Diffusion simulation test method and device for gas dissolved in oil

Abstract

The invention belongs to the technical field of oil-immersed transformer fault analysis, and discloses a diffusion simulation test method and device for gas dissolved in oil, and the method comprises the steps: building an oil input and gas extraction channel based on a gas transportation switch assembly at the top of a cylinder body, pressure difference is created through a gas vacuum pump, and oil filling operation is completed; a gas vacuum pump and a three-way ball valve are utilized to vacuumize and exhaust bubbles in oil in the cylinder body and air at the top of an oil surface, so that vacuum degassing operation is completed; performing gas injection operation, and simulating a sudden fault and a latent fault of the transformer according to different gas injection modes; based on the gas injection operation, oil sample extraction during the gas injection operation is carried out, and the oil supplementing operation of the test device is completed according to the liquid level position change. According to the invention, the diffusion rule of the dissolved gas in the oil under the discharge fault condition of the transformer can be simulated, and support is provided for more accurate understanding of the development process of the discharge fault of the transformer.

Description

Technical Field

[0001] The invention relates to the technical field of oil-immersed transformer fault analysis, and in particular to a diffusion simulation test method and device for gas dissolved in oil. Background Art

[0002] Dissolved Gas Analysis (DGA) is one of the important means of fault analysis for oil-immersed transformers, and has a significant effect on diagnosing potential faults inside the transformer and their development degree. However, due to the complex internal structure of the transformer, the installation of physical gas sensors faces many challenges, resulting in limited types and quantities of internal sensors, which can usually only provide data at local locations and are difficult to obtain distributed sensing information.

[0003] In practice, the oil dissolved gas analysis diagnostic method relies on chromatographic analysis of a single oil sample extracted from the transformer. Due to the limited number and distribution of oil sampling locations, this method is difficult to fully reflect the diffusion of dissolved gases in the transformer tank and oil circuit, thus affecting the accurate assessment of the occurrence and development of discharge faults in the transformer.

[0004] In terms of experimental equipment, the main technology currently used is the analysis and testing technology of dissolved gas in oil, but these tests often fail to fully consider the diffusion characteristics of dissolved gas and the spatial and time-varying distribution of dissolved gas during the occurrence and development of faults.

[0005] Therefore, how to provide a device that simulates the diffusion behavior of dissolved gas in oil under transformer discharge fault conditions in view of the complexity of the actual operating environment of the transformer, so as to reveal the spatial and time-varying distribution law of gas inside the transformer and provide support for a more accurate understanding of the development process of transformer discharge faults has become an urgent problem to be solved. Summary of the invention

[0006] The embodiment of the present invention provides a diffusion simulation test method and device for dissolved gas in oil, so as to solve the problem that it is difficult to fully reflect the diffusion condition of dissolved gas in the transformer oil tank and oil circuit in the prior art, and fails to fully consider the diffusion characteristics of dissolved gas and the spatial time-varying distribution of dissolved gas during the fault occurrence process, which affects the accurate evaluation of the occurrence and development process of discharge fault in the transformer.

[0007] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be a general review, nor is it intended to identify key / important components or to delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0008] According to a first aspect of an embodiment of the present invention, a diffusion simulation test method for dissolved gas in oil is provided.

[0009] In one embodiment, the diffusion simulation test method of dissolved gas in oil includes:

[0010] Based on the gas transport switch assembly on the top of the cylinder body, a three-way ball valve and an oil-passing valve are used to establish oil input and gas extraction channels, and a pressure difference is created through a gas vacuum pump. The oil-passing valve is adjusted according to the specified liquid level position to complete the oil filling operation of the test device.

[0011] According to the cylinder body after oil filling, use the gas vacuum pump and the three-way ball valve to exhaust the bubbles in the oil in the cylinder body and the air on the top of the oil surface by vacuuming, and adjust the valve state of the three-way ball valve according to the pressure indication number to complete the vacuum degassing operation of the test device;

[0012] Based on the cylinder body after vacuum degassing, the gas transport switch assembly and the micro-injection pump are used to perform the gas injection operation of the test device by adjusting the valve state and controlling the gas injection parameters. According to different gas injection modes, the sudden faults and latent faults of the transformer are simulated.

[0013] Based on the gas injection operation of the test device, the gas transport switch assembly and the three-way ball valve are used to adjust the valve state, and oil samples are extracted during the gas injection operation. According to the changes in the liquid level position, the oil replenishment operation of the test device is completed.

[0014] In one embodiment, based on the gas transport switch assembly at the top of the cylinder body, a three-way ball valve and an oil-passing valve are used to establish an oil input and gas extraction channel, and a pressure difference is created by a gas vacuum pump. The oil-passing valve is adjusted according to the specified liquid level position to complete the oil filling operation of the test device, including:

[0015] Based on the structure of the cylinder body, an oil-through valve and a gas-transport switch assembly are used to connect the oil input channel and the gas extraction channel through pipelines;

[0016] According to the sealing requirements of the cylinder body, the first three-way ball valve and the second three-way ball valve are used to adjust the valve switch state to obtain a sealed oil-filled environment;

[0017] Based on the principle of pressure difference, a gas vacuum pump is used to extract the gas in the cylinder body, so that the oil is automatically injected into the cylinder body until the oil reaches the specified liquid level position in the cylinder body, completing the oil filling operation.

[0018] In one embodiment, the oil input channel is composed of an oil valve at the bottom of the cylinder body and an oil pipeline connected to the oil valve, and the other end of the oil pipeline is placed in the oil;

[0019] The gas extraction channel is composed of a second three-way ball valve in the gas transport switch assembly at the top of the cylinder body, a gas pipeline connected to the valve port at the side end of the second three-way ball valve, and a gas vacuum pump connected to the other end of the gas pipeline.

