CN217484270U

CN217484270U - Detection device for directly measuring non-methane total hydrocarbon content

Info

Publication number: CN217484270U
Application number: CN202220408809.8U
Authority: CN
Inventors: 姬红波; 毕佳鑫; 周伟; 姬二鹤
Original assignee: Huadian Intelligent Control Beijing Technology Co ltd
Current assignee: Huadian Intelligent Control Beijing Technology Co ltd
Priority date: 2022-02-28
Filing date: 2022-02-28
Publication date: 2022-09-23
Anticipated expiration: 2032-02-28

Abstract

The utility model provides a detection apparatus for be used for direct measurement non-methane total hydrocarbon content relates to empty gas detection and analysis technical field. The device comprises a quantitative ring, a first multi-way valve, a methane analysis column, a detector, a second multi-way valve and an enrichment module, wherein two ends of the quantitative ring, two ends of the methane analysis column and a first gas port of the detector are respectively connected with different ports of the first multi-way valve in a one-to-one correspondence manner, two ends of the enrichment module are respectively connected with ports of the second multi-way valve, the first multi-way valve and the second multi-way valve are connected through pipelines, the first multi-way valve and the second multi-way valve are respectively communicated with a gas carrying pipeline, and the first multi-way valve and the second multi-way valve are respectively provided with a tail gas discharge port; wherein, the second multi-way valve is a six-way valve. The concentration of methane and non-methane total hydrocarbon is directly detected by switching the first multi-way valve and the six-way valve, the phenomenon that the absorption effect of the methane analysis column influences the Gaussian peak value of the non-methane total hydrocarbon is avoided, and the analysis error is reduced.

Description

Detection device for directly measuring non-methane total hydrocarbon content

Technical Field

The utility model relates to an empty gas detection surveys analysis technical field, especially relates to a detection device that is used for direct measurement non-methane total hydrocarbon content.

Background

The content of methane and non-methane total hydrocarbons in the ambient air is an important index in atmospheric environment monitoring, and the pollution state of Volatile Organic Compounds (VOCs) can be simply and visually represented. The existing measuring modes of methane and non-methane total hydrocarbon in ambient air include an indirect method and a direct method. The indirect method comprises the steps of respectively measuring the concentrations of total hydrocarbons and methane, and calculating the difference between the total hydrocarbons and the methane to obtain the concentration of non-methane total hydrocarbons. In the method, the measurement of the total hydrocarbon is interfered by oxygen, and the measurement system has an irrevocable systematic error on the measurement of the total hydrocarbon and the methane, so that the concentration of the total hydrocarbon and the concentration of the non-methane total hydrocarbon have a deviation, and the measured concentration of the non-methane total hydrocarbon also has a deviation from the actual concentration. At present, the common direct method is a back flushing method, wherein the back flushing method is to utilize carrier gas to bring all samples into a chromatographic column in a forward direction for separation, after a response signal of methane is obtained, the carrier gas reversely enters the chromatographic column through the switching of a multi-way valve, and residual components in the chromatographic column are blown out of the chromatographic column in a reverse direction and then are detected by a detector, so that the concentration of non-methane total hydrocarbons is obtained.

However, in actual use, the column exhibits irreversible adsorption of some of the VOC components entering the column, resulting in a low response of non-methane total hydrocarbons; meanwhile, due to the adsorption effect of the chromatographic column, the response of non-methane total hydrocarbons blown back at the detector is not a Gaussian peak, so that certain data deviation can be generated during data processing.

SUMMERY OF THE UTILITY MODEL

The utility model provides a detection apparatus for be used for direct measurement total hydrocarbon content of non-methane for methane and non-methane detect and have the deviation among the solution prior art, defect that the precision is low.

The utility model provides a detection device for direct measurement is total hydrocarbon content of non-methane, including ration ring, first multi-way valve, methane analysis post, detector, second multi-way valve and enrichment module, the both ends of ration ring, the both ends of methane analysis post and the first gas port of detector respectively with the different port one-to-one of first multi-way valve is connected, the both ends of enrichment module respectively with the port of second multi-way valve links to each other, link to each other through the pipeline between first multi-way valve and the second multi-way valve, first multi-way valve with the second multi-way valve respectively with carry the trachea way intercommunication, first multi-way valve with the second multi-way valve is equipped with tail gas discharge port respectively; wherein, the second multi-way valve is a six-way valve.

