JP2010226771A - Coated-cable drawing structure of liquid-immersed apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a fluid from leaking out of a pressure container through the inside of the coat of a cable, in a structure of drawing out the coated cable of an electrical apparatus through the pressure container which is charged with a pressurized fluid. <P>SOLUTION: The pressure container 1 is charged with the pressurized fluid, such as, LNG. The coated cable 2 of the electrical apparatus is so drawn out to the outside which is low in pressure from the inside of the pressure container 1 so as to pierce this pressure container 1. The through part between this coated cable 2 and the pressure container 1 is blocked in a fluid-tight fashion by a blocking means, consisting of a ground packing 4 and a fastening ground 5. At least one location of the coated cable 2 is provided with a tubular compressing element 6, which is arranged around the coated cable 2 and is compressed to fasten the entire periphery of the coated cable 2 with a roughly equal pressure; so that even if the liquid infiltrates in the coat of the coated cable 2, it is unable to move out of the pressure container through the inside of the coat. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention covers a liquid immersion device having a structure in which a covered cable of an electric device is drawn out from a pressure vessel filled with pressurized liquid, such as a motor for a submerged pump. The present invention relates to a cable drawer structure.

  Conventionally, pressurized liquefied gas such as liquefied natural gas (LNG) or liquefied petroleum gas (LPG) has been filled in a pressure vessel. When taking out liquefied gas from the pressure vessel, A pump is in use. The liquefied gas pump is generally used as a submerged pump in which a driving motor is integrated because the pump body is used in a state where the pump body is immersed in the liquefied gas in the pressure vessel.

  The submerged pump has a structure in which the drive motor portion is completely immersed in the liquefied gas, for example, as described in FIG. For this reason, a power line (covered cable) for supplying power to the drive motor needs to be drawn out of the liquefied gas in the pressure vessel to the outside of the vessel and connected to an external power supply device.

  In this case, since the liquefied gas in the pressure vessel is flammable and is filled at a high pressure, it is necessary to avoid leakage to the outside of the vessel. For this reason, it is general that the covered cable is pulled out from the pressure vessel through the terminal box and connected to the external power supply device. Further, since the covered cable is disposed through the pressure vessel, the penetrating portion is provided with a closing means such as a gland packing and a fastening gland so as to keep liquid tight.

  By the way, the sheathed cable is electrically connected to the stator winding of the motor immersed in the liquefied gas in the pressure vessel, and the connecting portion strips the sheath of the sheathed cable to electrically connect the core wire. By connecting and covering the periphery so as to be liquid-tight with a sealant or the like, a measure is taken to prevent the fluid from penetrating into the covered cable.

  However, there is a pressure difference between the inside and outside of the pressure vessel through which the sheathed cable penetrates. When the pressure in the pressure vessel increases, the pressure difference between the inside and outside of the sheathed cable also increases, and the liquid in the pressure vessel moves inside the clothing of the sheathed cable. There is a risk of leaking out of the container through the pressure vessel.

  On the other hand, in the field of resin molding technology for electrical equipment, the lead wire is covered with a protective tube in order to prevent the resin molded from between the lead wire penetrating the die and the die, and this protective tube A technique has been proposed in which a part or all of the portion covered with the resin is pressure-bonded with a ring-shaped metal fitting to close the gap between the lead wire and the protective tube (see Patent Document 2).

JP 2006-129661 A Japanese Utility Model Publication No. 55-48371

  However, in a structure in which a covered cable (lead wire) is crimped via a protective tube with such a ring-shaped fitting, the covered cable cannot be tightened with almost uniform pressure over the entire circumference, and the part that is weakly tightened partially May occur. Further, it cannot be tightened with the same pressure every time, and a weakly tightened portion is generated, and there is a risk that fluid may permeate the inside of the sheath of the sheathed cable and leak out of the container.

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to provide a structure in which a sheathed cable of an electric device is drawn out through a pressure vessel filled with pressurized liquid. It is an object of the present invention to provide a covered cable lead-out structure for a liquid immersion device that can prevent leakage of the cover from the pressure vessel through the inside of the cover of the covered cable.

