System and method for online detection of gas components after discharge of high-power gas switch

Abstract

The invention relates to a system and a method for online detection of gas components after discharge of a high-power gas switch, and solves the technical problem that a conventional gas component detection method fails due to the fact that the gas components are gradually decomposed or compounded as time goes on after discharge of an existing high-power gas switch. The device comprises an input gas source, a flow controller, a third valve, a pressure sensor, a vacuum pump and a Fourier spectrum gas analyzer which are connected in sequence, the pressure sensor is connected with the gas switch cavity; the input gas source is specifically as follows: a helium source is connected with a flow controller through a first valve, and a zero-level air source is connected with the flow controller through a second valve; a gas outlet of the gas switch cavity is connected with the vacuum pump through a fourth valve and is connected with the Fourier spectrum gas analyzer through a fifth valve; the Fourier spectrometer is connected with the flow controller through an eighth valve; and the eighth valve is a two-position three-way valve.

Description

Technical Field

[0001] The present invention relates to pulse power technology, and particularly to a system and method for on-line detection of gas components after the discharge of a high-power gas switch. Background Art

[0002] With the progress of technology, pulse power equipment or devices are increasingly widely used in scientific research and industrial and agricultural production. Among them, the gas switch, as the core component of the pulse power device, is the key to the stable and reliable operation of the pulse power device, and the ambient temperature has an important impact on the normal operation of the gas switch. The ambient temperature will change the self-breakdown characteristics, triggering characteristics, etc. of the gas switch. In addition, when the gas switch operates under conditions of repetitive frequency or pulsed high current, its own temperature will change greatly. This poses high requirements for the self-breakdown characteristics and triggering characteristics of the gas switch within a large temperature change range.

[0003] In order to obtain the conditions or laws for the stable operation of the gas switch at different ambient temperatures, it is necessary to conduct in-depth research on the discharge mechanism of the gas switch, such as the ablation characteristics of the switch electrodes under the action of pulsed high current, the conduction process of the gas medium under high voltage, and the influence of the gas composition change caused by the electrode ablation products on the discharge mechanism of the gas switch. Among them, the composition of the gas gradually changes with the increase in the number of discharges, which will further affect the conduction process of the switch and cause a decrease in the discharge stability of the switch. Therefore, mastering the change of the gas composition in the discharge products of the gas switch is of great significance for analyzing the discharge mechanism of the gas switch and improving the discharge stability of the gas switch.

[0004] However, there are great difficulties in detecting the gas components after the discharge of the existing gas switch. Because the unknown gas components generated after the discharge of the gas switch are relatively complex, the real-time performance of conventional gas component detection methods is poor, which will lead to detection failure. For example, during the process of taking out the gas for inspection, some gas components will gradually decompose or recombine over time, bringing great interference to the detection results. In addition, opening the gas switch cavity itself will also bring interference to the detection results, resulting in low detection accuracy. Therefore, a method capable of timely on-line detection after the discharge of the gas switch is needed, especially for the detection of some trace gas components, so as to timely master the gas components after the discharge of the gas switch and facilitate the analysis of the discharge mechanism of the gas switch. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problem that the gas components after the discharge of the existing high-power gas switch will gradually decompose or recombine over time, making the conventional gas component detection methods ineffective, and to provide a system and method for on-line detection of gas components after the discharge of a high-power gas switch.

[0006] The concept of the present invention is as follows:

[0007] Using zero - grade air as the gas insulation medium, filling a certain pressure of zero - grade air into the switch cavity, ensuring that the pressure and humidity of the filled zero - grade air are consistent. After multiple discharge experiments, analyzing the trace gas components after the discharge of zero - grade air to achieve on - line detection of the gas composition.

[0008] In order to achieve the above - mentioned purpose and concept, the technical solution provided by the present invention is as follows:

[0009] A system for on - line detection of gas components after the discharge of a high - power gas switch. The gas switch includes a gas - switch cavity and a pulse capacitor connected to the gas - switch cavity. The pulse capacitor is used to achieve spark discharge of the gas medium inside the gas - switch cavity.

[0010] The special features are as follows:

[0011] It includes an input gas source, a flow controller, a third valve, a pressure sensor, a vacuum pump, and a Fourier - transform spectroscopy gas analyzer connected in sequence. The output end of the pressure sensor is connected to the air inlet of the gas - switch cavity.

