RU191757U1 - GAS AND FUEL BURNER BURNER - Google Patents

Abstract

The utility model relates to the field of power engineering, in particular to devices for burning gaseous and liquid fuels in boiler furnaces and in furnaces. For these purposes, combined gas-oil burners are used, in which, depending on the practical need, gas or fuel oil can be separately burned. A special area of applicability of the inventive burner is the furnace of energy steam boilers of TPPs with increased power when using them as waste flare gases from refineries and methane-hydrogen fractions with low heat of combustion. The task to which the proposed model is aimed is to reduce fuel underburning and increase efficiency A positive technical result is achieved by applying axial shockless twisting of air at the outlet of the air supply channels and computerized selection I twist the parameters in accordance with the fuel consumption and heat of combustion, as well as the use in each of the air supply channels of the profiled rotary blades of axial air swirls with an unshocked input, the use of a gas analyzer of the composition of the combusted gas, flow meters with control valves on each of the gas supply pipes and the use of liquid fuel flow meter with a control valve at the nozzle inlet. Before igniting the burner, the boiler’s common smoke exhausters (usually 2 pcs.) and common blower fans (both but 2 pcs.) and made the furnace ventilation. The total preliminary air flow rate to the boiler and the flow rate of fuel gas or liquid fuel are set in accordance with the heat load. After ventilation of the furnace, according to the heat load of the boiler, the control unit switches on the gas flow rate for each gas supply pipe in accordance with the fuel analyzer composition using the gas analyzer using the control valve of the flow meter , the air-fuel mixture is ignited with a pilot light and the air twist parameter in the channels is set by the angle of the blades using an electric motor At design conditions and fuel at rated load, the angle of inclination of the blades to the axis of the burner for the external channel is 25 ... 30 angular degrees, for the central channel is about 40 angular degrees, the intermediate channel is about 45 angular degrees. According to the size of the signal from the flame control sensor, the unit is computer programmed the optimal angle of axial rotation of the gas supply pipes and the optimal extension length of the gas supply pipes into the furnace are established. Uniform combustion of fuel occurs due to the shockless entry of air into the axial swirlers from the blades The gas analyzer fixes the content of combustible components and transmits data to the unit for determining the calorific value of the boiler. When the boiler is set for a given heat load, the unit gives an electrical signal to increase gas fuel supply by means of regulating valves of flow meters on gas supply pipes. This leads to an increase in heat generation and an increase in the temperature of the combustion products in the furnace and to an increase in the boiler efficiency. When high-calorie gas is supplied for burning, the signal from the gas analyzer processed by the unit is fed to gas flow meters, the control valves of which reduce gas consumption, and the temperature in the furnace decreases, preventing loss of heat with flue gases and increasing boiler efficiency. When using liquid fuel at the command of the unit, the flow meter control valves shut off the gas supply to the pipes 4 and the control valves open th valve of the flow meter to supply liquid fuel to the nozzle. Maintaining uniform burnout along the length of the flame to prevent chemical underburning and optimal temperature in the furnace is similar to burning gas fuel, taking into account a certain decrease in the temperature of combustion products at the outlet of the furnace (by 50 ... 100 ° C when burning M100 fuel oil with a moisture content of up to 3%).

Description

The utility model relates to the field of power engineering, in particular to devices for burning gaseous and liquid fuels in boiler furnaces and in furnaces. For these purposes, combined gas-oil burners are used, in which, depending on the practical need, gas or fuel oil can be separately burned. A special area of applicability of the inventive burner is the furnace of energy steam boilers of thermal power plants of high power when using them as fuel waste flare gases of refineries and methane-hydrogen fractions with low calorific value.

Known burner for separate combustion of gas and fuel oil, containing an external air supply channel with a tangential electric drive swirl, a central air supply channel with a tangential electric drive swirl, an intermediate air supply channel with a tangential electric swirl, gas supply pipes, nozzle, ignitor, torch control sensor, electric motor a servo-driver for moving the nozzle, electric motors with servo-drivers for moving the gas pipes, annular gas supply Héctor, a computerized control unit (see. patent №2403498 «burner for burning gas and fuel" on 10 November 2010 YG).

