Self-checking method of gas circulation device

Abstract

The invention discloses a self-checking method of a gas circulation device, the method is applied to the gas circulation device, and the method comprises the following steps: collecting an initial pressure value of a gas chamber to be tested when the current gas is uniformly mixed; controlling the gas circulation device to perform primary gas mixing, and performing volume calculation according to the gas flow rate, the gas decomposition product concentration, the initial pressure value and the current pressure value when the gas in the to-be-measured gas chamber is conveyed to the first gas chamber, so as to obtain the volume of the to-be-measured gas chamber obtained by calculation when the current gas is mixed uniformly; and performing difference comparison according to the volume of the to-be-measured gas chamber obtained by calculation when the current gas is uniformly mixed and the volume of the to-be-measured gas chamber obtained by calculation when the historical gas is uniformly mixed, and determining whether the concentration measuring device for the gas decomposition products has a fault or not. Before the gas circulation device is used for detecting the concentration of the gas decomposition product every time, the gas circulation device is self-detected based on the calculated volume of the gas chamber to be detected, so that the problem of the gas circulation device can be found in time, and the accuracy of concentration detection is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas concentration detection, and in particular to a self-checking method of a gas circulating device. BACKGROUND

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

[0003] Therefore, monitoring SF6 decomposition products is crucial for assessing the insulation condition inside the equipment, diagnosing potential faults, and predicting the service life of the equipment, and is a key means for equipment condition maintenance and ensuring the safe operation of the power grid. However, existing gas monitoring techniques still have the problem of large error in the concentration detection results of gas decomposition products. SUMMARY

[0004] Therefore, it is necessary to propose a self-checking method of a gas circulating device to eliminate the detection error caused by the concentration detection equipment by self-checking the gas circulating device, thereby improving the accuracy of concentration detection.

[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides a self-checking method of a gas circulating device, which is applied to a gas circulating device, the gas circulating device comprising a first gas chamber and a second gas chamber, the first gas chamber and the second gas chamber are both used to connect with a to-be-detected gas chamber, the first gas chamber is connected with the second gas chamber, and the method comprises: acquiring an initial pressure value of the to-be-detected gas chamber at the time of current gas mixing; controlling the gas circulating device to perform a gas mixing, the gas mixing refers to a process of controlling the gas in the to-be-detected gas chamber to transport 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 are transmitted back to the to-be-detected gas chamber according to a preset path; performing volume calculation according to the gas flow rate, the gas decomposition product concentration, the initial pressure value and the current pressure value when the gas in the to-be-detected gas chamber is transported to the first gas chamber, to obtain the volume of the to-be-detected gas chamber calculated at the time of current gas mixing; performing difference comparison according to the volume of the to-be-detected gas chamber calculated at the time of current gas mixing and the volume of the to-be-detected gas chamber calculated at the time of historical gas mixing, to determine whether the gas circulating device has a fault.

[0006] Further, the volume of the to-be-tested gas chamber calculated at the current gas mixing time is compared with the volume of the to-be-tested gas chamber calculated at the historical gas mixing time to determine whether the gas circulating device is malfunctioning, specifically comprising: calculating an average value of the volume of the to-be-tested gas chamber calculated at the historical gas mixing time to obtain a standard volume; calculating a difference value between the volume of the to-be-tested gas chamber calculated at the current gas mixing time and the volume of the to-be-tested gas chamber calculated at the last gas mixing time to obtain a volume error calculated at the current gas mixing time; when the volume error is greater than a preset multiple of the standard volume, it is considered that the gas circulating device is malfunctioning, wherein the preset multiple is any numerical value less than 1.

[0007] Further, the volume of the to-be-tested gas chamber at the current gas mixing time is calculated by the following formula:

[0008] In the formula, is the volume of the to-be-tested gas chamber calculated at the current gas mixing time, is a pressure value at normal pressure, is a gas flow rate when the gas in the to-be-tested gas chamber is transmitted to the first gas chamber; is a gas transmission time when the gas in the to-be-tested gas chamber is transmitted to the first gas chamber; is an initial pressure value in the to-be-tested gas chamber at the current gas mixing time; is a current pressure value of the to-be-tested gas chamber at the current gas mixing time.

[0009] Further, one gas mixing process specifically comprises: controlling the gas in the to-be-tested gas chamber to be delivered to the first gas chamber and collecting the current pressure value of the to-be-tested gas chamber in real time; when the current pressure value in the to-be-tested gas chamber reaches a preset first pressure value, the gas delivery is stopped; controlling the gas in the to-be-tested gas chamber to be delivered to the second gas chamber until the gas transmission is stopped after the pressure between the to-be-tested gas chamber and the second gas chamber is balanced; after the to-be-tested gas chamber stops transmitting gas to the second gas chamber, controlling the gas in the first gas chamber to be delivered to the second gas chamber until the gas transmission is stopped after the pressure between the first gas chamber and the second gas chamber is balanced; after the first gas chamber stops transmitting gas to the second gas chamber, controlling the gas in the second gas chamber to be delivered to the to-be-tested gas chamber until the gas transmission is stopped after the pressure between the second gas chamber and the to-be-tested gas chamber is balanced, to realize one gas mixing.

[0010] Further, the one-time gas mixing process specifically comprises: controlling the gas in the to-be-tested gas chamber to be delivered into the first gas chamber, and collecting the current pressure value of the to-be-tested gas chamber in real time; when the current pressure value of the to-be-tested gas chamber reaches a preset second pressure value, stopping the gas delivery; controlling the gas in the to-be-tested gas chamber to be delivered into the second gas chamber, and stopping the gas delivery after the pressure between the to-be-tested gas chamber and the second gas chamber is balanced; after the to-be-tested gas chamber stops delivering the gas into the second gas chamber, controlling the gas in the first gas chamber to be delivered into the to-be-tested gas chamber, and stopping the gas delivery when the current pressure value of the to-be-tested gas chamber reaches a preset third pressure value; controlling the gas in the second gas chamber to be delivered into the to-be-tested gas chamber, and stopping the gas delivery when the current pressure value of the to-be-tested gas chamber reaches a preset fourth pressure value, so as to realize one-time gas mixing.

