Method for collecting and quantitatively detecting gas containing methane and volatile organic compounds

Abstract

The invention relates to a collaborative collection and quantitative detection method for gas containing methane and volatile organic compounds, and belongs to the field of greenhouse gas emission detection technology research in the petroleum and natural gas industry. The detection method comprises the following steps: sequentially arranging a gas-collecting hood opening collector, a first airflow driving element and a wind speed measuring assembly on a gas collecting pipeline; collecting the escaping gas at the collection point by using a gas collection pipeline; performing wind speed detection on the collected flowing gas; meanwhile, extracting the flowing gas to obtain a first part of gas and a second part of gas; in the flow process of the first part of gas, measuring the methane concentration of the first part of gas; and in the flow process of the second part of gas, measuring the concentration of volatile organic compounds in the second part of gas. According to the device and the method, synchronous qualitative and quantitative detection of the methane and the VOCs in the gas containing the methane and the VOCs is realized while the gas containing the methane and the VOCs is collected, and the defects in the prior art are overcome.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of greenhouse gas emission detection in the oil and gas industry, and particularly relates to a method for collecting and quantitatively detecting methane and volatile organic compound gases. BACKGROUND

[0002] In nature, natural gas and oilfield gas contain a large amount of methane and volatile organic compounds (hereinafter referred to as VOCs). With the development of the domestic oil and gas industry, the application scale of various measures is increasing, and the emission and leakage of methane and VOCs are continuously increasing, which causes great safety and environmental protection hidden dangers in the production process and easily causes great air pollution. Therefore, it is necessary to carry out methane and VOCs detection in the production, processing and transportation process of natural gas and oilfield gas, which can effectively control the emission and leakage of methane and VOCs and has important protection for the safety production of the oil and gas industry.

[0003] With the continuous development of methane and VOCs leakage detection and control technology in the domestic oil and gas industry, the detection technology is more detailed. In addition, the gas emission in the oil and gas upstream is basically homologous, which has the practical possibility of methane and VOCs detection, and the development of methane and VOCs detection technology is a prerequisite for carrying out emission accounting of the oil and gas industry. The methane and VOCs detection instrument is used to detect all possible leakage components, find the leakage position, and timely repair, so as to reduce the emission of pollutants.

[0004] At present, there are various methane detection and VOCs detection technologies. For example, in the prior art, a second harmonic signal related to the methane concentration is output by a TDLAS system, and the signal is analyzed to determine the methane concentration. This method can only detect the concentration of methane and cannot realize the quantification of methane. For example, in the prior art, air samples are pumped through an adsorbent to collect VOCs; the collected VOCs are enriched by a VOCs adsorption and treatment device; the enriched VOCs samples are analyzed by GC-FID / MS combined technology to analyze the components and concentration of VOCs in the air; the content of formaldehyde in indoor air is analyzed by acetylacetone spectrophotometry; standard sample solutions of various volatile compounds are prepared and standard curves are drawn, and the enriched VOCs samples are analyzed to obtain corresponding detection results. This method only determines the concentration of VOCs and the content of formaldehyde, and still cannot realize the quantification of methane and VOCs, and cannot realize the simultaneous quantification of methane and VOCs emissions. For example, in the prior art, a VOCs detection system is used to online and real-time detect the gas VOCs value entering the monitoring area, the VOCs value in the monitoring area, and the gas VOCs value discharged from the monitoring area; and online and real-time detect the gas VOCs value entering the tail gas treatment device, the gas VOCs value discharged from the tail gas treatment device; and send the VOCs values detected at each monitoring point to the central control system; the central control system compares each detected VOCs value with the corresponding preset threshold value; if the value is higher than the preset threshold value, the corresponding equipment control is performed. This method also detects the concentration of VOCs alone, and still cannot realize the quantification of methane and VOCs, and cannot realize the simultaneous quantification of methane and VOCs emissions. SUMMARY

[0005] In view of the above problems, the present application provides a method for collecting and quantitatively detecting methane and volatile organic gas.

