Combustible gas monitoring system and method

Abstract

The invention relates to the technical field of gas monitoring, and discloses a combustible gas monitoring system and method, and the system comprises a gas detection unit which generates first data according to the concentration of environment combustible gas; the ultrasonic leakage detection unit is used for generating second data according to the environment decibel value, and the control analysis unit can be used for judging whether gas leakage, leakage position and leakage amount exist or not according to the first data and the second data and sending out a corresponding control instruction; the method comprises the steps that first data are generated and transmitted, second data are generated and transmitted, the first data and the second data are analyzed, whether gas leakage exists or not, the leakage position and the leakage amount can be judged, and a corresponding control instruction is sent out; the system especially has obvious advantages in leakage of high-pressure combustible gas with trace or small leakage, can accurately eliminate hidden dangers of small leakage, can work normally in severe environments of low temperature, strong wind, heavy rain and the like, ensures effectiveness of monitoring, and forms a complete and comprehensive safety protection system.

Description

Technical Field

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

[0002] The traditional high-pressure outdoor combustible gas level monitoring system is equipped with infrared combustible gas detectors and optical flame detectors. When the monitored gas or liquid volatilizes and leaks in the air, the detector generates an electrical signal proportional to the concentration of the measured gas in the air. The signal is transmitted to the controller. When the concentration reaches a certain alarm value, the controller will issue an audible and visual alarm. The detector installation position needs to be reasonable, effective and safe to monitor combustible gas leaks efficiently and accurately. The concentration of the measured gas leakage must reach a certain value to trigger the system alarm.

[0003] The traditional high-pressure outdoor flammable gas multi-directional monitoring system is limited by the principle of flammable gas detectors and will be affected by outdoor rain and wind direction. As a result, under extreme climatic conditions, the outdoor ambient temperature is too low and will also affect the monitoring and measurement of the flammable gas monitoring probe. It is not suitable for use in low-temperature environments. At the same time, the flammable gas detector is prone to form a monitoring blind spot, and cannot effectively detect gas leaks in a timely manner, which poses a greater safety risk. Small gas leaks or leaks that do not reach the alarm value are not easy to detect, which is prone to safety hazards. At the same time, the measured gas is relatively single, and a flammable gas detector can only monitor one gas and cannot monitor flammable gas leaks other than this type. The monitoring range of each probe is also small, and can only monitor an area with a radius of 2-3 meters. If the monitoring area is large, more monitoring probes need to be installed, which will increase manpower and material expenditures, and the cost of future preparation and maintenance will also increase. When the outdoor environment is below -10℃, the measurement of the traditional flammable probe monitor will be affected, which greatly reduces the effectiveness of measurement and monitoring. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is that the monitoring effectiveness of the traditional combustible probe monitor is low.

[0005] The above technical problem is solved by the following technical solution: The present invention proposes a combustible gas monitoring system, which includes a gas detection unit, an ultrasonic leak detection unit and a control and analysis unit.

[0006] In a preferred embodiment of the combustible gas monitoring system of the present invention: the gas detection unit is installed in the monitoring area and generates first data according to the ambient combustible gas concentration, including at least one combustible gas detection probe and a combustible gas detection controller that cooperates with the combustible gas detection probe.

[0007] The ultrasonic leak detection unit is installed in the monitoring area and generates second data according to the environmental decibel value, and includes at least one ultrasonic leak detection device.

[0008] The control and analysis unit includes a control and analysis system, which receives and analyzes the first data transmitted by the combustible gas detection controller, receives and analyzes the second data transmitted by the ultrasonic leak detection device, and determines whether there is a gas leak, the leak location and the leak amount based on the first data and the second data, and issues corresponding control instructions.

[0009] In a preferred implementation of the combustible gas monitoring system of the present invention: the control and analysis unit also includes a gas pipeline shut-off valve, the gas pipeline shut-off valve is connected to the control and analysis system, the gas pipeline shut-off valve is connected to the combustible gas detection controller, and the gas pipeline shut-off valve is arranged on the combustible gas main pipeline.

[0010] In a preferred implementation of the combustible gas monitoring system of the present invention: the control and analysis unit also includes a combustible gas detection controller control valve loop, connecting the gas pipeline shut-off valve and the combustible gas detection controller.

