Transformer oil temperature measuring device

Abstract

The utility model provides a transformer oil temperature measuring device which comprises a transformer box body, at least one detection hole is formed in the side face of the transformer box body from top to bottom, and the detection hole is communicated with a heat conduction pipe arranged in the transformer box body; one end of the heat conduction pipe is closed, and the other end of the heat conduction pipe is open. According to the device, the heat conduction pipe extending into the transformer box body is arranged, the temperature sensor is installed in the heat conduction pipe, the temperature sensor indirectly obtains the oil temperature in the transformer box body through the heat conduction pipe, and the purpose that the sensor does not make direct contact with transformer oil and the oil temperature in the transformer box body is obtained is achieved; the device overcomes the defects that the possibility of pollution to insulating oil of the transformer is increased due to the fact that a temperature sensor needs to extend into the transformer in an existing device for measuring the oil temperature of the transformer, the temperature sensor is inconvenient to maintain and install, and the safety and stability of the transformer are easily affected.

Description

Technical Field

[0001] This application relates to the technical field of transformers, and particularly to a transformer oil temperature measuring device. Background Art

[0002] During the operation of a power transformer connected to the grid, due to the presence of no-load loss and load loss, the transformer inevitably consumes electrical energy from the grid. After being converted into heat, it is dissipated into the external environment through the heat dissipation and cooling system. The service life of a transformer is mainly determined by the life of the insulating materials inside it. For every 6°C increase in temperature, the life of the insulating materials is reduced by half, and the service life of the transformer is also reduced by half. The oil-immersed power transformer is filled with transformer oil that plays a role in cooling and insulation. The heat generated by the transformer is dissipated into the external environment through the transformer oil. Therefore, the measurement and control of the oil temperature are the basis and key to maintaining the safe operation of the transformer.

[0003] Currently, when monitoring the oil temperature of a transformer, it is necessary to insert the tested oil temperature sensor into the transformer. However, this method has the possibility of increasing the pollution of the transformer insulating oil. At the same time, the maintenance and installation of the oil temperature sensor are inconvenient, which is likely to affect the safe and stable operation of the transformer. Utility Model Content

[0004] This application provides a transformer oil temperature measuring device to solve the problems that when monitoring the oil temperature of a transformer, inserting the oil temperature sensor into the transformer increases the possibility of polluting the transformer insulating oil, and at the same time, the maintenance and installation of the oil temperature sensor are inconvenient, which is likely to affect the safe and stable operation of the transformer.

[0005] This application provides a transformer oil temperature measuring device, which includes a transformer box body. At least one detection hole is opened on the side surface of the transformer box body from top to bottom, and the detection hole is communicated with a heat conduction tube arranged inside the transformer box body;

[0006] One end of the heat conduction tube is closed and the other end is open, and a temperature sensor is installed inside the heat conduction tube;

[0007] The temperature sensor is electrically connected to a controller arranged on one side surface of the transformer box body.

[0008] Optionally, the heat conduction tube includes a heat conduction shell;

[0009] A heat conduction layer is arranged inside the heat conduction shell;

[0010] A hollow accommodating cavity is formed in the central part of the heat conduction layer for installing the temperature sensor;

[0011] The heat conduction layer includes an outer wire mesh closely attached to the heat conduction layer and an inner wire mesh coaxially arranged with the outer wire mesh; the space between the outer wire mesh and the inner wire mesh is filled with heat conduction powder.

[0012] Optionally, multiple heat pipes are provided on the side of the transformer housing;

[0013] One end of the heat pipe passes through the side of the transformer housing and extends into the transformer housing, and the other end is located outside the transformer housing;

[0014] A plurality of heat dissipation fins are arranged on the heat pipe in an array along the axis direction of the heat pipe,

[0015] The multiple heat pipes are arranged at a certain inclination angle with the horizontal plane.

[0016] Optionally, cold fans are respectively installed at the four corners of the transformer housing;

[0017] The cold fans are fixed by a connecting frame connected to the transformer housing;

[0018] The cold fans are electrically connected to the controller.

