CS229495B1 - Apparatus for controlling burner performance with high flue gas velocity - Google Patents

Abstract

The invention relates to a device for controlling the burner output at high exhaust gas velocity. The purpose of the invention is to maintain the exhaust gas output velocity in the entire control range of outputs. This purpose is achieved according to the invention by using an electromagnetic pulse valve in the gas fuel supply circuit to the burner and powering its control unit from a pulse converter. The device connection diagram is shown in the figure.

Description

The invention relates to a burner control device and a high flue gas velocity.

Existing systems for controlling the performance of gas-fired burners used for heating furnaces, boilers, etc. are based on a proportional change of the fuel quantity setting, or a step change of this amount from a maximum to a minimum value, or from a> minimum to a maintenance value. The proportional mode is usually ensured by manually or automatically adjusting the control valve in the fuel supply circuit with a possible change in the amount of combustion air. In such regulation, the output velocity of the flue gas changes simultaneously. High-speed burners, used for firing ceramic goods, for example, achieve optimum efficiency in the firing process thanks to the high flue gas velocity and its reduction significantly reduces the resulting off-rate.

in

This disadvantage is overcome by the burner power control device according to the invention, which consists of an electromagnetic pulse valve located in the burner gas supply circuit, the electrical control system of which is connected to a pulse converter consisting of a power thyristor connected in parallel to the series by combining a coupling capacitor and a switching thyristor with a control electrode connected to the first monostable flip-flop, wherein the power thyristor control electrode is connected to the second monostable flip-flop.

The advantage of this device jo flue maintain speed throughout the entire control range of capacities, wherein _the power control may be conducted in Volm wide limits, proportional to management systems can not achieve.

229 495

An exemplary embodiment of a burner power control device is shown in the accompanying drawing, in which a schematic diagram of the circuit is shown.

The high speed burner power control device comprises an electromagnetic pulse valve 11 located in the burner fuel supply circuit and a control unit for supplying its electrical control system. The electric control system of the pulse valve 1 is connected to a power supply source 2 via a power thyristor 2, to which a series combination of coupling capacitor 4 is connected in parallel.

switching thyristor 2 · control thyristor 2 control electrode is connected to the first monostable flip-flop 5, power thyristor 2 control electrode is connected to the second monostable flip-flop 2 * Power to both monostable flip-flops

6. »X is from the power supply Switching thyristor 2 J® is connected ^{to the} power supply 2 via a resistor, 8.

The switching thyristor 6 ensures, via the coupling capacitor 4, the switching off of the current switching thyristor 2 to the pulse valve control system. Similarly, the power thyristor 2 switches off the switching thyristor 6 by its closing. The switching time T _{s of the} power thyristor is given by the switching off time of the switching thyristor 6, and this time is controlled by the first monostable flip-flop <>. Switching time of the switching thyristor 2 J® by the duration T X disconnection of the circuit of the thyristor, which is controlled by the second monostable circuit 2 · Set the time _T off hlavníhστtyristoru 2 is made by changing the size of the timing element, or changing the internal control voltage in the circuits of the second monostable multivibrator? By varying the switch-off time T _, the frequency of the supply voltage of the control system of the solenoid pulse valve 1 and thus the power of the respective burner changes. If both monostable flip-flops j, 2 are identical, changes in component parameters, supply voltage fluctuations and changes in ambient temperature have no effect on the change in the ratio of the on-time T to the off-time T, and therefore the torch output.

The power P of the pulse-controlled burner is given by T

P = ----------. P m. τ max

229 495 where P _max j® maximum burner output, switching frequency is given by _{f =} - ( _Hz )

T + T β v

In view of the possibility of influencing the firing process, it is advantageous that the switching time T of the pulse valve should be as small as tens of milliseconds. Due to the primary air cooling of the combustion chamber of high-speed burners, the switch-off time Ty can be selected in units of seconds without affecting the re-ignition of the gas. For T = 30 to 60 msoc and s

T _v = 30 msec to 8 sec, the switching frequency of pulse valve F is 16.66 to 0.125 Hz, which corresponds to a control range of 1: 133. Such a range cannot be achieved by the current proportional control of the fuel quantity.

Claims (1)

An apparatus for controlling the performance of a high flue gas burner, comprising an electromagnetic pulse valve (1) located in a burner fuel supply circuit, the electrical control system of which is connected to a pulse converter consisting of a power thyristor (3) connected in parallel a series combination of the coupling capacitor (A) and the switching thyristors (5) with a control electrode connected to the first monostable flip-flop (δ), the control olecirode of the power thyristors (3) being connected to the second monostable. flip-flop (7).