Gas chromatograph and detection control method thereof

Abstract

The present invention discloses a gas chromatograph and a detection control method thereof, the gas chromatograph comprises: a first separation module for separating a first batch of measurement components in a gas to be detected and a second batch of measurement components in the gas to be detected, allowing the first batch of measurement components and the second batch of measurement components to pass through, and temporarily storing a third batch of measurement components in the gas to be detected; the second separation module is used for separating a first batch of measurement components in the to-be-measured gas and allowing the first batch of measurement components to pass through, and temporarily storing a second batch of measurement components; the detection module is used for detecting the component content in the to-be-detected gas; and the reversing valve is used for switching the content detection of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components. According to the invention, the first separation module and the second separation module are integrated to the single gas chromatograph, and the content of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components in the to-be-detected gas is detected through switching of the reversing valves, so that one-time detection of the components of the to-be-detected gas is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of chromatography analysis, and in particular to a gas chromatograph and a detection and control method thereof. Background Art

[0002] As an important analytical instrument, gas chromatograph is widely used in many fields such as chemistry, environment, energy, and electricity. Traditional gas chromatographs are usually designed to analyze specific types of gas samples. By selecting appropriate chromatographic columns, molecular sieves, and carrier gases, effective separation and detection of various components in gas samples can be achieved. However, with the continuous advancement of science and technology and the increasing diversification of industrial production needs, higher requirements are placed on the analytical capabilities and flexibility of gas chromatographs.

[0003] In the field of transformer equipment fault diagnosis, gas composition analysis in insulating oil is an important means to determine the operating status of transformer equipment and predict faults. Insulating oil is a complex mixture of hydrocarbons of various molecular weights. In the case of discharge or overheating, some CH or CC bonds in the insulating oil may break, releasing active hydrogen atoms and unstable hydrocarbons. These substances then undergo a series of complex chemical reactions to generate characteristic fault gases such as hydrogen, methane, ethane, ethylene and acetylene. By monitoring the content of these characteristic fault gases, power workers can evaluate whether the operating status of the transformer is healthy. At the same time, if the oil pillow, body, pipeline, flange and other parts of the transformer are not tightly sealed, air may penetrate, resulting in an increase in the oxygen and nitrogen content in the insulating oil. The national standard has clear provisions on the total gas content in insulating oil to ensure the safe operation of the transformer. Therefore, power workers judge the sealing performance of transformer equipment by monitoring the total gas content in the insulating oil, including the content of hydrogen, oxygen and nitrogen.

[0004] A gas chromatograph is an instrument specifically used to monitor the composition of faulty gases in insulating oil. It determines the type of fault, location of the fault, and severity of the fault in transformer equipment through auxiliary analysis. The detection principle of the instrument is based on gas chromatography, a technology that separates based on time differences. In gas chromatography, a vaporized mixture or gas is passed through a chromatographic column containing a specific substance, and different compounds are separated due to the different adsorption properties of the substance in the chromatographic column. The peak appearance time of each component, that is, the retention time, is used to qualitatively identify each component, and the size of the peak, whether it is peak height or peak area, is an indicator of the component content. In this way, the gas chromatograph can accurately analyze the characteristic gas in the insulating oil and provide important data for the maintenance and fault diagnosis of transformer equipment.

[0005] When analyzing the gas in insulating oil, a traditional gas chromatograph can only analyze specific fault characteristic gases, but cannot detect the total gas content of multiple fault characteristic gases at the same time, which limits its accuracy and comprehensiveness in fault diagnosis to a certain extent. At present, a large number of domestic users need to equip two instruments when using gas chromatographs to detect the content of fault characteristic gases in insulating oil. One instrument is equipped with a chromatographic column to measure the fault characteristic gases such as H2, CH4, C2H6, C2H4, C2H2, CO, CO2, etc. in the insulating oil; the other instrument is equipped with a molecular sieve to measure the content of H2, O2, and N2 in the insulating oil, and then the content of each fault gas is accumulated to form the total gas content in the insulating oil. The original design instrument has a single function and no backup. Once the instrument fails, it will affect the normal detection of the sample, and when measuring the total gas content, two instruments must be used at the same time to complete the measurement. In addition, traditional carrier gases such as nitrogen cannot meet the analysis requirements in the analysis scenario of accurate detection of nitrogen in insulating oil, and a more suitable carrier gas alternative needs to be found. Summary of the invention

[0006] The technical problem to be solved by the present invention is that, in view of at least one defect of the related technology mentioned in the above background technology: when detecting the total gas content of multiple fault characteristic gases, two gas chromatographs need to be used simultaneously for measurement, and a gas chromatograph and a detection control method thereof are provided.

[0007] The technical solution adopted by the present invention to solve the technical problem is: construct a gas chromatograph, comprising:

[0008] A first separation module is used to separate a first batch of measurement components in the gas to be measured and a second batch of measurement components in the gas to be measured, and to allow the first batch of measurement components and the second batch of measurement components to pass through, and to temporarily store a third batch of measurement components in the gas to be measured;

[0009] A second separation module is used to separate a first batch of measurement components from the gas to be measured and allow the first batch of measurement components to pass through, and temporarily store the second batch of measurement components;

[0010] A detection module, used to detect the component content in the gas to be tested; and

[0011] A reversing valve, the reversing valve is used to switch the content detection of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components, the reversing valve comprises a first valve port, a second valve port, a third valve port, a fourth valve port, a fifth valve port and a sixth valve port;

[0012] Among them, the outlet end of the first separation module is connected to the first valve port, the inlet end of the second separation module is connected to the second valve port, the outlet end of the second separation module is connected to the third valve port, the fourth valve port is connected to the fifth valve port, and the inlet end of the detection module is connected to the sixth valve port.

