CN102017039B - Heat dissipating means for circuit-breaker and circuit-breaker with such heat dissipating means - Google Patents

Abstract

The circuit breaker includes a vacuum interrupter, a fixed contact end and a movable contact end arranged in the vacuum interrupter, the fixed contact end is supported in the vacuum interrupter, and the first a fixed contact rod extending outwardly, supporting said movable contact end within said vacuum interrupter for reciprocating movement between contacting and separating from a fixed contact end and extending outwardly from a second end of the vacuum interrupter a movable contact rod, a first conductor connected to the fixed contact rod, a second conductor connected to the movable contact rod, and an electrical conductor arranged for at least one of the fixed contact end and the movable contact end At least one radiator. The radiator is a hollow body comprising an outer surface and an inner surface; a plurality of fins are arranged on the inner surface, wherein at least one groove is opened on each fin in a direction substantially perpendicular to the direction of air convection, wherein The direction in which the fins limit air convection is parallel to the direction in which the movable contact rod reciprocates.

Description

Circuit breaker and its cooling device

technical field

The present invention relates to circuit breakers, in particular to medium voltage circuit breakers. More specifically, the present invention relates to a heat sink for heat generated by current flowing through a circuit breaker. the

Background technique

A circuit breaker (CB) is a well known overload protection device for equipment such as high power equipment (eg engines, power lines, transformers, generators, etc.). When the current flows through the CB, the resistance of the CB's contact end, contact rod and conductor generates heat. Assuming a constant resistance, such as R, the heat generated by a flowing current I is approximately I ² R. In practice, the resistance R will increase as the temperature of the contacts, contact rods and electrical conductors increases, and the heat generated is responsible for the temperature increase. Therefore, the actual heat generated will be far greater than the theoretically calculated value. Generally speaking, because the high temperature brought by heat can cause early aging of the insulation unit, misoperation of the protection circuit, and even deformation of the contact terminal and contact rod, and finally cause CB failure, the resistance of the contact terminal, contact rod and conductor of the CB The heat generated is disadvantageous.

Therefore, for a long time, how to dissipate heat from a CB has been a hot issue in the field, and different devices and methods have been developed for this. the

Figure 1 shows a pole armature disclosed in published Chinese patent application CN1427431. The pole armature comprises a pole head 2 and a pole support 3 , each of which is equipped with cooling fins 9 . This heat dissipation method is suitable for fixed CBs, but not for movable CBs. Also, since the pole armature is submerged in SF6 gas, insulation is not an important factor to consider. the

Patent application US5,753,875 discloses a method for dissipating heat generated in a CB. In this publication, as shown in Figure 2A, a heat sink 43 is placed between the fixed and movable contact bars to enhance the heat dissipation of the CB. FIG. 2B shows a detailed structure of the heat sink 43 . Heat sink 43 comprises a set of laminations each having a central opening and radially extending slots dividing each lamination into a plurality of fingers. When assembled, the slots of the laminations form a plurality of radially extending channels through the heat sink. Air flowing through this channel will carry heat away from the radiator, which improves heat dissipation from the CB. In practice, the size of the heat sink is very large in order to dissipate heat efficiently; however, the space available for the heat sink of a CB, especially for a movable CB as shown in the above-mentioned patent application, is very limited. In addition, charge concentration will be formed at the corners of the fingers, which is detrimental to the insulation of the CB. the

Patent application WO2006/040243 provides a heat dissipation solution for connecting one electrical conductor to another through the cooling part of the device, for example connecting the contact rod of a CB to his moving contact end. Fig. 3 shows the structure of the device. As shown in FIG. 3, the structure of the connection part is complicated and additional space is required for the cooling part, which is disadvantageous for a CB whose available space is limited. the

Contents of the invention

The present invention aims at providing a heat dissipation path for a CB and more efficiently using the space available for heat dissipation components in a CB. The invention has no negative impact on the insulation of the CB. the

One embodiment of the present invention is based on using the outer and inner surfaces of the heat sink to improve heat dissipation while reducing space requirements. In this embodiment, the heat dissipation part is designed so that cool air can flow through it naturally and effectively remove the heat generated in the CB. the

