SU906039A1

SU906039A1 - Device for monitoring power mode of three-phase electric arc furnace

Info

Publication number: SU906039A1
Application number: SU792811745A
Authority: SU
Inventors: Волемир Данилович Смоляренко; Владимир Иванович Дрогин; Вячеслав Григорьевич Мишаков; Александр Петрович Татаров; Владимир Андреевич Харченко
Original assignee: Предприятие П/Я Г-4696; Донецкий Металлургический Завод Им. В.И. Ленина
Priority date: 1979-08-29
Filing date: 1979-08-29
Publication date: 1982-02-15

Description

изобретение относитс к электро термий.The invention relates to electrothermal.

Известно устройство дл контрол энергетического режима дуговых электропечей , содержащее датчики фазных тока и напр жени , первой производной тока дуги по времени, блоки выделени напр жени дуги, мощности дуги, вычислени действующих значений тока, напр жени и активной мощности дуги, и блок измерени скорости нагрева металла 1.A device for monitoring the energy mode of electric arc furnaces is known, comprising phase current and voltage sensors, a first time derivative of the arc current, arc voltage separation units, arc power, calculating effective current values, voltage and active arc power, and a heating rate measuring unit metal 1.

Недостатком этого устройства вл етс низка точность и инерционность .A disadvantage of this device is low accuracy and inertia.

Наиболее близким к предлагаемому по техническому существу вл етс устройство дл контрол энергетического режима трехфазной дуговой электропечи , содержащее дл каждой фазы датчики фазного тока, напр жени и первой производной тока по времени, блок определени напр жени дуги, соединенный входом с выходами датчиков фазных тока,напр жени и дат чиков первой производной тока по времени трех фаз, блок определени мощности дуги, входы которого соединены с выходами датчика тока и блока определени напр жени дуги.Closest to the technically proposed is a device for monitoring the energy mode of a three-phase electric arc furnace, containing for each phase sensors of phase current, voltage and first derivative of current over time, arc voltage detection unit connected by input with outputs of phase current sensors, for example the sensor and the sensor of the first derivative of the current with respect to the time of the three phases, the arc power detection unit, the inputs of which are connected to the outputs of the current sensor and the arc voltage detection unit.

и блок определени интенсивности нагрева металла 2.and a unit for determining the intensity of heating of the metal 2.

Недостатком этого устройства вл етс низка точность.A disadvantage of this device is low accuracy.

Цель изобретени - повышение точности контрол .The purpose of the invention is to improve the accuracy of control.

Поставленна цель достигаетс за счет того, что блок измерени интенсивности нагрева металла выпол10 нен в виде последовательно соединенных элементов умножени , вьвделени действующего значени сигнала и функционального преобразовател , причем входы элемента умножени , ко15 торые служат входами указанного блока , соединены с выходами датчика тока и блока определени мощности дуги, а выход функционального преобразовател служит выходом блока оп20 ределени интенсивности нагрева металла .This goal is achieved due to the fact that the unit for measuring the intensity of heating of the metal is made in the form of serially connected multiplication elements, isolating the effective value of the signal and the functional converter, the inputs of the multiplication element which serve as the inputs of the specified block are connected to the outputs of the current sensor and the determining unit arc power, and the output of the functional converter serves as the output of the unit determining the intensity of heating of the metal.

На чертеже представлена блок-схема устройства дл контрол энергетического режима дуговой электропечи 25 дл одной фазы.The drawing shows a block diagram of a device for monitoring the energy mode of an electric arc furnace 25 for a single phase.

Устройство контрол энергетического режима дуговой электропечи содержит датчик 1, тока, датчики 2-4 первой производной тока по The device for monitoring the energy mode of an electric arc furnace contains a sensor 1, current, sensors 2-4 of the first derivative of current

Claims

30 times, respectively, 1st, 2nd, 3rd phase, phase voltage sensor 5, voltage detector block 6 LUGI, arc power detection block 7, radiation emission shaping unit 8, metal heating intensity determination block 9, consisting of the multiplication element 10, the selection element of the effective value of the signal 11 and the functional converter 12, the output of which serves as the output of block 9, the selection elements of the effective values of the signal 13-16. A signal proportional to the arc power from the output of block 7 is fed to one of the inputs of multiplication unit 10, to the second input of which a signal proportional to the arc current is taken from current sensor 1. The output signal equal to the product of the instantaneous values of arc power and arc current, is fed to the input of block 11 and an output signal proportional to the actual value of the product of the active arc power (Rd) to the arc current (Td) is fed to the functional block 15 of the metal heating intensity, where, in accordance with the functional dependence V f (P -I A) / determined for a particular installation, is converted into the magnitude of the heating rate of the metal. The use of the factor Pd1d as a parameter characterizing the intensity of heating of the slit is due to the fact that the heating of the metal in the electric arc furnace depends both on the active power of the arcs Rd. And on the location of the arcs relative to the bath surface (which determines the arc voltage Od) and immersion of the arc in the melt under the influence of electromagnetic forces generated by the arc current 1. Factor Rd I L contains all the parameters that determine the heating of the metal to the arcs on the progfiled furnaces. Experiments have shown that the intensity (speed) of metal heating is closely correlated with the factor Rd-1d, and the dependence V f (Rd, is described by a power function. For example, on DSV-40 furnace, this dependence has the form at 0.097 + 0.021х, relays V 0.735 .. The well-known solution of the ACS with a device for direct temperature measurement does not provide an operative control of the intensity of metal overheating due to the low resistance of sensors and high inertia H3f. The proposed device due to the implementation of the load intensity determination unit By using the active power and arc current signals, continuous operational control over the heating of the metal during the entire melting can be implemented, which until now has not been possible in electric arc furnaces. The use of new elements to determine the intensity factor of the heating of the metal energy regime of an electric arc furnace from a known one, since it allows more simply and with great speed to control the energy parameter — a factor of the intensity of metal heating, h about in turn reduces the time of melting and improve the technical-economic performance of the furnace operation. Technical and economic effect. For example, for a 100-ton chipboard, the reduction in melting time is about 5%. This corresponds to an increase in furnace productivity from 200 to 204 thousand tons per year, due to which the economic effect of the proposal is (at a value of fixed costs of 10 rubles / ton) 40 thousand rubles / g per 100 tonnes DSP. An apparatus for monitoring the energy mode of a three-phase electric arc furnace, comprising for each phase sensors of phase current, voltage and first derivative of current over time, an arc voltage detection unit connected by input with outputs of sensors of phase current, voltage and sensors of first derivative of current with respect to time of all phases, an arc power detection unit, the inputs of which are connected to the current sensor outputs and an arc voltage detection unit, and a metal heating intensity determination unit, characterized by In order to increase the control accuracy, the block for determining the intensity of the metal overheating unit is made in the form of serially connected multiplication elements, extracting the effective value of the Signal and the functional converter, the inputs of the multiplication element, which serve as inputs for the specified block, are connected to the outputs of the current sensor and the arc power block and the output of the functional converter serves as an output of the heating intensity determination unit of the meter. Sources of information taken into account in the examination 1. Pirozhnikov V., V., Kablukovsky A.F. Automation of control and management of electric steel plants. M., Metallurgists, 1974, p. 130-132.

2.Farnasov G.A. Automation of steel melting processes. M., | Metallurgists 1972, p. 147-150.

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