[0013] In some embodiments, the first valve port is communicated with the second valve port, the second valve port is communicated with the third valve port via the second separation module, the third valve port is communicated with the sixth valve port, and the fourth valve port is communicated with the fifth valve port, the gas to be measured is separated into the first batch of measurement components and the second batch of measurement components after passing through the first separation module, the first batch of measurement components and the second batch of measurement components are separated into the first batch of measurement components after passing through the first valve port, the second valve port and the second separation module, and the first batch of measurement components enter the detection module after passing through the third valve port and the sixth valve port, forming a detection path for detecting the content of the first batch of measurement components in the gas to be measured;

[0014] When the first valve port is communicated with the fourth valve port, the second valve port is communicated with the third valve port, the fourth valve port is communicated with the fifth valve port, and the fifth valve port is communicated with the sixth valve port, the third batch of measurement components temporarily stored in the first separation module in the gas to be measured enters the detection module after passing through the first separation module, the first valve port, the fourth valve port, the fifth valve port and the sixth valve port, thereby forming a detection path for detecting the content of the third batch of measurement components in the gas to be measured;

[0015] When the first valve port is communicated with the second valve port, the second valve port is communicated with the third valve port via the second separation module, the third valve port is communicated with the sixth valve port, and the fourth valve port is communicated with the fifth valve port, the second batch of measurement components temporarily present in the gas to be measured in the second separation module enter the detection module after passing through the second separation module, the third valve port and the sixth valve port, thereby forming a detection path for detecting the content of the second batch of measurement components in the gas to be measured.

[0016] In some embodiments, the gas chromatograph further comprises:

[0017] The sample loading module is used for the carrier gas to carry the gas to be tested into the first separation module, and the outlet end of the sample loading module is connected to the inlet end of the first separation module.

[0018] In some embodiments, the sample loading module comprises:

[0019] A gas sample unit, used for introducing the gas to be tested, wherein the outlet of the gas sample unit is connected to the inlet of the first separation module;

[0020] A carrier gas unit is used to introduce a carrier gas to carry the gas to be tested, wherein the carrier gas is argon gas, and an outlet end of the carrier gas unit is connected to an inlet end of the first separation module.

[0021] In some embodiments, the first valve port is connected to the second valve port, the second valve port is connected to the third valve port via the second separation module, the third valve port is connected to the sixth valve port, and the fourth valve port is connected to the fifth valve port, the carrier gas enters the detection module after passing through the first separation module, the first valve port, the second valve port, the second separation module, the third valve port and the sixth valve port, forming a preparation path for the carrier gas.

[0022] In some embodiments, the gas chromatograph further comprises:

[0023] The damping module is used to control the flow rate of the gas to be measured, the inlet end of the damping module is connected to the fourth valve port, and the outlet end of the damping module is connected to the fifth valve port.

[0024] In some embodiments, the detection module includes:

[0025] A first detection unit, the first detection unit is used to detect components obtained by separating the gas to be tested;

[0026] A conversion unit, the conversion unit is used to convert the components of the gas to be tested obtained by separation to obtain the converted components of the gas to be tested;

[0027] A second detection unit, the second detection unit is used to detect the converted components of the gas to be detected; and

[0028] A data processing unit, the data processing unit is used to process the detection data of the first detection unit and the second detection unit;

[0029] Wherein, the sixth valve port is connected to the inlet end of the first detection unit, the outlet end of the first detection unit is connected to the inlet end of the conversion unit, and the outlet end of the conversion unit is connected to the inlet end of the second detection unit;

[0030] The data processing unit is communicatively connected with the first detection unit and the second detection unit.

[0031] In some embodiments, the first batch of measurement components includes a gas of at least one of the following chemical formulas: H2;

[0032] The second batch of measurement components includes gases of at least one of the following chemical formulas: CO, CH4, O2, N2;

[0033] The third batch of measurement components includes gases of at least one of the following chemical formulas: CO2, C2H2, C2H4, C2H6.

[0034] The present invention also constructs a detection control method applied to any of the gas chromatographs described above, comprising the following steps:

[0035] Detection of the first batch of measurement components: controlling the first valve port to be connected with the second valve port, the second valve port to be connected with the third valve port via the second separation module, the third valve port to be connected with the sixth valve port, and the fourth valve port to be connected with the fifth valve port, so as to switch to a detection path for detecting the content of the first batch of measurement components in the gas to be measured, and perform detection of the content of the first batch of measurement components in the gas to be measured;

[0036] Detection of the third batch of measurement components: after the detection of the first batch of measurement components is completed, the first valve port is controlled to be connected to the fourth valve port, the second valve port is controlled to be connected to the third valve port, the fourth valve port is controlled to be connected to the fifth valve port, and the fifth valve port is controlled to be connected to the sixth valve port, so as to switch to a detection path for detecting the content of the third batch of measurement components in the gas to be tested, and perform detection of the content of the third batch of measurement components in the gas to be tested; and

[0037] Detection of the second batch of measurement components: After the detection of the third batch of measurement components is completed, the first valve port is controlled to be connected with the second valve port, the second valve port is connected with the third valve port via the second separation module, the third valve port is connected with the sixth valve port, and the fourth valve port is connected with the fifth valve port, so as to switch to a detection path for detecting the content of the second batch of measurement components in the gas to be tested, and perform detection of the content of the second batch of measurement components in the gas to be tested.

