Two-stage combustor with double-layer vortex reverse flow

Abstract

A two-stage combustor (100) with double layer swirl counter flow includes a combustor body (105) and a flame tube (110) containing an ignition device and an outlet nozzle (120). An air passage (112) having a first swirler (1) is provided between the burner body (105) and the flame tube (110). The flame tube (110) is composed of a first section (I11a) and a second section (lib), which are separated by a partition wall (115) comprising an outlet nozzle (120). The front wall (125) of the first section (111a) has an annular shape to form an inlet nozzle (130) inside the first section (111a). A first fuel supply (150a) is located in the inlet nozzle (130). A second swirler (2) and a third swirler (3) are provided inside the first section (111a) and the second section (111b) and in the vicinity of the partition wall (115), which second swirler (2) and third swirler (3) communicate with the air passage (112) and are connected to a second fuel supply (150b) and a third fuel supply (150c), respectively. The first swirler (1) is combined with an inlet nozzle. An outlet portion of the second section of the flame tube (110) has a trapezoidal shape.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority of Russian Patent Application No. 2022126445, filed on October 11, 2022, the content of which is incorporated herein by reference in its entirety. Technical field

[0003] Embodiments of the present invention relate to fuel combustion devices, and particularly to vortex burners. Background art

[0004] The present invention relates to fuel combustion devices, and particularly to vortex burners.

[0005] The prior art is a device for burning fuel described in the invention patent RU2708011 (publication date: December 03, 2019). The device comprises three types of fuel supply devices. The first type of fuel supply device is made in the form of an injection nozzle located inside a swirler, the outlet opening of the flow channel of the injection nozzle is perpendicular to the end wall of the swirler, and the outlet opening of the channel is made at the minimum cross - section of the flow channel of the tangential nozzle swirler. The second type of device comprises at least one centrifugal nozzle. The third type of device is made in the form of a branch pipe, which is installed in an axial hole in the end wall of the flame tube. The second type of fuel supply device and the third type of fuel supply device are located at the end of the flame tube opposite to the swirler. Effect: The present invention provides enhanced start - up reliability and provides stable operation for liquid fuel, gaseous fuel, and ballast fuel having both non - combustible components and water, as well as fuel (including pulverized solid combustible components and their mixtures with water).

[0006] The specified device for burning fuel is closest in technical essence to the claimed present invention and is used as a prototype.

[0007] Its disadvantages are insufficient fuel combustion efficiency, which is due to significant circumferential non - uniformity in the air supply distribution between the tangential nozzle swirler and the front wall, and in a wide range of operating modes, i.e., in part - load or near - lean - stall modes, it is impossible to provide efficient after - combustion of fuel, and in such a design, the emissions of CO oxides may increase unacceptably. In addition, the design using a tubular combustion chamber in the prototype may be limited, especially because it cannot be used in gas turbine installations, since in gas turbine installations, air must be supplied evenly along the flame tube, and additional transition pipes with special configurations are required to connect to the nozzle equipment of the installation device. Summary of the invention

[0008] A two-stage burner with a double-layer vortex countercurrent flow includes: a burner body and a flame tube. The flame tube contains an outlet nozzle and an ignition device coaxially installed in the flame tube. There is an air passage between the burner body and the flame tube, and a first swirler is placed in this air passage. The flame tube is composed of a first section and a second section, and the first section and the second section are separated by a partition wall including the outlet nozzle. The front wall of the first section has an annular shape, so as to form an inlet nozzle inside the first section, and the inlet nozzle communicates with the air passage. A first fuel supply device is located in the inlet nozzle. There are a second swirler and a third swirler inside the first section and the second section and near the partition wall. The second swirler and the third swirler communicate with the air passage respectively and are connected to a second fuel supply device and a third fuel supply device. The first swirler is combined with the inlet nozzle. The outlet part of the second section of the flame tube has a trapezoidal shape.

[0009] Effect: Due to the use of profiled ends in the flame tube, the presence of two combustion zones, and the uniform air supply to the passage between the body and the flame tube, the formation of the combustion zone is improved and the efficient afterburning of fuel is achieved in a wide range of operating modes. Description of the Drawings

[0010] It is particularly pointed out and clearly claimed in the concluding part of the specification as the subject matter regarded as the invention. However, both the organization and method of operation of the present invention, as well as its objectives, features, and advantages, can be best understood by referring to the following detailed description in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a schematic diagram of a two-stage burner according to an embodiment of the present invention.

[0012] It will be understood that, for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, for clarity, the dimensions of some elements may be exaggerated relative to other elements. In addition, where considered appropriate, reference numerals may be repeated in the figures to indicate corresponding or similar elements. Detailed Description of the Embodiment

[0013] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, those skilled in the art will understand that the present invention can also 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.

