A multi-channel natural gas analyzer

Abstract

The invention discloses a multi-channel natural gas analyzer, which relates to the field of natural gas processing technology. In order to solve the problem that the overall quality of natural gas cannot be fully reflected, especially for some low-concentration or difficult-to-detect components, as the number of detected components increases, the complexity and maintenance difficulty increase, resulting in a decrease in system reliability and an increase in maintenance costs; a multi-channel natural gas analyzer includes an analysis channel, a valve group, a chromatographic column and a detector; through three independent and collaborative analysis channels, different component groups in natural gas are efficiently analyzed respectively, ensuring the accuracy and reliability of the analysis results, reducing mutual interference between different components, each channel is equipped with a specific valve group, chromatographic column combination and detector to ensure the accuracy and sensitivity of the analysis, the capture technology of the second and third channels, and efficient capture and release of specific components are achieved, enhancing the flexibility of the multi-channel natural gas analyzer.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas processing, and in particular to a multi-channel natural gas analyzer. Background Art

[0002] In the field of natural gas processing, energy analysis and environmental monitoring, accurate analysis of natural gas components is crucial. Existing natural gas analyzers often focus on the detection of a single or a few components, which is difficult to meet the needs of comprehensive analysis of complex natural gas components. For example, the Chinese patent with publication number: CN113189952B discloses a natural gas purification plant product natural gas quality control interlock system and control method, including a controller, a product natural gas output shut-off valve, and a vent shut-off valve. It also includes: a water dew point online analyzer for detecting the water dew point value of natural gas, which is transmitted to a water dew point comparator; a carbon dioxide online analyzer for detecting carbon dioxide in natural gas, which is transmitted to a carbon dioxide comparator; a calorific value online analyzer for detecting the calorific value of natural gas, which is transmitted to a calorific value comparator; a hydrogen sulfide online analyzer for detecting hydrogen sulfide in natural gas, which is transmitted to a hydrogen sulfide comparator; a total sulfur online analyzer for detecting total sulfur in natural gas, which is sent to a total sulfur comparator; the comparator compares the instantaneous value with the set value, and the controller interlocks and controls the product natural gas output shut-off valve and the vent shut-off valve.

[0003] Although the above patent can prevent the export of unqualified natural gas and ensure the safe operation of the device, it cannot fully reflect the overall quality of natural gas, especially for some low-concentration or difficult-to-detect components. As the number of detected components increases, the complexity of the system and the difficulty of maintenance will also increase accordingly, resulting in a decrease in system reliability and an increase in maintenance costs. Summary of the invention

[0004] The object of the present invention is to provide a multi-channel natural gas analyzer, which can efficiently analyze different component groups in natural gas through three independent and collaborative analysis channels. Each channel is equipped with a specific valve group, chromatographic column combination and detector to ensure the accuracy and sensitivity of the analysis, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A multi-channel natural gas analyzer comprises an analysis channel, a valve group, a chromatographic column and a detector, wherein three analysis channels are provided, including a first channel, a second channel and a third channel, and each of the analysis channels is independent of each other; three valve groups are provided, each valve group corresponds to and controls a gas flow path of the analysis channel; six chromatographic columns are provided, which are evenly distributed in each of the analysis channels; three detectors are provided, which are respectively installed at the end of each of the analysis channels; the valve group, the chromatographic column and the detector exchange data with a control system.

[0007] Furthermore, the chromatographic columns are arranged in three groups, including: a chromatographic column group for analyzing C3-C6 components, a chromatographic column group for analyzing CO 2 and ethane, and one chromatographic column group for analyzing oxygen, nitrogen and methane; the analysis channel is used to analyze different components in natural gas, wherein the first channel is equipped with a chromatographic column group for analyzing C3-C6 components, and the second channel is equipped with two chromatographic columns for analyzing CO 2 and ethane, and the third channel is configured with a chromatographic column group for analyzing oxygen, nitrogen and methane; the valve group is set as a ten-way valve.

[0008] Furthermore, the analysis channel is connected to a gas supply system for providing the same carrier gas source to each of the analysis channels; wherein the gas supply system comprises:

[0009] A carrier gas source, used for providing high-purity carrier gas;

[0010] A pressure reducing valve, located after the carrier gas source, is used to adjust the carrier gas from a high pressure state to a pressure range suitable for the operation of the chromatographic analyzer;

[0011] The pressure stabilizing valve is located after the pressure reducing valve and is used to stabilize the pressure of the carrier gas;

[0012] A gas distributor is used to evenly distribute the carrier gas that has been decompressed and stabilized to each analysis channel;

[0013] A gas supply pipeline, used to connect the gas distributor with each analysis channel;

[0014] The gas purification device is used to purify the carrier gas and remove impurities and moisture in the gas, wherein the gas purification device is arranged between the carrier gas source and the pressure reducing valve and in front of the entrance of each analysis channel.

[0015] Furthermore, the control system is used to coordinate and control the actions of each valve group, adjust the temperature of each chromatographic column, collect the detector signal in real time and perform analysis and processing; wherein the detector is used to detect the gas components in each analysis channel after separation by the chromatographic column group.

