An on-line monitoring and hierarchical storage method for hydrogen isotope abundance

Abstract

The present invention belongs to the technical field of hydrogen isotope abundance monitoring, and particularly relates to an on-line monitoring and hierarchical storage method for hydrogen isotope abundance, which is used for monitoring the abundance of hydrogen isotope products in the hydrogen isotope separation process and storing the hydrogen isotope products, and includes the following steps: Step S1, obtaining first thermal conductivity correlation data by using a thermal conductivity detector; Step S2, obtaining second thermal conductivity correlation data through the first thermal conductivity correlation data and influencing factors; Step S3, obtaining a standard thermal conductivity change rate according to the second thermal conductivity correlation data; Step S4, determining the abundance situation of the hydrogen isotope product according to the second thermal conductivity correlation data; determining the time point at which the abundance of the hydrogen isotope product generates a hierarchical change according to the standard thermal conductivity change rate; Step S5, performing hierarchical storage on the hydrogen isotope products.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen isotope abundance monitoring, and particularly relates to an on-line monitoring and hierarchical storage method for hydrogen isotope abundance. Background Art

[0002] Hydrogen has three isotopes: protium, deuterium, and tritium, and deuterium and tritium are fuels for fusion reactors. As a stable isotope of hydrogen, deuterium also has wide applications in scientific research, medical treatment, industry, etc. Therefore, the separation of hydrogen isotopes is of great significance. At present, the on-line analysis technology of hydrogen isotopes by thermal conductivity detection (TCD) has been studied and applied in related separation fields. When TCD analyzes a hydrogen isotope mixture, it gives a mixed peak of all components. When the number of components is greater than 2, the concentration values of each component cannot be obtained by calculation from the mixed peak shape. Therefore, it is still very difficult to obtain very accurate hydrogen isotope composition information instantaneously by on-line analysis using TCD at the present stage. For the hydrogen isotope separation process, due to the on-line sub-packaging of products with different abundances, the demand for instant judgment of the hydrogen isotope abundance range of process products is particularly strong. At present, the related separation mass production process lacks an on-line judgment of product abundance and a chain hierarchical storage mechanism for process automation. Summary of the Invention

[0003] Aiming at the on-line grading requirement for the isotope abundance of products in the hydrogen isotope separation process, the purpose of the present invention is to provide a method that can determine the hydrogen isotope abundance range according to the calculation result of on-line thermal conductivity monitoring, divide the product grades according to the hydrogen isotope abundance range, and chain the pipeline switching equipment to automatically regulate the product flow direction according to the grading result to achieve hierarchical storage.

[0004] To achieve the above object, the technical solution adopted by the present invention is an on-line monitoring and hierarchical storage method for hydrogen isotope abundance, which is used to monitor the abundance of hydrogen isotope products in the hydrogen isotope separation process and store the hydrogen isotope products, and includes the following steps:

[0005] Step S1, obtaining first thermal conductivity correlation data by using a thermal conductivity detector;

[0006] Step S2, obtaining second thermal conductivity correlation data through the first thermal conductivity correlation data and influence factors;

[0007] Step S3, obtaining a standard thermal conductivity change rate according to the second thermal conductivity correlation data;

[0008] Step S4, determining the abundance situation of the hydrogen isotope product according to the second thermal conductivity correlation data; determining the time point of grade change of the hydrogen isotope product according to the standard thermal conductivity change rate;

[0009] Step S5, performing hierarchical storage on the hydrogen isotope products.

[0010] Further, before the step S1, the influence factors are determined. The influence factors refer to the influence factors of the pressure, flow rate, and temperature of a hydrogen isotope gas with a certain composition on the indication value of the thermal conductivity detector. The influence factors are obtained by exploring the influence law of the indication value of the thermal conductivity detector by the pressure, flow rate, and temperature of the hydrogen isotope gas with a certain composition within the accessible pressure, flow rate, and temperature range of the hydrogen isotope separation process; the hydrogen isotope gas with a certain composition refers to a specific product gas with a representative composition within the possible composition range of the hydrogen isotope product, and is freely determined according to the actual product composition range.