[0038] In some embodiments, the first batch of measurement components detection also includes:

[0039] Gas chromatograph preparation steps: perform self-check, control the first valve port to be connected with the second valve port, the second valve port to be connected with the third valve port via the second separation module, the third valve port to be connected with the sixth valve port, the fourth valve port to be connected with the fifth valve port, so as to switch to the carrier gas preparation path and introduce the carrier gas.

[0040] By implementing the present invention, the following beneficial effects are achieved:

[0041] The present invention integrates the first separation module and the second separation module into a single gas chromatograph, and uses a reversing valve to switch and detect the contents of the first batch of measurement components, the second batch of measurement components, and the third batch of measurement components in the gas to be measured, thereby realizing a one-time detection of the gas components to be measured by a gas chromatograph during a single sampling process, significantly improving the detection efficiency. This design reduces the sampling amount and analysis workload of the gas to be measured, and effectively reduces time and cost. At the same time, the gas chromatograph can complete the analysis of complex samples in a relatively short time with its high separation efficiency and rapid analysis capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0043] Figure 1 A schematic diagram showing a first internal communication state of a reversing valve in a gas chromatograph according to an embodiment of the present invention is shown;

[0044] Figure 2 A schematic diagram showing a second internal communication state of a reversing valve in a gas chromatograph according to an embodiment of the present invention is shown;

[0045] Figure 3 The quality control gas analysis spectrum before transformation of an embodiment of the gas chromatograph of the present invention is shown;

[0046] Figure 4 The figure shows the quality control gas analysis spectrum after modification in one embodiment of the gas chromatograph of the present invention;

[0047] Figure 5 The figure shows the analysis results of the gas chromatograph before and after the modification of one embodiment of the gas chromatograph of the present invention. DETAILED DESCRIPTION

[0048] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0049] It should be noted that the flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0050] The block diagrams shown in the accompanying drawings are only functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0051] Some embodiments of the present invention disclose a gas chromatograph, comprising a first separation module 1, a second separation module 2, a detection module 3 and a reversing valve 4, as follows:

[0052] The first separation module 1 is used to separate the first batch of measurement components in the gas to be measured and the second batch of measurement components in the gas to be measured, and to allow the first batch of measurement components and the second batch of measurement components to pass through, and to temporarily store the third batch of measurement components in the gas to be measured. The second separation module 2 is used to separate the first batch of measurement components in the gas to be measured and allow the first batch of measurement components to pass through, and to temporarily store the second batch of measurement components. The detection module 3 is used to detect the component content in the gas to be measured.

[0053] The reversing valve 4 is used to switch the content detection of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components. The reversing valve 4 includes a first valve port 41, a second valve port 42, a third valve port 43, a fourth valve port 44, a fifth valve port 45 and a sixth valve port 46.

[0054] Among them, the outlet end of the first separation module 1 is connected to the first valve port 41, the inlet end of the second separation module 2 is connected to the second valve port 42, the outlet end of the second separation module 2 is connected to the third valve port 43, the fourth valve port 44 is connected to the fifth valve port 45, and the inlet end of the detection module 3 is connected to the sixth valve port 46.

[0055] In some embodiments, the first separation module 1 is a chromatographic column, which is used to separate the first batch of measurement components and the second batch of measurement components in the gas to be measured and allow the first batch of measurement components and the second batch of measurement components to pass through, and temporarily store the third batch of measurement components in the gas to be measured.

[0056] The second separation module 2 is a molecular sieve, which is used to separate the first batch of measurement components in the gas to be measured and allow the first batch of measurement components to pass through, and temporarily store the second batch of measurement components.

[0057] Among them, the gas to be measured refers to a gas used to determine whether there is a characteristic gas of insulating oil failure inside a transformer device filled with insulating oil, including at least one of the following characteristic gases of insulating oil failure: H2, CO, CH4, O2, N2, CO2, C2H2, C2H4 and C2H6. The first batch of measurement components includes a gas of at least one of the following chemical formulas: H2. The second batch of measurement components includes a gas of at least one of the following chemical formulas: CO, CH4, O2, N2. The third batch of measurement components includes a gas of at least one of the following chemical formulas: CO2, C2H2, C2H4, C2H6. It can be understood that at least one can be one, two, three or any number. Preferably, the first batch of measurement components includes a gas of the following chemical formula: H2. The second batch of measurement components includes a gas of the following chemical formulas: CO, CH4, O2, N2. The third batch of measurement components includes a gas of the following chemical formulas: CO2, C2H2, C2H4, C2H6.

[0058] In some embodiments, the reversing valve 4 is used to switch the content detection of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components. The reversing valve 4 includes a first valve port 41, a second valve port 42, a third valve port 43, a fourth valve port 44, a fifth valve port 45 and a sixth valve port 46.

[0059] Among them, the reversing valve 4 has two internal communication states, such as Figure 1 As shown, the first internal communication state is: the first valve port 41 is connected to the second valve port 42 , the third valve port 43 is connected to the sixth valve port 46 , and the fourth valve port 44 is connected to the fifth valve port 45 .

