A gas detection system and method

Abstract

The present invention relates to a gas detection system and method. The system includes a detection tube and a control module. The detection tube is provided with a first sensor and a second sensor along the gas flow direction. The control module determines the type of gas flowing into the detection tube at least based on the differential response of the dual sensors. An air extraction unit and a polarizing filter membrane for sucking gas at a predetermined position in the detection tube are further provided in the detection tube. The air extraction unit is arranged between the first sensor and the second sensor so that the gas entering the detection tube through the suction action of the air extraction unit sequentially passes through the first sensor and the second sensor. By providing the first sensor and the second sensor and arranging the polarizing filter membrane between the first sensor and the second sensor, the present invention accurately determines the gas type and concentration through the differential response of the two sensors, eliminates the influence of interfering gases on the methane concentration detection, provides the selectivity of the sensor to methane, and is applicable to portable and accurate detection for outdoor gas pipeline network inspection.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and particularly to a gas detection system and method. Background Art

[0002] Natural gas, as a clean and convenient environmental protection energy, has generally entered people's daily lives. In recent years, although the urban gas pipeline network has been continuously developed and improved, accidents caused by gas leakage occur frequently across the country every year, causing heavy losses to the country and the people. Therefore, gas leakage has attracted more and more extensive attention. How to perform portable and accurate gas detection on the gas pipeline network is an urgent problem to be solved in the existing technology. Therefore, a gas detection system and method are needed to realize convenient outdoor inspection of the gas pipeline network.

[0003] In addition, the existing technology often relies on staff to conduct carpet-like inspections on each gas pipeline. However, due to the long length of the gas pipeline network, scattered staff, and the lack of efficient means for integrating gas pipeline network data, the inspection work of the gas pipeline network cannot achieve the effect of thorough and accurate inspection, and accidents often occur when thorough and accurate inspection is not achieved.

[0004] Chinese Patent CN215415308U discloses a portable combustible gas detector, including a detector main body. A wire tube is arranged on the surface of the detector main body. The wire tube is a flexible metal wire tube. A detection probe is arranged on the upper surface of the wire tube. The outer surface of the detection probe is threadedly connected with a threaded sleeve. A square frame is fixedly connected to the inner surface of the threaded sleeve. One end of the square frame is fixedly connected with a motor. A fan blade is arranged on the outer surface of the driving shaft of the motor. An air inlet hole is arranged on the lower surface of the threaded sleeve. By providing an external air inlet component, the fan blade can be driven by the motor to rotate, so as to conduct air outward. The air flow quickly enters through the air inlet hole and can be sensed by the detection probe, which is convenient for increasing the air intake detection amount. The detection is sensitive, and it is convenient to use and carry. The defect of this patent is that the gas components and concentrations sensed by the detection probe are easily affected by interfering gases in the gas, and its detection accuracy is low, and there may be missed detection phenomena.

[0005] Chinese Patent CN112730519A discloses a portable methane micro-leakage quantification detector and its detection method. The detector includes a gas collection and flow device, a methane concentration detection device, and an air flow detection device. The methane concentration detection device and the air flow detection device are arranged on the gas collection and flow device; the gas collection and flow device includes a detection part sealing bag, an intake hose, a DC pipeline fan, and an air outlet connected in sequence, and the detection part sealing bag is wrapped around the pipeline test point. To solve the technical problem that a portable methane micro-leakage quantification detector is needed for the leakage of pipelines, other equipment, and components in the gas pipeline network, a portable methane micro-leakage quantification detector and its detection method are proposed, which are used to detect the methane leakage amount of each pipeline and other device equipment at the end of the gas transmission and distribution pipeline network. The defect of this patent is that the scale and quality of this device still require staff to carry it in a backpack, and it still lacks portability. Secondly, the semiconductor sensor detection method adopted, compared with the double-sensor differential response detection method of the methane concentration detection device of the present invention, has low accuracy and cannot eliminate the influence of interfering gases.

[0006] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, although the inventor studied a large number of documents and patents when making this invention, all details and contents are not listed in detail due to space limitations. However, this does not mean that this invention does not possess the features of these prior arts. On the contrary, this invention already possesses all the features of the prior arts, and the applicant reserves the right to add relevant prior arts in the background art. Summary of the Invention

[0007] In the prior art, the detection of flammable gases usually uses a catalytic flammable gas detector, which mainly utilizes the thermal effect principle of catalytic combustion. The sensor in the catalytic flammable gas detector can measure the gas under certain temperature conditions by using the resistance change of a refractory metal platinum wire after heating. When the gas enters the detector, an oxidation reaction (flameless combustion) is caused on the surface of the platinum wire, and the heat generated makes the temperature of the platinum wire rise, and the resistivity of the platinum wire changes. Therefore, when the temperature of the platinum wire changes due to high temperature and other factors, the resistivity of the platinum wire changes, and the detected data also changes. However, the defect of this prior art is that the combustion values of different gases are different, and the sensor measures the resistance change caused by combustion rather than the change in concentration. Therefore, different gases may have different readings even at the same concentration. It has no selectivity within the gas range, and the sensor is easily affected by compounds in the gas, resulting in a reduced service life. This detector also has many disadvantages such as too high working temperature and inability to be used in an oxygen-deficient environment.

