A combustible gas alarm control system and method

Abstract

The present invention relates to the field of combustible gas detection technology, and in particular to a combustible gas alarm control system and method. The system includes a gas monitoring module, the gas monitoring module includes a plurality of combustible gas detectors; a concentration analysis module, the data processing module includes a programmable logic controller and a communication interface; a power protection module, the power protection module includes a power chip and a protection circuit, the power chip is connected to the protection circuit, and the output end of the protection circuit is connected to the programmable logic controller; an alarm module, the alarm module includes an audible and visual alarm and an alarm control circuit. The technical solution of the present invention increases the adaptability of the combustible gas alarm control system, and through the diffusion of combustible gas, the approximate location and danger level of the gas leakage source are judged, providing a solution for combustible gas detection.

Description

Technical Field

[0001] The present invention relates to the technical field of combustible gas detection, and in particular to a combustible gas alarm control system and method. Background Art

[0002] In the prior art, the combustible gas alarm controller can detect the concentration of combustible gas leaked in the air. When a combustible gas leak is detected, an alarm is issued in time to remind people to evacuate. With the popularization of combustible gas in life, especially in the catering industry, combustible gas storage points are designed in multiple areas. The loss of life and property caused by combustible gas leakage is also immeasurable. The combustible gas alarm control system can detect the concentration of combustible gas in the air in real time, and plays an irreplaceable role in the field of combustible gas detection. However, the current combustible gas alarm control system has problems such as poor adaptability and insufficient data analysis capabilities. In terms of the system itself, when the external voltage is unstable, it is easy to cause the system to work abnormally. In terms of detection, it can only detect the concentration of combustible gas in the air, and cannot judge the degree of danger based on the combustible gas leakage rate. When faced with the situation where combustible gas is installed in multiple areas, it cannot accurately determine the leakage area of ​​the combustible gas. If an alarm controller is set in each area, it will undoubtedly increase the installation cost. At this stage, a combustible gas alarm control system and method are needed. Summary of the invention

[0003] In order to solve the problems of poor adaptability and insufficient data analysis capability of a combustible gas alarm control system, the present invention provides a combustible gas alarm control system and method.

[0004] In a first aspect, the present invention provides a combustible gas alarm control system, which adopts the following technical solution:

[0005] A combustible gas alarm control system, comprising:

[0006] A gas monitoring module, wherein the gas monitoring module includes a plurality of combustible gas detectors, and the combustible gas detectors are installed according to the distribution positions of the gas pipelines;

[0007] The concentration analysis module, the data processing module includes a programmable logic controller and a communication interface, and the programmable logic controller is connected to the combustible gas detector and the host computer through the communication interface;

[0008] A power protection module, the power protection module comprising a power chip and a protection circuit, the power chip is connected to the protection circuit, and the output end of the protection circuit is connected to a programmable logic controller;

[0009] The alarm module comprises an audible and visual alarm and an alarm control circuit, wherein the audible and visual alarm is connected to the alarm control circuit, and the alarm control circuit is respectively connected to a programmable logic controller and a power chip.

[0010] Furthermore, the communication interface includes an M-BUS communication interface and an RS-485 bus communication interface. The programmable logic controller is connected to multiple combustible gas detectors via the M-BUS communication interface, and the programmable logic controller is connected to a host computer via the RS-485 bus communication interface. The host computer sends the set alarm threshold and alarm level to the programmable logic controller.

[0011] Furthermore, the protection circuit includes a low-voltage protection circuit, a high-voltage protection circuit, a power switch and a regulating winding. The power switch is respectively connected to the low-voltage protection circuit and the high-voltage protection circuit. The low-voltage protection circuit is connected in parallel with the high-voltage protection circuit and then connected to the regulating winding.

[0012] Furthermore, the low-voltage protection circuit includes a low-voltage protection resistor, a low-voltage detector and a first diode, the low-voltage protection resistor is connected to the regulating winding, the other end of the low-voltage protection resistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the low-voltage detector through a power chip.

[0013] Furthermore, the high-voltage protection circuit includes a high-voltage protection resistor, a high-voltage detector and a second diode. The high-voltage protection resistor is connected to the regulating winding and is connected in parallel with the low-voltage protection resistor. The other end of the high-voltage protection resistor is connected to the cathode of the second diode, and the anode of the second diode is connected to the high-voltage detector through a power chip.

