RU2770788C1 - Heating device - Google Patents

Abstract

FIELD: heating equipment.

SUBSTANCE: claimed heating device can be widely used in various sectors of the national economy and industry as a highly efficient longitudinal heater of a long length. The heating device contains power cores and heating elements. The device is made in the form of a cable assembly containing at least two heating elements arranged sequentially one after the other along the device, while the heating elements and the power cores are twisted together or the heating elements are placed in the outer part of the device.

EFFECT: significant increase in the length of the heating device is achieved while maintaining high heating efficiency along its entire length, as well as a significant increase in the ease of installation.

14 cl, 9 dwg

Description

Application area

The claimed heating device can be widely used in various branches of the national economy and industry as a highly efficient longitudinal heater of great length.

State of the art

Many heating devices are known from the prior art based on heating resistive and self-regulating cables and tapes.

From the prior art, a heating device based on a resistive cable with insulation is known, which contains insulated conductive heating conductors connected at one end of the cable to each other, and connected to an adjustable current source at the other ends (RU 166929 U1, 12/20/2016).

Also known from the prior art is an electric heating cable containing several heating wires in an electrically insulating material covered by a braid, an outer sheath made of electrically insulating material with an optical module placed in it, made in the form of a tube of dielectric material, inside which there is at least one optical fiber (RU 124104 U1, 01/10/2013).

A flat three-phase heating cable is also known, containing conductive conductors insulated with a heat-resistant sheath, laid parallel to each other in the form of a middle and two side conductors, each of which is made of multi-wire, while the conductors at one end are free for connection to a power source, and at the lower end are free the cores are interconnected in a star and insulated to form a closed electrical network (RU 2615503 C2, 04/05/2017).

The prior art also known self-regulating heating tape, consisting of two isolated from each other conductive wires 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).

And the prior art known flexible heating device containing power wires and flexible tape heating elements (see RU 2118070 C1, 20.08.1998). This technical solution is taken as a prototype.

The disadvantage of the known devices is the inability to heat long sections of heated surfaces, such as pipelines.

Implementation of the technical solution

The objective of the claimed technical solution is to create a highly efficient heating device capable of providing heat over a long distance from a single power source.

The technical result of the claimed technical solution consists in a significant increase in the length of the heating device while maintaining high heating efficiency along its entire length, as well as in a significant increase in ease of installation.

The claimed technical result is achieved through the use of the following set of essential features of the claimed heating device, namely: the heating device contains power wires, heating elements, while the device is made in the form of a cable assembly containing at least two heating elements arranged in series one after another. friend along the device.

In particular cases of execution of the heating device, the heating elements and power wires can be twisted together. The heating element may be in the form of a tape or strip, or a cable. The power supply conductors are a single-phase or 3-phase power supply system. The heating elements may be resistive heating wires or self-regulating cables or tapes. The heating elements can also be resistive strips or strips consisting of several separate heating wires. Heating elements can be placed on the outside of the device. The heating elements may include a heating wire and a self-regulating cable made together and in thermal communication. The heating device may include an additional power core connected only to the heating wire. Power wires, additional power wire and heating elements can be twisted together. The heating device may include a protective sheath. The heating device may comprise a moisture protection layer, or may comprise an electrical or electromagnetic protection layer or screen.

Graphic materials explaining the essence of the solution

The essence of the claimed technical solution is illustrated by graphic materials, where:

Fig. 1a shows a general view of the heating device indicating the heating and separation zones in the embodiment of the resistive wire as a heating element;

On Fig.1b - a combined view of the heating device with the opening of the areas of connection and separation in the embodiment of the resistive wire as a heating element;

On Figv - shows the electrical circuit of the heating device in the embodiment of the resistive wire as a heating element;

Figure 2a shows a general view of the heating device indicating the heating and separation zones in the embodiment of the resistive wire as a heating element and with an electromagnetic protection screen;

Figure 2b - shows a combined view of the heating device with the opening of the areas of connection and separation in the embodiment of the resistive wire as a heating element and with an electromagnetic shield;

On Figv - shows the electrical circuit of the heating device in the embodiment of the resistive wire as a heating element and with an electromagnetic protection screen;

Fig. 3a shows a general view of the heating device indicating the heating and separation zones in the embodiment of the heating element, consisting of a heating wire and a self-regulating cable, and with an electromagnetic protection screen;

Fig. 3b shows a combined view of the heating device with the opening of the connection and separation zones in the embodiment of the heating element, consisting of a heating wire and a self-regulating cable, and with an electromagnetic protection screen;

On Figv - shows the electrical circuit of the heating device in the embodiment of the heating element, consisting of a heating wire and a self-regulating cable, and with an electromagnetic shield;

Designations on all Figs. identical.

