The invention relates to gas turbine engines, and more particularly to a diffusion flame burner for a gas turbine engine.
When operating in an oil mode, oil is injected from the central nozzle 30 into the combustor 11 and air or water is injected into the combustor 11 through atomizing holes 12 that are positioned around the central nozzle 30. During a startup of the oil mode (i.e. low load) of the gas turbine engine, oil is injected from the central nozzle 30 at a low flow rate, and air is injected from the atomizing holes 12 at a sufficient flow rate and at a sufficient injection pressure, in an effort to atomize the injected oil. For example, during the startup mode at low injection pressure, the injected oil from the central nozzle 30 may not be sufficiently atomized for ignition in the combustor 11 and the injected air from the atomizing holes 12 is used to help atomize the oil. Subsequently during engine loading after startup, the oil is injected from the central nozzle 30 at a high flow rate, and water is injected from the atomizing holes 12 at a sufficient flow rate and a sufficient injection pressure, to atomize the injected oil.
In one construction, a gas turbine engine operable using either one of a first fuel and a second fuel includes a water supply and a diffusion flame burner including an innermost spray cone, a plurality of spray cones positioned around the innermost spray cone and grouped into a plurality of stages, and a plurality of outlets positioned around the innermost spray cone. A plurality of valves is arranged to connect the first fuel, the second fuel, and the water supply to the diffusion flame burner and a controller is operable to configure the plurality of valves at least in part in response to which of the first fuel and the second fuel is being consumed. When consuming the first fuel, the valves are configured to deliver a mixture of the first fuel and a quantity of water to the plurality of outlets, and to deliver a quantity of water to the plurality of spray cones, and to selectively activate one or more of the stages to allow passage through only the spray cones of the activated stages.
In another construction, a gas turbine engine operable using either one of a first fuel and a second fuel includes a water supply and a diffusion flame burner including an innermost spray cone, a plurality of spray cones positioned around the innermost spray cone and grouped into a first quantity of stages, and a plurality of outlets positioned around the innermost spray cone. The engine also includes a first quantity of water flow paths, each one of the water flow paths positioned to connect the water supply to one and only one of the stages of the first quantity of stages and a first quantity of fuel flow paths, each one of the fuel flow paths positioned to direct the second fuel to one and only one of the stages of the first quantity of stages. The engine also includes a first quantity of water valves, each one of the water valves positioned in one and only one water flow path and a first quantity of fuel valves, each one of the fuel valves positioned in one and only one fuel flow path. A controller operates when the gas turbine is consuming the first fuel to close each of the fuel valves and to selectively open one or more of the water valves, and when the gas turbine is consuming the second fuel to close each of the water valves and to selectively open one or more of the fuel valves.
In yet another construction, a gas turbine engine operable using either one of a first fuel and a second fuel includes a water supply, a sensor operable to measure a turbine parameter, and a diffusion flame burner including, an innermost spray cone, a plurality of spray cones positioned around the innermost spray cone and grouped into a first quantity of stages, and a plurality of outlets positioned around the innermost spray cone. A controller operates to determine which of the first fuel and the second fuel is being consumed by the gas turbine engine. The controller directs one of the first fuel and a mixture of the first fuel and water to the outlets and selectively activates one or more of the first quantity of stages at least partially in response to the measured turbine parameter to deliver water through the activated spray cones when the first fuel is being consumed, and selectively directs water to the innermost spray cone and selectively activates one or more of the first quantity of stages at least partially in response to the measured turbine parameter to deliver the second fuel through the activated spray cones when the second fuel is being consumed.
The invention is explained in the following description in view of the drawings that show:
The present inventors have recognized several limitations of the conventional diffusion flame burner used to inject oil and atomizing water into the combustor during an oil mode operation of the gas turbine engine or to inject a premixture of natural gas and water and atomizing water into the combustor during a gas mode operation of the gas turbine engine. As appreciated by one skilled in the art, the level of NOx (Oxides of Nitrogen) is proportional to a combustion temperature within the combustor 11, and is subject to rigorous industrial standards. When operating in the oil mode, in addition to atomizing the oil injected from the central nozzle 30, the injected water from the atomizing holes 12 reduces the local flame zone temperature within the combustor 11, and thus advantageously reduces the production of NOx within the combustor 11. However, the present inventors recognized various adverse effects of the injected water from the atomizing holes 12, including that the injected water follows a jet-like stream which escapes the flame area, strikes the inner surface of the combustor 11, resulting in undesired water cold spot damage to the inner surface of the combustor 11. Additionally, the present inventors recognized that the injection pressure of the water from the atomizing holes 12 is not optimal for the atomization of the oil at all power levels. Specifically, at low power levels, the flow rate of water is low and the injection pressure of water is low from the atomizing holes 12, which may be insufficient to atomize the injected oil from the oil nozzle 30.
