A parallel switch cabinet hard busbar device

Abstract

The present invention discloses a parallel switch cabinet hard bus coupling device, which includes at least two parallel switch cabinet units, each switch cabinet unit is provided with a parallel cabinet chamber with mutually consistent positions, the parallel cabinet chamber is provided with a plurality of T-type connectors, the T-type connectors of different switch cabinet units are connected through a hard bus, the overall shape of the hard bus is a U-shaped structure, the hard bus includes a conductive copper core, a conductive rubber layer, an outer insulating layer and a hard outer conductor layer arranged in sequence from the inside to the outside, each parallel cabinet chamber has a bus window with completely the same shape and consistent positions on the side, and a lifting bus clamping mechanism is provided on the bus window. The present invention connects two switch cabinets through a U-shaped hard bus, so that the cable casing is not easy to crack, and the lifting bus clamping mechanism can facilitate the rapid installation and removal of the hard bus, solving the problem that gravity causes the bending and joints of the cable to easily cause power risk hazards.

Description

Technical Field

[0001] The invention relates to the technical field of switch cabinets, and in particular to a hard busbar device for parallel switch cabinets. Background Art

[0002] A switch cabinet is an electrical device whose main function is to open, close, control and protect electrical equipment during power generation, transmission, distribution and energy conversion in the power system. In actual use, different types of cabinets such as circuit breaker cabinets, contactor cabinets (FC circuits), load switch cabinets (FS circuits) are often connected to a busbar for use. Different load circuits are protected and controlled by different switch elements, which can reduce the cost of switchgear. The two switch cabinets are connected by cables, and the cables of the prior art often need to be bent multiple times to achieve the connection effect when used, or extended cables are used to overcome the difficulty of bending. After the cable is bent, the bending part is subjected to the bending pressure, and the integrity of the pipeline is destroyed. In the high-voltage switch cabinet, frequent and long-term high-voltage current passes through, especially at the bending part, which is very likely to cause power risk hazards, including cable bulging and bursting. Summary of the invention

[0003] The present invention aims to solve the problems existing in the above-mentioned prior art and provides a hard busbar device for a parallel switch cabinet, which facilitates the parallel connection between two switches and has more reliable stability after the connection.

[0004] The present invention solves its technical problems by adopting a technical solution: a hard busbar coupling device for parallel switch cabinets, the hard busbar coupling device comprising at least two parallel switch cabinet units, each switch cabinet unit is provided with a parallel cabinet chamber with mutually consistent positions, the parallel cabinet chamber is provided with a plurality of T-type connectors, the T-type connectors of different switch cabinet units are connected through a hard busbar, the overall shape of the hard busbar is a U-shaped structure, the hard busbar comprises a conductive copper core, a conductive rubber layer, an outer insulating layer and a hard outer conductor layer arranged in sequence from the inside to the outside, each of the parallel cabinet chambers has a busbar window with completely the same shape and consistent positions on the side, the busbar window is provided with a lifting busbar clamping mechanism, the lifting busbar clamping mechanism comprises a clamping plate symmetrically arranged up and down, the clamping plate is slidably connected to the inner wall of the parallel cabinet chamber, one end of the clamping plate is provided with a clamping port, the clamping port is provided with a protective pad, one end of the clamping plate is fixedly connected to a spring, the spring is connected to a lifting screw, a nut is threadedly connected to the lifting screw, the nut is connected to a rotating support, and the rotating support is fixedly connected to the inner wall of the parallel cabinet chamber.

[0005] For further improvement, a sealing air cushion is provided on the protective cushion, and the sealing air cushion is connected to an elastic air storage bag through an air pipe, and a high-voltage insulating gas is provided in the elastic air storage bag.

[0006] For further improvement, the protective pad is provided with an arc-shaped shielding net, and elastic contact pieces located on the surface of the protective pad are provided at both ends of the arc-shaped shielding net.

[0007] Further improvement, the protective pad consists of a glass fiber layer, an epoxy resin layer and a silicone rubber layer which are arranged in sequence from the inside to the outside.

[0008] Further improvement, the hard outer conductor layer is made of a bent copper tube, a spiral pneumatic tube is provided on the inner wall of the hard outer conductor layer, and an air nozzle connected to the spiral pneumatic tube is provided on the outer wall of the hard outer conductor layer.