[0011] Further, the gas circulation device further comprises a first densimeter, a flow meter and an infrared gas analyzer, wherein the first densimeter is used to be connected with the to-be-tested gas chamber, and the flow meter and the infrared gas analyzer are both arranged between the to-be-tested gas chamber and the first gas chamber. The first densimeter is used to measure the pressure value of the to-be-tested gas chamber. The flow meter is used to collect the gas flow rate when the gas in the to-be-tested gas chamber is delivered into the first gas chamber. The infrared gas analyzer is used to collect the gas decomposition product concentration when the gas in the to-be-tested gas chamber is delivered into the first gas chamber.

[0012] Further, the gas circulation device further comprises a first electromagnetic valve, a second electromagnetic valve, a pressure reducing valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve and a second densimeter. The second densimeter is connected with the second gas chamber and is used to measure the pressure value of the second gas chamber. One end of the first electromagnetic valve is connected with the gas chamber to be measured, one end of the pressure reducing valve is connected with the other end of the first electromagnetic valve and one end of the second electromagnetic valve respectively, the other end of the second electromagnetic valve is connected with one gas port of the second gas chamber, the other end of the pressure reducing valve is connected with one end of the flow meter, one end of the flow meter is connected with one end of the third electromagnetic valve, the other end of the third electromagnetic valve is connected with one end of the infrared gas analyzer, the other end of the infrared gas analyzer is connected with one end of the fourth electromagnetic valve, the other end of the fourth electromagnetic valve is connected with one gas port of the first gas chamber, the other gas port of the first gas chamber is connected with one end of the fifth electromagnetic valve, the other end of the fifth electromagnetic valve is connected with the other gas port of the second gas chamber; When the gas in the gas chamber to be measured is transmitted into the first gas chamber, the first electromagnetic valve, the pressure reducing valve, the third electromagnetic valve and the fourth electromagnetic valve are controlled to be opened; when the gas transmission from the gas chamber to be measured to the first gas chamber stops, the first electromagnetic valve, the pressure reducing valve, the third electromagnetic valve and the fourth electromagnetic valve are controlled to be closed; When the gas in the gas chamber to be measured is transmitted into the second gas chamber, the first electromagnetic valve and the second electromagnetic valve are controlled to be opened; when the gas transmission from the gas chamber to be measured to the second gas chamber stops, the first electromagnetic valve and the second electromagnetic valve are controlled to be closed; When the gas in the first gas chamber is transmitted into the second gas chamber, or the gas in the second gas chamber is transmitted into the first gas chamber, the fifth electromagnetic valve is controlled to be opened; when the gas transmission from the first gas chamber to the second gas chamber stops, or the gas transmission from the second gas chamber to the first gas chamber stops, the fifth electromagnetic valve is controlled to be closed.

[0013] Further, a thermoelectric refrigerator is installed inside the first gas chamber cavity, which is used to refrigerate the first gas chamber, reduce the pressure value in the first gas chamber, and realize the transmission of the gas in the gas chamber to be measured into the first gas chamber, or the transmission of the gas in the second gas chamber into the first gas chamber. The thermoelectric refrigerator is also used to heat the first gas chamber, increase the pressure value in the first gas chamber, and realize the transmission of the gas in the first gas chamber into the second gas chamber, or the transmission of the gas in the first gas chamber into the gas chamber to be measured.

[0014] Further, an electric heating wire is installed outside the second gas chamber cavity, which is used to heat the second gas chamber, increase the pressure value in the second gas chamber, and realize the transmission of the gas in the second gas chamber into the gas chamber to be measured, or the transmission of the gas in the second gas chamber into the first gas chamber.

[0015] Further, a gas diffuser is installed at the gas port of the second gas chamber, for when the gas enters the second gas chamber, the gas drives the paddle of the gas diffuser to rotate.

[0016] By adopting the embodiment of the present application, the following beneficial effects are achieved: The embodiment of the present application provides a self-checking method of a gas circulation device, the method is applied to the gas circulation device, the gas circulation device comprises a first gas chamber and a second gas chamber, the first gas chamber and the second gas chamber are used for being connected with a to-be-tested gas chamber, the first gas chamber is connected with the second gas chamber, and the method comprises the following steps: collecting an initial pressure value when current gas mixing of the to-be-tested gas chamber is completed; controlling the gas circulation device to perform gas mixing once, the gas mixing refers to the process that the gas in the to-be-tested gas chamber is controlled to be respectively transported to the first gas chamber and the second gas chamber, and the gas in the first gas chamber and the gas in the second gas chamber are transmitted back to the to-be-tested gas chamber according to a preset path; performing volume calculation according to a gas flow rate when the gas in the to-be-tested gas chamber is transported to the first gas chamber, a gas decomposition product concentration, the initial pressure value and a current pressure value, to obtain a volume of the to-be-tested gas chamber calculated at the current gas mixing; and performing difference comparison on the volume of the to-be-tested gas chamber calculated at the current gas mixing and a volume of the to-be-tested gas chamber calculated at historical gas mixing, to determine whether a concentration measuring device of the gas decomposition product fails. The present application performs self-checking on the gas circulation device based on the calculated volume of the to-be-tested gas chamber before the gas decomposition product concentration is detected by the gas circulation device each time, so that problems of the gas circulation device can be found in time, and the accuracy of the gas decomposition product concentration detection is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0018] Among them: Figure 1 It is a flowchart of the self-checking method of the gas circulation device in the embodiment of the present application. Figure 2 It is a structural diagram of the gas circulation device in the embodiment of the present application. Figure 3 It is a structural diagram of the gas diffuser in the embodiment of the present application. DETAILED DESCRIPTION

[0019] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described in order to make the technical solutions in the embodiments of the present application apparent to those skilled in the art. Obviously, the described embodiments are only a part rather than all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts should fall into the scope of the present application.

