阅读说明：本技术 一种氘氚混合气中微量杂质含量的分析系统及方法 (System and method for analyzing content of trace impurities in deuterium-tritium mixed gas ) 是由 王伟伟 毛义武 夏立东 沈春雷 陈晓华 李海容 张伟光 周晓松 任兴碧 龙兴贵 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种氘氚混合气中微量杂质含量的分析系统,该系统采取三通阀组合、背压阀、负压罐等特定组合方式,实现了连续负压取样分析、尤其实现了少量氚样品连续的负压取样及在线分析,同时解决了安全防护问题。本发明通过设置两个平行测试通道,一个是化学纯度测试通道,另一个是同位素纯度测试通道,避免了液氮低温下对部分杂质气体的吸附作用。本发明还公开了一种氘氚混合气中微量杂质含量的分析方法,该方法化学纯度测试通道以氦气作为载气,通过特定阀切组合、特定柱组合、检测器,完成O<Sub>2</Sub>,N<Sub>2</Sub>,CH<Sub>4</Sub>,CO,CO<Sub>2</Sub>,C<Sub>2</Sub>H<Sub>6</Sub>的分析测定；同位素测试通道以氖气作载气,利用特制的金属毛细柱、检测器,完成H<Sub>2</Sub>,HD,HT,D<Sub>2</Sub>,DT,T<Sub>2</Sub>的测定；本发明使用Ne做载气,一方面可以增加检测器对氢同位素的检测灵敏度,另一方面可以实现对He的定性与定量。(The invention discloses an analysis system for trace impurity content in deuterium-tritium mixed gas, which adopts specific combination modes such as a three-way valve combination, a back pressure valve, a negative pressure tank and the like to realize continuous negative pressure sampling analysis, particularly continuous negative pressure sampling and on-line analysis of a small amount of tritium samples and solve the problem of safety protection. According to the invention, two parallel testing channels are arranged, one is a chemical purity testing channel, and the other is an isotope purity testing channel, so that the adsorption effect of liquid nitrogen on part of impurity gases at low temperature is avoided. The invention also discloses an analysis method of the content of trace impurities in the deuterium-tritium mixed gas, and the method takes helium as carrier gas in a chemical purity test channel, and completes O through a specific valve-cutting combination, a specific column combination and a detector 2 ，N 2 ，CH 4 ，CO，CO 2 ，C 2 H 6 The analytical determination of (3); the isotope test channel uses neon gas as carrier gas, and uses specially-made metal capillary column and detector to implement H 2 ，HD，HT，D 2 ，DT，T 2 Measuring; the invention uses Ne as carrier gas, which can increase the detection sensitivity of detector to hydrogen isotope and realize the qualitative and quantitative He.)

1. The system for analyzing the content of trace impurities in the deuterium-tritium mixed gas is characterized by comprising a chemical purity testing channel, an isotope purity testing channel, a sample input unit and a sample recovery unit, wherein the input ends of the chemical purity testing channel and the isotope purity testing channel are connected with the sample input unit, and the output ends of the chemical purity testing channel and the isotope purity testing channel are connected with the sample recovery unit; the chemical purity testing channel comprises a first sample valve group, a six-way valve G (7), a six-way valve H (8), a chromatographic column I (9), a chromatographic column II (10), a chromatographic column III (11) and a helium ionization detector (14), wherein the first sample valve group is connected with the chromatographic column I (9), the six-way valve H (8) is respectively connected with the chromatographic column I (9), the chromatographic column II (10) and the chromatographic column III (11), and the six-way valve G (7) is respectively connected with the chromatographic column II (10), the chromatographic column III (11) and the helium ionization detector (14); the isotope purity testing channel comprises a second sample introduction valve group, a chromatographic column IV (12) and a thermal conductivity detector (23) which are connected in sequence.

