JP2014526029A - Annular cylindrical combustor with graded and tangential fuel-air nozzles for use in gas turbine engines - Google Patents

Abstract

Combustion devices used in gas turbine engines to generate shafts for propulsion generation or power generation include an annular cylindrical combustor with a fuel and air inlet passage and nozzle system. Providing an optimal combustion environment for fuel and air. Fuel, air, and / or fuel air are arranged at various longitudinal positions and distributed circumferentially to direct flow in a tangential or substantially tangential direction of the cylindrical liner. Combustion devices provide optimal mixing of fuel and air, create a combustion environment that can reduce pollutant emissions, reduce the need for expensive pollutant suppression devices, increase ignition and flame stability, and pilot To reduce the problem and improve the vibration reduction.

Description

  The present invention relates to an apparatus for assisting in the production of a combustion of a fuel-air mixture in a gas turbine engine. Such devices include, but are not limited to, fuel air nozzles, combustor liners, casings, and flow transitions used in military and civil aircraft, power generation, and other gas turbine related applications. Parts are included.

  Gas turbine engines include mechanical devices that draw work from combustion gases that flow at very high temperatures, high pressures, and high speeds. The extracted work can be used to drive the generator for power generation or provide the necessary propulsion for the aircraft. A typical gas turbine engine includes a multistage compressor in which the atmosphere is compressed to a high pressure. The compressed air is then mixed in the combustor to a defined fuel / air ratio and the temperature is raised. The high-temperature and high-pressure combustion gas is expanded through a turbine that extracts work, and provides necessary propulsive force or drives a generator depending on the application. The turbine includes at least one stage, each consisting of a row of blades and a row of vanes. The blades are circumferentially arranged on the rotating hub axle, and each blade has a height across the hot gas flow path. The non-rotating vane stages are arranged circumferentially, and the vanes also extend across the hot gas flow path. Included inventions include gas turbine engine combustors and components that introduce fuel and air into the apparatus described above.

  The combustor section of a gas turbine engine may be of several different types, such as a tube / tube type, a ring type, and an annular tube type combustor formed by combining the two. In this component, the compressed fuel-air mixture passes through a fuel-air swirler or fuel-air nozzle, where the combustion reaction of the mixture occurs to create a hot gas stream that is reduced in density and accelerated downstream. To do. Cylindrical combustors typically have individual circumferentially spaced cylinders that separately contain the flames of each nozzle. The flow from each cylinder is directed through a conduit and merged with an annular transition piece before entering the first stage vane. In the annular combustor type, the fuel air nozzles are generally distributed in the circumferential direction, and the air-fuel mixture is introduced into a single annular chamber where combustion takes place. The flow simply exits from the downstream end of the ring to the first stage turbine without the need for transition components. The major difference between the last type of annular cylinder combustor is that the combustor has individual cylinders surrounded by an annular casing containing air supplied to each cylinder. Each type has advantages and disadvantages depending on the application.

  In combustors for gas turbines, it is typical for a fuel air nozzle to provide a swirl to the mixture for several reasons. One reason is to promote mixing and enhance combustion, and another reason is to add swirl to stabilize the flame and prevent it from being blown out, so that the fuel air The fuel mixture can be made thinner to reduce emissions. The fuel air nozzle can take different configurations, such as one to multiple annular inlets each with swirl vanes.

  As with other gas turbine components, it is necessary to implement a cooling method to prevent combustor material from melting. A typical method for cooling the combustor is bleed cooling performed by surrounding the combustor liner with an additional offset liner. The compressor discharge air passes between the two liners and enters the hot gas flow passage through the dilution holes and the cooling passage. This technique removes heat from the component and forms a thin boundary layer film of cold air between the liner and the combustion gas to prevent heat transfer to the liner. The dilution holes serve two purposes depending on the axial position in the liner. That is, the dilution holes closer to the fuel air nozzle aid in gas mixing to enhance combustion and supply unburned air for combustion. The holes closer to the turbine will then cool the hot gas stream and can be designed to manipulate the temperature profile at the combustor outlet.

  It can be appreciated that several methods and techniques can be incorporated into the design of a combustor for a gas turbine engine to improve combustion and low emissions. While gas turbines tend to produce less pollutants than other power generation methods, there is still room for improvement in this area. Some countries have government regulations that regulate emissions, and technology needs to be improved to meet these requirements.