According to the utility model provides a pair of a detection device for direct measurement is total hydrocarbon content of non-methane, the enrichment module is including enrichment pipe and accuse temperature subassembly, enrichment intraductal adsorbent that embeds, accuse temperature subassembly is used for control enrichment pipe's temperature.

According to the utility model provides a pair of detection device for direct measurement is not total hydrocarbon content of methane, the detector includes flame ionization detector.

According to the utility model provides a pair of a detection device for direct measurement is not total hydrocarbon content of methane, first multi-way valve is ten logical valves.

According to the utility model provides a pair of a detection device for direct measurement non-methane total hydrocarbon content, the exhaust port of second multi-ported valve links to each other with second exhaust-gas emission pipeline, install the aspiration pump on the second exhaust-gas emission pipeline.

According to the utility model provides a pair of a detection device for direct measurement is total hydrocarbon content of non-methane still includes flow controller, flow controller install in second exhaust emission pipeline.

According to the utility model provides a pair of a detection device for direct measurement is total hydrocarbon content of non-methane still includes calibration unit, calibration unit with the introduction port of first multi-ported valve is linked together.

According to the utility model provides a pair of a detection device for direct measurement total hydrocarbon content of non-methane, first pipeline is connected to the introduction port of first multi-way valve, install the three-way valve on the first pipeline, an air inlet of three-way valve with the gas outlet of calibration unit links to each other.

According to the utility model provides a pair of a detection device for direct measurement is total hydrocarbon content of non-methane still includes first box and second box, first multi-ported valve the ration ring methane analytical column with the detector is all installed in the first box, the second multi-ported valve with the enrichment module is all installed in the second box.

According to the utility model provides a pair of a detection device for direct measurement non-methane total hydrocarbon content, the second multi-way valve is two, is first valve body and second valve body respectively, first valve body with first multi-way valve links to each other, the second valve body with first valve body links to each other, the enrichment module is installed on the second valve body, first valve body with the second valve body communicates with the carrier gas pipeline respectively, and after non-methane detection stage, the carrier gas gets into second valve body and blowback along first valve body the enrichment module.

The utility model provides a detection device for directly measuring non-methane total hydrocarbon content, the carrier gas brings the sample gas in the quantitative ring into the methane analysis column for separation, and then enters the detector for methane concentration detection; the carrier gas carries the non-methane total hydrocarbons desorbed in the enrichment module into a detector to detect the concentration of the non-methane total hydrocarbons. In the whole detection process, the concentration of non-methane total hydrocarbons is directly detected by using the characteristic that the adsorbent does not adsorb methane in an enrichment mode without oxygen interference, the phenomenon that a chromatographic column is used in the traditional subtraction method and the Gaussian peak value of the non-methane total hydrocarbons is influenced by the adsorption effect of the chromatographic column is avoided, and the analysis error is reduced; and the whole detection process is switched by means of the first multi-way valve and the six-way valve, so that the detection of the non-methane total hydrocarbons and the methane is two independent gas paths which are not interfered with each other, the concentration of the methane and the non-methane total hydrocarbons is directly detected, the precision is high, and the error is small.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the following briefly introduces the drawings required for the embodiments or the prior art descriptions, and obviously, the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a detection device for directly measuring the content of non-methane total hydrocarbons provided by the present invention in a sampling stage;

FIG. 2 is a schematic diagram of the detection apparatus for directly measuring the content of non-methane total hydrocarbons shown in FIG. 1 in the stage of methane detection;

FIG. 3 is a schematic diagram of the detection apparatus for directly measuring the non-methane total hydrocarbon content shown in FIG. 1 at a non-methane detection stage;

FIG. 4 is a schematic structural diagram of another detection device for directly measuring the content of non-methane total hydrocarbons provided by the present invention;

FIG. 5 is a schematic structural diagram of another detection device for directly measuring the content of non-methane total hydrocarbons provided by the present invention in a sampling stage;

FIG. 6 is a schematic diagram of the detection device for directly measuring the content of non-methane total hydrocarbons shown in FIG. 5 in the methane detection stage;

FIG. 7 is a schematic diagram of the detection apparatus for directly measuring the non-methane total hydrocarbon content shown in FIG. 5 in a non-methane detection stage;

FIG. 8 is a schematic diagram of the detection apparatus for directly measuring non-methane total hydrocarbon content shown in FIG. 5 during a back-flushing stage of the enrichment module;

FIG. 9 is a detection peak pattern for detecting non-methane total hydrocarbons by using the detection device for directly measuring the content of non-methane total hydrocarbons provided by the present invention;

FIG. 10 is a detection peak pattern for detecting non-methane total hydrocarbons by the prior indirect method.

