transformer

Abstract

This invention relates to a transformer. The transformer includes: a transformer body, comprising an oil tank, a transformer core, and a surrounding shield, the surrounding shield being arranged circumferentially around the transformer core; the oil tank having a first oil inlet channel, a second oil inlet channel, and an oil outlet; the inlet of a cooling channel communicating with the first oil inlet channel; and the surrounding shield being configured to controllably connect or disconnect the cooling channel from the second oil inlet channel; the outlet of the cooling channel communicating with the oil outlet; a first cooling system, the outlet of which is connected to the first oil inlet channel, and the inlet of the first cooling system communicating with the oil outlet; and a second cooling system, the outlet of which is connected to the second oil inlet channel, and the inlet of the second cooling system communicating with the oil outlet.

Description

Technical Field

[0001] The invention relates to the technical field of transformer cooling, in particular to a transformer. Background Art

[0002] For large-capacity transformers, the ODAF cooling method is generally used, that is, forced oil circulation air cooling. The cooling system of this method consists of a forced oil cooler, which can be switched on and off one by one according to temperature or load. It has a good cooling effect, low oil surface temperature rise and coil temperature rise, and has a strong overload capacity. Therefore, the ODAF cooling method can take away the heat in the winding in time when the transformer is overloaded. However, once the transformer is unloaded or lightly loaded, the heat generated is small, and only a few coolers are needed to take away the heat generated by the transformer. However, due to the use of the ODAF cooling method, more than one set of coolers must continue to operate. If no cooler is running, heat will accumulate in the transformer, endangering the safety of the transformer. If the cooler continues to operate, the rated power of the cooler's oil pump and transformer fan is relatively large, which will cause a large waste of energy. In addition, if all the coolers are damaged, the transformer must cut off the load in a short time, which is not conducive to the stability of the power grid. Summary of the invention

[0003] Based on this, it is necessary to provide a transformer that improves the above defects in view of the problem that the transformer adopts ODAF cooling method in the prior art, which will cause large energy waste when no-load or light-loaded, and when all the coolers are damaged, the transformer must cut off the load in a short time, which is not conducive to the stability of the power grid.

[0004] A transformer, comprising:

[0005] The transformer body comprises an oil tank, and a body and a screen contained in an inner cavity of the oil tank, wherein the screen is arranged around the body in a circumferential direction to form a cooling channel for a cooling medium to pass through between the screen and the body; the oil tank comprises a first oil inlet channel, a second oil inlet channel and an oil outlet, the inlet of the cooling channel is connected to the first oil inlet channel, and the screen is configured to controllably connect or cut off the cooling channel and the second oil inlet channel, and the outlet of the cooling channel is connected to the oil outlet;

[0006] a first cooling system, whose outlet is communicated with the first oil inlet passage, and whose inlet is communicated with the oil outlet, so that the first cooling system, the first oil inlet passage and the cooling passage form a first cooling circuit for circulating cooling medium; and

[0007] The outlet of the second cooling system is connected to the second oil inlet channel, and the inlet of the second cooling system is connected to the oil outlet, so that the second cooling system, the second oil inlet channel and the cooling channel form a second cooling circuit for circulating cooling medium.

[0008] In one embodiment, the first cooling system is an ODAF cooling system, and the second cooling system is an ONAF or ONAN cooling system.

[0009] In one embodiment, the enclosure includes an inner enclosure and an outer enclosure that are stacked, the inner enclosure is connected to a shrink sheet, the outer enclosure has a second oil inlet hole that is connected to the second oil inlet channel, and the second oil inlet hole is arranged opposite to the shrink sheet;

[0010] The shrinkage plate includes a first state of bending toward the inner side of the inner enclosure and a second state of being closely attached to the second oil inlet hole of the outer enclosure; under the extrusion of the cooling medium entering the cooling channel from the first oil inlet channel, the shrinkage plate is deformed from the first state to the second state to close the second oil inlet hole.

[0011] In one embodiment, the bottom end of the inner screen has a plurality of first notches spaced apart along the circumferential direction, and the shrinkage sheet is formed between every two adjacent first notches;

[0012] The outer enclosure has a plurality of the second oil inlet holes corresponding one-to-one to the plurality of the shrinkage sheets.

