Self-inspection method for gas circulation devices

Abstract

This invention discloses a self-testing method for a gas circulation device. The method, applied to a gas circulation device, includes: acquiring the initial pressure value of the gas chamber under test during current gas mixing; controlling the gas circulation device to perform one gas mixing cycle; calculating the volume of the gas chamber under test based on the gas flow rate when the gas in the gas chamber under test is delivered to the first gas chamber, the concentration of gas decomposition products, the initial pressure value, and the current pressure value; comparing the difference between the volume of the gas chamber under test calculated during the current gas mixing cycle and the volume of the gas chamber under test calculated during historical gas mixing cycles to determine whether the gas decomposition product concentration measuring device is malfunctioning. By performing a self-test on the gas circulation device based on the calculated volume of the gas chamber under test before each gas decomposition product concentration detection, problems with the gas circulation device can be detected in a timely manner, ensuring the accuracy of concentration detection.

Description

Technical Field

[0001] This invention relates to the field of gas concentration detection technology, and more particularly to a self-testing method for gas circulation devices. Background Technology

[0002] Sulfur hexafluoride (SF6) is widely used in high-voltage electrical equipment (such as GIS switchgear, circuit breakers, and instrument transformers) due to its excellent insulation and arc-quenching properties. However, arc discharge or overheating faults inside high-voltage electrical equipment can cause SF6 gas to decompose, producing toxic and corrosive products such as SO2, HF, and H2S, leading to insulation degradation, equipment explosions, and environmental hazards.

[0003] Therefore, monitoring SF6 decomposition products is crucial for assessing the insulation condition of equipment, diagnosing potential faults, and predicting equipment lifespan. It is a key means of condition-based maintenance and ensuring the safe operation of the power grid. However, existing gas monitoring technologies still suffer from significant errors in detecting the concentration of gas decomposition products. Summary of the Invention

[0004] Therefore, it is necessary to propose a self-testing method for gas circulation devices to address the above problems. This method aims to eliminate detection errors caused by concentration detection equipment and improve the accuracy of concentration detection by performing self-testing on the gas circulation devices.

[0005] To achieve the above objectives, the first aspect of this application provides a self-testing method for a gas circulation device. The method is applied to a gas circulation device comprising a first gas chamber and a second gas chamber, both of which are connected to a gas chamber to be tested. The first gas chamber is connected to the second gas chamber. The method includes:

[0006] Collect the initial pressure value of the gas in the test chamber when the gas is currently mixed;

[0007] Controlling the gas circulation device to perform one gas mixing operation refers to the process of controlling the gas in the test chamber to deliver gas to the first gas chamber and the second gas chamber respectively, and the gas in the first gas chamber and the gas in the second gas chamber being transported back to the test chamber according to a preset path.

[0008] The volume of the gas chamber to be tested is calculated based on the gas flow rate when the gas in the gas chamber to be tested is delivered to the first gas chamber, the concentration of gas decomposition products, the initial pressure value, and the current pressure value.

[0009] The volume of the gas chamber to be tested, calculated when the gas is currently mixed, is compared with the volume of the gas chamber to be tested when the gas is historically mixed to determine whether the gas circulation device is malfunctioning.

[0010] Furthermore, the step of comparing the difference between the volume of the gas chamber to be tested calculated based on the current gas mixing and the volume of the gas chamber to be tested calculated based on historical gas mixing to determine whether the gas circulation device has malfunctioned specifically includes:

[0011] The standard volume is obtained by averaging the volume of the test chamber calculated during historical gas mixing.

[0012] The volume error calculated during the current gas mixing is obtained by comparing the volume of the gas chamber to be tested calculated during the current gas mixing with the volume of the gas chamber to be tested calculated during the previous gas mixing.

[0013] When the volume error is greater than the standard volume by a preset multiple, the gas circulation device is considered to be malfunctioning, wherein the preset multiple is any value less than 1.

[0014] Furthermore, the volume of the test chamber when the current gas is mixed is calculated using the following formula:

[0015]

[0016] In the formula, The volume of the gas chamber to be tested is calculated when the gas is currently mixed. This is the pressure value under normal atmospheric pressure. The gas flow rate is the gas velocity when the gas in the chamber to be tested is transferred to the first chamber. The gas transmission time is the time it takes for the gas in the chamber to be tested to be transferred to the first chamber. This is the initial pressure value in the gas chamber to be tested when the gas is currently mixed. This is the current pressure value of the gas chamber under test when the gas is mixed.

[0017] Furthermore, the primary gas mixing process specifically includes:

[0018] The gas in the chamber to be tested is controlled to be delivered to the first chamber, and the current pressure value of the chamber to be tested is collected in real time; when the current pressure value in the chamber to be tested reaches the preset first pressure value, the gas delivery is stopped.

[0019] The gas in the chamber to be tested is controlled to be transported to the second chamber until the pressure between the chamber to be tested and the second chamber is balanced, and then the gas transmission is stopped.

[0020] After the gas supply from the test chamber to the second chamber is stopped, the gas in the first chamber is controlled to be delivered to the second chamber until the pressure between the first chamber and the second chamber is balanced and the gas supply is stopped.

[0021] After the first gas chamber stops transmitting gas to the second gas chamber, the gas in the second gas chamber is controlled to be delivered to the gas chamber to be tested until the pressure between the second gas chamber and the gas chamber to be tested is balanced, and then the gas transmission is stopped to achieve gas mixing once.

