A method for preparing a trace multi-component mixed gas

Abstract

The invention relates to the field of gas preparation and metering technology, and in particular to a method for preparing a trace multi-component mixed gas, which solves the technical problem in the prior art that there is a lack of a method for preparing a mixed gas that can reach a calibration level or a conventional level standard and can complete the addition of multiple components at one time. The method specifically comprises the following steps: determining the credibility of the trace multi-component gas, calculating the addition amount of each component, preparing a multi-component intermediate gas, mixing the multi-component intermediate gas, completing the preparation of the trace multi-component mixed gas at one time with the multi-component intermediate gas, mixing the finished product and analyzing and testing it, mixing the finally prepared trace multi-component mixed gas, and analyzing and testing it. The effect of the technical solution is that it provides a method for preparing a simple and reliable constant multi-component gas mixture, which has the advantages of low cost and rapid preparation.

Description

Technical Field

[0001] The invention relates to the technical field of gas preparation and metering, and in particular to a method for preparing a trace multi-component mixed gas. Background Art

[0002] Under the current trend, the continuous development of metrology engineering technology enables refined metrology to provide more accurate data information for production and life, thereby improving quality and efficiency, and providing a more reliable technical basis for reasonable management and cost savings;

[0003] In the current way, the requirements for the preparation of mixed gases are getting higher and higher. Some traditional preparation methods and devices can no longer meet the current industry status and demand level. The reason is that the traditional preparation process of trace multi-component mixed gases is to prepare the intermediate gases of each component in advance, and then add them one by one in sequence. The amount of individual components added may be very small, and no matter whether partial pressure or weighing is used, the preparation process is relatively long. During this period, the errors and uncertainties introduced due to various reasons are relatively large, resulting in relatively low quality of the final product and unsatisfactory success rate.

[0004] In addition, in the prior art, when research work related to gas is performed, it is often necessary to continuously prepare mixed gases of different proportions in large quantities. In these studies, there are many gas components involved, and the range of component proportions is very wide. If the standard gas manufacturer is relied on for supply, not only is the price very expensive, but it is also difficult to ensure the consistency and continuity of the gas preparation used in the test, thus affecting the reliability of the test results.

[0005] Therefore, the prior art lacks a mixed gas configuration process method that can reach calibration-level or conventional-level standards and can add multiple components at one time. Summary of the invention

[0006] The present invention aims to solve the technical problem in the prior art that there is a lack of a mixed gas preparation process method that can reach calibration level or conventional level standards and can add multiple components at one time, and provides a trace multi-component mixed gas preparation process method.

[0007] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0008] A method for preparing a trace multi-component mixed gas, comprising:

[0009] Step S1, a step of judging the credibility of trace multi-components;

[0010] By judging whether the components of the plurality of trace components are compatible with each other, it is judged whether the multi-component mixed gas can be prepared;

[0011] The identification is based on the physical and chemical properties of the plurality of trace components recorded in the database for identification and judgment;

[0012] Step S2, calculating the addition amount of each component;

[0013] When it is determined to be configurable, the dilution calculation formula of the relevant multi-component gas components is retrieved to determine the maximum addition amount of each trace component in the multi-component mixed gas;

[0014] Step S3, preparing a multi-component intermediate gas;

[0015] According to the calculated amount of trace components added, the component magnification is confirmed, and a bottle of intermediate gas containing the multi-component mixed gas is configured according to the amount of the magnification;

[0016] Step S4, mixing the multi-component intermediate gas;

[0017] The successfully mixed and prepared multi-component intermediate gas containing all trace components can be sampled and tested to ensure the uniformity of the configured intermediate gas;

[0018] Step S5, using the multi-component intermediate gas to complete the configuration of a trace amount of multi-component mixed gas at one time;

[0019] Verify and calculate the added amount again, complete the one-time addition of trace multi-components, and then add the required diluent gas to complete the final preparation of the multi-component mixed gas;

[0020] Step S6, the finished product is mixed and analyzed and tested, the final prepared trace multi-component mixed gas is mixed and analyzed and tested.

[0021] Specifically, the identification process of the judgment identification is:

[0022] The default is that the temperature and pressure conditions of the trace gas are the same;

[0023] The following contents are completed through the judgment and recognition system, including:

[0024] A component library module, which is used to record the names of gases;

[0025] A property library module, which associates the property library information of the gas when the component library module retrieves the name of the trace gas, and the property library information includes physical properties and chemical properties;

[0026] A component pre-generation module, which can receive the names of multiple gases configured by the component cry module;

[0027] A preset recording module is used to record a combination of names of associated gases that do not have a mixture of gas components;

[0028] The identification module distinguishes whether the gas combination of the current component pre-generation module has a condition that the configuration is not possible based on the preset recording module.

