JPH07118863B2 - Difficult-to-use ice and snow type electric wire - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ice-and-snow-type electric wire that is hard to adhere to the electric wire and is also capable of reducing wind pressure on the electric wire.

[Prior art and problems] If there is icing snow on the wires, the snow will grow in a tubular shape or overhang in a wing shape depending on the weather conditions and the quality of the snow at that time. It is well known that, in the worst case, it will cause the tower to collapse, leading to a serious accident.

Therefore, various attempts to prevent such a snow damage accident of the electric wire have been proposed for a long time. Recently, an attempt was made to attach a ring or a spiral rod to a power transmission line at predetermined intervals to prevent the snow from moving around the outer circumference of the electric wire and to induce the fall of the snow due to its own weight. Although it has been approved, it has been confirmed that it is effective only for a certain snow quality under extremely limited weather conditions and is not a versatile one.

Many people agree that the most effective way to remove ice and snow adhering to electric wires is to melt the snow with heat. Many snow-melting devices have been proposed so far. For example, in what seems to be a relatively high possibility method, a ferromagnetic material having a low Curie point is attached or wound around the electric wire, and heat generation due to hysteresis loss due to the magnetic material is promoted in the vicinity of the outside temperature during snowfall. There is an attempt to melt the snow with this heat. However, even if such a magnetic material is actually attached to an electric wire, the transmission line that has a small heat capacity and is installed in a high place in the air that is blown in the cold is like a natural cooling device. However, it doesn't matter to melt snow.

For this reason, there is also a proposal to directly wind the heater wire around the electric wire. However, in the case of this proposal, wasteful heat generation in the heater wire is extremely large, a large amount of energy is dissipated in vain other than melting the snow, and a large amount of power is consumed over a long distance. It is believed that there is no possibility of. However, this gives a great suggestion that if some means can be used to control this useless dissipated energy and electric power can be used only for snow melting, it will open the door to the development of groundbreaking icing and snow protection. Can not be denied.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and although the excellent effect is certainly recognized among the above-mentioned proposals, the waste of electric power for other purposes is too large. It focuses on a heater heating method that is large and has not yet seen the possibility of realization.In short, devoting the heater wire to devoting only to snow melting, suppressing the meaningless dissipation of heat that was too large so far, The snow melting efficiency has been significantly enhanced, and in combination with a spiral rod, the effect of hard-to-ice ice and snow is effectively enhanced, and the increase in wind pressure load of the wire when the spiral rod is wound around the wire to make hard-to-ice snow is minimized. It is intended to provide an ice-and-snow-type electric wire that can be reduced to the limit.

[Summary of the Invention] That is, the present invention first focuses on using an accident control type heater wire as a heater wire wound around an electric wire, and the heating temperature is set to an optimum temperature for snow melting. When it is going to get hotter, it stops heating the heater wire itself, eliminating the great waste of power consumption, which was the biggest drawback so far, and skillfully combining such a heater wire with a spiral rod. We have found the optimum configuration to reduce the wind pressure load of the electric wire, which is considered to increase, together with the improvement of the hard-to-freeze snow effect.

[Examples] Hereinafter, the present invention will be described based on the description.

FIG. 3 is a view for explaining one embodiment of the hard-to-ice ice and snow type electric wire according to the present invention, in which the spiral rod 3 is wound around the electric wire 10 and adjacent to the spiral rod 3.
A self-controlled heater wire 1 having a smaller diameter than this is wound.

It has already been described that the spiral rod 3 is wound around the outer circumference of the electric wire 10 so as to prevent icing snow or wind noise on the electric wire 10. FIG. 2 is an explanatory view showing the cross-sectional situation, but a recess 3a is formed from the point where the electric wire 10 having a circular cross section and the spiral rod 3 having the same circular cross section are in contact with each other, and this recess 3a is formed. It has recently been discovered that supercooled water droplets are trapped and ice formation 20 is formed. Icing like this
Since it is clear that the formation of 20 significantly reduces the effect of preventing the snow accretion of the spiral rod 3, the hard-to-ice ice type electric wire of the present invention has the self-controlled heater wire 1 attached to the spiral rod 3 as described above. Is attached to prevent such icing 20 from occurring.

FIG. 1 is a diagram for explaining a situation in which the self-controlled heater wire 1 wound around the electric wire 10 is spirally wound around the electric wire 10 using the current transformer 2 as a power source.

The self-controlled heater wire here means that the heating operation continues until the temperature of the heater wire itself reaches a predetermined temperature, but when the temperature of the heater wire becomes higher than the predetermined temperature, the heater wire itself automatically heats. It is intended to refer to a heater wire that is configured to reduce its motion and thereby reduce the temperature of the heater wire, again automatically increasing the heating motion of the heater wire itself and operating at that balance. Various configurations can be considered for the heater wire that operates in this way, but it is relatively inexpensive and easy to manufacture, the shape can be freely selected, and the technology is already being established. There is a self-regulating plastic heater wire. In other words, PTC (Positive Te
mperature Coefficient) characteristic, 2
That is, a heating element, which is made of polyethylene resin as a base and is mixed with carbon black, is interposed between the conductors of the book. When the heater wire is low in temperature, a conductive path is formed between the conductors due to the chain of carbon black, and heat is generated, but when the temperature is high, the base polyethylene resin expands, and as a result, the conductive path due to the carbon black is cut and the amount of heat generated. Becomes smaller, and as described above, the conductive paths are turned on and off in a well balanced manner. Therefore, the above-mentioned balance temperatures can be selected by selecting the base material, the shape of carbon black and the mixing ratio, so select them so that they will balance at the temperature at which the snow melts well, and waste heat dissipation due to excessive heating. Can be prevented.