[0022] Furthermore, the primary gas mixing process specifically includes:

[0023] The gas in the chamber to be tested is controlled to be delivered to the first chamber, and the current pressure value of the chamber to be tested is collected in real time; when the current pressure value in the chamber to be tested reaches the preset second pressure value, the gas delivery is stopped.

[0024] The gas in the chamber to be tested is controlled to be transported to the second chamber until the pressure between the chamber to be tested and the second chamber is balanced, and then the gas transmission is stopped.

[0025] After the gas supply to the second gas chamber is stopped in the test chamber, the gas in the first gas chamber is controlled to be supplied to the test chamber. When the current pressure value in the test chamber reaches the preset third pressure value, the gas supply is stopped.

[0026] The gas in the second chamber is controlled to be delivered to the test chamber. When the current pressure value in the test chamber reaches the preset fourth pressure value, the gas delivery is stopped to achieve gas mixing once.

[0027] Furthermore, the gas circulation device also includes: a first density meter, a flow meter, and an infrared gas analyzer, wherein the first density meter is used to connect to the gas chamber to be tested, and the flow meter and the infrared gas analyzer are both disposed between the gas chamber to be tested and the first gas chamber;

[0028] The first density meter is used to measure the pressure value of the gas chamber to be tested;

[0029] The flow meter is used to collect the gas flow rate when the gas in the gas chamber to be measured is transferred to the first gas chamber;

[0030] The infrared gas analyzer is used to collect the concentration of gas decomposition products when the gas in the test chamber is transferred to the first chamber.

[0031] Furthermore, the gas circulation device also includes: a first solenoid valve, a second solenoid valve, a pressure reducing valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, and a second density gauge.

[0032] The second density meter is connected to the second air chamber and is used to measure the pressure value of the second air chamber;

[0033] One end of the first solenoid valve is connected to the gas chamber to be tested. One end of the pressure reducing valve is connected to the other end of the first solenoid valve and one end of the second solenoid valve. The other end of the second solenoid valve is connected to one gas port of the second gas chamber. The other end of the pressure reducing valve is connected to one end of the flow meter. One end of the flow meter is connected to one end of the third solenoid valve. The other end of the third solenoid valve is connected to one end of the infrared gas analyzer. The other end of the infrared gas analyzer is connected to one end of the fourth solenoid valve. The other end of the fourth solenoid valve is connected to one gas port of the first gas chamber. The other gas port of the first gas chamber is connected to one end of the fifth solenoid valve. The other end of the fifth solenoid valve is connected to the other gas port of the second gas chamber.

[0034] When the gas in the test chamber is transferred to the first chamber, the first solenoid valve, the pressure reducing valve, the third solenoid valve, and the fourth solenoid valve are opened; when the test chamber stops transferring gas to the first chamber, the first solenoid valve, the pressure reducing valve, the third solenoid valve, and the fourth solenoid valve are closed.

[0035] When the gas in the test chamber is transferred to the second chamber, the first and second solenoid valves are opened; when the test chamber stops transferring gas to the second chamber, the first and second solenoid valves are closed.

[0036] When gas in the first chamber is transferred to the second chamber, or gas in the second chamber is transferred to the first chamber, the fifth solenoid valve is opened; when the first chamber stops transferring gas to the second chamber, or the second chamber stops transferring gas to the first chamber, the fifth solenoid valve is closed.

[0037] Furthermore, a thermoelectric cooler is installed inside the first air chamber to cool the first air chamber and reduce the pressure value inside the first air chamber, so as to realize the transfer of gas from the test air chamber to the first air chamber, or the transfer of gas from the second air chamber to the first air chamber.

[0038] The thermoelectric cooler is also used to heat the first gas chamber and increase the pressure value inside the first gas chamber, so as to realize the transfer of gas from the first gas chamber to the second gas chamber, or the transfer of gas from the first gas chamber to the gas chamber to be tested.

[0039] Furthermore, an electric heating wire is installed on the outside of the second air chamber to heat the second air chamber and increase the pressure value inside the second air chamber, so as to realize the transfer of gas in the second air chamber to the air chamber to be tested, or the transfer of gas in the second air chamber to the first air chamber.

[0040] Furthermore, a gas diffuser is installed at the air inlet of the second air chamber, so that when gas enters the second air chamber, the gas drives the blades of the gas diffuser to rotate.

[0041] The embodiments of the present invention have the following beneficial effects:

[0042] This invention proposes a self-testing method for a gas circulation device. The method is applied to a gas circulation device including a first gas chamber and a second gas chamber, both of which are connected to a test gas chamber. The first gas chamber is connected to the second gas chamber. The method includes: acquiring the initial pressure value of the test gas chamber when the gas is currently mixed; controlling the gas circulation device to perform one gas mixing operation, where gas mixing refers to controlling the gas in the test gas chamber to be transported to the first and second gas chambers respectively, and the gas in the first and second gas chambers is transported back to the test gas chamber according to a preset path; calculating the volume of the test gas chamber at the current gas mixing time based on the gas flow rate, gas decomposition product concentration, initial pressure value, and current pressure value when the gas in the test gas chamber is transported to the first gas chamber; comparing the difference between the volume of the test gas chamber calculated at the current gas mixing time and the volume of the test gas chamber calculated at historical gas mixing times to determine whether the gas decomposition product concentration measuring device is malfunctioning. This invention performs a self-check on the gas circulation device based on the calculated volume of the gas chamber to be tested before each gas decomposition product concentration detection, thereby promptly identifying problems with the gas circulation device and ensuring the accuracy of gas decomposition product concentration detection. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] in:

[0045] Figure 1 This is a flowchart illustrating the self-testing method of the gas circulation device in an embodiment of the present invention.

