TWO-STAGE BURNER WITH TWO-LAYER VORTEX COUNTERCURRENT FLOW

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of Russian Patent Application No. 2022126445, filed Oct. 11, 2022, the contents of which are all incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

Embodiments of the invention relate to fuel combustion devices, in particular to vortex burners.

BACKGROUND

The invention relates to fuel combustion devices, in particular to vortex burners.

The prior art is a device for burning fuel, described in the patent for the invention RU 2708011, publ. Mar. 12, 2019. The device contains three types of fuel supply devices. The first type of fuel supply devices is made in the form of jet nozzles located in the swirler, the outlet openings of the flow channels of which are perpendicular to the end wall of the swirler, and the outlet openings of the channels exit in the minimum cross section of the flow channels of the tangential nozzle swirler. The second type of devices contains at least one centrifugal nozzle. The third type of devices is made in the form of a branch pipe installed in the axial hole on the end wall of the flame tube. The second and third types of fuel supply devices are located at the end of the flame tube opposite from the swirler. EFFECT: invention provides increased launch reliability and stable operation on liquid, gaseous and ballasted fuels both with non-combustible components and water, as well as fuel, including crushed solid combustible components and their mixtures with water.

The specified device for burning fuel is the closest in technical essence to the claimed invention and was used as a prototype.

Its disadvantage is the insufficient efficiency of fuel combustion, due to the occurrence of a significant circumferential unevenness in the distribution of air supply between the tangential nozzle swirler and the front wall, and efficient afterburning of fuel is not provided in a wide range of operating modes, namely, at partial loads or modes near poor stall in such design, an unacceptable increase in emissions of CO oxides is possible. Also, the use of the design of the tubular combustion chamber in the prototype may be limited, in particular, due to the impossibility of use in gas turbine plants, in which air must be supplied evenly along the flame tube, and an additional transition pipe of a special configuration is required for connection with the nozzle apparatus of the installation.

SUMMARY OF THE INVENTION

Two-stage burner with a two-layer vortex counter current flow comprises a burner body and a flame tube containing an ignition device coaxially installed in it, and an outlet nozzle, between the burner body and the flame tube there is an air channel with the first swirler placed in it. The flame tube is made of the first section and the second section, separated by a partition wall comprising an outlet nozzle, the front wall of the first section has a toroidal shape, forming an inlet nozzle inside the first section, which is connected to the air channel. The first fuel supply device is located in the inlet nozzle, inside the first and second sections near the partition wall there are second and third swirlers connected to the air channel and to the second and third fuel supply devices, respectively. The first swirler is combined with the inlet nozzle. The outlet part of the second section of the flame tube has a trapezoidal shape.

EFFECT: improved formation of the combustion zone and efficient afterburning of fuel in a wide range of operating modes due to the use of a profiled end in the flame tube and the presence of two combustion zones, as well as a uniform air supply to the channel between the body and the flame tube.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

FIG. 1 is a schematic illustration of a two stage burner according to embodiments of the invention.

It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non-transitory storage medium that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term set when used herein may include one or more items. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently.

The technical result of the claimed invention consists in improved formation of the combustion zone and efficient afterburning of fuel in a wide range of operating modes due to the use of a profiled end in the flame tube and the presence of two combustion zones, as well as a uniform air supply to the channel between the housing and the flame tube. In this case, it is possible to use the second section of the flame tube as a transition pipe for connection with a gas turbine plant.

This result is achieved by the fact that a two-stage burner with a two-layer vortex countercurrent flow is proposed, containing a burner body and a flame tube containing an ignition device coaxially installed in it, and an outlet nozzle, between the burner body and the flame tube there is an air channel with the first swirler placed in it, while the flame tube is made in the form of two sections interconnected and between which the outlet nozzle is located, the front wall of the first section has a toroidal shape, forming the inlet nozzle inside the section, which is connected to the air channel, the first fuel supply device is located in the inlet nozzle, inside each section at the outlet nozzle there are the second and third swirlers connected to the air channel, and the second and third fuel supply devices, respectively.

The toroidal shape of the front wall of the burner makes it possible to reduce the resistance to the air flow passing through the air channel to the inlet nozzle, and contributes to the creation of a swirling paraxial flow and a combustion stabilization zone inside the flame tube. In one of the embodiments of the invention, the location of the first swirler can be combined with the inlet nozzle.

The implementation of the two-section flame tube allows efficient afterburning of combustion products from the first section in the second in the entire range of operating modes due to the creation in each section of a separate vortex flow of the fuel-air mixture and combustion products: counter-current (in the first section) and direct-flow (in the second section). Also, this embodiment of the pipe allows you to significantly expand the range of stable operation of the combustion chamber with low emission characteristics of emissions.

To be able to use the proposed burner in gas turbine plants, the end part of the second section of the flame tube on the side of the outlet of the combustion products has a trapezoidal shape for the possibility of connection with the turbine nozzle apparatus of the gas turbine plant.

Reference is now made to FIG. 1 which is a schematic illustration of a two-stage burner 100 according to embodiments of the present invention.

