Device for detecting trace halide in hydrogen

Abstract

The utility model relates to the technical field of gas analysis, and discloses a device for detecting trace halide in hydrogen, which comprises a six-way pneumatic switching valve, and a sample gas inlet is connected to a first channel of the six-way pneumatic switching valve through a first flowmeter; a quantitative ring is connected between a second channel and a fifth channel of the six-way pneumatic switching valve; a third channel of the six-way pneumatic switching valve is connected to the inlet end of the separation cavity, and a plurality of separation packed columns are further arranged in the separation cavity. A carrier gas inlet is connected to a fourth channel of the six-way pneumatic switching valve through a third flowmeter; a sixth channel of the six-way pneumatic switching valve is connected to a sample gas outlet; the temperature sensor and the electric heater are arranged in the separation cavity. The device disclosed by the utility model can realize separation and detection of trace halides in hydrogen, and solves the problem of potential safety hazards existing in a high-temperature oxidation step of a hydrogen sample containing halides through the separation cavity.

Description

Technical Field

[0001] The utility model relates to the technical field of gas analysis, in particular to a detection device for trace halides in hydrogen. Background Art

[0002] Hydrogen energy is a secondary energy source with abundant sources, green and low-carbon, and wide applications. It is of great significance to building a clean, low-carbon, safe and efficient energy system and achieving the goals of carbon peak and carbon neutrality.

[0003] At present, hydrogen energy development and utilization technologies represented by fuel cells have made major breakthroughs, providing important solutions for achieving zero-emission energy utilization. Most of my country's hydrogen fuel sources are obtained by electrolyzing salt and purifying it. If the production process is unstable, halides will enter the finished hydrogen fuel, posing risks to the operation of the fuel cell. GB / T "Hydrogen Fuel for Proton Exchange Membrane Fuel Cell Vehicles" has strict requirements on the impurities of hydrogen for fuel cells, among which the content of total halide impurities (calculated as halide ions) shall not exceed 0.05μmol / mol.

[0004] At present, there are many methods for detecting halogens in hydrogen fuel at home and abroad, such as gas chromatography-mass spectrometry, gas chromatography-electron capture method, solution absorption-ion chromatography, etc. Among them, solution absorption-ion chromatography is widely accepted due to its strong applicability and other advantages. However, when using this method, the sample must first be subjected to high-temperature oxidation decomposition. When the sample contains a large amount of hydrogen, the high-temperature oxidation step has safety hazards, which leads to certain limitations of this method.

[0005] Therefore, developing a device that can separate hydrogen from halides and measure the total halide content is of great significance to the field of hydrogen fuel cells. Utility Model Content

[0006] The technical problem solved by the utility model is that when the halide content in hydrogen is determined by solution absorption-ion chromatography, there is a potential safety hazard in the high-temperature oxidation step due to the presence of hydrogen.

[0007] In order to solve the above technical problems, the technical solution adopted by the utility model is: a detection device for trace halides in hydrogen, comprising a six-way pneumatic switching valve, wherein a sample gas inlet is connected to a first channel of the six-way pneumatic switching valve through a first flowmeter; a quantitative ring is connected between the second channel and the fifth channel of the six-way pneumatic switching valve; the third channel of the six-way pneumatic switching valve is connected to the inlet end of a separation chamber, and a plurality of separation filling columns are also arranged in the separation chamber; the carrier gas inlet is connected to a fourth channel of the six-way pneumatic switching valve through a third flowmeter; and the sixth channel of the six-way pneumatic switching valve is connected to a sample gas outlet;

[0008] It also includes a temperature sensor and an electric heater arranged in the separation chamber; the outlet end of the separation chamber is connected to the inlet end of the three-way electromagnetic switching valve, one outlet end of the three-way electromagnetic switching valve is connected in sequence to the first one-way valve and the stoppered tubular absorption bottle, and the stoppered tubular absorption bottle is provided with an exhaust port; the other outlet end of the three-way electromagnetic switching valve is connected in sequence to the second one-way valve and the tubular furnace, and then connected to the stoppered tubular absorption bottle through the third one-way valve;

[0009] The device also comprises an oxygen delivery tube, which is provided with a second flow meter and connected to the tube furnace.

[0010] Particularly, the stoppered tubular absorption bottle is a porous inert sieve plate absorption bottle.