[0046] Figure 2 This is a structural diagram of the gas circulation device in an embodiment of the present invention;

[0047] Figure 3 This is a structural diagram of a gas diffuser in an embodiment of the present invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] To ensure the accuracy of measuring the concentration of decomposition products in the test chamber based on a gas circulation device, one embodiment of the present invention proposes a self-testing method for the gas circulation device. Please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a flowchart illustrating the self-testing method of the gas circulation device in an embodiment of the present invention. The method is applied to a gas circulation device, which includes a first gas chamber and a second gas chamber. Both the first and second gas chambers are connected to the gas chamber to be tested. The first gas chamber is connected to the second gas chamber. The method includes:

[0050] Step 110: Collect the initial pressure value when the gas in the test chamber is mixed.

[0051] In this embodiment of the invention, the gas circulation device is used to mix the gas in the test chamber and detect the concentration of gas decomposition products. However, if the gas circulation device malfunctions, it can lead to poor mixing and large errors in the gas decomposition product concentration detection results. Therefore, self-testing of the gas circulation device is crucial and an important means to ensure the accuracy of the gas decomposition product concentration detection results in the test chamber.

[0052] Before the gas in the test chamber is mixed by the gas circulation control device, the initial pressure value in the test chamber is collected.

[0053] Step 120: Control the gas circulation device to perform one gas mixing operation. Gas mixing refers to the process of controlling the gas in the test chamber to deliver gas to the first and second chambers respectively, and the gas in the first and second chambers being transported back to the test chamber according to a preset path.

[0054] In this embodiment of the invention, the test chamber is filled with SF6 gas. Before measuring the concentration of decomposition products of the SF6 gas in the test chamber, the SF6 gas in the test chamber needs to be mixed to accelerate the diffusion rate of the decomposition products in the test chamber, so that representative gas can be obtained during gas sampling and detection, and more accurately reflect the true state of the test chamber.

[0055] The gas mixing process is achieved based on a gas circulation device, in which both the first and second gas chambers are connected to the gas chamber to be tested, and the first and second gas chambers are also connected. One gas mixing process involves controlling the gas chamber to be tested to move along a preset path through the first, second, and test gas chambers, and finally return to the test gas chamber.

[0056] In this embodiment of the invention, while the gas circulation device performs gas mixing and decomposition product concentration detection in the gas chamber to be tested, it further performs self-testing on the gas circulation device. Without adding redundant operation steps, it also ensures the gas mixing effect and the accuracy of the gas decomposition product concentration detection results.

[0057] Step 130: Calculate the volume of the gas chamber to be tested based on the gas flow rate, gas decomposition product concentration, initial pressure value, and current pressure value when the gas in the gas chamber to be tested is transported to the first gas chamber.

[0058] In this embodiment, a flow meter and an infrared gas analyzer can be installed between the first gas chamber and the gas chamber to be tested, and a density meter can be installed on the gas chamber to be tested. While the gas circulation device mixes the gas in the gas chamber to be tested, the flow meter collects the current pressure value of the gas chamber to be tested, and the infrared gas analyzer collects the gas flow rate and gas decomposition product concentration in real time when the gas in the gas chamber to be tested is transported to the first gas chamber. During the gas transmission process, it is necessary to collect the gas decomposition product concentration and gas flow rate at the sampling point in real time in order to calculate the target gas decomposition product concentration in the gas chamber to be tested. By collecting the gas decomposition product concentration and gas flow rate in real time during the gas transmission process, relevant gas data can be obtained in a timely and accurate manner, providing a more accurate basis for subsequent calculation of gas decomposition product concentration, thereby improving the reliability of the detection results.

[0059] Since the volume of the gas chamber to be tested is constant, the volume of the gas chamber to be tested can be dynamically calculated based on the gas flow rate, the concentration of gas decomposition products, the initial pressure value, and the current pressure value. This determines the volume of the gas chamber to be tested during each gas cycle. By comparing the volume of the gas chamber to be tested obtained each time with the standard volume, it can be determined whether there is a fault in the gas circulation device, such as the flow meter or density meter.

[0060] By collecting gas flow rate, gas decomposition product concentration and current pressure value in real time during gas mixing, and calculating the volume of the gas chamber to be tested based on these data, the calculated volume can be compared with the standard volume or historical volume data to quickly and accurately determine whether there is a fault in the gas circulation device. This allows for timely detection and handling of device faults, ensuring the normal operation of the gas circulation device and avoiding detection errors and safety hazards caused by device malfunctions.

[0061] Step 140: Compare the difference between the volume of the gas chamber to be tested calculated when the gas is mixed now and the volume of the gas chamber to be tested calculated when the gas is mixed in the past to determine whether the gas circulation device is malfunctioning.