[0011] In a preferred embodiment of the combustible gas monitoring system of the present invention: the control and analysis unit also includes a control and analysis system control valve loop, connecting the gas pipeline shut-off valve and the control and analysis system.

[0012] In a preferred implementation of the combustible gas monitoring system of the present invention: the control and analysis unit also includes a control and analysis system receiving signal circuit, which connects the combustible gas detection controller and the control and analysis system.

[0013] In a preferred implementation of the combustible gas monitoring system of the present invention: the control and analysis unit also includes a combustible gas detection probe signal circuit, connecting the combustible gas detection probe and the combustible gas detection controller.

[0014] In a preferred embodiment of the combustible gas monitoring system of the present invention: the combustible gas detection probe includes a measuring sensor, a sensor protection cover, a measuring control panel, a measuring display panel, an audible and visual alarm device, an alarm indication, a fault indication and a calibration detection panel; the casing of the combustible gas detection probe is provided with a grounding point; the combustible gas detection controller has high alarm and high-high alarm functions, and can realize sound alarm through a built-in alarm relay.

[0015] In a preferred embodiment of the combustible gas monitoring system of the present invention: the control and analysis system analyzes and determines whether there is a false alarm, the leakage location and the leakage amount based on the first data of the combustible gas detection probe and the second data of the ultrasonic leak detection device, and realizes valve partition shutdown.

[0016] In a preferred implementation of the combustible gas monitoring system of the present invention: the ultrasonic leak detection device adopts a one-to-many detection control mode to cover multiple monitoring areas.

[0017] The present invention also provides a combustible gas monitoring method, which includes generating and transmitting first data, generating and transmitting second data, and analyzing the first data and the second data.

[0018] In a preferred implementation manner of the combustible gas monitoring method of the present invention: first data is generated and transmitted, the combustible gas concentration in the environment is monitored in real time by the gas detection unit, the first data is generated, and the data is transmitted to the control and analysis system; second data is generated and transmitted, the ultrasonic decibel value in the environment is monitored in real time by the ultrasonic leak detection unit, the second data is generated, and the data is transmitted to the control and analysis system; the first data and the second data are analyzed, the control and analysis system receives and analyzes the first data and the second data, determines whether there is a gas leak, the leak location and the leak amount, and issues corresponding control instructions according to the analysis results.

[0019] The beneficial effects of the present invention are: adopting a dual-source data fusion algorithm, through the real-time cross-validation of the combustible gas concentration and the ultrasonic decibel value by the control analysis system, the accuracy, reliability and efficiency of the high-pressure combustible gas leakage detection are improved, and the combustible gas leakage and the alarm fault can be judged according to the alarm conditions of the combustible gas detection probe, the ultrasonic leak detection device and the combustible gas detection controller. When the ultrasonic leak detection device and at least one of the gas detection probe or the controller alarm at the same time, the leakage is determined first, because the ultrasonic detection and the gas concentration detection are complementary, and the false alarm probability is low; only the probe alarm or only the controller alarm is attributed to the equipment failure or interference, because there is a lack of other equipment evidence; the controller alarm depends on the probe signal. If the probe does not alarm but the controller alarms, it may be an internal fault of the controller and needs to be replaced; the ultrasonic failure to alarm may be due to the low-pressure leakage not generating enough sound waves, and it needs to be judged in combination with the pressure system state. The system is designed based on the redundancy of equipment and the complementarity of detection principles. It gives priority to multiple alarms to determine the leakage, and is cautious about single alarms. In actual use, the response strategy can be dynamically adjusted in combination with the on-site environment, including but not limited to pressure level, gas type and equipment historical failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments of the present invention are briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention, but are not intended to limit the present invention. Among them: Figure 1 A schematic diagram of a combustible gas monitoring system is shown.

[0021] In the figure: 1. Gas detection unit; 11. Combustible gas detection probe; 12. Combustible gas detection controller; 2. Ultrasonic leak detection unit; 21. Ultrasonic leak detection device; 3. Control and analysis unit; 31. Control and analysis system; 32. Gas pipeline shut-off valve; 33. Combustible gas detection controller control valve circuit; 34. Control and analysis system control valve circuit; 35. Control and analysis system receiving signal circuit; 36. Combustible gas detection probe signal circuit; 22. Ultrasonic leak detection detection range; 4. Combustible gas main pipeline. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with specific implementation methods and drawings.

