SF6 / N2 mixed gas detection and recovery device and method

Abstract

The invention provides an SF6 / N2 mixed gas detection and recovery device, a mixed gas detection system is used for detecting humidity, purity and decomposition products of SF6 / N2 mixed gas in electrical equipment, and the mixed gas recovery system is provided with a mixed gas separation and recovery path and a mixed gas recovery and reuse path. When the mixed gas detection system detects that the mixed gas detection amount is smaller than a preset value, the mixed gas recovery system is switched to the mixed gas separation and recovery path for recovery through the control system; and when the mixed gas detection system detects that the mixed gas detection amount is greater than or equal to a preset value, the mixed gas recovery system is switched to the mixed gas recovery and reuse path through the control system for recovery. The invention also provides an SF6 / N2 mixed gas detection and recovery method. The mixed gas recovery system is provided with two working modes, namely the mixed gas separation and recovery path and the mixed gas recovery and reuse path, and the two modes can better meet the use environment requirements of electrical equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of SF6 / N2 mixed gas detection, and in particular to a SF6 / N2 mixed gas detection and recovery device and method. Background Art

[0002] In order to achieve the goal of energy conservation and emission reduction in the power system, mixed gas is actively used instead of sulfur hexafluoride gas alone as an insulating medium to reduce the serious impact of large-scale use of sulfur hexafluoride gas on the greenhouse effect. At present, the use of mixed gas as an insulating medium in gas insulated switchgear (GIS) is gradually increasing. Compared with the operation and maintenance technology of electrical equipment that uses sulfur hexafluoride gas alone, it is relatively mature, but it is still necessary to analyze the characteristics of the mixed gas, detect the composition, recycle and recycle it to achieve energy conservation and environmental protection. Summary of the invention

[0003] To solve the above problems, the present invention aims to propose a SF6 / N2 mixed gas detection and recovery device and method. By setting two working modes in the mixed gas recovery system, namely: a mixed gas separation and recovery path and a mixed gas recovery and reuse path, the two working modes can better meet the use environment requirements of electrical equipment. The first working mode (mixed gas separation and recovery path) is used when the mixed gas detection amount is small, and the second working mode (mixed gas recovery and reuse path) is used when the mixed gas detection amount is large or the equipment is overhauled, etc., thereby realizing the reuse of the mixed gas after detection and achieving the purpose of low carbon and environmental protection.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A SF6 / N2 mixed gas detection and recovery device comprises a mixed gas detection system, a mixed gas recovery system and a control system. The mixed gas detection system is used to detect the humidity, purity and decomposition products of the SF6 / N2 mixed gas in electrical equipment. The mixed gas recovery system is provided with a mixed gas separation recovery path and a mixed gas recovery and reuse path. When the mixed gas detection system detects that the detected amount of the mixed gas is less than a predetermined value, the mixed gas recovery system switches to the mixed gas separation recovery path for recovery through the control system; when the mixed gas detection system detects that the detected amount of the mixed gas is greater than or equal to the predetermined value, the mixed gas recovery system switches to the mixed gas recovery and reuse path for recovery through the control system.

[0006] Furthermore, the mixed gas detection system includes a first flow regulating valve, a first buffer tank, a first compressor and a comprehensive detection module; the first flow regulating valve is connected to the mixed gas inlet, and the first buffer tank, the first compressor and the comprehensive detection module are connected in sequence on the intake pipeline, and the first buffer tank is equipped with a first pressure sensor.

[0007] Furthermore, the working process of the mixed gas detection system is as follows: after the SF6 / N2 mixed gas is introduced, it first enters the first buffer tank. When the gas pressure in the first buffer tank reaches the set threshold, the first compressor is controlled by the first pressure sensor and the control system to compress the SF6 / N2 mixed gas to the comprehensive detection module for the humidity, purity and decomposition products of the mixed gas.

[0008] Furthermore, the comprehensive detection module includes a humidity sensor, a purity sensor and a portable gas chromatograph which are sequentially connected along a gas pipeline.

[0009] Furthermore, the mixed gas recovery system includes a pretreatment module, a mixed gas separation and recovery module, and a mixed gas recovery and reuse module, the pretreatment module is connected to the gas outlet pipe of the comprehensive detection module; the mixed gas separation and recovery module and the mixed gas recovery and reuse module are connected in parallel to the pretreatment module, a first solenoid valve is installed between the mixed gas separation and recovery module and the pretreatment module, and a second solenoid valve is installed between the mixed gas recovery and reuse module and the pretreatment module.