[0062] In this embodiment, the error is calculated by comparing the volume of the gas chamber to be tested calculated when the current gas is mixed with the volume of the gas chamber to be tested calculated when the historical gas is mixed. If the error is large, it indicates that the current gas circulation device is faulty; if the error is small, it indicates that the current gas circulation device is normal and the gas mixing and concentration detection operations can continue to be performed.

[0063] This invention, through simultaneous gas mixing and concentration detection, monitors the operating status of the gas decomposition product concentration measuring device in real time, promptly identifying faults and taking corresponding maintenance measures to avoid errors in gas decomposition product concentration detection caused by measuring device malfunctions. It enhances the self-diagnostic capability of the gas circulation device, enabling it to autonomously diagnose faults in its own measuring device without relying on external detection equipment.

[0064] In one embodiment of the present invention, step 140, comparing the difference between the volume of the gas chamber to be tested calculated during the current gas mixing and the volume of the gas chamber to be tested calculated during historical gas mixing, to determine whether the gas circulation device has malfunctioned, specifically includes:

[0065] Step 141: Calculate the average volume of the gas chamber to be tested obtained when the historical gas was mixed, and obtain the standard volume.

[0066] In this embodiment, the volume of the test chamber calculated during all gas mixing before this gas mixing is obtained, and the average value of the volumes of the test chambers calculated during these historical gas mixing is calculated. This average value is used as the standard volume of the test chamber.

[0067] Considering that the volume of the gas chamber to be tested calculated each time the gas is mixed may have a certain detection error, fluctuating within the range of the standard volume, the average value of the gas chamber volume calculated in the past gas mixing is selected as the standard volume of the gas chamber to be tested to reduce the judgment error.

[0068] Step 142: Calculate the volume error calculated when mixing the gas under test based on the difference between the volume of the gas chamber under test calculated when mixing the gas under test at the current time and the volume of the gas chamber under test calculated at the previous time.

[0069] In this embodiment, the volume error calculated during the current gas mixing is determined by calculating the difference between the volume of the gas chamber to be tested calculated during the current gas mixing and the volume of the gas chamber to be tested calculated during the previous gas mixing. Based on the volume error during the current gas mixing, it is determined whether there is a fault in the gas circulation device.

[0070] Step 143: When the volume error is greater than the standard volume of the preset multiple, the gas circulation device is considered to be faulty. The preset multiple is any value less than 1.

[0071] In this embodiment, the preset multiplier can be adjusted arbitrarily, and it can be any value less than 1.

[0072] When the volume error is greater than the standard volume of a preset multiple, the gas decomposition product concentration measuring device is considered to be malfunctioning. For example, when the volume error is greater than 5% of the standard volume, the gas circulation device is considered to be malfunctioning and needs to be repaired in time to avoid large errors when detecting the concentration of gas decomposition products.

[0073] This invention, by comprehensively considering historical volume data and calculating the average value as the standard volume, effectively filters out volume fluctuations caused by external interference or accidental factors, reducing false alarms and missed alarms, and improving the stability and reliability of the entire monitoring system. The volume error is calculated each time the gas is mixed and compared with the preset multiple of the standard volume, providing a quantitative basis for fault assessment of the gas circulation device. This helps maintenance personnel to more accurately understand the operating status of the device, rationally arrange maintenance plans, take measures in advance, and reduce maintenance costs and equipment downtime. This step realizes the automated self-testing function of the gas circulation device, enabling it to autonomously diagnose faults in its own measuring devices without relying on external testing equipment. This not only improves the system's independence and autonomy but also enhances its intelligence level and reduces the need for manual intervention.

[0074] In one embodiment of the present invention, the volume of the gas chamber to be tested when the gas is mixed is calculated by the following formula:

[0075]

[0076] In the formula, This represents the volume of the gas chamber being tested, calculated when the gas is currently homogenized. This is the pressure value under normal atmospheric pressure. The gas flow rate is the gas velocity when the gas in the chamber to be tested is transferred to the first chamber. The gas transfer time is the time it takes for the gas in the chamber to be tested to be transferred to the first chamber. This represents the initial pressure value in the gas chamber under test when the gas is currently mixed. This represents the current pressure value of the gas chamber under test when the gas is mixed.

[0077] Based on the above-described self-testing method for the gas circulation device, an embodiment of the present invention conducts relevant experimental tests to test the detection effect of the self-testing method for the gas circulation device under different experimental conditions.

[0078] For details, please refer to Table 1, which shows the self-test results of the gas circulation device under different experimental conditions. According to Table 1, the gas mixing from the first to the fifth time was in normal operation of the gas circulation device. Under these conditions, the error between the initial volume of the gas chamber to be tested detected by the self-test method of the gas circulation device and the volume calculated after mixing was small, which was within the allowable gas circulation volume error of a normal gas circulation device. The sixth and seventh gas circulations used a damaged flow sensor and a pressure sensor, respectively. Under these conditions, the error between the initial volume of the gas chamber to be tested detected by the self-test method of the gas circulation device and the volume calculated after mixing was large, which was outside the allowable gas circulation volume error of a normal gas circulation device.

[0079] Based on the experimental data, it can be seen that the self-testing method of the gas circulation device proposed in the embodiments of the present invention can effectively detect whether there is a fault in the gas circulation device, and realize effective self-testing of the gas circulation device, so as to avoid the distortion of the concentration detection results caused by the fault of the gas circulation device during the concentration detection process based on the gas circulation device.

