Online monitoring device for dissolved gas in transformer oil

Abstract

The invention provides an online monitoring device for dissolved gas in transformer oil, which comprises a gas inlet, a coarse filter, a compressor, a first electromagnetic valve, a one-way valve, a dedusting and dehumidifying filter and a two-position five-way valve which are connected in sequence, a port A of the two-position five-way valve is connected with a first purification pipe, a port B of the two-position five-way valve is connected with a second purification pipe, a port P of the two-position five-way valve is connected with a dust removal and dehumidification filter, the first purification pipe is further connected with a second electromagnetic valve, the second purification pipe is further connected with a third electromagnetic valve, and the second electromagnetic valve and the third electromagnetic valve are further connected with an air storage tank. A fourth electromagnetic valve is further arranged between the second electromagnetic valve and the third electromagnetic valve; when the compressor is normally started, the port P and the port A of the first electromagnetic valve are communicated, and compressed gas enters the dust removal and dehumidification filter through the one-way valve. The accuracy of the device is not affected while the workload of replacing the gas cylinder is reduced; pure dehumidification and hydrocarbon removal pure air meeting working requirements is provided, and the analysis sensitivity of detectors such as FID is improved.

Description

Technical Field

[0001] The invention relates to the technical field of on-line monitoring of dissolved gas in transformer oil, and in particular to an on-line monitoring device for dissolved gas in transformer oil. Background Art

[0002] Online monitoring of insulating oil by chromatography is an effective and proven method for real-time analysis of dissolved gas content in insulating oil. It generally uses an FID (hydrogen flame ionizer) as a detector. For proper operation, the instrument requires pure nitrogen as a carrier gas. However, high-purity nitrogen is relatively expensive. Therefore, current online monitoring systems for dissolved gas in transformer oil often use an air generator as the air source. However, untreated air can easily lead to air path contamination and unstable baselines when used in online monitoring systems. Therefore, the air must undergo a series of purification processes before use. Air purification typically involves multiple stages of filtration to achieve clean air output. The first stage is typically a mechanical dust and humidity removal device. Using stainless steel filters and an air path structure to redirect the airflow, individual water droplets coalesce and condense in a condenser. The droplets then grow larger, combine with other contaminants, and flow by gravity into a reservoir chamber, where they are discharged through an automatic drain valve. This process removes a significant amount of water, with the remaining water then being adsorbed through a purification pipe. For example, a purification tube equipped with color-changing silica gel is used to remove trace moisture from the air, while molecular sieves and activated carbon are used to remove other types of trace impurities.

[0003] Traditional air generators use disposable adsorbent in their purification tubes. These dehumidification adsorbents must be replaced periodically after saturation, requiring only manual inspection to determine when to replace them. Furthermore, conventional air generator systems lack hydrocarbon removal devices. The introduction of unremoved carrier gas can cause detector baseline drift, severely impacting the accuracy of test results. Summary of the Invention

[0004] The purpose of the present invention is to provide an online monitoring device for dissolved gas in transformer oil, which solves the technical problem of how to reduce the workload of replacing gas cylinders without affecting the accuracy of the device.

[0005] In one aspect, an online monitoring device for dissolved gas in transformer oil is provided, comprising:

[0006] An air inlet, a coarse-effect filter, a compressor, a first solenoid valve, a one-way valve, a dust removal and dehumidification filter, and a two-position five-way valve are connected in sequence; port A of the two-position five-way valve is connected to a first purification pipe, port B of the two-position five-way valve is connected to a second purification pipe, port P of the two-position five-way valve is connected to a dust removal and dehumidification filter, the first purification pipe is also connected to a second solenoid valve, the second purification pipe is also connected to a third solenoid valve, the second solenoid valve and the third solenoid valve are also connected to an air storage tank, respectively, and a fourth solenoid valve is further provided between the second solenoid valve and the third solenoid valve;

[0007] When the compressor starts normally, the P port and the A port of the first solenoid valve are connected, and the compressed gas passes through the one-way valve and enters the dust removal and dehumidification filter, and the dust removal and dehumidification filter is used to filter out moisture and particulate impurities in the air;