[0009] For further improvement, a dehumidification structure is provided on the clamping plate, and the dehumidification structure includes a plurality of moisture absorption holes arranged on the inner surface of the clamping plate and a dehumidification cavity arranged inside the clamping plate, a moisture absorption cotton plate is provided in the dehumidification cavity, and a plurality of solid moisture absorption beads are fixedly provided on one side of the moisture absorption cotton plate, and a dehumidification heat dissipation pipe connected to the outside is provided on the dehumidification cavity, and a unidirectional moisture-conducting cotton rope is provided in the dehumidification heat dissipation pipe, and the inner end of the unidirectional moisture-conducting cotton rope is connected in series with the solid moisture-absorbing beads or the moisture-absorbing cotton plate, and a heat dissipation hole is provided on the back of the switch cabinet unit, and the outer end of the unidirectional moisture-conducting cotton rope is fixedly provided on the outside of the heat dissipation hole.

[0010] For further improvement, a semiconductor refrigeration sheet is fixedly arranged on one side of the moisture-absorbing cotton plate, the cooling end of the semiconductor refrigeration sheet is attached to the moisture-absorbing cotton plate, and the heat dissipation end of the semiconductor refrigeration sheet is connected to the dehumidification and heat dissipation pipeline.

[0011] For further improvement, the T-type connector is connected to a lightning arrester, including an insulating jacket and an upper electrode, a resistor group and a lower electrode arranged inside the insulating jacket, the resistor group includes several layers of insulating honeycomb sheets, and a plurality of zinc oxide resistors are arranged in parallel on the insulating honeycomb sheets, and the zinc oxide resistors of adjacent insulating honeycomb sheets are connected in series accordingly.

[0012] For further improvement, a sintered metal shielding layer is provided between the insulating honeycomb sheet and the zinc oxide resistor sheet; an insulating gasket is provided between adjacent insulating honeycomb sheets, and an elastic contact for connecting the zinc oxide resistor sheet in series is provided on the insulating gasket.

[0013] For further improvement, the insulating gasket is provided with a first exhaust pipeline, the inner end of the first exhaust pipeline is connected to the holes on the insulating honeycomb sheet, the outer end of the first exhaust pipe is connected to the second exhaust pipeline, the second exhaust pipeline is located between the insulating honeycomb sheet and the inner wall of the insulating jacket, and the insulating jacket is provided with a one-way exhaust valve connected to the second exhaust pipeline.

[0014] The beneficial effects of the present invention are as follows: the present invention connects two switch cabinets through a U-shaped hard busbar, and the hard busbar includes a conductive copper core, a conductive rubber layer, an outer insulating layer and a hard outer conductor layer arranged in sequence from the inside to the outside, which can effectively shield the dispersed electric field internally, and the whole is fully insulated, fully sealed, and fully shielded, safe and reliable. The overall structure is small and compact, and all bending angles can be consistent, which beautifies the overall installation line space of the switch lifting cabinet; the shape of the hard outer conductor layer can be processed by copper tube bending according to the center distance of the cabinet, and the bending radius is flexible. The cable inlet and outlet lines are not easily twisted by long-term mechanical stress, which can easily lead to cracking of the casing and other phenomena. In addition, the switch cabinet is provided with a busbar window and a lifting busbar clamping mechanism, which can facilitate the rapid installation and disassembly of the hard busbar, and solves the problem that gravity causes the cable bends and joints to easily cause electrical risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a side structural schematic diagram of the present invention.

[0016] Figure 2 It is a rear view structural schematic diagram of the present invention.

[0017] Figure 3 This is a structural diagram of the hard busbar.

[0018] Figure 4 It is a schematic diagram of the structure of the dehumidification structure and the pad.

[0019] Figure 5 This is a schematic diagram of the structure of a lightning arrester.

[0020] Figure 6 It is a schematic diagram of the structure of the arc shielding net.

