Combustible gas detector
By introducing protection resistor and differential amplifier circuits into the combustible gas gas detector, combined with temperature detection module and voltage stabilization state detection, the problems of sensor vulnerability and complex circuits are solved, and the self-diagnosis of the sensor and the stability of the detector are improved.
Patent Information
- Application Number
- CN202421779025.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-26
- Publication Date
- 2025-08-05
- Estimated Expiration
- 2034-07-26
AI Technical Summary
Existing combustible gas detectors are susceptible to wiring errors under constant pressure, which may damage the sensor, and lack self-diagnosis function, the circuit structure is complex, and the temperature cannot be adjusted effectively, resulting in insufficient stability and safety of the detector.
The protective resistor is used to prevent overcurrent from damaging the sensor, combined with the differential amplifier circuit, the temperature detection module and the voltage stabilization state detection module, the sensor status is monitored through the controller module, realize the self-diagnosis function, and protect the sensor and control board through the power monitoring module.
It improves the protection effect of the sensor, simplifies the circuit structure, enhances the stability and safety of the detector, reduces the probability of system failure, and achieves good temperature characteristics and self-diagnosis functions.
Smart Images
Figure CN223192929U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of combustible gas detection, in particular to a combustible gas detector. Background Art
[0002] A combustible gas detector is a detector that responds to the concentration of a single or multiple combustible gases.
[0003] Currently, combustible gas detectors in industrial safety basically use catalytic combustion to detect combustible gases. The sensor power supply has two modes: constant current and constant voltage. Without considering the influence of sensor wire resistance, the constant current mode has a relatively large error, while the constant voltage mode has a relatively high accuracy.
[0004] However, in related technologies, incorrect sensor wiring in constant pressure mode can affect sensor performance and potentially damage the sensor, potentially damaging the control board. Furthermore, current zero-point adjustment schemes for flammable gas detectors in industrial safety applications are outdated or complex. They lack effective ambient temperature detection, making temperature adjustment and compensation difficult. Self-diagnosis capabilities are poor, and the control chip has too few analog peripherals. This results in complex circuit structures for mid- to high-end flammable gas detectors, making production inconvenient and incapable of detecting and adjusting damage. Summary of the Invention
[0005] The utility model relates to a combustible gas detector, which can sensitively sense its own fault conditions, protect the sensor from damage, reduce system costs, and improve the stability and safety of the detector.
[0006] The combustible gas detector includes an explosion-proof host component and an explosion-proof sensor component;
[0007] The explosion-proof sensor assembly includes a combustible gas sensor and a protective resistor;
[0008] The protective resistor is connected in series to the signal output line of the combustible gas sensor to prevent the combustible gas sensor from being damaged by overcurrent due to incorrect connection.
[0009] In an optional embodiment, the flameproof host assembly further includes a power module;
[0010] The power module includes a sensor voltage-stabilized power supply and a sensor power switch;
[0011] The sensor voltage-stabilized power supply is connected to the combustible gas sensor and is used to supply power to the combustible gas sensor;
[0012] The sensor power switch is connected to the sensor regulated power supply and the switching voltage regulated module.
[0013] In an optional embodiment, the flameproof host assembly further includes a controller module, an overvoltage sampling module, and a sensor power supply monitoring module;
[0014] The sensor power supply monitoring module is connected to the controller module;
[0015] The sensor voltage-stabilized power supply monitoring module is used to detect the power supply status of the sensor voltage-stabilized power supply and send it to the controller module.
[0016] In an optional embodiment, the sensor power supply monitoring module is implemented as a sensor power supply voltage sampling module;
[0017] The controller module includes an analog-to-digital conversion third input module;
[0018] The sensor power supply voltage sampling module is connected to the third input module of the analog-to-digital conversion.
[0019] In an optional embodiment, the explosion-proof host assembly further includes a differential amplification module;
[0020] The controller also includes a first analog-to-digital conversion input module and a second digital-to-analog conversion output module;
[0021] The input of the differential amplifier module is connected to the protection resistor;
[0022] The differential amplifier module is connected to the first analog-to-digital conversion input module and the second digital-to-analog conversion output module.