[0016] Furthermore, the control system comprises:

[0017] The temperature control module is used to build an interactive channel with each chromatographic column, control the heating and cooling operations of each chromatographic column, adjust the temperature range of each chromatographic column according to the preset temperature parameters, and formulate the carrier gas flow rate control strategy;

[0018] A signal acquisition module is used to collect the output signal of each detector and transmit the pre-processed output signal to the chromatographic analysis module for analysis and processing;

[0019] The chromatographic analysis module is used to receive the pre-processed output signal transmitted by the signal acquisition module, and perform chromatogram drawing, peak identification, peak area calculation, quantitative analysis and component identification;

[0020] The user interaction module is used to provide a display interface, and the display interface generates and displays a report on the content of each component.

[0021] Further, the temperature range of each chromatographic column is adjusted according to the preset temperature parameters, including:

[0022] During the heating and cooling process of each chromatographic column, the temperature real-time data of the chromatographic column is monitored in real time;

[0023] Compare the real-time temperature data with a preset target temperature value to obtain a temperature difference between the real-time temperature data and the preset target temperature value;

[0024] Comparing the temperature difference with a preset difference threshold;

[0025] When the temperature difference exceeds a preset difference threshold, the temperature real-time data of the chromatographic column is controlled in real time according to the preset initial temperature adjustment gradient;

[0026] When the temperature real-time data of the chromatographic column is controlled in real time according to the initial temperature adjustment gradient, corresponding adjusted temperature data corresponding to each temperature adjustment performed according to the initial temperature adjustment gradient is obtained in real time;

[0027] Retrieving a theoretical temperature value corresponding to the adjusted temperature data corresponding to the temperature adjustment, and obtaining a deviation value between the adjusted temperature data corresponding to the temperature adjustment and the theoretical temperature value;

[0028] The temperature adjustment coefficient is obtained by using the deviation value between the adjusted temperature data corresponding to the temperature adjustment and its theoretical temperature value; wherein the temperature adjustment coefficient is obtained by the following formula:

[0029]

[0030] Among them, K Trepresents the temperature adjustment coefficient; ΔT represents the initial temperature adjustment gradient; R represents the heat capacity of the chromatographic column; D represents the thermal conductivity of the chromatographic column; n represents the number of temperature adjustments experienced by the temperature adjustment unit with the initial temperature adjustment gradient as the temperature adjustment unit; t represents the adjustment time of the current temperature adjustment; T ci represents the actual temperature corresponding to the i-th temperature adjustment; T thi represents the theoretical temperature value corresponding to the i-th temperature adjustment; T tar Indicates the target temperature corresponding to the current temperature control; ε indicates the minimum constant, which is used to prevent the denominator from being 0; γ i represents the adjustment sensitivity coefficient corresponding to the i-th temperature adjustment;

[0031] When the temperature difference is not lower than a preset difference threshold, the initial temperature adjustment gradient is adjusted to obtain an adjusted temperature adjustment gradient;

[0032] According to the adjusted temperature, the gradient control is used to control the temperature real-time data of the chromatographic column in real time so that it reaches the preset target temperature value.

[0033] Further, when the temperature difference is not lower than a preset difference threshold, the initial temperature adjustment gradient is adjusted to obtain an adjusted temperature adjustment gradient, including:

[0034] When the temperature difference is not lower than a preset difference threshold, calling the temperature adjustment coefficient;

[0035] Retrieve the corresponding system execution response time when temperature adjustment is performed according to the initial temperature adjustment gradient and the temperature acquisition response time of the temperature sensor used for temperature detection;

[0036] The initial temperature adjustment gradient is adjusted by using the temperature adjustment coefficient in combination with the corresponding system execution response time when the temperature adjustment is performed according to the initial temperature adjustment gradient and the temperature acquisition response time of the temperature sensor used for temperature detection to obtain an adjusted temperature adjustment gradient;

[0037] The adjusted temperature gradient is obtained by the following formula:

[0038]

[0039] Where, ΔT k represents the adjusted temperature adjustment gradient; ΔT represents the initial temperature adjustment gradient; n represents the number of temperature adjustments experienced by taking the initial temperature adjustment gradient as the temperature adjustment unit; K T represents the temperature regulation coefficient; γ i represents the adjustment sensitivity coefficient corresponding to the i-th temperature adjustment; t sysi represents the system execution response time corresponding to the i-th temperature adjustment; tseni Indicates the temperature acquisition response time of the temperature sensor used for temperature detection. T sys01 and T sys02 Indicates the maximum and minimum system execution response time corresponding to temperature regulation.

[0040] Furthermore, the temperature control module adjusts the temperature range of each chromatographic column, and further includes:

[0041] Injection control: The gas sample is injected into the chromatographic column connected in series to the analysis channel through the analysis channel of the ten-way valve, and the helium supplied by the gas supply system carries the gas sample through the chromatographic column for separation;

[0042] Backflush control: When the heavier components in the C3-C6 components approach the end of the chromatographic column, the ten-port valve is controlled to switch to the backflush mode. The backflush gas flow enters from the other end of the chromatographic column to discharge the unseparated and separated heavy components out of the system.