[0008] In view of the deficiencies of the prior art, the technical solution of the present invention is to provide a gas detection system, which at least includes a detection tube and a control module, and the detection tube is connected to the control module. The detection tube is provided with a first sensor and a second sensor along the gas flow direction, and the control module determines the type of gas flowing into the detection tube at least based on the differential response of the dual sensors. An air extraction unit and a polar filter membrane for sucking gas at a predetermined position in the detection tube are further provided in the detection tube. The air extraction unit is arranged between the first sensor and the second sensor so that the gas sucked into the detection tube by the air extraction unit sequentially passes through the first sensor and the second sensor, thereby determining the type of gas based on the differential response of the dual sensors. By providing the first sensor and the second sensor, and arranging a polar filter membrane between the first sensor and the second sensor, the present invention accurately determines the type and concentration of gas through the differential response of the two sensors, eliminates the influence of interfering gases on the detection of methane concentration, provides the selectivity of the sensor to methane, and is applicable to portable and accurate detection for outdoor inspection of gas pipelines.

[0009] According to a preferred embodiment, the gas is pumped into a gas sensor array composed of the first sensor and the second sensor by the air extraction unit, and the gas sensor array sends the measured gas component concentration to the signal processing circuit of the control module through A / D sampling, and the signal processing circuit is connected to the processing unit.

[0010] According to a preferred embodiment, the polar filter membrane is used to filter the interfering gases present in the gas, so that methane in the gas passes through the non-polar filter membrane to the second sensor. The interfering gases are at least composed of ethanol and / or water. The polar filter membrane can adopt, for example, a PTFE membrane to filter the interfering gases composed of ethanol and / or water, so as to accurately detect the methane concentration in the gas.

[0011] According to a preferred embodiment, the second sensor detects the gas after passing through the polar filter membrane and obtains a second response, the first sensor detects the gas sucked by the air extraction unit and obtains a first response, and the first sensor and the second sensor send the first response and the second response to the signal processing circuit, and the signal processing circuit sends them to the processing unit after processing. Among them, the processing unit determines the type of gas and determines whether the methane gas concentration in the gas exceeds the safety threshold by comparing the difference between the first response and the second response.

[0012] According to a preferred embodiment, the difference between the first response and the second response refers to: when there is data interference, the responses of the first sensor and the second sensor are basic responses; when the first response is greater than the basic response and the second response is less than the basic response, the gas contains polar molecules blocked by the polar filter membrane and does not contain methane gas; when the first response is greater than the basic response, the second response is greater than the basic response, and the first response is greater than 0.8 times the second response and less than 1.2 - 5 times the second response, the methane gas concentration is judged according to the concentration conversion algorithm, and it is judged whether it exceeds the safety threshold; when the first response is greater than the basic response, the second response is greater than the basic response, and the first response is greater than 1.2 - 5 times the second response, then the gas contains non-polar interfering gas.

[0013] According to a preferred embodiment, in the case where the gas contains non-polar interfering gas, the processing unit calculates the types and concentrations of the components in the gas according to the ratio of the first response and the second response.

[0014] According to a preferred embodiment, the control module is further provided with a communication interface circuit for connecting to an intelligent device to perform data interaction.

[0015] According to a preferred embodiment, a shunt channel is provided in the detection tube, and a filter membrane and a sensor are provided in the shunt channel based on several mixed components in the gas to realize the distinction and concentration detection of several mixed components.

[0016] The present invention also relates to a gas detection method, which at least includes: the first sensor and the second sensor judge the type of gas flowing into the detection tube at least based on the differential response of the dual sensors; the first sensor and the second sensor are arranged along the gas flow direction of the detection tube; a gas pumping unit and a polar filter membrane for pumping gas at a predetermined position in the detection tube are further provided in the detection tube, and the gas pumping unit is arranged between the first sensor and the second sensor so that the gas entering the detection tube through the pumping action of the gas pumping unit passes through the first sensor and the second sensor in sequence, thereby judging the type of gas based on the differential response of the dual sensors.

[0017] According to a preferred embodiment, the gas is pumped into a gas sensor array composed of the first sensor and the second sensor by the gas pumping unit, and the concentration of the components in the measured gas is sent to the signal processing circuit of the control module through A / D sampling in the gas sensor array, and the signal processing circuit is connected to the processing unit.