[0023] In an optional embodiment, the flameproof host assembly further includes an overvoltage sampling module, and the controller module includes a comparator;
[0024] The overvoltage sampling module is connected to the sensor's regulated power supply, and the overvoltage sampling module is connected to the signal input terminal of the comparator;
[0025] The signal output terminal of the comparator is connected to the sensor power switch;
[0026] The comparator is used to receive the signal from the overvoltage sampling module to perform overvoltage detection, and send a control signal to the sensor power switch based on the detection result.
[0027] In an optional embodiment, the flameproof host assembly further includes a switching voltage regulator module, a linear voltage regulator module, and a power supply voltage sampling module;
[0028] The controller also includes an analog-to-digital conversion fourth input module;
[0029] The switching voltage regulator module is connected to the sensor power switch, and the switching voltage regulator module is connected to the linear voltage regulator module;
[0030] The switching voltage regulator module and the power supply voltage sampling module are connected via a 24V input power line;
[0031] The power supply voltage sampling module is connected to the fourth input module of the analog-to-digital conversion.
[0032] In an optional embodiment, the flameproof host assembly further includes a temperature sampling module;
[0033] The controller also includes an analog-to-digital conversion fifth input module;
[0034] The temperature sampling module is connected to the fifth input module of the analog-to-digital conversion.
[0035] In an optional embodiment, the explosion-proof host assembly further includes a signal input module;
[0036] The signal input module is connected to the controller;
[0037] The signal input module is implemented with three-way signal input function.
[0038] In an optional embodiment, the flameproof host assembly further includes a communication module, a visualization result output module, a relay output module, and a current output module;
[0039] The controller includes a digital-to-analog conversion output terminal;
[0040] The communication module is communicatively connected with the output end of the controller;
[0041] The visualization result output module is connected to the output terminal of the controller;
[0042] The relay output module is connected to the output terminal of the controller;
[0043] The current output module is connected to the first digital-to-analog conversion output module of the controller.
[0044] The beneficial effects of the technical solution provided by the utility model include at least:
[0045] In the combustible gas detector, a differential amplifier circuit, a temperature detection module, and a voltage stabilization status detection module are installed in conjunction with the controller module and the combustible gas sensor. This allows the controller module to monitor the sensor's voltage status and ambient temperature during operation, thereby determining the sensor's operating status during combustible gas detection. While maintaining a simple circuit structure, the detector, housing the combustible gas sensor, provides comprehensive self-diagnostic functionality and excellent temperature characteristics. The sensor protection resistor, voltage stabilization power switch, and overvoltage sampling module protect the sensor and control board's power supply from damage, reducing the probability of system failures caused by high currents generated by sensor short circuits. BRIEF DESCRIPTION OF THE DRAWINGS
[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0047] Figure 1 The figure shows a simplified structural block diagram of the combustible gas detector of the present application.
[0048] Figure 2 A schematic diagram of the circuit structure connection of the combustible gas detector of the present application is shown.
[0049] Figure 3 A schematic diagram showing the connection relationship between the combustible gas sensor and the differential amplifier module of the present application is shown.
[0050] Figure 4 The figure shows a schematic structural diagram of the DC24V voltage sampling module of the present application.
[0051] Figure 5 The figure shows a schematic structural diagram of the temperature sample module of the present application.
[0052] Figure 6 The figure shows a schematic structural diagram of the signal input module of the present application. DETAILED DESCRIPTION
[0053] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0054] The present application provides a combustible gas detector, comprising an explosion-proof host assembly and an explosion-proof sensor assembly, wherein the explosion-proof sensor assembly comprises a combustible gas sensor and a protective resistor. The protective resistor is used to prevent overcurrent damage caused by incorrect connection of the combustible gas sensor.
