared thermopile module, the signal of telecommunication of the content of methane gas concentration gets into and obtains digital signal after enlargiing, analog-to-digital conversion in the NTC chip, digital signal passes through the pin post and is connected with the remote alarm subassembly, sends alarm signal to outside electronic equipment through the remote alarm subassembly and reports to the police.
Preferably, the thermopile infrared sensor further comprises a base, the infrared thermopile module, the NTC chip and the pin column are all arranged on the base, and the infrared thermopile module is located at the center of the base.
Preferably, the filtering module comprises an infrared narrowband filter and a tube cap, and the infrared narrowband filter is located on the tube cap.
Preferably, the input end of the NTC chip is connected with the infrared thermopile module through a wire; and the output end of the NTC chip is connected with the pin column through a wire.
Preferably, the number of the infrared narrow-band filters is matched with that of the infrared thermopile modules.
Preferably, the infrared thermopile module is an infrared thermopile chip; the infrared narrowband filter can filter out infrared rays with specific wavelengths.
The other technical scheme of the invention is realized as follows: a control method of the natural gas alarm device comprises the following steps:
the control method comprises the following steps:
s1, starting the natural gas alarm device, and detecting the content of the current methane gas concentration in real time by a methane gas concentration detection module;
s2, judging whether the content of the current methane gas concentration is within a content threshold value of a preset value, if not, executing S3, and if so, continuing to execute the current process;
and S3, when the preset value is exceeded, the control module sends an alarm signal to an alarm to give an alarm, sends the alarm signal to external electronic equipment through a remote alarm assembly to give an alarm, and transmits a gas concentration signal to a display module to be displayed.
Compared with the prior art, the methane gas concentration detection module and the control module are arranged in the box body, so that the purposes of measuring the indoor methane gas concentration by using an NDIR detection technology and simultaneously realizing indoor alarm and remote alarm are achieved.
Drawings
Fig. 1 is a schematic perspective view of a natural gas alarm device provided in embodiment 1 of the present invention;
fig. 2 is an exploded schematic view of a natural gas alarm device provided in embodiment 1 of the present invention;
fig. 3 is a schematic structural diagram of a gas concentration detection module in a natural gas alarm device according to embodiment 1 of the present invention;
fig. 4 is a schematic structural diagram of a dual-channel infrared thermopile gas sensor in a natural gas alarm device provided in embodiment 1 of the present invention;
FIG. 5 is an equivalent circuit diagram of an NTC chip in a dual-channel infrared thermopile gas sensor in a natural gas alarm device provided in embodiment 1 of the present invention;
fig. 6 is a schematic structural diagram of a single-channel infrared thermopile gas sensor in a natural gas alarm device according to embodiment 1 of the present invention;
FIG. 7 is an equivalent circuit diagram of an NTC chip in a single-channel infrared thermopile gas sensor in a natural gas alarm device according to embodiment 1 of the present invention;
fig. 8 is a flow chart of a control method of a natural gas alarm device according to embodiment 1 of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the description of the present invention, it is to be understood that the terms "vertical", "lateral", "longitudinal", "front", "rear", "left", "right", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention, and do not mean that the device or member to which the present invention is directed must have a specific orientation or position, and thus, cannot be construed as limiting the present invention.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The natural gas alarm device provided by the embodiment of the invention is arranged in a kitchen and comprises a box body 1 which is internally provided with a ventilation port 11, a methane gas concentration detection module 2, a control module 3, a gas concentration alarm module and a display module 5,
the methane gas concentration detection module 2 is used for detecting the methane concentration in the air and transmitting the detected signal to the control module 3;
the control module 3 is used for receiving the methane concentration signal detected by the methane gas concentration detection module 2;
when methane gas enters the box body 1 through the ventilation port 11 and contacts the methane gas concentration detection module 2, the methane gas concentration detection module 2 detects the content of the methane gas concentration, the control module 3 judges whether the content of the methane gas concentration exceeds a preset value according to a content electric signal of the methane gas concentration fed back by the methane gas concentration detection module 2, and when the content of the methane gas concentration exceeds the preset value, the control module 3 sends an alarm signal to the gas concentration alarm module to alarm and transmits the gas concentration signal to the display module 5 to display.