[0018] The beneficial technical effects of the present invention:

[0019] The present invention provides a first sensor and a second sensor, and a polarizing filter membrane is arranged between the first sensor and the second sensor. The type and concentration of gas are accurately determined through the differential responses of the two sensors. The polarizing filter membrane eliminates the influence of interfering gases on the detection of methane concentration. The detection method of differential responses of the two sensors of the present invention has selectivity for methane and is suitable for portable and accurate detection during the inspection of outdoor gas pipe networks. The differential response method of the two sensors adopted by the present invention quantitatively determines by differentially comparing the response values of the gas in the sensors. The response value is proportional to the component concentration, so as to obtain the methane concentration in the target gas, and a filter membrane is provided to filter the interfering components in the gas. This detection method avoids the problem that when other mixed gases are contained in the target gas, the concentration measured by the calorific value is interfered by the mixed gas, resulting in the non-selectivity of the detector, and this detection method does not generate heat to cause the reduction of the service life of the detector. Its portable manner enables the device to be used in a variety of complex environments. For example, when inspecting the underground gas pipe network in the city, the oxygen content is low in a narrow environment, resulting in the problem of inability to burn. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a preferred embodiment of the detection tube of the present invention;

[0021] Figure 2 is a module flowchart of a preferred embodiment of the control module of the present invention.

[0022] LIST OF REFERENCE NUMERALS

[0023] 1: Detection tube; 2: Control module; 101: First sensor; 102: Second sensor; 103: Air extraction unit; 104: Polarizing filter membrane; 105: Air outlet; 201: Signal processing circuit; 202: Processing unit; 203: Communication interface circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] The following will be described in detail with reference to the accompanying drawings.

[0026] Intelligent devices: including but not limited to any wireless terminal, such as mobile phones, smart phones, etc.; including computing devices, which include a wireless cellular communication port, a memory, and a processor, where the processor is configured to execute application program instructions, and where the smart phone has local and personal area wireless communication ports, a GPS receiver, and a patient interface.

[0027] Server: any type of computer or processing system, including but not limited to mobile terminals, personal computers (PCs), personal digital assistants (PDAs), mainframe computers, network devices, systems or other devices or combinations of devices having a database capable of storing and processing patient information. It is broadly defined to cover any device or combination of devices having at least one processor that executes instructions from a storage medium.

[0028] Example 1

[0029] The present application relates to a gas detection system, which at least includes a detection tube 1 and a control module 2, and the detection tube 1 is connected to the control module 2. The detection tube 1 is provided with a first sensor 101 and a second sensor 102 along the gas flow direction. The control module 2 determines the type of gas flowing into the detection tube 1 at least based on the differential response of the dual sensors. An air extraction unit 103 and a polar filter membrane 104 for sucking gas at a predetermined position in the detection tube 1 are also provided in the detection tube 1. The air extraction unit 103 is arranged between the first sensor 101 and the second sensor 102 so that the gas sucked into the detection tube 1 by the suction action of the air extraction unit 103 passes through the first sensor 101 and the second sensor 102 in sequence, thereby determining the type of gas based on the differential response of the dual sensors. The first sensor 101 and the second sensor 102 can be set as a methane sensor array, such as a metal oxide-based one. The present application also provides a component for removing the influence of interfering gases such as humidity and ethanol. The detection tube 1 internally houses the first sensor 101 and the second sensor 102, where the first sensor 101 is a more distal sensor and the second sensor 102 is a more proximal sensor, and they are separated by a dehumidification membrane or a VOC filter membrane in the middle. The type and concentration of the gas are judged by using the differential response of the dual sensors, and a pump suction component can be adopted at the tail end to accelerate the gas flow rate. The polar filter membrane 104 is a porous polar filter cotton (dehumidification membrane or VOC filter membrane). According to the principle of "like dissolves like", polar molecules are easily soluble in polar solvents and non-polar molecules are easily soluble in non-polar solvents. The filter membrane can adopt a polar filter membrane, including a PTFE membrane, etc., to filter interfering gases such as ethanol and humidity, so as to ensure that the passage of the target gas methane is not affected. By setting the first sensor 101 and the second sensor 102 and arranging the polar filter membrane 104 between the first sensor 101 and the second sensor 102, the present invention accurately judges the type and concentration of the gas through the differential response of the two sensors, eliminates the influence of interfering gases on the detection of methane concentration, provides the selectivity of the sensor to methane, and is applicable to portable and accurate detection for outdoor gas pipeline network inspection. It should be noted that for the functions required in specific embodiments of the present invention, a polar filter membrane 104 based on like dissolves like is proposed, but this does not mean that the present invention does not include other principles required to achieve the same effect. Under the inspiration of the corresponding functions of the present invention, various solutions based on other principles are conceived, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention.

[0030] According to a preferred embodiment, the gas is pumped into the gas sensor array composed of the first sensor 101 and the second sensor 102 by the air extraction unit 103. The gas sensor array sends the measured gas component concentration to the signal processing circuit 201 of the control module 2 through A / D sampling, and the signal processing circuit 201 is connected to the processing unit 202. An air outlet 105 for discharging the detected gas is provided behind the second sensor 102.

