CN2207677Y - Super-long heat resistant cable - Google Patents

Abstract

The utility model discloses a super-long type heat resistant cable whose length is more than 5 times longer than the length of a parallel type heat resistant cable. The super-long type heat resistant cable whose length is more than 5 times longer than the length of a parallel type heat resistant cable solves the problem of the heat resistance of a long distance or a large opening diameter pipeline. An auxiliary wire core is added on the basis of the structure of the existing parallel type heat resistant cable. A power supply is connected with one electricity transmitting wire core and the auxiliary wire core on the head end of the super-long type heat resistant cable whose length is more than 5 times longer than the length of a parallel type heat resistant cable, and the other electricity transmitting wire core is connected with the auxiliary wire core on the tail end of the super-long type heat resistant cable whose length is more than 5 times longer than the length of a parallel type heat resistant cable. After the super-long type heat resistant cable whose length is more than 5 times longer than the length of a parallel type heat resistant cable is energized, the potential in the two electricity transmitting wire cores descends, and the heads and the tails of the two electricity transmitting wire cores are opposite. The resistance of the two electricity transmitting wire cores between the head end and the tail end causes the working voltage difference of each heating node to obtain mutual compensation. The power of each heating node of the overall length is equal, the surface temperature of each heating node is uniform, and the using length of each heating node is increased.

Description

Super-long heat resistant cable

The utility model relates to a kind of accompanying-heat cable that is used to solve long distance or large diameter pipeline companion heat problem.

At present, the maximal use length of known parallel accompanying-heat cable has only tens meters, maximum more than 100 meters, can not be used for companion's heat of long distance or large diameter pipeline.This is because there is resistance in transmission pressure, each heating joint from head end to tail end all can produce certain pressure drop, causes to produce the heating power error between head end and tail end, when using length long, this heating power error is very big, causes parallel accompanying-heat cable surface temperature inhomogeneous.As will increasing use length, diameter that must overstriking transmission of electricity core, various cost of raw and processed materials increase considerably with its volume, cause waste.In addition, parallel accompanying-heat cable also has following shortcoming 1): the material of heater element is the very high high resistant heating wire (as Cr20Ni80) of nickel content, and this class material scolding tin difficulty causes heater element and transmission of electricity core rosin joint to connect.Behind the parallel accompanying-heat cable heating power, the oxidation gradually of both contact surfaces has increased contact resistance, causes heating unstable.2): be not quite similar because the radiating state of laying environment is installed, it is overheated to cause the bad part of radiating state to occur with the heater element that does not have obvious positive temperature coefficient, causes to burn out accidents such as short circuit.

The purpose of this utility model provides a kind of length of using than the long super long type accompanying-heat cable more than 5 times of parallel accompanying-heat cable, it has not only solved the accompanying-heat cable problem that range of application is restricted owing to use length is not enough, and the overall length temperature is even, the reliability height, and the life-span improves greatly.

The purpose of this utility model is achieved in that on existing parallel accompanying-heat cable architecture basics, only increases an auxiliary core and auxiliary core insulating barrier, and at its head end, two power lines are connected with auxiliary core with a transmission of electricity core respectively; At its tail end, another root transmission of electricity core is connected with auxiliary core.After the energising, the voltage drop head and the tail of two transmissions of electricity in the core oppositely, operating voltage difference of each heating joint that the resistance of two transmission of electricity cores causes between head end and tail end is compensated mutually, and each heating joint power is equated, then the overall length surface temperature is even, and this has just increased use length.Heater element adopts the PTC heating wire to replace original high resistant nichrome wire in addition, has overcome the phenomenon of heating instability and easy burn-out.This is because the PTC heating wire is a kind of electrothermal alloy with obvious positive temperature coefficient, makes heater element tool finite temperature with it, the characteristics of easy burn-out or automatic temperature-control not, but and have solderability, so it is the desirable heater element of super long type accompanying-heat cable.

Owing to adopt such scheme, only increase very little cost (auxiliary core and auxiliary core insulating barrier), just can obtain the parallel accompanying-heat cable of use length more than 5 times, and the overall length temperature is even, has certain temperature-limiting character, the life-span improves greatly.

Below in conjunction with accompanying drawing and example the utility model is further specified.

Fig. 1 is a super long type accompanying-heat cable shape assumption diagram.

Fig. 2 is a super long type accompanying-heat cable winding diagram.

Among the figure: 1. armouring 2. insulating barriers 3. heating wire 4. skeletons 5. core insulating barriers 6. transmission of electricity cores 7. anticorrosive coats 8. auxiliary core insulating barriers 9. auxiliary cores 10. tie points 11. heating joints are long

As seen from Figure 1, the utility model only increases the mode of connection of an auxiliary core (9) and Fig. 2: at head end, power supply is connected with auxiliary core (9) with a transmission of electricity core (6); At tail end, another root transmission of electricity core (6) is connected with auxiliary core (9), adopt power supply two phase lines respectively from super long type accompanying-heat cable head end and the transmission of electricity of tail end rightabout, opposite ［ the voltage drop direction that is the core (6) of transmitting electricity being connected with tail end of head end is to tail end from head end to the direction of voltage drops in two transmission of electricity cores (6); The voltage drop direction of the transmission of electricity core (6) that tail end is connected with auxiliary core (9) is to head end from tail end ］, the voltage at each heating joint two ends is compensated, the heating power of each heating joint is equated, the overall length surface temperature is even, the head and the tail power error can think very little, this has just improved use length greatly, and this point is confirmed with everywhere surface temperature between measurement head end and tail end.Example: now design parallel accompanying-heat cable, heating power 40W/m, the design power error of two ends is 55m for ± 10% o'clock maximal use length, 83 ℃ of its head end temperature, 74 ℃ of tail end temperature; When increasing use length to 150m, the head end temperature is 98 ℃, and the tail end temperature is 61 ℃; When increasing use length to 350m, the head end temperature reaches 132 ℃, and the tail end temperature has only 33 ℃, can't work.Now change system into the super long type accompanying-heat cable, under the constant situation of heat generating core basic structure, increase an auxiliary core, when using length, measure overall length surface temperature everywhere: 81 ℃ of head end temperature, 79 ℃ of tail ends, 82 ℃ and 80.5 ℃ at middle part as 350m.This super long type accompanying-heat cable is described when using length greater than 5 times, the overall length heating is still very even.

Realize that preferred plan of the present utility model is to adopt the PTC heating wire of obvious positive temperature coefficient under the existing constant situation of super long type accompanying-heat cable structure as far as possible, this PTC heating wire also should have higher electric resistivity and corrosion resistance except that having the high electrical resistance value, the thermal strain of this more favourable raising super long type accompanying-heat cable and raising life-span.

Claims (3)

1, a kind of super long type accompanying-heat cable, form it is characterized in that having auxiliary core (9), tie point (10) and PTC heating wire (3) by transmission of electricity core (6), core insulating barrier (5), skeleton (4), PTC heating wire (3), insulating barrier (2), armouring (1), anticorrosive coat (7), auxiliary core (9), auxiliary core insulating barrier (8) and tie point (10).

2, super long type accompanying-heat cable according to claim 1 is characterized in that adopting the PTC heating wire to make heater element, and this PTC heating wire should have: 1) tangible positive temperature coefficient (being ptc characteristics), 2) but solderability.

3, super long type accompanying-heat cable according to claim 1 is characterized in that: at its head end, power supply is connected with auxiliary core (9) with a transmission of electricity core (6); At its tail end, another root transmission of electricity core (6) is connected with auxiliary core (9), forms tie point (10).

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