[0012] The input gas source includes a helium gas source and a zero - grade air source. The helium gas source is connected to the input end of the flow controller through a first valve, and the zero - grade air source is connected to the input end of the flow controller through a second valve.

[0013] The air outlet of the gas - switch cavity is externally connected to two output branches. One output branch is connected to the input end of the vacuum pump through a fourth valve. The other output branch is connected to the air inlet of the Fourier - transform spectroscopy gas analyzer through a fifth valve.

[0014] The air outlet of the Fourier - transform spectrometer is connected to the output end of the flow controller through an eighth valve. The eighth valve is a two - position three - way valve. Its NC port is vacant, the NO port is connected to the output end of the flow controller, and the COM port is connected to the air outlet of the Fourier - transform spectrometer.

[0015] Further, on the gas path between the fifth valve and the Fourier - transform spectroscopy gas analyzer, a sixth valve, a diaphragm pump, and a seventh valve are also arranged in sequence. Both the sixth valve and the seventh valve are two - position three - way valves. Their NC ports are respectively connected to both ends of the diaphragm pump, the NO ports are connected to each other, and the COM ports are respectively connected to the fifth valve and the air inlet of the Fourier - transform spectroscopy gas analyzer.

[0016] Further, a muffler is provided at the output end of the vacuum pump.

[0017] Further, the first valve, the second valve, the third valve, the fourth valve, and the fifth valve are solenoid valves.

[0018] Furthermore, the helium source includes a helium cylinder and a pressure reducing valve, which is used to adjust the pressure of the output helium through the pressure reducing valve.

[0019] Furthermore, the minimum vacuum degree of the vacuum pump is less than 10Pa; the accuracy of the flow controller is greater than 0.01L / min; and the accuracy of the pressure sensor is greater than 1Pa.

[0020] The present invention also provides a method for online detection of gas components after discharge of a high-power gas switch, which is implemented by the above-mentioned system for online detection of gas components after discharge of a high-power gas switch, and the special feature thereof is that it comprises the following steps:

[0021] S1, vacuum chamber

[0022] Close the first valve, the third valve, and the fifth valve, switch the eighth valve to open the NC port and close the NO port, open the fourth valve, and use a vacuum pump to evacuate the gas switch cavity;

[0023] According to the reading of the pressure sensor, when the vacuum degree A of the gas switch cavity satisfies: A<10Pa, the fourth valve and the vacuum pump are closed; otherwise, the vacuuming process is continued;

[0024] S2, injection of zero-grade air

[0025] Turn on the flow controller, open the second valve and the third valve, and the zero-grade air source injects zero-grade air into the gas switch cavity;

[0026] According to the reading of the pressure sensor, when the pressure B of the gas switch cavity satisfies: B>10kPa, close the third valve and the second valve, and read the intake volume of zero-level air in the flow controller; otherwise, continue to inject zero-level air;

[0027] S3, cavity discharge experiment

[0028] Turn on the pulse capacitor and conduct a spark discharge experiment on the gas switch cavity. The number of discharges C satisfies: C>100;

[0029] S4, helium injection

[0030] Open the first valve and the third valve, switch the eighth valve to close the NC port and open the NO port, and inject helium into the gas switch cavity from the helium source. The amount of helium gas intake is determined according to the detection requirements of the Fourier spectrum gas analyzer;

[0031] S5, discharge of helium and gas products

[0032] Close the first valve and the third valve, switch the eighth valve to open the NC port and close the NO port, open the fifth valve, and helium gas will enter the Fourier transform spectroscopy gas analyzer together with the gas products of the spark discharge experiment, and be discharged from the NC port of the eighth valve through the outlet of the Fourier transform spectroscopy gas analyzer;

[0033] S6. Analyze the trace gas components

[0034] Use the Fourier transform spectroscopy gas analyzer to compare the helium gas in step S4 and the helium gas mixed with gas products in step S5 to analyze the trace gas components in the gas products;

[0035] Repeat steps S1 - S6, find the average value of the trace gas components after measuring at least three times, and convert the measurement result to the result before dilution, which is the content of the decomposition products in the actual gas.