[0013] In one of the embodiments, the bottom end of the outer enclosure has a plurality of second notches arranged at intervals along the circumferential direction and serving as the second oil inlet holes, and the plurality of second notches and the plurality of first notches are staggered in the radial direction of the enclosure.

[0014] In one embodiment, an oil sealing structure is provided in the oil tank, and the oil sealing structure divides the inner cavity of the oil tank into a containing cavity and an oil inlet cavity located below the containing cavity, and the device body and the surrounding screen are arranged in the containing cavity;

[0015] The oil tank also has a first inlet connected to the oil inlet chamber and a second inlet connected to the accommodating chamber, the outlet of the first cooling system is connected to the first inlet, the input port of the cooling channel is connected to the oil inlet chamber, the outlet of the second cooling system is connected to the second inlet, and the second oil inlet hole is connected to the accommodating chamber.

[0016] In one of the embodiments, the transformer further includes a lower supporting plate arranged at the bottom of the transformer body, and the enclosure support is arranged on the lower supporting plate.

[0017] In one of the embodiments, the transformer further comprises a plurality of stays arranged in the cooling channel, one end of each of the stays abuts against the device body, and the other end of each of the stays abuts against the enclosure.

[0018] In one embodiment, the first cooling system includes a cooler and a delivery pump, the outlet of the cooler is communicated with the first oil inlet channel, and the inlet of the cooler is communicated with the oil outlet;

[0019] The delivery pump is arranged between the inlet of the cooler and the oil outlet, or between the outlet of the cooler and the first oil inlet channel.

[0020] In one embodiment, the second cooling system includes a fin-type radiator, the outlet of the fin-type radiator is communicated with the second oil inlet channel, and the inlet of the fin-type radiator is communicated with the oil outlet.

[0021] For the above transformer, the first cooling system can be used to cool the transformer when it is in a heavy load state, and the second cooling system can be used to cool the transformer when it is in a light load or no-load state. When the transformer is in a heavy load state, the cooling channel and the second oil inlet channel are cut off, so that the cooling medium of the second cooling system cannot enter the cooling channel through the second oil inlet channel. At this time, the cooling medium in the first cooling system enters the cooling channel through the first oil inlet channel and flows toward the output port of the cooling channel to drive the heat of the device body (i.e., cool the device body). The cooling medium in the cooling channel enters the first cooling system again through the output port of the cooling channel, the oil outlet on the oil tank and the inlet of the first cooling system in turn, thereby circulating.

[0022] When the transformer is in a light load or no-load state, the first cooling system stops running, and the cooling channel is connected to the second oil inlet channel. At this time, the cooling medium in the second cooling system enters the cooling channel through the second oil inlet channel and flows to the output port of the cooling channel to take away the heat of the transformer body (i.e., cool the transformer body). The cooling medium in the cooling channel enters the second cooling system again through the output port of the cooling channel, the oil outlet on the oil tank, and the inlet of the second cooling system in turn, and circulates in this way.

[0023] In this way, the transformer has two cooling systems, namely the first cooling system and the second cooling system. The first cooling system can be used to cool the transformer body when the transformer is in a heavy load state, and the second cooling system can be used to cool the transformer body when the transformer is in a light load or no-load state, thereby avoiding a large waste of energy when the transformer is light load or no-load. Moreover, when the first cooling system fails, the transformer only needs to be switched to a light load state, that is, the transformer can carry a small amount of load. At this time, the second cooling system is used to cool the transformer body without completely cutting off the transformer load, which is beneficial to the stability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a transformer in one embodiment of the present invention;

[0025] Figure 2 for Figure 1 The schematic diagram of the operation of the first cooling system of the transformer under heavy load is shown;

[0026] Figure 3 for Figure 1 The schematic diagram of the operation of the second cooling system of the transformer under light load or no load condition is shown;

[0027] Figure 4 for Figure 1 A partial enlarged view of the transformer at point A is shown;

[0028] Figure 5 for Figure 1 A schematic diagram of the structure of the transformer enclosure shown;

[0029] Figure 6 for Figure 5 A schematic structural diagram of the inner layer of the screen shown;

[0030] Figure 7 for Figure 5 A schematic diagram of the structure of the outer screen of the screen shown. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0037] See also Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of the present invention provides a transformer, including a transformer body 10 , a first cooling system 20 and a second cooling system 30 .