2. The system for analyzing the trace impurity content in a deuterium-tritium mixed gas as recited in claim 1, wherein the first sample valve set comprises a three-way valve a (1), a three-way valve B (2), a three-way valve C (3), and a quantitative ring P (20) connected between the three-way valve B (2) and the three-way valve C (3); the second sampling valve group comprises a three-way valve D (4), a three-way valve E (5), a three-way valve F (6) and a quantitative ring Q (21) connected between the three-way valve E (5) and the three-way valve F (6).

3. The system for analyzing the trace impurity content in a deuterium-tritium mixed gas as recited in claim 1, wherein the sample input unit comprises a sample tank (23), a pressure sensor (24), and a vacuum unit (25).

4. The system for analyzing the trace impurity content in a deuterium-tritium mixed gas as recited in claim 1, wherein the sample recovery unit comprises a back pressure valve X (15), a back pressure valve Y (16), a back pressure valve Z (17), a negative pressure tank a (18), a negative pressure tank b (19), a recovery chemical bed (22); the system comprises a six-way valve G (7), a negative pressure tank a (18), a backpressure valve X (15), a backpressure valve Y (16), a thermal conductivity detector (13), a negative pressure tank a (18), a three-way valve D (4), a three-way valve A (1), a recovery chemical bed (22), a three-way valve B (2) and a three-way valve E (5), wherein the backpressure valve X (15) is connected between the six-way valve G (7) and the negative pressure tank a (18).

5. The system for analyzing the trace impurity content in the deuterium-tritium mixed gas as recited in claim 1, wherein in the chemical purity test channel, the chromatographic column I (9) is a Porapak-Q micro-packed column, the chromatographic column II (10) is a 5A molecular sieve micro-packed column, and the chromatographic column III (11) is a Porapak-Q micro-packed column.

6. The system for analyzing the trace impurity content in a deuterium-tritium mixed gas as recited in claim 1, wherein in the isotopic purity testing channel, the chromatographic column IV (12) is MnSO₄The modified alumina capillary is opened, and separation of hydrogen isotope and He can be realized in liquid nitrogen soaking.

7. A method for analyzing the trace impurity content in a deuterium-tritium mixed gas based on the system for analyzing the trace impurity content in the deuterium-tritium mixed gas as described in any one of claims 1 to 6, the method for analyzing the trace impurity content in the deuterium-tritium mixed gas comprising the steps of:

(a) inputting a deuterium-tritium mixed sample;

(b) impurity component CO in deuterium-tritium mixed sample₂、C₂H₆、O₂、N₂、CH₄Testing the concentration of CO;

(c) testing the content of impurities He and H isotopes in a deuterium-tritium mixed sample;

(d) and recovering the residual mixed deuterium-tritium sample, and preparing the input of the next mixed deuterium-tritium sample.

8. The method of claim 7, wherein the method comprises the following steps: the step (c) is specifically as follows: the quantitative ring Q (21) is collected and vacuumized by using the negative pressure tank (19), namely, the negative pressure tank b (19) collects and vacuums the residual carrier gas in the quantitative ring Q (21) by using the negative pressure tank (19) through the first valve port of the three-way valve D (4), the second valve port of the three-way valve D (4), the first valve port of the three-way valve E (5) and the third valve port of the three-way valve E (5);

after the collection is finished, the deuterium-tritium mixed gas to be detected is conveyed to a quantitative ring Q (21) through the first valve port of the three-way valve E5 and the second valve port of the three-way valve E5;

the high-purity neon carrier gas is conveyed into the chromatographic column IV (12) through the third valve port of the three-way valve D (4), the third valve port of the three-way valve E (5) and the third valve port of the three-way valve E (5) to the deuterium-tritium mixed gas to be detected in the quantitative ring Q (21) through the second valve port of the three-way valve F (6) and the third valve port of the three-way valve F (6);

flowing out of the chromatographic column IV (12) by the deuterium-tritium mixed gas to be detected, and separating impurity components He and H in the deuterium-tritium mixed gas to be detected₂HD, HT and component D₂、DT、T₂Separating, and delivering the high-purity neon carrier gas to a thermal conductivity detector (13) to obtain impurity components He and H₂HD, HT and component D₂、DT、T₂A chromatographic signal of (a);

he and H are mixed₂、HD、D₂The peak area of each component is compared with the standard curve to obtain He and H₂、HD、D₂The concentration of each component;

obtaining HT, DT and T by hydrogen isotope exchange equilibrium equation₂The concentration of each component;

according to the above H₂、HD、HT、D₂、DT、T₂The content of H isotope was determined from the concentrations of the respective components.