[0043] Capture control: According to CO 2 The physical and chemical properties of ethane, oxygen, nitrogen and methane are determined by controlling the ten-way valve to guide the gas sample to the capture device for low-temperature capture and adsorption capture.

[0044] Furthermore, the temperature control module optimizes the carrier gas flow rate control strategy, specifically:

[0045] Initial flow rate: Obtain the specifications and packing characteristics of each chromatographic column, and set the initial carrier gas flow rate according to the specifications of the chromatographic column and the characteristics of the packing;

[0046] Flow rate adjustment: During the temperature rise process of adjusting the temperature range, adjust the carrier gas flow rate of each chromatographic column according to the separation of each component in each analysis channel and the changes in the chromatogram.

[0047] Furthermore, the chromatographic analysis module specifically includes:

[0048] Determine the data length of the preprocessed signal according to the preprocessed signal time series of the signal acquisition module, and establish a time horizontal axis based on the data length, and a vertical axis is signal strength;

[0049] Inputting data points of the preprocessed signal into the time axis, and sequentially connecting the data points based on the time series to form the outline of the chromatogram;

[0050] Detecting a local maximum in the chromatogram, determining the peak of the chromatogram based on the local maximum, and determining the start and end points of each peak according to the capping position;

[0051] Integrate each calculated peak to obtain the area of ​​each peak;

[0052] The identified peaks are compared with the data in the standard database to determine the types of components in the gas sample, and the concentration of each component is calculated based on the quantitative relationship between the area of ​​each peak and the known concentration.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] Through three independent and collaborative analysis channels, different component groups in natural gas can be efficiently analyzed, ensuring the accuracy and reliability of the analysis results and reducing mutual interference between different components. Each channel is equipped with a specific valve group, chromatographic column combination and detector to ensure the accuracy and sensitivity of the analysis. The capture technology of the second and third channels can achieve efficient capture and release of specific components, enhancing the flexibility of this multi-channel natural gas analyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a module diagram of a multi-channel natural gas analyzer of the present invention;

[0056] Figure 2 A chromatogram of a channel of a multi-channel natural gas analyzer of the present invention;

[0057] Figure 3 It is a channel dichroic chromatogram of a multi-channel natural gas analyzer of the present invention;

[0058] Figure 4 This is a three-channel chromatogram of the multi-channel natural gas analyzer of the present invention. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 of 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.

[0060] In order to solve the technical problem that the overall quality of natural gas cannot be fully reflected, especially for some low-concentration or difficult-to-detect components, as the number of detected components increases, the complexity and maintenance difficulty of the system will increase accordingly, resulting in a decrease in system reliability and an increase in maintenance costs, please refer to Figure 1-4 , this embodiment provides the following technical solutions:

[0061] A multi-channel natural gas analyzer includes an analysis channel, a valve group, a chromatographic column and a detector. The analysis channels are provided with three channels, including a first channel, a second channel and a third channel. Each analysis channel is independent of each other. The analysis channels are used to analyze different components in natural gas. The first channel is provided with a chromatographic column group for analyzing C3-C6 components, and the second channel is provided with two chromatographic columns for analyzing CO 2 The third channel is equipped with a chromatographic column group for analyzing oxygen, nitrogen and methane; the valve group is a ten-way valve; there are three valve groups, each of which corresponds to and controls the gas flow path of an analysis channel; there are six chromatographic columns, which are evenly distributed in each analysis channel; the chromatographic columns are set into three groups, including: a chromatographic column group for analyzing C3-C6 components, 12% UCW982 chromatographic columns and 25% DC200 chromatographic columns, and a group for analyzing CO 2 and ethane, HAYESEP Q chromatographic column, a chromatographic column group for analyzing oxygen, nitrogen and methane, HAYESEP Q chromatographic column and MOLS I EVE 5A chromatographic column; three detectors are set, which are installed at the end of each analysis channel respectively; the valve group, chromatographic columns and detectors exchange data with the control system.

[0062] In this embodiment, three independent analysis channels are set up, each channel focuses on analyzing different components in natural gas, which greatly improves the analysis efficiency, enables multiple components to be detected and analyzed at the same time, and reduces the analysis time. Each analysis channel is configured with a specific chromatographic column group to ensure the accurate separation and detection of each component, and improve the accuracy and reliability of the analysis. At the same time, the precise control of the valve group ensures the effective transmission and separation of the gas sample in the chromatographic column. The integrated detector system can simultaneously acquire data from multiple channels, which improves the efficiency and accuracy of data acquisition. The control system can automatically adjust the temperature, flow rate and other conditions according to the preset parameters and programs to optimize the separation effect, and process and analyze the data output by the detector in real time, which improves the analysis efficiency, accuracy and reliability.