[0006] The first object of the present application is to provide a method for collecting methane and volatile organic gas, comprising:

[0007] The gas collection hood collector, the first gas flow driving element and the wind speed measuring assembly are sequentially arranged on the gas collection pipeline;

[0008] The escaping gas at the collection point is collected by the gas collection pipeline;

[0009] The flowing gas collected is detected for wind speed;

[0010] According to the collection point information and the speed of the flowing gas, the escaping gas is completely collected.

[0011] In the specific embodiments of the present application, the gas hood mouth collector includes a sampling tube type gas hood mouth collector, a bag type gas hood mouth collector, a corrugated sampling tube type gas hood mouth collector, a beveled sampling tube type gas hood mouth collector, and a sampling coil type gas hood mouth collector.

[0012] A second object of the present application is to provide a quantitative detection method for methane and volatile organic gas, comprising:

[0013] The gas hood mouth collector, the first gas flow driving element, and the wind speed measuring assembly are sequentially arranged on the gas collection pipeline.

[0014] The escaping gas at the collection point is collected by the gas collection pipeline.

[0015] The speed of the flowing gas is detected.

[0016] The entire collection of the escaping gas is completed according to the collection point information and the speed of the flowing gas.

[0017] Meanwhile, the flowing gas is extracted to obtain a first part of gas and a second part of gas.

[0018] During the process of the first part of gas, the methane concentration of the first part of gas is measured.

[0019] During the process of the second part of gas, the volatile organic concentration of the second part of gas is measured.

[0020] In the specific embodiments of the present application, when the escaping gas at the collection point is collected, the gas volume of the collected escaping gas is 100-400 L / min.

[0021] In the specific embodiments of the present application, when the methane concentration of the first part of gas is measured during the process of the first part of gas, at least two methane measuring sensors with different ranges are used.

[0022] In the specific embodiments of the present application, when the methane concentration of the first part of gas is measured during the process of the first part of gas, two methane measuring sensors with different ranges are used, one methane measuring sensor is a methane measuring sensor with a methane volume concentration greater than or equal to a fixed volume concentration, and the other methane measuring sensor is a methane measuring sensor with a methane volume concentration less than the fixed volume concentration.

[0023] In the specific embodiments of the present application, when the volatile organic concentration of the second part of gas is measured during the process of the second part of gas, at least two volatile organic measuring sensors with different ranges are used.

[0024] In the embodiment of the present application, the two volatile organic compound measuring sensors with different ranges are used in the second part of the gas flow process, one of which has a range of 100 ppb-6000 ppm, and the other has a range of 1 ppb-50 ppm.

[0025] In the embodiment of the present application, the volatile organic compound measuring sensor includes an electrochemical volatile organic compound measuring sensor, a non-dispersive infrared volatile organic compound measuring sensor, a photoionization volatile organic compound measuring sensor, and a catalytic combustion volatile organic compound measuring sensor.

[0026] In the embodiment of the present application, the quantitative detection method of the gas containing methane and volatile organic compounds further includes:

[0027] The methane concentration and volatile organic compound concentration information are sent to an alarm system.

[0028] The alarm system selects whether to alarm according to the methane concentration and volatile organic compound concentration information and an alarm value.

[0029] In the embodiment of the present application, the quantitative detection method of the gas containing methane and volatile organic compounds further includes:

[0030] The methane concentration and volatile organic compound concentration information and the information of the collection point are transmitted to a centralized control room.

[0031] The third object of the present application is to provide a quantitative detection device of a gas containing methane and volatile organic compounds, which includes a gas collection pipeline, a methane measuring pipeline, and a volatile organic compound measuring pipeline.

[0032] The gas collection pipeline is provided with a gas hood collector, a first airflow driving element, and a wind speed measuring assembly.

[0033] The methane measuring pipeline is provided with a methane measuring element and a second airflow driving element.

[0034] The volatile organic compound measuring pipeline is provided with a volatile organic compound measuring element and a third airflow driving element.

[0035] In the gas flow direction of the gas collection pipeline, the gas hood collector, the first airflow driving element, the wind speed measuring assembly, the communication position of the gas collection pipeline and the methane measuring pipeline, or the communication position of the gas collection pipeline and the volatile organic compound measuring pipeline are sequentially arranged.

[0036] The second gas flow driving element and the methane measuring element are sequentially arranged in the gas flowing direction of the methane measuring pipeline.