[0031] According to a preferred embodiment, the polarizing filter membrane 104 is used to filter interfering gases present in the gas, allowing methane in the gas to pass through the polarizing filter membrane 104 to the second sensor 102. The interfering gas consists of at least ethanol and / or water. The polarizing filter membrane 104 can use, for example, a PTFE membrane to filter the interfering gas composed of ethanol and / or water, thereby accurately detecting the methane concentration in the gas.

[0032] According to a preferred embodiment, the second sensor 102 detects the gas after passing through the polarizing filter membrane 104 and obtains a second response, and the first sensor 101 detects the gas aspirated by the air extraction unit 103 and obtains a first response. The first sensor 101 and the second sensor 102 send the first response and the second response to the signal processing circuit 201, and the signal processing circuit 201 sends them to the processing unit 202 after processing. Among them, the processing unit 202 determines the type of gas and determines whether the methane gas concentration in the gas exceeds the safety threshold by comparing the difference between the first response and the second response. Since the polarizing filter membrane 104 is provided between the two sensors, the differential response characteristics of the two sensors can reflect the type of gas.

[0033] According to a preferred embodiment, the difference between the first response and the second response means that when there is data interference, the responses of the first sensor 101 and the second sensor 102 are basic responses, and this basic response is set as th. When the first response is greater than th and the second response is less than th, the gas contains polar molecules blocked by the polar filter membrane 104 and does not contain methane gas; when the first response is greater than th, the second response is greater than th, and the first response is greater than 0.8 times the second response and less than 1.2 to 5 times the second response, the methane gas concentration is judged according to the concentration conversion algorithm, and it is judged whether it exceeds the safety threshold; when the first response is greater than th, the second response is greater than th, and the first response is greater than 1.2 to 5 times the second response, then the gas contains non-polar interfering gases. The above setting method simplifies the actual use scenario, and the first sensor 101 and the second sensor 102 use the same type of sensor. Assume that data interference will cause the response to be th. When the first response > th and the second response < th, the target gas is high-humidity water molecules or other polar molecules blocked by the filter membrane, and the processing unit 202 does not perform the concentration conversion algorithm to judge the methane gas concentration; the first response > th, the second response > th, and (1.2 to 5) × the second response > the first response > 0.8 × the second response, then the target gas contains methane gas, the methane gas concentration is judged according to the concentration conversion algorithm, and it is judged whether it exceeds the safety threshold to determine whether to alarm; the first response > th, the second response > th, and the first response > (1.2 to 5) the second response, then the target gas still contains non-polar interfering gases, and then according to the ratio of the first response / the second response, combined with the machine learning algorithm, the types and concentrations of various mixed gases are calculated. It should be noted that the above basic response refers to the sensor response threshold caused by the methane concentration that needs to be alarmed. The above 1.2 to 5 shows the required response range for the specific embodiment of the present invention and does not mean that it does not include the required response ranges for other implementations with the same effect.

[0034] In the prior art, the detection of flammable gases usually adopts a catalytic flammable gas detector, which mainly utilizes the thermal effect principle of catalytic combustion. The sensor in the catalytic flammable gas detector can measure the gas by using the change in the resistance of a refractory metal platinum wire after heating under certain temperature conditions. When the gas enters the detector, an oxidation reaction (flameless combustion) is caused on the surface of the platinum wire, and the heat generated makes the temperature of the platinum wire rise, and the resistivity of the platinum wire changes. Therefore, when the temperature of the platinum wire changes due to factors such as high temperature, the resistivity of the platinum wire changes, and the detected data also changes. However, the defect of this prior art is that the combustion values of different gases are different, and the sensor measures the resistance change caused by combustion rather than the change in concentration. Therefore, different gases may have different readings even at the same concentration. In the gas range, it has no selectivity, and the sensor is easily affected by compounds in the gas, resulting in a reduced service life. This detector also has many disadvantages such as too high working temperature and inability to be used in an oxygen-deficient environment.

[0035] Different from the prior art which detects by the change in resistivity, the dual-sensor differential response method adopted by the present invention quantitatively measures by differentially comparing the response values of the gas in the sensors. The response value is proportional to the component concentration, so as to obtain the methane concentration in the target gas, and a filter membrane is provided to filter the interfering components in the gas. This detection method avoids the problem that the concentration measured by the combustion value is interfered by the mixed gas when other mixed gases are contained in the target gas, resulting in the non-selectivity of the detector, and this detection method will not generate heat to cause the service life of the detector to decrease. Its portable form enables the device to be used in a variety of complex environments. For example, when inspecting the underground gas pipeline network in the city, the oxygen content is low in a narrow environment, resulting in the problem of inability to burn.