  In order to achieve the above object, the covered cable lead-out structure of the immersion apparatus according to the present invention includes a pressure vessel filled with pressurized liquid and a low pressure from the inside of the pressure vessel so as to penetrate the pressure vessel. Covered cable of electrical equipment drawn out to outside, closing means for liquid-tightly closing the penetration between the covered cable and the pressure vessel, and provided on at least one location of the covered cable and disposed on the outer periphery of the covered cable And a cylindrical compressor that is compression-molded and clamps the entire circumference of the coated cable with substantially uniform pressure.

  According to the present invention, a cylindrical compressor is disposed on the outer periphery of the covered cable and provided by compression molding at least at one location of the covered cable, thereby tightening the entire circumference of the covered cable with a substantially uniform pressure. Can do. As a result, even if the liquid penetrates into the covered cable in the pressure vessel filled with the pressurized liquid, the movement of the liquid is prevented at the location tightened by the compressor, and the outside of the pressure vessel Liquid does not leak into the space.

It is sectional drawing which shows one Embodiment of the covering cable drawer | drawing-out structure of the immersion apparatus by this invention. It is sectional drawing cut | disconnected along the II-II line | wire of FIG. 1, and seeing in the direction of the arrow. It is an expanded sectional view which shows an example of the cylindrical compressor used by this invention.

  Hereinafter, the covered cable lead-out structure of the immersion apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a covered cable lead-out structure for an immersion apparatus according to the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

  1 and 2, a pressure vessel 1 is, for example, a frame of a motor for a submerged pump, and a motor element (not shown) including a stator winding is accommodated inside (on the left side in the drawing). The pressure vessel 1 is filled with a pressurized liquid (such as LNG, LPG, or DME), and cools the motor element. The covered cable 2 connected to the stator winding in the pressure vessel 1 passes through the through hole 3 of the pressure vessel 1 as a lead wire and is drawn into the terminal box 10 (right side in the drawing) outside the pressure vessel 1. ing. The space in the terminal box is placed in an atmospheric pressure having a lower pressure than that in the pressure vessel 1.

  The through portion of the covered cable 2 that penetrates the pressure vessel 1 is provided with closing means that constitutes a liquid tight structure of the through portion. The closing means is composed of a gland packing 4 loaded so as to close the through-hole 3 and a fastening gland 5 screwed firmly to compress the gland packing 4.

  Further, a cylindrical compressor 6 is provided at one location of the covered cable 2 located in the pressure vessel 1. The entire axial direction, or both axial ends or a part of the axial direction of the compressor 6 is compression-molded, and the coated cable 2 is tightened with almost uniform pressure over the entire circumference. 7 is configured to prevent liquid from leaking out of the pressure vessel 1 through the inside of the pressure vessel 1. The compressor 6 can also be provided on the covered cable 2 located outside the pressure vessel 1.

  The compression method of the compressor 6 can be performed by compressing the entire circumference at once, but it is preferable to shift the circumference in the circumferential direction as shown in FIG. That is, first, the position aa ′ of the outer periphery of the compressor 6 facing 180 degrees is sandwiched by a dedicated compression jig having a die (not shown) and compressed by applying pressure twice or more. . Next, the angle is shifted in the circumferential direction, and the b-b 'portion is compressed by applying pressure of 2 degrees or more. Thereafter, in the same manner, the compression compression molding is repeatedly performed up to the f-f 'portion by sequentially shifting in the circumferential direction.

  By adopting such a compression method, the cylindrical compressor 6 can be smoothly deformed, and the coated cable 2 can be tightened almost uniformly over the entire circumference thereof. Even if the compression operation is repeatedly performed, the molding can be performed so that an expected compression result is obtained each time.

  In addition, using a dedicated compression jig having hexagonal dice that can be divided, first, the aa ′, cc ′, and ee ′ portions are simultaneously compressed, and then the circumferential angle is set to 30 degrees. A method of simultaneously compressing the bb ′, dd ′, and ff ′ portions by shifting can also be employed.

