Detection System for Gas Cut-off Valve

Abstract

The present application provides a detection system for a gas cut-off valve, comprising: a valve state detection circuit, a controller and an alarm. The valve state detection circuit is respectively connected to the gas cut-off valve and the controller, and the controller is connected to the alarm. The valve state detection circuit is configured to, when receiving a unit step signal from the controller, input a unit step signal to an RL circuit composed of the gas cut-off valve and the valve state detection circuit, and input the level signal of the valve state detection circuit to the controller. The level signal of the valve state detection circuit is output by the valve state detection circuit when the RL circuit is under the action of the unit step signal. The controller is configured to input an alarm signal to the alarm according to the change of the level signal of the valve state detection circuit. The alarm is configured to give an alarm according to the received alarm signal. By combining the valve state detection circuit, the controller and the alarm, the effects of the safety and reliability of gas use are achieved.

Description

Technical Field

[0001] The present application relates to equipment detection technology, and in particular to a detection system for a gas cut-off valve. Background Art

[0002] With the wide promotion of the application of gas (such as natural gas), gas has become one of the most important energy sources. The accident risk of gas explosion caused by gas leakage is increasing. Therefore, it is very necessary to adopt preventive measures to reduce the risk of gas explosion. As a safety device in the gas transmission and distribution system, the gas cut-off valve is widely used in the fields of gas (such as medium and low pressure) transmission and distribution, gas thermal energy plants, commercial catering kitchens, residential houses and other occasions. When gas leakage or other safety accidents occur, it can quickly cut off the gas pipeline to prevent gas leakage and cause casualties.

[0003] In the prior art, when gas leakage or other safety accidents occur, a gas meter installed at the rear end of the pipeline of the gas cut-off valve or an alarm installed on the wall will generate a valve closing signal to drive the gas cut-off valve to perform a valve closing action to cut off the gas supply and ensure the safety of personnel and property.

[0004] However, through the above solutions in the prior art, there may be problems such as the gas cut-off valve itself fails to respond to the alarm or the valve closing signal due to reasons such as the failure of the gas cut-off valve itself, resulting in personal safety accidents and property losses. Summary of the Invention

[0005] The present application provides a detection system for a gas cut-off valve to solve the problems that due to reasons such as the failure of the gas cut-off valve itself, it fails to respond to the alarm or the valve closing signal, resulting in personal safety accidents and property losses.

[0006] The present application provides a detection system for a gas cut-off valve, the system includes: a valve state detection circuit, a controller and an alarm; the valve state detection circuit is respectively connected to the gas cut-off valve and the controller, and the controller is connected to the alarm;

[0007] The valve state detection circuit is configured to, when receiving a unit step signal from the controller, input the unit step signal to an RL circuit composed of the gas cut-off valve and the valve state detection circuit, and input a level signal of the valve state detection circuit to the controller, where the level signal of the valve state detection circuit is output by the valve state detection circuit when the RL circuit is under the action of the unit step signal;

[0008] The controller is configured to input an alarm signal to the alarm according to the change of the level signal of the valve state detection circuit;

[0009] The alarm is used to give an alarm according to the received alarm signal.

[0010] In some embodiments, the valve state detection circuit includes: a comparator and a detection sub-circuit; the comparator and the detection sub-circuit are respectively connected to the gas cut-off valve, and the comparator is connected to the detection sub-circuit;

[0011] The comparator is configured to input a unit step signal to the RL circuit when receiving the unit step signal;

[0012] The detection sub-circuit is configured to input a level signal of the detection sub-circuit to the controller according to the voltage signal output by the RL circuit under the action of the unit step signal.

[0013] In some embodiments, the comparator includes: a first operational amplifier and a first voltage dividing circuit, and the first operational amplifier is respectively connected to the detection sub-circuit, the controller, the first voltage dividing circuit, and the gas cut-off valve; wherein,

[0014] The first operational amplifier is configured to input the unit step signal to the RL circuit when receiving the driving signal output by the controller;

[0015] The first voltage dividing circuit is used for voltage division of the first operational amplifier.

