RU2270402C1 - Fuel burner - Google Patents

Abstract

FIELD: heat-and-power engineering.

SUBSTANCE: fuel burner can be used for burning of fuel in low emission combustion engines of different grids like gas turbine plants, gas turbine engines, furnace, boilers et cetera. Fuel burner is provided with first and second liquid fuel feed collectors connected with first and second liquid fuel feed nozzles, gas-shaped fuel feed pipes connected with first collector. Axes of collectors are parallel to axis of mixing chamber and are disposed at some distance from mixing chamber being equal to 0,7-0,9 radius of input of air supply into mixing chamber. Device also has cone-shaped flame stabilizer, front cap of mixing chamber inside which the first gas-shaped fuel collector is disposed, additional diffuser section which is connected in series with diffuser section of mixing chamber. Output of additional diffuser section is connected with input of combustion chamber. Output of central pipe is disposed at input of diffuser section. Cone-shaped stabilizer is connected with output of central pipe to form circular channel inside diffuser section of mixing chamber. Liquid fuel feed first nozzles are disposed onto central pipe at input of diffuser section of mixing chamber are disposed in perpendicular to its axis. Swirler is disposed at output of diffuser section of mixing chamber. Gas-shaped fuel second nozzles are disposed at output of stabilizer and are connected with pipes for feeding gas-shaped fuel, which is disposed coaxial inside central pipe. Liquid fuel second nozzles are disposed onto axis of mixing chamber at stabilizer's output.

EFFECT: reduced emission characteristics; simplified design of front unit of mixer.

3 cl, 5 dwg

Description

The invention relates to a power system and can be used to burn fuel in low emission combustion chambers of various energy systems: gas turbine units (GTU), gas turbine engines (GTE), furnaces, boilers, etc.

A device for burning gaseous, liquid, as well as medium or low calorific fuel (Patent ER No. 908671 from 04/14/90, "Device for burning gaseous, liquid, as well as medium or low calorific fuel", cl. 6 F 23 D 17 / 00), comprising a mixing chamber, a swirl, an air inlet to the mixing chamber, first and second gaseous fuel inlets, first and second liquid fuel inlets.

The device has the following disadvantages. The insufficiently good quality of mixing gaseous and liquid fuels with air leads to significant fluctuations in the concentration of fuel and, as a result, to an increased level of emission of nitrogen oxides.

A device is known (RF Patent No. 2227247 dated 12.28.01 "Device for burning fuel") for burning gaseous fuel, which is closest to the proposed one. The specified device contains a combustion chamber and a mixing chamber, a device for igniting the air-fuel mixture, a swirl, a central tube of the mixing chamber, an air inlet to the mixing chamber, first and second gaseous fuel supply manifolds connected to the first and second gaseous fuel supply nozzles, each mixing chamber is located coaxially around the central pipe, forming an annular channel consisting of successively arranged sections of confuser and diffuser.

This chamber has the best emission characteristics N _ox ≤10 ppm on gaseous fuel in comparison with the analogue.

The specified device has the following disadvantages. The operation of a low-emission combustion chamber (LCC) on liquid fuel is not provided, which limits the possibility of using this chamber in regions where there is no main natural gas. The complex shape and constructive solution of the front device of the mixer limit the possibility of its manufacture and increase the cost of construction.

The technical problem solved by the invention is to reduce the emission characteristics when implementing a dual-fuel (liquid and gaseous fuel) fuel combustion scheme, as well as to change and simplify the design of the front-end device of the mixer without affecting the basic characteristics of the NCC.

