A combined cycle power plant is capable of improving power output and power generation efficiency by cooling intake air supplied to a gas turbine. The plant includes a gas turbine power generation system, an operating fluid power generation system, and a cooling system. The gas turbine power generation system includes an air compressor for compressing air supplied through an air incoming path, a gas turbine for generating rotary power by burning a mixture of fuel and the air compressed by the air compressor, and a first generator for generating electricity by using the rotary power of the gas turbine. The operating fluid power generation system heats an operating fluid by using combustion gas discharged from the gas turbine and generates electricity using the heated operating fluid. The cooling system cools air supplied from the air compressor by supplying the operating fluid to an upstream side of the air compressor.

Provided herein is a power generation system and method for transforming thermal energy, such as waste heat, into mechanical energy and/or electrical energy. The system employs features designed to accelerate start times, reduce size, lower cost, and be more environmentally friendly. Tire system may include multiple compressors on separate pinion shafts with multiple expanders, a temperature valve upstream of compressors with a mass management system downstream, an intercooler between compressors, and a cascade exchanger. In one embodiment, the system is configured to drive a synchronous generator, with the separate pinion shafts rotating at two separate, but constant, speeds.

Systems and methods for transferring and converting heat to a power cycle using a plurality of heat transfer fluids, loops and heat exchange devices to convert heat to useful work and/or power. Power is generated using intermediate heat transfer loops (IHTL) and an intermediate heat transfer fluid (IHTF) to cool the hot exhaust power cycle fluid (PCF) stream that is at or above its critical conditions. The temperature of the IHTF can be increased by 100° C., 150° C., 200° C., 250° C., 300° C., 350° C., 400° C., 450° C., 500° C., 550° C. or more by exchanging heat with the PCF, either directly or indirectly.

The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

Power generation systems are described. The systems include a shaft, a compressor operably coupled to a first end of the shaft, a turbine operably coupled to a second end of the shaft, a generator operably coupled to the shaft between the compressor and the turbine, and a working fluid arranged in a closed-loop flow path that flows through each of the compressor and the turbine to drive rotation of the shaft. The shaft includes an internal fluid conduit configured to receive a portion of the working fluid at one of the first end and the second end and convey the portion of the working fluid through the generator to the other of the first end and the second end, wherein the portion of the working fluid is rejoined with a primary flow path of the working fluid.

An assembly with a piston reciprocated with the aid of a floating head in fluid communication with the piston. The assembly may utilize a floating head that is shifted in position to promote reciprocation of the piston through the aid of pressure supplied to the floating head from a pressure volume regulator. Alternatively, the floating head may be in fluid communication with the piston at one side of the head and isolated at the other side. In this manner changing volume and pressure at this other side of the head during reciprocation may ultimately lead to floating head movement toward the piston, thereby promoting the continued reciprocation. Additional efficiencies may also be realized through unique hydraulic layouts for both operating and working fluid circulations.

An energy storage plant includes a casing for the storage of a working fluid other than atmospheric air, in a gaseous phase and in equilibrium of pressure with the atmosphere; a tank for the storage of said working fluid in a liquid or supercritical phase with a temperature close to the critical temperature; wherein said critical temperature is close to the ambient temperature. The plant is configured to carry out a closed thermodynamic cyclic transformation, first in one direction in a charge configuration and then in the opposite direction in a discharge configuration, between said casing and said tank; wherein in the charge configuration the plant stores heat and pressure and in the discharge configuration generates energy.

The systems and methods described herein integrate a supercritical fluid power generation system with a LNG production/NGL separation system. A heat exchanger thermally couples the supercritical fluid power generation system with the LNG production/NGL separation system. A relatively cool heat transfer medium, such as carbon dioxide, passes through the heat exchanger and cools a first portion of extracted natural gas. The relatively warm heat transfer medium returns to the supercritical fluid power generation system where a compressor and a thermal input device, such as a combustor, are used to increase the pressure and temperature of the heat transfer medium above its critical point to provide a supercritical heat transfer medium. A second portion of the extracted natural gas may be used as fuel for the thermal input device.

Electrical/mechanical power is derived from oxycombustion of hydrocarbons, preferably LNG, in a first of two nested cycles each operating on a Brayton cycle to provide a source of power, without mixing of working fluids between the two cycles. Each cycle employs CO.sub.2 as a working fluid, the first cycle operating under low pressure conditions in which CO.sub.2 is sub-critical, and the other cycle operating under higher pressure conditions in which CO.sub.2 is supercritical. The first cycle serves as a source of heat for the second cycle by gas/gas heat exchange which cools the products of combustion and circulating working fluid in the first cycle and heats working fluid in the second cycle.

A turbo generator rotor assembly is provided and includes a generator, first and second bearings on a compressor-side and a turbine-side of the generator and a combination seal configuration in which leakage from the compressor cools the first bearing, the generator and the second bearing. The combination seal configuration leads to minimal leakage past the turbine with the generator and the first and second bearings being cooled with leakage flow from the compressor.