  In connection with the present invention, while being able to operate in a typical manner, the polluting emissions resulting from the combustion of the fuel-air mixture can be minimized and other problems encountered are addressed. A new and improved combustor design is provided. The present invention provides a typical annular cylinder with fuel and air nozzles and / or dilution holes that directs compressor discharge air and compressed fuel to a combustor at various positions in the front-rear and circumferential directions. Composed of a type combustor. A unique feature of the present invention is that the fuel and air nozzles are arranged in such a way as to create an environment that facilitates mixing of the combustion reactants and products. Staged fuel and air nozzles that primarily inject fuel into the upstream nozzles and other combinations of downstream nozzles that primarily inject air facilitates mixing of the combustion reactants and NOx Create a specific oxygen concentration in the combustion zone that significantly reduces production. In this device, there is no attached / fixed flame, rather there is an area in the cylinder near the front wall where diffusion combustion occurs. The new configuration of separated fuel and air nozzles dilutes the air that is injected downstream or diffuses upstream, thus reducing the oxygen concentration with which the flame contacts and increasing the maximum flame temperature. It means to lower. Thereby, this invention can reduce discharge | emission. Also, the introduction of the compressor discharge air downstream of the combustion zone allows any CO generated during combustion to be burned / consumed before entering the first stage turbine. In effect, the combustor improves gas turbine emissions levels, thereby reducing the need for emissions control devices and minimizing the environmental impact of the devices. In addition to this improvement, tangentially burning fuel nozzles and fuel air nozzles greatly accelerate the ignition process of the combustor by directing any initial flame tip to the adjacent burner nozzle of each cylinder. .

2 is a two-dimensional schematic showing an annular cylindrical configuration with a nozzle attached to an outer cylindrical liner that injects fuel and air into a common plane. 2 is a two-dimensional schematic showing a rough idea of a tangential nozzle applied to a cylinder of an annular cylindrical combustor. FIG. 6 is an isometric side view of the upstream portion of the example configuration of the present invention. 1 is an isometric cross-sectional view of the present invention. FIG. 4B is an enlarged view of the map of FIG. 4A. It is sectional drawing which shows the cross section AA defined in FIG. It is sectional drawing which shows the cross section BB defined in FIG.

  FIG. 1 shows an example of the general configuration of an annular cylindrical combustor with cylinders 1 spaced circumferentially at a common radius, all of which are cylindrical outer liner 2 and cylindrical The inner liner 3 is surrounded. The figure also shows a nozzle configuration in the circumferential direction of the cylinder. FIG. 2 shows the cylinder in more detail. The cylindrical liner 4 forms a cylindrical volume with a fuel / air nozzle 5 for injecting fuel or air. The nozzle forms an angle 8 between the nozzle center line 6 and the tangent of the cylindrical liner 4 intersecting the nozzle center line 6. This angle defines the circumferential direction of the nozzle.

  FIG. 2 also shows the general operation of the cylinder in the configuration of an example annular tube combustor in which fuel or air 9 is injected into the cylinder 1 at an angle 8. In the present invention, the flame 10 which is not fixed is generated and propagates in a path 11 which follows the cylindrical liner through the cylinder. These tangentially directed nozzles will cause the flow from each nozzle to interact with an adjacent nozzle downstream. This important feature allows a flame directed from one nozzle to ignite fuel at an adjacent downstream nozzle, enhancing ignition and mitigating the problem of igniting multiple burner nozzles.

  FIG. 3 shows the leading or upstream portion of an example cylinder with the downstream portion removed. The present invention comprises a plurality of nozzle rows spaced along the longitudinal direction of the cylinder. Each row of nozzles 12, 13 may comprise at least one nozzle and can be offset from the row of adjacent nozzles by a circumferential angle. Specifically, the nozzles 12 in the row near the front wall 15 inject all or most of the fuel into the cylinder by the above-described method, and the nozzles 13 downstream of these injections are compressor discharge air. Or a fuel-air mixture is injected into the cylinder in a similar manner. The cylinder may also include several rows of circumferentially spaced holes 14 or passages for cooling air to enter the cylinder anywhere.

  FIGS. 4A and 4B show the most upstream surface 15 of the cylinder, which may be provided with holes 16 similar to dilution holes through which compressor discharge air can enter the cylinder. FIGS. 5 and 6 show how the nozzles 12, 13 of each nozzle combination can be shifted by a circumferential angle. Different rows of nozzles allow separate injections of fuel and air to create areas of the combustion reaction near the front wall that do not result in large oxygen concentrations, which in effect reduces the maximum flame temperature. Become. Smoke gas moving upstream toward the front wall can be diluted by the combustion products, causing the combustion reactants to have a lower oxygen concentration. This combustion environment created by graded fuel and air nozzles allows for emission reduction.