[0080] Table 1. Self-inspection results of the gas circulation device under different experimental conditions.

[0081]

[0082] In one embodiment of the present invention, a primary gas mixing process specifically includes:

[0083] Step 210: Control the gas in the test chamber to be delivered to the first chamber, and collect the current pressure value of the test chamber in real time; when the current pressure value in the test chamber reaches the preset first pressure value, stop the gas delivery.

[0084] In this embodiment, the gas mixing process and concentration detection can be achieved based on a gas circulation device. First, the gas in the test chamber is transported to the first chamber until the current pressure value in the test chamber reaches a preset first pressure value. This first pressure value can be set randomly, but it must be ensured that the current pressure value in the test chamber is not lower than a preset alarm pressure value.

[0085] Step 220: Control the gas in the test chamber to be transported to the second chamber until the pressure between the test chamber and the second chamber is balanced, then stop the gas transmission.

[0086] Specifically, after the pressure value in the test chamber reaches the first pressure value, the gas in the test chamber is transferred to the second chamber until the pressure in the test chamber and the second chamber are balanced. Once the pressure in the test chamber and the second chamber are balanced, the transfer of gas from the test chamber to the second chamber can be stopped.

[0087] Step 230: After the gas in the test chamber stops being transferred to the second chamber, control the gas in the first chamber to be transferred to the second chamber until the pressure between the first and second chambers is balanced and then stop the gas transfer.

[0088] Specifically, once the pressure in the test chamber and the second chamber is balanced and gas transmission stops, the gas in the first chamber is controlled to be transported to the second chamber for gas mixing, until the pressure between the first and second chambers is balanced and gas transmission stops.

[0089] Step 240: After the gas transfer from the first gas chamber to the second gas chamber is stopped, control the gas in the second gas chamber to be transferred to the gas chamber to be tested until the pressure between the second gas chamber and the gas chamber to be tested is balanced and then stop the gas transfer to achieve gas mixing once.

[0090] Specifically, after the pressure between the first and second gas chambers is balanced and gas transmission stops, the gas in the second gas chamber is controlled to be transported to the gas chamber to be tested for gas mixing, until the pressure between the second and the gas chamber to be tested is balanced and gas transmission stops, thus completing one gas mixing operation.

[0091] This invention achieves gas circulation between different chambers by controlling the gas in the test chamber to be sequentially transported to the first chamber, the second chamber, and then back to the test chamber. This ensures thorough mixing of the gas decomposition products within the test chamber, accelerating the diffusion rate of the decomposition products and overcoming the slow natural diffusion rate. This results in more representative gas samples collected from thoroughly mixed gas, avoiding measurement errors caused by localized concentration differences and improving the accuracy of gas decomposition product concentration detection. Furthermore, the gas mixing operation is applicable to test chambers of different volumes, reducing differences in concentration characteristics caused by varying gas diffusion patterns in different chambers. This also reduces judgment errors due to differences in chamber volume and enhances the universality of the measurement method in various high-voltage electrical equipment.

[0092] In one embodiment of the present invention, a primary gas mixing process specifically includes:

[0093] Step 310: Control the gas in the test chamber to be delivered to the first chamber, and collect the current pressure value of the test chamber in real time; when the current pressure value in the test chamber reaches the preset second pressure value, stop the gas delivery.

[0094] In this embodiment, the gas mixing process and concentration detection can be achieved based on a gas circulation device. First, the gas in the test chamber is transported to the first chamber until the current pressure value in the test chamber reaches a preset second pressure value. This second pressure value can be set randomly, but it must be ensured that the current pressure value in the test chamber is not lower than a preset alarm pressure value. The second pressure value and the first pressure value can be the same or different, and there is no restriction here.

[0095] Step 320: Control the gas in the test chamber to be transported to the second chamber until the pressure between the test chamber and the second chamber is balanced, then stop the gas transmission.

[0096] Specifically, after the pressure value in the test chamber reaches the second pressure value, the gas in the test chamber is transferred to the second chamber until the pressure in the test chamber and the second chamber are balanced. Once the pressure in the test chamber and the second chamber are balanced, the transfer of gas from the test chamber to the second chamber can be stopped.

[0097] Step 330: After the gas supply to the second gas chamber is stopped in the test chamber, control the gas in the first gas chamber to be supplied to the test chamber. When the current pressure value in the test chamber reaches the preset third pressure value, stop the gas supply.

[0098] Specifically, after the pressure in the test chamber and the second chamber is balanced and the gas transmission stops, the gas in the first chamber is controlled to be transported to the test chamber for gas mixing. When the current pressure value in the test chamber reaches the preset third pressure value, the gas transmission stops.

[0099] Step 340: Control the gas in the second gas chamber to be transported to the gas chamber to be tested. When the current pressure value in the gas chamber to be tested reaches the preset fourth pressure value, stop the gas transport to achieve gas mixing once.

[0100] Specifically, after the gas supply from the first gas chamber to the test gas chamber is stopped, the gas in the second gas chamber is controlled to be transported to the test gas chamber for gas mixing. When the current pressure value in the test gas chamber reaches the preset fourth pressure value, the gas supply is stopped.