Implementation of the technical solution

To date, there is a need for heating pipelines, various sections of the surface of great length from 0.5 to 20 km or more without an accompanying network and a large number of accompanying boxes. Modern heating devices made on the basis of resistive and self-regulating cables and tapes have a length limit of up to 250 meters due to the design features. With an increase in the length of the heating device while maintaining a given heating power, it was necessary to increase the cross section of the heating wires or increase the number of power sources, i.e. use an accompanying network. An increase in the cross-section of the heating conductors was limited by the dimensions of the heating device and was not economically justified, therefore, in most cases, the heated surface of a large length was heated by several sequentially located heating devices with several power sources.

The claimed heating device is capable of having a greater length of up to 20 km or more without increasing the cross section of the heating elements, and receiving power from a single source of electric current. The claimed technical solution expands the traditional functionality of self-regulating and resistive cables and wires, which are technically difficult to make for long lengths, and also expands the arsenal of heating equipment. The possibility of using the entire family of heating cables is expanding. At the same time, the traditional dimensions of the heating device are preserved, the process of installation and operation is simplified due to the preservation of the traditional flexibility and weight of the linear section of the heating device and the absence of a large number of junction boxes.

The possibility of creating a heating device of great length is ensured by the presence of not only heating elements in the device, but also by the presence of power current-carrying power wires.

The heating device is a longitudinal cable assembly containing power supply wires 1 along the entire length and several heating elements 2 arranged in series one after another along the entire length of the device. The power conductors are a phase conductor L ( L 1 ) and a neutral conductor N . The heating elements 2 are connected to the power wires 1, forming parallel connections along the entire heating device (Fig. 1a, 1b, 1c).

The heating device in the form of a cable assembly can be divided in the separation zones ( D ) between the heating elements 2. In this way, a heating device of a given length can be obtained. After dividing the device into parts, each separated part will remain operational and represent a separate independent heating device. In Fig.1a, 1b, 2a, 2b, 3a, 3b marked heating zone, separation zone ( D ), as well as connecting and end couplings. The boundaries of the heating zones are designated H1, Hn - the beginning of the first, subsequent heating section, K1 , Kn - the end of the first, subsequent heating section. Also in the above Figs. cross sections A-A, B-B, C-C of the heating device in various versions are presented, as well as a view of the separation zone ( D ).

Since the power conductors 1, located along the entire heating device, are made of an extremely low resistance material, such as copper or aluminum, electrical energy through these conductors 1 can be transmitted over considerable distances of 10 km or more from a single power source. At the same time, up to a certain length, the supply voltage in the electrical circuit and power wires 1 changes slightly. Therefore, if there is a sufficiently powerful power supply, the output power of the heating elements 2 over the entire long length of the heating device will be the same, which will provide highly efficient heating over the entire length of the heating device.

In the heating device, the heating elements 2 are physically located in parallel with the power wires 1. For ease of transportation, installation, reliable connection of the heating elements 2 along their entire length with the power wires 1, the heating elements 2 and the power wires 1 can be twisted together (Fig. 1a, 1b, 2a, 2b). In such a twisted form, the heating device can be used without a common sheath. A shell can be used to ensure the device is solid.

Power conductors 1 can be a single-phase or 3-phase power supply system. The supply conductors 1 may preferably be made of metals with low resistance, such as copper or aluminium.

Heating elements 2 can be made in the form of a heating tape or strip. The heating elements 2 can also be resistive heating wires 3 or self-regulating cables 4 or tapes. In Fig.1a, 1b, 1c, 2a, 2b, 2c shows an embodiment of the device using a resistive wire as a heating element 2.

The heating elements 2 can also be resistive strips or strips or wires, consisting of several individual heating wires. Resistive cores can be made of resistance alloys.

3a, 3b, 3c shows a general view of the device using a self-regulating cable 4 and a resistive heating wire 3 (auxiliary), which are made together as heating elements. In this case, such an implementation of the device implies the presence of a shell. On FIG. 3c shows the electrical diagram of the connection of the heating elements with the power wires 1 in the heating device, which indicates the thermal connection 5 between the self-regulating cable 4 and the heating resistive wire 3. In this embodiment of the device, the self-regulating cable 4 and the heating wire 3, made together connection 5, conventionally taken as a (single) heating element 2.

If there is a thermal connection 5 in the heating element 2 between its components, the heating device may contain an additional power core 6 ( L 2 ) associated only with the auxiliary heating resistive wire 3 (Fig. 3a, 3b, 3c). The inclusion of an additional power core 6 ( L 2) provides the ability to control the power of the heating element by supplying power or its absence on the resistive wire 3. In this case, the power cores 1 ( L 1 , N ), additional power core 6 and heating elements 2 (consisting of self-regulating cable 4 and auxiliary heating wire 3) can also be twisted together. The additional power supply conductor 6 ( L 2) can be made of the same metals as the supply conductors 1 ( L 1 , N ).

