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.

Clean combustion and equilibration equipment and methods are provided to progressively deliver, combust and equilibrate mixture of fuel, oxidant and aqueous diluent in a plurality of combustion regions and in one or more equilibration regions to further progress oxidation of products of incomplete combustion, in a manner that sustains combustion while controlling temperatures and residence times sufficiently to reduce CO and NOx emissions to below 25 ppmvd, and preferably to below 3 ppmvd at 15% O.sub.2.

A combustor includes an outer cylinder, a combustor liner, a plurality of main nozzles, an air flow channel part, and a plurality of water injection parts. The air flow channel part sends air introduced from an outside to between an inner peripheral surface of the outer cylinder and an outer peripheral surface of the combustor liner into the combustor liner. The plurality of water injection parts are provided on the inner peripheral surface of the outer cylinder at intervals in a circumferential direction around a central axis. The plurality of water injection parts inject water into the air flowing through the air flow channel part. The water injection part includes a first nozzle and a second nozzle. The first nozzle injects water to a first side in the circumferential direction. The second nozzle injects water to a second side in the circumferential direction.

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.

A combustor includes an outer cylinder, a combustor liner, a plurality of main nozzles, an air flow channel part, and a plurality of water injection parts. The air flow channel part sends air introduced from an outside to between an inner peripheral surface of the outer cylinder and an outer peripheral surface of the combustor liner into the combustor liner. The plurality of water injection parts are provided on the inner peripheral surface of the outer cylinder at intervals in a circumferential direction around a central axis. The plurality of water injection parts inject water into the air flowing through the air flow channel part. The water injection part includes a first nozzle and a second nozzle. The first nozzle injects water to a first side in the circumferential direction. The second nozzle injects water to a second side in the circumferential direction.

The present disclosure provides for improving flame propagation in a combustor, particularly in a combustor for use in a power production system and method. At least one stream being passed into the combustor (e.g., a fuel, an oxidant, a diluent, a coolant, a working fluid, water, or steam) can be independently heated to a temperature that is about the autoignition temperature of the fuel or greater. Further, flame stabilization, including promoting ignition, can be improved as described herein through controlled addition of one or more NOx species into the combustor or combustion chamber.

A combustion chamber assembly unit for a fuel-operated vehicle heater includes a combustion chamber housing (14) elongated in a direction of a housing longitudinal axis (L), with a combustion chamber (16) radially outwardly bounded by a circumferential wall (18), and with a combustion chamber bottom (20) axially delimiting the combustion chamber (16). A combustion air feed volume (36) is provided that is open to the combustion chamber (16) via a plurality of passage openings (38). A cooling medium feed device (46) is provided for feeding a liquid cooling medium to the combustion air feed volume (36).

According to the present invention, in a heating furnace in which a fuel is burned by mixing the fuel supplied through a fuel supply pipe with combustion air supplied through a combustion air supply pipe by a combustion burner, a cooling medium guiding pipe through which cooling air for cooling the fuel supply pipe is guided into the furnace is provided to the outer peripheral side of the fuel supply pipe, and a cooling water supply pipe through which cooling water is supplied via a cooling water adjusting valve is connected to the cooling medium guiding pipe.

A combustion chamber assembly unit for a fuel-operated vehicle heater includes a combustion chamber housing (14) elongated in a direction of a housing longitudinal axis (L), with a combustion chamber (16) radially outwardly bounded by a circumferential wall (18), and with a combustion chamber bottom (20) axially delimiting the combustion chamber (16). A combustion air feed volume (36) is provided that is open to the combustion chamber (16) via a plurality of passage openings (38). A cooling medium feed device (46) is provided for feeding a liquid cooling medium to the combustion air feed volume (36).

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.