Two-stage burner 100 with a two-layer vortex countercurrent flow comprises a housing 105 and a flame tube 110 containing an ignition device and made of two sections (see Fig.). An air channel 112 is made between the body or housing 105 and the flame tube 110, through which the air mixture enters the flame tube 110. The first swirler 1 is located in this channel 112, which ensures the creation of a paraxial vortex in the flame tube, passing along its entire length.

The first section 111a and the second section 111b of the flame tube are interconnected and separated by a partition wall 115 having an opening in which the outlet nozzle 120 of the flame tube 110 is located. The outlet nozzle 120 is a cylindrical ring with a diameter of D2 with a longitudinal length exceeding the thickness of the baffle. The flame tube 110 and the outlet nozzle 120 are arranged coaxially relative to each other. Preferably, the main body of the flame tube has a cylindrical shape.

The front wall 125 of the first section 111a has a toroidal shape (or W-shaped profile). At the same time, the form is made in such a way that the part protruding inside the first section is an inlet window 130, which is connected with an air channel, which practically repeats the shape of the front wall of the first section and goes into the inlet window. The specified window 130 is an inlet nozzle with a diameter of D1, through which the air flow for the paraxial vortex enters. Preferably, the first swirler 1 is located either near the inlet nozzle or directly in the inlet nozzle itself. The first fuel supply device 150a is also located in the inlet nozzle 130.

The toroidal shape of the front wall 125 and, accordingly, the air channel in this area, contributes to a smooth reversal of the air flow in the opposite direction and the creation of an axial flow in the flame tube 105. The presence of a swirler in the channel makes such a flow swirling and efficient for mixing with the fuel from the first fuel feeder 150a.

On the inner surfaces of the first and second sections 111a. 111b, the second swirler 2 and the third swirl 3, respectively, are installed, which are connected to the air channel 112. These swirlers are located near the partition wall 115 and create peripheral vortices of fuel-air mixtures in their sections. In this case, the second swirler 2 ensures the creation of a vortex movement in the first section 111a, directed opposite to the axial vortex movement (a countercurrent flow is created). And the third swirler 3 creates a paraxial vortex in the second section 111b, moving unidirectionally with the paraxial flow (concurrent flow is created).

The second swirler 2 and the third swirl 3 are connected to the second and third fuel supply devices 150b, 150c, respectively.

The partition wall 115 between the sections makes it possible to separate the combustion zones, forming a combustion zone 1 and a combustion zone 2, thereby facilitating the afterburning of residual gases from the first section to the second.

Three fuel supply devices 150a, 150b, 150c provide an increase in the range of stable operation of the claimed burner 100 when its load changes. So, during the operation of a two-stage burner 100 at low power levels (less than 30% of the maximum), fuel is not supplied to the third fuel supply device, afterburning of the residual gases of the first section is carried out due to the air flow from the third swirler.

Methane, propane, butane, diesel, kerosene or gasoline can be used as fuel. It is also possible, in some burner applications, to supply a low-calorie fuel such as syngas or pyrolysis gas to the third fuel supply.

Conducted practical tests have shown that the proposed design of the burner works most efficiently with the values of the diameter of the inlet nozzle D1, corresponding to 0.2-0.4 D, and the diameter of the outlet nozzle D2, corresponding to 0.6-0.8 D, where D is the diameter of the flame tube.

To use the proposed two-stage burner 100 as part of a gas turbine plant, the second section 111B of the flame tube 105 has a profiled shape that allows you to connect to the nozzle apparatus of the turbine of the gas turbine plant without using additional adapters in the form of nozzles. In this embodiment, the second section 111b is a gas collector. Structurally, it is made as follows: the front part of the second section, attached to the first section, has a cylindrical design, and the outlet part, which is connected to the gas turbine plant, has a trapezoidal shape.

The operation of a two-stage burner with a two-layer vortex countercurrent flow is carried out as follows. Air is supplied to the air channel, which enters the corresponding sections of the flame tube through the first, second and third swirlers. The first and second fuel supply devices are supplied with fuel, which is mixed with air to form a fuel-air mixture. The fuel-air mixture from the second swirler moves in a spiral along the inner surface of the first section, creating a peripheral vortex that cools the walls of the flame tube. Reaching the toroidal wall, this vortex unfolds and merges with the central vortex formed by the first swirler from the inlet nozzle, forming a stable combustion stabilization zone, which is ignited in the start mode by the ignition device installed in the first section. Combustion products come from the first section to the second through the outlet nozzle, where they mix with the air flow from the third swirler to burn off residual combustible gases. The presence of three swirlers 1, 2, 3 through which air enters, allows you to reduce the combustion temperature and control harmful emissions of nitrogen oxides and carbon oxides. When the rated power of the burner is reached, it is possible to supply fuel through the third fuel supply device, which is mixed with the air flow of the third swirler to form a fuel-air mixture, followed by its ignition in the axial zone of the second section.

Unless explicitly stated, the method embodiments described herein are not constrained to a particular order in time or chronological sequence. Additionally, some of the described method elements may be skipped, or they may be repeated, during a sequence of operations of a method.

While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Various embodiments have been presented. Each of these embodiments may of course include features from other embodiments presented, and embodiments not specifically described may include various features described herein.