[0019] Optionally, the transformer housing is also communicated with an oil conservator installed above the transformer housing through a pipeline provided with a gas relay;

[0020] An air bag is arranged in the oil conservator, and the air bag is communicated with an air filter box through a pipeline.

[0021] Optionally, one end of the air filter box is communicated with the oil conservator through a pipeline, and the other end is provided with an opening and is communicated with the atmosphere;

[0022] The air filter box is sequentially provided with a first filter screen layer, a first activated carbon adsorption layer, a discolored silica gel layer, a second activated carbon adsorption layer and a second filter screen layer along the gas inlet direction.

[0023] Optionally, the heat pipe is arranged at an inclination angle of 15 to 75° with the horizontal plane.

[0024] The transformer oil temperature measuring device of the present application is provided with a heat conduction pipe extending into the transformer housing, and a temperature sensor is installed in the heat conduction pipe. The temperature sensor indirectly obtains the oil temperature in the transformer housing through the heat conduction pipe, achieving the purpose of knowing the oil temperature in the transformer housing without the sensor directly contacting the transformer oil, overcoming the disadvantages that the existing device for measuring the transformer oil temperature needs to extend the temperature sensor into the transformer, which increases the possibility of polluting the transformer insulating oil, and the maintenance and installation of the temperature sensor are inconvenient, which is likely to affect the safety and stability of the transformer. In addition, in the present application, at least one detection hole is provided on the transformer housing. When multiple detection holes are provided, the oil temperature data of different parts of the transformer housing can be obtained, and the carrying load of the transformer housing can be grasped as a whole. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 Schematic diagram of a transformer oil temperature measuring device provided by an embodiment of the present application;

[0027] Figure 2 Cross-sectional structure schematic diagram of a heat conduction tube provided by an embodiment of the present application;

[0028] Figure 3 Three-dimensional structure schematic diagram of a transformer oil temperature measuring device provided by an embodiment of the present application;

[0029] Figure 4 Three-dimensional structure schematic diagram of another angle of a transformer oil temperature measuring device provided by an embodiment of the present application;

[0030] Figure 5 Internal structure schematic diagram of an oil conservator provided by an embodiment of the present application;

[0031] Figure 6 Structure schematic diagram of an air filter box provided by an embodiment of the present application.

[0032] Explanation of reference numerals:

[0033] 1. Transformer box body; 2. Heat conduction tube; 3. Heat pipe; 4. Oil conservator; 5. Air filter box; 11. Temperature sensor; 12. Controller; 13. Cooling fan; 14. Connecting frame; 15. Buchholz relay; 21. Heat conduction shell; 22. Heat conduction layer; 31. Heat dissipation fins; 41. Airbag; 51. First filter screen layer; 52. First activated carbon adsorption layer; 53. Color-changing silica gel layer; 54. Second activated carbon adsorption layer; 55. Second filter screen layer; 221. Outer wire mesh; 222. Inner wire mesh. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following clearly and completely describes the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts also belong to the scope of protection of the present application.

[0035] Such as Figure 1As shown in the figure, the present application provides a transformer oil temperature measuring device, including a transformer box body 1. At least one detection hole is opened from top to bottom on the side surface of the transformer box body 1, and the detection hole is communicated with a heat conduction pipe 2 arranged inside the transformer box body 1;

[0036] One end of the heat conduction pipe 2 is closed and the other end is open, and a temperature sensor 11 is installed inside the heat conduction pipe 2;

[0037] The temperature sensor 11 is electrically connected to a controller 12 arranged on one side surface of the transformer box body 1.

