The present disclosure provides systems and methods for power production. In particular, the systems and methods utilize the addition of heat to an expanded turbine exhaust stream in order to increase the available quantity of heat for recuperation and use therein for heating a compressed carbon dioxide stream for recycle back to a combustor of the power production system and method.

The present disclosure relates to a novel gas turbine system having applications, for example, in thermal power generation in an environmentally friendly manner. The multiloop gas turbine system may have multiple functional units each comprising a compressor, a regenerator, a combustion unit, and a turbine. Typically, exhaust flow of a turbine of a preceding loop may be routed to the combustion unit of the next loop, allowing mixing of exhaust flow with hot compressed air of the next loop, and the expanded exhaust from the turbine of the ultimate loop is fed back into the regenerators of each loop to recover exhaust heat.

A combined cooling, heating and power system is formed by integrating a CO.sub.2 and ORC cycle systems, and an LNG cold energy utilization system on the basis of an SOFC/GT hybrid power generation system. The combined systems provide utilization of energy and low carbon dioxide emission. The SOFC/GT is used as a prime mover, high-temperature, medium-temperature, and low-temperature waste heat of the system are recovered through a CO.sub.2 and ORC cycles, cold energy (for air conditioning and refrigeration), heat, power, natural gas, ice, and dry ice is provided by using LNG as a cold source of the CO.sub.2 cycle and the ORC cycle, and low carbon dioxide emission of the system is achieved by condensation and separation of CO.sub.2 from flue gas, so energy losses of the combined system is reduced, and efficient and cascade utilization of energy is achieved, thereby providing energy conservation and emission reduction effect.

A control method of a centrifugal compressor (C) mechanically coupled to an expansion turbine (TorC), the centrifugal compressor (C) being provided with at least a control system (20) of the absorbed power. The control method of the rotation speed of the turbine-centrifugal compressor group performs the following steps: acting on the centrifugal compressor control system (20) of the absorbed power by means of a first controller (PID-f), in order to keep constant the rotational speed of the compressor mechanically coupled to the expansion turbine; ensuring that the centrifugal compressor (C) remains in a stable operating condition by means of an admission valve (Vi) of the expansion turbine (TorC).

The invention relates to a shaft-hub connection (1), particularly for mounting a rotor wheel on a shaft (10). The shaft-hub connection (1) comprises a shaft (10), a hub (20) and a filler material (30). The shaft (10) comprises an end section (11) on one end. A receiving region (21) is arranged in the hub (20). The end section (11) is arranged in the receiving region (21), with an intermediate layer of the filler material (30) positioned inbetween. The filler material (30) forms undercuts in the axial and rotational direction, in relation to the end section (11) and in relation to the receiving region (21), so as to create a positive embodiment of the shaft-hub connnection (1).

Cogeneration system (200, 300) comprising: a boiler (201, 301) able to heat water for domestic use; a combustor (201a, 301a) placed into the boiler; a compressor (204, 304); a heat exchanger (202, 302) for the exchange of thermal energy between the combustion fumes generated in the combustor (201a, 301a) and a fluid coming from the compressor (204, 304); a gas turbine (203, 303); a current generator (205, 305) and a current converter (206, 306) able to produce electrical energy; a main fumes/water exchanger (207, 307) able to recover thermal energy.

The cogeneration system (200, 300) comprises also a by-pass valve (210, 310) configured to adjust the flow of fluid entering the gas turbine (203, 303).

A gas turbine engine includes a primary flowpath fluidly connecting a compressor section, a combustor section, and a turbine section. A heat exchanger is disposed in the primary flowpath downstream of the turbine section. The heat exchanger includes a first inlet for receiving fluid from the primary flowpath and a first outlet for expelling fluid received at the first inlet. The heat exchanger further includes a second inlet fluidly connected to a supercritical CO2 (sCO2) bottoming cycle and a second outlet connected to the sCO2 coolant circuit. The sCO2 bottoming cycle is a recuperated Brayton cycle.

A gas turbine engine includes a first shaft coupled to a first turbine and a first compressor, a second shaft coupled to a second turbine and a second compressor, and a third shaft coupled to a third turbine and a fan assembly. The turbine engine includes a heat rejection heat exchanger configured to reject heat from a closed loop system with air passed from the fan assembly, and a combustor positioned to receive compressed air from the second compressor as a core stream. The closed-loop system includes the first, second, and third turbines and the first compressor and receives energy input from the combustor.

Power is produced by operating first and second nested cycles utilising CO.sub.2 as working fluid without mixing of working fluid between the nested cycles. The first cycle comprises a semi-open loop operating under low pressure conditions in which CO.sub.2 is sub-critical. The second cycle comprises a closed loop operating under higher pressure conditions in which CO.sub.2 is supercritical. The first cycle operates in a Brayton cycle including oxycombustion of hydrocarbons, preferably LNG, in a combustion chamber under low pressure conditions, expansion for power production to provide a first power source, cooling in a recuperator, compression, reheating by counter-current passage via the recuperator, and return of working fluid heated by the recuperator back to the combustion chamber. Water and excess CO.sub.2 resulting from the oxycombustion step are separated from the first cycle. The first cycle serves as a source of heat for the second cycle by gas/gas heat exchange in a gas/gas heat exchanger which results in cooling of the products of combustion and circulating working fluid in the first cycle and heating of working fluid in the second cycle. The second cycle is operated in a Brayton cycle including heating of working fluid in the second cycle by the gas/gas heat exchanger, expansion for power generation to provide a second power source, cooling in two-stages by first and second recuperator steps, compression, reheating by counter-current passage via the first recuperator step, and return of working fluid heated by the first recuperator step back to the gas/gas heat exchanger. Working fluid in the first cycle following the compression step is heated by working fluid in the second cycle by counter-current passage via the second recuperator step.

The present disclosure relates to a power generation system and related methods that use supercritical fluids, whereby a portion of the supercritical fluid is recuperated.