[0021] Explanation of reference numerals: 1. switch cabinet unit, 11. cabinet chamber, 12. T-connector, 13. busbar window, 2. hard busbar, 21. conductive copper core, 22. conductive rubber layer, 23. outer insulation layer, 24. hard outer conductor layer, 25. spiral air tube, 26. air nozzle, 3. lifting busbar clamping mechanism, 31. clamping plate, 32. lifting screw, 33. spring, 4. protective pad, 41. sealing air cushion, 42. elastic air storage bag, 43. arc shielding net, 44. elastic contact sheet, 45. glass fiber layer, 46. epoxy resin Layer, 47, silicone rubber layer, 5, dehumidification structure, 51, moisture absorption hole, 52, dehumidification chamber, 53, moisture absorption cotton plate, 54, solid moisture absorption beads, 55, dehumidification heat dissipation pipeline, 56, one-way moisture conductive cotton rope, 57, semiconductor refrigeration plate, 6, lightning arrester, 61, insulating jacket, 611, second exhaust pipeline, 612, one-way exhaust valve, 62, upper electrode, 63, lower electrode, 64, zinc oxide resistor, 65, sintered metal shielding layer, 66, insulating gasket, 661, elastic contact, 662, first exhaust pipeline, 67, insulating honeycomb sheet. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] Example 1: Refer to the attached Figure 1-2 A hard busbar coupling device for parallel switch cabinets, the hard busbar coupling device includes at least two parallel switch cabinet units 1, each switch cabinet unit 1 is provided with a parallel cabinet room 11 with mutually consistent positions, the parallel cabinet room 11 can also be called a cable room or a busbar room, a plurality of T-type connectors 12 are arranged in the parallel cabinet room 11, and the T-type connectors 12 of different switch cabinet units 1 are connected through a hard busbar 2, the overall shape of the hard busbar 2 is a U-shaped structure, the hard busbar 2 includes a conductive copper core 21, a conductive rubber layer 22, an outer insulating layer 23 and a hard outer conductor layer 24 arranged in sequence from the inside to the outside. The conductive rubber layer 22 realizes the effect of electromagnetic shielding, the outer insulating layer 23 has the effect of insulation, and the hard outer conductor layer 24 has the function of support and shielding, which can effectively disperse the electric field, as shown in the attached Figure 3As shown, the hard outer conductor layer 24 is made of copper tube bending, and the intermediate length of current transmission is reduced. Secondly, the rigidity replaces the flexible conductor to improve the strength of the product. The hard busbar connection can be standardized according to the specific installation port of the switch cabinet, ignoring the distance space of the cabinet, and adapting to the small product scene setting to the greatest extent. A spiral pneumatic tube 25 is provided on the inner wall of the hard outer conductor layer 24, and a gas nozzle 26 connected to the spiral pneumatic tube 25 is provided on the outer wall of the hard outer conductor layer 24. When the spiral pneumatic tube 25 is not inflated, it is convenient to insert the cable into the hard outer conductor layer 24. After the cable passes through, the spiral pneumatic tube 25 is inflated through the gas nozzle 26. The volume of the spiral pneumatic tube 25 expands, forming a spiral elastic support for the cable, which can prevent the cable from loosening and bending in the hard outer conductor layer 24, and can also be suspended to improve the insulation performance, and is not easily affected by thermal expansion and contraction. In the high-voltage switch cabinet, frequent and long-term high-voltage current passes through, and the cable is not easy to cause power risk hazards at the bend, reducing the occurrence of cable bulging, bursting and other phenomena.

[0024] Each of the side panels 11 has a busbar window 13 with the same shape and position. The busbar window 13 facilitates the passage of the bent hard busbar 2. The busbar window 13 is provided with a lifting busbar clamping mechanism 3, which can support and fix the hard busbar 2. The lifting busbar clamping mechanism 3 includes a clamping plate 31 symmetrically arranged up and down. The clamping plate 31 is slidably connected to the inner wall of the cabinet chamber 11. One end of the clamping plate 31 is provided with a clamping port, and the clamping port is provided with a protective pad 4, which can be adapted to the shape of the hard busbar 2. The function of the protective pad 4 is the same as that of the high-voltage wall bushing, and is used for insulation and support of the conductive part passing through the wall or other grounding objects. One end of the clamping plate 31 is fixedly connected to a spring 33, and the spring 33 is connected to a lifting screw 32. A nut is threadedly connected to the lifting screw 32, and the nut is connected to a rotating support, and the rotating support is fixedly connected to the inner wall of the cabinet chamber 11. When the worker turns the nut with a wrench, the lifting screw 32 can be threadedly driven to extend and retract, and the clamping plate 31 can be pulled up and down by the spring 33 to achieve elastic clamping of the hard busbar 2, thereby facilitating the adjustment of the installation height of the hard busbar 2 and facilitating the maintenance and replacement of the hard busbar 2 at a later stage.

