"Electrotechnical Market" magazine

June 1, 2016

In no.2 (68) of “Electrotechnical Market” magazine, 2016, in the category “Special Features” an article was published on “The Russian market of industrial electrical heating systems: the road to import substitution.”

"Electrotechnical Market" magazine

The Russian market of industrial electrical heating systems: the road to import substitution

Over the last 25 years, the Russian market of industrial electric heating systems has changed dramatically: from total domination by foreign suppliers and lack of competition to becoming one of the largest consumers of domestically produced systems.

The significance of EHS in industry and fuel and energy companies

The modern electrical heating systems (EHS) represent an integrated solution, which have replaced, because of their obvious advantages, other heating methods used for processing equipment, pipelines and tanks.

The modern EHS is a convenient, flexible and cost-effective tool for maintaining the requisite temperatures at various sites. The advantages of such systems are low material consumption, easy installation, corrosion resistance and automatic control, ensuring optimum temperatures are maintained with the required accuracy and in accordance with the specified parameters.

Electric heating systems are used in industry to provide solutions for the following:

  • maintaining the desired process temperature, which may be above the ambient temperature throughout the year;
  • frost protection of equipment in the winter;
  • heating oil and petroleum products, technical liquids and chemicals during transportation and storage;
  • frost protection of buildings and structures;
  • anti-condensation heating.

The development of the Russian market of industrial EHS is owed to two key factors. Firstly, it can be owed to sequential movement of oil production in the northern and eastern regions of the country. Due to the climatic conditions of the Russian North, the use of electric heating systems is a necessary technology to ensure safe and continuous operation of industrial enterprises and life support systems.

Second, the technical availability and ease of use of EHS significantly reduce the cost of construction, installation and maintenance. EHS make it possible to control the temperature of the heated site and adjust the heating with the help of modern information systems.

Design, manufacture, installation and operation of the EHS in conjunction have become a sub-sector of industry, which caters to the fuel and energy and defense companies, housing and communal services, construction and other strategic sectors of Russian industry.

According to figures, “Special Systems and Technologies” Group Enterprise (SST Group) is Russia’s largest developer and producer of heating cables and EHS, of which the main consumers are oil and gas companies. They account for 70% of all projects (Fig. 1). The remaining 30% of EHS projects comprise architectural and building projects, 74% of which focus on roof and gutter heating systems and 26% are for open space heating systems (Fig. 2).

For oil and gas companies, EHS ensure the smooth functioning of pipeline transport in the collection and transportation of oil and oil products, tank farms for storage and handling, and process plants during processing. In Russian climatic conditions and the active development of the Russian North, the application of EHS at fuel and energy companies is absolutely essential and one of the key technologies for the industry.

Figure 3 shows SST Group statistics on implemented projects in the oil and gas industry. Production (well pads, pipelines for maintenance of well pressure, pipes for produced water and well viscosity) accounted for 31% of the projects, of which 19% dealt with processing plants, 40% dealt with preparation of oil and oil products for transportation, while terminals and tank farms accounted for 10%.

The reliability of EHS has a direct influence on the safe and continuous operation of facilities at all stages of production and processing in oil and gas companies. Therefore, customers place a number of mandatory requirements on them:

  • performance of basic tasks, i.e. the sustainable allocation of rated capacity, in accordance with a predetermined algorithm for the works;
  • reliable operation of the system over a sustained period (10 to 50 years), without any system failure and requiring little maintenance;
  • optimum cost, in order to ensure functionality and reliability of the system.

Base elements

Each electric heating system consists of the following prerequisite components:

  • a heating part, providing the basic function of the EHS;
  • power and control system, which controls the EHS operation in the most fuel-efficient mode and fulfils the safety requirements.

The structure of the EHS may also include thermal insulation, fastenings and auxiliary elements.

The heating of the EHS can be carried out based on constant power resistive heating cables, induction resistant heaters (SKIN-system) or self-regulating heating cables.

Figure 4 shows the distribution of EHS projects in the oil and gas industry by types of heating element.