[0008] When the first purification pipe is used as the working pipe, compressed air flows from the P port to the A port of the two-position five-way valve, and the gas purified by the molecular sieve in the first purification pipe is output to the gas storage tank and the fourth solenoid valve respectively through the second solenoid valve, and then output to the two-position five-way valve through the fourth solenoid valve and the second purification pipe;

[0009] When the second purification pipe is used as the working pipe, compressed air flows from the P port to the B port of the two-position five-way valve, and the gas purified by the molecular sieve in the second purification pipe is output to the gas storage tank and the fourth solenoid valve respectively through the third solenoid valve, and is output to the two-position five-way valve through the fourth solenoid valve and the first purification pipe.

[0010] Preferably, the outlet of the gas storage tank is also connected in sequence to a pressure-stabilizing valve, a pressure gauge, a hydrocarbon removal device, a cooler, a mesh filter, and a gas source switching solenoid valve; the pressure-stabilizing valve and the pressure gauge are used to monitor the gas pressure parameters in the gas storage tank, the cooler is used to cool the gas output by the hydrocarbon removal device, and the gas source switching solenoid valve switches the gas source output.

[0011] Preferably, the gas tank is also provided with a pressure switch, which outputs a start signal to the compressor when the pressure in the gas tank is lower than a preset lower pressure limit; and outputs a stop signal to the compressor when the pressure in the gas tank is higher than a preset upper pressure limit.

[0012] Preferably, the hydrocarbon removal device includes at least an outer shell, a heating block and a spiral conversion tube wrapped around the heating block, the conversion tube is filled with a granular metal catalyst, a ceramic fiber insulation layer is filled between the heating block and the outer shell, and a fixed column is arranged in the ceramic fiber insulation layer.

[0013] Preferably, a heating rod and a temperature measuring resistor are provided on the heating block, and control lines of the temperature measuring resistor and the heating rod are led out to the control circuit through reserved via holes.

[0014] Preferably, it also includes a wastewater and waste gas discharge port, which is respectively connected to the dust removal and dehumidification filter, the EA port and the EB port of the two-position five-way valve for removing the filtered gas or moisture.

[0015] Preferably, it also includes that when the compressor is started, the P port and the N port of the first solenoid valve are connected and the air is discharged through the N port. After the compressor is started normally, the first solenoid valve is controlled to be powered on and switched to be connected between the P port and the A port.

[0016] Preferably, the cooler is composed of a spiral metal gas pipe and a fan, and the metal gas pipe is arranged at the outlet of the hydrocarbon removal device.

[0017] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0018] The online monitoring device for dissolved gas in transformer oil provided by the present invention replaces the original gas circuit system that requires high-purity nitrogen, reducing the workload of replacing gas cylinders while maintaining the accuracy of the device. It provides pure air that meets working requirements and has been dehumidified and dehydrogenated, thereby improving the analytical sensitivity of detectors such as FID. It does not require the replacement of adsorbent dehumidifiers, has no consumables, has a long service life, and requires no maintenance during daily operation. It uses a high-temperature catalytic dehydrogenation device to ensure that the hydrocarbon content of the output air is less than 0.1ppm. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0020] Figure 1 Schematic diagram of an online monitoring device for dissolved gas in transformer oil according to an embodiment of the present invention.

[0021] Figure 2 Schematic diagram of a hydrocarbon removal device in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0023] like Figure 1 FIG. 1 is a schematic diagram of an embodiment of an online monitoring device for dissolved gas in transformer oil provided by the present invention. In this embodiment, the device comprises:

[0024] The air inlet 1, the coarse-effect filter 2, the compressor 3, the first solenoid valve 4, the one-way valve 5, the dust removal and dehumidification filter 6, and the two-position five-way valve 7 are connected in sequence; the A port of the two-position five-way valve 7 is connected to the first purification pipe 8, the B port of the two-position five-way valve 7 is connected to the second purification pipe 9, the P port of the two-position five-way valve 7 is connected to the dust removal and dehumidification filter 6, the first purification pipe 8 is also connected to the second solenoid valve 11, the second purification pipe 9 is also connected to the third solenoid valve 12, the second solenoid valve 11 and the third solenoid valve 12 are also connected to the gas storage tank 13 respectively, and a fourth solenoid valve 10 is also arranged between the second solenoid valve 11 and the third solenoid valve 12; it also includes a wastewater and waste gas discharge port 22, which is respectively connected to the dust removal and dehumidification filter 6, the EA port and the EB port of the two-position five-way valve 7, for removing the filtered gas or moisture. The oil-free compressor 3 uses a diaphragm compressor 3 to suck air from the inlet, and a dehumidification and dust removal condensation filter is set at the outlet of the compressor 3. After the air is compressed in the compressor 3, high-pressure, high-humidity compressed air comes out. After passing through a certain length of pipeline to the dust removal and dehumidification filter 6, it will gradually cool down. At the same pressure, as the gas temperature decreases, the air will become oversaturated. The tiny water droplets formed by oversaturation will condense into larger water droplets in the dust removal and dehumidification condensation filter, mixed with dust and other impurities and fall to the bottom of the filter. Then, through the control of the system, the discharge solenoid valve is opened to discharge regularly. A starting solenoid valve is set behind the compressor 3 to ensure that the compressor 3 starts under normal pressure.

[0025] When the compressor 3 is started, the P port and N port of the first solenoid valve 4 are connected and emptied through the N port. After the compressor 3 starts normally, the first solenoid valve 4 is controlled to be powered on and switched to the P port and A port for connection; when the compressor 3 starts normally, the P port and A port of the first solenoid valve 4 are connected, and the compressed gas passes through the one-way valve 5 into the dust removal and dehumidification filter 6, and the dust removal and dehumidification filter 6 is used to filter out moisture and particulate impurities in the air; air is sucked in from the air inlet 1, passes through the coarse-effect filter 2 to filter out larger impurities in the air, and enters the compressor 3. The outlet of the compressor 3 is connected to the input end of the starting solenoid valve 4. When the compressor 3 starts, the P and N ports of the starting solenoid valve 4 are connected, and the N port is emptied to ensure that the compressor 3 starts at normal pressure. After the compressor 3 starts normally, the starting solenoid 4 is powered on and switched to the P and A ports. The compressed gas passes through the one-way valve 5 into the dust removal and dehumidification filter 6 to filter out some moisture and particulate impurities in the air. The solenoid valve is opened periodically to discharge moisture and other impurities at the bottom of the filter.

[0026] It should be noted that the gas purified by the filter 6 enters the molecular sieve purification tube through the two-position five-way valve 7, and the flow direction of the gas can be controlled by the first solenoid valve 7 and the fourth solenoid valve 10, the second solenoid valve 11, and the third solenoid valve 12.

[0027] When the first purification pipe 8 is used as a working pipe, compressed air flows from the P port of the two-position five-way valve 7 to the A port, and the gas purified by the molecular sieve in the first purification pipe 8 is output to the gas storage tank 13 and the fourth solenoid valve 10 respectively through the second solenoid valve 11, and is output to the two-position five-way valve 7 through the fourth solenoid valve 10 and the second purification pipe 9; when the molecular sieve first purification pipe 8 is used as a working pipe, compressed air flows from the P port of the two-position five-way valve 7 to the A port, the A port of the five-way solenoid valve 7 is connected to the inlet of the first purification pipe 8, and the gas purified by the molecular sieve in the purification pipe is output from The outlet of the purification tube flows out, and part of the purified gas flowing out of the outlet flows to the gas storage tank 13 through the solenoid valve 12, and part flows to the outlet of the second molecular sieve purification tube 9 through the solenoid valve 10. After the purified gas enters the molecular sieve purification tube, because the inlet of the purification tube is connected to the wastewater and waste gas discharge port 22 through the EA port of the two-position five-way valve 7, the outlet pressure is atmospheric pressure, the pressure in the molecular sieve purification tube is reduced, and the volume of the purified gas expands, further reducing the moisture content. When the airflow flows through the molecular sieve in the opposite direction, it takes away the moisture adsorbed on the molecular sieve, thereby achieving the purpose of automatic activation without the need for heating.