The embodiments of the heating elements 2 are not limited to the above examples and can be supplemented by variations and combinations of heating elements known from the prior art.

Heating elements 2 can be placed both in the outer part of the heating device and in the inner part, for example, between the power wires 1 and possible additional wires 6.

The heating device may contain an external protective shell for ease of installation, operation, and also protecting the heating device from aggressive environmental influences or mechanical external influences.

The heating device may also contain a moisture protection layer, or contain an electrical or electromagnetic protection layer or shield, depending on the operating conditions. On Fig.2a,2b,2c,3a,3b,3c shows the embodiments of the heating device with the shield of electromagnetic protection 7 ( PE ).

The heating device is produced in large lengths and is supplied for installation in coils or drums. During production, the general required parameters of the heating device are set depending on the expected length and power of the heating device. The cross-sections of the power wires and heating elements are set, the components of the heating elements are selected, if necessary, the materials of the wires, the cross-sections and their number are selected. Depending on the expected operating conditions, shells, layers and screens are additionally applied.

Depending on the power supply system of the heating device, on the possible components of the heating elements, the required number of power wires is selected during production.

After determining the main design parameters, a cable longitudinal assembly of the heating device is performed, mainly by twisting.

Subsequently, the device is divided into separate heating sections (separate heating devices) of the required length and connected to the power supply.

The claimed technical solution improves the ease of installation due to the single design of the heater and the absence of junction boxes, as well as the possibility of separating the device if necessary. In any version of the device design, there will be one coupling and one end.

Implementation example

A heating device 1 km long was manufactured at the factory. The device is designed to operate on a single-phase power supply. The power supply conductors are insulated, made of copper with a constant cross section of 4 cm ² . A stranded resistive wire insulated from a polymeric material was used as heating elements. A resistance alloy was chosen as the material of the resistive cores. The heating wire has a length of 30 m. A separation zone of 0.3 m is formed between two successive heating elements. A total of 32 heating elements are installed in the heating device. Power cores and heating elements are a cable assembly and are twisted together. Marks are made on the shell of the device to indicate the boundaries of the separation zones, in which it is possible to divide the device into independent separate heating devices. The power of each heating element is 600 W, and the entire device, 1 km long, is 19 kW.

The consumer needs to heat a pipeline 800 m long. To do this, it is enough to separate 200 m of the device in the separation zone from the finished heating device 1 km long. The remaining device, 800 m long, is transferred to the consumer. Separation of a part of the device is carried out at the enterprise, while additional separation, if necessary, can be carried out by the consumer during installation.

When mounting the heating device on a pipeline 800 m long, the consumer calculates the required power to power the heating device. If the consumer wishes to obtain the full power of a heating device, 800 m long of which contains 26 heating elements, each of which has a power of 600 W, then the consumer needs to provide a power supply from one source of 15 kW.

To heat a pipeline 800 m long, an 800 m heating device is mounted on the outer surface of the pipeline and, on the one hand, is connected to a power source with a power of 15 kW through a transformer, on the other side of the heating device, the power wires are shorted.

Claims (14)

1. A heating device containing power wires, heating elements, characterized in that the device is made in the form of a cable assembly containing at least two heating elements located one after another along the device, while the heating elements and power wires are twisted together or heating elements are located in the outer part of the device. 2. Heating device according to claim 1, characterized in that the heating element is made in the form of a tape, or a strip, or a cable. 3. The heating device according to claim 1, characterized in that the power wires are a single-phase power system. 4. Heating device according to claim 1, characterized in that the power wires are a 3-phase power system. 5. Heating device according to claim 1, characterized in that the heating elements are resistive heating wires. 6. Heating device according to claim 1, characterized in that the heating elements are self-regulating cables or tapes. 7. Heating device according to claim 1, characterized in that the heating elements are resistive strips or strips consisting of several individual heating wires. 8. Heating device according to claim 1, characterized in that the heating elements comprise a heating wire and a self-regulating cable made together and in thermal communication. 9. The heating device according to claim 8, characterized in that it contains an additional power core associated only with the heating wire. 10. The heating device according to claim 9, characterized in that the power wires, the additional power wire and the heating elements are twisted together. 11. Heating device according to claim 1, characterized in that it contains a protective sheath. 12. Heating device according to claim 1, characterized in that it contains a layer of moisture protection. 13. Heating device according to claim 1, characterized in that it contains a layer or screen of electrical or electromagnetic protection. 14. The heating device according to claim 1, characterized in that it contains a single outer protective shell, which houses the device with all connection elements.

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