[0038] The transformer body 10 includes an oil tank 11, a body 12 and a screen 13, and the body 12 and the screen 13 are accommodated in an inner cavity 112 of the oil tank 11. The screen 13 is arranged around the body 12 in a circumferential direction to form a cooling channel 14 for cooling medium to pass through between the screen 13 and the body 12, and an input port 141 of the cooling channel 14 is located at the bottom of the screen 13, and an output port 142 of the cooling channel 14 is located at the top of the screen 13. The oil tank 11 has a first oil inlet channel, a second oil inlet channel and an oil outlet 115. The input port 141 of the cooling channel 14 is connected to the first oil inlet channel, so that the cooling medium in the first oil inlet channel can enter the cooling channel 14 through the input port 141 of the cooling channel 14 and cool the body 12. The enclosure 13 is configured to controllably connect or block the cooling channel 14 with the second oil inlet channel, so that the cooling medium in the second oil inlet channel can enter the cooling channel 14 when the cooling channel 14 is connected with the second oil inlet channel, and cool the body 12. The output port 142 of the cooling channel 14 is connected with the oil outlet 115, so that the cooling medium outputted from the output port 142 of the cooling channel 14 can be discharged from the oil outlet 115 to the outside of the oil tank 11.

[0039] The outlet of the first cooling system 20 is communicated with the first oil inlet channel, and the inlet of the first cooling system 20 is communicated with the oil outlet 115, so that the first cooling system 20, the first oil inlet channel and the cooling channel 14 form a first cooling circuit for the circulation of cooling medium. The outlet of the second cooling system 30 is communicated with the second oil inlet channel, and the inlet of the second cooling system 30 is communicated with the oil outlet 115, so that the second cooling system 30, the second oil inlet channel and the cooling channel 14 form a second cooling circuit for the circulation of cooling medium. Optionally, the cooling medium may be cooling oil.

[0040] For the transformer, the first cooling system 20 can be used to cool the transformer when it is in a heavy load state, and the second cooling system 30 can be used to cool the transformer when it is in a light load or no load state. Figure 2 , Figure 2 The dotted arrow in the figure indicates the flow direction of the cooling medium), the cooling channel 14 is cut off from the second oil inlet channel, so that the cooling medium of the second cooling system 30 cannot enter the cooling channel 14 through the second oil inlet channel. At this time, the cooling medium in the first cooling system 20 enters the cooling channel 14 through the first oil inlet channel, and flows toward the output port 142 of the cooling channel 14 to drive the heat of the device body 12 (i.e., cool the device body 12). The cooling medium in the cooling channel 14 enters the first cooling system 20 again through the output port 142 of the cooling channel 14, the oil outlet 115 on the oil tank 11, and the inlet of the first cooling system 20 in turn, and circulates in this way.

[0041] When the transformer is lightly loaded or unloaded (see Figure 3 , Figure 3 The dotted arrow in the figure indicates the flow direction of the cooling medium), the first cooling system 20 stops running, and the cooling channel 14 is connected to the second oil inlet channel. At this time, the cooling medium in the second cooling system 30 enters the cooling channel 14 through the second oil inlet channel, and flows toward the output port 142 of the cooling channel 14 to take away the heat of the device body 12 (i.e., cool the device body 12). The cooling medium in the cooling channel 14 enters the second cooling system 30 again through the output port 142 of the cooling channel 14, the oil outlet 115 on the oil tank 11, and the inlet of the second cooling system 30 in turn, and circulates in this way.

[0042] In this way, the transformer has two cooling systems, namely the first cooling system 20 and the second cooling system 30. When the transformer is in a heavy load state, the first cooling system 20 can be used to cool the body 12, and when the transformer is in a light load or no-load state, the second cooling system 30 can be used to cool the body 12, thereby avoiding a large waste of energy when the transformer is light load or no-load. In addition, when the first cooling system 20 fails, the transformer only needs to be switched to a light load state, that is, the transformer can carry a small amount of load. At this time, the second cooling system 30 is used to cool the body 12, and there is no need to completely cut off the transformer load, which is beneficial to the stability of the power grid.