[0036] According to a preferred embodiment, in the case where the gas contains non-polar interfering gases, the processing unit 202 calculates the types and concentrations of the components in the gas according to the ratio of the first response and the second response. For example, when the ratio of the first response and the second response is 1 and greater than the basic response, it indicates that methane gas is contained in the target gas.

[0037] According to a preferred embodiment, the control module 2 is also provided with a communication interface circuit 203 for connecting to an intelligent device to perform data interaction. The interacted data includes sensor calibration, sensor fault self-check, and methane concentration data storage, etc., so as to perform real-time recording and intelligent alarm through the intelligent device.

[0038] According to a preferred embodiment, a flow dividing channel is provided in the detection tube 1. In the flow dividing channel, a filter membrane and a sensor are provided based on several mixed components in the gas to distinguish and detect the concentrations of several mixed components. The flow dividing channel is, for example, a channel that divides the target gas into two streams after the air extraction unit 103. Filter membranes and sensors for detecting the corresponding gas components are provided in the two flow dividing channels, such as filter membranes and sensors for detecting methane and ethane, to distinguish whether the target gas is natural gas or biogas. After the two flow dividing channels converge, they are connected to the air outlet 105.

[0039] According to a preferred embodiment, the detection tube 1 is configured to have a filtering structure for mixed flow and flow division. The detection tube 1 is integrally configured as a flow channel structure, and a plurality of mixed flow channels and flow dividing channels are distributed among its flow channels. Specifically, at least one spacer block arranged along the flow axis is configured in the flow channel of the detection tube. The spacer block is used to divide the flow channel into at least two flow dividing channels, and the plurality of flow dividing channels are arranged in parallel, that is, the gas is divided here and can all pass through all the flow dividing channels. Thus, when the air flow flows in the detection tube 1, it can flow out from multiple flow dividing channels and complete impinging mixing in the mixing channel, so that the internal components and distribution state of the air flow change, especially the components in the gas are remixed. Preferably, the spacer block is configured in the following manner: the cross-sectional area from its upstream position where it first contacts the air flow to its downstream position where it finally contacts the air flow changes in a distribution manner from small to large and then to small, and preferably, it is configured in a manner of a curve change similar to a normal distribution. The above configuration method enables the separation and remixing of interfering components at different positions before the air flow enters the flow dividing channel, in the flow dividing channel, and after leaving the flow dividing channel, and accelerates the contact between the interfering components and the channel wall in the flow dividing channel, so that the interfering components can be separated more effectively. Further, the filter membrane in this solution can be configured in the flow dividing channel, and preferably, a filter membrane is also configured in the mixing area, so that the interfering gas passing through the flow dividing channel can be collected by the filter membrane in a manner close to the channel wall, and the interfering gas that is not completely collected can be further recovered by the filter membrane after mixing in the mixing area at a higher flow rate. Further, the first sensor is configured in the mixing area before the flow dividing channel, and the second sensor is configured after the filter membrane in the mixing area after the flow dividing channel, so that the second sensor can obtain better differential response data when generating a second response to the redistributed and filtered gas, and the result is more accurate.

[0040] The present invention also relates to a gas detection method, which at least includes: the first sensor 101 and the second sensor 102 determine the type of gas flowing into the detection tube 1 at least based on the differential response of the dual sensors; the first sensor 101 and the second sensor 102 are arranged along the gas flow direction of the detection tube 1; wherein an air extraction unit 103 and a polar filter membrane 104 for sucking gas at a predetermined position in the detection tube 1 are further provided in the detection tube 1, and the air extraction unit 103 is arranged between the first sensor 101 and the second sensor 102 so that the gas entering the detection tube 1 through the suction action of the air extraction unit 103 passes through the first sensor 101 and the second sensor 102 in sequence, thereby determining the type of gas based on the differential response of the dual sensors.

[0041] According to a preferred embodiment, the gas is pumped into the gas sensor array composed of the first sensor 101 and the second sensor 102 through the air extraction unit 103, and the component concentration in the measured gas is sent to the signal processing circuit 201 of the control module 2 through A / D sampling in the gas sensor array, and the signal processing circuit 201 is connected to the processing unit 202.

[0042] Embodiment 2

[0043] This embodiment is a further and / or supplementary to the above embodiment, and the repeated content will not be elaborated.

[0044] According to a preferred embodiment, the detection tube 1 is a single tube and internally provided with a methane sensor array, for example, based on metal oxide, to remove the influence of interfering gases such as humidity and ethanol.

[0045] According to a preferred embodiment, the detection tube 1 is a single tube and internally provided with the first sensor 101 and the second sensor 102 with one far and one near, separated by a polar filter membrane 104 in the middle, such as a dehumidification membrane or a VOC filter membrane, to judge the type and concentration of gas by using the differential response of the dual sensors, and a pump suction type air extraction unit 103 can be adopted at the tail end to accelerate the gas flow rate.