[0037] The third gas flow driving element and the volatile organic compound measuring element are sequentially arranged in the gas flowing direction of the volatile organic compound measuring pipeline.

[0038] The gas collecting pipeline is used for carrying the collected flowing gas.

[0039] The gas collecting cover and the first gas flow driving element are used for collecting the diffused gas at the collecting point.

[0040] The wind speed measuring assembly is used for measuring the wind speed of the collected flowing gas.

[0041] The second gas flow driving element and the third gas flow driving element are used for simultaneously extracting the flowing gas to obtain the first part of gas and the second part of gas.

[0042] The methane measuring pipeline is used for carrying the first part of gas.

[0043] The methane measuring element is used for measuring the methane concentration of the first part of gas during the flowing process of the first part of gas.

[0044] The volatile organic compound measuring pipeline is used for carrying the second part of gas.

[0045] The volatile organic compound measuring element is used for measuring the volatile organic compound concentration of the second part of gas during the flowing process of the second part of gas.

[0046] In the embodiment of the present application, the first gas flow driving element, the second gas flow driving element, the third gas flow driving element, the volatile organic compound measuring element and the methane measuring element are all signal connected to the control module.

[0047] The control module is signal connected to an alarm system and a terminal receiving control system.

[0048] In the embodiment of the present application, the terminal receiving control system is signal connected to an image system, a communication system and a GPS positioning system; and the communication system is signal connected to the control module.

[0049] The present application has the following advantages:

[0050] The application provides a quantitative detection method and device for methane and volatile organic compound (VOC) gas, which realizes the collection of the methane and VOC gas, the synchronous qualitative and quantitative detection of the methane and VOC in the methane and VOC gas, overcomes the defects of the prior art, and first realizes the real-time adjustment and control of the multi-speed all-collected fugitive gas of the gas collection pipeline through the wind speed monitoring assembly and the first driving airflow element on the gas collection pipeline; second, the synchronous quantification of the methane and VOC emission is realized through the simultaneous extraction technology and the detection of the methane and VOC during the flow process of the extracted gas, and the collaborative quantification measurement of the pollutants and carbon is realized.

[0051] In addition, the application also has the following effects:

[0052] 1. The gas collection pipeline adopts wind speed monitoring, the frequency of the first airflow driving element (fan) is adjusted synchronously to control the wind speed at the gas hood mouth collector, the methane and VOC fugitive gas can be collected, the on-site conditions can be adjusted in time, and the influence of environmental factors is small.

[0053] 2. At least two sensors are combined to form the methane detection element and the VOC detection element, the detection efficiency is improved through the collaborative detection and the separate detection.

[0054] 3. The terminal receiving control system can realize the functions of data collection, data editing and data transmission, optimizes the data form combined with the position information and the image, and is more convenient for the maintenance work of the on-site leakage point.

[0055] 4. The alarm system sets different alarm levels according to the detected different methane and VOC concentrations, and can be transmitted to the centralized control room through the communication system.

[0056] Other features and advantages of the application will be set forth in the specification, and in part will become apparent from the specification, or can be learned by practice of the application. The objectives and other advantages of the application can be realized and obtained by the structure indicated in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0058] Figure 1Structure diagram of the clamping connection pipe in the gas collecting hood mouth collector in a methane and volatile organic gas collecting method according to an embodiment of the present application is shown;

[0059] Figure 2 Structure diagram of the hard connection pipe in the gas collecting hood mouth collector in a methane and volatile organic gas collecting method according to an embodiment of the present application is shown;

[0060] Figure 3 Flow chart of a methane and volatile organic gas quantitative detection method according to an embodiment of the present application is shown;

[0061] Figure 4 Structure diagram of a set of methane and volatile organic gas quantitative detection devices according to an embodiment of the present application is shown;

[0062] Figure 5 Structure diagram of a set of methane and volatile organic gas quantitative detection devices according to an embodiment of the present application is shown;

[0063] In the figure, 10 is a first clamping end, 11 is a clasp, 20 is a first connection end, 30 is a second connection end, and 40 is a third connection end. DETAILED DESCRIPTION

[0064] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0065] A methane and volatile organic gas collecting method according to an embodiment of the present application comprises:

[0066] In the first step, a gas collecting hood mouth collector, a first gas flow driving element and a wind speed measuring assembly are sequentially arranged on a gas collecting pipeline;

[0067] In the second step, the escaping gas at the collection point is collected by the gas collecting pipeline;

[0068] In the third step, the collected flowing gas is detected for wind speed;

[0069] In the fourth step, the escaping gas is completely collected according to the information of the collection point and the speed of the flowing gas.