[0043] It should be noted that when the transformer is in a heavy load state, the body 12 generates more heat, and when the transformer is in a light load or no load state, the body 12 generates less heat, so the cooling effect of the first cooling system 20 is better than the cooling effect of the second cooling system 30. Since the cooling effect of the first cooling system 20 is better than the cooling effect of the second cooling system 30, the operating energy consumption of the first cooling system 20 is greater than the operating energy consumption of the second cooling system 30. In this way, when the transformer is in a light load or no load state, the first cooling system 20 stops running, and the second cooling system 30 is used to cool the body 12, which can meet the cooling demand and save energy.

[0044] It should also be noted that, specifically in the embodiment shown in the drawings, the top of the oil tank 11 has two oil outlets 115 , and the two oil outlets 115 are connected to the inlet of the first cooling system 20 and the inlet of the second cooling system 30 respectively.

[0045] Specifically in the embodiment, the first cooling system 20 is an ODAF cooling system, and the second cooling system 30 is an ONAF or ONAN cooling system. It can be understood that the "O" in ODAF indicates that the internal cooling medium is cooling oil, the "D" indicates that the internal cooling medium circulation mode is guided circulation, the "A" indicates that the external cooling medium is air, and the "F" indicates that the external cooling medium circulation mode is forced circulation. The "O" in ONAF indicates that the internal cooling medium is cooling oil, the "N" indicates that the internal cooling medium circulation mode is natural circulation, the "A" indicates that the external cooling medium is air, and the "F" indicates that the external cooling medium circulation mode is forced circulation. The "O" in ONAN indicates that the internal cooling medium is cooling oil, the "N" indicates that the internal cooling medium circulation mode is natural circulation, the "A" indicates that the external cooling medium is air, and the "N" indicates that the external cooling medium circulation mode is natural circulation.

[0046] Specifically in the embodiment, the first cooling system 20 includes a cooler 21 and a delivery pump 22. The outlet of the cooler 21 is connected to the first oil inlet channel, the inlet of the cooler 21 is connected to the oil outlet 115, and the delivery pump 22 is arranged between the inlet of the cooler 21 and the oil outlet 115, thereby forming a first cooling circuit. In this way, when the transformer is in a heavy load state (see Figure 2 ), the delivery pump 22 is started, and the cooling medium cooled by the cooler 21 is pumped to the first oil inlet channel by the delivery pump 22, and then enters the cooling channel 14 from the first oil inlet channel, and flows from the input port 141 to the output port 142 of the cooling channel 14 (taking away the heat generated by the device body 12 to cool the device body 12), and the cooling medium output from the output port 142 of the cooling channel 14 enters the cooler 21 again through the inlet of the cooler 21, and is cooled again by the cooler 21, and the cycle is repeated.

[0047] It should be noted that, in other embodiments, the delivery pump 22 may also be disposed between the inlet of the cooler 21 and the first oil inlet passage, which is not limited herein.

[0048] Furthermore, the first cooling system 20 also includes an external refrigeration system connected to the cooler 21, and the refrigeration system passes an external cooling medium into the cooler 21, so that the cooling medium in the cooler 21 exchanges heat with the external cooling medium to reduce the temperature of the cooling medium in the cooler 21, and the cooled cooling medium continues to enter the cooling channel 14 through the first oil inlet channel, thereby cooling the body 12. It should be noted that the external refrigeration system can adopt relatively mature existing technologies, which will not be described in detail here. The external cooling medium can be air.

[0049] Specifically in the embodiment, the second cooling system 30 includes a plate radiator 31, the outlet of the plate radiator 31 is connected to the second oil inlet channel, and the inlet of the plate radiator 31 is connected to the oil outlet 115, thereby forming a second cooling circuit. Figure 3 ), the first cooling system 20 stops running (i.e., the delivery pump 22 stops pumping), at which time the second oil inlet channel is connected to the cooling channel 14, and the cooling medium output from the outlet of the fin radiator 31 enters the cooling channel 14 through the second oil inlet channel. The cooling medium in the cooling channel 14 absorbs the heat generated by the body 12 and its temperature rises, so that its density decreases. At this time, the cooling medium in the cooling channel 14 floats to the oil outlet 115 and is discharged from the oil outlet 115, and then enters the fin radiator 31 through the inlet of the fin radiator 31. The cooling medium entering the fin radiator 31 has its temperature reduced under the heat dissipation effect of the fin radiator 31, so that its density increases. At this time, the cooling medium in the fin radiator 31 floats down to the outlet of the fin radiator 31, and enters the cooling channel 14 again through the second oil inlet channel, so as to circulate.