[0060] like Figure 2 As shown, the second internal communication state is: the first valve port 41 is connected to the fourth valve port 44 , the second valve port 42 is connected to the third valve port 43 , and the fifth valve port 45 is connected to the sixth valve port 46 .

[0061] For example, the reversing valve 4 is a six-way valve, and nitrogen is used as the power gas source of the six-way valve to provide power when the six-way valve switches the internal connection state. The six-way valve here is only an example and is not intended to limit the present application. It can also be other.

[0062] In some embodiments, Figure 1 As shown, the first valve port 41 is connected with the second valve port 42, the second valve port 42 is connected with the third valve port 43 via the second separation module 2, the third valve port 43 is connected with the sixth valve port 46, and the fourth valve port 44 is connected with the fifth valve port 45, the carrier gas enters the detection module 3 after passing through the first separation module 1, the first valve port 41, the second valve port 42, the second separation module 2, the third valve port 43 and the sixth valve port 46, forming a preparation path for the carrier gas.

[0063] like Figure 1 As shown, when the first valve port 41 is connected with the second valve port 42, the second valve port 42 is connected with the third valve port 43 via the second separation module 2, the third valve port 43 is connected with the sixth valve port 46, and the fourth valve port 44 is connected with the fifth valve port 45, the gas to be measured is separated into the first batch of measurement components and the second batch of measurement components after passing through the first separation module 1, the first batch of measurement components and the second batch of measurement components are separated into the first batch of measurement components after passing through the first valve port 41, the second valve port 42 and the second separation module 2, and the first batch of measurement components enter the detection module 3 after passing through the third valve port 43 and the sixth valve port 46, forming a detection path for detecting the content of the first batch of measurement components in the gas to be measured.

[0064] like Figure 2As shown, when the first valve port 41 is connected with the fourth valve port 44, the second valve port 42 is connected with the third valve port 43, the fourth valve port 44 is connected with the fifth valve port 45, and the fifth valve port 45 is connected with the sixth valve port 46, the third batch of measurement components temporarily present in the gas to be measured in the first separation module 1 enters the detection module 3 after passing through the first separation module 1, the first valve port 41, the fourth valve port 44, the fifth valve port 45 and the sixth valve port 46, forming a detection path for detecting the content of the third batch of measurement components in the gas to be measured.

[0065] like Figure 1 As shown, when the first valve port 41 is connected with the second valve port 42, the second valve port 42 is connected with the third valve port 43 via the second separation module 2, the third valve port 43 is connected with the sixth valve port 46, and the fourth valve port 44 is connected with the fifth valve port 45, the second batch of measurement components temporarily present in the second separation module 2 in the gas to be measured enters the detection module 3 after passing through the second separation module 2, the third valve port 43 and the sixth valve port 46, thereby forming a detection path for detecting the content of the second batch of measurement components in the gas to be measured.

[0066] In some embodiments, the gas chromatograph further includes a sample loading module 5 , which is used for carrying the gas to be tested into the first separation module 1 with carrier gas, and the outlet end of the sample loading module 5 is connected to the inlet end of the first separation module 1 .

[0067] In some embodiments, the sample loading module 5 includes a sample gas unit 51 and a carrier gas unit 52. The sample gas unit 51 is used to introduce the gas to be tested, and the outlet end of the sample gas unit 51 is connected to the inlet end of the first separation module 1. The carrier gas unit 52 is used to introduce a carrier gas to carry the gas to be tested, and the carrier gas is argon gas. The outlet end of the carrier gas unit 52 is connected to the inlet end of the first separation module 1.

[0068] In some embodiments, the gas chromatograph further includes a damping module 6 , which is used to control the flow rate of the gas to be measured. The inlet end of the damping module 6 is connected to the fourth valve port 44 , and the outlet end of the damping module 6 is connected to the fifth valve port 45 .

[0069] In some embodiments, Figure 1 As shown, the detection module 3 includes a first detection unit 31, a conversion unit 32, a second detection unit 33 and a data processing unit 34, which are specifically as follows:

[0070] The first detection unit 31 is used to detect the components obtained after separation of the gas to be tested. The conversion unit 32 is used to convert the components obtained after separation of the gas to be tested to obtain the converted components of the gas to be tested. The second detection unit 33 is used to detect the converted components of the gas to be tested. The data processing unit 34 is used to process the detection data of the first detection unit 31 and the second detection unit 33.

[0071] The sixth valve port 46 is connected to the inlet of the first detection unit 31, the outlet of the first detection unit 31 is connected to the inlet of the conversion unit 32, and the outlet of the conversion unit 32 is connected to the inlet of the second detection unit 33. The data processing unit 34 is connected to the first detection unit 31 and the second detection unit 33 in communication.

[0072] In some embodiments, the first detection unit 31 is a thermal conductivity detector (TCD). When the gas to be measured passes through the thermal conductivity detector, the temperature of the heating wire will change due to the difference in thermal conductivity between the gas to be measured and the carrier gas. This change will cause the resistance of the heating wire to change, which is then measured and converted into a signal. The thermal conductivity detector (TCD) here is only an example and is not intended to be a limitation of the present application. It can also be other.