[0055] The combustible gas sensor involved in the embodiments of this application is implemented as a catalytic combustion gas sensor, model NAP-57A, NAP-55A (for civilian use), or other suitable models. This combustible gas sensor is installed in an explosion-proof sensor assembly to ensure that the combustible gas detector meets explosion-proof requirements. The combustible gas sensor assembly is connected to the differential amplifier module via a three-wire input and output method. Protective resistors are provided on the signal output lines. This ensures that in the event of a wiring error, the current flowing through the combustible gas sensor is significantly lower than normal, protecting the sensor from damage. In this case, the controller module can also detect the error.
[0056] Figure 1FIG1 shows a structural block diagram of a combustible gas sensor provided by an exemplary embodiment of the present application. Figure 2 A schematic diagram of the specific connection relationship of a combustible gas detector provided by an exemplary embodiment of the present application is shown. Figure 1 as well as Figure 2 , further explain the structure of the combustible gas detector involved in the application:
[0057] In an optional embodiment, the explosion-proof host assembly also includes a power supply module; the power supply module includes a sensor voltage-stabilized power supply 7 and a sensor power switch 6; the sensor voltage-stabilized power supply 7 is connected to the combustible gas sensor 3 for supplying power to the combustible gas sensor 3; the sensor power switch 6 is connected to the sensor voltage-stabilized power supply 7 and the switching voltage-stabilizing module 21.
[0058] In an optional embodiment, the explosion-proof host assembly also includes a controller module 5, an overvoltage sampling module 9 and a sensor power monitoring module; the sensor power monitoring module is connected to the controller module 5; the sensor power monitoring module is used to detect the power supply status of the sensor regulated power supply 7 and send it to the controller module 5.
[0059] In the embodiment of the present application, the controller module 5 is implemented as a C8051 series CPU, and includes a combination of modules such as FLASH, RAM, digital I / O, UART, analog comparator, analog-to-digital converter (A / D), and digital-to-analog converter (D / A). The present application does not limit the specific implementation of the controller module 5.
[0060] In an optional embodiment, the sensor power supply monitoring module is implemented as a sensor power supply voltage sampling module 24; the controller module 5 includes an analog-to-digital conversion third input module 55; the sensor power supply voltage sampling module 24 is connected to the analog-to-digital conversion third input module 55.
[0061] In an optional embodiment, the explosion-proof host assembly also includes a differential amplifier module 4; the controller module 5 also includes a first analog-to-digital conversion input module 54 and a second digital-to-analog conversion output module 51; the input of the differential amplifier module 4 is connected to the protective resistor 31; the differential amplifier module 4 is connected to the first analog-to-digital conversion input module 54 and the second digital-to-analog conversion output module 51.
[0062] Please refer to Figure 3The diagram shows the connection between the combustible gas sensor 3, the differential amplifier module 4, the sensor voltage regulator 7, and the sensor power switch 6. The combustible gas sensor 3, along with the protective resistor 31, is assembled in the explosion-proof sensor assembly and connected via three wires: P1, P2, and P3. P3 is connected to GND, P1 to the sensor voltage regulator 7, and P2 to the signal input of the differential amplifier module 4. The zero adjustment input of the differential amplifier module 4 is connected to the second digital-to-analog converter output module 51. The output of the second digital-to-analog converter output module 51 and the sensor power supply are combined via resistors R22, R24, and R25 to generate a high-resolution voltage for zeroing the differential amplifier module 4. After zeroing, the differential amplifier module 4 amplifies the output signal of the combustible gas sensor, which is then fed to the corresponding channel of the first analog-to-digital converter input module 54. The input of the sensor power switch 6 is connected to the output of the switching voltage regulator module 21, the switch output is connected to the input of the sensor voltage regulator 7, and the control terminal of the sensor power switch 6 is connected to the output of the overvoltage comparator. The output of the sensor voltage-stabilized power supply 7 is also sent to the input of the overvoltage sampling module 9 and the input of the sensor power supply voltage sampling module 24 at the same time.