[0023] The terms used in the present invention are those general terms currently widely used in the art in consideration of the functions of the present invention, but these terms may vary according to the intention of a person of ordinary skill in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in this case, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as a general description based on the meaning of the terms and the present invention.

[0024] Reference Figure 1 This embodiment provides a combustible gas monitoring system, including a gas detection unit 1, an ultrasonic leak detection unit 2 and a control and analysis unit 3.

[0025] Specifically, the gas detection unit 1 is installed in the monitoring area and generates first data according to the ambient combustible gas concentration, including at least one combustible gas detection probe 11 and a combustible gas detection controller 12 that cooperates with the combustible gas detection probe 11. The first data includes at least one of the following information: real-time combustible gas concentration value; comparison result of the combustible gas concentration with the preset alarm threshold, i.e., high alarm and high high alarm; identification information of the combustible gas detection probe 11.

[0026] There is a one-to-one correspondence between a combustible gas detection probe 11 and a combustible gas detection controller 12. A combustible gas detection probe 11 is installed in a place prone to leakage, such as a flange connection, a valve, a measuring instrument, a filter device, and a storage device. When the combustible gas detection probe 11 detects that the content of the leaked combustible gas exceeds the alarm value, the combustible gas detection probe 11 will issue an audible and visual alarm.

[0027] The combustible gas detection controller 12 converts the first data transmitted by the combustible gas detection probe 11 into a 4~20mA current signal. Furthermore, the combustible gas detection controller 12 will also send out an audible and visual alarm when receiving the first data and determining that the leakage value reaches the alarm value. Specifically, in the alarm triggering conditions, the high alarm threshold can be set to 20% of the lower explosion limit of the combustible gas, and the high-high alarm threshold can be set to 40% of the lower explosion limit of the combustible gas. When the concentration value exceeds the high alarm threshold, the high alarm is triggered; when the concentration value exceeds the high-high alarm threshold, the high-high alarm is triggered.

[0028] The control and analysis unit 3 also includes a combustible gas detection controller controlling a valve circuit 33, which connects the gas pipeline shut-off valve 32 and the combustible gas detection controller 12. When the combustible gas detection controller 12 receives the first data and determines that the leakage value reaches the alarm value, the combustible gas detection controller 12 will control the valve circuit 33 to shut off the gas pipeline shut-off valve 32 through the combustible gas detection controller, thereby further reducing leakage and ensuring system safety.

[0029] Specifically, the control and analysis unit 3 also includes a control and analysis system control valve loop 34, which connects the gas pipeline shut-off valve 32 and the control and analysis system 31; the control and analysis unit 3 also includes a control and analysis system receiving signal loop 35, which connects the combustible gas detection controller 12 and the control and analysis system 31; the control and analysis unit 3 also includes a combustible gas detection probe signal loop 36, which connects the combustible gas detection probe 11 and the combustible gas detection controller 12.

[0030] When the combustible gas detection controller 12 receives the first data of a combustible gas detection probe 11 through the combustible gas detection probe signal circuit 36, it will then pass the first data to the control and analysis system 31 through the control and analysis system receiving signal circuit 35; the control and analysis system 31 analyzes the first data, and when it is determined that the leakage is serious, the control and analysis system 31 uses the control and analysis system control valve circuit 34 to send a control signal to the gas pipeline shut-off valve 32 to close the valve, thereby further reducing leakage and ensuring system safety.

[0031] The ultrasonic leak detection unit 2 is installed at the center of the monitoring area and generates second data according to the environmental decibel value, and includes at least one ultrasonic leak detection device 21.

[0032] The detection range of the ultrasonic leak detection device 21 is centered on the device itself and has a detection radius of 20m, forming an ultrasonic leak detection range 22.

[0033] The installation height of the ultrasonic leak detection device 21 is controlled at 2-3m. If the equipment is installed too low, there will be many obstacles that affect the measurement. The ultrasonic leak detection can also be installed in the equipment-intensive area to ensure that a stronger signal can be monitored. The ultrasonic leak detection device 21 will detect a current environmental signal value. The signal value is sent to the DCS control and analysis system 31 for analysis and judgment. The environmental signal value refers to the real-time collection of the sound wave signal in the environment by the built-in ultrasonic sensor. The monitoring frequency range includes the characteristic frequency generated by the corresponding gas leakage, within 30kHz~100kHz, and the sound wave signal is converted into a decibel value as the second data, and transmitted to the control and analysis system 31 through a 4~20mA analog signal.