[0046] According to a preferred embodiment, the air extraction unit 103 can be placed between the first sensor 101 and the second sensor 102 to increase the pumping effect on the external gas.

[0047] According to a preferred embodiment, the detection tube 1 is a single tube, internally provided with a methane sensor array, and also provided with a chromatographic column inside. The methane sensor is located at the tail end of the chromatographic column. The chromatographic column can separate different gases according to the different boiling points, polarities, and adsorption properties of the flowing components, or judge the type of gas by using the flowing time of the gas.

[0048] According to a preferred embodiment, the detection tube 1 is a single tube with a first sensor 101 and a second sensor 102 disposed at a distance and close to each other inside, and a chromatographic column is also provided inside. The first sensor 101 and the second sensor 102 are respectively located at the two ends of the chromatographic column head and tail, and the second sensor 102 further determines the gas type.

[0049] According to a preferred embodiment, the detection tube 1 is a three-section single tube with a first sensor 101 and a second sensor 102 disposed at a distance and close to each other inside. The first section and the third section are respectively provided with the first sensor 101 and the second sensor 102 inside, the second section is a VOC adsorption tube, and the adsorption tube can be internally provided with a VOC adsorbent. The second section is a consumable. Whether the second adsorption tube needs to be replaced is judged according to the responses of the first sensor 101 and the second sensor 102; the three-section detection tube is connected by threads. When a problem occurs in the second tube containing the filter membrane, the thread is turned open for replacement. Specifically, when the first sensor 101 inside the first section has a response while the second sensor 102 has no response, the device gives an alarm signal and the second tube needs to be replaced; or alcohol gas can be used for testing, and the device working mode is changed to the test mode. When the test result is that both the first sensor 101 and the second sensor 102 have responses, it is tested that the second tube needs to be replaced.

[0050] Embodiment 3

[0051] This embodiment is a further and / or supplementary to the above embodiment, and the repeated content will not be described again.

[0052] The traditional inspection of gas pipe networks mainly relies on the staff to conduct a carpet inspection on each gas pipe. However, due to the long gas pipe network, the dispersion of the staff, and the lack of an efficient means of integrating gas pipe network data, the inspection work of the gas pipe network cannot achieve the effect of precise inspection and complete inspection, and accidents often occur when precise inspection and complete inspection are not achieved. The processing unit 202 provided in the present invention is connected to the server to solve the problem of difficult management and integration in the inspection work of gas pipe networks.

[0053] Preferably, from the perspective of global resource allocation, the server determines the inspection path of the staff and the specific concentration of methane at each inspection point through the GPS unit integrated in the control module 2, so as to provide a plan for the inspection of each staff member and achieve the overall planning of the inspection of urban gas pipe networks. Ensure that the staff can easily conduct inspections according to the corresponding inspection plan given by the server. This inspection plan fully considers the objective indicators in the inspection process, including the inspection trajectory of the staff, the inspection density of personnel, the methane concentration, and the precise positioning of hazards. Effectively solve the problems of the current inspection of gas pipelines, such as the lack of real-time overall planning, unclear inspection quality, and the inability to effectively implement the safety plan due to the lack of data integration.

[0054] Preferably, the GPS positioning unit integrated in the control module 2 continuously reads the positioning information sent by satellites to apply the longitude and latitude information to the inspection route and determine the inspection points of the staff in real time. After the staff detects the methane concentration at the inspection point through the detection pipe 1, the concentration is saved in the server in a one-to-one correspondence with each detection point, and the inspection trajectory can be recorded in real time. The server conducts inspection command and dispatch for the above corresponding information of the gas pipeline network to determine the inspection path of the staff and various work tasks to be carried out. The decisions and instructions made by the server are distributed to intelligent devices to achieve interactive task processing.