[0070] As Figure 1 and Figure 2As shown, in the first step, the gas hood port collector comprises a clamping connecting pipe and / or a rigid connecting pipe;

[0071] The clamping connecting pipe comprises a first clamping end 10 and a first connecting end 20, which are integrally formed, the diameter of the first clamping end 10 is greater than or equal to the first connecting end 20, a group of buckles 11 are symmetrically arranged on the outer peripheral wall of the first clamping end 10, and the buckles 11 are movably connected with the first clamping end 10; the first clamping end 10 is used for clamping on a pipeline or a collection point, and the first connecting end 20 is used for connecting a pipeline;

[0072] The rigid connecting pipe comprises a second connecting end 30 and a third connecting end 40, which are integrally formed, the diameter of the second connecting end 30 is greater than or equal to the third connecting end 40, and the second connecting end 30 and the third connecting end 40 are both used for connecting a pipeline or a bag;

[0073] The clamping connecting pipe and the rigid connecting pipe are arranged to adapt to the complex conditions (including the planar small point type of the escape point, the more escape point positions and the closer distance type of the escape point, the uneven surface type of the leakage component, the small gap type of the escape point located in a concealed position, and the flange leakage point) of the natural gas and oil field gas production, processing and transportation field, so as to realize the collection of all the escape gas of the escape point and improve the accuracy of subsequent detection.

[0074] The clamping connecting pipe and the threaded pipe are assembled, such as the clamping of the clamping connecting pipe at both ends of the threaded pipe at one end, to form the sampling pipe type gas hood port collector in the application, one end of which is connected with a detection host, and the other end can directly realize the direct collection of the planar small point type, such as the valve grease injection hole, etc. The size of the clamping connecting pipe and the threaded pipe is not limited in the application, and the specific size can be flexibly changed according to the actual escape point.

[0075] The rigid connecting pipe and the bag are combined, such as the connection of the rigid connecting pipe at the sealing opening of the bag, to form the bag type gas hood port collector in the application, which is used to cover the more escape point positions and the closer distance type of the escape point or the larger amount of escape gas and the larger leakage component, such as the valve stem, and then the rigid connecting pipe is sealed at the opening of the bag through a rope or a bandage, and the rigid connecting pipe is used to connect the detection host. In the bag type gas hood port collector, the escape point is completely covered by the bag, and the collection of all the escape gas is realized.

[0076] The bag type gas hood port collector can also connect the clamping connecting pipe and / or the threaded pipe through the rigid connecting pipe at the opening of the bag, and then connect the detection host;

[0077] The hard connecting pipe, straight pipe, elbow pipe and trumpet-shaped corrugated collecting cover mouth are assembled to form the corrugated sampling pipe type gas collection cover mouth collector in the application, the trumpet-shaped corrugated collecting cover mouth is connected by the straight pipe, elbow pipe and hard connecting pipe in sequence, the trumpet-shaped corrugated collecting cover mouth covers the uneven surface of the leaking component, and the hard connecting pipe is connected to the detection host, and the entire collection of the fugitive gas can be realized through the telescopic corrugated collecting cover mouth.

[0078] The corrugated sampling pipe type gas collection cover mouth collector can be further connected to the clamping connecting pipe and / or threaded pipe through the hard connecting pipe, and then connected to the detection host.

[0079] The hard connecting pipe and the straight pipe with a flat design bevel are assembled to form the beveled sampling pipe type gas collection cover mouth collector in the application, the third connecting end 40 of the hard connecting pipe is inserted into the end of the straight pipe away from the bevel, the bevel is used to collect the fugitive gas of the fugitive point in a hidden position or a position with a very small gap, the hard connecting pipe is connected to the detection host, and the entire collection of the fugitive gas of the fugitive point in a hidden position or a position with a very small gap can be realized through the flat design bevel.