9. The method of claim 8, wherein the method comprises the following steps: the chromatographic column IV (12) in the step (c) is MnSO₄The modified alumina capillary is opened, and separation of hydrogen isotope and He can be realized in liquid nitrogen soaking.

10. The method of claim 7, wherein the method comprises the following steps: the step (d) is specifically as follows: after the test is finished, the residual deuterium-tritium mixed gas in the sample tank (23) is absorbed by the recovery chemical bed (22); residual carrier gas in the quantitative ring P (20) and the quantitative ring Q (21) is recycled into the negative pressure tank b (19), and the pressure in the negative pressure tank b (19) is not more than 10Pa after recycling; the tritium-containing carrier gas flowing out of the back pressure valve X (15), the back pressure valve Y (16), and the back pressure valve Z (17) is recovered in the negative pressure tank a (18).

Technical Field

The invention belongs to the field of energy, and particularly relates to a system and a method for analyzing the content of trace impurities in a deuterium-tritium mixed gas.

Background

Tritium is an important strategic energy material and has important significance in the fields of industry, national defense, scientific research and the like. In order to ensure the purity and quality of tritium, it is necessary to analyze impurities in tritium. The trace impurities in the tritium are mainly derived from a tritium decay product, air, gas released from the inner surface of the pipeline and gas generated after the tritium reacts with the inner wall material. The main components are He and H₂O，O₂，N₂，CH₄，CO，CO₂，C₂H₆. The reaction of the water in the air with the chemical bed material produces oxides and H₂，H₂After the mixed gas reacts with deuterium-tritium mixed gas and isotope exchange is carried out, impurity components such as HD, HT and the like are generated. In order to test the protium content of the impurities, it is necessary to determine H₂，HD，HT，D₂，DT，T₂These six hydrogen isotope molecular ratios. Since the measurement of six hydrogen isotope molecules is carried out at liquid nitrogen temperature, H₂O，O₂，N₂，CH₄，CO，CO₂，C₂H₆Will be adsorbed by the material.

The existing tritium measuring device (such as a tritium measuring device and a tritium measuring method, and patent publication No. CN101149438A) can measure the total amount of tritium, but cannot give the isotope ratio and the impurity content. The existing hydrogen isotope analysis system (for example, a gas chromatography detection system and a method for analyzing hydrogen isotopes and trace impurity components in He, patent publication No. (CN105572250B), which can only obtain the isotope ratio and impurity content of non-tritium-containing hydrogen isotopes, but has the defect that the analysis requirement of tritium-containing hydrogen isotopes cannot be met, and in addition, the above technology has the following technical defects:

1. the chromatographic peak formed by a large amount of hydrogen isotopes can cover up trace impurity gases (such as O)₂，N₂) The chromatographic peak of the reagent can not accurately determine the content of impurities;

2. the hydrogen isotope analysis system adopts positive pressure gas flow sampling, the sampling mode can consume more tritium, and the tritium is a scarce resource, so that the sampling requirement of the tritium is difficult to meet;

3. tritium is radioactive, and positive pressure sampling is not beneficial to protection of tritium;

4. after the test, the tritium sample flows out along with the positive pressure carrier gas, negative pressure collection is needed and then treatment is carried out according to radioactive waste, and the stability of the carrier gas flow can be influenced by the negative pressure collection;

5. the positive pressure carrier gas retained in the quantitative ring after sample introduction by the six-way valve switching mode can prevent the negative pressure sample from entering again, and further the negative pressure repeated test of the same sample can not be carried out for many times.

Disclosure of Invention

In view of this, the invention aims to provide an analysis system for trace impurity content in a deuterium-tritium mixed gas, which can realize continuous negative pressure sampling and low tritium consumption.

