RU2765481C1 - Heating device (versions) - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: disclosed group of technical solutions relates to heating devices based on a self-regulating heating tape or cable and can be used in various industries. Heating device comprises a self-regulating conducting polymer matrix with two current-conducting conductors, insulation, a screening braid and an outer shell. Insulation is placed between polymer matrix with current-conducting conductors and screening braid. In one version, the device comprises an additional heating core in thermal connection with the matrix. In another version, one of the current-conducting conductors is made heating. In another version, both conductors are heating. In another version of the device, at least one insulated heating conductor, which is in thermal connection with the matrix, is woven into the screening braid.

EFFECT: enabling creation of a heating device (versions) having high energy efficiency, as well as increasing heating efficiency and possibility of external control of the device power.

12 cl, 7 dwg

Description

Application area

The claimed group of technical solutions relates to heating devices based on a self-regulating heating tape or cable and can be used in various industries.

State of the art

Heating devices containing self-regulating tapes or cables are well known in the art.

A self-regulating tape or cable is a conductive carbon (polymer) matrix (base) in which conductive wires are placed, between which conductive particles are dispersed in the matrix.

The matrix is characterized by a significant dependence of conductivity on temperature, and the negative temperature coefficient of resistance of conductive plastics is orders of magnitude greater than that of copper or steel. This provides self-regulation of the thermal power of the heating cable or tape. A self-regulating heating tape or cable can change its power locally, only in the overheating zone.

In the process of heating, the polymer base expands, the distance between the conductive particles enclosed in the base increases, as a result of which the number of conductive bonds (paths) in the matrix between the conductive particles decreases, due to which the resistance of the matrix increases, its electrical conductivity decreases, while the heating of that area where overheating of a section of tape or cable has occurred. After the section of the tape or cable cools down, the polymer base takes on close to its original dimensions, and heating continues.

Self-regulating heating tapes or cables can heat the device from -50°C to +270°C. Self-adjusting tape or cable may reduce power consumption depending on operating temperature conditions.

It should be noted that a feature of self-regulating cables is the presence of a starting current. The starting current is a negative phenomenon, since it can exceed the rated current of the cable up to 2-7 times, depending on the external temperature conditions. The starting current occurs in the first seconds of operation of the self-regulating cable and significantly affects the cross-sections of the supply cables.

A self-regulating heating tape is known from the prior art, consisting of two conductive wires insulated from each other, placed in a conductive polymer matrix enclosed in a polymer insulating sheath. The tape contains a shielding braid and a common outer sheath (see CN 109379793 A, 22.022019).

The disadvantage of the known solution, as well as many similar ones known from the prior art, lies in the low operational properties, consisting in the inability to control the heating power, insufficient efficiency due to the presence of a high starting current.

Essence disclosure

The task of the claimed group of technical solutions is to create a heating device (options) based on a self-regulating heating matrix with high performance properties.

The technical result consists in creating a heating device (options) with high energy efficiency by reducing the starting current of the device. Another technical result of the claimed technical solution (options) is to increase the heating efficiency and the possibility of external control of its power due to the presence of an additional heating core or replacement of the conductive core of the matrix with a heating core.

The claimed technical result is achieved through the use of the following set of essential features: the heating device contains a self-regulating conductive polymer matrix with two conductive wires, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive wires and the shielding braid, according to the claimed technical solution, the device contains an additional heating core, which is in thermal connection with the matrix.

Also, the technical result is achieved through the use of another set of essential features: the heating device contains a self-regulating conductive polymer matrix with two conductive cores, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive cores and the shielding braid, while one of the conductive the core is made heating.

Also, the technical result is achieved through the use of an alternative set of essential features: a heating device containing a self-regulating conductive polymer matrix with two conductive wires, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive wires and the shielding braid, while both conductive conductors are made heating.

Also, the technical result is achieved through the use of another set of essential features: the heating device contains a self-regulating conductive polymer matrix with two conductive wires, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive wires and the shielding braid, while in the shielding braid at least one insulated heating wire is interwoven and is in thermal connection with the matrix.

In private versions of the claimed group of technical solutions, the heating core can be spirally wound on the tape insulation. The heating wire can be placed between the insulation and the shielding braid of the heating device. The heating core can be placed between the shielding braid and the outer sheath of the heating device. The heating core can be placed on the outer side of the shell, while maintaining the thermal connection with the matrix. The heating core can be made of nichrome or steel, or resistance alloys.

Brief description of the drawings

On FIG. 1 shows a cross section of a heating device with an additional heating core in thermal connection with the matrix and placed on the outer side of the shell.