[0011] Further, in the step S1, the first thermal conductivity correlation data refers to the indication value of the thermal conductivity detector.

[0012] Further, in the step S2, the second thermal conductivity correlation data is to instantaneously calculate the corrected standard thermal conductivity correlation data according to the first thermal conductivity correlation data and by integrating the influence factors.

[0013] Further, in the step S4, the time point of the grade change refers to the moment when the abundance of the hydrogen isotope product reaches a significant change that can distinguish grades.

[0014] Further, in the step S5, the classified storage means that according to the abundance grade of the hydrogen isotope product fed back by the abundance of the hydrogen isotope product and the time point of the grade change, the control valve on the path leading to the storage tank corresponding to the product of the corresponding abundance grade is automatically controlled, so that the hydrogen isotope product of the corresponding abundance grade flows into the corresponding storage tank for temporary storage.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. By using the first thermal conductivity correlation data and integrating the influence factors (the pressure, flow rate, and temperature factors of the detection object, where the detection object refers to a hydrogen isotope gas with a certain composition), the more real hydrogen isotope abundance situation can be calculated and fed back from the indication value of the TCD detector, and to a certain extent, the influence of the pressure, flow rate, and temperature of the detection object on the detection result of the TCD detector is eliminated.

[0017] 2. The basic abundance situation of the hydrogen isotope product is determined according to the second thermal conductivity correlation data; the moment when the abundance of the hydrogen isotope product has a significant change is determined according to the standard thermal conductivity change rate. The product grades are automatically divided according to the abundance interval, and the pipeline switch equipment is interlocked, and the product flow direction is regulated according to the classification result, realizing the automatic classified storage of the hydrogen isotope product.

[0018] 3. The pipeline design reserves the analysis and feedback time, and the classified control is more accurate.

[0019] 4. Based on flow rate and pressure feedback, provide an automatic protection function for the temperature-sensing element of the TCD detector. Description of the Drawings

[0020] Figure 1 is a flowchart of a method for on-line monitoring and hierarchical storage of hydrogen isotope abundance described in the specific embodiments of the present invention; Specific Embodiments

[0021] The present invention will be further described below in conjunction with the drawings and embodiments.

[0022] A method for on-line monitoring and hierarchical storage of hydrogen isotope abundance provided by the present invention is used to monitor the abundance of hydrogen isotope products (referred to as "products" for short) in the hydrogen isotope separation process and store the hydrogen isotope products, including two processes:

[0023] The first process is to determine the influencing factors

[0024] The influencing factors refer to the influencing factors of the pressure, flow rate and temperature of the hydrogen isotope product on the indication value of the thermal conductivity detector. The influencing factors are obtained by exploring the influence law of the indication value of the thermal conductivity detector by the pressure, flow rate and temperature of a certain composition of hydrogen isotope gas within the accessible pressure, flow rate and temperature range of the hydrogen isotope separation process; the process of determining the influencing factors is to clarify and quantify the influence of pressure, flow rate and temperature on the detector indication value, so as to take this influence into account in actual measurement; generally, for a specific application scenario, the process of determining the influencing factors is only done once, and the obtained influencing factors can be directly applied in subsequent actual measurements. A certain composition of hydrogen isotope gas refers to a specific product gas with a representative composition within the possible composition range of the hydrogen isotope product, which is freely determined according to the actual product composition range.

[0025] Use a thermal conductivity detector with sufficient resolution (i.e., TCD detector) as the basic means for hydrogen isotope abundance monitoring to monitor the hydrogen isotope products involved in the separation process;

[0026] Thermal conductivity detection is based on the difference in thermal conductivity of different gases. When flowing through the detection cell, it will cause the resistance value of the temperature-sensitive thermal element to change, and the quantity is determined based on the generated electrical signal. Since the difference in thermal conductivity of hydrogen isotope gases is small, the thermal conductivity cell, gas path system, temperature control system and signal processing system of the conventional thermal conductivity detector can be appropriately optimized to increase the measurement signal difference between hydrogen isotopes and generate sufficient resolution;

[0027] Explore the influence rules of the indication value of the TCD detector on the pressure, flow rate, and temperature of the detection object, and obtain the influence factors of the pressure, flow rate, and temperature of the hydrogen isotope gas with a certain composition on the indication value of the thermal conductivity detector; the influence factors are obtained by exploring the influence rules of the indication value of the thermal conductivity detector on the pressure, flow rate, and temperature of the hydrogen isotope gas with a certain composition involved in the hydrogen isotope separation process within the accessible pressure, flow rate, and temperature ranges of the hydrogen isotope separation process.