[0010] Furthermore, the mixed gas separation and recovery module includes a second flow regulating valve, a second buffer tank, a second compressor, a water bath heating device, a membrane separation device) and an SF6 gas storage cylinder. The second buffer tank is equipped with a second pressure sensor. The high-concentration SF6 after membrane separation is stored in the SF6 gas storage cylinder. An SF6 purity detector is installed between the membrane separation device and the SF6 gas storage cylinder.

[0011] Furthermore, the mixed gas recycling and reuse module includes a first mixed gas storage cylinder and a second mixed gas storage cylinder, the first mixed gas storage cylinder is used for recycling and reusing the mixed gas with a qualified mixing ratio after detection, the second mixed gas storage cylinder is used for recycling and reusing the mixed gas with an unqualified mixing ratio after detection, a third solenoid valve is installed between the first mixed gas storage cylinder and the second solenoid valve, a fourth solenoid valve is installed between the second mixed gas storage cylinder and the second solenoid valve, a first gas replenishment port and a second gas replenishment port are provided between the second mixed gas storage cylinder and the fourth solenoid valve, which are respectively used for replenishing SF6 and N2 for proportional preparation, a fifth solenoid valve and a first mass flow controller are installed on the SF6 gas replenishment gas circuit, and a sixth solenoid valve and a second mass flow controller are installed on the N2 gas replenishment gas circuit.

[0012] Furthermore, in the mixed gas separation and recovery module of the mixed gas recovery system, the mixed gas is separated by membrane separation technology to obtain SF6 gas with a concentration greater than 95%. Specifically, according to the concentration of the separated SF6 gas detected by the SF6 purity detector, the control system improves the efficiency of membrane separation by controlling the second flow regulating valve to control the flow, controlling the second compressor to control the pressure, and controlling the temperature in the water bath heating device to increase the concentration of the obtained SF6 gas until the target concentration is reached.

[0013] In order to achieve the above object, the present invention also provides a recovery method of a SF6 / N2 mixed gas detection and recovery device, including two working modes:

[0014] The first working mode: used for the case where the amount of mixed gas detected is small. In the first working mode, the control system controls the first solenoid valve to open and the second solenoid valve to close, and the mixed gas is recovered through the mixed gas separation and recovery module;

[0015] The second working mode: It is used for the detection of large amounts of mixed gas or equipment overhaul. In the second working mode, the control system controls the first solenoid valve to close and the second solenoid valve to open. The mixed gas is recovered through the mixed gas recovery and reuse module, and the recovered mixed gas is directly reused and recharged into the electrical equipment for use.

[0016] Furthermore, in the second working mode, when the mixed gas ratio after detection is qualified, the control system controls the third solenoid valve to open and the fourth solenoid valve to close; when the mixed gas ratio after detection is unqualified, the control system controls the third solenoid valve to close and the fourth solenoid valve to open, and at the same time controls the fifth solenoid valve or the sixth solenoid valve to open or close according to the need for SF6 or N2 gas replenishment.

[0017] Beneficial effect: The present invention sets two working modes in the mixed gas recovery system, namely: a mixed gas separation and recovery path and a mixed gas recovery and reuse path. The two working modes can better meet the use environment requirements of electrical equipment. The first working mode (mixed gas separation and recovery path) is used when the mixed gas detection amount is small, and the second working mode (mixed gas recovery and reuse path) is used when the mixed gas detection amount is large or the equipment is overhauled, etc., thereby realizing the reuse of the mixed gas after detection and achieving the purpose of low carbon and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0019] Figure 1A schematic diagram of the structure of a mixed gas detection system of a SF6 / N2 mixed gas detection and recovery device according to an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the structure of a mixed gas recovery system of a SF6 / N2 mixed gas detection and recovery device according to an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the structure of a mixed gas separation and recovery module in a mixed gas recovery system of a SF6 / N2 mixed gas detection and recovery device according to an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the structure of a mixed gas recovery and reuse module in a mixed gas recovery system of an SF6 / N2 mixed gas detection and recovery device according to an embodiment of the present invention;

[0023] Figure 5 This is a flow chart of the SF6 / N2 mixed gas detection and recovery method described in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0026] Example 1

[0027] See also Figure 1-5 : A SF6 / N2 mixed gas detection and recovery device comprises a mixed gas detection system 1, a mixed gas recovery system 2 and a control system, wherein the mixed gas detection system 1 is used to detect the humidity, purity and decomposition products of the SF6 / N2 mixed gas in electrical equipment, and the mixed gas recovery system 2 is provided with a mixed gas separation recovery path and a mixed gas recovery and reuse path, when the mixed gas detection system 1 detects that the detected amount of mixed gas is less than a predetermined value, the mixed gas recovery system 2 switches to the mixed gas separation recovery path for recovery through the control system; when the mixed gas detection system 1 detects that the detected amount of mixed gas is greater than or equal to a predetermined value, the mixed gas recovery system 2 switches to the mixed gas recovery and reuse path for recovery through the control system.