[0034] When the ambient frequency value is greater than the set judgment value, it is assumed by default that there is a leak in the environment. In order to avoid short-term release of gas or other interference in the surrounding area, a 15-second delay is set to ensure reliable alarm.

[0035] The control and analysis unit 3 includes a control and analysis system 31, which receives and analyzes the first data transmitted by the combustible gas detection controller 12, receives and analyzes the second data transmitted by the ultrasonic leak detection device 21, and determines whether there is a gas leak, the leak location and the leak amount based on the first data and the second data, and issues corresponding control instructions.

[0036] The control and analysis system 31 can comprehensively judge the on-site gas leakage situation and the operation status of the monitoring equipment. According to the judgment and analysis results, the control and analysis system 31 can use the control and analysis system to control the valve loop 34 to directly act on the gas pipeline shut-off valve 32, completely disconnecting the gas supply source to ensure equipment safety.

[0037] The combustible gas detection probe 11 includes a measurement sensor, a sensor protection cover, a measurement control board, a measurement display panel, an audible and visual alarm device, an alarm indication, a fault indication and a calibration detection panel.

[0038] The measuring sensor is responsible for detecting the presence of combustible gas; the sensor protection cover is used to protect the sensor from damage by the external environment; the measuring control board is the control core of the combustible gas detection probe 11, and is used to process the signals received by the sensor; the measuring display panel displays the gas concentration and other related information; the sound and light alarm device emits an sound and light alarm when it detects that the combustible gas concentration exceeds the warning value; the alarm indication and fault indication are used to display whether the combustible gas detection probe 11 is in an alarm state or a fault occurs; the calibration detection panel is used to regularly calibrate the probe to ensure its accuracy.

[0039] The shell of the combustible gas detection probe 11 is provided with a grounding point.

[0040] The shell of the combustible gas detection probe 11 is explosion-proof and can withstand the pressure generated by the explosion of combustible gas, preventing the combustible gas detection probe 11 from being damaged, thereby improving the stability of monitoring. The grounding point is used to connect the combustible gas detection probe 11 to the ground wire to ensure that when combustible gas is detected, if the probe itself generates electric sparks, the electric sparks can be safely guided to the ground through the ground wire to avoid causing explosions or fires.

[0041] The combustible gas detection controller 12 has high alarm and high-high alarm functions, and can realize sound alarm through the built-in alarm relay.

[0042] High alarm refers to the alarm signal issued by the controller when the combustible gas concentration reaches a preset higher threshold but has not yet reached the dangerous level. High-high alarm refers to the more urgent alarm signal issued by the controller when the combustible gas concentration reaches or exceeds a higher dangerous level threshold.

[0043] The control and analysis system 31 analyzes and determines whether there is a false alarm, the leakage position and the leakage amount according to the first data of the combustible gas detection probe 11 and the second data of the ultrasonic leak detection device 21, and realizes the valve partition shutdown.

[0044] The ultrasonic leak detection device 21 adopts a one-to-many detection control mode, covering multiple monitoring areas.

[0045] There are various alarm conditions of the combustible gas detection probe 11, the ultrasonic leak detection device 21 and the combustible gas detection controller 12, and the corresponding possible conditions and conclusions are shown in Table 1.

[0046] Table 1: Combustible gas monitoring system alarm analysis and judgment table , It can be seen that when the ultrasonic leak detection device and at least one of the gas detection probe or controller alarm at the same time, the leak is determined first, because the ultrasonic detection and gas concentration detection are complementary, and the probability of false alarm is low; only the probe alarm or only the controller alarm is attributed to equipment failure or interference, because there is a lack of other equipment evidence; the controller alarm depends on the probe signal. If the probe does not alarm but the controller alarms, it may be an internal fault of the controller and needs to be replaced; the ultrasonic failure to alarm may be due to the low-pressure leakage not generating enough sound waves, and it needs to be judged in combination with the pressure system status. When only the combustible gas detection controller 12 alarms, since the failure rate of the combustible gas detection controller 12 is extremely low, it is judged that the combustible gas detection controller 12 is faulty or the combustible gas detection probe 11 is faulty. The system is designed based on equipment redundancy and complementary detection principles. It prioritizes multiple alarms to determine leaks and is cautious about single alarms. In actual use, the response strategy can be dynamically adjusted in combination with the on-site environment, including but not limited to pressure level, gas type and historical equipment failure rate.