Thus, the present inventors have developed an improved diffusion flame burner operating in the oil mode, which injects the atomizing water into the combustor with a swirl cone-like spray, as opposed to the jet-like stream of the conventional diffusion flame burner, thereby increasing the tendency of spray water to self-atomize early and hence reducing the impact of the atomizing water with the inner surface of the combustor 11. The hollow cone-like spray diffuses the water over a wider area, thereby enhancing the atomization of the oil with the injected water. Additionally, since the cone-like spray spreads the water out over a wider area, the impact of the spray (i.e., force per unit area) with the inner surface of the combustor is reduced. Such spray nozzles that form cone-like sprays are available, such as Swirl type nozzle provided by Parker Hannifin Company, for example.
Additionally, when operating in the gas mode, the improved diffusion flame burner provides water injection through staged nozzles, thereby ensuring an optimal injection pressure of the water, over a wide range of injection parameters of the premixture of natural gas and water. For example, the improved diffusion flame burner provides water injection through the circumferentially staged nozzles at the optimal injection pressure, over a wide range of flow rates of gas to the primary outlets, thereby ensuring atomization of the injected secondary stage water over the wide range of gas flow rates. This improves water and gas mixing which ultimately improves NOx.
During the gas mode operation of the gas turbine engine 136, a water line 123 supplies water from the water supply 122 through one or more stage valves 160, 162, 164, 166 and to the diffusion flame burner 110 within the combustor 111. A controller 150 is connected to the stage valves 160, 162, 164, 166, and selectively opens one or more of the stage valves 160, 162, 164, 166, so that the water supplied from the water supply 122 passes through the one or more opened stage valves and to the diffusion flame burner 110. Additionally, a combined water and natural gas line 129 supplies a combination of water from the water supply 122 and natural gas from the natural gas supply 128 to the diffusion flame burner 110 within the combustor 111.
During an oil mode operation of the gas turbine engine 136, water lines 123, 127 supplies water from the water supply 122 to the diffusion flame burner 110 within the combustor 111. Additionally, during the oil mode, an oil line 125 supplies oil from the oil supply 124 through one or more stage valves 170, 172, 174, 176 and to the diffusion flame burner 110 within the combustor 111. The controller 150 is connected to the control valves 170, 172, 174, 176, and selectively opens one or more of the stage valves 170, 172, 174, 176, so that oil supplied from the oil supply 124 passes through the one or more opened stage valves and to the diffusion flame burner 110. As illustrated in
During the gas mode operation of the gas turbine engine 136, the outlets 134 of the diffusion flame burner 110 are attached to the water supply 122 and the natural gas supply 128 along the combined water and gas line 129 of
During the oil mode operation of the gas turbine engine 136, the central spray cone 130 positioned at the center 132 of the spray cones 112 is attached to the water supply 122 along the water lines 123, 127 of
Although
During the gas mode operation, the outlets 134 inject the water/natural gas premixture and the spray cones 112 inject the water at a sufficient flow rate and at the optimal injection pressure, to atomize the natural gas and to reduce the combustion temperature of the water/natural gas premixture within the combustor 111. To inject the water at the sufficient flow rate, the controller 150 opens a sufficient number of the stage valves 160, 162, 164, 166 so that a sufficient number of stages 114, 116, 118, 120 of the spray cones 112 are activated, resulting in a sufficient flow rate of water through the spray cones 112. During the gas mode, the injected water through the number of activated stages of the spray cones 112 is injected at the optimal injection pressure, to reduce the combustion temperature of the water/natural gas premixture within the combustor 111.
If the controller 150 determines that the gas turbine engine 136 is to operate in the gas mode, the controller 150 selectively activates one or more stages 114, 116, 118, 120 of the spray cones 112 by selectively opening one or more of the stage valves 160, 162, 164, 166, along with the other control steps for the gas mode discussed herein. If the controller 150 determines that the gas turbine engine 136 is to operate in the oil mode, the controller selectively activates the one or more stages 114, 116, 118, 120 of the spray cones by selectively opening one or more of the stage valves 170, 172, 174, 176 along with the other control steps for the oil mode discussed herein. The input sensor 168 may be a flow rate sensor to measure a flow rate of the oil through the oil line 125, a pressure sensor to measure a pressure of an air flow 154 (
While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.
Number | Date | Country | |
---|---|---|---|
Parent | 14470014 | Aug 2014 | US |
Child | 16381111 | US |