JP5001225B2 - Static induction machine - Google Patents

Description

  The present invention relates to a static induction appliance such as a transformer or a reactor, and more particularly to a static induction appliance in which a cooling medium is filled in a tank that houses an electric appliance body and a plurality of heat radiation ribs are provided on the outer surface of the tank.

  A static induction electric appliance in which a cooling medium is filled in a tank that houses an electric appliance main body and a plurality of heat radiating ribs are provided on the outer surface of the tank has already been proposed, as disclosed in, for example, Japanese Patent Application Laid-Open No. H10-228707.

JP-A-1-108713

  As shown in FIGS. 11 and 12, the stationary induction device described in Patent Document 1 includes a plurality of heat radiation ribs 15 that are long in the height direction of the tank 4 around the peripheral wall of the tank 4 in which the main body 1 is housed. Forming. The heat radiating rib 15 is formed with a space 15 </ b> A that opens into the tank 4 so that the cooling medium 8 filled in the tank 4 can flow therethrough.

  In the static induction appliance configured as described above, the heat is generated by the loss generated from the electric appliance body 1 and the temperature rises. However, the heat is transmitted to the cooling medium 8 and cooled. Then, the cooling medium 8 that has absorbed the heat flows through the space 15 </ b> A of the heat radiating rib 15, thereby releasing the absorbed heat to the outside of the tank 4.

  By the way, the cooling medium 8 in the vicinity of the electric appliance main body 1 rises in temperature due to the transmitted heat, and its density decreases, and as shown by the arrow, it rises in the tank 4. On the other hand, the heated cooling medium 8 above the tank 4 is cooled by the external air A through the peripheral wall of the tank 4 and the heat dissipating ribs 15 that are separated from the main body 1. Since the cooling medium 8 that has been cooled to lower the temperature has a higher density, it flows along the tank 4 and the heat radiating ribs 15 toward the lower side of the tank 4. The cooling medium 8 reaching the lower side of the tank 4 again takes heat from the electric body 1 and generates a flow upward, and circulates in the tank 4 in the order of a → b → c → d → e → a by natural convection. To do.

  In general, the driving force ΔPdrive for natural convection of the cooling medium 8 includes the specific weight γ of the cooling medium 8, the volume expansion coefficient β, the difference Δh between the center height of the heat radiating rib 15 and the winding center height, and the tank of the cooling medium 8. It is assumed that ΔPdrive = γ · β · Δh · Δθ is expressed by using the temperature difference Δθ between the upper and lower portions.

  The relationship between the position of the cooling medium 8 and the temperature in the height direction of the tank 4 corresponding to the circulation of a → b → c → d → e → a by natural convection of the cooling medium 8 shown in FIG. 11 is shown. 13. In FIG. 13, a value obtained by subtracting the area oa-eo from the areas oc-c and d-o is equal to Δh · Δθ, and this subtracted value is proportional to the driving force ΔPdrive.

  However, as a result of measuring in detail the temperature of the insulating oil that is the cooling medium 8 at each position in the height direction of the tank 4 in a temperature rise test performed using a transformer that is an actual static induction electric appliance, The temperature change of the insulating oil descending inside is not the linear temperature decrease shown in c, d-oe in FIG. 13 but the upper part of the tank 4 like c, d-oe shown in FIG. It was found that the temperature drop at the bottom of the tank 4 was small, and the temperature suddenly dropped at the lower part of the tank 4.

  From these facts, the driving force of the cooling medium 8 causing the natural convection is proportional to the value obtained by subtracting the area oa-eo from the areas obac, do in FIG. The circulating flow rate of 8 is actually less than generally considered.

  From the above, there is a problem that the temperature difference of the cooling medium 8 at the upper and lower parts of the tank 4 becomes large, the temperature of the cooling medium 8 at the upper part of the tank 4 becomes high, and the electric appliance body 1 cannot be sufficiently cooled.

  The reason why the temperature of the cooling medium 8 descending in the heat radiating rib 15 in this way only slightly decreases in the upper part of the tank 4 and rapidly decreases in the lower part will be described with reference to FIG.