The method of winding a heater wire around an electric wire to melt snow consumes too much power as described above, and it is considered impossible to realize it.However, since the present invention uses a self-regulating heater wire, power consumption is reduced. It should be epoch-making that consumption could be kept to a minimum and bright prospects could be obtained toward the realization of snow melting using the heater method.

As a power source for heating the heater wire 1, it is possible to freely select electricity storage by wind power or solar thermal power generation, or an ordinary battery, but as shown in FIG. 1, the current transformer 2 attached to the electric wire 10 is used as a power source. If so, it is simple and reliable. Therefore, if a sensor or a command device is set so that the operation of the power source such as the current transformer 2 can be linked with the snowfall situation, the waste of power consumption can be further reduced.

Furthermore, by attaching a tape-like substance (for example, fluorocarbon resin) having a small friction coefficient to the surface of the electric wire 10 in a spiral shape or a ring shape, and winding the self-controlling heater wire 1 on the tape-like material, a heater by repeated thermal expansion can be obtained. It is possible to prevent damage to the wires. Then, the difficult-to-adhere ice-and-snow type electric wire of the present invention, which is formed by winding the spiral rod 3 and the heater wire 1 adjacently,
In addition, it can also exhibit excellent effects. That is, when the heater 1 having a small diameter is arranged along with the spiral rod 3 having a large diameter as shown in FIG. 3, the surface flattening effect shown by the tangent line Q in FIG. The heater 1 arranged as described above significantly reduces the increase in the wind pressure of the electric wire 10 due to the winding. The effect of reducing the wind pressure is generally that the diameter d _{2 of the} heater 1 is 0.3d ₁ ≦ d ₂ ≦ the diameter d ₁ of the spiral rod 3.
It was also confirmed by wind tunnel experiments that it was remarkable at 0.8d ₁ . On the contrary, such a relationship is the same even if the heater has a large diameter and a small-diameter spiral rod is attached to the heater in the same arrangement relationship as shown in FIG. Since d ₂ is d _{1 in} the figure, the condition is 0.3d ₂ ≦ d ₁ ≦ 0.8d ₂ .

As described above, the filaments having different diameters are arranged adjacent to each other, which also has an effect of preventing damage when passing through the air vehicle. Furthermore, the above configuration can be expected to have an effect of reducing corona noise which is easily generated by winding the spiral rod by appropriately selecting the relationship with the outer diameter D of the electric wire.

[Effects of the Invention] As described above in detail, according to the present invention, while the effect is conventionally recognized, the heater is attached to the power transmission line, which has been denied the feasibility because it consumes too much electric power. The proposition of melting snow and snow is solved at once, and it is about to be put into the limelight for its feasibility, and the objection of this proposal is extremely large.

[Brief description of drawings]

FIG. 1 is an explanatory view of a self-controlled heater wire used by winding it around an electric wire, FIG. 2 is an explanatory sectional view showing an example of winding a conventional spiral rod, and FIG. It is explanatory drawing of one Example of an icing snow type electric wire. 1: Self-regulating heater, 2: Current transformer, 3: Spiral rod, 10: Electric wire.

Front page continuation (72) Inventor Kiyoshi Shimojima 3550 Kidayo-cho, Tsuchiura-shi, Ibaraki Hitachi Wire & Cable Co., Ltd. (72) Inventor Kenji Yamamoto 1500 Kawajiri-cho, Hitachi, Ibaraki Hitachi Cable Co., Ltd.Toyoura factory (72) Inventor Yukio Shimazaki 5-1-1 Hidakacho, Hitachi City, Ibaraki Hitachi Cable Electric Wire Co., Ltd. (56) Bibliography Sho 61-124447 (JP, U) Shokai 59-107529 ( JP, U) JP 59-181914 (JP, B2)

Claims (2)

[Claims] 1. A spiral rod and a self-controlling heater wire having a wire diameter different from that of the spiral rod are wound around the outer circumference of the electric wire, and the wire diameter of the spiral rod is d ₁ , and the self-suppressing heater. when the wire diameter of the wire was _{d 2, 0.3d 1 ≦ d 2} ≦ 0.8d 1 or 0.3d ₂ ≦ d ₁ ≦ 0.8d ₂ configured to fire wearing snow and ice electric wire comprising so. 2. The ice-and-snow-type electric wire as claimed in claim 1, wherein the power source for the self-controlled heater wire is obtained from a current transformer attached to the electric wire.