[0063] In an optional embodiment, the explosion-proof host assembly also includes an overvoltage sampling module 9, and the controller module includes a comparator; the overvoltage sampling module 9 is connected to the sensor voltage-stabilized power supply 7, and the overvoltage sampling module 9 is connected to the signal input end of the comparator; the signal output end of the comparator is connected to the sensor power switch 6; the comparator is used to receive the signal of the overvoltage sampling module 9 to perform overvoltage detection, and send a control signal to the sensor power switch 6 based on the detection result.
[0064] In an optional embodiment, the explosion-proof host assembly also includes a switching voltage regulator module 21, a linear voltage regulator module 22 and a power supply voltage sampling module 23; the controller module 5 also includes an analog-to-digital conversion fourth input module 53; the switching voltage regulator module 21 is connected to the sensor power switch 6, and the switching voltage regulator module 21 is connected to the linear voltage regulator module 22; the switching voltage regulator module 21 is connected to the power supply voltage sampling module 23 through a 24V input power line; the power supply voltage sampling module 23 is connected to the analog-to-digital conversion fourth input module 53.
[0065] It should be noted that, in the embodiment of the present application, the first analog-to-digital conversion input module 54, the third analog-to-digital conversion input module 55, the fourth analog-to-digital conversion input module 53, and the fifth analog-to-digital conversion input module 56 can be implemented as different input ports of the same analog-to-digital conversion input module, or as different analog-to-digital conversion input modules. The present application does not limit the actual form of the analog-to-digital conversion input module. This description also applies to the digital-to-analog conversion output module.
[0066] Figure 4The schematic diagram of the overvoltage sampling module in an exemplary embodiment of the present invention is shown. It is a simple resistor divider circuit, with the upper divider resistors R33 and R39 connected in series. The divider input is connected to +24VDC, and the divider output is connected to the fourth input module 53 of the analog-to-digital conversion.
[0067] In an optional embodiment, the explosion-proof host assembly further includes a temperature sampling module 10 ; the controller further includes an analog-to-digital conversion fifth input module 56 ; the temperature sampling module 10 is connected to the analog-to-digital conversion fifth input module 56 .
[0068] Figure 5 The schematic diagram of the structure of the temperature sampling module in an exemplary case of the present application is shown. It is a resistor voltage divider circuit, R50 is an MF52 temperature measurement thermistor, and the voltage divider output is sent to the fifth input module 56 of the analog-to-digital conversion.
[0069] In an optional embodiment, the explosion-proof host assembly further includes a signal input module 1 ; the signal input module 1 is connected to the controller module 5 ; the signal input module 1 is implemented as an input module with three-way signal input function.
[0070] In the embodiment of the present application, the structure of the signal input module is as follows: Figure 6 The signal input module provides three inputs, two of which are optically isolated and used to reset the relay and zero point, and the other is a Hall effect detector input. The gas detector can be set using a magnet.
[0071] In an optional embodiment, the explosion-proof host assembly also includes a communication module 13, a visualization result output module 14, a relay output module 114 and a current output module 8; the controller module 5 includes a first digital-to-analog conversion output module 52; the communication module 13 is communicatively connected to the output end of the controller module 5; the visualization result output module 14 is connected to the output end of the controller module 5; the relay output module 114 is connected to the output end of the controller module 5; and the current output module 8 is connected to the first digital-to-analog conversion output module 52 of the controller module 5.
[0072] Optionally, the communication module is implemented as an RS485 module for MODBUS communication.
[0073] Correspondingly, the controller module 5 sets the output of the first digital-to-analog conversion output module 52 to drive the 4-20MA output module 8 to output the corresponding 4-20MA current, sets the visualization result output module 14 to display the combustible gas concentration and alarm status, and sets the relay output module 114 to generate the corresponding alarm contact output according to the detected combustible gas concentration.