[0028] The mixed gas recovery system of this embodiment is provided with two working modes, namely: a mixed gas separation recovery path and a mixed gas recovery and reuse path. The two working modes can better meet the use environment requirements of the electrical equipment. The first working mode, the mixed gas separation recovery path, is used in the case of a small amount of mixed gas detection. The second working mode, the mixed gas recovery and reuse path, is used in the case of a large amount of mixed gas detection or equipment overhaul.

[0029] In a specific example, the mixed gas detection system 1 includes a first flow regulating valve 11, a first buffer tank 12, a first compressor 13 and a comprehensive detection module 15; the first flow regulating valve 11 is connected to the mixed gas inlet, and the first buffer tank 12, the first compressor 13 and the comprehensive detection module 15 are connected in sequence on the intake pipeline, and the first buffer tank is equipped with a first pressure sensor 14.

[0030] In a specific example, the working process of the mixed gas detection system 1 is as follows: after the SF6 / N2 mixed gas is introduced, it first enters the first buffer tank 12. When the gas pressure in the first buffer tank 12 reaches the set threshold, the first compressor 13 is controlled by the first pressure sensor 14 and the control system to compress the SF6 / N2 mixed gas to the comprehensive detection module 15 to detect the humidity, purity and decomposition products of the mixed gas.

[0031] In a specific example, the comprehensive detection module 15 includes a humidity sensor 151, a purity sensor 152 and a portable gas chromatograph 153 which are sequentially connected according to a gas pipeline.

[0032] It should be noted that the humidity detection in this embodiment can use the resistance-capacitance method and the dew point method to detect the trace water content in the mixed gas, the purity detection uses a thermal conductivity sensor to detect the mixing ratio of the gas, and a portable gas chromatograph can be used to analyze components such as carbon monoxide, carbon tetrafluoride, sulfur dioxide, carbon dioxide, hydrogen sulfide, and nitrogen trifluoride; and the control system can adjust the flow rate by controlling the first flow control valve to improve the detection efficiency.

[0033] In a specific example, the mixed gas recovery system 2 includes a pretreatment module 21, a mixed gas separation and recovery module 22, and a mixed gas recovery and reuse module 23, wherein the pretreatment module 21 is connected to the gas outlet pipe of the comprehensive detection module 15; the mixed gas separation and recovery module 22 and the mixed gas recovery and reuse module 23 are connected in parallel to the pretreatment module 21, a first solenoid valve 24 is installed between the mixed gas separation and recovery module 22 and the pretreatment module 21, and a second solenoid valve 25 is installed between the mixed gas recovery and reuse module 23 and the pretreatment module 21.

[0034] The pretreatment module of this embodiment uses silica gel, molecular sieve and activated carbon to remove moisture and impurities in the mixed gas; the control system can control the on and off of the first solenoid valve and the second solenoid valve, thereby completing the switching between the mixed gas separation and recovery path and the mixed gas recovery and reuse path.

[0035] In a specific example, the mixed gas separation and recovery module 22 includes a second flow regulating valve 221, a second buffer tank 222, a second compressor 223, a water bath heating device 224, a membrane separation device 225 and a SF6 gas storage cylinder 226. The second buffer tank 222 is equipped with a second pressure sensor 227. The high-concentration SF6 after membrane separation is stored in the SF6 gas storage cylinder 226. An SF6 purity detector 228 is installed between the membrane separation device 225 and the SF6 gas storage cylinder 226.