The disadvantages of the known burner:

1. It is impossible to widely control the length of the torch, since a tangent twist of the air at the inlet is carried out in a known burner, which leads to uneven combustion of fuel along the length of the torch and incomplete combustion of the air-fuel mixture and to chemical underburning.

2. When burning fuel with a low calorific value, too much ballast air is supplied and the temperature in the flare core decreases, and with a high calorific value, the temperature in the flare core increases, which leads to an increase in the temperature of the flue gases and in both cases the efficiency decreases.

These shortcomings are eliminated in the design of the inventive burner, which is aimed at solving the problem of reducing underburning of fuel and increasing the efficiency of the boiler.

This goal was solved by applying axial shockless twist of air at the outlet of the air supply channels instead of tangential shock twist at the inlet of a known design, and computerized selection of the twist parameters in accordance with the fuel consumption and heat of combustion. A positive technical result is achieved by using profiled rotary blades of axial air swirls in each of the air supply channels with an unshocked inlet, using a gas analyzer of the composition of the combusted gas, flow meters with control valves on each of the gas supply pipes, and using a liquid-fuel flow meter with a control valve at the inlet to the nozzle .

The rotation angle of the blades is optimized according to a computer program automatically in accordance with the heat of combustion of the fuel gas, its flow rate, the consumption of liquid fuel and the magnitude of the thermal radiation of the torch.

The inventive design is shown in the drawing, where the positions denote the following elements and nodes:

1 - external air supply channel;

2 - the central channel of the air supply;

3 - an intermediate air supply channel;

4 - gas supply pipes;

5 - nozzle;

6 - ignitor;

7 - flame control sensor;

8 - electric motors with servos to rotate the axial blades of the external swirl;

9 - electric motors with servos to rotate the axial blades of the intermediate swirler;

10 - electric motors with servos to rotate the axial blades of the central swirl;

11 - an electric motor with a servo drive for moving the nozzle,

12 - electric motors with servos for moving gas supply pipes;

13 - computerized control unit;

14 - axial blades of the external air swirl;

15 - axial blades of the intermediate air swirl;

16 - axial blades of the central air swirl;

17 - gas analyzer of the composition of the combusted gas;

18 - annular gas supply manifold;

19 - gas flow meters with control valves;

20 - liquid fuel flow meter with a control valve.

The dashed thin lines in the drawing show the electrical connections of the computerized control unit 13 with electric motors for moving elements and assemblies, with a gas analyzer 17, with flow meters 19, 20, with a flame control sensor 7, with an ignitor 6.

Dotted dotted lines show the axes for turning the axial blades of the air swirls. The inflection lines and the ends of the cylindrical surfaces at the inlet and outlet of the burner are not conventionally indicated in the drawing. The air supply to the burner is three-flow and is carried out, according to the drawing, from above the common duct.

The purpose and interaction of elements and nodes is as follows.

The outer cylindrical channel 1 of the air supply is the main component bearing a mechanical load on which all other elements and assemblies are mounted.

The central channel 2 of the air supply, located coaxially to the external channel 1, serves to supply the flow swirled by means of the blades 16 into the root part of the fuel supplied to the combustion.

The intermediate air supply channel 3, located coaxially with the external channel 1 and the central channel 2, is used for diffusion vortex mixing of air-fuel mixtures obtained from the effects of air swirls using axial blades of the outer 14 and central 16 air swirls.

The distribution of the total air supplied to the burner through the inlet channels: the outer channel is about 60%, the intermediate channel is about 25%, the central one is about 15%. The air can be twisted as one-sided - all channels with the help of axial blades swirl air in one direction: to the right or left or mixed - the channels swirl air in different directions.

The gas supply pipes 4 are arranged peripherally coaxially around the circumference between the outer 1 and intermediate 2 channels with the possibility of rotation around its axis and longitudinal axial movement by electric motors with servos 12 according to a computer program from block 13 in accordance with the required length and diameter of the torch for a given flow and heat fuel combustion, determined by the sensor 7, the gas analyzer 17, the flow meters 19, 20 and the heat load of the boiler.

The number and output diameter of the gas supply pipes are selected based on the thermal power of the burner. The drawing conventionally shows two gas supply pipes. Each of the gas supply pipes 4 has the possibility of separate rotation from other pipes around its axis and axial movement.