According to one aspect of the present invention, a circuit breaker is provided. The circuit breaker includes a fixed contact end and a movable contact end arranged in the vacuum interrupter; a fixed contact rod, which supports the fixed contact end in the vacuum interrupter and extends from the first vacuum interrupter extending outward at one end; a movable contact rod supporting said movable contact end within said vacuum interrupter for reciprocating movement between contacting and separating from a fixed contact end and extending from a second end of the vacuum interrupter toward extending outward; and a first conductor connected with the fixed contact rod; a second conductor connected with the movable contact rod. The circuit breaker also includes at least one heat sink for heat generated by the circuit breaker. The radiator is a hollow body comprising an exterior and an interior. A plurality of fins are arranged on the inner surface, wherein at least one groove is opened on each fin in a direction substantially perpendicular to the direction of air convection, wherein the fins define the direction of air convection and are in contact with the movable The direction of the reciprocating movement of the rod is parallel. Outer and inner surfaces are formed on the exterior and interior, respectively. The interior constitutes a channel for air convection. Air is convected in a direction parallel to the reciprocating direction of the movable contact rod. Multiple fins are arranged on the inner surface to enhance heat dissipation. The interior is configured for accommodating electrical conductors and forming an interior space. In another preferred embodiment, the interior and exterior are divided by a common face, wherein the interior extends to an air channel and the exterior extends to another air channel than the interior air channel. the

In a preferred embodiment, the first electrical conductor is connected to the fixed contact rod at the first overlapping end; the second electrical conductor is connected to the movable contact rod at the second overlapping end; and the heat sink is connected to the first overlapping end. A lapped end is connected to at least one of the second lapped ends. the

In another preferred embodiment, the heat sink is secured to the second lap end of the circuit breaker and externally forms a base frame having a plurality of through-slots formed on its outer surface. That is, the groove extends from one side edge (eg, upper edge) of the outer surface to an opposite side edge (eg, lower edge). Fins are attached to the face of the base frame and extend inwardly onto the inner surface. Furthermore, the fins are separated from each other for air flow. the

In another preferred embodiment, the heat sink is secured to the first lap end of the circuit breaker and includes a base frame, wherein the base frame includes three sides. Two of the faces are opposite and parallel to each other. The third face is perpendicular to and connects the two faces to form a "U" shaped pedestal. The two faces are in the form of a barrier with uprights parallel to each other and separated. A plurality of fins extend from each upright to the interior space of the base frame. The fins are parallel to each other and perpendicular to the columns so as to form a plurality of comb structures juxtaposed and separated from each other. the

In another preferred embodiment, the switchgear further includes a connecting piece for connecting the electrical conductor of the CB with its movable contact rod, wherein the connecting piece includes a first connecting unit for connecting the movable contact rod and a A second connecting unit for connecting conductors. The second connection unit includes a flexible connection piece divided into a plurality of separate pieces in order to improve connection reliability and increase a heat dissipation area. the

In another preferred embodiment, the flexible link comprises at least three separate members. the

In another preferred embodiment, at least one longitudinal groove is formed in each of the separators. the

In another preferred embodiment, each separating member includes an overlapping portion for connecting the second electrical conductor. the

In another preferred embodiment, the overlapping portion comprises at least one longitudinal groove cutting said overlapping portion into sub-separations. the

In another preferred embodiment, the first connection unit has a hole for accommodating the movable contact rod, and a flange is formed on the inner surface of the hole, and after installation, the flange is in contact with the movable contact rod. The end faces of the rods are joined. the

According to one embodiment of the invention, the electrical conductor is a hollow cylinder with longitudinal grooves formed therein. Wherein, the inner surface of the cylinder has longitudinal ribs so that the inner surface is undulating in the circumferential direction. the

In another preferred embodiment, the first electrical conductor includes an overlapping portion and a conductive portion, the conductive portion is a hollow cylinder with longitudinal grooves formed therein, and the inner surface of the cylinder has longitudinal ribs. the

In another preferred embodiment, the second electrical conductor includes an overlapping portion and a conductive portion, the conductive portion is a hollow cylinder with longitudinal grooves formed therein, and the inner surface of the cylinder has longitudinal ribs. the

Description of drawings

Figure 1 shows an existing conductive device with cooling components;