[0036] In a specific example, the mixed gas recycling and reuse module 23 includes a first mixed gas storage cylinder 231 and a second mixed gas storage cylinder 232. The first mixed gas storage cylinder 231 is used for recycling and reusing the mixed gas with a qualified mixing ratio after detection, and the second mixed gas storage cylinder 232 is used for recycling and reusing the mixed gas with an unqualified mixing ratio after detection. A third solenoid valve 233 is installed between the first mixed gas storage cylinder 231 and the second solenoid valve 25, and a fourth solenoid valve 234 is installed between the second mixed gas storage cylinder 232 and the second solenoid valve 25. A first gas replenishment port 235 and a second gas replenishment port 236 are provided between the second mixed gas storage cylinder 232 and the fourth solenoid valve 234, which are respectively used for replenishing SF6 and N2 for proportional preparation. A fifth solenoid valve 237 and a first mass flow controller 238 are installed on the SF6 gas replenishment gas path, and a sixth solenoid valve 239 and a second mass flow controller 2310 are installed on the N2 gas replenishment gas path.

[0037] In a specific example, in the mixed gas separation and recovery module 22 of the mixed gas recovery system 2, the membrane separation technology is used to separate the mixed gas to obtain SF6 gas with a concentration greater than 95%. Specifically, according to the concentration of the separated SF6 gas detected by the SF6 purity detector 228, the control system improves the efficiency of membrane separation by controlling the second flow regulating valve 221 for flow control, controlling the second compressor 223 for pressure control, and controlling the temperature in the water bath heating device 224, thereby improving the concentration of the obtained SF6 gas until the target concentration is reached.

[0038] Example 2

[0039] To achieve the above purpose, see Figure 5 :This embodiment also provides a recovery method of a SF6 / N2 mixed gas detection and recovery device, including two working modes:

[0040] The first working mode: used when the amount of mixed gas detected is small. In the first working mode, the control system controls the first solenoid valve 24 to open and the second solenoid valve 25 to close, and the mixed gas is recovered through the mixed gas separation and recovery module 22;

[0041] The second working mode: used for the case where the amount of mixed gas detected is large or the equipment is overhauled. In the second working mode, the control system controls the first solenoid valve 24 to close and the second solenoid valve 25 to open, and the mixed gas is recovered through the mixed gas recovery and reuse module 23, and the recovered mixed gas is directly reused and recharged into the electrical equipment for use.

[0042] In a specific example, in the second working mode, when the mixed gas ratio after detection is qualified, the control system controls the third solenoid valve 233 to open and the fourth solenoid valve 234 to close; when the mixed gas ratio after detection is unqualified, the control system controls the third solenoid valve 233 to close and the fourth solenoid valve 234 to open, and at the same time controls the fifth solenoid valve 237 or the sixth solenoid valve 239 to open or close according to the need for SF6 or N2 gas replenishment.

[0043] In the second working mode, a large amount of mixed gas can be directly recharged into the electrical equipment after being recycled, realizing the reuse of the mixed gas after detection and achieving the goal of low carbon and environmental protection.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A SF6 / N2 mixed gas detection and recovery device, characterized in that: The invention comprises a mixed gas detection system (1), a mixed gas recovery system (2) and a control system. The mixed gas detection system (1) is used to detect the humidity, purity and decomposition products of the SF6 / N2 mixed gas in the electrical equipment. The mixed gas recovery system (2) is provided with a mixed gas separation recovery path and a mixed gas recovery and reuse path. When the mixed gas detection system (1) detects that the detected amount of the mixed gas is less than a predetermined value, the mixed gas recovery system (2) switches to the mixed gas separation recovery path for recovery through the control system; when the mixed gas detection system (1) detects that the detected amount of the mixed gas is greater than or equal to the predetermined value, the mixed gas recovery system (2) switches to the mixed gas recovery and reuse path for recovery through the control system.

2. The SF6 / N2 mixed gas detection and recovery device according to claim 1 is characterized in that: The mixed gas detection system (1) comprises a first flow regulating valve (11), a first buffer tank (12), a first compressor (13) and a comprehensive detection module (15); the first flow regulating valve (11) is connected to a mixed gas inlet, and the first buffer tank (12), the first compressor (13) and the comprehensive detection module (15) are sequentially connected on an intake pipeline; the first buffer tank is provided with a first pressure sensor (14).

3. The SF6 / N2 mixed gas detection and recovery device according to claim 2 is characterized in that: The working process of the mixed gas detection system (1) is as follows: after the SF6 / N2 mixed gas is introduced, it first enters the first buffer tank (12); when the gas pressure in the first buffer tank (12) reaches a set threshold, the first compressor (13) is controlled by the first pressure sensor (14) and the control system to compress the SF6 / N2 mixed gas into the comprehensive detection module (15) to measure the humidity, purity and decomposition products of the mixed gas.