In order to achieve the purpose, the invention specifically adopts the following technical scheme:

the system for analyzing the content of trace impurities in the deuterium-tritium mixed gas is characterized by comprising a chemical purity testing channel, an isotope purity testing channel, a sample input unit and a sample recovery unit, wherein the input ends of the chemical purity testing channel and the isotope purity testing channel are connected with the sample input unit, and the output ends of the chemical purity testing channel and the isotope purity testing channel are connected with the sample recovery unit; the chemical purity testing channel comprises a first sample valve group, a six-way valve G, a six-way valve H, a chromatographic column I, a chromatographic column II, a chromatographic column III and a helium ionization detector, wherein the first sample valve group is connected with the chromatographic column I, the six-way valve H is respectively connected with the chromatographic column I, the chromatographic column II and the chromatographic column III, and the six-way valve G is respectively connected with the chromatographic column II, the chromatographic column III and the helium ionization detector; the isotope purity testing channel comprises a second sample introduction valve group, a chromatographic column IV and a thermal conductivity detector which are connected in sequence.

Further, the first sample injection valve group comprises a three-way valve A, a three-way valve B, a three-way valve C and a quantitative ring P connected between the three-way valve B and the three-way valve C, wherein the three-way valve A, the three-way valve B and the three-way valve C are sequentially connected; the second sampling valve group comprises a three-way valve D, a three-way valve E, a three-way valve F and a quantitative ring Q connected between the three-way valve E and the three-way valve F, wherein the three-way valve D, the three-way valve E and the three-way valve F are sequentially connected.

Further, the sample input unit comprises a sample tank, a pressure sensor and a vacuum unit.

Further, the sample recovery unit comprises a back pressure valve X, a back pressure valve Y, a back pressure valve Z, a negative pressure tank a, a negative pressure tank b and a recovery chemical bed; the back pressure valve X is connected between the six-way valve G and the negative pressure tank a, the back pressure valve Y is connected between the helium ionization detector and the negative pressure tank a, the back pressure valve Z is connected between the thermal conductivity detector and the negative pressure tank a, the negative pressure tank B is connected with the three-way valve D and the three-way valve A, and the recovery chemical bed is connected with the three-way valve B and the three-way valve E.

Furthermore, in the chemical purity test channel, a chromatographic column I is a Porapak-Q micro-packed column, a chromatographic column II is a 5A molecular sieve micro-packed column, and a chromatographic column III is a Porapak-Q micro-packed column.

Furthermore, in the isotope purity testing channel, a chromatographic column IV is MnSO₄The modified alumina capillary is opened, and separation of hydrogen isotope and He can be realized in liquid nitrogen soaking.

The invention also provides an analysis method of the trace impurity content in the deuterium-tritium mixed gas based on the analysis system of the trace impurity content in the deuterium-tritium mixed gas, and the analysis method of the trace impurity content in the deuterium-tritium mixed gas comprises the following steps:

(a) inputting a deuterium-tritium mixed sample;

(b) impurity component CO in deuterium-tritium mixed sample₂、C₂H₆、O₂、N₂、CH₄Testing the concentration of CO;

(c) testing the content of impurities He and H isotopes in a deuterium-tritium mixed sample;

(d) and recovering the residual mixed deuterium-tritium sample, and preparing the input of the next mixed deuterium-tritium sample.

Further, the step (c) is specifically as follows: and collecting and vacuumizing the quantitative ring Q by using a negative pressure tank, namely collecting and vacuumizing the residual carrier gas in the quantitative ring Q by using the negative pressure tank for the negative pressure tank b through a first valve port of a three-way valve D, a second valve port of the three-way valve D, a first valve port of a three-way valve E and a third valve port of the three-way valve E.