[0073] In some embodiments, the conversion unit 32 is a nickel converter, which is used to convert carbon monoxide and carbon dioxide into methane, thereby improving the detection sensitivity of the flame ionization detector (FID) to carbon monoxide and carbon dioxide. The nickel converter here is only an example and is not intended to limit the present application. It can also be other types.

[0074] In some embodiments, the second detection unit 33 is a flame ionization detector (FID). The working principle of the flame ionization detector is to generate a flame in a mixture of hydrogen and air, introduce the substance to be tested into the flame, cause it to undergo an oxidation reaction and produce ionization, and then these ions are detected by the ionization detector to generate a weak current, which is converted into a voltage signal after amplification for recording and processing the detection results. The flame ionization detector (FID) here is only an example and is not intended to be a limitation of the present application. It can also be other.

[0075] Some embodiments of the present invention further disclose a detection control method of the gas chromatograph described in any of the above embodiments, comprising: a first batch of measurement component detection step, a third batch of measurement component detection step, and a second batch of measurement component detection step, specifically as follows:

[0076] The first batch of measurement component detection step: control the first valve port 41 to be connected with the second valve port 42, the second valve port 42 to be connected with the third valve port 43 via the second separation module 2, the third valve port 43 to be connected with the sixth valve port 46, and the fourth valve port 44 to be connected with the fifth valve port 45, so as to switch to the detection path for detecting the content of the first batch of measurement components in the gas to be measured, and detect the content of the first batch of measurement components in the gas to be measured;

[0077] The third batch of measurement component detection step: after the first batch of measurement component detection is completed, the first valve port 41 is controlled to be connected with the fourth valve port 44, the second valve port 42 is controlled to be connected with the third valve port 43, the fourth valve port 44 is controlled to be connected with the fifth valve port 45, and the fifth valve port 45 is controlled to be connected with the sixth valve port 46, so as to switch to the detection path for detecting the content of the third batch of measurement components in the gas to be tested, and the content of the third batch of measurement components in the gas to be tested is detected;

[0078] Second batch measurement component detection step: After the third batch of measurement component detection is completed, the first valve port 41 is controlled to be connected with the second valve port 42, the second valve port 42 is connected with the third valve port 43 through the second separation module 2, the third valve port 43 is connected with the sixth valve port 46, and the fourth valve port 44 is connected with the fifth valve port 45, so as to switch to the detection path for detecting the content of the second batch of measurement components in the gas to be tested, and detect the content of the second batch of measurement components in the gas to be tested.

[0079] For example: Figure 1 As shown, the first batch of measurement component detection: control the first valve port 41 to be connected with the second valve port 42, the second valve port 42 to be connected with the third valve port 43 through the second separation module 2, the third valve port 43 to be connected with the sixth valve port 46, the fourth valve port 44 to be connected with the fifth valve port 45, the sample gas unit 51 adds the gas to be tested, and the carrier gas carries the gas to be tested into the instrument for separation and detection of each component. The first batch of measurement components (H2) preferentially pass through the first separation module 1 (chromatographic column) and the second separation module 2 (molecular sieve), and the content is detected by the first detection unit 31 (TCD). At this time, the second batch of measurement components (CO, CH4, O2, N2) are temporarily stored in the second separation module 2 (molecular sieve), and the third batch of measurement components (CO2, C2H2, C2H4, C2H6) are temporarily stored in the first separation module 1 (chromatographic column).

[0080] like Figure 2 As shown, the third batch of measurement component detection: after the first batch of measurement components (H2) are detected, the first valve port 41 is controlled to be connected with the fourth valve port 44, the second valve port 42 is connected with the third valve port 43, the fourth valve port 44 is connected with the fifth valve port 45, and the fifth valve port 45 is connected with the sixth valve port 46. At this time, a closed space is formed between the second separation module 2, the second valve port 42 and the third valve port 43, and the second batch of measurement components (CO, CH4, O2, N2) are temporarily stored in the second separation module 2 (molecular The third batch of measurement components (CO2, C2H2, C2H4, C2H6) temporarily stored in the first separation module 1 (chromatographic column) are carried by the carrier gas to the downstream first detection unit 31 (TCD), conversion unit 32 (nickel converter), and second detection unit 33 (FID). The third batch of measurement components (CO2, C2H2, C2H4, C2H6) are converted into CH4 in the conversion unit 32 (nickel converter), and finally their contents are detected in the second detection unit 33 (FID).

[0081] like Figure 1 As shown, the second batch of measurement component detection: after the third batch of measurement components (CO2, C2H2, C2H4, C2H6) detection is completed, the first valve port 41 is controlled to be connected with the second valve port 42, the second valve port 42 is connected with the third valve port 43 via the second separation module 2, the third valve port 43 is connected with the sixth valve port 46, the fourth valve port 44 is connected with the fifth valve port 45, at this time the closed space is opened, O2 and N2 are brought into the first detection unit 31 (TCD) by the carrier gas to detect the content, CO and CH4 are brought into the conversion unit 32 (nickel converter) and the second detection unit 33 (FID) by the carrier gas to complete the content detection.

[0082] In some embodiments, the first batch of measurement component detection steps also include:

[0083] Gas chromatograph preparation steps: perform self-inspection, control the first valve port 41 to be connected with the second valve port 42, the second valve port 42 to be connected with the third valve port 43 via the second separation module 2, the third valve port 43 to be connected with the sixth valve port 46, the fourth valve port 44 to be connected with the fifth valve port 45, to switch to the carrier gas preparation path and introduce the carrier gas.

