Abstract: In a catalytic combustor for gas turbines, the dimensions of the preheater and premix duct, the location of the preheater and premix fuel nozzles, and the number and location of air orifices in the combustor can inner liner are configured to result in low NOx production during both preheating combustion and catalytic combustion. Placement of the air orifices helps reduce the potential for autoignition within the premix duct, while enhancing fuel-air mixture uniformity upstream of the catalyst. At the same time, the overall configuration is optimized to result in the relative compactness of the catalytic combustor, making it particularly suitable for applications such as automotive turbine engines and microturbines.

Abstract: A prime mover such as a microturbine generator is operated to generate dc power, and an inverter is controlled to convert the dc power to ac power. The ac power is supplied to an electric motor. The frequency of the ac power is ramped up during motor startup to reduce motor inrush current. The frequency or current of the ac power may be varied in response to process requirements during normal operation of the motor.

Abstract: A microturbine power generating system includes a battery source for providing startup power. Dc power provided by the battery source is converted to three-phase ac power, and the three-phase ac power is supplied to stator windings of an electrical generator of the system. The three-phase ac power causes the electrical generator to operate as a starter motor. An up chopper may be used to reduce the required voltage of the battery source. A down chopper may be used to charge the battery source during normal operation of the microturbine power generating system. The down chopper can allow the battery source to supply backup power in the event the electrical generator experiences a failure.