[0038] In the present application, the detection holes can be arranged at different heights of the transformer box body 1 to facilitate measuring the oil temperatures at different positions inside the transformer box body 1, so as to more comprehensively understand the oil temperature situation inside the transformer box body 1 as a whole. It should be noted that since the temperature directly obtained by the temperature sensor 11 is the oil temperature conducted through the heat conduction pipe 2, and there is always a certain thermal resistance in the heat conduction pipe 2, the temperature directly obtained by the temperature sensor 11 is always on the low side. Therefore, temperature correction needs to be carried out during actual measurement, that is, the actual temperature is the temperature directly obtained by the temperature sensor 11 plus the temperature lost after passing through the heat conduction pipe 2.

[0039] The controller 12 is a device with data processing and operation functions, such as a microcomputer, etc.

[0040] In the present application, the heat conduction pipes 2 and the detection holes are arranged in one-to-one correspondence. The connection manner between the heat conduction pipe 2 and the detection hole can be integral molding, welding, stamping or other methods to ensure the tight connection between the heat conduction pipe 2 and the transformer box body 1.

[0041] During use, the temperature sensor 11 is installed into the heat conduction pipe 2. The connection manner between the temperature sensor 11 and the heat conduction pipe 2 can be detachable methods such as threaded connection, plug-in connection or snap connection. During the operation of the transformer, the oil temperature data can be fed back to the controller 12 through the temperature sensor 11 (the actual temperature fed back should be the sum of the temperature measured by the thermometer and the temperature difference of the thermal resistance of the heat conduction pipe 2, that is, temperature correction needs to be carried out before use), and the controller 12 makes subsequent instructions according to the data analyzed and transmitted back by the temperature sensor 11.

[0042] The transformer oil temperature measuring device of the present application is provided with a heat conduction tube 2 extending into the transformer box body 1, and a temperature sensor 11 is installed in the heat conduction tube 2. The temperature sensor 11 indirectly obtains the oil temperature inside the transformer box body 1 through the heat conduction tube 2, achieving the purpose of knowing the oil temperature inside the transformer box body 1 without the sensor 11 directly contacting the transformer oil, overcoming the disadvantages of the existing transformer oil temperature measuring devices that need to extend the temperature sensor into the transformer, which increases the possibility of polluting the transformer insulating oil, and the maintenance and installation of the temperature sensor are inconvenient, which is likely to affect the safety and stability of the transformer. In addition, in the present application, the transformer box body 1 is provided with at least one detection hole. When multiple detection holes are provided, the oil temperature data of different parts of the transformer box body 1 can be obtained, and the carrying load of the transformer box body 1 can be grasped as a whole.

[0043] As Figure 2 shown, optionally, the heat conduction tube 2 includes a heat conduction shell 21;

[0044] A heat conduction layer 22 is arranged inside the heat conduction shell 21;

[0045] A hollow accommodation cavity is formed in the central part of the heat conduction layer 22 for installing the temperature sensor 11;

[0046] The heat conduction layer 22 includes an outer wire mesh 221 closely attached to the heat conduction layer 22 and an inner wire mesh 222 coaxially arranged with the outer wire mesh 221; the space between the outer wire mesh 221 and the inner wire mesh 222 is filled with heat conduction powder.

[0047] In the present application, the heat conduction powder is graphite powder or silicon carbide powder with a particle size of 80-100 mesh. The above materials have high thermal conductivity and small thermal resistance, which can effectively reduce the measurement error.

[0048] The outer wire mesh 221 and the inner wire mesh 222 are woven from materials with high thermal conductivity such as copper wire to reduce the measurement error. The outer wire mesh 221 and the inner wire mesh 222 are used in combination to prevent the heat conduction powder from spilling (the apertures of the outer wire mesh 221 and the inner wire mesh 222 are smaller than the particle size of the heat conduction powder, which can achieve the purpose of preventing the heat conduction powder from spilling).

[0049] As Figure 3 and Figure 4 shown, optionally, multiple heat pipes 3 are arranged on the side of the transformer box body 1;

[0050] One end of the heat pipe 3 passes through the side of the transformer box body 1 and extends into the transformer box body 1, and the other end is located outside the transformer box body 1;

[0051] A plurality of heat dissipation fins 31 are arranged on the heat pipe 3 in an array along the axis direction of the heat pipe 3,

[0052] The multiple heat pipes 3 are arranged at a certain inclination angle with the horizontal plane.