[0050] See also Figures 4 to 7 As shown, in an embodiment of the present invention, the screen 13 includes an inner screen 131 and an outer screen 132 which are stacked, the inner screen 131 is connected to a shrinkage plate 1311, the outer screen 132 has a second oil inlet hole 1321 connected to the second oil inlet channel, and the second oil inlet hole 1321 is arranged opposite to the shrinkage plate 1311.

[0051] The shrinkage piece 1311 includes a first state of bending toward the inner side of the inner layer enclosure 131 (see Figure 4) and a second state where the shrinkage sheet 1311 is in close contact with the second oil inlet hole 1321 of the outer layer enclosure 132. That is, when the shrinkage sheet 1311 is in the first state, the shrinkage sheet 1311 bends toward the inner side of the inner layer enclosure 131 to open the second oil inlet hole 1321, so that the cooling medium in the second oil inlet channel can enter the cooling channel 14 through the second oil inlet hole 1321; when the shrinkage sheet 1311 is in the second state, the shrinkage sheet 1311 is in close contact with the second oil inlet hole 1321 of the outer layer enclosure 132, so that the second oil inlet hole 1321 is closed by the shrinkage sheet 1311, so that the cooling medium in the second oil inlet channel cannot enter the cooling channel 14 through the second oil inlet hole 1321.

[0052] Under the squeezing effect of the cooling medium entering the cooling channel 14 from the first oil inlet channel, the shrinkage sheet 1311 can be deformed from the first state to the second state to close the second oil inlet hole 1321 .

[0053] In this way, when the transformer is in a heavy load state, the first cooling system 20 is running (i.e., the delivery pump 22 pumps the cooling medium), and the cooling medium in the first oil inlet channel enters the cooling channel 14, so that the pressure of the cooling medium in the cooling channel 14 increases, thereby squeezing the shrinkage sheet 1311 to deform toward the outer screen 132 until it is tightly attached to the second oil inlet hole 1321 of the outer screen 132, so as to close the second oil inlet hole 1321 and prevent the cooling medium in the second cooling system 30 from entering the cooling channel 14 (i.e., the second cooling system 30 stops running at this time).

[0054] When the transformer is in a light load or no-load state, the first cooling system 20 stops moving (i.e., the delivery pump 22 stops pumping the cooling medium), and the cooling medium in the first oil inlet channel stops entering the cooling channel 14, so that the pressure of the cooling medium in the cooling channel 14 decreases, and the shrinkage sheet 1311 rebounds to the inner side of the inner layer enclosure 131, so that the shrinkage sheet 1311 is separated from the outer layer enclosure 132. At this time, the second oil inlet channel is connected to the cooling channel 14 through the second oil inlet hole 1321. Since the cooling medium in the cooling channel 14 increases in temperature after absorbing the heat of the body 12, the density decreases and floats upward to the oil outlet 115. At the same time, the temperature of the cooling medium in the plate radiator 31 decreases, so that the density increases and floats downward to the outlet of the plate radiator 31. Then, the cooling medium output by the plate radiator 31 enters the cooling channel 14 through the second oil inlet channel and the second oil inlet hole 1321 in turn, and the cooling medium output by the oil outlet 115 enters the plate radiator 31 through the inlet of the plate radiator 31, and the cycle is thus formed.

[0055] Specifically in the embodiment, the bottom end of the inner layer enclosure 131 has a plurality of first notches 1312 arranged at intervals along the circumferential direction, and a shrinkage piece 1311 is formed between each two adjacent first notches 1312. The outer layer enclosure 132 has a plurality of second oil inlet holes 1321 corresponding to the plurality of shrinkage pieces 1311. In this way, by machining and forming a plurality of first notches 1312 at the bottom of the inner layer enclosure 131, a shrinkage piece 1311 is formed between two adjacent first notches 1312, and the machining is convenient and quick.

[0056] Furthermore, the bottom end of the outer screen 132 has a plurality of second notches which are arranged at intervals along the circumferential direction and serve as the above-mentioned second oil inlet holes 1321. The plurality of second notches and the plurality of first notches 1312 are staggered in the radial direction of the screen 13, so that each second notch is opposite to the shrinkage piece 1311 between two adjacent first notches 1312, so as to facilitate the use of the shrinkage piece 1311 to open or close the corresponding second notch.