[0020] In one embodiment, according to the cylinder body after oil filling, using a gas vacuum pump and a three-way ball valve, the bubbles in the oil in the cylinder body and the air on the top of the oil surface are exhausted by vacuuming, and the valve state of the three-way ball valve is adjusted according to the pressure indication number to complete the vacuum degassing operation of the test device, which includes:

[0021] Based on the cylinder body after oil filling, a communication channel between the cylinder body and the gas vacuum pump is established by adjusting the valve position using the second three-way ball valve;

[0022] According to the vacuum degassing principle, a gas vacuum pump is used to gradually reduce the pressure inside the cylinder body by continuous pumping, and the pressure change is monitored by the indication of the pressure gauge;

[0023] Based on the preset target pressure value, the second three-way ball valve is used to control the connection state between the cylinder body and the airbag by adjusting the valve position to complete the vacuum degassing operation.

[0024] In one embodiment, based on the cylinder body after vacuum degassing, the gas transport switch assembly and the micro-injection pump are used to perform the gas injection operation of the test device by adjusting the valve state and controlling the gas injection parameters, and according to different gas injection modes, the sudden faults and latent faults of the transformer are simulated, including:

[0025] According to the cylinder body after vacuum degassing, a gas injection channel between the cylinder body and the air bag is established by controlling the valve switches using the second three-way ball valve and the first two-way ball valve;

[0026] Based on the air inlet of the second two-way ball valve, a micro-injection pump is connected through a gas pipeline to perform timed and quantitative gas injection;

[0027] Based on different fault simulation requirements, the parameter adjustment function of the micro-injection pump is used to set different gas flow rates and injection times to obtain fast gas injection mode and slow gas injection mode. According to the fast gas injection mode and slow gas injection mode, the sudden faults and latent faults of the transformer are simulated.

[0028] In one embodiment, the rapid gas injection mode includes setting the flow parameters and injection time of the microinjection pump so that the gas injection rate is greater than a first preset threshold value and the gas injection time is less than the first preset time;

[0029] The slow gas injection mode includes setting the flow parameters and injection time of the microinjection pump so that the gas injection rate is less than a second preset threshold, the gas injection time is greater than the second preset time, and the second preset threshold is less than the first preset threshold, and the second preset time is greater than the first preset time;

[0030] The sudden fault of the transformer includes a fault condition in which a gas amount greater than a first preset amount is generated within a time period less than a first preset time;

[0031] The latent fault of the transformer includes a fault condition in which a gas amount less than a second preset gas amount is continuously generated for a time period greater than a second preset time, and the second preset gas amount is less than the first preset gas amount.

[0032] In one embodiment, based on the gas injection operation of the test device, the valve state is adjusted by using the gas transport switch assembly and the three-way ball valve, and oil samples are extracted during the gas injection operation. According to the change in the liquid level position, the oil replenishment operation of the test device is completed, including:

[0033] The internal temperature of the cylinder body is adjusted by using a heating resistor, and the pressure balance state inside and outside the cylinder body is established by adjusting the second three-way ball valve;

[0034] According to the oil sampling standard, the first three-way ball valve and the syringe are used to obtain the specified volume of oil sample during the gas injection operation by flushing the pipeline, adjusting the valve state and performing the sampling operation;

[0035] Based on the change of the liquid level position in the cylinder body, a syringe and a gas transport switch assembly are used to inject new oil by adjusting the second three-way ball valve to complete the replenishment of the oil in the cylinder body.

[0036] In one embodiment, according to the oil sampling standard, using the first three-way ball valve and the syringe, by flushing the pipeline, adjusting the valve state and performing the sampling operation, obtaining the oil sample of the specified volume during the gas injection operation includes:

[0037] Insert the syringe into the first three-way ball valve interface and fix it to obtain a sampling connection pipeline, and adjust the first three-way ball valve until the side valve port is connected to the cylinder body;

[0038] Flush the sampling connection pipeline, connect the syringe and the cylinder body and flush the syringe, adjust the first three-way ball valve to the side valve port to communicate with the syringe, and empty the oil sample in the syringe;

[0039] By adjusting the first three-way ball valve to connect the syringe with the cylinder body, a specified volume of oil sample is obtained to complete a single oil sample extraction.

[0040] According to a second aspect of an embodiment of the present invention, a diffusion simulation test device for dissolved gas in oil is provided.

[0041] In one embodiment, the diffusion simulation test device for dissolved gas in oil includes a cylindrical body, with circular cover plates symmetrically arranged at the top and bottom ends of the cylindrical body, the circular cover plate and the cylindrical body being connected by a plurality of screws, and a sealing assembly being arranged between the circular cover plate and the cylindrical body, and an exhaust one-way valve and a pressure gauge are arranged through one side of the top of the circular cover plate at the top end of the cylindrical body.

[0042] In one embodiment, a plurality of equidistant and evenly arranged oil extraction port assemblies are provided through one side of the cylindrical body, a gas transport switch assembly is provided on the top of the circular cover plate at the top of the cylindrical body, and a conical assembly connected to the gas transport switch assembly is provided through the inner side of the circular cover plate at the top of the cylindrical body.

[0043] In one embodiment, the sealing assembly includes an annular groove formed on the outer side of the bottom end of the circular cover plate, and an O-shaped sealing ring matched with the cylindrical body is arranged in the annular groove.

[0044] In one embodiment, the oil extraction port assembly includes a mounting through hole opened on one side of the cylindrical body, a first three-way ball valve is arranged at one end of the mounting through hole, and a threaded groove matching the first three-way ball valve is opened on the inner side of the mounting through hole.