Figure 2A shows a CB with a heat sink on its contact rod according to the prior art;

Fig. 2 B shows the detailed structure of the radiator of CB shown in Fig. 2;

Figure 3 shows a connecting part with a cooling part for connecting the contact rod of the CB to its movable contact end;

4A and 4B show the structure of a heat sink according to a preferred embodiment of the present invention;

Fig. 5A-5C shows the structure of the heat dissipation part according to another preferred embodiment of the present invention;

6A and 6B show the structure of the connecting part according to a preferred embodiment of the present invention;

Figure 6C shows a cross-sectional view of the structure of the connecting part after being installed in the CB;

Fig. 7 shows the structure of the movable contact rod according to the preferred embodiment of the present invention;

Figure 8 shows the structure of a fixed contact rod according to a preferred embodiment of the present invention; and

Fig. 9 shows the assembly of a CB according to a preferred embodiment of the present invention, which includes heat dissipation components and connection components. the

Detailed ways

Figure 9 shows an assembled view of a switchgear, eg a circuit breaker (CB) 1 according to the invention. CB1 includes: a vacuum interrupter 2, which accommodates fixed contacts and movable contacts (not shown) for connecting and/or cutting off circuits. The corresponding fixed contact rod supports the fixed contact end in the vacuum interrupter 2 and extends outward from the upper end of the vacuum interrupter 2, and the movable contact rod supports the movable contact end in the vacuum interrupter 2 and extends from the vacuum interrupter. The lower end of the arc chamber 2 extends outward. The combination of the second contact rod and the movable contact end can reciprocate in the vacuum interrupter 2 so as to contact and/or separate from the fixed contact end. The general principle of CB is described above, which is not shown in the figure, but should be obvious to those skilled in the art. The CB of the present invention also includes electrical conductors 3 and 4, connecting the CB to the equipment to be protected (not shown), such as an engine, power line, transformer or generator. The CB also includes a connector 9 for connecting the movable contact end to the electrical conductor 4 , an operating mechanism case 8 and an insulator 7 . The operating mechanism cover 8 houses an operating mechanism for operating the CB. The insulator 7 insulates the operating part from the load part. According to FIG. 9 , the heat dissipation component 5 is arranged at the overlapping end of the conductor 3 and the fixed contact rod. In addition, another heat dissipation component 6 is arranged at the overlapping end of the connecting piece 9 and the conductor 4 . It should be understood that the heat dissipation component may be arranged in other locations where heat can be conducted. For example, heat dissipation components can also be arranged at the connectors and conductors. It has a better effect when the heat dissipating component is arranged relatively close to the heat source, such as the contact terminal in a circuit breaker. In addition, an operating lever 10 is connected to the movable contact and is operated by the operating mechanism to switch on and/or off the CB. the

FIG. 4A shows the structure of the heat dissipation component 5, and FIG. 4B shows a cross-sectional view of the heat dissipation component 5 along the line I-I in FIG. 4A to output its detailed internal structure. After installation, the heat dissipation component 5 will be adapted to the conductor 4 shown in FIG. 7 . After installation, the outer slot 51 on the heat dissipation component 5 is perpendicular to the ground. the

The heat sink 5 includes a base frame 51 , and the base frame 51 includes three faces 511 , 512 , 513 whose outer surfaces form the exterior of the heat sink 5 . A semi-open hole 53 is opened on the surface 513 for passing the conductor 4 . The diameter of the hole 53 matches the outer diameter of the corresponding part of the conductor 4, so that the surface of the hole 53 is completely and firmly bonded to the outer surface 42a of the corresponding part of the conductor 4 after installation. Therefore, heat can be efficiently conducted from the conductor to the heat dissipation member 5 through the contact surface therebetween. Faces 511 and 512 are opposite and extend in a direction substantially parallel to each other and perpendicular to face 513, whereby the three faces 511, 512, 513 form a pedestal, ie a "U" shaped pedestal. After installation, the inner surface 511a of the face 511 will join the outer surface portion 41a of the electrical conductor 4 and the inner surface 512a will join the corresponding portion of the electrical conductor 4 . A plurality of fins 52 extending in a substantially vertical direction from the face 513 are disposed on the inner surface of the heat dissipation member and extend toward the inner space of the base frame. The fin is formed with a port 54 for passage of the operating rod 10 . As shown in the drawings, the interior of the cooling component 5 is equipped with vertical passages 55 for effective air convection. The fins 52 are separated from each other so that cool air can be naturally convected. More specifically, the fins 52 heat the cool air in the heat sink. Because heated air is less dense than cold air, the heated air will circulate and convect through channels 55 . During the gas convection, the heat generated in the device is carried away. It should be clear that the direction of air convection is parallel to the direction of reciprocating movement of the movable contact rod. For example, as shown in FIG. 9, when the circuit breaker is installed vertically, the channel 55 and the direction of convection are perpendicular to the ground. the