[0055] According to a preferred embodiment, each control module 2 is bound to the identity information of the staff and the intelligent device. The server comprehensively records various types of data obtained by the control module 2, such as methane concentration and positioning signals. The server is further configured to: when the staff measures the methane concentration at the inspection point and the GPS positioning unit sends its own positioning information to the server, establish a gas pipeline network model to determine the methane concentration information corresponding to the inspection point; the server selects the next inspection point of the staff through this gas pipeline network model, and the server generates an inspection route from the current coordinates of the staff to the next inspection point based on this selection and in combination with the public map; wherein the server generates at least two inspection routes from the current coordinates of the staff to the next inspection point at least by accessing the public map database; the server also obtains sudden dangerous events on this inspection route through the gas pipeline network model, and further selects the generated inspection route by avoiding or passing through the range where the sudden dangerous event is located. The above sudden dangerous events can be areas blocked due to excessive pedestrian flow and / or areas where accidents occur. The above sudden dangerous events can also be areas where methane leakage occurs. If the sudden dangerous event is an area blocked due to excessive pedestrian flow and / or where an accident occurs, the inspection route is planned in a way to avoid this area. If the sudden dangerous event is an area where methane leakage occurs, the inspection route is planned in a way to pass through the inspection point close to the methane leakage, so as to comprehensively detect the surrounding area when methane leakage occurs. Specifically, the server obtains the current coordinates of the staff by accessing the longitude and latitude information of the GPS positioning unit, and obtains the inspection route based on the current coordinates of the staff in combination with the publicly available map database. Preferably, the server generates the inspection route in the following way. The server takes the next inspection point reached by the staff as the end point, and at the same time retrieves each inspection point data and distance information associated with this next inspection point to complete the basic generation of the inspection route. The server can mark the landmark buildings and / or reference points of the inspection route according to the publicly available map database, and determine the accuracy of the inspection route in a multi-point marking manner. The intelligent device of the staff receives the line data of the inspection route generated by the server, rather than the specific parameters of the gas pipeline network. The generation of the inspection route is generated in the server and is not affected by the GPS positioning unit and / or the intelligent device, thus avoiding the specific parameters of the gas pipeline network being cached in the GPS positioning unit and / or the intelligent device due to the inspection route planning by the intelligent device carried by the staff, and further reducing the risk of specific parameter leakage. The server of the present invention enhances the scientific means of safety prevention management by setting each inspection section and inspection route of the gas pipeline network through the GPS positioning unit and deploying the work of the staff, and at the same time realizes the remote monitoring of the staff, achieving the purpose of centralized management.Preferably, during the inspection process, the staff can also use the camera function of the smart device to report, handle and follow up on sudden accidents and safety hazards in a timely manner to avoid increasing the degree of harm caused by methane leakage. The server also records the process and results of handling various abnormal situations or accidents. The server can enable the staff to upload all the inspection tracks and inspection data during the inspection process, provide inspection tracks and data queries, check the gas pipeline network resource data, and obtain more scientific inspection resource data. The server analyzes the inspection resource data to make a good gas leakage prevention plan. The server records the inspection status of the staff according to the GPS positioning unit. The server can also establish a unified data pool. The GPS information of the gas pipeline network and its ancillary facilities is closely combined with the pipeline network leak detection equipment and staff, which can quickly provide real and accurate gas pipeline network data, and can realize functions such as rapid leak detection, real-time upload, regional division, real-time trajectory, and precise positioning, providing a reliable and scientific basis for the daily management, analysis and statistics, and safety prediction of the outdoor gas pipeline network. Realize inspection management, third-party construction monitoring, hidden danger management, statistical management, attendance management, meter reading management and other functions.

[0056] The complexity and real-time nature of the gas pipeline inspection planning determine that the inspection route may change in real time to ensure that the staff can deal with methane leaks in a timely manner. Therefore, it is a very important technical measure to coordinate the inspection route through the server, combine intelligent devices and control module 2, especially divide sudden dangerous events, derive safe, reliable and rapid inspection routes, and connect various inspection points.

[0057] According to a preferred embodiment, the detection tube 1 and the control module 2 of the present invention can be connected to a mobile phone through a mobile phone charging port for charging or data transmission, so as to realize a convenient outdoor gas pipeline network inspection. The detection tube 1 and the control module 2 can be configured with a large-capacity battery (with a remaining power prompt). The present invention also includes an alarm instrument, which includes the following functions: data storage function, alarm function, battery undervoltage prompt, wireless communication mode and sampling probe. The alarm instrument can also use the mobile phone module to realize sensor calibration, sensor fault self-check and intelligent alarm functions. The communication mode of the alarm instrument: data transmission through a mobile phone (such as type-C port) through a protocol; communication through a Bluetooth module, and data transmission in conjunction with a mobile phone program or WeChat applet. The alarm instrument can be developed and set up through a mobile phone program, wherein the system of the mobile phone can be Android and / or IOS system. The alarm instrument can establish a database through tools such as MongoDB, SQL and Oracle. The positioning function of the alarm instrument can be used for GPS positioning, realizing real-time inspection, real-time trajectory, trajectory playback, equipment power management, pipeline management, official website drawing, third-party supervision, equipment management, account management and attendance photography and clocking in.

[0058] Throughout the text, the features led by "preferably" are only optional ways and should not be construed as being necessarily provided. Therefore, the applicant reserves the right to waive or delete relevant preferred features at any time.

[0059] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also fall within the scope of the disclosure of the present invention and within the protection scope of the present invention. Those skilled in the art should understand that the specification and drawings of the present invention are illustrative and do not constitute a limitation on the claims. The protection scope of the present invention is defined by the claims and their equivalents.