The following experiment was conducted on this embodiment. The coated cable 2 has a size of 13 to 15 mm ² , an outer diameter of 8.5 to 9.4 mm, a thickness of the coating 7 of 1.9 to 2.1 mm, and the material of the coating 7 is a fluoroethylene resin or vinyl chloride Insulating material such as, and the core wire 8 is a stranded wire of a conductive material such as copper. The compressor 6 has a cylindrical shape made of a conductive material such as copper or aluminum which is the same or different from the core wire 8, and has an outer diameter of 14.0 to 15.5 mm, an inner diameter of 10.5 to 11.7 mm, and a length of 38. ~ 42 mm.

  This compressor 6 is inserted into the covered cable 2 and the angle is shifted by a pressure of 9.0 to 10.0 tons using a dedicated jig having a hexagonal pressing surface and having a separable die 2 After compression, it was compression molded as shown in FIGS. The compression rate is 96%.

Experiments were conducted on fluid leakage by applying water pressure from one end of the coated cable 2 to the compression molded portion of the compressor 6. The water pressures were 2, 4, 6, 8, and 10 kg / cm ² , respectively, for 10 minutes, and when the amount of leakage was measured, no leakage from the other end of the covered cable 2 was confirmed.

  FIG. 3 is an enlarged cross-sectional view showing an example of a cylindrical compressor used in the present invention. As shown in FIG. 3, the cylindrical compressor 6 is formed with tapered portions 6a, 6a at both ends in the axial direction. Accordingly, the dimensions of the respective parts were changed as shown in Table 1, and it was inserted into various coated cables as shown in Table 2 and compression molded to test fluid leakage.

The cylindrical compressor 6 shown in FIG. 3 has an axial length of 40 mm, a tapered portion having an axial length of 7 mm, an outer diameter φA, an inner diameter φB, an inner diameter φC, and an outer diameter of the tapered portion. The dimensions of each part of φD are the dimensions of A, B, C, and D in Table 1.

In this way, using the compressors with different dimensions of each part A to D, as shown in Table 2, it is attached to the corresponding size of the covered cable, and compression molding is performed with different compression ratios, and the amount of liquid leakage is measured. did. As a result, in any experimental example, no leakage from the other end of the coated cable was confirmed.

  Further, from the experimental examples so far, the compression ratio of the compressor may be liquid leakage when it is 84% or less, and may be disconnected when it is 96% or more, and it is 85 to 95%. It was found desirable to be within range.

DESCRIPTION OF SYMBOLS 1 ... Pressure vessel 2 ... Covered cable 3 ... Through-hole 4 ... Gland packing 5 ... Fastening gland 6 ... Compressor 6a ... Tapered part 7 ... Cover 8 ... Core wire

Claims (4)

A pressure vessel filled with pressurized liquid;
A sheathed cable for an electrical device that is drawn out from the inside of the pressure vessel to the outside at a low pressure so as to penetrate the pressure vessel;
Closure means for liquid-tightly closing the penetrating portion between the sheathed cable and the pressure vessel;
A cylindrical compressor provided in at least one location of the covered cable, disposed on the outer periphery of the covered cable, and compression-molded to clamp the entire circumference of the covered cable with a substantially uniform pressure;
Covered cable lead-out structure for immersion equipment.   2. The covered cable drawing structure for an immersion apparatus according to claim 1, wherein at least a part of the compressor in the axial direction is tightened with substantially uniform pressure over the entire circumference.   3. The compressor according to claim 1, wherein the compressor is compressed while shifting the position in the circumferential direction by a jig that presses between both sides in the radial direction and is clamped with substantially uniform pressure over the entire circumference. Covered cable lead-out structure for the described immersion equipment.   The covered cable drawing structure for an immersion apparatus according to any one of claims 1 to 3, wherein the compressor is tightened so that a compression ratio is 85% to 96%.

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