[0045] In one embodiment, the gas transport switch assembly includes a second three-way ball valve arranged in the middle of a circular cover plate passing through the top of the cylinder body, a first two-way ball valve is arranged at the top of the second three-way ball valve, and the top of the first two-way ball valve is connected to the airbag through a quick-connect connector.

[0046] In one embodiment, the conical component includes a funnel-shaped ventilation groove opened on the inner side of the bottom end of the circular cover plate at the top end of the cylindrical body, the top end of the funnel-shaped ventilation groove passes through the circular cover plate to open a fixed through hole, the top end of the fixed through hole is provided with a second three-way ball valve, and the inner side of the fixed through hole is provided with a threaded groove that cooperates with the second three-way ball valve.

[0047] In one embodiment, a second two-way ball valve is provided through the middle of the bottom of the circular cover plate at the bottom end of the cylindrical body, and the bottom end of the second two-way ball valve is connected to the microinjection pump, an oil valve is provided through one side of the bottom of the circular cover plate at the bottom end of the cylindrical body, and a plurality of tripods arranged in a circle are provided on the outer side of the bottom of the circular cover plate at the bottom end of the cylindrical body, and a bracket is provided at the bottom end of the tripod.

[0048] In one embodiment, a heating resistor wire is provided through the top of the inner side of the cylinder body, a U-shaped oil channel pipe is provided on the side of the cylinder body away from the oil extraction port assembly, and a plurality of insulating cardboards are suspended in the middle of the inner side of the cylinder body.

[0049] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0050] (1) The present invention can simulate the diffusion law of dissolved gas in oil under transformer discharge fault conditions, and integrates the functions of oil injection, vacuum degassing, trace timed and quantitative gas injection, oil sample extraction, oil flow circulation, and uneven temperature distribution. A plurality of oil sampling points are arranged at equal intervals at different heights from top to bottom, and the concentration of dissolved gas in the oil sample can be detected in conjunction with a gas chromatograph, thereby exploring the diffusion law of dissolved gas in the oil tank, and providing support for a more accurate understanding of the development process of transformer discharge faults.

[0051] (2) The test device of the present invention is designed with a conical component on the inner side of the circular cover plate at the top of the cylindrical body. By constructing a passage for free gas, it is convenient to collect the free gas. Combined with the gas transport switch component and the air bag, it can separate the free gas from the transformer oil, preventing the free gas from continuing to dissolve on the liquid surface and interfering with the test results. At the same time, the concentration of dissolved gas in the oil, the oil volume, the gas volume in the air bag and the gas injection volume at equilibrium can be used to determine and verify the free amount and dissolved amount of gas.

[0052] (3) The test device of the present invention can realize the filling of transformer oil into the cylinder body and the vacuum operation of the cylinder body through the gas transport switch assembly at the top of the cylinder body and the oil valve at the bottom of the cylinder body, so as to eliminate the interference of tiny bubbles in the initial oil sample on the test.

[0053] (4) The design of the test device of the present invention also takes into account the actual operating conditions of the transformer, the uneven internal temperature distribution and the adsorption effect of oil flow and insulating cardboard, so that the test results are closer to the real transformer.

[0054] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0056] Figure 1 It is a schematic flow chart of a diffusion simulation test method of dissolved gas in oil according to an exemplary embodiment;

[0057] Figure 2 It is a structural schematic diagram of a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0058] Figure 3 is a top view of a cylinder body in a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0059] Figure 4 is a bottom view of a cylinder body in a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0060] Figure 5 It is a structural schematic diagram of a sealing component in a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0061] Figure 6 It is a structural schematic diagram of an oil inlet assembly in a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0062] Figure 7 It is a structural schematic diagram of a gas transport switch assembly in a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0063] Figure 8 It is a structural schematic diagram of a cone assembly in a diffusion simulation test device for dissolved gas in oil according to an exemplary embodiment;

[0064] Fig. 9 It is a schematic diagram of an oil sample extraction process in a diffusion simulation test method of dissolved gas in oil according to an exemplary embodiment.

[0065] In the figure:

[0066] 1. First three-way ball valve; 2. Screws; 3. O-ring; 4. Exhaust check valve; 5. Pressure gauge; 6. Air bag; 7. Round cover plate; 8. Cylinder body; 9. Oil valve; 10. Bracket; 11. Tripod; 12. First two-way ball valve; 13. Heating resistor wire; 14. Insulating cardboard; 15. Micro-injection pump; A. Sealing assembly; B. Oil inlet assembly; C. Gas transport switch assembly; D. Conical assembly. DETAILED DESCRIPTION

[0067] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0068] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used herein to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this article and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description herein, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal connection of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0069] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0070] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0071] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0072] It should be understood that, although the various steps in the flow chart are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0073] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0074] Figure 1 An embodiment of a diffusion simulation test method of dissolved gas in oil according to the present invention is shown.

[0075] In this optional embodiment, the diffusion simulation test method of dissolved gas in oil includes:

[0076] Step S101: Based on the gas transport switch assembly C on the top of the cylinder body 8, a three-way ball valve and an oil valve 9 are used to establish an oil input and gas extraction channel, and a pressure difference is created by a gas vacuum pump. The oil valve 9 is adjusted according to the specified liquid level position to complete the oil filling operation of the test device;

[0077] Specifically, a diffusion simulation test method of dissolved gas in oil of the present invention comprises ① filling the test device with oil; ② vacuum degassing; ③ injecting gas into the test device; and ④ extracting oil samples during the diffusion process of dissolved gas.

[0078] Specifically, ① filling the test device with oil. The components and structures required in this step are mainly the oil valve 9 at the bottom of the cylinder body 8 and the gas transport switch assembly C at the top of the cylinder body 8.