[0020] To ensure the accuracy of measuring the concentration of decomposition products of the to-be-measured gas chamber based on the gas circulation device, an embodiment of the present application provides a self-checking method of the gas circulation device, please refer to Figure 1 , Figure 1 FIG. 1 is a flowchart of the self-checking method of the gas circulation device in the embodiment of the present application, and the method is applied to the gas circulation device. The gas circulation device comprises a first gas chamber and a second gas chamber, and the first gas chamber and the second gas chamber are both used to be connected with the to-be-measured gas chamber. The first gas chamber is connected with the second gas chamber. The method comprises the following steps. Step 110: collecting an initial pressure value when the current gas in the to-be-measured gas chamber is mixed.

[0021] In the embodiment of the present application, the gas circulation device is used to mix the gas in the to-be-measured gas chamber and detect the concentration of decomposition products of the gas. However, if the gas circulation device fails, the mixing effect will be poor and the error of the detection result of the concentration of decomposition products of the gas will be large. Therefore, it is important to self-check the gas circulation device, which is also an important means to ensure the accuracy of the detection result of the concentration of decomposition products of the gas in the to-be-measured gas chamber.

[0022] Before controlling the gas circulation device to mix the gas in the to-be-measured gas chamber, the initial pressure value in the to-be-measured gas chamber is collected.

[0023] Step 120: controlling the gas circulation device to perform a gas mixing. The gas mixing refers to the process that the gas in the to-be-measured gas chamber is controlled to be transported to the first gas chamber and the second gas chamber respectively, and the gas in the first gas chamber and the second gas chamber is transmitted back to the to-be-measured gas chamber according to a preset path.

[0024] In the embodiment of the present application, the to-be-measured gas chamber is filled with SF6 gas. Before measuring the concentration of decomposition products of the SF6 gas in the to-be-measured gas chamber, the SF6 gas in the to-be-measured gas chamber needs to be mixed to accelerate the diffusion speed of the decomposition products in the to-be-measured gas chamber, so that the representative gas can be taken for detection, and the real state in the to-be-measured gas chamber can be more accurately reflected.

[0025] The gas mixing process is realized based on a gas circulation device, the first gas chamber and the second gas chamber in the gas circulation device are communicated with the to-be-tested gas chamber, and the first gas chamber is communicated with the second gas chamber. The first gas mixing process is a process of controlling the to-be-tested gas chamber to be transported in the first gas chamber, the second gas chamber and the to-be-tested gas chamber according to a preset path, and finally returned to the to-be-tested gas chamber.

[0026] The embodiment of the present application further performs self-checking on the gas circulation device while the gas circulation device performs gas mixing and decomposition product concentration detection on the gas in the to-be-tested gas chamber, thereby ensuring the gas mixing effect and the accuracy of the gas decomposition product concentration detection result without increasing redundant operation steps.

[0027] In step 130, the volume of the to-be-tested gas chamber is calculated according to the gas flow rate, the gas decomposition product concentration, the initial pressure value and the current pressure value when the gas in the to-be-tested gas chamber is transported to the first gas chamber.

[0028] In the embodiment, the flow meter and the infrared gas analyzer are installed between the first gas chamber and the to-be-tested gas chamber, and the densimeter is installed on the to-be-tested gas chamber. While the gas circulation device performs gas mixing on the gas in the to-be-tested gas chamber, the current pressure value of the to-be-tested gas chamber is collected by the flow meter, and the gas flow rate and the gas decomposition product concentration when the gas in the to-be-tested gas chamber is transported to the first gas chamber are collected by the infrared gas analyzer. In the process of gas transmission, the gas decomposition product concentration and the gas flow rate corresponding to the sampling point moment are collected in real time, so as to calculate the target gas decomposition product concentration in the to-be-tested gas chamber. By collecting the gas decomposition product concentration and the gas flow rate in real time during the gas transportation process, the related data of the gas can be obtained in time and accurately, which provides a more accurate basis for subsequent gas decomposition product concentration calculation, thereby improving the reliability of the detection result.

[0029] Since the volume of the to-be-tested gas chamber is constant, the volume of the to-be-tested gas chamber can be dynamically calculated based on the gas flow rate, the gas decomposition product concentration, the initial pressure value and the current pressure value, so as to determine the volume of the to-be-tested gas chamber in each gas circulation. By comparing the volume of the to-be-tested gas chamber calculated each time with the standard volume, whether the gas circulation device has a fault, such as the flow meter, the densimeter, etc., can be determined.

[0030] By collecting the gas flow rate, the gas decomposition product concentration and the current pressure value in real time during the gas mixing process, and calculating the volume of the to-be-tested gas chamber based thereon, the calculated volume is compared with the standard volume or historical volume data, so as to quickly and accurately determine whether the gas circulation device has a fault, thereby discovering and processing the device fault in time, ensuring the normal operation of the gas circulation device, and avoiding detection errors and safety hazards caused by device faults.

[0031] Step 140, according to the current gas mixing time calculation obtained from the volume of the gas chamber and the historical gas mixing time calculation obtained from the volume of the gas chamber, the difference is compared, and whether the gas circulating device fails is determined.

[0032] In the embodiment, by calculating the error between the volume of the measured gas chamber calculated at the current gas mixing time and the volume of the measured gas chamber calculated at the historical gas mixing time, when the error is large, it indicates that the current gas circulating device has a fault; when the error is small, it indicates that the current gas circulating device is normal, and the gas mixing and concentration detection operation can be continued.