[0028] Since the pressure, flow rate, and temperature of the detected hydrogen isotope product will have a relatively significant impact on the indication value of the TCD detector, although the relevant process conditions in actual production are relatively stable, it is still necessary to consider the changes in the indication value of the TCD detector caused by possible changes in the above factors. For example, the influence rules of the above factors on the indication value of the TCD detector can be added to the data analysis method of the detection results by using the method of fitting relevant variables.

[0029] For the mass production process of hydrogen isotope separation, if the quality of the two-end products, that is, the single-isotope pure gas, is mainly concerned, the influence of the aforementioned pressure, flow rate, and temperature variables on the indication value of the TCD detector can be explored by using only the single-isotope pure gas as the experimental test object to obtain the influence rules of the indication value of the TCD detector on the pressure, flow rate, and temperature of the detection object within the accessible pressure, flow rate, and temperature ranges of the process. Taking the separation of hydrogen and deuterium and high-purity deuterium gas as the main products of the process as an example, high-purity deuterium gas and high-purity hydrogen gas are respectively selected as the research objects, and the single-variable experimental method is used. Within the possible pressure, flow rate, and temperature ranges of the system products, the pressure, flow rate, and temperature experimental points are selected for on-line thermal conductivity monitoring under stable conditions. According to the test results, the change dependence relationships between the indication value of the TCD detector and the pressure, flow rate, and temperature of deuterium gas and hydrogen gas are obtained respectively. This dependence relationship can be obtained through appropriate data fitting methods based on the experimental data. Further, on the premise that the experimental analysis and calculation processing conditions permit, the change dependence relationship between the indication value of the TCD detector and the fluid pressure, flow rate, and temperature can also be analyzed and correlated synchronously.

[0030] The second process is to monitor the abundance of the hydrogen isotope product and make a grading judgment and storage based on it, including the following steps:

[0031] Step S1: Obtain the first thermal conductivity correlation data by using a thermal conductivity detector. The first thermal conductivity correlation data refers to the thermal conductivity correlation data (on-line thermal conductivity correlation data) of the hydrogen isotope product displayed by on-line monitoring the thermal conductivity detector, that is, the indication value of the thermal conductivity detector.

[0032] For the large-scale production of hydrogen isotope separation, the process parameters have been relatively fixed. Therefore, during normal separation production, the outflow conditions of the products are also relatively stable. At this time, the thermal conductivity monitoring data (i.e., the thermal conductivity correlation data) shown by the hydrogen isotope products with a certain composition should also be in a relatively stable state. Therefore, under relatively ideal production conditions, the qualitative judgment of the composition change of the hydrogen isotope products can be directly based on the thermal conductivity correlation data (the first thermal conductivity correlation data) of the hydrogen isotope products.

[0033] Step S2, obtain the second thermal conductivity correlation data through the first thermal conductivity correlation data and the influencing factors. The second thermal conductivity correlation data is the standard thermal conductivity correlation data corrected by condition parameters calculated immediately by integrating the influencing factors based on the first thermal conductivity correlation data; (that is, based on the online thermal conductivity correlation data, integrating the pressure, flow rate, and temperature factors, and calculating and obtaining the standard thermal conductivity correlation data immediately)

[0034] The second thermal conductivity correlation data refers to the thermal conductivity correlation data under standard conditions, that is, the TCD detector indication data under a certain pressure, flow rate, and temperature. The standard conditions can be specified according to the system requirements.

