RU2484370C1 - Method for selective monitoring of main flame of each burner on multiburner boiler - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: several burners are installed on the boiler external wall in one or several rows throughout the furnace height or in its corners. An igniter and a pilot burner are arranged in the housing of each burner. Pilot burner is intended for ignition and monitoring of availability of the main burner flame. Air and gas is supplied to the pilot burner at constant pressure. Flame of each pilot burner is monitored using the method that excludes the influence of flames of other working burners, for example with an ionisation sensor. Availability of the main flame of each burner is guaranteed with availability of flame of its constantly operating pilot burner. Automatic gas equipment units are installed before burners, and their control is performed by means of a burner control cabinet.

EFFECT: invention allows creating a reliable method excluding false information on availability of flame on that burner at its loss.

1 cl, 1 dwg

Description

The invention relates to a power system, namely, to the selective control of the main flame of each burner on a multi-burner boiler of high power, i.e. to the reliability of the presence of the torch of each individual burner, regardless of their number and location on the boiler. The method can be applied during the operation of steam power and hot water boilers of thermal power plants.

In this case, a multi-burner is considered a boiler, the heating of which is carried out by more than one burner.

In the absence of a torch of one of the burners, the boiler safety system gives a command to turn off the gas supply to this burner.

An important requirement for the control system of the torch of a burner on a multi-burner boiler is an individual (selective) control of the torch of each burner. In this case, the fact of the extinction or separation of the torch from the burner into which the fuel is supplied must be reliably detected by the flame control sensor mounted on this burner. This means that this sensor should respond only to the extinction or separation of the torch on this burner in the presence of torches of the remaining burners of the multi-burner boiler unit, regardless of their location. The specified property of the flame sensor is called selectivity.

According to section 7 “Special requirements for explosion safety during operation of gas supply systems of thermal power plants (TPPs) and boiler rooms” PB 12-529-03 of the Safety Rules for gas distribution and gas consumption systems, approved by Resolution No. 9 of Gosgortekhnadzor of Russia dated March 18, 2003, namely, paragraph 7.35 “Each burner of the boiler must be equipped with a protective ignition device (ZZU) that provides a torch at the burner in the ignition mode and selective control of the torch of the burner in all modes of operation of the boiler, including the ignition mode."

Thus, the selectivity of the control of the torch of each burner installed on multi-burner boilers is the main system requirement for the design of the burners.

A known method of controlling the presence of a burner flame by radiation (SU, copyright certificate No. 714100, published 05.02.1980), measured by two sensors, sighted in one zone of the controlled flame, by forming the difference of the signals issued by the sensors, and comparing it with a given setting . The known invention is directed to the creation of reliable selective control of the flame of an individual burner on a multi-burner boiler.

A known method of controlling the torch of the burner of a boiler unit (SU, copyright certificate No. 1539468, publ. 01/30/1990) by measuring with the aid of an optical sensor the radiant flux of the root of the torch of the burner installed in the furnace wall. In the known invention, in order to increase the reliability of control in a multi-burner boiler by reducing the effect of radiation from the walls of the furnace and other burners, only that part of the radiant flux of the torch root is measured, which propagates parallel to the wall of the furnace and the sight axis of the sensor.

A known method of selective control of the flame of a burner (RU, patent No. 2282789, publ. 06/20/2003), adopted as a prototype, which consists in the fact that they record radiation in the infrared region of one or more products of combustion of one of the zones of the torch of the burner. The registration of radiation is carried out in the wings of the spectral lines of radiation of the product or product of combustion, in which the radiation intensity is less than half the maximum value of the intensity, and the presence of radiation is judged on the presence of a flame. The objective of the invention is to increase the reliability of the control of the flame of a burner of a heat energy device by providing, recording, emitting only high-temperature combustion products while ensuring registration of the torch of only “own” burner in the presence of any quantity of burning torches in the boiler.

The disadvantage of all these known methods for selective control of the torch of a burner on a multi-burner boiler is the fact that for selective control of the torch of burners, control sensors are installed outside the design of the burners, namely on the screens of the boilers. This requires changes in the design of the boilers. Moreover, in the known methods, the main flame of the “separate” burner is monitored on a multi-burner boiler. In the event of its extinction or detachment, it is possible that the sensor shows the presence of the main torch due to the presence of torches of other working burners. In addition, in the known methods, the torch is controlled in one of the flame zones, which does not allow us to speak about the reliability of the control during operation of the burner in a wide pressure range.

The objective of the invention is to provide a reliable method for the selective control of the main torch of each burner on a multi-burner boiler, eliminating false information about the presence of a torch on this burner when it goes out or comes off. The proposed method solves the problem of ensuring the constant presence of the main torch of each burner to ensure the explosion safety of the gas-using installation.