[0033] The embodiment of the application can monitor the running state of the concentration measuring device of the gas decomposition product in real time while mixing and detecting the gas, discover faults in time and take corresponding maintenance measures, avoid the concentration detection error of the gas decomposition product caused by the failure of the measuring device, enhance the self-checking ability of the gas circulating device, and enable it to complete the fault diagnosis of the measuring device itself without relying on external detection equipment.

[0034] In an embodiment of the application, step 140, according to the current gas mixing time calculation obtained from the volume of the gas chamber and the historical gas mixing time calculation obtained from the volume of the gas chamber, the difference is compared, and whether the gas circulating device fails is determined, specifically comprising: Step 141, calculating the average value of the volume of the measured gas chamber calculated at the historical gas mixing time, to obtain a standard volume.

[0035] In the embodiment, the volume of the measured gas chamber calculated at all gas mixing times before the current gas mixing is obtained, and the average value of the volume of the measured gas chamber calculated at the historical gas mixing time is calculated, which is taken as the standard volume of the volume of the measured gas chamber.

[0036] Considering that the volume of the measured gas chamber calculated each time the gas mixing is performed may have a certain detection error, and the standard volume is floating up and down within a certain range, the average value of the volume of the measured gas chamber calculated at the historical gas mixing time is selected as the standard volume of the volume of the measured gas chamber to reduce the judgment error.

[0037] Step 142, calculating the difference between the volume of the measured gas chamber calculated at the current gas mixing time and the volume of the measured gas chamber calculated at the last gas mixing time, to obtain the volume error calculated at the current gas mixing time.

[0038] In the embodiment, the volume error calculated at the current gas mixing is determined by calculating the difference between the volume of the to-be-tested gas chamber calculated at the current gas mixing and the volume of the to-be-tested gas chamber calculated at the last gas mixing, so as to determine whether the gas circulating device has a fault based on the volume error at the current gas mixing.

[0039] In step 143, when the volume error is greater than the standard volume with a preset multiple, it is considered that the gas circulating device has a fault, wherein the preset multiple is any value less than 1.

[0040] In the embodiment, the preset multiple can be adjusted arbitrarily, which is any value less than 1.

[0041] When the volume error is greater than the standard volume with a preset multiple, it is considered that the gas circulating device has a fault, for example, when the volume error is greater than 5% of the standard volume, it is considered that the gas circulating device has a fault, which needs to be repaired in time to avoid a large error in detecting the concentration of the gas decomposition product.

[0042] The embodiment of the present application can effectively filter out the volume fluctuation caused by external interference or accidental factors by comprehensively considering the historical volume data and calculating the average value as the standard volume, reduce false alarms and missed alarms, and improve the stability and reliability of the entire monitoring system. The volume error is calculated at each gas mixing and compared with the standard volume with a preset multiple to provide a quantitative basis for fault evaluation of the gas circulating device. This helps maintenance personnel to more accurately understand the running state of the device, reasonably arrange the maintenance plan, take measures in advance, and reduce maintenance cost and equipment downtime. The step realizes the automatic self-checking function of the gas circulating device, which can independently complete the fault diagnosis of the measurement device without relying on external detection equipment. This not only improves the independence and autonomy of the system, but also enhances the intelligent level of the system and reduces the need for manual intervention.

[0043] In an embodiment of the present application, the volume of the to-be-tested gas chamber at the current gas mixing is calculated by the following formula:

[0044] In the formula, V is the volume of the to-be-tested gas chamber calculated at the current gas mixing, P is the pressure value at normal pressure, V is the gas flow rate when the gas in the to-be-tested gas chamber is transmitted to the first gas chamber; T is the gas transmission time when the gas in the to-be-tested gas chamber is transmitted to the first gas chamber; P0 is the initial pressure value in the to-be-tested gas chamber at the current gas mixing; P1 is the current pressure value of the to-be-tested gas chamber at the current gas mixing.

[0045] Based on the above self-checking method of the gas circulation device, an embodiment of the present application carries out relevant experimental tests to test the detection effect of the self-checking method of the gas circulation device under different experimental conditions.

[0046] Specifically, reference can be made to Table 1, which is a table of self-checking results of the gas circulation device under different experimental conditions. As can be seen from Table 1, the first to fifth gas mixing is in the normal operation state of the gas circulation device. Based on this condition, the error between the initial volume of the to-be-tested gas chamber and the calculated volume after mixing detected by the self-checking method of the gas circulation device is small, which is within the allowable gas circulation volume error of the normal gas circulation device. The sixth and seventh gas circulation respectively uses a damaged flow sensor and a damaged pressure sensor. Based on this condition, the error between the initial volume of the to-be-tested gas chamber and the calculated volume after mixing detected by the self-checking method of the gas circulation device is large, which is outside the allowable gas circulation volume error of the normal gas circulation device.

[0047] Based on the experimental data, it can be seen that the self-checking method of the gas circulation device proposed in the embodiment of the present application can effectively detect whether the gas circulation device has a fault, and realize effective self-checking of the gas circulation device to avoid distortion of the concentration detection result caused by the fault of the gas circulation device in the process of concentration detection based on the gas circulation device.

[0048] Table 1: Self-checking results of the gas circulation device under different experimental conditions

[0049] In an embodiment of the present application, the process of one-time gas mixing specifically includes: Step 210, control the gas in the to-be-tested gas chamber to be delivered to the first gas chamber, and collect the current pressure value of the to-be-tested gas chamber in real time; when the current pressure value in the to-be-tested gas chamber reaches a preset first pressure value, stop the gas delivery.

[0050] In the embodiment, the gas mixing process and concentration detection can be realized based on the gas circulation device. First, the gas in the to-be-tested gas chamber is delivered to the first gas chamber until the current pressure value in the to-be-tested gas chamber reaches a preset first pressure value. The first pressure value can be randomly set, but it is required to ensure that the current pressure value in the to-be-tested gas chamber is not lower than a preset alarm pressure value.