After the scheme is adopted, the methane gas concentration detection module 2 and the control module 3 are arranged in the box body, so that the indoor methane gas concentration is measured by applying an NDIR detection technology, and the purpose of alarming after the methane gas concentration is detected is realized.
Further, the gas concentration alarm module comprises an alarm 4 and a remote alarm assembly, the control module 3 sends an alarm signal to the alarm 4 to give an alarm, and sends the alarm signal to external electronic equipment to give an alarm through the remote alarm assembly.
Like this, through setting up alarm 4 and remote alarm subassembly to couple together control module 3 and alarm 4 and remote alarm subassembly, effectual realized reminding whether normal purpose of indoor methane concentration, and then promoted the market competitiveness and the quality of whole device.
Wherein remote alarm subassembly can with cell-phone direct communication, namely behind the special APP of user's cell-phone installation, can read alarm information and methane concentration information that control module sent.
The remote alarm component can be one or more of a low-power Bluetooth BLE module, a Wifi module, a ZigBee module, a Lora module, an NB-IOT module or a 4G-CAT1 module.
When the remote alarm component is a low-power-consumption Bluetooth BLE module, a plurality of natural gas alarm devices form a network in a plane area with a certain area through a Bluetooth pass function, and a user can operate a special APP through a mobile phone and read data of any node in the network in the area of a local area network;
when the remote alarm subassembly is the Wifi module, in the plane area of certain area, control module in a plurality of natural gas alarm device can pass through the Wifi module and connect wireless router, constitutes the LAN, perhaps connects the high in the clouds server through wireless router, regularly uploads data, perhaps reports alarm information in the proruption.
When the remote alarm subassembly is the zigBee module, can be in the plane area of certain area, a plurality of natural gas alarm device constitute a network, and all data gather the zigBee main node after, upload to the high in the clouds by the main node.
When the remote alarm subassembly is the Lora module, can constitute the network in a three-dimensional region, in whole three-dimensional region, control module's data can be sent to the Lora server in real time among all natural gas alarm device to by the Lora server with data transmission to high in the clouds.
When the remote alarm component is an NB-IOT or 4G-CAT1 module, in a larger area, data of control modules in all the natural gas alarm devices can be connected with a communication base station through the NB-IOT module or the 4G-CAT1 module and directly sent to the cloud.
When the remote alarm subassembly is wireless module, constitutes the LAN, and the user can operate special APP in the cell-phone, directly reads the data of an arbitrary node in the LAN in the region of LAN, and the high in the clouds is also sent to the data simultaneously, and special APP in the user's operatable cell-phone visits the data of an arbitrary node in the high in the clouds in any place, sends emergency alarm information to the high in the clouds back, and the high in the clouds can direct propelling movement report to the police to user's cell-phone.
When the remote alarm component power carrier module is arranged in a three-dimensional area, a power carrier main node is arranged in a power control room or a monitoring room, and the main node can be directly connected with each natural gas alarm device in the three-dimensional area through a 220V live wire.
Further, as shown in fig. 3, the methane gas concentration detection module 2 includes an upper cover 21, a bottom plate 22, an infrared light source 23, an infrared thermopile gas sensor 24 and a waterproof breathable film 25, the upper cover 21 and the bottom plate 22 are connected in a matching manner to form a gas chamber for detecting methane gas concentration, the infrared light source 23 and the infrared thermopile gas sensor 24 are disposed in the gas chamber and fixedly connected to the bottom plate 22, and the waterproof breathable film 25 is disposed above the upper cover 21 to prevent external atmospheric water vapor components from entering the gas chamber to affect the detected gas concentration.
Further, waterproof ventilated membrane 25 is formed by polypropylene surface fabric, polymer ventilated membrane, network strengthening rib and polypropylene surface fabric through the hot melt adhesive layer suppression, can effectually avoid outside atmosphere steam composition to get into the air chamber and influence the detection gas concentration.