[0084] For example: Figure 1 As shown, after the instrument completes the startup performance measurement and quality control verification, the first valve port 41 is controlled to be connected with the second valve port 42, the second valve port 42 is connected with the third valve port 43 via the second separation module 2, the third valve port 43 is connected with the sixth valve port 46, and the fourth valve port 44 is connected with the fifth valve port 45, so as to switch to the preparation path for the carrier gas and introduce the carrier gas. The startup performance measurement and quality control verification here are only examples and are not intended to be a limitation on the present application.

[0085] The following is a specific embodiment of the present invention:

[0086] The present invention relates to the transformation of an existing gas chromatograph, which mainly includes a chromatographic column, a molecular sieve, a six-way valve, a ten-element standard gas, a ten-element quality control gas, argon and nitrogen. The core of the transformation is to add a chromatographic column or a molecular sieve to an existing gas chromatograph, and use a reversing valve to switch and detect the contents of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components in the gas to be measured, so as to realize a one-time detection of the gas components to be measured by a gas chromatograph in a single sampling process, and replace the nitrogen carrier gas originally used with argon, thereby enhancing the instrument's ability to analyze nitrogen in insulating oil. In addition, by re-debugging and setting the operating parameters of the instrument, the present invention realizes the function of a chromatograph being able to simultaneously analyze the types of fault characteristic gases and the total gas content of the fault characteristic gases.

[0087] In the relevant technology, the two original gas chromatographs in the power plant are equipped with thermal conductivity detectors (TCD) and flame ionization detectors (FID). Among them, the No. 1 chromatograph measures the hydrogen (H2), methane (CH4), ethylene (C2H4), ethane (C2H6), acetylene (C2H2), carbon monoxide (CO) and carbon dioxide (CO2) in the fault characteristic gas of the insulating oil by installing a chromatographic column; while the No. 2 chromatograph measures the hydrogen (H2), oxygen (O2) and nitrogen (N2) content in the fault characteristic gas of the insulating oil by installing a molecular sieve, and adds them to the fault characteristic gas content detected by the No. 1 chromatograph to obtain the total gas content of the fault characteristic gas of the insulating oil sample. The implementation of this transformation plan mainly follows the following seven steps:

[0088] In the first step of the renovation plan, chromatograph No. 1 was originally equipped with only one column and no molecular sieves, and could only analyze fault characteristic gases such as hydrogen (H2), methane (CH4), ethylene (C2H4), ethane (C2H6), acetylene (C2H2), carbon monoxide (CO), and carbon dioxide (CO2). In the renovation plan, a molecular sieve was added downstream of the column to expand its analytical capabilities to include oxygen (O2) and nitrogen (N2). Similarly, chromatograph No. 2 was originally equipped with only molecular sieves and no chromatographic columns, and could only analyze hydrogen (H2), oxygen (O2), and nitrogen (N2). In the renovation, a chromatographic column was added upstream of the molecular sieve to increase the analytical capabilities of hydrogen (H2), methane (CH4), ethylene (C2H4), ethane (C2H6), acetylene (C2H2), carbon monoxide (CO), and carbon dioxide (CO2). With these modifications, both chromatographs are now able to analyze a wider range of gas components.

[0089] In the second step of the transformation plan, the carrier gas of the gas chromatograph was changed from nitrogen to argon. The main purpose of this change was to enable the chromatograph to analyze the nitrogen content in the insulating oil. If the carrier gas is not changed, the nitrogen in the insulating oil will be masked by the nitrogen used as the carrier gas, resulting in an inability to perform accurate analysis. By switching to argon as the carrier gas, this interference can be avoided, thereby achieving effective detection of the nitrogen content in the insulating oil.

[0090] In the third step of the transformation plan, the nitrogen originally designed as the No. 1 chromatograph carrier gas was reconfigured to be used as the power source of the six-way valve. This change enables the six-way valve to obtain the required power when switching to ensure its normal operation. At the same time, the specific configuration of the six-way valve can be set and adjusted accordingly according to the actual analysis needs to meet the operation requirements of the chromatograph under different analysis conditions.

[0091] In the fourth step of the transformation plan, the standard gas used by the chromatograph was updated. The original three-element standard gas and eight-element standard gas were used, but now it is changed to ten-element standard gas. This new ten-element standard gas is composed according to the content ratio of each component, including nine fault characteristic gases, including hydrogen (H2), methane (CH4), ethylene (C2H4), ethane (C2H6), acetylene (C2H2), carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), and nitrogen (N2), as well as argon as a balance gas, a total of ten gases. Such a change allows the standard gas to more comprehensively cover the types of gases that need to be analyzed, thereby improving the accuracy and reliability of chromatograph analysis.

[0092] In the fifth step of the modification plan, the chromatograph needs to be re-debugged and the operating parameters set. After adding the chromatographic column or molecular sieve, completing the pipeline modification and carrier gas replacement, the instrument must be carefully debugged and verified. The purpose of this process is to select the best operating parameters to ensure that the chromatograph can analyze the gas sample efficiently and accurately. The parameters that need to be adjusted and optimized include furnace temperature, hydrogen flow rate, air flow rate, reference gas flow rate, tail gas flow rate, carrier gas flow rate, heater temperature, peak time, and detection sensitivity. The precise setting of these parameters is crucial to the performance of the chromatograph and directly affects the accuracy and repeatability of the analysis results. Through this step, it can be ensured that the chromatograph can achieve the expected analysis effect after the modification.