In order to conduct heat more efficiently from the conductor 4, the heat dissipation member 5 is adapted to increase the contact surface with the conductor. For example, the surface 52 a of a part of the fin 52 has the profile of the portion 42 a of the outer surface of the conductor 4 . And some fins also have a special shape, that is, their surface 52b has a shape matching the other part 41b of the outer surface of the conductor 4 . the

As mentioned above, the heat is carried away by the cool air circulating through the channels 55 of the heat sink 5 . With the above structure, first, the heat generated in the circuit breaker is conducted to the heat dissipation member 5 . Secondly, the circuit breaker is thus cooled by the air convection occurring in the channels 55 of the heat sink 5 . Furthermore, the fins 52 are designed to extend in a direction substantially parallel to the insertion direction of the conductor 4 . As a result, the contact area between the heat dissipation member and the conductor is significantly increased. Because the increased contact area improves heat transfer, heat can be dissipated more effectively to the surroundings. Convection simulations show that embodiments according to the present invention improve heat transfer efficiency by 10-30%, depending on the total contact area of the fins (heat dissipation). the

In order to increase the heat dissipation area, a plurality of fins 51a are arranged on the outer surface of the base frame 51 . In order to make better use of gas convection, it is preferable to form the grooves vertically as shown in FIGS. 4A and 4B. That is, after installation, the groove extends in a direction perpendicular to the ground. the

In addition, as shown in FIG. 9 , the connection piece 9 is located above the heat dissipation component 5 , and the air flowing through the component 5 is guided to the connection piece 9 to further improve heat dissipation. It should be clear that the heat sink 5 can also be mounted on at least one contact bar and conductor. the

FIG. 5A shows the structure of the heat dissipation component 6 , and FIG. 5B and FIG. 5C are cross-sectional views along II-II and III-III in FIG. 5A , which respectively show the structure of the component 6 in detail. As shown in FIG. 8 , after installation, the heat dissipation component 6 will cooperate with the conductor 3 as a whole. the

The heat dissipation component 6 also includes a base frame 61 including surfaces 611 , 612 , 613 . The face 611 and the face 612 are opposite and parallel to each other. Face 613 is perpendicular to face 611 and face 612 and connects face 611 and face 612 so as to form a "U" shaped pedestal. Face 611 and face 612 are in the form of a barrier with uprights 611A parallel to each other and spaced apart. The fins 62 extend from each column 611A toward the inner space of the base frame 61 . Fins 62 are parallel to each other and substantially perpendicular to posts 611A so as to form a plurality of comb structures juxtaposed and separated from each other. the

In an embodiment of the present invention, each comb structure is formed by alternately combining a plurality of short fins and long fins. The short and long fins are joined with the end faces of each coplanar with the corresponding end faces of the other fins to form the back of a comb-like structure for the uprights of the barrier. The other ends or free ends of the long fins serve as fins extending based on the inner space of the base frame. the

In the embodiment of the present invention, the heat dissipation component 6 includes a two-part structure as shown in FIG. 5 . That is, one part includes the face 611 and the face 612a and the fin 62 extending therefrom, and the other part includes the face 612 and the face 611a and the fin 62 extending therefrom. The two parts are combined with each other so as to form the integral heat sink 6 . In the configuration described above, the fins 62 extending from the two opposite faces form the channel 63 and their opposite free ends receive the beams 311 or 312 so that when installed each free end firmly engages the sides 311a, 311b, or 312a, 312b . With this configuration, heat generated in the conductor 3 can be directly conducted to the heat dissipation member 6 . the