  Since the air A flowing in from the lower end between the adjacent cooling ribs 15 is in contact with the heat radiating rib 15 until reaching the upper end, the temperature distribution 15I of the air A around the heat radiating rib 15 is shown by a two-dotted line. And the distribution of the heated air A becomes wider as it goes above the heat radiating rib 15. For this reason, cooling with outside air having a low temperature cannot be expected in the upper part of the heat radiating rib 15, and heat transfer from the cooling medium 8 is small. On the other hand, since the temperature of the air A is low in the lower part of the heat radiating rib 15, the distribution of the heated air A is narrow and the heat transfer from the cooling medium 8 is increased. Therefore, the temperature of the cooling medium 8 descending in the heat radiating rib 15 is only slightly lowered at the upper part of the tank 4 and is rapidly lowered at the lower part.

  The object of the present invention is to sufficiently cool the cooling medium also in the upper part of the heat radiating rib, thereby increasing the driving force for the natural convection of the cooling medium in the tank and improving the overall cooling performance. It is to provide an induction machine.

  In order to achieve the above object, the present invention provides a plurality of vertically extending heat dissipating ribs around the peripheral wall of a tank that contains an electric body and is filled with a cooling medium, and is located in the height direction between adjacent heat dissipating ribs. The outside air disturbing means for disturbing the outside air flowing upward along the space between the heat radiating ribs is provided in the section.

  As described above, since the outside air disturbing means is provided, the outside air heated by cooling the lower portion of the cooling rib is disturbed by the outside air disturbing means in the middle, and thereby the outside air having a low ambient temperature is called between the heat dissipating ribs. Since it is mixed and mixed, the temperature of the heated outside air is lowered. And the upper part of a thermal radiation rib can be cooled with the external air which this temperature fell. As a result, the distribution of the heated outside air around the upper portion of the heat dissipating rib comes closer to the distribution of the heated air at the lower portion of the heat dissipating rib, which promotes cooling of the cooling medium and causes natural convection in the tank. The driving force of the cooling medium can be increased.

  As described above, according to the present invention, the cooling medium is sufficiently cooled even in the upper part of the heat radiating rib, thereby increasing the driving force for the natural convection of the cooling medium in the tank and improving the overall cooling performance. A static induction device that can be obtained can be obtained.

  Hereinafter, a first embodiment of a static induction apparatus according to the present invention will be described based on a transformer shown in FIGS. 1 and 2.

  The transformer according to the present embodiment includes an electric body 1 composed of a winding 3 attached to an iron core 2, a tank 4 that houses the electric body 1, and insulating oil, air, and nitrogen filled in the tank. The lower heat-dissipating rib 5 and the upper heat-dissipating rib 6 are formed in the peripheral wall of the tank 4 and have spaces 5A and 6A through which the coolant 8 flows. Is provided.

  The spaces 5A, 6A of the lower heat radiating rib 5 and the upper heat radiating rib 6 are opened facing the inside of the tank 4, respectively, so that the cooling medium 8 flows through the tank 4 and the spaces 5A, 6A. . A plurality of the lower radiating ribs 5 and the upper radiating ribs 6 are provided around the peripheral wall of the tank 4, and are formed side by side along the same line along the height direction of the peripheral wall of the tank 4.

  An air flow path 7 continuous in the circumferential direction of the tank 4 is formed between the lower heat radiating rib 5 and the upper heat radiating rib 6.

  Since the transformer according to the present embodiment has the above-described configuration, heat generated in the electric body 1 is transmitted to the tank 4, the lower radiating rib 5, and the upper radiating rib 6 by natural convection of the cooling medium 8. Cooling is performed by the outside air A <b> 1 and A <b> 2 flowing in contact with the outer surfaces of the heat radiating rib 5 and the upper heat radiating rib 6.

  The flow of the outside air A1, A2 at this time is as shown in FIG. That is, the outside air A1 flowing from below between the adjacent lower radiating ribs 5 is deprived of heat from the outer surface of the lower radiating ribs 5 and gradually decreases in density. Layered and flows upward. Since the outside air A1 in contact with the lower radiating rib 5 is always in contact from the lower end to the upper end of the lower radiating rib 5, the outside air A1 heated in contact with the lower radiating rib 5 has a temperature distribution that is narrow at the lower end and wide at the upper end. 5I.

  Therefore, in the case of an integrated configuration in which the lower heat radiating rib 5 and the upper heat radiating rib 6 are vertically connected, the temperature distribution of the heated outside air rising in the vicinity of the upper heat radiating rib 6 is considerably widened. Therefore, the temperature of the cooling medium 8 in the upper part of the tank 4 and the outside air temperature are close to each other. As a result, the efficiency of transferring the heat of the raised cooling medium 8 to the outside air via the upper heat radiation rib 6 is improved. The temperature of the cooling medium 8 is lowered and cannot be sufficiently cooled.

