A closed-loop Brayton cycle system utilizes supercritical carbon dioxide as the working fluid for the system to achieve higher efficiencies than can be achieved with traditional open-loop gas turbine engines. A bleed channel is used to direct a flow of cooling fluid to cool the turbine blades during operation of the system, preventing damage to the turbine blades during operation of the system. The bleed channel includes a bleed inlet fluidly coupled between a first recuperator and a second recuperator and a bleed outlet fluidly coupled to the turbine blades. The bleed channel is configured to direct the flow of cooling fluid to the turbine blades at a desired temperature and pressure.

The disclosure concerns a waste heat recovery cycle system and related method in which a Brayton cycle system operates in combination with a Rankine cycle system. The Brayton cycle system has a heater configured to circulate a fluid, namely an inert gas, in heat exchange relationship with a heating source, such as an exhaust gas of a different system, in order to recover waste heat from such different system by heating the inert gas. The Rankine cycle system has a heat exchanger configured to circulate a second fluid, in heat exchange relationship with the inert gas of the Brayton cycle system to heat the second fluid while at the same time cooling the inert gas. The second fluid can be selected among fluids having a boiling point at a temperature lower than the temperature of the inert gas from the expansion unit/group in the Brayton cycle system.

The present disclosure relates to methods for starting and rapidly decelerating a turbomachine in a power generation system that utilizes a supercritical fluid in a closed cycle.

A system for using excess energy of a power generation system and an sCO2 (supercritical carbon dioxide) stream to store and generate power. An air separation unit uses the excess energy to cool and liquify ambient air into liquid nitrogen (L-N2) and liquid oxygen (L-O2). The L-O2 and L-N2 are stored until energy is desired. An L-O2 energy discharge path has an oxygen heat exchanger that vaporizes and heats the oxygen, a combustor that combusts the oxygen and fuel to produce exhaust, and a first turbine is driven by the exhaust to produce energy. An L-N2 energy discharge path has a nitrogen heat exchanger that vaporizes and heats the L-N2, thereby providing expanded nitrogen, and a second turbine is driven by the expanded nitrogen to produce energy. Heat for the heat exchangers on both discharge paths is provided by the sCO2 stream.

The present invention relates to a high pressure process for Pre-Combustion and Post-Combustion CO.sub.2 capture (HP/MP/LP gasification) from a CO.sub.2 gas stream (CO2-Stream) by way of CO.sub.2 total subcritical condensation (CO2-CC), separation of liquid CO.sub.2, higher pressure elevation of obtained liquid CO.sub.2 via HP pump, superheating of CO.sub.2 up to high temperature for driving of a set of CO.sub.2 expander turbines for additional power generation (CO2-PG), EOR or sequestration (First new Thermodynamic Cycle). The obtained liquid CO.sub.2 above, will be pressurized at a higher pressure and blended with HP water obtaining high concentrated electrolyte, that is fed into HP low temperature electrochemical reactor (HPLTE-Syngas Generator) wherefrom the cathodic syngas and anodic oxygen will be performed. In particular the generated HP oxygen/syngas will be utilized for sequential combustion (“H.sub.2/O.sub.2-torches”) for super-efficient hydrogen based fossil power generation (Second new Thermodynamic Cycle).

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

A trans-critical thermodynamic system includes an expansion device and a separator. The expansion device receives a supercritical fluid containing solutes. The expansion device is operable to expand the supercritical fluid to produce a sub-critical gas by reducing a temperature and/or a pressure of the supercritical fluid. The separator removes the solutes from the sub-critical gas.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

Aircraft power plants including combustion engines, and associated methods for recuperating waste heat from such aircraft power plants are described. A method includes transferring the heat rejected by the internal combustion engine to supercritical CO.sub.2 (sCO.sub.2) used as a working fluid in a heat engine. The heat engine converts at least some the heat transferred to the sCO.sub.2 to mechanical energy to perform useful work onboard the aircraft.

A combined cooling, heating and power system is formed by integrating a CO.sub.2 cycle subsystem, an ORC cycle subsystem, and an LNG cold energy utilization subsystem based on an SOFC/GT hybrid power generation subsystem. The combined system can achieve efficient and cascade utilization of energy and low carbon dioxide emission. An SOFC/GT hybrid system is used as a prime mover. High-, medium-, and low-temperature waste heat of the system are recovered through CO.sub.2 and ORC cycles, respectively. Cold energy (for air conditioning and refrigeration), heat, power, natural gas, ice, and dry ice can be provided by using LNG as a cold source of the CO.sub.2 and ORC cycles. Low CO.sub.2 emission is achieved by condensation and separation of CO.sub.2 from flue gas, so energy loss of the system can be reduced, and efficient and cascade utilization of energy can be achieved, thereby realizing energy conservation and emission reduction.