The objective of this work is to explore methods to reduce combustor rumble in a water-injected gas turbine. Attempts to\r\nuse water injection as a means to reduce NOX emissions in gas turbines have been largely unsuccessful because of increased\r\ncombustion instability levels. This pulsation causes chronic fretting, wear, and fatigue that damages combustor components. Of\r\ngreater concern is that liberated fragments could cause extensive damage to the turbine section. Combustion instability can be tied\r\nto the insufficient atomization of injected water; large water droplets evaporate non-uniformly that lead to energy absorption in\r\nchaotic pulses. Added pulsation is amplified by the combustion process and acoustic resonance. Effervescent atomization, where\r\ngas bubbles are injected, is beneficial by producing finely atomized droplets; the gas bubbles burst as they exit the nozzles creating\r\nadditional energy to disperse the liquid. A new concept for effervescent atomization dubbed ââ?¬Å?flash atomizationââ?¬Â is presented where\r\nwater is heated to just below its boiling point in the supply line so that some of it will flash to steam as it leaves the nozzle. An\r\nadvantage of flash atomization is that available heat energy can be used rather than mechanical energy to compress injection gas\r\nfor conventional effervescent atomization.
Loading....