After the collection is finished, the deuterium-tritium mixed gas to be detected is conveyed to the quantitative ring Q through the first valve port of the three-way valve E5 and the second valve port of the three-way valve E5;

the high-purity neon carrier gas is conveyed into the chromatographic column IV through the ③ th valve port of the three-way valve D, the ① th valve port of the three-way valve D, the ③ th valve port of the three-way valve E and the ① th valve port of the three-way valve E, the deuterium-tritium mixed gas to be detected in the quantitative ring Q is conveyed into the chromatographic column IV through the ② th valve port of the three-way valve F and the ① th valve port of the three-way valve F, the deuterium-tritium mixed gas to be detected flows out of the chromatographic column IV, and impurity components₂HD, HT and component D₂、DT、T₂Separating, and delivering the high-purity neon carrier gas to a thermal conductivity detector to obtain impurity components He and H₂HD, HT and component D₂、DT、T₂A chromatographic signal of (a);

he and H are mixed₂、HD、D₂The peak area of each component is compared with the standard curve to obtain He and H₂、HD、D₂The concentration of each component;

obtaining HT, DT and T by hydrogen isotope exchange equilibrium equation₂The concentration of each component;

according to the above H₂、HD、HT、D₂、DT、T₂The content of H isotope was determined from the concentrations of the respective components.

Further, the chromatographic column IV in the step (c) is MnSO₄The modified alumina capillary is opened, and separation of hydrogen isotope and He can be realized in liquid nitrogen soaking.

Further, the step (d) is specifically as follows: after the test is finished, the residual deuterium-tritium mixed gas in the sample tank is absorbed by the recovery chemical bed; residual carrier gas in the quantitative ring P and the quantitative ring Q is recycled into the negative pressure tank b, and the pressure in the negative pressure tank b is not more than 10Pa after recycling; the tritium-containing carrier gas flowing out of the back pressure valve X, the back pressure valve Y and the back pressure valve Z is recycled into the negative pressure tank a.

The invention adopts specific combination modes of three-way valve combination, a back pressure valve, a negative pressure tank and the like, realizes continuous negative pressure sampling analysis, particularly realizes continuous negative pressure sampling and on-line analysis of a small amount of tritium samples, and simultaneously solves the problem of safety protection. According to the invention, two parallel testing channels are arranged, one is a chemical purity testing channel, and the other is an isotope purity testing channel, so that the adsorption effect of liquid nitrogen on part of impurity gases at low temperature is avoided.

Drawings

FIG. 1 is a system for analyzing the trace impurity content in a deuterium-tritium mixed gas according to the present invention;

in the figure 1, a three-way valve A2, a three-way valve B3, a three-way valve C4, a three-way valve D5, a three-way valve E6, a three-way valve F7, a six-way valve G8, a six-way valve H9, a chromatographic column I10, a chromatographic column II11, a chromatographic column III 12, a chromatographic column IV 13, a thermal conductivity detector 14, a helium ionization detector 15, a back pressure valve X16, a back pressure valve Y17, a back pressure valve Z18, a negative pressure tank a 19, a negative pressure tank B20, a quantitative ring P21, a quantitative ring Q22, a recovered chemical bed 23, a sample tank 24, a pressure sensor 25 and a vacuum.

Detailed Description

The invention is further explained below with reference to the drawings.

The system comprises a chemical purity testing channel, an isotope purity testing channel, a sample input unit and a sample recovery unit, wherein the input ends of the chemical purity testing channel and the isotope purity testing channel are connected with the sample input unit, and the output ends of the chemical purity testing channel and the isotope purity testing channel are connected with the sample recovery unit; the chemical purity testing channel comprises a first sample valve group, a six-way valve G7, a six-way valve H8, a chromatographic column I9, a chromatographic column II10, a chromatographic column III11 and a helium ionization detector 14, wherein the first sample valve group is connected with the chromatographic column I9, the six-way valve H8 is respectively connected with the chromatographic column I9, the chromatographic column II10 and the chromatographic column III11, and the six-way valve G7 is respectively connected with the chromatographic column II10, the chromatographic column III11 and the helium ionization detector 14; the isotope purity test channel comprises a second sample introduction valve group, a chromatographic column IV12 and a thermal conductivity detector 13 which are sequentially connected, wherein the combination formed by the chromatographic column I9, the chromatographic column II10, the chromatographic column III11, the six-way valve G7 and the six-way valve H8 can realize the impurity O in tritium at normal temperature₂，N₂，CH₄，CO，CO₂，C₂H₆Separation of (4).

