Abstract: The present invention is embodied in a heat exchanger, which allows differential thermal expansion of its elements while providing a bypass seal. In at least one embodiment, the heat exchanger includes, a shell for containing a first gas, a core positioned within the shell, and a seal positioned between the core and the shell. The seal allows at least some differential expansion between the shell and the core while restricting the flow of the first gas past the seal. This allows a space for expansion of the core to exist between the core and the shell, while preventing the first gas from bypassing the core by traveling through the expansion space. As such, the seal forces the first gas to pass through the core, greatly increasing heat transfer from the first gas to the core. Preferably, the seal is mounted to the core at a position at least adjacent to the free (moveable) end or ends of the core. The seal can be folded into several layers such that the folds abut both the core and the shell.

Abstract: A turbocharger having an electric motor for assisting spin up of the rotor employs a shaft carrying the turbine and compressor impeller with a unitary pinned semi-floating bearing supporting the shaft and a spacer collar carrying the electric motor magnet. The unitary bearing has integral thrust faces engaging a hub of the turbine wheel and the spacer collar. A reduced diameter of the shaft received in the spacer collar allows the collar to engage a greater diameter bearing land allowing the attachment of the compressor impeller with a nut on the shaft extending through a bore in the impeller to firmly engage the impeller, spacer collar and bearing land of the shaft to fix the rotor length. The pinned semi-floating bearing with integral thrust faces provides enhanced reaction moments for negative spring forces created by the electric motor in operation and the additional length of the rotor created by the motor.

Abstract: An Exhaust Gas Recirulation (EGR) valve is integrated onto a turbocharger by providing an EGR outlet in a flange in the volute of the turbine housing and a mating valve assembly extending from a mating flange with an elbow. The outlet direction of the elbow is adjustable to a plurality of directions by positioning the mating flange relative to the EGR outlet flange.

Abstract: A vane and post arrangement for a variable geometry turbocharger employs vanes having a hole in a first end surface receiving a post extending from a surface of the nozzle in the turbine housing. A second end surface on each vane incorporates an extending tab which is received in a respective slot in a unison ring for rotation of the vanes on the posts upon movement of the unison ring.

Abstract: A combustor dome for use in a combustor has an igniter mounted in a central bore. Moving outward from the bore is a concentric pilot fuel passageway. Concentric about the pilot fuel passageway is an air passageway. Lastly, concentric about the air passageway is a premix passageway. The outlets of the pilot fuel passageway, the air passageway, and the premix passageway are generally coplanar.

Abstract: A power generating system, including a first shaft, a first compressor, a second compressor and a turbine. In a further embodiment, the system also includes a second turbine, a second shaft and a generator. Each of the first compressor, the second compressor and the turbine are connected to the first shaft whereby the first shaft, the first compressor, the second compressor and the turbine all rotate at the same speed. The first compressor and second compressor are of disparate flow types.

Abstract: A load site voltage regulation control system. The load site receives electrical power from a utility over transmission lines. The load site also receives electrical power from a local generator unit operating with an inverter. The local generator unit and inverter arc coupled to the load by an EMI filter and a transformer. Voltage at the load is controlled by adjusting the inverter voltage using an inverter voltage command. The inverter voltage command is based on load voltage, inverter voltage, EMI filter voltage, utility supplied current, and inverter current. In one embodiment, the inverter voltage is adjusted to minimize utility supplied reactive and real power and to actively dampen EMI filter voltage, with the inverter voltage command being developed though a multi-loop PPI control system.

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 load site voltage regulation control system. The load site receives electrical power from a utility over transmission lines. The load site also receives electrical power from a local generator unit operating with an inverter. The local generator unit and inverter are coupled to the load by an EMI filter and a transformer. Voltage at the load is controlled by adjusting the inverter voltage using an inverter voltage command. The inverter voltage command is based on load voltage, inverter voltage, EMI filter voltage, utility supplied current, and inverter current. In one embodiment, the inverter voltage is adjusted to minimize utility supplied reactive and real power and to actively dampen EMI filter voltage, with the inverter voltage command being developed though a multi-loop PPI control system.

Abstract: A rotating group for a microturbine power generation system includes an electrical generator rotor, a turbine and a compressor intermediate the generator and the turbine. The turbine, compressor and electrical generator rotor are secured together by a tieshaft. The tieshaft is prestressed such that faces of the turbine, electrical generator rotor and compressor maintain contact during high-speed, high-temperature operation of the system.

Abstract: A power generation system includes multiple generators that are operated in parallel. An inverter of one of the generators is always operated in voltage mode. Inverters of the other generators are switched between voltage and current modes.

Abstract: A microturbine power generation system includes an electrical generator, a turbine and a compressor intermediate the generator and the turbine. Rotating components of the turbine, compressor and electrical generator are secured together by a tie-bolt. The tie-bolt is pre-stressed such that faces of the rotating components of the turbine, electrical generator and compressor maintain contact during high-speed, high-temperature operation of the system. The tie-bolt includes a thermally less conductive short portion that is secured to the rotating component of the turbine wheel, and an elongated portion that extends through the rotating components of the compressor and electrical generator. The short, thermally less conductive portion of the tie-bolt inhibits heat from propagating from the turbine end towards the compressor. The short, thermally less conductive portion can be a titanium rod that is inertia-welded between the elongated portion of the tie-bolt and the rotating component of the turbine.

Abstract: A microturbine power generating system includes a reservoir that is pressurized with compressor air during system operation. The pressurized air in the reservoir is used to purge combustor fuel nozzles of residue after combustion in the combustor has ceased.

Abstract: A microturbine engine core with gas bearings used to support a rotating group is provided, including air flow control devices downstream of the gas bearings to maintain high pressures. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 C.F.R. 1.72(b).

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 microturbine power generation system includes an electrical generator, a turbine and a compressor intermediate the generator and the turbine. The turbine, compressor and electrical generator are secured together by a tieshaft. The tieshaft is prestressed such that faces of the turbine, electrical generator and compressor maintain contact during high-speed, high-temperature operation of the system.

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 generating system includes an electrical generator and a turbine having a fixed inlet nozzle geometry. Maximum thermodynamic efficiency of the microturbine power generating system is achieved by maintaining the turbine inlet at or near maximum temperature. When power demanded of the system is constant, power is supplied by the electrical generator. When an increase in power is demanded, at least a portion of the entire demand is supplied by a battery or other energy storage device until the electrical generator can satisfy the increased power demand. Conversely, when a decrease in power is demanded, the load on the generator is temporarily increased (effectively putting a brake on the generator and turbine) and such load is absorbed by the battery or other energy storage device.

Abstract: A microturbine power generation system includes an electric generator, a rectifier for rectifying an output of the electric generator, and an inverter for up-chopping an output of the rectifier. The inverter can also be controlled to provide an excitation current to windings of the electric generator. The excitation current causes the electric generator to operate as a motor. The electric generator can be operated as a starter motor for the system.