Further, as shown in fig. 4 and 6, the infrared thermopile gas sensor 24 includes a filter module 241, an infrared thermopile module 242, an NTC chip 243, and a pin post 244, the input end of the NTC chip 243 being connected to the infrared thermopile module 242, and the output end being connected to the pin post 244;
after the methane gas contacts the filtering module 241, the infrared thermopile module 242 detects the concentration of the methane gas, an electric signal of the concentration of the methane gas enters the NTC chip 243 to be amplified and subjected to analog-to-digital conversion to obtain a digital signal, and the digital signal is communicated with the outside through the pin 244.
Thus, with the above structure, after infrared radiation energy emitted by methane gas passes through the filtering module 241, the infrared radiation energy is absorbed by the thermopile module 242 and generates a thermoelectric signal, the thermoelectric signal enters the NTC chip 243 to be amplified and subjected to analog-to-digital conversion to obtain a digital signal, the digital signal is connected with the remote alarm component through the pin 244, and the alarm signal is sent to external electronic equipment through the remote alarm component to alarm;
the external electronic equipment is one of a mobile phone, a tablet and a notebook computer.
In the above process, the infrared thermopile module 242 and the NTC chip 243 are integrated in this embodiment, and compared with the prior art that an analog sensor is required to be used in combination with a peripheral signal amplifying circuit and a signal processing circuit, the present invention obviously reduces the volume and the complexity of the peripheral circuit on the premise of consistent functions.
Further, the thermopile infrared sensor further includes a base 245, the infrared thermopile module 242, the NTC chip 243, and the pin 244 are all disposed on the base 245, and the infrared thermopile module 242 is located at the center of the base 245.
Further, the filtering module 241 includes an infrared narrowband filter 2411 and a tube cap 2412, and the infrared narrowband filter 2411 is located on the tube cap 2412.
Further, the input end of the NTC chip 243 is connected to the infrared thermopile module 242 through a gold wire; the output terminal of the NTC chip 243 is connected to the pin post 244 through a gold wire.
Specifically, the infrared narrowband filter 2411 may filter out infrared rays of a specific wavelength;
specifically, moisture, methane gas, etc. in the atmosphere have a strong absorption effect on infrared light with a specific wavelength, and if infrared radiation in the whole wavelength range emitted by an object is allowed to pass through the sensor optical window, the radiation energy received by the thermopile sensor is easily interfered by the concentration of atmospheric components, so that the output result of the sensor is influenced. The silicon-based infrared filter loaded on the optical window of the sensor can selectively transmit infrared light in a specific wavelength range, and by designing the transmission-cut-off wavelength parameters of the filter, an atmospheric absorption waveband causing interference can be shielded outside the sensor, so that the radiation energy received by the thermopile sensor is only related to the surface temperature of a measured object and is not interfered by the concentration of atmospheric components.
Further, the input end of the NTC chip 243 is connected to the infrared thermopile module 242 through a wire; the output terminal of the NTC chip 243 is connected to the pin post 244 through a wire.
Further, at least two infrared narrow band filters 2411 and at least two infrared thermopile modules 242 are respectively arranged, and the number of the infrared narrow band filters 2411 is matched with that of the infrared thermopile modules 242.
In a specific embodiment, when the infrared narrowband filter 2411 and the infrared thermopile module 242 are configured as one, the infrared thermopile infrared sensor formed by the infrared narrowband filter 2411 is a single-channel infrared thermopile gas sensor, as specifically shown in fig. 6; when the two infrared narrowband filter 2411 and the two infrared thermopile modules 242 are provided, the infrared thermopile infrared sensor formed by the two infrared narrowband filter 2411 and the two infrared thermopile modules 242 is a dual-channel infrared thermopile gas sensor, which is specifically shown in fig. 4.
Further, the infrared thermopile module 242 is an infrared thermopile chip.
The NTC chip is used for monitoring the ambient temperature of the infrared thermopile sensor W and compensating the output voltage of the infrared thermopile sensor W.