[0063] In this embodiment, three independent and collaborative analysis channels are used to efficiently analyze different component groups in natural gas, thereby ensuring the accuracy and reliability of the analysis results and reducing mutual interference between different components. Each channel is equipped with a specific valve group, chromatographic column combination and detector to ensure the accuracy and sensitivity of the analysis. The capture technology of the second and third channels achieves efficient capture and release of specific components, thereby enhancing the flexibility of this multi-channel natural gas analyzer.

[0064] In this embodiment, the analysis channel is connected to the gas supply system, which is used to provide the same carrier gas source for each analysis channel; wherein the gas supply system includes: a carrier gas source, which is used to provide high-purity carrier gas; a pressure reducing valve, located after the carrier gas source, which is used to adjust the carrier gas from a high-pressure state to a pressure range suitable for the operation of the chromatograph analyzer, to ensure the stable operation of the system, while avoiding damage to the system components caused by excessive pressure; a pressure stabilizing valve, located after the pressure reducing valve, which is used to stabilize the pressure of the carrier gas, to ensure the accuracy and repeatability of the analysis results; a gas distributor, which is used to evenly distribute the carrier gas that has been reduced pressure and stabilized to each analysis channel, to ensure that each analysis channel can obtain the same flow and pressure of the carrier gas; a gas supply pipeline, which is used to connect the gas distributor to each analysis channel, and each channel is connected to the gas distributor through an independent pipeline, which helps to reduce mutual interference between channels and improve the accuracy and reliability of the analysis; a gas purification device, which is used to purify the carrier gas and remove impurities and moisture in the gas to ensure the accuracy of the analysis results. Wherein, the gas purification device is arranged between the carrier gas source and the pressure reducing valve and in front of the entrance of each analysis channel.

[0065] In this embodiment, the gas supply system is a supply device using helium as a carrier gas, providing a unified carrier gas source for all channels. The carrier gas source provides high-purity carrier gas, which is adjusted to an appropriate pressure by a pressure reducing valve, stabilized by a pressure stabilizing valve, and then evenly distributed to each analysis channel by a gas distributor. Each analysis channel is connected to the gas distributor through an independent pipeline to ensure that each channel obtains a consistent carrier gas flow rate and pressure; in the first channel, a ten-way valve is used to realize the injection and backflush functions to optimize the separation effect of C3-C6 components; in the second and third channels, a ten-way valve is used in combination with a capture technology to effectively capture and separate CO 2 , ethane, oxygen, nitrogen and methane and other components to improve detection sensitivity and accuracy.

[0066] In this embodiment, the control system is used to coordinate and control the actions of each valve group, adjust the temperature of each chromatographic column, collect the signal of the detector in real time and perform analysis and processing; wherein the detector is used to detect the gas components in each analysis channel after separation by the chromatographic column group;

[0067] In this embodiment, the control system includes:

[0068] The temperature control module is used to build an interactive channel with each chromatographic column, control the heating and cooling operations of each chromatographic column, adjust the temperature range of each chromatographic column according to the preset temperature parameters, and formulate a carrier gas flow control strategy to optimize the separation effect of different components;

[0069] Specifically, the temperature range of each chromatographic column is adjusted according to the preset temperature parameters, including:

[0070] During the heating and cooling process of each chromatographic column, the temperature real-time data of the chromatographic column is monitored in real time;

[0071] Compare the real-time temperature data with a preset target temperature value to obtain a temperature difference between the real-time temperature data and the preset target temperature value;

[0072] Comparing the temperature difference with a preset difference threshold;

[0073] When the temperature difference exceeds a preset difference threshold, the temperature real-time data of the chromatographic column is controlled in real time according to the preset initial temperature adjustment gradient;

[0074] When the temperature real-time data of the chromatographic column is controlled in real time according to the initial temperature adjustment gradient, corresponding adjusted temperature data corresponding to each temperature adjustment performed according to the initial temperature adjustment gradient is obtained in real time;

[0075] Retrieving a theoretical temperature value corresponding to the adjusted temperature data corresponding to the temperature adjustment, and obtaining a deviation value between the adjusted temperature data corresponding to the temperature adjustment and the theoretical temperature value;

[0076] The temperature adjustment coefficient is obtained by using the deviation value between the adjusted temperature data corresponding to the temperature adjustment and its theoretical temperature value; wherein the temperature adjustment coefficient is obtained by the following formula:

[0077]

[0078] Among them, K T represents the temperature adjustment coefficient; ΔT represents the initial temperature adjustment gradient; R represents the heat capacity of the chromatographic column; D represents the thermal conductivity of the chromatographic column; n represents the number of temperature adjustments experienced by the temperature adjustment unit with the initial temperature adjustment gradient as the temperature adjustment unit; t represents the adjustment time of the current temperature adjustment; T ci represents the actual temperature corresponding to the i-th temperature adjustment; T thi represents the theoretical temperature value corresponding to the i-th temperature adjustment; T tar Indicates the target temperature corresponding to the current temperature control; ε indicates the minimum constant, which is used to prevent the denominator from being 0; γ i represents the adjustment sensitivity coefficient corresponding to the i-th temperature adjustment;

[0079] When the temperature difference is not lower than a preset difference threshold, the initial temperature adjustment gradient is adjusted to obtain an adjusted temperature adjustment gradient;

[0080] According to the adjusted temperature, the gradient control is used to control the temperature real-time data of the chromatographic column in real time so that it reaches the preset target temperature value.