[0016] In some embodiments, the detection sub-circuit includes: a second operational amplifier and a pull-up resistor, and the second operational amplifier is respectively connected to the first operational amplifier, the pull-up resistor, the controller, and the gas cut-off valve, and the pull-up resistor is further connected to the first operational amplifier and the gas cut-off valve; wherein,

[0017] The pull-up resistor is used to form an RL circuit with the inductor in the gas cut-off valve;

[0018] The second operational amplifier inputs the level signal of the detection sub-circuit to the controller based on the voltage signal output by the inductor under the action of the unit step signal.

[0019] In some embodiments, the detection sub-circuit includes: a second voltage dividing circuit, and the second voltage dividing circuit is connected to the second operational amplifier; wherein,

[0020] The second voltage dividing circuit is used for voltage division of the second operational amplifier.

[0021] In some embodiments, the system further includes a valve closing signal acquisition circuit, and the valve closing signal acquisition circuit is respectively connected to the gas cut-off valve and the controller;

[0022] The valve closing signal acquisition circuit is used to divide the voltage of the gas cut-off valve to obtain a voltage signal after voltage division processing, and input the voltage signal after voltage division processing into the controller;

[0023] The controller is used to input an alarm signal to the alarm according to the voltage signal after voltage division processing.

[0024] In some embodiments, the detection system further includes: a diode, and the diode is respectively connected to the valve state detection circuit and the gas cut-off valve; wherein,

[0025] The diode is used to block the current flowing from the gas cut-off valve to the valve state detection circuit.

[0026] In some embodiments, the detection system further includes: a triode and a PMOS transistor, the PMOS transistor is respectively connected to the diode, the gas cut-off valve, and the triode, and the triode is respectively connected to the controller and the PMOS transistor; wherein,

[0027] The triode is used to receive a high-level signal input by the controller, conduct based on the high-level signal input by the controller, and input a voltage signal to the PMOS;

[0028] The PMOS transistor is used to conduct according to the voltage signal input by the triode.

[0029] In some embodiments, the controller is specifically used to determine the level flip time of the level signal of the valve state detection circuit according to the change of the level signal of the valve state detection circuit, and input an alarm signal to the alarm according to the level flip time.

[0030] In some embodiments, the controller is specifically used to determine the inductance of the inductor in the gas cut-off valve according to the level flip time, and input an alarm signal to the alarm according to the inductance.

[0031] In some embodiments, the detection system further includes: an NMOS transistor and a PMOS transistor, the PMOS transistor is respectively connected to the diode, the gas cut-off valve, and the NMOS transistor, and the NMOS transistor is also connected to the controller; wherein,

[0032] The NMOS transistor is used to receive a high-level signal input by the controller, conduct based on the high-level signal input by the controller, and input a voltage signal to the PMOS;

[0033] The PMOS transistor is used to conduct according to the voltage signal input by the NMOS transistor.

[0034] In some embodiments, the alarm includes: a sound alarm and / or a light alarm.

[0035] The detection system of the gas cut-off valve provided by the present application detects whether the gas cut-off valve is in an open state or a closed state by combining a valve state detection circuit and a controller, and the controller outputs an alarm signal to the alarm, so that the alarm issues an alarm based on the alarm signal. By this means, disadvantages such as safety accidents caused by the failure of the gas cut-off valve itself to respond to the closing valve drive voltage signal are avoided, and the safety and reliability of gas use are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present disclosure and, together with the specification, are used to explain the principles of the present disclosure.

[0037] Figure 1 Schematic diagram of the detection system of the gas cut-off valve according to an embodiment of the present application;

[0038] Figure 2 Schematic diagram of the valve state detection circuit according to an embodiment of the present application;

[0039] Figure 3 Schematic diagram of the response test circuit of the unit step signal of the RL circuit;

[0040] Figure 4 Schematic diagram of the detection system of the gas cut-off valve according to an embodiment of the present application

[0041] Figure 5 Schematic diagram of the circuit principle of the detection system of the gas cut-off valve according to an embodiment of the present application;

[0042] Through the above-mentioned accompanying drawings, specific embodiments of the present disclosure have been shown, and there will be more detailed descriptions hereinafter. These drawings and the textual descriptions are not intended to limit the scope of the concept of the present disclosure in any way, but to illustrate the concept of the present disclosure to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0044] The terms involved in the present application are explained as follows:

[0045] Gas cut-off valve: A new type of safety supporting device for gas pipeline projects, which can be applied to the following scenarios: connected to a combustible gas leakage monitoring instrument, when the instrument detects combustible gas leakage, it automatically and quickly closes the main gas supply valve, cuts off the gas supply, and timely prevents the occurrence of serious accidents.

