SU1096451A1 - Method of automatic control of burning process in natural draught heating furnace - Google Patents

Abstract

A METHOD FOR AUTOMATIC CONTROL OF THE COMBUSTION PROCESS IN A HEATING FURNACE WITH A NATURAL CHAIN by measuring the vacuum in the furnace and affecting the traction, is only because, in order to improve the efficiency of burning, the density of dry and wet flue gases is measured and their ratio is measured and use it for corrective action-. STI on t gu. . : d

Description

The invention relates to methods for automatically controlling the combustion process in a furnace with natural propulsion and can be used in the petrochemical, gas processing and other industries. 5 A known method for automatically controlling the combustion process by changing the fuel consumption depending on the amount of vacuum in the furnace [1 J. to

However, this method does not provide an optimal combustion process, since it does not allow to maintain an optimal ratio of fuel and gas consumption in all operating modes of a heating furnace.

There is also a method for automatically controlling the ratio of fuel and air consumption with correction by momentum from a meter of oxygen content in combustion products ['2].

However, the control method does not ensure the maintenance of the optimal ratio of fuel consumption 25 and air, since it does not allow measuring the oxygen content in the combustion products with the necessary accuracy, and has a high inertia.

The purpose of the invention is to increase the efficiency of fuel combustion.

This goal is achieved by the fact that according to the method of automatically controlling the combustion process in a heating furnace with natural draft by measuring the vacuum in the furnace and affecting the draft, the density of dry and wet flue gases is additionally measured, their ratio is determined, and they are used for corrective impact on traction.

The drawing shows a block diagram of a device for implementing the proposed method. 45

The device comprises a heating furnace 1, through the chimney 2 of which flue gas is discharged, a rarefaction sensor 3, a regulator 4, an actuator 5, a density sensor for wet 6 and dry 7 flue gases, del. te.pi 8 and 9, factors 10 and 11 and sum-, mator 12.

The method is as follows.

The flue gas from the heating furnace 1 is discharged through the chimney 2. The vacuum in the heating furnace 1 is measured by a rarefaction sensor 3 and regulated by a regulator 4 connected to the actuator 5 mounted on the chimney 2. The density of the wet flue gas is measured by the density sensor 6, and the dry - by the sensor 7 density. The divider 8 determines the ratio of the densities of dry and wet flue gases, which is multiplied by a constant factor in the factor 10 and a constant factor in the factor 11, the output signal of which is supplied to the divider 9, the second input of which receives the output signal of the adder 12, associated with the output of the factor 10 The signal from the output of the divider 9 enters the camera task controller 4.

When changing (for example, higher, nii). excess air coefficient changes (decreases) the output signal of the dry flue gas density sensor 7, changes (increases) the output signal of the wet flue gas density sensor 6, which leads to a change (increase) in the output signal of the divider 8, causing a change (decrease) in the output signals of the factors 10 and 11, the adder 12 and the divider 9. The changed output signal of the divider 9, which enters the control chamber of the controller 4, violates the balance in the controller, which leads to a change in the output signal of the controller 4 and causes a change position of the actuator 5, which changes the cross section of the chimney 2, which leads to a change (increase) in the vacuum in the heating furnace and changes (reduces) the flow of air into the heater.

Thus, the automatic control system of the combustion process in a heating furnace with natural draft operating in this way maintains the coefficient of excess air in the furnace at the minimum acceptable value, which ensures high fuel combustion efficiency.

Claims (1)

METHOD FOR AUTOMATIC CONTROL OF THE BURNING PROCESS IN A HEATING FURNACE WITH NATURAL THRAW by measuring the vacuum in the furnace and the impact on draft, characterized in that, in order to increase combustion efficiency, the density of dry and wet flue gases is additionally measured, their ratio is determined and used for correcting energy consumption - Traction.