[0081] The technical effect of the above technical solution is that by real-time monitoring of the temperature of the chromatographic column and comparing it with the preset target temperature, the temperature deviation can be discovered and corrected in time to ensure that the temperature of the chromatographic column is always kept within the target range, thereby improving the accuracy and repeatability of the experiment. When the temperature difference exceeds the preset threshold, the system can automatically perform real-time control according to the preset initial temperature adjustment gradient, and dynamically adjust the temperature adjustment gradient according to the actual situation of temperature adjustment to ensure that the target temperature is reached quickly and accurately.

[0082] By obtaining the deviation between the adjusted temperature data and its theoretical temperature value during temperature adjustment, and using the deviation to calculate the temperature adjustment coefficient, the temperature adjustment strategy can be continuously optimized to improve the efficiency and stability of temperature control. This technical solution takes into account factors such as the heat capacity and thermal conductivity of the chromatographic column, making the temperature control strategy more in line with the actual situation and able to adapt to different types of chromatographic columns and different experimental conditions. By real-time monitoring and comparing temperature data, overheating or overcooling of the chromatographic column can be detected and prevented in a timely manner, thereby protecting the chromatographic column from damage and extending its service life.

[0083] In summary, this technical solution realizes precise, dynamic and intelligent control of the temperature of the chromatographic column, improves the accuracy and repeatability of the experiment, and protects the chromatographic column from damage.

[0084] Specifically, when the temperature difference is not lower than a preset difference threshold, the initial temperature adjustment gradient is adjusted to obtain an adjusted temperature adjustment gradient, including:

[0085] When the temperature difference is not lower than a preset difference threshold, calling the temperature adjustment coefficient;

[0086] Retrieve the corresponding system execution response time when temperature adjustment is performed according to the initial temperature adjustment gradient and the temperature acquisition response time of the temperature sensor used for temperature detection;

[0087] The initial temperature adjustment gradient is adjusted by using the temperature adjustment coefficient in combination with the corresponding system execution response time when the temperature adjustment is performed according to the initial temperature adjustment gradient and the temperature acquisition response time of the temperature sensor used for temperature detection to obtain an adjusted temperature adjustment gradient;

[0088] The adjusted temperature gradient is obtained by the following formula:

[0089]

[0090] Where, ΔT k represents the adjusted temperature adjustment gradient; ΔT represents the initial temperature adjustment gradient; n represents the number of temperature adjustments experienced by taking the initial temperature adjustment gradient as the temperature adjustment unit; KT represents the temperature regulation coefficient; γ i represents the adjustment sensitivity coefficient corresponding to the i-th temperature adjustment; t sysi represents the system execution response time corresponding to the i-th temperature adjustment; t seni Indicates the temperature acquisition response time of the temperature sensor used for temperature detection. T sys01 and T sys02 Indicates the maximum and minimum system execution response time corresponding to temperature regulation.

[0091] The technical effect of the above technical solution is that when the temperature difference exceeds the preset threshold, the initial temperature adjustment gradient is finely adjusted by introducing parameters such as the temperature adjustment coefficient, the system execution response time, and the temperature acquisition response time of the temperature sensor, so that the temperature change of the chromatographic column can be more accurately controlled, the temperature fluctuation can be reduced, and the accuracy of the experimental results can be improved. The system execution response time and the temperature acquisition response time of the temperature sensor are taken into consideration. These factors often affect the real-time and accuracy of temperature control in actual operation. By incorporating these factors into the adjustment formula, the temperature adjustment process can be optimized, the unnecessary waiting time can be reduced, and the efficiency of temperature adjustment can be improved.

[0092] This technical solution enables the system to adapt to different experimental conditions and chromatographic column characteristics by dynamically adjusting the temperature adjustment gradient. At the same time, by introducing parameters such as the adjustment sensitivity coefficient, the temperature control strategy can be flexibly adjusted according to actual conditions to improve the stability and reliability of the system. During the temperature adjustment process, if the adjustment gradient is too large or too small, it may cause temperature overshoot or under-adjustment. By real-time monitoring of the temperature difference and dynamically adjusting the temperature adjustment gradient, these problems can be effectively avoided, the chromatographic column can be protected from damage, and the normal progress of the experiment can be ensured. For experimenters, accurate and stable temperature control means a higher experimental success rate and more reliable data results. This can not only improve their work efficiency and satisfaction, but also provide a more solid experimental foundation for scientific research.

[0093] In summary, this technical solution achieves accurate, efficient and stable control of the chromatographic column temperature by comprehensively considering multiple factors and dynamically adjusting the initial temperature adjustment gradient, which has significant technical effects and practical value.