[0036] Further, in step S5, before the helium gas mixed with the gas products of the spark discharge experiment enters the Fourier transform spectroscopy gas analyzer, the states of the sixth valve and the seventh valve can be switched to filter out the particulate matters mixed in the gas products by using a diaphragm pump.

[0037] Further, in step S4, the intake volume of helium gas should meet the detection requirements for the trace gas components of the Fourier transform spectroscopy gas analyzer 2 - 3 times.

[0038] Further, in step S1, the range of the vacuum degree A should meet 1 - 10 Pa;

[0039] In step S2, the range of the pressure B should meet 10 kPa - 100 kPa;

[0040] In step S3, the range of the number of discharges C is 100 - 10000 times.

[0041] Advantages of the present invention compared with the prior art:

[0042] 1. The present invention provides a method for on - line detection of gas components after high - power gas switch discharge, effectively reducing the detection threshold of gas components after gas switch discharge. Using the method of injecting inert gas for detection, it has strong real - time performance and low requirements for the content of gas components, can perform on - line detection of trace gas components, effectively solve the problem that the conventional gas component detection method fails after gas switch discharge, and is of great significance for analyzing the discharge mechanism of gas switches and improving the discharge stability of switches.

[0043] 2. The present invention provides a system for on-line detection of gas components after the discharge of a high-power gas switch. By using multiple solenoid valves to control the gas path and injecting helium to carry out gas products, the real-time detection of gas components after the discharge of the gas switch is realized, which plays an important role in quickly grasping the gas composition after the switch discharge. In addition, this system can be integrated into the original gas switch discharge system and has high practical value. Brief Description of the Drawings

[0044] Figure 1 is a schematic structural diagram of an embodiment of a system for on-line detection of gas components after the discharge of a high-power gas switch according to the present invention;

[0045] Figure 2 is a schematic diagram of the principle of an embodiment of a method for on-line detection of gas components after the discharge of a high-power gas switch according to the present invention.

[0046] The reference numerals in the drawings are explained as follows:

[0047] 1 - Gas switch cavity; 2 - Pulse capacitor; 3 - Helium gas source; 4 - Zero-grade air source; 5 - Flow controller; 6 - Pressure sensor; 7 - Fourier transform spectroscopy gas analyzer; 8 - Muffler;

[0048] V1 - First valve; V2 - Second valve; V3 - Third valve; V4 - Fourth valve; V5 - Fifth valve; V6 - Sixth valve; V7 - Seventh valve; V8 - Eighth valve;

[0049] M1 - Vacuum pump; M2 - Diaphragm pump. Detailed Embodiments

[0050] The following will further explain the specific technical solutions in the embodiments of the present invention with reference to the drawings.

[0051] The present invention provides a system and method for on-line detection of gas components after the discharge of a high-power gas switch, mainly solving the problem that the gas components after the large-current discharge of the existing coaxial gas switch cannot be detected on-line. This method uses a Fourier transform spectroscopy gas analyzer to on-line measure the gas component composition of the gas switch discharge products. The steps mainly include evacuating the cavity, injecting a fixed amount of zero-grade air, conducting a discharge experiment, and performing Fourier transform spectroscopy analysis on the products and analyzing trace gas components, etc.

[0052] Figure 1A system for on-line detection of gas components after discharge of a high-power gas switch provided by an embodiment of the present invention is used for on-line detection of gas components of a gas switch, and includes an input gas source, a flow controller 5, a third valve V3, a pressure sensor 6, a vacuum pump M1, and a Fourier spectral gas analyzer 7 connected in sequence; the gas switch includes a gas switch cavity 1 and a pulse capacitor 2 connected to the gas switch cavity 1, and the pulse capacitor 2 is used to realize spark discharge of the gas medium inside the gas switch cavity 1.

[0053] The output end of the pressure sensor 6 is connected to the air inlet of the gas switch cavity 1.

[0054] The input gas source includes a helium gas source 3 and a zero-grade air source 4; the helium gas source 3 is connected to the input end of the flow controller 5 through a first valve V1. The helium gas source 3 includes a helium gas cylinder and a pressure reducing valve, and helium gas is output after being adjusted by the helium gas cylinder through the pressure reducing valve. The zero-grade air source 4 is connected to the input end of the flow controller 5 through a second valve V2. Specifically, the second valve V2 is connected in parallel between the first valve V1 and the flow controller 5.