[0079] Specifically, the oil valve 9 at the bottom of the cylinder body 8 is connected to a pipeline, and the other end of the pipeline is placed in the oil. The side valve port of the second three-way ball valve in the gas transport switch assembly C at the top of the cylinder body 8 is connected to the gas vacuum pump through a pipeline. Before filling the oil, check whether the six first three-way ball valves 1 on the side wall of the cylinder body 8 are closed. If they are correct, adjust the second three-way ball valve in the top gas transport switch assembly C to connect the side of the cylinder body 8 with the side valve port, then open the oil valve 9 at the bottom of the cylinder body 8, turn on the air vacuum pump, and let the transformer oil enter the cylinder body 8 through the oil valve 9 through the pressure difference between the inside and outside of the cylinder body 8. When the liquid level in the cylinder body 8 reaches the specified position, close the bottom oil valve 9 to complete the oil filling operation of the cylinder body 8.

[0080] Step S103, according to the cylinder body 8 filled with oil, use the gas vacuum pump and the three-way ball valve to exhaust the bubbles in the oil and the air on the top of the oil surface by vacuuming, and adjust the valve state of the three-way ball valve according to the indication of the pressure gauge 5 to complete the vacuum degassing operation of the test device;

[0081] Specifically, ② vacuum degassing. The components and structures required for this step are mainly the gas transport switch assembly C at the top of the cylinder body 8.

[0082] Specifically, the side valve port of the second three-way ball valve in the gas transport switch assembly C at the top of the cylinder body 8 is connected to the gas vacuum pump through a pipeline, and the second three-way ball valve in the top gas transport switch assembly C is adjusted to connect the cylinder body 8 side with the side valve port, turn on the air vacuum pump, observe the pressure display, and when the pressure reaches the specified position, adjust the second three-way ball valve to connect the cylinder body 8 side with the air bag side. The tiny bubbles in the oil and the air on the top of the oil surface are discharged by vacuuming to prevent interference with the test results.

[0083] Step S105: Based on the cylinder body 8 after vacuum degassing, the gas transport switch assembly C and the micro-injection pump 15 are used to perform the gas injection operation of the test device by adjusting the valve state and controlling the gas injection parameters, and according to different gas injection modes, the sudden fault and latent fault of the transformer are simulated;

[0084] Specifically, ③ gas injection of the test device. The components and structures required for this step are mainly the gas transport pipeline structure at the bottom of the cylinder body 8 and the micro-injection pump 15.

[0085] Specifically, the second three-way ball valve in the gas transport switch assembly C is adjusted to the state that the cylinder body is connected to the airbag 6, the first two-way ball valve 12 in the gas transport switch assembly C is opened, and the switch of the airbag 6 is opened at the same time, so that the airbag 6 is connected to the cylinder body 8 and the U-shaped oil channel pipe. The threaded through hole set at the center of the bottom circular cover plate 7 is connected to the second two-way ball valve for gas injection. The device supports fast gas injection and slow gas injection, that is, the micro-injection pump 15 is installed with a syringe to connect the second two-way ball valve inlet at the bottom of the cylinder body 8 through the gas pipeline, the second two-way ball valve at the bottom of the cylinder body 8 is opened, the flow rate of the micro-injection pump 15 is set, and the gas injection is performed in a timed and quantitative manner. By adjusting the parameters of the injection pump, fast gas injection can be achieved to simulate sudden transformer failures (short gas production time, large instantaneous gas production) and slow gas injection can be achieved to simulate latent transformer failures (long gas production duration, slow gas production speed).

[0086] Step S107, based on the gas injection operation of the test device, the valve state is adjusted using the gas transport switch assembly C and the three-way ball valve, and oil samples are extracted during the gas injection operation, and the oil replenishment operation of the test device is completed according to the change in the liquid level position.

[0087] Specifically, ④ Extraction of oil samples during the dissolved gas diffusion process. This step extracts oil samples during the gas injection operation of the test device, simulates the extraction of oil samples during the dissolved gas diffusion process, and replenishes the oil of the test device.

[0088] Specifically, when the temperature of the heating resistor 13 reaches a stable state, gas is injected into the cylinder body 8 according to step ③. At this time, the second three-way ball valve of the gas transport switch assembly C on the top of the cylinder body 8 is adjusted to allow the cylinder body 8 to communicate with the outside, or a high-purity nitrogen bottle is connected through a pipeline (to prevent the gas components in the air from interfering with the test), so that the air pressure in the cylinder body 8 is greater than or equal to the outside air pressure, which is convenient for subsequent oil sample extraction. At fixed intervals, oil samples are extracted from the six first three-way ball valves 1 on the side of the cylinder body 8 through the oil extraction port assembly B. The extraction operation is performed in accordance with the oil sampling standard (in this embodiment, the oil sampling method GB7252): insert the glass syringe into the interface of the first three-way ball valve 1 and fix it, adjust the first three-way ball valve 1 to connect the cylinder body 8 with the side end valve port, flush the connecting pipeline, then connect the syringe and the cylinder body 8, flush the syringe, then adjust the first three-way ball valve 1 to connect the syringe with the side end valve port, empty the oil sample in the syringe, then connect the syringe with the cylinder body 8, and take out 40ml of oil sample. The connection operation diagram is shown in Fig. 9 shown.

[0089] Specifically, considering that the liquid level in the cylinder body 8 drops after multiple oil samplings, after each oil sampling, a glass syringe is filled with new oil to connect the side valve port of the second three-way ball valve of the gas transport switch assembly C, the second three-way ball valve is adjusted to be connected to the cylinder body 8, and the oil is slowly injected to replenish the oil.

