JP2013228192A - Combustor apparatus for stoichiometric combustion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustor apparatus which achieves high efficiency combustion in gas turbine applications where a low oxygen working fluid is used.SOLUTION: The present invention relates to a gas turbine combustor with a specific fuel and oxidizer flow arrangement that provides high combustion efficiency for stoichiometric diffusion combustion in gas turbine applications operating with oxygen-deficient working fluids.

Description

  The present invention relates to gas turbine combustor geometries having specific fuel and oxidant flow arrangements that provide high combustion efficiency for stoichiometric diffusion combustion in gas turbine applications operating with oxygen-deficient working fluids.

  Gas turbine applications that use a low oxygen working fluid are known. Examples of such applications are carbon capture, oxyfuel, and high exhaust recirculation, all of which require high combustion efficiency in order to be economically viable. However, it has not been possible until now to achieve such a high combustion efficiency.

US Patent Application Publication No. 2010/0170253

  In gas turbine applications where a low oxygen working fluid is used, there is a need for high efficiency combustion. The present invention seeks to satisfy that need.

  In one aspect, the present invention provides a combustor comprising a housing having an inner surface, an interior space, a nozzle, and a liner assembly disposed within the housing. The liner is provided with one or more liner mixing holes and one or more liner dilution holes. The liner assembly is a longitudinally extending path along the combustor between the liner assembly and the inner surface of the housing to transfer the working fluid away from the inner surface of the housing and into the interior space through the mixing and dilution holes of the liner Is defined. Liner mixing and dilution holes are axially positioned at specific locations within the liner assembly depending on the diameter of the liner.

  The combustor of the present invention ensures sufficient hardware durability while providing a stable flame and high combustion efficiency. Because carbon capture, oxyfuel, and high exhaust recirculation applications require near stoichiometric combustion, the combustor of the present invention provides high efficiency combustion, where fuel and oxidant are gases. Combustion is reliably completed before being diluted with the turbine working fluid.

  Accordingly, the combustor of the present invention is cost effective in gas turbine applications where a low oxygen working fluid is used to achieve improved combustion efficiency compared to that obtained using conventional combustors. Provide an efficient solution.

It is a partial perspective view inside the combustor of this invention. 1 is a side view of a liner assembly of a combustor of the present invention showing mixing and dilution holes. FIG. It is a perspective view of the nozzle structure used in the combustor of this invention. It is a schematic sectional drawing of a combustor. FIG. 2 is a schematic diagram of a counter-swirl nozzle configuration. FIG. 2 is a schematic view of a parallel flow swirl (co-swir) nozzle configuration. FIG. 3 is a partial side view of a nozzle showing a built-in igniter.

  Referring to the drawings, FIG. 1 shows a perspective view of the interior of a combustor 2 of the present invention having a housing 4 having an inner surface 6 and an interior space 8. The liner assembly 10 is disposed within the housing 4 and defines a path 12 spaced longitudinally along the length of the combustor 2 between the liner assembly 10 and the inner surface 6 and spaced apart from the inner surface 6 of the housing. A working fluid rich in diluent of the gas turbine (GT) flows along 6.

  1 and 3 also show a nozzle 14 provided at one end of the combustor 2. The nozzle 14 is in fluid communication with the internal space 8 of the combustor 2. The nozzle 14 is provided with a series of concentric openings that define the fuel holes 16.

  The nozzle structure used in the present invention is disclosed in U.S. Patent Application Publication No. 2009/0223227 filed on March 5, 2008, assigned to the present applicant (the disclosure of which is incorporated herein by reference). Is described in detail.

  FIG. 2 shows the liner assembly 10 with liner mixing holes 18, 20, liner dilution holes 40, 42 and liner cooling holes 44, 46, 48 at different axial positions along the liner 10. In accordance with the present invention, the liner mixing holes 18, 20 are sized and arranged in an axial position within the liner assembly 10 to provide good mixing and complete combustion of the fuel components. In one embodiment, for example, the liner mixing holes 18, 20 are sized to provide about 10% of the GT flow, ie, the flow available from the compressor to the combustor. The jet injected from the fuel nozzle through the liner mixing hole limits the expansion of the oxidant stream that promotes shear mixing between the fuel and the oxidant. The location of the liner mixing holes can be optimized to avoid flame quenching. This is discussed below in connection with FIG.

  FIG. 4 shows liner mixing holes 18, 20 located at an axial distance L of generally 0.65 to 1.05 D from nozzle 14 (where D is the inner diameter of liner 10). The liner mixing holes produce 1.05-1.4D1 jet penetration into the interior space 8 of the liner, where D1 is the diameter of the mixing hole.

  The cooling holes 44, 46, 48 are arranged at different axial positions, for example about 30-32% of the GT working fluid at the compressor discharge (ie at the compressor outlet position and at the combustor start position). Designed to accept. The size and number of cooling holes at any particular location is based on the desired efficient heat transfer at that location.

  A crown hole 28 receives approximately 6-9% of the GT working fluid at the compressor discharge. The crown hole 28 produces a recirculating bubble 50 of length L2 between 0.65 and 1.05 D (where D is the inner diameter of the liner 10). This increases the combustion efficiency.

