RU73536U1 - HEATING CABLE - Google Patents

Abstract

The proposed utility model relates to resistive heating cables and cable temperature control systems. A heating cable is included in the equipment of oil wells to prevent the formation of paraffin hydrate plugs and for track heating of oil pipelines. The purpose of this utility model is to create an efficient and reliable heating cable. To achieve this goal, the heating cable, including control wires with temperature sensors and heating wires, on top of which the armor and the outer sheath are applied, it is proposed to perform as follows: - each control wire - of three twisted insulated copper wires placed in the sheath of the control wires, - all control wires twist the cores into the core and place them in the intermediate casing, - over the intermediate casing, lay the heating cores electrically separated by a cordelle with one twine, laid along the cable length, and placed in the insulation of heating living under armor.

Description

The proposed utility model relates to resistive heating cables and cable temperature control systems. A heating cable is included in the equipment of oil wells to prevent the formation of paraffin hydrate plugs and for track heating of oil pipelines.

A device for heating oil wells is known (RF Patent No. 35823 of 12/01/2003). This device comprises a cable lowered into the tubing with a heating element made of at least two parts and connected to a power source, characterized in that the electrical resistance of at least one part of the heating element varies along the length of the cable.

The cable in the device contains, located outside and covering the heating elements, armor made of two layers of steel wire with different direction of turns with a diameter of 0.8-1.7 mm and the number of wires 12-36 in each layer.

The device contains temperature sensors installed inside the heating element of the cable.

The cable armor is grounded through the protective disconnect device of the heating element of the cable from the power source by the value of the maximum leakage current. Cable armor has a sheath made of polymer material.

The disadvantage of this design is the difficulty of manufacturing a cable with a variable resistance along the length. In addition, a change in resistance along the length of the cable will adversely affect the reliability of the cable during prolonged operation.

The purpose of this utility model is to create an efficient and reliable heating cable.

To achieve this goal, a heating cable, including control cables connected to temperature sensors, and heating cores, on top of which armor and an outer sheath are applied, is proposed to be performed as follows:

- each control wire - of three twisted insulated copper wires placed in the shell of the control wires,

- connect the test cores to temperature sensors (resistance thermocouples), twist into the core and place in the intermediate shell,

- on top of the intermediate shell, in one layer, lay heating cores electrically separated by a cordelet laid along the length of the cable and placed in the insulation of the heating cores under the armor.

Additional differences of the proposed heating cable is the following:

- the armor is made in one layer of galvanized steel wires imposed with a gap,

- temperature sensors are located on the cable sections that are most susceptible to overheating, in the remaining parts of the cable, the control cores are replaced by cords made from the composition of a block copolymer of propylene with ethylene and having the same diameter as the control cores,

- heating cores are made of copper or aluminum wires,

- insulation of the cores, as well as the intermediate and outer shells are made of a composition of a block copolymer of propylene with ethylene.

An additional difference is that there can be two or three heating cores. The cable, divided by the cordele into two heating cores, is connected to a direct current source. The cable, divided by the cordele into three heating cores, is connected to a three-phase AC source.

Figure 1 shows a sectional view of one embodiment of a heating cable, where

1. - copper wire control wire;

2. - isolation of the control core;

3. - the shell of the control cores;

4. - an intermediate shell;

5. - copper or aluminum wires of heating cores;

6. - insulating cord, for insulation between heating cores;

7. - insulation of heating cores;

8. - galvanized steel wire armor;

9. - the outer shell.

Figure 2 shows the connection of the temperature sensor to the control cores

1 - copper wire control wire;

2 - isolation of the control core;

9 - the shell of the control cores;

10 - temperature sensor (resistance thermoconverter);

11 - the place of the junction of the sheath of the control conductor and cordel;

12-cordele.

In the proposed cable, twisted control cores, consisting of insulated copper wires 1, are enclosed in a sheath 3. Temperature sensors 10 are connected to control cores on different cable lengths. heating cores 5, which are electrically separated by a cordele 6 from a composition of a block copolymer of propylene with ethylene. An insulation 7 of the composition of a block copolymer of propylene with ethylene was applied to the heating cores. As an armor, one layer of galvanized steel wire 8. is imposed on the insulation. Steel galvanized wire 8 is imposed with a gap. On the steel wire 8, the outer sheath 9 is applied from a composition of a block copolymer of propylene with ethylene. At one end of the cable, the heating cores are electrically interconnected and the outer sheath is fused to prevent contact of the cores with the external environment. A metal tip filled with epoxy glue is put on the fused end. This tip is crimped onto the cable for better sealing.

The sequence of operations in the manufacture of the proposed cable is as follows:

- isolation of control cores by extrusion on an extrusion line;

- production of cordels by extrusion on an extrusion line;

- twisting control insulated conductors on a twisting machine;

- the imposition of an intermediate shell on twisted control cores by extrusion on an extrusion line;

- connection of temperature sensors to control wires and connection to the cordelet;

- twisting control wires, temperature sensors and cordels on a twisting machine;

- the imposition of an intermediate shell by extrusion on an extrusion line;

- laying of coils of aluminum or copper wires on a twisting machine with a dividing cordele;

- application of insulation by extrusion on an extrusion line;

- Laying of coils of galvanized steel wires on a twisting machine;

- the imposition of the outer shell by extrusion on an extrusion line;

- termination of the cable end and crimping with a metal tip.

For the production of the proposed cable, equipment is used by SEVGEOKABEL LLC and SEVKABEL OJSC.

Materials used in this cable:

- copper wire grade MM, MT TU16.K71-087-90;

- aluminum wire AT, GOST 6132-79

- resistance thermoconverters copper or platinum;

- composition of a block copolymer of propylene with ethylene 02-MK TU2211-001-36295287-2002;

- galvanized steel wire rope of group G or C GOST 7372;

The proposed cable has a number of advantages compared with known designs, namely:

- the radial arrangement of the power heating cores allows you to effectively give off heat to the environment, since the cores are as close as possible to the cable surface;

- the proposed design allows the manufacture of a cable with a small outer diameter;

- the proposed cable design also allows you to make a cable with the necessary properties, using significantly less copper;

- due to the fact that one layer of armor imposed with a gap is used, it is possible to reduce the cable overheating, which means to increase its service life.

Claims (7)

1. Heating cable, including heating and control cores with temperature sensors, on top of which armor and an outer sheath are applied, characterized in that each control conductor consists of at least three twisted insulated copper wires placed in the casing of the control cores, all control the cores are twisted into a core and placed in an intermediate sheath, over which insulated heating cores are laid with a single coil, which are electrically separated by a cordelet laid along the length of the cable, and placed us into the insulation of the heating conductors. 2. The heating cable according to claim 1, characterized in that the armor is made in one layer of galvanized steel wires superimposed with a gap. 3. The heating cable according to claim 2, characterized in that the temperature sensors are located on the cable sections that are most susceptible to overheating, in the remaining parts of the cable the control cores are replaced with cords made from the composition of a block copolymer of propylene with ethylene and having the same diameter as the control veins. 4. The heating cable according to claim 3, characterized in that the heating cores are made of copper or aluminum wires. 5. The heating cable according to claim 4, characterized in that the insulation of the cores, as well as the intermediate and outer shells are made of a composition of a block copolymer of propylene with ethylene. 6. The heating cable according to any one of claims 1 to 5, characterized in that it contains 2 heating cores. 7. The heating cable according to any one of claims 1 to 5, characterized in that it contains 3 heating cores.