[0090] In this optional embodiment, based on the gas transport switch assembly C on the top of the cylinder body 8, a three-way ball valve and an oil valve 9 are used to establish an oil input and gas extraction channel, and a pressure difference is created by a gas vacuum pump. The oil valve 9 is adjusted according to the specified liquid level position to complete the oil filling operation of the test device, including:

[0091] Step S1011, based on the structure of the cylinder body 8, using the bottom oil valve 9 and the top gas transport switch assembly C, through pipeline connection, to establish an oil input channel and a gas extraction channel;

[0092] Step S1013, according to the sealing requirements of the cylinder body 8, using the first three-way ball valve 1 on one side and the second three-way ball valve on the top, by adjusting the valve switch state, a sealed oil-filled environment is obtained;

[0093] Step S1015: Based on the pressure difference principle, a gas vacuum pump is used to extract the gas in the cylinder body, so that the oil is automatically injected into the cylinder body 8 until the oil reaches the specified liquid level position in the cylinder body 8, thereby completing the oil filling operation.

[0094] In this optional embodiment, the oil input channel is composed of an oil valve 9 at the bottom of the cylinder body 8 and an oil pipeline connected to the oil valve 9, and the other end of the oil pipeline is placed in the oil;

[0095] The gas extraction channel is composed of a second three-way ball valve in the gas transport switch assembly C at the top of the cylinder body 8, a gas pipeline connected to the side valve port of the second three-way ball valve, and a gas vacuum pump connected to the other end of the gas pipeline.

[0096] In this optional embodiment, according to the cylinder body 8 filled with oil, a gas vacuum pump and a three-way ball valve are used to exhaust tiny bubbles in the oil and air on the top of the oil surface by vacuuming, and the valve state of the three-way ball valve is adjusted according to the indication of the pressure gauge 5 to complete the vacuum degassing operation of the test device, which includes:

[0097] Step S1031: Based on the cylinder body 8 filled with oil, a communication channel between the cylinder body 8 and the gas vacuum pump is established by adjusting the valve position using the second three-way ball valve;

[0098] Step S1033, according to the vacuum degassing principle, using a gas vacuum pump, gradually reduce the pressure in the cylinder body 8 by continuous pumping, and monitor the pressure change through the indication of the pressure gauge 5;

[0099] Step S1035: Based on the preset target pressure value, the second three-way ball valve is used to control the connection state between the cylinder body 8 and the airbag 6 by adjusting the valve position to complete the vacuum degassing operation.

[0100] In this optional embodiment, based on the cylinder body 8 after vacuum degassing, the gas transport switch assembly C and the micro-injection pump 15 are used to perform the gas injection operation of the test device by adjusting the valve state and controlling the gas injection parameters, and according to different gas injection modes, the sudden faults and latent faults of the transformer are simulated, including:

[0101] Step S1051, based on the cylinder body 8 after vacuum degassing, using the second three-way ball valve and the first two-way ball valve 12, by controlling the valve switches, a gas injection channel is established between the cylinder body 8 and the airbag 6;

[0102] Step S1053, based on the air inlet of the second two-way ball valve, connect the micro-injection pump 15 through the air delivery pipeline to perform timed and quantitative gas injection;

[0103] Step S1055, based on different fault simulation requirements, using the parameter adjustment function of the micro-injection pump 15, by setting different gas flow rates and injection times, a fast gas injection mode and a slow gas injection mode are obtained, and according to the fast gas injection mode and the slow gas injection mode, sudden faults and latent faults of the transformer are simulated.

[0104] In this optional embodiment, the rapid gas injection mode includes setting the flow parameters and injection time of the microinjection pump 15 so that the gas injection rate is greater than the first preset threshold value and the gas injection time is less than the first preset time;

[0105] The slow gas injection mode includes setting the flow parameters and injection time of the microinjection pump 15 so that the gas injection rate is less than the second preset threshold, the gas injection time is greater than the second preset time, and the second preset threshold is less than the first preset threshold, and the second preset time is greater than the first preset time;

[0106] The sudden fault of the transformer includes a fault condition in which a gas volume greater than a first preset amount is generated within a time period less than a first preset time, specifically, such as local overheating of the transformer, arc discharge, etc.;

[0107] The latent fault of the transformer includes a fault condition in which a gas quantity less than a second preset gas quantity is continuously generated within a time period greater than the second preset time, and the second preset gas quantity is less than the first preset gas quantity, specifically, such as local low-temperature overheating and partial discharge of the transformer.

[0108] In this optional embodiment, based on the gas injection operation of the test device, the gas transport switch assembly C and the three-way ball valve are used to adjust the valve state, and oil samples are extracted during the gas injection operation. According to the change in the liquid level position, the oil replenishment operation of the test device is completed, including:

[0109] Step S1071, using the heating resistor 13 to adjust the temperature inside the cylinder body 8, and by adjusting the second three-way ball valve, establishing a pressure balance inside and outside the cylinder body 8;

[0110] Step S1073, according to the oil sampling standard, using the first three-way ball valve 1 and the syringe, by flushing the pipeline, adjusting the valve state and performing the sampling operation, obtain the oil sample of the specified volume during the gas injection operation;

[0111] Step S1075: Based on the change in the liquid level position in the cylinder body 8, new oil is injected by adjusting the second three-way ball valve using a syringe and a gas transport switch assembly C to complete the replenishment of the oil in the cylinder body 8.

[0112] In this optional embodiment, according to the oil sampling standard, by using the first three-way ball valve 1 and the syringe, by flushing the pipeline, adjusting the valve state and performing the sampling operation, the oil sample of the specified volume during the gas injection operation is obtained, including:

[0113] Step S10731, insert the syringe into the interface of the first three-way ball valve 1 and fix it to obtain a sampling connection pipeline, and adjust the first three-way ball valve 1 until the side valve port is connected to the cylinder body 8;

[0114] Step S10733, flushing the sampling connection pipeline, connecting the syringe and the cylinder body 8 and flushing the syringe, adjusting the first three-way ball valve 1 to connect the side valve port with the syringe, and emptying the oil sample in the syringe;

[0115] Step S10735: adjust the first three-way ball valve 1 to connect the syringe with the cylinder body 8 to obtain a specified volume of oil sample, thereby completing a single oil sample extraction.