[0094] In this embodiment, the temperature control module adjusts the temperature range of each chromatographic column, and further includes:

[0095] Injection control: The gas sample is injected into the chromatographic column connected in series to the analysis channel through the analysis channel of the ten-way valve, and the helium supplied by the gas supply system carries the gas sample through the chromatographic column for separation;

[0096] Backflush control: When the heavier components in the C3-C6 components approach the end of the chromatographic column, the ten-port valve is controlled to switch to the backflush mode. The backflush gas flow enters from the other end of the chromatographic column to discharge the unseparated and separated heavy components out of the system.

[0097] Capture control: According to CO 2 The physical and chemical properties of ethane, oxygen, nitrogen and methane are determined by controlling the ten-way valve to guide the gas sample to the capture device for low-temperature capture and adsorption capture. 2 Due to its high quadrupole moment, it can be used for adsorption capture, especially for CO 2 With highly selective adsorbents, ethane is captured by cryogenic capture or specific adsorbents, and oxygen and nitrogen are captured by chemical capture, such as using specific chemical reagents to react with them, or adsorption capture, such as using adsorbents with high selectivity for oxygen and nitrogen, to achieve efficient separation;

[0098] In this embodiment, at the initial stage of injection, a slower heating rate is preset to fully separate low-boiling point components, such as C3 and C4 components. As the temperature rises, the heating rate is gradually increased to better separate high-boiling point components, such as C5 and C6 components. A constant temperature stage is set near the expected peak temperature of each key component to ensure sufficient separation and accurate detection of the components, and a final temperature threshold is set to ensure that all components can be completely eluted from the chromatographic column.

[0099] The temperature control module optimizes the carrier gas flow rate control strategy, specifically:

[0100] Initial flow rate: Obtain the specifications and packing characteristics of each chromatographic column, set the initial carrier gas flow rate according to the specifications of the chromatographic column and the characteristics of the packing, and ensure effective diffusion and separation of the sample in the chromatographic column;

[0101] Flow rate adjustment: During the temperature rise process of adjusting the temperature range, adjust the carrier gas flow rate of each chromatographic column according to the separation of each component in each analysis channel and the change of the chromatogram;

[0102] In this embodiment, each peak on the chromatogram represents a component, and information such as the position, height, width and shape of the peak can provide clues to the separation effect. The distance between two adjacent chromatographic peaks and their respective peak widths can reflect the separation degree. The greater the separation degree, the better the separation effect between the two components. For components that are difficult to separate, the flow rate can be appropriately reduced to improve the separation degree; for components that have been fully separated, the flow rate can be increased to shorten the analysis time.

[0103] In this embodiment, the chromatographic column configuration of the first channel and the design of the injection and backflush functions of the ten-port valve further include a column temperature program and a carrier gas flow rate control strategy to optimize the separation efficiency of the C3-C6 components, and the trapping technology of the second and third channels includes but is not limited to low temperature trapping, adsorption trapping or chemical trapping to achieve efficient trapping and release for specific components;

[0104] A signal acquisition module is used to collect the output signal of each detector and transmit the pre-processed output signal to the chromatographic analysis module for analysis and processing;

[0105] The chromatographic analysis module is used to receive the pre-processed output signal transmitted by the signal acquisition module, perform chromatogram drawing, peak identification, peak area calculation, quantitative analysis and component identification, automatically compare the standard database, quickly determine the type and concentration of each component in the gas sample, and transmit the analysis results to the user interaction module for display;

[0106] The user interaction module is used to provide a display interface, which generates and displays reports on the content of each component. Users can enter commands through the touch screen or keyboard to view real-time analysis data, adjust parameter settings, print analysis results, etc.

[0107] In this embodiment, the temperature control module realizes precise control of the temperature of the chromatographic column by constructing an interactive channel with each chromatographic column, including temperature adjustment in the injection, backflushing and capture stages, and optimization of the heating rate; at the same time, the introduction of the carrier gas flow rate control strategy dynamically adjusts the flow rate according to the chromatographic column specifications, filler characteristics and separation conditions, ensuring the effective separation and accurate detection of each component in the gas sample, greatly improving the accuracy and reliability of the analysis; further, by optimizing the column temperature program and carrier gas flow rate control strategy for the separation efficiency of the C3-C6 components, combined with the injection and backflushing function design of the ten-way valve, the separation efficiency of the components is effectively improved; at the same time, the capture technology of the second and third channels realizes efficient capture and release for specific components, further improving the separation and detection capabilities of the system.

[0108] In this embodiment, the entire analysis process is highly automated, from signal acquisition to chromatographic analysis to result display. The signal acquisition module collects the detector output signal in real time, and the chromatographic analysis module automatically draws chromatograms, identifies peaks, calculates peak areas, performs quantitative analysis, and identifies components, and compares them with the standard database to quickly determine the type and concentration of each component in the gas sample, greatly reducing human intervention and improving analysis efficiency and accuracy. The user interaction module provides an intuitive display interface, making operation more convenient and flexible, and improving user experience.