[0046] Unit step signal: It means that when t < 0, the signal value is constantly 0, and when t > 0, the signal value is constantly 1.

[0047] RL circuit: It refers to a resistor-inductor circuit (Resistor-inductor circuit), also known as an RL filter or RL network, which is composed of a resistor and an inductor in series or parallel and is driven by a voltage source.

[0048] Operational amplifier: Abbreviated as "op-amp", it refers to a circuit unit with a very high amplification factor.

[0049] Diode: A two-terminal electronic component with asymmetric conductance. An ideal diode has zero resistance between its two electrodes (anode and cathode) when forward-conducting, and infinite resistance when reverse-biased, that is, current is only allowed to flow through the diode in a single direction. Therefore, a diode has the characteristic of unidirectional conductivity and can play roles such as rectification.

[0050] Bipolar Junction Transistor: Also known as a bipolar transistor or a crystal triode, it is a semiconductor device that controls current. Its function is to amplify a weak signal into an electrical signal with a larger amplitude value, and it is also used as a non-contact switch.

[0051] PMOS transistor: It refers to an N-type substrate, P-channel MOS transistor that transports current by the flow of holes. Its full English name is: Positive channel Metal Oxide Semiconductor.

[0052] NMOS transistor: It refers to an N-type Metal-Oxide-Semiconductor. Its full English name is N-Metal-Oxide-Semiconductor.

[0053] Resistor: A current-limiting component. After connecting a resistor to a circuit, the resistance value of the resistor is fixed, usually with two leads, and it can limit the magnitude of the current passing through the branch it is connected to.

[0054] Capacitor: A device that stores electric charge, consisting of two conductors close to each other with a non-conductive insulating medium in between.

[0055] It should be noted that in the related art, the controller sends a valve closing drive voltage signal to the gas cut-off valve, but the on-off state of the gas cut-off valve cannot be detected. When the gas cut-off valve itself fails and cannot respond to the valve closing drive voltage signal of the alarm or the controller, it may cause the gas cut-off valve to fail to perform the normal valve closing action, and the controller cannot determine the on-off state of the gas cut-off valve, and cannot perform fault alarm, thus causing casualty accidents and the like.

[0056] Through creative labor, the inventors of the present application obtained the inventive concept of the present application: combining a valve state detection circuit to detect the state of the valve of the gas cut-off valve and perform alarm accordingly, thereby improving safety.

[0057] Based on the above inventive concept, the present application provides a detection system for a gas cut-off valve.

[0058] Please refer to Figure 1 , Figure 1 which is a schematic diagram of a detection system for a gas cut-off valve according to an embodiment of the present application.

[0059] As Figure 1 shown, the detection system for a gas cut-off valve according to an embodiment of the present application includes:

[0060] a valve state detection circuit 100, a controller 200, and an alarm 300. The valve state detection circuit 100 is respectively connected to the controller 200 and the gas cut-off valve, and the controller 200 is connected to the alarm 300. Among them,

[0061] The valve state detection circuit 100 is configured to input a unit step signal to an RL circuit composed of the gas cut-off valve and the valve state detection circuit 100 when receiving a unit step signal from the controller 200, and input the level signal of the valve state detection circuit to the controller 200. The level signal of the valve state detection circuit is output by the valve state detection circuit 100 under the action of the unit step signal in the RL circuit.

[0062] Exemplarily, it can be determined whether gas leaks through sensors and circuits, etc. When it is determined that gas leaks, the controller 200 can input a unit step signal to the valve state detection circuit 100.

[0063] The valve state detection circuit 100 can form an RL circuit with the gas cut-off valve. Correspondingly, when the valve state detection circuit 100 receives a unit step signal input by the controller 200, the valve state detection circuit 100 can input the unit step signal to the RL circuit and input the level signal of the valve state detection circuit when it is affected by the unit step signal in the RL circuit to the controller 200.