[0116] Figure 2-Figure 8 An embodiment of a diffusion simulation test device for dissolved gas in oil according to the present invention is shown.

[0117] In this optional embodiment, the diffusion simulation test device of dissolved gas in oil includes a cylindrical body 8, and circular cover plates 7 are symmetrically arranged at the top and bottom ends of the cylindrical body 8. The circular cover plate 7 is connected to the cylindrical body 8 by a plurality of screws 2, and a sealing assembly A is arranged between the circular cover plate 7 and the cylindrical body 8. An exhaust one-way valve 4 and a pressure gauge 5 are penetrated on one side of the top of the circular cover plate 7 at the top of the cylindrical body 8.

[0118] In this optional embodiment, a plurality of equidistant and evenly arranged oil extraction port assemblies B are provided through one side of the cylindrical body 8, a gas transport switch assembly C is provided on the top of the circular cover plate 7 at the top end of the cylindrical body 8, and a conical assembly D connected to the gas transport switch assembly C is provided through the inner side of the circular cover plate 7 at the top end of the cylindrical body 8.

[0119] In this optional embodiment, the sealing assembly A includes an annular groove formed on the outer side of the bottom end of the circular cover plate 7 , and an O-ring 3 matching with the cylindrical body 8 is disposed in the annular groove.

[0120] In this optional embodiment, the oil extraction port assembly B includes a mounting through hole opened on one side of the cylindrical body 8, a first three-way ball valve 1 is arranged at one end of the mounting through hole, and a threaded groove matching the first three-way ball valve 1 is opened on the inner side of the mounting through hole.

[0121] In this optional embodiment, the gas transport switch assembly C includes a second three-way ball valve arranged in the middle of the circular cover plate 7 that passes through the top of the cylindrical body 8, and a first two-way ball valve 12 is arranged at the top of the second three-way ball valve. The top of the first two-way ball valve 12 is connected to the airbag 6 through a quick-connect connector.

[0122] In this optional embodiment, the conical component D includes a funnel-shaped ventilation groove opened on the inner side of the bottom end of the circular cover plate 7 at the top end of the cylindrical body 8, and a fixed through hole is opened at the top end of the funnel-shaped ventilation groove through the circular cover plate 7, and a second three-way ball valve is provided at the top end of the fixed through hole, and a threaded groove matching the second three-way ball valve is opened on the inner side of the fixed through hole.

[0123] In this optional embodiment, a second two-way ball valve is provided through the middle of the bottom of the circular cover plate 7 at the bottom end of the cylindrical body 8, and the bottom end of the second two-way ball valve is connected to the microinjection pump 15, an oil valve 9 is provided through one side of the bottom of the circular cover plate 7 at the bottom end of the cylindrical body 8, and a plurality of tripods 11 arranged in a circle are provided on the outer side of the bottom of the circular cover plate 7 at the bottom end of the cylindrical body 8, and a bracket 10 is provided at the bottom end of the tripod 11.

[0124] In this optional embodiment, a heating resistor wire 13 is provided through the top of the inner side of the cylindrical body 8, a U-shaped oil channel pipe is provided on the side of the cylindrical body 8 away from the oil extraction port assembly B, and a number of insulating cardboards 14 are suspended in the middle of the inner side of the cylindrical body 8.

[0125] In order to facilitate understanding of the above technical solution of the present invention, the following is a detailed description of the device structure connection relationship and component functions of a diffusion simulation test device for dissolved gas in oil of the present invention as follows:

[0126] Specifically, in the above embodiment, the diffusion simulation test device of dissolved gas in oil includes a cylindrical body 8 made of acrylic material with a thickness of 3 cm and two upper and lower circular cover plates 7 made of acrylic material with a thickness of 3 cm. The cylindrical body 8 and the upper and lower circular cover plates 7 are connected by 6 screws 2, and an O-ring 3 is sandwiched between the circular cover plates 7 and the cylindrical body 8 to ensure airtightness.

[0127] Specifically, in the above embodiment, a conical component D is processed at the central position of the inner side of the top circular cover plate 7 to guide the gas to flow upward, a threaded through hole is arranged in the middle of the top circular cover plate 7 to connect the second three-way ball valve, the first two-way ball valve 12 is connected above the second three-way ball valve, and the other side of the first two-way ball valve 12 is connected to the airbag 6 through a pipeline via a quick-connect connector; the valve port on the other side of the second three-way ball valve is connected to a vacuum pump (not shown in the figure) for evacuating the cylinder body 8; the airbag 6 is used to collect free gas in the cylinder body 8 and balance the internal pressure of the cylinder body 8, and the airbag 6 pipeline connection is provided with a switch structure to prevent gas leakage during disassembly.

[0128] Specifically, the quick-insert connector facilitates the disassembly of the airbag 6; the top circular cover plate 7 is provided with threaded through holes at two other positions, which are respectively connected to the pressure gauge 5 and the exhaust check valve 4, wherein the pressure gauge 5 is used to measure the internal pressure of the cylinder body 8, and the exhaust check valve 4 is used to balance the pressure to prevent damage caused by excessive internal pressure of the cylinder body 8.

[0129] Specifically, six threaded through holes are evenly spaced on the side of the cylindrical body 8 and connected to the first three-way ball valve 1 as an oil extraction port assembly B for connecting a 100 ml glass syringe (not shown) to extract oil samples.