The specified technical problem is solved in that the device for burning fuel containing a combustion chamber and a mixing chamber, an ignition device for the air-fuel mixture, a swirler, a central tube of the mixing chamber, an air inlet to the mixing chamber, the first and second gaseous fuel supply manifolds connected to the first and second gaseous fuel injectors, each mixing chamber is located coaxially around the Central pipe, forming an annular channel, consisting of sequentially located sections confuser and diffuser, equipped with the first and second liquid fuel supply manifolds connected to the first and second liquid fuel supply nozzles, gaseous fuel supply pipes connected to the first manifold, the axes of which are parallel to the axis of the mixing chamber and are located at a distance from the axis of the mixing chamber equal to 0 , 7-0.9 of the radius of the inlet of the air supply to the mixing chamber, a cone-shaped flame stabilizer, the front cover of the mixing chamber, inside which the first gaseous fuel manifold is located, the diffuser section, which is connected in series with the diffuser section of the mixing chamber, the output of the additional diffuser section is connected to the input of the combustion chamber, the output of the central pipe is located at the entrance of the additional diffuser section, the cone-shaped stabilizer is connected to the output of the central pipe, forming an annular channel in the additional diffuser section of the mixing chamber , the first liquid fuel nozzles are located on the central pipe at the inlet of the diffuser section of the mixing chamber and perpendicular yarny its axis, the swirler is located at the exit of the diffuser mixing chamber, the second gaseous fuel nozzle disposed at the exit of the stabilizer and are connected to supply pipes of the gaseous fuel coaxially arranged in the central tube, the second liquid fuel supply nozzle arranged on the axis of the mixing chamber at the outlet stabilizer.

In addition, the device is additionally equipped with pylons mounted on the front cover and the central tube of the mixing chamber, and the first nozzles for supplying liquid fuel are mounted on the pylons, while the axes of these nozzles are perpendicular to the axis of the mixing chamber.

Figure 1 schematically shows the proposed device for burning fuel.

Figure 2 presents a section aa (figure 1) of a device for burning fuel.

Figure 3 presents a section bB (figure 1) of a device for burning fuel.

Figure 4 presents a device for burning fuel with a variant of the location of the first nozzles of liquid fuel on the pylons.

Figure 5 presents a section bb (figure 4).

The fuel burning device comprises an annular or cylindrical combustion chamber 1, a mixing chamber housing 2, a front cover 3 of the mixing chamber 2, a central pipe 4, a first gaseous fuel supply manifold 5, gaseous fuel supply pipes 6 from a first manifold 5 on which the first nozzles are located 7 gaseous fuel supply, the first manifold 8 of the supply of liquid fuel, the first nozzle 9 of the supply of liquid fuel, the second manifold 10 of the supply of gaseous fuel, the second nozzle 11 of the supply of gaseous fuel, the second lecturer liquid fuel supply 12, second nozzle 13, the supply of liquid fuel, the flame cone 14 of the stabilizer device 15, the ignition fuel-air mixture, pylons 16 and air supply port 17 into the mixing chamber 2, the swirler 18, air-fuel mixture.

Tubes 6 for supplying gaseous fuel are located at the entrance to the mixing chamber 2 at a distance from the axis equal to 0.7-0.9 of the radius of the inlet of the air supply to the mixing chamber 2 (Fig.2), the axis of the tubes 6 are parallel to the axis of the mixing chamber. Pylons 16 are installed on the front cover 3 and the Central tube 4 of the mixing chamber 2 (figure 4, figure 5). The first nozzles 9 for supplying liquid fuel are mounted on pylons 16, while the axes of these nozzles 9 are perpendicular to the axis of the mixing chamber 2. The first nozzles 7 of gaseous fuel are located perpendicular to the axis of the mixing chamber 2.

The second nozzles 11 of the gaseous fuel are located at the end of the conical flame stabilizer 14. The first nozzles 9 for supplying liquid fuel are located on the walls of the central pipe 4 (Fig. 1 and Fig. 3) or on pylons 16 (Fig. 4) in a narrow section of the mixing chamber 2 and are directed perpendicular to its axis. The device 15 ignition of the air-fuel mixture is mounted on the wall of the combustion chamber near its beginning.