Figure 2 shows a cross section of the heating device with an additional heating core, which is in thermal connection with the matrix and placed under the common outer shell of the device.

Figure 3 shows a cross section of the heating device, in which one of the conductive wires is made heating.

Figure 4 shows a cross section of the heating device, in which all two conductive wires are made heating.

Figure 5 shows a cross-section of the heating device, in which the heating core (one), which is in thermal connection with the matrix, is woven into a shield braid.

Figure 6 shows a cross section of a heating device in which the heating wires (multiple) in thermal communication with the matrix are woven into a shield braid.

Figure 7 shows the dependence of the starting current that occurs at the initial moment of heating the device on the heating time of the device for cases with and without an additional heating core in the traditional version of the device.

Implementation of the technical solution

The claimed versions of the heating device are made on the basis of self-regulating tapes and cables, consisting of a matrix and conductive cores.

Known self-regulating cables have a fairly large starting current, which is 2-7 or more times of its operating value. The reason for the high starting current is the use of a conductive matrix with a PTC coefficient in the design, which changes its electrical resistance depending on the ambient temperature.

In the "cold" state, the self-regulating cable has a small resistance, which also depends on the ambient temperature. When power is applied to the cable, it begins to heat up, its resistance begins to increase, and the current in the power circuit decreases. The starting current coefficient depends on the component composition and technologies used in the production of the cable matrix.

However, if there is an additional insulated heating wire 1 in the heating device, if there is a thermal connection between the heating wire 1 and the self-regulating conductive polymer matrix 2 (it is mainly understood that the heating wire and the polymer matrix are located close to each other with the possibility of rapid heating), the starting current of the self-regulating matrix 2 will be significantly reduced for due to the rapid heating of the heating core 1, which has a high resistance and heat transfer to a self-regulating matrix 2 with conductive cores 3 (Figure 1). Heating core 1 can be made of nichrome or steel or resistance alloys. The heating conductor 1 is insulated. Additional heating core 1 can be located both on the outside of the device (Figure 1) and inside the heating device, for example, under the outer shell (Figure 2). Heating and current-carrying conductors can be stranded.

Also reducing the starting current contributes to the use of the heating core 1 as one or two conductive cores 3 (Figure 3, Figure 4).

Therefore, with a decrease in the starting current in the self-regulating polymer matrix 2, the energy efficiency and functionality of the heating device as a whole will increase. Reducing the starting current creates opportunities for increasing the length of the heating device, reducing the cross-section of the supply cables of the supply network, current-carrying conductors by 2 or more times, which, in addition to obtaining a positive economic effect, helps to simplify the installation of the device and reduce the load on the power circuits.

In addition, the presence of an additional heating core 1 in the device increases the degree and efficiency of heating the surrounding space by the heating device. The same effect of increasing the heating efficiency will be obtained when using the heating wire as one or two conductive wires 3 (Fig.3, Fig.4).

Also, if there is an additional core 1 and an additional control wire (additional supply phase), it becomes possible to control the power of the heating device by changing the voltage on the additional control wire.

The claimed heating device, in addition to a self-regulating conductive polymer matrix 2 with two conductive conductors 3 and an additional heating conductor 1, also contains insulation 4, a shielding braid 5 and an outer sheath 6. Insulation 4 is placed between the polymer matrix 2 with conductive conductors 3 and a shielding braid 5. The conductors 3 can be made of copper or aluminum.

Insulation 4, for example, made of fluoropolymer thermoplastic, in addition to its intended purpose, protects the polymer matrix 2 and conductive wires 3 from moisture and mechanical stress, and also facilitates installation.

Shielding braid 5, for example, made of tinned copper, is designed for reliable grounding of the heating device and its electrical protection.

The outer shell 6, depending on the operating conditions, can be made of different materials, such as polymer and its compounds or metal.

Additional heating core 1 for more efficient and durable thermal connection with polymer matrix 2, as well as for uniform heat distribution over the heating device, should preferably be placed together with polymer matrix 2 and conductive cores 3.

Longitudinal placement of additional heating wire 1 along polymer matrix 2 between outer sheath 6 and shielding braid 5 or between sheath 5 and insulation 4 is allowed. the presence of a thermal connection between the heating conductor 1 and matrix 2.

In the embodiment of the heating device, in which one (Figure 3) or two (Figure 4) conductors are heated, it is allowed to exclude a separate additional heating conductor, while maintaining the above positive effects. With this embodiment of the device, energy efficiency is also increased by reducing the starting current I _start and heating efficiency by making the heating conductors as conductive conductors, while the design of the device is greatly simplified.