[0074] In summary, the devices provided in the various embodiments of the present application, in the combustible gas detector, are provided with a differential amplifier circuit, a temperature detection module, and a voltage stabilization state detection module corresponding to the controller module and the combustible gas sensor. This allows the controller module to know the voltage state and ambient temperature of the sensor during use, thereby determining the operating state of the combustible gas sensor during the combustible gas detection process. While maintaining a simple circuit structure, the detector containing the combustible gas sensor has a complete self-diagnostic function and good temperature characteristics. The provision of a sensor protection resistor, a voltage stabilization power switch, and an overvoltage sampling module protects the sensor and the control board power supply from damage and reduces the probability of system chaos and failure caused by high current generated by a sensor short circuit.
[0075] The above are only optional embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A combustible gas detector, characterized in that: The combustible gas detector includes an explosion-proof host component and an explosion-proof sensor component; The explosion-proof sensor assembly includes a combustible gas sensor and a protective resistor; The protective resistor is connected in series to the signal output line of the combustible gas sensor, and is used to prevent the combustible gas sensor from being damaged by overcurrent due to incorrect connection.
2. The combustible gas detector according to claim 1, characterized in that: The flameproof host assembly also includes a power module; The power supply module includes a sensor regulated power supply and a sensor power switch; The sensor voltage-stabilized power supply is connected to the combustible gas sensor and is used to supply power to the combustible gas sensor; The sensor power switch is connected to the sensor regulated power supply and the switch regulated module.
3. The combustible gas detector according to claim 2, characterized in that: The flameproof host assembly also includes a controller module, an overvoltage sampling module and a sensor power monitoring module; The sensor power supply monitoring module is connected to the controller module; The sensor regulated power supply monitoring module is used to detect the power supply status of the sensor regulated power supply and send the status to the controller module.
4. The combustible gas detector according to claim 3, characterized in that: The sensor power supply monitoring module is implemented as a sensor power supply voltage sampling module; The controller module includes a third analog-to-digital conversion input module; The sensor power supply voltage sampling module is connected to the third input module of the analog-to-digital conversion.
5. The combustible gas detector according to claim 3, characterized in that: The flameproof host assembly also includes a differential amplifier module; The controller further comprises a first analog-to-digital conversion input module and a second digital-to-analog conversion output module; The input of the differential amplifier module is connected to the protection resistor; The differential amplifier module is connected to the first analog-to-digital conversion input module and the second digital-to-analog conversion output module.
6. The combustible gas detector according to claim 3, characterized in that: The flameproof host assembly further includes an overvoltage sampling module, and the controller module includes a comparator; The overvoltage sampling module is connected to the sensor regulated power supply, and the overvoltage sampling module is connected to the signal input end of the comparator; The signal output terminal of the comparator is connected to the sensor power switch; The comparator is used to receive the signal from the overvoltage sampling module to perform overvoltage detection, and send a control signal to the sensor power switch based on the detection result.
7. The combustible gas detector according to claim 3, characterized in that: The flameproof host assembly also includes a switching voltage regulator module, a linear voltage regulator module and a power supply voltage sampling module; The controller also includes a fourth analog-to-digital conversion input module; The switching voltage stabilizing module is connected to the sensor power switch, and the switching voltage stabilizing module is connected to the linear voltage stabilizing module; The switching voltage stabilization module is connected to the power supply voltage sampling module via a 24V input power line; The power supply voltage sampling module is connected to the fourth input module of the analog-to-digital conversion.
8. The combustible gas detector according to claim 3, characterized in that: The flameproof host assembly also includes a temperature sampling module; The controller also includes an analog-to-digital conversion fifth input module; The temperature sampling module is connected to the fifth input module of the analog-to-digital conversion.
9. The combustible gas detector according to claim 3, characterized in that: The flameproof host assembly also includes a signal input module; The signal input module is connected to the controller; The signal input module is implemented to have a three-way signal input function.
10. The combustible gas detector according to claim 3, characterized in that: The flameproof host assembly also includes a communication module, a visualization result output module, a relay output module and a current output module; The controller includes a digital-to-analog conversion output terminal; The communication module is communicatively connected to the output end of the controller; The visualization result output module is connected to the output end of the controller; The relay output module is connected to the output end of the controller; The current output module is connected to the first digital-to-analog conversion output module of the controller.