When the two-channel infrared thermopile gas sensor W is adopted, the signal processing circuit comprises an NTC voltage division bridge circuit and a signal processing circuit as shown in FIG. 5; the signal processing circuit outputs the uV level weak voltage V output by the infrared thermopile sensor WtpDifferential amplification is carried out by using a low-noise and zero-temperature-drift operational amplifier U, and the amplification factor G of the differential amplification is obtained by using a resistor R1And a resistor R3Determining;
Figure BDA0003370181430000101
after the voltage signal is amplified, VoutAnd the gas concentration is converted into a digital signal through an analog-to-digital converter IC1, and gas concentration algorithm calculation is carried out:
Vtp＝(Vout-Vref)/G
the NTC voltage-dividing bridge circuit combines the NTC chip 243 in the infrared thermopile sensor W with the resistor R5The measurement is carried out by adopting a bridge circuit through a voltage division principle:
Figure BDA0003370181430000102
the acquired NTC divided voltage is converted into a digital signal through an analog-to-digital converter IC1, and the output voltage of the sensor is compensated.
The software algorithm is designed based on the beer-Lambert law, i.e.
I1＝I0e-klx
Wherein, I1Denotes the density of the target gas, I0Denotes the density of zero gas, k denotes the absorption coefficient of a particular gas and filter combination, l denotes the equivalent of the infrared light source and infrared thermopile sensor WOptical length, x represents gas concentration. For NDIR applications, methane gas does not absorb all of the infrared light at its infrared absorption peak, so the beer-Lambert law is modified to fit practical applications for measurement, i.e., measurements
Figure BDA0003370181430000111
Wherein m represents the absorption capacity of methane gas and has a value of less than 1; n represents an increase in the power term due to changes in the optical path length and scattering requirements of the light, which can make the equation fit exactly to the actual absorption data.
The calibration steps and the algorithm of the W gas concentration of the dual-channel infrared thermopile sensor in the signal processing algorithm are as follows:
1) injecting N into the gas chamber2Waiting for the stabilization of the methane gas, and constructing a methane gas zero-concentration environment;
2) measuring peak output V of a working channel1Peak output of reference channel V0And a current ambient temperature T0;
3) calculating W zero position Z of infrared thermopile sensor0(ratio of reference channel to working channel at zero methane gas concentration)
Figure BDA0003370181430000112
4) Injecting methane gas with concentration of x1 into the gas chamber, and measuring peak output V of the working channel4Peak output of reference channel V3And the current ambient temperature T1The concentration relationship is as follows:
Figure BDA0003370181430000113
Figure BDA0003370181430000114
where FA represents the fractional absorption of the gas.
5) The temperature coefficients of the parameters m and FA are calculated according to the formula
mT＝m0+i0*(T-T0)
(1-FAT)＝(1-FA)*(1+j*(T-T0))
Where mT represents the value at ambient temperature T, m0The expression is the value obtained at calibration, i0Temperature coefficient, T, representing parameter m0Represents the ambient temperature at calibration; FAT indicates a value at which the ring temperature is T, FA is a value obtained by calibration, and j indicates a temperature coefficient of the parameter FA. From the two parameters temperature coefficient, the temperature compensation of the coefficient m at various concentrations can be calculated, i.e.
mT＝m0+i*(T-T0)
Where i represents the correction coefficients of the parameters m and FA.
6) The methane gas concentration was calculated.
Figure BDA0003370181430000121
The alarm preset threshold value is set by reference to national standard GB/T50493 and 2019 petrochemical industry combustible gas and toxic gas detection alarm design standard; the lower explosion limit of methane gas is 5.0% VOL, the alarm value is less than or equal to 25% LEL (12500ppm), in order to guarantee safety, the alarm threshold is preset to be 10% LEL (5000ppm), the alarm threshold setting function is reserved, and a user can set the alarm threshold by himself within the range of 1000 ppm-5000 ppm. When the methane gas concentration is greater than or equal to the alarm threshold, a sound-light alarm of not less than 70dB is immediately sent out to remind a user that the methane gas concentration is too high.
The natural gas alarm device is internally integrated with wireless communication protocols such as WiFi and Bluetooth and can communicate with external electronic equipment; an external wired interface is reserved, and after the alarm is generated, the external equipment can be linked for emergency treatment; such as the linkage valve manipulator closing the gas valve, the linkage exhaust fan ventilating, etc. Effectively reduce the methane gas concentration and continuously rise, and prevent the danger.