Reference numerals:

10. a first multi-way valve; 20. a dosing ring; 30. a methane analytical column; 40. a detector; 50. a second multi-way valve; 51. a first valve body; 52. a second valve body; 60. an enrichment module; 70. an air pump; 80. a flow controller; 90. a three-way valve; 100. a first calibration line; 101. a first flow meter; 110. a second calibration pipe; 111. a second flow meter; 120. a bypass; 200. a box body; 210. a first case; 220. a second case.

Detailed Description

To make the objects, technical solutions and advantages of the present invention clearer, the drawings of the present invention are combined to clearly and completely describe the technical solutions of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without making creative efforts belong to the protection scope of the present invention.

The features of the terms first and second in the description and in the claims of the present application may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specified. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/", and generally means that the former and latter related objects are in an "or" relationship.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The detection device for directly measuring the content of non-methane total hydrocarbons according to the present invention will be described with reference to fig. 1 to 8.

As shown in fig. 1 to 3, a detection apparatus for directly measuring the content of non-methane total hydrocarbons according to an embodiment of the present invention includes a quantitative ring 20, a first multi-way valve 10, a methane analysis column 30, a detector 40, a second multi-way valve 50, and an enrichment module 60. Wherein, two ends of the quantitative ring 20, two ends of the methane analysis column 30 and the first gas port of the detector 40 are respectively connected with different ports of the first multi-way valve 10 in a one-to-one correspondence manner. Both ends of the enrichment module 60 are respectively connected with the ports of the second multi-way valve 50. The first multi-way valve 10 and the second multi-way valve 50 are connected through a pipeline, the first multi-way valve 10 and the second multi-way valve 50 are respectively communicated with a gas carrying pipeline, and the first multi-way valve 10 and the second multi-way valve 50 are respectively provided with a tail gas discharge port.

Wherein the first and second

multi-way valves

10, 50 each have a first and second conduction state.

As shown in fig. 1, in the sampling phase, the first multi-way valve 10 and the second multi-way valve 50 are both in the first on state, and the sample gas enters the first multi-way valve 10, flows through the dosing ring 20, enters the second multi-way valve 50, flows through the enrichment module 60, and is discharged from the tail gas discharge port of the second multi-way valve 50.

As shown in fig. 2, in the methane detection stage, the first multi-way valve 10 is in the second conducting state, the second multi-way valve 50 is in the first conducting state, and the carrier gas flows through the quantitative ring 20 and the methane analysis column 30 in sequence to enter the detector 40, so as to detect the concentration of methane.

In the non-methane detection phase, the first multi-way valve 10 is in the first conducting state, the carrier gas reversely enters the methane analysis column 30 to discharge the residual components in the methane analysis column 30 from the tail gas discharge port of the first multi-way valve 10, the second multi-way valve 50 is in the second conducting state, and the carrier gas brings the enriched non-methane total hydrocarbons in the enrichment module 60 into the detector 40 to detect the concentration of the non-methane total hydrocarbons.

As shown in fig. 3, the first multi-way valve 10 is provided with two carrier gas inlets through which the carrier gas passes. When the first multi-way valve 10 is in the first conduction state, one path of carrier gas flows through the methane analysis column 30 along the first multi-way valve 10 and then is discharged from a tail gas discharge port of the first multi-way valve 10; the other carrier gas is connected to the detector 40 via the first multi-way valve 10. When the first multi-way valve 10 is in the second conduction state, one path of carrier gas brings the gas in the quantitative ring 20 into the methane analysis column 30 along the first multi-way valve 10, and the gas enters the detector 40 for analysis after being separated from the methane analysis column 30; the other carrier gas is discharged from the tail gas discharge port of the first multi-way valve 10 through the first multi-way valve 10.