[0011] Particularly, the separation filling column is a molecular sieve filling column having a strong retention capacity for halides.

[0012] In particular, the six-way pneumatic switching valve, quantitative loop and all gas lines are silanized.

[0013] Compared with the prior art, the utility model has the following advantages and beneficial effects: the utility model device can quickly separate hydrogen, organic halides and inorganic halides in a halogenated hydrogen sample through a separation chamber, thereby completing a rapid detection of the halogen content in the fuel hydrogen, and can also effectively avoid the problem in the prior art that the rubber wrapped in hydrogen needs to be oxidized and heated, thereby causing safety hazards in the high-temperature oxidation step. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the connection relationship between the components when the six-way pneumatic switching valve is in the first state.

[0015] Figure 2 This is a schematic diagram of the connection relationship between the components when the six-way pneumatic switching valve is in the second state.

[0016] The meanings of the numbers in the figure are: six-way pneumatic switching valve—1; sample gas inlet—2; first flowmeter—21; quantitative ring—3; separation chamber—41; separation filling column—42; carrier gas inlet—5; third flowmeter—51; sample gas outlet—6; three-way electromagnetic switching valve—7; first one-way valve—81; second one-way valve—82; third one-way valve—83; stoppered tubular absorption bottle—9; exhaust port—91; tubular furnace—10; oxygen delivery tube—101; second flowmeter—102. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the utility model in conjunction with the accompanying drawings in the embodiments of the utility model, so as to have a further understanding of the concept of the utility model, the technical problems solved, the technical features constituting the technical solutions and the technical effects brought about.

[0018] like Figure 1-2 As shown, the utility model is a detection device for trace halides in hydrogen, comprising a six-way pneumatic switching valve 1, a sample gas inlet 2 is connected to the first channel of the six-way pneumatic switching valve 1 through a first flowmeter 21; a quantitative ring 3 is connected between the second channel and the fifth channel of the six-way pneumatic switching valve 1; the third channel of the six-way pneumatic switching valve 1 is connected to the inlet end of a separation chamber 41, and a plurality of separation filling columns 42 are also arranged in the separation chamber 41; the carrier gas inlet 5 is connected to the fourth channel of the six-way pneumatic switching valve 1 through a third flowmeter 51; the sixth channel of the six-way pneumatic switching valve 1 is connected to the sample gas outlet 6;

[0019] It also includes a temperature sensor and an electric heater disposed in the separation chamber 41; the outlet end of the separation chamber 41 is connected to the inlet end of the three-way electromagnetic switching valve 7, one outlet end of the three-way electromagnetic switching valve 7 is sequentially connected to the first check valve 81 and the plugged tubular absorption bottle 9, and the plugged tubular absorption bottle 9 is provided with an exhaust port 91; the other outlet end of the three-way electromagnetic switching valve 7 is sequentially connected to the second check valve 82 and the tubular furnace 10, and then connected to the plugged tubular absorption bottle 9 through the third check valve 83;

[0020] The oxygen delivery pipe 101 is also included. The oxygen delivery pipe 101 is provided with a second flow meter 102 and is connected to the tube furnace 10 .

[0021] In the utility model, in the initial state, the six-way pneumatic switching valve 1 is in the first state, at which time the first channel and the second channel, the third channel and the fourth channel, and the fifth channel and the sixth channel are connected respectively. At this time, the gas sample to be tested containing trace halogens enters along the sample gas inlet 2, and enters the quantitative ring 3 after passing through the first channel and the second channel. At this time, the count of the first flowmeter 21 is used to assist in recording the amount of the gas sample to be tested that is introduced, and the excess gas sample to be tested is discharged along the sample gas outlet 6 through the fifth channel and the sixth channel, and the carrier gas fills the separation chamber 41 through the fifth channel and the fourth channel. Then the six-way pneumatic switching valve 1 is switched to the second state, at which time the first channel and the sixth channel, the second channel and the third channel, and the fourth channel and the fifth channel are connected respectively, and the carrier gas introduces the quantitative halogen-containing hydrogen in the quantitative ring 3 into the separation chamber 41, and performs subsequent processing in the separation chamber 41.