The system for analyzing the content of trace impurities in the deuterium-tritium mixed gas can realize the cyclic operation of steps of quantitative ring vacuumizing, quantitative ring sampling and quantitative ring sampling through the combination of specific switches of three-way valves, and realizes the continuous negative pressure sampling of tritium samples. Aiming at the condition that a large amount of hydrogen isotopes cover trace impurities, the method blows most of hydrogen isotopes out of the chromatographic column through carrier gas in a six-way valve cut valve evacuation mode. The scheme adopts a back pressure valve-negative pressure tank combined mode, solves the problem of flow stability at the rear end of positive pressure carrier gas, and simultaneously recovers tritium-containing samples in the carrier gas into a negative pressure tank, thereby solving the safety protection problem of tritium.

Further, the first sample valve group comprises a three-way valve A1, a three-way valve B2, a three-way valve C3 and a quantitative loop P20 connected between the three-way valve B2 and the three-way valve C3. The specific connection relationship of the first sample injection valve group is as follows: the third valve port of the three-way valve A1 is connected with the third valve port of the three-way valve B2, the third valve port of the three-way valve B2 is connected with the left end of the quantitative ring P20, and the right end of the quantitative ring P20 is connected with the second valve port of the three-way valve C3.

Further, the second sample valve group comprises a three-way valve D4, a three-way valve E5, a three-way valve F6 and a quantitative loop Q21 connected between the three-way valve E5 and the three-way valve F6. The connection relationship of the second sample injection valve group is as follows: the third valve port of the three-way valve D4 is connected with the third valve port of the three-way valve E5, the third valve port of the three-way valve E5 is connected with the left end of the quantitative ring Q21, and the right end of the quantitative ring Q21 is connected with the second valve port of the three-way valve F6.

Further, the sample input unit comprises a sample tank 23, a pressure sensor 24 and a vacuum unit 25.

Further, the sample recovery unit includes a back pressure valve X15, a back pressure valve Y16, a back pressure valve Z17, a negative pressure tank a18, a negative pressure tank b19, a recovery chemical bed 22; wherein, backpressure valve X15 is connected between six-way valve G7 and negative pressure tank a18, backpressure valve Y16 is connected between helium ionization detector 14 and negative pressure tank a18, backpressure valve Z17 is connected between thermal conductivity detector 13 and negative pressure tank a18, negative pressure tank B19 is connected with three-way valve D4, three-way valve A1, recovery chemical bed 22 is connected with three-way valve B2, three-way valve E5.

Further, in the chemical purity test channel, the chromatographic column I9 is a Porapak-Q micro-packed column with a length of 3 meters and an outer diameter of 1/16 inches, the chromatographic column II10 is a 5A molecular sieve micro-packed column with a length of 3 meters and an outer diameter of 1/16 inches, and the chromatographic column III11 is a Porapak-Q micro-packed column with a length of 3 meters and an outer diameter of 1/16 inches.

Further, in the isotope purity test passage, the chromatographic column IV12 is MnSO with the length of 20 meters and the inner diameter of 0.53 mm₄The modified alumina capillary tube is opened, and separation of hydrogen isotope and He can be realized in liquid nitrogen soaking; whereinThe MnSO4 modified alumina capillary open tubular column specifically refers to MnSO₄Loaded on the surface and in the pores of alumina to regulate the pore size and perform the normal-secondary state catalysis.

The invention adopts specific combination modes of three-way valve combination, back pressure valve, negative pressure tank and the like, realizes the continuous negative pressure sampling analysis and safety protection problems, and particularly, the impurity analysis system only consumes tritium samples in quantitative rings and recovers the tritium samples in the pipeline between the chemical bed and the three-way valve, thereby realizing the minimum consumption of tritium and overcoming the defect that the traditional positive pressure flow gas sampling mode consumes a large amount of samples.