[0047] Finally, it should be pointed out that the methods and devices described in detail above are only embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. A combustible gas monitoring system, characterized in that: include, A gas detection unit (1) is installed in a monitoring area near a combustible gas main pipeline (4) and generates first data according to the ambient combustible gas concentration, comprising at least one combustible gas detection probe (11) and a combustible gas detection controller (12) coordinated with the combustible gas detection probe (11); An ultrasonic leak detection unit (2) is installed in a monitoring area near the combustible gas main pipeline (4) and generates second data according to the environmental decibel value, comprising at least one ultrasonic leak detection device (21); A control and analysis unit (3) comprises a control and analysis system (31) connected to the combustible gas main pipeline (4), wherein the control and analysis system (31) receives and analyzes the first data transmitted by the combustible gas detection controller (12), receives and analyzes the second data transmitted by the ultrasonic leak detection device (21), and determines whether there is a gas leak, a leak location, and a leak amount, or a combination of the three situations based on the first data and the second data, and issues corresponding control instructions to control the on and off of the combustible gas main pipeline (4).

2. The combustible gas monitoring system according to claim 1, characterized in that: The control and analysis unit (3) further comprises a gas pipeline shutoff valve (32), the gas pipeline shutoff valve (32) being connected to the control and analysis system (31), the gas pipeline shutoff valve (32) being connected to the combustible gas detection controller (12), and the gas pipeline shutoff valve (32) being arranged on the combustible gas main pipeline (4).

3. The combustible gas monitoring system according to claim 2, characterized in that: The control and analysis unit (3) further comprises a combustible gas detection controller control valve circuit (33), wherein the combustible gas detection controller control valve circuit (33) connects the gas pipeline shut-off valve (32) and the combustible gas detection controller (12).

4. The combustible gas monitoring system according to claim 3, characterized in that: The control and analysis unit (3) further comprises a control and analysis system control valve loop (34), wherein the control and analysis system control valve loop (34) connects the gas pipeline shut-off valve (32) and the control and analysis system (31).

5. The combustible gas monitoring system according to claim 4, characterized in that: The control and analysis unit (3) further comprises a control and analysis system receiving signal circuit (35), wherein the control and analysis system receiving signal circuit (35) is connected to the combustible gas detection controller (12) and the control and analysis system (31).

6. The combustible gas monitoring system according to claim 5, characterized in that: The control and analysis unit (3) further comprises a combustible gas detection probe signal circuit (36), wherein the combustible gas detection probe signal circuit (36) is connected to the combustible gas detection probe (11) and the combustible gas detection controller (12).

7. The combustible gas monitoring system according to claim 6, characterized in that: The combustible gas detection probe (11) comprises a measuring sensor, a sensor protection cover, a measuring control panel, a measuring display panel, an audible and visual alarm device, an alarm indication, a fault indication and a calibration detection panel; the shell of the combustible gas detection probe (11) is provided with a grounding point; the combustible gas detection controller (12) has high alarm and high-high alarm functions, and can realize an audible alarm through a built-in alarm relay.

8. The combustible gas monitoring system according to claim 7, characterized in that: The control and analysis system (31) analyzes and determines whether there is a gas leak, the leak location and the leak amount based on the first data of the combustible gas detection probe (11) and the second data of the ultrasonic leak detection device (21), thereby realizing valve zoning shutoff.

9. The combustible gas monitoring system according to claim 8, characterized in that: The ultrasonic leak detection device (21) adopts a one-to-many detection control mode, covering multiple monitoring areas.

10. A combustible gas monitoring method, characterized in that: Applicable to the combustible gas monitoring system according to any one of claims 1 to 9; and the method steps are: Generate and transmit first data, monitor the concentration of combustible gas in the environment in real time through the gas detection unit (1), generate first data, and transmit it to the control and analysis system (31); Generate and transmit second data, monitor the ultrasonic decibel value in the environment in real time through the ultrasonic leak detection unit (2), generate second data, and transmit it to the control and analysis system (31); Analyzing the first data and the second data, the control analysis system (31) receives and analyzes the first data and the second data, determines whether there is a gas leak, the leak location and the leak amount, and issues corresponding control instructions according to the analysis results.

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