[0064] A controller 200 is configured to detect changes in the level signal of the valve status detection circuit and input an alarm signal to the alarm 300.

[0065] Exemplarily, the controller 200 receives the level signal of the valve status detection circuit input by the valve status detection circuit 100 and can determine changes in the level signal of the valve status detection circuit, such as the level signal of the valve status detection circuit changing from a low-level signal to a high-level signal, etc.

[0066] In some embodiments, the controller 200 may include a single-chip microcomputer chip, and specifically may be STM32G070CB, R7F0C020M2DFB, etc. Corresponding capacitance and resistance circuits may be provided around it, which are not limited in this embodiment.

[0067] An alarm 300 is configured to give an alarm according to the received alarm signal.

[0068] Exemplarily, when the alarm 300 receives the alarm signal input by the controller 200, it gives a sound alarm and / or a light alarm, etc.

[0069] In some embodiments, the alarm may be composed of an LED lighting circuit and a buzzer circuit to trigger an audible and visual alarm, which is not limited in this embodiment.

[0070] It should be noted that in this embodiment, by combining the valve status detection circuit and the controller to detect the valve status of the gas cut-off valve and combining the alarm for alarm, the technical effects of improving the safety and reliability of gas use can be achieved.

[0071] It should be noted that the detection system of the gas cut-off valve may include a power supply circuit, and the power supply circuit supplies power to Figure 1 the valve status detection circuit 100, the controller 200, and the alarm 300 shown in

[0072] Exemplarily, the power supply circuit may be composed of chips, such as TPS5430, MD7602A50, etc., which are not limited in this embodiment.

[0073] Please refer to Figure 2 , Figure 2 which is a schematic diagram of the valve status detection circuit according to an embodiment of the present application.

[0074] As Figure 2 shown, the valve status detection circuit includes:

[0075] A first operational amplifier U1A is respectively connected to the controller, a first voltage-dividing circuit, a second operational amplifier U1B, a pull-up resistor R1, and a diode D1.

[0076] Among them, as Figure 2As shown, pin 3 of the first operational amplifier U1A can be connected to the controller and receive a unit step signal input by the controller based on pin 3 of the first operational amplifier U1A. At this time, pin 1 of the first operational amplifier U1A outputs a high level, and a unit step signal is applied to the RL circuit (i.e., the RL circuit composed of the pull-up resistor R1 and the inductance of the gas cut-off valve) through pin 1 of the first operational amplifier U1A.

[0077] Pin 2 of the first operational amplifier U1A is connected to the first voltage-dividing circuit, and the first voltage-dividing circuit includes R2, R3, and capacitor C1. Among them, R2 is respectively connected to the power supply VCC and capacitor C1, R3 is connected to capacitor C1, and is grounded.

[0078] Pin 8 of the first operational amplifier U1A is connected to the power supply VCC and grounded through capacitor C2.

[0079] Pin 4 of the first operational amplifier U1A is grounded.

[0080] As Figure 2 shown, pin 6 of the second operational amplifier U1B is respectively connected to pin 1 of the first operational amplifier U1A, the pull-up resistor R1, and the diode D1.

[0081] Pin 5 of the second operational amplifier U1B is connected to the second voltage-dividing circuit, and the second voltage-dividing circuit includes R4, R5, and C3. R4 is also connected to the power supply VCC, R5, and C3. R5 is also connected to C3, and both R5 and C3 are grounded.

[0082] Pin 7 of the second operational amplifier U1B is respectively connected to the controller and resistor R6, and R6 is also connected to the power supply VCC.

[0083] As Figure 2 shown, the diode D1 is also connected to the PMOS transistor Q1. The PMOS transistor Q1 is also connected to the gas cut-off valve, resistor R7, and transistor Q2. The transistor Q2 is also connected to the controller through resistor R8 (as a current-limiting resistor) and is grounded.

[0084] Combined with the circuit diagram as Figure 2 shown, the valve state detection circuit has two states. One state is the state of not being detected, and the other state is the detection state. Exemplarily, the description of the valve state detection circuit when it is in the state of not being detected is as follows:

[0085] The controller places the pin where resistor R8 is connected to triode Q2 at a low level through resistor R8. For example, it can be specifically implemented through the I / O port with output function. Correspondingly, triode Q2 is not turned on, and PMOS transistor Q1 is also not turned on. At this time, the unit step signal is not generated, and pin 1 of the first operational amplifier U1A defaults to output a low-level signal, while pin 7 of the second operational amplifier U1B defaults to output a high-level signal.