[0080] The beveled sampling pipe type gas collection cover mouth collector can be further connected to the clamping connecting pipe and / or threaded pipe through the hard connecting pipe, and then connected to the detection host.

[0081] The hard connecting pipe and the adhesive strip are assembled to form the sampling disc pipe type gas collection cover mouth collector in the application, the hard connecting pipe is attached to the flange leakage point, and then fixed on the flange through the adhesive strip, the sampling disc pipe type gas collection cover mouth collector with different lengths can be designed through the adhesive strip to adapt to the size of the flange, and the entire collection of the fugitive gas of the flange leakage point can be realized.

[0082] The sampling disc pipe type gas collection cover mouth collector can be further connected to the clamping connecting pipe and / or threaded pipe through the hard connecting pipe, and then connected to the detection host.

[0083] In the fourth step, the entire collection of the fugitive gas is completed according to the collection point information and the speed of the flowing gas.

[0084] The collection point information includes the type and position of the collection point (fugitive point).

[0085] The entire collection of the fugitive gas is completed according to the collection point information and the speed of the flowing gas, that is, the wind speed of the gas collection cover mouth collector is adjusted in time according to the type and position of the collection point (fugitive point) and the speed of the flowing gas, the entire collection of the fugitive gas of the methane and VOCs can be realized according to the on-site conditions.

[0086] As shown in Figure 3 A quantitative detection method of a gas containing methane and volatile organic compounds according to an embodiment of the application includes:

[0087] S1, sequentially arranging the gas hood mouth collector, the first gas flow driving element and the wind speed measuring assembly on the gas collection pipeline;

[0088] S2, collecting the diffused gas at the collection point by using the gas collection pipeline;

[0089] S3, detecting the wind speed of the collected flowing gas;

[0090] S4, completing the whole collection of the diffused gas according to the collection point information and the speed of the flowing gas;

[0091] S5, simultaneously extracting the flowing gas to obtain a first part of gas and a second part of gas;

[0092] S6, determining the methane concentration of the first part of gas in the process of the first part of gas flow;

[0093] S7, determining the volatile organic compound concentration of the second part of gas in the process of the second part of gas flow.

[0094] In step S2 in the embodiment of the present application, when the diffused gas at the collection point is collected, the gas amount of the collected diffused gas is 100-400 L / min;

[0095] In some embodiments of the present application, the speed of collecting the diffused gas can be realized by grading collection, and five grades are subdivided within 100-400 L / min.

[0096] In step S6 in the embodiment of the present application, when the methane concentration of the first part of gas is determined in the process of the first part of gas flow, at least two methane measuring sensors with different ranges are used;

[0097] Specifically, in the actual operation process, when the methane concentration in the first part of gas is determined by using at least two methane measuring sensors with different ranges, the at least two methane measuring sensors with different ranges can be detected cooperatively or respectively.

[0098] In step S6 in the embodiment of the present application, when the methane concentration of the first part of gas is determined in the process of the first part of gas flow, two methane measuring sensors with different ranges are used, one methane measuring sensor is a methane measuring sensor with a methane volume concentration greater than or equal to a fixed volume concentration, and the other methane measuring sensor is a methane measuring sensor with a methane volume concentration less than the fixed volume concentration;

[0099] In the embodiment of the present application, the fixed volume concentration is 5% VOL;

[0100] The two different range methane measuring sensors include a methane measuring sensor with a methane volume concentration greater than or equal to a fixed volume concentration and a methane measuring sensor with a methane volume concentration less than the fixed volume concentration, i.e., one methane measuring sensor is a high-concentration methane measuring sensor and the other methane measuring sensor is a low-concentration methane measuring sensor.

[0101] Specifically, in actual operation, the priority of the high-concentration methane measuring sensor and the low-concentration methane measuring sensor is set as follows:

[0102] The high-concentration methane measuring sensor is used by default, and when the detected concentration is lower than 5% VOL, the low-concentration methane measuring sensor is automatically switched to for concentration detection.

