Massachusetts Institute of Technology

Westinghouse Electric Corporation

Gas Research Institute

Eniricerche S.p.a.

Janos M Beer

Majed A Toqan

Arslan Kahn

Jan H Thijssen

Adel F Sarofim

Alessandro Marotta

Charles E Benson

Andrew J Syska

William E Young

Thomas E Dowdy

James A Dilmore

Alberto Beretta

Donald P Moreland

Majed A Togan

Maqed A Toqan

Geza Vermes

A combustor for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone.

Gas turbine topping combustor

An inverse combined steam-gas turbine cycle is disclosed. In the steam cycle, a fuel having a high nitrogen content such as coal or heavy fuel oil is burned in a boiler to raise steam to power a steam turbine. In the gas turbine cycle, a hydrocarbon fuel such as natural gas is burned in a gas combustor to power a gas turbine. The compressed exhaust gas (40. 42) from the steam cycle combustion is introduced into the gas combustor, where nitrogen oxides (NO.sub.x) in the exhaust gas may be reduced through reactions with the hydrocarbon fuel.

Inverse combined steam-gas turbine cycle for the reduction of emissions

Injection of additive such as ammonia or calcium compounds along with a small amount of hydrocarbon, preferably methane or natural gas, in a relatively high temperature region of the effluent stream for effectively reducing pollutants such as NO.sub.x and SO.sub.x. Preferably, injection is achieved by atomization of a liquid-form additive or additive solution with a small amount of gaseous hydrocarbon.

Reduction of combustion effluent pollutants

An apparatus for detecting the presence of polycyclic aromatic hydrocarbons in the effluent of a turbulent commercial combustion system for monitoring or controlling the composition of the effluent. The apparatus is a system for directyl selectively detecting the presence in the effluent high molecular weight polycyclic aromatic compounds having five or more rings by laser induced fluorescence. The system includes an illuminating source of select fluorescence excitation of wavelengths that induces substantial fluorescence by high molecular weight polycyclic aromatic hydrocarbons in the gas phase. Sampling structure is constructed to provide optical access to the effluent stream to sample the effluent stream at a select position where high molecular weight polycyclic aromatic compounds having five or more rings may be present in sufficient amounts that the fluorescence from the effluent at the select position at the excitation wavelength is predominantly from high molecular weight polycyclic aromatic compounds having five or more rings, when the high molecular weight polycyclic aromatic compounds are present in sufficient amounts. A detector detects the fluorescent signal from the illuminated effluent and an analyzer analyzes the signal to directly selectively determine the presence of the high molecular weight polycyclic aromatic hydrocarbons having five or more rings in the effluent.

Apparatus for the detection and control of aromatic compounds in

Low NO.sub.x burners for the combustion of gaseous, liquid and solid fuels. The fluid dynamic principle of radial stratification by the combustion of swirling flow and a strong radial gradient of the gas density in the transverse direction to the axis of flow rotation is used to damp turbulence near the burner and hence to increase the residence time of the fuel-rich pyrolyzing mixture before mixing with the rest of the combustion air to effect complete combustion.

Combustion system for reduction of nitrogen oxides

A gas-fired burner incorporating an air driven jet pump for mixing air, fuel, and recirculated flue gas is disclosed. The burner is configured for the staged introduction of combustion air to provide a fuel-rich combustion zone and a fuel-lean combustion zone. The burner achieves reduced NO.sub.x emission levels in high temperature applications which use preheated combustion air.

Staged air, recirculating flue gas low NO.sub.x burner

Detecting the presence of PAC's in the effluent of a combustions system by detecting the presence of a high molecular weight PAC's having five or more rings. A position along the effluent stream is selected at which high molecular weight PAC's may be present. The effluent is illuminated with radiation having a wavelength absorbed by the high molecular weight PAC's in the gas phase. The fluorescence from the illuminated effluent is detected, and analyzed by comparison to the known fluorescence of high molecular weight PAC's in the gas phase to determine the presence of the PAC's in the effluent. The effluent composition may be controlled in response to the detection.

Detection and control of aromatic compounds in combustion effluent

A combustor capable of reducing the noxious emissions such as fuel bound and thermal nitrogen oxide products, during combustion of high nitrogen bearing and high aromatic content fuels is disclosed. The combustor includes a plurality of substantially concentric pipes defining annular passages with annular divergent nozzles. The divergent nozzles may be formed by rings having a venturi shaped axial section to facilitate fast mixing of axially supplied air between adjacent annular passages. The longitudinal spacing between at least two adjacent nozzles defines first and second divergent cavities. A fuel rich torodial vortex is formed in proximity to a central fuel jet in the first cavity and advantageously converts fuel bound nitrogen to N.sub.2. A fuel lean torodial vortex formed in the second cavity mixes hot combustion products with additional gaseous reactant to complete the combustion while avoiding locally high temperatures, and thus thermal NOx formation. A ring of jet nozzles radially injects relatively small amounts of high pressure gaseous reactant or steam to form a throat to separate and stabilize the vortices. Alternatively, the pipe extending between the two cavities can include a convergent and divergent portion forming the throat between the cavities for separating and reinforcing the toroidal vortices. Guide vanes may be positioned in the annular passages to swirl the gaseous reactant entering the cavities to assist in the formation of the toroidal vortices.

Low NOx rich-lean combustor especially useful in gas turbines

A multi-annular swirl burner includes a plurality of overlapping tubular wall members which form a rich combustion zone and a lean combustion zone with a throat section therebetween. Annular passages are located between adjacent wall members, and vanes located therein input a tangential velocity to entering air. The tangential velocity of the swirling flows increases with increasing radius to produce centrifugal separating force on particulates moving from the rich combustion zone to the throat section. A collection system scavenges particulates from the throat section for disposal.

Growing community of inventors

Winchester, MA, United States of America

Janos M Beer