[0053] In this application, heat transfer mainly occurs through the vapor-liquid phase change of the working fluid inside the heat pipe 3, and the thermal resistance is very small. Therefore, it has a high heat conduction capacity. Using the heat pipe 3 as a cooling device for transformer oil has the characteristics of being fast and efficient.

[0054] Setting heat dissipation fins 31 on the heat pipe 3 can enhance heat dissipation and accelerate the cooling process.

[0055] As Figure 3 and Figure 4 shown, optionally, cold fans 13 are respectively installed at the four corners of the transformer housing 1;

[0056] The cold fans 13 are fixed by a connecting frame 14 connected to the transformer housing 1;

[0057] The cold fans 13 are electrically connected to the controller 12.

[0058] In this application, setting the cold fans 13 can enhance heat exchange and increase the cooling rate of the heat pipe 3 for transformer oil.

[0059] As Figure 3 , Figure 4 and Figure 5 shown, optionally, the transformer housing 1 is also connected to an oil conservator 4 installed above the transformer housing 1 through a pipeline provided with a gas relay 15;

[0060] An airbag 41 is arranged inside the oil conservator 4, and the airbag 41 is connected to an air filter box 5 through a pipeline.

[0061] In this application, during use, the oil in the transformer will expand and contract due to heat, resulting in a change in its volume. Setting the oil conservator 4 can maintain the stability of the oil pressure inside the transformer when the oil volume changes. That is, the oil conservator 4 provides additional storage space for the transformer oil. When the oil temperature inside the transformer rises, the oil volume expands, and the oil enters the oil conservator 4, squeezing the airbag 41. The air in the airbag 41 is discharged to the atmosphere after being filtered by the air filter box 5; conversely, when the oil temperature drops, the oil volume contracts, and the resilience of the airbag 41 itself will cause a negative pressure state inside the airbag 41. At this time, the airbag 41 inhales air from the outside, and the inhaled air enters the airbag 41 after being filtered by the air filter box 5.

[0062] In this application, the airbag 41 is made of oil-resistant elastic material or a layer of oil-resistant layer is cured or attached to other suitable materials. For example, the body of the airbag 41 can be made of elastic rubber, and a layer of polytetrafluoroethylene layer is attached to the part of its outer surface in contact with the oil. This can ensure that the airbag 41 has a certain resilience and buffering effect while also having the characteristics of being oil-resistant, so as to extend its service life.

[0063] As Figure 6As shown, optionally, one end of the air filter box 5 is connected to the conservator 4 through a pipeline, and the other end is provided with an opening and is connected to the atmosphere;

[0064] The air filter box 5 is sequentially provided with a first filter screen layer 51, a first activated carbon adsorption layer 52, a color-changing silica gel layer 53, a second activated carbon adsorption layer 54, and a second filter screen layer 55 along the gas inlet direction.

[0065] During use, the oil in the transformer will expand and contract due to heat, resulting in a change in its volume. The conservator 4 is provided to maintain the stability of the oil pressure inside the transformer when the oil volume changes. That is, the conservator 4 provides an additional storage space for the transformer oil. When the oil temperature inside the transformer rises, the oil volume expands, and the oil enters the conservator 4, squeezing the airbag 41. The air in the airbag 41 is filtered by the air filter box 5 and then discharged to the atmosphere; conversely, when the oil temperature drops, the oil volume contracts, and the resilience of the airbag 41 itself will cause the inside of the airbag 41 to be in a negative pressure state. At this time, the airbag 41 inhales air from the outside. The outside air passes through the first filter screen layer 51, the first activated carbon adsorption layer 52, the color-changing silica gel layer 53, the second activated carbon adsorption layer 54, and the second filter screen layer 55 in the air filter box 5 in sequence to intercept and adsorb solid particles, harmful gases, moisture, etc. in the air (to prevent substances such as moisture contained in the outside air from causing the aging of the airbag 41) and then enters the airbag 41. The airbag 41 expands and squeezes the oil in the conservator 4. At this time, the oil in the conservator 4 returns to the fuel tank. When the color of the color-changing silica gel in the color-changing silica gel layer 53 changes (for example, the blue silica gel turns pink), it indicates that the color-changing silica gel layer 53 has failed, reminding the operator to replace the air filter box 5 in time.