[0014] Although embodiments of the present invention are not limited in this regard, discussions using terms such as, for example, "processing", "computing", "calculating", "determining", "establishing", "analyzing", "inspecting", etc. may refer to one or more operations and / or processes of a computer, a computing platform, a computing system, or other electronic computing devices, where one or more operations and / or processes manipulate data represented as physical (e.g., electronic) quantities within computer registers and / or memories and / or convert it into other data also represented as physical quantities within computer registers and / or memories, or convert it into other data also represented as physical quantities within other non-transitory information storage media that can store instructions for performing the operations and / or processes. Although embodiments of the present invention are not limited in this regard, the terms "plurality" and "multiple" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "multiple" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, etc. When used herein, the term "set" may include one or more items. Unless explicitly stated, the method embodiments described herein are not limited to a particular order or sequence. Additionally, some of the described method embodiments or their elements may occur or be performed simultaneously, at the same point in time, or concurrently.

[0015] The technical effect of the claimed invention is that, due to the use of a shaped end portion in the combustion chamber, the presence of two combustion zones, and the uniform air supply to the channel between the housing and the combustion chamber, the formation of the combustion zones is improved and efficient afterburning of the fuel is achieved in a wide range of operating modes. In this case, the second section of the combustion chamber can be used as a transition duct for connection to a gas turbine unit.

[0016] This result is achieved by the fact that a two-stage burner with a double-layer vortex reverse flow is proposed, which includes a burner body and a combustion chamber. The combustion chamber contains an outlet nozzle and an ignition device coaxially installed in the combustion chamber. There is an air channel between the burner body and the combustion chamber, and a first swirler is placed in the air channel. At the same time, the combustion chamber is formed in the form of two interconnected sections, and the outlet nozzle is located between the two sections. The front wall of the first section has an annular shape, thereby forming an inlet nozzle inside the section. The inlet nozzle is in communication with the air channel, and a first fuel supply device is located in the inlet nozzle. A second swirler and a third swirler are present inside each section and at the outlet nozzle. The second swirler and the third swirler are respectively in communication with the air channel and connected to a second fuel supply device and a third fuel supply device.

[0017] The annular shape of the front wall of the burner enables reducing the resistance of the air flow through the air passage to the inlet nozzle and contributes to the formation of a swirling near-axial flow and a combustion stabilization zone inside the combustion chamber. In one of the embodiments of the present invention, the position of the first swirler can be combined with the inlet nozzle.

[0018] Due to the formation of separate vortex flows of the fuel-air mixture and combustion products in each section: a countercurrent flow (in the first section) and a direct flow (in the second section), the implementation of the two-stage combustion chamber allows for efficient afterburning of the combustion products from the first section in the second section throughout the entire operating mode range. In addition, this embodiment of the duct allows for a significant expansion of the stable operating range of the combustion chamber with low-emission characteristics.

[0019] In order to be able to use the proposed burner in a gas turbine unit, the end portion of the second section of the combustion chamber at the side of the outlet of the combustion products has a trapezoidal shape to facilitate connection to the turbine nozzle equipment of the gas turbine unit.

[0020] Now refer to Figure 1 , which Figure 1 is a schematic diagram of a two-stage burner 100 according to an embodiment of the present invention.

[0021] The two-stage burner 100 with a double-layer vortex reverse flow includes a housing 105 and a combustion chamber 110, which contains an ignition device and consists of two sections (see the attached drawings). An air passage 112 is formed between the body or housing 105 and the combustion chamber 110, and the air mixture enters the combustion chamber 110 through this air passage 112. The first swirler 1 is located in this passage 112, which ensures the formation of a near-axial vortex extending along the entire length of the combustion chamber.

[0022] The first section 111a and the second section 111b of the combustion chamber are interconnected and separated by a partition wall 115, which has an opening, and the outlet nozzle 120 of the combustion chamber 110 is located in this opening. The outlet nozzle 120 is a cylindrical ring body with a diameter of D2, where the longitudinal length exceeds the thickness of the partition. The combustion chamber 110 and the outlet nozzle 120 are arranged coaxially with respect to each other. Preferably, the main body of the combustion chamber has a cylindrical shape.

[0023] The front wall 125 of the first section 111a has an annular shape (or a W-shaped profile). At the same time, it is made in such a form that the part protruding into the interior of the first section is the inlet window 130, which communicates with an air passage that actually reproduces the shape of the front wall of the first section and converges into the inlet window. The window 130 is designated as an inlet nozzle with a diameter of D1, through which an air flow for a near-axis vortex enters. Preferably, the first swirler 1 is located near the inlet nozzle or directly within the inlet nozzle itself. The first fuel supply device 150a is also located in the inlet nozzle 130.

[0024] The annular shape of the front wall 125 and accordingly the air passage in this area contribute to the smooth commutation of the air flow in the opposite direction and the formation of an axial flow in the combustion chamber 105. The presence of the swirler in the passage causes this flow to form a swirl, thus effectively mixing with the fuel from the first fuel feeder 150a.