[0051] Step 220, control the gas in the to-be-tested gas chamber to be delivered to the second gas chamber, and stop the gas transmission after the pressure between the to-be-tested gas chamber and the second gas chamber is balanced.

[0052] Specifically, after the pressure value in the to-be-tested gas chamber reaches the first pressure value, the gas in the to-be-tested gas chamber is transported to the second gas chamber until the pressure in the to-be-tested gas chamber and the second gas chamber is balanced, and then the gas transmission from the to-be-tested gas chamber to the second gas chamber is stopped.

[0053] Step 230, after the to-be-tested gas chamber stops transmitting the gas to the second gas chamber, the gas in the first gas chamber is controlled to be transported to the second gas chamber until the pressure between the first gas chamber and the second gas chamber is balanced and the gas transmission is stopped.

[0054] Specifically, after the pressure in the to-be-tested gas chamber and the second gas chamber is balanced and the gas transmission is stopped, the gas in the first gas chamber is controlled to be transported to the second gas chamber for gas mixing until the pressure between the first gas chamber and the second gas chamber is balanced and the gas transmission is stopped.

[0055] Step 240, after the first gas chamber stops transmitting the gas to the second gas chamber, the gas in the second gas chamber is controlled to be transported to the to-be-tested gas chamber until the pressure between the second gas chamber and the to-be-tested gas chamber is balanced and the gas transmission is stopped, so as to realize one-time gas mixing.

[0056] Specifically, after the pressure between the first gas chamber and the second gas chamber is balanced and the gas transmission is stopped, the gas in the second gas chamber is controlled to be transported to the to-be-tested gas chamber for gas mixing until the pressure between the second gas chamber and the to-be-tested gas chamber is balanced and the gas transmission is stopped, and thus one-time gas mixing operation is realized.

[0057] In the embodiment of the application, the gas in the to-be-tested gas chamber is transported to the first gas chamber, the second gas chamber, and then back to the to-be-tested gas chamber, so that the circulation of the gas between different gas chambers is realized, the decomposition products in the to-be-tested gas chamber can be fully mixed, the diffusion speed of the decomposition products in the to-be-tested gas chamber is accelerated, the defect of slow natural diffusion speed is overcome, the gas sample collected based on the fully mixed gas is more representative, the measurement error caused by the local concentration difference of the gas is avoided, and thus the accuracy of the concentration detection of the decomposition products of the gas is improved. In addition, the gas mixing operation is suitable for to-be-tested gas chambers with different volumes, the concentration change characteristics caused by the different diffusion of the gas in the gas chambers with different volumes are reduced, the judgment error caused by the volume difference of the gas chambers is reduced, and the universality of the measurement method in different high-voltage electrical equipment is enhanced.

[0058] In an embodiment of the application, one-time gas mixing process specifically includes: Step 310, the gas in the to-be-tested gas chamber is controlled to be transported to the first gas chamber, and the current pressure value of the to-be-tested gas chamber is collected in real time; when the current pressure value in the to-be-tested gas chamber reaches the preset second pressure value, the gas transmission is stopped.

[0059] In the embodiment, the gas mixing process and concentration detection can be realized based on the gas circulating device. First, the gas in the to-be-tested gas chamber is transported to the first gas chamber until the current pressure value in the to-be-tested gas chamber reaches a preset second pressure value. The second pressure value can be randomly set, but the current pressure value in the to-be-tested gas chamber is ensured to be not lower than a preset alarm pressure value. The second pressure value and the first pressure value can be the same or different, which is not limited herein.

[0060] Step 320, the gas in the to-be-tested gas chamber is controlled to be transported to the second gas chamber until the pressure balance between the to-be-tested gas chamber and the second gas chamber is achieved, and then the gas transportation is stopped.

[0061] Specifically, after the pressure value in the to-be-tested gas chamber reaches the second pressure value, the gas in the to-be-tested gas chamber is transported to the second gas chamber until the pressure balance between the to-be-tested gas chamber and the second gas chamber is achieved. After the pressure balance between the to-be-tested gas chamber and the second gas chamber is achieved, the gas transportation from the to-be-tested gas chamber to the second gas chamber is stopped.

[0062] Step 330, after the to-be-tested gas chamber stops transporting the gas to the second gas chamber, the gas in the first gas chamber is controlled to be transported to the to-be-tested gas chamber. When the current pressure value in the to-be-tested gas chamber reaches a preset third pressure value, the gas transportation is stopped.

[0063] Specifically, after the pressure balance between the to-be-tested gas chamber and the second gas chamber is achieved and the gas transportation is stopped, the gas in the first gas chamber is controlled to be transported to the to-be-tested gas chamber for gas mixing. When the current pressure value in the to-be-tested gas chamber reaches a preset third pressure value, the gas transportation is stopped.

[0064] Step 340, the gas in the second gas chamber is controlled to be transported to the to-be-tested gas chamber. When the current pressure value in the to-be-tested gas chamber reaches a preset fourth pressure value, the gas transportation is stopped to realize one-time gas mixing.

[0065] Specifically, after the first gas chamber stops transporting the gas to the to-be-tested gas chamber, the gas in the second gas chamber is controlled to be transported to the to-be-tested gas chamber for gas mixing. When the current pressure value in the to-be-tested gas chamber reaches a preset fourth pressure value, the gas transportation is stopped.