In order to enhance heat dissipation, the present invention also provides an improved connecting piece 9 for connecting the movable contact rod of the CB to the corresponding part of the conductor 4 . 6A and 6B show the structure of this connector 9 . the

As shown in FIG. 6A, the connecting member 9 includes a first connecting unit 91 for connecting the movable contact rod and a second connecting unit 92 for connecting the second conductor 4. The first connecting unit 91 has a hole 911 for receiving the movable contact rod. The second connection unit 92 includes a flexible connection piece composed of a plurality of separate pieces 921 , 922 , 923 , 924 for improving connection reliability and increasing heat dissipation area. Compared with conventional connectors, the connector of the present invention includes a plurality of separate parts that may have a thinner profile to increase its flexibility. In a preferred embodiment, each separate part of the flexible link is equipped with at least one longitudinal slot 93 as shown in Figures 6A and 6B to further increase the flexibility. In another preferred embodiment, the lower end of the groove 93 extends down to the edge of the separator where the groove 93 is located, for example, the edge 921a of the separator 921, so that the fixed part 94 of the separator is divided into sub-separators, the second The contact between the connection piece and the electrical conductor 4 will be more reliable, so as to further reduce the contact resistance and thus further reduce the heat generated at the overlap due to the contact resistance. the

In a preferred embodiment of the invention, the hole 911 is equipped with a flange 912 to fit the movable contact end by the push rod (operating rod) 10 . As shown in FIG. 6C, the flange 912 is pushed toward one end of the movable contact rod and combined with it, so as to increase the contact area between the connecting piece 9 and the movable contact rod, thereby reducing the contact resistance and the heat generated thereby. . Another advantage of this structure is that the push rod 10 supports the link 9 so as to define the mounting position to simplify the installation of the CB before the final fixation of the link 9 to the movable contact rod. the

7 and 8 show structures of electrical conductors 4 and 3, respectively, according to an embodiment of the present invention. As shown in Figures 7 and 8, the electrical conductors include overlapping portions 31, 41 and conductive portions 32, 42, respectively. The overlapping portion 31 is designed to connect the fixed contact rod and accommodate the heat dissipation component 6 , and the overlapping portion 41 is designed to connect the connecting piece 9 and accommodate the heat dissipation component 5 . The conductive portions 32 and 42 are designed to further improve heat dissipation and conductivity. the

Take the conductive portion 42 as an example. As shown in FIG. 7, the conductive portion 42 is a hollow cylinder with longitudinal grooves 43 formed thereon, and the inner surface of the cylinder has longitudinal ribs 44 so that the inner surface is undulated in the circumferential direction. According to the above structure, the area of the inner surface is enlarged so that heat generated in the contact rod can be dissipated more effectively. According to the above structure, the cross-sectional area of the effectively conductive contact rod is increased to allow a larger area for the current flowing through the conductor. Below a given load, this means that the material used to form the conductors can be thinner, which provides more internal space for air flow to improve heat dissipation. the

Although the present invention has been shown and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that, without departing from the spirit and scope of the present invention as defined by the appended claims, various Various changes are made to it in form and detail. the

Claims (22)

1. a circuit breaker (1), comprising:

Vacuum interrupter (2);

Be arranged in fixedly contact jaw and movable contact in described vacuum interrupter (2);

Fixing contact lever, it is at fixing contact jaw and stretching out from the first end of described vacuum interrupter (2) described in described vacuum interrupter (2) inner support;

Movable contact lever, its at movable contact described in described vacuum interrupter (2) inner support in case with fixing contact jaw contact and separated between reciprocating motion and stretching out from the second end of vacuum interrupter (2);

The first electric conductor (3) being connected with described fixedly contact lever;

The second electric conductor (4) being connected with described movable contact lever; With

At least one radiator (5,6) at least one layout in described fixedly contact jaw and described movable contact;

It is characterized in that:

Described radiator (5,6) is the hollow body that comprises outer surface and inner surface; A plurality of fins (52,62) be arranged on described inner surface, wherein at each fin (52,62) above with the direction substantially vertical with cross-ventilated direction, have at least one groove, it is parallel with the reciprocating direction of described movable contact lever that wherein said fin (52,62) limits cross-ventilated direction.