  The present invention has been described above with reference to preferred embodiments. However, one of ordinary skill in the art appreciates that changes and modifications can be made in the described embodiments without departing from the spirit and scope of the invention. Various changes and modifications to the embodiments selected herein for purposes of illustration will readily occur to those skilled in the art. To the extent that such improvements and modifications do not depart from the spirit of the invention, they are intended to be included within the scope of the invention.

  Having fully described the invention in clear and concise language so that those skilled in the art may understand and practice the invention, the invention is claimed as follows.

Claims (19)

In an annular tube combustor for gas turbines used in power generation applications on the ground, vehicle or aircraft engine applications on the ground or sea,
A plurality of cylindrical liners circumferentially spaced, surrounded by two cylindrical liners, each having a plurality of tangential protrusions;
Circumferentially spaced fuel air nozzles with liners that coexist in a common plane perpendicular to the centerline of the cylinder and are all made of high temperature alloy or ceramic material;
An annular cylindrical combustor comprising:   Nozzles that are perpendicular to the front-rear direction and spaced circumferentially in a common plane near the front wall of the cylinder can inject only fuel or a fuel-rich fuel-air mixture, the fuel or the 2. An annular cylindrical combustor according to claim 1, wherein the fuel-air mixture can have a radial component and / or a longitudinal component while mainly having a circumferential component.   A nozzle that is perpendicular to the front-rear direction and spaced circumferentially in a common plane downstream from the nozzle according to claim 2 injects only compressor discharge air or fuel air of the nozzle according to claim 2 A fuel-air mixture having a fuel-air ratio with a fuel lower than the ratio can be injected. The annular cylindrical combustor according to claim 1, which can be provided.   The nozzle may have a constant or varying value in which the angle from plane to plane is in the range of 0 to 90 degrees as indicated by item 8 in FIG. The annular cylindrical combustor according to 1.   The annular cylindrical combustor of claim 1, wherein the nozzles in different planes can have the same fuel air ratio or different fuel air ratios.   The annular cylindrical combustor of claim 1, wherein the fuel air nozzles in the same plane can have the same fuel air ratio or different values of fuel air ratio.   The tangentially directed nozzles greatly enhance the combustion process of the combustor because adjacent nozzles direct flames to adjacent adjacent burners to assist each other in ignition. The annular cylindrical combustor according to 1.   The enhanced ignition process creates an essentially stable combustion that will reduce the vibration and noise induced by the flame instability caused by flame instability in partial and full load level operation. 6. An annular cylindrical combustor according to claim 5, wherein   The annular cylindrical combustor of claim 1, wherein the tangential fuel air nozzle configuration enhances reactant mixing for efficient combustion at very low load levels.   The annular cylindrical combustor of claim 1, wherein reactant fuel such as low BTU gas can be readily utilized and combusted in the combustor for enhanced flame stability.   Annular cylindrical combustion according to claim 1, characterized in that vortices that promote stable combustion at the burner outlet are created around the centerline of the cylinder (which is the main result of a tangential fuel-air nozzle). vessel.   The residence time required to burn the fuel-air mixture is shortened, resulting in a smaller combustion space, which reduces the size of the engine (important in all applications) and thereby (aircraft 2. An annular cylindrical combustor according to claim 1, wherein the ratio of weight to thrust (which is important in gas turbine applications) is reduced.   Achieving a more uniform temperature distribution at the combustor outlet allows the combustor to operate at higher combustion (ignition) temperatures without compromising the useful life of the combustor and turbine components The annular cylindrical combustor according to claim 1.   14. An annular tubular combustor according to claim 1, wherein the ability to operate at a higher combustion temperature as described in claim 13 results in improved engine efficiency and output, thereby reducing carbon dioxide emission levels. .   The cylindrical front wall liner can be provided with at least one hole or nozzle through which the compressor discharge air can be passed through the liner at a magnitude smaller than the nozzle described in claims 2 and 3. The annular cylindrical combustor according to claim 1.   The annular cylindrical combustor according to claim 1, wherein the radius and length of the cylinder can change in the front-rear direction depending on the size and shape of the gas turbine engine.   2. An annular cylindrical combustor according to claim 1, wherein any cooling method available for cooling gas turbine components can be used, such as, for example, impingement cooling, seepage cooling, steam cooling. .   2. The annular cylinder according to claim 1, wherein the nozzles coexisting in a common plane can be shifted from another combination of nozzles in different planes by a circumferential angle around the cylinder centerline. Combustor.   The air passages indicated as items 14 and 16 can be straight holes or can comprise a bell-shaped inlet made using spark electrical discharge machining (EDM). The annular cylindrical combustor as described.