[0130] Specifically, a threaded through hole connected to a second two-way ball valve for gas injection is provided at the center of the bottom circular cover plate 7, and a threaded through hole connected to an oil valve 9 is provided at another position of the bottom circular cover plate 7 for discharge and introduction of insulating oil in the cylindrical body 8.

[0131] Specifically, the bottom circular cover plate 7 is connected to four tripods 11 by gluing to support the cylinder body 8, and a metal bracket 10 is connected below the tripod 11 by gluing to elevate the cylinder body 8 for facilitating the injection of gas.

[0132] Specifically, the purpose of the heating resistor 13 is to simulate the internal temperature of the transformer, and the heating resistor 13 is placed only at the top position to ensure uneven temperature distribution between the upper and lower parts. The external lead wires of the heating resistor 13 support adjusting different temperatures to simulate different operating loads of the transformer.

[0133] Specifically, the purpose of the U-shaped oil passage is to simulate internal oil flow circulation. When the temperature distribution is uneven, the oil flow will form a circulation flow through the inside of the U-shaped oil passage.

[0134] Specifically, two insulating paperboards 14 are suspended in the cylindrical body 8 to simulate the adsorption effect of the insulating material on part of the diffusing gas.

[0135] Specifically, the purpose of the micro-injection pump 15 is to simulate the gas content and gas production rate corresponding to different energy discharge fault sizes inside the transformer. The micro-injection pump 15 can support gas content and injection gas rate to simulate fast gas injection and slow gas injection.

[0136] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A diffusion simulation test method for dissolved gas in oil, characterized in that: The diffusion simulation test method of dissolved gas in oil includes: Based on the gas transport switch assembly on the top of the cylinder body, a three-way ball valve and an oil-passing valve are used to establish oil input and gas extraction channels, and a pressure difference is created through a gas vacuum pump. The oil-passing valve is adjusted according to the specified liquid level position to complete the oil filling operation of the test device. According to the cylinder body after oil filling, use the gas vacuum pump and the three-way ball valve to exhaust the bubbles in the oil in the cylinder body and the air on the top of the oil surface by vacuuming, and adjust the valve state of the three-way ball valve according to the pressure indication number to complete the vacuum degassing operation of the test device; Based on the cylinder body after vacuum degassing, the gas transport switch assembly and the micro-injection pump are used to perform the gas injection operation of the test device by adjusting the valve state and controlling the gas injection parameters. According to different gas injection modes, the sudden faults and latent faults of the transformer are simulated. Based on the gas injection operation of the test device, the gas transport switch assembly and the three-way ball valve are used to adjust the valve state, and oil samples are extracted during the gas injection operation. According to the changes in the liquid level position, the oil replenishment operation of the test device is completed.

2. The diffusion simulation test method of dissolved gas in oil according to claim 1, characterized in that: The gas transport switch assembly based on the top of the cylinder body uses a three-way ball valve and an oil valve to establish an oil input and gas extraction channel, and creates a pressure difference through a gas vacuum pump. The oil valve is adjusted according to the specified liquid level position to complete the oil filling operation of the test device, including: Based on the structure of the cylinder body, an oil-through valve and a gas-transport switch assembly are used to connect the oil input channel and the gas extraction channel through pipelines; According to the sealing requirements of the cylinder body, the first three-way ball valve and the second three-way ball valve are used to adjust the valve switch state to obtain a sealed oil-filled environment; Based on the principle of pressure difference, a gas vacuum pump is used to extract the gas in the cylinder body, so that the oil is automatically injected into the cylinder body until the oil reaches the specified liquid level position in the cylinder body, completing the oil filling operation.

3. The diffusion simulation test method of dissolved gas in oil according to claim 2, characterized in that: The oil input channel is composed of an oil valve at the bottom of the cylinder body and an oil pipeline connected to the oil valve, and the other end of the oil pipeline is placed in the oil; The gas extraction channel is composed of a second three-way ball valve in the gas transport switch assembly at the top of the cylinder body, a gas pipeline connected to the valve port at the side end of the second three-way ball valve, and a gas vacuum pump connected to the other end of the gas pipeline.

4. The diffusion simulation test method of dissolved gas in oil according to claim 1, characterized in that: The vacuum degassing operation of the test device is completed by using a gas vacuum pump and a three-way ball valve to exhaust the bubbles in the oil in the cylinder body and the air on the top of the oil surface by vacuuming the cylinder body after filling with oil, and adjusting the valve state of the three-way ball valve according to the pressure indication number. The following includes: Based on the cylinder body after oil filling, a communication channel between the cylinder body and the gas vacuum pump is established by adjusting the valve position using the second three-way ball valve; According to the vacuum degassing principle, a gas vacuum pump is used to gradually reduce the pressure inside the cylinder body by continuous pumping, and the pressure change is monitored by the indication of the pressure gauge; Based on the preset target pressure value, the second three-way ball valve is used to control the connection state between the cylinder body and the airbag by adjusting the valve position to complete the vacuum degassing operation.

5. The diffusion simulation test method of dissolved gas in oil according to claim 1, characterized in that: The test device is based on the cylinder body after vacuum degassing, and uses the gas transport switch assembly and the micro-injection pump to perform the gas injection operation by adjusting the valve state and controlling the gas injection parameters. According to different gas injection modes, the sudden faults and latent faults of the transformer are simulated, including: According to the cylinder body after vacuum degassing, a gas injection channel between the cylinder body and the air bag is established by controlling the valve switches using the second three-way ball valve and the first two-way ball valve; Based on the air inlet of the second two-way ball valve, a micro-injection pump is connected through a gas pipeline to perform timed and quantitative gas injection; Based on different fault simulation requirements, the parameter adjustment function of the micro-injection pump is used to set different gas flow rates and injection times to obtain fast gas injection mode and slow gas injection mode. According to the fast gas injection mode and slow gas injection mode, the sudden faults and latent faults of the transformer are simulated.

