JPS6219050Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an OF cable or POF cable that performs the following radial flow internal oil-cooled forced cooling.

In radial flow cooling, as shown in Figure 1, cooled insulating oil is sent into the internal oil passage 12 of the cable 10 to perform internal oil cooling.
A part of the oil flows into the insulator 16 in the radial direction, and the oil exiting to the oil passage 20 inside the sheath 18 flows toward the terminal end side 22, for example, and the cooled oil is passed through the return pipe 24, for example. In this method, the oil is returned to the oil supply end 26, passed through the cooler 28, and fed into the cable 10 again by the pump 30 for circulation.

When low-temperature oil flows in the radial direction inside the insulator 16 (hereinafter referred to as radial flow), the insulator 16
This has the same effect as reducing the thermal resistance of

Therefore, the temperature rise of the conductor 14 can be kept low by internal oil cooling, and at the same time, the temperature can be kept even lower by the effect of radial flow.

The situation is schematically shown in "Figure 2".

100 shown above is a cable line, and 40 is a connection part. Below that, the temperature distribution of the conductor 14, etc. is also shown. Line 32 is the temperature of the conductor 14 in the case of the above-mentioned radial flow type internal oil cooling type. Also, line 34 indicates the conductor temperature assuming that only internal oil cooling is performed without radial flow. Line 36 shows the oil temperature. The shaded area 38 is the temperature decrease due to the effect of radial flow.

Even when radial flow is performed, the temperature of the conductor 14 (line 32) is naturally highest at the terminal end side 22 (the temperature is defined as T).

However, near the oil supply end 26, the temperature of the oil is low (line 36), so the temperature of the conductor 14 is also low, and even if there is no radial flow (line 34), there is a portion lower than the maximum temperature T (at Z). (part shown).

Therefore, the radial flow in that part is wasted.

Therefore, in the present invention, as shown in FIG. 3, the cable line 100 is divided into two parts 101 and 102, and the part 101 near the oil supply end 26 is used as a cable with a large oil flow resistance against radial flow. 10a, and is substantially only internally oil-cooled, and the portion 102 on the terminal side 22 is
The cable 10b is configured with a small oil flow resistance against radial flow, so that the effects of radial flow are superimposed.

Note that the boundary between 101 and 102 is the connection portion 40 included in the Z portion.

In this way, 1 on the terminal side from the connection part 40
The temperature rise of the conductor at 02 becomes as shown at 32' in FIG. 2, and the maximum temperature at the end becomes approximately equal to or less than T.

In this case, the gradient of temperature rise in the part 102 is 3
The reason why 2' is smaller than the temperature rise gradient 32 when the entire structure is a radial flow type is because the cable 10a is only internally oil-cooled and has no radial flow up to the connecting part 40 at the boundary. This is because the oil pressure at the connection part 40, which is the inlet of the flow type cable 10b, is high, and therefore the effect of reducing thermal resistance is large (cable 10b).
(The conductor temperature actually drops slightly near the entrance of point b).

An example of the cable 10a constituting the portion 101 is shown in FIG.

A polypropylene tape 42 or the like is wrapped around the insulator 16 to prevent almost any radial flow of oil.

An example of the cable 10b constituting the portion 102 is shown in FIG.

A reinforcing layer 44 is wound on the insulator 16, and D
The shaped wire 46 is spirally wound to increase the cross-sectional area of the sheath side oil passage 20. The reinforcing layer 44 is D
This is provided to prevent the shaped wire 46 from digging into the insulator 16. For example, it is made of a material through which oil easily flows, such as perforated plastic tape, embossed tape, perforated metal tape, or plain cloth.

Although the above explanation has been made regarding the OF cable, it is conceivable that radial flow type cooling can be performed on the POF cable as well if a hollow conductor is used.

In such cases, conventional reinforcing layers provide too much oil flow resistance to radial flow. Therefore,
If a perforated metal tape or the like is used for the reinforcing layer as in the above-mentioned cable 10b, radial flow can be performed in the same way as in the case of the OF cable.

Effect of the Invention: Since there is no unnecessary radial flow to the low temperature parts, the cooling section can be made longer if the same pump 30 and cooler 28 are used as when performing radial flow over the entire line.

[Brief explanation of the drawing]

Fig. 1 is a general explanatory diagram of the radial flow type internal oil cooling system, Fig. 2 is an explanatory diagram of the temperature distribution of the conductor 14, Fig. 3 is an explanatory diagram of the embodiment of the present invention, and Figs. 4 and 5 are , is a sectional view of an example of a cable used in the present invention. 10...Cable, 12...Internal oil passage, 14
... Conductor, 16 ... Insulator, 20 ... Sheath side oil passage, 22 ... Termination side, 26 ... Oil supply end side, 10
0...Cable line.

Claims (1)

[Scope of utility model registration request] The oil-filled cable line 100 is divided into two in the length direction, and the oil supply end side is constituted by an internal oil-cooled cable 10a with almost no radial flow,
An oil-filled cable line characterized in that the terminal end portion is constructed of a radial flow type cable 10b with low oil flow resistance in the radial direction.