[0066] Optionally, the heat pipe 3 is arranged at an inclination angle of 15 to 75° with the horizontal plane.

[0067] In this application, the heat pipe adopted is a gravity heat pipe. During its operation, the working liquid inside it undergoes a phase change to transfer heat. During operation, when one end of the heat pipe is heated, the working liquid here vaporizes, and the vaporized working liquid moves to the other end and releases heat and liquefies at the other end, thereby releasing heat. During the above working process, the vaporized working liquid will be affected by gravity when moving. If it is placed vertically, the steam in the evaporation section needs to flow against gravity to the condensation section, and the direction is opposite to the direction of the working medium reflux. A large shear force will be generated between the two, and the starting speed of the gravity heat pipe will also be slow, and the heat transfer performance will decline; if it is placed horizontally, it is difficult for the working medium to reflux, resulting in the heat pipe being difficult to work. Therefore, arranging the heat pipe obliquely can ensure the reflux of the working medium while enabling the steam to flow smoothly.

[0068] A transformer oil temperature measuring device has the following working process:

[0069] In use, the temperature sensor 11 is installed in the heat conduction pipe 2. The connection mode between the temperature sensor 11 and the heat conduction pipe 2 can be detachable modes such as screw connection, plug connection or snap connection. During the operation of the transformer, the oil temperature data can be fed back to the controller 12 through the temperature sensor 11 (the actual temperature fed back should be the sum of the temperature measured by the thermometer and the temperature difference through the thermal resistance of the heat conduction pipe 2, that is, the temperature needs to be corrected before use). The controller 12 makes subsequent instructions based on the analysis of the data transmitted back by the temperature sensor 11.

[0070] During the operation of the transformer, the heat generated is conducted to the oil in the transformer casing 1, and then the heat in the oil is conducted to the outside through the heat pipe 3, and the heat conduction is accelerated through the heat dissipation fins 31, so that the oil temperature in the transformer casing 1 can be maintained at a lower temperature.

[0071] When the oil temperature value transmitted back by the temperature sensor 11 is higher than the preset first alarm oil temperature (such as 50 °C), the controller 12 controls two cooling fans 13 located on opposite sides of the transformer casing 1 to turn on and blow air towards the heat pipe 3 to strengthen the air convection, thereby accelerating the reduction of the oil temperature.

[0072] When the oil temperature value transmitted back by the temperature sensor 11 is higher than the preset second alarm oil temperature (such as 70 °C), the controller 12 controls all four cooling fans 13 at the four corners of the transformer casing 1 to turn on and blow air towards the heat pipe 3 to strengthen the air convection, thereby accelerating the reduction of the oil temperature.

[0073] When the oil temperature value transmitted back by the temperature sensor 11 is higher than the preset third alarm oil temperature (such as 90 °C), the controller 12 controls all four cooling fans 13 at the four corners of the transformer casing 1 to turn on and blow air towards the heat pipe 3, and at the same time cuts off the switch to stop the operation of this transformer. When the oil temperature cools down to a suitable working temperature, the transformer is switched back to the working state.