As shown in fig. 1 to 3, the second multi-way valve 50 is provided with a carrier gas inlet, and when the second multi-way valve 50 is in the first conduction state, the carrier gas enters the second multi-way valve 50 and enters the first multi-way valve 10 through a communication pipe between the second multi-way valve 50 and the first multi-way valve 10. Specifically, in the sampling stage, the carrier gas enters the first multi-way valve 10, passes through the methane analysis column 30, and is discharged from the tail gas discharge port of the first multi-way valve 10; in the methane detection stage, the carrier gas enters the first multi-way valve 10, and then is carried into the methane analysis column 30 for separation through the gas in the quantitative converter 20, and flows to the detector 40 after separation. When the second multi-way valve 50 is in the second conducting state, the carrier gas enters the second multi-way valve 50 and carries the adsorbed sample gas in the enrichment module 60 to the detector 40 for concentration detection of the non-methane total hydrocarbons.

It should be noted that the discharge time of each gas in the methane analysis column 30 is different, and the first multi-way valve 10 can be switched after the detector 40 obtains a complete methane detection signal, so that the carrier gas discharges the remaining components in the methane analysis column 30, and at the same time, the carrier gas discharges the sample gas remaining in the enrichment module 60 through the second multi-way valve 50.

The embodiment of the utility model provides a detection device for direct measurement total hydrocarbon content of non-methane, with the help of the switching direct detection methane of first multi-way valve 10 and second multi-way valve 50 and the concentration of the total hydrocarbon of non-methane, sampling stage, sample gas is through quantitative ring 20 and enrichment module 60, and when detecting methane concentration, the carrier gas brings the sample gas in quantitative ring 20 into methane analytical column 30 and separates, then gets into detector 40 and carries out methane concentration detection; in the non-methane concentration detection stage, the carrier gas desorbs the non-methane total hydrocarbons adsorbed by the enrichment module 60 and then brings the desorbed non-methane total hydrocarbons into the detector 40 to detect the concentration of the non-methane total hydrocarbons, the concentration of the non-methane total hydrocarbons is detected in an enrichment mode in the whole detection process, oxygen interference is avoided, the desorbed non-methane total hydrocarbons directly enter the detector 40 to detect the concentration of the non-methane total hydrocarbons, a chromatographic column is prevented from being used in the traditional differential subtraction method, the Gaussian peak value of the non-methane total hydrocarbons is prevented from being influenced by the adsorption effect of the chromatographic column, and the analysis error is reduced.

The enrichment module 60 includes an enrichment tube with an adsorbent disposed therein and a temperature control assembly for controlling the temperature of the enrichment tube.

Specifically, in the sampling stage, the temperature control assembly controls the temperature in the enrichment pipe to be kept at minus 20 ℃ so that the enrichment pipe can adsorb the non-methane total hydrocarbons. During the non-methane detection phase, the temperature control assembly controls the temperature of the enrichment tube to increase so that non-methane total hydrocarbons adsorbed within the enrichment tube are carried into the detector 40 for analysis. And controlling the temperature of the enrichment pipe to rise at a temperature rise rate of more than 100 ℃/s in the temperature rise process, so as to ensure that the enriched non-methane total hydrocarbons can be rapidly taken out and enter the detector 40 for analysis under the drive of the carrier gas.

Optionally, the enrichment pipe adopts a mode of combining a plurality of adsorbents in a segmented manner to improve the enrichment effect of the enrichment pipe, so that the enrichment pipe has the enrichment effect on most organic matters in the air. For example, the adsorbent comprises Carbopack C, Carbopack B and carbopen 1000, and the C2-C18 compounds are enriched at low temperature by mixing the Carbopack C, Carbopack B and carbopen 1000. It should be noted that when a plurality of adsorbents are used in the enrichment tube, the gas flow passes through the weak adsorbent and then the strong adsorbent when flowing. Of course, the enrichment pipe can also only adopt an adsorbent to adsorb, and the embodiment of the utility model discloses does not do specifically and restrict here.