4. The SF6 / N2 mixed gas detection and recovery device according to claim 2 is characterized in that: The comprehensive detection module (15) comprises a humidity sensor (151), a purity sensor (152) and a portable gas chromatograph (153) which are sequentially connected according to a gas pipeline.

5. The SF6 / N2 mixed gas detection and recovery device according to claim 1 is characterized in that: The mixed gas recovery system (2) comprises a pretreatment module (21), a mixed gas separation recovery module (22) and a mixed gas recovery and reuse module (23); the pretreatment module (21) is connected to the gas outlet pipeline of the comprehensive detection module (15); the mixed gas separation recovery module (22) and the mixed gas recovery and reuse module (23) are connected in parallel to the pretreatment module (21); a first solenoid valve (24) is installed between the mixed gas separation recovery module (22) and the pretreatment module (21); and a second solenoid valve (25) is installed between the mixed gas recovery and reuse module (23) and the pretreatment module (21).

6. The SF6 / N2 mixed gas detection and recovery device according to claim 5, characterized in that: The mixed gas separation and recovery module (22) comprises a second flow regulating valve (221), a second buffer tank (222), a second compressor (223), a water bath heating device (224), a membrane separation device (225) and an SF6 gas storage cylinder (226); the second buffer tank (222) is provided with a second pressure sensor (227); high-concentration SF6 after membrane separation is stored in the SF6 gas storage cylinder (226); and an SF6 purity detector (228) is provided between the membrane separation device (225) and the SF6 gas storage cylinder (226).

7. The SF6 / N2 mixed gas detection and recovery device according to claim 5, characterized in that: The mixed gas recycling module (23) comprises a first mixed gas storage cylinder (231) and a second mixed gas storage cylinder (232), wherein the first mixed gas storage cylinder (231) is used for recycling mixed gas with a qualified mixing ratio after detection, and the second mixed gas storage cylinder (232) is used for recycling mixed gas with an unqualified mixing ratio after detection, and a third solenoid valve (233) is installed between the first mixed gas storage cylinder (231) and the second solenoid valve (25), and the second mixed gas storage cylinder (232) is used for recycling mixed gas with an unqualified mixing ratio after detection. ) is provided between the second solenoid valve (25), a first gas supply port (235) and a second gas supply port (236) are provided between the second mixed gas storage bottle (232) and the fourth solenoid valve (234), and are used for supplying SF6 and N2 respectively so as to make a proportional mixture. A fifth solenoid valve (237) and a first mass flow controller (238) are installed on the SF6 supply gas circuit, and a sixth solenoid valve (239) and a second mass flow controller (2310) are installed on the N2 supply gas circuit.

8. The SF6 / N2 mixed gas detection and recovery device according to claim 6, characterized in that: In the mixed gas separation and recovery module (22) of the mixed gas recovery system (2), the mixed gas is separated by using membrane separation technology to obtain SF6 gas with a concentration greater than 95%. Specifically, according to the concentration of the separated SF6 gas detected by the SF6 purity detector (228), the control system improves the efficiency of membrane separation by controlling the second flow regulating valve (221) to control the flow, controlling the second compressor (223) to control the pressure, and controlling the temperature in the water bath heating device (224), thereby improving the concentration of the obtained SF6 gas until the target concentration is reached.

9. A recovery method of the SF6 / N2 mixed gas detection and recovery device according to any one of claims 1 to 8, characterized in that: There are two working modes: The first working mode is used when the amount of mixed gas detected is small. In the first working mode, the control system controls the first solenoid valve (24) to open and the second solenoid valve (25) to close, and the mixed gas is recovered through the mixed gas separation and recovery module (22); The second working mode is used when the amount of mixed gas detected is large or when the equipment is overhauled. In the second working mode, the control system controls the first solenoid valve (24) to close and the second solenoid valve (25) to open, and the mixed gas is recovered through the mixed gas recovery and reuse module (23), and the recovered mixed gas is directly reused and recharged into the electrical equipment for use.

10. The recovery method of the SF6 / N2 mixed gas detection and recovery device according to claim 9, characterized in that: In the second working mode, when the mixed gas mixing ratio after detection is qualified, the control system controls the third solenoid valve (233) to open and the fourth solenoid valve (234) to close; when the mixed gas mixing ratio after detection is unqualified, the control system controls the third solenoid valve (233) to close and the fourth solenoid valve (234) to open, and at the same time controls the fifth solenoid valve (237) or the sixth solenoid valve (239) to open or close according to the need for SF6 or N2 gas replenishment.

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