A hydrogen mixing system and method for mixing hydrogen into argon

Abstract

The application discloses a mixed system and a mixed method of argon mixed with hydrogen, which comprises a mixer, a hydrogen control pipeline, a flow control device arranged on the hydrogen control pipeline, an argon control pipeline, a flow metering device arranged on the argon control pipeline, a concentration detection device arranged at an output end of the mixer, and a PID control system, wherein a hydrogen concentration value detected by the concentration detection device is transmitted to the PID control system, the PID control system feeds back a control signal to the flow control device after comparing the detected hydrogen concentration value with a preset hydrogen concentration value, and the flow control device outputs a certain hydrogen flow under the control of the control signal. In the application, the PID control system can analyze data of concentration detection and flow detection, thereby controlling the output of the flow control device, and the proportion accuracy of hydrogen in the electronic mixed gas is improved, and the mixing accuracy is effectively improved.

Description

Technical Field

[0001] This application relates to the technical field of electronic mixed gas mixing, and in particular to an argon-hydrogen mixing system and mixing method. Background Technology

[0002] Gases diluted to a certain ratio are called "electron mixtures," and these "electron mixtures" are required in all semiconductor manufacturing processes. In addition to ensuring high precision in their concentration, "electron mixtures" also need to have excellent quality. In other words, the electronic mixture must ensure that the harmful impurities contained in the mixed gas do not exceed a certain value.

[0003] In the mixing process of "electronic mixed gas", gases with different concentration values ​​need to be fully mixed to achieve a stable mixed gas concentration required by the process.

[0004] Regarding the aforementioned technologies, during the gas mixing process, the flow rate of the gas output at different concentrations changes in real time, resulting in low mixing accuracy and the output electronic mixed gas failing to meet high requirements. Summary of the Invention

[0005] To help solve the problem of low mixing accuracy of electronic mixed gases, this application provides an argon-hydrogen mixing system and a mixing method.

[0006] The argon-hydrogen mixing system and mixing method provided in this application adopt the following technical solution:

[0007] First aspect

[0008] An argon-hydrogen mixing system, comprising:

[0009] Mixer;

[0010] A hydrogen control line, the output end of which is connected to the input end of the mixer, and a flow control device is provided on the hydrogen control line;

[0011] An argon gas control pipeline, the output end of which is connected to the input end of the mixer, and a flow metering device is installed on the argon gas control pipeline;

[0012] A concentration detection device is installed at the output end of the mixer;

[0013] The PID control system is electrically connected to the concentration detection device, the flow control device, and the flow metering device. The hydrogen concentration value detected by the concentration detection device is transmitted to the PID control system. The PID control system compares and analyzes the detected hydrogen concentration value with the preset hydrogen concentration value and then feeds back a control signal to the flow control device to control the flow control device to output a certain hydrogen flow rate.

[0014] By adopting the above technical solution, the concentration detection device detects the hydrogen concentration in the argon-hydrogen mixture in real time. When the hydrogen concentration exceeds the preset value, the PID control system controls the flow control device, which outputs a certain amount of hydrogen, thus ensuring that the concentration ratio of hydrogen and argon reaches the preset value and guaranteeing the mixing accuracy. This application's solution utilizes a PID control system to detect and control the hydrogen concentration in real time, improving the mixing accuracy. Furthermore, a flow metering device is installed only on the argon control pipeline, while a flow control device is installed on the hydrogen control pipeline. This arrangement aims to ensure more accurate data detection by the flow metering device. The detected data is fed back to the PID control system, which analyzes both the concentration and flow detection data. [Concentration analysis, as the detection value, is the primary control method, while flow analysis serves as a comparison value.] The concentration analysis results are fed back to the hydrogen flow control device (MFC), controlling the MFC output value. The argon flow reading value and the hydrogen flow reading value are compared, and the comparison result (hydrogen flow reading value / (argon flow reading value + hydrogen flow reading value) × 100%) is compared with the set hydrogen concentration. For example, if the hydrogen concentration is set to 3.5% and the control mode is concentration control, and the concentration is less than 3.5%, the MFC output value will increase after PID adjustment until it approaches the set hydrogen concentration value, at which point the MFC output value will remain constant. The hydrogen MFC output value is currently readable. The hydrogen flow rate is compared with the argon flow rate; if the comparison result deviates significantly from the set value of 3.5%, an alarm is triggered if the deviation exceeds ±5% (for example, a ±5% deviation of the set value of 3.5% would be 3.325%-3.675%, and the comparison result exceeds this range, the system alarms). This logic reflects the reliability of concentration control. This further improves the accuracy of the hydrogen proportion in the electronic gas mixture, effectively improving the mixing accuracy.

[0015] Optionally, the output end of the mixer is connected to a mixed gas output pipeline, and a buffer tank is installed on the mixed gas output pipeline. The concentration detection device includes a first hydrogen concentration analyzer and a second hydrogen concentration analyzer. The first hydrogen concentration analyzer is installed between the mixer and the buffer tank, and the second hydrogen concentration analyzer is installed at the output end of the buffer tank. Both the first and second hydrogen concentration analyzers are electrically connected to the PID control system.

[0016] By adopting the above technical solution, two concentration analyzers are used to detect the mixed gas. On the one hand, the data detected by the two concentration analyzers are compared to determine whether there is a problem with the detection accuracy of the concentration analyzers, thereby ensuring the mixing accuracy. On the other hand, when the mixed gas is just output from the output end of the buffer, the gas mixing may not be sufficient, and the detected data may have some deviation. However, after buffering by the buffer tank, the detection accuracy can be effectively guaranteed. The improved detection accuracy can then be fed back to the PID control system to control the output hydrogen concentration of the flow control device, thereby further improving the mixing accuracy.

[0017] Optionally, a hydrogen concentration difference alarm device is installed between the first hydrogen concentration analyzer and the second hydrogen concentration analyzer.

[0018] By adopting the above technical solution, when the numerical deviations detected by the first hydrogen concentration analyzer and the second hydrogen concentration analyzer are large, the hydrogen concentration difference alarm device will sound an alarm, and personnel will come to check. The purpose of this setting is to accurately determine the abnormal situation of hydrogen concentration, and at the same time, to check whether the hydrogen concentration analyzer is working properly, thereby ensuring the accuracy of subsequent mixing.

[0019] Optionally, a hydrogen pressure alarm device is connected to the hydrogen control pipeline at the output end of the flow control device, and a hydrogen shut-off valve is provided on the hydrogen control pipeline at the input end of the flow control device; an argon pressure alarm device is connected to the argon control pipeline at the output end of the flow metering device, and an argon shut-off valve is provided on the argon control pipeline at the input end of the flow metering device.

[0020] By adopting the above technical solutions, it is convenient for personnel to quickly identify problems and resolve them.

[0021] Optionally, the hydrogen control pipeline is provided with a hydrogen backup control pipeline, which is equipped with a backup hydrogen shut-off valve, a backup flow control device, and a backup hydrogen pressure alarm device that are electrically connected to the PID control system.

[0022] The argon control pipeline is equipped with an argon backup control pipeline, which includes a backup argon shut-off valve, a backup flow metering device, and a backup argon pressure alarm device that are electrically connected to the PID control system.

[0023] By adopting the above technical solution, when the pressure is below a certain limit for a period of time, the PID control system can automatically switch the control pipeline to ensure the normal operation of the mixing process. This setting further improves the applicability of the system.

[0024] Optionally, the buffer tank is connected to a mixed gas pressure alarm device and a buffer tank pressure relief device.

[0025] By adopting the above technical solution, it is beneficial to monitor the pressure inside the buffer tank. Furthermore, when used in conjunction with a hydrogen concentration alarm, it can provide both concentration and pressure alarms. The combined effect of these two systems improves the system's sensitivity, thereby ensuring its reliability. Additionally, installing a pressure relief device on the buffer tank facilitates pressure release, further ensuring safety.

[0026] Optionally, a test line is provided on the mixed gas output line, the test line is located between the mixer and the buffer tank, and a vent control valve is provided on the test line.

[0027] By adopting the above technical solution, the venting control valve can be opened during equipment commissioning for convenient adjustment.

[0028] Second aspect

[0029] A method for mixing argon and hydrogen includes the following steps:

[0030] S1. Adjust the pressure of the hydrogen control pipeline and the pressure of the argon control pipeline;

[0031] S2. Open the argon gas shut-off valve and open the hydrogen gas shut-off valve;

[0032] S3. The hydrogen pressure in the hydrogen control pipeline is reduced and then input into the flow control device; the argon pressure in the argon control pipeline is reduced and then input into the flow metering device.

[0033] S4. The concentration detection device feeds back the signal to the PID control system, which then controls the flow control device to control the flow rate. The hydrogen concentration range is 3.5%-10% v / v.

[0034] S5. When the difference between the values ​​detected by the first hydrogen concentration analyzer and the second hydrogen concentration analyzer is greater than ±0.5%, one of the hydrogen concentration analyzers is deactivated and the other hydrogen concentration analyzer is selected as the main controller.

[0035] By adopting the above technical solution, on the one hand, the data can be accurately detected, reducing the occurrence of reduced mixing accuracy due to substandard equipment precision; on the other hand, the values ​​detected by the hydrogen concentration analyzer can be analyzed and compared with the values ​​detected by the flow control device and the flow metering device, thereby comprehensively judging whether the equipment in the system is abnormal, thus enabling precise monitoring of the system status and improving the reliability and safety of the mixing system.

[0036] Optionally, the following steps may also be included:

[0037] S6. Periodically sample and test the mixed gas. When the values ​​detected by the first hydrogen concentration analyzer and the second hydrogen concentration analyzer deviate from the actual measured value of the sample by more than ±0.5%, switch the flow metering device to participate in the concentration ratio control. The argon flow rate value detected by the flow metering device is fed back to the PID control system. The PID control system controls the hydrogen flow rate of the flow control device and adjusts the hydrogen flow rate value to the hydrogen set value.

[0038] Flow relationship: A / (A+B) = hydrogen concentration value%, where A is the standard flow rate of the flow control device and B is the standard flow rate of the flow metering device.

[0039] By adopting the above technical solution, compared with the traditional method of installing flow control devices on both control pipelines, the flow control upper limit of this application is higher. The commonly used mixing mode in the market uses MFC control for both hydrogen and argon. The mixing mode of this application uses MFC control for hydrogen (low concentration), while argon is supplied according to downstream usage without flow control. With a hydrogen concentration requirement of 3.5%, the total system flow rate can be 28 times greater than traditional control. With a hydrogen concentration requirement of 10%, the total system flow rate can be 10 times greater than traditional control. This application's solution offers a larger mixing flow rate and high mixing accuracy, capable of meeting the needs of large-volume gas consumption.

[0040] Optionally, the following steps may also be included:

[0041] S21. After the argon gas shut-off valve is opened, the argon gas pressure alarm device will participate in the control of the argon gas control pipeline after 1.5s-2.5s. When the pressure value detected by the argon gas pressure alarm device is lower than 0.45Mpa, the argon gas pressure alarm device will sound an alarm to remind personnel to check the argon gas control pipeline. When the pressure value detected by the argon gas pressure alarm device is lower than 0.4Mpa, the argon gas pressure alarm device will sound an alarm after 1.5s-2.5s, triggering an interlock to open the backup argon gas shut-off valve. The backup argon gas pressure alarm device will participate in the control of the backup argon gas control pipeline after 1.5s-2.5s.

[0042] S22. After the argon gas shut-off valve is opened, the hydrogen pressure alarm device will participate in the control of the hydrogen control pipeline after 1.5s-2.5s. When the pressure value detected by the hydrogen pressure alarm device is lower than 0.45Mpa, the hydrogen pressure alarm device will sound an alarm to remind personnel to check the hydrogen control pipeline. When the pressure value detected by the hydrogen pressure alarm device is lower than 0.4Mpa, the hydrogen pressure alarm device will sound an alarm after 1.5s-2.5s, triggering an interlock to open the backup hydrogen shut-off valve. The backup hydrogen pressure alarm device will participate in the control of the backup hydrogen control pipeline after 1.5s-2.5s.

[0043] By adopting the above technical solution, a pressure alarm and pipeline switching scheme is creatively designed, which can accurately determine the changes in hydrogen and argon pressure during the mixing process. When either of them is abnormal, the system can respond quickly, allowing personnel to conduct manual inspections to determine if there is an anomaly. The purpose of this design is to ensure the normal production of the mixed gas while also enabling rapid monitoring of abnormal situations. When the anomaly exceeds the set range, the system can automatically switch to a backup device, ensuring both safety and the normal operation of production.

[0044] In summary, this application includes at least one of the following beneficial technical effects:

[0045] 1. The proposed solution utilizes a PID control system to detect and control hydrogen concentration in real time, thereby improving mixing accuracy. Furthermore, a flow metering device is installed only on the argon control line, while a flow control device is installed on the hydrogen control line. This arrangement ensures more accurate data from the flow metering device, which is then fed back to the PID control system. The PID control system combines the concentration and flow data for analysis, improving the accuracy of the hydrogen content in the electronic gas mixture and effectively enhancing mixing precision.

[0046] 2. The combined use of concentration analysis and flow control can, on the one hand, enable accurate data detection, reducing the occurrence of reduced mixing accuracy due to substandard equipment precision; on the other hand, the values ​​detected by the hydrogen concentration analyzer can be analyzed and compared with the values ​​detected by the flow control device and the flow metering device, thereby comprehensively judging whether the equipment in the system is abnormal, thus enabling precise monitoring of the system status and improving the reliability and safety of the mixing system.

[0047] 3. In this application, the technical personnel and the PID control system jointly assess abnormal situations. Because gas pressure fluctuates significantly during actual mixing, the PID control system needs to sensitively detect anomalies and trigger alarms. After an alarm is triggered, whether these anomalies are normal requires manual assessment and handling. This setup aims to ensure both normal system operation and timely detection of abnormal situations, greatly improving system reliability and safety. Attached Figure Description

[0048] Figure 1 This is a system flowchart illustrating the overall structure of an embodiment of this application.

[0049] Figure 2 This application embodiment mainly illustrates the system flow diagram of the hydrogen control pipeline and the argon control pipeline.

[0050] Figure 3 This application embodiment mainly illustrates the system flowchart of the concentration detection device.

[0051] Explanation of reference numerals in the attached figures:

[0052] 10. Hydrogen control pipeline; 101. Flow control device; 102. Hydrogen shut-off valve; 103. Hydrogen filtration device; 104. Hydrogen pressure reducing device; 105. Hydrogen pressure alarm device; 11. Hydrogen backup control pipeline; 111. Backup hydrogen shut-off valve; 112. Backup flow control device; 113. Backup hydrogen pressure alarm device;

[0053] 20. Argon control pipeline; 201. Flow metering device; 202. Argon shut-off valve; 203. Argon filter; 204. Argon pressure reducing device; 205. Argon pressure alarm device; 21. Argon backup control pipeline; 211. Backup argon shut-off valve; 212. Backup flow metering device; 213. Backup argon pressure alarm device;

[0054] 30. Mixer; 301. Mixed gas output pipeline; 302. Debugging pipeline; 303. Vent control valve; 304. Mixed gas shut-off valve;

[0055] 40. Buffer tank; 401. Mixed gas pressure alarm device; 402. Buffer tank pressure relief device;

[0056] 50. Concentration detection device; 501. First hydrogen concentration analyzer; 502. Second hydrogen concentration analyzer; 503. Hydrogen concentration difference alarm device;

[0057] 60. PID control system. Detailed Implementation

[0058] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0059] This application discloses an argon-hydrogen mixing system, referring to... Figure 1 The system includes a hydrogen control line 10, an argon control line 20, a mixer 30, a buffer tank 40, a concentration detection device 50, and a PID control system 60. The outputs of both the hydrogen control line 10 and the argon control line 20 are connected to the input of the mixer 30. The hydrogen control line 10 is equipped with a flow control device 101 for measuring and controlling the hydrogen flow rate; the flow control device 101 can be a flow controller (MFC). The argon control line 20 is equipped with a flow metering device 201 for measuring the argon flow rate; the flow metering device 201 can be a flow meter (MFM).

[0060] Reference Figure 2 and Figure 3The mixer 30 has a mixed gas output pipeline 301 connected to its output end. A buffer tank 40 is connected to the mixed gas output pipeline 301. The concentration detection device 50 includes a first hydrogen concentration analyzer 501 and a second hydrogen concentration analyzer 502. The first hydrogen concentration analyzer 501 is installed on the mixed gas output pipeline 301 and located between the mixer 30 and the buffer tank 40. The second hydrogen concentration analyzer 502 is installed at the output end of the buffer tank 40. The PID control system 60 is electrically connected to the first hydrogen concentration analyzer 501, the second hydrogen concentration analyzer 502, the flow control device 101, and the flow metering device 201. The concentration detection device 50 detects the hydrogen concentration value and feeds the value back to the PID control system 60. The PID control system 60 controls the flow control device 101 according to the hydrogen concentration value, adjusting the output value of the flow control device 101 to ensure that the hydrogen concentration value reaches the preset value, thereby ensuring the mixing accuracy.

[0061] Reference Figure 2 Along the gas flow direction, the hydrogen control pipeline 10 is sequentially equipped with a hydrogen shut-off valve 102, a hydrogen filter 103, a hydrogen pressure reducing device 104, and a hydrogen pressure alarm device 105, all electrically connected to the PID control system 60. A flow control device 101 is positioned between the hydrogen pressure reducing device 104 and the hydrogen pressure alarm device 105. The hydrogen shut-off valve 102 is used to open and close the hydrogen control pipeline 10. The hydrogen filter 103 can be a filter valve to filter impurities in the hydrogen. The hydrogen pressure reducing device 104 can be a pressure reducing valve to adjust the hydrogen pressure, allowing the hydrogen pressure in the hydrogen control pipeline 10 to be adjusted to 0.7 MPa-0.8 MPa. Preferably, the hydrogen pressure is adjusted to 0.75 MPa.

[0062] The hydrogen pressure alarm device 105 is used to detect the hydrogen pressure on the hydrogen control pipeline 10. When the pressure value detected by the hydrogen pressure alarm device 105 is lower than 0.45 MPa, the hydrogen pressure alarm device 105 will sound an alarm to remind personnel to check the hydrogen control pipeline 10. The personnel check mainly checks whether the pressure of the upstream gas supply source is normal and whether there is any leakage in the pipeline.

[0063] Meanwhile, a backup hydrogen control pipeline 11 is provided on the hydrogen control pipeline 10. The backup hydrogen control pipeline 11 is provided with a backup hydrogen shut-off valve 111, a backup flow control device 112, and a backup hydrogen pressure alarm device 113, which are electrically connected to the PID control system 60. The other devices are the same as those in the hydrogen control pipeline 10.

[0064] When the pressure value detected by the hydrogen pressure alarm device 105 is lower than 0.4 MPa for 1.5s-2.5s, preferably lower than 0.4 MPa for 2.0s, the hydrogen pressure alarm device 105 alarms, triggering an interlock to open the backup hydrogen shut-off valve 111. The backup hydrogen pressure alarm device 113 participates in the control of the backup hydrogen control pipeline 10 after 1.5s-2.5s, preferably after 2.0s.

[0065] Similarly, along the gas flow direction, the argon control pipeline 20 is sequentially equipped with an argon shut-off valve 202, an argon filter 203, an argon pressure reducing device 204, and an argon pressure alarm device 205, all electrically connected to the PID control system 60. The flow control device 101 is located between the pressure reducing device and the argon pressure alarm device 205. The argon shut-off valve 202 is used to open and close the argon control pipeline 20. The argon filter 203 can be a filter valve to filter impurities in the argon gas. The argon pressure reducing device 204 can be a pressure reducing valve to adjust the argon pressure so that the argon pressure in the argon control pipeline 20 can be adjusted to 0.55 MPa-0.65 MPa. Preferably, the argon pressure is adjusted to 0.6 MPa.

[0066] Argon pressure alarm device 205 is used to detect the argon pressure on argon control pipeline 20. When the pressure value detected by argon pressure alarm device 205 is lower than 0.45 MPa, argon pressure alarm device 205 will sound an alarm to remind personnel to check argon control pipeline 20.

[0067] Meanwhile, the argon control pipeline 20 is equipped with an argon backup control pipeline 21. The argon backup control pipeline 21 is equipped with a backup argon shut-off valve 211, a backup flow control device 112, and a backup argon pressure alarm device 213, which are electrically connected to the PID control system 60. The other devices are the same as those in the argon control pipeline 20.

[0068] When the pressure value detected by the argon pressure alarm device 205 is lower than 0.4 MPa for 1.5s-2.5s, preferably lower than 0.4 MPa for 2.0s, the argon pressure alarm device 205 alarms, triggering an interlock to open the backup argon shut-off valve 211. The backup argon pressure alarm device 213 participates in the control of the backup argon control pipeline 20 after 1.5s-2.5s, preferably after 2.0s.

[0069] The reason for this configuration is that, during the actual mixing process, the pressure of hydrogen and argon gases fluctuates significantly. The PID control system 60 needs to sensitively detect abnormalities in various parts of the mixing system and trigger alarms. After an alarm is triggered, whether these abnormalities are normal requires manual judgment and handling. This configuration ensures the normal operation of the system and allows for timely identification of abnormal situations, greatly improving the system's reliability and safety.

[0070] In addition, a flow ratio alarm device is installed between the flow control device 101 and the flow metering device 201. When the deviation between the gas flow rate output by the flow control device 101 and the flow metering device 201 and the preset value is greater than ±5%, the flow ratio alarm device will sound an alarm to remind personnel to check and judge.

[0071] For example, if the preset hydrogen flow rate is 10%, then the deviation range of the preset hydrogen flow rate is 10% × (95% - 105%) = 9.5% - 10.5%. Assuming that the hydrogen concentration value read by the flow control device 101 (hydrogen concentration value = hydrogen flow rate reading value / (argon flow rate reading value + hydrogen flow rate reading value) × 100%) is 9.2%, then the flow ratio alarm device will sound an alarm.

[0072] After the flow ratio alarm device sounds, personnel can manually switch between hydrogen backup control line 11 and argon backup control line 21, and then perform data detection and comparison to ensure mixing accuracy.

[0073] The ±5% alarm value is a programmable setting, which is adjustable. The setting is adjusted based on the customer's sensitivity to gas deviation and the alarm frequency during commissioning. If the user does not wish to frequently switch control logic and the concentration control effect is acceptable, this alarm value can be increased.

[0074] Reference Figure 2 and Figure 3 After the mixer 30 mixes hydrogen and argon and outputs the mixed gas, the first hydrogen concentration analyzer 501 detects the hydrogen concentration in the freshly mixed gas, and the second hydrogen concentration analyzer 502 detects the hydrogen concentration in the fully mixed gas. The two can be used together to detect whether the equipment is abnormal, reduce detection deviation, improve detection accuracy, and thus improve mixing accuracy.

[0075] For example, the first hydrogen concentration analyzer 501 or the second hydrogen concentration analyzer 502 can be selected as the primary controller, while the other hydrogen concentration analyzer can be used for comparison or deactivated.

[0076] When another hydrogen concentration analyzer is used for comparison, a hydrogen concentration difference alarm device 503 is installed between the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502. When the difference between the values ​​detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 is greater than ±0.5%, the hydrogen concentration difference alarm device 503 will sound an alarm. Personnel can then choose to disable one of the hydrogen concentration analyzers and select the other hydrogen concentration analyzer as the master analyzer.

[0077] For example, if the system is set to a hydrogen concentration of 10% v / v, and the first hydrogen concentration analyzer 501, acting as the main controller, detects a hydrogen concentration of 9.4% v / v, while the second hydrogen concentration analyzer 502 detects a value of 10% v / v, then the difference between the two is greater than ±0.5%, triggering the hydrogen concentration difference alarm device 503. Personnel can then switch the second hydrogen concentration analyzer 502 to become the main controller. If, at this time, the value detected by the first hydrogen concentration analyzer 501 is still around 9.4% v / v, then it can be determined that the accuracy of the first hydrogen concentration analyzer 501 is deviated and requires calibration.

[0078] Meanwhile, during the actual mixing process, the mixed gas will be sampled and tested periodically. The sampling and testing period can be once a month, or it can be determined based on feedback from the back-end users. When the values ​​detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 deviate from the actual measured value of the sampling test by more than ±0.5% (for example, the values ​​detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 are 9.4%, while the actual measured value of the sampling test is 10%), it proves that the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 have failed. At this time, the flow metering device 201 is switched to participate in the hydrogen concentration proportional control. The argon flow rate value detected by the flow metering device 201 is fed back to the PID control system 60. The PID control system 60 controls the flow control device 101 to output a certain hydrogen flow rate, controlling the hydrogen concentration value to reach the hydrogen set value.

[0079] Flow relationship: A / (A+B) = hydrogen concentration value%, where A is the standard flow rate of the flow control device and B is the standard flow rate of the flow metering device.

[0080] For example, if the system hydrogen setting is 10% v / v, the flow metering device 201 will feed back the argon reading value to the PID control system 60. The PID control system 60 will control the flow control device 101 to output a certain hydrogen flow rate so that the argon concentration reaches 90% v / v, and the hydrogen concentration reaches 10% v / v, thus realizing the automatic adjustment of the system.

[0081] In addition, a test line 302 is installed on the mixed gas output line 301 between the mixer 30 and the buffer tank 40. A vent control valve 303 is installed on the test line 302. A mixed gas shut-off valve 304 is also installed on the mixed gas output line 301 between the mixer 30 and the buffer tank 40. When testing is required, the mixed gas shut-off valve 304 is closed and the vent control valve 303 is opened. During testing, any mixed gas can be discharged through the test line 302. When normal mixing is required, the mixed gas shut-off valve 304 is opened and the vent control valve 303 is closed.

[0082] Meanwhile, the output end of the buffer tank 40 is also connected to a mixed gas pressure alarm device 401 and a buffer tank pressure relief device 402, which are electrically connected to the PID control system 60. The mixed gas pressure alarm device 401 detects the pressure of the mixed gas output from the buffer tank 40. When the pressure exceeds 0.88 MPa, the mixed gas pressure alarm device 401 alarms, and manual judgment and handling are required after the alarm. Personnel mainly check whether the gas supply at the end of the system has stopped and whether the pressure reducing device in the system is working properly. When the internal pressure of the buffer tank 40 exceeds 1 MPa, the PID control system 60 controls the buffer tank pressure relief device 402 to automatically relieve pressure, ensuring the safety of the mixing system.

[0083] The implementation principle of the argon-hydrogen mixing system in this application embodiment is as follows: In this application, concentration analysis and flow control are used in combination. On the one hand, the data can be accurately detected, reducing the occurrence of reduced mixing accuracy due to substandard equipment accuracy. On the other hand, the value detected by the hydrogen concentration analyzer can be analyzed and compared with the values ​​detected by the flow control device 101 and the flow metering device 201, thereby comprehensively judging whether the equipment in the system is abnormal, thus accurately monitoring the system status and improving the reliability and safety of the mixing system.

[0084] This application also discloses a method for mixing argon and hydrogen, comprising the following steps:

[0085] S1. Adjust the pressure of hydrogen control line 10 to 0.9Mpa-1Mpa, and adjust the pressure of argon control line 20 to 0.75Mpa-0.85Mpa.

[0086] Preferably, the pressure in hydrogen control line 10 is adjusted to 0.9 MPa, and the pressure in argon control line 20 is adjusted to 0.8 MPa. This adjustment facilitates subsequent gas depressurization and ensures system safety.

[0087] S21. Open the argon gas shut-off valve 202. After opening the argon gas shut-off valve 202, the argon gas pressure alarm device 205 will participate in the control of the argon gas control pipeline 20 after 2 seconds. When the pressure value detected by the argon gas pressure alarm device 205 is lower than 0.45 MPa, the argon gas pressure alarm device 205 will sound an alarm, reminding personnel to check the argon gas control pipeline 20. The detection process mainly involves checking the pressure of the upstream gas supply source and checking for leaks in the pipeline. When the pressure value detected by the argon gas pressure alarm device 205 is lower than 0.4 MPa for 2 seconds, the argon gas pressure alarm device 205 will sound an alarm, triggering a chain to open the backup argon gas shut-off valve 211, using the backup argon gas control pipeline 20. The backup argon gas pressure alarm device 213 will participate in the control of the backup argon gas control pipeline 20 after 2 seconds. The argon gas shut-off valve 202 will shut off the argon gas control pipeline 20 2 seconds after the backup argon gas shut-off valve 211 is opened.

[0088] S22. After the hydrogen shut-off valve 102 is opened, the hydrogen pressure alarm device 105 participates in the control of the hydrogen control pipeline 10 after 2 seconds. When the pressure value detected by the hydrogen pressure alarm device 105 is lower than 0.45 MPa, the hydrogen pressure alarm device 105 alarms to remind personnel to check the hydrogen control pipeline 10. When the pressure value detected by the hydrogen pressure alarm device 105 is lower than 0.4 MPa for 2 seconds, the hydrogen pressure alarm device 105 alarms, triggering a chain to open the backup hydrogen shut-off valve 111. The backup hydrogen pressure alarm device 113 participates in the control of the backup hydrogen control pipeline 10 after 2 seconds. The hydrogen shut-off valve 102 shuts off the hydrogen control pipeline 10 2 seconds after the backup hydrogen shut-off valve 111 is opened.

[0089] S3. The hydrogen pressure in the hydrogen control pipeline 10 is reduced to 0.7Mpa-0.8Mpa before being fed into the flow control device 101. The argon pressure in the argon control pipeline 20 is reduced to 0.55Mpa-0.65Mpa before being fed into the flow metering device 201.

[0090] Preferably, the hydrogen pressure in the hydrogen control line 10 is reduced to 0.75 MPa before being input into the flow control device 101, and the argon pressure in the argon control line 20 is reduced to 0.6 MPa before being input into the flow metering device 201. The mixer 30 mixes the hydrogen and argon, and after mixing, the mixed gas is output from the mixed gas output line 301.

[0091] S4. The concentration detection device 50 feeds back a signal to the PID control system 60, which controls the flow control device 101 to perform flow control. The hydrogen concentration range is 3.5%-10% v / v.

[0092] Specifically, the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 detect the hydrogen concentration in the mixed gas and feed the detected values ​​back to the PID control system 60. The PID control system 60 then controls the flow control device 101 to output a certain hydrogen flow rate, so that the hydrogen concentration detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 reaches the preset value.

[0093] S5. When the difference between the values ​​detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 is greater than ±0.5%, one of the hydrogen concentration analyzers is deactivated and the other hydrogen concentration analyzer is selected as the main controller.

[0094] For example, assuming the system is set to a hydrogen concentration of 10% v / v, the first hydrogen concentration analyzer 501 acts as the main controller and detects a hydrogen value of 9.4% v / v, while the second hydrogen concentration analyzer 502 detects a value of 10% v / v. Therefore, it can be determined that the second hydrogen concentration analyzer 502 needs to be switched to the main controller. If, at this time, the first hydrogen concentration analyzer 501 still detects a hydrogen value of 9.4% v / v, then it can be determined that the first hydrogen concentration analyzer 501 is malfunctioning and needs calibration.

[0095] In another mode, the hydrogen concentration can also be controlled based on the flow rate.

[0096] S6. Periodically sample and test the mixed gas. When the values ​​detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 deviate from the actual measured value of the sampling test by more than ±0.5%, switch the flow metering device 201 to participate in the concentration ratio control. The argon flow rate value detected by the flow metering device 201 is fed back to the PID control system 60. The PID control system 60 controls the hydrogen flow rate of the flow control device 101 and adjusts the hydrogen concentration value to the hydrogen set value.

[0097] Flow relationship: A / (A+B) = hydrogen concentration value%, where A is the standard flow rate of the flow control device and B is the standard flow rate of the flow metering device.

[0098] Specifically, the mixed gas can be sampled and tested based on user feedback, or it can be tested periodically, with a period of one week or one month. When the values ​​detected by the first hydrogen concentration analyzer 501 and the second hydrogen concentration analyzer 502 deviate from the actual measured values ​​of the sampled gas by more than ±0.5%, it can be determined that both hydrogen concentration analyzers have failed. At this time, the PID control system 60 switches the flow metering device 201 to participate in the concentration ratio control.

[0099] For example, if the system is set to a hydrogen concentration of 10% v / v, and the first hydrogen concentration analyzer 501, acting as the main controller, detects a hydrogen concentration of 9.4% v / v, while the second hydrogen concentration analyzer 502 detects a concentration of 9.3% v / v, and the actual sampled concentration is 10% v / v, then both the first and second hydrogen concentration analyzers 501 and 502 have failed. In this case, the flow metering device 201 is switched to participate in the concentration ratio control.

[0100] The specific process is as follows: the argon flow rate detected by the flow metering device 201 is fed back to the PID control system 60. The PID control system 60 controls the flow control device 101 according to the argon flow rate, so that the flow control device 101 outputs a certain hydrogen flow rate. Since the hydrogen flow rate and the argon flow rate enter the mixer 30 together, when the argon flow rate changes, the hydrogen flow rate also changes accordingly. Thus, by changing the hydrogen flow rate, the purpose of controlling the hydrogen concentration is achieved.

[0101] The advantage of this adjustment method is that when the concentration control method fails, flow control can be used to supplement the system concentration, which can effectively improve the system's operational stability and achieve the goal of stable system operation.

[0102] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An argon-hydrogen mixing system, characterized in that, include: Mixer (30); A hydrogen control line (10) is provided, the output end of which is connected to the input end of a mixer (30), and a flow control device (101) is provided on the hydrogen control line (10). Argon control line (20), the output end of the argon control line (20) is connected to the input end of the mixer (30), and a flow metering device (201) is provided on the argon control line (20); A concentration detection device (50) is provided at the output end of the mixer (30); The PID control system (60) is electrically connected to the concentration detection device (50), the flow control device (101), and the flow metering device (201). The PID control system (60) is configured to perform the following operations: a) The hydrogen concentration value detected by the concentration detection device (50) is used as the primary control signal. After comparing and analyzing the hydrogen concentration value with the preset hydrogen concentration value, the control signal is fed back to the flow control device (101) to control the flow control device (101) to output a certain hydrogen flow rate. as well as b) Read the hydrogen flow rate value of the flow control device (101) and the argon flow rate value of the flow metering device (201), calculate the flow rate comparison concentration value based on the two flow rates, and compare the flow rate comparison concentration value with the preset hydrogen concentration value to verify the reliability of the concentration control based on the primary control signal.

2. The argon-hydrogen mixing system according to claim 1, characterized in that: The output end of the mixer (30) is connected to a mixed gas output pipeline (301), and a buffer tank (40) is provided on the mixed gas output pipeline (301). The concentration detection device (50) includes a first hydrogen concentration analyzer (501) and a second hydrogen concentration analyzer (502). The first hydrogen concentration analyzer (501) is located between the mixer (30) and the buffer tank (40), and the second hydrogen concentration analyzer (502) is located at the output end of the buffer tank (40). Both the first hydrogen concentration analyzer (501) and the second hydrogen concentration analyzer (502) are electrically connected to the PID control system (60).

3. The argon-hydrogen mixing system according to claim 2, characterized in that: A hydrogen concentration difference alarm device (503) is provided between the first hydrogen concentration analyzer (501) and the second hydrogen concentration analyzer (502).

4. The argon-hydrogen mixing system according to claim 1, characterized in that: A hydrogen pressure alarm device (105) is connected to the hydrogen control pipeline (10) at the output end of the flow control device (101), and a hydrogen shut-off valve (102) is provided on the hydrogen control pipeline (10) at the input end of the flow control device (101); an argon pressure alarm device (205) is connected to the argon control pipeline (20) at the output end of the flow metering device (201), and an argon shut-off valve (202) is provided on the argon control pipeline (20) at the input end of the flow metering device (201).

5. The argon-hydrogen mixing system according to claim 4, characterized in that: The hydrogen control pipeline (10) is provided with a hydrogen backup control pipeline (11), and the hydrogen backup control pipeline (11) is provided with a backup hydrogen shut-off valve (111), a backup flow control device (112) and a backup hydrogen pressure alarm device (113) that are electrically connected to the PID control system (60). The argon control pipeline (20) is provided with an argon backup control pipeline (21), and the argon backup control pipeline (21) is provided with a backup argon shut-off valve (211), a backup flow metering device (212), and a backup argon pressure alarm device (213) that are electrically connected to the PID control system (60).

6. The argon-hydrogen mixing system according to claim 2, characterized in that: The buffer tank (40) is connected to a mixed gas pressure alarm device (401) and a buffer tank pressure relief device (402).

7. The argon-hydrogen mixing system according to claim 2, characterized in that: The mixed gas output pipeline (301) is provided with a test pipeline (302), which is located between the mixer (30) and the buffer tank (40). The test pipeline (302) is provided with a vent control valve (303).

8. A method for mixing argon and hydrogen, based on the argon-hydrogen mixing system according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Adjust the pressure of hydrogen control line (10) and argon control line (20); S2. Open the argon gas shut-off valve (202) and the hydrogen gas shut-off valve (102). S3. The hydrogen pressure in the hydrogen control pipeline (10) is reduced and then input into the flow control device (101), and the argon pressure in the argon control pipeline (20) is reduced and then input into the flow metering device (201). S4. The concentration detection device (50) feeds back a signal to the PID control system (60), and the PID control system (60) controls the flow control device (101) to perform flow control. The hydrogen concentration range is 3.5%-10% v / v. S5. When the difference between the values ​​detected by the first hydrogen concentration analyzer (501) and the second hydrogen concentration analyzer (502) is greater than ±0.5%, one of the hydrogen concentration analyzers is deactivated and the other hydrogen concentration analyzer is selected as the main controller.

9. The method for mixing argon and hydrogen according to claim 8, characterized in that: It also includes the following steps: S6. Periodically sample and test the mixed gas. When the values ​​detected by the first hydrogen concentration analyzer (501) and the second hydrogen concentration analyzer (502) deviate from the actual measured value of the sampling test by more than ±0.5%, switch the flow metering device (201) to participate in the concentration ratio control. The argon flow rate value detected by the flow metering device (201) is fed back to the PID control system (60). The PID control system (60) controls the hydrogen flow rate of the flow control device (101) to adjust the hydrogen concentration value to the hydrogen set value. Flow relationship: A / (A+B) = hydrogen concentration value%, A is the standard flow rate of the flow control device (101), and B is the standard flow rate of the flow metering device (201).

10. The method for mixing argon and hydrogen according to claim 8, characterized in that: It also includes the following steps: S21. After the argon gas shut-off valve (202) is opened, the argon gas pressure alarm device (205) will participate in the control of the argon gas control pipeline (20) after 1.5s-2.5s. When the pressure value detected by the argon gas pressure alarm device (205) is lower than 0.45Mpa, the argon gas pressure alarm device (205) will alarm to remind personnel to check the argon gas control pipeline (20). When the pressure value detected by the argon gas pressure alarm device (205) is lower than 0.4Mpa after 1.5s-2.5s, the argon gas pressure alarm device (205) will alarm to trigger the interlock to drive the backup argon gas shut-off valve (211) to open. The backup argon gas pressure alarm device (213) will participate in the control of the backup argon gas control pipeline (20) after 1.5s-2.5s. S22. After the argon shut-off valve (202) is opened, the hydrogen pressure alarm device (105) will participate in the control of the hydrogen control pipeline (10) after 1.5s-2.5s. When the pressure value detected by the hydrogen pressure alarm device (105) is lower than 0.45Mpa, the hydrogen pressure alarm device (105) will alarm to remind personnel to check the hydrogen control pipeline (10). When the pressure value detected by the hydrogen pressure alarm device (105) is lower than 0.4Mpa after 1.5s-2.5s, the hydrogen pressure alarm device (105) will alarm and trigger the interlock to drive the backup hydrogen shut-off valve (111) to open. The backup hydrogen pressure alarm device (113) will participate in the control of the backup hydrogen control pipeline (10) after 1.5s-2.5s.

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