A device for burning fuel works as follows. Air through the inlet 17 enters the mixing chamber 2 and then into the combustion chamber 1. When the air flows around the stabilizer 14, a recirculation flow zone is formed, which is used to stabilize the flame. Gaseous fuel from the second manifold 10 is supplied through the central pipe 4 and the second nozzles 11 at the stabilizer section 14 to the recirculation zone, where the air-fuel mixture is created to start the combustion chamber 1. After the ignition device 15 is turned on, the air-fuel mixture lights up behind the stabilizer 14, creating a burning center in the axial zone of the combustion chamber 1. To enter the low-emission combustion mode, gaseous fuel is supplied to the first collector 5 through tubes 6 of the nozzle 7, which, mixed with air in the mixing chamber 2, creates AET homogeneous fuel-air mixture which passes through the swirler 18 to the top of the combustion chamber 1. This fuel mixture is ignited by the flame recirculation zone, creating a primary combustion front. After ignition of the air-fuel mixture, the gaseous fuel consumption of the second manifold 10 is reduced to a minimum or shut off completely, and the fuel consumption of the first collector increases to the calculated value.

When operating on liquid hydrocarbon fuel, the combustion chamber 1 is launched using liquid fuel supplied through the second manifold 12 and the second nozzles 13 located at the axis of the stabilizer 14. After ignition of the fuel, a combustion center is created in the axial zone of combustion chamber 1. To enter the low emission mode of burning liquid hydrocarbon fuel from the first manifold 8 and the first nozzles 9 is fed into the mixing chamber 2, where it evaporates and mixes with the air stream, creating a fuel-air mixture, which, getting into the combustion chamber 1, ignites from the flare of the recirculation zone, creating a main combustion front. As the consumption of liquid fuel from the first manifold 8 increases, the consumption of liquid fuel from the second manifold 12 decreases to zero and the combustion chamber 1 is brought to the low emission combustion mode of the liquid fuel.

The efficiency of the low-emission operation of the combustion chamber on gaseous fuel is achieved by efficiently mixing the fuel with air and creating a homogeneous air-fuel mixture.

The effective operation of the combustion chamber on liquid fuel is achieved by efficiently evaporating and mixing the liquid fuel in the mixing chamber before it enters the combustion chamber.

Claims (3)

1. A device for burning fuel containing a combustion chamber and a mixing chamber, an ignition device for the air-fuel mixture, a swirler, a central tube of the mixing chamber, an air inlet to the mixing chamber, first and second gaseous fuel supply manifolds connected to the first and second gaseous fuel supply nozzles , each mixing chamber is located coaxially around the central pipe, forming an annular channel consisting of successively arranged sections of confuser and diffuser, characterized by m, that it is equipped with first and second liquid fuel supply manifolds connected to the first and second liquid fuel supply nozzles, gaseous fuel supply pipes connected to the first collector, the axes of which are parallel to the axis of the mixing chamber and are located at a distance from the axis of the mixing chamber equal to 0 , 7 ÷ 0.9 of the radius of the inlet of the air supply to the mixing chamber, a cone-shaped flame stabilizer, the front cover of the mixing chamber, inside which the first collector of gaseous fuel is located, with an additional diffuser a part that is connected in series with the diffuser section of the mixing chamber, the output of the additional diffuser section is connected to the input of the combustion chamber, the output of the central pipe is located at the entrance of the additional diffuser section, the conical stabilizer is connected to the output of the central pipe, forming an annular channel in the additional diffuser section of the mixing chamber, the first liquid fuel nozzles are located on the central pipe at the inlet of the diffuser section of the mixing chamber and are perpendicular to its axis, vortex Tel located at the exit of the diffuser mixing chamber, the second gaseous fuel nozzle disposed at the exit of the stabilizer and are connected to supply pipes of the gaseous fuel coaxially arranged in the central tube, the second liquid fuel supply nozzle arranged on the axis of the mixing chamber at the outlet stabilizer. 2. The device for burning fuel according to claim 1, characterized in that it is additionally equipped with pylons mounted on the front cover and the Central tube of the mixing chamber. 3. The device for burning fuel according to claim 1, characterized in that the first nozzles for supplying liquid fuel are mounted on pylons, while the axes of these nozzles are perpendicular to the axis of the mixing chamber.

Images