6. The diffusion simulation test method of dissolved gas in oil according to claim 5, characterized in that: The rapid gas injection mode includes setting the flow parameters and injection time of the microinjection pump so that the gas injection rate is greater than a first preset threshold value and the gas injection time is less than the first preset time; The slow gas injection mode includes setting the flow parameters and injection time of the microinjection pump so that the gas injection rate is less than a second preset threshold, the gas injection time is greater than the second preset time, and the second preset threshold is less than the first preset threshold, and the second preset time is greater than the first preset time; The sudden fault of the transformer includes a fault condition in which a gas amount greater than a first preset amount is generated within a time period less than a first preset time; The latent fault of the transformer includes a fault condition in which a gas quantity less than a second preset gas quantity is continuously generated for a time period greater than a second preset time, and the second preset gas quantity is less than the first preset gas quantity.

7. The diffusion simulation test method of dissolved gas in oil according to claim 1, characterized in that: The gas injection operation based on the test device, using the gas transport switch assembly and the three-way ball valve to adjust the valve state, and extracting oil samples during the gas injection operation, and completing the oil replenishment operation of the test device according to the change of the liquid level position includes: The internal temperature of the cylinder body is adjusted by using a heating resistor, and the pressure balance state inside and outside the cylinder body is established by adjusting the second three-way ball valve; According to the oil sampling standard, the first three-way ball valve and the syringe are used to obtain the specified volume of oil sample during the gas injection operation by flushing the pipeline, adjusting the valve state and performing the sampling operation; Based on the change of the liquid level position in the cylinder body, a syringe and a gas transport switch assembly are used to inject new oil by adjusting the second three-way ball valve to complete the replenishment of the oil in the cylinder body.

8. The diffusion simulation test method of dissolved gas in oil according to claim 7, characterized in that: The method of obtaining the oil sample of the specified volume during the gas injection operation by flushing the pipeline, adjusting the valve state and performing the sampling operation according to the oil sampling standard includes: Insert the syringe into the first three-way ball valve interface and fix it to obtain a sampling connection pipeline, and adjust the first three-way ball valve until the side valve port is connected to the cylinder body; Flush the sampling connection pipeline, connect the syringe and the cylinder body and flush the syringe, adjust the first three-way ball valve to the side valve port to communicate with the syringe, and empty the oil sample in the syringe; By adjusting the first three-way ball valve to connect the syringe with the cylinder body, a specified volume of oil sample is obtained to complete a single oil sample extraction.

9. A diffusion simulation test device for dissolved gas in oil, characterized in that: The diffusion simulation test device for dissolved gas in oil includes a cylindrical body, and circular cover plates are symmetrically arranged at the top and bottom ends of the cylindrical body. The circular cover plate is connected to the cylindrical body by a plurality of screws, and a sealing component is arranged between the circular cover plate and the cylindrical body. An exhaust one-way valve and a pressure gauge are penetrated on one side of the top of the circular cover plate at the top end of the cylindrical body.

10. The diffusion simulation test device for dissolved gas in oil according to claim 9, characterized in that: A plurality of equidistant and evenly arranged oil extraction port assemblies are provided through one side of the cylindrical body, a gas transport switch assembly is provided on the top of the circular cover plate at the top end of the cylindrical body, and a conical assembly connected to the gas transport switch assembly is provided through the inner side of the circular cover plate at the top end of the cylindrical body.

11. The diffusion simulation test device for dissolved gas in oil according to claim 10, characterized in that: The sealing assembly comprises an annular groove arranged on the outer side of the bottom end of the circular cover plate, and an O-shaped sealing ring matched with the cylindrical body is arranged in the annular groove.

12. The diffusion simulation test device for dissolved gas in oil according to claim 10, characterized in that: The oil extraction port assembly comprises a mounting through hole opened on one side of the cylindrical body, a first three-way ball valve is arranged at one end of the mounting through hole, and a threaded groove matching with the first three-way ball valve is opened on the inner side of the mounting through hole.

13. The diffusion simulation test device for dissolved gas in oil according to claim 10, characterized in that: The gas transport switch assembly includes a second three-way ball valve arranged in the middle of a circular cover plate passing through the top of the cylinder body, a first two-way ball valve is arranged at the top of the second three-way ball valve, and the top of the first two-way ball valve is connected to the airbag through a quick-connect connector.

14. The diffusion simulation test device for dissolved gas in oil according to claim 10, characterized in that: The conical component includes a funnel-shaped ventilation groove opened on the inner side of the bottom end of the circular cover plate at the top end of the cylindrical body, the top end of the funnel-shaped ventilation groove passes through the circular cover plate to open a fixed through hole, the top end of the fixed through hole is provided with a second three-way ball valve, and the inner side of the fixed through hole is provided with a threaded groove that cooperates with the second three-way ball valve.

15. The diffusion simulation test device for dissolved gas in oil according to claim 10, characterized in that: A second two-way ball valve is provided through the middle of the bottom of the circular cover plate at the bottom end of the cylindrical body, and the bottom end of the second two-way ball valve is connected to a microinjection pump, an oil valve is provided through one side of the bottom of the circular cover plate at the bottom end of the cylindrical body, and a plurality of tripods arranged in a circle are provided on the outer side of the bottom of the circular cover plate at the bottom end of the cylindrical body, and a bracket is provided at the bottom end of the tripod.

16. The diffusion simulation test device for dissolved gas in oil according to claim 15, characterized in that: A heating resistor wire is provided through the top of the inner side of the cylinder body, a U-shaped oil channel pipe is provided on the side of the cylinder body away from the oil extraction port assembly, and a plurality of insulating paperboards are suspended in the middle of the inner side of the cylinder body.

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