[0035] During actual production, the output conditions cannot be completely stable. At this time, the change in the apparent thermal conductivity correlation data (the first thermal conductivity correlation data) cannot reflect the true abundance change of the hydrogen isotope products because the pressure, flow rate, and temperature of the detected hydrogen isotope gas (i.e., the isotope products) will have a relatively significant impact on the detection signal of the TCD detector. Therefore, it is necessary to integrate the influence rules of pressure, flow rate, and temperature on the thermal conductivity correlation data into the detection data analysis method. Based on the online thermal conductivity correlation data (the first thermal conductivity correlation data) as the basic data, calculate the second thermal conductivity correlation data corrected by condition parameters as the true parameter representation of the abundance composition change of the hydrogen isotope products.

[0036] For the large-scale production process of hydrogen isotope separation, if the quality of the two-end products, that is, the high-purity single hydrogen isotope gas, is mainly concerned, the influence of the aforementioned pressure, flow rate, and temperature variables on the TCD detector indication can be explored only with the high-purity single hydrogen isotope gas as the experimental test object within the pressure, flow rate, and temperature ranges accessible to the process.

[0037] Step S3, calculate the feedback standard thermal conductivity change rate according to the immediate second thermal conductivity correlation data (i.e., the standard thermal conductivity correlation data) calculated in Step S2;

[0038] Step S4, determine the (basic) abundance situation of the hydrogen isotope products according to the second thermal conductivity correlation data; determine the time point (moment) of the hierarchical change in the abundance of the hydrogen isotope products according to the standard thermal conductivity change rate; the time point of the hierarchical change refers to the moment when the abundance of the hydrogen isotope products reaches a significant change that can distinguish the levels;

[0039] According to the second thermal conductivity correlation data of the product, calculate the change rate of the standard thermal conductivity correlation data in real time. The relevant calculation method correlates the influence rules of the aforementioned pressure, flow rate, and temperature changes on the indication value of the TCD detector. Based on the obtained change result of the standard thermal conductivity correlation rate, determine the moment when the abundance of the hydrogen isotope product changes significantly, and automatically control the control valve on the path to the storage tank corresponding to the product of the corresponding grade, so that the product of the corresponding grade flows into the corresponding storage tank for temporary storage.

[0040] The feasibility of this part of the operation is based on the established correlation between the second thermal conductivity correlation data obtained in the early stage and the basic abundance of the hydrogen isotope product. At the same time, according to the aforementioned correlation, obtain the second thermal conductivity correlation data information corresponding to the fractional abundances of different grades of products. In addition, since the second thermal conductivity correlation data includes the fitting relationship for system pressure, flow rate, and temperature, it is to a certain extent empirical calculation data, so there may still be a certain degree of deviation from the actual abundance change of the product. Therefore, it is necessary to establish appropriate determination conditions for the moment of change in the abundance of products of different grades. When the standard thermal conductivity change rate meets the condition limit, it can be determined that the product abundance has crossed the fractional change, and it is necessary to change the grade of the discharge storage tank.

[0041] Step S5: According to the product abundance grade determined in step S4 and the moment of significant abundance change, store the hydrogen isotope products in different grades. Storing in different grades means automatically controlling the control valve on the path to the storage tank corresponding to the product of the corresponding abundance grade according to the abundance grade of the hydrogen isotope product reflected by the abundance of the hydrogen isotope product and the time point of grade change (the moment of change in hydrogen isotope abundance) reflected by the (standard thermal conductivity change rate), so that the hydrogen isotope product of the corresponding abundance grade flows into the corresponding storage tank for temporary storage.

[0042] According to the correlation between the aforementioned second thermal conductivity correlation data and the basic abundance of the hydrogen isotope product, obtain the second thermal conductivity correlation data information corresponding to the fractional abundances of different grades of products, and based on this, make a timely abundance grade judgment. When it is detected that the standard thermal conductivity change rate has met the relevant determination conditions, it is determined that the product abundance has crossed the fractional change, and it is necessary to change the grade of the discharge storage tank. Immediately and automatically control the control valve on the path to the storage tank corresponding to the product of the corresponding grade, so that the product of the corresponding grade flows into the corresponding storage tank for temporary storage.

