In one aspect a propulsion system comprises an engine and a drive assembly coupled to the engine, comprising a first driveshaft rotatable in a first direction about a first axis, a first fan coupled to the first driveshaft to rotate in the first direction, and a clutch assembly to selectively disengage the first fan from the first driveshaft. Other aspects may be described.

In one aspect of the present disclosure, a process for producing dean energy from oil bearing reservoirs comprises the steps of: utilizing in-situ combustion to combust oil within an oil-bearing formation so as to generate thermal energy; producing the generated thermal energy to a surface using a purpose-built closed loop well system, the closed loop well system comprising a plurality of horizontal lateral circulation wells to circulate a working fluid between the ground-level surface and the subterranean oil-bearing formation so as to capture the generated thermal energy in the oil-bearing formation and transfer the captured generated thermal energy to the surface; and producing a plurality of combustion products to the surface using a plurality of production wells. A system for operating the process of producing clean energy from oil bearing reservoirs is also provided.

The invention is directed to a turbo-engine, particularly internal combustion engine, comprising a housing and therein a bladeless turbine section (30; 42; 67) of the stacked disc- or Tesla-type construction, wherein the turbine section (30; 42; 67) has a plurality of closely spaced discs (32; 49; 61) arranged for common rotation about a rotation axis in the housing, said turbine section (30; 42; 67) is adapted for passing with tangential flow components a working fluid stream from a radially inner region to a radially outer region of said turbine section (30; 42; 67) while adopting energy from said working fluid stream for rotating the discs (30; 49; 61). Preferably, the turbo-engine further comprises a compressor section (40; 66) of the stacked disc- or Tesla-type construction having a plurality of closely spaced discs (45; 61) arranged for common rotation about said rotation axis and a combustion zone (41; 64), wherein said compressor section (40; 66) being arranged coaxially with—and radially inwardly of the turbine section (30; 42; 67) with the combustion zone (41; 64) provided radially between the compressor section and the turbine section.

Systems and methods are provided for a turbocharger system for use with a process gas capture system. In one example, the turbocharger system comprises: a heat exchanger positioned to receive inlet gas from a gas generating system via a first inlet; a low pressure compressor driven by a low pressure turbine and coupled to a first outlet of the heat exchanger; a mid-pressure compressor driven by a mid-pressure turbine and coupled in series with the low pressure compressor, the mid-pressure compressor configured to receive low pressure compressed gas from the low pressure compressor; and a high pressure compressor driven by a high pressure turbine and coupled in series with the mid-pressure compressor, the high pressure compressor configured to receive mid-pressure compressed gas from the mid-pressure compressor and output high pressure compressed gas to the process gas capture system and a second inlet of the heat exchanger.

Systems and methods are provided for a turbocharger system for use with a process gas capture system. In one example, the turbocharger system comprises: a heat exchanger positioned to receive inlet gas from a gas generating system via a first inlet; a low pressure compressor driven by a low pressure turbine and coupled to a first outlet of the heat exchanger; a mid-pressure compressor driven by a mid-pressure turbine and coupled in series with the low pressure compressor, the mid-pressure compressor configured to receive low pressure compressed gas from the low pressure compressor; and a high pressure compressor driven by a high pressure turbine and coupled in series with the mid-pressure compressor, the high pressure compressor configured to receive mid-pressure compressed gas from the mid-pressure compressor and output high pressure compressed gas to the process gas capture system and a second inlet of the heat exchanger.

Systems and methods are provided for a turbocharger system for use with a process gas capture system. In one example, the turbocharger system comprises: a heat exchanger positioned to receive inlet gas from a gas generating system via a first inlet; a low pressure compressor driven by a low pressure turbine and coupled to a first outlet of the heat exchanger; a mid-pressure compressor driven by a mid-pressure turbine and coupled in series with the low pressure compressor, the mid-pressure compressor configured to receive low pressure compressed gas from the low pressure compressor; and a high pressure compressor driven by a high pressure turbine and coupled in series with the mid-pressure compressor, the high pressure compressor configured to receive mid-pressure compressed gas from the mid-pressure compressor and output high pressure compressed gas to the process gas capture system and a second inlet of the heat exchanger.

Systems and methods are provided for a turbocharger system for use with a process gas capture system. In one example, the turbocharger system comprises: a heat exchanger positioned to receive inlet gas from a gas generating system via a first inlet; a low pressure compressor driven by a low pressure turbine and coupled to a first outlet of the heat exchanger; a mid-pressure compressor driven by a mid-pressure turbine and coupled in series with the low pressure compressor, the mid-pressure compressor configured to receive low pressure compressed gas from the low pressure compressor; and a high pressure compressor driven by a high pressure turbine and coupled in series with the mid-pressure compressor, the high pressure compressor configured to receive mid-pressure compressed gas from the mid-pressure compressor and output high pressure compressed gas to the process gas capture system and a second inlet of the heat exchanger.

A compressed-air energy-storage system is described. The system includes a first compressor arrangement for compressing an air stream; a thermal energy storage unit, where through compressed air from the first compressor arrangement exchanges heat against a heat accumulation means; an air storage device arranged and configured for receiving and accumulating compressed air from the thermal energy storage unit; at least one expander for receiving compressed air from the air storage device and producing useful power therefrom. A further compressor arrangement is located between the thermal energy storage unit and the air storage device.

A compressed-air energy-storage system is described. The system includes a first compressor arrangement for compressing an air stream; a thermal energy storage unit, where through compressed air from the first compressor arrangement exchanges heat against a heat accumulation means; an air storage device arranged and configured for receiving and accumulating compressed air from the thermal energy storage unit; at least one expander for receiving compressed air from the air storage device and producing useful power therefrom. A further compressor arrangement is located between the thermal energy storage unit and the air storage device.

In a conventional screw compressor, two mating rotors which resemble screws are assembled in parallel with each other within a housing. These rotors are very costly to manufacture, and it is very difficult to extract all of the gas that has been compressed between the lobes of the rotor screws. This invention eliminates the twist of the lobes around the rotor of a conventional screw compressor. In this invention, the lobes are manufactured in line with the axis of the rotor (axially). As a result, the costs of manufacturing the rotors are reduced dramatically, and the natural tendency for the gas to be driven towards the center of the female rotor is taken advantage of, making it much easier to extract practically all of the gas that has been compressed between the lobes.