[0109] In this embodiment, the chromatographic analysis module specifically includes:

[0110] Determine the data length of the preprocessed signal according to the preprocessed signal time series of the signal acquisition module, establish the time horizontal axis based on the data length, and the vertical axis is the signal strength;

[0111] The data points of the preprocessed signal are input into the time axis, and the data points are sequentially connected based on the time series to form the outline of the chromatogram;

[0112] Detecting a local maximum in the chromatogram, determining the peak of the chromatogram based on the local maximum, and determining the start and end points of each peak according to the capping position;

[0113] Integrate each calculated peak to obtain the area of ​​each peak;

[0114] The identified peaks are compared with the data in the standard database to determine the types of components in the gas sample. The concentration of each component is calculated based on the quantitative relationship between the area of ​​each peak and the known concentration. The standard database stores chromatograms, retention times, peak shapes and other information of various known compounds. The types of components in the sample can be quickly determined during the comparison process.

[0115] In this embodiment, the peak top is determined by detecting the local maximum value in the chromatogram, and the starting and ending points of each peak are determined accordingly, and each chromatographic peak is accurately divided, and the peak area is obtained by integrating and calculating each peak. Since there is a quantitative relationship between the peak area and the concentration of the gas component, multiple gas components can be identified by comparing the data in the standard database, and the concentration of each component in the gas sample can be accurately calculated, thereby improving the accuracy and reliability of gas sample analysis, greatly simplifying the experimental process, reducing the workload of experimenters, and improving the accuracy and repeatability of experimental results.

[0116] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-channel natural gas analyzer, comprising an analysis channel, a valve group, a chromatographic column and a detector, characterized in that: There are three analysis channels, including a first channel, a second channel and a third channel, and each of the analysis channels is independent of each other; there are three valve groups, each of which corresponds to and controls the gas flow path of one of the analysis channels; there are six chromatographic columns, which are evenly distributed in each of the analysis channels; The detectors are provided with three and are respectively installed at the end of each of the analysis channels; The valve group, chromatographic column and detector perform data exchange with the control system; The control system comprises: The temperature control module is used to build an interactive channel with each chromatographic column, control the heating and cooling operations of each chromatographic column, adjust the temperature range of each chromatographic column according to the preset temperature parameters, and formulate the carrier gas flow rate control strategy; A signal acquisition module is used to collect the output signal of each detector and transmit the pre-processed output signal to the chromatographic analysis module for analysis and processing; The chromatographic analysis module is used to receive the pre-processed output signal transmitted by the signal acquisition module, and perform chromatogram drawing, peak identification, peak area calculation, quantitative analysis and component identification; A user interaction module, used to provide a display interface, which generates and displays a report on the content of each component; Adjust the temperature range of each column according to preset temperature parameters, including: During the heating and cooling process of each chromatographic column, the temperature real-time data of the chromatographic column is monitored in real time; Compare the real-time temperature data with a preset target temperature value to obtain a temperature difference between the real-time temperature data and the preset target temperature value; Comparing the temperature difference with a preset difference threshold; When the temperature difference exceeds a preset difference threshold, the temperature real-time data of the chromatographic column is controlled in real time according to the preset initial temperature adjustment gradient; When the temperature real-time data of the chromatographic column is controlled in real time according to the initial temperature adjustment gradient, corresponding adjusted temperature data corresponding to each temperature adjustment performed according to the initial temperature adjustment gradient is obtained in real time; Retrieving a theoretical temperature value corresponding to the adjusted temperature data corresponding to the temperature adjustment, and obtaining a deviation value between the adjusted temperature data corresponding to the temperature adjustment and the theoretical temperature value; The temperature adjustment coefficient is obtained by using the deviation value between the adjusted temperature data corresponding to the temperature adjustment and its theoretical temperature value; wherein the temperature adjustment coefficient is obtained by the following formula: Among them, K T represents the temperature adjustment coefficient; ΔT represents the initial temperature adjustment gradient; R represents the heat capacity of the chromatographic column; D represents the thermal conductivity of the chromatographic column; n represents the number of temperature adjustments experienced by the temperature adjustment unit with the initial temperature adjustment gradient as the temperature adjustment unit; t represents the adjustment time of the current temperature adjustment; T ci represents the actual temperature corresponding to the i-th temperature adjustment; T thi represents the theoretical temperature value corresponding to the i-th temperature adjustment; T tar Indicates the target temperature corresponding to the current temperature control; ε indicates the minimum constant, which is used to prevent the denominator from being 0; γ i represents the adjustment sensitivity coefficient corresponding to the i-th temperature adjustment; When the temperature difference is not lower than a preset difference threshold, the initial temperature adjustment gradient is adjusted to obtain an adjusted temperature adjustment gradient; According to the adjusted temperature, the gradient control is used to control the temperature real-time data of the chromatographic column in real time so that it reaches the preset target temperature value.

2. A multi-channel natural gas analyzer as claimed in claim 1, characterized in that: The chromatographic columns are arranged into three groups, one group is used for analyzing C3-C6 components, one group is used for analyzing CO2 and ethane, and one group is used for analyzing oxygen, nitrogen and methane; the analysis channel is used for analyzing different components in natural gas, wherein the first channel is equipped with a chromatographic column group for analyzing C3-C6 components, the second channel is equipped with two chromatographic column groups for analyzing CO2 and ethane, and the third channel is equipped with a chromatographic column group for analyzing oxygen, nitrogen and methane; the valve group is arranged as a ten-way valve.

