SU926439A1 - Apparatus for automatic control of combustion process - Google Patents

Description

(W) DEVICE FOR AUTOMATIC REGULATION

I

This invention relates to the automation of a fuel combustion process with a slight excess of air.

A device for automatically controlling the combustion process is known, comprising a fuel-air ratio controller connected to fuel and air flow sensors and through a switch with a control input to an optical density sensor for flue gases 1.

A disadvantage of the known device is the low quality of regulation.

The purpose of the invention is to improve the accuracy of regulation.

The goal is achieved by the fact that the device additionally contains a correction device and a differentiator, wherein the correction device is inserted into the communication line of the flue gas optical density sensor with a switch, and the differentiator is connected to the DIRECTION OF THE COMBUSTION

flue gas optical density, and the output to the control input of the switch.

Figure 1 shows the functional diagram of one of the possible variants of the device; figure 2 - the dependence of the magnitude of the signal at the output of the sensor optical density of flue gases from the coefficient of air flow.

ten

The sensors of fuel consumption 1 (| figure 1) and air 2 with their outputs are connected to controller 3 of the ratio of current or air. Flue gas optical density sensor output.

Claims (2)

15 is connected to the input of the secondary device 5; the first output is connected through the differentiator 6 to the control input of the switch 7; The second output of the secondary device 5 of the sub20 is connected to a correction device 8, the output of which is connected to the second input of the switch 7. The output of the switch 7 is connected to the third input regulator 3 fuel-air ratio. Figure 2 shows the dependence of the signal U on the output of the flue gas optical density sensor on the air flow rate in the inflection area near the point M, at which the slope becomes negligible, is used depending on the relationship between points A and B. The device works as follows . The air-to-air ratio controller 3, acting on the executive mechanisms for regulating the supply of fuel and air (not shown), controls the fuel-air ratio approximately equal to the dependency point M in FIG. 2. For various reasons, the actual burning mode may correspond to the AM or MB zone of the dependence in Fig. 2, i.e. mechanical underburning or with excess air. . The output signal of the differentiator 6 corresponding to the dependence point M in FIG. 2 is selected as the threshold value of the control signal of the switch 7. During operation, for example, in the mechanical underburner AM, the signal level at the output of the differentiator 6 is higher than the threshold value. In this case, the signal exceeding the threshold value at the output of the differentiator 6 causes the switch 7 to switch to a state in which it passes the signal of the correction device 8 to the third input of the controller 3 and does not pass the signal of the differentiator 6 The signal of the device 8 acts in the regulator 3 to increase the flow coefficient air, and the mode is brought to a state corresponding to the point M of dependence in FIG. 2, after which the corrective action is deactivated. In operation, for example, in the zone of excess air MB, the signal level at the output of differentiator 6 is below the threshold value and sufficient to affect the controller 3. At the same time, the signal at the output of differentiator 6 is smaller than the threshold value and causes the switch 7 to switch to passes the signal of the differentiator 6 to the third input of the controller 3 and does not pass the signal of the device 8. The signal of the differentiator 6 operates in the controller 3 to reduce the air flow coefficient, and the mode returns to the state corresponding to The dependence point M in FIG. 2. Thus, the burning mode will be continuously adjusted so that it will be maintained in the vicinity of point M on the left or on the right. Apparatus of the Invention A device for automatically controlling the combustion process, comprising a fuel-air ratio controller connected to fuel and air flow sensors and through a switch with a control input to an optical density sensor for flue gases, characterized in that, in order to improve the control accuracy, the device additionally contains a correction device and a differentiator, with the correction device introduced into the communication line of the flue gas optical density sensor with a switch, and ifferentsiator its input connected to the sensor optical flue gas density, and output to the control input of the switch. Sources of information taken into account in the examination 1. USSR certificate of authorship If 352090, cl. F 23 N 3/00, 1968.