[0057] Please continue to see Figures 1 to 3 As shown, specifically in the embodiment, an oil sealing structure 113 is provided in the oil tank 11, and the oil sealing structure 113 divides the inner cavity 112 of the oil tank 11 into a containing cavity 1121 and an oil inlet cavity 1122 located below the containing cavity 1121, and the body 12 and the screen 13 are arranged in the containing cavity 1121. The oil tank 11 also has a first inlet 211 connected to the oil inlet cavity 1122 and a second inlet 311 connected to the containing cavity 1121, the outlet of the first cooling system 20 is connected to the first inlet 211, the input port 141 of the cooling channel 14 is connected to the oil inlet cavity 1122, the outlet of the second cooling system 30 is connected to the second inlet 311, and the second oil inlet hole 1321 is connected to the containing cavity 1121. In this way, when the transformer is in a heavy load state (see Figure 2 ), the cooling medium of the first cooling system 20 enters the cooling channel 14 through the first inlet 211, the oil inlet cavity 1122, and the input port 141 of the cooling channel 14 in sequence. When the transformer is in a light load or no-load state (see Figure 3 ), the cooling medium of the second cooling system 30 enters into the cooling channel 14 through the second inlet 311, the accommodating cavity 1121, and the second oil inlet hole 1321 in sequence.

[0058] See also Figure 1 and Figure 4 As shown, in the embodiment of the present invention, the transformer further comprises a lower support plate 114 disposed at the bottom of the transformer body 12. The screen 13 is supported and disposed on the lower support plate 114. Optionally, the screen 13 can be made of cardboard. Of course, the screen 13 can also be made of other insulating materials, which is not limited here.

[0059] Furthermore, the lower support plate 114 has an annular limiting groove 1142 on one side facing the enclosure 13, and the bottom end support of the enclosure 13 is arranged in the annular limiting groove 1142. In this way, the annular limiting groove 1142 is used to limit the enclosure 13, so as to prevent the enclosure 13 from being misplaced, and to facilitate the assembly of the enclosure 13. It can be understood that the width of the annular limiting groove 1142 is greater than the thickness of the enclosure 13, so as to provide sufficient space for the elastic deformation of the shrinking piece 1311, that is, to avoid the annular limiting groove 1142 from interfering with the movement of the shrinking piece 1311 to open and close the second oil inlet hole 1321.

[0060] Furthermore, the transformer further includes a plurality of stays (not shown) disposed in the cooling channel 14, one end of each stay abutting against the device body 12, and the other end of each stay abutting against the screen 13, so that the screen 13 is supported tightly against the circumferential outer side of the device body 12 by the plurality of stays, so that the screen 13 is fixed relative to the device body 12. Optionally, the stays may be made of wood. Of course, the stays may also be made of other insulating materials, which are not limited here.

[0061] Specifically in the embodiment, the lower support plate 114 is supported and arranged on the oil sealing structure 113, and the body 12 and the surrounding screen 13 are supported and arranged on the lower support plate 114, so that the lower support plate 114 and the body 12 are supported and fixed by the oil sealing structure 113. The oil sealing structure 113 has a first connecting hole 1131, and the lower support plate 114 has a second connecting hole 1141. The first connecting hole 1131 connects the oil inlet cavity 1122 and the second connecting hole 1141, and the second connecting hole 1141 connects the first connecting hole 1131 and the input port 141 of the cooling channel 14. It should be noted that the first inlet 211, the oil inlet cavity 1122, the first connecting hole 1131 and the second connecting hole 1141 form the above-mentioned first oil inlet channel. The second inlet 311, the accommodating cavity 1121 and the second notch form the above-mentioned second oil inlet channel.