[0022] When the gas sample to be tested enters the separation chamber 41, it fully contacts with the separation filling column 42 in the separation chamber 41, and the organic halide in the gas sample to be tested is adsorbed by the separation filling column 42. The remaining gas sample to be tested passes through the three-way electromagnetic switching valve 7, and then along one of the branches, passes through the first one-way valve 81, and enters the stoppered tubular absorption bottle 9. When the sample gas to be tested in the separation chamber 41 is completely discharged into the stoppered tubular absorption bottle 9, the separation chamber 41 is heated by an electric heater to release the organic halide adsorbed by the separation filling column 42, and then the organic halide passes through the three-way electromagnetic switching valve 7 along another branch, and then passes through the second one-way valve 82 and is discharged into the tubular furnace 10. In the tubular furnace 10, the oxygen input by the oxygen delivery pipe 101 is used for quantitative combustion, and the combustion products of the organic halide after combustion are passed through the third one-way valve 83 into the stoppered tubular absorption bottle 9. Finally, the stoppered tubular absorption bottle 9 is used to absorb the inorganic halide and the organic halide decomposed by combustion in the gas sample to be tested. After the absorption is completed, the absorption solution is analyzed by ion chromatography, which can reflect the level of trace halides in the hydrogen sample gas to be tested.

[0023] As a preferred embodiment, the stoppered tubular absorption bottle is a porous inert sieve plate absorption bottle.

[0024] In this embodiment, a specific type of stoppered tubular absorption bottle 9 is provided. The porous inert sieve plate absorption bottle can ensure that the sample gas can fully contact with the absorption medium in the absorption bottle, thereby ensuring the absorption effect.

[0025] As a preferred embodiment, the separation filling column 42 is a molecular sieve filling column having a strong retention capacity for halides.

[0026] As a preferred embodiment, the six-way pneumatic switching valve 1, the quantitative ring 3 and all gas circuits are silanized.

[0027] In this embodiment, the silanization treatment can shield the hydroxyl active sites in the six-way pneumatic switching valve 1, the quantitative ring 3 and the gas path, so as to reduce the adsorption and decomposition of impurities.

[0028] The words “connection” and “fixation” appearing in the description of the present invention may refer to fixed connection, processing and forming, welding, or mechanical connection. The specific meanings of the above terms in the present invention shall be understood according to the specific circumstances.

[0029] In the description of the present invention, the terms "center", "upper", "lower", "horizontal", "inner", "outer", etc., which indicate the orientation or position relationship, are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying a specific orientation that the device or element referred to must have, and therefore cannot be understood as a limitation on the present invention.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A detection device for trace halides in hydrogen, characterized in that: The invention comprises a six-way pneumatic switching valve (1), wherein a sample gas inlet (2) is connected to a first channel of the six-way pneumatic switching valve (1) via a first flow meter (21); a quantitative ring (3) is connected between a second channel and a fifth channel of the six-way pneumatic switching valve (1); a third channel of the six-way pneumatic switching valve (1) is connected to an inlet end of a separation chamber (41), wherein a plurality of separation filling columns (42) are further arranged in the separation chamber (41); a carrier gas inlet (5) is connected to a fourth channel of the six-way pneumatic switching valve (1) via a third flow meter (51); and a sixth channel of the six-way pneumatic switching valve (1) is connected to a sample gas outlet (6); It also includes a temperature sensor and an electric heater disposed in the separation chamber (41); the outlet end of the separation chamber (41) is connected to the inlet end of a three-way electromagnetic switching valve (7); one outlet end of the three-way electromagnetic switching valve (7) is connected in sequence to a first one-way valve (81) and a stoppered tubular absorption bottle (9); the stoppered tubular absorption bottle (9) is provided with an exhaust port (91); the other outlet end of the three-way electromagnetic switching valve (7) is connected in sequence to a second one-way valve (82) and a tubular furnace (10), and then connected to the stoppered tubular absorption bottle (9) through a third one-way valve (83); It also includes an oxygen delivery pipe (101), on which a second flow meter (102) is provided and connected to the tubular furnace (10).

2. A detection device for trace halides in hydrogen as claimed in claim 1, characterized in that: The stoppered tubular absorption bottle (9) is a porous inert sieve plate absorption bottle.

3. A device for detecting trace halides in hydrogen as claimed in claim 1, characterized in that: The separation filling column (42) is a molecular sieve filling column having a strong retention capacity for halides.

4. A device for detecting trace halides in hydrogen as claimed in claim 1, characterized in that: The six-way pneumatic switching valve (1), the quantitative ring (3) and all gas lines are silanized.

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