[0029] Specifically, the process of calculating the addition amount of each component includes configuring a precondition;

[0030] The configuration preconditions are: N2 gas under the same temperature and pressure conditions;

[0031] The concentration of the mixed gas is calculated as follows: the concentration of the i-th gas is:

[0032] Ci(%)=Vi / (V1+V2+Vn)×100%.

[0033] Specifically, the method of using the multi-component intermediate gas to complete the configuration of a trace amount of multi-component mixed gas at one time is:

[0034] The ratio of the mixed gas is changed by controlling the flow rate of the gas in the gas path, and the gas distribution accuracy is less than 2% molar concentration.

[0035] Specifically, the finished product is mixed and analyzed by chromatographic analysis;

[0036] The chromatographic column uses a plurality of stainless steel tubes, the working temperature of the chromatographic column is 40-65 degrees Celsius, and helium is used as the carrier gas with a flow rate of 25-40 ml·min-1.

[0037] Specifically, during the configuration of the trace multi-component mixed gas, the changes in temperature and air pressure are corrected using the empirical formula of the rotor flowmeter, and the pressure regulating valve and the needle valve are repeatedly adjusted to ensure that the pressure of each gas path is stable and consistent.

[0038] Specifically, the mixed flow rate of the intermediate gas is 1000-1500 ml·min-1.

[0039] Specifically, the mixed flow rate of the intermediate gas can be obtained by a soap film flowmeter under standard conditions or the same preset conditions to obtain the actual configured flow rate, and the specific formula is: v = 100 × 60 / t;

[0040] Wherein, t is the average time; 100 is the calibrated volume of the soap film flowmeter, and the calibrated volume is 100 ml.

[0041] The present invention has the following beneficial effects:

[0042] In the first aspect, a method for preparing a constant multi-component gas mixture is provided, which has the advantages of low cost and rapid configuration;

[0043] Secondly, there are five gas components in the experimental example of this scheme, and according to the application of the judgment process of this method, the configuration of more gases can actually be expanded. The control test of the experimental example shows that its gas brewing accuracy is close to the level of calibration-grade standard gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0045] Figure 1 A diagram showing the steps of the method of the present invention;

[0046] Figure 2 It is a comparison chart of the CO2 gas distribution theoretical value and the chromatographic measurement result of the present invention;

[0047] Figure 3 The comparison chart of the N2 gas distribution theoretical value and the chromatographic measurement result of the present invention is shown in FIG.

[0048] Figure 4 The comparison chart of the H2 gas distribution theoretical value and the chromatographic measurement result of the present invention is shown in FIG.

[0049] Figure 5 The technical indicators of the chromatographic column in the embodiment of the present invention;

[0050] Figure 6 This is a relationship diagram of the judgment and identification system of the present invention. DETAILED DESCRIPTION

[0051] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention; it should be noted that in this application, for the convenience of description, the "left side" in the current view is the "first end", the "right side" is the "second end", the "upper side" is the "first end", and the "lower side" is the "second end". The purpose of such description is to clearly express the technical solution, and it should not be understood as an improper limitation on the technical solution of this application.

[0052] The present invention aims to solve the technical problem in the prior art that there is a lack of a mixed gas preparation process method that can reach the calibration level or conventional level standard and can complete the addition of multiple components at one time, and provide the method for preparing a trace multi-component mixed gas; and the improvement idea of ​​the method is to realize the preparation of a constant multi-component gas mixture based on the basic principle of dynamic volumetric gas matching, and the main content is: the process of preparing a trace multi-component mixed gas in the traditional process, which requires the simultaneous preparation of multiple bottles of intermediate gas, is changed to the centralized preparation of only one bottle of intermediate gas containing all components after accurate calculation, and the process of adding components one by one is changed to the addition of all components at one time. The experimental examples provided in the technical solution can prepare five components of the mixed gas, and the volume concentration range of the prepared gas mixture is 0.1%-99%; the theoretical ratio of the mixed gas of different compositions and the analysis results of gas chromatography show that the gas matching accuracy of this method is between the calibration level and the conventional level indicators; the gases in the experimental examples are nitrogen, hydrogen, carbon monoxide, carbon dioxide and argon.