[0055] The air outlet of the gas switch cavity 1 is externally connected to two output branches: one output branch is connected to the input end of the vacuum pump M1 through a fourth valve V4; a muffler 8 is provided at the output end of the vacuum pump M1; the other output branch is connected to the air inlet of the Fourier spectral gas analyzer 7 through a fifth valve V5, a sixth valve V6, a diaphragm pump M2, and a seventh valve V7. Both the sixth valve V6 and the seventh valve V7 are two-position three-way valves, the NC ports of which are respectively connected to both ends of the diaphragm pump M2, the NO ports are connected to each other, and the COM ports are respectively connected to the fifth valve V5 and the air inlet of the Fourier spectral gas analyzer 7. Specifically, the fourth valve V4 is connected in parallel between the fifth valve V5 and the air outlet of the gas switch cavity 1. The function of the diaphragm pump M2 is to filter out the particulate matter mixed in the gas after switch discharge to avoid damaging the Fourier spectrometer. The diaphragm pump M2 can filter particulate matter with a minimum diameter of 1 μm.

[0056] The air outlet of the Fourier spectrometer 7 is connected to the output end of the flow controller 5 through an eighth valve V8; the eighth valve V8 is a two-position three-way valve, the NC port of which is vacant (i.e., connected to the atmosphere), the NO port is connected to the output end of the flow controller 5, and the COM port is connected to the air outlet of the Fourier spectrometer 7. The eighth valve V8 fills the Fourier spectral gas analyzer 7 with the decompressed helium gas for comparison and analysis of gas components.

[0057] Among them, the minimum vacuum degree of the vacuum pump M1 is less than 10 Pa; the accuracy of the flow controller 5 is greater than 0.01 L / min; the accuracy of the pressure sensor 6 is greater than 1 Pa. The first valve V1, the second valve V2, the third valve V3, the fourth valve V4, and the fifth valve V5 are solenoid valves.

[0058] Figure 2 A method for on-line detection of gas components after discharge of a high-power gas switch according to an embodiment of the present invention includes the following steps:

[0059] S1, evacuate the cavity

[0060] Close the first valve V1, the third valve V3 and the fifth valve V5, switch the eighth valve V8 to open the NC port and close the NO port, open the fourth valve V4, and use the vacuum pump M1 to evacuate the gas switch cavity 1;

[0061] Judge according to the reading of the pressure sensor 6. When the vacuum degree A of the gas switch cavity 1 satisfies the range of 1 to 10 Pa, close the fourth valve V4 and the vacuum pump M1; otherwise, continue the evacuation process.

[0062] S2, inject zero-grade air

[0063] Open the flow controller 5, open the second valve V2 and the third valve V3, and the zero-grade air source 4 injects zero-grade air into the gas switch cavity 1;

[0064] Judge according to the reading of the pressure sensor 6. When the pressure B of the gas switch cavity 1 satisfies the range of 10 kPa to 100 kPa (gauge pressure), close the third valve V3 and the second valve V2, and read the intake volume of zero-grade air in the flow controller 5; otherwise, continue to inject zero-grade air. Read the intake volume of zero-grade air to ensure normal pressure.

[0065] S3, cavity discharge experiment

[0066] Open the pulse capacitor 2 and conduct a spark discharge experiment on the gas switch cavity 1. The range of the discharge times C is 100 to 10,000 times.

[0067] S4, inject helium

[0068] Since the air pressure in the cavity is still normal pressure after the gas switch discharges, it is necessary to inject helium to drive the product gas in the cavity to flow into the Fourier spectroscopy gas separator through the flow of helium.

[0069] Open the first valve V1 and the third valve V3, switch the eighth valve V8 to close the NC port and open the NO port, and the helium source 3 injects helium into the gas switch cavity 1. The intake volume of helium is determined according to the detection requirements of the Fourier spectroscopy gas analyzer 7. The intake volume of helium should meet the detection requirements of trace gas components of the Fourier spectroscopy gas analyzer 7 for 2 to 3 times.

