SU1394001A1 - Method of feeding electric-gas burner - Google Patents

Abstract

The invention improves the accuracy of the adjustment. At the outputs of the current transformer 3 and the voltage sensor 5, signals respectively proportional to the current and voltage on the load are generated, which are rectified with the help of rectifiers 6, 7 and fed to the inputs of the logarithmic divider 8. The latter divides the output of the output signals. one on the other. At the output of the divider, a signal is formed that is proportional to the conductivity of the medium. Max., The value of conductivity during each pulse is detected by an amplitude detector 9 with a reset and then added to the signal of the reference voltage setting unit 11 and the integrator 12 with a reset. The information input of the latter is connected to the output of the rectifier 6. As a result, a signal is generated at the output of the integrator 12, which is proportional to the average value of the current over the half-period of the supply voltage. In this way, the duration of the subsequent voltage pulse feeding the electrolysis gas torch is adjusted. 4 il. with S (L

Description

The invention relates to methods for feeding electric gas burners used to obtain a high-temperature flow of combustion products by heating a flame with a diffuse electrical discharge in gas-flame processing of building materials, such as glass and brick, as well as in melting furnaces for various purposes.

The aim of the invention is to improve the accuracy of the regulation of

Fig. Fig. 1 shows diagrams of the variation of voltage U, current i, and conductivity g as a function of time tj in Fig. 2 — an example of the execution of a block diagram of a device implementing the method; Fig 3 is a functional circuit of a thyristor controller; Fig 4 - diagrams of operation of functional elements

devices

The impulse voltage (Fig, 1) is the sinusoidal voltage U, the duration of which is determined by the angle of regulation oi.

The instantaneous value of the current i of the current-conducting medium is determined by its conductivity g and voltage U at the considered time point.

l

t -Q, where w is the angular frequency

supply network.

Fluctuating the conductivity of a medium causes a load current to fluctuate, the value of which must be maintained at a certain (specified) level. The deviation of the average current from the supply voltage half-period specified during the next pulse can be compensated for by changing the duration in the next half-period of the supply voltage. The average value of the current pulse (Fig. 1) for the half-period of the supply voltage is proportional to its volt-second area (shaded area) and corresponds to the specified value for the established value of conductivity g, and the angle of regulation of the resulting pulse. The duration of the subsequent pulse is corrected (reduced) depending on from the new value of the conductivity of the medium g,.,. It should be noted that the conductivity of the medium is proportional to the amplitude value of the current only at the initial moment of the formation of a pulse.

50

about

five

"G

0

Therefore, in the theoretical case, the time drop of the moment of the beginning of the pulse and the change in the conductivity of the medium, the regulation of the duration of the subsequent pulse will be adequate (by angle)

The device (Fig. 2) contains a thyristor regulator 1, the power input of which is connected to the alternating voltage source 2, and the output through the current transformer 3 is connected to an electro-gas burner 4 and the voltage sensor 5 input, the current transformer 3 and sensor 5 outputs voltage through the corresponding rectifiers 6 and 7 are connected to the inputs of the logarithmic divider 8, the output of which is connected to the information input of the amplitude detector 9 with a reset, the adder 10, the inputs of which are connected, to the outputs of the unit 11 of the reference voltage, integrate ora 12 with reset and amplitude detector 9 with reset, and the output to the control input of the thyristor controller 1, and its synchronizing output is connected to the reset, they inputs respectively an integrator 12 with a reset and amplitude detector 9 with a reset

The thyristor controller (FIG. 3) contains about threshold threshold comparators 13 and K, the inputs of which are combined and connected to the output of the source 15 of the synchronization voltage, and the outputs respectively to the inputs of the logic element 2NE-16 and the inputs of logic elements I 17 and 18, integrator 19 with a reset, the information input of which is connected to the reference voltage adjuster 20, and the reset input to the output of the 2E-I logic element 16, a comparator 21, the first input of which is connected to the output of the integrator 19 with a reset, the second input 22 - with the output of the adder 10 (), and out d through the monostable multivibrator 23 - with the combined second inputs of the AND gates 24, 17 and 18 (fig.Z) and reset inputs of the integrator 12 with reset (Fig. 2) and the amplitude detector 9 with reset; the input devices 25 and 26 of the corresponding counter-connected thyristors of the thyristor switch 27, whose inputs are connected to the outputs of the logic elements I 17 and 18, respectively, the outputs 28 and 29 of the thyristor switch

3139АОО

torus 27 is connected respectively to the output of the alternating voltage source 2 and to the input of the current transformer 3 (Fig 2).

FiGoA shows voltage diagrams at the output of the following elements of the device: and - source 15

synchronization voltage, U integrator 19 with reset, U com-

Parator 13, U4 comparator 14,

Uj-logical element 16, Ug-logical element 17, logical

element 18, Ug - one-shot 23,

and g - comparator 21.

The device works as follows

The output signal of the synchronizing voltage source 15 (Figs. 3 and 4 is sinusoidal, phase coincident with voltage U (figlo, using single threshold comparators 13 and 14 (working in antiphase) is converted into two antiphase, rectangular pulses ( Fig. 4) with a duration of approximately 178 elogrado At the moment when the synchronization voltage passes through the Zero signal, the output of the single-threshold comparators 13 and 14 simultaneously takes on a low level (logical zero). A high level pulse of 4 eLo degrees is formed (figure 4). This pulse resets (zeroes) the integrator 19 with a reset (phyo). During the absence of a pulse, a linearly increasing voltage is formed at the output of the integrator 19 (sawtooth) the slope of which is set by the reference voltage adjuster 20 and the time setting parameters of the circuit. The sawtooth voltage is compared with the output signal of the adder 10 (input 32 per FIG. 3) and at the time it is exceeded, a square is formed at the output of the comparator 21 pulse monostable multivibrator 23 which is triggered at the output of one of the vibrator are formed pulses elogrado about 2 and 100 Hz. Using the logic elements And 17 and 18, the output pulses of the one-shot 23 are distributed on

five

0 5 0 0 5

five

the corresponding thyristors of the thyristor switch 27, Galvanic separation of the power and control circuits is carried out by means of the input devices 25 and 26 of the corresponding thyristors Each thyristor operates in a certain half-period of the supply voltage (phGo) o Output signal of the one-oscillator 23 (output 24) with a reset (preparation for measurement) of the intergrator 12 with a reset of the 9 detector with a reset (FIG. 2) „

At the outputs of the current transformer 3 and the voltage sensor 5, signals respectively proportional to the current and voltage on the load (medium) are generated, which are rectified using rectifiers 6 and 7 and fed to the inputs of the logarithmic divider B. The logarithm divider 8 divides the output signal rectifier 6 for output value. rectifier signal 7 As a result, a signal proportional to the conductivity of the medium is formed at its output. The maximum conductivity value during each pulse is detected by an amplitude detector 9 with a reset and then added to the signals of the reference voltage setting unit 11 and integrator 12 with a reset. The information input of the integrator 12 with a reset is connected to the output of the rectifier 6, with the result that at its output a signal is formed that is proportional to the average value of the current over the half-period of the supply voltage.

Claims (1)

Invention Formula The method of feeding the electro-gas burner by pulsed voltage by measuring the average current value of the preceding pulse and adjusting the duration of the subsequent pulse, characterized in that, in order to improve the control accuracy, the voltage value of the previous pulse is measured, the average current is divided by the voltage value and adjustment is made depending on the particular Phi.1 Phi. J