[0014] Furthermore, the power chip includes an input port, a multiplexing port, an output port and a MOS tube, the input port is connected to an external power supply, the output port is connected to the gate of the power switch, the multiplexing port is connected in series with the high-voltage detector and the low-voltage detector connected in parallel, and the drain of the MOS tube is connected to the regulating winding.

[0015] Furthermore, the alarm control circuit includes a first transistor, a second transistor, a capacitor and a speaker, the base of the first transistor is connected to the output end of the programmable logic controller, the collector of the first transistor is connected to the speaker, the capacitor is connected in parallel with the speaker, the base of the second transistor is connected to the output end of the power supply chip, and the emitter of the second transistor is connected to the voltage input end of the programmable logic controller.

[0016] In a second aspect, a combustible gas alarm control method includes:

[0017] Construct a geometric model based on the detection area and discretize the geometric model to determine the number and distribution location of combustible gas detectors;

[0018] The combustible gas concentration is detected by combustible gas detectors at different distribution positions, and the concentration growth rate of the combustible gas is calculated based on the concentration change between the combustible gas detectors;

[0019] The host computer is used to calculate the concentration ratio and diffusion rate between the combustible gas detectors, and the programmable logic controller determines the gas leakage source location and the alarm level according to the concentration ratio.

[0020] Furthermore, the method of determining the number and distribution positions of combustible gas detectors includes obtaining a distribution map of combustible gas pipelines and the positions of gas outlet points in the detection area, determining the position distribution of each edge in the geometric model according to the distribution map of combustible gas pipelines, and constructing the geometric model with the gas outlet points as vertices, dividing the geometric model into discrete grid units with equal unit areas according to the optimal sensing area of ​​the combustible gas detector, and setting a combustible gas detector at the center point of the discrete grid unit.

[0021] Furthermore, the programmable logic controller determines the location of the gas leakage source according to the concentration ratio, including using a host computer to connect the location of the combustible gas detector in the geometric model and form a connecting line, segmenting the connecting line according to the concentration ratio, recording the segmentation points as marking points, and connecting all the marking points to form a new geometric figure, and the center point of the geometric figure is the location of the gas leakage source.

[0022] In summary, the present invention has the following beneficial technical effects:

[0023] 1. A combustible gas alarm control system of the present invention, through the protection of the power chip and the protection circuit, ensures that the alarm control system will not be damaged due to excessively high or low voltage when a combustible gas leak or other reasons lead to line failure. When an internal line failure occurs, an alarm can be issued in time to remind technicians to perform maintenance, thereby increasing the adaptability of the combustible gas alarm control system.

[0024] 2. A combustible gas alarm control method of the present invention ensures that when a combustible gas leak occurs, it can be detected and an alarm can be issued in a timely manner through the reasonable position distribution of combustible gas detectors, thereby ensuring the timeliness of the combustible gas alarm control system. According to the gas concentration detected by the combustible gas detectors at different positions, the position simulation is performed using simulation software to promptly discover the general location of the leakage source, provide the processing personnel with a position reference value of the leakage source, and ensure the timeliness of problem handling. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1This is an overall circuit diagram of a power supply chip in a combustible gas alarm control system according to Example 1 of the present invention.

[0026] Figure 2 This is a protection circuit diagram of a combustible gas alarm control system in Example 1 of the present invention.

[0027] Figure 3 This is an alarm control circuit diagram of a combustible gas alarm control system in Example 1 of the present invention.

[0028] Figure 4 This is a flow chart of a combustible gas alarm control method in Example 2 of the present invention.

[0029] Figure 5 It is a three-dimensional model diagram of a combustible gas alarm control method in Example 2 of the present invention.

[0030] Figure 6 It is a discrete grid unit diagram in a combustible gas alarm control method in Example 2 of the present invention.

[0031] Among them, 1. primary winding; 2. secondary winding; 3. regulating winding; 4. power switch; 5. rectifier; 6. high-voltage protection resistor; 7. low-voltage protection resistor; 8. second diode; 9. first diode; 10. multiplexing port; 11. current source; 12. first transistor; 13. second transistor. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] Example 1

[0034] A combustible gas alarm control system of this embodiment includes:

[0035] A combustible gas alarm control system, comprising:

[0036] A gas monitoring module, wherein the gas monitoring module includes a plurality of combustible gas detectors, and the combustible gas detectors are installed according to the distribution positions of the gas pipelines;

[0037] The concentration analysis module, the data processing module includes a programmable logic controller and a communication interface, and the programmable logic controller is connected to the combustible gas detector and the host computer through the communication interface;

[0038] A power protection module, the power protection module comprising a power chip and a protection circuit, the power chip is connected to the protection circuit, and the output end of the protection circuit is connected to a programmable logic controller;

[0039] The alarm module comprises an audible and visual alarm and an alarm control circuit, wherein the audible and visual alarm is connected to the alarm control circuit, and the alarm control circuit is respectively connected to a programmable logic controller and a power chip.