The embodiment of the present invention provides a detector 40 comprising a flame ionization detector. The flame ionization detector can obtain the Gaussian peak value of the non-methane total hydrocarbon, and the content of the non-methane total hydrocarbon is obtained by analysis of analysis software. In the sampling stage, the enrichment module 60 continuously adsorbs the non-methane in the sample gas, and when the concentration of the non-methane total hydrocarbons is to be detected, the non-methane enriched in the enrichment module 60 is desorbed by heating and is carried into the detector 40 by the carrier gas for detection.

The detector 40 further comprises an amplifier connected to the output of the flame ionization detector for amplifying the signal output by the flame ionization detector. Specifically, in the methane detection stage, the amplifier automatically adjusts the signal amplification factor to 10 times of the normal amplification factor so as to improve the detection lower limit of methane. During the non-methane total hydrocarbon detection stage, the amplifier automatically adjusts the amplification factor to the normal amplification factor. The adjustment of the amplifier can keep the corresponding degree of methane and non-methane total hydrocarbon relatively consistent, and reduce the measurement error caused by different responsivity.

Optionally, the first multi-way valve 10 is a ten-way valve, and the second multi-way valve 50 is a six-way valve.

As shown in fig. 1, the first multi-way valve 10 has ten ports, which are, in order, a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, a ninth port, and a tenth port in the circumferential direction. The second multi-way valve 50 has six ports, in order, a first port, a second port, a third port, a fourth port, a fifth port, and a sixth port.

The first port of the first multi-way valve 10 is for the entry of sample gas. The second port of the first multi-way valve 10 is connected to the first port of the second multi-way valve 50. The third port and the tenth port of the first multi-way valve 10 are connected to both ends of the dosing ring 20, respectively. The fourth and seventh ports of the first multi-way valve 10 are used for the introduction of carrier gas. The fifth port and the ninth port of the first multi-way valve 10 are connected with two ends of the methane analysis column 30, the sixth port of the first multi-way valve 10 is connected with the detector 40, and the eighth port of the first multi-way valve 10 is a tail gas discharge port.

The second and fifth ports of the second multi-way valve 50 are connected to both ends of the enrichment module 60, respectively. A third port of the second multi-way valve 50 is connected with the detector 40, a fourth port of the second multi-way valve 50 is a carrier gas inlet, and a sixth port of the second multi-way valve 50 is an exhaust gas discharge port.

When the first multi-way valve 10 is in the first on state, the first port communicates with the second port, the third port communicates with the fourth port, the fifth port communicates with the sixth port, the seventh port communicates with the eighth port, and the ninth port communicates with the tenth port. Under the condition that the first multi-way valve 10 is in the second conduction state, the first port is communicated with the tenth port, the second port is communicated with the third port, the fourth port is communicated with the fifth port, the sixth port is communicated with the seventh port, and the eighth port is communicated with the ninth port. When the second multi-way valve 50 is in the first on state, the first port communicates with the second port, the third port communicates with the fourth port, and the fifth port communicates with the sixth port. When the second multi-way valve 50 is in the second on state, the first port communicates with the sixth port, the second port communicates with the third port, and the fourth port communicates with the fifth port.

As shown in fig. 1, in the detection apparatus for directly measuring the content of non-methane total hydrocarbons, the tail gas discharge port of the second multi-way valve 50 is connected to a second tail gas discharge pipeline, and a suction pump 70 is installed on the second tail gas discharge pipeline.

During the sampling phase, the suction pump 70 is actuated to cause the sample gas to flow from the first multi-way valve 10 to the second multi-way valve 50. The sampling stage is controlled by the controller for time, and the sampling is determined to be finished when the preset time is reached.

On the basis of the above embodiment, the second exhaust gas discharge pipeline is further provided with a flow controller 80. The inflow of the sample gas is controlled by means of a flow controller 80. During the use stage, the suction pump 70 and the flow controller 80 cooperate to control the sample gas to flow into the first and second

multi-way valves

10 and 50 at a constant flow rate.

As shown in fig. 1, the detection apparatus for directly measuring the content of non-methane total hydrocarbons provided by the embodiment of the present invention further includes a calibration unit, and the calibration unit is connected to the sample inlet of the first multi-way valve 10.