[0043] Considering the time consumed for analysis and calculation, according to the product discharge flow rate, analysis feedback time, and pipeline diameter, reserve a sufficient length of pipeline from the rear end of the TCD detector to before the product fractional storage tank to fully consider the lag degree of the analysis result, ensure that when obtaining the fractional operation logic instruction, the real product corresponding to the analysis result has not yet obtained a clear fractional flow direction, and ensure that the high-grade product storage tank will not be diluted by low-grade products due to the delay of the analysis result.

[0044] To effectively protect the thermosensitive resistance element of the TCD detector, pressure monitoring devices are respectively arranged at the front and rear ends of the detection cell of the measurement wall and the reference wall of the TCD detector. Combining with the front-end flow data, the gas states in the two walls are comprehensively judged, and the results are correlated with the detector bridge current. When the monitored pressures at the front and rear ends and the front-end flow are all within the normal range, it indicates that the thermosensitive element is in a protected state, and the bridge current can be applied according to the detection requirements; when there is flow at the front end, but the monitored pressures at the front and rear ends are abnormal, such as both the front and rear ends are relatively low or even have no pressure, it indicates that the system may be in passive evacuation, and it is necessary to ensure that the thermosensitive element is in a currentless state to prevent the thermosensitive resistance element from being oxidized or even burned by high temperature.

[0045] The device described in the present invention is not limited to the embodiments described in the specific implementation manners. Those skilled in the art can obtain other implementation manners according to the technical solution of the present invention, which also belong to the scope of the technical innovation of the present invention.

Claims

1. An on-line monitoring and hierarchical storage method for hydrogen isotope abundance, which is used to monitor the abundance of hydrogen isotope products in the hydrogen isotope separation process and store the hydrogen isotope products, includes the following steps: Step S1, obtaining first thermal conductivity correlation data by using a thermal conductivity detector; Step S2, obtaining second thermal conductivity correlation data through the first thermal conductivity correlation data and influence factors; Step S3, obtaining a standard thermal conductivity change rate according to the second thermal conductivity correlation data; Step S4, determining the abundance situation of the hydrogen isotope product according to the second thermal conductivity correlation data; determining the time point of the grade change of the abundance of the hydrogen isotope product according to the standard thermal conductivity change rate; Step S5, hierarchically storing the hydrogen isotope product.

2. An on-line monitoring and hierarchical storage method for hydrogen isotope abundance according to claim 1, characterized in that: before said step S1, the influence factors are determined, and the influence factors refer to the influence factors of the pressure, flow rate and temperature of a hydrogen isotope gas with a certain composition on the indication value of the thermal conductivity detector, and the influence factors are obtained by exploring the influence law of the indication value of the thermal conductivity detector by the pressure, flow rate and temperature of the hydrogen isotope gas with a certain composition within the accessible pressure, flow rate and temperature range of the hydrogen isotope separation process; the hydrogen isotope gas with a certain composition refers to a specific product gas with a representative composition within the possible composition range of the hydrogen isotope product, and is freely determined according to the actual product composition range.

3. An on-line monitoring and hierarchical storage method for hydrogen isotope abundance according to claim 1, characterized in that: in said step S1, the first thermal conductivity correlation data refers to the indication value of the thermal conductivity detector.

4. An on-line monitoring and hierarchical storage method for hydrogen isotope abundance according to claim 1, characterized in that: in said step S2, the second thermal conductivity correlation data is the standard thermal conductivity correlation data calculated and corrected immediately by integrating the influence factors according to the first thermal conductivity correlation data.

5. An on-line monitoring and hierarchical storage method for hydrogen isotope abundance according to claim 1, characterized in that: in said step S4, the time point of the grade change refers to the moment when the abundance of the hydrogen isotope product reaches a significant change that can distinguish grades.

6. An on-line monitoring and hierarchical storage method for hydrogen isotope abundance according to claim 1, characterized in that: in said step S5, the hierarchical storage means automatically controlling the control valve on the path leading to the storage tank for products of the corresponding abundance grade according to the abundance grade of the hydrogen isotope product reflected by the abundance of the hydrogen isotope product and the time point of the grade change, so that the hydrogen isotope product of the corresponding abundance grade flows into the corresponding storage tank for temporary storage.

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