[0053] In a specific embodiment, please refer to Figure 1 As shown, a method for preparing a trace multi-component mixed gas comprises:

[0054] Step S1, a step of judging the credibility of trace multi-components;

[0055] By judging whether the components of the plurality of trace components are compatible with each other, it is judged whether the multi-component mixed gas can be prepared;

[0056] The identification is based on the physical and chemical properties of the plurality of trace components recorded in the database for identification and judgment;

[0057] Step S2, calculating the addition amount of each component;

[0058] When it is determined to be configurable, the dilution calculation formula of the relevant multi-component gas components is retrieved to determine the maximum addition amount of each trace component in the multi-component mixed gas;

[0059] Step S3, preparing a multi-component intermediate gas;

[0060] According to the calculated amount of trace components added, the component magnification is confirmed, and a bottle of intermediate gas containing the multi-component mixed gas is configured according to the amount of the magnification;

[0061] Step S4, mixing the multi-component intermediate gas;

[0062] The successfully mixed and prepared multi-component intermediate gas containing all trace components can be sampled and tested to ensure the uniformity of the configured intermediate gas;

[0063] Step S5, using the multi-component intermediate gas to complete the configuration of a trace amount of multi-component mixed gas at one time;

[0064] Verify and calculate the added amount again, complete the one-time addition of trace multi-components, and then add the required diluent gas to complete the final preparation of the multi-component mixed gas;

[0065] Step S6, the finished product is mixed and analyzed and tested, the final prepared trace multi-component mixed gas is mixed and analyzed and tested.

[0066] In a specific embodiment, see Figure 1 , 6 As shown, the identification process of the judgment identification is:

[0067] The default is that the temperature and pressure conditions of the trace gas are the same;

[0068] The identification system 100 completes the following contents by judging:

[0069] A component library module 10, which is used to record the name of the gas;

[0070] A property library module 20, which associates the property library information of the gas when the component library module 10 retrieves the name of the trace gas, and the property library information includes physical properties and chemical properties;

[0071] A component pre-generation module 30, which can receive the names of multiple gases configured by the component cry module 10;

[0072] A preset recording module 40 is used to record the combination of names of associated gases that do not have a gas component mixture;

[0073] The identification module 50 is used to distinguish whether the gas combination of the current component pre-generation module 30 has a condition that the configuration is not possible based on the preset recording module 40.

[0074] It should be noted that: for laboratories or small-scale configuration experiments, the steps of the above process can be completed manually, specifically by manually judging the possibility of the existence of a gas combination and manually judging the properties of the combination. Obviously, for conventional configurations, the content of this embodiment is intended to provide a preference for identifying more possibilities.

[0075] In a specific embodiment, see Figure 1 , 6 As shown, the process of calculating the addition amount of each component includes a configuration precondition;

[0076] The configuration preconditions are: N2 gas under the same temperature and pressure conditions;

[0077] The concentration of the mixed gas is calculated as follows: the concentration of the i-th gas is:

[0078] Ci(%)=Vi / (V1+V2+Vn)×100%.

[0079] In a specific embodiment, see Figure 1 , 6 As shown, the method of using the multi-component intermediate gas to complete the configuration of the trace multi-component mixed gas at one time is:

[0080] The ratio of the mixed gas is changed by controlling the flow rate of the gas in the gas path, and the gas distribution accuracy is less than 2% molar concentration.

[0081] In a specific embodiment, see Figure 1 , 6 As shown, the finished product is mixed and analyzed by chromatography during the detection process;

[0082] The chromatographic column uses a plurality of stainless steel tubes, and the operating temperature of the chromatographic column is 40-65 degrees Celsius.

[0083] Helium was used as carrier gas with a flow rate of 25-40 ml·min-1.

[0084] In a specific embodiment, see Figure 1 , 6 As shown, during the configuration of the trace multi-component mixed gas, the changes in temperature and air pressure are corrected using the empirical formula of the rotor flowmeter, and the pressure regulating valve and the needle valve are repeatedly adjusted to ensure that the pressure of each gas path is stable and consistent.

[0085] In a specific embodiment, see Figure 1 , 6 As shown, the mixed flow rate of the intermediate gas is 1000-1500 ml·min-1.

[0086] In a specific embodiment, see Figure 1 , 6 As shown, the mixed flow rate of the intermediate gas can be obtained by a soap film flowmeter under standard conditions or the same preset conditions to obtain the actual configuration flow rate, and the specific formula is: v = 100 × 60 / t;

[0087] Wherein, t is the average time; 100 is the calibrated volume of the soap film flowmeter, and the calibrated volume is 100 ml.

[0088] The advantages of this technical solution are:

[0089] In the first aspect, a method for preparing a constant multi-component gas mixture is provided, which has the advantages of low cost and rapid configuration;

[0090] Secondly, there are five gas components in the experimental example of this scheme, and according to the application of the judgment process of this method, the configuration of more gases can actually be expanded. The control test of the experimental example shows that its gas brewing accuracy is close to the level of calibration-grade standard gas.