[0086] Exemplarily, the description of the valve state detection circuit when detecting the state is as follows:

[0087] The controller places the pin where resistor R8 is connected to triode Q2 at a high level through resistor R8. For example, it can be specifically implemented through the I / O port with output function. Correspondingly, triode Q2 is turned on, and PMOS transistor Q1 is also turned on.

[0088] The controller inputs a unit step signal to pin 3 of the first operational amplifier U1A. For example, it can be specifically implemented through the I / O port with output function. Correspondingly, pin 1 of the first operational amplifier U1A applies a unit step signal to the RL circuit. At this time, pin 1 of the first operational amplifier U1A outputs a high-level signal.

[0089] Correspondingly, the output level signal of pin 7 of the second operational amplifier U1B is at a low level. Due to the unit step response property of the inductor, the voltage across the inductor in the gas cut-off valve gradually decreases. When the voltage across the inductor reaches the voltage threshold, the output level signal of pin 7 of the second operational amplifier U1B flips from low level to high level.

[0090] Combined with the above analysis, it can be seen that the second voltage division circuit can be used to divide the voltage for the second operational amplifier. In some embodiments, the voltage threshold can be determined based on the second voltage division circuit. For example, the voltage division threshold = VCC * (R5 / (R4 + R5)). That is, due to the unit step response property of the inductor, the voltage across the inductor in the gas cut-off valve gradually decreases. When the voltage across the inductor drops to VCC * (R5 / (R4 + R5)), the output level signal of pin 7 of the second operational amplifier U1B is at a high level.

[0091] The controller receives the level signal output by pin 7 of the second operational amplifier U1B. For example, it can be specifically implemented through the I / O port with ADC function. And the controller records the time from when the controller starts to control the application of the unit step signal to the moment when the output level signal of pin 7 of the second operational amplifier U1B undergoes a level flip (i.e., the level flip time), and then determines whether the gas cut-off valve is in the open valve state or the closed valve state based on the level flip time.

[0092] In some embodiments, the inductance of the gas shut-off valve has different electric quantities when the gas shut-off valve is in the closed state and the open state. Accordingly, the controller can determine the inductance of the inductance in the gas shut-off valve based on the level flip time, that is, determine the inductance of L in the RL circuit, and determine whether the gas shut-off valve is in the open state or the closed state according to the inductance. When the controller 200 determines that the gas shut-off valve is in the open state, an alarm signal is input to the alarm, and the alarm sounds an alarm based on the alarm signal.

[0093] It is worth noting that the diode D1 blocks the current from the gas shut-off valve to the valve state detection circuit, preventing the current from the gas shut-off valve from flowing back to the valve state detection circuit. In some embodiments, the diode D1 may not be provided, and this embodiment is not limited thereto.

[0094] Now combined with Figure 3 The principle of the unit step signal response test of the RL circuit is described as an example. Figure 3 The schematic diagram of the test circuit for the unit step signal response of the RL circuit.

[0095] like Figure 3 As shown, the resistor R and the inductor L form an RL circuit, S is a switch, U is the power supply voltage, and the voltage on the inductor L is U L (t), the voltage U on the inductor L L The relationship between (t) and time t can be expressed based on Formula 1:

[0096]

[0097] in, is the time constant of the inductor L, L is the inductance of the inductor, R is the resistance of the resistor, U is the power supply voltage, and e is a constant.

[0098] By transforming equation 1, we can get equation 2:

[0099]

[0100] Based on formula 2, we can know that if U L The ratio of K to U is a fixed value. For inductors with different inductances, the fixed value formulas shown in Equation 3 and Equation 4 can be obtained. Equation 3:

[0101]

[0102] Formula 4:

[0103]

[0104] Accordingly, based on equation 3 and equation 4, the relationship between the inductances of different inductances can be obtained as equation 5:

[0105]

[0106] Based on the above analysis, it can be known that and then substitute them into Equation 5 to obtain the expression of the change between time and inductance, Equation 6: Equation 6:

[0107]

[0108] Combined with the above analysis, it can be known that in this embodiment, based on the change relationship between time and inductance, it is possible to determine whether the gas cut-off valve is in the open valve state or the closed valve state, thereby improving the safety of gas use.