  In this regard, according to the present embodiment, the outside air is disturbed between the lower heat release rib 5 and the upper heat release rib 6 before the temperature distribution 5I of the heated outside air A1 in the vicinity of the lower heat release rib 5 becomes wider. Since the air flow path 7 that is the outside air disturbing means is formed, the outside air A1 that flows between the adjacent lower heat radiation ribs 5 and the vicinity thereof in a layered manner and flows upward is low in temperature flowing into the air flow path 7. The flow is disturbed by the outside air A3. That is, the outside air A1 that has risen while raising the temperature between the adjacent lower heat radiation ribs 5 is disturbed and mixed by the outside air A3 that has not risen in temperature in the air flow path 7 part, thereby lowering the increased temperature. .

  The air whose temperature has decreased due to the disturbance becomes the outside air A2 and flows between the adjacent upper heat dissipating ribs 6, rises along the above upper heat dissipating ribs 6, and has a temperature distribution 6I similar to the outside air A1 of the lower heat dissipating ribs 5. Thus, the cooling medium 8 can be cooled.

  As a result, the temperature of the outside air A2 that cools the upper heat radiation rib 6 can be lowered as compared with the heat radiation rib formed continuously from the bottom to the top. Further, since the upper heat radiation rib 6 is cooled by the outside air A2 from the lower end of the upper heat radiation rib 6, the temperature distribution 6I of the heated outside air A2 in the height direction near the upper heat radiation rib 6 is the temperature of the lower heat radiation rib 5. Similar to distribution 5I. As a result, the temperature difference between the temperature of the cooling medium 8 in the upper part of the tank 4 and the temperature of the outside air A2 in the vicinity of the upper radiating rib 6 becomes large, and a large amount of heat is transferred from the upper radiating rib 6 to the outside air A2. It is possible to sufficiently cool the heated cooling medium 8 in the upper part of the.

  From the above, the temperature change of the cooling medium 8 circulating in the tank 4, the lower heat radiating rib 5, and the upper heat radiating rib 6 is as shown in FIG. That is, the temperature change at each position of the cooling medium 8 rising in the tank 4 is abc, d, which is the same as the conventional one, but the cooling medium descending in the lower heat radiation rib 5 and the upper heat radiation rib 6. The change in temperature at each position of 8 is c, de, fg, and hi, and the temperature is reduced substantially linearly. This is a temperature change that approximates the temperature change shown in FIG. 13, and a value obtained by subtracting the area oaio from the areas obac, de, fg, and h-0 increases. Since the driving force of the natural convection of the cooling medium 8 increases in proportion thereto, the circulation flow rate of the cooling medium 8 can be increased.

  The increase in the circulation flow rate of the cooling medium 8 reduces the temperature difference of the cooling medium 8 in the height direction in the tank 4 and increases the heat transfer coefficient from the electric body 1 to the cooling medium 8. Thereby, the temperature rise of the electric body 1 can be suppressed and the cooling performance of the transformer can be improved, so that the capacity can be increased and the size can be reduced.

  In the above embodiment, the air flow path 7 is formed along the peripheral wall of the tank 4 in the divided part of the heat radiating ribs 5 and 6 divided into the upper and lower parts. By forming two or more paths, the temperature difference of the cooling medium 8 in the height direction in the tank 4 can be further reduced, and the heat transfer rate from the electric appliance body 1 to the cooling medium 8 can be further increased. can do.

  Moreover, although the air flow path 7 which penetrates between the radiation ribs 5 and 6 along the circumference | surroundings of the surrounding wall of the tank 4 was formed as an external air disturbance means, in the structure which integrated the radiation ribs 5 and 6, it raises to a radiation rib. An obstacle that blocks the flow of outside air may be provided as outside air disturbing means, so that outside air having a low ambient temperature may be mixed.

  Further, in the structure in which the heat radiating ribs 5 and 6 are integrated, an outside air introduction means for introducing outside air having a low temperature to the heat radiating rib side is provided in the middle portion in the height direction of the heat radiating ribs to lower the temperature of the heated outside air. You may make it make it.

  Next, a second embodiment of the static induction device according to the present invention will be described based on the transformer shown in FIGS. Since the same reference numerals as those in FIGS. 1 to 3 indicate the same components, detailed description thereof will not be repeated.