[0025] Embodiment 2: As attached Figure 4 As shown, on the basis of embodiment 1, the protective pad 4 is provided with a sealing air cushion 41, and the sealing air cushion 41 is connected to an elastic air storage bag 42 through an air pipe, and a high-voltage insulating gas is provided in the elastic air storage bag 42. Figure 6As shown, the protective pad 4 is provided with an arc-shaped shielding net 43, and elastic contact sheets 44 located on the surface of the protective pad 4 are provided at both ends of the arc-shaped shielding net 43. The protective pad 4 is composed of a glass fiber layer 45, an epoxy resin layer 46 and a silicone rubber layer 47 arranged in sequence from the inside to the outside. When the clamping plate 31 clamps the hard busbar 2, the upper side of the sealing air cushion 41 is squeezed and split, and the gas inside it is discharged to the elastic air storage bag 42, and the volume is reduced to form an arc shape, so as to adapt to fill the space between the hard busbar 2 and the protective pad 4, and play the role of sealing, insulation and support. When the clamping plate 31 does not clamp the hard busbar 2, the sealing air cushion 41 is not squeezed, and the gas in the elastic air storage bag 42 is filled into the sealing air cushion 41, and the volume expands to form a semicircle, thereby sealing the busbar window, and playing the role of sealing and isolation.

[0026] Embodiment 3: As attached Figure 3 As shown, on the basis of embodiment 1 or 2, the clamping plate 31 is provided with a dehumidification structure 5, the dehumidification structure 5 includes a plurality of moisture absorption holes 51 arranged on the inner surface of the clamping plate 31 and a dehumidification chamber 52 arranged inside the clamping plate 31, a moisture absorption cotton plate 53 is arranged in the dehumidification chamber 52, a plurality of solid moisture absorption beads 54 are fixedly arranged on one side of the moisture absorption cotton plate 53, a dehumidification heat dissipation duct 55 connected to the outside is arranged in the dehumidification heat dissipation duct, a unidirectional moisture conduction cotton rope 56 is arranged in the dehumidification heat dissipation duct, the inner end of the unidirectional moisture conduction cotton rope 56 is connected in series with the solid moisture absorption beads 54 or the moisture absorption cotton plate 53, a heat dissipation hole is arranged on the back of the switch cabinet unit 1, and the outer end of the unidirectional moisture conduction cotton rope 56 is fixedly arranged on the outer side of the heat dissipation hole. Condensation often occurs in the cabinet chamber 11, and a dehumidification device needs to be arranged to prevent condensation from affecting the equipment in the switch cabinet. The air in the cabinet chamber 11 can enter the dehumidification chamber 52 through the moisture absorption hole 51. The moisture absorption cotton board 53 and the solid moisture absorption beads 54 in the dehumidification chamber 52 can absorb moisture and dry the air. The outer end of the unidirectional moisture-conducting cotton rope 56 is heated by the hot air blown out from the heat dissipation hole on the switch cabinet unit 1. The moisture of the moisture absorption cotton board 53 and the solid moisture absorption beads 54 is guided to the outside through the penetration of the unidirectional moisture-conducting cotton rope 56 for automatic evaporation, thereby improving the moisture absorption effect and extending the service life of the dehumidification structure.

[0027] A semiconductor cooling sheet 57 is fixedly arranged on one side of the moisture-absorbing cotton plate 53, and the cooling end of the semiconductor cooling sheet 57 is attached to the moisture-absorbing cotton plate 53, and the heat dissipation end of the semiconductor cooling sheet 57 is connected to the dehumidification heat dissipation pipe 55. After the semiconductor cooling sheet 57 is powered on, the cooling end can cool the moisture-absorbing cotton plate 53, which plays a role of condensation and dehumidification. The heat of the heat dissipation end of the semiconductor cooling sheet 57 can be conducted and dissipated through the dehumidification heat dissipation pipe 55, and the moisture conduction effect of the unidirectional moisture-conducting cotton rope 56 is improved by heating the entire unidirectional moisture-conducting cotton rope 56.