[0040] The communication interface includes an M-BUS communication interface and an RS-485 bus communication interface. The programmable logic controller is connected to multiple combustible gas detectors via the M-BUS communication interface. The programmable logic controller is connected to a host computer via the RS-485 bus communication interface. The host computer sends the set alarm threshold and alarm level to the programmable logic controller.

[0041] The protection circuit includes a low voltage protection circuit, a high voltage protection circuit, a power switch and a regulating winding. The power switch is connected to the low voltage protection circuit and the high voltage protection circuit respectively. The low voltage protection circuit is connected in parallel with the high voltage protection circuit and then connected to the regulating winding.

[0042] The low-voltage protection circuit includes a low-voltage protection resistor, a low-voltage detector and a first diode. The low-voltage protection resistor is connected to the regulating winding, the other end of the low-voltage protection resistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the low-voltage detector through a power chip.

[0043] The high-voltage protection circuit includes a high-voltage protection resistor, a high-voltage detector and a second diode. The high-voltage protection resistor is connected to the regulating winding and is connected in parallel with the low-voltage protection resistor. The other end of the high-voltage protection resistor is connected to the cathode of the second diode. The anode of the second diode is connected to the high-voltage detector through a power chip.

[0044] The power chip includes an input port, a multiplexing port, an output port and a MOS tube, the input port is connected to an external power supply, the output port is connected to the gate of a power switch, the multiplexing port is connected in series with a high-voltage detector and a low-voltage detector connected in parallel, and the drain of the MOS tube is connected to a regulating winding.

[0045] The alarm control circuit includes a first transistor, a second transistor, a capacitor and a speaker, the base of the first transistor is connected to the output end of the programmable logic controller, the collector of the first transistor is connected to the speaker, the capacitor is connected in parallel with the speaker, the base of the second transistor is connected to the output end of the power chip, and the emitter of the second transistor is connected to the voltage input end of the programmable logic controller.

[0046] Specifically,

[0047] A combustible gas alarm control system of this embodiment includes the following contents:

[0048] like Figure 1As shown, the commonly used alternating current is connected to the input port (VDD) of the current chip after filtering to provide power supply for the system. The output port (GATE) of the power chip is connected to the gate of the power switch 4. When the power chip outputs a low level, the power switch 4 is in an off state. When the power chip outputs a high level, the power switch 4 is turned on. The power switch 4 provides the controller with a signal for connection and closing. Inside the power chip, the source of the MOS tube is connected to the regulating winding 3, and the drain is connected to the rectifier 5 through a rectifier resistor. The rectifier 5 is the diode in the high-voltage protection circuit and the low-voltage protection circuit. For the convenience of description Figure 1 Only an overall introduction is given, the specific route map is in Figure 2 Given in.

[0049] When the power switch 4 is in the off state, the voltage at the same-name end of the primary winding 1 and the secondary winding 2 is reduced, and the regulating winding plays a regulating role. When the voltage at the same-name end of the primary winding 1 and the secondary winding 2 is reduced, the voltage of the regulating winding is reduced accordingly, and the voltage of the source of the MOS tube connected by the regulating winding 3 is reduced, and then the voltage transmitted to the low-voltage protection circuit by the drain connected to the rectifier 5 is reduced. When the output at the output end is a high level, the effect is opposite to that when it is a low level. When it is a high level, the power switch is turned on, and the voltage at the same-name end of the primary winding 1 and the secondary winding 2 increases, thereby increasing the voltage entering the high-voltage protection circuit. The primary winding, the secondary winding and the regulating winding circuit play a certain buffering role on the protection circuit. The power chip also includes a feedback port (FB), and the feedback port is connected to a feedback component composed of a coupling device, which is used to receive a feedback signal of a DC output and transmit the feedback signal to the power chip for signal detection.