2. circuit breaker as claimed in claim 1 (1), wherein the surface (52b) of a plurality of fins (52) has the outer surface of cooperation electric conductor (4).

3. circuit breaker as claimed in claim 1 (1), wherein the first electric conductor (3) is connected in the first bond end with described fixedly contact lever; The second electric conductor (4) is connected in the second bond end with described movable contact lever; And described radiator (5,6) and the first bond end are connected with at least one in the second bond end.

4. circuit breaker as claimed in claim 1 (1), wherein said radiator (5) also comprises first surface (511,611), second (512,612) and the 3rd (513,613); First surface (511,611) and second (512,612) parallel to each other and respectively from two edges of the 3rd (513,613) with identical, substantially extend with the 3rd direction that (513,613) are vertical.

5. circuit breaker as claimed in claim 4 (1), wherein said fin (52) is from the described inner surface that inner surface stretches out and only its one end is fixed to described the 3rd (513) of the 3rd (513).

6. circuit breaker as claimed in claim 1 (1), after wherein said outer surface is formed with and installs its direction with substantially vertical a plurality of grooves (51a).

7. circuit breaker as claimed in claim 4 (1), has in wherein said the 3rd for by the mouth (53) of the second electric conductor (4).

8. circuit breaker as claimed in claim 7 (1), the diameter of wherein said mouthful (53) matches with the overall diameter of the second electric conductor (4), so that described the 3rd (513,613) and described the second electric conductor (4) combination securely after installing.

9. circuit breaker as claimed in claim 4 (1), wherein said fin (52) from the 3rd (513,613) to extend internally and to be separated from each other with the 3rd basic vertical direction.

10. circuit breaker as claimed in claim 4 (1), wherein said first surface (611) and described second (612) are formed with a plurality of parallel to each other and columns (611a) of separating.

11. circuit breakers as claimed in claim 10 (1), with the direction of substantially vertical described column (611a), each from described column (611a) extends internally wherein said fin (62), and is separated from each other.

12. circuit breakers as claimed in claim 10 (1), each in wherein said column (611a) is replaced in conjunction with forming by a plurality of short fins and long fin, each in wherein said short fin and long fin has the end face coplanar with the end face of other fins, and the other end of described long fin forms fin (62).

13. circuit breakers (1) as described in one of claim 7 to 9, wherein said circuit breaker (1) comprises at least two radiators (6).

14. circuit breakers as claimed in claim 1 (1), also comprise the connector (9) for the second electric conductor (4) is connected with described movable contact lever, described connector (9) comprise for connect first linkage unit (91) of described removable contact lever with for being connected second linkage unit (92) of the second electric conductor (4), wherein the second linkage unit (92) comprises by the separation member (921 that is connected to the first linkage unit (91), 922,923,924) flexible connecting member forming.

15. circuit breakers as claimed in claim 14 (1), wherein said flexible connecting member is comprised of at least three separation members.

16. circuit breakers as claimed in claim 14 (1), wherein form at least one cannelure (93) in each in described separation member.

17. circuit breakers (1) as described in one of claim 14 to 16, wherein described in each, separation member comprises the overlap (94) for connecting the second electric conductor (4).

18. circuit breakers as claimed in claim 17 (1), wherein said overlap (94) comprises at least one cannelure (93) of described overlap (94) cutting.

19. circuit breakers as claimed in claim 14 (1), wherein said the first linkage unit (91) has the hole (911) for holding described movable contact lever, on the inner surface of described hole (911), form flange (912), and after installing, described flange (912) is combined with the end face of described movable contact lever.

20. circuit breakers as claimed in claim 1 (1), wherein the first electric conductor (3) comprises overlap (31) and current-carrying part (32), described current-carrying part (32) is the hollow cylinder that is formed with cannelure (33) on it, and described cylindrical inner surface has longitudinal rib (34).

21. circuit breakers as claimed in claim 1 (1), wherein the second electric conductor (4) comprises overlap (41) and current-carrying part (42), described current-carrying part (42) is the hollow cylinder that is formed with cannelure (43) on it, and described cylindrical inner surface has longitudinal rib (44).

22. circuit breakers as claimed in claim 1 (1), wherein said circuit breaker is removable circuit breaker.

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