SU1183812A1 - System of automatic regulation of furnace temperature - Google Patents

Abstract

SYSTEM OF AUTOMATIC REGULATION OF TEMPERATURE IN THE OVEN, consisting of a sensor and temperature setter, a regulator, distinguishing a-I so that, in order to improve the quality of heat treatment, a sensor and setpoint gauge of fuel consumption, limiters of the minimum and maximum of the signal, reversive eletro are introduced into it ; variable speed drive to the input; which is connected 1 sensor and, chick. temperature, and the output is connected to the input of the t-fuel flow rate setpoint, the outputs of the maximum signal limiter and the minimum signal limiter are connected to the controller inputs, and the maximum signal limiter input is connected to the sensor output. And the temperature setpoint device, and to the input ( For the minimum limiter of the signal, the outputs of the sensor and the unit for fuel consumption.

Description

1 The invention relates to systems for the automatic regulation of the thermal regime of a heating furnace and can be used in the metallurgical and machine-building industry. The aim of the invention is to improve the quality of heat treatment. FIG. 1 is a block diagram of an automatic temperature control system; in fig. 2 - schedules of operation of maximum and minimum limiters. The automatic temperature control system includes a temperature sensor 1, a temperature setpoint 2 electric drive 3, a fuel consumption sensor 4, a fuel consumption setpoint 5, maximum limiter 6, minimum limiter 7, regulator 8, control object 9. At steady state operation of the system, the actual temperature of the control object 9 and the actual fuel consumption correspond to the specified ones. The output signal of the temperature sensor 1 is equal to the output signal of the temperature setting device 2, the output signal of the fuel consumption sensor 4 is equal to the output signal of the fuel consumption setting device 5. The difference between the signals at the inputs of limiter 6 of the maximum and drive 3 is zero, their output signals are also zero. In this case, the actuator 3 does not change the position of the fuel flow setting device 5, the difference of the signals at the inputs of the limiter 7 does not change and equals zero, the output (the 1st signal of the limiter 7 minimum is zero. With a zero total signal at the inputs of the regulator 8, the flow rate The fuel at the control facility 9 remains unchanged. When the temperature of the control object 9 deviates from the maximum limiter 6 specified at the output of the limiter, a signal appears that is initially proportional to the difference of the signals at the inputs and upon reaching some value it grows (Fig. 2a). When this signal is applied, the regulator changes the fuel consumption at the control facility 9 so as to compensate for the deviation of the temperature from the specified one. The inputs of the limiter 712 are minimums. As it increases, the signal at the output of limiter 7s minimum is first absent, and after that, as the difference of the signals at the inputs exceeds a certain value, becomes proportional to it (FIG. 2b). The signals at the inputs of regulator 8 are turned on in antiphase, and at the moment when they are compared (Fig. 2c, point A), the total signal becomes equal to zero and regulator 8 stops the change in fuel consumption. Thus, with any change in heat load or temperature setting, fuel consumption can vary only within a limited range. When the sensor 1 and the setpoint 2 of the differential temperature are present at the outputs, the electric drive 3 changes the position of the fuel consumption setting device 3 at a speed proportional to the input signal and shifts the range of change of fuel consumption so as to compensate for the mismatch of the control object 9 specified. When the temperature reaches a predetermined value, the signal at the input of the actuator 3 becomes zero, and the shift in the range of change in fuel consumption is stopped. The dependence of the speed of the electric drive 3 on its input signal is chosen so that, on the one hand, to ensure normal operation of the control object 9 in all modes, and on the other hand, to prevent sudden changes in fuel consumption. The ability to change fuel consumption only in a limited range greatly improves the stability of the automatic control system and the accuracy of temperature maintenance in all operating modes of the heating furnace, whereas in the existing automatic temperature control systems the controllers with their constant adjustment to the control process do not provide high-quality heating furnace operation in all modes. The use in the system of automatic temperature control of maximum and minimum limiters, variable speed reversing electric drive that controls the fuel consumption settingter allows to improve the quality of metal heating, reduce fuel consumption and reduce the reduction in fuel consumption.

regulation processes with abrupt changes in consumption exclude emergency situations due to fuel.

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Claims (1)

'AUTOMATIC TEMPERATURE CONTROL SYSTEM IN FURNACES, consisting of a sensor and a temperature setpoint,' a regulator, is distinguished by the fact that, in order to improve the quality of heat treatment, a sensor and a fuel flow rate setter, signal minimum and maximum limiters are introduced into it , reversible electro / variable speed drive, to the input; of which the temperature sensor is connected, and the output is connected to the input of the fuel consumption meter, the outputs of the signal maximum limiter and signal minimum limiter are connected to the regulator inputs, and the signal maximum limiter input is connected. The outputs of the temperature sensor and §, and input ι do the signal minimum limiter - and the outputs of the sensor and the fuel consumption adjuster., p>