[0091] It should be noted that the gas distribution error is mainly reflected in the stability of the air flow velocity, the accuracy of the flow velocity measurement and the consistency of the conditions of each gas path, which determine the gas distribution effect;

[0092] Thirdly, in research work such as solving interference problems in simultaneous analysis of multi-component gases, studying the interaction laws between gases, examining the advantages and disadvantages of polluted gas treatment methods, or testing the performance of gas catalysts or conducting process simulation tests, the use of this method to continuously prepare constant multi-component gas mixtures is the most preferred application method, which has the advantages of high efficiency and speed.

[0093] In addition, for the theoretical results of gas matching, this method can also be used in the laboratory to prepare standard mixed gases for calibration instruments.

[0094] Please see attached Figure 2 , 3 As shown in Figure 4, the parallelism and accuracy of the content determination results are slightly poor because the analytical conditions at this time are not optimal for the quantitative determination of nitrogen. The situation of the other components is similar to that of hydrogen. The repeatability of the data in the experiment is not affected by the change in the number of mixed gas components; this shows that the gas mixture is homogeneous and the performance of the gas distributor is stable.

[0095] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing a trace multi-component mixed gas, characterized in that: include: Step S1, a step of judging the credibility of trace multi-components; Determining whether the multi-component mixed gas can be prepared by determining whether each component of the plurality of trace components is compatible with each other; The identification is based on the physical and chemical properties of the plurality of trace components recorded in the database for identification and judgment; Step S2, calculating the addition amount of each trace component; When it is determined to be configurable, the dilution calculation formula of the relevant multiple gas components is retrieved to determine the maximum addition amount of each trace component in the group of multi-component mixed gas; Step S3, preparing a multi-component intermediate gas; According to the calculated maximum addition amount of the trace component, the component magnification factor is confirmed, and based on the amount of the magnification factor, a bottle of intermediate gas containing the multi-component mixed gas is prepared; Step S4, mixing the multi-component intermediate gas; Mix and prepare the successfully prepared multi-component intermediate gas containing all trace components, and conduct sampling inspection to ensure the uniformity of the prepared intermediate gas; Step S5, using the multi-component intermediate gas to complete the configuration of a trace amount of multi-component mixed gas at one time; Verify and calculate the added amount again, complete the one-time addition of trace multi-components, and then add the required diluent gas to complete the final preparation of the multi-component mixed gas; Step S6, mixing the finished product and analyzing and testing, mixing the final prepared trace multi-component mixed gas, and analyzing and testing; The identification process of the judgment identification is: The default is that the temperature and pressure conditions of the trace gas are the same; The following contents are completed by the judgment and recognition system (100), specifically including: A component library module (10), which is used to record the name of the gas; A property library module (20) which associates the property library information of the gas when the component library module (10) retrieves the name of the trace gas, wherein the property library information includes physical properties and chemical properties; A component pre-generation module (30) capable of receiving the names of a plurality of gases configured by the component cry module (10); A preset recording module (40) is used to record a combination of names of associated gases that do not have a gas component mixture; an identification module (50) for distinguishing whether the gas combination of the current component pre-generation module (30) has a condition that does not meet the configuration possibility according to the preset recording module (40); The process of calculating the addition amount of each component includes configuring a precondition; The configuration preconditions are: n gases under the same temperature and pressure conditions; The concentration of the mixed gas is calculated as follows: the concentration of the i-th gas is: Ci(%)=Vi / (V1+V2+…+Vn)×100%; The method of using the multi-component intermediate gas to complete the configuration of the trace multi-component mixed gas at one time is: The ratio of the mixed gas is changed by controlling the flow rate of the gas in the gas path, and the gas distribution accuracy is less than 2% molar concentration; The mixed flow rate of the intermediate gas is 1000-1500 ml·min -1 .

2. The method for preparing a trace multi-component mixed gas according to claim 1, characterized in that: The finished product is mixed and analyzed by chromatographic analysis; The chromatographic column uses multiple stainless steel tubes, the working temperature of the chromatographic column is 40-65 degrees Celsius, and helium is used as the carrier gas with a flow rate of 25-40ml·min -1 .

3. The method for preparing a trace multi-component mixed gas according to claim 2, characterized in that: During the configuration of the trace multi-component mixed gas, the changes in temperature and air pressure are corrected using the empirical formula of the rotor flowmeter, and the pressure regulating valve and the needle valve are repeatedly adjusted to ensure that the pressure of each gas path is stable and consistent.

4. The method for preparing a micro-amount of multi-component mixed gas according to claim 3, wherein the mixed flow rate of the intermediate gas is measured by a soap film flowmeter to obtain the actual configured flow rate under standard conditions or the same preset conditions, and the specific formula is: v = 100 × 60 / t; in, t is the average time; 100 is the calibrated volume of the soap film flowmeter, and the calibrated volume is 100 ml.

Images