  In the present embodiment, the configuration different from the first embodiment is that a lower heat radiating rib 5 having a P1 pitch and an upper heat radiating rib 6 having a P2 pitch that is the same as the P1 pitch are arranged on the peripheral wall of the tank 4. It is a point installed with a 1/2 pitch shift with respect to the circumferential direction.

  In such a configuration, of the outside air A1 rising between the adjacent lower heat radiating ribs 5, the low temperature outside air A1 flowing outside the temperature distribution 5I of the heated outside air along the upper heat radiating ribs 6. Since the outside air A2 flowing in contact with the upper radiating rib 6 becomes lower in temperature than the outside air A2 of the first embodiment, the temperature distribution 6I of the heated outside air A2 in the vicinity of the upper radiating rib 6 is increased. Can be made closer to the temperature distribution 5I in the vicinity of the lower heat radiation rib 5. Of course, considering the lower temperature of the outside air A2 due to the outside air A3 flowing into the air flow path 7 formed between the lower radiating rib 5 and the upper radiating rib 6, the cooling performance of the transformer as compared with the first embodiment. Needless to say, can be improved.

  By the way, in this embodiment, the lower radiating rib 5 and the upper radiating rib 6 are shifted by 1/2 pitch in the circumferential direction, but the lower radiating rib 5 and the upper radiating rib 6 are shifted in the circumferential direction. If so, the cooling performance of the transformer can be improved as compared with the first embodiment, and therefore, the present invention is not necessarily limited to being shifted by 1/2 pitch.

  FIG. 8 shows a third embodiment of a static induction electric machine according to the present invention, and a configuration different from the first embodiment is that the shapes of the lower heat radiating rib 9 and the upper heat radiating rib 10 are different.

  That is, in the present embodiment, the projecting dimension L2 of the upper radiating rib 10 from the peripheral wall of the tank 4 is formed larger than the projecting dimension L1 of the lower radiating rib 9, and the height dimension H2 of the upper radiating rib 10 is set downward. It is formed larger than the height dimension H1 of the heat dissipating rib 9.

  By forming in this way, the heat transfer area of the upper heat dissipation rib 10 with the cooling medium 8 is larger than that of the lower heat dissipation rib 9, and the tip of the upper heat dissipation rib 10 has finished cooling the lower heat dissipation rib 9. Since it is not affected by the outside air, the cooling efficiency by the outside air is improved.

  Even if the protruding dimension L2 of the upper radiating rib 10 and the protruding dimension L1 of the lower radiating rib 9 are made the same, the height dimension H2 of the upper radiating rib 10 is made larger than the height dimension H1 of the lower radiating rib 9. Well, the height dimension H2 of the upper heat radiation rib 10 and the height dimension H1 of the lower heat radiation rib 9 are the same, and the projecting dimension L2 of the tank 4 of the upper heat radiation rib 10 is formed larger than the projecting dimension L1 of the lower heat radiation rib 9. Even so, an effect equal to or greater than that of the first embodiment can be obtained.

  FIG. 9 shows a fourth embodiment of a static induction electric machine according to the present invention. The structure different from the first embodiment is that the rib pitch of the upper heat radiating rib 12 is smaller than the rib pitch of the lower heat radiating rib 11. For example, the pitch is ½ pitch.

  With this configuration, the heat transfer area of the upper heat dissipating rib 12 with the cooling medium 8 is almost twice the heat transfer area of the lower heat dissipating rib 11. The temperature lowering effect can be increased. As a result, the driving force of the cooling medium 8 descending in the upper heat radiating rib 12 is increased, the circulation flow rate is increased, and the cooling performance of the transformer can be further improved as compared with the first and second embodiments. it can.

  The present embodiment may be combined with any one of the configurations of the third embodiment or the entire configuration to increase the heat transfer area of the upper heat dissipation rib 12 more than the heat transfer area of the lower heat dissipation rib 11. By increasing the driving force of the cooling medium 8 and increasing the circulation flow rate, the cooling performance of the transformer can be further improved. That is, there are three configurations in which the projecting dimension of the upper heat dissipation rib is larger than that of the lower heat dissipation rib, the height dimension of the upper heat dissipation rib is larger than that of the lower heat dissipation rib, and the interval between adjacent upper heat dissipation ribs is narrower than that of the lower heat dissipation rib. The combination of at least one and all of the configurations, or the selective combination from the three configurations, is designed and manufactured taking into consideration the specifications and capacity of the transformer, as well as the installation location, thereby further improving the cooling performance Can be made.