Claims

1. A gas detection system, characterized in that, It includes at least a detection tube (1) and a control module (2), and the detection tube (1) is connected to the control module (2). The detection tube (1) is provided with a first sensor (101) and a second sensor (102) along the gas flow direction, and the control module (2) determines the type of gas flowing into the detection tube (1) at least based on the differential response of the dual sensors. A polarizing filter membrane (104) and a gas pumping unit (103) for pumping gas at a predetermined position in the detection tube (1) are further provided in the detection tube (1). The gas pumping unit (103) is arranged between the first sensor (101) and the second sensor (102) so that the gas entering the detection tube (1) by the pumping action of the gas pumping unit (103) sequentially passes through the first sensor (101) and the second sensor (102), thereby quantitatively measuring by differentially comparing the response values of the gas in the sensors. At least one spacer block arranged along the flow axis for dividing the flow channel into at least two sub-flow channels is configured in the detection tube (1). In the sub-flow channels, filter membranes and sensors corresponding to the gas components are provided based on several mixed components in the gas to achieve the distinction and concentration detection of several mixed components. The cross-sectional area of the spacer block at the upstream position where it first contacts the air flow to the cross-sectional area at the downstream position where it finally contacts the air flow is configured in a manner of first getting smaller, then larger, and then smaller.

2. The gas detection system according to claim 1, wherein The gas is pumped into the gas sensor array composed of the first sensor (101) and the second sensor (102) by the gas pumping unit (103). The gas sensor array sends the measured gas component concentration to the signal processing circuit (201) of the control module (2) through A / D sampling, and the signal processing circuit (201) is connected to the processing unit (202).

3. The gas detection system according to claim 2, wherein, The polarizing filter membrane (104) is used to filter the interfering gas present in the gas, so that methane in the gas passes through the polarizing filter membrane (104) to the second sensor (102). The interfering gas is at least composed of ethanol and / or water.

4. The gas detection system according to claim 3, wherein, The second sensor (102) detects the gas after passing through the polarizing filter membrane (104) and obtains a second response. The first sensor (101) detects the gas pumped by the gas pumping unit (103) and obtains a first response. The first sensor (101) and the second sensor (102) send the first response and the second response to the signal processing circuit (201), and the signal processing circuit (201) processes and then sends it to the processing unit (202), where the processing unit (202) determines the type of gas and determines whether the methane gas concentration in the gas exceeds the safety threshold by comparing the difference between the first response and the second response.

5. The gas detection system according to claim 4, characterized in that, Comparing the difference between the first response and the second response means that when there is data interference, the responses of the first sensor (101) and the second sensor (102) are basic responses. When the first response is greater than the basic response and the second response is less than the basic response, the gas contains polar molecules blocked by the polar filter membrane (104) and does not contain methane gas; When the first response is greater than the basic response, the second response is greater than the basic response, and the first response is greater than 0.8 times the second response and less than 1.2 - 5 times the second response, the methane gas concentration is judged according to the concentration conversion algorithm, and it is judged whether it exceeds the safety threshold; When the first response is greater than the basic response, the second response is greater than the basic response, and the first response is greater than 1.2 - 5 times the second response, then the gas contains non-polar interfering gases.

6. The gas detection system according to claim 5, characterized in that, In the case where the gas contains non-polar interfering gases, the processing unit (202) calculates the types and concentrations of the components in the gas according to the ratio of the first response to the second response.

7. The gas detection system according to claim 6, wherein, The control module (2) is further provided with a communication interface circuit (203) for connecting to an intelligent device to perform data interaction.

8. A gas detection method, characterized in that, The method at least includes: The first sensor (101) and the second sensor (102) judge the type of the gas flowing into the detection tube (1) at least based on the differential response of the dual sensors; The first sensor (101) and the second sensor (102) are arranged along the gas flow direction of the detection tube (1); wherein, An air extraction unit (103) and a polar filter membrane (104) for sucking gas at a predetermined position in the detection tube (1) are further provided in the detection tube (1). The air extraction unit (103) is arranged between the first sensor (101) and the second sensor (102) so that the gas entering the detection tube (1) through the suction action of the air extraction unit (103) passes through the first sensor (101) and the second sensor (102) in sequence, thereby quantitatively measuring by differentially comparing the response values of the gas in the sensors. At least one spacer block arranged along the flow axis is configured in the detection tube (1) to divide the flow channel into at least two shunt channels. Filters and sensors corresponding to the gas components are provided in the shunt channels based on several mixed components in the gas to realize the distinction and concentration detection of several mixed components. The cross-sectional area of the upstream position where the spacer block first contacts the air flow to the cross-sectional area of the downstream position where it finally contacts the air flow is configured in a manner of first getting smaller, then getting larger, and then getting smaller.

9. The gas detection method according to claim 8, characterized in that, The gas is pumped into the gas sensor array composed of the first sensor (101) and the second sensor (102) by the air extraction unit (103). The concentration of the components in the measured gas is sent to the signal processing circuit (201) of the control module (2) through A / D sampling, and the signal processing circuit (201) is connected to the processing unit (202).

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