[0101] This invention achieves gas circulation between different chambers by controlling the gas in the test chamber to be sequentially transported to the first chamber, the second chamber, and then back to the test chamber. This circulation ensures thorough mixing of the gas decomposition products in the test chamber, accelerating the diffusion rate of the decomposition products and overcoming the slow natural diffusion rate. Thorough mixing ensures that the collected gas sample is more representative, avoiding measurement errors caused by local concentration differences, thereby improving the accuracy of gas decomposition product concentration detection. The gas mixing operation is applicable to test chambers of different volumes, reducing the differences in concentration variation characteristics caused by different gas diffusion conditions in different chambers, and minimizing judgment errors caused by differences in chamber volume. This makes the measurement method more universally applicable to different high-voltage electrical equipment and can adapt to the detection needs of various devices.

[0102] One embodiment of the present invention proposes a gas circulation device based on thermal cycling; please refer to the following for details. Figure 2 , Figure 2 The diagram shows the structure of the gas circulation device in this embodiment of the invention. In this embodiment, the gas circulation device includes: a first density meter 5, a flow meter 15, and an infrared gas analyzer 6. The first density meter 5 is connected to the gas chamber 16 to be tested, and both the flow meter 15 and the infrared gas analyzer 6 are positioned between the gas chamber 16 and the first gas chamber 1. The first density meter 5 measures the pressure value of the gas chamber 16; the flow meter 15 collects the gas flow rate when the gas in the gas chamber 16 is transferred to the first gas chamber 1; and the infrared gas analyzer 6 collects the concentration of gas decomposition products when the gas in the gas chamber 16 is transferred to the first gas chamber 1.

[0103] In this embodiment, the gas circulation device further includes: a first solenoid valve 7, a second solenoid valve 8, a pressure reducing valve 11, a third solenoid valve 9, a fourth solenoid valve 10, a fifth solenoid valve 12, and a second density gauge 13; the second density gauge 13 is connected to the second gas chamber 2 and is used to measure the pressure value of the second gas chamber 2; one end of the first solenoid valve 7 is connected to the gas chamber 16 to be measured; one end of the pressure reducing valve 11 is connected to the other end of the first solenoid valve 7 and one end of the second solenoid valve 8 respectively; the other end of the second solenoid valve 8 is connected to one gas port of the second gas chamber 2; the other end of the pressure reducing valve 11 is connected to one end of the flow meter 15; one end of the flow meter 15 is connected to one end of the third solenoid valve 9; the other end of the third solenoid valve 9 is connected to one end of the infrared gas analyzer 6; the other end of the infrared gas analyzer 6 is connected to one end of the fourth solenoid valve 10; the other end of the fourth solenoid valve 10 is connected to one gas port of the first gas chamber 1; and the other gas port of the first gas chamber 1 is connected to one end of the fifth solenoid valve 12. The other end of the fifth solenoid valve 12 is connected to another air port of the second air chamber 2. When the gas in the test chamber 16 is transferred to the first air chamber 1, the first solenoid valve 7, the pressure reducing valve 11, the third solenoid valve 9, and the fourth solenoid valve 10 are controlled to open. When the test chamber 16 stops transferring gas to the first air chamber 1, the first solenoid valve 7, the pressure reducing valve 11, the third solenoid valve 9, and the fourth solenoid valve 10 are controlled to close. When the gas in the test chamber 16 is transferred to the second air chamber 2, the first solenoid valve 7 and the second solenoid valve 8 are controlled to open. When the test chamber 16 stops transferring gas to the second air chamber 2, the first solenoid valve 7 and the second solenoid valve 8 are controlled to close. When the gas in the first air chamber 1 is transferred to the second air chamber 2, or the gas in the second air chamber 2 is transferred to the first air chamber 1, the fifth solenoid valve 12 is controlled to open. When the first air chamber 1 stops transferring gas to the second air chamber 2, or the second air chamber 2 stops transferring gas to the first air chamber 1, the fifth solenoid valve 12 is controlled to close.

[0104] In this embodiment, a thermoelectric cooler 4 is installed inside the cavity of the first gas chamber 1 to cool the first gas chamber 1 and reduce the pressure value inside the first gas chamber 1, so as to realize the transfer of gas in the test gas chamber 16 to the first gas chamber 1, or the transfer of gas in the second gas chamber 2 to the first gas chamber 1; the thermoelectric cooler 4 is also used to heat the first gas chamber 1 and increase the pressure value inside the first gas chamber 1, so as to realize the transfer of gas in the first gas chamber 1 to the second gas chamber 2, or the transfer of gas in the first gas chamber 1 to the test gas chamber 16.

[0105] In this embodiment, an electric heating wire 3 is installed on the outside of the second air chamber 2 to heat the second air chamber 2 and increase the pressure value inside the second air chamber 2, so as to realize the transmission of gas in the second air chamber 2 to the test air chamber 16, or the transmission of gas in the second air chamber 2 to the first air chamber 1.

[0106] In this embodiment, a gas diffuser 14 is installed at the air inlet of the second air chamber 2, so that when gas enters the second air chamber 2, the gas drives the blades 17 of the gas diffuser 14 to rotate.

