CN213149960U

CN213149960U - Internet of things intelligent gas meter alarm system

Info

Publication number: CN213149960U
Application number: CN202021484413.9U
Authority: CN
Inventors: 向海堂; 陈君涛; 魏小军; 李勇
Original assignee: Chengdu Qinchuan IoT Technology Co Ltd
Current assignee: Chengdu Qinchuan IoT Technology Co Ltd
Priority date: 2020-07-24
Filing date: 2020-07-24
Publication date: 2021-05-07
Anticipated expiration: 2030-07-24

Abstract

The utility model relates to a thing networking intelligent gas table alarm system, including gas sensor, MCU monolithic controller and essential signal output circuit: the gas sensor is used for sending a detection concentration signal of leaked gas to the MCU; the MCU is used for sending a level signal to trigger the intrinsic signal output circuit after the gas concentration reaches a set threshold value; and the intrinsic signal output circuit outputs the current signal to the gas meter. The output signal is a two-wire three-state switch signal, 4mA represents that the alarm is connected but not in an alarm state, and 20mA represents that the alarm is connected and in an alarm state; 0mA represents a wire break state or an alarm is not connected, so that the function consumption is reduced, the active current signal with the two wires has the strongest anti-interference capability, and meanwhile, the two-wire current signal can transmit analog quantity, digital quantity, multi-state switching value and the like.

Description

Internet of things intelligent gas meter alarm system

Technical Field

The utility model relates to a thing networking intelligent gas table technical field, specifically speaking relates to a thing networking intelligent gas table alarm system.

Background

In the existing gas meter metering field, a cut-off valve is arranged in most gas meters, the gas meters can receive signals of an external gas alarm to realize a safety cut-off function, when gas leakage accidents occur, the gas volume concentration of gas leakage in air reaches the action threshold of the gas leakage alarm, the gas alarm sends out alarm signals to a safety cut-off membrane type gas meter, the gas meters actively cut off safety valves arranged in the gas meters, because the action threshold value of the gas alarm is far smaller than the gas explosion concentration threshold, the gas explosion of residences caused by the gas leakage accidents can be effectively prevented, under the condition that residences and population are more and more dense, if gas leakage occurs, fire or explosion is caused, the life and property safety of the masses can be seriously threatened, therefore, the gas safety of each household is ensured to be an indispensable ring in safety work, a large number of gas leakage alarm devices are also on the market, and meanwhile, a gas meter, as a gas metering device for household gas opening, must meet the intrinsic safety requirement, i.e., an electrical circuit in which electric sparks and thermal effects generated in normal operation or in a specified fault state cannot ignite a specified explosive mixture.

Chinese patent grant publication no: CN208126616U discloses a protection device and protection alarm system, which is characterized in that, the protection device is connected with a gas meter, the protection device includes: the detection module comprises a sensing circuit for detecting the gas concentration of the leaked fuel gas; the output module comprises a comparison circuit, an optical coupling circuit connected with the comparison circuit and an output circuit, and two ends of the output circuit are respectively connected with the optical coupling circuit and the gas meter; when the gas concentration transmitted by the sensing circuit is determined to be larger than a preset threshold value, the comparison circuit transmits a trigger signal to the output circuit through the optical coupling circuit, so that the gas meter closes a valve after detecting the trigger signal through the output circuit.

Above-mentioned patent passes through power module and steps down the commercial power and commutates and convert low pressure safety stabilization electric current into through power supply conversion circuit behind the filtering, for the protection device power supply has improved gas protection device's power consumption security, when can solving gas alarm and being connected with the gas table, the unsafe characteristic of gas alarm does not destroy the intrinsic safety of gas table self. However, when the gas meter identifies the passive switching value signal, an excitation power supply needs to be applied, the gas meter is mostly powered by a battery, the power consumption requirement is strict, and the gas meter cannot provide large electric energy to ensure the reliability of signal detection, so that the signal of the gas meter identification alarm is easily interfered by the outside.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to solve the above-mentioned problem that exists among the prior art, provide a thing networking intelligent gas table alarm system, there is two kinds of states of infrared receiving tube to export sampling signal when sheltering from and not sheltering from through the testing light source, through active current type essential safety output circuit output alarm state signal, output broken string, three kinds of states of connection and warning.

In order to achieve the above purpose, the utility model adopts the following technical scheme.