The invention also provides an analysis method of the trace impurity content in the deuterium-tritium mixed gas based on the analysis system of the trace impurity content in the deuterium-tritium mixed gas, and the analysis method of the trace impurity content in the deuterium-tritium mixed gas comprises the following steps:

(a) inputting a deuterium-tritium mixed sample;

(b) testing the chemical purity of the deuterium-tritium mixed sample;

(c) testing the isotopic purity of the deuterium-tritium mixed sample;

(d) and recovering the residual mixed deuterium-tritium sample, and preparing the input of the next mixed deuterium-tritium sample.

According to the invention, two parallel testing channels are arranged, one is a chemical purity testing channel, and the other is an isotope purity testing channel, so that the adsorption effect of liquid nitrogen on part of impurity gases at low temperature is avoided.

The system for analyzing the content of trace impurities in the deuterium-tritium mixed gas can realize the cyclic operation of steps of quantitative ring vacuumizing, quantitative ring sampling and realize the continuous negative pressure sampling of the tritium sample through the specific opening and closing combination of the three-way valves. Aiming at the condition that a large amount of hydrogen isotopes cover trace impurities, the method blows most of hydrogen isotopes out of the chromatographic column through carrier gas in a six-way valve cut valve evacuation mode. The scheme adopts a back pressure valve-negative pressure tank combined mode, solves the problem of flow stability at the rear end of positive pressure carrier gas, and simultaneously recovers tritium-containing samples in the carrier gas into a negative pressure tank, thereby solving the safety protection problem of tritium.

In particular, the amount of the solvent to be used,

the step (a) is as follows: the vacuum unit 25 performs a vacuum pumping operation on the pipe connected between the second valve port of the three-way valve B2 and the sample tank 23. After the vacuumizing is stopped, the deuterium-tritium mixed gas to be detected in the sample tank 23 is released to enter a pipeline connected with the sample tank 23 and a second valve port of the three-way valve B2, and the pressure sensor 24 measures the pressure of the deuterium-tritium mixed gas to be detected.

The step (b) is as follows:

the quantitative ring P20 is collected and vacuumized by using the negative pressure tank 19, namely, the negative pressure tank B19 collects residual gases such as carrier gas in the quantitative ring P20 through the first valve port of the three-way valve A1, the second valve port of the three-way valve A1, the first valve port of the three-way valve B2 and the third valve port of the three-way valve B2 until the quantitative ring P is in a vacuum state;

after the collection is finished, the deuterium-tritium mixed gas to be detected is conveyed to a quantitative ring P20 through the first valve port of the three-way valve B2 and the second valve port of the three-way valve B2;

the high-purity helium carrier gas is conveyed into a chromatographic column I9 through a ③ valve port of a three-way valve A1, a ① valve port of a three-way valve A1, a ③ valve port of a three-way valve B2 and a ① valve port of a three-way valve B2 from a quantitative ring P20 to be detected through the ② valve port of a three-way valve C3 and the ① valve port of a three-way valve C3, the deuterium-tritium mixed gas to be detected flows out of the chromatographic column I9, and impurity components CO in the deuterium-tritium mixed gas to be detected are separated₂、C₂H₆With impurity component O₂、N₂、CH₄、CO；

Wherein the carrier gas separates the separated impurity component CO₂、C₂H₆Separating by feeding into chromatographic column III11 via ③ st valve port and ④ st valve port of six-way valve H8, and separating CO2 and C₂H₆The impurity component CO flows into the helium ionization detector 14 through the ⑤ valve port of the six-way valve G7 and the ⑥ valve port of the six-way valve G7₂、C₂H₆A chromatographic signal of (a);