  FIG. 10 shows a fifth embodiment of the static induction electric machine according to the present invention, and a different configuration from the first embodiment is an attachment range of the heat radiation rib to the peripheral wall of the tank 4.

  In the present embodiment, the attachment range of the upper heat radiation rib 14 to the peripheral wall of the tank 4 is made wider than the attachment range of the lower heat radiation rib 13.

  By configuring in this way, the number of the upper radiating ribs 14 is larger than that of the lower radiating ribs 13, and as a result, the heat transfer area of the upper radiating ribs 14 can be made larger than that of the lower radiating ribs 13. In addition, the same effects as those of the third embodiment can be obtained.

  As described above, according to each embodiment of the present invention, the cooling efficiency of the transformer can be improved without changing the internal structure of the transformer, and the possibility of use is extremely high.

  By the way, in each said embodiment, although the space was formed inside as a heat radiating rib and the structure which distribute | circulates the cooling medium 8 in space by facing this space in the tank 4 was demonstrated, as a heat radiating rib, It goes without saying that the present invention can be applied even if a heat radiating fin made of a plate material is used. Each embodiment has been described by taking a transformer as an example of a static induction electric appliance. However, for example, as in a reactor, the electric appliance body is housed in a tank, the tank is filled with a cooling medium, and heat is radiated to the tank peripheral wall. The present invention can be applied to any static induction machine provided with a rib.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a transformer showing a first embodiment of a static induction electric machine according to the present invention. The external view of FIG. FIG. 3 is a schematic diagram showing a temperature distribution in the vicinity of a heat radiating rib in FIG. 2 and a flow of outside air. FIG. 2 is a relationship diagram illustrating temperatures at respective positions of a cooling medium inside the transformer of FIG. 1. FIG. 2 is a diagram corresponding to FIG. 2 of a transformer illustrating a second embodiment of a static induction electric machine according to the present invention. FIG. 6 is a schematic diagram showing a temperature distribution in the vicinity of the heat dissipating ribs in FIG. 5 and a flow of outside air. The expanded sectional view which follows the AA line of FIG. The expansion side view of the radiation rib of the transformer which shows 3rd Embodiment of the static induction | electrical_connection apparatus by this invention. The equivalent figure of FIG. 2 of the transformer which shows 4th Embodiment of the static induction machine by this invention. FIG. 2 is a diagram corresponding to FIG. 2 of a transformer showing a fifth embodiment of a static induction electric machine according to the present invention. The equivalent figure of FIG. 1 which shows the conventional transformer. The external view of FIG. FIG. 12 is an assumed relationship diagram illustrating temperatures at respective positions of the cooling medium in FIG. 11. FIG. 12 is an actual measurement relationship diagram illustrating temperatures at respective positions of the cooling medium in FIG. 11. FIG. 13 is a schematic diagram showing a temperature distribution in the vicinity of the heat dissipating ribs in FIG. 12 and a flow of outside air.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric appliance main body, 2 ... Iron core, 3 ... Winding, 4 ... Tank, 5, 9, 11, 13 ... Lower radiating rib, 5A ... Space, 5I, 6I, 15I ... Temperature distribution, 6, 10, 12, 14 ... upper heat radiation rib, 6A ... space, 7 ... air flow path, 8 ... cooling medium, 15 ... heat radiation rib.

Claims (5)

In a static induction appliance comprising an electrical appliance main body, a tank containing the electrical appliance main body and filled with a cooling medium, and a plurality of vertically extending thermal radiating ribs provided around the peripheral wall of the tank, Divided into multiple in the vertical direction to form an air flow path in the circumferential direction of the tank to constitute the outside air disturbing means, and the upper and lower radiating ribs have the same pitch in the circumferential direction And a heat induction rib located in the upper part and a heat radiation rib located in the lower part are arranged shifted in the circumferential direction of the peripheral wall of the tank.   The static induction device according to claim 1, wherein the heat dissipating rib located in the upper part and the heat dissipating rib located in the lower part are arranged with a 1/2 pitch shift in the circumferential direction of the peripheral wall of the tank.   The static induction device according to claim 1 or 2, wherein the heat dissipating rib located in the upper part is installed in a wider range in the circumferential direction of the tank than the heat dissipating rib located in the lower part.   The static induction machine according to claim 1, wherein a space in which the cooling medium filled in the tank flows is opened inside the tank.   The static induction apparatus according to claim 1, wherein the heat radiation rib is a heat radiation fin formed in a solid plate shape.

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