[0066] The embodiment of the present application realizes the circulation flow of the gas between different gas chambers by controlling the gas in the to-be-tested gas chamber to be sequentially delivered to the first gas chamber, the second gas chamber and then back to the to-be-tested gas chamber. The circulation flow can fully mix the decomposition products of the gas in the to-be-tested gas chamber, accelerate the diffusion speed of the decomposition products in the to-be-tested gas chamber and overcome the defect of slow natural diffusion speed. The fully mixed gas can ensure that the collected gas sample is more representative, avoid the measurement error caused by the local concentration difference of the gas and thus improve the accuracy of the concentration detection of the decomposition products of the gas. The gas mixing operation is suitable for the to-be-tested gas chambers of different volumes, reduces the concentration change characteristic difference caused by the different diffusion conditions of the gas in the gas chambers of different volumes and reduces the judgment error caused by the volume difference of the gas chambers. This makes the measurement method have better universality in different high-voltage electrical equipment and can adapt to the detection requirements of various equipment.

[0067] An embodiment of the present application provides a gas circulation device based on thermal cycle, and the specific reference is made to Figure 2 , Figure 2 Fig. 1 is a structural diagram of the gas circulation device in the embodiment of the present application. In the embodiment, the gas circulation device comprises a first densimeter 5, a flow meter 15 and an infrared gas analyzer 6. The first densimeter 5 is used to be connected with a to-be-tested gas chamber 16, and the flow meter 15 and the infrared gas analyzer 6 are both arranged between the to-be-tested gas chamber 16 and a first gas chamber 1. The first densimeter 5 is used to measure the pressure value of the to-be-tested gas chamber 16. The flow meter 15 is used to collect the flow speed of the gas when the gas in the to-be-tested gas chamber 16 is delivered to the first gas chamber 1. The infrared gas analyzer 6 is used to collect the concentration of the decomposition products of the gas when the gas in the to-be-tested gas chamber 16 is delivered to the first gas chamber 1.

[0068] In the embodiment, the gas circulation device further comprises a first electromagnetic valve 7, a second electromagnetic valve 8, a pressure reducing valve 11, a third electromagnetic valve 9, a fourth electromagnetic valve 10, a fifth electromagnetic valve 12 and a second density meter 13. The second density meter 13 is connected with the second gas chamber 2 and used for measuring the pressure value of the second gas chamber 2. One end of the first electromagnetic valve 7 is connected with the to-be-measured gas chamber 16. One end of the pressure reducing valve 11 is connected with the other end of the first electromagnetic valve 7 and one end of the second electromagnetic valve 8 respectively. The other end of the second electromagnetic valve 8 is connected with one gas port of the second gas chamber 2. The other end of the pressure reducing valve 11 is connected with one end of the flow meter 15. One end of the flow meter 15 is connected with one end of the third electromagnetic valve 9. The other end of the third electromagnetic valve 9 is connected with one end of the infrared gas analyzer 6. The other end of the infrared gas analyzer 6 is connected with one end of the fourth electromagnetic valve 10. The other end of the fourth electromagnetic valve 10 is connected with one gas port of the first gas chamber 1. The other gas port of the first gas chamber 1 is connected with one end of the fifth electromagnetic valve 12. The other end of the fifth electromagnetic valve 12 is connected with the other gas port of the second gas chamber 2. When the gas in the to-be-measured gas chamber 16 is transmitted into the first gas chamber 1, the first electromagnetic valve 7, the pressure reducing valve 11, the third electromagnetic valve 9 and the fourth electromagnetic valve 10 are controlled to be opened. When the to-be-measured gas chamber 16 stops transmitting the gas into the first gas chamber 1, the first electromagnetic valve 7, the pressure reducing valve 11, the third electromagnetic valve 9 and the fourth electromagnetic valve 10 are controlled to be closed. When the gas in the to-be-measured gas chamber 16 is transmitted into the second gas chamber 2, the first electromagnetic valve 7 and the second electromagnetic valve 8 are controlled to be opened. When the to-be-measured gas chamber 16 stops transmitting the gas into the second gas chamber 2, the first electromagnetic valve 7 and the second electromagnetic valve 8 are controlled to be closed. When the gas in the first gas chamber 1 is transmitted into the second gas chamber 2 or the gas in the second gas chamber 2 is transmitted into the first gas chamber 1, the fifth electromagnetic valve 12 is controlled to be opened. When the first gas chamber 1 stops transmitting the gas into the second gas chamber 2 or the second gas chamber 2 stops transmitting the gas into the first gas chamber 1, the fifth electromagnetic valve 12 is controlled to be closed.

[0069] In the embodiment, the thermoelectric cooler 4 is installed inside the cavity of the first gas chamber 1 and used for refrigerating the first gas chamber 1, reducing the pressure value in the first gas chamber 1, so as to realize the transmission of the gas in the to-be-measured gas chamber 16 into the first gas chamber 1 or the transmission of the gas in the second gas chamber 2 into the first gas chamber 1. The thermoelectric cooler 4 is also used for heating the first gas chamber 1, increasing the pressure value in the first gas chamber 1, so as to realize the transmission of the gas in the first gas chamber 1 into the second gas chamber 2 or the transmission of the gas in the first gas chamber 1 into the to-be-measured gas chamber 16.

[0070] In the embodiment, the electric heating wire 3 is installed outside the cavity of the second gas chamber 2 and used for heating the second gas chamber 2, increasing the pressure value in the second gas chamber 2, so as to realize the transmission of the gas in the second gas chamber 2 into the to-be-measured gas chamber 16 or the transmission of the gas in the second gas chamber 2 into the first gas chamber 1.

[0071] In the embodiment, the gas port of the second gas chamber 2 is provided with a gas diffuser 14, which is driven to rotate by the gas when the gas enters the second gas chamber 2.