  The dilution holes 40 and 42 are located at an axial distance L3 of 1.3 to 1.7 D (where D is the inner diameter of the liner). The dilution holes produce a L4 jet penetration that is 1.4 to 1.6 times D2, where D2 is the diameter of the dilution hole. Strong shear mixing occurs between the oxidant and the fuel, leading to a rapid reaction during a short residence time, developing a larger reaction zone. Furthermore, mixing with the GT working fluid helps to keep the flame away from the nozzle while controlling the peak temperature of the flame. The dilution holes accept 8-11% of the total combustor flow.

  The central passage 24 of the nozzle is generally used for oxidant streams such as air, oxygen, diluted oxygen or fuel. The outer passages 22, 26 are intended for gas turbine (GT) working fluids (generally diluent rich fluids). The passages 22, 24, 26 are generally inclined to create a counter-rotating flow between the oxidant and the GT working fluid. This is illustrated in FIG. 5, which schematically shows the gas leaving the nozzle and entering the interior space 8 in the form of a counter-flow swirl. FIG. 6 shows an example of a parallel flow swirl where gas exits the nozzle and enters the internal space 8 in the form of a parallel flow swirl.

  The central passage 24 of the nozzle 14 generally includes oblique fuel injection holes having an angle in the range of 40-60 degrees to produce a strong swirl flow. The central annular passage 24 of the nozzle is intended for gaseous fuel flow and generally has a cone angle of 20 to 26 degrees with respect to the nozzle axis and guides a counterclockwise swirl and It is tilted by a swirl angle of 5 to 16 degrees (see FIG. 5). The outer annular passage 26 of the nozzle is generally intended for dilution flow and has a cone angle of 30 to 36 degrees and a swirl angle of 5 to 16 degrees with respect to the nozzle axis to induce clockwise rotation. Is tilted by. In such a flow arrangement, strong shear mixing between the oxidant and the fuel results in a rapid reaction during a short residence time, developing a larger reaction zone than the conventional arrangement.

  The central passage 24 of the nozzle is designed to flow a mixed fluid containing 20-80% of the oxidant and 80-20% of the GT working fluid at the compressor discharge. Mixing is optimized to control reaction rate and flame temperature to reduce dissociation loss from the reaction zone. The outer passage 26 is designed to flow 25-30% of the total combustor flow. This flow arrangement serves to delay the combustion reaction downstream of the nozzle, thereby avoiding the potential risk of damaging hardware.

  FIG. 7 shows a built-in igniter 30 in the nozzle 14 for igniting combustible fuel. The igniter is generally placed at an angle of 25-30 degrees with respect to the longitudinal axis of the nozzle. A pilot nozzle 52 may alternatively be provided for startup applications. The pilot nozzle, if present, is typically located in the middle of the fuel nozzle that allows liquid fuel to pass through.

  Although the present invention has been described with respect to what is presently considered to be the most practical and preferred embodiments, the invention is not limited to the disclosed embodiments, but on the contrary, the appended claims It should be understood that various modifications and equivalent arrangements included in the spirit and scope of the scope are intended to be included.

2 Combustor 4 Housing 6 Inner surface 8 Internal space 10 Liner 12 Path 14 Nozzle 16 Fuel hole 18, 20 Liner mixing hole 22, 26 Outer passage 24 Central passage 26 Outer annular passage 28 Crown hole 30 Built-in igniter 40, 42 44, 46, 48 Liner cooling hole 50 Bubble 52 Pilot nozzle

Claims (13)

  A combustor comprising a housing having an inner surface, a nozzle, and a liner assembly disposed within the housing, wherein the liner has an inner space and is spaced from the inner surface of the housing to allow the working fluid to pass through the inner space. A longitudinally extending path along the combustor for transfer to the liner, and the liner is provided with mixing and dilution holes disposed longitudinally along the liner as a function of the inner diameter of the liner The combustor.   The combustor according to claim 1, wherein the liner mixing hole is disposed at an axial distance of 0.65 to 1.05 D from the nozzle, where D is an inner diameter of the liner.   The combustor of claim 1, wherein the liner mixing holes produce a 1.05 to 1.4 D1 jet penetration in the interior space of the liner, where D1 is the diameter of the mixing holes.   The combustor according to claim 1, wherein the dilution hole is disposed at an axial distance of 1.3 to 1.7 D from the nozzle (where D is an inner diameter of the liner).   The combustor of claim 1, wherein the dilution holes cause 1.4 to 1.6 D2 jet penetration in the interior space of the liner, where D2 is the diameter of the dilution holes.   The combustor of claim 1, wherein a crown hole is provided to receive about 6-9% of the working fluid.   The combustor of claim 5, wherein the crown hole produces a recirculation bubble having a length of 0.65 to 1.05 D, where D is the inner diameter of the liner.   The combustor of claim 1, wherein the dilution holes receive 8-11% of the total combustor flow.   The combustor according to claim 1, further comprising a cooling hole that receives 30 to 32% of the working fluid of the compressor discharge.   The combustor of claim 1, wherein the outer passage flows 25-30% of the working fluid in the compressor discharge.   The combustor of claim 1, wherein an internal igniter is provided to ignite the working fluid.   The combustor of claim 1, wherein the nozzle passage is inclined to create an opposing rotational flow between the oxidant and the working fluid.   The combustor of claim 1, wherein the nozzle passage is inclined to produce a parallel rotating flow between the oxidant and the working fluid.