The technical result is achieved by the fact that for the selective control of the main torch of each burner on a multi-burner boiler, a pilot burner is placed in the body of each burner, air and gas are supplied with constant pressure to each pilot burner, the torch of each pilot burner is controlled in a way that excludes the influence of the torches of other working burners , guarantee the presence of the main torch of each burner by the presence of the torch of a continuously operating pilot burner.,

The control of the main torch of each burner on a multi-burner boiler is carried out by controlling the presence of the torch of each pilot burner. The invention is illustrated by a functional diagram, where:

1 - burner;

2 - boiler wall;

3 - ignitor;

4 - pilot burner;

5 - sensor monitoring the torch of the pilot burner;

6 - automatic gas equipment unit (BGA);

7 - burner control cabinet (SHUG).

Several burners 1 are installed counterclockwise on the external walls 2 of the boiler in one or several rows along the height of the furnace (furnace chamber) or along its corners. Each burner 1 is made with separate supply of air and fuel. An ignitor 3 and a pilot burner 4 are installed in the housing of each burner 1.

The ignition torch igniter 3 is carried out by a device for electric ignition, which is under high voltage. The presence of the pilot flame is monitored by the pilot flame monitor. The pilot flame is controlled by a sensor, the principle of which eliminates the possibility of another torch influencing it, for example, by an ionization sensor, the principle of which is based on the electrical conductivity of the torch.

The pilot burner 4 is ignited from the pilot light 4. The pilot burner in the design of burner 1 is used to ignite and control the main torch of the burner. Each pilot burner is made with separate supply of air and fuel. For guaranteed control of the main torch, the pilot burner is placed in the burner housing 1 so that the mouth of the torch during operation is located inside the embrasure of the burner 1. Air and gas are supplied to the pilot burner 4 with a constant pressure (p = const), which provides constant power to the pilot burners and torch stabilization of the pilot burner. The pilot torch control 4 is carried out by the pilot torch control sensor 5 (hereinafter referred to as the sensor). In this case, a sensor is used, the principle of which excludes the possibility of another torch influencing it, for example, the main torch of this burner or the torch of other working burners. Pilot torch plume control, as a rule, is carried out by an ionization sensor, the control electrode of which is always located in the pilot torch plume area.

Automatic gas equipment units (hereinafter referred to as BGA) 6 are installed in front of the burners, which are controlled by the burner control cabinet (hereinafter referred to as SHUG) 7. BGA 6 are designed for the automatic supply of natural gas as fuel to the main burner, pilot burner and igniter and perform the following functions: flow control gas, providing automatic pressure testing of the shutoff valves included in the unit, ensuring safe ignition and gas cut-off in case of violation of the technological parameters of the boiler. The signals from the control devices for the torches of the pilot burners and igniters are supplied to the BCG 7, where the command to turn off the burner 1 when the torch of the pilot burner 4 is lost is implemented.

The implementation of the method is as follows.

To ignite and control each burner on a multi-burner boiler, the following procedure is carried out:

- gas 3 is supplied to the igniter 3 located in the burner housing 1;

- ignite the igniter 3 with an electric ignition device and verify the presence of its torch using the ignition torch control sensor;

- carry out the supply of air and gas with constant pressure to the pilot burner 4. The gas-air mixture formed at the outlet of the pilot burner is ignited from the igniter 3. At the same time, the pilot torch is continuously monitored by the sensor 5;

- after operation of the pilot flame control sensor 5, the gas supply to the pilot 3 is turned off;

- supply air and gas to the burner 1. The gas-air mixture formed at the outlet of the burner is ignited from a steady constantly burning torch of the pilot burner 4. When the main torch is extinguished or tears off, the continuously working pilot burner ignites the main torch again, which ensures its constant presence;

- if the control sensor 5 shows the absence of a pilot torch torch, BGA 6 will stop the gas supply to the entire burner.

The presence of the torch of each continuously operating pilot burner on the multi-burner boiler ensures the presence of the main torches of the burners, and the control of the torch of each pilot burner provides selective control of the main torch of each burner on the multi-burner boiler.

Claims (1)

The method of selective control of the main torch of each burner on a multi-burner boiler, which consists in the fact that a pilot burner is placed in the body of each burner, air and gas are supplied with constant pressure to each pilot burner, the torch of each pilot burner is controlled in a way that excludes the influence of the torches of other working burners , guarantee the presence of the main torch of each burner by the presence of the torch of a continuously operating pilot burner.

Images