[0028] When the second purification pipe 9 is used as the working pipe, compressed air flows from port P to port B of the two-position five-way valve 7, and the gas purified by the molecular sieve in the second purification pipe 9 is output to the gas storage tank 13 and the fourth solenoid valve 10 through the third solenoid valve 12, and then output to the two-position five-way valve 7 through the fourth solenoid valve 10 and the first purification pipe 8. When the B pipe is switched to work, the compressed air flows from port P to port B of the two-position five-way valve 77. The port B of the five-way solenoid valve 7 is connected to the air inlet 1 of the second purification pipe 9. The gas is purified by the molecular sieve in the pipe and flows to the outlet of the second purification pipe 9. Part of the purified gas flowing out of the outlet flows through the solenoid valve 12 to the gas storage tank 13, and part flows through the solenoid valve 10 to the outlet of the molecular sieve first purification pipe 8. It then flows back through the first purification pipe 8 to automatically activate the first purification pipe 8, and part enters the gas storage tank 13 through the solenoid valve 12.

[0029] In a specific embodiment, the outlet of the gas storage tank 13 is connected in sequence to a pressure-stabilizing valve 15, a pressure gauge 16, a hydrocarbon removal device 17, a cooler 18, a mesh filter 19, and a gas source switching solenoid valve 20. The pressure-stabilizing valve 15 and the pressure gauge 16 are used to monitor the air pressure parameters within the gas storage tank 13. The cooler 18 is used to cool the gas output from the hydrocarbon removal device 17. The gas source switching solenoid valve 20 switches the gas source output. The gas storage tank 13 is also equipped with a pressure switch 14. When the pressure within the gas storage tank 13 falls below a preset lower pressure limit, it outputs a start signal to the compressor 3; when the pressure within the gas storage tank 13 exceeds a preset upper pressure limit, it outputs a stop signal to the compressor 3. The cooler 18 consists of a spiral metal gas pipe and a fan. The metal gas pipe is located at the outlet of the hydrocarbon removal device 17. The pressure switch 14 is installed on the gas storage tank 13. The compressor 3 starts operating when the pressure falls below 0.45 MPa and stops operating when the pressure within the gas storage tank 13 exceeds 0.6 MPa. The outlet of the gas storage tank 13 is provided with a pressure-stabilizing valve 15 , and the outlet pressure of the pressure regulator is adjusted to 0.35 MPa. The outlet of the pressure-stabilizing valve 15 is provided with a pressure gauge 16 , which can display the output pressure of the gas source module.

[0030] In a specific embodiment, Figure 2As shown, the hydrocarbon removal device 17 comprises at least a housing 171, a heating block 175, and a helical conversion tube 173 wrapped around the heating block 175. The conversion tube 173 is filled with a granular metal catalyst 174. A ceramic fiber insulation layer 172 is placed between the heating block 175 and the housing 171, and a fixing post 1710 is disposed within the ceramic fiber insulation layer 172. A heating rod 179 and a temperature-measuring resistor 176 are disposed on the heating block 175. Control lines for the temperature-measuring resistor 176 and the heating rod 179 are connected to a control circuit through a reserved via 1711. The hydrocarbon removal device 17 comprises a helical stainless steel conversion tube 173 filled with a granular precious metal catalyst 174, which is wrapped around a cylindrical heating block 175. The heating block 175 is equipped with a heating rod 179 and a temperature-measuring platinum resistor 176, enabling precise temperature control. An insulation material 172 is filled between the heating block 175 and the outer shell 171. The insulation material is made of high-temperature resistant ceramic fiber material. A fixed column 1710 is provided between the heating block 175 and the outer shell 171. The control lines of the platinum resistor and the heating rod 179 are led out to the control circuit through the reserved through-hole 1711. A 10um metal sintered mesh filter 19 is provided at the outlet to further filter the tiny particles in the gas. An air source switching solenoid valve 20 is provided at the outlet, which can be used to switch the air source to the air source module or the spare cylinder connected from the spare cylinder interface 22. The dehydrocarbon removal device 17 requires high temperature when working. A cooler 18 is provided at the outlet of the dehydrocarbon removal device 17. The cooler 18 is composed of a spiral metal gas pipe, and the heat of the cooler 18 is dissipated by the fan.