EHS projects on the basis of self-regulating cables make up 61%. These systems are used in extraction, processing and storage facilities, which requires heating small lengths of piping and process equipment.

EHS projects on the basis of SKIN-systems, which make up 33%, and based on resistance cables (6%) are used in oil transportation facilities, where it is necessary to heat the length of the pipeline.

Resistance heating cables with constant power are those in which heat generation occurs due to the Joule heating effect, by passing an electric current through the heater core. The heating section (ribbon) of a resistant cable is constructed so that the entire length of the heating conductor can fully drop the applied voltage to an area, but the elements do not overheat the section above the acceptable values. The length of heating section typically ranges from several to hundreds of meters. Resistant ribbon cables may have one, two or more parallel heating conductors, with a linear or spiral shape. Forcible cutting of resistance cables and ribbons along the length is inadmissible.

The constant power heating cable solutions are usually presented in the form of multi-core cables for heating long pipelines, heaters for heating medium-length polymer-insulated pipes and heaters in metal casings with mineral insulation for work under extremely high (up to 600 ° C) temperatures.

Induction-resistant heater — A short-circuited coaxial line, the inner-insulated conductor of which is freely placed in a ferromagnetic tube. After heating, the conductor is electrically connected to the arm tube, while at the beginning of the shoulder between the tube and the conductor, the AC voltage power supply is fed.

A conductor wire passing through the current induces a magnetic field that interacts with the current of the reverse direction, flowing through the pipe. The heating of the ferromagnetic steel pipe is carried out by heat generated by the current flowing therein and reverse induction heating tubes in an alternating electromagnetic field produced by the conductor by direct current, i.e. due to the combined induction-resistive heating.

The induction-resistance heater is mounted on the heated pipeline so as to ensure there is reliable thermal contact. Structurally, one or more heating elements are attached (or welded) to the heat-insulated pipe along its entire length (Fig. 5). Heat from the heating elements is transferred through the heat transfer pipe and the transported product.

Induction-Resistive EHS, also referred to as SKIN-systems have a number of important advantages:

  • power supply from one end. By design, this system’s power supply is fed from one end of the heated area, eliminating the accompanying grid.
  • Electrical safety. The outer surface of the heating element is grounded and has zero earth potential.
  • efficiency at large lengths of pipeline. The most efficient way to heat any trunk pipelines of great length without an accompanying network.
  • high durability and reliability. This design employs a SKIN-system in which the magnetic field-inducing high-voltage cable is placed in a steel tube and is protected from external influences.

Specific power heaters for such systems can usually operate at a capacity of 20 — 60 W/m, but can reach 120 W/m. The operating temperature supported by the wire ranges from 5 ° C to 140 ° C. Supply voltage up to 5 kV.

The most effective and commonly used heating element of the electrical heating industry is the self-regulating cable.

Self-regulating cables — Heating elements with specific properties, in which the fuel element is a conductive polymer material called matrix.

Due to the strong dependence of the matrix resistance to temperature of the heated object, self-regulating heating cables are capable of changing their heat locally.

When the temperature of any area of the heated object rises, the heat generation of the self-regulating cable in this zone drops (Fig. 6).

Self-regulating cables have a number of significant advantages over other types of heating elements. The unique properties of these cables prevent the system itself, as well as the object, from overheating. The use of self-regulating cables allows for on-site installation, using self-regulating cables segments of the desired length. The self-regulating cables’ automatic response to external temperature effects allows you to integrate EHS on the basis of self-regulating heating cables for external control and monitoring systems. One of the important advantages of self-regulating cables is energy efficiency. Only as much energy as is necessary for heating the object is consumed. The design of the cable, namely material conductors, insulating and protective membranes, depends on the operating conditions: the presence of moisture, corrosive environments, solar radiation, and supported temperature ranges or factors.

An important feature of self-regulating cables is their inrush current differing significantly from the current consumed by steady-state cables. Moreover, each type of cable is characterized by its dependency type. This property affects the construction of the power supply network and determination of the nominal launch protection equipment.