[0103] In step S7 of the embodiment of the present application, at least two different range volatile organic compound measuring sensors are used for measuring the volatile organic compound concentration of the second part of the gas during the second part of the gas flow process.

[0104] In step S7 of the embodiment of the present application, the two different range volatile organic compound measuring sensors include a volatile organic compound measuring sensor with a range of 100 ppb-6000 ppm and another volatile organic compound measuring sensor with a range of 1 ppb-50 ppm, which improves the detection accuracy, and the low-range 1 ppb-50 ppm is used preferentially, and the high-range is automatically switched to when the range is exceeded.

[0105] The volatile organic compound measuring sensor includes an electrochemical volatile organic compound measuring sensor, a non-dispersive infrared volatile organic compound measuring sensor, a photoionization volatile organic compound measuring sensor, and a catalytic combustion volatile organic compound measuring sensor.

[0106] In some other embodiments of the present application, the quantitative detection method of the methane-containing and volatile organic compound-containing gas further includes:

[0107] A1, the methane concentration and volatile organic compound concentration information are sent to an alarm system;

[0108] A2, the alarm system selects whether to alarm according to the methane concentration and volatile organic compound concentration information and an alarm value.

[0109] In step A1 of the embodiment of the present application, specifically, the methane concentration and volatile organic compound concentration information are sent to a control module, and the control module sends the methane concentration and volatile organic compound concentration information to an alarm system.

[0110] In step A2 of the embodiment of the present application, specifically,

[0111] Set alarm values. Data above the alarm values ​​and data below the alarm values ​​form two sets of inventory data. The alarm value data serves as the basis for leak repair, and the two sets of data together serve as quantitative indicators for methane and / or volatile organic compound emissions:

[0112] When the methane concentration and volatile organic compound concentration values ​​received by the alarm system are higher than the alarm values, they are transmitted to the centralized control room through the communication system for early warning;

[0113] If the methane concentration and volatile organic compound concentration values ​​received by the alarm system are lower than the alarm values, no early warning will be sent.

[0114] In some other embodiments of the present invention, the method for quantitatively detecting methane and volatile organic compound-containing gases further includes:

[0115] The methane concentration and volatile organic compound concentration information as well as the information of the collection points are transmitted to the centralized control room;

[0116] Specifically:

[0117] The methane concentration and volatile organic compound concentration information are transmitted to the centralized control room through the control module;

[0118] The information of the collection point (including the location information of the collection point measured by the GPS positioning system and the image information of the collection point measured by the imaging system) is directly transmitted to the terminal receiving control system and then transmitted to the control module;

[0119] The control module integrates the detection results with the image and positioning information into the form of an image, and then transmits it to the centralized control room through the communication system.

[0120] like Figure 4 As shown, a quantitative detection device for methane and volatile organic compound gas according to an embodiment of the present invention includes a gas collecting pipeline and a methane measuring pipeline and a volatile organic compound measuring pipeline both connected to the gas collecting pipeline;

[0121] The gas collection pipeline is provided with a gas collecting hood collector, a first airflow driving element and an anemometer component, such as a thermal anemometer, a constant current anemometer, a constant temperature anemometer, a three-cup eddy current sensor, a three-cup optical coupler sensor, etc.

[0122] The methane measuring pipeline is provided with a methane measuring element and a second airflow driving element;

[0123] The volatile organic compound measuring pipeline is provided with a volatile organic compound measuring element and a third airflow driving element;

[0124] The gas collecting hood collector, the first gas flow driving element, the wind speed measuring assembly, the communication position of the gas collecting pipeline and the methane measuring pipeline or the communication position of the gas collecting pipeline and the volatile organic compound measuring pipeline are sequentially arranged in the gas flow direction of the gas collecting pipeline.

[0125] The arrangement of the communication position of the gas collecting pipeline and the methane measuring pipeline and the communication position of the gas collecting pipeline and the volatile organic compound measuring pipeline is not limited, which can be arranged at the same position or sequentially, as long as the stability of the gas flow after the wind speed measuring element is not affected, and the extraction of the gas flow is very small for measurement, and there is no influence simultaneously or sequentially.

[0126] The second gas flow driving element and the methane measuring element are sequentially arranged in the gas flow direction of the methane measuring pipeline.