The power line carrier module is integrated in the natural gas alarm device, alarm information can be directly sent to the control room in a power line carrier communication mode, and the control room can cut off the whole gas supply pipeline according to leakage points.
The natural gas alarm device components are all arranged in a standard box body 1 in the electric decoration industry, as shown in figure 6; the box body 1 is provided with air holes around for air circulation, so that air can diffuse into the device, and the methane gas concentration can be conveniently tested.
In the embodiment of the invention, the methane gas concentration measuring module 2 is mainly used for detecting the concentration of indoor methane gas, the methane gas concentration measuring module 2 is installed in an industry standard natural gas alarm device (namely, a box body 1), and as shown in fig. 1, ventilation openings 11 are formed in the periphery of the box body 1 and are used for indoor air flowing, so that indoor air is diffused into the device, and the indoor methane gas concentration can be conveniently tested.
The display module 5 displays the reading of the methane gas concentration measuring module 2 and built-in wireless communication. The low-power consumption display module is installed on the panel of the display module 5, and the display module 5 can be a negative segment code LCD, or an off-white dot matrix LCD module, or a low-power consumption TFTLCD module or an OLED module.
In addition, as shown in fig. 7, which is an equivalent circuit diagram of the NTC chip 243, it can be seen from fig. 7 that the voltage signal output by the methane gas concentration measuring module 2 is amplified, analog-to-digital converted, and then sent to the main control chip IC2 for algorithm processing, so as to finally obtain the current methane gas concentration.
In addition, as can be seen from fig. 7, the output voltages of the first to third pins of the infrared thermopile module 242 are amplified by the operational amplifier U, and the second to fourth pins of the infrared thermopile sensor W are converted into voltage signals by the voltage dividing circuit, and then the voltage signals are respectively sent to the analog-to-digital converter IC1 to convert the voltage analog signals into digital signals for external communication.
The input end of the NTC chip 243 is connected to the infrared thermopile module 242 through a gold wire.
The output end of the NTC chip 243 is connected to the pin post 244 through a gold wire.
The working process of the thermopile infrared sensor integrated with the analog front end provided by the embodiment mainly comprises the following steps:
firstly, an object to be measured emits infrared radiation energy, and the optical filter 11 filters out unwanted infrared rays and retains the needed infrared rays;
step two, the infrared thermopile module 242 absorbs and generates a thermoelectric signal, and the hot spot signal enters the NTC chip 243 through a gold wire;
in the NTC chip 243, the thermoelectric signal first enters the input selector, then is amplified by the amplifier U, and then is converted into a digital signal by the analog-to-digital converter IC1, and the digital signal can be communicated with the outside through a different interface.
The infrared thermopile sensor integrated with the analog front end provided by the embodiment has the following advantages:
firstly, miniaturization is realized, specifically:
in the prior art, an infrared thermopile sensor W is needed to be matched with a peripheral signal amplifying circuit and a signal processing circuit, so that the peripheral circuit is overstaffed and complicated; in the case that the functions of the present embodiment are the same as those of the prior art, the volume of the present embodiment is miniaturized, which lays a foundation for the miniaturization of the subsequent modules of the user.
Secondly, improve user development efficiency, specifically do:
the embodiment outputs digital signals, can directly communicate with the main control chip IC2, does not need a user to process original voltage signals, improves development efficiency and saves time.
Finally, the cost is reduced, specifically:
the NTC chip 243 can receive two paths of infrared thermopile sensor W signals, can be perfectly matched with NDIR dual-channel gas measurement, and can convert the NDIR dual-channel gas measurement signals into digital signals by using only one NTC chip 243.
The use principle of the natural gas alarm device provided by the embodiment 1 of the invention is as follows:
the device is mainly installed on an indoor wall, indoor air enters the device from the air holes 11 formed in the box body (namely a natural gas alarm device) 1 through natural diffusion, a methane gas concentration measuring module 2 is integrated in the device, and after methane gas enters the gas concentration measuring module 2, the output signal of a sensor in the methane gas concentration measuring module 2 is changed due to the fact that the methane gas has an absorption effect on infrared radiation with specific wavelength, and the current methane gas concentration content can be calculated according to the beer-Lambert gas absorption law; the measured methane gas concentration data may be remotely alarmed via a different communication protocol or wired connection.