Taking the first multi-way valve 10 as an example of a ten-way valve, the calibration unit is used to provide a set standard gas, and is connected to the first port of the first multi-way valve 10. The calibration unit can be started to calibrate the whole device at the beginning of use or after a period of use.

As shown in fig. 1, the calibration unit includes a first calibration pipe 100 and a second calibration pipe 110, wherein the first calibration pipe 100 is provided with a first flow meter 101, the second calibration pipe 110 is provided with a second flow meter 111, the first calibration pipe 100 is used for providing the standard gas, and the second calibration pipe 110 is used for providing the dilution gas. During the calibration process, the switching of the first and second

multi-way valves

10, 50 is consistent with the sample gas detection process. In the standard gas intake stage, the first multi-way valve 10 and the second multi-way valve 50 are both in the first conduction state, and the standard gas and the diluent gas are mixed to enter the first multi-way valve 10 according to a set program. In the detection phase, the first multi-way valve 10 is switched to the second conduction state, the second multi-way valve 50 is in the first conduction state, and the carrier gas pushes the standard substance into the detector 40 for detection. Then, the second multi-way valve 50 is switched to the second conduction state, the first multi-way valve 10 is switched to the first conduction state, and the carrier gas brings the standard gas in the enrichment module 60 into the detector 40 to detect the concentration of the standard gas, so that the whole device is calibrated to improve the detection precision.

To ensure proper operation of the first flow meter 101 and the second flow meter 111, the calibration unit is also provided with a bypass 120.

Specifically, the sample inlet of the first multi-way valve 10 is connected to a first pipeline, a three-way valve 90 is installed on the first pipeline, one gas inlet of the three-way valve 90 is connected to the gas outlet of the calibration unit, and the other gas inlet of the three-way valve 90 is used for introducing sample gas.

As shown in fig. 1 to 3, an outlet of the three-way valve 90 is connected to a first port of the first multi-way valve 10, and is calibrated or detected by a switching control device of the three-way valve 90.

In an alternative embodiment, the sample gas is connected to the first port of the first multi-way valve 10 through a pipeline, the standard gas is connected to the first port of the first multi-way valve 10 through another pipeline, and each pipeline is provided with a valve, and the on/off of the corresponding pipeline is controlled by the on/off of the valve. Specifically, during calibration, the valve on the standard gas flow line is controlled to open and the valve on the sample gas flow line is controlled to close. And when the non-methane concentration of the methane is detected, controlling the valve on the standard gas circulation pipeline to be closed and controlling the valve on the sample gas circulation pipeline to be opened. Namely, the switching function of the three-way valve is realized by the mutual matching of the two valves.

As shown in fig. 1 to 3, the detection apparatus for directly measuring the content of non-methane total hydrocarbons provided by the embodiment of the present invention includes a first tank 210 and a second tank 220. Wherein the first multi-way valve 10, the quantitative ring 20, the methane analysis column 30 and the detector 40 are all installed in the first tank 210. The second multi-way valve 50 and the enrichment module 60 are both mounted within the second tank 220.

As shown in fig. 1, the first box 210 has a sample gas inlet, a tail gas outlet, a carrier gas inlet, a fuel gas inlet and a combustion-supporting gas inlet which are communicated with the detector 40, and two pipe openings connected with the second multi-way valve 50 in the second box 220. The second box 220 is provided with a carrier gas inlet, an exhaust gas outlet and two pipe ports connected to the first multi-way valve 10 in the first box 210.

In another alternative embodiment, as shown in FIG. 4, the first multi-way valve 10, the quantification ring 20, the methane analysis column 30, the detector 40, the second multi-way valve 50, and the enrichment module 60 are all mounted within a housing 200. Compare in the structural style of two boxes, the mounting means of same box makes the volume of whole device littleer, and the integrated level is higher, can practice thrift installation space.

As shown in fig. 4, when one box body 200 is adopted, an air inlet, two tail gas ports, a carrier gas port, a combustion-supporting gas inlet and a fuel gas inlet are reserved on the box body 200. It should be noted that, in the installation manner of the same box, the heating area and the heat dissipation area need to be separated, so as to avoid mutual influence.