[0127] The third gas flow driving element and the volatile organic compound measuring element are sequentially arranged in the gas flow direction of the volatile organic compound measuring pipeline.

[0128] The gas collecting pipeline is used for carrying the collected flowing gas.

[0129] The gas collecting hood collector and the first gas flow driving element are used for collecting the diffused gas at the collection point.

[0130] The wind speed measuring assembly is used for detecting the wind speed of the collected flowing gas.

[0131] The second gas flow driving element and the third gas flow driving element are used for simultaneously extracting the flowing gas to obtain a first part of gas and a second part of gas.

[0132] The methane measuring pipeline is used for carrying the first part of gas.

[0133] The methane measuring element is used for measuring the methane concentration of the first part of gas during the flow process of the first part of gas.

[0134] The volatile organic compound measuring pipeline is used for carrying the second part of gas.

[0135] The volatile organic compound measuring element is used for measuring the volatile organic compound concentration of the second part of gas during the flow process of the second part of gas.

[0136] In the embodiment of the present application, the first gas flow driving element, the second gas flow driving element and the third gas flow driving element can all be gas pumps.

[0137] The air pump of the first air flow driving element is a speed-adjustable air pump, which can be controlled by PWM or frequency conversion, the air pump flow is selected as 100-400L / min, which can be adjusted in five gears, so that the speed of collecting the escaped gas can be collected in different gears, and the speed is subdivided into five gears within 100-400L / min.

[0138] Specifically,

[0139] According to the data display of the wind speed measuring element, the frequency of the first air flow driving element (100-400L / min, which can be adjusted in five gears) is adjusted synchronously, the wind speed of the cover opening is adjusted according to the on-site conditions during detection, and quantitative collection of methane and VOCs escaped gas is realized.

[0140] As Figure 5 shown, in some other embodiments of the application, the first air flow driving element, the second air flow driving element, the third air flow driving element, the volatile organic compound measuring element and the methane measuring element are all signal-connected to the control module.

[0141] The control module is signal-connected to an alarm system and a terminal receiving control system.

[0142] In some other embodiments of the application, the terminal receiving control system is signal-connected to an image system, a communication system and a GPS positioning system.

[0143] The communication system is signal-connected to the control module.

[0144] The terminal receiving control system can remotely control the operation of the instrument through Bluetooth or 5G communication.

[0145] The terminal receiving control system can realize functions such as data collection, data editing and data transmission.

[0146] The GPS positioning system can track the position of the leakage point.

[0147] The image system can take pictures and videos of the leakage point.

[0148] The communication system can transmit detection data, leakage point position, leakage point photos and alarm information to a centralized control room.

[0149] Although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A collection method of a gas containing methane and volatile organic compounds, characterized by, The application relates to a gas collecting device and a gas collecting method. The gas collecting device comprises a gas collecting hood, a first gas flow driving element and a wind speed measuring component. The gas collecting device collects the diffused gas at the collecting point. The wind speed of the collected flowing gas is detected. The diffused gas is completely collected according to the collecting point information and the speed of the flowing gas.

2. The method of claim 1, wherein the methane and volatile organic compounds are collected. The gas collecting hood comprises a sampling tube type gas collecting hood, a bag type gas collecting hood, a corrugated sampling tube type gas collecting hood, an inclined sampling tube type gas collecting hood and a sampling disc tube type gas collecting hood.

3. A method for quantitative detection of a gas containing methane and volatile organic compounds, characterized by, The application relates to a gas collecting device and a gas collecting method. The gas collecting device comprises a gas collecting hood, a first gas flow driving element and a wind speed measuring component. The gas collecting device collects the diffused gas at the collecting point. The wind speed of the collected flowing gas is detected. The diffused gas is completely collected according to the collecting point information and the speed of the flowing gas. Meanwhile, the flowing gas is extracted to obtain a first part of gas and a second part of gas. The methane concentration of the first part of gas is detected during the flowing process of the first part of gas. The volatile organic compound concentration of the second part of gas is detected during the flowing process of the second part of gas.

4. The method according to claim 3, wherein the amount of the methane and volatile organic compound gas is quantitatively detected. The gas volume of the diffused gas collected is 100-400 L / min.