[0107] In one embodiment, the initial pressure value P0 (pressure value at 20°C) of the test chamber 16 is read through the first density table 5. The first solenoid valve 7, pressure reducing valve 11, third solenoid valve 9, and fourth solenoid valve 10 are opened, and the cooling function of the thermoelectric cooler 4 is activated to cool the first chamber 1, reducing the temperature inside the first chamber 1 to the SF6 gas liquefaction temperature T0 below the initial pressure value P0. At this time, the pressure of the first chamber 1 is less than the pressure of the test chamber 16, and the gas in the test chamber 16 will enter the first chamber 1 after passing through the flow meter 15 and the infrared gas analyzer 6. The current pressure value of the test chamber 16 is read in real time through the first density table 5, and the concentration data of gas decomposition products is detected by the infrared gas analyzer 6. When the current pressure value of the test chamber 16 reaches the preset first pressure value, the first solenoid valve 7, pressure reducing valve 11, third solenoid valve 9, and fourth solenoid valve 10 are closed.

[0108] In one embodiment, the first solenoid valve 7 and the second solenoid valve 8 are opened to allow the gas in the gas chamber 16 to be tested to quickly enter the second gas chamber 2 until the pressure is balanced, that is, when the pressure values ​​monitored by the first density gauge 5 and the second density gauge 13 are equal, the first solenoid valve 7 and the second solenoid valve 8 are closed.

[0109] In one embodiment, the fifth solenoid valve 12 is opened, and the thermoelectric cooler 4 is switched to heating function, causing the gas in the first gas chamber 1 to vaporize and pressurize before entering the second gas chamber 2. Under these conditions, the volume of the second gas chamber 2 is greater than the volume of the first gas chamber 1. A gas diffuser 14 is installed at the gas inlet of the second gas chamber 2, as can be seen from [reference needed]. Figure 3 , Figure 3 The diagram shows the structure of the gas diffuser 14 in this embodiment of the invention. It can be seen that the gas diffuser 14 includes a blade 17. When gas enters the second gas chamber 2, the gas drives the blade 17 to rotate, expanding the inlet diffusion direction and further ensuring the mixing effect of the gas within the second gas chamber 2. The gas in the first gas chamber 1 continuously heats up; the higher the temperature, the more gas enters the second gas chamber 2. When the pressure in the second gas chamber 2 is balanced with that in the first gas chamber 1, the fifth solenoid valve 12 is closed, and the thermoelectric cooler 4 stops heating and reverses its cooling process to facilitate the next gas cycle.

[0110] In one embodiment, the heating wire 3 of the second gas chamber 2 is turned on, and the first solenoid valve 7 and the second solenoid valve 8 are also turned on. The gas in the second gas chamber 2 is heated by the heating wire 3, thereby increasing the pressure of the gas in the second gas chamber 2 due to the increased temperature. The gas in the second gas chamber 2 is then refilled into the test gas chamber 16. Since the gas refilled into the test gas chamber 16 is at a higher temperature, it will form turbulence and enter the test gas chamber 16 to accelerate the movement of gas molecules in the test gas chamber 16, thereby accelerating the gas mixing process. When the pressure value recorded by the first density meter 5 no longer changes, that is, when the pressure of the test gas chamber 16 and the second gas chamber 2 is balanced, the heating wire 3 of the second gas chamber 2, the first solenoid valve 7, and the second solenoid valve 8 are turned off.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A self-testing method for a gas circulation device, characterized in that, The method is applied to a gas circulation device, which includes a first gas chamber and a second gas chamber. Both the first and second gas chambers are connected to a gas chamber to be tested. The first gas chamber is connected to the second gas chamber. The method includes: Collect the initial pressure value of the gas in the test chamber when the gas is currently mixed; Controlling the gas circulation device to perform one gas mixing operation refers to the process of controlling the gas in the test chamber to deliver gas to the first gas chamber and the second gas chamber respectively, and the gas in the first gas chamber and the gas in the second gas chamber being transported back to the test chamber according to a preset path. The volume of the gas chamber under test is calculated based on the gas flow rate when the gas in the gas chamber under test is delivered to the first gas chamber, the gas transmission time, the initial pressure value, and the current pressure value, so as to obtain the volume of the gas chamber under test when the gas is mixed. The volume of the gas chamber to be tested, calculated when the gas is mixed in the current state, is compared with the volume of the gas chamber to be tested when the gas is mixed in the past to determine whether the gas circulation device is malfunctioning. Specifically, the step of comparing the difference between the volume of the gas chamber to be tested calculated based on the current gas mixing and the volume of the gas chamber to be tested calculated based on historical gas mixing to determine whether the gas circulation device has malfunctioned includes: The standard volume is obtained by averaging the volume of the test chamber calculated during historical gas mixing. The volume error calculated during the current gas mixing is obtained by comparing the volume of the gas chamber to be tested calculated during the current gas mixing with the volume of the gas chamber to be tested calculated during the previous gas mixing. When the volume error is greater than the standard volume by a preset multiple, the gas circulation device is considered to be malfunctioning, wherein the preset multiple is any value less than 1; The gas mixing process specifically includes: The gas in the chamber to be tested is controlled to be delivered to the first chamber, and the current pressure value of the chamber to be tested is collected in real time; when the current pressure value in the chamber to be tested reaches the preset first pressure value, the gas delivery is stopped. The gas in the chamber to be tested is controlled to be transported to the second chamber until the pressure between the chamber to be tested and the second chamber is balanced, and then the gas transmission is stopped. After the gas supply from the test chamber to the second chamber is stopped, the gas in the first chamber is controlled to be delivered to the second chamber until the pressure between the first chamber and the second chamber is balanced and the gas supply is stopped. After the first gas chamber stops transmitting gas to the second gas chamber, the gas in the second gas chamber is controlled to be delivered to the gas chamber to be tested until the pressure between the second gas chamber and the gas chamber to be tested is balanced and then the gas transmission is stopped to achieve gas mixing once. Alternatively, a single gas mixing process specifically includes: The gas in the chamber to be tested is controlled to be delivered to the first chamber, and the current pressure value of the chamber to be tested is collected in real time; when the current pressure value in the chamber to be tested reaches the preset second pressure value, the gas delivery is stopped. The gas in the chamber to be tested is controlled to be transported to the second chamber until the pressure between the chamber to be tested and the second chamber is balanced, and then the gas transmission is stopped. After the gas supply to the second gas chamber is stopped in the test chamber, the gas in the first gas chamber is controlled to be supplied to the test chamber. When the current pressure value in the test chamber reaches the preset third pressure value, the gas supply is stopped. The gas in the second chamber is controlled to be delivered to the test chamber. When the current pressure value in the test chamber reaches the preset fourth pressure value, the gas delivery is stopped to achieve gas mixing once.

