A fuel nozzle apparatus for a gas turbine engine includes: a first pilot fuel injector disposed on a centerline axis of the fuel nozzle which defines a direction of air flow through the fuel nozzle, the first pilot fuel injector being of a pressure atomizing type; an annular second pilot fuel injector at least partially surrounding the first pilot fuel injector, the second pilot fuel injector being of an air blast type and having a fuel outlet disposed axially downstream and radially outboard of the first pilot fuel injector; an annular venturi surrounding the first and second pilot fuel injectors, the venturi including a throat of minimum diameter; an array of inner swirl vanes extending between the first pilot fuel injector and the second pilot fuel injector; and an array of outer swirl vanes extending between the second pilot fuel injector and the venturi.

A gravity-style furnace subunit for a gas-induced draft furnace. A heat conduction tube configured to be located inside of a gas-induced draft furnace cabinet, the heat conduction tube being separated from a row of draft-induced heat conduction tubes inside the cabinet. A burner assembly having a burner tube located within the heat conduction tube through an inlet opening of the heat conduction tube. The burner assembly permits air flow through the inlet opening into the heat conduction tube. A pilot assembly located within the heat conduction tube and adjacent to the burner tube. A thermopile module having located adjacent to a flame outlet of the pilot assembly within the heat conduction tube. A gas valve configured to control gas flow to the burner assembly, the gas valve electrically coupled to the thermopile module and to actuate gas flow there-through when the thermopile module generates a predefined voltage difference.

The invention relates to particular burners, and e.g. to a burner comprising a central main fuel lance, a pilot fuel conduit, a main oxidant conduit, an auxiliary oxidant conduit, and optionally a secondary fuel conduit, which are arranged in a particular and advantageous way to surround each other at least in their downstream sections. The invention further relates to furnaces including the burners and methods of operating the burners. Among others, the burners of the present invention allow a particularly advantageous way of including a pilot burner as an integral part of the main burner to ignite liquid fuel flame in a cold furnace. If required, the pilot flame can assist in extending the flammability limit or operating range of the liquid fuel burner.

A gravity-style furnace subunit for a gas-induced draft furnace. A heat conduction tube configured to be located inside of a gas-induced draft furnace cabinet, the heat conduction tube being separated from a row of draft-induced heat conduction tubes inside the cabinet. A burner assembly having a burner tube located within the heat conduction tube through an inlet opening of the heat conduction tube. The burner assembly permits air flow through the inlet opening into the heat conduction tube. A pilot assembly located within the heat conduction tube and adjacent to the burner tube. A thermopile module having located adjacent to a flame outlet of the pilot assembly within the heat conduction tube. A gas valve configured to control gas flow to the burner assembly, the gas valve electrically coupled to the thermopile module and to actuate gas flow there-through when the thermopile module generates a predefined voltage difference.

To provide a multifuel gas turbine combustor capable of combusting gases containing hydrogen in a high concentration with a low NOx while maintaining a low emission performance brought about by the pre-mixture combustion in the main burner, the gas turbine combustor includes a main burner (12) for supplying to and combusting a premixed gas (M), containing a first fuel (F1), within a first combustion region (S1) of a combustion chamber (10), and a supplemental burner (20) for supplying to and combusting a second fuel (F2) of a composition different from that of the first fuel (F1) within a second combustion region (S2) defined downstream of the first combustion region (S1) within the combustion chamber (10). The first fuel (F1) is of a hydrocarbon system and the second fuel (F2) is a gas containing hydrogen in a concentration exceeding the stable combustion limiting concentration of the hydrogen.

A pre-film liquid fuel cartridge (20) includes a primary liquid fuel passage (106), a plurality of inner fuel ports (116) and a plurality of outer fuel ports (124) that are in fluid communication with the primary liquid fuel passage. An inner pre-filming surface (142) is defined downstream from the plurality of inner fuel ports. The inner pre-filming surface (142) terminates at a first shear edge (140). An outer pre-filming surface (152) is defined downstream from the plurality of outer fuel ports. The outer pre-filming surface (152) terminates at a second shear edge (154). The first and second shear edges are relatively oriented so that a first pre-filmed liquid fuel sheet exiting the first shear edge intersects with a second pre-filmed liquid fuel sheet exiting the second shear edge, thereby atomizing the first and second pre-filmed liquid fuel sheets.