As shown in fig. 5 to 8, there are two second multi-way valves 50, which are a first valve body 51 and a second valve body 52. Both ends of the enrichment module 60 are mounted on the second valve body 52, and the first valve body 51 is communicated with another carrier gas pipeline. The carrier gas enters the second valve body 52 through the first valve body 51 to blow back the enrichment module 60, so as to prevent the residual gas in the enrichment module 60 from affecting the analysis result of the enrichment module 60.

As shown in fig. 5, the first valve body 51 is provided with two exhaust gas discharge ports, wherein one exhaust gas discharge port is provided with a suction pump 70 and a flow controller 80, and a sample gas flow passage is formed in the sampling stage; the other discharge port is used for discharging the redundant gas when the enrichment module 60 is back blown after non-methane detection.

As shown in fig. 5, in the sampling phase, the first valve body 51 and the second valve body 52 are both in the first conduction state, and the sample gas is discharged from the first multi-way valve 10, then passes through the first valve body 51, enters the second valve body 52, enters the first valve body 51 through the enrichment module 60, and is discharged from the exhaust gas discharge port of the first valve body 51. At this time, in order to save the carrier gas, the carrier gas line provided in the first valve body 51 may be closed.

In the methane detection stage, as shown in fig. 6, the first valve body 51 and the second valve body 52 are both in the first conduction state; in the non-methane detection stage, as shown in fig. 7, the first valve body 51 and the second valve body 52 are both in the second conduction state, and the carrier gas brings the non-methane adsorbed by the enrichment module 60 into the detector 40 for detection. The specific process is similar to the above embodiment, and is not described herein again. In addition, after the non-methane detection is completed, as shown in fig. 8, the second valve body 52 is switched to the first conducting state, the first valve body 51 is still in the second conducting state, the carrier gas pipeline connected to the first valve body 51 is opened, and the carrier gas enters the second valve body 52 through the first valve body 51 to perform high-temperature back flushing on the enrichment module 60 and is discharged from the other exhaust gas discharge port of the first valve body 51. Specifically, the first port and the sixth port in the first valve body 51 are connected, and the first port and the second port in the second valve body 52 are connected. The carrier gas sequentially passes through the fourth port of the first valve body 51, the fifth port of the first valve body 51, the third port of the second valve body 52, the fourth port of the second valve body 52, the enrichment module 60, the first port of the second valve body 52, the second port of the first valve body 51 and the third port of the first valve body 51, is then discharged from the third port of the first valve body 51, and is blown back to the enrichment module 60 during the flow of the carrier gas.

In addition, the fuel gas provided by the embodiment of the utility model can be provided by a hydrogen steel cylinder or a hydrogen generator; the combustion-supporting gas can be provided by a zero-gas steel cylinder or a zero-gas air generator; the carrier gas and diluent gas may be provided from a nitrogen cylinder or nitrogen generator.

Utilize the utility model discloses a detection device for direct measurement total hydrocarbon content of non-methane that provides directly measures the content of methane and total hydrocarbon of non-methane, and the result is shown as table 1.

TABLE 1 USE the utility model provides a detection device for direct measurement non-methane total hydrocarbon content directly detects non-methane total hydrocarbon content of methane

The contents of total hydrocarbons and methane were obtained indirectly and the values of non-methane total hydrocarbons were calculated, and the results are shown in table 2.

TABLE 2 detection of non-methane content of methane by conventional indirect method

As can be seen from tables 1 and 2, the embodiment of the utility model provides a detection device for direct measurement non-methane total hydrocarbon content measured data's accuracy is higher than indirect method measuring result. The embodiment of the utility model provides a detection device for direct measurement total hydrocarbon content of non-methane adsorbs non-methane through enrichment module 60, has discharged the interference of oxygen in the chromatographic column, improves the responsivity of total hydrocarbon of non-methane in detector 40 through the enrichment method, reduces the measuring error that the signal is weak to be brought, promotes the detection accuracy.

In addition, the embodiment of the utility model provides a detection limit that is used for the non-methane total hydrocarbon of the detection device of direct measurement non-methane total hydrocarbon content is shown as table 3, and methane detection limit is shown as table 4.

TABLE 3 detection limits for non-methane Total hydrocarbons

TABLE 4 detection limits for methane

When the content of the non-methane total hydrocarbons in the methane is detected by an indirect method, the detection limit of the non-methane total hydrocarbons is shown in table 5, and the detection limit of the methane is shown in table 6.