The nozzle 5 is used to burn liquid fuel and is placed in the coaxial channel along the axis inside the burner (in the drawing, the channel is not indicated by the position). Axial movement and rotation around the axis to control the length and diameter of the liquid fuel torch is carried out according to a computer program from block 13 in accordance with the load of the boiler, the thermal radiation of the torch detected by the sensor 7.

When burning gas fuel, the nozzle 5 is removed from the burner to prevent burn-out of the spray nozzle (not indicated in the drawing) and stored on the rack of the boiler service site. When switching from gaseous fuel to a liquid nozzle 5, it is inserted into the coaxial channel, attached to the nozzles of the spraying agent - superheated water vapor and heated liquid fuel - fuel oil, and also via an electric communication line to the control unit 13.

The ignitor 6 is used for electric ignition of the fuel during the initial start-up of the burner by a signal from the control unit 13.

The flame control sensor 7 is used to measure the intensity of thermal radiation of the flame with the generation of an electrical signal and transmit the value of the value of this signal to the control unit 13.

Electric motors with servos 8, 9, 10 are electrically connected to the control unit 13 and provide shockless rotation of the axial blades 14, 15, 16 by a certain angle relative to the axis of the burner with adjustable axial parameter of twist and air flow.

the axial arrangement of the blades in the inventive burner with shockless air inlet allows to achieve a positive technical result - uniform combustion of fuel along the entire length of the torch and its complete combustion without chemical burnout.

The blades 14, 15, 16 are located on the output sections of the air supply channels 1, 2, 3, profiled, mounted on an axis (in the drawing, the axes are shown by dashed lines), which are rotated by a certain angle with the blades using electric motors with servos 8, 9, 10 at a computer command from block 13 in accordance with the heat of combustion of the fuel.

The gas analyzer 17 is used to quantify the content of combustible components in the gaseous fuel supplied to the combustion and transmit data in the form of an electric signal via electrical communication to block 13, in which its calorific value is determined by the program and an electric signal is supplied to electric motors 8, 9, 10, 12, performing mechanical rotation of the blades 14, 15, 16 and gas supply pipes 4 in accordance with the calorific value of the fuel.

In accordance with the calorific value, block 13, according to a computer program, also supplies electric signals to gas flow meters with control valves 19, with which the fuel consumption for each gas supply pipe is established, and with the help of electric drive blades 14, 15, 16, the length and diameter of the torch. This allows, in comparison with the known burner, to achieve optimal temperatures in the combustion zone and in the furnace without exceeding or lowering the temperature of the combustion products leaving the furnace.

The presence of a gas analyzer 17, gas flow meters with control valves 19 on the gas supply pipes 4, axial blades 14, 15, 16 with electric drives 8, 9, 10 connected technologically with a computerized control unit 13 and with electric motors 12 for moving the gas supply pipes 4 allows to achieve a positive technical result - increase efficiency.

At low exhaust gas temperatures and excess ballast in the form of air, the temperature of steam overheating in superheaters drops and boiler efficiency decreases, and at high exhaust gas temperatures, the efficiency decreases due to losses to the atmosphere with the exhaust gases.

The temperature of superheated steam at a high temperature of the combustion products at the outlet of the furnace to the superheater is also limited by the technological regulation on the strength conditions of the metal of the pipes of the superheater to a value of 560 ° C by switching on the injection desuperheaters. Therefore, in addition to direct heat losses with highly heated emissions of combustion products into the atmosphere, indirect losses are observed with the operation of desuperheaters. This also leads to a decrease in boiler efficiency.

The annular gas supply manifold 18, on which the gas analyzer 17 is located, serves to distribute fuel gas through the gas supply pipes 4. The common gas supply pipe to the burner manifold 17 is not conventionally shown in the drawing.

The liquid fuel consumption of the liquid fuel nozzle 5 is electrically connected to the block 13 and is used to measure and control the liquid fuel consumption according to the intensity of the flame thermal radiation measured by the sensor 7.

The inventive burner operates as follows.