Example 2
As shown in fig. 8, the control method of the natural gas alarm device according to embodiment 2 of the present invention includes the following steps:
s1, starting the natural gas alarm device, and detecting the content of the current methane gas concentration in real time by the methane gas concentration detection module 2;
s2, judging whether the content of the current methane gas concentration is within a content threshold value of a preset value, if not, executing S3, and if so, continuing to execute the current process;
and S3, when the preset value is exceeded, the control module 3 sends an alarm signal to the alarm 4 to give an alarm, sends the alarm signal to external electronic equipment to give an alarm through the remote alarm assembly, and transmits a gas concentration signal to the display module 5 to display.
After the scheme is adopted, by adopting the control method in the embodiment 2 of the invention, the purpose of measuring the indoor methane gas concentration by using an NDIR detection technology is realized, when the indoor methane gas concentration exceeds a preset threshold value, the indoor methane gas concentration is alarmed through an alarm and is remotely sent to external electronic equipment for alarming, and a gas concentration signal is transmitted to a display module (5) for displaying.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A natural gas alarm device is arranged in a kitchen and is characterized by comprising a box body (1) which is internally provided with a ventilation port (11), a methane gas concentration detection module (2), a control module (3), a gas concentration alarm module and a display module (5),
the methane gas concentration detection module (2) is used for detecting the methane concentration in the air and transmitting the detected signal to the control module (3);
the control module (3) is used for receiving a methane concentration signal detected by the methane gas concentration detection module (2);
when methane gas enters the box body (1) through the ventilation opening (11) and contacts the methane gas concentration detection module (2), the methane gas concentration detection module (2) detects the content of the methane gas concentration, the control module (3) judges whether the content of the methane gas concentration exceeds a preset value according to a content electric signal of the methane gas concentration fed back by the methane gas concentration detection module (2), and when the content of the methane gas concentration exceeds the preset value, the control module (3) sends an alarm signal to the gas concentration alarm module to alarm and transmits the gas concentration signal to the display module (5) to display.
2. The natural gas alarm device according to claim 1, wherein the gas concentration alarm module comprises an alarm (4) and a remote alarm component, and the control module (3) sends an alarm signal to the alarm to give an alarm and sends the alarm signal to external electronic equipment to give an alarm through the remote alarm component.
3. The natural gas alarm device according to claim 2, wherein the methane gas concentration detection module (2) comprises an upper cover body (21), a bottom plate (22), an infrared light source (23), an infrared thermopile gas sensor (24) and a waterproof breathable film (25), the upper cover body (21) and the bottom plate (22) are connected in a matching mode to form a gas chamber for detecting methane gas concentration, the infrared light source (23) and the infrared thermopile gas sensor (24) are arranged in the gas chamber and fixedly connected with the bottom plate (22), and the waterproof breathable film (25) is arranged above the upper cover body (21) and used for preventing external atmospheric water vapor components from entering the gas chamber to influence detection of methane gas concentration.
4. A natural gas alarm device according to claim 3, wherein the infrared thermopile gas sensor (24) comprises a filter module (241), an infrared thermopile module (242), an NTC chip (243) and a pin post (244), wherein the NTC chip (243) has an input end connected with the infrared thermopile module (242) and an output end connected with the pin post (244);
the methane gas contacts filtering module (241) back, by infrared thermopile module (242) detect out the content of methane gas concentration, the signal of telecommunication of the content of methane gas concentration gets into NTC chip (243) and enlargies, obtain digital signal after the analog-to-digital conversion, digital signal passes through pin post (244) and is connected with the remote alarm subassembly, sends alarm signal to outside electronic equipment through the remote alarm subassembly and reports to the police.
5. The natural gas alarm device according to claim 4, wherein the thermopile infrared sensor further comprises a base (245), the infrared thermopile module (242), the NTC chip (243) and the pin column (244) are all disposed on the base (245), and the infrared thermopile module (242) is located at the center of the base (245).
6. The natural gas alarm device of claim 5, wherein the filtering module (241) comprises an infrared narrowband filter (2411) and a cap (2412), and the infrared narrowband filter (2411) is located on the cap (2412).