[0028] Embodiment 4: As attached Figure 5As shown, on the basis of embodiment 1 or 3, the T-type connector 12 is connected with a lightning arrester 6, including an insulating jacket 61 and an upper electrode 62, a resistor group and a lower electrode 63 arranged inside the insulating jacket 61, the resistor group includes several layers of insulating honeycomb sheets 67, the insulating honeycomb sheets 67 are made of high temperature resistant insulating materials such as alkali-free glass and alumina ceramics, a laminated structure or an integrated fired structure, and a plurality of zinc oxide resistors 64 are arranged in parallel on the insulating honeycomb sheets 67, and the zinc oxide resistors 64 of adjacent insulating honeycomb sheets 67 are connected in series. Since a plurality of zinc oxide resistors 64 are arranged in parallel on the insulating honeycomb sheets 67, the lightning arrester 6 forms a parallel circuit structure with multiple paths, and is not easy to fail due to damage to one path when struck by lightning, and the performance is slightly reduced at most, the impact resistance is strong, the service life of the lightning arrester is extended, and it is safer.

[0029] A sintered metal shielding layer 65 is provided between the insulating honeycomb sheet 67 and the zinc oxide resistor sheet 64; the sintered metal shielding layer 65 can absorb arc heat, make the electric field uniform (or evenly distribute the voltage along the resistor sheet), reduce the current flowing through the resistor sheet, greatly improve the overvoltage absorption capacity, and reduce the degradation rate of the resistor sheet. An insulating gasket 66 is provided between adjacent insulating honeycomb sheets 67, and an elastic contact 661 for connecting the zinc oxide resistor sheet 64 in series is provided on the insulating gasket 66. The insulating gasket 66 can avoid the zinc oxide resistor sheet 64 from generating a gap, and the elastic contact 661 can ensure the continuous contact of the zinc oxide resistor sheet 64, so as to avoid the zinc oxide resistor sheet 64 from loosening and poor contact due to bumps or aging of the outer skin of the arrester.

[0030] The insulating gasket 66 is provided with a first exhaust pipe 662, the inner end of the first exhaust pipe 662 is connected to the hole on the insulating honeycomb sheet 67, the outer end of the first exhaust pipe is connected to the second exhaust pipe 611, the second exhaust pipe 611 is located between the insulating honeycomb sheet 67 and the inner wall of the insulating jacket 61, and the insulating jacket 61 is provided with a one-way exhaust valve 612 connected to the second exhaust pipe 611. When the zinc oxide lightning arrester is running in the later period of its product life, the resistor deteriorates and causes the leakage current to rise. When the discharge is serious, the gas pressure and temperature inside the lightning arrester increase sharply. The gas pressure can be relieved through the first exhaust pipe 662, the second exhaust pipe 611 and the one-way exhaust valve 612 to avoid causing the zinc oxide lightning arrester body to explode.

[0031] Although the present invention has been shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein within the scope of the claims.

Claims

1. A parallel switch cabinet hard bus coupling device, the hard bus coupling device comprising at least two parallel switch cabinet units (1), each switch cabinet unit (1) is provided with a parallel cabinet chamber (11) whose positions are consistent with each other, a plurality of T-type connectors (12) are provided in the parallel cabinet chamber (11), and the T-type connectors (12) of different switch cabinet units (1) are connected via a hard busbar (2), characterized in that: The overall shape of the hard busbar (2) is a U-shaped structure. The hard busbar (2) comprises a conductive copper core (21), a conductive rubber layer (22), an outer insulating layer (23) and a hard outer conductor layer (24) which are arranged in sequence from the inside to the outside. A busbar window (13) having a shape completely identical to each other and a position consistent with each other is provided on the side of each cabinet chamber (11). The busbar window (13) is provided with a lifting busbar clamping mechanism (3). The lifting busbar clamping mechanism (3) comprises a clamping plate (31) symmetrically arranged up and down. The clamping plate (31) is slidably connected to the inner wall of the cabinet chamber (11). One end of the clamping plate (31) is provided with a clamping opening. The clamping opening is provided with a protective pad (4). One end of the clamping plate (31) is fixedly connected to a spring (33). The spring (33) is connected to a lifting screw (32). A nut is threadedly connected to the lifting screw (32). The nut is connected to a rotating support. The rotating support is fixedly connected to the inner wall of the cabinet chamber (11). The hard outer conductor layer (24) is made by bending a copper tube, a spiral pneumatic tube (25) is provided on the inner wall of the hard outer conductor layer (24), and an air nozzle (26) connected to the spiral pneumatic tube (25) is provided on the outer wall of the hard outer conductor layer (24).