[0050] like Figure 2 As shown, Figure 2 To protect the specific circuit diagram of the circuit, the multiplexing port 10 is connected in series with the high-voltage detector and the low-voltage detector connected in parallel to complete the voltage detection, the high-voltage protection resistor 6 is connected in series with the second diode 8, and the low-voltage protection resistor 7 is connected in series with the first diode 9. The unidirectional conductivity of the diode is used to make the current flow between the two circuits in sequence, and the buffering effect on the circuit current is achieved by parallel connection with the regulating winding. The current of the current source 11 flows to the protection circuit through the switch, and the voltage in the circuit is monitored by the high-voltage detector and the low-voltage detector.

[0051] like Figure 3 As shown, Figure 3The utility model is an alarm control circuit, which is connected to a programmable logic controller to realize alarm control of a sound and light alarm. The base of the first transistor 12 is connected to the output end of the programmable logic controller, and the graded alarm of the sound and light alarm is realized by controlling the transistor current. The base of the second transistor 13 is connected to the output end (OUT) of the power chip, and the emitter is connected to the voltage input end (VDD) of the programmable logic controller. The sound and light alarm is divided into a fault alarm and a concentration alarm. When the internal voltage of the control system is unstable, the fault alarm is triggered. The buzzer and indicator light in the sound and light alarm realize the change of the alarm level according to the different currents in the circuit. The concentration alarm is completed by controlling the current of the alarm control circuit through the programmable logic controller according to the set alarm threshold.

[0052] Example 2

[0053] The difference between this embodiment and embodiment 1 is that this embodiment provides a combustible gas alarm control method, including: constructing a geometric model according to the detection area and discretizing the geometric model to determine the number and distribution positions of the combustible gas detectors;

[0054] The combustible gas concentration is detected by combustible gas detectors at different distribution positions, and the concentration growth rate of the combustible gas is calculated based on the concentration change between the combustible gas detectors;

[0055] The host computer is used to calculate the concentration ratio and diffusion rate between the combustible gas detectors, and the programmable logic controller determines the gas leakage source location and the alarm level according to the concentration ratio.

[0056] The method of determining the number and distribution positions of combustible gas detectors includes obtaining a distribution map of combustible gas pipelines and the positions of gas outlet points in the detection area, determining the position distribution of each edge in the geometric model according to the distribution map of combustible gas pipelines, and constructing the geometric model with the gas outlet points as vertices, dividing the geometric model into discrete grid units with equal unit areas according to the optimal sensing area of ​​the combustible gas detectors, and setting a combustible gas detector at the center point of the discrete grid unit.

[0057] The programmable logic controller determines the location of the gas leakage source according to the concentration ratio, including using a host computer to connect the location of the combustible gas detector in the geometric model and form a connecting line, segmenting the connecting line according to the concentration ratio, recording the segmentation points as marking points, and connecting all the marking points to form a new geometric figure, wherein the center point of the geometric figure is the location of the gas leakage source.

[0058] Specifically,

[0059] A combustible gas alarm control method of this embodiment includes the following contents:

[0060] like Figure 4As shown, before installing the combustible gas alarm control system, the combustible gas pipeline distribution map and the location of the gas outlet point in the detected area are first obtained, and the geometric model is constructed using simulation software. The geometric model is constructed according to the gas pipeline distribution map, and the distribution position of the gas pipeline in the detection interval is made to fit the edges of the geometric model as much as possible, and the gas outlet point is used as the vertex of the geometric model for construction.

[0061] like Figure 6 As shown, the geometric model is divided into discrete grid units with equal unit area, a combustible gas detector is set at the center point of the discrete grid unit and the position coordinates are recorded, and the combustible gas detector is numbered. Figure 6 The number represented in the figure is the number of the detector that detects the combustible gas concentration for the first time. The area represented by the discrete grid unit is the optimal sensing area of ​​the combustible gas detector, and the shape of the discrete grid unit is limited. In this embodiment, a triangle is selected. Detection point 1, detection point 2 and detection point 3 are the positions of the discrete grids where the combustible gas detector is located. The center point is determined by drawing a vertical line to the area where the detector that detects the combustible gas concentration is located. That is, after the center point is determined, the two-dimensional grid is converted into a three-dimensional model.

[0062] like Figure 5 As shown, a three-dimensional coordinate system is constructed, and the position coordinates of the combustible gas detectors with combustible gas concentration values ​​are connected. The ratio of the combustible gas concentrations detected by the combustible gas detectors at both ends of the straight line is calculated, that is, the ratio is calculated based on the concentration data obtained by the combustible gas detectors at both ends of the straight line, and the straight line between the combustible gas detectors is divided according to the ratio, and the marking points are determined according to the division points. All the marking points are connected to form a new geometric figure, and the center point position of the new geometric figure corresponds to the center point position of the two-dimensional grid converted into a three-dimensional model. The center position of the three-dimensional model is the approximate position of the gas leakage source.