[0072] In an embodiment, the initial pressure value P0 of the gas chamber 16 to be measured (pressure value at 20℃) is read by the first densimeter 5. The first electromagnetic valve 7, the pressure reducing valve 11, the third electromagnetic valve 9 and the fourth electromagnetic valve 10 are opened, the refrigeration function of the thermoelectric refrigerator 4 is turned on, the first gas chamber 1 is refrigerated, and the temperature in the first gas chamber 1 is reduced to the liquefaction temperature T0 of SF6 gas at the initial pressure value P0. At this time, the pressure in the first gas chamber 1 is less than the pressure in the gas chamber 16 to be measured, and the gas in the gas chamber 16 to be measured enters the first gas chamber 1 through the flowmeter 15 and the infrared gas analyzer 6. The current pressure value of the gas chamber 16 to be measured is read by the first densimeter 5 in real time, the concentration data of the gas decomposition products is detected by the infrared gas analyzer 6, and when the current pressure value of the gas chamber 16 to be measured reaches the preset first pressure value, the first electromagnetic valve 7, the pressure reducing valve 11, the third electromagnetic valve 9 and the fourth electromagnetic valve 10 are closed.

[0073] In an embodiment, the first electromagnetic valve 7 and the second electromagnetic valve 8 are opened, so that the gas in the gas chamber 16 to be measured enters the second gas chamber 2 rapidly until the pressure is balanced, that is, the pressure values monitored by the first densimeter 5 and the second densimeter 13 are equal, and then the first electromagnetic valve 7 and the second electromagnetic valve 8 are closed.

[0074] In an embodiment, the fifth electromagnetic valve 12 is opened, and the thermoelectric refrigerator 4 is switched to the heating function, so that the gas in the first gas chamber 1 is vaporized and pressurized to enter the second gas chamber 2. Under this condition, the volume of the second gas chamber 2 is greater than that of the first gas chamber 1. The gas port of the second gas chamber 2 is provided with a gas diffuser 14, which can be referred to Figure 3 , Figure 3 The structure of the gas diffuser 14 in the embodiment of the application can be seen from the structure diagram of the gas diffuser 14. The gas diffuser 14 includes a paddle 17, which is driven to rotate by the gas when the gas enters the second gas chamber 2, so as to expand the diffusion direction of the gas and further ensure the mixing effect of the gas in the second gas chamber 2. The gas in the first gas chamber 1 continues to be heated, and the higher the temperature is, the more gas enters the second gas chamber 2. When the pressure of the second gas chamber 2 is balanced with that of the first gas chamber 1, the fifth electromagnetic valve 12 is closed, and the thermoelectric refrigerator 4 stops heating and reversely refrigerates for the next gas circulation.

[0075] In one embodiment, the electric heating wire 3 of the second gas chamber 2 is turned on, the first electromagnetic valve 7 and the second electromagnetic valve 8 are turned on, the gas in the second gas chamber 2 is heated by the electric heating wire 3, the pressure of the gas in the second gas chamber 2 is increased due to the temperature rise, the gas in the second gas chamber 2 is backfilled to the to-be-tested gas chamber 16, and due to the high temperature of the gas backfilled to the to-be-tested gas chamber 16, a turbulent flow is formed into the to-be-tested gas chamber 16 to accelerate the movement of the gas molecules in the to-be-tested gas chamber 16, and then to accelerate the gas mixing process. When the pressure value recorded by the first densimeter 5 no longer changes, that is, after the pressure of the to-be-tested gas chamber 16 and the second gas chamber 2 is balanced, the electric heating wire 3 of the second gas chamber 2, the first electromagnetic valve 7 and the second electromagnetic valve 8 are turned off.

[0076] The technical features of the above embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present application.

[0077] The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A self-checking method of a gas circulating device, characterized by, The method is applied to a gas circulation device, the gas circulation device comprising a first gas chamber and a second gas chamber, the first gas chamber and the second gas chamber are both used for connecting with a to-be-tested gas chamber, the first gas chamber is connected with the second gas chamber, and the method comprises the following steps: An initial pressure value of the to-be-tested gas chamber when current gas mixing is collected; The gas circulation device is controlled to perform a gas mixing, the gas mixing refers to a process that gas in the to-be-tested gas chamber is controlled to be respectively transported to the first gas chamber and the second gas chamber, and gas in the first gas chamber and gas in the second gas chamber are transmitted back to the to-be-tested gas chamber according to a preset path; A volume of the to-be-tested gas chamber when current gas mixing is calculated according to a gas flow rate, a gas decomposition product concentration, the initial pressure value and a current pressure value when the gas in the to-be-tested gas chamber is transported to the first gas chamber; Whether the gas circulation device is faulty is determined according to a difference comparison between the volume of the to-be-tested gas chamber when current gas mixing is calculated and a volume of the to-be-tested gas chamber when historical gas mixing is calculated.

2. The method of claim 1, wherein, The difference comparison between the volume of the to-be-tested gas chamber when current gas mixing is calculated and the volume of the to-be-tested gas chamber when historical gas mixing is calculated to determine whether the gas circulation device is faulty specifically comprises the following steps: An average value of the volume of the to-be-tested gas chamber when historical gas mixing is calculated is calculated to obtain a standard volume; A volume error when current gas mixing is calculated is obtained by calculating a difference value between the volume of the to-be-tested gas chamber when current gas mixing is calculated and the volume of the to-be-tested gas chamber when last gas mixing is calculated; When the volume error is greater than a preset multiple of the standard volume, it is considered that the gas circulation device is faulty, wherein the preset multiple is any numerical value less than 1.

3. The method of claim 1, wherein, The volume of the to-be-tested gas chamber when current gas mixing is calculated is obtained by the following formula: wherein, V is the volume of the gas chamber to be measured calculated at the time of current gas mixing, P is the pressure value at normal pressure, F is the gas flow rate when the gas in the gas chamber to be measured is transferred to the first gas chamber; T is the gas transfer time when the gas in the gas chamber to be measured is transferred to the first gas chamber; P0 is the initial pressure value in the gas chamber to be measured at the time of current gas mixing; P is the current pressure value of the gas chamber to be measured at the time of current gas mixing.