In another embodiment of the device, an additional heating core (Figure 5) or a plurality of cores (Figure 6) is placed by weaving into the shielding braid 5 (Figure 5).

An advantage of weaving a heating wire or a plurality of wires 1 into the shield braid 5 is that a significant number of heating wires 1 can be woven simultaneously for uniform heating. This placement of at least one heating wire 1 ensures reliable thermal communication with the self-regulating polymer matrix 2 and therefore also provides energy efficiency and significant heating efficiency of the device.

All the embodiments of the heating device described above provide a reduction in the starting current I _start and increase its energy efficiency and heating efficiency. At the same time, the design of the device, where there are no additional cores, and the current-carrying cores are replaced by heating ones, are simpler and more convenient for installation and operation, as well as less expensive in their production.

Figure 7 shows the dependences of the starting current I _start with the traditional implementation of the heating device (tape), as well as for cases where an additional heating core is present. Figure 7 shows three dependences of the starting current for cases with an additional heating core I _{start with load. lived.} at different power of the additional heating core (a, b, c), as well as the time the heating device reaches the operating current I _slave .

The supply of current-conducting wires and additional heating wires can be carried out from one phase or from different (independent) ones.

To control the power of the device, the auxiliary phase can be supplied with a different or pulsating voltage in time. To eliminate the starting current, the auxiliary phase can be supplied with a constant voltage for 3-5 seconds, and then turned off.

Implementation example 1

A medium-temperature heating device is produced, in which a self-regulating matrix of polymer material, inside which there are two conductive cores, is applied with insulation from a fluoropolymer thermoplastic and a shielding braid of tinned copper. Next, the device is enclosed in an outer polymeric sheath, on the outer part of which an additional heating insulated core is wound. The additional core is made of steel and is insulated. Conductors are made of copper.

Implementation example 2

A low-temperature heating device is produced, in which a self-regulating matrix of polymeric material, inside of which there are two conductive cores, is applied thermoplastic elastomer insulation and a shielding braid of tinned copper. Next, the device is enclosed in an outer polymer shell. One conductive core is made of copper, and the other is made of steel and is heating.

Implementation example 3

A low-temperature heating device is produced, in which a self-regulating matrix of polymeric material, inside of which there are two conductive cores, is applied thermoplastic elastomer insulation and a shielding braid of tinned copper. Next, the device is enclosed in an outer polymer shell. The conductive conductors are made of steel and are heating.

Implementation example 4

A high-temperature heating device is manufactured, in which a self-regulating matrix of polymer material, inside which there are two conductive wires, is applied polymer insulation and a shielding braid of tinned copper. One heating, insulated core made of steel is woven into the shielding braid. Next, the device is enclosed in an outer polymer shell. The conductors are made of copper or coated copper wires, such as zinc coating.

Claims (12)

1. A heating device containing a self-regulating conductive polymer matrix with two conductive wires, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive wires and the shielding braid, characterized in that it contains an additional heating wire that is in thermal communication with matrix. 2. Heating device according to claim 1, characterized in that the heating wire is helically wound around the matrix insulation. 3. The heating device according to claim 1, characterized in that the heating core is placed between the insulation and the shielding braid. 4. Heating device according to claim 1, characterized in that the heating core is placed between the shielding braid and the outer sheath. 5. The heating device according to claim 1, characterized in that the heating core is located on the outer side of the shell, while maintaining a thermal connection with the matrix. 6. Heating device according to claim 1, characterized in that the heating core is made of nichrome or steel or resistance alloys. 7. A heating device containing a self-regulating conductive polymer matrix with two conductive cores, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive cores and the shielding braid, characterized in that one of the conductive cores is made heating. 8. Heating device according to claim 7, characterized in that the heating core is made of nichrome or steel or resistance alloys. 9. A heating device containing a self-regulating conductive polymer matrix with two conductive wires, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive wires and the shielding braid, characterized in that both conductive wires are made heating. 10. Heating device according to claim 9, characterized in that the heating conductors are made of nichrome or steel or resistance alloys. 11. A heating device containing a self-regulating conductive polymer matrix with two conductive wires, insulation, a shielding braid, an outer sheath, and the insulation is placed between the polymer matrix with conductive wires and the shielding braid, characterized in that at least one insulated heating wire in thermal connection with the matrix. 12. Heating device according to claim 11, characterized in that the heating core is made of nichrome or steel or resistance alloys.

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