[0063] The alarm level is determined based on the lower explosion limit and leakage rate of the combustible gas, and is set by the host computer connected to the programmable logic controller. The first-level alarm setting value of the combustible gas is less than or equal to 25% of the lower explosion limit, and the second-level alarm setting value of the combustible gas should be less than or equal to 50% of the lower explosion limit. When the concentration of the combustible gas is greater than 50% of the lower explosion limit, the third-level alarm is triggered. The calculation of the combustible gas leakage rate adopts the plume model, and the plume model formula is:

[0064] ,

[0065] Among them, C is the concentration of combustible gas, Q is the leakage rate, h is the effective source height, x, y, z are the coordinates of the point, σ y is the crosswind diffusion coefficient, σ zis the vertical diffusion coefficient; the approximate time required for the combustible gas concentration to reach the lower explosion limit is determined based on the leakage rate.

[0066] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A combustible gas alarm control method, characterized in that , the method is based on a combustible gas alarm control system, the method comprising: Construct a geometric model based on the detection area and discretize the geometric model to determine the number and distribution location of combustible gas detectors; The combustible gas concentration is detected by combustible gas detectors at different distribution positions, and the concentration growth rate of the combustible gas is calculated based on the concentration change between the combustible gas detectors; The host computer calculates the concentration ratio and diffusion rate between combustible gas detectors, and the programmable logic controller determines the gas leakage source location and alarm level according to the concentration ratio; The determining of the number and distribution positions of the combustible gas detectors includes obtaining a combustible gas pipeline distribution map and a location of a gas outlet point in a detection area, determining the location distribution of each edge in a geometric model according to the combustible gas pipeline distribution map, and constructing the geometric model with the gas outlet point as a vertex, dividing the geometric model into discrete grid units with equal unit area according to the optimal sensing area of ​​the combustible gas detector, and setting a combustible gas detector at the center point of the discrete grid unit; The programmable logic controller determines the location of the gas leakage source according to the concentration ratio, including using a host computer to connect the location of the combustible gas detector in the geometric model to form a connecting line, segmenting the connecting line according to the concentration ratio, recording the segmentation points as marking points, and connecting all the marking points to form a new geometric figure, wherein the center point of the geometric figure is the location of the gas leakage source; The system comprises: a gas monitoring module, the gas monitoring module comprises a plurality of combustible gas detectors, the combustible gas detectors are installed according to the distribution positions of the gas pipelines; A concentration analysis module, wherein the concentration analysis module comprises a programmable logic controller and a communication interface, wherein the programmable logic controller is connected to the combustible gas detector and the host computer respectively through the communication interface; A power protection module, the power protection module comprising a power chip and a protection circuit, the power chip is connected to the protection circuit, and the output end of the protection circuit is connected to a programmable logic controller; An alarm module, the alarm module comprising an audible and visual alarm and an alarm control circuit, the audible and visual alarm being connected to the alarm control circuit, and the alarm control circuit being respectively connected to a programmable logic controller and a power chip; The communication interface includes an M-BUS communication interface and an RS-485 bus communication interface. The programmable logic controller is connected to a plurality of combustible gas detectors via the M-BUS communication interface. The programmable logic controller is connected to a host computer via the RS-485 bus communication interface. The host computer sends the set alarm threshold and alarm level to the programmable logic controller. The protection circuit comprises a low voltage protection circuit, a high voltage protection circuit, a power switch and a regulating winding, wherein the power switch is connected to the low voltage protection circuit and the high voltage protection circuit respectively, and the low voltage protection circuit is connected to the high voltage protection circuit in parallel and then connected to the regulating winding; The low voltage protection circuit comprises a low voltage protection resistor, a low voltage detector and a first diode, wherein the low voltage protection resistor is connected to the regulating winding, the other end of the low voltage protection resistor is connected to the cathode of the first diode, and the anode of the first diode is connected to the low voltage detector through a power chip; The high-voltage protection circuit includes a high-voltage protection resistor, a high-voltage detector and a second diode. The high-voltage protection resistor is connected to the regulating winding and is connected in parallel with the low-voltage protection resistor. The other end of the high-voltage protection resistor is connected to the anode of the second diode, and the cathode of the second diode is connected to the high-voltage detector through a power chip.

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