System and method for igniting a combustor

Abstract

An ignition system for a combustor includes an access port through a wall of the combustor and a laser outside the combustor and aligned with the access port to generate a beam along a path. A lens in the path of the beam focuses the beam at a focal point inside the combustor, and a shutter has a first position in the path and a second position out of the path. A method for igniting a combustor includes generating a beam along a path, focusing the beam to a focal point inside the combustor, and moving a shutter from a first position in the path to a second position outside of the path.

Description

FIELD OF THE INVENTION[0001]The present invention generally involves a system and method for igniting a combustor. In particular embodiments, the system and method may employ a laser to provide a focused beam for igniting a fuel in the combustor.BACKGROUND OF THE INVENTION[0002]Combustors are known in the art for igniting fuel with air to produce combustion gases having a high temperature and pressure. For example, gas turbine systems, aircraft engines, and numerous other combustion-based systems include one or more combustors that mix a working fluid such as air with fuel and ignite the mixture to produce high temperature and pressure combustion gases. Each combustor generally includes an igniter to initiate the combustion which then becomes self-sustaining. In addition, the igniter may be used to re-initiate the combustion when needed. For example, gas turbine systems having multiple combustors may occasionally experience an interruption in combustion in a single combustor which, ...

AI Technical Summary

Benefits of technology

"The present invention is an ignition system for a combustor that uses a laser and a shutter to ignite a fuel-air mixture in a controlled manner. The system includes an access port and a laser outside the combustor that generates a beam of laser light that is focused inside the combustor through a lens or a fiber-optic bundle. The shutter is positioned in the path of the beam and can be moved from a first position to a second position to control the ignition. The technical effects of this invention include improved ignition control and efficiency, reduced emissions, and improved safety during combustion processes."

Problems solved by technology

For example, gas turbine systems having multiple combustors may occasionally experience an interruption in combustion in a single combustor which, if not promptly re-ignited, may result in an unanticipated or unscheduled shut down of the gas turbine system.

Inserting the sparkplug into the combustor may interfere with the flow of fuel, air, and combustion gases in the combustor, and increasing the width of the fuel spray to reach the sparkplug may reduce the efficiency of the combustor once combustion is initiated and self-sustaining.

However, the sparkplug may become inoperable in the event the mechanism for extending and retracting the sparkplug malfunctions.

However, foreign object debris, oil, fuel, combustion gases, and other contaminants tend to foul the window or lens over time.

As the window or lens becomes fouled, the window or lens may refract or distort the laser beam.

Moreover, the new focal point of the laser beam may result in damage to the combustor and / or the laser.

Material fouling of the lens surface can produce rapid heating of the lens surface as a result of absorption of the laser energy by the fouling material.

A rapid temperature change at the lens surface can result in permanent degradation or failure of the lens.

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