[0093] In the sixth step of the modification plan, once the chromatograph has been debugged and verified, the next step is to recalibrate the instrument's analytical curve using standard gas. This ensures that all parameters meet the required standards and requirements. After the calibration is completed, the content of each component will be verified using quality control gas to ensure the accuracy and stability of the instrument's analysis. The quality control gas analysis spectrum before the modification can be referenced Figure 3 , and the modified quality control gas analysis chart is shown in Figure 4 These graphs provide an intuitive comparison of the modification effects, helping to evaluate whether the modification was successful and whether the instrument performance has been improved. This step can confirm whether the chromatograph can meet the functional requirements of analyzing fault characteristic gases and total gas content after modification.

[0094] In the seventh step of the transformation plan, it is necessary to measure and compare the actual samples of the transformed chromatograph. The purpose of this step is to ensure that the transformed chromatograph can provide accurate and reliable data in actual applications. To this end, different samples of the same transformer equipment will be monitored and the data before and after the transformation will be compared (indicated by a white background). If the fluctuations in various parameters are small and consistent with historical trends, this indicates that the transformation is successful. The data after the transformation (indicated by a gray background) generally shows a slow upward trend, which is consistent with the extension of the transformer operation time and the natural increase in gas content, and is a normal phenomenon. The specific gas chromatograph analysis results before and after the transformation can be seen in detail. Figure 5 , which provides a detailed data comparison to verify the modification effect and the improvement of instrument performance. Through this step, it can be finally confirmed whether the modification has achieved the expected analytical effect and ensure that the chromatograph can provide high-quality data support for future sample analysis.

[0095] By implementing the present invention, the following beneficial effects are achieved:

[0096] Compared with the prior art, the present invention can complete the comprehensive detection of nine insulating oil characteristic fault gases, including H2 (hydrogen), CH4 (methane), C2H6 (ethane), C2H4 (ethylene), C2H2 (acetylene), CO (carbon monoxide), CO2 (carbon dioxide), O2 (oxygen), and N2 (nitrogen) in a single sampling process. This one-time detection capability greatly improves the detection efficiency because it reduces the sampling amount of insulating oil and the workload of analytical detection, thereby reducing the time and cost consumption in the detection process. In addition, the gas chromatograph of the present invention has the characteristics of high separation efficiency and rapid analysis, and can complete the analysis of complex samples in a shorter time. This means that compared with the existing methods, the present invention can not only reduce the sample usage, but also improve the detection sensitivity. This high-sensitivity detection capability is crucial for early identification and prevention of potential faults in transformer equipment.

[0097] It is understandable that the above embodiments only express some implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above embodiments or technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the present invention, that is, the embodiments described in "some embodiments" can be freely combined with any of the above and below embodiments. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the scope of the claims of the present invention.

Claims

1. A gas chromatograph, characterized in that: include: A first separation module (1) is used to separate a first batch of measurement components in the gas to be measured and a second batch of measurement components in the gas to be measured, and to allow the first batch of measurement components and the second batch of measurement components to pass through, and to temporarily store a third batch of measurement components in the gas to be measured; A second separation module (2) is used to separate a first batch of measurement components from the gas to be measured and allow the first batch of measurement components to pass through, and temporarily store the second batch of measurement components; A detection module (3) is used to detect the content of components in the gas to be detected; and a reversing valve (4), the reversing valve (4) being used for switching the content detection of the first batch of measurement components, the second batch of measurement components and the third batch of measurement components, the reversing valve (4) comprising a first valve port (41), a second valve port (42), a third valve port (43), a fourth valve port (44), a fifth valve port (45) and a sixth valve port (46); Wherein, the outlet end of the first separation module (1) is connected to the first valve port (41), the inlet end of the second separation module (2) is connected to the second valve port (42), the outlet end of the second separation module (2) is connected to the third valve port (43), the fourth valve port (44) is connected to the fifth valve port (45), and the inlet end of the detection module (3) is connected to the sixth valve port (46).

2. The gas chromatograph according to claim 1, characterized in that The first valve port (41) is in communication with the second valve port (42), the second valve port (42) is in communication with the third valve port (43) via the second separation module (2), the third valve port (43) is in communication with the sixth valve port (46), and the fourth valve port (44) is in communication with the fifth valve port (45), the gas to be measured is separated into the first batch of measurement components and the second batch of measurement components after passing through the first separation module (1), the first batch of measurement components and the second batch of measurement components are separated into the first batch of measurement components after passing through the first valve port (41), the second valve port (42) and the second separation module (2), and the first batch of measurement components enter the detection module (3) after passing through the third valve port (43) and the sixth valve port (46), thereby forming a detection path for detecting the content of the first batch of measurement components in the gas to be measured; When the first valve port (41) is in communication with the fourth valve port (44), the second valve port (42) is in communication with the third valve port (43), the fourth valve port (44) is in communication with the fifth valve port (45), and the fifth valve port (45) is in communication with the sixth valve port (46), the third batch of measurement components in the gas to be measured that are temporarily stored in the first separation module (1) enter the detection module (3) after passing through the first separation module (1), the first valve port (41), the fourth valve port (44), the fifth valve port (45) and the sixth valve port (46), thereby forming a detection path for detecting the content of the third batch of measurement components in the gas to be measured; The first valve port (41) is communicated with the second valve port (42), the second valve port (42) is communicated with the third valve port (43) via the second separation module (2), the third valve port (43) is communicated with the sixth valve port (46), and the fourth valve port (44) is communicated with the fifth valve port (45), the second batch of measurement components temporarily stored in the second separation module (2) in the gas to be measured enters the detection module (3) after passing through the second separation module (2), the third valve port (43) and the sixth valve port (46), thereby forming a detection path for detecting the content of the second batch of measurement components in the gas to be measured.