TABLE 5 Total Hydrocarbon detection limits

TABLE 6 detection limits of methane

It can be seen from table 3 to table 5 that current indirect method technique can't reach a lower detection level, the detection device for directly measuring non-methane total hydrocarbon content that this application provided passes through enrichment module 60, the mode that adopts the enrichment is measured after carrying out the enrichment concentration to non-methane total hydrocarbon, can effectually improve the detection limit of non-methane total hydrocarbon, it switches the adjustment through the magnification of amplifier in the detector 40 to measure methane, the amplification of methane at detector 40 response signal has been improved, the detection limit of methane is improved. Taking Beijing as an example, the concentration level of methane and non-methane total hydrocarbons in ambient air in Beijing over the years is generally between 80 ppb and 100ppb, and the detection limit of the existing indirect method technology on the total hydrocarbons and methane cannot accurately monitor the methane and the non-methane total hydrocarbons in the ambient air. Because total hydrocarbon and methane concentration level are lower in the ambient air, the embodiment of the utility model provides a detection device for direct measurement total hydrocarbon content of non-methane can effectively detect the concentration of methane and total hydrocarbon of non-methane in the air.

In addition, as shown in fig. 9 and fig. 10, the utility model provides a peak spectrogram that is used for the detection device of direct measurement non-methane total hydrocarbon content to obtain compares in the peak spectrogram that traditional direct method obtained at non-methane detection stage, and peak type symmetry is better, makes things convenient for analysis software to carry out integral computation, helps promoting the analysis result degree of accuracy.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a detection device for direct measurement is not total hydrocarbon content of methane, its characterized in that, includes quantitative ring, first multi-way valve, methane analysis post, detector, second multi-way valve and enrichment module, the both ends of quantitative ring, the both ends of methane analysis post with the first gas port of detector respectively with the different port one-to-one of first multi-way valve is connected, the both ends of enrichment module respectively with the port of second multi-way valve links to each other, link to each other through the pipeline between first multi-way valve and the second multi-way valve, first multi-way valve with the second multi-way valve respectively with carry the gas pipeline intercommunication, first multi-way valve with the second multi-way valve is equipped with the tail gas discharge mouth respectively, wherein, the second multi-way valve is the six-way valve.

2. The apparatus of claim 1, wherein the enrichment module comprises an enrichment tube and a temperature control component, the enrichment tube is internally provided with an adsorbent, and the temperature control component is used for controlling the temperature of the enrichment tube.

3. The detection apparatus for directly measuring the content of non-methane total hydrocarbons according to claim 1, wherein said detector comprises a flame ionization detector.

4. The device as claimed in any one of claims 1 to 3, wherein the first multi-way valve is a ten-way valve.

5. The apparatus according to claim 1, wherein the exhaust gas outlet of the second multi-way valve is connected to a second exhaust gas outlet pipeline, and the second exhaust gas outlet pipeline is provided with a suction pump.

6. The device for directly measuring the content of the non-methane total hydrocarbons according to claim 5, further comprising a flow controller, wherein the flow controller is installed on the second tail gas exhaust pipeline.

7. The device of claim 1, further comprising a calibration unit in communication with the sample inlet of the first multi-way valve.

8. The apparatus according to claim 7, wherein the sample inlet of the first multi-way valve is connected to a first pipeline, a three-way valve is installed on the first pipeline, and a gas inlet of the three-way valve is connected to a gas outlet of the calibration unit.

9. The apparatus of claim 1, further comprising a first housing and a second housing, wherein the first multi-way valve, the quantification ring, the methane analysis column, and the detector are all mounted in the first housing, and the second multi-way valve and the enrichment module are all mounted in the second housing.

10. The apparatus of claim 1, wherein the number of the second multi-way valves is two, and the two second multi-way valves are respectively a first valve body and a second valve body, the first valve body is connected with the first multi-way valve, the second valve body is connected with the first valve body, the enrichment module is mounted on the second valve body, the first valve body and the second valve body are respectively communicated with the carrier gas pipeline, and after the non-methane detection stage is completed, the carrier gas enters the second valve body along the first valve body and backflows the enrichment module.