The submerged arc furnace generally refers to the electric arc furnace, cracking furnace, calcium carbide furnace, ferrosilicon furnace, and other important smelting equipment in the metallurgical industry. The electric energy consumption is amazing, commonly known as “electric tiger”. The statistics of many users of EAF show that the cost of electricity is as high as 70% in the production cost of products, which becomes a heavy pressure on enterprises. Improving the energy efficiency level of EAF and improving the comprehensive energy efficiency of EAF is of vital significance to the development of metallurgical enterprises. In view of this vast market, Huineng Power Electric has launched coseino series industrial furnace power saver. The introduction of this project will open up broad market space for China’s energy efficiency industry.
After more than one year of on-site installation and testing, Huineng power electric technicians have accumulated rich on-site experience and collected a large number of test data, laying a solid theoretical and practical foundation for the leap of energy efficiency technology of industrial furnace series. Huineng power energy efficiency researchers cooperated with a number of domestic and foreign enterprises with rich experience in the field of industrial control to launch a new generation of arc furnace energy efficiency control system Coseitop. The new system strengthened the energy-saving effect, completely overcome the shortcomings of early products, took the lead in introducing advanced technology of industrial control, and realized the integrated information control system in the industrial furnace With the successful application of the system, the energy-saving effect is significantly improved. The birth of this energy efficiency system will provide the best choice for the realization of energy-saving and consumption reduction, improvement of product quality, and control automation of industrial furnaces in China’s metallurgical industry.
Energy Consumption of Electric Arc Furnace
The electric arc furnace smelting uses the heat generated by the electric arc between the graphite electrode and the iron (molten iron) to melt the iron and overheat the iron. The structure of the EAF body is shown in the following figure:
The electric energy consumption in the power grid is mainly composed of two parts. One part is the electric energy generated by the electric arc furnace discharge, which is all the electric energy consumption of steel-making. The energy loss of this part mainly includes heat loss of furnace lining (7% – 14%), the heat loss of water cooling system (3% – 8%), heat loss caused by furnace filling and charging (2% – 3%), heat loss caused by opening radiation (1% – 2%), heat loss caused by high-temperature furnace gas (2% – 3%), heat loss caused by electrode radiation (1% – 3%). The other part is the power loss of high-voltage cable, transformer, and short network line, which is useless power consumption.
There are two ways to improve the energy efficiency of electric arc furnaces:
[1] Transient and high-order harmonic suppression technology represented by coseino series products. This technology can effectively filter the transient, surge, and high-order harmonics of the electric arc furnace power grid system, improve the power environment, improve the efficiency of the power supply system, reduce line loss, and other aspects to achieve safety and energy saving. This technology has contributed to the improvement of the energy efficiency level of EAF in the early stage, but its shortcomings are also obvious:
(1) The test cycle is long and it is not easy to compare.
(2) The energy-saving effect is not ideal. On the whole, it is difficult to satisfy the majority of users.
[2] With the development of EAF energy efficiency technology, an energy-saving control system based on industrial control technology has emerged. The focus of this system is to control the movement of the electrode by sampling the operation parameters of EAF and to change the manual control to automatic control, so as to realize the reasonable scheduling of EAF power supply system, so as to achieve the effect of energy-saving. This technology also has some disadvantages:
(1) It lacks the effective improvement of the power quality of the whole EAF system from the system point of view, the lack of solutions to the resulting power waste, and the existence of “energy consumption loopholes”.
(2) The early industrial control technology is not perfect, there are many problems such as low level of intelligence, insufficient control accuracy, poor reliability, and so on. Many users feel that the energy-saving effect is not ideal, and the failure rate is high, sometimes affecting the normal production, so the comprehensive benefit is not high.
Working principle of the energy-efficient control system of coseitop electric arc furnace
The energy efficiency control system of electric arc furnace coseitop mainly aims at many problems existing in the existing electrode control system of an electric arc furnace, such as three-phase imbalance, difficult control of arc voltage and current, frequent arc breaking and short circuit, etc., and the useless power consumption in the electric energy consumption is large. From the aspect of automatic control, this paper takes this aspect as the starting point and optimizes and transforms this key part of electric energy waste to achieve the goal of power-saving. It can input the corresponding parameters into the electric arc furnace energy efficiency control system in the form of digital according to the power required by the field operator in each stage of the process of the electric arc furnace, and input the voltage, current, power, and dead zone into the electric arc furnace energy efficiency control system in the form of digital according to the power required by the field operator in each stage of the process of the electric arc furnace. The system automatically stores these parameters, and automatically measures the actual situation on site The operation parameters and grid data are adjusted automatically according to the standard process parameters to adapt to the different working conditions of the electric arc furnace, so as to achieve accurate cooperation, realize the optimization of system control, maximize the potential of energy efficiency improvement, and create as many economic benefits as possible for users. The system runs reliably and has multiple protection modes, which can completely eliminate users’ worries.