5. The method for quantitative detection of a gas containing methane and volatile organic compounds according to claim 3, characterized in that, At least two methane measuring sensors with different ranges are used to detect the methane concentration of the first part of gas.

6. The method for quantitative detection of a gas containing methane and volatile organic compounds according to claim 3, characterized in that, Two methane measuring sensors with different ranges are used to detect the methane concentration of the first part of gas, one of which is a methane measuring sensor with a methane volume concentration greater than or equal to a fixed volume concentration, and the other is a methane measuring sensor with a methane volume concentration less than the fixed volume concentration.

7. The method according to claim 3, wherein the amount of the methane and volatile organic compound gas is quantitatively detected. At least two volatile organic compound measuring sensors with different ranges are used to detect the volatile organic compound concentration of the second part of gas.

8. The method for quantitative detection of methane and volatile organic compounds gas according to claim 3, characterized in that, The ranges of the two volatile organic compound measuring sensors are 100 ppb-6000 ppm and 1 ppb-50 ppm respectively.

9. The method according to claim 3, wherein the amount of the methane and volatile organic compound gas is quantitatively detected. The volatile organic compound measuring sensor comprises an electrochemical volatile organic compound measuring sensor, a non-dispersive infrared volatile organic compound measuring sensor, a photoionization volatile organic compound measuring sensor and a catalytic combustion volatile organic compound measuring sensor.

10. The method for quantitative detection of a gas containing methane and volatile organic compounds according to claim 3, characterized in that, The application further relates to a gas collecting device and a gas collecting method. The methane concentration and volatile organic compound concentration information are sent to an alarm system. The alarm system selects whether to alarm according to the methane concentration and volatile organic compound concentration information and an alarm value.

11. The quantitative detection method of the gas containing methane and volatile organic compounds according to any one of claims 3-10, characterized in that, The methane concentration and volatile organic compound concentration information and the information of the collecting point are transmitted to a centralized control room. The application relates to a gas collecting device and a gas collecting method.

12. A quantitative detection device of a gas containing methane and volatile organic compounds, characterized in that, ​ The gas collecting pipeline is provided with a gas hood collector, a first gas flow driving element and a wind speed measuring assembly; The methane measuring pipeline is provided with a methane measuring element and a second gas flow driving element; The volatile organic compound measuring pipeline is provided with a volatile organic compound measuring element and a third gas flow driving element; In the gas flow direction of the gas collecting pipeline, the gas hood collector, the first gas flow driving element, the wind speed measuring assembly, the communication position of the gas collecting pipeline and the methane measuring pipeline or the communication position of the gas collecting pipeline and the volatile organic compound measuring pipeline are sequentially arranged; In the gas flow direction of the methane measuring pipeline, the second gas flow driving element and the methane measuring element are sequentially arranged; In the gas flow direction of the volatile organic compound measuring pipeline, the third gas flow driving element and the volatile organic compound measuring element are sequentially arranged; The gas collecting pipeline is used for carrying the collected flowing gas; The gas hood collector and the first gas flow driving element are used for collecting the escaping gas at the collection point; The wind speed measuring assembly is used for detecting the wind speed of the collected flowing gas; The second gas flow driving element and the third gas flow driving element are used for simultaneously extracting the flowing gas to obtain a first part of gas and a second part of gas; The methane measuring pipeline is used for carrying the first part of gas; The methane measuring element is used for measuring the methane concentration of the first part of gas during the flow process of the first part of gas; The volatile organic compound measuring pipeline is used for carrying the second part of gas; The volatile organic compound measuring element is used for measuring the volatile organic compound concentration of the second part of gas during the flow process of the second part of gas.

13. The device for quantitative detection of a gas containing methane and volatile organic compounds according to claim 12, characterized in that, The first gas flow driving element, the second gas flow driving element, the third gas flow driving element, the volatile organic compound measuring element and the methane measuring element are all signal connected to the control module; The control module is signal connected to an alarm system and a terminal receiving control system.

14. The quantitative detection device of methane and volatile organic compounds gas according to claim 12 or 13, characterized in that, The terminal receiving control system is signal connected to an image system, a communication system and a GPS positioning system; the communication system is signal connected to the control module.

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