4. The method of claim 1, wherein, The process of one-time gas mixing specifically comprises the following steps: The gas in the to-be-tested gas chamber is controlled to be transported to the first gas chamber, and a current pressure value of the to-be-tested gas chamber is collected in real time; when the current pressure value of the to-be-tested gas chamber reaches a preset first pressure value, the gas transportation is stopped; The gas in the to-be-tested gas chamber is controlled to be transported to the second gas chamber, and the gas transportation is stopped after the pressure between the to-be-tested gas chamber and the second gas chamber is balanced; After the to-be-tested gas chamber stops transporting the gas to the second gas chamber, the gas in the first gas chamber is controlled to be transported to the second gas chamber, and the gas transportation is stopped after the pressure between the first gas chamber and the second gas chamber is balanced; After the first gas chamber stops transporting the gas to the second gas chamber, the gas in the second gas chamber is controlled to be transported to the to-be-tested gas chamber, and the gas transportation is stopped after the pressure between the second gas chamber and the to-be-tested gas chamber is balanced, so as to realize one-time gas mixing.

5. The method of claim 1, wherein, The process of one-time gas mixing specifically comprises the following steps: controlling the gas in the to-be-tested gas chamber to be delivered into the first gas chamber, and collecting the current pressure value of the to-be-tested gas chamber in real time; when the current pressure value of the to-be-tested gas chamber reaches a preset second pressure value, stopping the gas delivery; controlling the gas in the to-be-tested gas chamber to be delivered into the second gas chamber, and stopping the gas delivery after the pressure between the to-be-tested gas chamber and the second gas chamber is balanced; after the to-be-tested gas chamber stops delivering the gas into the second gas chamber, controlling the gas in the first gas chamber to be delivered into the to-be-tested gas chamber, and stopping the gas delivery when the current pressure value of the to-be-tested gas chamber reaches a preset third pressure value; controlling the gas in the second gas chamber to be delivered into the to-be-tested gas chamber, and stopping the gas delivery when the current pressure value of the to-be-tested gas chamber reaches a preset fourth pressure value, so as to realize the mixing of the gas once.

6. The method according to any one of claims 4 or 5, wherein, The gas circulation device further comprises a first densimeter, a flow meter and an infrared gas analyzer, wherein the first densimeter is used to be connected with the to-be-tested gas chamber, and the flow meter and the infrared gas analyzer are both arranged between the to-be-tested gas chamber and the first gas chamber. The first densimeter is used to measure the pressure value of the to-be-tested gas chamber. The flow meter is used to collect the flow rate of the gas when the gas in the to-be-tested gas chamber is delivered into the first gas chamber. The infrared gas analyzer is used to collect the concentration of the decomposition product of the gas when the gas in the to-be-tested gas chamber is delivered into the first gas chamber.

7. The method of claim 6, wherein, The gas circulation device further comprises a first electromagnetic valve, a second electromagnetic valve, a pressure reducing valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve and a second densimeter. The second densimeter is connected with the second gas chamber and is used to measure the pressure value of the second gas chamber. One end of the first electromagnetic valve is used to be connected with the to-be-tested gas chamber, one end of the pressure reducing valve is connected with the other end of the first electromagnetic valve and one end of the second electromagnetic valve respectively, the other end of the second electromagnetic valve is connected with one gas port of the second gas chamber, the other end of the pressure reducing valve is connected with one end of the flow meter, one end of the flow meter is connected with one end of the third electromagnetic valve, the other end of the third electromagnetic valve is connected with one end of the infrared gas analyzer, the other end of the infrared gas analyzer is connected with one end of the fourth electromagnetic valve, the other end of the fourth electromagnetic valve is connected with one gas port of the first gas chamber, the other gas port of the first gas chamber is connected with one end of the fifth electromagnetic valve, and the other end of the fifth electromagnetic valve is connected with the other gas port of the second gas chamber. When the gas in the to-be-tested gas chamber is delivered into the first gas chamber, the first electromagnetic valve, the pressure reducing valve, the third electromagnetic valve and the fourth electromagnetic valve are controlled to be opened; after the to-be-tested gas chamber stops delivering the gas into the first gas chamber, the first electromagnetic valve, the pressure reducing valve, the third electromagnetic valve and the fourth electromagnetic valve are controlled to be closed. When the gas in the to-be-tested gas chamber is delivered into the second gas chamber, the first electromagnetic valve and the second electromagnetic valve are controlled to be opened; after the to-be-tested gas chamber stops delivering the gas into the second gas chamber, the first electromagnetic valve and the second electromagnetic valve are controlled to be closed. When the gas in the first gas chamber is transmitted into the second gas chamber, or the gas in the second gas chamber is transmitted into the first gas chamber, the fifth electromagnetic valve is controlled to be opened; when the first gas chamber stops transmitting gas to the second gas chamber, or the second gas chamber stops transmitting gas to the first gas chamber, the fifth electromagnetic valve is controlled to be closed.

8. The method of claim 6, wherein, A thermoelectric refrigerator is installed inside the first gas chamber cavity, used for refrigerating the first gas chamber, reducing the pressure value in the first gas chamber, so as to realize the transmission of the gas in the to-be-tested gas chamber into the first gas chamber, or the transmission of the gas in the second gas chamber into the first gas chamber. The thermoelectric refrigerator is also used for heating the first gas chamber, increasing the pressure value in the first gas chamber, so as to realize the transmission of the gas in the first gas chamber into the second gas chamber, or the transmission of the gas in the first gas chamber into the to-be-tested gas chamber.

9. The method of claim 6, wherein, An electric heating wire is installed outside the second gas chamber cavity, used for heating the second gas chamber, increasing the pressure value in the second gas chamber, so as to realize the transmission of the gas in the second gas chamber into the to-be-tested gas chamber, or the transmission of the gas in the second gas chamber into the first gas chamber.

10. The method of claim 6, wherein, A gas diffuser is installed at the gas port of the second gas chamber, used for rotating the paddle of the gas diffuser when the gas enters the second gas chamber.

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