Metallurgical Knowledge
How to solve the problem of low power factor of ore - smelting furnace

2016-05-19 hit:

Method and principle

The general case of submerged arc furnace in order to solve the problem of low power factor, China now commonly used way to solve the capacitance compensation, reactive power compensation is usually carried out in the high end, but due to the high voltage end compensation can not solve the three-phase equilibrium problem, and because of the short net impedance accounted for the entire system inductance of 70%, so the high voltage side the compensation does not reduce the busbar system inductance, improve busbar power factor. The purpose of increasing the output of the transformer is only meaningful for the power supply department.

It is also a part of the unit in the new furnace adopts high voltage reactive power compensation measures at the same time, to solve the above problems, can compensate power factor, a substantial increase in the short end end ultra lower power consumption, a large number of reactive power consumption and the imbalance of the furnace transformer low voltage busbar, effective improve the implementation of power factor and reactive power compensation technology transformation, from the point of the technology is reliable, mature, economically speaking, input and output is proportional to the. In the low voltage side of furnace for three-phase reactive power consumption and the arrangement length caused by inconsistent busbar imbalance and the implementation of reactive power compensation on the spot, both in improving the power factor, harmonic absorption, or in production and consumption, have incomparable advantage of high compensation. But because of the high cost, at the same time because of the bad working condition, so life is greatly affected, while low voltage reactive power compensation busbar brings harmonic increase, so measures must be taken to suppress the 3 to 7 harmonics, so that the investment increase, the investment recovery period and long follow-up, and high maintenance costs, poor comprehensive benefits. Generally applies only to new furnaces.

Is there a way to improve the power factor of the short end, and no harmonic, but can suppress the harmonic, the answer is: yes.

Our company according to the actual situation of ore smelting, smelting industry with many years old expert's experience, through detailed scientific calculation, the development of system short low impedance furnace developed, can greatly reduce the short net impedance, improve the power factor, the highest can be increased to 0.95, has many features and the original low frequency ore furnace DC submerged arc furnace. Can reduce the harmonic components, and automatically change the reactive power compensation.

1, from the short net structure, to further reduce the impedance by special arrangement and the shortest route.

2, take the microcomputer control electrode from the control structure, so that the current in any case has the highest electric efficiency, it has the advantages of low frequency, direct current furnace, and reduce the impact on the power grid. The output of the transformer is improved, the active power loss is reduced, and the smelting consumption is reduced; secondly, the higher power factor is obtained under the condition of low power consumption, and the output of the furnace is increased. Our system can achieve:

1) to improve the power factor to more than 0.9

(2) direct power saving rate from 5% to 20%,

(3) increase the output by 5% ~ 10%,

A: low impedance busbar system

Because our products are according to the specific circumstances of individual customer's special design, is not universal, so please fill in the questionnaire, so that we can give you make the most suitable for your products, bring the maximum economic benefit for you.

B: energy efficiency controller

Aiming at the imbalance between the electrodes, if furnace customers did not take the electrode automatic control, we also provide a set of arc furnace efficiency controller, this system is based on the arc furnace electrode as the control object, using PC as the host machine, using the method of neural network and fuzzy control combined control, solve the difficult problem of arc furnace multi variable, strong coupling and nonlinear model to establish the. The operator only needs to electric power according to the various stages of the smelting process of arc furnace process requirements, to the computer with numerical form voltage, current or power (set), the computer control system will automatically in real time to detect value parameters (voltage, current) of A/D conversion to compare with the preset value operation. According to the mathematical model to analyze and judge, and then issued a directive to the driving cylinder (motor) drive electrode movement, stream size change arc, make the system quickly to correct the deviation, the sustain electrode running in a given range. In order to reduce the number of short arc and arc, optimize the furnace condition, so as to achieve the purpose of saving electricity.

The higher energy efficiency system will furnace simulation circuit of arc original regulator upgraded to a computer system with intelligent digital control, so whether it is in the melting stage, or in the oxidation and reduction period, the system can automatically according to the selection strategy of furnace optimization control, and by minimizing current fluctuations, to improve the active power supply system and the corresponding power factor.

1, functional characteristics

The system uses digital technology, the implementation of point to point control, in the WINDOWS (according to the need to be equipped with the network) platform, the realization of three-phase power frequency arc furnace measurement, control, pipe integration function. The system used on the market of industrial computer and a special driving power (or frequency), the original analog circuit control with intelligent control for upgrading the performance of the computer system, the overall performance reached the control performance of foreign ultra high power furnace:

1, remarkable power saving: good tracking performance of the system, the current fluctuation is decreased to the minimum, the impact of the power grid, the power supply efficiency decreased more than 50% increased by more than 10%, compared with non computer control, reduce the electricity consumption per ton of steel 5% - 15%;

2, the production efficiency can be improved significantly: the melting rate increased about 5%, oxidation (temperature) to shorten the average time of 5 minutes or more, molten steel costs can be reduced by 20 - 100 yuan / ton, iron production increased more than 5%.

3, low electrode consumption: excellent comprehensive performance can reduce the electrode consumption by more than 10%;

4, the high quality of molten steel: the wide range of control characteristics of the system, to solve the old regulator in the reduction of the problem of easy to rise, especially for the smelting of ultra-low carbon steel is particularly prominent.

5, the system data transmission using shielded cable, reliable grounding system can be a variety of strong electromagnetic interference in the operation of the arc furnace.

6, the operation of the system interface is very friendly, full Chinese menu, as long as the junior middle school education level of employees, a little training can be on the operation - detection of arc voltage and arc current of the actual value and fluctuation curve.

7, installation and commissioning, maintenance is simple: system equipment installation commissioning at the scene only 3 hours can be put into operation, without changing the original system, the system can make the equipment failure rate is 90% lower than that of transformer or transformer changes only need to modify the software parameter.

8, this system provides a reliable platform for the transformation of the steel plant, can realize the power control and management of multiple power grids, can fundamentally solve the problem of small and medium steel continuous casting.

Two: technical parameters

1, the upper and lower electrode reaction time is less than 0.2 seconds;

2, the maximum electrode speed of more than 3 M / s;

3, the main circuit short circuit trip time is not less than 3 seconds, the short-circuit current is rated current of 3 times;

4, dead zone: according to the actual situation of the scene and the user needs to be adjusted between + 20%;

5, the system overload capacity of 1.5 times, with overvoltage, undervoltage, lack of phase and over-current protection function;

6, the system operating environment: temperature 0~50℃ DEG C, relative humidity is less than 85%