[0109] Please refer to Figure 4 , Figure 4 which is a schematic diagram of the detection system of the gas cut-off valve according to an embodiment of the present application.

[0110] As Figure 4 shown, the detection system of the gas cut-off valve according to the embodiment of the present application further includes: a valve closing signal acquisition circuit 400, and the valve closing signal acquisition circuit 400 is respectively connected to the controller 200, the valve switch circuit and the gas cut-off valve. Among them,

[0111] The valve closing signal acquisition circuit 400 is used to perform voltage division processing on the voltage applied to the gas cut-off valve by the valve switch circuit to obtain a voltage signal after voltage division processing, and input the voltage signal after voltage division processing into the controller 200.

[0112] The controller 200 is used to input an alarm signal to the alarm 300 according to the voltage signal after voltage division processing input by the valve closing signal acquisition circuit 400.

[0113] It should be noted that when the valve switch circuit provides a valve closing drive voltage signal for the gas cut-off valve, the gas cut-off valve cuts off the gas flow based on the valve closing drive voltage signal, that is, the gas cut-off valve switches from the open valve state to the closed valve state. In order to ensure the reliability of the valve closing drive voltage signal and make the gas cut-off valve in the closed valve state, the valve closing signal acquisition circuit 400 is introduced in this embodiment to determine whether the gas cut-off valve is in the closed valve state or the open valve state based on the voltage signal after voltage division processing.

[0114] Please refer to Figure 5 , Figure 5 which is a schematic diagram of the circuit principle of the detection system of the gas cut-off valve according to the embodiment of the present application.

[0115] As Figure 5As shown in the figure, the valve closing signal acquisition circuit 400 includes: resistor R9, resistor R10, capacitor C4, resistor R11 (current-limiting resistor). Resistor R9 is respectively connected to the valve switch circuit, the gas cut-off valve, resistor R10, capacitor C4, and resistor R11. Resistor R10 is also connected to capacitor C4 and resistor R11. Resistor R10 and capacitor C4 are also grounded. Resistor R11 is also connected to the controller 200. Among them,

[0116] After the valve closing drive voltage signal is divided by resistor R9 and resistor R10, it is input to the controller through resistor R11. The controller determines whether the gas cut-off valve is in the valve-closed state or the valve-open state based on the voltage signal after voltage division processing. And if the gas cut-off valve is in the valve-open state, that is, the gas can still flow, an alarm signal is output to the alarm so that the alarm can give an alarm based on the alarm signal.

[0117] For example, the voltage of the valve closing drive voltage signal of the gas cut-off valve is X (V), and the voltage of the valve closing determination voltage signal determined by the controller based on the collected voltage signal after voltage division processing is Y (V). If Y < X, the controller determines that the gas cut-off valve is in the valve-open state and outputs an alarm signal to the alarm; if Y = X, the controller determines that the gas cut-off valve is in the valve-closed state.

[0118] As Figure 5 shown in the figure, the valve switch circuit includes: relay J, diode D2, triode Q3, resistor 12, MOS tube Q4, resistor R13, triode Q5, resistor 14, diode D3. The pin 1 of relay J is respectively connected to the power supply VDD and diode D2. The pin 12 of relay J is respectively connected to diode D2 and diode D3. Diode D2 is also respectively connected to the power supply VDD and diode D3. Triode Q3 is connected to the controller through resistor 12. The pin 5 of relay J is connected to the power supply VDD. The pin 6 of relay J is respectively connected to resistor R13 and MOS tube Q4. Triode Q5 is respectively connected to resistor R13 and MOS tube Q4, and triode Q5 is also connected to the controller through resistor 14 and is grounded. Diode D3 is respectively connected to MOS tube Q4, the valve closing signal acquisition circuit 400, and the gas cut-off valve, and is grounded. Among them,

[0119] The controller can output a high level based on the I / O port with output function. This high level, after passing through resistor R12, serves as the base drive voltage of triode Q3. Accordingly, triode Q3 conducts.