3. A multi-channel natural gas analyzer as claimed in claim 2, characterized in that: The analysis channel is connected to a gas supply system for providing the same carrier gas source to each of the analysis channels; wherein the gas supply system comprises: A carrier gas source, used for providing high-purity carrier gas; A pressure reducing valve, located after the carrier gas source, is used to adjust the carrier gas from a high pressure state to a pressure range suitable for the operation of the chromatographic analyzer; The pressure stabilizing valve is located after the pressure reducing valve and is used to stabilize the pressure of the carrier gas; A gas distributor is used to evenly distribute the carrier gas that has been decompressed and stabilized to each analysis channel; A gas supply pipeline, used to connect the gas distributor with each analysis channel; The gas purification device is used to purify the carrier gas and remove impurities and moisture in the gas, wherein the gas purification device is arranged between the carrier gas source and the pressure reducing valve and in front of the entrance of each analysis channel.

4. A multi-channel natural gas analyzer as claimed in claim 3, characterized in that: The control system is used to coordinate and control the actions of each valve group, adjust the temperature of each chromatographic column, collect the detector signal in real time and analyze and process it; wherein the detector is used to detect the gas components in each analysis channel after separation by the chromatographic column group.

5. A multi-channel natural gas analyzer as claimed in claim 4, characterized in that: When the temperature difference is not lower than the preset difference threshold, the initial temperature adjustment gradient is adjusted to obtain an adjusted temperature adjustment gradient, including: When the temperature difference is not lower than a preset difference threshold, calling the temperature adjustment coefficient; Retrieve the corresponding system execution response time when temperature adjustment is performed according to the initial temperature adjustment gradient and the temperature acquisition response time of the temperature sensor used for temperature detection; The initial temperature adjustment gradient is adjusted by using the temperature adjustment coefficient in combination with the corresponding system execution response time when the temperature adjustment is performed according to the initial temperature adjustment gradient and the temperature acquisition response time of the temperature sensor used for temperature detection to obtain an adjusted temperature adjustment gradient; The adjusted temperature gradient is obtained by the following formula: Where, ΔT k represents the adjusted temperature adjustment gradient; ΔT represents the initial temperature adjustment gradient; n represents the number of temperature adjustments experienced by taking the initial temperature adjustment gradient as the temperature adjustment unit; K T represents the temperature regulation coefficient; γ i represents the adjustment sensitivity coefficient corresponding to the i-th temperature adjustment; t sysi represents the system execution response time corresponding to the i-th temperature adjustment; t seni Indicates the temperature acquisition response time of the temperature sensor used for temperature detection; T sys01 and T sys02 Indicates the maximum and minimum system execution response time corresponding to temperature adjustment.

6. A multi-channel natural gas analyzer as claimed in claim 5, characterized in that: The temperature control module adjusts the temperature range of each chromatographic column, and also includes: Injection control: The gas sample is injected into the chromatographic column connected in series to the analysis channel through the analysis channel of the ten-way valve, and the helium supplied by the gas supply system carries the gas sample through the chromatographic column for separation; Backflush control: When the heavier components in the C3-C6 components approach the end of the chromatographic column, the ten-port valve is controlled to switch to the backflush mode. The backflush gas flow enters from the other end of the chromatographic column to discharge the unseparated and separated heavy components out of the system. Capture control: According to the physical and chemical properties of CO2, ethane, oxygen, nitrogen and methane, the ten-way valve is controlled to guide the gas sample to the capture device for low-temperature capture and adsorption capture.

7. A multi-channel natural gas analyzer as claimed in claim 6, characterized in that: The temperature control module optimizes the carrier gas flow rate control strategy, specifically: Initial flow rate: Obtain the specifications and packing characteristics of each chromatographic column, and set the initial carrier gas flow rate according to the specifications of the chromatographic column and the characteristics of the packing; Flow rate adjustment: During the temperature rise process of adjusting the temperature range, adjust the carrier gas flow rate of each chromatographic column according to the separation of each component in each analysis channel and the changes in the chromatogram.

8. A multi-channel natural gas analyzer as claimed in claim 7, characterized in that: The chromatographic analysis module specifically comprises: Determine the data length of the preprocessed signal according to the preprocessed signal time series of the signal acquisition module, and establish a time horizontal axis based on the data length, and a vertical axis is signal strength; Inputting data points of the preprocessed signal into the time axis, and sequentially connecting the data points based on the time series to form the outline of the chromatogram; Detecting a local maximum in the chromatogram, determining the peak of the chromatogram based on the local maximum, and determining the start and end points of each peak according to the capping position; Integrate each calculated peak to obtain the area of ​​each peak; The identified peaks are compared with the data in the standard database to determine the types of components in the gas sample, and the concentration of each component is calculated based on the quantitative relationship between the area of ​​each peak and the known concentration.

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