The utility model provides an thing networking intelligent gas table alarm system, includes gas sensor, MCU monolithic controller and essential signal output circuit:

the gas sensor is used for sending a detection concentration signal of leaked gas to the MCU;

the MCU is used for sending a level signal to trigger the intrinsic signal output circuit after the gas concentration reaches a set threshold value;

the intrinsic signal output circuit outputs a current signal to the gas meter;

when the MCU single chip controller determines that the concentration of the gas transmitted by the gas sensor is greater than a preset threshold value, the MCU single chip controller triggers an output level signal to trigger an essential signal output circuit to output XmA current so as to send an alarm signal, and the gas meter closes a valve after receiving the alarm signal;

when the MCU single chip controller determines that the concentration of the gas transmitted by the gas sensor is smaller than a preset threshold value, the MCU single chip controller does not output a level signal, and the essential signal output circuit outputs YmA current to detect that the alarm works normally.

Gas sensor includes heating element and gas sensing resistor, be provided with heating resistor between the electrode terminal A and the electrode terminal B of sensor, direct current voltage 5V is connected to the electrode terminal A and the electrode terminal C of sensor, the electrode terminal B end of sensor is connected with the one end of resistance R1, there are resistance R1's the other end and heating resistor D ground connection, the electrode terminal B and the MCU monolithic controller of sensor are connected.

The intrinsic signal output circuit comprises an LM317 three-terminal regulator, wherein an input end Vi of the LM317 three-terminal regulator is connected with a voltage VCC, an output end Vo is connected with one end of a resistor R3 and an emitting electrode of a PNP type triode Q3 in parallel, a control end Adj is connected with one end of a resistor R4 and the other end of a resistor R3, the other end of the resistor R4 is connected with a collecting electrode of a PNP type triode Q3, a base electrode of the PNP type triode Q3 is connected with a collecting electrode of an NPN type triode Q2, a collecting electrode of the NPN type triode Q2 is connected with an MCU single-chip controller, the emitting electrode of the NPN type triode Q2 is connected with one end of a gas meter and then grounded, and the control end Adj, the resistor R3.

And a diode D1, a fuse F1 and a resistor R1 are connected between the connection point of the control end Adj, the resistor R3 and the resistor R4 and the gas meter in sequence.

The collector of the NPN type triode Q1 is connected with the anode of a diode D1, and a fuse F1 and a resistor R1 are connected between the cathode of the diode D1 and the gas meter.

And voltage-stabilizing diodes TVI, TV2 and TV3 are connected in parallel between the junction of the control terminal Adj, the resistor R3 and the resistor R4 and the emitter of the NPN type triode Q2.

Still include the circuit power supply, the circuit power supply obtains 12V, 5V and 3.3V's direct current voltage with the 220V alternating current through AD/DC converting circuit, 12V provides voltage for the VCC, 5V provides voltage for gas sensor, 3.3V provides voltage for MCU single chip controller.

The XmA =20mA and Y =4 mA.

The beneficial effect of this application is.

1. By outputting a signal which is a two-wire three-state electric quantity signal, the LM317 three-terminal voltage stabilizer, the resistor R3, the resistor R4 and the PNP type triode Q3 form a constant current circuit, the current control precision is high, the precision alternating current stabilized power supply has the advantages of high response speed, high constant current precision, long-term stable work and suitability for various loads (resistive, inductive and capacitive), 4mA represents that an alarm is connected but not in an alarm state, and 20mA represents that the alarm is connected and in an alarm state; 0mA represents a broken wire state or an unconnected state of the alarm, whether the alarm is in a normal working state or not is convenient to detect, the connected state of the alarm is maintained through 4mA low current under the condition that no alarm is available, remote signal transmission is achieved, a two-wire active current signal is adopted, the active current signal has the strongest anti-interference capacity, and meanwhile, the two-wire current signal can transmit analog quantity, digital quantity, multi-state switching quantity and the like.

2. Through resistance-type semiconductor metal oxide (SnO 2) formula sensor, the essential element of sensor is gas sensitive resistor and heat tracing circuit, and heat tracing circuit is gas sensitive resistor heating for gas sensitive resistor obtains stable operating temperature condition, and gas sensitive resistor adsorbs reductive gases such as CH4 and makes it take place oxidation reaction, thereby changes gas sensitive resistor's resistance value, and gas sensitive resistor connects in series the fixed resistance, on being connected to the power, exports the voltage signal value that corresponds with gas concentration.

3. D1, F1, R1, TV1, TV2 and TV3 form a Zener safety gate circuit to ensure that the voltage and current values of output signals meet safety requirements, three voltage stabilizing diodes of TV1, TV2 and TV3 are used in parallel, and the output voltage can be ensured not to exceed 13V (the specification of the voltage stabilizing diodes is 13V) even if two voltage stabilizing diodes are in failure.

Drawings

Fig. 1 is a functional block diagram of the circuit of the present invention.