2. A parallel switch cabinet hard bus coupling device according to claim 1, characterized in that: The protective pad (4) is provided with a sealing air cushion (41), the sealing air cushion (41) is connected to an elastic air storage bag (42) via an air pipe, and the elastic air storage bag (42) is provided with insulating gas.

3. A parallel switch cabinet hard bus coupling device according to claim 1, characterized in that: The protective pad (4) is provided with an arc-shaped shielding net (43), and elastic contact pieces (44) located on the surface of the protective pad (4) are provided at both ends of the arc-shaped shielding net (43).

4. A parallel switch cabinet hard bus coupling device according to claim 1, characterized in that: The protective pad (4) is composed of a glass fiber layer (45), an epoxy resin layer (46), and a silicone rubber layer (47) which are arranged in sequence from the inside to the outside.

5. The parallel switch cabinet hard bus coupling device according to claim 1, characterized in that: The holding plate (31) is provided with a dehumidification structure (5), the dehumidification structure (5) comprising a plurality of moisture absorption holes (51) arranged on the inner surface of the holding plate (31) and a dehumidification chamber (52) arranged inside the holding plate (31), a moisture absorption cotton plate (53) being arranged inside the dehumidification chamber (52), a plurality of solid moisture absorption beads (54) being fixedly arranged on one side of the moisture absorption cotton plate (53), a dehumidification heat dissipation duct (55) communicating with the outside being arranged on the dehumidification chamber (52), a unidirectional moisture conduction cotton rope (56) being arranged inside the dehumidification heat dissipation duct, the inner end of the unidirectional moisture conduction cotton rope (56) being connected in series with the solid moisture absorption beads (54) or the moisture absorption cotton plate (53), a heat dissipation hole being arranged on the back side of the switch cabinet unit (1), the outer end of the unidirectional moisture conduction cotton rope (56) being fixedly arranged on the outer side of the heat dissipation hole.

6. A parallel switch cabinet hard bus coupling device according to claim 5, characterized in that: A semiconductor refrigeration sheet (57) is fixedly provided on one side of the moisture-absorbing cotton plate (53); a cooling end of the semiconductor refrigeration sheet (57) is in contact with the moisture-absorbing cotton plate (53); and a heat dissipation end of the semiconductor refrigeration sheet (57) is connected to a dehumidification and heat dissipation pipeline (55).

7. The parallel switch cabinet hard bus coupling device according to claim 1, characterized in that: The T-shaped connector (12) is connected to a lightning arrester (6), comprising an insulating jacket (61) and an upper electrode (62), a resistor group and a lower electrode (63) arranged inside the insulating jacket (61); the resistor group comprises a plurality of layers of insulating honeycomb sheets (67); a plurality of zinc oxide resistors (64) are arranged in parallel on the insulating honeycomb sheets (67); and the zinc oxide resistors (64) of adjacent insulating honeycomb sheets (67) are connected in series.

8. A parallel switch cabinet hard bus coupling device according to claim 7, characterized in that: A sintered metal shielding layer (65) is provided between the insulating honeycomb sheet (67) and the zinc oxide resistor sheet (64); an insulating gasket (66) is provided between adjacent insulating honeycomb sheets (67); and a resilient contact (661) for connecting the zinc oxide resistor sheet (64) in series is provided on the insulating gasket (66).

9. A parallel switch cabinet hard bus coupling device according to claim 8, characterized in that: The insulating gasket (66) is provided with a first exhaust pipeline (662), the inner end of the first exhaust pipeline (662) is connected to a hole on the insulating honeycomb sheet (67), the outer end of the first exhaust pipe is connected to a second exhaust pipeline (611), the second exhaust pipeline (611) is located between the insulating honeycomb sheet (67) and the inner wall of the insulating jacket (61), and the insulating jacket (61) is provided with a one-way exhaust valve (612) connected to the second exhaust pipeline (611).

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