[0025] A second swirler 2 and a third swirler 3 are respectively installed on the inner surfaces of the first section 111a and the second section 111b, and the second swirler 2 and the third swirler 3 communicate with the air passage 112. These swirlers are located near the partition wall 115 and form a circumferential vortex of the fuel-air mixture in their sections. In this case, the second swirler 2 ensures the formation of a vortex motion in the first section 111a, which is directed opposite to the axial vortex motion (forming a reverse flow). And the third swirler 3 forms a near-axis vortex in the second section 111b, which moves in the same direction as the near-axis flow (forming a cocurrent flow).

[0026] The second swirler 2 and the third swirler 3 are respectively connected to a second fuel supply device 150b and a third fuel supply device 150c.

[0027] The partition wall 115 between the sections enables the combustion zones to be separated, forming combustion zone 1 and combustion zone 2, thus facilitating afterburning of the residual combustion gas from the first section in the second section.

[0028] The three fuel supply devices 150a, 150b, 150c expand the stable operating range of the claimed burner 100 when the load changes. Thus, during operation of the two-stage burner 100 at a low power level (less than 30% of the maximum value), the third fuel supply device does not supply fuel, and the afterburning of the residual combustion gas in the first section is carried out due to the air flow from the third swirler.

[0029] Methane, propane, butane, diesel, kerosene or gasoline can be used as fuel. In some burner applications, low-calorific fuels such as synthesis gas or pyrolysis gas can also be supplied to the third fuel supply device.

[0030] The actual tests conducted have shown that the proposed burner design operates with the highest efficiency when the diameter D1 of the inlet nozzle is a value corresponding to 0.2D to 0.4D and the diameter D2 of the outlet nozzle is a value corresponding to 0.6D to 0.8D, where D is the diameter of the flame tube.

[0031] In order 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 shaped configuration that allows connection to the nozzle device of the turbine of the gas turbine plant without using an additional adapter in the form of a nozzle. In the present embodiment, the second section 111b is a gas collector. Structurally, it is configured as follows: the front portion attached to the first section in the second section has a cylindrical design, and the outlet portion connected to the gas turbine plant has a trapezoidal shape.

[0032] The operation of the two-stage burner with a double-vortex reverse flow is as follows. Air is supplied to the air passage and enters the corresponding sections of the flame tube through the first swirler, the second swirler, and the third swirler. The first fuel supply device and the second fuel supply device are supplied with fuel, and the fuel is mixed with air to form a fuel-air mixture. The fuel-air mixture from the second swirler moves in a spiral manner along the inner surface of the first section, thereby forming a circumferential vortex that cools the wall of the flame tube. When the vortex reaches the annular wall, the vortex unfolds and merges with the central vortex formed by the first swirler from the inlet nozzle, thereby forming a stable combustion stabilization zone that is ignited by an ignition device installed in the first section in the start-up mode. The combustion products enter the second section from the first section through the outlet nozzle, where the combustion products are mixed with the air flow from the third swirler to burn the remaining combustible gases. Air enters through the three existing swirlers 1, 2, 3, allowing the combustion temperature to be reduced and the harmful emissions of nitrogen oxides and carbon oxides to be controlled. When the rated power of the burner is reached, fuel can be supplied through the third fuel supply device, and the fuel is mixed with the air flow from the third swirler to form a fuel-air mixture, which is then ignited in the axial zone of the second section.

[0033] Unless explicitly stated, the method embodiments described herein are not limited to a specific time sequence or an order of occurrence arranged in chronological order. Additionally, during a series of operations of the method, some of the method elements described may be skipped, or may be repeated.

[0034] Although certain features of the present invention have been illustrated and described herein, many modifications, substitutions, variations, and equivalents will now occur to those of ordinary skill in the art. Accordingly, it is to be understood that the appended claims are intended to cover all such modifications and variations as fall within the true spirit of the present invention.

[0035] Various embodiments have been presented. Of course, each of these embodiments may include features from other of the presented embodiments, and embodiments not specifically described may include various features described herein.

Claims

1. A two-stage burner with a double-layer vortex reverse flow, the two-stage burner comprising a burner body and a flame tube, the flame tube including an outlet nozzle and an ignition device coaxially installed in the flame tube. There is an air passage between the burner body and the flame tube. A first swirler is placed in the air passage. At the same time, the flame tube is composed of a first section and a second section, and the first section and the second section are separated by a partition wall including the outlet nozzle. The front wall of the first section has an annular shape, so as to form an inlet nozzle inside the first section. The inlet nozzle communicates with the air passage. A first fuel supply device is located in the inlet nozzle. A second swirler and a third swirler exist inside the first section and the second section and at the partition wall. The second swirler and the third swirler are respectively communicated with the air passage and connected to a second fuel supply device and a third fuel supply device.

2. The two-stage burner according to claim 1, wherein, The first swirler is combined with the inlet nozzle.

3. The two-stage burner according to claim 1, wherein, The outlet of the second section of the flame tube has a trapezoidal shape.

4. The two-stage burner according to claim 1, wherein, The diameter of the inlet nozzle corresponds to 0.2D to 0.4D, and the diameter of the outlet nozzle is 0.6D to 0.8D, where D is the diameter of the flame tube.

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