Fig. 2 is a schematic structural diagram of the gas sensor of the present invention.

Fig. 3 is a circuit diagram of the two-wire tri-state electric quantity signal implementation circuit of the present invention.

Fig. 4 is a power supply circuit diagram of the present invention.

The reference numbers in the figures are: 1. gas sensor, 2, MCU monolithic controller, 3, essence signal output circuit.

Detailed Description

Example 1

As shown in fig. 1 to 4, an alarm system of an internet of things intelligent gas meter comprises a gas sensor 1, an MCU monolithic controller 2 and an essential signal output circuit 3:

the gas sensor 1 is used for sending a detection concentration signal of leaked gas to the MCU 2;

the MCU 2 is used for sending a level signal to trigger the intrinsic signal output circuit 3 after the gas concentration reaches a set threshold value;

the intrinsic signal output circuit outputs a current signal to the gas meter;

when the MCU monolithic controller 2 determines that the concentration of the gas transmitted by the gas sensor 1 is greater than a preset threshold value, the MCU monolithic controller 2 triggers an output level signal to trigger the essential signal output circuit 3 to output XmA current so as to send an alarm signal, and the gas meter closes a valve after receiving the alarm signal;

when the MCU singlechip controller 2 determines that the gas concentration transmitted by the gas sensor 1 is smaller than a preset threshold value, the MCU singlechip controller 2 does not output a level signal, and the essential signal output circuit 3 outputs YmA current to detect that the alarm works normally.

Gas sensor 1 includes heating element and gas sensing resistor, be provided with heating resistor between the electrode terminal A and the electrode terminal B of sensor, direct current voltage 5V is connected to the electrode terminal A and the electrode terminal C of sensor, the electrode terminal B end of sensor is connected with the one end of resistance R1, there are resistance R1's the other end and heating resistor D ground connection, the electrode terminal B and the MCU monolithic controller of sensor are connected.

Still include the circuit power supply, the circuit power supply obtains 12V, 5V and 3.3V's direct current voltage with the 220V alternating current through AD/DC converting circuit, 12V provides voltage for the VCC, 5V provides voltage for gas sensor 1, 3.3V provides voltage for MCU monolithic controller 2.

The XmA =20mA and Y =4 mA.

The LM317 three-terminal regulator, a resistor R3, a resistor R4 and a PNP type triode Q3 form a constant current circuit. When the alarm is not given, the Q3 is cut off, the output current is 1.23V/R3, the output current is 1.25V/R3, when the R3 is 309 omega, the output current is about 4mA which is the current flowing through the resistor R3 when the output loop is connected, and the alarm is connected but is not given an alarm; when the gas sensor 1 detects gas leakage, an alarm is generated, the MCU single chip controller 2 emits high voltage to enable the gas to be conducted through an NPN type triode Q2, a PNP type triode Q3 is also conducted, the current flowing through R4 is 1.25V/R3, when R4 is 76.8 omega, the current flowing through R4 is 16mA, the resistor R3 is connected with the resistor R4 in parallel, the total output current is 1.25V/R3+1.25/R4, the sum of the currents flowing through R3 and R4 is about 20mA, the alarm is connected and in an alarm state, and the gas meter is automatically closed to cut off gas leakage; if the circuit is broken, the output current loop is disconnected, and no current is output.

By outputting a signal which is a two-wire three-state electric quantity signal, the LM317 three-terminal voltage stabilizer, the resistor R3, the resistor R4 and the PNP type triode Q3 form a constant current circuit, the current control precision is high, the precision alternating current stabilized power supply has the advantages of high response speed, high constant current precision, long-term stable work and suitability for various loads (resistive, inductive and capacitive), 4mA represents that an alarm is connected but not in an alarm state, and 20mA represents that the alarm is connected and in an alarm state; 0mA represents a broken wire state or an unconnected state of the alarm, whether the alarm is in a normal working state or not is convenient to detect, the connected state of the alarm is maintained through 4mA low current under the condition that no alarm is available, remote signal transmission is achieved, a two-wire active current signal is adopted, the active current signal has the strongest anti-interference capacity, and meanwhile, the two-wire current signal can transmit analog quantity, digital quantity, multi-state switching quantity and the like.

Through resistance-type semiconductor metal oxide (SnO 2) formula sensor, the essential element of sensor is gas sensitive resistor and heat tracing circuit, and heat tracing circuit is gas sensitive resistor heating for gas sensitive resistor obtains stable operating temperature condition, and gas sensitive resistor adsorbs reductive gases such as CH4 and makes it take place oxidation reaction, thereby changes gas sensitive resistor's resistance value, and gas sensitive resistor connects in series the fixed resistance, on being connected to the power, exports the voltage signal value that corresponds with gas concentration.