[0120] Accordingly, the power supply VDD supplies power to relay J, and a current flows through the coil inside relay J, causing the contact switch state to change (relay J switches from the initial closure of pins 4 and 5 to the closure of pins 5 and 6).

[0121] Accordingly, the controller outputs a high level based on the I / O port of the output function. After passing through the resistor R14, this high level serves as the base drive voltage of the triode Q5. Correspondingly, the triode Q5 conducts, and the MOS transistor Q4 also conducts. The valve closing drive voltage signal output from the pin 6 of the relay J acts on the gas cut-off valve, causing the gas cut-off valve to close.

[0122] Among them, the diodes D2 and D3 are energy discharge diodes. The diode D2 is for discharging the energy of the internal coil (inductive load) of the relay J, and the diode D3 is for discharging the energy of the internal coil (inductive load) of the gas cut-off valve.

[0123] In some embodiments, the pin 6 of the relay J can also be connected to the capacitor C5, and C5 is also respectively connected to the resistor R13 and the MOS transistor Q4. The capacitor C5 is a filter capacitor, which is used to filter out the voltage spikes and noise of the valve closing drive voltage signal output by the relay J, making the valve closing drive voltage signal more stable.

[0124] It should be noted that:

[0125] On the one hand, in the circuit schematic diagram as Figure 5 shown, the triode Q2 can be an NMOS transistor; the resistor R5 can be an adjustable resistor; the diodes D2 and D3 can be removed.

[0126] On the other hand, for the selection of relevant parameters such as the models of the components (such as capacitors, resistors, diodes, and triodes, etc.) as shown in Figure 5 , it can be achieved based on requirements, historical records, and tests, etc. This embodiment does not make any limitations.

[0127] On yet another aspect, the detection system of the gas cut-off valve can include: a valve closing signal acquisition circuit, a controller, and an alarm. That is, in one example, it can be determined whether the gas cut-off valve is in the open valve state or the closed valve state based on the valve closing signal acquisition circuit, the controller, and the alarm; in another example, it can also be determined whether the gas cut-off valve is in the open valve state or the closed valve state based on the valve state detection circuit, the controller, and the alarm; in yet another example, it can also be determined whether the gas cut-off valve is in the open valve state or the closed valve state based on the valve closing signal acquisition circuit, the valve state detection circuit, the controller, and the alarm.

[0128] It should be noted that if the detection system of the gas cut-off valve includes: a valve closing signal acquisition circuit, a valve state detection circuit, a controller, and an alarm, that is, it is determined whether the gas cut-off valve is in the open valve state or the closed valve state based on the valve closing signal acquisition circuit, the valve state detection circuit, the controller, and the alarm, it can include the following examples:

[0129] In one example, it is possible to first determine whether the gas cut-off valve is in the open state or the closed state based on the valve closing signal acquisition circuit. When it is determined that the gas cut-off valve is in the closed state based on the valve closing signal acquisition circuit, further determine whether the gas cut-off valve is in the open state or the closed state based on the valve state detection circuit. And when it is determined that the gas cut-off valve is in the open state based on the valve state detection circuit, an alarm is issued based on the alarm device.

[0130] In another example, it is possible to first determine whether the gas cut-off valve is in the open state or the closed state based on the valve state detection circuit. When it is determined that the gas cut-off valve is in the closed state based on the valve state detection circuit, further determine whether the gas cut-off valve is in the open state or the closed state based on the valve closing signal acquisition circuit. And when it is determined that the gas cut-off valve is in the open state based on the valve closing signal acquisition circuit, an alarm is issued based on the alarm device.

[0131] In yet another example, it is possible to simultaneously determine whether the gas cut-off valve is in the open state or the closed state based on the valve state detection circuit and the valve closing signal acquisition circuit respectively. And when it is determined that the gas cut-off valve is in the open state based on one of the circuits, an alarm is issued based on the alarm device.

