Abstract: A heat exchanger having a cold side flow path adjacent to and thermally coupled with a hot side flow path or other heat source, such that heat is transferred to the cold side flow path; and means for introducing evaporative fluid into the cold side flow path.

Abstract: A microturbine power generation system includes an electrical generator, a turbine, a compressor and a combustor. Hot expanding gases leaving the combustor are expanded by the turbine. The resulting turbine power is used for driving the compressor and the electrical generator. A recuperator recovers heat from a turbine exhaust stream and raises the temperature of compressed air prior to combustion. Fluid injection is accomplished in the system by using one or more nozzles to spray small fluid droplets, on the order of hundreds of microns or less in diameter, into the combustion air either upstream or downstream of the compressor, or both. The evaporative effect of the injected fluid is used to cool the generator components and to increase the effectiveness of the recuperator. The injected fluid also adds mass to the hot, expanding gases entering the turbine.

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 primary compressor, an electrical generator and a turbine that can be rotated as a unit. Hot, expanding gases resulting from combustion are expanded through the turbine, and the resulting turbine power is used for powering the electrical generator. The microturbine power generating system further includes an auxiliary compressor that is driven by the turbine power. During operation of the system, a small portion of air can be bled off the primary compressor and further compressed in the auxiliary compressor to provide an auxiliary supply of pressurized air. The heat of high pressure compression is recovered to increase the overall efficiency of the machine.

Abstract: A microturbine power generation system includes a turbine having a diffuser. A plurality of openings are located in the diffuser. When an exhaust stream is leaving the turbine, ambient air is drawn through the openings and into the turbine exhaust stream. The ambient air lowers the temperature of the turbine exhaust stream.

Abstract: A system for generating electricity comprises a fuel cell, a heating stage, and an integral, power generator. The power generator comprises a compressor, an electricity generator and a turbine. Hot exhaust gas from the fuel cell is used for driving the turbine, which in turn drives the generator and the compressor. Both the fuel cell and the generator produce electricity. The compressor is used for compressing air for use in the fuel cell. A portion of the waste heat from the turbine drive gas is used for preheating the air utilized in the fuel cell.