2. The method as described in claim 1, characterized in that, The volume of the gas chamber to be tested when the gas is mixed is calculated by the following formula: In the formula, The volume of the gas chamber to be tested is calculated when the gas is currently mixed. This is the pressure value under normal atmospheric pressure. The gas flow rate is the gas velocity when the gas in the chamber to be tested is transferred to the first chamber. The gas transmission time is the time when the gas in the chamber to be tested is transferred to the first chamber. This is the initial pressure value in the gas chamber to be tested when the gas is currently mixed. This is the current pressure value of the gas chamber under test when the gas is mixed.

3. The method as described in claim 1, characterized in that, The gas circulation device further includes: a first density meter, a flow meter, and an infrared gas analyzer, wherein the first density meter is used to connect to the gas chamber to be tested, and the flow meter and the infrared gas analyzer are both disposed between the gas chamber to be tested and the first gas chamber; The first density meter is used to measure the pressure value of the gas chamber to be tested; The flow meter is used to collect the gas flow rate when the gas in the gas chamber to be measured is transferred to the first gas chamber; The infrared gas analyzer is used to collect the concentration of gas decomposition products when the gas in the test chamber is transferred to the first chamber.

4. The method as described in claim 3, characterized in that, The gas circulation device further includes: a first solenoid valve, a second solenoid valve, a pressure reducing valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, and a second density gauge. The second density meter is connected to the second air chamber and is used to measure the pressure value of the second air chamber; One end of the first solenoid valve is connected to the gas chamber to be tested. One end of the pressure reducing valve is connected to the other end of the first solenoid valve and one end of the second solenoid valve. The other end of the second solenoid valve is connected to one gas port of the second gas chamber. The other end of the pressure reducing valve is connected to one end of the flow meter. The other end of the flow meter is connected to one end of the third solenoid valve. The other end of the third solenoid valve is connected to one end of the infrared gas analyzer. The other end of the infrared gas analyzer is connected to one end of the fourth solenoid valve. The other end of the fourth solenoid valve is connected to one gas port of the first gas chamber. The other gas port of the first gas chamber is connected to one end of the fifth solenoid valve. The other end of the fifth solenoid valve is connected to the other gas port of the second gas chamber. When the gas in the test chamber is transferred to the first chamber, the first solenoid valve, the pressure reducing valve, the third solenoid valve, and the fourth solenoid valve are opened; when the test chamber stops transferring gas to the first chamber, the first solenoid valve, the pressure reducing valve, the third solenoid valve, and the fourth solenoid valve are closed. When the gas in the test chamber is transferred to the second chamber, the first and second solenoid valves are opened; when the test chamber stops transferring gas to the second chamber, the first and second solenoid valves are closed. When gas in the first chamber is transferred to the second chamber, or gas in the second chamber is transferred to the first chamber, the fifth solenoid valve is opened; when the first chamber stops transferring gas to the second chamber, or the second chamber stops transferring gas to the first chamber, the fifth solenoid valve is closed.

5. The method as described in claim 3, characterized in that, A thermoelectric cooler is installed inside the first air chamber to cool the first air chamber and reduce the pressure value inside the first air chamber, so as to realize the transfer of gas from the test air chamber to the first air chamber, or the transfer of gas from the second air chamber to the first air chamber. The thermoelectric cooler is also used to heat the first gas chamber and increase the pressure value inside the first gas chamber, so as to realize the transfer of gas from the first gas chamber to the second gas chamber, or the transfer of gas from the first gas chamber to the gas chamber to be tested.

6. The method as described in claim 3, characterized in that, An electric heating wire is installed on the outside of the second air chamber to heat the second air chamber and increase the pressure value inside the second air chamber, so as to realize the transfer of gas in the second air chamber to the air chamber to be tested, or the transfer of gas in the second air chamber to the first air chamber.

7. The method as described in claim 3, characterized in that, A gas diffuser is installed at the air inlet of the second air chamber, which drives the blades of the gas diffuser to rotate when gas enters the second air chamber.

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