[0132] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include known common knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0133] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A detection system for a gas cut-off valve, characterized in that, the system includes: a valve state detection circuit, a valve closing signal acquisition circuit, a controller and an alarm; the valve state detection circuit is respectively connected to the gas cut-off valve and the controller, the controller is connected to the alarm, and the valve closing signal acquisition circuit is respectively connected to the gas cut-off valve, a valve switch circuit and the controller, wherein the valve state of the gas cut-off valve is determined based on the valve state detection circuit and the valve closing signal acquisition circuit at the same time, and the valve state is an open valve state or a closed valve state; the valve state detection circuit is configured to input the unit step signal to the RL circuit composed of the gas cut-off valve and the valve state detection circuit when receiving the unit step signal from the controller, and input the level signal of the valve state detection circuit to the controller, and the level signal of the valve state detection circuit is output by the valve state detection circuit when the RL circuit is under the action of the unit step signal; the valve closing signal acquisition circuit is configured to perform voltage division processing on the voltage applied to the gas cut-off valve by the valve switch circuit to obtain a voltage signal after voltage division processing, and input the voltage signal after voltage division processing to the controller; the controller is configured to determine the valve state of the gas cut-off valve according to the change of the level signal of the valve state detection circuit, and determine the valve state of the gas cut-off valve according to the voltage signal after voltage division processing; it is also configured to input an alarm signal to the alarm when it is determined that the gas cut-off valve is in an open valve state based on the valve state detection circuit and / or the valve closing signal acquisition circuit; the alarm is configured to give an alarm according to the received alarm signal.

2. The detection system according to claim 1, characterized in that, the valve state detection circuit includes: a comparator and a detection sub-circuit; the comparator and the detection sub-circuit are respectively connected to the gas cut-off valve, and the comparator is connected to the detection sub-circuit; the comparator is configured to input the unit step signal to the RL circuit when receiving the unit step signal; the detection sub-circuit is configured to input the level signal of the detection sub-circuit to the controller according to the voltage signal output by the RL circuit under the action of the unit step signal.

3. The detection system according to claim 2, characterized in that, the comparator includes: a first operational amplifier and a first voltage division circuit, and the first operational amplifier is respectively connected to the detection sub-circuit, the controller, the first voltage division circuit, and the gas cut-off valve; wherein, the first operational amplifier is configured to input the unit step signal to the RL circuit when receiving the drive signal output by the controller; the first voltage division circuit is configured to divide the voltage for the first operational amplifier.

4. The detection system according to claim 3, characterized in that, The detection sub - circuit includes: a second operational amplifier and a pull - up resistor. The second operational amplifier is connected to the first operational amplifier, the pull - up resistor, the controller, and the gas cut - off valve respectively. The pull - up resistor is also connected to the first operational amplifier and the gas cut - off valve; wherein, the pull - up resistor is used to form an RL circuit with the inductor in the gas cut - off valve; the second operational amplifier inputs the level signal of the detection sub - circuit to the controller based on the voltage signal output by the inductor under the action of the unit step signal.

5. The detection system according to claim 4, wherein, the detection sub - circuit includes: a second voltage - dividing circuit. The second voltage - dividing circuit is connected to the second operational amplifier; wherein, the second voltage - dividing circuit is used to divide the voltage for the second operational amplifier.

6. The detection system according to any one of claims 1 to 5, wherein, the detection system further includes: a diode. The diode is connected to the valve state detection circuit and the gas cut - off valve respectively; wherein, the diode is used to block the current flowing from the gas cut - off valve to the valve state detection circuit.

7. The detection system according to claim 6, wherein, the detection system further includes: a triode and a PMOS transistor. The PMOS transistor is connected to the diode, the gas cut - off valve, and the triode respectively. The triode is connected to the controller and the PMOS transistor respectively; wherein, the triode is used to receive the high - level signal input by the controller, conduct based on the high - level signal input by the controller, and input a voltage signal to the PMOS transistor; the PMOS transistor is used to conduct according to the voltage signal input by the triode.

8. The detection system according to any one of claims 1 to 5, wherein, the controller is specifically used to determine the level flip - flop time of the level signal of the valve state detection circuit according to the change of the level signal of the valve state detection circuit, and input an alarm signal to the alarm according to the level flip - flop time.

9. The detection system according to claim 8, wherein, the controller is specifically used to determine the inductance of the inductor in the gas cut - off valve according to the level flip - flop time, and input an alarm signal to the alarm according to the inductance.

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