A combustible ice efficient combustion system comprises a combustible ice storage unit and a combustion unit, the front end of the furnace of the combustion unit is provided with a combustor, the rear end of the furnace of the combustion unit is connected with a flue gas main pipe, the combustor is provided with a first fuel gas inlet, a second fuel gas inlet, a combustion-supporting gas inlet and a flue gas outlet, the first fuel gas inlet is provided with a combustion nozzle, the combustion nozzle is provided with a first gas inlet, a second gas inlet and a mixed gas outlet, the first gas inlet is connected with the combustible ice storage unit through a high-pressure natural gas pipeline, the second gas inlet is connected with an air source, and the mixed gas outlet is connected with the first fuel gas inlet of the combustor.

A method for transferring thermal energy to a separate endothermic process includes: (a) providing a carbon dioxide (CO.sub.2) stream and a carbonaceous fuel to a heater; (b) reacting the carbonaceous fuel in the heater to produce a heated stream; (c) transferring heat from the heated stream to the separate endothermic process; (d) separating the CO.sub.2 stream from the heated stream after (c); and (e) recycling the CO.sub.2 stream to the heater after (d).

Emissions of NO.sub.X and/or CO are reduced at the stack by systems and methods wherein a primary fuel is thoroughly mixed with a specific range of excess combustion air. The primary fuel-air mixture is then discharged and anchored within a combustion chamber of a burner. Further, the systems and methods provide for dynamically controlling NO.sub.X content in emissions from a furnace by adjusting the flow of primary fuel and of a secondary stage fuel, and in some cases controlling the amount or placement of combustion air into the furnace.

A burner and methods of using the burner. The burner utilizes bypass conduits to separate the combustion air that is passed to the primary combustion zone into two or more portions. The two portions are injected into the primary combustion zone at different points so as to reduce the flame temperature. A NOx reducing medium may be mixed with the combustion air in the bypass conduit. The NOx reducing medium may be flue gases from a combustion chamber having the primary combustion zone.

A burner and methods of using the burner. The burner utilizes bypass conduits to separate the combustion air that is passed to the primary combustion zone into two or more portions. The two portions are injected into the primary combustion zone at different points so as to reduce the flame temperature. A NOx reducing medium may be mixed with the combustion air in the bypass conduit. The NOx reducing medium may be flue gases from a combustion chamber having the primary combustion zone.

The leakage reduction system includes a heat exchanger, a duct arrangement and a separation arrangement. The heat exchanger includes a rotor assembly rotatably mounted along a rotor post. The heat exchanger further includes a second inlet plenum, whereat the duct arrangement is configured. Further, the separation arrangement is incorporated at the duct arrangement dividing thereto into primary and secondary inlets. Through the primary inlet, a flue gas enriched with Oxygen is carried, and through the secondary inlet a recycled flue gas flow is allowed to be carried, keeping the Oxygen enriched recycled flue gas flow substantially away from turnover towards the flue gas flow to avoid turnover towards a flue gas flow, reducing leakage thereof.

The leakage reduction system includes a heat exchanger, a duct arrangement and a separation arrangement. The heat exchanger includes a rotor assembly rotatably mounted along a rotor post. The heat exchanger further includes a second inlet plenum, whereat the duct arrangement is configured. Further, the separation arrangement is incorporated at the duct arrangement dividing thereto into primary and secondary inlets. Through the primary inlet, a flue gas enriched with Oxygen is carried, and through the secondary inlet a recycled flue gas flow is allowed to be carried, keeping the Oxygen enriched recycled flue gas flow substantially away from turnover towards the flue gas flow to avoid turnover towards a flue gas flow, reducing leakage thereof.

Exemplary arrangements relate to a method for incinerating waste on a combustion grate of a furnace and an apparatus for carrying out such a method. Oxygen mixed with carrier gas is supplied to the combustion for incineration as an oxygen and carrier gas mixture. The carrier gas comprises recirculated combustion gas from the furnace and may have a CO.sub.2 concentration of from 10% to 99%.

[Problems to be Solved] An exhaust duct (4) for assembly into a combustion apparatus has: a burner (1) to eject air-fuel mixture downward; and a combustion box (3) disposed on a lower side of the burner (1). The exhaust duct includes: a riser duct section (42) elongated in a vertical direction and having, at a lower portion thereof, an inlet port (41) connected to an exhaust port (35) for combustion gas which is opened in a lower portion of the combustion box (3); and a flat horizontal duct section (43) bent at an upper end of the riser duct section (42) so as to be elongated forward. By restraining the resonance of an upper wall part (431) and a lower wall part (432) of the horizontal duct section (43), noises due to resonance sounds are reduced.

[Solving Means] The natural frequencies in an upper wall part (431) and the lower wall part (432) of the horizontal duct section (43) are varied from each other. For example, the lower wall part (432) is fixed to a burner body (11) in order to vary the natural frequencies of the upper wall part (431) and of the lower wall part (432) from each other.

A fuel nozzle for a combustor of an aircraft engine includes a nozzle body defining an a fuel passage, extending therethrough between a fuel inlet and a fuel outlet located at the outlet end that at least partially defines a nozzle tip, for directing a fuel flow into the combustor via the nozzle tip. A core air passage extends through the nozzle body for directing a core air flow into the combustor via the nozzle tip. At least two flow restrictors are disposed in series within the core air passage, the flow restrictors including an upstream flow restrictor and a downstream flow restrictor each having an orifice therein. The restricted air flow passage having a cross-sectional area smaller than that of the core air passage. The orifice in the upstream flow restrictor being at least partially offset from the orifice in the downstream flow restrictor.