[0074] During the use of the transformer, the oil in the transformer will expand and contract due to heat, resulting in volume changes. The oil conservator 4 is provided to maintain the stability of the oil pressure inside the transformer when the oil volume changes. That is, the oil conservator 4 provides additional storage space for the transformer oil. When the oil temperature inside the transformer rises, the oil volume expands, and the oil enters the oil conservator 4, squeezing the airbag 41. The air in the airbag 41 is discharged to the atmosphere after being filtered by the air filter box 5. Conversely, when the oil temperature drops, the oil volume shrinks, and the resilience of the airbag 41 itself causes a negative pressure state inside the airbag 41. At this time, the airbag 41 inhales air from the outside. The outside air passes through the first filter layer 51, the first activated carbon adsorption layer 52, the discoloring silica gel layer 53, the second activated carbon adsorption layer 54, and the second filter layer 55 in the air filter box 5 in sequence to intercept and adsorb solid particles, harmful gases, moisture, etc. in the air and then enter the airbag 41. The airbag 41 expands and squeezes the oil in the oil conservator 4. At this time, the oil in the oil conservator 4 returns to the fuel tank.

[0075] In this application, an airbag 41 is arranged in the oil conservator 4. While ensuring that the oil conservator 4 can maintain the stability of the oil pressure inside the transformer, it can prevent the direct contact between the transformer oil and the air, thereby effectively preventing the occurrence of adverse consequences such as deterioration and degradation caused by the contact between the transformer oil and the air.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A transformer oil temperature measuring device, comprising a transformer box body (1), characterized in that, At least one detection hole is provided in the side surface of the transformer box body (1) from top to bottom, and the detection hole is communicated with a heat conduction pipe (2) arranged in the transformer box body (1); One end of the heat conduction pipe (2) is closed and the other end is open, and a temperature sensor (11) is installed in the heat conduction pipe (2); The temperature sensor (11) is electrically connected to a controller (12) arranged on one side surface of the transformer box body (1).

2. The transformer oil temperature measuring device according to claim 1, characterized in that, The heat conduction pipe (2) includes a heat conduction shell (21); A heat conduction layer (22) is arranged in the heat conduction shell (21); A hollow accommodation cavity is formed in the central part of the heat conduction layer (22) for installing the temperature sensor (11); The heat conduction layer (22) includes an outer wire mesh (221) closely attached to the heat conduction layer (22) and an inner wire mesh (222) arranged coaxially with the outer wire mesh (221); the space between the outer wire mesh (221) and the inner wire mesh (222) is filled with heat conduction powder.

3. The transformer oil temperature measuring device according to claim 1, wherein, A plurality of heat pipes (3) are arranged on the side surface of the transformer box body (1); One end of the heat pipe (3) penetrates through the side surface of the transformer box body (1) and extends into the transformer box body (1), and the other end is located outside the transformer box body (1); A plurality of heat dissipation fins (31) are arranged in an array along the axial direction of the heat pipe (3) on the heat pipe (3), The plurality of heat pipes (3) are arranged at a certain inclination angle with the horizontal plane.

4. The transformer oil temperature measuring device according to claim 1, characterized in that, Cooling fans (13) are respectively installed at the four corners of the transformer box body (1); The cooling fans (13) are fixed by a connecting frame (14) connected to the transformer box body (1); The cooling fans (13) are electrically connected to the controller (12).

5. The transformer oil temperature measuring device according to claim 2, characterized in that, The transformer box body (1) is also communicated with an oil conservator (4) installed above the transformer box body (1) through a pipeline provided with a gas relay (15); An air bag (41) is arranged in the oil conservator (4), and the air bag (41) is communicated with an air filter box (5) through a pipeline.

6. The transformer oil temperature measuring device according to claim 5, characterized in that, One end of the air filter box (5) is communicated with the oil conservator (4) through a pipeline, and the other end is provided with an opening and is communicated with the atmosphere; The air filter box (5) is sequentially provided with a first filter screen layer (51), a first activated carbon adsorption layer (52), a discolored silica gel layer (53), a second activated carbon adsorption layer (54) and a second filter screen layer (55) along the gas inlet direction.

7. The transformer oil temperature measuring device according to claim 3, characterized in that, The heat pipe (3) is arranged at an inclination angle of 15 to 75° with the horizontal plane.

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