[0070] S5, discharge helium and gas products

[0071] Close the first valve V1 and the third valve V3, switch the eighth valve V8 to open the NC port and close the NO port, open the fifth valve V5, and the gas product of the helium-mixed spark discharge experiment enters the Fourier spectrum gas analyzer 7 and is discharged from the NC port of the eighth valve V8 through the outlet of the Fourier spectrum gas analyzer 7.

[0072] Before the gas product of the helium mixed spark discharge experiment enters the Fourier spectrum gas analyzer 7, the states of the sixth valve V6 and the seventh valve V7 can be switched as needed, and the diaphragm pump M2 can be used to filter out particulate matter mixed in the gas product.

[0073] S6, Analysis of trace gas components

[0074] The helium in step S4 and the helium mixed with the gas product in step S5 are compared by using a Fourier spectrum gas analyzer 7 to analyze the trace gas components in the gas product.

[0075] Repeat steps S1-S6, measure at least three times, and then find the average value of the trace gas components. The measured results are converted to the results before dilution, which is the decomposition product content in the actual gas. After the helium is injected, the concentration of the product gas will decrease. Therefore, the amount of helium injected needs to be precisely controlled so that after the analyzer obtains the product gas concentration, the concentration before dilution can be obtained by converting the amount of helium injected and the original cavity volume.

[0076] This method mainly uses zero-level air for gas insulation experiments, and fills the experimental cavity with zero-level air. The pressure of the zero-level air needs to be controlled, and the air in the environment cannot be allowed to enter the experimental cavity to avoid affecting the experimental results due to excessive impurity gas components. Each time the air is inflated, it is necessary to ensure that the pressure of the zero-level air is consistent. After the switch cavity is subjected to a discharge experiment, the decomposition products under zero-level air discharge can be analyzed. Since the pressure inside the experimental cavity is low and cannot be detected directly, the detection system of the present invention can complete the vacuum treatment and the injection of zero-level air to achieve operations such as trace gas detection under micro-pressure.

[0077] The above content is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A system for on-line detection of gas components after discharge of a high-power gas switch. The gas switch includes a gas switch cavity (1) and a pulse capacitor (2) connected to the gas switch cavity (1). The pulse capacitor (2) is used to achieve spark discharge of the gas medium inside the gas switch cavity (1). It is characterized in that: It includes an input gas source, a flow controller (5), a third valve (V3), a pressure sensor (6) connected in sequence, as well as a vacuum pump (M1) and a Fourier spectroscopy gas analyzer (7). The output end of the pressure sensor (6) is connected to the air inlet of the gas switch cavity (1). The input gas source includes a helium gas source (3) and a zero-grade air source (4). The helium gas source (3) is connected to the input end of the flow controller (5) through a first valve (V1), and the zero-grade air source (4) is connected to the input end of the flow controller (5) through a second valve (V2). The air outlet of the gas switch cavity (1) is externally connected to two output branches. One output branch is connected to the input end of the vacuum pump (M1) through a fourth valve (V4). The other output branch is connected to the air inlet of the Fourier spectroscopy gas analyzer (7) through a fifth valve (V5). The air outlet of the Fourier spectrometer (7) is connected to the output end of the flow controller (5) through an eighth valve (V8). The eighth valve (V8) is a two-position three-way valve, its NC port is vacant, the NO port is connected to the output end of the flow controller (5), and the COM port is connected to the air outlet of the Fourier spectrometer (7).

2. The system for on-line detection of gas components after discharge of a high-power gas switch according to claim 1, characterized in that: On the gas path between the fifth valve (V5) and the Fourier spectroscopy gas analyzer (7), a sixth valve (V6), a diaphragm pump (M2) and a seventh valve (V7) are further arranged in sequence. Both the sixth valve (V6) and the seventh valve (V7) are two-position three-way valves, their NC ports are respectively connected to both ends of the diaphragm pump (M2), the NO ports are connected to each other, and the COM ports are respectively connected to the air inlet of the fifth valve (V5) and the Fourier spectroscopy gas analyzer (7).

3. The system for on-line detection of gas components after discharge of a high-power gas switch according to claim 2, characterized in that: A muffler (8) is provided at the output end of the vacuum pump (M1).