3. The gas chromatograph according to claim 1, characterized in that: The gas chromatograph also includes: The sample loading module (5) is used for carrying the gas to be tested into the first separation module (1) with a carrier gas, and the outlet end of the sample loading module (5) is connected to the inlet end of the first separation module (1).

4. The gas chromatograph according to claim 3, characterized in that: The sample loading module (5) comprises: A sample gas unit (51) is used to introduce the gas to be tested, and the outlet end of the sample gas unit (51) is connected to the inlet end of the first separation module (1); A carrier gas unit (52) is used to introduce a carrier gas to carry the gas to be tested, wherein the carrier gas is argon gas, and an outlet end of the carrier gas unit (52) is connected to an inlet end of the first separation module (1).

5. The gas chromatograph according to claim 3 or 4, characterized in that: The first valve port (41) is connected to the second valve port (42), the second valve port (42) is connected to the third valve port (43) via the second separation module (2), the third valve port (43) is connected to the sixth valve port (46), and the fourth valve port (44) is connected to the fifth valve port (45), the carrier gas enters the detection module (3) after passing through the first separation module (1), the first valve port (41), the second valve port (42), the second separation module (2), the third valve port (43) and the sixth valve port (46), thereby forming a preparation path for the carrier gas.

6. The gas chromatograph according to claim 1, characterized in that: The gas chromatograph also includes: The damping module (6) is used to control the flow rate of the gas to be measured, wherein the inlet end of the damping module (6) is connected to the fourth valve port (44), and the outlet end of the damping module (6) is connected to the fifth valve port (45).

7. The gas chromatograph according to claim 1, characterized in that: The detection module (3) comprises: A first detection unit (31), the first detection unit (31) is used to detect components obtained by separating the gas to be detected; A conversion unit (32), the conversion unit (32) is used to convert the components of the gas to be tested obtained by separation to obtain the converted components of the gas to be tested; A second detection unit (33), the second detection unit (33) is used to detect the converted components of the gas to be detected; and A data processing unit (34), the data processing unit (34) being used for processing detection data of the first detection unit (31) and the second detection unit (33); The sixth valve port (46) is connected to the inlet end of the first detection unit (31), the outlet end of the first detection unit (31) is connected to the inlet end of the conversion unit (32), and the outlet end of the conversion unit (32) is connected to the inlet end of the second detection unit (33); The data processing unit (34) is communicatively connected to the first detection unit (31) and the second detection unit (33).

8. The gas chromatograph according to claim 1, characterized in that: The first batch of measurement components includes a gas of at least one of the following chemical formulas: H2; The second batch of measurement components includes gases of at least one of the following chemical formulas: CO, CH4, O2, N2; The third batch of measurement components includes gases of at least one of the following chemical formulas: CO2, C2H2, C2H4, C2H6.

9. A detection and control method for a gas chromatograph according to any one of claims 1 to 8, characterized in that: The following steps are involved: Detection of the first batch of measurement components: controlling the first valve port (41) to be connected to the second valve port (42), the second valve port (42) to be connected to the third valve port (43) via the second separation module (2), the third valve port (43) to be connected to the sixth valve port (46), the fourth valve port (44) to be connected to the fifth valve port (45), so as to switch to a detection path for detecting the content of the first batch of measurement components in the gas to be measured, and perform detection of the content of the first batch of measurement components in the gas to be measured; Detection of the third batch of measurement components: after the detection of the first batch of measurement components is completed, the first valve port (41) is controlled to be connected with the fourth valve port (44), the second valve port (42) is controlled to be connected with the third valve port (43), the fourth valve port (44) is controlled to be connected with the fifth valve port (45), and the fifth valve port (45) is controlled to be connected with the sixth valve port (46), so as to switch to a detection path for detecting the content of the third batch of measurement components in the gas to be measured, and to detect the content of the third batch of measurement components in the gas to be measured; as well as, Detection of the second batch of measurement components: after the detection of the third batch of measurement components is completed, the first valve port (41) is controlled to be connected with the second valve port (42), the second valve port (42) is controlled to be connected with the third valve port (43) via the second separation module (2), the third valve port (43) is connected with the sixth valve port (46), and the fourth valve port (44) is controlled to be connected with the fifth valve port (45), so as to switch to a detection path for detecting the content of the second batch of measurement components in the gas to be measured, and to detect the content of the second batch of measurement components in the gas to be measured.

10. The detection and control method of gas chromatograph according to claim 9, characterized in that: The first batch of measuring components is preceded by: Gas chromatograph preparation steps: perform self-check, control the first valve port (41) to be connected with the second valve port (42), the second valve port (42) to be connected with the third valve port (43) via the second separation module (2), the third valve port (43) to be connected with the sixth valve port (46), the fourth valve port (44) to be connected with the fifth valve port (45), so as to switch to the preparation path for carrier gas and introduce carrier gas.

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