impurity component O in deuterium-tritium mixed gas to be detected₂、N₂、CH₄CO is conveyed to the chromatographic column II10 through the ③ valve port of the six-way valve H8 and the ② valve port of the six-way valve H8 to realize separation, and the CO is subjected to separationMost hydrogen isotopes in the deuterium-tritium mixed gas to be detected enter a negative pressure tank a18 from a ① th valve port of a six-way valve G7, a ② th valve port of a six-way valve G7, a ③ th valve port of the six-way valve G7, a ④ th valve port of a six-way valve G7 and a back pressure valve X15, and a small part of hydrogen isotopes and an impurity component O in the deuterium-tritium mixed gas to be detected₂、N₂、CH₄CO flows into the helium ionization detector 14 through a ① valve port of a six-way valve G7 and a ② valve port of a six-way valve G7 to obtain an impurity component O₂、N₂、CH₄Chromatographic signal for CO;

the impurity components of CO₂、C₂H₆、O₂、N₂、CH₄And comparing the peak area of CO with a standard curve to obtain the concentration of each impurity component.

Specifically, the step (c) is as follows: the quantitative ring Q21 is collected and vacuumized by the negative pressure tank 19, namely, the negative pressure tank b19 collects and vacuums the residual carrier gas in the quantitative ring Q21 to the quantitative ring Q21 by the negative pressure tank 19 through the first valve port of the three-way valve D4, the second valve port of the three-way valve D4, the first valve port of the three-way valve E5 and the third valve port of the three-way valve E5.

After the collection is finished, the deuterium-tritium mixed gas to be detected is conveyed to a quantitative ring Q21 through the first valve port of the three-way valve E5 and the second valve port of the three-way valve E5;

the high-purity neon carrier gas is conveyed into the chromatographic column IV12 through a ③ valve port of a three-way valve D4, a ① valve port of a three-way valve D4, a ③ valve port of a three-way valve E5 and a ① valve port of a three-way valve E5, the deuterium-tritium mixed gas to be detected in the quantitative ring Q21 is conveyed into the chromatographic column IV12 through the ② valve port of a three-way valve F6 and the ① valve port of a three-way valve F6, the deuterium-tritium mixed gas to be detected flows out of the chromatographic column IV12, and impurity components He and H in₂HD, HT and component D₂、DT、T₂Separating, and delivering high-purity neon carrier gas to thermal conductivity detector 13 to obtain impurity components He and H₂HD, HT and component D₂、DT、T₂A chromatographic signal of (a);

he and H are mixed₂、HD、D₂The peak area of each component is compared with the standard curve to obtain He and H₂、HD、D₂The concentration of each component;

obtaining HT, DT and T by hydrogen isotope exchange equilibrium equation₂The concentration of each component;

according to the above H₂、HD、HT、D₂、DT、T₂The content of H isotope was determined from the concentrations of the respective components.

Therefore, the method for analyzing trace impurities in the deuterium-tritium mixed gas can be used for analyzing trace impurities in tritium and also can be used for quantitative analysis of D/T in the deuterium-tritium mixed gas.

The invention relates to a method for analyzing the content of trace impurities in deuterium-tritium mixed gas, wherein a chemical purity test channel takes helium as carrier gas, and O is completed through a specific valve-cutting combination, a specific column combination and a detector₂，N₂，CH₄，CO，CO₂，C₂H₆The analytical determination of (3); the isotope test channel uses neon gas as carrier gas, and uses specially-made metal capillary column and detector to implement H₂，HD，HT，D₂，DT，T₂Measuring; ne is used as carrier gas, so that on one hand, the detection sensitivity of the detector to hydrogen isotopes can be increased, and on the other hand, the qualitative and quantitative determination of He can be realized.

Further, the step (d) is specifically as follows: after the test is finished, the residual deuterium-tritium mixed gas in the sample tank 23 is absorbed by the recovery chemical bed 22. The residual carrier gas in the quantitative ring P20 and the quantitative ring Q21 is recycled into the negative pressure tank b19, and the pressure in the negative pressure tank b19 is not more than 10Pa after recycling. The tritium-containing carrier gas flowing out of the back pressure valve X15, the back pressure valve Y16 and the back pressure valve Z17 is recovered into the negative pressure tank a18, and the pressure in the negative pressure tank a18 after recovery is not more than 70 kPa.