D1, F1, R1, TV1, TV2 and TV3 form a Zener safety gate circuit, the voltage and current values of output signals are ensured to meet safety requirements, three voltage stabilizing diodes of TV1, TV2 and TV3 are used in parallel, and even if two of the voltage stabilizing diodes are in fault, the output voltage is ensured not to exceed 13V (the specification of the voltage stabilizing diode is 13V) even if a front-stage circuit is in fault, wherein the resistor R1 is a current limiting resistor, and when the R1 is 20 omega, the output current is not to exceed two 65mA even if a rear-stage circuit is in short circuit.

In the description of the present invention, it should be noted that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

The above-mentioned embodiments only express the specific embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, without departing from the technical idea of the present application, several changes and modifications can be made, which are all within the protection scope of the present application.

Claims

1. The utility model provides an thing networking intelligent gas table alarm system, includes gas sensor (1), MCU monolithic controller (2) and essential signal output circuit (3), its characterized in that:

the gas sensor (1) is used for sending a detection concentration signal of leaked gas to the MCU (microprogrammed control Unit) single chip controller (2);

the MCU (MCU) single chip controller (2) is used for sending a level signal to trigger the intrinsic signal output circuit (3) after the gas concentration reaches a set threshold value;

the intrinsic signal output circuit outputs a current signal to the gas meter;

when the MCU (2) determines that the concentration of the gas transmitted by the gas sensor (1) is greater than a preset threshold value, the MCU (2) triggers an output level signal to trigger an essential signal output circuit (3) to output XmA current so as to send an alarm signal, and the gas meter closes a valve after receiving the alarm signal;

when the MCU single chip controller (2) determines that the concentration of the gas transmitted by the gas sensor (1) is smaller than a preset threshold value, the MCU single chip controller (2) does not output a level signal, and the essential signal output circuit (3) outputs YmA current to detect normal operation of the alarm.

2. The alarm system of the internet of things intelligent gas meter according to claim 1, characterized in that: gas sensor (1) includes heating element and gas resistance, be provided with heating resistor between the electrode terminal A of sensor and the electrode terminal B, direct current voltage 5V is connected to the electrode terminal A and the electrode terminal C of sensor, the electrode terminal B of sensor holds the one end of connecting resistance R1, resistance R1's the other end and heating resistor D ground connection, the electrode terminal B of sensor is connected with MCU monolithic controller.

3. The alarm system of the internet of things intelligent gas meter according to claim 2, characterized in that: the intrinsic signal output circuit (3) comprises an LM317 three-terminal regulator, wherein an input end Vi of the LM317 three-terminal regulator is connected with a voltage VCC, an output end Vo is connected with one end of a resistor R3 and an emitting electrode of a PNP type triode Q3 in parallel, a control end Adj is connected with one end of a resistor R4 and the other end of a resistor R3, the other end of the resistor R4 is connected with a collector of a PNP type triode Q3, a base electrode of the PNP type triode Q3 is connected with a collector of an NPN type triode Q2, a collector of the NPN type triode Q2 is connected with an MCU single-chip controller, the emitting electrode of the NPN type triode Q2 is connected with one end of a gas meter and then grounded, and the control end Adj, the resistor R3 and the resistor R.

4. The alarm system of the internet of things intelligent gas meter according to claim 3, characterized in that: and a diode D1, a fuse F1 and a resistor R1 are connected between the connection point of the control end Adj, the resistor R3 and the resistor R4 and the gas meter in sequence.

5. The alarm system of the internet of things intelligent gas meter according to claim 3, characterized in that: the collector of the NPN type triode Q1 is connected with the anode of a diode D1, and a fuse F1 and a resistor R1 are connected between the cathode of the diode D1 and the gas meter.

6. The alarm system of the internet of things intelligent gas meter according to claim 3, characterized in that: and voltage-stabilizing diodes TVI, TV2 and TV3 are connected in parallel between the junction of the control terminal Adj, the resistor R3 and the resistor R4 and the emitter of the NPN type triode Q2.

7. The alarm system of the internet of things intelligent gas meter according to claim 1, characterized in that: still include the circuit power supply, the circuit power supply obtains 12V, 5V and 3.3V's direct current voltage with the 220V alternating current through AD/DC converting circuit, 12V provides voltage for VCC, 5V provides voltage for gas sensor (1), 3.3V provides voltage for MCU monolithic controller (2).

8. The alarm system of the internet of things intelligent gas meter according to claim 1, characterized in that: the XmA =20mA and Y =4 mA.