Before igniting the burner, the boiler’s common smoke exhausters (usually 2 pcs.) And common blow fans (usually 2 pcs.) Are turned on and the furnace is ventilated. The total preliminary air flow rate to the boiler and the flow rate of fuel gas or liquid fuel are set in accordance with the heat load.

After the combustion chamber ventilation, according to the heat load of the boiler, the control unit 13 turns on the gas flow rate for each gas supply pipe 4 in accordance with the fuel composition of the gas analyzer 17 using the control valve of the flow meter 19, the air-fuel mixture is ignited with the pilot 6 and the air twist parameter is set for channels 1, 2, 3 by the angle of inclination of the blades 14, 15, 16 using electric motors 8, 9, 10.

In design conditions and fuel at rated load, the angle of inclination of the blades to the axis of the burner for the outer channel is 25 ... 30 angular degrees, for the central channel about 40 angular degrees, intermediate - about 45 angular degrees.

By the magnitude of the signal of the flare control sensor, unit 13, using a computer program, sets the optimal axial rotation angle of the gas supply pipes 4 and the optimal extension length of the gas supply pipes into the furnace (flexible adapters from the gas supply pipes 4 to the collector 18 are not shown conventionally in the drawing).

In the inventive burner there is a uniform combustion of fuel due to the shockless entry of air into the axial swirlers with blades 14, 15, 16 and no chemical underburning is formed.

When applying for burning low-calorie gas, the gas analyzer 17 records the content of combustible components and transmits data to block 13 to determine the calorific value.

When installed for a given heat load of the boiler, to prevent excessive ballast air, unit 13 generates an electrical signal to command to increase the supply of gas fuel using the control valves of the flow meters 19 on the gas supply pipes. This leads to an increase in heat generation and an increase in the temperature of the combustion products in the furnace and to an increase in the boiler efficiency.

When high-calorific gas is supplied for burning, the signal from the gas analyzer 17 processed by block 13 is fed to gas flow meters 19, the control valves of which reduce gas consumption and the temperature in the furnace decreases, preventing heat loss with flue gases and increasing the boiler efficiency.

When using liquid fuel, at the command of block 13, the control valves of the flow meters 19 shut off the gas supply to the pipes 4, and the control valve of the flow meter 20 opens to supply liquid fuel to the nozzle 5. Maintaining uniform burnup along the length of the flame to prevent chemical underburning and optimal temperature in the furnace is similar to burning gas fuel, taking into account a certain decrease in the temperature of the combustion products at the outlet of the furnace (by 50 ... 100 ° C when burning M100 fuel oil with a moisture content of up to 3%).

Claims (1)

Burner for separate combustion of gas and fuel oil, containing an external air supply channel with an electric drive swirl, a central air supply channel with an electric drive swirl, an intermediate air supply channel with an electric drive swirl, gas supply pipes, a nozzle, an ignitor, a torch control sensor, an electric motor with a servo drive for moving the nozzle , electric motors with servos for moving gas supply pipes, electric motors with servos for swirls of external, central and industrial air supply channels, annular gas supply manifold, computerized control unit connected by electrical connections to the igniter, torch control sensor, electric swirls, gas supply pipes and nozzles, characterized in that the electric swirls are made axial with shaped blades located on the outlet sections of the channels under the channels air, in addition there is a gas analyzer of the composition of the combusted gaseous fuel located at the inlet to the gas supply a torus and technologically connected by electrical connection to the control unit, there are additionally gas flow meters with control valves located at the inlet of each of the gas supply pipes after the annular gas supply manifold and technologically connected by electrical connections to the control unit, there is a liquid fuel flow meter with a control valve located at the inlet to the nozzle and technologically connected by electrical connection with the control unit, and automatic regulation of the size and temperature of the torch in the furnace, the selection of the optimal fuel combustion process is carried out according to a computer program from the control unit on the basis of processing by the control unit of the measurement results of the gas analyzer of the composition of the burned gas, measurements of the radiation intensity by the torch control sensor by means of complex automatic computerized change of the air twist in the channels with axial blade swirls in combination with axial movement and turning the gas supply pipes, changing the gas flow to each of the gas supply pipes with gas flow meters with control valves and nozzle movement, and when burning liquid fuel and changing its flow rate through the nozzle using a liquid fuel flow meter with a control valve.

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