Today EHS on the basis of self-regulating heating cables is used for heating pipelines, water pipelines on well pad territories, the BPS processing platforms, initial water and gas installations, and oil gathering platforms, and other processing facilities. Self-regulating heating cables are suitable for heating pipes, especially those that are branched with a variable cross-section, with integrated fittings, pumps and other process equipment. Their major drawback is the constraint in terms of cable length and, what’s more, the greater the linear power capacity, the smaller the maximum length of the heating section. In cables with a linear output of 15 — 25 W/m, the maximum length at negative temperatures is 190 — 120 m, and for those with a linear power output of 45 — 60 W/m the length can be no more than 80 — 60 m, for a power output of 80 — 95 W/m it is 40 — 50 m.

SST Group announced the launch of a full manufacturing cycle of conductive plastic and self-regulating heating cables on this basis. The new production line was deployed at the SST GroupGamma Special Design Bureau.

Import substitution — a new reality

The bulk of EHS consumed by industrial enterprises are those that operate on the basis of self-regulating cables. Annually, Russian industry consumes about 7.5 thousand kilometers of self-regulating cables, of which, the oil and gas sector accounts for about 70%. The largest share of the market is occupied by SST Group (Russia) and a number of manufacturers from the US and EU countries. Several Russian manufacturers of cables and wires produce a limited range of heating cables for special purposes, but their share in total consumption is small. In addition, Russia imports products from Southeast Asia, however, these do not always meet the quality and reliability criteria.

In 2016, a momentous event took place within the Russian market, which in the near future may significantly reduce the market share of foreign manufacturers. SST Group announced the launch of a full manufacturing cycle of conductive plastic and self-regulating heating cables on this basis. The new production line was deployed at the SST GroupGamma Special Design Bureau.

The launch of a full manufacturing cycle of self-regulating cables completed the process of infrastructure formation for the realization of the import substitution process in the area of industrial EHS. Fuel and energy, defence companies and other strategic industries can use all the necessary elements for electrical heating systems, insulation and thermal protection equipment manufactured domestically. In Russia, there is an industry design centre and a network of professional engineering companies, which offer EHS support at all stages of the life cycle.

A unified competence and responsibility centrehas been established at SST Group to ensure the reliability of all EHS components, the use of the most precise design solutions, and the quality of installation and systems maintenance. The reliability of Russian EHS is ensured via an end-to-end quality control system: from individual parts up to ready-made solutions, from design expertise to monitoring of operating parameters.

The Russian application for the manufacturing of EHS eliminates the technological risks in strategic sectors and ensures:

  • the reliable operation of industrial facilities and oil and gas companies in all climatic zones, whether on land, underground and sea, irrespective of the time of year;
  • the ability for production to be halted and then subsequently re-started by operating personnel;
  • a reduction in accidents and the replacement of “frozen” equipment;
  • a reduction of energy intensity in manufacturing, as compared with other methods to ensure continuous running.

In addition, the appearance of EHS, 100% made in Russia, will cleanse the domestic market of low-quality and counterfeit products, reduce dependence on imports for Russian consumers of heating cables for EHS, as well as increase the level of energy and technological security of Russian fuel and energy and defence industry sectors.

References:

  1. Strupinsky ML, Khrenkov NN, Kuvaldin AB: Design and operation of electric heating systems in the oil and gas industry. Reference book. — Moscow; “Infra — Engineering” Publishing, 2015. — 272 pages
  2. Strupinsky ML “Domestically manufactured self-regulating cables — Energy system security elements for Russian industry and fuel and energy companies”, the report at the scientific and practical conference: “The full cycle manufacture of conductive plastic and self-regulating heating cables in Russia: a technological breakthrough and an important milestone for the import substitution program”, March 24 2016.
  3. Prokofiev MV, Khrenkov NN “25 years of experience and expertise at SST Group in the design of electric heating systems based on self-regulating cable companies,” the report on the scientific and practical conference: "The full cycle manufacture of conductive plastic and self-regulating heating cables in Russia: a technological breakthrough and an important milestone for the import substitution program, "March 24, 2016.

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