4. The system for on-line detection of gas components after discharge of a high-power gas switch according to claim 3, characterized in that: The first valve (V1), the second valve (V2), the third valve (V3), the fourth valve (V4) and the fifth valve (V5) are solenoid valves.

5. The system for on-line detection of gas components after discharge of a high-power gas switch according to claim 4, characterized in that: The helium gas source (3) includes a helium gas cylinder and a pressure reducing valve, which is used to adjust the pressure of the output helium gas through the pressure reducing valve.

6. The system for on-line detection of gas components after discharge of a high-power gas switch according to claim 1, characterized in that: The minimum vacuum degree of the vacuum pump (M1) is less than 10 Pa; the accuracy of the flow controller (5) is greater than 0.01 L / min; the accuracy of the pressure sensor (6) is greater than 1 Pa.

7. A method for on-line detection of gas components after discharge of a high-power gas switch, which is implemented by a system for on-line detection of gas components after discharge of a high-power gas switch according to any one of claims 1-6, characterized in that, It includes the following steps: S1, evacuating the cavity Close the first valve (V1), the third valve (V3) and the fifth valve (V5), switch the eighth valve (V8) to the NC port open and the NO port closed, open the fourth valve (V4), and use the vacuum pump (M1) to evacuate the gas switch cavity (1). Judge according to the reading of the pressure sensor (6). When the vacuum degree A of the gas switch cavity (1) satisfies: A < 10 Pa, close the fourth valve (V4) and the vacuum pump (M1); otherwise, continue the evacuation process. S2, injecting zero-grade air Open the flow controller (5), open the second valve (V2) and the third valve (V3), and the zero-grade air source (4) injects zero-grade air into the gas switch cavity (1). Judge according to the reading of the pressure sensor (6). When the pressure B of the gas switch cavity (1) satisfies: B > 10 kPa, close the third valve (V3) and the second valve (V2), and read the intake volume of zero-grade air in the flow controller (5). Otherwise, continue to inject zero-grade air; S3, cavity discharge experiment Open the pulsed capacitor (2) and conduct a spark discharge experiment on the gas switch cavity (1). The number of discharges C satisfies: C > 100; S4, injecting helium Open the first valve (V1) and the third valve (V3), switch the eighth valve (V8) to the NC port closed and the NO port open, and the helium source (3) injects helium into the gas switch cavity (1). The intake volume of helium is determined according to the detection requirements of the Fourier transform spectroscopy gas analyzer (7). S5, discharging helium and gas products Close the first valve (V1) and the third valve (V3), switch the eighth valve (V8) to the NC port open and the NO port closed, open the fifth valve (V5), and the helium will enter the Fourier transform spectroscopy gas analyzer (7) together with the gas products of the spark discharge experiment, and is discharged from the NC port of the eighth valve (V8) through the outlet of the Fourier transform spectroscopy gas analyzer (7). S6, analyzing the trace gas components Use the Fourier transform spectroscopy gas analyzer (7) to compare the helium in step S4 and the helium mixed with gas products in step S5 to analyze the trace gas components in the gas products. Repeat steps S1 - S6. After measuring at least three times, find the average value of the trace gas components, and convert the measurement result to the result before dilution, which is the content of decomposition products in the actual gas.

8. A method for on-line detection of gas components after high-power gas switch discharge according to claim 7, characterized in that: In step S5, before the helium mixed with the gas products of the spark discharge experiment enters the Fourier transform spectroscopy gas analyzer (7), the states of the sixth valve (V6) and the seventh valve (V7) can be switched, and the diaphragm pump (M2) is used to filter out the particulate matter mixed in the gas products.

9. A method for on-line detection of gas components after discharge of a high-power gas switch, according to claim 8, characterized in that: In step S4, the intake amount of helium should meet the detection requirements of the trace gas components of the Fourier transform spectroscopic gas analyzer (7) for 2 to 3 times.

10. A method for on-line detection of gas components after discharge of a high-power gas switch, according to claim 9, characterized in that: In step S1, the range of vacuum degree A should meet 1 to 10 Pa; In step S2, the range of pressure B should meet 10 kPa to 100 kPa; In step S3, the range of the number of discharges C is 100 to 10,000 times.

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