SU974083A1 - Method and device for controlling furnace thermal mode - Google Patents

Description

(54) WAY OF MANAGING THE HEAT MODE

FURNACES AND DEVICE FOR HIMSELF | IMPLEMENTATION

FIELD OF THE INVENTION The invention relates to glass and metallurgical production, in particular, to casting under pressure.

Closest to the invention is a method for controlling thermal conditions in an electric furnace. This method consists in measuring the temperature of the melt, comparing it with a predetermined temperature and changing the power introduced into the working zone of the furnace, summing the voltage of setting an electric power regulator with the voltage of an additional signal, the amplitude of which corresponds to a given amplitude of temperature fluctuations parameters of the thermal regulator to restore the specified amplitude of temperature fluctuations. A device implementing this method consists of a measuring unit, the first output of which is connected to the first input of the first adder, the second one of which receives a temperature setting signal, and the output is connected to the first input of the thermal regulator, the output of which is connected to the first input of the second adder, the second input of which is connected to the k pulse generator / and the output is connected to the amplifier input, the first output of which is connected to the third input of the second adder, and the second output to the input of the electrode displacement drive device; the output of the latter is connected to the input of the refining device, the output of which is connected to the input of the measuring unit, the second output of the latter is connected to the input of the calculating device, the output of which is connected to the first input of the third adder, to the second input of which a temperature amplitude setting signal is output and the output connected with the input of the correction device, the output of which is connected to the second input of the thermal mode controller lj.

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The disadvantage of this method is the possibility of significant overshoot and delay when changing the parameters of the controller according to the temperature signal of the level change, due to the large thermal inertia of the control object.

Claims (2)

The purpose of the invention is to improve the accuracy and speed of heat regulation by the operation mode of an electric furnace. The goal is achieved by the fact that in the known method of controlling the I thermal mode of the furnace by measuring the temperature of the melt, comparing it. depending on the magnitude and sign of the mismatch, taking into account the amplitude of the fluctuations of the temperature | Tours, the melt level is additionally measured, compared to the predetermined value, and the power supply is corrected depending on the shape and the sign of the mismatch. To achieve this goal in a known device containing a temperature sensor, the first computing unit, the corrective unit, the first and second adders, the temperature sensor, the output of which is connected to the input of the first computing unit and the input of the first adder, the output of which is connected to the first input of the controller , the output of the latter is connected to the input of the execution unit, the output of the first computing unit is connected to the input of the second adder, the second input of the controller is connected to the output of the correction unit, the auxiliary but the melt level sensor, the second computing unit, the third and fourth adders, the melt level sensor are connected to the input of the second computing unit, the output of which is connected to the input of a third of its adder, the output of the latter is connected to the first output of the fourth adder, the second output of which is connected to the output the second adder, and the output is connected to the input of the correction unit. The drawing shows the principal on the device diagram. The device contains temperature sensor 1, sensor 2 level, controller 3, actuator 4, first 5 and second computing units, correction device 7, fourth adder 8, first 9, second 10 and third 11 adders, control unit 12 (working area). In the process of melt jagging, the thermal controller maintains the set temperature of the working zone of the furnace. However, during the process, the volume of the melt in the heating installation changes and, as a result, a change in the predetermined thermal mode occurs. Therefore, it is necessary to change the parameters of the thermal regulator depending on the volume of the melt volume. The thermal regime of an electric furnace is controlled as follows. The temperature of the melt is measured, compared with the set point. The error signal changes the power input to. working area of the furnace. The voltage setting of the electric power regulator is summed with the voltage of the additional signal, the amplitude of which corresponds to a given amplitude of temperature fluctuations of the melt in the working zone. This signal is then summed with the error signal. by level. The resulting signal is fed to a correction device that changes the parameters of the controller. The device works as follows. The signal corresponding to the temperature of the melt in the working zone of the furnace from the temperature sensor 1 enters the adder 9, where it is compared with the setpoint temperature. The magnitude of the error is fed to the input of the thermal controller 3, which changes the amount of heat supplied to the working area of the object 12 by means of an actuator 4. The first unit 5 records the amplitude of temperature fluctuations of the melt in the working area, the signal from the output of unit 5 goes to the adder 10, where is compared with a given value of the amplitude of oscillation. The signal difference goes to the first input of the adder 8. The second input of the adder 8 receives a signal from the output of the adder 11, which is the difference between the signal for setting the melt level in the working zone of the object 12 and the output signal of the second block b. The input of block 6 receives a signal from the output of the level sensor 2, corresponding to the melt x in the working zone of the object 12. The output signal of the adder 8 goes to the input of the correction device 7, which changes the parameters of the thermal controller 3. The proposed method and device for controlling the thermal regime The furnaces allow, by changing the parameters of the controller, the total error signal in the amplitude of fluctuations in the temperature of the melt and directly in the level to increase the accuracy and speed of temperature control by 40%. Claim 1. Method of controlling the thermal mode of the furnace by measuring the temperature of the melt, comparing it from the target and changing the energy supply to the furnace depending on the magnitude and sign of the mismatch, taking into account the amplitude of temperature fluctuations, in order to improve accuracy and speed, measure the level of the melt, compare it with a given and additionally corrects the supply of energy depending on the magnitude and sign of the mismatch. 2. An apparatus for carrying out the method of claim 1, comprising a temperature sensor, a first computing unit a correction unit, a first and second adders, the temperature sensor of which is connected to the input of the first computing unit and the input of the first adder whose output is connected to the first controller input, the output of the latter is connected to the input of the execution unit, the output of the first computing unit is connected to the input of the second adder, the second input of the controller is connected to the output of the correction unit, which is the only one m, that, in order to increase accuracy and speed, 8 it was inserted a rasplar level sensor, a second computing unit, a third and fourth adders, the melt level sensor being connected to the input of the second computing unit, the output of which is connected to the input of the third adders, the output of the latter connecting first Fourth input: that adder, the second input of which is connected to the output of the second adder, and the output is connected to. input correction block. Sources of information taken into account in the examination 1. USSR author's certificate 335677, cl. G 05 D 23/00, 1970.