[0031] In summary, the implementation of the embodiments of the present invention has the following beneficial effects:

[0032] The online monitoring device for dissolved gas in transformer oil provided by the present invention replaces the original gas circuit system that requires high-purity nitrogen, reducing the workload of replacing gas cylinders while maintaining the accuracy of the device. It provides pure air that meets working requirements and has been dehumidified and dehydrogenated, thereby improving the analytical sensitivity of detectors such as FID. It does not require the replacement of adsorbent dehumidifiers, has no consumables, has a long service life, and requires no maintenance during daily operation. It uses a high-temperature catalytic dehydrogenation device to ensure that the hydrocarbon content of the output air is less than 0.1ppm.

[0033] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. An online monitoring device for dissolved gas in transformer oil, characterized in that: include: An air inlet, a coarse-effect filter, a compressor, a first solenoid valve, a one-way valve, a dust removal and dehumidification filter, and a two-position five-way valve are connected in sequence; port A of the two-position five-way valve is connected to a first purification pipe, port B of the two-position five-way valve is connected to a second purification pipe, port P of the two-position five-way valve is connected to a dust removal and dehumidification filter, the first purification pipe is also connected to a second solenoid valve, the second purification pipe is also connected to a third solenoid valve, the second solenoid valve and the third solenoid valve are also connected to an air storage tank, respectively, and a fourth solenoid valve is further provided between the second solenoid valve and the third solenoid valve; When the compressor starts normally, the P port and the A port of the first solenoid valve are connected, and the compressed gas passes through the one-way valve and enters the dust removal and dehumidification filter, and the dust removal and dehumidification filter is used to filter out moisture and particulate impurities in the air; When the first purification pipe is used as the working pipe, compressed air flows from the P port to the A port of the two-position five-way valve, and the gas purified by the molecular sieve in the first purification pipe is output to the gas storage tank and the fourth solenoid valve respectively through the second solenoid valve, and then output to the two-position five-way valve through the fourth solenoid valve and the second purification pipe; When the second purification pipe is used as the working pipe, compressed air flows from the P port to the B port of the two-position five-way valve, and the gas purified by the molecular sieve in the second purification pipe is output to the gas storage tank and the fourth solenoid valve respectively through the third solenoid valve, and is output to the two-position five-way valve through the fourth solenoid valve and the first purification pipe.

2. The device according to claim 1, wherein The outlet of the gas storage tank is also connected in sequence to a pressure-stabilizing valve, a pressure gauge, a hydrocarbon removal device, a cooler, a mesh filter, and a gas source switching solenoid valve; the pressure-stabilizing valve and the pressure gauge are used to monitor the gas pressure parameters in the gas storage tank, the cooler is used to cool the gas output by the hydrocarbon removal device, and the gas source switching solenoid valve switches the gas source output.

3. The device according to claim 2, wherein The gas tank is also provided with a pressure switch, which outputs a start signal to the compressor when the pressure in the gas tank is lower than the preset lower pressure limit; and outputs a stop signal to the compressor when the pressure in the gas tank is higher than the preset upper pressure limit.

4. The device according to claim 3, characterized in that The hydrocarbon removal device comprises at least an outer shell, a heating block and a spiral conversion tube wound around the heating block, the conversion tube is filled with a granular metal catalyst, a ceramic fiber insulation layer is filled between the heating block and the outer shell, and a fixing column is provided in the ceramic fiber insulation layer.

5. The device according to claim 4, characterized in that A heating rod and a temperature measuring resistor are provided on the heating block, and control lines of the temperature measuring resistor and the heating rod are led out to the control circuit through reserved via holes.

6. The device according to claim 1, wherein It also includes a wastewater and waste gas discharge port, which is respectively connected to the dust removal and dehumidification filter, the EA port and the EB port of the two-position five-way valve for removing the filtered gas or moisture.

7. The device according to claim 1, wherein It also includes that when the compressor is started, the P port and the N port of the first solenoid valve are connected and the air is discharged through the N port. After the compressor is started normally, the first solenoid valve is controlled to be powered on and switched to be connected between the P port and the A port.

8. The device according to claim 2, wherein The cooler is composed of a spiral metal gas pipe and a fan, and the metal gas pipe is arranged at the outlet of the hydrocarbon removal device.

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