7. The natural gas alarm device according to claim 6, wherein the input end of the NTC chip (243) is connected with the infrared thermopile module (242) through a wire; the output end of the NTC chip (243) is connected with the pin post (244) through a wire.
8. The natural gas alarm device according to claim 7, wherein the number of the infrared narrowband filters (2411) and the number of the infrared thermopile modules (242) are at least two, and the number of the infrared narrowband filters (2411) is matched with the number of the infrared thermopile modules (242).
9. A natural gas alarm device according to any one of claims 4 to 8 wherein the infrared thermopile module (242) is an infrared thermopile chip; the infrared narrowband filter (2411) can filter out infrared rays with specific wavelengths.
10. A control method of a natural gas alarm device according to any one of claims 1 to 9, characterized in that the control method comprises the steps of:
s1, starting the natural gas alarm device, and detecting the content of the current methane gas concentration in real time by the methane gas concentration detection module (2);
s2, judging whether the content of the current methane gas concentration is within a content threshold value of a preset value, if not, executing S3, and if so, continuing to execute the current process;
and S3, when the preset value is exceeded, the control module (3) sends an alarm signal to an alarm to give an alarm, sends the alarm signal to external electronic equipment to give an alarm through a remote alarm assembly, and transmits a gas concentration signal to the display module (5) to be displayed.
CN202111396636.9A 2021-09-23 2021-11-23 Natural gas alarm device and control method thereof Pending CN114038166A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN2021111145502 2021-09-23
CN202111114550 2021-09-23

Publications (1)

Publication Number Publication Date
CN114038166A true CN114038166A (en) 2022-02-11

Family

ID=80138483

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111396636.9A Pending CN114038166A (en) 2021-09-23 2021-11-23 Natural gas alarm device and control method thereof

Country Status (1)

Country Link
CN (1) CN114038166A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114608755A (en) * 2022-03-15 2022-06-10 北京埃德尔黛威新技术有限公司 Detection method for rapidly identifying and positioning natural gas leakage
CN116935589A (en) * 2023-09-12 2023-10-24 南京科力赛克安全设备有限公司 Gas detection system and method for wall-mounted gas detection alarm

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114608755A (en) * 2022-03-15 2022-06-10 北京埃德尔黛威新技术有限公司 Detection method for rapidly identifying and positioning natural gas leakage
CN116935589A (en) * 2023-09-12 2023-10-24 南京科力赛克安全设备有限公司 Gas detection system and method for wall-mounted gas detection alarm

Similar Documents

Publication Publication Date Title
US11137163B2 (en) Environment monitoring and management systems and methods
CN114038166A (en) Natural gas alarm device and control method thereof
US7378954B2 (en) Safety indicator and method
EP2763117B1 (en) Chemical alert system using a portable device with integrated chemical sensor
Gugliermetti et al. A cheap and third-age-friendly home device for monitoring indoor air quality
KR20170045606A (en) Infants and babies safety keeping service system
CN109521067A (en) Portable device and method with environment sensing function
WO2021233221A1 (en) Agricultural multifunctional carbon dioxide monitoring instrument
CN114832138B (en) Method and device for detecting sterilizing effect of UVC ultraviolet radiation
CN113432655A (en) Laboratory safety real-time monitoring system
CN114002394A (en) Multifunctional air quality detection device and detection method thereof
CN216719223U (en) Natural gas alarm device
CN215892720U (en) Carbon dioxide gas concentration adjusting device
CN204117318U (en) A kind of gas alarm
CN208283365U (en) A kind of portable air mass detecting instrument
CN202838615U (en) Gas alarm
CN202795678U (en) Gas alarm
CN211294125U (en) Internet of things module for gas leakage alarm
CN205785300U (en) Portable intelligent environment monitoring device
CN113739398A (en) Carbon dioxide gas concentration adjusting device and control method thereof
Gecova et al. Air condition sensor on KNX network
CN202711432U (en) Gas alarm
CN202771580U (en) Gas alarm device
CN111854829A (en) Display method and display device for environmental comfort
CN202855036U (en) Gas alarm

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination