Mixing valve and system

Abstract

The present application relates to a mixed gas distribution device and system, which includes a first gas source device, a first pressure reducing device, a first flow control device, a second gas source device, a second pressure reducing device, a second flow control device, a gas mixing device, a first solenoid valve, a gas concentration detection device, a second solenoid valve and a one-way valve. The first gas source device, the first pressure reducing device and the first flow control device are connected in sequence; the second gas source device, the second pressure reducing device and the second flow control device are connected in sequence; the gas mixing device, the first solenoid valve, the second solenoid valve and the one-way valve are connected in sequence; the first solenoid valve is also connected to the gas concentration detection device; the gas mixing device is connected to the first flow control device and the second flow control device; the one-way valve is connected to the back-end gas-using equipment. The above-mentioned mixed gas distribution device is conducive to expanding the application scenarios of the mixed gas distribution device.

Description

Technical Field

[0001] The present application relates to the technical field of mixed gas distribution, and in particular to a mixed gas distribution device and system. Background Art

[0002] With the development of science and technology, a certain concentration of gas needs to be prepared in the research of gas-sensitive materials and gas preparation. The commercially available gases are generally pure single gases or fixed high-concentration gases, which cannot meet the needs of experiments or gas preparation. Therefore, it is necessary to prepare the target gas through a mixed gas preparation device.

[0003] Traditional mixed gas distribution devices achieve the preparation of target gas based on the weighing method, that is, the production of mixed gas is carried out by calculating the mass of the gas filled in. However, when the concentration of the target gas is very low, the mixed gas is easily affected by the internal and external environment of the gas distribution system, resulting in fluctuations in gas concentration and affecting the gas distribution accuracy.

[0004] Therefore, the traditional hybrid valve distribution device has the disadvantage of limited application scenarios. Summary of the invention

[0005] Based on this, it is necessary to provide a hybrid gas distribution device and system to expand the application scenarios of the hybrid gas distribution device and system.

[0006] A mixed gas distribution device, comprising a first gas source device, a first pressure reducing device, a first flow control device, a second gas source device, a second pressure reducing device, a second flow control device, a gas mixing device, a first solenoid valve, a gas concentration detection device, a second solenoid valve and a one-way valve;

[0007] The first gas source device, the first pressure reducing device and the first flow control device are connected in sequence; the second gas source device, the second pressure reducing device and the second flow control device are connected in sequence; the gas mixing device, the first solenoid valve, the second solenoid valve and the one-way valve are connected in sequence; the first solenoid valve is also connected to the gas concentration detection device;

[0008] The gas mixing device is connected to the gas outlets of the first flow control device and the second flow control device;

[0009] The one-way valve is connected to the rear-end gas-using equipment; the first pressure reducing device, the first flow control device, the second pressure reducing device, the second flow control device, the first solenoid valve, the gas concentration detection device, the second solenoid valve and the one-way valve are all connected to the control device.

[0010] In one of the embodiments, the gas concentration detection device is also connected to the second solenoid valve.

[0011] In one embodiment, both the first pressure reducing device and the second pressure reducing device are single-pole pressure reducing valves.

[0012] In one embodiment, both the input port and the output port of the unipolar pressure reducing valve are provided with pressure gauges.

[0013] In one embodiment, the first flow control device and the second flow control device are both mass flow control devices.

[0014] In one embodiment, the mass flow control device has an accuracy of ≤±1% FS, a linearity of ≤±0.5% FS, a repeatability of ≤±0.2% FS, a response time of ≤1 sec, a withstand pressure of ≥3 MPa, and a gas leakage rate of ≤1×10 - 10 Pa·m 3 / sec mass flow control device.

[0015] In one embodiment, the gas mixing device is a static mixer.

[0016] In one embodiment, the first solenoid valve and the second solenoid valve are both two-position five-way solenoid valves; the two working positions of the first solenoid valve are respectively connected to the gas concentration detection device and the second solenoid valve; the two working positions of the second solenoid valve are respectively connected to the gas concentration detection device and the first solenoid valve.

[0017] A hybrid gas distribution system comprises a control device and the above-mentioned hybrid gas distribution device; the control device is connected to the hybrid gas distribution device.

[0018] In one of the embodiments, the hybrid gas distribution system further includes a display device, and the display device is connected to the control device.

[0019] The above-mentioned mixed gas distribution device is equipped with a one-way valve to connect to the rear-end gas-using equipment, which can reduce the impact of the external atmosphere on the low-concentration mixed gas, reduce gas concentration fluctuations, improve the gas distribution accuracy of the low-concentration mixed gas, and is conducive to expanding the application scenarios of the mixed gas distribution device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a structural principle diagram of a mixed gas distribution device in one embodiment;

[0022] Figure 2 It is a structural principle diagram of a mixing gas distribution device in another embodiment;

[0023] Figure 3 It is a structural block diagram of a hybrid gas distribution system in one embodiment;

[0024] Figure 4 It is a structural block diagram of a hybrid gas distribution system in another embodiment;

[0025] Figure 5 4 is a comparison diagram of the measured concentration and the calculated concentration of the target gas in the mixed gas in one embodiment. DETAILED DESCRIPTION

[0026] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0028] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first air source device may be referred to as a second air source device, and similarly, a second air source device may be referred to as a first air source device. Both the first air source device and the second air source device are air source devices, but they are not the same air source device.

[0029] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0030] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0031] The mixing and distribution device of standard gas is an experimental device that will be encountered in relevant tests and production. In general, the output concentration of the mixed gas that needs to be configured is relatively high. For such a high-concentration mixed gas, the existing mixing and distribution device can meet the requirements. However, for some mixed gas occasions that require very low concentrations and require continuous and stable output, the output gas stability and accuracy of the existing mixing and distribution device are often relatively poor. After research, the applicant found that the reason for this problem is: when performing low-concentration mixed gas distribution, the mixed gas is prone to turbulence, and this turbulence is superimposed on the influence of the external atmosphere, which is easy to cause gas fluctuations, and then cause the output gas stability and accuracy to deteriorate. Based on this, the present application proposes a new type of mixing and distribution device and system. By configuring a one-way valve to connect the back-end gas-using equipment, it can reduce the influence of the external atmosphere on the low-concentration mixed gas, reduce gas concentration fluctuations, and improve the gas distribution accuracy of the low-concentration mixed gas, thereby expanding the application scenarios of the mixing and distribution device.

[0032] In one embodiment, Figure 1 As shown, a mixed gas distribution device is provided, including a first gas source device 1, a first pressure reducing device 2, a first flow control device 3, a second gas source device 4, a second pressure reducing device 5, a second flow control device 6, a gas mixing device 7, a first solenoid valve 8, a gas concentration detection device 9, a second solenoid valve 10 and a one-way valve 11. The first gas source device 1, the first pressure reducing device 2 and the first flow control device 3 are connected in sequence; the second gas source device 4, the second pressure reducing device 5 and the second flow control device 6 are connected in sequence; the gas mixing device 7, the first solenoid valve 8, the second solenoid valve 10 and the one-way valve 11 are connected in sequence; the first solenoid valve 8 is also connected to the gas concentration detection device 9. The gas mixing device 7 is connected to the first flow control device 3 and the second flow control device 6. The one-way valve 11 is connected to the back-end gas-using equipment. The first pressure reducing device 2, the first flow control device 3, the second pressure reducing device 5, the second flow control device 6, the first solenoid valve 8, the gas concentration detection device 9, the second solenoid valve 10 and the one-way valve 11 are all connected to the control device.

[0033] Among them, the first gas source device 1 and the second gas source device 4 can be a device including a gas storage device and a gas path, or can be only a gas path connecting a gas station. The first pressure reducing device 2 and the second pressure reducing device 5 include one or more pressure reducing valves, which can reduce the high-pressure gas to the target pressure for processing and use. The connection mode of multiple pressure reducing valves is not unique, for example, they can be parallel, series or mixed. The type of pressure reducing valve is also not unique, for example, it can be a diaphragm pressure reducing valve, a spring diaphragm pressure reducing valve, a piston pressure reducing valve, a lever pressure reducing valve or a bellows pressure reducing valve. In one embodiment, the first pressure reducing device 2 and the second pressure reducing device 5 are both unipolar pressure reducing valves, which are not only low in cost, but also have a filter configured inside to protect the poppet from external contamination. Further, in one embodiment, the input port and output port of the unipolar pressure reducing valve are both equipped with a pressure gauge, which can facilitate users to read the pressure information in time and improve work convenience. In addition, in one embodiment, the output port of the unipolar pressure reducing valve is connected to a hose connector with an inner diameter of 6mm, and the output pressure is up to 0.4MPa, which can avoid safety accidents caused by excessive output pressure.

[0034] The first flow control device 3 and the second flow control device 6 are devices that can realize gas flow control. The type of the flow control device can be a volume flow control device or a mass flow control device. In one embodiment, the first flow control device 3 and the second flow control device 6 are both mass flow control devices, which can not only directly measure the mass flow of the fluid passing through the flow meter, but also measure the density and temperature of the fluid. In this way, the measurement error caused by the change in fluid density caused by temperature change during volume flow calculation can be overcome, which is conducive to improving the accuracy of flow control. Furthermore, the type of the mass flow control device is not unique, for example, it can be an electromagnetic flowmeter, an ultrasonic flowmeter or a Coriolis flowmeter. In one embodiment, the mass flow control device has an accuracy of ≤±1% FS, a linearity of ≤±0.5% FS, a repeatability of ≤±0.2% FS, a response time of ≤1sec, a pressure resistance of ≥3MPa and a leakage rate of ≤1×10 -10 The Pa·m3 / sec mass flow control device has the advantages of high accuracy, high linearity, high repeatability, short response time, low leakage rate and good pressure resistance, and can meet the requirements of high-precision mixed gas distribution.

[0035] The gas mixing device 7 refers to a device that can be used to mix two or more gases, and the gas mixing device 7 can be a dynamic mixer or a static mixer. In one embodiment, the gas mixing device 7 is a static mixer, which destroys the turbulence of the mixed gas entering the inside through the internal spoiler, avoids the sparse and dense distribution of the mixed gas caused by the turbulence, and further affects the detection results of the gas concentration of the subsequent module, and is also conducive to improving the stability of the output gas concentration.

[0036] The first solenoid valve 8 and the second solenoid valve 10 are devices that can adjust parameters such as the flow direction and flow rate of the fluid. The solenoid valve can be a distributed direct-acting solenoid valve or a pilot solenoid valve. The one-way valve 11, also known as a check valve or a non-return valve, is a valve body that can prevent the reverse flow of the fluid. The one-way valve can be a straight-through one-way valve or a right-angle one-way valve. In one embodiment, the conduction pressure of the one-way valve 11 is 0.05MPa, which can ensure stable output when the mixed gas concentration is low (for example, less than 1ppm), reduce the impact of the external atmosphere on the low-concentration mixed gas, and create conditions for subsequent extreme tests or production.

[0037] Specifically, the first gas source device 1 and the second gas source device 4 are used to introduce the target gas and the background gas, respectively, and the gas concentration detection device 9 is used to detect the concentration of the target gas. To ensure the accuracy of gas mixing, the target gas and the background gas both use standard gas with a concentration of 99.999%. Take the case where the first gas source device 1 is used to introduce the target gas and the second gas source device 4 is used to introduce the background gas as an example. When the gas distribution starts, the control device controls the first pressure reducing device 2 and the second pressure reducing device 5 so that the target gas and the background gas enter the corresponding flow control device at the rated pressure respectively. In one embodiment, the target gas and the background gas enter the corresponding flow control device at the same rated pressure to simplify the control process. The value of the rated pressure is not unique, for example, it can be 1.1bar, 1.2bar or 1.3bar. The control device then obtains the target concentration and adjusts the working parameters of the first flow control device 3 and the second flow control device 6 according to the target concentration. After the target gas and the background gas pass through the corresponding flow control device, they reach the gas mixing device 7, and after being fully mixed, they reach the gas concentration detection device 9 through the first solenoid valve 8 to detect the target gas concentration. When the target gas concentration reaches the target concentration, the control device adjusts the working modes of the first solenoid valve 8, the second solenoid valve 10 and the one-way valve 11, so that the mixed gas passes through the first solenoid valve 8 and the second solenoid valve 10 in sequence, and then is discharged to the back-end gas-using equipment through the one-way valve 11. It can be understood that the mixed gas of the gas concentration detection device 9 can be discharged through the exhaust device.

[0038] Furthermore, during the gas supply process, the control device can also obtain the concentration detection result of the gas concentration detection device 9 in real time, and dynamically adjust the working parameters of the first flow control device 3 and the second flow control device 6 according to the concentration detection result to improve the concentration stability of the output mixed gas.

[0039] In addition, before the mixed gas enters the gas concentration detection device 9, the control device can adjust the working parameters of the first pressure reducing device 2 and the first flow control device 3, and introduce the target gas of the rated concentration in advance, so that the lower limit of the detectable concentration of the mixed gas can be improved. For example, if the target gas with a concentration of 1ppm is introduced in advance, if the target gas detection concentration in the mixed gas reaches 1.1ppm, the lower limit of the detectable concentration is increased to 0.1ppm after deducting the target gas with a concentration of 1ppm introduced in advance, so as to achieve the upgrade of the mixed gas distribution device.

[0040] The above-mentioned mixed gas distribution device is equipped with a one-way valve to connect to the back-end gas-using equipment, which can reduce the impact of the external atmosphere on the low-concentration mixed gas, reduce gas concentration fluctuations, and improve the gas distribution accuracy of the low-concentration mixed gas, which is conducive to expanding the application scenarios of the mixed gas distribution device. The whole process is automatically feedback closed-loop control without human interference; the target gas and the background gas only need one cavity to complete the gas mixing, and the number of solenoid valves used is also very small, the gas path is also very simple, the structure is simple, the size is small, the production cost is low, the weight is light, and it is easy to carry. The relevant training and operation are very convenient, which can improve the convenience of use.

[0041] In one embodiment, Figure 2 As shown, the gas concentration detection device 9 is also connected to a second solenoid valve 10 .

[0042] Specifically, the gas concentration detection device 9 is also connected to the second solenoid valve 10. By controlling the working modes of the first solenoid valve 8 and the second solenoid valve 10, three different gas paths can be formed, namely, the first solenoid valve 8-gas concentration detection device 9, the first solenoid valve 8-gas concentration detection device 9-second solenoid valve 10, and the first solenoid valve 8-second solenoid valve 10. During the gas distribution process, the gas path can be selected as needed. During the gas distribution process, the gas path of the first solenoid valve 8-gas concentration detection device 9-second solenoid valve 10 can be selected to dynamically measure the concentration of the mixed gas, and the working parameters of the first flow control device 3 and the second flow control device 6 can be adjusted accordingly, which is conducive to improving the control accuracy.

[0043] In one embodiment, the first solenoid valve 8 and the second solenoid valve 10 are both two-position five-way solenoid valves; the two working positions of the first solenoid valve 8 are respectively connected to the gas concentration detection device 9 and the second solenoid valve 10; the two working positions of the second solenoid valve 10 are respectively connected to the gas concentration detection device 9 and the first solenoid valve 8.

[0044] Among them, two-position means that the solenoid valve core has two working positions; five-way means that the solenoid valve has five air pipe interfaces. The entire solenoid valve can be divided into two parts: the valve body part and the control valve core part. The valve body part includes the left end cover, valve body shell, valve core, and right end cover; the control valve core part includes the solenoid valve coil, control valve core, and end cover nut. Figure 1 and Figure 2 As shown, the inlet and outlet of the valve core of the two-position five-way solenoid valve are bidirectionally conductive, that is, the arrow inside the valve does not indicate the direction of the airflow; P1 and P2 are the electromagnets on both sides of the two-position five-way valve respectively.

[0045] Specifically, when the target concentration is lower than a preset value (e.g., 1ppm), the gas flow rate in the detector can be reduced to an extremely low value by switching the two-position five-way solenoid valve, further eliminating the influence of airflow fluctuations on detection stability at low concentrations. The specific operation is as follows: when gas distribution starts, the control device controls the electromagnet P1 on the left side of the first solenoid valve 8 to be in an open state, and the electromagnet P2 on the right side of the second solenoid valve 10 to be in an open state. At this time, the mixed gas enters the gas concentration detection device 9 through the first solenoid valve 8, and is then discharged through the second solenoid valve 10.

[0046] When the target gas concentration detection value in the mixed gas tends to be stable, the control device closes the left electromagnet P1 of the first solenoid valve 8 and opens the right electromagnet P2, and at the same time closes the right electromagnet P2 of the second solenoid valve 10 and opens the left electromagnet P1. At this time, the mixed gas no longer enters the gas concentration detection device 9 after passing through the first solenoid valve 8, but is directly discharged through the second solenoid valve 10, and the gas chamber of the gas concentration detection device 9 is locked on both sides of the first solenoid valve 8 and the second solenoid valve 10, which can reduce the impact of airflow fluctuations on the detection results.

[0047] In the above embodiment, the first solenoid valve 8 and the second solenoid valve 10 are both two-position five-way solenoid valves. When the target concentration is low, the influence of airflow fluctuations on the detection results can be reduced by switching the working modes of the first solenoid valve 8 and the second solenoid valve 10, which is beneficial to improving the detection accuracy.

[0048] In one embodiment, Figure 3 As shown, a hybrid gas distribution system is provided, including a control device 100 and the above-mentioned hybrid gas distribution device 200; the control device 100 is connected to the hybrid gas distribution device 200.

[0049] The control device 100 may be a hardware module including various processing chips and their peripheral circuits and having logic operation functions. The processing chip may be a single chip microcomputer, a DSP (Digital Signal Process) chip or an FPGA (Field Programmable Gate Array) chip.

[0050] Specifically, as described above, the control device 100 is specifically connected to the first pressure reducing device 2, the first flow control device 3, the second pressure reducing device 5, the second flow control device 6, the first solenoid valve 8, the gas concentration detection device 9, the second solenoid valve 10 and the one-way valve 11 in the mixed gas distribution device 200. When the gas distribution starts, the control device 100 controls the first pressure reducing device 2 and the second pressure reducing device 5 so that the target gas and the background gas enter the corresponding flow control device at the rated pressure respectively. In one embodiment, the target gas and the background gas enter the corresponding flow control device at the same rated pressure to simplify the control process. The value of the rated pressure is not unique, for example, it can be 1.1bar, 1.2bar or 1.3bar. The control device 100 then obtains the target concentration and adjusts the working parameters of the first flow control device 3 and the second flow control device 6 according to the target concentration. After the target gas and the background gas pass through the corresponding flow control device respectively, they reach the gas mixing device 7, and after being fully mixed, they reach the gas concentration detection device 9 through the first solenoid valve 8 to detect the target gas concentration. When the target gas concentration reaches the target concentration, the control device 100 adjusts the working modes of the first solenoid valve 8, the second solenoid valve 10 and the one-way valve 11, so that the mixed gas passes through the first solenoid valve 8 and the second solenoid valve 10 in sequence, and then is discharged to the back-end gas-using equipment through the one-way valve 11. It can be understood that the mixed gas of the gas concentration detection device 9 can be discharged through the exhaust device.

[0051] Furthermore, during the gas supply process, the control device 100 can also obtain the concentration detection results of the gas concentration detection device 9 in real time, and dynamically adjust the working parameters of the first flow control device 3 and the second flow control device 6 according to the concentration detection results to improve the concentration stability of the output mixed gas.

[0052] In addition, before the mixed gas enters the gas concentration detection device 9, the control device 100 can adjust the working parameters of the first pressure reducing device 2 and the first flow control device 3, and introduce the target gas of the rated concentration in advance, so that the lower limit of the detectable concentration of the mixed gas can be improved. For example, if the target gas with a concentration of 1ppm is introduced in advance, if the target gas detection concentration in the mixed gas reaches 1.1ppm, the lower limit of the detectable concentration is increased to 0.1ppm after deducting the target gas with a concentration of 1ppm introduced in advance, so as to realize the upgrade of the mixed gas distribution device 200.

[0053] The above-mentioned mixed gas distribution system is equipped with a one-way valve to connect the back-end gas-using equipment, which can reduce the impact of the outside atmosphere on the low-concentration mixed gas, reduce the gas concentration fluctuation, and improve the gas distribution accuracy of the low-concentration mixed gas, which is conducive to expanding the application scenarios of the mixed gas distribution system. The whole process is automatically feedback closed-loop control without human interference; the target gas and the background gas only need one cavity to complete the gas mixing, and the number of solenoid valves used is also very small, the gas circuit is also very simple, the structure is simple, the size is small, the production cost is low, the weight is light, and it is easy to carry. The relevant training and operation are very convenient, which can improve the convenience of use.

[0054] In one embodiment, Figure 4 As shown, the hybrid gas distribution system also includes a display device 300, which is connected to the control device 100. The display device 300 can be various display screens or touch screens, which can display the operating status of the hybrid gas distribution system and the working parameters of each component. For example, the gas path of the hybrid gas distribution device 200, the flow values ​​of the first flow control device 3 and the second flow control device 6, and the target gas concentration detected by the gas concentration detection device 9, etc.

[0055] In the above embodiment, the display device 300 is configured to display the operating status of the hybrid gas distribution system and the working parameters of each component, which can facilitate the staff to obtain the operating status of the hybrid gas distribution system in time and improve the convenience of use.

[0056] For ease of understanding, the following Figure 2 and Figure 4 , the mixed valve system is described in detail.

[0057] In one embodiment, Figure 4 As shown, the hybrid gas distribution system includes a control device 100, and a hybrid gas distribution device 200 and a display device connected to the control device 100. Figure 2As shown, the mixed gas distribution device 200 includes a first gas source device 1, a first pressure reducing device 2, a first flow control device 3, a second gas source device 4, a second pressure reducing device 5, a second flow control device 6, a gas mixing device 7, a first solenoid valve 8, a gas concentration detection device 9, a second solenoid valve 10 and a one-way valve 11. The first gas source device 1, the first pressure reducing device 2 and the first flow control device 3 are connected in sequence; the second gas source device 4, the second pressure reducing device 5 and the second flow control device 6 are connected in sequence; the gas mixing device 7, the first solenoid valve 8, the second solenoid valve 10 and the one-way valve 11 are connected in sequence; the first solenoid valve 8 is also connected to the gas concentration detection device 9. The gas inlet of the gas mixing device 7 is connected to the gas outlet of the first flow control device 3 and the second flow control device 6; the gas outlet of the gas mixing device 7 is connected to the first solenoid valve 8; the gas concentration detection device 9 is also connected to the second solenoid valve 10. The one-way valve 11 is connected to the back-end gas-using equipment. The first pressure reducing device 2 , the first flow control device 3 , the second pressure reducing device 5 , the second flow control device 6 , the first solenoid valve 8 , the gas concentration detection device 9 , the second solenoid valve 10 and the one-way valve 11 are all connected to the control device 100 .

[0058] Furthermore, the first pressure reducing device 2 and the second pressure reducing device 5 are both unipolar pressure reducing valves. The input port and the output port of the unipolar pressure reducing valve are both equipped with pressure gauges, and the output port is connected to a hose connector with an inner diameter of 6 mm, and the maximum output pressure is 0.4 MPa. The first flow control device 3 and the second flow control device 6 are both mass flow control devices. The parameters of the mass flow control device are: accuracy ≤±1% FS, linearity ≤±0.5% FS, repeatability ≤±0.2% FS, response time ≤1 sec, pressure resistance ≥3 MPa and leakage rate ≤1×10-10 Pa·m3 / sec. The gas mixing device 7 is a static mixer. The first solenoid valve 8 and the second solenoid valve 10 are both two-position five-way solenoid valves; the two working positions of the first solenoid valve 8 are respectively connected to the gas concentration detection device 9 and the second solenoid valve 10; the two working positions of the second solenoid valve 10 are respectively connected to the gas concentration detection device 9 and the first solenoid valve 8. The conduction pressure of the one-way valve 11 is 0.05 MPa.

[0059] Specifically, the first gas source device 1 is used to introduce the target gas, the second gas source device 4 is used to introduce the background gas, and the gas concentration detection device 9 is used to detect the concentration of the target gas. To ensure the accuracy of gas mixing, both the target gas and the background gas use standard gas with a concentration of 99.999%. When the gas distribution starts, the control device 100 controls the first pressure reducing device 2 and the second pressure reducing device 5 so that the target gas and the background gas enter the corresponding flow control device at the rated pressure respectively. In one embodiment, the target gas and the background gas enter the corresponding flow control device at the same rated pressure to simplify the control process. The value of the rated pressure is not unique, for example, it can be 1.1bar, 1.2bar or 1.3bar. The control device 100 then obtains the target concentration and adjusts the working parameters of the first flow control device 3 and the second flow control device 6 according to the target concentration. After the target gas and the background gas pass through the corresponding flow control device respectively, they reach the gas mixing device 7, and after being fully mixed, they reach the gas concentration detection device 9 through the first solenoid valve 8 to detect the target gas concentration. When the target gas concentration reaches the target concentration, the control device 100 adjusts the working modes of the first solenoid valve 8, the second solenoid valve 10 and the one-way valve 11, so that the mixed gas passes through the first solenoid valve 8 and the second solenoid valve 10 in sequence, and then is discharged to the back-end gas-using equipment through the one-way valve 11. It can be understood that the mixed gas of the gas concentration detection device 9 can be discharged through the exhaust device.

[0060] Furthermore, during the gas supply process, the control device 100 can also obtain the concentration detection results of the gas concentration detection device 9 in real time, and dynamically adjust the working parameters of the first flow control device 3 and the second flow control device 6 according to the concentration detection results to improve the concentration stability of the output mixed gas.

[0061] In addition, before the mixed gas enters the gas concentration detection device 9, the control device 100 can adjust the working parameters of the first pressure reducing device 2 and the first flow control device 3, and introduce the target gas of the rated concentration in advance, so that the lower limit of the detectable concentration of the mixed gas can be improved. For example, if the target gas with a concentration of 1ppm is introduced in advance, if the target gas detection concentration in the mixed gas reaches 1.1ppm, the lower limit of the detectable concentration is increased to 0.1ppm after deducting the target gas with a concentration of 1ppm introduced in advance, so as to realize the upgrade of the mixed gas distribution device 200.

[0062] The mixed gas distribution system provided in the above embodiment can achieve the continuous and stable output of the target gas at low concentration through the cooperation of high-precision mass flow controller, static mixer, one-way valve and solenoid valve, and provide facility support for some specific test occasions. For example, oil-immersed transformers. For oil-immersed transformers, the types and concentrations of various gases dissolved in transformer oil are very important parameters reflecting the operating status of the transformer, and have been widely used in the field of transformer online monitoring. So when developing such detection equipment, it is necessary to verify and judge its instrument performance. At present, the method of configuring standard oil samples with different concentration gradients is often adopted. However, in the process of making standard oil samples, due to the different solubility of different gases in oil (some gases are extremely difficult to dissolve in oil) and the influence of the external environment, it is very time-consuming and laborious to prepare a series of oil samples that are stable and gradient-changing within a very low concentration range, and the effect is often very unsatisfactory. In this case, the use of the mixed gas distribution system proposed in this application can not only configure different mixed gas concentrations within the low concentration range, but also effectively reduce the influence of the external atmosphere through the action of the one-way valve and the solenoid valve, so that the mixed gas can be output stably and continuously, providing a set of efficient solutions for the development of online monitoring detectors for dissolved gases in oil.

[0063] Taking acetylene as the target gas and nitrogen as the background gas as an example, the gas concentration detection device 9 is used to detect the concentration of acetylene. Under different flow rates, the theoretical calculation formula for the concentration of the target gas (acetylene) in the mixed gas is:

[0064]

[0065] In the formula, P is the concentration of the target gas (acetylene) in the mixed gas, A is the flow rate of the target gas (acetylene), and B is the flow rate of the background gas (nitrogen). To simplify the expression, the mixed gas concentration value is used to refer to the target gas concentration value in the mixed gas.

[0066] According to the above formula, the target gas and background gas flow ratio values ​​and the calculated mixed gas concentration values ​​are shown in Table 1 below.

[0067] Table 1: Correspondence between target gas and background gas flow ratio and mixed gas concentration

[0068]

[0069] The actual concentration of the mixed gas obtained through actual measurement is shown in Table 2 below.

[0070] Table 2: Comparison of calculated and measured concentrations of mixed gases

[0071]

[0072] By comparing the measured concentration of the target gas in the mixed gas with the calculated concentration, the performance of the mixed gas distribution system can be verified. Figure 5 As shown, the measured concentration has a smaller fluctuation than the calculated concentration, which is about 0.1ppm. The test lower limit of the mixed gas distribution system can reach 0.5ppm, the resolution is 0.01ppm, the linearity in the range of 0-10ppm is better than 1%, and the measurement response time T90 is about 15s.

[0073] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0074] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A mixed gas distribution device, It is characterized in that It includes a first gas source device, a first pressure reducing device, a first flow control device, a second gas source device, a second pressure reducing device, a second flow control device, a gas mixing device, a first solenoid valve, a gas concentration detection device, a second solenoid valve and a one-way valve; The first gas source device, the first pressure reducing device and the first flow control device are connected in sequence; the second gas source device, the second pressure reducing device and the second flow control device are connected in sequence; the gas mixing device, the first solenoid valve, the second solenoid valve and the one-way valve are connected in sequence; the first solenoid valve is also connected to the gas concentration detection device; The gas mixing device is connected to the first flow control device and the second flow control device; The one-way valve is connected to the back-end gas-using equipment; the first pressure reducing device, the first flow control device, the second pressure reducing device, the second flow control device, the first solenoid valve, the gas concentration detection device, the second solenoid valve and the one-way valve are all connected to the control device; the gas concentration detection device is also connected to the second solenoid valve; the two working positions of the first solenoid valve are respectively connected to the gas concentration detection device and the second solenoid valve; the two working positions of the second solenoid valve are respectively connected to the gas concentration detection device and the first solenoid valve; between the first solenoid valve and the second solenoid valve, there is a first gas passage passing through the gas concentration detection device and a second gas passage not passing through the gas concentration detection device; when the target concentration of the target gas is lower than the preset value, the first gas passage is opened when the gas distribution starts and the gas concentration detection value is not stable; the second gas passage is opened when the gas concentration detection value tends to be stable, and the gas chamber of the gas concentration detection device is locked on both sides of the first solenoid valve and the second solenoid valve; the conduction pressure of the one-way valve is 0.05MPa to ensure that the output is stable when the target concentration is lower than the preset value; the first solenoid valve and the second solenoid valve are both two-position five-way solenoid valves.

2. The mixing gas distribution device according to claim 1, It is characterized in that The first pressure reducing device and the second pressure reducing device are both single-pole pressure reducing valves.

3. The hybrid gas distribution device according to claim 2, It is characterized in that The input port and output port of the unipolar pressure reducing valve are both provided with pressure gauges.

4. The hybrid gas distribution device according to claim 3, It is characterized in that The output port of the unipolar pressure reducing valve is connected with a hose connector with an inner diameter of 6 mm.

5. The hybrid gas distribution device according to claim 1, It is characterized in that The first flow control device and the second flow control device are both mass flow control devices.

6. The hybrid gas distribution device according to claim 5, It is characterized in that The mass flow control device has an accuracy of ≤±1% FS, a linearity of ≤±0.5% FS, a repeatability of ≤±0.2% FS, a response time of ≤1 sec, a pressure resistance of ≥3 MPa and a gas leakage rate of ≤1×10 -10 Pa·m 3 / sec mass flow control device.

7. The hybrid gas distribution device according to claim 1, It is characterized in that The gas mixing device is a static mixer.

8. The hybrid gas distribution device according to claim 1, It is characterized in that The two-position five-way solenoid valve comprises a valve body part and a control valve core part.

9. A hybrid gas distribution system, It is characterized in that It comprises a control device and a mixing and distributing device as claimed in any one of claims 1 to 8; the control device is connected to the mixing and distributing device.

10. The hybrid gas distribution system according to claim 9, It is characterized in that It also includes a display device, which is connected to the control device.

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