[0062] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A transformer, characterized in that: include: A transformer body (10) comprises an oil tank (11), a body (12) and a screen (13) contained in an inner cavity (112) of the oil tank (11); the screen (13) is arranged around the body (12) in a circumferential direction to form a cooling channel (14) between the screen (13) and the body (12) for a cooling medium to pass through; the oil tank (11) comprises a first oil inlet channel, a second oil inlet channel and an oil outlet (115); an inlet (141) of the cooling channel (14) is in communication with the first oil inlet channel, and the screen (13) is configured to controllably connect or block the cooling channel (14) and the second oil inlet channel; an outlet (142) of the cooling channel (14) is in communication with the oil outlet (115); a first cooling system (20), the outlet of which is in communication with the first oil inlet passage, and the inlet of the first cooling system (20) is in communication with the oil outlet (115), so that the first cooling system (20), the first oil inlet passage and the cooling passage (14) form a first cooling circuit for circulating a cooling medium; and a second cooling system (30), the outlet of which is in communication with the second oil inlet passage, and the inlet of the second cooling system (30) is in communication with the oil outlet (115), so that the second cooling system (30), the second oil inlet passage and the cooling passage (14) form a second cooling circuit for the circulation of cooling medium; The enclosure (13) comprises an inner enclosure (131) and an outer enclosure (132) which are stacked, the inner enclosure (131) being connected to a shrinkage sheet (1311), the outer enclosure (132) having a second oil inlet hole (1321) communicating with the second oil inlet passage, and the second oil inlet hole (1321) being arranged opposite to the shrinkage sheet (1311); The shrinkage sheet (1311) includes a first state of bending toward the inner side of the inner enclosure (131) and a second state of being closely attached to the second oil inlet hole (1321) of the outer enclosure (132); under the extrusion of the cooling medium entering the cooling channel (14) from the first oil inlet channel, the shrinkage sheet (1311) is deformed from the first state to the second state to close the second oil inlet hole (1321).

2. The transformer according to claim 1, characterized in that: The first cooling system (20) is an ODAF cooling system, and the second cooling system (30) is an ONAF or ONAN cooling system.

3. The transformer according to claim 1, characterized in that: The bottom end of the inner layer enclosure (131) has a plurality of first notches (1312) arranged at intervals along the circumferential direction, and the shrinkage sheet (1311) is formed between every two adjacent first notches (1312); The outer enclosure (132) has a plurality of the second oil inlet holes (1321) corresponding one-to-one to the plurality of the shrinkage sheets (1311).

4. The transformer according to claim 3, characterized in that: The bottom end of the outer enclosure (132) has a plurality of second notches arranged at intervals along the circumferential direction and serving as the second oil inlet holes (1321); the plurality of second notches and the plurality of first notches (1312) are arranged in a staggered manner in the radial direction of the enclosure (13).

5. The transformer according to claim 1, characterized in that: An oil sealing structure (113) is provided in the oil tank (11), and the oil sealing structure (113) divides the inner cavity (112) of the oil tank (11) into a containing cavity (1121) and an oil inlet cavity (1122) located below the containing cavity (1121); the device body (12) and the surrounding screen (13) are arranged in the containing cavity (1121); The oil tank (11) further comprises a first inlet (211) connected to the oil inlet chamber (1122) and a second inlet (311) connected to the accommodating chamber (1121); the outlet of the first cooling system (20) is connected to the first inlet (211); the input port (141) of the cooling channel (14) is connected to the oil inlet chamber (1122); the outlet of the second cooling system (30) is connected to the second inlet (311); and the second oil inlet hole (1321) is connected to the accommodating chamber (1121).

6. The transformer according to claim 1, characterized in that: The transformer further comprises a lower supporting plate (114) arranged at the bottom of the transformer body (12), and the surrounding screen (13) is supported and arranged on the lower supporting plate (114).

7. The transformer according to claim 6, characterized in that: The transformer further comprises a plurality of stays arranged in the cooling channel (14), one end of each stay abutting against the device body (12), and the other end of each stay abutting against the surrounding screen (13).

8. The transformer according to claim 1, characterized in that: The first cooling system (20) comprises a cooler (21) and a delivery pump (22), the outlet of the cooler (21) being in communication with the first oil inlet channel, and the inlet of the cooler (21) being in communication with the oil outlet (115); The delivery pump (22) is arranged between the inlet of the cooler (21) and the oil outlet (115), or between the outlet of the cooler (21) and the first oil inlet channel.

9. The transformer according to claim 1, characterized in that: The second cooling system (30) comprises a fin-type radiator (31), the outlet of the fin-type radiator (31) being in communication with the second oil inlet passage, and the inlet of the fin-type radiator (31) being in communication with the oil outlet (115).

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